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1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/acpi.h>
4#include <linux/array_size.h>
5#include <linux/bitmap.h>
6#include <linux/cleanup.h>
7#include <linux/compat.h>
8#include <linux/debugfs.h>
9#include <linux/device.h>
10#include <linux/err.h>
11#include <linux/errno.h>
12#include <linux/file.h>
13#include <linux/fs.h>
14#include <linux/idr.h>
15#include <linux/interrupt.h>
16#include <linux/irq.h>
17#include <linux/irqdesc.h>
18#include <linux/kernel.h>
19#include <linux/list.h>
20#include <linux/lockdep.h>
21#include <linux/module.h>
22#include <linux/nospec.h>
23#include <linux/of.h>
24#include <linux/pinctrl/consumer.h>
25#include <linux/seq_file.h>
26#include <linux/slab.h>
27#include <linux/srcu.h>
28#include <linux/string.h>
29
30#include <linux/gpio.h>
31#include <linux/gpio/driver.h>
32#include <linux/gpio/machine.h>
33
34#include <uapi/linux/gpio.h>
35
36#include "gpiolib-acpi.h"
37#include "gpiolib-cdev.h"
38#include "gpiolib-of.h"
39#include "gpiolib-swnode.h"
40#include "gpiolib-sysfs.h"
41#include "gpiolib.h"
42
43#define CREATE_TRACE_POINTS
44#include <trace/events/gpio.h>
45
46/* Implementation infrastructure for GPIO interfaces.
47 *
48 * The GPIO programming interface allows for inlining speed-critical
49 * get/set operations for common cases, so that access to SOC-integrated
50 * GPIOs can sometimes cost only an instruction or two per bit.
51 */
52
53/* Device and char device-related information */
54static DEFINE_IDA(gpio_ida);
55static dev_t gpio_devt;
56#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
57
58static int gpio_bus_match(struct device *dev, const struct device_driver *drv)
59{
60 struct fwnode_handle *fwnode = dev_fwnode(dev);
61
62 /*
63 * Only match if the fwnode doesn't already have a proper struct device
64 * created for it.
65 */
66 if (fwnode && fwnode->dev != dev)
67 return 0;
68 return 1;
69}
70
71static const struct bus_type gpio_bus_type = {
72 .name = "gpio",
73 .match = gpio_bus_match,
74};
75
76/*
77 * Number of GPIOs to use for the fast path in set array
78 */
79#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
80
81static DEFINE_MUTEX(gpio_lookup_lock);
82static LIST_HEAD(gpio_lookup_list);
83
84static LIST_HEAD(gpio_devices);
85/* Protects the GPIO device list against concurrent modifications. */
86static DEFINE_MUTEX(gpio_devices_lock);
87/* Ensures coherence during read-only accesses to the list of GPIO devices. */
88DEFINE_STATIC_SRCU(gpio_devices_srcu);
89
90static DEFINE_MUTEX(gpio_machine_hogs_mutex);
91static LIST_HEAD(gpio_machine_hogs);
92
93const char *const gpio_suffixes[] = { "gpios", "gpio", NULL };
94
95static void gpiochip_free_hogs(struct gpio_chip *gc);
96static int gpiochip_add_irqchip(struct gpio_chip *gc,
97 struct lock_class_key *lock_key,
98 struct lock_class_key *request_key);
99static void gpiochip_irqchip_remove(struct gpio_chip *gc);
100static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
101static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
102static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
103
104static bool gpiolib_initialized;
105
106const char *gpiod_get_label(struct gpio_desc *desc)
107{
108 struct gpio_desc_label *label;
109 unsigned long flags;
110
111 flags = READ_ONCE(desc->flags);
112
113 label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu,
114 srcu_read_lock_held(&desc->gdev->desc_srcu));
115
116 if (test_bit(FLAG_USED_AS_IRQ, &flags))
117 return label ? label->str : "interrupt";
118
119 if (!test_bit(FLAG_REQUESTED, &flags))
120 return NULL;
121
122 return label ? label->str : NULL;
123}
124
125static void desc_free_label(struct rcu_head *rh)
126{
127 kfree(container_of(rh, struct gpio_desc_label, rh));
128}
129
130static int desc_set_label(struct gpio_desc *desc, const char *label)
131{
132 struct gpio_desc_label *new = NULL, *old;
133
134 if (label) {
135 new = kzalloc(struct_size(new, str, strlen(label) + 1),
136 GFP_KERNEL);
137 if (!new)
138 return -ENOMEM;
139
140 strcpy(new->str, label);
141 }
142
143 old = rcu_replace_pointer(desc->label, new, 1);
144 if (old)
145 call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label);
146
147 return 0;
148}
149
150/**
151 * gpio_to_desc - Convert a GPIO number to its descriptor
152 * @gpio: global GPIO number
153 *
154 * Returns:
155 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
156 * with the given number exists in the system.
157 */
158struct gpio_desc *gpio_to_desc(unsigned gpio)
159{
160 struct gpio_device *gdev;
161
162 scoped_guard(srcu, &gpio_devices_srcu) {
163 list_for_each_entry_srcu(gdev, &gpio_devices, list,
164 srcu_read_lock_held(&gpio_devices_srcu)) {
165 if (gdev->base <= gpio &&
166 gdev->base + gdev->ngpio > gpio)
167 return &gdev->descs[gpio - gdev->base];
168 }
169 }
170
171 return NULL;
172}
173EXPORT_SYMBOL_GPL(gpio_to_desc);
174
175/* This function is deprecated and will be removed soon, don't use. */
176struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
177 unsigned int hwnum)
178{
179 return gpio_device_get_desc(gc->gpiodev, hwnum);
180}
181
182/**
183 * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given
184 * hardware number for this GPIO device
185 * @gdev: GPIO device to get the descriptor from
186 * @hwnum: hardware number of the GPIO for this chip
187 *
188 * Returns:
189 * A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given
190 * chip for the specified hardware number or %ENODEV if the underlying chip
191 * already vanished.
192 *
193 * The reference count of struct gpio_device is *NOT* increased like when the
194 * GPIO is being requested for exclusive usage. It's up to the caller to make
195 * sure the GPIO device will stay alive together with the descriptor returned
196 * by this function.
197 */
198struct gpio_desc *
199gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum)
200{
201 if (hwnum >= gdev->ngpio)
202 return ERR_PTR(-EINVAL);
203
204 return &gdev->descs[array_index_nospec(hwnum, gdev->ngpio)];
205}
206EXPORT_SYMBOL_GPL(gpio_device_get_desc);
207
208/**
209 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
210 * @desc: GPIO descriptor
211 *
212 * This should disappear in the future but is needed since we still
213 * use GPIO numbers for error messages and sysfs nodes.
214 *
215 * Returns:
216 * The global GPIO number for the GPIO specified by its descriptor.
217 */
218int desc_to_gpio(const struct gpio_desc *desc)
219{
220 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
221}
222EXPORT_SYMBOL_GPL(desc_to_gpio);
223
224
225/**
226 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
227 * @desc: descriptor to return the chip of
228 *
229 * *DEPRECATED*
230 * This function is unsafe and should not be used. Using the chip address
231 * without taking the SRCU read lock may result in dereferencing a dangling
232 * pointer.
233 *
234 * Returns:
235 * Address of the GPIO chip backing this device.
236 */
237struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
238{
239 if (!desc)
240 return NULL;
241
242 return gpio_device_get_chip(desc->gdev);
243}
244EXPORT_SYMBOL_GPL(gpiod_to_chip);
245
246/**
247 * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor
248 * belongs.
249 * @desc: Descriptor for which to return the GPIO device.
250 *
251 * This *DOES NOT* increase the reference count of the GPIO device as it's
252 * expected that the descriptor is requested and the users already holds a
253 * reference to the device.
254 *
255 * Returns:
256 * Address of the GPIO device owning this descriptor.
257 */
258struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc)
259{
260 if (!desc)
261 return NULL;
262
263 return desc->gdev;
264}
265EXPORT_SYMBOL_GPL(gpiod_to_gpio_device);
266
267/**
268 * gpio_device_get_base() - Get the base GPIO number allocated by this device
269 * @gdev: GPIO device
270 *
271 * Returns:
272 * First GPIO number in the global GPIO numberspace for this device.
273 */
274int gpio_device_get_base(struct gpio_device *gdev)
275{
276 return gdev->base;
277}
278EXPORT_SYMBOL_GPL(gpio_device_get_base);
279
280/**
281 * gpio_device_get_label() - Get the label of this GPIO device
282 * @gdev: GPIO device
283 *
284 * Returns:
285 * Pointer to the string containing the GPIO device label. The string's
286 * lifetime is tied to that of the underlying GPIO device.
287 */
288const char *gpio_device_get_label(struct gpio_device *gdev)
289{
290 return gdev->label;
291}
292EXPORT_SYMBOL(gpio_device_get_label);
293
294/**
295 * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device
296 * @gdev: GPIO device
297 *
298 * Returns:
299 * Address of the GPIO chip backing this device.
300 *
301 * *DEPRECATED*
302 * Until we can get rid of all non-driver users of struct gpio_chip, we must
303 * provide a way of retrieving the pointer to it from struct gpio_device. This
304 * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the
305 * chip can dissapear at any moment (unlike reference-counted struct
306 * gpio_device).
307 *
308 * Use at your own risk.
309 */
310struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)
311{
312 return rcu_dereference_check(gdev->chip, 1);
313}
314EXPORT_SYMBOL_GPL(gpio_device_get_chip);
315
316/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
317static int gpiochip_find_base_unlocked(u16 ngpio)
318{
319 unsigned int base = GPIO_DYNAMIC_BASE;
320 struct gpio_device *gdev;
321
322 list_for_each_entry_srcu(gdev, &gpio_devices, list,
323 lockdep_is_held(&gpio_devices_lock)) {
324 /* found a free space? */
325 if (gdev->base >= base + ngpio)
326 break;
327 /* nope, check the space right after the chip */
328 base = gdev->base + gdev->ngpio;
329 if (base < GPIO_DYNAMIC_BASE)
330 base = GPIO_DYNAMIC_BASE;
331 if (base > GPIO_DYNAMIC_MAX - ngpio)
332 break;
333 }
334
335 if (base <= GPIO_DYNAMIC_MAX - ngpio) {
336 pr_debug("%s: found new base at %d\n", __func__, base);
337 return base;
338 } else {
339 pr_err("%s: cannot find free range\n", __func__);
340 return -ENOSPC;
341 }
342}
343
344/**
345 * gpiod_get_direction - return the current direction of a GPIO
346 * @desc: GPIO to get the direction of
347 *
348 * Returns:
349 * 0 for output, 1 for input, or an error code in case of error.
350 *
351 * This function may sleep if gpiod_cansleep() is true.
352 */
353int gpiod_get_direction(struct gpio_desc *desc)
354{
355 unsigned long flags;
356 unsigned int offset;
357 int ret;
358
359 /*
360 * We cannot use VALIDATE_DESC() as we must not return 0 for a NULL
361 * descriptor like we usually do.
362 */
363 if (IS_ERR_OR_NULL(desc))
364 return -EINVAL;
365
366 CLASS(gpio_chip_guard, guard)(desc);
367 if (!guard.gc)
368 return -ENODEV;
369
370 offset = gpio_chip_hwgpio(desc);
371 flags = READ_ONCE(desc->flags);
372
373 /*
374 * Open drain emulation using input mode may incorrectly report
375 * input here, fix that up.
376 */
377 if (test_bit(FLAG_OPEN_DRAIN, &flags) &&
378 test_bit(FLAG_IS_OUT, &flags))
379 return 0;
380
381 if (!guard.gc->get_direction)
382 return -ENOTSUPP;
383
384 ret = guard.gc->get_direction(guard.gc, offset);
385 if (ret < 0)
386 return ret;
387
388 /*
389 * GPIO_LINE_DIRECTION_IN or other positive,
390 * otherwise GPIO_LINE_DIRECTION_OUT.
391 */
392 if (ret > 0)
393 ret = 1;
394
395 assign_bit(FLAG_IS_OUT, &flags, !ret);
396 WRITE_ONCE(desc->flags, flags);
397
398 return ret;
399}
400EXPORT_SYMBOL_GPL(gpiod_get_direction);
401
402/*
403 * Add a new chip to the global chips list, keeping the list of chips sorted
404 * by range(means [base, base + ngpio - 1]) order.
405 *
406 * Returns:
407 * -EBUSY if the new chip overlaps with some other chip's integer space.
408 */
409static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)
410{
411 struct gpio_device *prev, *next;
412
413 lockdep_assert_held(&gpio_devices_lock);
414
415 if (list_empty(&gpio_devices)) {
416 /* initial entry in list */
417 list_add_tail_rcu(&gdev->list, &gpio_devices);
418 return 0;
419 }
420
421 next = list_first_entry(&gpio_devices, struct gpio_device, list);
422 if (gdev->base + gdev->ngpio <= next->base) {
423 /* add before first entry */
424 list_add_rcu(&gdev->list, &gpio_devices);
425 return 0;
426 }
427
428 prev = list_last_entry(&gpio_devices, struct gpio_device, list);
429 if (prev->base + prev->ngpio <= gdev->base) {
430 /* add behind last entry */
431 list_add_tail_rcu(&gdev->list, &gpio_devices);
432 return 0;
433 }
434
435 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
436 /* at the end of the list */
437 if (&next->list == &gpio_devices)
438 break;
439
440 /* add between prev and next */
441 if (prev->base + prev->ngpio <= gdev->base
442 && gdev->base + gdev->ngpio <= next->base) {
443 list_add_rcu(&gdev->list, &prev->list);
444 return 0;
445 }
446 }
447
448 synchronize_srcu(&gpio_devices_srcu);
449
450 return -EBUSY;
451}
452
453/*
454 * Convert a GPIO name to its descriptor
455 * Note that there is no guarantee that GPIO names are globally unique!
456 * Hence this function will return, if it exists, a reference to the first GPIO
457 * line found that matches the given name.
458 */
459static struct gpio_desc *gpio_name_to_desc(const char * const name)
460{
461 struct gpio_device *gdev;
462 struct gpio_desc *desc;
463 struct gpio_chip *gc;
464
465 if (!name)
466 return NULL;
467
468 guard(srcu)(&gpio_devices_srcu);
469
470 list_for_each_entry_srcu(gdev, &gpio_devices, list,
471 srcu_read_lock_held(&gpio_devices_srcu)) {
472 guard(srcu)(&gdev->srcu);
473
474 gc = srcu_dereference(gdev->chip, &gdev->srcu);
475 if (!gc)
476 continue;
477
478 for_each_gpio_desc(gc, desc) {
479 if (desc->name && !strcmp(desc->name, name))
480 return desc;
481 }
482 }
483
484 return NULL;
485}
486
487/*
488 * Take the names from gc->names and assign them to their GPIO descriptors.
489 * Warn if a name is already used for a GPIO line on a different GPIO chip.
490 *
491 * Note that:
492 * 1. Non-unique names are still accepted,
493 * 2. Name collisions within the same GPIO chip are not reported.
494 */
495static void gpiochip_set_desc_names(struct gpio_chip *gc)
496{
497 struct gpio_device *gdev = gc->gpiodev;
498 int i;
499
500 /* First check all names if they are unique */
501 for (i = 0; i != gc->ngpio; ++i) {
502 struct gpio_desc *gpio;
503
504 gpio = gpio_name_to_desc(gc->names[i]);
505 if (gpio)
506 dev_warn(&gdev->dev,
507 "Detected name collision for GPIO name '%s'\n",
508 gc->names[i]);
509 }
510
511 /* Then add all names to the GPIO descriptors */
512 for (i = 0; i != gc->ngpio; ++i)
513 gdev->descs[i].name = gc->names[i];
514}
515
516/*
517 * gpiochip_set_names - Set GPIO line names using device properties
518 * @chip: GPIO chip whose lines should be named, if possible
519 *
520 * Looks for device property "gpio-line-names" and if it exists assigns
521 * GPIO line names for the chip. The memory allocated for the assigned
522 * names belong to the underlying firmware node and should not be released
523 * by the caller.
524 */
525static int gpiochip_set_names(struct gpio_chip *chip)
526{
527 struct gpio_device *gdev = chip->gpiodev;
528 struct device *dev = &gdev->dev;
529 const char **names;
530 int ret, i;
531 int count;
532
533 count = device_property_string_array_count(dev, "gpio-line-names");
534 if (count < 0)
535 return 0;
536
537 /*
538 * When offset is set in the driver side we assume the driver internally
539 * is using more than one gpiochip per the same device. We have to stop
540 * setting friendly names if the specified ones with 'gpio-line-names'
541 * are less than the offset in the device itself. This means all the
542 * lines are not present for every single pin within all the internal
543 * gpiochips.
544 */
545 if (count <= chip->offset) {
546 dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
547 count, chip->offset);
548 return 0;
549 }
550
551 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
552 if (!names)
553 return -ENOMEM;
554
555 ret = device_property_read_string_array(dev, "gpio-line-names",
556 names, count);
557 if (ret < 0) {
558 dev_warn(dev, "failed to read GPIO line names\n");
559 kfree(names);
560 return ret;
561 }
562
563 /*
564 * When more that one gpiochip per device is used, 'count' can
565 * contain at most number gpiochips x chip->ngpio. We have to
566 * correctly distribute all defined lines taking into account
567 * chip->offset as starting point from where we will assign
568 * the names to pins from the 'names' array. Since property
569 * 'gpio-line-names' cannot contains gaps, we have to be sure
570 * we only assign those pins that really exists since chip->ngpio
571 * can be different of the chip->offset.
572 */
573 count = (count > chip->offset) ? count - chip->offset : count;
574 if (count > chip->ngpio)
575 count = chip->ngpio;
576
577 for (i = 0; i < count; i++) {
578 /*
579 * Allow overriding "fixed" names provided by the GPIO
580 * provider. The "fixed" names are more often than not
581 * generic and less informative than the names given in
582 * device properties.
583 */
584 if (names[chip->offset + i] && names[chip->offset + i][0])
585 gdev->descs[i].name = names[chip->offset + i];
586 }
587
588 kfree(names);
589
590 return 0;
591}
592
593static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
594{
595 unsigned long *p;
596
597 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
598 if (!p)
599 return NULL;
600
601 /* Assume by default all GPIOs are valid */
602 bitmap_fill(p, gc->ngpio);
603
604 return p;
605}
606
607static void gpiochip_free_mask(unsigned long **p)
608{
609 bitmap_free(*p);
610 *p = NULL;
611}
612
613static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc)
614{
615 struct device *dev = &gc->gpiodev->dev;
616 int size;
617
618 /* Format is "start, count, ..." */
619 size = device_property_count_u32(dev, "gpio-reserved-ranges");
620 if (size > 0 && size % 2 == 0)
621 return size;
622
623 return 0;
624}
625
626static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc)
627{
628 struct device *dev = &gc->gpiodev->dev;
629 unsigned int size;
630 u32 *ranges;
631 int ret;
632
633 size = gpiochip_count_reserved_ranges(gc);
634 if (size == 0)
635 return 0;
636
637 ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL);
638 if (!ranges)
639 return -ENOMEM;
640
641 ret = device_property_read_u32_array(dev, "gpio-reserved-ranges",
642 ranges, size);
643 if (ret) {
644 kfree(ranges);
645 return ret;
646 }
647
648 while (size) {
649 u32 count = ranges[--size];
650 u32 start = ranges[--size];
651
652 if (start >= gc->ngpio || start + count > gc->ngpio)
653 continue;
654
655 bitmap_clear(gc->valid_mask, start, count);
656 }
657
658 kfree(ranges);
659 return 0;
660}
661
662static int gpiochip_init_valid_mask(struct gpio_chip *gc)
663{
664 int ret;
665
666 if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask))
667 return 0;
668
669 gc->valid_mask = gpiochip_allocate_mask(gc);
670 if (!gc->valid_mask)
671 return -ENOMEM;
672
673 ret = gpiochip_apply_reserved_ranges(gc);
674 if (ret)
675 return ret;
676
677 if (gc->init_valid_mask)
678 return gc->init_valid_mask(gc,
679 gc->valid_mask,
680 gc->ngpio);
681
682 return 0;
683}
684
685static void gpiochip_free_valid_mask(struct gpio_chip *gc)
686{
687 gpiochip_free_mask(&gc->valid_mask);
688}
689
690static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
691{
692 /*
693 * Device Tree platforms are supposed to use "gpio-ranges"
694 * property. This check ensures that the ->add_pin_ranges()
695 * won't be called for them.
696 */
697 if (device_property_present(&gc->gpiodev->dev, "gpio-ranges"))
698 return 0;
699
700 if (gc->add_pin_ranges)
701 return gc->add_pin_ranges(gc);
702
703 return 0;
704}
705
706bool gpiochip_line_is_valid(const struct gpio_chip *gc,
707 unsigned int offset)
708{
709 /* No mask means all valid */
710 if (likely(!gc->valid_mask))
711 return true;
712 return test_bit(offset, gc->valid_mask);
713}
714EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
715
716static void gpiod_free_irqs(struct gpio_desc *desc)
717{
718 int irq = gpiod_to_irq(desc);
719 struct irq_desc *irqd = irq_to_desc(irq);
720 void *cookie;
721
722 for (;;) {
723 /*
724 * Make sure the action doesn't go away while we're
725 * dereferencing it. Retrieve and store the cookie value.
726 * If the irq is freed after we release the lock, that's
727 * alright - the underlying maple tree lookup will return NULL
728 * and nothing will happen in free_irq().
729 */
730 scoped_guard(mutex, &irqd->request_mutex) {
731 if (!irq_desc_has_action(irqd))
732 return;
733
734 cookie = irqd->action->dev_id;
735 }
736
737 free_irq(irq, cookie);
738 }
739}
740
741/*
742 * The chip is going away but there may be users who had requested interrupts
743 * on its GPIO lines who have no idea about its removal and have no way of
744 * being notified about it. We need to free any interrupts still in use here or
745 * we'll leak memory and resources (like procfs files).
746 */
747static void gpiochip_free_remaining_irqs(struct gpio_chip *gc)
748{
749 struct gpio_desc *desc;
750
751 for_each_gpio_desc_with_flag(gc, desc, FLAG_USED_AS_IRQ)
752 gpiod_free_irqs(desc);
753}
754
755static void gpiodev_release(struct device *dev)
756{
757 struct gpio_device *gdev = to_gpio_device(dev);
758
759 /* Call pending kfree()s for descriptor labels. */
760 synchronize_srcu(&gdev->desc_srcu);
761 cleanup_srcu_struct(&gdev->desc_srcu);
762
763 ida_free(&gpio_ida, gdev->id);
764 kfree_const(gdev->label);
765 kfree(gdev->descs);
766 cleanup_srcu_struct(&gdev->srcu);
767 kfree(gdev);
768}
769
770static const struct device_type gpio_dev_type = {
771 .name = "gpio_chip",
772 .release = gpiodev_release,
773};
774
775#ifdef CONFIG_GPIO_CDEV
776#define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
777#define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
778#else
779/*
780 * gpiolib_cdev_register() indirectly calls device_add(), which is still
781 * required even when cdev is not selected.
782 */
783#define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
784#define gcdev_unregister(gdev) device_del(&(gdev)->dev)
785#endif
786
787static int gpiochip_setup_dev(struct gpio_device *gdev)
788{
789 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
790 int ret;
791
792 device_initialize(&gdev->dev);
793
794 /*
795 * If fwnode doesn't belong to another device, it's safe to clear its
796 * initialized flag.
797 */
798 if (fwnode && !fwnode->dev)
799 fwnode_dev_initialized(fwnode, false);
800
801 ret = gcdev_register(gdev, gpio_devt);
802 if (ret)
803 return ret;
804
805 ret = gpiochip_sysfs_register(gdev);
806 if (ret)
807 goto err_remove_device;
808
809 dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base,
810 gdev->base + gdev->ngpio - 1, gdev->label);
811
812 return 0;
813
814err_remove_device:
815 gcdev_unregister(gdev);
816 return ret;
817}
818
819static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
820{
821 struct gpio_desc *desc;
822 int rv;
823
824 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
825 if (IS_ERR(desc)) {
826 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
827 PTR_ERR(desc));
828 return;
829 }
830
831 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
832 if (rv)
833 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
834 __func__, gc->label, hog->chip_hwnum, rv);
835}
836
837static void machine_gpiochip_add(struct gpio_chip *gc)
838{
839 struct gpiod_hog *hog;
840
841 mutex_lock(&gpio_machine_hogs_mutex);
842
843 list_for_each_entry(hog, &gpio_machine_hogs, list) {
844 if (!strcmp(gc->label, hog->chip_label))
845 gpiochip_machine_hog(gc, hog);
846 }
847
848 mutex_unlock(&gpio_machine_hogs_mutex);
849}
850
851static void gpiochip_setup_devs(void)
852{
853 struct gpio_device *gdev;
854 int ret;
855
856 guard(srcu)(&gpio_devices_srcu);
857
858 list_for_each_entry_srcu(gdev, &gpio_devices, list,
859 srcu_read_lock_held(&gpio_devices_srcu)) {
860 ret = gpiochip_setup_dev(gdev);
861 if (ret)
862 dev_err(&gdev->dev,
863 "Failed to initialize gpio device (%d)\n", ret);
864 }
865}
866
867static void gpiochip_set_data(struct gpio_chip *gc, void *data)
868{
869 gc->gpiodev->data = data;
870}
871
872/**
873 * gpiochip_get_data() - get per-subdriver data for the chip
874 * @gc: GPIO chip
875 *
876 * Returns:
877 * The per-subdriver data for the chip.
878 */
879void *gpiochip_get_data(struct gpio_chip *gc)
880{
881 return gc->gpiodev->data;
882}
883EXPORT_SYMBOL_GPL(gpiochip_get_data);
884
885int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
886{
887 u32 ngpios = gc->ngpio;
888 int ret;
889
890 if (ngpios == 0) {
891 ret = device_property_read_u32(dev, "ngpios", &ngpios);
892 if (ret == -ENODATA)
893 /*
894 * -ENODATA means that there is no property found and
895 * we want to issue the error message to the user.
896 * Besides that, we want to return different error code
897 * to state that supplied value is not valid.
898 */
899 ngpios = 0;
900 else if (ret)
901 return ret;
902
903 gc->ngpio = ngpios;
904 }
905
906 if (gc->ngpio == 0) {
907 dev_err(dev, "tried to insert a GPIO chip with zero lines\n");
908 return -EINVAL;
909 }
910
911 if (gc->ngpio > FASTPATH_NGPIO)
912 dev_warn(dev, "line cnt %u is greater than fast path cnt %u\n",
913 gc->ngpio, FASTPATH_NGPIO);
914
915 return 0;
916}
917EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);
918
919int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
920 struct lock_class_key *lock_key,
921 struct lock_class_key *request_key)
922{
923 struct gpio_device *gdev;
924 unsigned int desc_index;
925 int base = 0;
926 int ret = 0;
927
928 /*
929 * First: allocate and populate the internal stat container, and
930 * set up the struct device.
931 */
932 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
933 if (!gdev)
934 return -ENOMEM;
935
936 gdev->dev.type = &gpio_dev_type;
937 gdev->dev.bus = &gpio_bus_type;
938 gdev->dev.parent = gc->parent;
939 rcu_assign_pointer(gdev->chip, gc);
940
941 gc->gpiodev = gdev;
942 gpiochip_set_data(gc, data);
943
944 /*
945 * If the calling driver did not initialize firmware node,
946 * do it here using the parent device, if any.
947 */
948 if (gc->fwnode)
949 device_set_node(&gdev->dev, gc->fwnode);
950 else if (gc->parent)
951 device_set_node(&gdev->dev, dev_fwnode(gc->parent));
952
953 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
954 if (gdev->id < 0) {
955 ret = gdev->id;
956 goto err_free_gdev;
957 }
958
959 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
960 if (ret)
961 goto err_free_ida;
962
963 if (gc->parent && gc->parent->driver)
964 gdev->owner = gc->parent->driver->owner;
965 else if (gc->owner)
966 /* TODO: remove chip->owner */
967 gdev->owner = gc->owner;
968 else
969 gdev->owner = THIS_MODULE;
970
971 ret = gpiochip_get_ngpios(gc, &gdev->dev);
972 if (ret)
973 goto err_free_dev_name;
974
975 gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
976 if (!gdev->descs) {
977 ret = -ENOMEM;
978 goto err_free_dev_name;
979 }
980
981 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
982 if (!gdev->label) {
983 ret = -ENOMEM;
984 goto err_free_descs;
985 }
986
987 gdev->ngpio = gc->ngpio;
988 gdev->can_sleep = gc->can_sleep;
989
990 scoped_guard(mutex, &gpio_devices_lock) {
991 /*
992 * TODO: this allocates a Linux GPIO number base in the global
993 * GPIO numberspace for this chip. In the long run we want to
994 * get *rid* of this numberspace and use only descriptors, but
995 * it may be a pipe dream. It will not happen before we get rid
996 * of the sysfs interface anyways.
997 */
998 base = gc->base;
999 if (base < 0) {
1000 base = gpiochip_find_base_unlocked(gc->ngpio);
1001 if (base < 0) {
1002 ret = base;
1003 base = 0;
1004 goto err_free_label;
1005 }
1006
1007 /*
1008 * TODO: it should not be necessary to reflect the
1009 * assigned base outside of the GPIO subsystem. Go over
1010 * drivers and see if anyone makes use of this, else
1011 * drop this and assign a poison instead.
1012 */
1013 gc->base = base;
1014 } else {
1015 dev_warn(&gdev->dev,
1016 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
1017 }
1018
1019 gdev->base = base;
1020
1021 ret = gpiodev_add_to_list_unlocked(gdev);
1022 if (ret) {
1023 chip_err(gc, "GPIO integer space overlap, cannot add chip\n");
1024 goto err_free_label;
1025 }
1026 }
1027
1028 ATOMIC_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
1029 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
1030
1031 ret = init_srcu_struct(&gdev->srcu);
1032 if (ret)
1033 goto err_remove_from_list;
1034
1035 ret = init_srcu_struct(&gdev->desc_srcu);
1036 if (ret)
1037 goto err_cleanup_gdev_srcu;
1038
1039#ifdef CONFIG_PINCTRL
1040 INIT_LIST_HEAD(&gdev->pin_ranges);
1041#endif
1042
1043 if (gc->names)
1044 gpiochip_set_desc_names(gc);
1045
1046 ret = gpiochip_set_names(gc);
1047 if (ret)
1048 goto err_cleanup_desc_srcu;
1049
1050 ret = gpiochip_init_valid_mask(gc);
1051 if (ret)
1052 goto err_cleanup_desc_srcu;
1053
1054 for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
1055 struct gpio_desc *desc = &gdev->descs[desc_index];
1056
1057 desc->gdev = gdev;
1058
1059 if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {
1060 assign_bit(FLAG_IS_OUT,
1061 &desc->flags, !gc->get_direction(gc, desc_index));
1062 } else {
1063 assign_bit(FLAG_IS_OUT,
1064 &desc->flags, !gc->direction_input);
1065 }
1066 }
1067
1068 ret = of_gpiochip_add(gc);
1069 if (ret)
1070 goto err_free_valid_mask;
1071
1072 ret = gpiochip_add_pin_ranges(gc);
1073 if (ret)
1074 goto err_remove_of_chip;
1075
1076 acpi_gpiochip_add(gc);
1077
1078 machine_gpiochip_add(gc);
1079
1080 ret = gpiochip_irqchip_init_valid_mask(gc);
1081 if (ret)
1082 goto err_free_hogs;
1083
1084 ret = gpiochip_irqchip_init_hw(gc);
1085 if (ret)
1086 goto err_remove_irqchip_mask;
1087
1088 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
1089 if (ret)
1090 goto err_remove_irqchip_mask;
1091
1092 /*
1093 * By first adding the chardev, and then adding the device,
1094 * we get a device node entry in sysfs under
1095 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1096 * coldplug of device nodes and other udev business.
1097 * We can do this only if gpiolib has been initialized.
1098 * Otherwise, defer until later.
1099 */
1100 if (gpiolib_initialized) {
1101 ret = gpiochip_setup_dev(gdev);
1102 if (ret)
1103 goto err_remove_irqchip;
1104 }
1105 return 0;
1106
1107err_remove_irqchip:
1108 gpiochip_irqchip_remove(gc);
1109err_remove_irqchip_mask:
1110 gpiochip_irqchip_free_valid_mask(gc);
1111err_free_hogs:
1112 gpiochip_free_hogs(gc);
1113 acpi_gpiochip_remove(gc);
1114 gpiochip_remove_pin_ranges(gc);
1115err_remove_of_chip:
1116 of_gpiochip_remove(gc);
1117err_free_valid_mask:
1118 gpiochip_free_valid_mask(gc);
1119err_cleanup_desc_srcu:
1120 cleanup_srcu_struct(&gdev->desc_srcu);
1121err_cleanup_gdev_srcu:
1122 cleanup_srcu_struct(&gdev->srcu);
1123err_remove_from_list:
1124 scoped_guard(mutex, &gpio_devices_lock)
1125 list_del_rcu(&gdev->list);
1126 synchronize_srcu(&gpio_devices_srcu);
1127 if (gdev->dev.release) {
1128 /* release() has been registered by gpiochip_setup_dev() */
1129 gpio_device_put(gdev);
1130 goto err_print_message;
1131 }
1132err_free_label:
1133 kfree_const(gdev->label);
1134err_free_descs:
1135 kfree(gdev->descs);
1136err_free_dev_name:
1137 kfree(dev_name(&gdev->dev));
1138err_free_ida:
1139 ida_free(&gpio_ida, gdev->id);
1140err_free_gdev:
1141 kfree(gdev);
1142err_print_message:
1143 /* failures here can mean systems won't boot... */
1144 if (ret != -EPROBE_DEFER) {
1145 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1146 base, base + (int)gc->ngpio - 1,
1147 gc->label ? : "generic", ret);
1148 }
1149 return ret;
1150}
1151EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1152
1153/**
1154 * gpiochip_remove() - unregister a gpio_chip
1155 * @gc: the chip to unregister
1156 *
1157 * A gpio_chip with any GPIOs still requested may not be removed.
1158 */
1159void gpiochip_remove(struct gpio_chip *gc)
1160{
1161 struct gpio_device *gdev = gc->gpiodev;
1162
1163 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1164 gpiochip_sysfs_unregister(gdev);
1165 gpiochip_free_hogs(gc);
1166 gpiochip_free_remaining_irqs(gc);
1167
1168 scoped_guard(mutex, &gpio_devices_lock)
1169 list_del_rcu(&gdev->list);
1170 synchronize_srcu(&gpio_devices_srcu);
1171
1172 /* Numb the device, cancelling all outstanding operations */
1173 rcu_assign_pointer(gdev->chip, NULL);
1174 synchronize_srcu(&gdev->srcu);
1175 gpiochip_irqchip_remove(gc);
1176 acpi_gpiochip_remove(gc);
1177 of_gpiochip_remove(gc);
1178 gpiochip_remove_pin_ranges(gc);
1179 gpiochip_free_valid_mask(gc);
1180 /*
1181 * We accept no more calls into the driver from this point, so
1182 * NULL the driver data pointer.
1183 */
1184 gpiochip_set_data(gc, NULL);
1185
1186 /*
1187 * The gpiochip side puts its use of the device to rest here:
1188 * if there are no userspace clients, the chardev and device will
1189 * be removed, else it will be dangling until the last user is
1190 * gone.
1191 */
1192 gcdev_unregister(gdev);
1193 gpio_device_put(gdev);
1194}
1195EXPORT_SYMBOL_GPL(gpiochip_remove);
1196
1197/**
1198 * gpio_device_find() - find a specific GPIO device
1199 * @data: data to pass to match function
1200 * @match: Callback function to check gpio_chip
1201 *
1202 * Returns:
1203 * New reference to struct gpio_device.
1204 *
1205 * Similar to bus_find_device(). It returns a reference to a gpio_device as
1206 * determined by a user supplied @match callback. The callback should return
1207 * 0 if the device doesn't match and non-zero if it does. If the callback
1208 * returns non-zero, this function will return to the caller and not iterate
1209 * over any more gpio_devices.
1210 *
1211 * The callback takes the GPIO chip structure as argument. During the execution
1212 * of the callback function the chip is protected from being freed. TODO: This
1213 * actually has yet to be implemented.
1214 *
1215 * If the function returns non-NULL, the returned reference must be freed by
1216 * the caller using gpio_device_put().
1217 */
1218struct gpio_device *gpio_device_find(const void *data,
1219 int (*match)(struct gpio_chip *gc,
1220 const void *data))
1221{
1222 struct gpio_device *gdev;
1223 struct gpio_chip *gc;
1224
1225 might_sleep();
1226
1227 guard(srcu)(&gpio_devices_srcu);
1228
1229 list_for_each_entry_srcu(gdev, &gpio_devices, list,
1230 srcu_read_lock_held(&gpio_devices_srcu)) {
1231 if (!device_is_registered(&gdev->dev))
1232 continue;
1233
1234 guard(srcu)(&gdev->srcu);
1235
1236 gc = srcu_dereference(gdev->chip, &gdev->srcu);
1237
1238 if (gc && match(gc, data))
1239 return gpio_device_get(gdev);
1240 }
1241
1242 return NULL;
1243}
1244EXPORT_SYMBOL_GPL(gpio_device_find);
1245
1246static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)
1247{
1248 return gc->label && !strcmp(gc->label, label);
1249}
1250
1251/**
1252 * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the
1253 * GPIO device by its backing chip's label
1254 * @label: Label to lookup
1255 *
1256 * Returns:
1257 * Reference to the GPIO device or NULL. Reference must be released with
1258 * gpio_device_put().
1259 */
1260struct gpio_device *gpio_device_find_by_label(const char *label)
1261{
1262 return gpio_device_find((void *)label, gpio_chip_match_by_label);
1263}
1264EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
1265
1266static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)
1267{
1268 return device_match_fwnode(&gc->gpiodev->dev, fwnode);
1269}
1270
1271/**
1272 * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
1273 * the GPIO device by its fwnode
1274 * @fwnode: Firmware node to lookup
1275 *
1276 * Returns:
1277 * Reference to the GPIO device or NULL. Reference must be released with
1278 * gpio_device_put().
1279 */
1280struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
1281{
1282 return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
1283}
1284EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
1285
1286/**
1287 * gpio_device_get() - Increase the reference count of this GPIO device
1288 * @gdev: GPIO device to increase the refcount for
1289 *
1290 * Returns:
1291 * Pointer to @gdev.
1292 */
1293struct gpio_device *gpio_device_get(struct gpio_device *gdev)
1294{
1295 return to_gpio_device(get_device(&gdev->dev));
1296}
1297EXPORT_SYMBOL_GPL(gpio_device_get);
1298
1299/**
1300 * gpio_device_put() - Decrease the reference count of this GPIO device and
1301 * possibly free all resources associated with it.
1302 * @gdev: GPIO device to decrease the reference count for
1303 */
1304void gpio_device_put(struct gpio_device *gdev)
1305{
1306 put_device(&gdev->dev);
1307}
1308EXPORT_SYMBOL_GPL(gpio_device_put);
1309
1310/**
1311 * gpio_device_to_device() - Retrieve the address of the underlying struct
1312 * device.
1313 * @gdev: GPIO device for which to return the address.
1314 *
1315 * This does not increase the reference count of the GPIO device nor the
1316 * underlying struct device.
1317 *
1318 * Returns:
1319 * Address of struct device backing this GPIO device.
1320 */
1321struct device *gpio_device_to_device(struct gpio_device *gdev)
1322{
1323 return &gdev->dev;
1324}
1325EXPORT_SYMBOL_GPL(gpio_device_to_device);
1326
1327#ifdef CONFIG_GPIOLIB_IRQCHIP
1328
1329/*
1330 * The following is irqchip helper code for gpiochips.
1331 */
1332
1333static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1334{
1335 struct gpio_irq_chip *girq = &gc->irq;
1336
1337 if (!girq->init_hw)
1338 return 0;
1339
1340 return girq->init_hw(gc);
1341}
1342
1343static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1344{
1345 struct gpio_irq_chip *girq = &gc->irq;
1346
1347 if (!girq->init_valid_mask)
1348 return 0;
1349
1350 girq->valid_mask = gpiochip_allocate_mask(gc);
1351 if (!girq->valid_mask)
1352 return -ENOMEM;
1353
1354 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1355
1356 return 0;
1357}
1358
1359static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1360{
1361 gpiochip_free_mask(&gc->irq.valid_mask);
1362}
1363
1364static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
1365 unsigned int offset)
1366{
1367 if (!gpiochip_line_is_valid(gc, offset))
1368 return false;
1369 /* No mask means all valid */
1370 if (likely(!gc->irq.valid_mask))
1371 return true;
1372 return test_bit(offset, gc->irq.valid_mask);
1373}
1374
1375#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1376
1377/**
1378 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1379 * to a gpiochip
1380 * @gc: the gpiochip to set the irqchip hierarchical handler to
1381 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1382 * will then percolate up to the parent
1383 */
1384static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1385 struct irq_chip *irqchip)
1386{
1387 /* DT will deal with mapping each IRQ as we go along */
1388 if (is_of_node(gc->irq.fwnode))
1389 return;
1390
1391 /*
1392 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1393 * irqs upfront instead of dynamically since we don't have the
1394 * dynamic type of allocation that hardware description languages
1395 * provide. Once all GPIO drivers using board files are gone from
1396 * the kernel we can delete this code, but for a transitional period
1397 * it is necessary to keep this around.
1398 */
1399 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1400 int i;
1401 int ret;
1402
1403 for (i = 0; i < gc->ngpio; i++) {
1404 struct irq_fwspec fwspec;
1405 unsigned int parent_hwirq;
1406 unsigned int parent_type;
1407 struct gpio_irq_chip *girq = &gc->irq;
1408
1409 /*
1410 * We call the child to parent translation function
1411 * only to check if the child IRQ is valid or not.
1412 * Just pick the rising edge type here as that is what
1413 * we likely need to support.
1414 */
1415 ret = girq->child_to_parent_hwirq(gc, i,
1416 IRQ_TYPE_EDGE_RISING,
1417 &parent_hwirq,
1418 &parent_type);
1419 if (ret) {
1420 chip_err(gc, "skip set-up on hwirq %d\n",
1421 i);
1422 continue;
1423 }
1424
1425 fwspec.fwnode = gc->irq.fwnode;
1426 /* This is the hwirq for the GPIO line side of things */
1427 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1428 /* Just pick something */
1429 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1430 fwspec.param_count = 2;
1431 ret = irq_domain_alloc_irqs(gc->irq.domain, 1,
1432 NUMA_NO_NODE, &fwspec);
1433 if (ret < 0) {
1434 chip_err(gc,
1435 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1436 i, parent_hwirq,
1437 ret);
1438 }
1439 }
1440 }
1441
1442 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1443
1444 return;
1445}
1446
1447static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1448 struct irq_fwspec *fwspec,
1449 unsigned long *hwirq,
1450 unsigned int *type)
1451{
1452 /* We support standard DT translation */
1453 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1454 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1455 }
1456
1457 /* This is for board files and others not using DT */
1458 if (is_fwnode_irqchip(fwspec->fwnode)) {
1459 int ret;
1460
1461 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1462 if (ret)
1463 return ret;
1464 WARN_ON(*type == IRQ_TYPE_NONE);
1465 return 0;
1466 }
1467 return -EINVAL;
1468}
1469
1470static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1471 unsigned int irq,
1472 unsigned int nr_irqs,
1473 void *data)
1474{
1475 struct gpio_chip *gc = d->host_data;
1476 irq_hw_number_t hwirq;
1477 unsigned int type = IRQ_TYPE_NONE;
1478 struct irq_fwspec *fwspec = data;
1479 union gpio_irq_fwspec gpio_parent_fwspec = {};
1480 unsigned int parent_hwirq;
1481 unsigned int parent_type;
1482 struct gpio_irq_chip *girq = &gc->irq;
1483 int ret;
1484
1485 /*
1486 * The nr_irqs parameter is always one except for PCI multi-MSI
1487 * so this should not happen.
1488 */
1489 WARN_ON(nr_irqs != 1);
1490
1491 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1492 if (ret)
1493 return ret;
1494
1495 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1496
1497 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1498 &parent_hwirq, &parent_type);
1499 if (ret) {
1500 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1501 return ret;
1502 }
1503 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1504
1505 /*
1506 * We set handle_bad_irq because the .set_type() should
1507 * always be invoked and set the right type of handler.
1508 */
1509 irq_domain_set_info(d,
1510 irq,
1511 hwirq,
1512 gc->irq.chip,
1513 gc,
1514 girq->handler,
1515 NULL, NULL);
1516 irq_set_probe(irq);
1517
1518 /* This parent only handles asserted level IRQs */
1519 ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,
1520 parent_hwirq, parent_type);
1521 if (ret)
1522 return ret;
1523
1524 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1525 irq, parent_hwirq);
1526 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1527 ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);
1528 /*
1529 * If the parent irqdomain is msi, the interrupts have already
1530 * been allocated, so the EEXIST is good.
1531 */
1532 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1533 ret = 0;
1534 if (ret)
1535 chip_err(gc,
1536 "failed to allocate parent hwirq %d for hwirq %lu\n",
1537 parent_hwirq, hwirq);
1538
1539 return ret;
1540}
1541
1542static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1543 unsigned int offset)
1544{
1545 return offset;
1546}
1547
1548/**
1549 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1550 * @domain: The IRQ domain used by this IRQ chip
1551 * @data: Outermost irq_data associated with the IRQ
1552 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1553 *
1554 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1555 * used as the activate function for the &struct irq_domain_ops. The host_data
1556 * for the IRQ domain must be the &struct gpio_chip.
1557 *
1558 * Returns:
1559 * 0 on success, or negative errno on failure.
1560 */
1561static int gpiochip_irq_domain_activate(struct irq_domain *domain,
1562 struct irq_data *data, bool reserve)
1563{
1564 struct gpio_chip *gc = domain->host_data;
1565 unsigned int hwirq = irqd_to_hwirq(data);
1566
1567 return gpiochip_lock_as_irq(gc, hwirq);
1568}
1569
1570/**
1571 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1572 * @domain: The IRQ domain used by this IRQ chip
1573 * @data: Outermost irq_data associated with the IRQ
1574 *
1575 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1576 * be used as the deactivate function for the &struct irq_domain_ops. The
1577 * host_data for the IRQ domain must be the &struct gpio_chip.
1578 */
1579static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1580 struct irq_data *data)
1581{
1582 struct gpio_chip *gc = domain->host_data;
1583 unsigned int hwirq = irqd_to_hwirq(data);
1584
1585 return gpiochip_unlock_as_irq(gc, hwirq);
1586}
1587
1588static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1589{
1590 ops->activate = gpiochip_irq_domain_activate;
1591 ops->deactivate = gpiochip_irq_domain_deactivate;
1592 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1593
1594 /*
1595 * We only allow overriding the translate() and free() functions for
1596 * hierarchical chips, and this should only be done if the user
1597 * really need something other than 1:1 translation for translate()
1598 * callback and free if user wants to free up any resources which
1599 * were allocated during callbacks, for example populate_parent_alloc_arg.
1600 */
1601 if (!ops->translate)
1602 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1603 if (!ops->free)
1604 ops->free = irq_domain_free_irqs_common;
1605}
1606
1607static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1608{
1609 struct irq_domain *domain;
1610
1611 if (!gc->irq.child_to_parent_hwirq ||
1612 !gc->irq.fwnode) {
1613 chip_err(gc, "missing irqdomain vital data\n");
1614 return ERR_PTR(-EINVAL);
1615 }
1616
1617 if (!gc->irq.child_offset_to_irq)
1618 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1619
1620 if (!gc->irq.populate_parent_alloc_arg)
1621 gc->irq.populate_parent_alloc_arg =
1622 gpiochip_populate_parent_fwspec_twocell;
1623
1624 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1625
1626 domain = irq_domain_create_hierarchy(
1627 gc->irq.parent_domain,
1628 0,
1629 gc->ngpio,
1630 gc->irq.fwnode,
1631 &gc->irq.child_irq_domain_ops,
1632 gc);
1633
1634 if (!domain)
1635 return ERR_PTR(-ENOMEM);
1636
1637 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1638
1639 return domain;
1640}
1641
1642static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1643{
1644 return !!gc->irq.parent_domain;
1645}
1646
1647int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1648 union gpio_irq_fwspec *gfwspec,
1649 unsigned int parent_hwirq,
1650 unsigned int parent_type)
1651{
1652 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1653
1654 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1655 fwspec->param_count = 2;
1656 fwspec->param[0] = parent_hwirq;
1657 fwspec->param[1] = parent_type;
1658
1659 return 0;
1660}
1661EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1662
1663int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1664 union gpio_irq_fwspec *gfwspec,
1665 unsigned int parent_hwirq,
1666 unsigned int parent_type)
1667{
1668 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1669
1670 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1671 fwspec->param_count = 4;
1672 fwspec->param[0] = 0;
1673 fwspec->param[1] = parent_hwirq;
1674 fwspec->param[2] = 0;
1675 fwspec->param[3] = parent_type;
1676
1677 return 0;
1678}
1679EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1680
1681#else
1682
1683static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1684{
1685 return ERR_PTR(-EINVAL);
1686}
1687
1688static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1689{
1690 return false;
1691}
1692
1693#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1694
1695/**
1696 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1697 * @d: the irqdomain used by this irqchip
1698 * @irq: the global irq number used by this GPIO irqchip irq
1699 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1700 *
1701 * This function will set up the mapping for a certain IRQ line on a
1702 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1703 * stored inside the gpiochip.
1704 *
1705 * Returns:
1706 * 0 on success, or negative errno on failure.
1707 */
1708static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1709 irq_hw_number_t hwirq)
1710{
1711 struct gpio_chip *gc = d->host_data;
1712 int ret = 0;
1713
1714 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1715 return -ENXIO;
1716
1717 irq_set_chip_data(irq, gc);
1718 /*
1719 * This lock class tells lockdep that GPIO irqs are in a different
1720 * category than their parents, so it won't report false recursion.
1721 */
1722 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1723 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1724 /* Chips that use nested thread handlers have them marked */
1725 if (gc->irq.threaded)
1726 irq_set_nested_thread(irq, 1);
1727 irq_set_noprobe(irq);
1728
1729 if (gc->irq.num_parents == 1)
1730 ret = irq_set_parent(irq, gc->irq.parents[0]);
1731 else if (gc->irq.map)
1732 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1733
1734 if (ret < 0)
1735 return ret;
1736
1737 /*
1738 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1739 * is passed as default type.
1740 */
1741 if (gc->irq.default_type != IRQ_TYPE_NONE)
1742 irq_set_irq_type(irq, gc->irq.default_type);
1743
1744 return 0;
1745}
1746
1747static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1748{
1749 struct gpio_chip *gc = d->host_data;
1750
1751 if (gc->irq.threaded)
1752 irq_set_nested_thread(irq, 0);
1753 irq_set_chip_and_handler(irq, NULL, NULL);
1754 irq_set_chip_data(irq, NULL);
1755}
1756
1757static const struct irq_domain_ops gpiochip_domain_ops = {
1758 .map = gpiochip_irq_map,
1759 .unmap = gpiochip_irq_unmap,
1760 /* Virtually all GPIO irqchips are twocell:ed */
1761 .xlate = irq_domain_xlate_twocell,
1762};
1763
1764static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
1765{
1766 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1767 struct irq_domain *domain;
1768
1769 domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,
1770 &gpiochip_domain_ops, gc);
1771 if (!domain)
1772 return ERR_PTR(-EINVAL);
1773
1774 return domain;
1775}
1776
1777static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1778{
1779 struct irq_domain *domain = gc->irq.domain;
1780
1781#ifdef CONFIG_GPIOLIB_IRQCHIP
1782 /*
1783 * Avoid race condition with other code, which tries to lookup
1784 * an IRQ before the irqchip has been properly registered,
1785 * i.e. while gpiochip is still being brought up.
1786 */
1787 if (!gc->irq.initialized)
1788 return -EPROBE_DEFER;
1789#endif
1790
1791 if (!gpiochip_irqchip_irq_valid(gc, offset))
1792 return -ENXIO;
1793
1794#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1795 if (irq_domain_is_hierarchy(domain)) {
1796 struct irq_fwspec spec;
1797
1798 spec.fwnode = domain->fwnode;
1799 spec.param_count = 2;
1800 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1801 spec.param[1] = IRQ_TYPE_NONE;
1802
1803 return irq_create_fwspec_mapping(&spec);
1804 }
1805#endif
1806
1807 return irq_create_mapping(domain, offset);
1808}
1809
1810int gpiochip_irq_reqres(struct irq_data *d)
1811{
1812 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1813 unsigned int hwirq = irqd_to_hwirq(d);
1814
1815 return gpiochip_reqres_irq(gc, hwirq);
1816}
1817EXPORT_SYMBOL(gpiochip_irq_reqres);
1818
1819void gpiochip_irq_relres(struct irq_data *d)
1820{
1821 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1822 unsigned int hwirq = irqd_to_hwirq(d);
1823
1824 gpiochip_relres_irq(gc, hwirq);
1825}
1826EXPORT_SYMBOL(gpiochip_irq_relres);
1827
1828static void gpiochip_irq_mask(struct irq_data *d)
1829{
1830 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1831 unsigned int hwirq = irqd_to_hwirq(d);
1832
1833 if (gc->irq.irq_mask)
1834 gc->irq.irq_mask(d);
1835 gpiochip_disable_irq(gc, hwirq);
1836}
1837
1838static void gpiochip_irq_unmask(struct irq_data *d)
1839{
1840 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1841 unsigned int hwirq = irqd_to_hwirq(d);
1842
1843 gpiochip_enable_irq(gc, hwirq);
1844 if (gc->irq.irq_unmask)
1845 gc->irq.irq_unmask(d);
1846}
1847
1848static void gpiochip_irq_enable(struct irq_data *d)
1849{
1850 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1851 unsigned int hwirq = irqd_to_hwirq(d);
1852
1853 gpiochip_enable_irq(gc, hwirq);
1854 gc->irq.irq_enable(d);
1855}
1856
1857static void gpiochip_irq_disable(struct irq_data *d)
1858{
1859 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1860 unsigned int hwirq = irqd_to_hwirq(d);
1861
1862 gc->irq.irq_disable(d);
1863 gpiochip_disable_irq(gc, hwirq);
1864}
1865
1866static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1867{
1868 struct irq_chip *irqchip = gc->irq.chip;
1869
1870 if (irqchip->flags & IRQCHIP_IMMUTABLE)
1871 return;
1872
1873 chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
1874
1875 if (!irqchip->irq_request_resources &&
1876 !irqchip->irq_release_resources) {
1877 irqchip->irq_request_resources = gpiochip_irq_reqres;
1878 irqchip->irq_release_resources = gpiochip_irq_relres;
1879 }
1880 if (WARN_ON(gc->irq.irq_enable))
1881 return;
1882 /* Check if the irqchip already has this hook... */
1883 if (irqchip->irq_enable == gpiochip_irq_enable ||
1884 irqchip->irq_mask == gpiochip_irq_mask) {
1885 /*
1886 * ...and if so, give a gentle warning that this is bad
1887 * practice.
1888 */
1889 chip_info(gc,
1890 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1891 return;
1892 }
1893
1894 if (irqchip->irq_disable) {
1895 gc->irq.irq_disable = irqchip->irq_disable;
1896 irqchip->irq_disable = gpiochip_irq_disable;
1897 } else {
1898 gc->irq.irq_mask = irqchip->irq_mask;
1899 irqchip->irq_mask = gpiochip_irq_mask;
1900 }
1901
1902 if (irqchip->irq_enable) {
1903 gc->irq.irq_enable = irqchip->irq_enable;
1904 irqchip->irq_enable = gpiochip_irq_enable;
1905 } else {
1906 gc->irq.irq_unmask = irqchip->irq_unmask;
1907 irqchip->irq_unmask = gpiochip_irq_unmask;
1908 }
1909}
1910
1911static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
1912 struct irq_domain *domain,
1913 bool allocated_externally)
1914{
1915 if (!domain)
1916 return -EINVAL;
1917
1918 if (gc->to_irq)
1919 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1920
1921 gc->to_irq = gpiochip_to_irq;
1922 gc->irq.domain = domain;
1923 gc->irq.domain_is_allocated_externally = allocated_externally;
1924
1925 /*
1926 * Using barrier() here to prevent compiler from reordering
1927 * gc->irq.initialized before adding irqdomain.
1928 */
1929 barrier();
1930
1931 gc->irq.initialized = true;
1932
1933 return 0;
1934}
1935
1936/**
1937 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1938 * @gc: the GPIO chip to add the IRQ chip to
1939 * @lock_key: lockdep class for IRQ lock
1940 * @request_key: lockdep class for IRQ request
1941 *
1942 * Returns:
1943 * 0 on success, or a negative errno on failure.
1944 */
1945static int gpiochip_add_irqchip(struct gpio_chip *gc,
1946 struct lock_class_key *lock_key,
1947 struct lock_class_key *request_key)
1948{
1949 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1950 struct irq_chip *irqchip = gc->irq.chip;
1951 struct irq_domain *domain;
1952 unsigned int type;
1953 unsigned int i;
1954 int ret;
1955
1956 if (!irqchip)
1957 return 0;
1958
1959 if (gc->irq.parent_handler && gc->can_sleep) {
1960 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1961 return -EINVAL;
1962 }
1963
1964 type = gc->irq.default_type;
1965
1966 /*
1967 * Specifying a default trigger is a terrible idea if DT or ACPI is
1968 * used to configure the interrupts, as you may end up with
1969 * conflicting triggers. Tell the user, and reset to NONE.
1970 */
1971 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1972 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1973 type = IRQ_TYPE_NONE;
1974
1975 gc->irq.default_type = type;
1976 gc->irq.lock_key = lock_key;
1977 gc->irq.request_key = request_key;
1978
1979 /* If a parent irqdomain is provided, let's build a hierarchy */
1980 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1981 domain = gpiochip_hierarchy_create_domain(gc);
1982 } else {
1983 domain = gpiochip_simple_create_domain(gc);
1984 }
1985 if (IS_ERR(domain))
1986 return PTR_ERR(domain);
1987
1988 if (gc->irq.parent_handler) {
1989 for (i = 0; i < gc->irq.num_parents; i++) {
1990 void *data;
1991
1992 if (gc->irq.per_parent_data)
1993 data = gc->irq.parent_handler_data_array[i];
1994 else
1995 data = gc->irq.parent_handler_data ?: gc;
1996
1997 /*
1998 * The parent IRQ chip is already using the chip_data
1999 * for this IRQ chip, so our callbacks simply use the
2000 * handler_data.
2001 */
2002 irq_set_chained_handler_and_data(gc->irq.parents[i],
2003 gc->irq.parent_handler,
2004 data);
2005 }
2006 }
2007
2008 gpiochip_set_irq_hooks(gc);
2009
2010 ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);
2011 if (ret)
2012 return ret;
2013
2014 acpi_gpiochip_request_interrupts(gc);
2015
2016 return 0;
2017}
2018
2019/**
2020 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
2021 * @gc: the gpiochip to remove the irqchip from
2022 *
2023 * This is called only from gpiochip_remove()
2024 */
2025static void gpiochip_irqchip_remove(struct gpio_chip *gc)
2026{
2027 struct irq_chip *irqchip = gc->irq.chip;
2028 unsigned int offset;
2029
2030 acpi_gpiochip_free_interrupts(gc);
2031
2032 if (irqchip && gc->irq.parent_handler) {
2033 struct gpio_irq_chip *irq = &gc->irq;
2034 unsigned int i;
2035
2036 for (i = 0; i < irq->num_parents; i++)
2037 irq_set_chained_handler_and_data(irq->parents[i],
2038 NULL, NULL);
2039 }
2040
2041 /* Remove all IRQ mappings and delete the domain */
2042 if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
2043 unsigned int irq;
2044
2045 for (offset = 0; offset < gc->ngpio; offset++) {
2046 if (!gpiochip_irqchip_irq_valid(gc, offset))
2047 continue;
2048
2049 irq = irq_find_mapping(gc->irq.domain, offset);
2050 irq_dispose_mapping(irq);
2051 }
2052
2053 irq_domain_remove(gc->irq.domain);
2054 }
2055
2056 if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
2057 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2058 irqchip->irq_request_resources = NULL;
2059 irqchip->irq_release_resources = NULL;
2060 }
2061 if (irqchip->irq_enable == gpiochip_irq_enable) {
2062 irqchip->irq_enable = gc->irq.irq_enable;
2063 irqchip->irq_disable = gc->irq.irq_disable;
2064 }
2065 }
2066 gc->irq.irq_enable = NULL;
2067 gc->irq.irq_disable = NULL;
2068 gc->irq.chip = NULL;
2069
2070 gpiochip_irqchip_free_valid_mask(gc);
2071}
2072
2073/**
2074 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
2075 * @gc: the gpiochip to add the irqchip to
2076 * @domain: the irqdomain to add to the gpiochip
2077 *
2078 * This function adds an IRQ domain to the gpiochip.
2079 *
2080 * Returns:
2081 * 0 on success, or negative errno on failure.
2082 */
2083int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
2084 struct irq_domain *domain)
2085{
2086 return gpiochip_irqchip_add_allocated_domain(gc, domain, true);
2087}
2088EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
2089
2090#else /* CONFIG_GPIOLIB_IRQCHIP */
2091
2092static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
2093 struct lock_class_key *lock_key,
2094 struct lock_class_key *request_key)
2095{
2096 return 0;
2097}
2098static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
2099
2100static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
2101{
2102 return 0;
2103}
2104
2105static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
2106{
2107 return 0;
2108}
2109static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
2110{ }
2111
2112#endif /* CONFIG_GPIOLIB_IRQCHIP */
2113
2114/**
2115 * gpiochip_generic_request() - request the gpio function for a pin
2116 * @gc: the gpiochip owning the GPIO
2117 * @offset: the offset of the GPIO to request for GPIO function
2118 *
2119 * Returns:
2120 * 0 on success, or negative errno on failure.
2121 */
2122int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
2123{
2124#ifdef CONFIG_PINCTRL
2125 if (list_empty(&gc->gpiodev->pin_ranges))
2126 return 0;
2127#endif
2128
2129 return pinctrl_gpio_request(gc, offset);
2130}
2131EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2132
2133/**
2134 * gpiochip_generic_free() - free the gpio function from a pin
2135 * @gc: the gpiochip to request the gpio function for
2136 * @offset: the offset of the GPIO to free from GPIO function
2137 */
2138void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
2139{
2140#ifdef CONFIG_PINCTRL
2141 if (list_empty(&gc->gpiodev->pin_ranges))
2142 return;
2143#endif
2144
2145 pinctrl_gpio_free(gc, offset);
2146}
2147EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2148
2149/**
2150 * gpiochip_generic_config() - apply configuration for a pin
2151 * @gc: the gpiochip owning the GPIO
2152 * @offset: the offset of the GPIO to apply the configuration
2153 * @config: the configuration to be applied
2154 *
2155 * Returns:
2156 * 0 on success, or negative errno on failure.
2157 */
2158int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
2159 unsigned long config)
2160{
2161#ifdef CONFIG_PINCTRL
2162 if (list_empty(&gc->gpiodev->pin_ranges))
2163 return -ENOTSUPP;
2164#endif
2165
2166 return pinctrl_gpio_set_config(gc, offset, config);
2167}
2168EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2169
2170#ifdef CONFIG_PINCTRL
2171
2172/**
2173 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2174 * @gc: the gpiochip to add the range for
2175 * @pctldev: the pin controller to map to
2176 * @gpio_offset: the start offset in the current gpio_chip number space
2177 * @pin_group: name of the pin group inside the pin controller
2178 *
2179 * Calling this function directly from a DeviceTree-supported
2180 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2181 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2182 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2183 *
2184 * Returns:
2185 * 0 on success, or negative errno on failure.
2186 */
2187int gpiochip_add_pingroup_range(struct gpio_chip *gc,
2188 struct pinctrl_dev *pctldev,
2189 unsigned int gpio_offset, const char *pin_group)
2190{
2191 struct gpio_pin_range *pin_range;
2192 struct gpio_device *gdev = gc->gpiodev;
2193 int ret;
2194
2195 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2196 if (!pin_range) {
2197 chip_err(gc, "failed to allocate pin ranges\n");
2198 return -ENOMEM;
2199 }
2200
2201 /* Use local offset as range ID */
2202 pin_range->range.id = gpio_offset;
2203 pin_range->range.gc = gc;
2204 pin_range->range.name = gc->label;
2205 pin_range->range.base = gdev->base + gpio_offset;
2206 pin_range->pctldev = pctldev;
2207
2208 ret = pinctrl_get_group_pins(pctldev, pin_group,
2209 &pin_range->range.pins,
2210 &pin_range->range.npins);
2211 if (ret < 0) {
2212 kfree(pin_range);
2213 return ret;
2214 }
2215
2216 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2217
2218 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2219 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2220 pinctrl_dev_get_devname(pctldev), pin_group);
2221
2222 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2223
2224 return 0;
2225}
2226EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2227
2228/**
2229 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2230 * @gc: the gpiochip to add the range for
2231 * @pinctl_name: the dev_name() of the pin controller to map to
2232 * @gpio_offset: the start offset in the current gpio_chip number space
2233 * @pin_offset: the start offset in the pin controller number space
2234 * @npins: the number of pins from the offset of each pin space (GPIO and
2235 * pin controller) to accumulate in this range
2236 *
2237 * Calling this function directly from a DeviceTree-supported
2238 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2239 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2240 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2241 *
2242 * Returns:
2243 * 0 on success, or a negative errno on failure.
2244 */
2245int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
2246 unsigned int gpio_offset, unsigned int pin_offset,
2247 unsigned int npins)
2248{
2249 struct gpio_pin_range *pin_range;
2250 struct gpio_device *gdev = gc->gpiodev;
2251 int ret;
2252
2253 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2254 if (!pin_range) {
2255 chip_err(gc, "failed to allocate pin ranges\n");
2256 return -ENOMEM;
2257 }
2258
2259 /* Use local offset as range ID */
2260 pin_range->range.id = gpio_offset;
2261 pin_range->range.gc = gc;
2262 pin_range->range.name = gc->label;
2263 pin_range->range.base = gdev->base + gpio_offset;
2264 pin_range->range.pin_base = pin_offset;
2265 pin_range->range.npins = npins;
2266 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2267 &pin_range->range);
2268 if (IS_ERR(pin_range->pctldev)) {
2269 ret = PTR_ERR(pin_range->pctldev);
2270 chip_err(gc, "could not create pin range\n");
2271 kfree(pin_range);
2272 return ret;
2273 }
2274 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2275 gpio_offset, gpio_offset + npins - 1,
2276 pinctl_name,
2277 pin_offset, pin_offset + npins - 1);
2278
2279 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2280
2281 return 0;
2282}
2283EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2284
2285/**
2286 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2287 * @gc: the chip to remove all the mappings for
2288 */
2289void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
2290{
2291 struct gpio_pin_range *pin_range, *tmp;
2292 struct gpio_device *gdev = gc->gpiodev;
2293
2294 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2295 list_del(&pin_range->node);
2296 pinctrl_remove_gpio_range(pin_range->pctldev,
2297 &pin_range->range);
2298 kfree(pin_range);
2299 }
2300}
2301EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2302
2303#endif /* CONFIG_PINCTRL */
2304
2305/* These "optional" allocation calls help prevent drivers from stomping
2306 * on each other, and help provide better diagnostics in debugfs.
2307 * They're called even less than the "set direction" calls.
2308 */
2309static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2310{
2311 unsigned int offset;
2312 int ret;
2313
2314 CLASS(gpio_chip_guard, guard)(desc);
2315 if (!guard.gc)
2316 return -ENODEV;
2317
2318 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
2319 return -EBUSY;
2320
2321 /* NOTE: gpio_request() can be called in early boot,
2322 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2323 */
2324
2325 if (guard.gc->request) {
2326 offset = gpio_chip_hwgpio(desc);
2327 if (gpiochip_line_is_valid(guard.gc, offset))
2328 ret = guard.gc->request(guard.gc, offset);
2329 else
2330 ret = -EINVAL;
2331 if (ret)
2332 goto out_clear_bit;
2333 }
2334
2335 if (guard.gc->get_direction)
2336 gpiod_get_direction(desc);
2337
2338 ret = desc_set_label(desc, label ? : "?");
2339 if (ret)
2340 goto out_clear_bit;
2341
2342 return 0;
2343
2344out_clear_bit:
2345 clear_bit(FLAG_REQUESTED, &desc->flags);
2346 return ret;
2347}
2348
2349/*
2350 * This descriptor validation needs to be inserted verbatim into each
2351 * function taking a descriptor, so we need to use a preprocessor
2352 * macro to avoid endless duplication. If the desc is NULL it is an
2353 * optional GPIO and calls should just bail out.
2354 */
2355static int validate_desc(const struct gpio_desc *desc, const char *func)
2356{
2357 if (!desc)
2358 return 0;
2359
2360 if (IS_ERR(desc)) {
2361 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2362 return PTR_ERR(desc);
2363 }
2364
2365 return 1;
2366}
2367
2368#define VALIDATE_DESC(desc) do { \
2369 int __valid = validate_desc(desc, __func__); \
2370 if (__valid <= 0) \
2371 return __valid; \
2372 } while (0)
2373
2374#define VALIDATE_DESC_VOID(desc) do { \
2375 int __valid = validate_desc(desc, __func__); \
2376 if (__valid <= 0) \
2377 return; \
2378 } while (0)
2379
2380int gpiod_request(struct gpio_desc *desc, const char *label)
2381{
2382 int ret = -EPROBE_DEFER;
2383
2384 VALIDATE_DESC(desc);
2385
2386 if (try_module_get(desc->gdev->owner)) {
2387 ret = gpiod_request_commit(desc, label);
2388 if (ret)
2389 module_put(desc->gdev->owner);
2390 else
2391 gpio_device_get(desc->gdev);
2392 }
2393
2394 if (ret)
2395 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2396
2397 return ret;
2398}
2399
2400static void gpiod_free_commit(struct gpio_desc *desc)
2401{
2402 unsigned long flags;
2403
2404 might_sleep();
2405
2406 CLASS(gpio_chip_guard, guard)(desc);
2407
2408 flags = READ_ONCE(desc->flags);
2409
2410 if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {
2411 if (guard.gc->free)
2412 guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));
2413
2414 clear_bit(FLAG_ACTIVE_LOW, &flags);
2415 clear_bit(FLAG_REQUESTED, &flags);
2416 clear_bit(FLAG_OPEN_DRAIN, &flags);
2417 clear_bit(FLAG_OPEN_SOURCE, &flags);
2418 clear_bit(FLAG_PULL_UP, &flags);
2419 clear_bit(FLAG_PULL_DOWN, &flags);
2420 clear_bit(FLAG_BIAS_DISABLE, &flags);
2421 clear_bit(FLAG_EDGE_RISING, &flags);
2422 clear_bit(FLAG_EDGE_FALLING, &flags);
2423 clear_bit(FLAG_IS_HOGGED, &flags);
2424#ifdef CONFIG_OF_DYNAMIC
2425 WRITE_ONCE(desc->hog, NULL);
2426#endif
2427 desc_set_label(desc, NULL);
2428 WRITE_ONCE(desc->flags, flags);
2429#ifdef CONFIG_GPIO_CDEV
2430 WRITE_ONCE(desc->debounce_period_us, 0);
2431#endif
2432 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_RELEASED);
2433 }
2434}
2435
2436void gpiod_free(struct gpio_desc *desc)
2437{
2438 VALIDATE_DESC_VOID(desc);
2439
2440 gpiod_free_commit(desc);
2441 module_put(desc->gdev->owner);
2442 gpio_device_put(desc->gdev);
2443}
2444
2445/**
2446 * gpiochip_dup_line_label - Get a copy of the consumer label.
2447 * @gc: GPIO chip controlling this line.
2448 * @offset: Hardware offset of the line.
2449 *
2450 * Returns:
2451 * Pointer to a copy of the consumer label if the line is requested or NULL
2452 * if it's not. If a valid pointer was returned, it must be freed using
2453 * kfree(). In case of a memory allocation error, the function returns %ENOMEM.
2454 *
2455 * Must not be called from atomic context.
2456 */
2457char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
2458{
2459 struct gpio_desc *desc;
2460 char *label;
2461
2462 desc = gpiochip_get_desc(gc, offset);
2463 if (IS_ERR(desc))
2464 return NULL;
2465
2466 if (!test_bit(FLAG_REQUESTED, &desc->flags))
2467 return NULL;
2468
2469 guard(srcu)(&desc->gdev->desc_srcu);
2470
2471 label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);
2472 if (!label)
2473 return ERR_PTR(-ENOMEM);
2474
2475 return label;
2476}
2477EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
2478
2479static inline const char *function_name_or_default(const char *con_id)
2480{
2481 return con_id ?: "(default)";
2482}
2483
2484/**
2485 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2486 * @gc: GPIO chip
2487 * @hwnum: hardware number of the GPIO for which to request the descriptor
2488 * @label: label for the GPIO
2489 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2490 * specify things like line inversion semantics with the machine flags
2491 * such as GPIO_OUT_LOW
2492 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2493 * can be used to specify consumer semantics such as open drain
2494 *
2495 * Function allows GPIO chip drivers to request and use their own GPIO
2496 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2497 * function will not increase reference count of the GPIO chip module. This
2498 * allows the GPIO chip module to be unloaded as needed (we assume that the
2499 * GPIO chip driver handles freeing the GPIOs it has requested).
2500 *
2501 * Returns:
2502 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2503 * code on failure.
2504 */
2505struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2506 unsigned int hwnum,
2507 const char *label,
2508 enum gpio_lookup_flags lflags,
2509 enum gpiod_flags dflags)
2510{
2511 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2512 const char *name = function_name_or_default(label);
2513 int ret;
2514
2515 if (IS_ERR(desc)) {
2516 chip_err(gc, "failed to get GPIO %s descriptor\n", name);
2517 return desc;
2518 }
2519
2520 ret = gpiod_request_commit(desc, label);
2521 if (ret < 0)
2522 return ERR_PTR(ret);
2523
2524 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2525 if (ret) {
2526 gpiod_free_commit(desc);
2527 chip_err(gc, "setup of own GPIO %s failed\n", name);
2528 return ERR_PTR(ret);
2529 }
2530
2531 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
2532
2533 return desc;
2534}
2535EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2536
2537/**
2538 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2539 * @desc: GPIO descriptor to free
2540 *
2541 * Function frees the given GPIO requested previously with
2542 * gpiochip_request_own_desc().
2543 */
2544void gpiochip_free_own_desc(struct gpio_desc *desc)
2545{
2546 if (desc)
2547 gpiod_free_commit(desc);
2548}
2549EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2550
2551/*
2552 * Drivers MUST set GPIO direction before making get/set calls. In
2553 * some cases this is done in early boot, before IRQs are enabled.
2554 *
2555 * As a rule these aren't called more than once (except for drivers
2556 * using the open-drain emulation idiom) so these are natural places
2557 * to accumulate extra debugging checks. Note that we can't (yet)
2558 * rely on gpio_request() having been called beforehand.
2559 */
2560
2561int gpio_do_set_config(struct gpio_desc *desc, unsigned long config)
2562{
2563 int ret;
2564
2565 CLASS(gpio_chip_guard, guard)(desc);
2566 if (!guard.gc)
2567 return -ENODEV;
2568
2569 if (!guard.gc->set_config)
2570 return -ENOTSUPP;
2571
2572 ret = guard.gc->set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2573#ifdef CONFIG_GPIO_CDEV
2574 /*
2575 * Special case - if we're setting debounce period, we need to store
2576 * it in the descriptor in case user-space wants to know it.
2577 */
2578 if (!ret && pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE)
2579 WRITE_ONCE(desc->debounce_period_us,
2580 pinconf_to_config_argument(config));
2581#endif
2582 return ret;
2583}
2584
2585static int gpio_set_config_with_argument(struct gpio_desc *desc,
2586 enum pin_config_param mode,
2587 u32 argument)
2588{
2589 unsigned long config;
2590
2591 config = pinconf_to_config_packed(mode, argument);
2592 return gpio_do_set_config(desc, config);
2593}
2594
2595static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2596 enum pin_config_param mode,
2597 u32 argument)
2598{
2599 struct device *dev = &desc->gdev->dev;
2600 int gpio = gpio_chip_hwgpio(desc);
2601 int ret;
2602
2603 ret = gpio_set_config_with_argument(desc, mode, argument);
2604 if (ret != -ENOTSUPP)
2605 return ret;
2606
2607 switch (mode) {
2608 case PIN_CONFIG_PERSIST_STATE:
2609 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2610 break;
2611 default:
2612 break;
2613 }
2614
2615 return 0;
2616}
2617
2618static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2619{
2620 return gpio_set_config_with_argument(desc, mode, 0);
2621}
2622
2623static int gpio_set_bias(struct gpio_desc *desc)
2624{
2625 enum pin_config_param bias;
2626 unsigned long flags;
2627 unsigned int arg;
2628
2629 flags = READ_ONCE(desc->flags);
2630
2631 if (test_bit(FLAG_BIAS_DISABLE, &flags))
2632 bias = PIN_CONFIG_BIAS_DISABLE;
2633 else if (test_bit(FLAG_PULL_UP, &flags))
2634 bias = PIN_CONFIG_BIAS_PULL_UP;
2635 else if (test_bit(FLAG_PULL_DOWN, &flags))
2636 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2637 else
2638 return 0;
2639
2640 switch (bias) {
2641 case PIN_CONFIG_BIAS_PULL_DOWN:
2642 case PIN_CONFIG_BIAS_PULL_UP:
2643 arg = 1;
2644 break;
2645
2646 default:
2647 arg = 0;
2648 break;
2649 }
2650
2651 return gpio_set_config_with_argument_optional(desc, bias, arg);
2652}
2653
2654/**
2655 * gpio_set_debounce_timeout() - Set debounce timeout
2656 * @desc: GPIO descriptor to set the debounce timeout
2657 * @debounce: Debounce timeout in microseconds
2658 *
2659 * The function calls the certain GPIO driver to set debounce timeout
2660 * in the hardware.
2661 *
2662 * Returns:
2663 * 0 on success, or negative errno on failure.
2664 */
2665int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2666{
2667 int ret;
2668
2669 ret = gpio_set_config_with_argument_optional(desc,
2670 PIN_CONFIG_INPUT_DEBOUNCE,
2671 debounce);
2672 if (!ret)
2673 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2674
2675 return ret;
2676}
2677
2678/**
2679 * gpiod_direction_input - set the GPIO direction to input
2680 * @desc: GPIO to set to input
2681 *
2682 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2683 * be called safely on it.
2684 *
2685 * Returns:
2686 * 0 on success, or negative errno on failure.
2687 */
2688int gpiod_direction_input(struct gpio_desc *desc)
2689{
2690 int ret;
2691
2692 VALIDATE_DESC(desc);
2693
2694 ret = gpiod_direction_input_nonotify(desc);
2695 if (ret == 0)
2696 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2697
2698 return ret;
2699}
2700EXPORT_SYMBOL_GPL(gpiod_direction_input);
2701
2702int gpiod_direction_input_nonotify(struct gpio_desc *desc)
2703{
2704 int ret = 0;
2705
2706 CLASS(gpio_chip_guard, guard)(desc);
2707 if (!guard.gc)
2708 return -ENODEV;
2709
2710 /*
2711 * It is legal to have no .get() and .direction_input() specified if
2712 * the chip is output-only, but you can't specify .direction_input()
2713 * and not support the .get() operation, that doesn't make sense.
2714 */
2715 if (!guard.gc->get && guard.gc->direction_input) {
2716 gpiod_warn(desc,
2717 "%s: missing get() but have direction_input()\n",
2718 __func__);
2719 return -EIO;
2720 }
2721
2722 /*
2723 * If we have a .direction_input() callback, things are simple,
2724 * just call it. Else we are some input-only chip so try to check the
2725 * direction (if .get_direction() is supported) else we silently
2726 * assume we are in input mode after this.
2727 */
2728 if (guard.gc->direction_input) {
2729 ret = guard.gc->direction_input(guard.gc,
2730 gpio_chip_hwgpio(desc));
2731 } else if (guard.gc->get_direction &&
2732 (guard.gc->get_direction(guard.gc,
2733 gpio_chip_hwgpio(desc)) != 1)) {
2734 gpiod_warn(desc,
2735 "%s: missing direction_input() operation and line is output\n",
2736 __func__);
2737 return -EIO;
2738 }
2739 if (ret == 0) {
2740 clear_bit(FLAG_IS_OUT, &desc->flags);
2741 ret = gpio_set_bias(desc);
2742 }
2743
2744 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2745
2746 return ret;
2747}
2748
2749static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2750{
2751 int val = !!value, ret = 0;
2752
2753 CLASS(gpio_chip_guard, guard)(desc);
2754 if (!guard.gc)
2755 return -ENODEV;
2756
2757 /*
2758 * It's OK not to specify .direction_output() if the gpiochip is
2759 * output-only, but if there is then not even a .set() operation it
2760 * is pretty tricky to drive the output line.
2761 */
2762 if (!guard.gc->set && !guard.gc->direction_output) {
2763 gpiod_warn(desc,
2764 "%s: missing set() and direction_output() operations\n",
2765 __func__);
2766 return -EIO;
2767 }
2768
2769 if (guard.gc->direction_output) {
2770 ret = guard.gc->direction_output(guard.gc,
2771 gpio_chip_hwgpio(desc), val);
2772 } else {
2773 /* Check that we are in output mode if we can */
2774 if (guard.gc->get_direction &&
2775 guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) {
2776 gpiod_warn(desc,
2777 "%s: missing direction_output() operation\n",
2778 __func__);
2779 return -EIO;
2780 }
2781 /*
2782 * If we can't actively set the direction, we are some
2783 * output-only chip, so just drive the output as desired.
2784 */
2785 guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), val);
2786 }
2787
2788 if (!ret)
2789 set_bit(FLAG_IS_OUT, &desc->flags);
2790 trace_gpio_value(desc_to_gpio(desc), 0, val);
2791 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2792 return ret;
2793}
2794
2795/**
2796 * gpiod_direction_output_raw - set the GPIO direction to output
2797 * @desc: GPIO to set to output
2798 * @value: initial output value of the GPIO
2799 *
2800 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2801 * be called safely on it. The initial value of the output must be specified
2802 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2803 *
2804 * Returns:
2805 * 0 on success, or negative errno on failure.
2806 */
2807int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2808{
2809 int ret;
2810
2811 VALIDATE_DESC(desc);
2812
2813 ret = gpiod_direction_output_raw_commit(desc, value);
2814 if (ret == 0)
2815 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2816
2817 return ret;
2818}
2819EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2820
2821/**
2822 * gpiod_direction_output - set the GPIO direction to output
2823 * @desc: GPIO to set to output
2824 * @value: initial output value of the GPIO
2825 *
2826 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2827 * be called safely on it. The initial value of the output must be specified
2828 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2829 * account.
2830 *
2831 * Returns:
2832 * 0 on success, or negative errno on failure.
2833 */
2834int gpiod_direction_output(struct gpio_desc *desc, int value)
2835{
2836 int ret;
2837
2838 VALIDATE_DESC(desc);
2839
2840 ret = gpiod_direction_output_nonotify(desc, value);
2841 if (ret == 0)
2842 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2843
2844 return ret;
2845}
2846EXPORT_SYMBOL_GPL(gpiod_direction_output);
2847
2848int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value)
2849{
2850 unsigned long flags;
2851 int ret;
2852
2853 flags = READ_ONCE(desc->flags);
2854
2855 if (test_bit(FLAG_ACTIVE_LOW, &flags))
2856 value = !value;
2857 else
2858 value = !!value;
2859
2860 /* GPIOs used for enabled IRQs shall not be set as output */
2861 if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
2862 test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {
2863 gpiod_err(desc,
2864 "%s: tried to set a GPIO tied to an IRQ as output\n",
2865 __func__);
2866 return -EIO;
2867 }
2868
2869 if (test_bit(FLAG_OPEN_DRAIN, &flags)) {
2870 /* First see if we can enable open drain in hardware */
2871 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2872 if (!ret)
2873 goto set_output_value;
2874 /* Emulate open drain by not actively driving the line high */
2875 if (value) {
2876 ret = gpiod_direction_input_nonotify(desc);
2877 goto set_output_flag;
2878 }
2879 } else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {
2880 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2881 if (!ret)
2882 goto set_output_value;
2883 /* Emulate open source by not actively driving the line low */
2884 if (!value) {
2885 ret = gpiod_direction_input_nonotify(desc);
2886 goto set_output_flag;
2887 }
2888 } else {
2889 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2890 }
2891
2892set_output_value:
2893 ret = gpio_set_bias(desc);
2894 if (ret)
2895 return ret;
2896 return gpiod_direction_output_raw_commit(desc, value);
2897
2898set_output_flag:
2899 /*
2900 * When emulating open-source or open-drain functionalities by not
2901 * actively driving the line (setting mode to input) we still need to
2902 * set the IS_OUT flag or otherwise we won't be able to set the line
2903 * value anymore.
2904 */
2905 if (ret == 0)
2906 set_bit(FLAG_IS_OUT, &desc->flags);
2907 return ret;
2908}
2909
2910/**
2911 * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
2912 *
2913 * @desc: GPIO to enable.
2914 * @flags: Flags related to GPIO edge.
2915 *
2916 * Returns:
2917 * 0 on success, or negative errno on failure.
2918 */
2919int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
2920{
2921 int ret = 0;
2922
2923 VALIDATE_DESC(desc);
2924
2925 CLASS(gpio_chip_guard, guard)(desc);
2926 if (!guard.gc)
2927 return -ENODEV;
2928
2929 if (!guard.gc->en_hw_timestamp) {
2930 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
2931 return -ENOTSUPP;
2932 }
2933
2934 ret = guard.gc->en_hw_timestamp(guard.gc,
2935 gpio_chip_hwgpio(desc), flags);
2936 if (ret)
2937 gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
2938
2939 return ret;
2940}
2941EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
2942
2943/**
2944 * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
2945 *
2946 * @desc: GPIO to disable.
2947 * @flags: Flags related to GPIO edge, same value as used during enable call.
2948 *
2949 * Returns:
2950 * 0 on success, or negative errno on failure.
2951 */
2952int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
2953{
2954 int ret = 0;
2955
2956 VALIDATE_DESC(desc);
2957
2958 CLASS(gpio_chip_guard, guard)(desc);
2959 if (!guard.gc)
2960 return -ENODEV;
2961
2962 if (!guard.gc->dis_hw_timestamp) {
2963 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
2964 return -ENOTSUPP;
2965 }
2966
2967 ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),
2968 flags);
2969 if (ret)
2970 gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
2971
2972 return ret;
2973}
2974EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
2975
2976/**
2977 * gpiod_set_config - sets @config for a GPIO
2978 * @desc: descriptor of the GPIO for which to set the configuration
2979 * @config: Same packed config format as generic pinconf
2980 *
2981 * Returns:
2982 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2983 * configuration.
2984 */
2985int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2986{
2987 int ret;
2988
2989 VALIDATE_DESC(desc);
2990
2991 ret = gpio_do_set_config(desc, config);
2992 if (!ret) {
2993 /* These are the only options we notify the userspace about. */
2994 switch (pinconf_to_config_param(config)) {
2995 case PIN_CONFIG_BIAS_DISABLE:
2996 case PIN_CONFIG_BIAS_PULL_DOWN:
2997 case PIN_CONFIG_BIAS_PULL_UP:
2998 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
2999 case PIN_CONFIG_DRIVE_OPEN_SOURCE:
3000 case PIN_CONFIG_DRIVE_PUSH_PULL:
3001 case PIN_CONFIG_INPUT_DEBOUNCE:
3002 gpiod_line_state_notify(desc,
3003 GPIO_V2_LINE_CHANGED_CONFIG);
3004 break;
3005 default:
3006 break;
3007 }
3008 }
3009
3010 return ret;
3011}
3012EXPORT_SYMBOL_GPL(gpiod_set_config);
3013
3014/**
3015 * gpiod_set_debounce - sets @debounce time for a GPIO
3016 * @desc: descriptor of the GPIO for which to set debounce time
3017 * @debounce: debounce time in microseconds
3018 *
3019 * Returns:
3020 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3021 * debounce time.
3022 */
3023int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
3024{
3025 unsigned long config;
3026
3027 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
3028 return gpiod_set_config(desc, config);
3029}
3030EXPORT_SYMBOL_GPL(gpiod_set_debounce);
3031
3032/**
3033 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
3034 * @desc: descriptor of the GPIO for which to configure persistence
3035 * @transitory: True to lose state on suspend or reset, false for persistence
3036 *
3037 * Returns:
3038 * 0 on success, otherwise a negative error code.
3039 */
3040int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
3041{
3042 VALIDATE_DESC(desc);
3043 /*
3044 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
3045 * persistence state.
3046 */
3047 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
3048
3049 /* If the driver supports it, set the persistence state now */
3050 return gpio_set_config_with_argument_optional(desc,
3051 PIN_CONFIG_PERSIST_STATE,
3052 !transitory);
3053}
3054
3055/**
3056 * gpiod_is_active_low - test whether a GPIO is active-low or not
3057 * @desc: the gpio descriptor to test
3058 *
3059 * Returns:
3060 * 1 if the GPIO is active-low, 0 otherwise.
3061 */
3062int gpiod_is_active_low(const struct gpio_desc *desc)
3063{
3064 VALIDATE_DESC(desc);
3065 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
3066}
3067EXPORT_SYMBOL_GPL(gpiod_is_active_low);
3068
3069/**
3070 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
3071 * @desc: the gpio descriptor to change
3072 */
3073void gpiod_toggle_active_low(struct gpio_desc *desc)
3074{
3075 VALIDATE_DESC_VOID(desc);
3076 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
3077 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3078}
3079EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
3080
3081static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)
3082{
3083 return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO;
3084}
3085
3086/* I/O calls are only valid after configuration completed; the relevant
3087 * "is this a valid GPIO" error checks should already have been done.
3088 *
3089 * "Get" operations are often inlinable as reading a pin value register,
3090 * and masking the relevant bit in that register.
3091 *
3092 * When "set" operations are inlinable, they involve writing that mask to
3093 * one register to set a low value, or a different register to set it high.
3094 * Otherwise locking is needed, so there may be little value to inlining.
3095 *
3096 *------------------------------------------------------------------------
3097 *
3098 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
3099 * have requested the GPIO. That can include implicit requesting by
3100 * a direction setting call. Marking a gpio as requested locks its chip
3101 * in memory, guaranteeing that these table lookups need no more locking
3102 * and that gpiochip_remove() will fail.
3103 *
3104 * REVISIT when debugging, consider adding some instrumentation to ensure
3105 * that the GPIO was actually requested.
3106 */
3107
3108static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
3109{
3110 struct gpio_device *gdev;
3111 struct gpio_chip *gc;
3112 int value;
3113
3114 /* FIXME Unable to use gpio_chip_guard due to const desc. */
3115 gdev = desc->gdev;
3116
3117 guard(srcu)(&gdev->srcu);
3118
3119 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3120 if (!gc)
3121 return -ENODEV;
3122
3123 value = gpio_chip_get_value(gc, desc);
3124 value = value < 0 ? value : !!value;
3125 trace_gpio_value(desc_to_gpio(desc), 1, value);
3126 return value;
3127}
3128
3129static int gpio_chip_get_multiple(struct gpio_chip *gc,
3130 unsigned long *mask, unsigned long *bits)
3131{
3132 lockdep_assert_held(&gc->gpiodev->srcu);
3133
3134 if (gc->get_multiple)
3135 return gc->get_multiple(gc, mask, bits);
3136 if (gc->get) {
3137 int i, value;
3138
3139 for_each_set_bit(i, mask, gc->ngpio) {
3140 value = gc->get(gc, i);
3141 if (value < 0)
3142 return value;
3143 __assign_bit(i, bits, value);
3144 }
3145 return 0;
3146 }
3147 return -EIO;
3148}
3149
3150/* The 'other' chip must be protected with its GPIO device's SRCU. */
3151static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
3152{
3153 guard(srcu)(&gdev->srcu);
3154
3155 return gc == srcu_dereference(gdev->chip, &gdev->srcu);
3156}
3157
3158int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3159 unsigned int array_size,
3160 struct gpio_desc **desc_array,
3161 struct gpio_array *array_info,
3162 unsigned long *value_bitmap)
3163{
3164 struct gpio_chip *gc;
3165 int ret, i = 0;
3166
3167 /*
3168 * Validate array_info against desc_array and its size.
3169 * It should immediately follow desc_array if both
3170 * have been obtained from the same gpiod_get_array() call.
3171 */
3172 if (array_info && array_info->desc == desc_array &&
3173 array_size <= array_info->size &&
3174 (void *)array_info == desc_array + array_info->size) {
3175 if (!can_sleep)
3176 WARN_ON(array_info->gdev->can_sleep);
3177
3178 guard(srcu)(&array_info->gdev->srcu);
3179 gc = srcu_dereference(array_info->gdev->chip,
3180 &array_info->gdev->srcu);
3181 if (!gc)
3182 return -ENODEV;
3183
3184 ret = gpio_chip_get_multiple(gc, array_info->get_mask,
3185 value_bitmap);
3186 if (ret)
3187 return ret;
3188
3189 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3190 bitmap_xor(value_bitmap, value_bitmap,
3191 array_info->invert_mask, array_size);
3192
3193 i = find_first_zero_bit(array_info->get_mask, array_size);
3194 if (i == array_size)
3195 return 0;
3196 } else {
3197 array_info = NULL;
3198 }
3199
3200 while (i < array_size) {
3201 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3202 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3203 unsigned long *mask, *bits;
3204 int first, j;
3205
3206 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3207 if (!guard.gc)
3208 return -ENODEV;
3209
3210 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3211 mask = fastpath_mask;
3212 bits = fastpath_bits;
3213 } else {
3214 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3215
3216 mask = bitmap_alloc(guard.gc->ngpio, flags);
3217 if (!mask)
3218 return -ENOMEM;
3219
3220 bits = bitmap_alloc(guard.gc->ngpio, flags);
3221 if (!bits) {
3222 bitmap_free(mask);
3223 return -ENOMEM;
3224 }
3225 }
3226
3227 bitmap_zero(mask, guard.gc->ngpio);
3228
3229 if (!can_sleep)
3230 WARN_ON(guard.gc->can_sleep);
3231
3232 /* collect all inputs belonging to the same chip */
3233 first = i;
3234 do {
3235 const struct gpio_desc *desc = desc_array[i];
3236 int hwgpio = gpio_chip_hwgpio(desc);
3237
3238 __set_bit(hwgpio, mask);
3239 i++;
3240
3241 if (array_info)
3242 i = find_next_zero_bit(array_info->get_mask,
3243 array_size, i);
3244 } while ((i < array_size) &&
3245 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3246
3247 ret = gpio_chip_get_multiple(guard.gc, mask, bits);
3248 if (ret) {
3249 if (mask != fastpath_mask)
3250 bitmap_free(mask);
3251 if (bits != fastpath_bits)
3252 bitmap_free(bits);
3253 return ret;
3254 }
3255
3256 for (j = first; j < i; ) {
3257 const struct gpio_desc *desc = desc_array[j];
3258 int hwgpio = gpio_chip_hwgpio(desc);
3259 int value = test_bit(hwgpio, bits);
3260
3261 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3262 value = !value;
3263 __assign_bit(j, value_bitmap, value);
3264 trace_gpio_value(desc_to_gpio(desc), 1, value);
3265 j++;
3266
3267 if (array_info)
3268 j = find_next_zero_bit(array_info->get_mask, i,
3269 j);
3270 }
3271
3272 if (mask != fastpath_mask)
3273 bitmap_free(mask);
3274 if (bits != fastpath_bits)
3275 bitmap_free(bits);
3276 }
3277 return 0;
3278}
3279
3280/**
3281 * gpiod_get_raw_value() - return a gpio's raw value
3282 * @desc: gpio whose value will be returned
3283 *
3284 * Returns:
3285 * The GPIO's raw value, i.e. the value of the physical line disregarding
3286 * its ACTIVE_LOW status, or negative errno on failure.
3287 *
3288 * This function can be called from contexts where we cannot sleep, and will
3289 * complain if the GPIO chip functions potentially sleep.
3290 */
3291int gpiod_get_raw_value(const struct gpio_desc *desc)
3292{
3293 VALIDATE_DESC(desc);
3294 /* Should be using gpiod_get_raw_value_cansleep() */
3295 WARN_ON(desc->gdev->can_sleep);
3296 return gpiod_get_raw_value_commit(desc);
3297}
3298EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3299
3300/**
3301 * gpiod_get_value() - return a gpio's value
3302 * @desc: gpio whose value will be returned
3303 *
3304 * Returns:
3305 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3306 * account, or negative errno on failure.
3307 *
3308 * This function can be called from contexts where we cannot sleep, and will
3309 * complain if the GPIO chip functions potentially sleep.
3310 */
3311int gpiod_get_value(const struct gpio_desc *desc)
3312{
3313 int value;
3314
3315 VALIDATE_DESC(desc);
3316 /* Should be using gpiod_get_value_cansleep() */
3317 WARN_ON(desc->gdev->can_sleep);
3318
3319 value = gpiod_get_raw_value_commit(desc);
3320 if (value < 0)
3321 return value;
3322
3323 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3324 value = !value;
3325
3326 return value;
3327}
3328EXPORT_SYMBOL_GPL(gpiod_get_value);
3329
3330/**
3331 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3332 * @array_size: number of elements in the descriptor array / value bitmap
3333 * @desc_array: array of GPIO descriptors whose values will be read
3334 * @array_info: information on applicability of fast bitmap processing path
3335 * @value_bitmap: bitmap to store the read values
3336 *
3337 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3338 * without regard for their ACTIVE_LOW status.
3339 *
3340 * This function can be called from contexts where we cannot sleep,
3341 * and it will complain if the GPIO chip functions potentially sleep.
3342 *
3343 * Returns:
3344 * 0 on success, or negative errno on failure.
3345 */
3346int gpiod_get_raw_array_value(unsigned int array_size,
3347 struct gpio_desc **desc_array,
3348 struct gpio_array *array_info,
3349 unsigned long *value_bitmap)
3350{
3351 if (!desc_array)
3352 return -EINVAL;
3353 return gpiod_get_array_value_complex(true, false, array_size,
3354 desc_array, array_info,
3355 value_bitmap);
3356}
3357EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3358
3359/**
3360 * gpiod_get_array_value() - read values from an array of GPIOs
3361 * @array_size: number of elements in the descriptor array / value bitmap
3362 * @desc_array: array of GPIO descriptors whose values will be read
3363 * @array_info: information on applicability of fast bitmap processing path
3364 * @value_bitmap: bitmap to store the read values
3365 *
3366 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3367 * into account.
3368 *
3369 * This function can be called from contexts where we cannot sleep,
3370 * and it will complain if the GPIO chip functions potentially sleep.
3371 *
3372 * Returns:
3373 * 0 on success, or negative errno on failure.
3374 */
3375int gpiod_get_array_value(unsigned int array_size,
3376 struct gpio_desc **desc_array,
3377 struct gpio_array *array_info,
3378 unsigned long *value_bitmap)
3379{
3380 if (!desc_array)
3381 return -EINVAL;
3382 return gpiod_get_array_value_complex(false, false, array_size,
3383 desc_array, array_info,
3384 value_bitmap);
3385}
3386EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3387
3388/*
3389 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3390 * @desc: gpio descriptor whose state need to be set.
3391 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3392 */
3393static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3394{
3395 int ret = 0, offset = gpio_chip_hwgpio(desc);
3396
3397 CLASS(gpio_chip_guard, guard)(desc);
3398 if (!guard.gc)
3399 return;
3400
3401 if (value) {
3402 ret = guard.gc->direction_input(guard.gc, offset);
3403 } else {
3404 ret = guard.gc->direction_output(guard.gc, offset, 0);
3405 if (!ret)
3406 set_bit(FLAG_IS_OUT, &desc->flags);
3407 }
3408 trace_gpio_direction(desc_to_gpio(desc), value, ret);
3409 if (ret < 0)
3410 gpiod_err(desc,
3411 "%s: Error in set_value for open drain err %d\n",
3412 __func__, ret);
3413}
3414
3415/*
3416 * _gpio_set_open_source_value() - Set the open source gpio's value.
3417 * @desc: gpio descriptor whose state need to be set.
3418 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3419 */
3420static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3421{
3422 int ret = 0, offset = gpio_chip_hwgpio(desc);
3423
3424 CLASS(gpio_chip_guard, guard)(desc);
3425 if (!guard.gc)
3426 return;
3427
3428 if (value) {
3429 ret = guard.gc->direction_output(guard.gc, offset, 1);
3430 if (!ret)
3431 set_bit(FLAG_IS_OUT, &desc->flags);
3432 } else {
3433 ret = guard.gc->direction_input(guard.gc, offset);
3434 }
3435 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3436 if (ret < 0)
3437 gpiod_err(desc,
3438 "%s: Error in set_value for open source err %d\n",
3439 __func__, ret);
3440}
3441
3442static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3443{
3444 CLASS(gpio_chip_guard, guard)(desc);
3445 if (!guard.gc)
3446 return;
3447
3448 trace_gpio_value(desc_to_gpio(desc), 0, value);
3449 guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), value);
3450}
3451
3452/*
3453 * set multiple outputs on the same chip;
3454 * use the chip's set_multiple function if available;
3455 * otherwise set the outputs sequentially;
3456 * @chip: the GPIO chip we operate on
3457 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3458 * defines which outputs are to be changed
3459 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3460 * defines the values the outputs specified by mask are to be set to
3461 */
3462static void gpio_chip_set_multiple(struct gpio_chip *gc,
3463 unsigned long *mask, unsigned long *bits)
3464{
3465 lockdep_assert_held(&gc->gpiodev->srcu);
3466
3467 if (gc->set_multiple) {
3468 gc->set_multiple(gc, mask, bits);
3469 } else {
3470 unsigned int i;
3471
3472 /* set outputs if the corresponding mask bit is set */
3473 for_each_set_bit(i, mask, gc->ngpio)
3474 gc->set(gc, i, test_bit(i, bits));
3475 }
3476}
3477
3478int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3479 unsigned int array_size,
3480 struct gpio_desc **desc_array,
3481 struct gpio_array *array_info,
3482 unsigned long *value_bitmap)
3483{
3484 struct gpio_chip *gc;
3485 int i = 0;
3486
3487 /*
3488 * Validate array_info against desc_array and its size.
3489 * It should immediately follow desc_array if both
3490 * have been obtained from the same gpiod_get_array() call.
3491 */
3492 if (array_info && array_info->desc == desc_array &&
3493 array_size <= array_info->size &&
3494 (void *)array_info == desc_array + array_info->size) {
3495 if (!can_sleep)
3496 WARN_ON(array_info->gdev->can_sleep);
3497
3498 guard(srcu)(&array_info->gdev->srcu);
3499 gc = srcu_dereference(array_info->gdev->chip,
3500 &array_info->gdev->srcu);
3501 if (!gc)
3502 return -ENODEV;
3503
3504 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3505 bitmap_xor(value_bitmap, value_bitmap,
3506 array_info->invert_mask, array_size);
3507
3508 gpio_chip_set_multiple(gc, array_info->set_mask, value_bitmap);
3509
3510 i = find_first_zero_bit(array_info->set_mask, array_size);
3511 if (i == array_size)
3512 return 0;
3513 } else {
3514 array_info = NULL;
3515 }
3516
3517 while (i < array_size) {
3518 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3519 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3520 unsigned long *mask, *bits;
3521 int count = 0;
3522
3523 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3524 if (!guard.gc)
3525 return -ENODEV;
3526
3527 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3528 mask = fastpath_mask;
3529 bits = fastpath_bits;
3530 } else {
3531 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3532
3533 mask = bitmap_alloc(guard.gc->ngpio, flags);
3534 if (!mask)
3535 return -ENOMEM;
3536
3537 bits = bitmap_alloc(guard.gc->ngpio, flags);
3538 if (!bits) {
3539 bitmap_free(mask);
3540 return -ENOMEM;
3541 }
3542 }
3543
3544 bitmap_zero(mask, guard.gc->ngpio);
3545
3546 if (!can_sleep)
3547 WARN_ON(guard.gc->can_sleep);
3548
3549 do {
3550 struct gpio_desc *desc = desc_array[i];
3551 int hwgpio = gpio_chip_hwgpio(desc);
3552 int value = test_bit(i, value_bitmap);
3553
3554 /*
3555 * Pins applicable for fast input but not for
3556 * fast output processing may have been already
3557 * inverted inside the fast path, skip them.
3558 */
3559 if (!raw && !(array_info &&
3560 test_bit(i, array_info->invert_mask)) &&
3561 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3562 value = !value;
3563 trace_gpio_value(desc_to_gpio(desc), 0, value);
3564 /*
3565 * collect all normal outputs belonging to the same chip
3566 * open drain and open source outputs are set individually
3567 */
3568 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3569 gpio_set_open_drain_value_commit(desc, value);
3570 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3571 gpio_set_open_source_value_commit(desc, value);
3572 } else {
3573 __set_bit(hwgpio, mask);
3574 __assign_bit(hwgpio, bits, value);
3575 count++;
3576 }
3577 i++;
3578
3579 if (array_info)
3580 i = find_next_zero_bit(array_info->set_mask,
3581 array_size, i);
3582 } while ((i < array_size) &&
3583 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3584 /* push collected bits to outputs */
3585 if (count != 0)
3586 gpio_chip_set_multiple(guard.gc, mask, bits);
3587
3588 if (mask != fastpath_mask)
3589 bitmap_free(mask);
3590 if (bits != fastpath_bits)
3591 bitmap_free(bits);
3592 }
3593 return 0;
3594}
3595
3596/**
3597 * gpiod_set_raw_value() - assign a gpio's raw value
3598 * @desc: gpio whose value will be assigned
3599 * @value: value to assign
3600 *
3601 * Set the raw value of the GPIO, i.e. the value of its physical line without
3602 * regard for its ACTIVE_LOW status.
3603 *
3604 * This function can be called from contexts where we cannot sleep, and will
3605 * complain if the GPIO chip functions potentially sleep.
3606 */
3607void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3608{
3609 VALIDATE_DESC_VOID(desc);
3610 /* Should be using gpiod_set_raw_value_cansleep() */
3611 WARN_ON(desc->gdev->can_sleep);
3612 gpiod_set_raw_value_commit(desc, value);
3613}
3614EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3615
3616/**
3617 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3618 * @desc: the descriptor to set the value on
3619 * @value: value to set
3620 *
3621 * This sets the value of a GPIO line backing a descriptor, applying
3622 * different semantic quirks like active low and open drain/source
3623 * handling.
3624 */
3625static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3626{
3627 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3628 value = !value;
3629 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3630 gpio_set_open_drain_value_commit(desc, value);
3631 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3632 gpio_set_open_source_value_commit(desc, value);
3633 else
3634 gpiod_set_raw_value_commit(desc, value);
3635}
3636
3637/**
3638 * gpiod_set_value() - assign a gpio's value
3639 * @desc: gpio whose value will be assigned
3640 * @value: value to assign
3641 *
3642 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3643 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3644 *
3645 * This function can be called from contexts where we cannot sleep, and will
3646 * complain if the GPIO chip functions potentially sleep.
3647 */
3648void gpiod_set_value(struct gpio_desc *desc, int value)
3649{
3650 VALIDATE_DESC_VOID(desc);
3651 /* Should be using gpiod_set_value_cansleep() */
3652 WARN_ON(desc->gdev->can_sleep);
3653 gpiod_set_value_nocheck(desc, value);
3654}
3655EXPORT_SYMBOL_GPL(gpiod_set_value);
3656
3657/**
3658 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3659 * @array_size: number of elements in the descriptor array / value bitmap
3660 * @desc_array: array of GPIO descriptors whose values will be assigned
3661 * @array_info: information on applicability of fast bitmap processing path
3662 * @value_bitmap: bitmap of values to assign
3663 *
3664 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3665 * without regard for their ACTIVE_LOW status.
3666 *
3667 * This function can be called from contexts where we cannot sleep, and will
3668 * complain if the GPIO chip functions potentially sleep.
3669 *
3670 * Returns:
3671 * 0 on success, or negative errno on failure.
3672 */
3673int gpiod_set_raw_array_value(unsigned int array_size,
3674 struct gpio_desc **desc_array,
3675 struct gpio_array *array_info,
3676 unsigned long *value_bitmap)
3677{
3678 if (!desc_array)
3679 return -EINVAL;
3680 return gpiod_set_array_value_complex(true, false, array_size,
3681 desc_array, array_info, value_bitmap);
3682}
3683EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3684
3685/**
3686 * gpiod_set_array_value() - assign values to an array of GPIOs
3687 * @array_size: number of elements in the descriptor array / value bitmap
3688 * @desc_array: array of GPIO descriptors whose values will be assigned
3689 * @array_info: information on applicability of fast bitmap processing path
3690 * @value_bitmap: bitmap of values to assign
3691 *
3692 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3693 * into account.
3694 *
3695 * This function can be called from contexts where we cannot sleep, and will
3696 * complain if the GPIO chip functions potentially sleep.
3697 *
3698 * Returns:
3699 * 0 on success, or negative errno on failure.
3700 */
3701int gpiod_set_array_value(unsigned int array_size,
3702 struct gpio_desc **desc_array,
3703 struct gpio_array *array_info,
3704 unsigned long *value_bitmap)
3705{
3706 if (!desc_array)
3707 return -EINVAL;
3708 return gpiod_set_array_value_complex(false, false, array_size,
3709 desc_array, array_info,
3710 value_bitmap);
3711}
3712EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3713
3714/**
3715 * gpiod_cansleep() - report whether gpio value access may sleep
3716 * @desc: gpio to check
3717 *
3718 * Returns:
3719 * 0 for non-sleepable, 1 for sleepable, or an error code in case of error.
3720 */
3721int gpiod_cansleep(const struct gpio_desc *desc)
3722{
3723 VALIDATE_DESC(desc);
3724 return desc->gdev->can_sleep;
3725}
3726EXPORT_SYMBOL_GPL(gpiod_cansleep);
3727
3728/**
3729 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3730 * @desc: gpio to set the consumer name on
3731 * @name: the new consumer name
3732 *
3733 * Returns:
3734 * 0 on success, or negative errno on failure.
3735 */
3736int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3737{
3738 int ret;
3739
3740 VALIDATE_DESC(desc);
3741
3742 ret = desc_set_label(desc, name);
3743 if (ret == 0)
3744 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3745
3746 return ret;
3747}
3748EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3749
3750/**
3751 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3752 * @desc: gpio whose IRQ will be returned (already requested)
3753 *
3754 * Returns:
3755 * The IRQ corresponding to the passed GPIO, or an error code in case of error.
3756 */
3757int gpiod_to_irq(const struct gpio_desc *desc)
3758{
3759 struct gpio_device *gdev;
3760 struct gpio_chip *gc;
3761 int offset;
3762
3763 /*
3764 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3765 * requires this function to not return zero on an invalid descriptor
3766 * but rather a negative error number.
3767 */
3768 if (IS_ERR_OR_NULL(desc))
3769 return -EINVAL;
3770
3771 gdev = desc->gdev;
3772 /* FIXME Cannot use gpio_chip_guard due to const desc. */
3773 guard(srcu)(&gdev->srcu);
3774 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3775 if (!gc)
3776 return -ENODEV;
3777
3778 offset = gpio_chip_hwgpio(desc);
3779 if (gc->to_irq) {
3780 int retirq = gc->to_irq(gc, offset);
3781
3782 /* Zero means NO_IRQ */
3783 if (!retirq)
3784 return -ENXIO;
3785
3786 return retirq;
3787 }
3788#ifdef CONFIG_GPIOLIB_IRQCHIP
3789 if (gc->irq.chip) {
3790 /*
3791 * Avoid race condition with other code, which tries to lookup
3792 * an IRQ before the irqchip has been properly registered,
3793 * i.e. while gpiochip is still being brought up.
3794 */
3795 return -EPROBE_DEFER;
3796 }
3797#endif
3798 return -ENXIO;
3799}
3800EXPORT_SYMBOL_GPL(gpiod_to_irq);
3801
3802/**
3803 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3804 * @gc: the chip the GPIO to lock belongs to
3805 * @offset: the offset of the GPIO to lock as IRQ
3806 *
3807 * This is used directly by GPIO drivers that want to lock down
3808 * a certain GPIO line to be used for IRQs.
3809 *
3810 * Returns:
3811 * 0 on success, or negative errno on failure.
3812 */
3813int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3814{
3815 struct gpio_desc *desc;
3816
3817 desc = gpiochip_get_desc(gc, offset);
3818 if (IS_ERR(desc))
3819 return PTR_ERR(desc);
3820
3821 /*
3822 * If it's fast: flush the direction setting if something changed
3823 * behind our back
3824 */
3825 if (!gc->can_sleep && gc->get_direction) {
3826 int dir = gpiod_get_direction(desc);
3827
3828 if (dir < 0) {
3829 chip_err(gc, "%s: cannot get GPIO direction\n",
3830 __func__);
3831 return dir;
3832 }
3833 }
3834
3835 /* To be valid for IRQ the line needs to be input or open drain */
3836 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3837 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3838 chip_err(gc,
3839 "%s: tried to flag a GPIO set as output for IRQ\n",
3840 __func__);
3841 return -EIO;
3842 }
3843
3844 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3845 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3846
3847 return 0;
3848}
3849EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3850
3851/**
3852 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3853 * @gc: the chip the GPIO to lock belongs to
3854 * @offset: the offset of the GPIO to lock as IRQ
3855 *
3856 * This is used directly by GPIO drivers that want to indicate
3857 * that a certain GPIO is no longer used exclusively for IRQ.
3858 */
3859void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3860{
3861 struct gpio_desc *desc;
3862
3863 desc = gpiochip_get_desc(gc, offset);
3864 if (IS_ERR(desc))
3865 return;
3866
3867 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3868 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3869}
3870EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3871
3872void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3873{
3874 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3875
3876 if (!IS_ERR(desc) &&
3877 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3878 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3879}
3880EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3881
3882void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3883{
3884 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3885
3886 if (!IS_ERR(desc) &&
3887 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3888 /*
3889 * We must not be output when using IRQ UNLESS we are
3890 * open drain.
3891 */
3892 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3893 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3894 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3895 }
3896}
3897EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3898
3899bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3900{
3901 if (offset >= gc->ngpio)
3902 return false;
3903
3904 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3905}
3906EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3907
3908int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3909{
3910 int ret;
3911
3912 if (!try_module_get(gc->gpiodev->owner))
3913 return -ENODEV;
3914
3915 ret = gpiochip_lock_as_irq(gc, offset);
3916 if (ret) {
3917 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3918 module_put(gc->gpiodev->owner);
3919 return ret;
3920 }
3921 return 0;
3922}
3923EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3924
3925void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3926{
3927 gpiochip_unlock_as_irq(gc, offset);
3928 module_put(gc->gpiodev->owner);
3929}
3930EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3931
3932bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3933{
3934 if (offset >= gc->ngpio)
3935 return false;
3936
3937 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3938}
3939EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3940
3941bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3942{
3943 if (offset >= gc->ngpio)
3944 return false;
3945
3946 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3947}
3948EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3949
3950bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3951{
3952 if (offset >= gc->ngpio)
3953 return false;
3954
3955 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3956}
3957EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3958
3959/**
3960 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3961 * @desc: gpio whose value will be returned
3962 *
3963 * Returns:
3964 * The GPIO's raw value, i.e. the value of the physical line disregarding
3965 * its ACTIVE_LOW status, or negative errno on failure.
3966 *
3967 * This function is to be called from contexts that can sleep.
3968 */
3969int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3970{
3971 might_sleep();
3972 VALIDATE_DESC(desc);
3973 return gpiod_get_raw_value_commit(desc);
3974}
3975EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3976
3977/**
3978 * gpiod_get_value_cansleep() - return a gpio's value
3979 * @desc: gpio whose value will be returned
3980 *
3981 * Returns:
3982 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3983 * account, or negative errno on failure.
3984 *
3985 * This function is to be called from contexts that can sleep.
3986 */
3987int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3988{
3989 int value;
3990
3991 might_sleep();
3992 VALIDATE_DESC(desc);
3993 value = gpiod_get_raw_value_commit(desc);
3994 if (value < 0)
3995 return value;
3996
3997 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3998 value = !value;
3999
4000 return value;
4001}
4002EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
4003
4004/**
4005 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
4006 * @array_size: number of elements in the descriptor array / value bitmap
4007 * @desc_array: array of GPIO descriptors whose values will be read
4008 * @array_info: information on applicability of fast bitmap processing path
4009 * @value_bitmap: bitmap to store the read values
4010 *
4011 * Read the raw values of the GPIOs, i.e. the values of the physical lines
4012 * without regard for their ACTIVE_LOW status.
4013 *
4014 * This function is to be called from contexts that can sleep.
4015 *
4016 * Returns:
4017 * 0 on success, or negative errno on failure.
4018 */
4019int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
4020 struct gpio_desc **desc_array,
4021 struct gpio_array *array_info,
4022 unsigned long *value_bitmap)
4023{
4024 might_sleep();
4025 if (!desc_array)
4026 return -EINVAL;
4027 return gpiod_get_array_value_complex(true, true, array_size,
4028 desc_array, array_info,
4029 value_bitmap);
4030}
4031EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
4032
4033/**
4034 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
4035 * @array_size: number of elements in the descriptor array / value bitmap
4036 * @desc_array: array of GPIO descriptors whose values will be read
4037 * @array_info: information on applicability of fast bitmap processing path
4038 * @value_bitmap: bitmap to store the read values
4039 *
4040 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4041 * into account.
4042 *
4043 * This function is to be called from contexts that can sleep.
4044 *
4045 * Returns:
4046 * 0 on success, or negative errno on failure.
4047 */
4048int gpiod_get_array_value_cansleep(unsigned int array_size,
4049 struct gpio_desc **desc_array,
4050 struct gpio_array *array_info,
4051 unsigned long *value_bitmap)
4052{
4053 might_sleep();
4054 if (!desc_array)
4055 return -EINVAL;
4056 return gpiod_get_array_value_complex(false, true, array_size,
4057 desc_array, array_info,
4058 value_bitmap);
4059}
4060EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
4061
4062/**
4063 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
4064 * @desc: gpio whose value will be assigned
4065 * @value: value to assign
4066 *
4067 * Set the raw value of the GPIO, i.e. the value of its physical line without
4068 * regard for its ACTIVE_LOW status.
4069 *
4070 * This function is to be called from contexts that can sleep.
4071 */
4072void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
4073{
4074 might_sleep();
4075 VALIDATE_DESC_VOID(desc);
4076 gpiod_set_raw_value_commit(desc, value);
4077}
4078EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
4079
4080/**
4081 * gpiod_set_value_cansleep() - assign a gpio's value
4082 * @desc: gpio whose value will be assigned
4083 * @value: value to assign
4084 *
4085 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
4086 * account
4087 *
4088 * This function is to be called from contexts that can sleep.
4089 */
4090void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
4091{
4092 might_sleep();
4093 VALIDATE_DESC_VOID(desc);
4094 gpiod_set_value_nocheck(desc, value);
4095}
4096EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
4097
4098/**
4099 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
4100 * @array_size: number of elements in the descriptor array / value bitmap
4101 * @desc_array: array of GPIO descriptors whose values will be assigned
4102 * @array_info: information on applicability of fast bitmap processing path
4103 * @value_bitmap: bitmap of values to assign
4104 *
4105 * Set the raw values of the GPIOs, i.e. the values of the physical lines
4106 * without regard for their ACTIVE_LOW status.
4107 *
4108 * This function is to be called from contexts that can sleep.
4109 *
4110 * Returns:
4111 * 0 on success, or negative errno on failure.
4112 */
4113int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
4114 struct gpio_desc **desc_array,
4115 struct gpio_array *array_info,
4116 unsigned long *value_bitmap)
4117{
4118 might_sleep();
4119 if (!desc_array)
4120 return -EINVAL;
4121 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
4122 array_info, value_bitmap);
4123}
4124EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
4125
4126/**
4127 * gpiod_add_lookup_tables() - register GPIO device consumers
4128 * @tables: list of tables of consumers to register
4129 * @n: number of tables in the list
4130 */
4131void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
4132{
4133 unsigned int i;
4134
4135 mutex_lock(&gpio_lookup_lock);
4136
4137 for (i = 0; i < n; i++)
4138 list_add_tail(&tables[i]->list, &gpio_lookup_list);
4139
4140 mutex_unlock(&gpio_lookup_lock);
4141}
4142
4143/**
4144 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
4145 * @array_size: number of elements in the descriptor array / value bitmap
4146 * @desc_array: array of GPIO descriptors whose values will be assigned
4147 * @array_info: information on applicability of fast bitmap processing path
4148 * @value_bitmap: bitmap of values to assign
4149 *
4150 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4151 * into account.
4152 *
4153 * This function is to be called from contexts that can sleep.
4154 *
4155 * Returns:
4156 * 0 on success, or negative errno on failure.
4157 */
4158int gpiod_set_array_value_cansleep(unsigned int array_size,
4159 struct gpio_desc **desc_array,
4160 struct gpio_array *array_info,
4161 unsigned long *value_bitmap)
4162{
4163 might_sleep();
4164 if (!desc_array)
4165 return -EINVAL;
4166 return gpiod_set_array_value_complex(false, true, array_size,
4167 desc_array, array_info,
4168 value_bitmap);
4169}
4170EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
4171
4172void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
4173{
4174 atomic_notifier_call_chain(&desc->gdev->line_state_notifier,
4175 action, desc);
4176}
4177
4178/**
4179 * gpiod_add_lookup_table() - register GPIO device consumers
4180 * @table: table of consumers to register
4181 */
4182void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
4183{
4184 gpiod_add_lookup_tables(&table, 1);
4185}
4186EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
4187
4188/**
4189 * gpiod_remove_lookup_table() - unregister GPIO device consumers
4190 * @table: table of consumers to unregister
4191 */
4192void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4193{
4194 /* Nothing to remove */
4195 if (!table)
4196 return;
4197
4198 mutex_lock(&gpio_lookup_lock);
4199
4200 list_del(&table->list);
4201
4202 mutex_unlock(&gpio_lookup_lock);
4203}
4204EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4205
4206/**
4207 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4208 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4209 */
4210void gpiod_add_hogs(struct gpiod_hog *hogs)
4211{
4212 struct gpiod_hog *hog;
4213
4214 mutex_lock(&gpio_machine_hogs_mutex);
4215
4216 for (hog = &hogs[0]; hog->chip_label; hog++) {
4217 list_add_tail(&hog->list, &gpio_machine_hogs);
4218
4219 /*
4220 * The chip may have been registered earlier, so check if it
4221 * exists and, if so, try to hog the line now.
4222 */
4223 struct gpio_device *gdev __free(gpio_device_put) =
4224 gpio_device_find_by_label(hog->chip_label);
4225 if (gdev)
4226 gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);
4227 }
4228
4229 mutex_unlock(&gpio_machine_hogs_mutex);
4230}
4231EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4232
4233void gpiod_remove_hogs(struct gpiod_hog *hogs)
4234{
4235 struct gpiod_hog *hog;
4236
4237 mutex_lock(&gpio_machine_hogs_mutex);
4238 for (hog = &hogs[0]; hog->chip_label; hog++)
4239 list_del(&hog->list);
4240 mutex_unlock(&gpio_machine_hogs_mutex);
4241}
4242EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
4243
4244static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4245{
4246 const char *dev_id = dev ? dev_name(dev) : NULL;
4247 struct gpiod_lookup_table *table;
4248
4249 list_for_each_entry(table, &gpio_lookup_list, list) {
4250 if (table->dev_id && dev_id) {
4251 /*
4252 * Valid strings on both ends, must be identical to have
4253 * a match
4254 */
4255 if (!strcmp(table->dev_id, dev_id))
4256 return table;
4257 } else {
4258 /*
4259 * One of the pointers is NULL, so both must be to have
4260 * a match
4261 */
4262 if (dev_id == table->dev_id)
4263 return table;
4264 }
4265 }
4266
4267 return NULL;
4268}
4269
4270static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4271 unsigned int idx, unsigned long *flags)
4272{
4273 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4274 struct gpiod_lookup_table *table;
4275 struct gpiod_lookup *p;
4276 struct gpio_chip *gc;
4277
4278 guard(mutex)(&gpio_lookup_lock);
4279
4280 table = gpiod_find_lookup_table(dev);
4281 if (!table)
4282 return desc;
4283
4284 for (p = &table->table[0]; p->key; p++) {
4285 /* idx must always match exactly */
4286 if (p->idx != idx)
4287 continue;
4288
4289 /* If the lookup entry has a con_id, require exact match */
4290 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4291 continue;
4292
4293 if (p->chip_hwnum == U16_MAX) {
4294 desc = gpio_name_to_desc(p->key);
4295 if (desc) {
4296 *flags = p->flags;
4297 return desc;
4298 }
4299
4300 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
4301 p->key);
4302 return ERR_PTR(-EPROBE_DEFER);
4303 }
4304
4305 struct gpio_device *gdev __free(gpio_device_put) =
4306 gpio_device_find_by_label(p->key);
4307 if (!gdev) {
4308 /*
4309 * As the lookup table indicates a chip with
4310 * p->key should exist, assume it may
4311 * still appear later and let the interested
4312 * consumer be probed again or let the Deferred
4313 * Probe infrastructure handle the error.
4314 */
4315 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4316 p->key);
4317 return ERR_PTR(-EPROBE_DEFER);
4318 }
4319
4320 gc = gpio_device_get_chip(gdev);
4321
4322 if (gc->ngpio <= p->chip_hwnum) {
4323 dev_err(dev,
4324 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4325 idx, p->chip_hwnum, gc->ngpio - 1,
4326 gc->label);
4327 return ERR_PTR(-EINVAL);
4328 }
4329
4330 desc = gpio_device_get_desc(gdev, p->chip_hwnum);
4331 *flags = p->flags;
4332
4333 return desc;
4334 }
4335
4336 return desc;
4337}
4338
4339static int platform_gpio_count(struct device *dev, const char *con_id)
4340{
4341 struct gpiod_lookup_table *table;
4342 struct gpiod_lookup *p;
4343 unsigned int count = 0;
4344
4345 scoped_guard(mutex, &gpio_lookup_lock) {
4346 table = gpiod_find_lookup_table(dev);
4347 if (!table)
4348 return -ENOENT;
4349
4350 for (p = &table->table[0]; p->key; p++) {
4351 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4352 (!con_id && !p->con_id))
4353 count++;
4354 }
4355 }
4356
4357 if (!count)
4358 return -ENOENT;
4359
4360 return count;
4361}
4362
4363static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
4364 struct device *consumer,
4365 const char *con_id,
4366 unsigned int idx,
4367 enum gpiod_flags *flags,
4368 unsigned long *lookupflags)
4369{
4370 const char *name = function_name_or_default(con_id);
4371 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4372
4373 if (is_of_node(fwnode)) {
4374 dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4375 desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
4376 } else if (is_acpi_node(fwnode)) {
4377 dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4378 desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
4379 } else if (is_software_node(fwnode)) {
4380 dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4381 desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
4382 }
4383
4384 return desc;
4385}
4386
4387struct gpio_desc *gpiod_find_and_request(struct device *consumer,
4388 struct fwnode_handle *fwnode,
4389 const char *con_id,
4390 unsigned int idx,
4391 enum gpiod_flags flags,
4392 const char *label,
4393 bool platform_lookup_allowed)
4394{
4395 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4396 const char *name = function_name_or_default(con_id);
4397 /*
4398 * scoped_guard() is implemented as a for loop, meaning static
4399 * analyzers will complain about these two not being initialized.
4400 */
4401 struct gpio_desc *desc = NULL;
4402 int ret = 0;
4403
4404 scoped_guard(srcu, &gpio_devices_srcu) {
4405 desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
4406 &flags, &lookupflags);
4407 if (gpiod_not_found(desc) && platform_lookup_allowed) {
4408 /*
4409 * Either we are not using DT or ACPI, or their lookup
4410 * did not return a result. In that case, use platform
4411 * lookup as a fallback.
4412 */
4413 dev_dbg(consumer,
4414 "using lookup tables for GPIO lookup\n");
4415 desc = gpiod_find(consumer, con_id, idx, &lookupflags);
4416 }
4417
4418 if (IS_ERR(desc)) {
4419 dev_dbg(consumer, "No GPIO consumer %s found\n", name);
4420 return desc;
4421 }
4422
4423 /*
4424 * If a connection label was passed use that, else attempt to use
4425 * the device name as label
4426 */
4427 ret = gpiod_request(desc, label);
4428 }
4429 if (ret) {
4430 if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4431 return ERR_PTR(ret);
4432
4433 /*
4434 * This happens when there are several consumers for
4435 * the same GPIO line: we just return here without
4436 * further initialization. It is a bit of a hack.
4437 * This is necessary to support fixed regulators.
4438 *
4439 * FIXME: Make this more sane and safe.
4440 */
4441 dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
4442 return desc;
4443 }
4444
4445 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4446 if (ret < 0) {
4447 gpiod_put(desc);
4448 dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret);
4449 return ERR_PTR(ret);
4450 }
4451
4452 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
4453
4454 return desc;
4455}
4456
4457/**
4458 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
4459 * @fwnode: handle of the firmware node
4460 * @con_id: function within the GPIO consumer
4461 * @index: index of the GPIO to obtain for the consumer
4462 * @flags: GPIO initialization flags
4463 * @label: label to attach to the requested GPIO
4464 *
4465 * This function can be used for drivers that get their configuration
4466 * from opaque firmware.
4467 *
4468 * The function properly finds the corresponding GPIO using whatever is the
4469 * underlying firmware interface and then makes sure that the GPIO
4470 * descriptor is requested before it is returned to the caller.
4471 *
4472 * Returns:
4473 * On successful request the GPIO pin is configured in accordance with
4474 * provided @flags.
4475 *
4476 * In case of error an ERR_PTR() is returned.
4477 */
4478struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
4479 const char *con_id,
4480 int index,
4481 enum gpiod_flags flags,
4482 const char *label)
4483{
4484 return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
4485}
4486EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
4487
4488/**
4489 * gpiod_count - return the number of GPIOs associated with a device / function
4490 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4491 * @con_id: function within the GPIO consumer
4492 *
4493 * Returns:
4494 * The number of GPIOs associated with a device / function or -ENOENT if no
4495 * GPIO has been assigned to the requested function.
4496 */
4497int gpiod_count(struct device *dev, const char *con_id)
4498{
4499 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4500 int count = -ENOENT;
4501
4502 if (is_of_node(fwnode))
4503 count = of_gpio_count(fwnode, con_id);
4504 else if (is_acpi_node(fwnode))
4505 count = acpi_gpio_count(fwnode, con_id);
4506 else if (is_software_node(fwnode))
4507 count = swnode_gpio_count(fwnode, con_id);
4508
4509 if (count < 0)
4510 count = platform_gpio_count(dev, con_id);
4511
4512 return count;
4513}
4514EXPORT_SYMBOL_GPL(gpiod_count);
4515
4516/**
4517 * gpiod_get - obtain a GPIO for a given GPIO function
4518 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4519 * @con_id: function within the GPIO consumer
4520 * @flags: optional GPIO initialization flags
4521 *
4522 * Returns:
4523 * The GPIO descriptor corresponding to the function @con_id of device
4524 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4525 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4526 */
4527struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4528 enum gpiod_flags flags)
4529{
4530 return gpiod_get_index(dev, con_id, 0, flags);
4531}
4532EXPORT_SYMBOL_GPL(gpiod_get);
4533
4534/**
4535 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4536 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4537 * @con_id: function within the GPIO consumer
4538 * @flags: optional GPIO initialization flags
4539 *
4540 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4541 * the requested function it will return NULL. This is convenient for drivers
4542 * that need to handle optional GPIOs.
4543 *
4544 * Returns:
4545 * The GPIO descriptor corresponding to the function @con_id of device
4546 * dev, NULL if no GPIO has been assigned to the requested function, or
4547 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4548 */
4549struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4550 const char *con_id,
4551 enum gpiod_flags flags)
4552{
4553 return gpiod_get_index_optional(dev, con_id, 0, flags);
4554}
4555EXPORT_SYMBOL_GPL(gpiod_get_optional);
4556
4557
4558/**
4559 * gpiod_configure_flags - helper function to configure a given GPIO
4560 * @desc: gpio whose value will be assigned
4561 * @con_id: function within the GPIO consumer
4562 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4563 * of_find_gpio() or of_get_gpio_hog()
4564 * @dflags: gpiod_flags - optional GPIO initialization flags
4565 *
4566 * Returns:
4567 * 0 on success, -ENOENT if no GPIO has been assigned to the
4568 * requested function and/or index, or another IS_ERR() code if an error
4569 * occurred while trying to acquire the GPIO.
4570 */
4571int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4572 unsigned long lflags, enum gpiod_flags dflags)
4573{
4574 const char *name = function_name_or_default(con_id);
4575 int ret;
4576
4577 if (lflags & GPIO_ACTIVE_LOW)
4578 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4579
4580 if (lflags & GPIO_OPEN_DRAIN)
4581 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4582 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4583 /*
4584 * This enforces open drain mode from the consumer side.
4585 * This is necessary for some busses like I2C, but the lookup
4586 * should *REALLY* have specified them as open drain in the
4587 * first place, so print a little warning here.
4588 */
4589 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4590 gpiod_warn(desc,
4591 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4592 }
4593
4594 if (lflags & GPIO_OPEN_SOURCE)
4595 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4596
4597 if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
4598 ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
4599 ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
4600 gpiod_err(desc,
4601 "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
4602 return -EINVAL;
4603 }
4604
4605 if (lflags & GPIO_PULL_UP)
4606 set_bit(FLAG_PULL_UP, &desc->flags);
4607 else if (lflags & GPIO_PULL_DOWN)
4608 set_bit(FLAG_PULL_DOWN, &desc->flags);
4609 else if (lflags & GPIO_PULL_DISABLE)
4610 set_bit(FLAG_BIAS_DISABLE, &desc->flags);
4611
4612 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4613 if (ret < 0)
4614 return ret;
4615
4616 /* No particular flag request, return here... */
4617 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4618 gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
4619 return 0;
4620 }
4621
4622 /* Process flags */
4623 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4624 ret = gpiod_direction_output_nonotify(desc,
4625 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4626 else
4627 ret = gpiod_direction_input_nonotify(desc);
4628
4629 return ret;
4630}
4631
4632/**
4633 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4634 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4635 * @con_id: function within the GPIO consumer
4636 * @idx: index of the GPIO to obtain in the consumer
4637 * @flags: optional GPIO initialization flags
4638 *
4639 * This variant of gpiod_get() allows to access GPIOs other than the first
4640 * defined one for functions that define several GPIOs.
4641 *
4642 * Returns:
4643 * A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4644 * requested function and/or index, or another IS_ERR() code if an error
4645 * occurred while trying to acquire the GPIO.
4646 */
4647struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4648 const char *con_id,
4649 unsigned int idx,
4650 enum gpiod_flags flags)
4651{
4652 struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4653 const char *devname = dev ? dev_name(dev) : "?";
4654 const char *label = con_id ?: devname;
4655
4656 return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
4657}
4658EXPORT_SYMBOL_GPL(gpiod_get_index);
4659
4660/**
4661 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4662 * function
4663 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4664 * @con_id: function within the GPIO consumer
4665 * @index: index of the GPIO to obtain in the consumer
4666 * @flags: optional GPIO initialization flags
4667 *
4668 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4669 * specified index was assigned to the requested function it will return NULL.
4670 * This is convenient for drivers that need to handle optional GPIOs.
4671 *
4672 * Returns:
4673 * A valid GPIO descriptor, NULL if no GPIO has been assigned to the
4674 * requested function and/or index, or another IS_ERR() code if an error
4675 * occurred while trying to acquire the GPIO.
4676 */
4677struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4678 const char *con_id,
4679 unsigned int index,
4680 enum gpiod_flags flags)
4681{
4682 struct gpio_desc *desc;
4683
4684 desc = gpiod_get_index(dev, con_id, index, flags);
4685 if (gpiod_not_found(desc))
4686 return NULL;
4687
4688 return desc;
4689}
4690EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4691
4692/**
4693 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4694 * @desc: gpio whose value will be assigned
4695 * @name: gpio line name
4696 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4697 * of_find_gpio() or of_get_gpio_hog()
4698 * @dflags: gpiod_flags - optional GPIO initialization flags
4699 *
4700 * Returns:
4701 * 0 on success, or negative errno on failure.
4702 */
4703int gpiod_hog(struct gpio_desc *desc, const char *name,
4704 unsigned long lflags, enum gpiod_flags dflags)
4705{
4706 struct gpio_device *gdev = desc->gdev;
4707 struct gpio_desc *local_desc;
4708 int hwnum;
4709 int ret;
4710
4711 CLASS(gpio_chip_guard, guard)(desc);
4712 if (!guard.gc)
4713 return -ENODEV;
4714
4715 if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))
4716 return 0;
4717
4718 hwnum = gpio_chip_hwgpio(desc);
4719
4720 local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
4721 lflags, dflags);
4722 if (IS_ERR(local_desc)) {
4723 clear_bit(FLAG_IS_HOGGED, &desc->flags);
4724 ret = PTR_ERR(local_desc);
4725 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4726 name, gdev->label, hwnum, ret);
4727 return ret;
4728 }
4729
4730 gpiod_dbg(desc, "hogged as %s%s\n",
4731 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4732 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4733 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4734
4735 return 0;
4736}
4737
4738/**
4739 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4740 * @gc: gpio chip to act on
4741 */
4742static void gpiochip_free_hogs(struct gpio_chip *gc)
4743{
4744 struct gpio_desc *desc;
4745
4746 for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)
4747 gpiochip_free_own_desc(desc);
4748}
4749
4750/**
4751 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4752 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4753 * @con_id: function within the GPIO consumer
4754 * @flags: optional GPIO initialization flags
4755 *
4756 * This function acquires all the GPIOs defined under a given function.
4757 *
4758 * Returns:
4759 * The GPIO descriptors corresponding to the function @con_id of device
4760 * dev, -ENOENT if no GPIO has been assigned to the requested function,
4761 * or another IS_ERR() code if an error occurred while trying to acquire
4762 * the GPIOs.
4763 */
4764struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4765 const char *con_id,
4766 enum gpiod_flags flags)
4767{
4768 struct gpio_desc *desc;
4769 struct gpio_descs *descs;
4770 struct gpio_device *gdev;
4771 struct gpio_array *array_info = NULL;
4772 int count, bitmap_size;
4773 unsigned long dflags;
4774 size_t descs_size;
4775
4776 count = gpiod_count(dev, con_id);
4777 if (count < 0)
4778 return ERR_PTR(count);
4779
4780 descs_size = struct_size(descs, desc, count);
4781 descs = kzalloc(descs_size, GFP_KERNEL);
4782 if (!descs)
4783 return ERR_PTR(-ENOMEM);
4784
4785 for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
4786 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4787 if (IS_ERR(desc)) {
4788 gpiod_put_array(descs);
4789 return ERR_CAST(desc);
4790 }
4791
4792 descs->desc[descs->ndescs] = desc;
4793
4794 gdev = gpiod_to_gpio_device(desc);
4795 /*
4796 * If pin hardware number of array member 0 is also 0, select
4797 * its chip as a candidate for fast bitmap processing path.
4798 */
4799 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4800 struct gpio_descs *array;
4801
4802 bitmap_size = BITS_TO_LONGS(gdev->ngpio > count ?
4803 gdev->ngpio : count);
4804
4805 array = krealloc(descs, descs_size +
4806 struct_size(array_info, invert_mask, 3 * bitmap_size),
4807 GFP_KERNEL | __GFP_ZERO);
4808 if (!array) {
4809 gpiod_put_array(descs);
4810 return ERR_PTR(-ENOMEM);
4811 }
4812
4813 descs = array;
4814
4815 array_info = (void *)descs + descs_size;
4816 array_info->get_mask = array_info->invert_mask +
4817 bitmap_size;
4818 array_info->set_mask = array_info->get_mask +
4819 bitmap_size;
4820
4821 array_info->desc = descs->desc;
4822 array_info->size = count;
4823 array_info->gdev = gdev;
4824 bitmap_set(array_info->get_mask, descs->ndescs,
4825 count - descs->ndescs);
4826 bitmap_set(array_info->set_mask, descs->ndescs,
4827 count - descs->ndescs);
4828 descs->info = array_info;
4829 }
4830
4831 /* If there is no cache for fast bitmap processing path, continue */
4832 if (!array_info)
4833 continue;
4834
4835 /* Unmark array members which don't belong to the 'fast' chip */
4836 if (array_info->gdev != gdev) {
4837 __clear_bit(descs->ndescs, array_info->get_mask);
4838 __clear_bit(descs->ndescs, array_info->set_mask);
4839 }
4840 /*
4841 * Detect array members which belong to the 'fast' chip
4842 * but their pins are not in hardware order.
4843 */
4844 else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
4845 /*
4846 * Don't use fast path if all array members processed so
4847 * far belong to the same chip as this one but its pin
4848 * hardware number is different from its array index.
4849 */
4850 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4851 array_info = NULL;
4852 } else {
4853 __clear_bit(descs->ndescs,
4854 array_info->get_mask);
4855 __clear_bit(descs->ndescs,
4856 array_info->set_mask);
4857 }
4858 } else {
4859 dflags = READ_ONCE(desc->flags);
4860 /* Exclude open drain or open source from fast output */
4861 if (test_bit(FLAG_OPEN_DRAIN, &dflags) ||
4862 test_bit(FLAG_OPEN_SOURCE, &dflags))
4863 __clear_bit(descs->ndescs,
4864 array_info->set_mask);
4865 /* Identify 'fast' pins which require invertion */
4866 if (gpiod_is_active_low(desc))
4867 __set_bit(descs->ndescs,
4868 array_info->invert_mask);
4869 }
4870 }
4871 if (array_info)
4872 dev_dbg(dev,
4873 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4874 array_info->gdev->label, array_info->size,
4875 *array_info->get_mask, *array_info->set_mask,
4876 *array_info->invert_mask);
4877 return descs;
4878}
4879EXPORT_SYMBOL_GPL(gpiod_get_array);
4880
4881/**
4882 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4883 * function
4884 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4885 * @con_id: function within the GPIO consumer
4886 * @flags: optional GPIO initialization flags
4887 *
4888 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4889 * assigned to the requested function it will return NULL.
4890 *
4891 * Returns:
4892 * The GPIO descriptors corresponding to the function @con_id of device
4893 * dev, NULL if no GPIO has been assigned to the requested function,
4894 * or another IS_ERR() code if an error occurred while trying to acquire
4895 * the GPIOs.
4896 */
4897struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4898 const char *con_id,
4899 enum gpiod_flags flags)
4900{
4901 struct gpio_descs *descs;
4902
4903 descs = gpiod_get_array(dev, con_id, flags);
4904 if (gpiod_not_found(descs))
4905 return NULL;
4906
4907 return descs;
4908}
4909EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4910
4911/**
4912 * gpiod_put - dispose of a GPIO descriptor
4913 * @desc: GPIO descriptor to dispose of
4914 *
4915 * No descriptor can be used after gpiod_put() has been called on it.
4916 */
4917void gpiod_put(struct gpio_desc *desc)
4918{
4919 if (desc)
4920 gpiod_free(desc);
4921}
4922EXPORT_SYMBOL_GPL(gpiod_put);
4923
4924/**
4925 * gpiod_put_array - dispose of multiple GPIO descriptors
4926 * @descs: struct gpio_descs containing an array of descriptors
4927 */
4928void gpiod_put_array(struct gpio_descs *descs)
4929{
4930 unsigned int i;
4931
4932 for (i = 0; i < descs->ndescs; i++)
4933 gpiod_put(descs->desc[i]);
4934
4935 kfree(descs);
4936}
4937EXPORT_SYMBOL_GPL(gpiod_put_array);
4938
4939static int gpio_stub_drv_probe(struct device *dev)
4940{
4941 /*
4942 * The DT node of some GPIO chips have a "compatible" property, but
4943 * never have a struct device added and probed by a driver to register
4944 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4945 * the consumers of the GPIO chip to get probe deferred forever because
4946 * they will be waiting for a device associated with the GPIO chip
4947 * firmware node to get added and bound to a driver.
4948 *
4949 * To allow these consumers to probe, we associate the struct
4950 * gpio_device of the GPIO chip with the firmware node and then simply
4951 * bind it to this stub driver.
4952 */
4953 return 0;
4954}
4955
4956static struct device_driver gpio_stub_drv = {
4957 .name = "gpio_stub_drv",
4958 .bus = &gpio_bus_type,
4959 .probe = gpio_stub_drv_probe,
4960};
4961
4962static int __init gpiolib_dev_init(void)
4963{
4964 int ret;
4965
4966 /* Register GPIO sysfs bus */
4967 ret = bus_register(&gpio_bus_type);
4968 if (ret < 0) {
4969 pr_err("gpiolib: could not register GPIO bus type\n");
4970 return ret;
4971 }
4972
4973 ret = driver_register(&gpio_stub_drv);
4974 if (ret < 0) {
4975 pr_err("gpiolib: could not register GPIO stub driver\n");
4976 bus_unregister(&gpio_bus_type);
4977 return ret;
4978 }
4979
4980 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4981 if (ret < 0) {
4982 pr_err("gpiolib: failed to allocate char dev region\n");
4983 driver_unregister(&gpio_stub_drv);
4984 bus_unregister(&gpio_bus_type);
4985 return ret;
4986 }
4987
4988 gpiolib_initialized = true;
4989 gpiochip_setup_devs();
4990
4991#if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4992 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4993#endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4994
4995 return ret;
4996}
4997core_initcall(gpiolib_dev_init);
4998
4999#ifdef CONFIG_DEBUG_FS
5000
5001static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
5002{
5003 bool active_low, is_irq, is_out;
5004 unsigned int gpio = gdev->base;
5005 struct gpio_desc *desc;
5006 struct gpio_chip *gc;
5007 int value;
5008
5009 guard(srcu)(&gdev->srcu);
5010
5011 gc = srcu_dereference(gdev->chip, &gdev->srcu);
5012 if (!gc) {
5013 seq_puts(s, "Underlying GPIO chip is gone\n");
5014 return;
5015 }
5016
5017 for_each_gpio_desc(gc, desc) {
5018 guard(srcu)(&desc->gdev->desc_srcu);
5019 is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
5020 if (is_irq || test_bit(FLAG_REQUESTED, &desc->flags)) {
5021 gpiod_get_direction(desc);
5022 is_out = test_bit(FLAG_IS_OUT, &desc->flags);
5023 value = gpio_chip_get_value(gc, desc);
5024 active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags);
5025 seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
5026 gpio, desc->name ?: "", gpiod_get_label(desc),
5027 is_out ? "out" : "in ",
5028 value >= 0 ? (value ? "hi" : "lo") : "? ",
5029 is_irq ? "IRQ " : "",
5030 active_low ? "ACTIVE LOW" : "");
5031 } else if (desc->name) {
5032 seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name);
5033 }
5034
5035 gpio++;
5036 }
5037}
5038
5039struct gpiolib_seq_priv {
5040 bool newline;
5041 int idx;
5042};
5043
5044static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
5045{
5046 struct gpiolib_seq_priv *priv;
5047 struct gpio_device *gdev;
5048 loff_t index = *pos;
5049
5050 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
5051 if (!priv)
5052 return NULL;
5053
5054 s->private = priv;
5055 if (*pos > 0)
5056 priv->newline = true;
5057 priv->idx = srcu_read_lock(&gpio_devices_srcu);
5058
5059 list_for_each_entry_srcu(gdev, &gpio_devices, list,
5060 srcu_read_lock_held(&gpio_devices_srcu)) {
5061 if (index-- == 0)
5062 return gdev;
5063 }
5064
5065 return NULL;
5066}
5067
5068static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
5069{
5070 struct gpiolib_seq_priv *priv = s->private;
5071 struct gpio_device *gdev = v, *next;
5072
5073 next = list_entry_rcu(gdev->list.next, struct gpio_device, list);
5074 gdev = &next->list == &gpio_devices ? NULL : next;
5075 priv->newline = true;
5076 ++*pos;
5077
5078 return gdev;
5079}
5080
5081static void gpiolib_seq_stop(struct seq_file *s, void *v)
5082{
5083 struct gpiolib_seq_priv *priv = s->private;
5084
5085 srcu_read_unlock(&gpio_devices_srcu, priv->idx);
5086 kfree(priv);
5087}
5088
5089static int gpiolib_seq_show(struct seq_file *s, void *v)
5090{
5091 struct gpiolib_seq_priv *priv = s->private;
5092 struct gpio_device *gdev = v;
5093 struct gpio_chip *gc;
5094 struct device *parent;
5095
5096 if (priv->newline)
5097 seq_putc(s, '\n');
5098
5099 guard(srcu)(&gdev->srcu);
5100
5101 gc = srcu_dereference(gdev->chip, &gdev->srcu);
5102 if (!gc) {
5103 seq_printf(s, "%s: (dangling chip)\n", dev_name(&gdev->dev));
5104 return 0;
5105 }
5106
5107 seq_printf(s, "%s: GPIOs %u-%u", dev_name(&gdev->dev), gdev->base,
5108 gdev->base + gdev->ngpio - 1);
5109 parent = gc->parent;
5110 if (parent)
5111 seq_printf(s, ", parent: %s/%s",
5112 parent->bus ? parent->bus->name : "no-bus",
5113 dev_name(parent));
5114 if (gc->label)
5115 seq_printf(s, ", %s", gc->label);
5116 if (gc->can_sleep)
5117 seq_printf(s, ", can sleep");
5118 seq_printf(s, ":\n");
5119
5120 if (gc->dbg_show)
5121 gc->dbg_show(s, gc);
5122 else
5123 gpiolib_dbg_show(s, gdev);
5124
5125 return 0;
5126}
5127
5128static const struct seq_operations gpiolib_sops = {
5129 .start = gpiolib_seq_start,
5130 .next = gpiolib_seq_next,
5131 .stop = gpiolib_seq_stop,
5132 .show = gpiolib_seq_show,
5133};
5134DEFINE_SEQ_ATTRIBUTE(gpiolib);
5135
5136static int __init gpiolib_debugfs_init(void)
5137{
5138 /* /sys/kernel/debug/gpio */
5139 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
5140 return 0;
5141}
5142subsys_initcall(gpiolib_debugfs_init);
5143
5144#endif /* DEBUG_FS */
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/acpi.h>
4#include <linux/bitmap.h>
5#include <linux/cleanup.h>
6#include <linux/compat.h>
7#include <linux/debugfs.h>
8#include <linux/device.h>
9#include <linux/err.h>
10#include <linux/errno.h>
11#include <linux/file.h>
12#include <linux/fs.h>
13#include <linux/idr.h>
14#include <linux/interrupt.h>
15#include <linux/irq.h>
16#include <linux/kernel.h>
17#include <linux/list.h>
18#include <linux/lockdep.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/pinctrl/consumer.h>
22#include <linux/seq_file.h>
23#include <linux/slab.h>
24#include <linux/spinlock.h>
25#include <linux/srcu.h>
26#include <linux/string.h>
27
28#include <linux/gpio.h>
29#include <linux/gpio/driver.h>
30#include <linux/gpio/machine.h>
31
32#include <uapi/linux/gpio.h>
33
34#include "gpiolib-acpi.h"
35#include "gpiolib-cdev.h"
36#include "gpiolib-of.h"
37#include "gpiolib-swnode.h"
38#include "gpiolib-sysfs.h"
39#include "gpiolib.h"
40
41#define CREATE_TRACE_POINTS
42#include <trace/events/gpio.h>
43
44/* Implementation infrastructure for GPIO interfaces.
45 *
46 * The GPIO programming interface allows for inlining speed-critical
47 * get/set operations for common cases, so that access to SOC-integrated
48 * GPIOs can sometimes cost only an instruction or two per bit.
49 */
50
51/* Device and char device-related information */
52static DEFINE_IDA(gpio_ida);
53static dev_t gpio_devt;
54#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
55
56static int gpio_bus_match(struct device *dev, struct device_driver *drv)
57{
58 struct fwnode_handle *fwnode = dev_fwnode(dev);
59
60 /*
61 * Only match if the fwnode doesn't already have a proper struct device
62 * created for it.
63 */
64 if (fwnode && fwnode->dev != dev)
65 return 0;
66 return 1;
67}
68
69static const struct bus_type gpio_bus_type = {
70 .name = "gpio",
71 .match = gpio_bus_match,
72};
73
74/*
75 * Number of GPIOs to use for the fast path in set array
76 */
77#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
78
79static DEFINE_MUTEX(gpio_lookup_lock);
80static LIST_HEAD(gpio_lookup_list);
81
82static LIST_HEAD(gpio_devices);
83/* Protects the GPIO device list against concurrent modifications. */
84static DEFINE_MUTEX(gpio_devices_lock);
85/* Ensures coherence during read-only accesses to the list of GPIO devices. */
86DEFINE_STATIC_SRCU(gpio_devices_srcu);
87
88static DEFINE_MUTEX(gpio_machine_hogs_mutex);
89static LIST_HEAD(gpio_machine_hogs);
90
91static void gpiochip_free_hogs(struct gpio_chip *gc);
92static int gpiochip_add_irqchip(struct gpio_chip *gc,
93 struct lock_class_key *lock_key,
94 struct lock_class_key *request_key);
95static void gpiochip_irqchip_remove(struct gpio_chip *gc);
96static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
97static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
98static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
99
100static bool gpiolib_initialized;
101
102const char *gpiod_get_label(struct gpio_desc *desc)
103{
104 struct gpio_desc_label *label;
105 unsigned long flags;
106
107 flags = READ_ONCE(desc->flags);
108 if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
109 !test_bit(FLAG_REQUESTED, &flags))
110 return "interrupt";
111
112 if (!test_bit(FLAG_REQUESTED, &flags))
113 return NULL;
114
115 label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu,
116 srcu_read_lock_held(&desc->gdev->desc_srcu));
117
118 return label->str;
119}
120
121static void desc_free_label(struct rcu_head *rh)
122{
123 kfree(container_of(rh, struct gpio_desc_label, rh));
124}
125
126static int desc_set_label(struct gpio_desc *desc, const char *label)
127{
128 struct gpio_desc_label *new = NULL, *old;
129
130 if (label) {
131 new = kzalloc(struct_size(new, str, strlen(label) + 1),
132 GFP_KERNEL);
133 if (!new)
134 return -ENOMEM;
135
136 strcpy(new->str, label);
137 }
138
139 old = rcu_replace_pointer(desc->label, new, 1);
140 if (old)
141 call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label);
142
143 return 0;
144}
145
146/**
147 * gpio_to_desc - Convert a GPIO number to its descriptor
148 * @gpio: global GPIO number
149 *
150 * Returns:
151 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
152 * with the given number exists in the system.
153 */
154struct gpio_desc *gpio_to_desc(unsigned gpio)
155{
156 struct gpio_device *gdev;
157
158 scoped_guard(srcu, &gpio_devices_srcu) {
159 list_for_each_entry_srcu(gdev, &gpio_devices, list,
160 srcu_read_lock_held(&gpio_devices_srcu)) {
161 if (gdev->base <= gpio &&
162 gdev->base + gdev->ngpio > gpio)
163 return &gdev->descs[gpio - gdev->base];
164 }
165 }
166
167 if (!gpio_is_valid(gpio))
168 pr_warn("invalid GPIO %d\n", gpio);
169
170 return NULL;
171}
172EXPORT_SYMBOL_GPL(gpio_to_desc);
173
174/* This function is deprecated and will be removed soon, don't use. */
175struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
176 unsigned int hwnum)
177{
178 return gpio_device_get_desc(gc->gpiodev, hwnum);
179}
180EXPORT_SYMBOL_GPL(gpiochip_get_desc);
181
182/**
183 * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given
184 * hardware number for this GPIO device
185 * @gdev: GPIO device to get the descriptor from
186 * @hwnum: hardware number of the GPIO for this chip
187 *
188 * Returns:
189 * A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given
190 * chip for the specified hardware number or %ENODEV if the underlying chip
191 * already vanished.
192 *
193 * The reference count of struct gpio_device is *NOT* increased like when the
194 * GPIO is being requested for exclusive usage. It's up to the caller to make
195 * sure the GPIO device will stay alive together with the descriptor returned
196 * by this function.
197 */
198struct gpio_desc *
199gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum)
200{
201 if (hwnum >= gdev->ngpio)
202 return ERR_PTR(-EINVAL);
203
204 return &gdev->descs[hwnum];
205}
206EXPORT_SYMBOL_GPL(gpio_device_get_desc);
207
208/**
209 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
210 * @desc: GPIO descriptor
211 *
212 * This should disappear in the future but is needed since we still
213 * use GPIO numbers for error messages and sysfs nodes.
214 *
215 * Returns:
216 * The global GPIO number for the GPIO specified by its descriptor.
217 */
218int desc_to_gpio(const struct gpio_desc *desc)
219{
220 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
221}
222EXPORT_SYMBOL_GPL(desc_to_gpio);
223
224
225/**
226 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
227 * @desc: descriptor to return the chip of
228 *
229 * *DEPRECATED*
230 * This function is unsafe and should not be used. Using the chip address
231 * without taking the SRCU read lock may result in dereferencing a dangling
232 * pointer.
233 */
234struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
235{
236 if (!desc)
237 return NULL;
238
239 return gpio_device_get_chip(desc->gdev);
240}
241EXPORT_SYMBOL_GPL(gpiod_to_chip);
242
243/**
244 * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor
245 * belongs.
246 * @desc: Descriptor for which to return the GPIO device.
247 *
248 * This *DOES NOT* increase the reference count of the GPIO device as it's
249 * expected that the descriptor is requested and the users already holds a
250 * reference to the device.
251 *
252 * Returns:
253 * Address of the GPIO device owning this descriptor.
254 */
255struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc)
256{
257 if (!desc)
258 return NULL;
259
260 return desc->gdev;
261}
262EXPORT_SYMBOL_GPL(gpiod_to_gpio_device);
263
264/**
265 * gpio_device_get_base() - Get the base GPIO number allocated by this device
266 * @gdev: GPIO device
267 *
268 * Returns:
269 * First GPIO number in the global GPIO numberspace for this device.
270 */
271int gpio_device_get_base(struct gpio_device *gdev)
272{
273 return gdev->base;
274}
275EXPORT_SYMBOL_GPL(gpio_device_get_base);
276
277/**
278 * gpio_device_get_label() - Get the label of this GPIO device
279 * @gdev: GPIO device
280 *
281 * Returns:
282 * Pointer to the string containing the GPIO device label. The string's
283 * lifetime is tied to that of the underlying GPIO device.
284 */
285const char *gpio_device_get_label(struct gpio_device *gdev)
286{
287 return gdev->label;
288}
289EXPORT_SYMBOL(gpio_device_get_label);
290
291/**
292 * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device
293 * @gdev: GPIO device
294 *
295 * Returns:
296 * Address of the GPIO chip backing this device.
297 *
298 * *DEPRECATED*
299 * Until we can get rid of all non-driver users of struct gpio_chip, we must
300 * provide a way of retrieving the pointer to it from struct gpio_device. This
301 * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the
302 * chip can dissapear at any moment (unlike reference-counted struct
303 * gpio_device).
304 *
305 * Use at your own risk.
306 */
307struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)
308{
309 return rcu_dereference_check(gdev->chip, 1);
310}
311EXPORT_SYMBOL_GPL(gpio_device_get_chip);
312
313/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
314static int gpiochip_find_base_unlocked(int ngpio)
315{
316 struct gpio_device *gdev;
317 int base = GPIO_DYNAMIC_BASE;
318
319 list_for_each_entry_srcu(gdev, &gpio_devices, list,
320 lockdep_is_held(&gpio_devices_lock)) {
321 /* found a free space? */
322 if (gdev->base >= base + ngpio)
323 break;
324 /* nope, check the space right after the chip */
325 base = gdev->base + gdev->ngpio;
326 if (base < GPIO_DYNAMIC_BASE)
327 base = GPIO_DYNAMIC_BASE;
328 }
329
330 if (gpio_is_valid(base)) {
331 pr_debug("%s: found new base at %d\n", __func__, base);
332 return base;
333 } else {
334 pr_err("%s: cannot find free range\n", __func__);
335 return -ENOSPC;
336 }
337}
338
339/**
340 * gpiod_get_direction - return the current direction of a GPIO
341 * @desc: GPIO to get the direction of
342 *
343 * Returns 0 for output, 1 for input, or an error code in case of error.
344 *
345 * This function may sleep if gpiod_cansleep() is true.
346 */
347int gpiod_get_direction(struct gpio_desc *desc)
348{
349 unsigned long flags;
350 unsigned int offset;
351 int ret;
352
353 /*
354 * We cannot use VALIDATE_DESC() as we must not return 0 for a NULL
355 * descriptor like we usually do.
356 */
357 if (!desc || IS_ERR(desc))
358 return -EINVAL;
359
360 CLASS(gpio_chip_guard, guard)(desc);
361 if (!guard.gc)
362 return -ENODEV;
363
364 offset = gpio_chip_hwgpio(desc);
365 flags = READ_ONCE(desc->flags);
366
367 /*
368 * Open drain emulation using input mode may incorrectly report
369 * input here, fix that up.
370 */
371 if (test_bit(FLAG_OPEN_DRAIN, &flags) &&
372 test_bit(FLAG_IS_OUT, &flags))
373 return 0;
374
375 if (!guard.gc->get_direction)
376 return -ENOTSUPP;
377
378 ret = guard.gc->get_direction(guard.gc, offset);
379 if (ret < 0)
380 return ret;
381
382 /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
383 if (ret > 0)
384 ret = 1;
385
386 assign_bit(FLAG_IS_OUT, &flags, !ret);
387 WRITE_ONCE(desc->flags, flags);
388
389 return ret;
390}
391EXPORT_SYMBOL_GPL(gpiod_get_direction);
392
393/*
394 * Add a new chip to the global chips list, keeping the list of chips sorted
395 * by range(means [base, base + ngpio - 1]) order.
396 *
397 * Return -EBUSY if the new chip overlaps with some other chip's integer
398 * space.
399 */
400static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)
401{
402 struct gpio_device *prev, *next;
403
404 lockdep_assert_held(&gpio_devices_lock);
405
406 if (list_empty(&gpio_devices)) {
407 /* initial entry in list */
408 list_add_tail_rcu(&gdev->list, &gpio_devices);
409 return 0;
410 }
411
412 next = list_first_entry(&gpio_devices, struct gpio_device, list);
413 if (gdev->base + gdev->ngpio <= next->base) {
414 /* add before first entry */
415 list_add_rcu(&gdev->list, &gpio_devices);
416 return 0;
417 }
418
419 prev = list_last_entry(&gpio_devices, struct gpio_device, list);
420 if (prev->base + prev->ngpio <= gdev->base) {
421 /* add behind last entry */
422 list_add_tail_rcu(&gdev->list, &gpio_devices);
423 return 0;
424 }
425
426 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
427 /* at the end of the list */
428 if (&next->list == &gpio_devices)
429 break;
430
431 /* add between prev and next */
432 if (prev->base + prev->ngpio <= gdev->base
433 && gdev->base + gdev->ngpio <= next->base) {
434 list_add_rcu(&gdev->list, &prev->list);
435 return 0;
436 }
437 }
438
439 synchronize_srcu(&gpio_devices_srcu);
440
441 return -EBUSY;
442}
443
444/*
445 * Convert a GPIO name to its descriptor
446 * Note that there is no guarantee that GPIO names are globally unique!
447 * Hence this function will return, if it exists, a reference to the first GPIO
448 * line found that matches the given name.
449 */
450static struct gpio_desc *gpio_name_to_desc(const char * const name)
451{
452 struct gpio_device *gdev;
453 struct gpio_desc *desc;
454 struct gpio_chip *gc;
455
456 if (!name)
457 return NULL;
458
459 guard(srcu)(&gpio_devices_srcu);
460
461 list_for_each_entry_srcu(gdev, &gpio_devices, list,
462 srcu_read_lock_held(&gpio_devices_srcu)) {
463 guard(srcu)(&gdev->srcu);
464
465 gc = srcu_dereference(gdev->chip, &gdev->srcu);
466 if (!gc)
467 continue;
468
469 for_each_gpio_desc(gc, desc) {
470 if (desc->name && !strcmp(desc->name, name))
471 return desc;
472 }
473 }
474
475 return NULL;
476}
477
478/*
479 * Take the names from gc->names and assign them to their GPIO descriptors.
480 * Warn if a name is already used for a GPIO line on a different GPIO chip.
481 *
482 * Note that:
483 * 1. Non-unique names are still accepted,
484 * 2. Name collisions within the same GPIO chip are not reported.
485 */
486static int gpiochip_set_desc_names(struct gpio_chip *gc)
487{
488 struct gpio_device *gdev = gc->gpiodev;
489 int i;
490
491 /* First check all names if they are unique */
492 for (i = 0; i != gc->ngpio; ++i) {
493 struct gpio_desc *gpio;
494
495 gpio = gpio_name_to_desc(gc->names[i]);
496 if (gpio)
497 dev_warn(&gdev->dev,
498 "Detected name collision for GPIO name '%s'\n",
499 gc->names[i]);
500 }
501
502 /* Then add all names to the GPIO descriptors */
503 for (i = 0; i != gc->ngpio; ++i)
504 gdev->descs[i].name = gc->names[i];
505
506 return 0;
507}
508
509/*
510 * gpiochip_set_names - Set GPIO line names using device properties
511 * @chip: GPIO chip whose lines should be named, if possible
512 *
513 * Looks for device property "gpio-line-names" and if it exists assigns
514 * GPIO line names for the chip. The memory allocated for the assigned
515 * names belong to the underlying firmware node and should not be released
516 * by the caller.
517 */
518static int gpiochip_set_names(struct gpio_chip *chip)
519{
520 struct gpio_device *gdev = chip->gpiodev;
521 struct device *dev = &gdev->dev;
522 const char **names;
523 int ret, i;
524 int count;
525
526 count = device_property_string_array_count(dev, "gpio-line-names");
527 if (count < 0)
528 return 0;
529
530 /*
531 * When offset is set in the driver side we assume the driver internally
532 * is using more than one gpiochip per the same device. We have to stop
533 * setting friendly names if the specified ones with 'gpio-line-names'
534 * are less than the offset in the device itself. This means all the
535 * lines are not present for every single pin within all the internal
536 * gpiochips.
537 */
538 if (count <= chip->offset) {
539 dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
540 count, chip->offset);
541 return 0;
542 }
543
544 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
545 if (!names)
546 return -ENOMEM;
547
548 ret = device_property_read_string_array(dev, "gpio-line-names",
549 names, count);
550 if (ret < 0) {
551 dev_warn(dev, "failed to read GPIO line names\n");
552 kfree(names);
553 return ret;
554 }
555
556 /*
557 * When more that one gpiochip per device is used, 'count' can
558 * contain at most number gpiochips x chip->ngpio. We have to
559 * correctly distribute all defined lines taking into account
560 * chip->offset as starting point from where we will assign
561 * the names to pins from the 'names' array. Since property
562 * 'gpio-line-names' cannot contains gaps, we have to be sure
563 * we only assign those pins that really exists since chip->ngpio
564 * can be different of the chip->offset.
565 */
566 count = (count > chip->offset) ? count - chip->offset : count;
567 if (count > chip->ngpio)
568 count = chip->ngpio;
569
570 for (i = 0; i < count; i++) {
571 /*
572 * Allow overriding "fixed" names provided by the GPIO
573 * provider. The "fixed" names are more often than not
574 * generic and less informative than the names given in
575 * device properties.
576 */
577 if (names[chip->offset + i] && names[chip->offset + i][0])
578 gdev->descs[i].name = names[chip->offset + i];
579 }
580
581 kfree(names);
582
583 return 0;
584}
585
586static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
587{
588 unsigned long *p;
589
590 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
591 if (!p)
592 return NULL;
593
594 /* Assume by default all GPIOs are valid */
595 bitmap_fill(p, gc->ngpio);
596
597 return p;
598}
599
600static void gpiochip_free_mask(unsigned long **p)
601{
602 bitmap_free(*p);
603 *p = NULL;
604}
605
606static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc)
607{
608 struct device *dev = &gc->gpiodev->dev;
609 int size;
610
611 /* Format is "start, count, ..." */
612 size = device_property_count_u32(dev, "gpio-reserved-ranges");
613 if (size > 0 && size % 2 == 0)
614 return size;
615
616 return 0;
617}
618
619static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc)
620{
621 struct device *dev = &gc->gpiodev->dev;
622 unsigned int size;
623 u32 *ranges;
624 int ret;
625
626 size = gpiochip_count_reserved_ranges(gc);
627 if (size == 0)
628 return 0;
629
630 ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL);
631 if (!ranges)
632 return -ENOMEM;
633
634 ret = device_property_read_u32_array(dev, "gpio-reserved-ranges",
635 ranges, size);
636 if (ret) {
637 kfree(ranges);
638 return ret;
639 }
640
641 while (size) {
642 u32 count = ranges[--size];
643 u32 start = ranges[--size];
644
645 if (start >= gc->ngpio || start + count > gc->ngpio)
646 continue;
647
648 bitmap_clear(gc->valid_mask, start, count);
649 }
650
651 kfree(ranges);
652 return 0;
653}
654
655static int gpiochip_init_valid_mask(struct gpio_chip *gc)
656{
657 int ret;
658
659 if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask))
660 return 0;
661
662 gc->valid_mask = gpiochip_allocate_mask(gc);
663 if (!gc->valid_mask)
664 return -ENOMEM;
665
666 ret = gpiochip_apply_reserved_ranges(gc);
667 if (ret)
668 return ret;
669
670 if (gc->init_valid_mask)
671 return gc->init_valid_mask(gc,
672 gc->valid_mask,
673 gc->ngpio);
674
675 return 0;
676}
677
678static void gpiochip_free_valid_mask(struct gpio_chip *gc)
679{
680 gpiochip_free_mask(&gc->valid_mask);
681}
682
683static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
684{
685 /*
686 * Device Tree platforms are supposed to use "gpio-ranges"
687 * property. This check ensures that the ->add_pin_ranges()
688 * won't be called for them.
689 */
690 if (device_property_present(&gc->gpiodev->dev, "gpio-ranges"))
691 return 0;
692
693 if (gc->add_pin_ranges)
694 return gc->add_pin_ranges(gc);
695
696 return 0;
697}
698
699bool gpiochip_line_is_valid(const struct gpio_chip *gc,
700 unsigned int offset)
701{
702 /* No mask means all valid */
703 if (likely(!gc->valid_mask))
704 return true;
705 return test_bit(offset, gc->valid_mask);
706}
707EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
708
709static void gpiodev_release(struct device *dev)
710{
711 struct gpio_device *gdev = to_gpio_device(dev);
712
713 /* Call pending kfree()s for descriptor labels. */
714 synchronize_srcu(&gdev->desc_srcu);
715 cleanup_srcu_struct(&gdev->desc_srcu);
716
717 ida_free(&gpio_ida, gdev->id);
718 kfree_const(gdev->label);
719 kfree(gdev->descs);
720 cleanup_srcu_struct(&gdev->srcu);
721 kfree(gdev);
722}
723
724static const struct device_type gpio_dev_type = {
725 .name = "gpio_chip",
726 .release = gpiodev_release,
727};
728
729#ifdef CONFIG_GPIO_CDEV
730#define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
731#define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
732#else
733/*
734 * gpiolib_cdev_register() indirectly calls device_add(), which is still
735 * required even when cdev is not selected.
736 */
737#define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
738#define gcdev_unregister(gdev) device_del(&(gdev)->dev)
739#endif
740
741static int gpiochip_setup_dev(struct gpio_device *gdev)
742{
743 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
744 int ret;
745
746 device_initialize(&gdev->dev);
747
748 /*
749 * If fwnode doesn't belong to another device, it's safe to clear its
750 * initialized flag.
751 */
752 if (fwnode && !fwnode->dev)
753 fwnode_dev_initialized(fwnode, false);
754
755 ret = gcdev_register(gdev, gpio_devt);
756 if (ret)
757 return ret;
758
759 ret = gpiochip_sysfs_register(gdev);
760 if (ret)
761 goto err_remove_device;
762
763 dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
764 gdev->base + gdev->ngpio - 1, gdev->label);
765
766 return 0;
767
768err_remove_device:
769 gcdev_unregister(gdev);
770 return ret;
771}
772
773static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
774{
775 struct gpio_desc *desc;
776 int rv;
777
778 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
779 if (IS_ERR(desc)) {
780 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
781 PTR_ERR(desc));
782 return;
783 }
784
785 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
786 if (rv)
787 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
788 __func__, gc->label, hog->chip_hwnum, rv);
789}
790
791static void machine_gpiochip_add(struct gpio_chip *gc)
792{
793 struct gpiod_hog *hog;
794
795 mutex_lock(&gpio_machine_hogs_mutex);
796
797 list_for_each_entry(hog, &gpio_machine_hogs, list) {
798 if (!strcmp(gc->label, hog->chip_label))
799 gpiochip_machine_hog(gc, hog);
800 }
801
802 mutex_unlock(&gpio_machine_hogs_mutex);
803}
804
805static void gpiochip_setup_devs(void)
806{
807 struct gpio_device *gdev;
808 int ret;
809
810 guard(srcu)(&gpio_devices_srcu);
811
812 list_for_each_entry_srcu(gdev, &gpio_devices, list,
813 srcu_read_lock_held(&gpio_devices_srcu)) {
814 ret = gpiochip_setup_dev(gdev);
815 if (ret)
816 dev_err(&gdev->dev,
817 "Failed to initialize gpio device (%d)\n", ret);
818 }
819}
820
821static void gpiochip_set_data(struct gpio_chip *gc, void *data)
822{
823 gc->gpiodev->data = data;
824}
825
826/**
827 * gpiochip_get_data() - get per-subdriver data for the chip
828 * @gc: GPIO chip
829 *
830 * Returns:
831 * The per-subdriver data for the chip.
832 */
833void *gpiochip_get_data(struct gpio_chip *gc)
834{
835 return gc->gpiodev->data;
836}
837EXPORT_SYMBOL_GPL(gpiochip_get_data);
838
839int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
840{
841 u32 ngpios = gc->ngpio;
842 int ret;
843
844 if (ngpios == 0) {
845 ret = device_property_read_u32(dev, "ngpios", &ngpios);
846 if (ret == -ENODATA)
847 /*
848 * -ENODATA means that there is no property found and
849 * we want to issue the error message to the user.
850 * Besides that, we want to return different error code
851 * to state that supplied value is not valid.
852 */
853 ngpios = 0;
854 else if (ret)
855 return ret;
856
857 gc->ngpio = ngpios;
858 }
859
860 if (gc->ngpio == 0) {
861 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
862 return -EINVAL;
863 }
864
865 if (gc->ngpio > FASTPATH_NGPIO)
866 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
867 gc->ngpio, FASTPATH_NGPIO);
868
869 return 0;
870}
871EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);
872
873int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
874 struct lock_class_key *lock_key,
875 struct lock_class_key *request_key)
876{
877 struct gpio_device *gdev;
878 unsigned int desc_index;
879 int base = 0;
880 int ret = 0;
881
882 /*
883 * First: allocate and populate the internal stat container, and
884 * set up the struct device.
885 */
886 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
887 if (!gdev)
888 return -ENOMEM;
889
890 gdev->dev.type = &gpio_dev_type;
891 gdev->dev.bus = &gpio_bus_type;
892 gdev->dev.parent = gc->parent;
893 rcu_assign_pointer(gdev->chip, gc);
894
895 gc->gpiodev = gdev;
896 gpiochip_set_data(gc, data);
897
898 /*
899 * If the calling driver did not initialize firmware node,
900 * do it here using the parent device, if any.
901 */
902 if (gc->fwnode)
903 device_set_node(&gdev->dev, gc->fwnode);
904 else if (gc->parent)
905 device_set_node(&gdev->dev, dev_fwnode(gc->parent));
906
907 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
908 if (gdev->id < 0) {
909 ret = gdev->id;
910 goto err_free_gdev;
911 }
912
913 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
914 if (ret)
915 goto err_free_ida;
916
917 if (gc->parent && gc->parent->driver)
918 gdev->owner = gc->parent->driver->owner;
919 else if (gc->owner)
920 /* TODO: remove chip->owner */
921 gdev->owner = gc->owner;
922 else
923 gdev->owner = THIS_MODULE;
924
925 ret = gpiochip_get_ngpios(gc, &gdev->dev);
926 if (ret)
927 goto err_free_dev_name;
928
929 gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
930 if (!gdev->descs) {
931 ret = -ENOMEM;
932 goto err_free_dev_name;
933 }
934
935 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
936 if (!gdev->label) {
937 ret = -ENOMEM;
938 goto err_free_descs;
939 }
940
941 gdev->ngpio = gc->ngpio;
942 gdev->can_sleep = gc->can_sleep;
943
944 scoped_guard(mutex, &gpio_devices_lock) {
945 /*
946 * TODO: this allocates a Linux GPIO number base in the global
947 * GPIO numberspace for this chip. In the long run we want to
948 * get *rid* of this numberspace and use only descriptors, but
949 * it may be a pipe dream. It will not happen before we get rid
950 * of the sysfs interface anyways.
951 */
952 base = gc->base;
953 if (base < 0) {
954 base = gpiochip_find_base_unlocked(gc->ngpio);
955 if (base < 0) {
956 ret = base;
957 base = 0;
958 goto err_free_label;
959 }
960
961 /*
962 * TODO: it should not be necessary to reflect the
963 * assigned base outside of the GPIO subsystem. Go over
964 * drivers and see if anyone makes use of this, else
965 * drop this and assign a poison instead.
966 */
967 gc->base = base;
968 } else {
969 dev_warn(&gdev->dev,
970 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
971 }
972
973 gdev->base = base;
974
975 ret = gpiodev_add_to_list_unlocked(gdev);
976 if (ret) {
977 chip_err(gc, "GPIO integer space overlap, cannot add chip\n");
978 goto err_free_label;
979 }
980 }
981
982 for (desc_index = 0; desc_index < gc->ngpio; desc_index++)
983 gdev->descs[desc_index].gdev = gdev;
984
985 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
986 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
987
988 ret = init_srcu_struct(&gdev->srcu);
989 if (ret)
990 goto err_remove_from_list;
991
992 ret = init_srcu_struct(&gdev->desc_srcu);
993 if (ret)
994 goto err_cleanup_gdev_srcu;
995
996#ifdef CONFIG_PINCTRL
997 INIT_LIST_HEAD(&gdev->pin_ranges);
998#endif
999
1000 if (gc->names) {
1001 ret = gpiochip_set_desc_names(gc);
1002 if (ret)
1003 goto err_cleanup_desc_srcu;
1004 }
1005 ret = gpiochip_set_names(gc);
1006 if (ret)
1007 goto err_cleanup_desc_srcu;
1008
1009 ret = gpiochip_init_valid_mask(gc);
1010 if (ret)
1011 goto err_cleanup_desc_srcu;
1012
1013 for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
1014 struct gpio_desc *desc = &gdev->descs[desc_index];
1015
1016 if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {
1017 assign_bit(FLAG_IS_OUT,
1018 &desc->flags, !gc->get_direction(gc, desc_index));
1019 } else {
1020 assign_bit(FLAG_IS_OUT,
1021 &desc->flags, !gc->direction_input);
1022 }
1023 }
1024
1025 ret = of_gpiochip_add(gc);
1026 if (ret)
1027 goto err_free_valid_mask;
1028
1029 ret = gpiochip_add_pin_ranges(gc);
1030 if (ret)
1031 goto err_remove_of_chip;
1032
1033 acpi_gpiochip_add(gc);
1034
1035 machine_gpiochip_add(gc);
1036
1037 ret = gpiochip_irqchip_init_valid_mask(gc);
1038 if (ret)
1039 goto err_free_hogs;
1040
1041 ret = gpiochip_irqchip_init_hw(gc);
1042 if (ret)
1043 goto err_remove_irqchip_mask;
1044
1045 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
1046 if (ret)
1047 goto err_remove_irqchip_mask;
1048
1049 /*
1050 * By first adding the chardev, and then adding the device,
1051 * we get a device node entry in sysfs under
1052 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1053 * coldplug of device nodes and other udev business.
1054 * We can do this only if gpiolib has been initialized.
1055 * Otherwise, defer until later.
1056 */
1057 if (gpiolib_initialized) {
1058 ret = gpiochip_setup_dev(gdev);
1059 if (ret)
1060 goto err_remove_irqchip;
1061 }
1062 return 0;
1063
1064err_remove_irqchip:
1065 gpiochip_irqchip_remove(gc);
1066err_remove_irqchip_mask:
1067 gpiochip_irqchip_free_valid_mask(gc);
1068err_free_hogs:
1069 gpiochip_free_hogs(gc);
1070 acpi_gpiochip_remove(gc);
1071 gpiochip_remove_pin_ranges(gc);
1072err_remove_of_chip:
1073 of_gpiochip_remove(gc);
1074err_free_valid_mask:
1075 gpiochip_free_valid_mask(gc);
1076err_cleanup_desc_srcu:
1077 cleanup_srcu_struct(&gdev->desc_srcu);
1078err_cleanup_gdev_srcu:
1079 cleanup_srcu_struct(&gdev->srcu);
1080err_remove_from_list:
1081 scoped_guard(mutex, &gpio_devices_lock)
1082 list_del_rcu(&gdev->list);
1083 synchronize_srcu(&gpio_devices_srcu);
1084 if (gdev->dev.release) {
1085 /* release() has been registered by gpiochip_setup_dev() */
1086 gpio_device_put(gdev);
1087 goto err_print_message;
1088 }
1089err_free_label:
1090 kfree_const(gdev->label);
1091err_free_descs:
1092 kfree(gdev->descs);
1093err_free_dev_name:
1094 kfree(dev_name(&gdev->dev));
1095err_free_ida:
1096 ida_free(&gpio_ida, gdev->id);
1097err_free_gdev:
1098 kfree(gdev);
1099err_print_message:
1100 /* failures here can mean systems won't boot... */
1101 if (ret != -EPROBE_DEFER) {
1102 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1103 base, base + (int)gc->ngpio - 1,
1104 gc->label ? : "generic", ret);
1105 }
1106 return ret;
1107}
1108EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1109
1110/**
1111 * gpiochip_remove() - unregister a gpio_chip
1112 * @gc: the chip to unregister
1113 *
1114 * A gpio_chip with any GPIOs still requested may not be removed.
1115 */
1116void gpiochip_remove(struct gpio_chip *gc)
1117{
1118 struct gpio_device *gdev = gc->gpiodev;
1119
1120 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1121 gpiochip_sysfs_unregister(gdev);
1122 gpiochip_free_hogs(gc);
1123
1124 scoped_guard(mutex, &gpio_devices_lock)
1125 list_del_rcu(&gdev->list);
1126 synchronize_srcu(&gpio_devices_srcu);
1127
1128 /* Numb the device, cancelling all outstanding operations */
1129 rcu_assign_pointer(gdev->chip, NULL);
1130 synchronize_srcu(&gdev->srcu);
1131 gpiochip_irqchip_remove(gc);
1132 acpi_gpiochip_remove(gc);
1133 of_gpiochip_remove(gc);
1134 gpiochip_remove_pin_ranges(gc);
1135 gpiochip_free_valid_mask(gc);
1136 /*
1137 * We accept no more calls into the driver from this point, so
1138 * NULL the driver data pointer.
1139 */
1140 gpiochip_set_data(gc, NULL);
1141
1142 /*
1143 * The gpiochip side puts its use of the device to rest here:
1144 * if there are no userspace clients, the chardev and device will
1145 * be removed, else it will be dangling until the last user is
1146 * gone.
1147 */
1148 gcdev_unregister(gdev);
1149 gpio_device_put(gdev);
1150}
1151EXPORT_SYMBOL_GPL(gpiochip_remove);
1152
1153/**
1154 * gpio_device_find() - find a specific GPIO device
1155 * @data: data to pass to match function
1156 * @match: Callback function to check gpio_chip
1157 *
1158 * Returns:
1159 * New reference to struct gpio_device.
1160 *
1161 * Similar to bus_find_device(). It returns a reference to a gpio_device as
1162 * determined by a user supplied @match callback. The callback should return
1163 * 0 if the device doesn't match and non-zero if it does. If the callback
1164 * returns non-zero, this function will return to the caller and not iterate
1165 * over any more gpio_devices.
1166 *
1167 * The callback takes the GPIO chip structure as argument. During the execution
1168 * of the callback function the chip is protected from being freed. TODO: This
1169 * actually has yet to be implemented.
1170 *
1171 * If the function returns non-NULL, the returned reference must be freed by
1172 * the caller using gpio_device_put().
1173 */
1174struct gpio_device *gpio_device_find(const void *data,
1175 int (*match)(struct gpio_chip *gc,
1176 const void *data))
1177{
1178 struct gpio_device *gdev;
1179 struct gpio_chip *gc;
1180
1181 /*
1182 * Not yet but in the future the spinlock below will become a mutex.
1183 * Annotate this function before anyone tries to use it in interrupt
1184 * context like it happened with gpiochip_find().
1185 */
1186 might_sleep();
1187
1188 guard(srcu)(&gpio_devices_srcu);
1189
1190 list_for_each_entry_srcu(gdev, &gpio_devices, list,
1191 srcu_read_lock_held(&gpio_devices_srcu)) {
1192 if (!device_is_registered(&gdev->dev))
1193 continue;
1194
1195 guard(srcu)(&gdev->srcu);
1196
1197 gc = srcu_dereference(gdev->chip, &gdev->srcu);
1198
1199 if (gc && match(gc, data))
1200 return gpio_device_get(gdev);
1201 }
1202
1203 return NULL;
1204}
1205EXPORT_SYMBOL_GPL(gpio_device_find);
1206
1207static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)
1208{
1209 return gc->label && !strcmp(gc->label, label);
1210}
1211
1212/**
1213 * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the
1214 * GPIO device by its backing chip's label
1215 * @label: Label to lookup
1216 *
1217 * Returns:
1218 * Reference to the GPIO device or NULL. Reference must be released with
1219 * gpio_device_put().
1220 */
1221struct gpio_device *gpio_device_find_by_label(const char *label)
1222{
1223 return gpio_device_find((void *)label, gpio_chip_match_by_label);
1224}
1225EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
1226
1227static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)
1228{
1229 return device_match_fwnode(&gc->gpiodev->dev, fwnode);
1230}
1231
1232/**
1233 * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
1234 * the GPIO device by its fwnode
1235 * @fwnode: Firmware node to lookup
1236 *
1237 * Returns:
1238 * Reference to the GPIO device or NULL. Reference must be released with
1239 * gpio_device_put().
1240 */
1241struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
1242{
1243 return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
1244}
1245EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
1246
1247/**
1248 * gpio_device_get() - Increase the reference count of this GPIO device
1249 * @gdev: GPIO device to increase the refcount for
1250 *
1251 * Returns:
1252 * Pointer to @gdev.
1253 */
1254struct gpio_device *gpio_device_get(struct gpio_device *gdev)
1255{
1256 return to_gpio_device(get_device(&gdev->dev));
1257}
1258EXPORT_SYMBOL_GPL(gpio_device_get);
1259
1260/**
1261 * gpio_device_put() - Decrease the reference count of this GPIO device and
1262 * possibly free all resources associated with it.
1263 * @gdev: GPIO device to decrease the reference count for
1264 */
1265void gpio_device_put(struct gpio_device *gdev)
1266{
1267 put_device(&gdev->dev);
1268}
1269EXPORT_SYMBOL_GPL(gpio_device_put);
1270
1271/**
1272 * gpio_device_to_device() - Retrieve the address of the underlying struct
1273 * device.
1274 * @gdev: GPIO device for which to return the address.
1275 *
1276 * This does not increase the reference count of the GPIO device nor the
1277 * underlying struct device.
1278 *
1279 * Returns:
1280 * Address of struct device backing this GPIO device.
1281 */
1282struct device *gpio_device_to_device(struct gpio_device *gdev)
1283{
1284 return &gdev->dev;
1285}
1286EXPORT_SYMBOL_GPL(gpio_device_to_device);
1287
1288#ifdef CONFIG_GPIOLIB_IRQCHIP
1289
1290/*
1291 * The following is irqchip helper code for gpiochips.
1292 */
1293
1294static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1295{
1296 struct gpio_irq_chip *girq = &gc->irq;
1297
1298 if (!girq->init_hw)
1299 return 0;
1300
1301 return girq->init_hw(gc);
1302}
1303
1304static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1305{
1306 struct gpio_irq_chip *girq = &gc->irq;
1307
1308 if (!girq->init_valid_mask)
1309 return 0;
1310
1311 girq->valid_mask = gpiochip_allocate_mask(gc);
1312 if (!girq->valid_mask)
1313 return -ENOMEM;
1314
1315 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1316
1317 return 0;
1318}
1319
1320static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1321{
1322 gpiochip_free_mask(&gc->irq.valid_mask);
1323}
1324
1325static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
1326 unsigned int offset)
1327{
1328 if (!gpiochip_line_is_valid(gc, offset))
1329 return false;
1330 /* No mask means all valid */
1331 if (likely(!gc->irq.valid_mask))
1332 return true;
1333 return test_bit(offset, gc->irq.valid_mask);
1334}
1335
1336#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1337
1338/**
1339 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1340 * to a gpiochip
1341 * @gc: the gpiochip to set the irqchip hierarchical handler to
1342 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1343 * will then percolate up to the parent
1344 */
1345static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1346 struct irq_chip *irqchip)
1347{
1348 /* DT will deal with mapping each IRQ as we go along */
1349 if (is_of_node(gc->irq.fwnode))
1350 return;
1351
1352 /*
1353 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1354 * irqs upfront instead of dynamically since we don't have the
1355 * dynamic type of allocation that hardware description languages
1356 * provide. Once all GPIO drivers using board files are gone from
1357 * the kernel we can delete this code, but for a transitional period
1358 * it is necessary to keep this around.
1359 */
1360 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1361 int i;
1362 int ret;
1363
1364 for (i = 0; i < gc->ngpio; i++) {
1365 struct irq_fwspec fwspec;
1366 unsigned int parent_hwirq;
1367 unsigned int parent_type;
1368 struct gpio_irq_chip *girq = &gc->irq;
1369
1370 /*
1371 * We call the child to parent translation function
1372 * only to check if the child IRQ is valid or not.
1373 * Just pick the rising edge type here as that is what
1374 * we likely need to support.
1375 */
1376 ret = girq->child_to_parent_hwirq(gc, i,
1377 IRQ_TYPE_EDGE_RISING,
1378 &parent_hwirq,
1379 &parent_type);
1380 if (ret) {
1381 chip_err(gc, "skip set-up on hwirq %d\n",
1382 i);
1383 continue;
1384 }
1385
1386 fwspec.fwnode = gc->irq.fwnode;
1387 /* This is the hwirq for the GPIO line side of things */
1388 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1389 /* Just pick something */
1390 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1391 fwspec.param_count = 2;
1392 ret = irq_domain_alloc_irqs(gc->irq.domain, 1,
1393 NUMA_NO_NODE, &fwspec);
1394 if (ret < 0) {
1395 chip_err(gc,
1396 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1397 i, parent_hwirq,
1398 ret);
1399 }
1400 }
1401 }
1402
1403 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1404
1405 return;
1406}
1407
1408static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1409 struct irq_fwspec *fwspec,
1410 unsigned long *hwirq,
1411 unsigned int *type)
1412{
1413 /* We support standard DT translation */
1414 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1415 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1416 }
1417
1418 /* This is for board files and others not using DT */
1419 if (is_fwnode_irqchip(fwspec->fwnode)) {
1420 int ret;
1421
1422 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1423 if (ret)
1424 return ret;
1425 WARN_ON(*type == IRQ_TYPE_NONE);
1426 return 0;
1427 }
1428 return -EINVAL;
1429}
1430
1431static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1432 unsigned int irq,
1433 unsigned int nr_irqs,
1434 void *data)
1435{
1436 struct gpio_chip *gc = d->host_data;
1437 irq_hw_number_t hwirq;
1438 unsigned int type = IRQ_TYPE_NONE;
1439 struct irq_fwspec *fwspec = data;
1440 union gpio_irq_fwspec gpio_parent_fwspec = {};
1441 unsigned int parent_hwirq;
1442 unsigned int parent_type;
1443 struct gpio_irq_chip *girq = &gc->irq;
1444 int ret;
1445
1446 /*
1447 * The nr_irqs parameter is always one except for PCI multi-MSI
1448 * so this should not happen.
1449 */
1450 WARN_ON(nr_irqs != 1);
1451
1452 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1453 if (ret)
1454 return ret;
1455
1456 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1457
1458 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1459 &parent_hwirq, &parent_type);
1460 if (ret) {
1461 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1462 return ret;
1463 }
1464 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1465
1466 /*
1467 * We set handle_bad_irq because the .set_type() should
1468 * always be invoked and set the right type of handler.
1469 */
1470 irq_domain_set_info(d,
1471 irq,
1472 hwirq,
1473 gc->irq.chip,
1474 gc,
1475 girq->handler,
1476 NULL, NULL);
1477 irq_set_probe(irq);
1478
1479 /* This parent only handles asserted level IRQs */
1480 ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,
1481 parent_hwirq, parent_type);
1482 if (ret)
1483 return ret;
1484
1485 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1486 irq, parent_hwirq);
1487 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1488 ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);
1489 /*
1490 * If the parent irqdomain is msi, the interrupts have already
1491 * been allocated, so the EEXIST is good.
1492 */
1493 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1494 ret = 0;
1495 if (ret)
1496 chip_err(gc,
1497 "failed to allocate parent hwirq %d for hwirq %lu\n",
1498 parent_hwirq, hwirq);
1499
1500 return ret;
1501}
1502
1503static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1504 unsigned int offset)
1505{
1506 return offset;
1507}
1508
1509/**
1510 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1511 * @domain: The IRQ domain used by this IRQ chip
1512 * @data: Outermost irq_data associated with the IRQ
1513 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1514 *
1515 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1516 * used as the activate function for the &struct irq_domain_ops. The host_data
1517 * for the IRQ domain must be the &struct gpio_chip.
1518 */
1519static int gpiochip_irq_domain_activate(struct irq_domain *domain,
1520 struct irq_data *data, bool reserve)
1521{
1522 struct gpio_chip *gc = domain->host_data;
1523 unsigned int hwirq = irqd_to_hwirq(data);
1524
1525 return gpiochip_lock_as_irq(gc, hwirq);
1526}
1527
1528/**
1529 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1530 * @domain: The IRQ domain used by this IRQ chip
1531 * @data: Outermost irq_data associated with the IRQ
1532 *
1533 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1534 * be used as the deactivate function for the &struct irq_domain_ops. The
1535 * host_data for the IRQ domain must be the &struct gpio_chip.
1536 */
1537static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1538 struct irq_data *data)
1539{
1540 struct gpio_chip *gc = domain->host_data;
1541 unsigned int hwirq = irqd_to_hwirq(data);
1542
1543 return gpiochip_unlock_as_irq(gc, hwirq);
1544}
1545
1546static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1547{
1548 ops->activate = gpiochip_irq_domain_activate;
1549 ops->deactivate = gpiochip_irq_domain_deactivate;
1550 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1551
1552 /*
1553 * We only allow overriding the translate() and free() functions for
1554 * hierarchical chips, and this should only be done if the user
1555 * really need something other than 1:1 translation for translate()
1556 * callback and free if user wants to free up any resources which
1557 * were allocated during callbacks, for example populate_parent_alloc_arg.
1558 */
1559 if (!ops->translate)
1560 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1561 if (!ops->free)
1562 ops->free = irq_domain_free_irqs_common;
1563}
1564
1565static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1566{
1567 struct irq_domain *domain;
1568
1569 if (!gc->irq.child_to_parent_hwirq ||
1570 !gc->irq.fwnode) {
1571 chip_err(gc, "missing irqdomain vital data\n");
1572 return ERR_PTR(-EINVAL);
1573 }
1574
1575 if (!gc->irq.child_offset_to_irq)
1576 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1577
1578 if (!gc->irq.populate_parent_alloc_arg)
1579 gc->irq.populate_parent_alloc_arg =
1580 gpiochip_populate_parent_fwspec_twocell;
1581
1582 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1583
1584 domain = irq_domain_create_hierarchy(
1585 gc->irq.parent_domain,
1586 0,
1587 gc->ngpio,
1588 gc->irq.fwnode,
1589 &gc->irq.child_irq_domain_ops,
1590 gc);
1591
1592 if (!domain)
1593 return ERR_PTR(-ENOMEM);
1594
1595 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1596
1597 return domain;
1598}
1599
1600static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1601{
1602 return !!gc->irq.parent_domain;
1603}
1604
1605int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1606 union gpio_irq_fwspec *gfwspec,
1607 unsigned int parent_hwirq,
1608 unsigned int parent_type)
1609{
1610 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1611
1612 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1613 fwspec->param_count = 2;
1614 fwspec->param[0] = parent_hwirq;
1615 fwspec->param[1] = parent_type;
1616
1617 return 0;
1618}
1619EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1620
1621int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1622 union gpio_irq_fwspec *gfwspec,
1623 unsigned int parent_hwirq,
1624 unsigned int parent_type)
1625{
1626 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1627
1628 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1629 fwspec->param_count = 4;
1630 fwspec->param[0] = 0;
1631 fwspec->param[1] = parent_hwirq;
1632 fwspec->param[2] = 0;
1633 fwspec->param[3] = parent_type;
1634
1635 return 0;
1636}
1637EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1638
1639#else
1640
1641static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1642{
1643 return ERR_PTR(-EINVAL);
1644}
1645
1646static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1647{
1648 return false;
1649}
1650
1651#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1652
1653/**
1654 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1655 * @d: the irqdomain used by this irqchip
1656 * @irq: the global irq number used by this GPIO irqchip irq
1657 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1658 *
1659 * This function will set up the mapping for a certain IRQ line on a
1660 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1661 * stored inside the gpiochip.
1662 */
1663static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1664 irq_hw_number_t hwirq)
1665{
1666 struct gpio_chip *gc = d->host_data;
1667 int ret = 0;
1668
1669 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1670 return -ENXIO;
1671
1672 irq_set_chip_data(irq, gc);
1673 /*
1674 * This lock class tells lockdep that GPIO irqs are in a different
1675 * category than their parents, so it won't report false recursion.
1676 */
1677 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1678 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1679 /* Chips that use nested thread handlers have them marked */
1680 if (gc->irq.threaded)
1681 irq_set_nested_thread(irq, 1);
1682 irq_set_noprobe(irq);
1683
1684 if (gc->irq.num_parents == 1)
1685 ret = irq_set_parent(irq, gc->irq.parents[0]);
1686 else if (gc->irq.map)
1687 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1688
1689 if (ret < 0)
1690 return ret;
1691
1692 /*
1693 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1694 * is passed as default type.
1695 */
1696 if (gc->irq.default_type != IRQ_TYPE_NONE)
1697 irq_set_irq_type(irq, gc->irq.default_type);
1698
1699 return 0;
1700}
1701
1702static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1703{
1704 struct gpio_chip *gc = d->host_data;
1705
1706 if (gc->irq.threaded)
1707 irq_set_nested_thread(irq, 0);
1708 irq_set_chip_and_handler(irq, NULL, NULL);
1709 irq_set_chip_data(irq, NULL);
1710}
1711
1712static const struct irq_domain_ops gpiochip_domain_ops = {
1713 .map = gpiochip_irq_map,
1714 .unmap = gpiochip_irq_unmap,
1715 /* Virtually all GPIO irqchips are twocell:ed */
1716 .xlate = irq_domain_xlate_twocell,
1717};
1718
1719static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
1720{
1721 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1722 struct irq_domain *domain;
1723
1724 domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,
1725 &gpiochip_domain_ops, gc);
1726 if (!domain)
1727 return ERR_PTR(-EINVAL);
1728
1729 return domain;
1730}
1731
1732static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1733{
1734 struct irq_domain *domain = gc->irq.domain;
1735
1736#ifdef CONFIG_GPIOLIB_IRQCHIP
1737 /*
1738 * Avoid race condition with other code, which tries to lookup
1739 * an IRQ before the irqchip has been properly registered,
1740 * i.e. while gpiochip is still being brought up.
1741 */
1742 if (!gc->irq.initialized)
1743 return -EPROBE_DEFER;
1744#endif
1745
1746 if (!gpiochip_irqchip_irq_valid(gc, offset))
1747 return -ENXIO;
1748
1749#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1750 if (irq_domain_is_hierarchy(domain)) {
1751 struct irq_fwspec spec;
1752
1753 spec.fwnode = domain->fwnode;
1754 spec.param_count = 2;
1755 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1756 spec.param[1] = IRQ_TYPE_NONE;
1757
1758 return irq_create_fwspec_mapping(&spec);
1759 }
1760#endif
1761
1762 return irq_create_mapping(domain, offset);
1763}
1764
1765int gpiochip_irq_reqres(struct irq_data *d)
1766{
1767 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1768 unsigned int hwirq = irqd_to_hwirq(d);
1769
1770 return gpiochip_reqres_irq(gc, hwirq);
1771}
1772EXPORT_SYMBOL(gpiochip_irq_reqres);
1773
1774void gpiochip_irq_relres(struct irq_data *d)
1775{
1776 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1777 unsigned int hwirq = irqd_to_hwirq(d);
1778
1779 gpiochip_relres_irq(gc, hwirq);
1780}
1781EXPORT_SYMBOL(gpiochip_irq_relres);
1782
1783static void gpiochip_irq_mask(struct irq_data *d)
1784{
1785 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1786 unsigned int hwirq = irqd_to_hwirq(d);
1787
1788 if (gc->irq.irq_mask)
1789 gc->irq.irq_mask(d);
1790 gpiochip_disable_irq(gc, hwirq);
1791}
1792
1793static void gpiochip_irq_unmask(struct irq_data *d)
1794{
1795 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1796 unsigned int hwirq = irqd_to_hwirq(d);
1797
1798 gpiochip_enable_irq(gc, hwirq);
1799 if (gc->irq.irq_unmask)
1800 gc->irq.irq_unmask(d);
1801}
1802
1803static void gpiochip_irq_enable(struct irq_data *d)
1804{
1805 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1806 unsigned int hwirq = irqd_to_hwirq(d);
1807
1808 gpiochip_enable_irq(gc, hwirq);
1809 gc->irq.irq_enable(d);
1810}
1811
1812static void gpiochip_irq_disable(struct irq_data *d)
1813{
1814 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1815 unsigned int hwirq = irqd_to_hwirq(d);
1816
1817 gc->irq.irq_disable(d);
1818 gpiochip_disable_irq(gc, hwirq);
1819}
1820
1821static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1822{
1823 struct irq_chip *irqchip = gc->irq.chip;
1824
1825 if (irqchip->flags & IRQCHIP_IMMUTABLE)
1826 return;
1827
1828 chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
1829
1830 if (!irqchip->irq_request_resources &&
1831 !irqchip->irq_release_resources) {
1832 irqchip->irq_request_resources = gpiochip_irq_reqres;
1833 irqchip->irq_release_resources = gpiochip_irq_relres;
1834 }
1835 if (WARN_ON(gc->irq.irq_enable))
1836 return;
1837 /* Check if the irqchip already has this hook... */
1838 if (irqchip->irq_enable == gpiochip_irq_enable ||
1839 irqchip->irq_mask == gpiochip_irq_mask) {
1840 /*
1841 * ...and if so, give a gentle warning that this is bad
1842 * practice.
1843 */
1844 chip_info(gc,
1845 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1846 return;
1847 }
1848
1849 if (irqchip->irq_disable) {
1850 gc->irq.irq_disable = irqchip->irq_disable;
1851 irqchip->irq_disable = gpiochip_irq_disable;
1852 } else {
1853 gc->irq.irq_mask = irqchip->irq_mask;
1854 irqchip->irq_mask = gpiochip_irq_mask;
1855 }
1856
1857 if (irqchip->irq_enable) {
1858 gc->irq.irq_enable = irqchip->irq_enable;
1859 irqchip->irq_enable = gpiochip_irq_enable;
1860 } else {
1861 gc->irq.irq_unmask = irqchip->irq_unmask;
1862 irqchip->irq_unmask = gpiochip_irq_unmask;
1863 }
1864}
1865
1866static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
1867 struct irq_domain *domain,
1868 bool allocated_externally)
1869{
1870 if (!domain)
1871 return -EINVAL;
1872
1873 if (gc->to_irq)
1874 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1875
1876 gc->to_irq = gpiochip_to_irq;
1877 gc->irq.domain = domain;
1878 gc->irq.domain_is_allocated_externally = allocated_externally;
1879
1880 /*
1881 * Using barrier() here to prevent compiler from reordering
1882 * gc->irq.initialized before adding irqdomain.
1883 */
1884 barrier();
1885
1886 gc->irq.initialized = true;
1887
1888 return 0;
1889}
1890
1891/**
1892 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1893 * @gc: the GPIO chip to add the IRQ chip to
1894 * @lock_key: lockdep class for IRQ lock
1895 * @request_key: lockdep class for IRQ request
1896 */
1897static int gpiochip_add_irqchip(struct gpio_chip *gc,
1898 struct lock_class_key *lock_key,
1899 struct lock_class_key *request_key)
1900{
1901 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1902 struct irq_chip *irqchip = gc->irq.chip;
1903 struct irq_domain *domain;
1904 unsigned int type;
1905 unsigned int i;
1906 int ret;
1907
1908 if (!irqchip)
1909 return 0;
1910
1911 if (gc->irq.parent_handler && gc->can_sleep) {
1912 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1913 return -EINVAL;
1914 }
1915
1916 type = gc->irq.default_type;
1917
1918 /*
1919 * Specifying a default trigger is a terrible idea if DT or ACPI is
1920 * used to configure the interrupts, as you may end up with
1921 * conflicting triggers. Tell the user, and reset to NONE.
1922 */
1923 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1924 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1925 type = IRQ_TYPE_NONE;
1926
1927 gc->irq.default_type = type;
1928 gc->irq.lock_key = lock_key;
1929 gc->irq.request_key = request_key;
1930
1931 /* If a parent irqdomain is provided, let's build a hierarchy */
1932 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1933 domain = gpiochip_hierarchy_create_domain(gc);
1934 } else {
1935 domain = gpiochip_simple_create_domain(gc);
1936 }
1937 if (IS_ERR(domain))
1938 return PTR_ERR(domain);
1939
1940 if (gc->irq.parent_handler) {
1941 for (i = 0; i < gc->irq.num_parents; i++) {
1942 void *data;
1943
1944 if (gc->irq.per_parent_data)
1945 data = gc->irq.parent_handler_data_array[i];
1946 else
1947 data = gc->irq.parent_handler_data ?: gc;
1948
1949 /*
1950 * The parent IRQ chip is already using the chip_data
1951 * for this IRQ chip, so our callbacks simply use the
1952 * handler_data.
1953 */
1954 irq_set_chained_handler_and_data(gc->irq.parents[i],
1955 gc->irq.parent_handler,
1956 data);
1957 }
1958 }
1959
1960 gpiochip_set_irq_hooks(gc);
1961
1962 ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);
1963 if (ret)
1964 return ret;
1965
1966 acpi_gpiochip_request_interrupts(gc);
1967
1968 return 0;
1969}
1970
1971/**
1972 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1973 * @gc: the gpiochip to remove the irqchip from
1974 *
1975 * This is called only from gpiochip_remove()
1976 */
1977static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1978{
1979 struct irq_chip *irqchip = gc->irq.chip;
1980 unsigned int offset;
1981
1982 acpi_gpiochip_free_interrupts(gc);
1983
1984 if (irqchip && gc->irq.parent_handler) {
1985 struct gpio_irq_chip *irq = &gc->irq;
1986 unsigned int i;
1987
1988 for (i = 0; i < irq->num_parents; i++)
1989 irq_set_chained_handler_and_data(irq->parents[i],
1990 NULL, NULL);
1991 }
1992
1993 /* Remove all IRQ mappings and delete the domain */
1994 if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
1995 unsigned int irq;
1996
1997 for (offset = 0; offset < gc->ngpio; offset++) {
1998 if (!gpiochip_irqchip_irq_valid(gc, offset))
1999 continue;
2000
2001 irq = irq_find_mapping(gc->irq.domain, offset);
2002 irq_dispose_mapping(irq);
2003 }
2004
2005 irq_domain_remove(gc->irq.domain);
2006 }
2007
2008 if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
2009 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2010 irqchip->irq_request_resources = NULL;
2011 irqchip->irq_release_resources = NULL;
2012 }
2013 if (irqchip->irq_enable == gpiochip_irq_enable) {
2014 irqchip->irq_enable = gc->irq.irq_enable;
2015 irqchip->irq_disable = gc->irq.irq_disable;
2016 }
2017 }
2018 gc->irq.irq_enable = NULL;
2019 gc->irq.irq_disable = NULL;
2020 gc->irq.chip = NULL;
2021
2022 gpiochip_irqchip_free_valid_mask(gc);
2023}
2024
2025/**
2026 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
2027 * @gc: the gpiochip to add the irqchip to
2028 * @domain: the irqdomain to add to the gpiochip
2029 *
2030 * This function adds an IRQ domain to the gpiochip.
2031 */
2032int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
2033 struct irq_domain *domain)
2034{
2035 return gpiochip_irqchip_add_allocated_domain(gc, domain, true);
2036}
2037EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
2038
2039#else /* CONFIG_GPIOLIB_IRQCHIP */
2040
2041static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
2042 struct lock_class_key *lock_key,
2043 struct lock_class_key *request_key)
2044{
2045 return 0;
2046}
2047static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
2048
2049static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
2050{
2051 return 0;
2052}
2053
2054static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
2055{
2056 return 0;
2057}
2058static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
2059{ }
2060
2061#endif /* CONFIG_GPIOLIB_IRQCHIP */
2062
2063/**
2064 * gpiochip_generic_request() - request the gpio function for a pin
2065 * @gc: the gpiochip owning the GPIO
2066 * @offset: the offset of the GPIO to request for GPIO function
2067 */
2068int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
2069{
2070#ifdef CONFIG_PINCTRL
2071 if (list_empty(&gc->gpiodev->pin_ranges))
2072 return 0;
2073#endif
2074
2075 return pinctrl_gpio_request(gc, offset);
2076}
2077EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2078
2079/**
2080 * gpiochip_generic_free() - free the gpio function from a pin
2081 * @gc: the gpiochip to request the gpio function for
2082 * @offset: the offset of the GPIO to free from GPIO function
2083 */
2084void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
2085{
2086#ifdef CONFIG_PINCTRL
2087 if (list_empty(&gc->gpiodev->pin_ranges))
2088 return;
2089#endif
2090
2091 pinctrl_gpio_free(gc, offset);
2092}
2093EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2094
2095/**
2096 * gpiochip_generic_config() - apply configuration for a pin
2097 * @gc: the gpiochip owning the GPIO
2098 * @offset: the offset of the GPIO to apply the configuration
2099 * @config: the configuration to be applied
2100 */
2101int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
2102 unsigned long config)
2103{
2104#ifdef CONFIG_PINCTRL
2105 if (list_empty(&gc->gpiodev->pin_ranges))
2106 return -ENOTSUPP;
2107#endif
2108
2109 return pinctrl_gpio_set_config(gc, offset, config);
2110}
2111EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2112
2113#ifdef CONFIG_PINCTRL
2114
2115/**
2116 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2117 * @gc: the gpiochip to add the range for
2118 * @pctldev: the pin controller to map to
2119 * @gpio_offset: the start offset in the current gpio_chip number space
2120 * @pin_group: name of the pin group inside the pin controller
2121 *
2122 * Calling this function directly from a DeviceTree-supported
2123 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2124 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2125 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2126 */
2127int gpiochip_add_pingroup_range(struct gpio_chip *gc,
2128 struct pinctrl_dev *pctldev,
2129 unsigned int gpio_offset, const char *pin_group)
2130{
2131 struct gpio_pin_range *pin_range;
2132 struct gpio_device *gdev = gc->gpiodev;
2133 int ret;
2134
2135 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2136 if (!pin_range) {
2137 chip_err(gc, "failed to allocate pin ranges\n");
2138 return -ENOMEM;
2139 }
2140
2141 /* Use local offset as range ID */
2142 pin_range->range.id = gpio_offset;
2143 pin_range->range.gc = gc;
2144 pin_range->range.name = gc->label;
2145 pin_range->range.base = gdev->base + gpio_offset;
2146 pin_range->pctldev = pctldev;
2147
2148 ret = pinctrl_get_group_pins(pctldev, pin_group,
2149 &pin_range->range.pins,
2150 &pin_range->range.npins);
2151 if (ret < 0) {
2152 kfree(pin_range);
2153 return ret;
2154 }
2155
2156 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2157
2158 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2159 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2160 pinctrl_dev_get_devname(pctldev), pin_group);
2161
2162 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2163
2164 return 0;
2165}
2166EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2167
2168/**
2169 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2170 * @gc: the gpiochip to add the range for
2171 * @pinctl_name: the dev_name() of the pin controller to map to
2172 * @gpio_offset: the start offset in the current gpio_chip number space
2173 * @pin_offset: the start offset in the pin controller number space
2174 * @npins: the number of pins from the offset of each pin space (GPIO and
2175 * pin controller) to accumulate in this range
2176 *
2177 * Returns:
2178 * 0 on success, or a negative error-code on failure.
2179 *
2180 * Calling this function directly from a DeviceTree-supported
2181 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2182 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2183 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2184 */
2185int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
2186 unsigned int gpio_offset, unsigned int pin_offset,
2187 unsigned int npins)
2188{
2189 struct gpio_pin_range *pin_range;
2190 struct gpio_device *gdev = gc->gpiodev;
2191 int ret;
2192
2193 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2194 if (!pin_range) {
2195 chip_err(gc, "failed to allocate pin ranges\n");
2196 return -ENOMEM;
2197 }
2198
2199 /* Use local offset as range ID */
2200 pin_range->range.id = gpio_offset;
2201 pin_range->range.gc = gc;
2202 pin_range->range.name = gc->label;
2203 pin_range->range.base = gdev->base + gpio_offset;
2204 pin_range->range.pin_base = pin_offset;
2205 pin_range->range.npins = npins;
2206 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2207 &pin_range->range);
2208 if (IS_ERR(pin_range->pctldev)) {
2209 ret = PTR_ERR(pin_range->pctldev);
2210 chip_err(gc, "could not create pin range\n");
2211 kfree(pin_range);
2212 return ret;
2213 }
2214 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2215 gpio_offset, gpio_offset + npins - 1,
2216 pinctl_name,
2217 pin_offset, pin_offset + npins - 1);
2218
2219 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2220
2221 return 0;
2222}
2223EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2224
2225/**
2226 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2227 * @gc: the chip to remove all the mappings for
2228 */
2229void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
2230{
2231 struct gpio_pin_range *pin_range, *tmp;
2232 struct gpio_device *gdev = gc->gpiodev;
2233
2234 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2235 list_del(&pin_range->node);
2236 pinctrl_remove_gpio_range(pin_range->pctldev,
2237 &pin_range->range);
2238 kfree(pin_range);
2239 }
2240}
2241EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2242
2243#endif /* CONFIG_PINCTRL */
2244
2245/* These "optional" allocation calls help prevent drivers from stomping
2246 * on each other, and help provide better diagnostics in debugfs.
2247 * They're called even less than the "set direction" calls.
2248 */
2249static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2250{
2251 unsigned int offset;
2252 int ret;
2253
2254 CLASS(gpio_chip_guard, guard)(desc);
2255 if (!guard.gc)
2256 return -ENODEV;
2257
2258 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
2259 return -EBUSY;
2260
2261 /* NOTE: gpio_request() can be called in early boot,
2262 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2263 */
2264
2265 if (guard.gc->request) {
2266 offset = gpio_chip_hwgpio(desc);
2267 if (gpiochip_line_is_valid(guard.gc, offset))
2268 ret = guard.gc->request(guard.gc, offset);
2269 else
2270 ret = -EINVAL;
2271 if (ret)
2272 goto out_clear_bit;
2273 }
2274
2275 if (guard.gc->get_direction)
2276 gpiod_get_direction(desc);
2277
2278 ret = desc_set_label(desc, label ? : "?");
2279 if (ret)
2280 goto out_clear_bit;
2281
2282 return 0;
2283
2284out_clear_bit:
2285 clear_bit(FLAG_REQUESTED, &desc->flags);
2286 return ret;
2287}
2288
2289/*
2290 * This descriptor validation needs to be inserted verbatim into each
2291 * function taking a descriptor, so we need to use a preprocessor
2292 * macro to avoid endless duplication. If the desc is NULL it is an
2293 * optional GPIO and calls should just bail out.
2294 */
2295static int validate_desc(const struct gpio_desc *desc, const char *func)
2296{
2297 if (!desc)
2298 return 0;
2299
2300 if (IS_ERR(desc)) {
2301 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2302 return PTR_ERR(desc);
2303 }
2304
2305 return 1;
2306}
2307
2308#define VALIDATE_DESC(desc) do { \
2309 int __valid = validate_desc(desc, __func__); \
2310 if (__valid <= 0) \
2311 return __valid; \
2312 } while (0)
2313
2314#define VALIDATE_DESC_VOID(desc) do { \
2315 int __valid = validate_desc(desc, __func__); \
2316 if (__valid <= 0) \
2317 return; \
2318 } while (0)
2319
2320int gpiod_request(struct gpio_desc *desc, const char *label)
2321{
2322 int ret = -EPROBE_DEFER;
2323
2324 VALIDATE_DESC(desc);
2325
2326 if (try_module_get(desc->gdev->owner)) {
2327 ret = gpiod_request_commit(desc, label);
2328 if (ret)
2329 module_put(desc->gdev->owner);
2330 else
2331 gpio_device_get(desc->gdev);
2332 }
2333
2334 if (ret)
2335 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2336
2337 return ret;
2338}
2339
2340static void gpiod_free_commit(struct gpio_desc *desc)
2341{
2342 unsigned long flags;
2343
2344 might_sleep();
2345
2346 CLASS(gpio_chip_guard, guard)(desc);
2347
2348 flags = READ_ONCE(desc->flags);
2349
2350 if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {
2351 if (guard.gc->free)
2352 guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));
2353
2354 clear_bit(FLAG_ACTIVE_LOW, &flags);
2355 clear_bit(FLAG_REQUESTED, &flags);
2356 clear_bit(FLAG_OPEN_DRAIN, &flags);
2357 clear_bit(FLAG_OPEN_SOURCE, &flags);
2358 clear_bit(FLAG_PULL_UP, &flags);
2359 clear_bit(FLAG_PULL_DOWN, &flags);
2360 clear_bit(FLAG_BIAS_DISABLE, &flags);
2361 clear_bit(FLAG_EDGE_RISING, &flags);
2362 clear_bit(FLAG_EDGE_FALLING, &flags);
2363 clear_bit(FLAG_IS_HOGGED, &flags);
2364#ifdef CONFIG_OF_DYNAMIC
2365 WRITE_ONCE(desc->hog, NULL);
2366#endif
2367 desc_set_label(desc, NULL);
2368 WRITE_ONCE(desc->flags, flags);
2369
2370 gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED);
2371 }
2372}
2373
2374void gpiod_free(struct gpio_desc *desc)
2375{
2376 VALIDATE_DESC_VOID(desc);
2377
2378 gpiod_free_commit(desc);
2379 module_put(desc->gdev->owner);
2380 gpio_device_put(desc->gdev);
2381}
2382
2383/**
2384 * gpiochip_dup_line_label - Get a copy of the consumer label.
2385 * @gc: GPIO chip controlling this line.
2386 * @offset: Hardware offset of the line.
2387 *
2388 * Returns:
2389 * Pointer to a copy of the consumer label if the line is requested or NULL
2390 * if it's not. If a valid pointer was returned, it must be freed using
2391 * kfree(). In case of a memory allocation error, the function returns %ENOMEM.
2392 *
2393 * Must not be called from atomic context.
2394 */
2395char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
2396{
2397 struct gpio_desc *desc;
2398 char *label;
2399
2400 desc = gpiochip_get_desc(gc, offset);
2401 if (IS_ERR(desc))
2402 return NULL;
2403
2404 if (!test_bit(FLAG_REQUESTED, &desc->flags))
2405 return NULL;
2406
2407 guard(srcu)(&desc->gdev->desc_srcu);
2408
2409 label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);
2410 if (!label)
2411 return ERR_PTR(-ENOMEM);
2412
2413 return label;
2414}
2415EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
2416
2417static inline const char *function_name_or_default(const char *con_id)
2418{
2419 return con_id ?: "(default)";
2420}
2421
2422/**
2423 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2424 * @gc: GPIO chip
2425 * @hwnum: hardware number of the GPIO for which to request the descriptor
2426 * @label: label for the GPIO
2427 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2428 * specify things like line inversion semantics with the machine flags
2429 * such as GPIO_OUT_LOW
2430 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2431 * can be used to specify consumer semantics such as open drain
2432 *
2433 * Function allows GPIO chip drivers to request and use their own GPIO
2434 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2435 * function will not increase reference count of the GPIO chip module. This
2436 * allows the GPIO chip module to be unloaded as needed (we assume that the
2437 * GPIO chip driver handles freeing the GPIOs it has requested).
2438 *
2439 * Returns:
2440 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2441 * code on failure.
2442 */
2443struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2444 unsigned int hwnum,
2445 const char *label,
2446 enum gpio_lookup_flags lflags,
2447 enum gpiod_flags dflags)
2448{
2449 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2450 const char *name = function_name_or_default(label);
2451 int ret;
2452
2453 if (IS_ERR(desc)) {
2454 chip_err(gc, "failed to get GPIO %s descriptor\n", name);
2455 return desc;
2456 }
2457
2458 ret = gpiod_request_commit(desc, label);
2459 if (ret < 0)
2460 return ERR_PTR(ret);
2461
2462 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2463 if (ret) {
2464 gpiod_free_commit(desc);
2465 chip_err(gc, "setup of own GPIO %s failed\n", name);
2466 return ERR_PTR(ret);
2467 }
2468
2469 return desc;
2470}
2471EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2472
2473/**
2474 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2475 * @desc: GPIO descriptor to free
2476 *
2477 * Function frees the given GPIO requested previously with
2478 * gpiochip_request_own_desc().
2479 */
2480void gpiochip_free_own_desc(struct gpio_desc *desc)
2481{
2482 if (desc)
2483 gpiod_free_commit(desc);
2484}
2485EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2486
2487/*
2488 * Drivers MUST set GPIO direction before making get/set calls. In
2489 * some cases this is done in early boot, before IRQs are enabled.
2490 *
2491 * As a rule these aren't called more than once (except for drivers
2492 * using the open-drain emulation idiom) so these are natural places
2493 * to accumulate extra debugging checks. Note that we can't (yet)
2494 * rely on gpio_request() having been called beforehand.
2495 */
2496
2497static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2498 unsigned long config)
2499{
2500 if (!gc->set_config)
2501 return -ENOTSUPP;
2502
2503 return gc->set_config(gc, offset, config);
2504}
2505
2506static int gpio_set_config_with_argument(struct gpio_desc *desc,
2507 enum pin_config_param mode,
2508 u32 argument)
2509{
2510 unsigned long config;
2511
2512 CLASS(gpio_chip_guard, guard)(desc);
2513 if (!guard.gc)
2514 return -ENODEV;
2515
2516 config = pinconf_to_config_packed(mode, argument);
2517 return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2518}
2519
2520static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2521 enum pin_config_param mode,
2522 u32 argument)
2523{
2524 struct device *dev = &desc->gdev->dev;
2525 int gpio = gpio_chip_hwgpio(desc);
2526 int ret;
2527
2528 ret = gpio_set_config_with_argument(desc, mode, argument);
2529 if (ret != -ENOTSUPP)
2530 return ret;
2531
2532 switch (mode) {
2533 case PIN_CONFIG_PERSIST_STATE:
2534 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2535 break;
2536 default:
2537 break;
2538 }
2539
2540 return 0;
2541}
2542
2543static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2544{
2545 return gpio_set_config_with_argument(desc, mode, 0);
2546}
2547
2548static int gpio_set_bias(struct gpio_desc *desc)
2549{
2550 enum pin_config_param bias;
2551 unsigned long flags;
2552 unsigned int arg;
2553
2554 flags = READ_ONCE(desc->flags);
2555
2556 if (test_bit(FLAG_BIAS_DISABLE, &flags))
2557 bias = PIN_CONFIG_BIAS_DISABLE;
2558 else if (test_bit(FLAG_PULL_UP, &flags))
2559 bias = PIN_CONFIG_BIAS_PULL_UP;
2560 else if (test_bit(FLAG_PULL_DOWN, &flags))
2561 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2562 else
2563 return 0;
2564
2565 switch (bias) {
2566 case PIN_CONFIG_BIAS_PULL_DOWN:
2567 case PIN_CONFIG_BIAS_PULL_UP:
2568 arg = 1;
2569 break;
2570
2571 default:
2572 arg = 0;
2573 break;
2574 }
2575
2576 return gpio_set_config_with_argument_optional(desc, bias, arg);
2577}
2578
2579/**
2580 * gpio_set_debounce_timeout() - Set debounce timeout
2581 * @desc: GPIO descriptor to set the debounce timeout
2582 * @debounce: Debounce timeout in microseconds
2583 *
2584 * The function calls the certain GPIO driver to set debounce timeout
2585 * in the hardware.
2586 *
2587 * Returns 0 on success, or negative error code otherwise.
2588 */
2589int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2590{
2591 return gpio_set_config_with_argument_optional(desc,
2592 PIN_CONFIG_INPUT_DEBOUNCE,
2593 debounce);
2594}
2595
2596/**
2597 * gpiod_direction_input - set the GPIO direction to input
2598 * @desc: GPIO to set to input
2599 *
2600 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2601 * be called safely on it.
2602 *
2603 * Return 0 in case of success, else an error code.
2604 */
2605int gpiod_direction_input(struct gpio_desc *desc)
2606{
2607 int ret = 0;
2608
2609 VALIDATE_DESC(desc);
2610
2611 CLASS(gpio_chip_guard, guard)(desc);
2612 if (!guard.gc)
2613 return -ENODEV;
2614
2615 /*
2616 * It is legal to have no .get() and .direction_input() specified if
2617 * the chip is output-only, but you can't specify .direction_input()
2618 * and not support the .get() operation, that doesn't make sense.
2619 */
2620 if (!guard.gc->get && guard.gc->direction_input) {
2621 gpiod_warn(desc,
2622 "%s: missing get() but have direction_input()\n",
2623 __func__);
2624 return -EIO;
2625 }
2626
2627 /*
2628 * If we have a .direction_input() callback, things are simple,
2629 * just call it. Else we are some input-only chip so try to check the
2630 * direction (if .get_direction() is supported) else we silently
2631 * assume we are in input mode after this.
2632 */
2633 if (guard.gc->direction_input) {
2634 ret = guard.gc->direction_input(guard.gc,
2635 gpio_chip_hwgpio(desc));
2636 } else if (guard.gc->get_direction &&
2637 (guard.gc->get_direction(guard.gc,
2638 gpio_chip_hwgpio(desc)) != 1)) {
2639 gpiod_warn(desc,
2640 "%s: missing direction_input() operation and line is output\n",
2641 __func__);
2642 return -EIO;
2643 }
2644 if (ret == 0) {
2645 clear_bit(FLAG_IS_OUT, &desc->flags);
2646 ret = gpio_set_bias(desc);
2647 }
2648
2649 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2650
2651 return ret;
2652}
2653EXPORT_SYMBOL_GPL(gpiod_direction_input);
2654
2655static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2656{
2657 int val = !!value, ret = 0;
2658
2659 CLASS(gpio_chip_guard, guard)(desc);
2660 if (!guard.gc)
2661 return -ENODEV;
2662
2663 /*
2664 * It's OK not to specify .direction_output() if the gpiochip is
2665 * output-only, but if there is then not even a .set() operation it
2666 * is pretty tricky to drive the output line.
2667 */
2668 if (!guard.gc->set && !guard.gc->direction_output) {
2669 gpiod_warn(desc,
2670 "%s: missing set() and direction_output() operations\n",
2671 __func__);
2672 return -EIO;
2673 }
2674
2675 if (guard.gc->direction_output) {
2676 ret = guard.gc->direction_output(guard.gc,
2677 gpio_chip_hwgpio(desc), val);
2678 } else {
2679 /* Check that we are in output mode if we can */
2680 if (guard.gc->get_direction &&
2681 guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) {
2682 gpiod_warn(desc,
2683 "%s: missing direction_output() operation\n",
2684 __func__);
2685 return -EIO;
2686 }
2687 /*
2688 * If we can't actively set the direction, we are some
2689 * output-only chip, so just drive the output as desired.
2690 */
2691 guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), val);
2692 }
2693
2694 if (!ret)
2695 set_bit(FLAG_IS_OUT, &desc->flags);
2696 trace_gpio_value(desc_to_gpio(desc), 0, val);
2697 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2698 return ret;
2699}
2700
2701/**
2702 * gpiod_direction_output_raw - set the GPIO direction to output
2703 * @desc: GPIO to set to output
2704 * @value: initial output value of the GPIO
2705 *
2706 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2707 * be called safely on it. The initial value of the output must be specified
2708 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2709 *
2710 * Return 0 in case of success, else an error code.
2711 */
2712int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2713{
2714 VALIDATE_DESC(desc);
2715 return gpiod_direction_output_raw_commit(desc, value);
2716}
2717EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2718
2719/**
2720 * gpiod_direction_output - set the GPIO direction to output
2721 * @desc: GPIO to set to output
2722 * @value: initial output value of the GPIO
2723 *
2724 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2725 * be called safely on it. The initial value of the output must be specified
2726 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2727 * account.
2728 *
2729 * Return 0 in case of success, else an error code.
2730 */
2731int gpiod_direction_output(struct gpio_desc *desc, int value)
2732{
2733 unsigned long flags;
2734 int ret;
2735
2736 VALIDATE_DESC(desc);
2737
2738 flags = READ_ONCE(desc->flags);
2739
2740 if (test_bit(FLAG_ACTIVE_LOW, &flags))
2741 value = !value;
2742 else
2743 value = !!value;
2744
2745 /* GPIOs used for enabled IRQs shall not be set as output */
2746 if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
2747 test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {
2748 gpiod_err(desc,
2749 "%s: tried to set a GPIO tied to an IRQ as output\n",
2750 __func__);
2751 return -EIO;
2752 }
2753
2754 if (test_bit(FLAG_OPEN_DRAIN, &flags)) {
2755 /* First see if we can enable open drain in hardware */
2756 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2757 if (!ret)
2758 goto set_output_value;
2759 /* Emulate open drain by not actively driving the line high */
2760 if (value) {
2761 ret = gpiod_direction_input(desc);
2762 goto set_output_flag;
2763 }
2764 } else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {
2765 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2766 if (!ret)
2767 goto set_output_value;
2768 /* Emulate open source by not actively driving the line low */
2769 if (!value) {
2770 ret = gpiod_direction_input(desc);
2771 goto set_output_flag;
2772 }
2773 } else {
2774 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2775 }
2776
2777set_output_value:
2778 ret = gpio_set_bias(desc);
2779 if (ret)
2780 return ret;
2781 return gpiod_direction_output_raw_commit(desc, value);
2782
2783set_output_flag:
2784 /*
2785 * When emulating open-source or open-drain functionalities by not
2786 * actively driving the line (setting mode to input) we still need to
2787 * set the IS_OUT flag or otherwise we won't be able to set the line
2788 * value anymore.
2789 */
2790 if (ret == 0)
2791 set_bit(FLAG_IS_OUT, &desc->flags);
2792 return ret;
2793}
2794EXPORT_SYMBOL_GPL(gpiod_direction_output);
2795
2796/**
2797 * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
2798 *
2799 * @desc: GPIO to enable.
2800 * @flags: Flags related to GPIO edge.
2801 *
2802 * Return 0 in case of success, else negative error code.
2803 */
2804int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
2805{
2806 int ret = 0;
2807
2808 VALIDATE_DESC(desc);
2809
2810 CLASS(gpio_chip_guard, guard)(desc);
2811 if (!guard.gc)
2812 return -ENODEV;
2813
2814 if (!guard.gc->en_hw_timestamp) {
2815 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
2816 return -ENOTSUPP;
2817 }
2818
2819 ret = guard.gc->en_hw_timestamp(guard.gc,
2820 gpio_chip_hwgpio(desc), flags);
2821 if (ret)
2822 gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
2823
2824 return ret;
2825}
2826EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
2827
2828/**
2829 * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
2830 *
2831 * @desc: GPIO to disable.
2832 * @flags: Flags related to GPIO edge, same value as used during enable call.
2833 *
2834 * Return 0 in case of success, else negative error code.
2835 */
2836int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
2837{
2838 int ret = 0;
2839
2840 VALIDATE_DESC(desc);
2841
2842 CLASS(gpio_chip_guard, guard)(desc);
2843 if (!guard.gc)
2844 return -ENODEV;
2845
2846 if (!guard.gc->dis_hw_timestamp) {
2847 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
2848 return -ENOTSUPP;
2849 }
2850
2851 ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),
2852 flags);
2853 if (ret)
2854 gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
2855
2856 return ret;
2857}
2858EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
2859
2860/**
2861 * gpiod_set_config - sets @config for a GPIO
2862 * @desc: descriptor of the GPIO for which to set the configuration
2863 * @config: Same packed config format as generic pinconf
2864 *
2865 * Returns:
2866 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2867 * configuration.
2868 */
2869int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2870{
2871 VALIDATE_DESC(desc);
2872
2873 CLASS(gpio_chip_guard, guard)(desc);
2874 if (!guard.gc)
2875 return -ENODEV;
2876
2877 return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2878}
2879EXPORT_SYMBOL_GPL(gpiod_set_config);
2880
2881/**
2882 * gpiod_set_debounce - sets @debounce time for a GPIO
2883 * @desc: descriptor of the GPIO for which to set debounce time
2884 * @debounce: debounce time in microseconds
2885 *
2886 * Returns:
2887 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2888 * debounce time.
2889 */
2890int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2891{
2892 unsigned long config;
2893
2894 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2895 return gpiod_set_config(desc, config);
2896}
2897EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2898
2899/**
2900 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2901 * @desc: descriptor of the GPIO for which to configure persistence
2902 * @transitory: True to lose state on suspend or reset, false for persistence
2903 *
2904 * Returns:
2905 * 0 on success, otherwise a negative error code.
2906 */
2907int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2908{
2909 VALIDATE_DESC(desc);
2910 /*
2911 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2912 * persistence state.
2913 */
2914 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2915
2916 /* If the driver supports it, set the persistence state now */
2917 return gpio_set_config_with_argument_optional(desc,
2918 PIN_CONFIG_PERSIST_STATE,
2919 !transitory);
2920}
2921
2922/**
2923 * gpiod_is_active_low - test whether a GPIO is active-low or not
2924 * @desc: the gpio descriptor to test
2925 *
2926 * Returns 1 if the GPIO is active-low, 0 otherwise.
2927 */
2928int gpiod_is_active_low(const struct gpio_desc *desc)
2929{
2930 VALIDATE_DESC(desc);
2931 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2932}
2933EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2934
2935/**
2936 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2937 * @desc: the gpio descriptor to change
2938 */
2939void gpiod_toggle_active_low(struct gpio_desc *desc)
2940{
2941 VALIDATE_DESC_VOID(desc);
2942 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2943}
2944EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2945
2946static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)
2947{
2948 return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO;
2949}
2950
2951/* I/O calls are only valid after configuration completed; the relevant
2952 * "is this a valid GPIO" error checks should already have been done.
2953 *
2954 * "Get" operations are often inlinable as reading a pin value register,
2955 * and masking the relevant bit in that register.
2956 *
2957 * When "set" operations are inlinable, they involve writing that mask to
2958 * one register to set a low value, or a different register to set it high.
2959 * Otherwise locking is needed, so there may be little value to inlining.
2960 *
2961 *------------------------------------------------------------------------
2962 *
2963 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2964 * have requested the GPIO. That can include implicit requesting by
2965 * a direction setting call. Marking a gpio as requested locks its chip
2966 * in memory, guaranteeing that these table lookups need no more locking
2967 * and that gpiochip_remove() will fail.
2968 *
2969 * REVISIT when debugging, consider adding some instrumentation to ensure
2970 * that the GPIO was actually requested.
2971 */
2972
2973static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2974{
2975 struct gpio_device *gdev;
2976 struct gpio_chip *gc;
2977 int value;
2978
2979 /* FIXME Unable to use gpio_chip_guard due to const desc. */
2980 gdev = desc->gdev;
2981
2982 guard(srcu)(&gdev->srcu);
2983
2984 gc = srcu_dereference(gdev->chip, &gdev->srcu);
2985 if (!gc)
2986 return -ENODEV;
2987
2988 value = gpio_chip_get_value(gc, desc);
2989 value = value < 0 ? value : !!value;
2990 trace_gpio_value(desc_to_gpio(desc), 1, value);
2991 return value;
2992}
2993
2994static int gpio_chip_get_multiple(struct gpio_chip *gc,
2995 unsigned long *mask, unsigned long *bits)
2996{
2997 if (gc->get_multiple)
2998 return gc->get_multiple(gc, mask, bits);
2999 if (gc->get) {
3000 int i, value;
3001
3002 for_each_set_bit(i, mask, gc->ngpio) {
3003 value = gc->get(gc, i);
3004 if (value < 0)
3005 return value;
3006 __assign_bit(i, bits, value);
3007 }
3008 return 0;
3009 }
3010 return -EIO;
3011}
3012
3013/* The 'other' chip must be protected with its GPIO device's SRCU. */
3014static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
3015{
3016 guard(srcu)(&gdev->srcu);
3017
3018 return gc == srcu_dereference(gdev->chip, &gdev->srcu);
3019}
3020
3021int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3022 unsigned int array_size,
3023 struct gpio_desc **desc_array,
3024 struct gpio_array *array_info,
3025 unsigned long *value_bitmap)
3026{
3027 int ret, i = 0;
3028
3029 /*
3030 * Validate array_info against desc_array and its size.
3031 * It should immediately follow desc_array if both
3032 * have been obtained from the same gpiod_get_array() call.
3033 */
3034 if (array_info && array_info->desc == desc_array &&
3035 array_size <= array_info->size &&
3036 (void *)array_info == desc_array + array_info->size) {
3037 if (!can_sleep)
3038 WARN_ON(array_info->chip->can_sleep);
3039
3040 ret = gpio_chip_get_multiple(array_info->chip,
3041 array_info->get_mask,
3042 value_bitmap);
3043 if (ret)
3044 return ret;
3045
3046 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3047 bitmap_xor(value_bitmap, value_bitmap,
3048 array_info->invert_mask, array_size);
3049
3050 i = find_first_zero_bit(array_info->get_mask, array_size);
3051 if (i == array_size)
3052 return 0;
3053 } else {
3054 array_info = NULL;
3055 }
3056
3057 while (i < array_size) {
3058 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3059 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3060 unsigned long *mask, *bits;
3061 int first, j;
3062
3063 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3064 if (!guard.gc)
3065 return -ENODEV;
3066
3067 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3068 mask = fastpath_mask;
3069 bits = fastpath_bits;
3070 } else {
3071 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3072
3073 mask = bitmap_alloc(guard.gc->ngpio, flags);
3074 if (!mask)
3075 return -ENOMEM;
3076
3077 bits = bitmap_alloc(guard.gc->ngpio, flags);
3078 if (!bits) {
3079 bitmap_free(mask);
3080 return -ENOMEM;
3081 }
3082 }
3083
3084 bitmap_zero(mask, guard.gc->ngpio);
3085
3086 if (!can_sleep)
3087 WARN_ON(guard.gc->can_sleep);
3088
3089 /* collect all inputs belonging to the same chip */
3090 first = i;
3091 do {
3092 const struct gpio_desc *desc = desc_array[i];
3093 int hwgpio = gpio_chip_hwgpio(desc);
3094
3095 __set_bit(hwgpio, mask);
3096 i++;
3097
3098 if (array_info)
3099 i = find_next_zero_bit(array_info->get_mask,
3100 array_size, i);
3101 } while ((i < array_size) &&
3102 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3103
3104 ret = gpio_chip_get_multiple(guard.gc, mask, bits);
3105 if (ret) {
3106 if (mask != fastpath_mask)
3107 bitmap_free(mask);
3108 if (bits != fastpath_bits)
3109 bitmap_free(bits);
3110 return ret;
3111 }
3112
3113 for (j = first; j < i; ) {
3114 const struct gpio_desc *desc = desc_array[j];
3115 int hwgpio = gpio_chip_hwgpio(desc);
3116 int value = test_bit(hwgpio, bits);
3117
3118 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3119 value = !value;
3120 __assign_bit(j, value_bitmap, value);
3121 trace_gpio_value(desc_to_gpio(desc), 1, value);
3122 j++;
3123
3124 if (array_info)
3125 j = find_next_zero_bit(array_info->get_mask, i,
3126 j);
3127 }
3128
3129 if (mask != fastpath_mask)
3130 bitmap_free(mask);
3131 if (bits != fastpath_bits)
3132 bitmap_free(bits);
3133 }
3134 return 0;
3135}
3136
3137/**
3138 * gpiod_get_raw_value() - return a gpio's raw value
3139 * @desc: gpio whose value will be returned
3140 *
3141 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3142 * its ACTIVE_LOW status, or negative errno on failure.
3143 *
3144 * This function can be called from contexts where we cannot sleep, and will
3145 * complain if the GPIO chip functions potentially sleep.
3146 */
3147int gpiod_get_raw_value(const struct gpio_desc *desc)
3148{
3149 VALIDATE_DESC(desc);
3150 /* Should be using gpiod_get_raw_value_cansleep() */
3151 WARN_ON(desc->gdev->can_sleep);
3152 return gpiod_get_raw_value_commit(desc);
3153}
3154EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3155
3156/**
3157 * gpiod_get_value() - return a gpio's value
3158 * @desc: gpio whose value will be returned
3159 *
3160 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3161 * account, or negative errno on failure.
3162 *
3163 * This function can be called from contexts where we cannot sleep, and will
3164 * complain if the GPIO chip functions potentially sleep.
3165 */
3166int gpiod_get_value(const struct gpio_desc *desc)
3167{
3168 int value;
3169
3170 VALIDATE_DESC(desc);
3171 /* Should be using gpiod_get_value_cansleep() */
3172 WARN_ON(desc->gdev->can_sleep);
3173
3174 value = gpiod_get_raw_value_commit(desc);
3175 if (value < 0)
3176 return value;
3177
3178 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3179 value = !value;
3180
3181 return value;
3182}
3183EXPORT_SYMBOL_GPL(gpiod_get_value);
3184
3185/**
3186 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3187 * @array_size: number of elements in the descriptor array / value bitmap
3188 * @desc_array: array of GPIO descriptors whose values will be read
3189 * @array_info: information on applicability of fast bitmap processing path
3190 * @value_bitmap: bitmap to store the read values
3191 *
3192 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3193 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3194 * else an error code.
3195 *
3196 * This function can be called from contexts where we cannot sleep,
3197 * and it will complain if the GPIO chip functions potentially sleep.
3198 */
3199int gpiod_get_raw_array_value(unsigned int array_size,
3200 struct gpio_desc **desc_array,
3201 struct gpio_array *array_info,
3202 unsigned long *value_bitmap)
3203{
3204 if (!desc_array)
3205 return -EINVAL;
3206 return gpiod_get_array_value_complex(true, false, array_size,
3207 desc_array, array_info,
3208 value_bitmap);
3209}
3210EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3211
3212/**
3213 * gpiod_get_array_value() - read values from an array of GPIOs
3214 * @array_size: number of elements in the descriptor array / value bitmap
3215 * @desc_array: array of GPIO descriptors whose values will be read
3216 * @array_info: information on applicability of fast bitmap processing path
3217 * @value_bitmap: bitmap to store the read values
3218 *
3219 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3220 * into account. Return 0 in case of success, else an error code.
3221 *
3222 * This function can be called from contexts where we cannot sleep,
3223 * and it will complain if the GPIO chip functions potentially sleep.
3224 */
3225int gpiod_get_array_value(unsigned int array_size,
3226 struct gpio_desc **desc_array,
3227 struct gpio_array *array_info,
3228 unsigned long *value_bitmap)
3229{
3230 if (!desc_array)
3231 return -EINVAL;
3232 return gpiod_get_array_value_complex(false, false, array_size,
3233 desc_array, array_info,
3234 value_bitmap);
3235}
3236EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3237
3238/*
3239 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3240 * @desc: gpio descriptor whose state need to be set.
3241 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3242 */
3243static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3244{
3245 int ret = 0, offset = gpio_chip_hwgpio(desc);
3246
3247 CLASS(gpio_chip_guard, guard)(desc);
3248 if (!guard.gc)
3249 return;
3250
3251 if (value) {
3252 ret = guard.gc->direction_input(guard.gc, offset);
3253 } else {
3254 ret = guard.gc->direction_output(guard.gc, offset, 0);
3255 if (!ret)
3256 set_bit(FLAG_IS_OUT, &desc->flags);
3257 }
3258 trace_gpio_direction(desc_to_gpio(desc), value, ret);
3259 if (ret < 0)
3260 gpiod_err(desc,
3261 "%s: Error in set_value for open drain err %d\n",
3262 __func__, ret);
3263}
3264
3265/*
3266 * _gpio_set_open_source_value() - Set the open source gpio's value.
3267 * @desc: gpio descriptor whose state need to be set.
3268 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3269 */
3270static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3271{
3272 int ret = 0, offset = gpio_chip_hwgpio(desc);
3273
3274 CLASS(gpio_chip_guard, guard)(desc);
3275 if (!guard.gc)
3276 return;
3277
3278 if (value) {
3279 ret = guard.gc->direction_output(guard.gc, offset, 1);
3280 if (!ret)
3281 set_bit(FLAG_IS_OUT, &desc->flags);
3282 } else {
3283 ret = guard.gc->direction_input(guard.gc, offset);
3284 }
3285 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3286 if (ret < 0)
3287 gpiod_err(desc,
3288 "%s: Error in set_value for open source err %d\n",
3289 __func__, ret);
3290}
3291
3292static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3293{
3294 CLASS(gpio_chip_guard, guard)(desc);
3295 if (!guard.gc)
3296 return;
3297
3298 trace_gpio_value(desc_to_gpio(desc), 0, value);
3299 guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), value);
3300}
3301
3302/*
3303 * set multiple outputs on the same chip;
3304 * use the chip's set_multiple function if available;
3305 * otherwise set the outputs sequentially;
3306 * @chip: the GPIO chip we operate on
3307 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3308 * defines which outputs are to be changed
3309 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3310 * defines the values the outputs specified by mask are to be set to
3311 */
3312static void gpio_chip_set_multiple(struct gpio_chip *gc,
3313 unsigned long *mask, unsigned long *bits)
3314{
3315 if (gc->set_multiple) {
3316 gc->set_multiple(gc, mask, bits);
3317 } else {
3318 unsigned int i;
3319
3320 /* set outputs if the corresponding mask bit is set */
3321 for_each_set_bit(i, mask, gc->ngpio)
3322 gc->set(gc, i, test_bit(i, bits));
3323 }
3324}
3325
3326int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3327 unsigned int array_size,
3328 struct gpio_desc **desc_array,
3329 struct gpio_array *array_info,
3330 unsigned long *value_bitmap)
3331{
3332 int i = 0;
3333
3334 /*
3335 * Validate array_info against desc_array and its size.
3336 * It should immediately follow desc_array if both
3337 * have been obtained from the same gpiod_get_array() call.
3338 */
3339 if (array_info && array_info->desc == desc_array &&
3340 array_size <= array_info->size &&
3341 (void *)array_info == desc_array + array_info->size) {
3342 if (!can_sleep)
3343 WARN_ON(array_info->chip->can_sleep);
3344
3345 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3346 bitmap_xor(value_bitmap, value_bitmap,
3347 array_info->invert_mask, array_size);
3348
3349 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3350 value_bitmap);
3351
3352 i = find_first_zero_bit(array_info->set_mask, array_size);
3353 if (i == array_size)
3354 return 0;
3355 } else {
3356 array_info = NULL;
3357 }
3358
3359 while (i < array_size) {
3360 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3361 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3362 unsigned long *mask, *bits;
3363 int count = 0;
3364
3365 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3366 if (!guard.gc)
3367 return -ENODEV;
3368
3369 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3370 mask = fastpath_mask;
3371 bits = fastpath_bits;
3372 } else {
3373 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3374
3375 mask = bitmap_alloc(guard.gc->ngpio, flags);
3376 if (!mask)
3377 return -ENOMEM;
3378
3379 bits = bitmap_alloc(guard.gc->ngpio, flags);
3380 if (!bits) {
3381 bitmap_free(mask);
3382 return -ENOMEM;
3383 }
3384 }
3385
3386 bitmap_zero(mask, guard.gc->ngpio);
3387
3388 if (!can_sleep)
3389 WARN_ON(guard.gc->can_sleep);
3390
3391 do {
3392 struct gpio_desc *desc = desc_array[i];
3393 int hwgpio = gpio_chip_hwgpio(desc);
3394 int value = test_bit(i, value_bitmap);
3395
3396 /*
3397 * Pins applicable for fast input but not for
3398 * fast output processing may have been already
3399 * inverted inside the fast path, skip them.
3400 */
3401 if (!raw && !(array_info &&
3402 test_bit(i, array_info->invert_mask)) &&
3403 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3404 value = !value;
3405 trace_gpio_value(desc_to_gpio(desc), 0, value);
3406 /*
3407 * collect all normal outputs belonging to the same chip
3408 * open drain and open source outputs are set individually
3409 */
3410 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3411 gpio_set_open_drain_value_commit(desc, value);
3412 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3413 gpio_set_open_source_value_commit(desc, value);
3414 } else {
3415 __set_bit(hwgpio, mask);
3416 __assign_bit(hwgpio, bits, value);
3417 count++;
3418 }
3419 i++;
3420
3421 if (array_info)
3422 i = find_next_zero_bit(array_info->set_mask,
3423 array_size, i);
3424 } while ((i < array_size) &&
3425 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3426 /* push collected bits to outputs */
3427 if (count != 0)
3428 gpio_chip_set_multiple(guard.gc, mask, bits);
3429
3430 if (mask != fastpath_mask)
3431 bitmap_free(mask);
3432 if (bits != fastpath_bits)
3433 bitmap_free(bits);
3434 }
3435 return 0;
3436}
3437
3438/**
3439 * gpiod_set_raw_value() - assign a gpio's raw value
3440 * @desc: gpio whose value will be assigned
3441 * @value: value to assign
3442 *
3443 * Set the raw value of the GPIO, i.e. the value of its physical line without
3444 * regard for its ACTIVE_LOW status.
3445 *
3446 * This function can be called from contexts where we cannot sleep, and will
3447 * complain if the GPIO chip functions potentially sleep.
3448 */
3449void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3450{
3451 VALIDATE_DESC_VOID(desc);
3452 /* Should be using gpiod_set_raw_value_cansleep() */
3453 WARN_ON(desc->gdev->can_sleep);
3454 gpiod_set_raw_value_commit(desc, value);
3455}
3456EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3457
3458/**
3459 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3460 * @desc: the descriptor to set the value on
3461 * @value: value to set
3462 *
3463 * This sets the value of a GPIO line backing a descriptor, applying
3464 * different semantic quirks like active low and open drain/source
3465 * handling.
3466 */
3467static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3468{
3469 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3470 value = !value;
3471 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3472 gpio_set_open_drain_value_commit(desc, value);
3473 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3474 gpio_set_open_source_value_commit(desc, value);
3475 else
3476 gpiod_set_raw_value_commit(desc, value);
3477}
3478
3479/**
3480 * gpiod_set_value() - assign a gpio's value
3481 * @desc: gpio whose value will be assigned
3482 * @value: value to assign
3483 *
3484 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3485 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3486 *
3487 * This function can be called from contexts where we cannot sleep, and will
3488 * complain if the GPIO chip functions potentially sleep.
3489 */
3490void gpiod_set_value(struct gpio_desc *desc, int value)
3491{
3492 VALIDATE_DESC_VOID(desc);
3493 /* Should be using gpiod_set_value_cansleep() */
3494 WARN_ON(desc->gdev->can_sleep);
3495 gpiod_set_value_nocheck(desc, value);
3496}
3497EXPORT_SYMBOL_GPL(gpiod_set_value);
3498
3499/**
3500 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3501 * @array_size: number of elements in the descriptor array / value bitmap
3502 * @desc_array: array of GPIO descriptors whose values will be assigned
3503 * @array_info: information on applicability of fast bitmap processing path
3504 * @value_bitmap: bitmap of values to assign
3505 *
3506 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3507 * without regard for their ACTIVE_LOW status.
3508 *
3509 * This function can be called from contexts where we cannot sleep, and will
3510 * complain if the GPIO chip functions potentially sleep.
3511 */
3512int gpiod_set_raw_array_value(unsigned int array_size,
3513 struct gpio_desc **desc_array,
3514 struct gpio_array *array_info,
3515 unsigned long *value_bitmap)
3516{
3517 if (!desc_array)
3518 return -EINVAL;
3519 return gpiod_set_array_value_complex(true, false, array_size,
3520 desc_array, array_info, value_bitmap);
3521}
3522EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3523
3524/**
3525 * gpiod_set_array_value() - assign values to an array of GPIOs
3526 * @array_size: number of elements in the descriptor array / value bitmap
3527 * @desc_array: array of GPIO descriptors whose values will be assigned
3528 * @array_info: information on applicability of fast bitmap processing path
3529 * @value_bitmap: bitmap of values to assign
3530 *
3531 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3532 * into account.
3533 *
3534 * This function can be called from contexts where we cannot sleep, and will
3535 * complain if the GPIO chip functions potentially sleep.
3536 */
3537int gpiod_set_array_value(unsigned int array_size,
3538 struct gpio_desc **desc_array,
3539 struct gpio_array *array_info,
3540 unsigned long *value_bitmap)
3541{
3542 if (!desc_array)
3543 return -EINVAL;
3544 return gpiod_set_array_value_complex(false, false, array_size,
3545 desc_array, array_info,
3546 value_bitmap);
3547}
3548EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3549
3550/**
3551 * gpiod_cansleep() - report whether gpio value access may sleep
3552 * @desc: gpio to check
3553 *
3554 */
3555int gpiod_cansleep(const struct gpio_desc *desc)
3556{
3557 VALIDATE_DESC(desc);
3558 return desc->gdev->can_sleep;
3559}
3560EXPORT_SYMBOL_GPL(gpiod_cansleep);
3561
3562/**
3563 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3564 * @desc: gpio to set the consumer name on
3565 * @name: the new consumer name
3566 */
3567int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3568{
3569 VALIDATE_DESC(desc);
3570
3571 return desc_set_label(desc, name);
3572}
3573EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3574
3575/**
3576 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3577 * @desc: gpio whose IRQ will be returned (already requested)
3578 *
3579 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3580 * error.
3581 */
3582int gpiod_to_irq(const struct gpio_desc *desc)
3583{
3584 struct gpio_device *gdev;
3585 struct gpio_chip *gc;
3586 int offset;
3587
3588 /*
3589 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3590 * requires this function to not return zero on an invalid descriptor
3591 * but rather a negative error number.
3592 */
3593 if (!desc || IS_ERR(desc))
3594 return -EINVAL;
3595
3596 gdev = desc->gdev;
3597 /* FIXME Cannot use gpio_chip_guard due to const desc. */
3598 guard(srcu)(&gdev->srcu);
3599 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3600 if (!gc)
3601 return -ENODEV;
3602
3603 offset = gpio_chip_hwgpio(desc);
3604 if (gc->to_irq) {
3605 int retirq = gc->to_irq(gc, offset);
3606
3607 /* Zero means NO_IRQ */
3608 if (!retirq)
3609 return -ENXIO;
3610
3611 return retirq;
3612 }
3613#ifdef CONFIG_GPIOLIB_IRQCHIP
3614 if (gc->irq.chip) {
3615 /*
3616 * Avoid race condition with other code, which tries to lookup
3617 * an IRQ before the irqchip has been properly registered,
3618 * i.e. while gpiochip is still being brought up.
3619 */
3620 return -EPROBE_DEFER;
3621 }
3622#endif
3623 return -ENXIO;
3624}
3625EXPORT_SYMBOL_GPL(gpiod_to_irq);
3626
3627/**
3628 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3629 * @gc: the chip the GPIO to lock belongs to
3630 * @offset: the offset of the GPIO to lock as IRQ
3631 *
3632 * This is used directly by GPIO drivers that want to lock down
3633 * a certain GPIO line to be used for IRQs.
3634 */
3635int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3636{
3637 struct gpio_desc *desc;
3638
3639 desc = gpiochip_get_desc(gc, offset);
3640 if (IS_ERR(desc))
3641 return PTR_ERR(desc);
3642
3643 /*
3644 * If it's fast: flush the direction setting if something changed
3645 * behind our back
3646 */
3647 if (!gc->can_sleep && gc->get_direction) {
3648 int dir = gpiod_get_direction(desc);
3649
3650 if (dir < 0) {
3651 chip_err(gc, "%s: cannot get GPIO direction\n",
3652 __func__);
3653 return dir;
3654 }
3655 }
3656
3657 /* To be valid for IRQ the line needs to be input or open drain */
3658 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3659 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3660 chip_err(gc,
3661 "%s: tried to flag a GPIO set as output for IRQ\n",
3662 __func__);
3663 return -EIO;
3664 }
3665
3666 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3667 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3668
3669 return 0;
3670}
3671EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3672
3673/**
3674 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3675 * @gc: the chip the GPIO to lock belongs to
3676 * @offset: the offset of the GPIO to lock as IRQ
3677 *
3678 * This is used directly by GPIO drivers that want to indicate
3679 * that a certain GPIO is no longer used exclusively for IRQ.
3680 */
3681void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3682{
3683 struct gpio_desc *desc;
3684
3685 desc = gpiochip_get_desc(gc, offset);
3686 if (IS_ERR(desc))
3687 return;
3688
3689 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3690 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3691}
3692EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3693
3694void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3695{
3696 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3697
3698 if (!IS_ERR(desc) &&
3699 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3700 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3701}
3702EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3703
3704void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3705{
3706 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3707
3708 if (!IS_ERR(desc) &&
3709 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3710 /*
3711 * We must not be output when using IRQ UNLESS we are
3712 * open drain.
3713 */
3714 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3715 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3716 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3717 }
3718}
3719EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3720
3721bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3722{
3723 if (offset >= gc->ngpio)
3724 return false;
3725
3726 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3727}
3728EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3729
3730int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3731{
3732 int ret;
3733
3734 if (!try_module_get(gc->gpiodev->owner))
3735 return -ENODEV;
3736
3737 ret = gpiochip_lock_as_irq(gc, offset);
3738 if (ret) {
3739 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3740 module_put(gc->gpiodev->owner);
3741 return ret;
3742 }
3743 return 0;
3744}
3745EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3746
3747void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3748{
3749 gpiochip_unlock_as_irq(gc, offset);
3750 module_put(gc->gpiodev->owner);
3751}
3752EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3753
3754bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3755{
3756 if (offset >= gc->ngpio)
3757 return false;
3758
3759 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3760}
3761EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3762
3763bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3764{
3765 if (offset >= gc->ngpio)
3766 return false;
3767
3768 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3769}
3770EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3771
3772bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3773{
3774 if (offset >= gc->ngpio)
3775 return false;
3776
3777 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3778}
3779EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3780
3781/**
3782 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3783 * @desc: gpio whose value will be returned
3784 *
3785 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3786 * its ACTIVE_LOW status, or negative errno on failure.
3787 *
3788 * This function is to be called from contexts that can sleep.
3789 */
3790int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3791{
3792 might_sleep();
3793 VALIDATE_DESC(desc);
3794 return gpiod_get_raw_value_commit(desc);
3795}
3796EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3797
3798/**
3799 * gpiod_get_value_cansleep() - return a gpio's value
3800 * @desc: gpio whose value will be returned
3801 *
3802 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3803 * account, or negative errno on failure.
3804 *
3805 * This function is to be called from contexts that can sleep.
3806 */
3807int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3808{
3809 int value;
3810
3811 might_sleep();
3812 VALIDATE_DESC(desc);
3813 value = gpiod_get_raw_value_commit(desc);
3814 if (value < 0)
3815 return value;
3816
3817 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3818 value = !value;
3819
3820 return value;
3821}
3822EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3823
3824/**
3825 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3826 * @array_size: number of elements in the descriptor array / value bitmap
3827 * @desc_array: array of GPIO descriptors whose values will be read
3828 * @array_info: information on applicability of fast bitmap processing path
3829 * @value_bitmap: bitmap to store the read values
3830 *
3831 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3832 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3833 * else an error code.
3834 *
3835 * This function is to be called from contexts that can sleep.
3836 */
3837int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3838 struct gpio_desc **desc_array,
3839 struct gpio_array *array_info,
3840 unsigned long *value_bitmap)
3841{
3842 might_sleep();
3843 if (!desc_array)
3844 return -EINVAL;
3845 return gpiod_get_array_value_complex(true, true, array_size,
3846 desc_array, array_info,
3847 value_bitmap);
3848}
3849EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3850
3851/**
3852 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3853 * @array_size: number of elements in the descriptor array / value bitmap
3854 * @desc_array: array of GPIO descriptors whose values will be read
3855 * @array_info: information on applicability of fast bitmap processing path
3856 * @value_bitmap: bitmap to store the read values
3857 *
3858 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3859 * into account. Return 0 in case of success, else an error code.
3860 *
3861 * This function is to be called from contexts that can sleep.
3862 */
3863int gpiod_get_array_value_cansleep(unsigned int array_size,
3864 struct gpio_desc **desc_array,
3865 struct gpio_array *array_info,
3866 unsigned long *value_bitmap)
3867{
3868 might_sleep();
3869 if (!desc_array)
3870 return -EINVAL;
3871 return gpiod_get_array_value_complex(false, true, array_size,
3872 desc_array, array_info,
3873 value_bitmap);
3874}
3875EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3876
3877/**
3878 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3879 * @desc: gpio whose value will be assigned
3880 * @value: value to assign
3881 *
3882 * Set the raw value of the GPIO, i.e. the value of its physical line without
3883 * regard for its ACTIVE_LOW status.
3884 *
3885 * This function is to be called from contexts that can sleep.
3886 */
3887void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3888{
3889 might_sleep();
3890 VALIDATE_DESC_VOID(desc);
3891 gpiod_set_raw_value_commit(desc, value);
3892}
3893EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3894
3895/**
3896 * gpiod_set_value_cansleep() - assign a gpio's value
3897 * @desc: gpio whose value will be assigned
3898 * @value: value to assign
3899 *
3900 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3901 * account
3902 *
3903 * This function is to be called from contexts that can sleep.
3904 */
3905void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3906{
3907 might_sleep();
3908 VALIDATE_DESC_VOID(desc);
3909 gpiod_set_value_nocheck(desc, value);
3910}
3911EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3912
3913/**
3914 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3915 * @array_size: number of elements in the descriptor array / value bitmap
3916 * @desc_array: array of GPIO descriptors whose values will be assigned
3917 * @array_info: information on applicability of fast bitmap processing path
3918 * @value_bitmap: bitmap of values to assign
3919 *
3920 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3921 * without regard for their ACTIVE_LOW status.
3922 *
3923 * This function is to be called from contexts that can sleep.
3924 */
3925int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3926 struct gpio_desc **desc_array,
3927 struct gpio_array *array_info,
3928 unsigned long *value_bitmap)
3929{
3930 might_sleep();
3931 if (!desc_array)
3932 return -EINVAL;
3933 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3934 array_info, value_bitmap);
3935}
3936EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3937
3938/**
3939 * gpiod_add_lookup_tables() - register GPIO device consumers
3940 * @tables: list of tables of consumers to register
3941 * @n: number of tables in the list
3942 */
3943void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3944{
3945 unsigned int i;
3946
3947 mutex_lock(&gpio_lookup_lock);
3948
3949 for (i = 0; i < n; i++)
3950 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3951
3952 mutex_unlock(&gpio_lookup_lock);
3953}
3954
3955/**
3956 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3957 * @array_size: number of elements in the descriptor array / value bitmap
3958 * @desc_array: array of GPIO descriptors whose values will be assigned
3959 * @array_info: information on applicability of fast bitmap processing path
3960 * @value_bitmap: bitmap of values to assign
3961 *
3962 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3963 * into account.
3964 *
3965 * This function is to be called from contexts that can sleep.
3966 */
3967int gpiod_set_array_value_cansleep(unsigned int array_size,
3968 struct gpio_desc **desc_array,
3969 struct gpio_array *array_info,
3970 unsigned long *value_bitmap)
3971{
3972 might_sleep();
3973 if (!desc_array)
3974 return -EINVAL;
3975 return gpiod_set_array_value_complex(false, true, array_size,
3976 desc_array, array_info,
3977 value_bitmap);
3978}
3979EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3980
3981void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
3982{
3983 blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
3984 action, desc);
3985}
3986
3987/**
3988 * gpiod_add_lookup_table() - register GPIO device consumers
3989 * @table: table of consumers to register
3990 */
3991void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3992{
3993 gpiod_add_lookup_tables(&table, 1);
3994}
3995EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3996
3997/**
3998 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3999 * @table: table of consumers to unregister
4000 */
4001void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4002{
4003 /* Nothing to remove */
4004 if (!table)
4005 return;
4006
4007 mutex_lock(&gpio_lookup_lock);
4008
4009 list_del(&table->list);
4010
4011 mutex_unlock(&gpio_lookup_lock);
4012}
4013EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4014
4015/**
4016 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4017 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4018 */
4019void gpiod_add_hogs(struct gpiod_hog *hogs)
4020{
4021 struct gpiod_hog *hog;
4022
4023 mutex_lock(&gpio_machine_hogs_mutex);
4024
4025 for (hog = &hogs[0]; hog->chip_label; hog++) {
4026 list_add_tail(&hog->list, &gpio_machine_hogs);
4027
4028 /*
4029 * The chip may have been registered earlier, so check if it
4030 * exists and, if so, try to hog the line now.
4031 */
4032 struct gpio_device *gdev __free(gpio_device_put) =
4033 gpio_device_find_by_label(hog->chip_label);
4034 if (gdev)
4035 gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);
4036 }
4037
4038 mutex_unlock(&gpio_machine_hogs_mutex);
4039}
4040EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4041
4042void gpiod_remove_hogs(struct gpiod_hog *hogs)
4043{
4044 struct gpiod_hog *hog;
4045
4046 mutex_lock(&gpio_machine_hogs_mutex);
4047 for (hog = &hogs[0]; hog->chip_label; hog++)
4048 list_del(&hog->list);
4049 mutex_unlock(&gpio_machine_hogs_mutex);
4050}
4051EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
4052
4053static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4054{
4055 const char *dev_id = dev ? dev_name(dev) : NULL;
4056 struct gpiod_lookup_table *table;
4057
4058 list_for_each_entry(table, &gpio_lookup_list, list) {
4059 if (table->dev_id && dev_id) {
4060 /*
4061 * Valid strings on both ends, must be identical to have
4062 * a match
4063 */
4064 if (!strcmp(table->dev_id, dev_id))
4065 return table;
4066 } else {
4067 /*
4068 * One of the pointers is NULL, so both must be to have
4069 * a match
4070 */
4071 if (dev_id == table->dev_id)
4072 return table;
4073 }
4074 }
4075
4076 return NULL;
4077}
4078
4079static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4080 unsigned int idx, unsigned long *flags)
4081{
4082 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4083 struct gpiod_lookup_table *table;
4084 struct gpiod_lookup *p;
4085 struct gpio_chip *gc;
4086
4087 guard(mutex)(&gpio_lookup_lock);
4088
4089 table = gpiod_find_lookup_table(dev);
4090 if (!table)
4091 return desc;
4092
4093 for (p = &table->table[0]; p->key; p++) {
4094 /* idx must always match exactly */
4095 if (p->idx != idx)
4096 continue;
4097
4098 /* If the lookup entry has a con_id, require exact match */
4099 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4100 continue;
4101
4102 if (p->chip_hwnum == U16_MAX) {
4103 desc = gpio_name_to_desc(p->key);
4104 if (desc) {
4105 *flags = p->flags;
4106 return desc;
4107 }
4108
4109 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
4110 p->key);
4111 return ERR_PTR(-EPROBE_DEFER);
4112 }
4113
4114 struct gpio_device *gdev __free(gpio_device_put) =
4115 gpio_device_find_by_label(p->key);
4116 if (!gdev) {
4117 /*
4118 * As the lookup table indicates a chip with
4119 * p->key should exist, assume it may
4120 * still appear later and let the interested
4121 * consumer be probed again or let the Deferred
4122 * Probe infrastructure handle the error.
4123 */
4124 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4125 p->key);
4126 return ERR_PTR(-EPROBE_DEFER);
4127 }
4128
4129 gc = gpio_device_get_chip(gdev);
4130
4131 if (gc->ngpio <= p->chip_hwnum) {
4132 dev_err(dev,
4133 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4134 idx, p->chip_hwnum, gc->ngpio - 1,
4135 gc->label);
4136 return ERR_PTR(-EINVAL);
4137 }
4138
4139 desc = gpio_device_get_desc(gdev, p->chip_hwnum);
4140 *flags = p->flags;
4141
4142 return desc;
4143 }
4144
4145 return desc;
4146}
4147
4148static int platform_gpio_count(struct device *dev, const char *con_id)
4149{
4150 struct gpiod_lookup_table *table;
4151 struct gpiod_lookup *p;
4152 unsigned int count = 0;
4153
4154 scoped_guard(mutex, &gpio_lookup_lock) {
4155 table = gpiod_find_lookup_table(dev);
4156 if (!table)
4157 return -ENOENT;
4158
4159 for (p = &table->table[0]; p->key; p++) {
4160 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4161 (!con_id && !p->con_id))
4162 count++;
4163 }
4164 }
4165
4166 if (!count)
4167 return -ENOENT;
4168
4169 return count;
4170}
4171
4172static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
4173 struct device *consumer,
4174 const char *con_id,
4175 unsigned int idx,
4176 enum gpiod_flags *flags,
4177 unsigned long *lookupflags)
4178{
4179 const char *name = function_name_or_default(con_id);
4180 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4181
4182 if (is_of_node(fwnode)) {
4183 dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4184 desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
4185 } else if (is_acpi_node(fwnode)) {
4186 dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4187 desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
4188 } else if (is_software_node(fwnode)) {
4189 dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4190 desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
4191 }
4192
4193 return desc;
4194}
4195
4196struct gpio_desc *gpiod_find_and_request(struct device *consumer,
4197 struct fwnode_handle *fwnode,
4198 const char *con_id,
4199 unsigned int idx,
4200 enum gpiod_flags flags,
4201 const char *label,
4202 bool platform_lookup_allowed)
4203{
4204 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4205 const char *name = function_name_or_default(con_id);
4206 /*
4207 * scoped_guard() is implemented as a for loop, meaning static
4208 * analyzers will complain about these two not being initialized.
4209 */
4210 struct gpio_desc *desc = NULL;
4211 int ret = 0;
4212
4213 scoped_guard(srcu, &gpio_devices_srcu) {
4214 desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
4215 &flags, &lookupflags);
4216 if (gpiod_not_found(desc) && platform_lookup_allowed) {
4217 /*
4218 * Either we are not using DT or ACPI, or their lookup
4219 * did not return a result. In that case, use platform
4220 * lookup as a fallback.
4221 */
4222 dev_dbg(consumer,
4223 "using lookup tables for GPIO lookup\n");
4224 desc = gpiod_find(consumer, con_id, idx, &lookupflags);
4225 }
4226
4227 if (IS_ERR(desc)) {
4228 dev_dbg(consumer, "No GPIO consumer %s found\n", name);
4229 return desc;
4230 }
4231
4232 /*
4233 * If a connection label was passed use that, else attempt to use
4234 * the device name as label
4235 */
4236 ret = gpiod_request(desc, label);
4237 }
4238 if (ret) {
4239 if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4240 return ERR_PTR(ret);
4241
4242 /*
4243 * This happens when there are several consumers for
4244 * the same GPIO line: we just return here without
4245 * further initialization. It is a bit of a hack.
4246 * This is necessary to support fixed regulators.
4247 *
4248 * FIXME: Make this more sane and safe.
4249 */
4250 dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
4251 return desc;
4252 }
4253
4254 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4255 if (ret < 0) {
4256 gpiod_put(desc);
4257 dev_dbg(consumer, "setup of GPIO %s failed\n", name);
4258 return ERR_PTR(ret);
4259 }
4260
4261 gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED);
4262
4263 return desc;
4264}
4265
4266/**
4267 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
4268 * @fwnode: handle of the firmware node
4269 * @con_id: function within the GPIO consumer
4270 * @index: index of the GPIO to obtain for the consumer
4271 * @flags: GPIO initialization flags
4272 * @label: label to attach to the requested GPIO
4273 *
4274 * This function can be used for drivers that get their configuration
4275 * from opaque firmware.
4276 *
4277 * The function properly finds the corresponding GPIO using whatever is the
4278 * underlying firmware interface and then makes sure that the GPIO
4279 * descriptor is requested before it is returned to the caller.
4280 *
4281 * Returns:
4282 * On successful request the GPIO pin is configured in accordance with
4283 * provided @flags.
4284 *
4285 * In case of error an ERR_PTR() is returned.
4286 */
4287struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
4288 const char *con_id,
4289 int index,
4290 enum gpiod_flags flags,
4291 const char *label)
4292{
4293 return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
4294}
4295EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
4296
4297/**
4298 * gpiod_count - return the number of GPIOs associated with a device / function
4299 * or -ENOENT if no GPIO has been assigned to the requested function
4300 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4301 * @con_id: function within the GPIO consumer
4302 */
4303int gpiod_count(struct device *dev, const char *con_id)
4304{
4305 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4306 int count = -ENOENT;
4307
4308 if (is_of_node(fwnode))
4309 count = of_gpio_count(fwnode, con_id);
4310 else if (is_acpi_node(fwnode))
4311 count = acpi_gpio_count(fwnode, con_id);
4312 else if (is_software_node(fwnode))
4313 count = swnode_gpio_count(fwnode, con_id);
4314
4315 if (count < 0)
4316 count = platform_gpio_count(dev, con_id);
4317
4318 return count;
4319}
4320EXPORT_SYMBOL_GPL(gpiod_count);
4321
4322/**
4323 * gpiod_get - obtain a GPIO for a given GPIO function
4324 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4325 * @con_id: function within the GPIO consumer
4326 * @flags: optional GPIO initialization flags
4327 *
4328 * Return the GPIO descriptor corresponding to the function con_id of device
4329 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4330 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4331 */
4332struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4333 enum gpiod_flags flags)
4334{
4335 return gpiod_get_index(dev, con_id, 0, flags);
4336}
4337EXPORT_SYMBOL_GPL(gpiod_get);
4338
4339/**
4340 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4341 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4342 * @con_id: function within the GPIO consumer
4343 * @flags: optional GPIO initialization flags
4344 *
4345 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4346 * the requested function it will return NULL. This is convenient for drivers
4347 * that need to handle optional GPIOs.
4348 */
4349struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4350 const char *con_id,
4351 enum gpiod_flags flags)
4352{
4353 return gpiod_get_index_optional(dev, con_id, 0, flags);
4354}
4355EXPORT_SYMBOL_GPL(gpiod_get_optional);
4356
4357
4358/**
4359 * gpiod_configure_flags - helper function to configure a given GPIO
4360 * @desc: gpio whose value will be assigned
4361 * @con_id: function within the GPIO consumer
4362 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4363 * of_find_gpio() or of_get_gpio_hog()
4364 * @dflags: gpiod_flags - optional GPIO initialization flags
4365 *
4366 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4367 * requested function and/or index, or another IS_ERR() code if an error
4368 * occurred while trying to acquire the GPIO.
4369 */
4370int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4371 unsigned long lflags, enum gpiod_flags dflags)
4372{
4373 const char *name = function_name_or_default(con_id);
4374 int ret;
4375
4376 if (lflags & GPIO_ACTIVE_LOW)
4377 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4378
4379 if (lflags & GPIO_OPEN_DRAIN)
4380 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4381 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4382 /*
4383 * This enforces open drain mode from the consumer side.
4384 * This is necessary for some busses like I2C, but the lookup
4385 * should *REALLY* have specified them as open drain in the
4386 * first place, so print a little warning here.
4387 */
4388 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4389 gpiod_warn(desc,
4390 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4391 }
4392
4393 if (lflags & GPIO_OPEN_SOURCE)
4394 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4395
4396 if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
4397 ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
4398 ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
4399 gpiod_err(desc,
4400 "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
4401 return -EINVAL;
4402 }
4403
4404 if (lflags & GPIO_PULL_UP)
4405 set_bit(FLAG_PULL_UP, &desc->flags);
4406 else if (lflags & GPIO_PULL_DOWN)
4407 set_bit(FLAG_PULL_DOWN, &desc->flags);
4408 else if (lflags & GPIO_PULL_DISABLE)
4409 set_bit(FLAG_BIAS_DISABLE, &desc->flags);
4410
4411 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4412 if (ret < 0)
4413 return ret;
4414
4415 /* No particular flag request, return here... */
4416 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4417 gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
4418 return 0;
4419 }
4420
4421 /* Process flags */
4422 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4423 ret = gpiod_direction_output(desc,
4424 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4425 else
4426 ret = gpiod_direction_input(desc);
4427
4428 return ret;
4429}
4430
4431/**
4432 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4433 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4434 * @con_id: function within the GPIO consumer
4435 * @idx: index of the GPIO to obtain in the consumer
4436 * @flags: optional GPIO initialization flags
4437 *
4438 * This variant of gpiod_get() allows to access GPIOs other than the first
4439 * defined one for functions that define several GPIOs.
4440 *
4441 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4442 * requested function and/or index, or another IS_ERR() code if an error
4443 * occurred while trying to acquire the GPIO.
4444 */
4445struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4446 const char *con_id,
4447 unsigned int idx,
4448 enum gpiod_flags flags)
4449{
4450 struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4451 const char *devname = dev ? dev_name(dev) : "?";
4452 const char *label = con_id ?: devname;
4453
4454 return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
4455}
4456EXPORT_SYMBOL_GPL(gpiod_get_index);
4457
4458/**
4459 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4460 * function
4461 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4462 * @con_id: function within the GPIO consumer
4463 * @index: index of the GPIO to obtain in the consumer
4464 * @flags: optional GPIO initialization flags
4465 *
4466 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4467 * specified index was assigned to the requested function it will return NULL.
4468 * This is convenient for drivers that need to handle optional GPIOs.
4469 */
4470struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4471 const char *con_id,
4472 unsigned int index,
4473 enum gpiod_flags flags)
4474{
4475 struct gpio_desc *desc;
4476
4477 desc = gpiod_get_index(dev, con_id, index, flags);
4478 if (gpiod_not_found(desc))
4479 return NULL;
4480
4481 return desc;
4482}
4483EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4484
4485/**
4486 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4487 * @desc: gpio whose value will be assigned
4488 * @name: gpio line name
4489 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4490 * of_find_gpio() or of_get_gpio_hog()
4491 * @dflags: gpiod_flags - optional GPIO initialization flags
4492 */
4493int gpiod_hog(struct gpio_desc *desc, const char *name,
4494 unsigned long lflags, enum gpiod_flags dflags)
4495{
4496 struct gpio_device *gdev = desc->gdev;
4497 struct gpio_desc *local_desc;
4498 int hwnum;
4499 int ret;
4500
4501 CLASS(gpio_chip_guard, guard)(desc);
4502 if (!guard.gc)
4503 return -ENODEV;
4504
4505 if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))
4506 return 0;
4507
4508 hwnum = gpio_chip_hwgpio(desc);
4509
4510 local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
4511 lflags, dflags);
4512 if (IS_ERR(local_desc)) {
4513 clear_bit(FLAG_IS_HOGGED, &desc->flags);
4514 ret = PTR_ERR(local_desc);
4515 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4516 name, gdev->label, hwnum, ret);
4517 return ret;
4518 }
4519
4520 gpiod_dbg(desc, "hogged as %s%s\n",
4521 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4522 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4523 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4524
4525 return 0;
4526}
4527
4528/**
4529 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4530 * @gc: gpio chip to act on
4531 */
4532static void gpiochip_free_hogs(struct gpio_chip *gc)
4533{
4534 struct gpio_desc *desc;
4535
4536 for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)
4537 gpiochip_free_own_desc(desc);
4538}
4539
4540/**
4541 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4542 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4543 * @con_id: function within the GPIO consumer
4544 * @flags: optional GPIO initialization flags
4545 *
4546 * This function acquires all the GPIOs defined under a given function.
4547 *
4548 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4549 * no GPIO has been assigned to the requested function, or another IS_ERR()
4550 * code if an error occurred while trying to acquire the GPIOs.
4551 */
4552struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4553 const char *con_id,
4554 enum gpiod_flags flags)
4555{
4556 struct gpio_desc *desc;
4557 struct gpio_descs *descs;
4558 struct gpio_array *array_info = NULL;
4559 struct gpio_chip *gc;
4560 int count, bitmap_size;
4561 size_t descs_size;
4562
4563 count = gpiod_count(dev, con_id);
4564 if (count < 0)
4565 return ERR_PTR(count);
4566
4567 descs_size = struct_size(descs, desc, count);
4568 descs = kzalloc(descs_size, GFP_KERNEL);
4569 if (!descs)
4570 return ERR_PTR(-ENOMEM);
4571
4572 for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
4573 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4574 if (IS_ERR(desc)) {
4575 gpiod_put_array(descs);
4576 return ERR_CAST(desc);
4577 }
4578
4579 descs->desc[descs->ndescs] = desc;
4580
4581 gc = gpiod_to_chip(desc);
4582 /*
4583 * If pin hardware number of array member 0 is also 0, select
4584 * its chip as a candidate for fast bitmap processing path.
4585 */
4586 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4587 struct gpio_descs *array;
4588
4589 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4590 gc->ngpio : count);
4591
4592 array = krealloc(descs, descs_size +
4593 struct_size(array_info, invert_mask, 3 * bitmap_size),
4594 GFP_KERNEL | __GFP_ZERO);
4595 if (!array) {
4596 gpiod_put_array(descs);
4597 return ERR_PTR(-ENOMEM);
4598 }
4599
4600 descs = array;
4601
4602 array_info = (void *)descs + descs_size;
4603 array_info->get_mask = array_info->invert_mask +
4604 bitmap_size;
4605 array_info->set_mask = array_info->get_mask +
4606 bitmap_size;
4607
4608 array_info->desc = descs->desc;
4609 array_info->size = count;
4610 array_info->chip = gc;
4611 bitmap_set(array_info->get_mask, descs->ndescs,
4612 count - descs->ndescs);
4613 bitmap_set(array_info->set_mask, descs->ndescs,
4614 count - descs->ndescs);
4615 descs->info = array_info;
4616 }
4617
4618 /* If there is no cache for fast bitmap processing path, continue */
4619 if (!array_info)
4620 continue;
4621
4622 /* Unmark array members which don't belong to the 'fast' chip */
4623 if (array_info->chip != gc) {
4624 __clear_bit(descs->ndescs, array_info->get_mask);
4625 __clear_bit(descs->ndescs, array_info->set_mask);
4626 }
4627 /*
4628 * Detect array members which belong to the 'fast' chip
4629 * but their pins are not in hardware order.
4630 */
4631 else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
4632 /*
4633 * Don't use fast path if all array members processed so
4634 * far belong to the same chip as this one but its pin
4635 * hardware number is different from its array index.
4636 */
4637 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4638 array_info = NULL;
4639 } else {
4640 __clear_bit(descs->ndescs,
4641 array_info->get_mask);
4642 __clear_bit(descs->ndescs,
4643 array_info->set_mask);
4644 }
4645 } else {
4646 /* Exclude open drain or open source from fast output */
4647 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4648 gpiochip_line_is_open_source(gc, descs->ndescs))
4649 __clear_bit(descs->ndescs,
4650 array_info->set_mask);
4651 /* Identify 'fast' pins which require invertion */
4652 if (gpiod_is_active_low(desc))
4653 __set_bit(descs->ndescs,
4654 array_info->invert_mask);
4655 }
4656 }
4657 if (array_info)
4658 dev_dbg(dev,
4659 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4660 array_info->chip->label, array_info->size,
4661 *array_info->get_mask, *array_info->set_mask,
4662 *array_info->invert_mask);
4663 return descs;
4664}
4665EXPORT_SYMBOL_GPL(gpiod_get_array);
4666
4667/**
4668 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4669 * function
4670 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4671 * @con_id: function within the GPIO consumer
4672 * @flags: optional GPIO initialization flags
4673 *
4674 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4675 * assigned to the requested function it will return NULL.
4676 */
4677struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4678 const char *con_id,
4679 enum gpiod_flags flags)
4680{
4681 struct gpio_descs *descs;
4682
4683 descs = gpiod_get_array(dev, con_id, flags);
4684 if (gpiod_not_found(descs))
4685 return NULL;
4686
4687 return descs;
4688}
4689EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4690
4691/**
4692 * gpiod_put - dispose of a GPIO descriptor
4693 * @desc: GPIO descriptor to dispose of
4694 *
4695 * No descriptor can be used after gpiod_put() has been called on it.
4696 */
4697void gpiod_put(struct gpio_desc *desc)
4698{
4699 if (desc)
4700 gpiod_free(desc);
4701}
4702EXPORT_SYMBOL_GPL(gpiod_put);
4703
4704/**
4705 * gpiod_put_array - dispose of multiple GPIO descriptors
4706 * @descs: struct gpio_descs containing an array of descriptors
4707 */
4708void gpiod_put_array(struct gpio_descs *descs)
4709{
4710 unsigned int i;
4711
4712 for (i = 0; i < descs->ndescs; i++)
4713 gpiod_put(descs->desc[i]);
4714
4715 kfree(descs);
4716}
4717EXPORT_SYMBOL_GPL(gpiod_put_array);
4718
4719static int gpio_stub_drv_probe(struct device *dev)
4720{
4721 /*
4722 * The DT node of some GPIO chips have a "compatible" property, but
4723 * never have a struct device added and probed by a driver to register
4724 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4725 * the consumers of the GPIO chip to get probe deferred forever because
4726 * they will be waiting for a device associated with the GPIO chip
4727 * firmware node to get added and bound to a driver.
4728 *
4729 * To allow these consumers to probe, we associate the struct
4730 * gpio_device of the GPIO chip with the firmware node and then simply
4731 * bind it to this stub driver.
4732 */
4733 return 0;
4734}
4735
4736static struct device_driver gpio_stub_drv = {
4737 .name = "gpio_stub_drv",
4738 .bus = &gpio_bus_type,
4739 .probe = gpio_stub_drv_probe,
4740};
4741
4742static int __init gpiolib_dev_init(void)
4743{
4744 int ret;
4745
4746 /* Register GPIO sysfs bus */
4747 ret = bus_register(&gpio_bus_type);
4748 if (ret < 0) {
4749 pr_err("gpiolib: could not register GPIO bus type\n");
4750 return ret;
4751 }
4752
4753 ret = driver_register(&gpio_stub_drv);
4754 if (ret < 0) {
4755 pr_err("gpiolib: could not register GPIO stub driver\n");
4756 bus_unregister(&gpio_bus_type);
4757 return ret;
4758 }
4759
4760 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4761 if (ret < 0) {
4762 pr_err("gpiolib: failed to allocate char dev region\n");
4763 driver_unregister(&gpio_stub_drv);
4764 bus_unregister(&gpio_bus_type);
4765 return ret;
4766 }
4767
4768 gpiolib_initialized = true;
4769 gpiochip_setup_devs();
4770
4771#if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4772 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4773#endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4774
4775 return ret;
4776}
4777core_initcall(gpiolib_dev_init);
4778
4779#ifdef CONFIG_DEBUG_FS
4780
4781static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4782{
4783 bool active_low, is_irq, is_out;
4784 unsigned int gpio = gdev->base;
4785 struct gpio_desc *desc;
4786 struct gpio_chip *gc;
4787 int value;
4788
4789 guard(srcu)(&gdev->srcu);
4790
4791 gc = srcu_dereference(gdev->chip, &gdev->srcu);
4792 if (!gc) {
4793 seq_puts(s, "Underlying GPIO chip is gone\n");
4794 return;
4795 }
4796
4797 for_each_gpio_desc(gc, desc) {
4798 guard(srcu)(&desc->gdev->desc_srcu);
4799 if (test_bit(FLAG_REQUESTED, &desc->flags)) {
4800 gpiod_get_direction(desc);
4801 is_out = test_bit(FLAG_IS_OUT, &desc->flags);
4802 value = gpio_chip_get_value(gc, desc);
4803 is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
4804 active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags);
4805 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s\n",
4806 gpio, desc->name ?: "", gpiod_get_label(desc),
4807 is_out ? "out" : "in ",
4808 value >= 0 ? (value ? "hi" : "lo") : "? ",
4809 is_irq ? "IRQ " : "",
4810 active_low ? "ACTIVE LOW" : "");
4811 } else if (desc->name) {
4812 seq_printf(s, " gpio-%-3d (%-20.20s)\n", gpio, desc->name);
4813 }
4814
4815 gpio++;
4816 }
4817}
4818
4819struct gpiolib_seq_priv {
4820 bool newline;
4821 int idx;
4822};
4823
4824static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4825{
4826 struct gpiolib_seq_priv *priv;
4827 struct gpio_device *gdev;
4828 loff_t index = *pos;
4829
4830 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
4831 if (!priv)
4832 return NULL;
4833
4834 s->private = priv;
4835 priv->idx = srcu_read_lock(&gpio_devices_srcu);
4836
4837 list_for_each_entry_srcu(gdev, &gpio_devices, list,
4838 srcu_read_lock_held(&gpio_devices_srcu)) {
4839 if (index-- == 0)
4840 return gdev;
4841 }
4842
4843 return NULL;
4844}
4845
4846static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4847{
4848 struct gpiolib_seq_priv *priv = s->private;
4849 struct gpio_device *gdev = v, *next;
4850
4851 next = list_entry_rcu(gdev->list.next, struct gpio_device, list);
4852 gdev = &next->list == &gpio_devices ? NULL : next;
4853 priv->newline = true;
4854 ++*pos;
4855
4856 return gdev;
4857}
4858
4859static void gpiolib_seq_stop(struct seq_file *s, void *v)
4860{
4861 struct gpiolib_seq_priv *priv = s->private;
4862
4863 srcu_read_unlock(&gpio_devices_srcu, priv->idx);
4864 kfree(priv);
4865}
4866
4867static int gpiolib_seq_show(struct seq_file *s, void *v)
4868{
4869 struct gpiolib_seq_priv *priv = s->private;
4870 struct gpio_device *gdev = v;
4871 struct gpio_chip *gc;
4872 struct device *parent;
4873
4874 guard(srcu)(&gdev->srcu);
4875
4876 gc = srcu_dereference(gdev->chip, &gdev->srcu);
4877 if (!gc) {
4878 seq_printf(s, "%s%s: (dangling chip)",
4879 priv->newline ? "\n" : "",
4880 dev_name(&gdev->dev));
4881 return 0;
4882 }
4883
4884 seq_printf(s, "%s%s: GPIOs %d-%d", priv->newline ? "\n" : "",
4885 dev_name(&gdev->dev),
4886 gdev->base, gdev->base + gdev->ngpio - 1);
4887 parent = gc->parent;
4888 if (parent)
4889 seq_printf(s, ", parent: %s/%s",
4890 parent->bus ? parent->bus->name : "no-bus",
4891 dev_name(parent));
4892 if (gc->label)
4893 seq_printf(s, ", %s", gc->label);
4894 if (gc->can_sleep)
4895 seq_printf(s, ", can sleep");
4896 seq_printf(s, ":\n");
4897
4898 if (gc->dbg_show)
4899 gc->dbg_show(s, gc);
4900 else
4901 gpiolib_dbg_show(s, gdev);
4902
4903 return 0;
4904}
4905
4906static const struct seq_operations gpiolib_sops = {
4907 .start = gpiolib_seq_start,
4908 .next = gpiolib_seq_next,
4909 .stop = gpiolib_seq_stop,
4910 .show = gpiolib_seq_show,
4911};
4912DEFINE_SEQ_ATTRIBUTE(gpiolib);
4913
4914static int __init gpiolib_debugfs_init(void)
4915{
4916 /* /sys/kernel/debug/gpio */
4917 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4918 return 0;
4919}
4920subsys_initcall(gpiolib_debugfs_init);
4921
4922#endif /* DEBUG_FS */