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