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