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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#include <linux/bitmap.h>
2#include <linux/kernel.h>
3#include <linux/module.h>
4#include <linux/interrupt.h>
5#include <linux/irq.h>
6#include <linux/spinlock.h>
7#include <linux/list.h>
8#include <linux/device.h>
9#include <linux/err.h>
10#include <linux/debugfs.h>
11#include <linux/seq_file.h>
12#include <linux/gpio.h>
13#include <linux/of_gpio.h>
14#include <linux/idr.h>
15#include <linux/slab.h>
16#include <linux/acpi.h>
17#include <linux/gpio/driver.h>
18#include <linux/gpio/machine.h>
19#include <linux/pinctrl/consumer.h>
20#include <linux/cdev.h>
21#include <linux/fs.h>
22#include <linux/uaccess.h>
23#include <linux/compat.h>
24#include <linux/anon_inodes.h>
25#include <linux/file.h>
26#include <linux/kfifo.h>
27#include <linux/poll.h>
28#include <linux/timekeeping.h>
29#include <uapi/linux/gpio.h>
30
31#include "gpiolib.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 struct bus_type gpio_bus_type = {
61 .name = "gpio",
62};
63
64/* gpio_lock prevents conflicts during gpio_desc[] table updates.
65 * While any GPIO is requested, its gpio_chip is not removable;
66 * each GPIO's "requested" flag serves as a lock and refcount.
67 */
68DEFINE_SPINLOCK(gpio_lock);
69
70static DEFINE_MUTEX(gpio_lookup_lock);
71static LIST_HEAD(gpio_lookup_list);
72LIST_HEAD(gpio_devices);
73
74static void gpiochip_free_hogs(struct gpio_chip *chip);
75static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
76 struct lock_class_key *lock_key,
77 struct lock_class_key *request_key);
78static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
79static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
80static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
81
82static bool gpiolib_initialized;
83
84static inline void desc_set_label(struct gpio_desc *d, const char *label)
85{
86 d->label = label;
87}
88
89/**
90 * gpio_to_desc - Convert a GPIO number to its descriptor
91 * @gpio: global GPIO number
92 *
93 * Returns:
94 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
95 * with the given number exists in the system.
96 */
97struct gpio_desc *gpio_to_desc(unsigned gpio)
98{
99 struct gpio_device *gdev;
100 unsigned long flags;
101
102 spin_lock_irqsave(&gpio_lock, flags);
103
104 list_for_each_entry(gdev, &gpio_devices, list) {
105 if (gdev->base <= gpio &&
106 gdev->base + gdev->ngpio > gpio) {
107 spin_unlock_irqrestore(&gpio_lock, flags);
108 return &gdev->descs[gpio - gdev->base];
109 }
110 }
111
112 spin_unlock_irqrestore(&gpio_lock, flags);
113
114 if (!gpio_is_valid(gpio))
115 WARN(1, "invalid GPIO %d\n", gpio);
116
117 return NULL;
118}
119EXPORT_SYMBOL_GPL(gpio_to_desc);
120
121/**
122 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
123 * hardware number for this chip
124 * @chip: GPIO chip
125 * @hwnum: hardware number of the GPIO for this chip
126 *
127 * Returns:
128 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
129 * in the given chip for the specified hardware number.
130 */
131struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
132 u16 hwnum)
133{
134 struct gpio_device *gdev = chip->gpiodev;
135
136 if (hwnum >= gdev->ngpio)
137 return ERR_PTR(-EINVAL);
138
139 return &gdev->descs[hwnum];
140}
141
142/**
143 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
144 * @desc: GPIO descriptor
145 *
146 * This should disappear in the future but is needed since we still
147 * use GPIO numbers for error messages and sysfs nodes.
148 *
149 * Returns:
150 * The global GPIO number for the GPIO specified by its descriptor.
151 */
152int desc_to_gpio(const struct gpio_desc *desc)
153{
154 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
155}
156EXPORT_SYMBOL_GPL(desc_to_gpio);
157
158
159/**
160 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
161 * @desc: descriptor to return the chip of
162 */
163struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
164{
165 if (!desc || !desc->gdev)
166 return NULL;
167 return desc->gdev->chip;
168}
169EXPORT_SYMBOL_GPL(gpiod_to_chip);
170
171/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
172static int gpiochip_find_base(int ngpio)
173{
174 struct gpio_device *gdev;
175 int base = ARCH_NR_GPIOS - ngpio;
176
177 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
178 /* found a free space? */
179 if (gdev->base + gdev->ngpio <= base)
180 break;
181 else
182 /* nope, check the space right before the chip */
183 base = gdev->base - ngpio;
184 }
185
186 if (gpio_is_valid(base)) {
187 pr_debug("%s: found new base at %d\n", __func__, base);
188 return base;
189 } else {
190 pr_err("%s: cannot find free range\n", __func__);
191 return -ENOSPC;
192 }
193}
194
195/**
196 * gpiod_get_direction - return the current direction of a GPIO
197 * @desc: GPIO to get the direction of
198 *
199 * Returns 0 for output, 1 for input, or an error code in case of error.
200 *
201 * This function may sleep if gpiod_cansleep() is true.
202 */
203int gpiod_get_direction(struct gpio_desc *desc)
204{
205 struct gpio_chip *chip;
206 unsigned offset;
207 int status = -EINVAL;
208
209 chip = gpiod_to_chip(desc);
210 offset = gpio_chip_hwgpio(desc);
211
212 if (!chip->get_direction)
213 return status;
214
215 status = chip->get_direction(chip, offset);
216 if (status > 0) {
217 /* GPIOF_DIR_IN, or other positive */
218 status = 1;
219 clear_bit(FLAG_IS_OUT, &desc->flags);
220 }
221 if (status == 0) {
222 /* GPIOF_DIR_OUT */
223 set_bit(FLAG_IS_OUT, &desc->flags);
224 }
225 return status;
226}
227EXPORT_SYMBOL_GPL(gpiod_get_direction);
228
229/*
230 * Add a new chip to the global chips list, keeping the list of chips sorted
231 * by range(means [base, base + ngpio - 1]) order.
232 *
233 * Return -EBUSY if the new chip overlaps with some other chip's integer
234 * space.
235 */
236static int gpiodev_add_to_list(struct gpio_device *gdev)
237{
238 struct gpio_device *prev, *next;
239
240 if (list_empty(&gpio_devices)) {
241 /* initial entry in list */
242 list_add_tail(&gdev->list, &gpio_devices);
243 return 0;
244 }
245
246 next = list_entry(gpio_devices.next, struct gpio_device, list);
247 if (gdev->base + gdev->ngpio <= next->base) {
248 /* add before first entry */
249 list_add(&gdev->list, &gpio_devices);
250 return 0;
251 }
252
253 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
254 if (prev->base + prev->ngpio <= gdev->base) {
255 /* add behind last entry */
256 list_add_tail(&gdev->list, &gpio_devices);
257 return 0;
258 }
259
260 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
261 /* at the end of the list */
262 if (&next->list == &gpio_devices)
263 break;
264
265 /* add between prev and next */
266 if (prev->base + prev->ngpio <= gdev->base
267 && gdev->base + gdev->ngpio <= next->base) {
268 list_add(&gdev->list, &prev->list);
269 return 0;
270 }
271 }
272
273 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
274 return -EBUSY;
275}
276
277/*
278 * Convert a GPIO name to its descriptor
279 */
280static struct gpio_desc *gpio_name_to_desc(const char * const name)
281{
282 struct gpio_device *gdev;
283 unsigned long flags;
284
285 spin_lock_irqsave(&gpio_lock, flags);
286
287 list_for_each_entry(gdev, &gpio_devices, list) {
288 int i;
289
290 for (i = 0; i != gdev->ngpio; ++i) {
291 struct gpio_desc *desc = &gdev->descs[i];
292
293 if (!desc->name || !name)
294 continue;
295
296 if (!strcmp(desc->name, name)) {
297 spin_unlock_irqrestore(&gpio_lock, flags);
298 return desc;
299 }
300 }
301 }
302
303 spin_unlock_irqrestore(&gpio_lock, flags);
304
305 return NULL;
306}
307
308/*
309 * Takes the names from gc->names and checks if they are all unique. If they
310 * are, they are assigned to their gpio descriptors.
311 *
312 * Warning if one of the names is already used for a different GPIO.
313 */
314static int gpiochip_set_desc_names(struct gpio_chip *gc)
315{
316 struct gpio_device *gdev = gc->gpiodev;
317 int i;
318
319 if (!gc->names)
320 return 0;
321
322 /* First check all names if they are unique */
323 for (i = 0; i != gc->ngpio; ++i) {
324 struct gpio_desc *gpio;
325
326 gpio = gpio_name_to_desc(gc->names[i]);
327 if (gpio)
328 dev_warn(&gdev->dev,
329 "Detected name collision for GPIO name '%s'\n",
330 gc->names[i]);
331 }
332
333 /* Then add all names to the GPIO descriptors */
334 for (i = 0; i != gc->ngpio; ++i)
335 gdev->descs[i].name = gc->names[i];
336
337 return 0;
338}
339
340static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
341{
342 unsigned long *p;
343
344 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
345 if (!p)
346 return NULL;
347
348 /* Assume by default all GPIOs are valid */
349 bitmap_fill(p, chip->ngpio);
350
351 return p;
352}
353
354static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
355{
356#ifdef CONFIG_OF_GPIO
357 int size;
358 struct device_node *np = gpiochip->of_node;
359
360 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
361 if (size > 0 && size % 2 == 0)
362 gpiochip->need_valid_mask = true;
363#endif
364
365 if (!gpiochip->need_valid_mask)
366 return 0;
367
368 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
369 if (!gpiochip->valid_mask)
370 return -ENOMEM;
371
372 return 0;
373}
374
375static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
376{
377 kfree(gpiochip->valid_mask);
378 gpiochip->valid_mask = NULL;
379}
380
381bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
382 unsigned int offset)
383{
384 /* No mask means all valid */
385 if (likely(!gpiochip->valid_mask))
386 return true;
387 return test_bit(offset, gpiochip->valid_mask);
388}
389EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
390
391/*
392 * GPIO line handle management
393 */
394
395/**
396 * struct linehandle_state - contains the state of a userspace handle
397 * @gdev: the GPIO device the handle pertains to
398 * @label: consumer label used to tag descriptors
399 * @descs: the GPIO descriptors held by this handle
400 * @numdescs: the number of descriptors held in the descs array
401 */
402struct linehandle_state {
403 struct gpio_device *gdev;
404 const char *label;
405 struct gpio_desc *descs[GPIOHANDLES_MAX];
406 u32 numdescs;
407};
408
409#define GPIOHANDLE_REQUEST_VALID_FLAGS \
410 (GPIOHANDLE_REQUEST_INPUT | \
411 GPIOHANDLE_REQUEST_OUTPUT | \
412 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
413 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
414 GPIOHANDLE_REQUEST_OPEN_SOURCE)
415
416static long linehandle_ioctl(struct file *filep, unsigned int cmd,
417 unsigned long arg)
418{
419 struct linehandle_state *lh = filep->private_data;
420 void __user *ip = (void __user *)arg;
421 struct gpiohandle_data ghd;
422 int vals[GPIOHANDLES_MAX];
423 int i;
424
425 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
426 /* TODO: check if descriptors are really input */
427 int ret = gpiod_get_array_value_complex(false,
428 true,
429 lh->numdescs,
430 lh->descs,
431 vals);
432 if (ret)
433 return ret;
434
435 memset(&ghd, 0, sizeof(ghd));
436 for (i = 0; i < lh->numdescs; i++)
437 ghd.values[i] = vals[i];
438
439 if (copy_to_user(ip, &ghd, sizeof(ghd)))
440 return -EFAULT;
441
442 return 0;
443 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
444 /* TODO: check if descriptors are really output */
445 if (copy_from_user(&ghd, ip, sizeof(ghd)))
446 return -EFAULT;
447
448 /* Clamp all values to [0,1] */
449 for (i = 0; i < lh->numdescs; i++)
450 vals[i] = !!ghd.values[i];
451
452 /* Reuse the array setting function */
453 gpiod_set_array_value_complex(false,
454 true,
455 lh->numdescs,
456 lh->descs,
457 vals);
458 return 0;
459 }
460 return -EINVAL;
461}
462
463#ifdef CONFIG_COMPAT
464static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
465 unsigned long arg)
466{
467 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
468}
469#endif
470
471static int linehandle_release(struct inode *inode, struct file *filep)
472{
473 struct linehandle_state *lh = filep->private_data;
474 struct gpio_device *gdev = lh->gdev;
475 int i;
476
477 for (i = 0; i < lh->numdescs; i++)
478 gpiod_free(lh->descs[i]);
479 kfree(lh->label);
480 kfree(lh);
481 put_device(&gdev->dev);
482 return 0;
483}
484
485static const struct file_operations linehandle_fileops = {
486 .release = linehandle_release,
487 .owner = THIS_MODULE,
488 .llseek = noop_llseek,
489 .unlocked_ioctl = linehandle_ioctl,
490#ifdef CONFIG_COMPAT
491 .compat_ioctl = linehandle_ioctl_compat,
492#endif
493};
494
495static int linehandle_create(struct gpio_device *gdev, void __user *ip)
496{
497 struct gpiohandle_request handlereq;
498 struct linehandle_state *lh;
499 struct file *file;
500 int fd, i, count = 0, ret;
501 u32 lflags;
502
503 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
504 return -EFAULT;
505 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
506 return -EINVAL;
507
508 lflags = handlereq.flags;
509
510 /* Return an error if an unknown flag is set */
511 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
512 return -EINVAL;
513
514 /*
515 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
516 * the hardware actually supports enabling both at the same time the
517 * electrical result would be disastrous.
518 */
519 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
520 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
521 return -EINVAL;
522
523 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
524 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
525 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
526 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
527 return -EINVAL;
528
529 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
530 if (!lh)
531 return -ENOMEM;
532 lh->gdev = gdev;
533 get_device(&gdev->dev);
534
535 /* Make sure this is terminated */
536 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
537 if (strlen(handlereq.consumer_label)) {
538 lh->label = kstrdup(handlereq.consumer_label,
539 GFP_KERNEL);
540 if (!lh->label) {
541 ret = -ENOMEM;
542 goto out_free_lh;
543 }
544 }
545
546 /* Request each GPIO */
547 for (i = 0; i < handlereq.lines; i++) {
548 u32 offset = handlereq.lineoffsets[i];
549 struct gpio_desc *desc;
550
551 if (offset >= gdev->ngpio) {
552 ret = -EINVAL;
553 goto out_free_descs;
554 }
555
556 desc = &gdev->descs[offset];
557 ret = gpiod_request(desc, lh->label);
558 if (ret)
559 goto out_free_descs;
560 lh->descs[i] = desc;
561 count = i;
562
563 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
564 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
565 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
566 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
567 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
568 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
569
570 ret = gpiod_set_transitory(desc, false);
571 if (ret < 0)
572 goto out_free_descs;
573
574 /*
575 * Lines have to be requested explicitly for input
576 * or output, else the line will be treated "as is".
577 */
578 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
579 int val = !!handlereq.default_values[i];
580
581 ret = gpiod_direction_output(desc, val);
582 if (ret)
583 goto out_free_descs;
584 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
585 ret = gpiod_direction_input(desc);
586 if (ret)
587 goto out_free_descs;
588 }
589 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
590 offset);
591 }
592 /* Let i point at the last handle */
593 i--;
594 lh->numdescs = handlereq.lines;
595
596 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
597 if (fd < 0) {
598 ret = fd;
599 goto out_free_descs;
600 }
601
602 file = anon_inode_getfile("gpio-linehandle",
603 &linehandle_fileops,
604 lh,
605 O_RDONLY | O_CLOEXEC);
606 if (IS_ERR(file)) {
607 ret = PTR_ERR(file);
608 goto out_put_unused_fd;
609 }
610
611 handlereq.fd = fd;
612 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
613 /*
614 * fput() will trigger the release() callback, so do not go onto
615 * the regular error cleanup path here.
616 */
617 fput(file);
618 put_unused_fd(fd);
619 return -EFAULT;
620 }
621
622 fd_install(fd, file);
623
624 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
625 lh->numdescs);
626
627 return 0;
628
629out_put_unused_fd:
630 put_unused_fd(fd);
631out_free_descs:
632 for (i = 0; i < count; i++)
633 gpiod_free(lh->descs[i]);
634 kfree(lh->label);
635out_free_lh:
636 kfree(lh);
637 put_device(&gdev->dev);
638 return ret;
639}
640
641/*
642 * GPIO line event management
643 */
644
645/**
646 * struct lineevent_state - contains the state of a userspace event
647 * @gdev: the GPIO device the event pertains to
648 * @label: consumer label used to tag descriptors
649 * @desc: the GPIO descriptor held by this event
650 * @eflags: the event flags this line was requested with
651 * @irq: the interrupt that trigger in response to events on this GPIO
652 * @wait: wait queue that handles blocking reads of events
653 * @events: KFIFO for the GPIO events
654 * @read_lock: mutex lock to protect reads from colliding with adding
655 * new events to the FIFO
656 * @timestamp: cache for the timestamp storing it between hardirq
657 * and IRQ thread, used to bring the timestamp close to the actual
658 * event
659 */
660struct lineevent_state {
661 struct gpio_device *gdev;
662 const char *label;
663 struct gpio_desc *desc;
664 u32 eflags;
665 int irq;
666 wait_queue_head_t wait;
667 DECLARE_KFIFO(events, struct gpioevent_data, 16);
668 struct mutex read_lock;
669 u64 timestamp;
670};
671
672#define GPIOEVENT_REQUEST_VALID_FLAGS \
673 (GPIOEVENT_REQUEST_RISING_EDGE | \
674 GPIOEVENT_REQUEST_FALLING_EDGE)
675
676static __poll_t lineevent_poll(struct file *filep,
677 struct poll_table_struct *wait)
678{
679 struct lineevent_state *le = filep->private_data;
680 __poll_t events = 0;
681
682 poll_wait(filep, &le->wait, wait);
683
684 if (!kfifo_is_empty(&le->events))
685 events = EPOLLIN | EPOLLRDNORM;
686
687 return events;
688}
689
690
691static ssize_t lineevent_read(struct file *filep,
692 char __user *buf,
693 size_t count,
694 loff_t *f_ps)
695{
696 struct lineevent_state *le = filep->private_data;
697 unsigned int copied;
698 int ret;
699
700 if (count < sizeof(struct gpioevent_data))
701 return -EINVAL;
702
703 do {
704 if (kfifo_is_empty(&le->events)) {
705 if (filep->f_flags & O_NONBLOCK)
706 return -EAGAIN;
707
708 ret = wait_event_interruptible(le->wait,
709 !kfifo_is_empty(&le->events));
710 if (ret)
711 return ret;
712 }
713
714 if (mutex_lock_interruptible(&le->read_lock))
715 return -ERESTARTSYS;
716 ret = kfifo_to_user(&le->events, buf, count, &copied);
717 mutex_unlock(&le->read_lock);
718
719 if (ret)
720 return ret;
721
722 /*
723 * If we couldn't read anything from the fifo (a different
724 * thread might have been faster) we either return -EAGAIN if
725 * the file descriptor is non-blocking, otherwise we go back to
726 * sleep and wait for more data to arrive.
727 */
728 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
729 return -EAGAIN;
730
731 } while (copied == 0);
732
733 return copied;
734}
735
736static int lineevent_release(struct inode *inode, struct file *filep)
737{
738 struct lineevent_state *le = filep->private_data;
739 struct gpio_device *gdev = le->gdev;
740
741 free_irq(le->irq, le);
742 gpiod_free(le->desc);
743 kfree(le->label);
744 kfree(le);
745 put_device(&gdev->dev);
746 return 0;
747}
748
749static long lineevent_ioctl(struct file *filep, unsigned int cmd,
750 unsigned long arg)
751{
752 struct lineevent_state *le = filep->private_data;
753 void __user *ip = (void __user *)arg;
754 struct gpiohandle_data ghd;
755
756 /*
757 * We can get the value for an event line but not set it,
758 * because it is input by definition.
759 */
760 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
761 int val;
762
763 memset(&ghd, 0, sizeof(ghd));
764
765 val = gpiod_get_value_cansleep(le->desc);
766 if (val < 0)
767 return val;
768 ghd.values[0] = val;
769
770 if (copy_to_user(ip, &ghd, sizeof(ghd)))
771 return -EFAULT;
772
773 return 0;
774 }
775 return -EINVAL;
776}
777
778#ifdef CONFIG_COMPAT
779static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
780 unsigned long arg)
781{
782 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
783}
784#endif
785
786static const struct file_operations lineevent_fileops = {
787 .release = lineevent_release,
788 .read = lineevent_read,
789 .poll = lineevent_poll,
790 .owner = THIS_MODULE,
791 .llseek = noop_llseek,
792 .unlocked_ioctl = lineevent_ioctl,
793#ifdef CONFIG_COMPAT
794 .compat_ioctl = lineevent_ioctl_compat,
795#endif
796};
797
798static irqreturn_t lineevent_irq_thread(int irq, void *p)
799{
800 struct lineevent_state *le = p;
801 struct gpioevent_data ge;
802 int ret, level;
803
804 /* Do not leak kernel stack to userspace */
805 memset(&ge, 0, sizeof(ge));
806
807 ge.timestamp = le->timestamp;
808 level = gpiod_get_value_cansleep(le->desc);
809
810 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
811 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
812 if (level)
813 /* Emit low-to-high event */
814 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
815 else
816 /* Emit high-to-low event */
817 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
818 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
819 /* Emit low-to-high event */
820 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
821 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
822 /* Emit high-to-low event */
823 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
824 } else {
825 return IRQ_NONE;
826 }
827
828 ret = kfifo_put(&le->events, ge);
829 if (ret != 0)
830 wake_up_poll(&le->wait, EPOLLIN);
831
832 return IRQ_HANDLED;
833}
834
835static irqreturn_t lineevent_irq_handler(int irq, void *p)
836{
837 struct lineevent_state *le = p;
838
839 /*
840 * Just store the timestamp in hardirq context so we get it as
841 * close in time as possible to the actual event.
842 */
843 le->timestamp = ktime_get_real_ns();
844
845 return IRQ_WAKE_THREAD;
846}
847
848static int lineevent_create(struct gpio_device *gdev, void __user *ip)
849{
850 struct gpioevent_request eventreq;
851 struct lineevent_state *le;
852 struct gpio_desc *desc;
853 struct file *file;
854 u32 offset;
855 u32 lflags;
856 u32 eflags;
857 int fd;
858 int ret;
859 int irqflags = 0;
860
861 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
862 return -EFAULT;
863
864 le = kzalloc(sizeof(*le), GFP_KERNEL);
865 if (!le)
866 return -ENOMEM;
867 le->gdev = gdev;
868 get_device(&gdev->dev);
869
870 /* Make sure this is terminated */
871 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
872 if (strlen(eventreq.consumer_label)) {
873 le->label = kstrdup(eventreq.consumer_label,
874 GFP_KERNEL);
875 if (!le->label) {
876 ret = -ENOMEM;
877 goto out_free_le;
878 }
879 }
880
881 offset = eventreq.lineoffset;
882 lflags = eventreq.handleflags;
883 eflags = eventreq.eventflags;
884
885 if (offset >= gdev->ngpio) {
886 ret = -EINVAL;
887 goto out_free_label;
888 }
889
890 /* Return an error if a unknown flag is set */
891 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
892 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
893 ret = -EINVAL;
894 goto out_free_label;
895 }
896
897 /* This is just wrong: we don't look for events on output lines */
898 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
899 ret = -EINVAL;
900 goto out_free_label;
901 }
902
903 desc = &gdev->descs[offset];
904 ret = gpiod_request(desc, le->label);
905 if (ret)
906 goto out_free_label;
907 le->desc = desc;
908 le->eflags = eflags;
909
910 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
911 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
912 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
913 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
914 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
915 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
916
917 ret = gpiod_direction_input(desc);
918 if (ret)
919 goto out_free_desc;
920
921 le->irq = gpiod_to_irq(desc);
922 if (le->irq <= 0) {
923 ret = -ENODEV;
924 goto out_free_desc;
925 }
926
927 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
928 irqflags |= IRQF_TRIGGER_RISING;
929 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
930 irqflags |= IRQF_TRIGGER_FALLING;
931 irqflags |= IRQF_ONESHOT;
932 irqflags |= IRQF_SHARED;
933
934 INIT_KFIFO(le->events);
935 init_waitqueue_head(&le->wait);
936 mutex_init(&le->read_lock);
937
938 /* Request a thread to read the events */
939 ret = request_threaded_irq(le->irq,
940 lineevent_irq_handler,
941 lineevent_irq_thread,
942 irqflags,
943 le->label,
944 le);
945 if (ret)
946 goto out_free_desc;
947
948 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
949 if (fd < 0) {
950 ret = fd;
951 goto out_free_irq;
952 }
953
954 file = anon_inode_getfile("gpio-event",
955 &lineevent_fileops,
956 le,
957 O_RDONLY | O_CLOEXEC);
958 if (IS_ERR(file)) {
959 ret = PTR_ERR(file);
960 goto out_put_unused_fd;
961 }
962
963 eventreq.fd = fd;
964 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
965 /*
966 * fput() will trigger the release() callback, so do not go onto
967 * the regular error cleanup path here.
968 */
969 fput(file);
970 put_unused_fd(fd);
971 return -EFAULT;
972 }
973
974 fd_install(fd, file);
975
976 return 0;
977
978out_put_unused_fd:
979 put_unused_fd(fd);
980out_free_irq:
981 free_irq(le->irq, le);
982out_free_desc:
983 gpiod_free(le->desc);
984out_free_label:
985 kfree(le->label);
986out_free_le:
987 kfree(le);
988 put_device(&gdev->dev);
989 return ret;
990}
991
992/*
993 * gpio_ioctl() - ioctl handler for the GPIO chardev
994 */
995static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
996{
997 struct gpio_device *gdev = filp->private_data;
998 struct gpio_chip *chip = gdev->chip;
999 void __user *ip = (void __user *)arg;
1000
1001 /* We fail any subsequent ioctl():s when the chip is gone */
1002 if (!chip)
1003 return -ENODEV;
1004
1005 /* Fill in the struct and pass to userspace */
1006 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1007 struct gpiochip_info chipinfo;
1008
1009 memset(&chipinfo, 0, sizeof(chipinfo));
1010
1011 strncpy(chipinfo.name, dev_name(&gdev->dev),
1012 sizeof(chipinfo.name));
1013 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1014 strncpy(chipinfo.label, gdev->label,
1015 sizeof(chipinfo.label));
1016 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1017 chipinfo.lines = gdev->ngpio;
1018 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1019 return -EFAULT;
1020 return 0;
1021 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1022 struct gpioline_info lineinfo;
1023 struct gpio_desc *desc;
1024
1025 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1026 return -EFAULT;
1027 if (lineinfo.line_offset >= gdev->ngpio)
1028 return -EINVAL;
1029
1030 desc = &gdev->descs[lineinfo.line_offset];
1031 if (desc->name) {
1032 strncpy(lineinfo.name, desc->name,
1033 sizeof(lineinfo.name));
1034 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1035 } else {
1036 lineinfo.name[0] = '\0';
1037 }
1038 if (desc->label) {
1039 strncpy(lineinfo.consumer, desc->label,
1040 sizeof(lineinfo.consumer));
1041 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1042 } else {
1043 lineinfo.consumer[0] = '\0';
1044 }
1045
1046 /*
1047 * Userspace only need to know that the kernel is using
1048 * this GPIO so it can't use it.
1049 */
1050 lineinfo.flags = 0;
1051 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1052 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1053 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1054 test_bit(FLAG_EXPORT, &desc->flags) ||
1055 test_bit(FLAG_SYSFS, &desc->flags))
1056 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1057 if (test_bit(FLAG_IS_OUT, &desc->flags))
1058 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1059 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1060 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1061 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1062 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1063 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1064 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1065
1066 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1067 return -EFAULT;
1068 return 0;
1069 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1070 return linehandle_create(gdev, ip);
1071 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1072 return lineevent_create(gdev, ip);
1073 }
1074 return -EINVAL;
1075}
1076
1077#ifdef CONFIG_COMPAT
1078static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1079 unsigned long arg)
1080{
1081 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1082}
1083#endif
1084
1085/**
1086 * gpio_chrdev_open() - open the chardev for ioctl operations
1087 * @inode: inode for this chardev
1088 * @filp: file struct for storing private data
1089 * Returns 0 on success
1090 */
1091static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1092{
1093 struct gpio_device *gdev = container_of(inode->i_cdev,
1094 struct gpio_device, chrdev);
1095
1096 /* Fail on open if the backing gpiochip is gone */
1097 if (!gdev->chip)
1098 return -ENODEV;
1099 get_device(&gdev->dev);
1100 filp->private_data = gdev;
1101
1102 return nonseekable_open(inode, filp);
1103}
1104
1105/**
1106 * gpio_chrdev_release() - close chardev after ioctl operations
1107 * @inode: inode for this chardev
1108 * @filp: file struct for storing private data
1109 * Returns 0 on success
1110 */
1111static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1112{
1113 struct gpio_device *gdev = container_of(inode->i_cdev,
1114 struct gpio_device, chrdev);
1115
1116 put_device(&gdev->dev);
1117 return 0;
1118}
1119
1120
1121static const struct file_operations gpio_fileops = {
1122 .release = gpio_chrdev_release,
1123 .open = gpio_chrdev_open,
1124 .owner = THIS_MODULE,
1125 .llseek = no_llseek,
1126 .unlocked_ioctl = gpio_ioctl,
1127#ifdef CONFIG_COMPAT
1128 .compat_ioctl = gpio_ioctl_compat,
1129#endif
1130};
1131
1132static void gpiodevice_release(struct device *dev)
1133{
1134 struct gpio_device *gdev = dev_get_drvdata(dev);
1135
1136 list_del(&gdev->list);
1137 ida_simple_remove(&gpio_ida, gdev->id);
1138 kfree_const(gdev->label);
1139 kfree(gdev->descs);
1140 kfree(gdev);
1141}
1142
1143static int gpiochip_setup_dev(struct gpio_device *gdev)
1144{
1145 int status;
1146
1147 cdev_init(&gdev->chrdev, &gpio_fileops);
1148 gdev->chrdev.owner = THIS_MODULE;
1149 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1150
1151 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1152 if (status)
1153 return status;
1154
1155 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1156 MAJOR(gpio_devt), gdev->id);
1157
1158 status = gpiochip_sysfs_register(gdev);
1159 if (status)
1160 goto err_remove_device;
1161
1162 /* From this point, the .release() function cleans up gpio_device */
1163 gdev->dev.release = gpiodevice_release;
1164 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1165 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1166 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1167
1168 return 0;
1169
1170err_remove_device:
1171 cdev_device_del(&gdev->chrdev, &gdev->dev);
1172 return status;
1173}
1174
1175static void gpiochip_setup_devs(void)
1176{
1177 struct gpio_device *gdev;
1178 int err;
1179
1180 list_for_each_entry(gdev, &gpio_devices, list) {
1181 err = gpiochip_setup_dev(gdev);
1182 if (err)
1183 pr_err("%s: Failed to initialize gpio device (%d)\n",
1184 dev_name(&gdev->dev), err);
1185 }
1186}
1187
1188int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1189 struct lock_class_key *lock_key,
1190 struct lock_class_key *request_key)
1191{
1192 unsigned long flags;
1193 int status = 0;
1194 unsigned i;
1195 int base = chip->base;
1196 struct gpio_device *gdev;
1197
1198 /*
1199 * First: allocate and populate the internal stat container, and
1200 * set up the struct device.
1201 */
1202 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1203 if (!gdev)
1204 return -ENOMEM;
1205 gdev->dev.bus = &gpio_bus_type;
1206 gdev->chip = chip;
1207 chip->gpiodev = gdev;
1208 if (chip->parent) {
1209 gdev->dev.parent = chip->parent;
1210 gdev->dev.of_node = chip->parent->of_node;
1211 }
1212
1213#ifdef CONFIG_OF_GPIO
1214 /* If the gpiochip has an assigned OF node this takes precedence */
1215 if (chip->of_node)
1216 gdev->dev.of_node = chip->of_node;
1217#endif
1218
1219 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1220 if (gdev->id < 0) {
1221 status = gdev->id;
1222 goto err_free_gdev;
1223 }
1224 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1225 device_initialize(&gdev->dev);
1226 dev_set_drvdata(&gdev->dev, gdev);
1227 if (chip->parent && chip->parent->driver)
1228 gdev->owner = chip->parent->driver->owner;
1229 else if (chip->owner)
1230 /* TODO: remove chip->owner */
1231 gdev->owner = chip->owner;
1232 else
1233 gdev->owner = THIS_MODULE;
1234
1235 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1236 if (!gdev->descs) {
1237 status = -ENOMEM;
1238 goto err_free_gdev;
1239 }
1240
1241 if (chip->ngpio == 0) {
1242 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1243 status = -EINVAL;
1244 goto err_free_descs;
1245 }
1246
1247 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1248 if (!gdev->label) {
1249 status = -ENOMEM;
1250 goto err_free_descs;
1251 }
1252
1253 gdev->ngpio = chip->ngpio;
1254 gdev->data = data;
1255
1256 spin_lock_irqsave(&gpio_lock, flags);
1257
1258 /*
1259 * TODO: this allocates a Linux GPIO number base in the global
1260 * GPIO numberspace for this chip. In the long run we want to
1261 * get *rid* of this numberspace and use only descriptors, but
1262 * it may be a pipe dream. It will not happen before we get rid
1263 * of the sysfs interface anyways.
1264 */
1265 if (base < 0) {
1266 base = gpiochip_find_base(chip->ngpio);
1267 if (base < 0) {
1268 status = base;
1269 spin_unlock_irqrestore(&gpio_lock, flags);
1270 goto err_free_label;
1271 }
1272 /*
1273 * TODO: it should not be necessary to reflect the assigned
1274 * base outside of the GPIO subsystem. Go over drivers and
1275 * see if anyone makes use of this, else drop this and assign
1276 * a poison instead.
1277 */
1278 chip->base = base;
1279 }
1280 gdev->base = base;
1281
1282 status = gpiodev_add_to_list(gdev);
1283 if (status) {
1284 spin_unlock_irqrestore(&gpio_lock, flags);
1285 goto err_free_label;
1286 }
1287
1288 spin_unlock_irqrestore(&gpio_lock, flags);
1289
1290 for (i = 0; i < chip->ngpio; i++) {
1291 struct gpio_desc *desc = &gdev->descs[i];
1292
1293 desc->gdev = gdev;
1294
1295 /* REVISIT: most hardware initializes GPIOs as inputs (often
1296 * with pullups enabled) so power usage is minimized. Linux
1297 * code should set the gpio direction first thing; but until
1298 * it does, and in case chip->get_direction is not set, we may
1299 * expose the wrong direction in sysfs.
1300 */
1301 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
1302 }
1303
1304#ifdef CONFIG_PINCTRL
1305 INIT_LIST_HEAD(&gdev->pin_ranges);
1306#endif
1307
1308 status = gpiochip_set_desc_names(chip);
1309 if (status)
1310 goto err_remove_from_list;
1311
1312 status = gpiochip_irqchip_init_valid_mask(chip);
1313 if (status)
1314 goto err_remove_from_list;
1315
1316 status = gpiochip_init_valid_mask(chip);
1317 if (status)
1318 goto err_remove_irqchip_mask;
1319
1320 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1321 if (status)
1322 goto err_remove_chip;
1323
1324 status = of_gpiochip_add(chip);
1325 if (status)
1326 goto err_remove_chip;
1327
1328 acpi_gpiochip_add(chip);
1329
1330 /*
1331 * By first adding the chardev, and then adding the device,
1332 * we get a device node entry in sysfs under
1333 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1334 * coldplug of device nodes and other udev business.
1335 * We can do this only if gpiolib has been initialized.
1336 * Otherwise, defer until later.
1337 */
1338 if (gpiolib_initialized) {
1339 status = gpiochip_setup_dev(gdev);
1340 if (status)
1341 goto err_remove_chip;
1342 }
1343 return 0;
1344
1345err_remove_chip:
1346 acpi_gpiochip_remove(chip);
1347 gpiochip_free_hogs(chip);
1348 of_gpiochip_remove(chip);
1349 gpiochip_free_valid_mask(chip);
1350err_remove_irqchip_mask:
1351 gpiochip_irqchip_free_valid_mask(chip);
1352err_remove_from_list:
1353 spin_lock_irqsave(&gpio_lock, flags);
1354 list_del(&gdev->list);
1355 spin_unlock_irqrestore(&gpio_lock, flags);
1356err_free_label:
1357 kfree_const(gdev->label);
1358err_free_descs:
1359 kfree(gdev->descs);
1360err_free_gdev:
1361 ida_simple_remove(&gpio_ida, gdev->id);
1362 /* failures here can mean systems won't boot... */
1363 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1364 gdev->base, gdev->base + gdev->ngpio - 1,
1365 chip->label ? : "generic");
1366 kfree(gdev);
1367 return status;
1368}
1369EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1370
1371/**
1372 * gpiochip_get_data() - get per-subdriver data for the chip
1373 * @chip: GPIO chip
1374 *
1375 * Returns:
1376 * The per-subdriver data for the chip.
1377 */
1378void *gpiochip_get_data(struct gpio_chip *chip)
1379{
1380 return chip->gpiodev->data;
1381}
1382EXPORT_SYMBOL_GPL(gpiochip_get_data);
1383
1384/**
1385 * gpiochip_remove() - unregister a gpio_chip
1386 * @chip: the chip to unregister
1387 *
1388 * A gpio_chip with any GPIOs still requested may not be removed.
1389 */
1390void gpiochip_remove(struct gpio_chip *chip)
1391{
1392 struct gpio_device *gdev = chip->gpiodev;
1393 struct gpio_desc *desc;
1394 unsigned long flags;
1395 unsigned i;
1396 bool requested = false;
1397
1398 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1399 gpiochip_sysfs_unregister(gdev);
1400 gpiochip_free_hogs(chip);
1401 /* Numb the device, cancelling all outstanding operations */
1402 gdev->chip = NULL;
1403 gpiochip_irqchip_remove(chip);
1404 acpi_gpiochip_remove(chip);
1405 gpiochip_remove_pin_ranges(chip);
1406 of_gpiochip_remove(chip);
1407 gpiochip_free_valid_mask(chip);
1408 /*
1409 * We accept no more calls into the driver from this point, so
1410 * NULL the driver data pointer
1411 */
1412 gdev->data = NULL;
1413
1414 spin_lock_irqsave(&gpio_lock, flags);
1415 for (i = 0; i < gdev->ngpio; i++) {
1416 desc = &gdev->descs[i];
1417 if (test_bit(FLAG_REQUESTED, &desc->flags))
1418 requested = true;
1419 }
1420 spin_unlock_irqrestore(&gpio_lock, flags);
1421
1422 if (requested)
1423 dev_crit(&gdev->dev,
1424 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1425
1426 /*
1427 * The gpiochip side puts its use of the device to rest here:
1428 * if there are no userspace clients, the chardev and device will
1429 * be removed, else it will be dangling until the last user is
1430 * gone.
1431 */
1432 cdev_device_del(&gdev->chrdev, &gdev->dev);
1433 put_device(&gdev->dev);
1434}
1435EXPORT_SYMBOL_GPL(gpiochip_remove);
1436
1437static void devm_gpio_chip_release(struct device *dev, void *res)
1438{
1439 struct gpio_chip *chip = *(struct gpio_chip **)res;
1440
1441 gpiochip_remove(chip);
1442}
1443
1444static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1445
1446{
1447 struct gpio_chip **r = res;
1448
1449 if (!r || !*r) {
1450 WARN_ON(!r || !*r);
1451 return 0;
1452 }
1453
1454 return *r == data;
1455}
1456
1457/**
1458 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1459 * @dev: the device pointer on which irq_chip belongs to.
1460 * @chip: the chip to register, with chip->base initialized
1461 * @data: driver-private data associated with this chip
1462 *
1463 * Context: potentially before irqs will work
1464 *
1465 * The gpio chip automatically be released when the device is unbound.
1466 *
1467 * Returns:
1468 * A negative errno if the chip can't be registered, such as because the
1469 * chip->base is invalid or already associated with a different chip.
1470 * Otherwise it returns zero as a success code.
1471 */
1472int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1473 void *data)
1474{
1475 struct gpio_chip **ptr;
1476 int ret;
1477
1478 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1479 GFP_KERNEL);
1480 if (!ptr)
1481 return -ENOMEM;
1482
1483 ret = gpiochip_add_data(chip, data);
1484 if (ret < 0) {
1485 devres_free(ptr);
1486 return ret;
1487 }
1488
1489 *ptr = chip;
1490 devres_add(dev, ptr);
1491
1492 return 0;
1493}
1494EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1495
1496/**
1497 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1498 * @dev: device for which which resource was allocated
1499 * @chip: the chip to remove
1500 *
1501 * A gpio_chip with any GPIOs still requested may not be removed.
1502 */
1503void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1504{
1505 int ret;
1506
1507 ret = devres_release(dev, devm_gpio_chip_release,
1508 devm_gpio_chip_match, chip);
1509 WARN_ON(ret);
1510}
1511EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1512
1513/**
1514 * gpiochip_find() - iterator for locating a specific gpio_chip
1515 * @data: data to pass to match function
1516 * @match: Callback function to check gpio_chip
1517 *
1518 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1519 * determined by a user supplied @match callback. The callback should return
1520 * 0 if the device doesn't match and non-zero if it does. If the callback is
1521 * non-zero, this function will return to the caller and not iterate over any
1522 * more gpio_chips.
1523 */
1524struct gpio_chip *gpiochip_find(void *data,
1525 int (*match)(struct gpio_chip *chip,
1526 void *data))
1527{
1528 struct gpio_device *gdev;
1529 struct gpio_chip *chip = NULL;
1530 unsigned long flags;
1531
1532 spin_lock_irqsave(&gpio_lock, flags);
1533 list_for_each_entry(gdev, &gpio_devices, list)
1534 if (gdev->chip && match(gdev->chip, data)) {
1535 chip = gdev->chip;
1536 break;
1537 }
1538
1539 spin_unlock_irqrestore(&gpio_lock, flags);
1540
1541 return chip;
1542}
1543EXPORT_SYMBOL_GPL(gpiochip_find);
1544
1545static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1546{
1547 const char *name = data;
1548
1549 return !strcmp(chip->label, name);
1550}
1551
1552static struct gpio_chip *find_chip_by_name(const char *name)
1553{
1554 return gpiochip_find((void *)name, gpiochip_match_name);
1555}
1556
1557#ifdef CONFIG_GPIOLIB_IRQCHIP
1558
1559/*
1560 * The following is irqchip helper code for gpiochips.
1561 */
1562
1563static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1564{
1565 if (!gpiochip->irq.need_valid_mask)
1566 return 0;
1567
1568 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1569 if (!gpiochip->irq.valid_mask)
1570 return -ENOMEM;
1571
1572 return 0;
1573}
1574
1575static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1576{
1577 kfree(gpiochip->irq.valid_mask);
1578 gpiochip->irq.valid_mask = NULL;
1579}
1580
1581bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1582 unsigned int offset)
1583{
1584 if (!gpiochip_line_is_valid(gpiochip, offset))
1585 return false;
1586 /* No mask means all valid */
1587 if (likely(!gpiochip->irq.valid_mask))
1588 return true;
1589 return test_bit(offset, gpiochip->irq.valid_mask);
1590}
1591EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1592
1593/**
1594 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1595 * @gpiochip: the gpiochip to set the irqchip chain to
1596 * @irqchip: the irqchip to chain to the gpiochip
1597 * @parent_irq: the irq number corresponding to the parent IRQ for this
1598 * chained irqchip
1599 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1600 * coming out of the gpiochip. If the interrupt is nested rather than
1601 * cascaded, pass NULL in this handler argument
1602 */
1603static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1604 struct irq_chip *irqchip,
1605 unsigned int parent_irq,
1606 irq_flow_handler_t parent_handler)
1607{
1608 unsigned int offset;
1609
1610 if (!gpiochip->irq.domain) {
1611 chip_err(gpiochip, "called %s before setting up irqchip\n",
1612 __func__);
1613 return;
1614 }
1615
1616 if (parent_handler) {
1617 if (gpiochip->can_sleep) {
1618 chip_err(gpiochip,
1619 "you cannot have chained interrupts on a "
1620 "chip that may sleep\n");
1621 return;
1622 }
1623 /*
1624 * The parent irqchip is already using the chip_data for this
1625 * irqchip, so our callbacks simply use the handler_data.
1626 */
1627 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1628 gpiochip);
1629
1630 gpiochip->irq.parents = &parent_irq;
1631 gpiochip->irq.num_parents = 1;
1632 }
1633
1634 /* Set the parent IRQ for all affected IRQs */
1635 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1636 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1637 continue;
1638 irq_set_parent(irq_find_mapping(gpiochip->irq.domain, offset),
1639 parent_irq);
1640 }
1641}
1642
1643/**
1644 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1645 * @gpiochip: the gpiochip to set the irqchip chain to
1646 * @irqchip: the irqchip to chain to the gpiochip
1647 * @parent_irq: the irq number corresponding to the parent IRQ for this
1648 * chained irqchip
1649 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1650 * coming out of the gpiochip. If the interrupt is nested rather than
1651 * cascaded, pass NULL in this handler argument
1652 */
1653void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1654 struct irq_chip *irqchip,
1655 unsigned int parent_irq,
1656 irq_flow_handler_t parent_handler)
1657{
1658 if (gpiochip->irq.threaded) {
1659 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1660 return;
1661 }
1662
1663 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1664 parent_handler);
1665}
1666EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1667
1668/**
1669 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1670 * @gpiochip: the gpiochip to set the irqchip nested handler to
1671 * @irqchip: the irqchip to nest to the gpiochip
1672 * @parent_irq: the irq number corresponding to the parent IRQ for this
1673 * nested irqchip
1674 */
1675void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1676 struct irq_chip *irqchip,
1677 unsigned int parent_irq)
1678{
1679 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1680 NULL);
1681}
1682EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1683
1684/**
1685 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1686 * @d: the irqdomain used by this irqchip
1687 * @irq: the global irq number used by this GPIO irqchip irq
1688 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1689 *
1690 * This function will set up the mapping for a certain IRQ line on a
1691 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1692 * stored inside the gpiochip.
1693 */
1694int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1695 irq_hw_number_t hwirq)
1696{
1697 struct gpio_chip *chip = d->host_data;
1698 int err = 0;
1699
1700 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1701 return -ENXIO;
1702
1703 irq_set_chip_data(irq, chip);
1704 /*
1705 * This lock class tells lockdep that GPIO irqs are in a different
1706 * category than their parents, so it won't report false recursion.
1707 */
1708 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1709 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1710 /* Chips that use nested thread handlers have them marked */
1711 if (chip->irq.threaded)
1712 irq_set_nested_thread(irq, 1);
1713 irq_set_noprobe(irq);
1714
1715 if (chip->irq.num_parents == 1)
1716 err = irq_set_parent(irq, chip->irq.parents[0]);
1717 else if (chip->irq.map)
1718 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1719
1720 if (err < 0)
1721 return err;
1722
1723 /*
1724 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1725 * is passed as default type.
1726 */
1727 if (chip->irq.default_type != IRQ_TYPE_NONE)
1728 irq_set_irq_type(irq, chip->irq.default_type);
1729
1730 return 0;
1731}
1732EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1733
1734void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1735{
1736 struct gpio_chip *chip = d->host_data;
1737
1738 if (chip->irq.threaded)
1739 irq_set_nested_thread(irq, 0);
1740 irq_set_chip_and_handler(irq, NULL, NULL);
1741 irq_set_chip_data(irq, NULL);
1742}
1743EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1744
1745static const struct irq_domain_ops gpiochip_domain_ops = {
1746 .map = gpiochip_irq_map,
1747 .unmap = gpiochip_irq_unmap,
1748 /* Virtually all GPIO irqchips are twocell:ed */
1749 .xlate = irq_domain_xlate_twocell,
1750};
1751
1752static int gpiochip_irq_reqres(struct irq_data *d)
1753{
1754 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1755
1756 if (!try_module_get(chip->gpiodev->owner))
1757 return -ENODEV;
1758
1759 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1760 chip_err(chip,
1761 "unable to lock HW IRQ %lu for IRQ\n",
1762 d->hwirq);
1763 module_put(chip->gpiodev->owner);
1764 return -EINVAL;
1765 }
1766 return 0;
1767}
1768
1769static void gpiochip_irq_relres(struct irq_data *d)
1770{
1771 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1772
1773 gpiochip_unlock_as_irq(chip, d->hwirq);
1774 module_put(chip->gpiodev->owner);
1775}
1776
1777static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1778{
1779 if (!gpiochip_irqchip_irq_valid(chip, offset))
1780 return -ENXIO;
1781
1782 return irq_create_mapping(chip->irq.domain, offset);
1783}
1784
1785/**
1786 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1787 * @gpiochip: the GPIO chip to add the IRQ chip to
1788 * @lock_key: lockdep class for IRQ lock
1789 * @request_key: lockdep class for IRQ request
1790 */
1791static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1792 struct lock_class_key *lock_key,
1793 struct lock_class_key *request_key)
1794{
1795 struct irq_chip *irqchip = gpiochip->irq.chip;
1796 const struct irq_domain_ops *ops;
1797 struct device_node *np;
1798 unsigned int type;
1799 unsigned int i;
1800
1801 if (!irqchip)
1802 return 0;
1803
1804 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1805 chip_err(gpiochip, "you cannot have chained interrupts on a "
1806 "chip that may sleep\n");
1807 return -EINVAL;
1808 }
1809
1810 np = gpiochip->gpiodev->dev.of_node;
1811 type = gpiochip->irq.default_type;
1812
1813 /*
1814 * Specifying a default trigger is a terrible idea if DT or ACPI is
1815 * used to configure the interrupts, as you may end up with
1816 * conflicting triggers. Tell the user, and reset to NONE.
1817 */
1818 if (WARN(np && type != IRQ_TYPE_NONE,
1819 "%s: Ignoring %u default trigger\n", np->full_name, type))
1820 type = IRQ_TYPE_NONE;
1821
1822 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1823 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1824 "Ignoring %u default trigger\n", type);
1825 type = IRQ_TYPE_NONE;
1826 }
1827
1828 gpiochip->to_irq = gpiochip_to_irq;
1829 gpiochip->irq.default_type = type;
1830 gpiochip->irq.lock_key = lock_key;
1831 gpiochip->irq.request_key = request_key;
1832
1833 if (gpiochip->irq.domain_ops)
1834 ops = gpiochip->irq.domain_ops;
1835 else
1836 ops = &gpiochip_domain_ops;
1837
1838 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1839 gpiochip->irq.first,
1840 ops, gpiochip);
1841 if (!gpiochip->irq.domain)
1842 return -EINVAL;
1843
1844 /*
1845 * It is possible for a driver to override this, but only if the
1846 * alternative functions are both implemented.
1847 */
1848 if (!irqchip->irq_request_resources &&
1849 !irqchip->irq_release_resources) {
1850 irqchip->irq_request_resources = gpiochip_irq_reqres;
1851 irqchip->irq_release_resources = gpiochip_irq_relres;
1852 }
1853
1854 if (gpiochip->irq.parent_handler) {
1855 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1856
1857 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1858 /*
1859 * The parent IRQ chip is already using the chip_data
1860 * for this IRQ chip, so our callbacks simply use the
1861 * handler_data.
1862 */
1863 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1864 gpiochip->irq.parent_handler,
1865 data);
1866 }
1867 }
1868
1869 acpi_gpiochip_request_interrupts(gpiochip);
1870
1871 return 0;
1872}
1873
1874/**
1875 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1876 * @gpiochip: the gpiochip to remove the irqchip from
1877 *
1878 * This is called only from gpiochip_remove()
1879 */
1880static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1881{
1882 unsigned int offset;
1883
1884 acpi_gpiochip_free_interrupts(gpiochip);
1885
1886 if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
1887 struct gpio_irq_chip *irq = &gpiochip->irq;
1888 unsigned int i;
1889
1890 for (i = 0; i < irq->num_parents; i++)
1891 irq_set_chained_handler_and_data(irq->parents[i],
1892 NULL, NULL);
1893 }
1894
1895 /* Remove all IRQ mappings and delete the domain */
1896 if (gpiochip->irq.domain) {
1897 unsigned int irq;
1898
1899 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1900 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1901 continue;
1902
1903 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1904 irq_dispose_mapping(irq);
1905 }
1906
1907 irq_domain_remove(gpiochip->irq.domain);
1908 }
1909
1910 if (gpiochip->irq.chip) {
1911 gpiochip->irq.chip->irq_request_resources = NULL;
1912 gpiochip->irq.chip->irq_release_resources = NULL;
1913 gpiochip->irq.chip = NULL;
1914 }
1915
1916 gpiochip_irqchip_free_valid_mask(gpiochip);
1917}
1918
1919/**
1920 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1921 * @gpiochip: the gpiochip to add the irqchip to
1922 * @irqchip: the irqchip to add to the gpiochip
1923 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1924 * allocate gpiochip irqs from
1925 * @handler: the irq handler to use (often a predefined irq core function)
1926 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1927 * to have the core avoid setting up any default type in the hardware.
1928 * @threaded: whether this irqchip uses a nested thread handler
1929 * @lock_key: lockdep class for IRQ lock
1930 * @request_key: lockdep class for IRQ request
1931 *
1932 * This function closely associates a certain irqchip with a certain
1933 * gpiochip, providing an irq domain to translate the local IRQs to
1934 * global irqs in the gpiolib core, and making sure that the gpiochip
1935 * is passed as chip data to all related functions. Driver callbacks
1936 * need to use gpiochip_get_data() to get their local state containers back
1937 * from the gpiochip passed as chip data. An irqdomain will be stored
1938 * in the gpiochip that shall be used by the driver to handle IRQ number
1939 * translation. The gpiochip will need to be initialized and registered
1940 * before calling this function.
1941 *
1942 * This function will handle two cell:ed simple IRQs and assumes all
1943 * the pins on the gpiochip can generate a unique IRQ. Everything else
1944 * need to be open coded.
1945 */
1946int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
1947 struct irq_chip *irqchip,
1948 unsigned int first_irq,
1949 irq_flow_handler_t handler,
1950 unsigned int type,
1951 bool threaded,
1952 struct lock_class_key *lock_key,
1953 struct lock_class_key *request_key)
1954{
1955 struct device_node *of_node;
1956
1957 if (!gpiochip || !irqchip)
1958 return -EINVAL;
1959
1960 if (!gpiochip->parent) {
1961 pr_err("missing gpiochip .dev parent pointer\n");
1962 return -EINVAL;
1963 }
1964 gpiochip->irq.threaded = threaded;
1965 of_node = gpiochip->parent->of_node;
1966#ifdef CONFIG_OF_GPIO
1967 /*
1968 * If the gpiochip has an assigned OF node this takes precedence
1969 * FIXME: get rid of this and use gpiochip->parent->of_node
1970 * everywhere
1971 */
1972 if (gpiochip->of_node)
1973 of_node = gpiochip->of_node;
1974#endif
1975 /*
1976 * Specifying a default trigger is a terrible idea if DT or ACPI is
1977 * used to configure the interrupts, as you may end-up with
1978 * conflicting triggers. Tell the user, and reset to NONE.
1979 */
1980 if (WARN(of_node && type != IRQ_TYPE_NONE,
1981 "%pOF: Ignoring %d default trigger\n", of_node, type))
1982 type = IRQ_TYPE_NONE;
1983 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1984 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1985 "Ignoring %d default trigger\n", type);
1986 type = IRQ_TYPE_NONE;
1987 }
1988
1989 gpiochip->irq.chip = irqchip;
1990 gpiochip->irq.handler = handler;
1991 gpiochip->irq.default_type = type;
1992 gpiochip->to_irq = gpiochip_to_irq;
1993 gpiochip->irq.lock_key = lock_key;
1994 gpiochip->irq.request_key = request_key;
1995 gpiochip->irq.domain = irq_domain_add_simple(of_node,
1996 gpiochip->ngpio, first_irq,
1997 &gpiochip_domain_ops, gpiochip);
1998 if (!gpiochip->irq.domain) {
1999 gpiochip->irq.chip = NULL;
2000 return -EINVAL;
2001 }
2002
2003 /*
2004 * It is possible for a driver to override this, but only if the
2005 * alternative functions are both implemented.
2006 */
2007 if (!irqchip->irq_request_resources &&
2008 !irqchip->irq_release_resources) {
2009 irqchip->irq_request_resources = gpiochip_irq_reqres;
2010 irqchip->irq_release_resources = gpiochip_irq_relres;
2011 }
2012
2013 acpi_gpiochip_request_interrupts(gpiochip);
2014
2015 return 0;
2016}
2017EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2018
2019#else /* CONFIG_GPIOLIB_IRQCHIP */
2020
2021static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2022 struct lock_class_key *lock_key,
2023 struct lock_class_key *request_key)
2024{
2025 return 0;
2026}
2027
2028static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2029static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2030{
2031 return 0;
2032}
2033static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2034{ }
2035
2036#endif /* CONFIG_GPIOLIB_IRQCHIP */
2037
2038/**
2039 * gpiochip_generic_request() - request the gpio function for a pin
2040 * @chip: the gpiochip owning the GPIO
2041 * @offset: the offset of the GPIO to request for GPIO function
2042 */
2043int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2044{
2045 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2046}
2047EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2048
2049/**
2050 * gpiochip_generic_free() - free the gpio function from a pin
2051 * @chip: the gpiochip to request the gpio function for
2052 * @offset: the offset of the GPIO to free from GPIO function
2053 */
2054void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2055{
2056 pinctrl_gpio_free(chip->gpiodev->base + offset);
2057}
2058EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2059
2060/**
2061 * gpiochip_generic_config() - apply configuration for a pin
2062 * @chip: the gpiochip owning the GPIO
2063 * @offset: the offset of the GPIO to apply the configuration
2064 * @config: the configuration to be applied
2065 */
2066int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2067 unsigned long config)
2068{
2069 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2070}
2071EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2072
2073#ifdef CONFIG_PINCTRL
2074
2075/**
2076 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2077 * @chip: the gpiochip to add the range for
2078 * @pctldev: the pin controller to map to
2079 * @gpio_offset: the start offset in the current gpio_chip number space
2080 * @pin_group: name of the pin group inside the pin controller
2081 */
2082int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2083 struct pinctrl_dev *pctldev,
2084 unsigned int gpio_offset, const char *pin_group)
2085{
2086 struct gpio_pin_range *pin_range;
2087 struct gpio_device *gdev = chip->gpiodev;
2088 int ret;
2089
2090 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2091 if (!pin_range) {
2092 chip_err(chip, "failed to allocate pin ranges\n");
2093 return -ENOMEM;
2094 }
2095
2096 /* Use local offset as range ID */
2097 pin_range->range.id = gpio_offset;
2098 pin_range->range.gc = chip;
2099 pin_range->range.name = chip->label;
2100 pin_range->range.base = gdev->base + gpio_offset;
2101 pin_range->pctldev = pctldev;
2102
2103 ret = pinctrl_get_group_pins(pctldev, pin_group,
2104 &pin_range->range.pins,
2105 &pin_range->range.npins);
2106 if (ret < 0) {
2107 kfree(pin_range);
2108 return ret;
2109 }
2110
2111 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2112
2113 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2114 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2115 pinctrl_dev_get_devname(pctldev), pin_group);
2116
2117 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2118
2119 return 0;
2120}
2121EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2122
2123/**
2124 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2125 * @chip: the gpiochip to add the range for
2126 * @pinctl_name: the dev_name() of the pin controller to map to
2127 * @gpio_offset: the start offset in the current gpio_chip number space
2128 * @pin_offset: the start offset in the pin controller number space
2129 * @npins: the number of pins from the offset of each pin space (GPIO and
2130 * pin controller) to accumulate in this range
2131 *
2132 * Returns:
2133 * 0 on success, or a negative error-code on failure.
2134 */
2135int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2136 unsigned int gpio_offset, unsigned int pin_offset,
2137 unsigned int npins)
2138{
2139 struct gpio_pin_range *pin_range;
2140 struct gpio_device *gdev = chip->gpiodev;
2141 int ret;
2142
2143 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2144 if (!pin_range) {
2145 chip_err(chip, "failed to allocate pin ranges\n");
2146 return -ENOMEM;
2147 }
2148
2149 /* Use local offset as range ID */
2150 pin_range->range.id = gpio_offset;
2151 pin_range->range.gc = chip;
2152 pin_range->range.name = chip->label;
2153 pin_range->range.base = gdev->base + gpio_offset;
2154 pin_range->range.pin_base = pin_offset;
2155 pin_range->range.npins = npins;
2156 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2157 &pin_range->range);
2158 if (IS_ERR(pin_range->pctldev)) {
2159 ret = PTR_ERR(pin_range->pctldev);
2160 chip_err(chip, "could not create pin range\n");
2161 kfree(pin_range);
2162 return ret;
2163 }
2164 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2165 gpio_offset, gpio_offset + npins - 1,
2166 pinctl_name,
2167 pin_offset, pin_offset + npins - 1);
2168
2169 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2170
2171 return 0;
2172}
2173EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2174
2175/**
2176 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2177 * @chip: the chip to remove all the mappings for
2178 */
2179void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2180{
2181 struct gpio_pin_range *pin_range, *tmp;
2182 struct gpio_device *gdev = chip->gpiodev;
2183
2184 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2185 list_del(&pin_range->node);
2186 pinctrl_remove_gpio_range(pin_range->pctldev,
2187 &pin_range->range);
2188 kfree(pin_range);
2189 }
2190}
2191EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2192
2193#endif /* CONFIG_PINCTRL */
2194
2195/* These "optional" allocation calls help prevent drivers from stomping
2196 * on each other, and help provide better diagnostics in debugfs.
2197 * They're called even less than the "set direction" calls.
2198 */
2199static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2200{
2201 struct gpio_chip *chip = desc->gdev->chip;
2202 int status;
2203 unsigned long flags;
2204
2205 spin_lock_irqsave(&gpio_lock, flags);
2206
2207 /* NOTE: gpio_request() can be called in early boot,
2208 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2209 */
2210
2211 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2212 desc_set_label(desc, label ? : "?");
2213 status = 0;
2214 } else {
2215 status = -EBUSY;
2216 goto done;
2217 }
2218
2219 if (chip->request) {
2220 /* chip->request may sleep */
2221 spin_unlock_irqrestore(&gpio_lock, flags);
2222 status = chip->request(chip, gpio_chip_hwgpio(desc));
2223 spin_lock_irqsave(&gpio_lock, flags);
2224
2225 if (status < 0) {
2226 desc_set_label(desc, NULL);
2227 clear_bit(FLAG_REQUESTED, &desc->flags);
2228 goto done;
2229 }
2230 }
2231 if (chip->get_direction) {
2232 /* chip->get_direction may sleep */
2233 spin_unlock_irqrestore(&gpio_lock, flags);
2234 gpiod_get_direction(desc);
2235 spin_lock_irqsave(&gpio_lock, flags);
2236 }
2237done:
2238 spin_unlock_irqrestore(&gpio_lock, flags);
2239 return status;
2240}
2241
2242/*
2243 * This descriptor validation needs to be inserted verbatim into each
2244 * function taking a descriptor, so we need to use a preprocessor
2245 * macro to avoid endless duplication. If the desc is NULL it is an
2246 * optional GPIO and calls should just bail out.
2247 */
2248static int validate_desc(const struct gpio_desc *desc, const char *func)
2249{
2250 if (!desc)
2251 return 0;
2252 if (IS_ERR(desc)) {
2253 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2254 return PTR_ERR(desc);
2255 }
2256 if (!desc->gdev) {
2257 pr_warn("%s: invalid GPIO (no device)\n", func);
2258 return -EINVAL;
2259 }
2260 if (!desc->gdev->chip) {
2261 dev_warn(&desc->gdev->dev,
2262 "%s: backing chip is gone\n", func);
2263 return 0;
2264 }
2265 return 1;
2266}
2267
2268#define VALIDATE_DESC(desc) do { \
2269 int __valid = validate_desc(desc, __func__); \
2270 if (__valid <= 0) \
2271 return __valid; \
2272 } while (0)
2273
2274#define VALIDATE_DESC_VOID(desc) do { \
2275 int __valid = validate_desc(desc, __func__); \
2276 if (__valid <= 0) \
2277 return; \
2278 } while (0)
2279
2280int gpiod_request(struct gpio_desc *desc, const char *label)
2281{
2282 int status = -EPROBE_DEFER;
2283 struct gpio_device *gdev;
2284
2285 VALIDATE_DESC(desc);
2286 gdev = desc->gdev;
2287
2288 if (try_module_get(gdev->owner)) {
2289 status = gpiod_request_commit(desc, label);
2290 if (status < 0)
2291 module_put(gdev->owner);
2292 else
2293 get_device(&gdev->dev);
2294 }
2295
2296 if (status)
2297 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2298
2299 return status;
2300}
2301
2302static bool gpiod_free_commit(struct gpio_desc *desc)
2303{
2304 bool ret = false;
2305 unsigned long flags;
2306 struct gpio_chip *chip;
2307
2308 might_sleep();
2309
2310 gpiod_unexport(desc);
2311
2312 spin_lock_irqsave(&gpio_lock, flags);
2313
2314 chip = desc->gdev->chip;
2315 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2316 if (chip->free) {
2317 spin_unlock_irqrestore(&gpio_lock, flags);
2318 might_sleep_if(chip->can_sleep);
2319 chip->free(chip, gpio_chip_hwgpio(desc));
2320 spin_lock_irqsave(&gpio_lock, flags);
2321 }
2322 desc_set_label(desc, NULL);
2323 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2324 clear_bit(FLAG_REQUESTED, &desc->flags);
2325 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2326 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2327 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2328 ret = true;
2329 }
2330
2331 spin_unlock_irqrestore(&gpio_lock, flags);
2332 return ret;
2333}
2334
2335void gpiod_free(struct gpio_desc *desc)
2336{
2337 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2338 module_put(desc->gdev->owner);
2339 put_device(&desc->gdev->dev);
2340 } else {
2341 WARN_ON(extra_checks);
2342 }
2343}
2344
2345/**
2346 * gpiochip_is_requested - return string iff signal was requested
2347 * @chip: controller managing the signal
2348 * @offset: of signal within controller's 0..(ngpio - 1) range
2349 *
2350 * Returns NULL if the GPIO is not currently requested, else a string.
2351 * The string returned is the label passed to gpio_request(); if none has been
2352 * passed it is a meaningless, non-NULL constant.
2353 *
2354 * This function is for use by GPIO controller drivers. The label can
2355 * help with diagnostics, and knowing that the signal is used as a GPIO
2356 * can help avoid accidentally multiplexing it to another controller.
2357 */
2358const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2359{
2360 struct gpio_desc *desc;
2361
2362 if (offset >= chip->ngpio)
2363 return NULL;
2364
2365 desc = &chip->gpiodev->descs[offset];
2366
2367 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2368 return NULL;
2369 return desc->label;
2370}
2371EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2372
2373/**
2374 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2375 * @chip: GPIO chip
2376 * @hwnum: hardware number of the GPIO for which to request the descriptor
2377 * @label: label for the GPIO
2378 *
2379 * Function allows GPIO chip drivers to request and use their own GPIO
2380 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2381 * function will not increase reference count of the GPIO chip module. This
2382 * allows the GPIO chip module to be unloaded as needed (we assume that the
2383 * GPIO chip driver handles freeing the GPIOs it has requested).
2384 *
2385 * Returns:
2386 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2387 * code on failure.
2388 */
2389struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2390 const char *label)
2391{
2392 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2393 int err;
2394
2395 if (IS_ERR(desc)) {
2396 chip_err(chip, "failed to get GPIO descriptor\n");
2397 return desc;
2398 }
2399
2400 err = gpiod_request_commit(desc, label);
2401 if (err < 0)
2402 return ERR_PTR(err);
2403
2404 return desc;
2405}
2406EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2407
2408/**
2409 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2410 * @desc: GPIO descriptor to free
2411 *
2412 * Function frees the given GPIO requested previously with
2413 * gpiochip_request_own_desc().
2414 */
2415void gpiochip_free_own_desc(struct gpio_desc *desc)
2416{
2417 if (desc)
2418 gpiod_free_commit(desc);
2419}
2420EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2421
2422/*
2423 * Drivers MUST set GPIO direction before making get/set calls. In
2424 * some cases this is done in early boot, before IRQs are enabled.
2425 *
2426 * As a rule these aren't called more than once (except for drivers
2427 * using the open-drain emulation idiom) so these are natural places
2428 * to accumulate extra debugging checks. Note that we can't (yet)
2429 * rely on gpio_request() having been called beforehand.
2430 */
2431
2432/**
2433 * gpiod_direction_input - set the GPIO direction to input
2434 * @desc: GPIO to set to input
2435 *
2436 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2437 * be called safely on it.
2438 *
2439 * Return 0 in case of success, else an error code.
2440 */
2441int gpiod_direction_input(struct gpio_desc *desc)
2442{
2443 struct gpio_chip *chip;
2444 int status = -EINVAL;
2445
2446 VALIDATE_DESC(desc);
2447 chip = desc->gdev->chip;
2448
2449 if (!chip->get || !chip->direction_input) {
2450 gpiod_warn(desc,
2451 "%s: missing get() or direction_input() operations\n",
2452 __func__);
2453 return -EIO;
2454 }
2455
2456 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2457 if (status == 0)
2458 clear_bit(FLAG_IS_OUT, &desc->flags);
2459
2460 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2461
2462 return status;
2463}
2464EXPORT_SYMBOL_GPL(gpiod_direction_input);
2465
2466static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2467 enum pin_config_param mode)
2468{
2469 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2470
2471 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2472}
2473
2474static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2475{
2476 struct gpio_chip *gc = desc->gdev->chip;
2477 int val = !!value;
2478 int ret;
2479
2480 if (!gc->set || !gc->direction_output) {
2481 gpiod_warn(desc,
2482 "%s: missing set() or direction_output() operations\n",
2483 __func__);
2484 return -EIO;
2485 }
2486
2487 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2488 if (!ret)
2489 set_bit(FLAG_IS_OUT, &desc->flags);
2490 trace_gpio_value(desc_to_gpio(desc), 0, val);
2491 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2492 return ret;
2493}
2494
2495/**
2496 * gpiod_direction_output_raw - set the GPIO direction to output
2497 * @desc: GPIO to set to output
2498 * @value: initial output value of the GPIO
2499 *
2500 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2501 * be called safely on it. The initial value of the output must be specified
2502 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2503 *
2504 * Return 0 in case of success, else an error code.
2505 */
2506int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2507{
2508 VALIDATE_DESC(desc);
2509 return gpiod_direction_output_raw_commit(desc, value);
2510}
2511EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2512
2513/**
2514 * gpiod_direction_output - set the GPIO direction to output
2515 * @desc: GPIO to set to output
2516 * @value: initial output value of the GPIO
2517 *
2518 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2519 * be called safely on it. The initial value of the output must be specified
2520 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2521 * account.
2522 *
2523 * Return 0 in case of success, else an error code.
2524 */
2525int gpiod_direction_output(struct gpio_desc *desc, int value)
2526{
2527 struct gpio_chip *gc;
2528 int ret;
2529
2530 VALIDATE_DESC(desc);
2531 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2532 value = !value;
2533 else
2534 value = !!value;
2535
2536 /* GPIOs used for IRQs shall not be set as output */
2537 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2538 gpiod_err(desc,
2539 "%s: tried to set a GPIO tied to an IRQ as output\n",
2540 __func__);
2541 return -EIO;
2542 }
2543
2544 gc = desc->gdev->chip;
2545 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2546 /* First see if we can enable open drain in hardware */
2547 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2548 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2549 if (!ret)
2550 goto set_output_value;
2551 /* Emulate open drain by not actively driving the line high */
2552 if (value)
2553 return gpiod_direction_input(desc);
2554 }
2555 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2556 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2557 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2558 if (!ret)
2559 goto set_output_value;
2560 /* Emulate open source by not actively driving the line low */
2561 if (!value)
2562 return gpiod_direction_input(desc);
2563 } else {
2564 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2565 PIN_CONFIG_DRIVE_PUSH_PULL);
2566 }
2567
2568set_output_value:
2569 return gpiod_direction_output_raw_commit(desc, value);
2570}
2571EXPORT_SYMBOL_GPL(gpiod_direction_output);
2572
2573/**
2574 * gpiod_set_debounce - sets @debounce time for a GPIO
2575 * @desc: descriptor of the GPIO for which to set debounce time
2576 * @debounce: debounce time in microseconds
2577 *
2578 * Returns:
2579 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2580 * debounce time.
2581 */
2582int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2583{
2584 struct gpio_chip *chip;
2585 unsigned long config;
2586
2587 VALIDATE_DESC(desc);
2588 chip = desc->gdev->chip;
2589 if (!chip->set || !chip->set_config) {
2590 gpiod_dbg(desc,
2591 "%s: missing set() or set_config() operations\n",
2592 __func__);
2593 return -ENOTSUPP;
2594 }
2595
2596 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2597 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2598}
2599EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2600
2601/**
2602 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2603 * @desc: descriptor of the GPIO for which to configure persistence
2604 * @transitory: True to lose state on suspend or reset, false for persistence
2605 *
2606 * Returns:
2607 * 0 on success, otherwise a negative error code.
2608 */
2609int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2610{
2611 struct gpio_chip *chip;
2612 unsigned long packed;
2613 int gpio;
2614 int rc;
2615
2616 VALIDATE_DESC(desc);
2617 /*
2618 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2619 * persistence state.
2620 */
2621 if (transitory)
2622 set_bit(FLAG_TRANSITORY, &desc->flags);
2623 else
2624 clear_bit(FLAG_TRANSITORY, &desc->flags);
2625
2626 /* If the driver supports it, set the persistence state now */
2627 chip = desc->gdev->chip;
2628 if (!chip->set_config)
2629 return 0;
2630
2631 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2632 !transitory);
2633 gpio = gpio_chip_hwgpio(desc);
2634 rc = chip->set_config(chip, gpio, packed);
2635 if (rc == -ENOTSUPP) {
2636 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2637 gpio);
2638 return 0;
2639 }
2640
2641 return rc;
2642}
2643EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2644
2645/**
2646 * gpiod_is_active_low - test whether a GPIO is active-low or not
2647 * @desc: the gpio descriptor to test
2648 *
2649 * Returns 1 if the GPIO is active-low, 0 otherwise.
2650 */
2651int gpiod_is_active_low(const struct gpio_desc *desc)
2652{
2653 VALIDATE_DESC(desc);
2654 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2655}
2656EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2657
2658/* I/O calls are only valid after configuration completed; the relevant
2659 * "is this a valid GPIO" error checks should already have been done.
2660 *
2661 * "Get" operations are often inlinable as reading a pin value register,
2662 * and masking the relevant bit in that register.
2663 *
2664 * When "set" operations are inlinable, they involve writing that mask to
2665 * one register to set a low value, or a different register to set it high.
2666 * Otherwise locking is needed, so there may be little value to inlining.
2667 *
2668 *------------------------------------------------------------------------
2669 *
2670 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2671 * have requested the GPIO. That can include implicit requesting by
2672 * a direction setting call. Marking a gpio as requested locks its chip
2673 * in memory, guaranteeing that these table lookups need no more locking
2674 * and that gpiochip_remove() will fail.
2675 *
2676 * REVISIT when debugging, consider adding some instrumentation to ensure
2677 * that the GPIO was actually requested.
2678 */
2679
2680static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2681{
2682 struct gpio_chip *chip;
2683 int offset;
2684 int value;
2685
2686 chip = desc->gdev->chip;
2687 offset = gpio_chip_hwgpio(desc);
2688 value = chip->get ? chip->get(chip, offset) : -EIO;
2689 value = value < 0 ? value : !!value;
2690 trace_gpio_value(desc_to_gpio(desc), 1, value);
2691 return value;
2692}
2693
2694static int gpio_chip_get_multiple(struct gpio_chip *chip,
2695 unsigned long *mask, unsigned long *bits)
2696{
2697 if (chip->get_multiple) {
2698 return chip->get_multiple(chip, mask, bits);
2699 } else if (chip->get) {
2700 int i, value;
2701
2702 for_each_set_bit(i, mask, chip->ngpio) {
2703 value = chip->get(chip, i);
2704 if (value < 0)
2705 return value;
2706 __assign_bit(i, bits, value);
2707 }
2708 return 0;
2709 }
2710 return -EIO;
2711}
2712
2713int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2714 unsigned int array_size,
2715 struct gpio_desc **desc_array,
2716 int *value_array)
2717{
2718 int i = 0;
2719
2720 while (i < array_size) {
2721 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2722 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2723 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2724 int first, j, ret;
2725
2726 if (!can_sleep)
2727 WARN_ON(chip->can_sleep);
2728
2729 /* collect all inputs belonging to the same chip */
2730 first = i;
2731 memset(mask, 0, sizeof(mask));
2732 do {
2733 const struct gpio_desc *desc = desc_array[i];
2734 int hwgpio = gpio_chip_hwgpio(desc);
2735
2736 __set_bit(hwgpio, mask);
2737 i++;
2738 } while ((i < array_size) &&
2739 (desc_array[i]->gdev->chip == chip));
2740
2741 ret = gpio_chip_get_multiple(chip, mask, bits);
2742 if (ret)
2743 return ret;
2744
2745 for (j = first; j < i; j++) {
2746 const struct gpio_desc *desc = desc_array[j];
2747 int hwgpio = gpio_chip_hwgpio(desc);
2748 int value = test_bit(hwgpio, bits);
2749
2750 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2751 value = !value;
2752 value_array[j] = value;
2753 trace_gpio_value(desc_to_gpio(desc), 1, value);
2754 }
2755 }
2756 return 0;
2757}
2758
2759/**
2760 * gpiod_get_raw_value() - return a gpio's raw value
2761 * @desc: gpio whose value will be returned
2762 *
2763 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2764 * its ACTIVE_LOW status, or negative errno on failure.
2765 *
2766 * This function should be called from contexts where we cannot sleep, and will
2767 * complain if the GPIO chip functions potentially sleep.
2768 */
2769int gpiod_get_raw_value(const struct gpio_desc *desc)
2770{
2771 VALIDATE_DESC(desc);
2772 /* Should be using gpio_get_value_cansleep() */
2773 WARN_ON(desc->gdev->chip->can_sleep);
2774 return gpiod_get_raw_value_commit(desc);
2775}
2776EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2777
2778/**
2779 * gpiod_get_value() - return a gpio's value
2780 * @desc: gpio whose value will be returned
2781 *
2782 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2783 * account, or negative errno on failure.
2784 *
2785 * This function should be called from contexts where we cannot sleep, and will
2786 * complain if the GPIO chip functions potentially sleep.
2787 */
2788int gpiod_get_value(const struct gpio_desc *desc)
2789{
2790 int value;
2791
2792 VALIDATE_DESC(desc);
2793 /* Should be using gpio_get_value_cansleep() */
2794 WARN_ON(desc->gdev->chip->can_sleep);
2795
2796 value = gpiod_get_raw_value_commit(desc);
2797 if (value < 0)
2798 return value;
2799
2800 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2801 value = !value;
2802
2803 return value;
2804}
2805EXPORT_SYMBOL_GPL(gpiod_get_value);
2806
2807/**
2808 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2809 * @array_size: number of elements in the descriptor / value arrays
2810 * @desc_array: array of GPIO descriptors whose values will be read
2811 * @value_array: array to store the read values
2812 *
2813 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2814 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2815 * else an error code.
2816 *
2817 * This function should be called from contexts where we cannot sleep,
2818 * and it will complain if the GPIO chip functions potentially sleep.
2819 */
2820int gpiod_get_raw_array_value(unsigned int array_size,
2821 struct gpio_desc **desc_array, int *value_array)
2822{
2823 if (!desc_array)
2824 return -EINVAL;
2825 return gpiod_get_array_value_complex(true, false, array_size,
2826 desc_array, value_array);
2827}
2828EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2829
2830/**
2831 * gpiod_get_array_value() - read values from an array of GPIOs
2832 * @array_size: number of elements in the descriptor / value arrays
2833 * @desc_array: array of GPIO descriptors whose values will be read
2834 * @value_array: array to store the read values
2835 *
2836 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2837 * into account. Return 0 in case of success, else an error code.
2838 *
2839 * This function should be called from contexts where we cannot sleep,
2840 * and it will complain if the GPIO chip functions potentially sleep.
2841 */
2842int gpiod_get_array_value(unsigned int array_size,
2843 struct gpio_desc **desc_array, int *value_array)
2844{
2845 if (!desc_array)
2846 return -EINVAL;
2847 return gpiod_get_array_value_complex(false, false, array_size,
2848 desc_array, value_array);
2849}
2850EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2851
2852/*
2853 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2854 * @desc: gpio descriptor whose state need to be set.
2855 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2856 */
2857static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2858{
2859 int err = 0;
2860 struct gpio_chip *chip = desc->gdev->chip;
2861 int offset = gpio_chip_hwgpio(desc);
2862
2863 if (value) {
2864 err = chip->direction_input(chip, offset);
2865 if (!err)
2866 clear_bit(FLAG_IS_OUT, &desc->flags);
2867 } else {
2868 err = chip->direction_output(chip, offset, 0);
2869 if (!err)
2870 set_bit(FLAG_IS_OUT, &desc->flags);
2871 }
2872 trace_gpio_direction(desc_to_gpio(desc), value, err);
2873 if (err < 0)
2874 gpiod_err(desc,
2875 "%s: Error in set_value for open drain err %d\n",
2876 __func__, err);
2877}
2878
2879/*
2880 * _gpio_set_open_source_value() - Set the open source gpio's value.
2881 * @desc: gpio descriptor whose state need to be set.
2882 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2883 */
2884static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2885{
2886 int err = 0;
2887 struct gpio_chip *chip = desc->gdev->chip;
2888 int offset = gpio_chip_hwgpio(desc);
2889
2890 if (value) {
2891 err = chip->direction_output(chip, offset, 1);
2892 if (!err)
2893 set_bit(FLAG_IS_OUT, &desc->flags);
2894 } else {
2895 err = chip->direction_input(chip, offset);
2896 if (!err)
2897 clear_bit(FLAG_IS_OUT, &desc->flags);
2898 }
2899 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2900 if (err < 0)
2901 gpiod_err(desc,
2902 "%s: Error in set_value for open source err %d\n",
2903 __func__, err);
2904}
2905
2906static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2907{
2908 struct gpio_chip *chip;
2909
2910 chip = desc->gdev->chip;
2911 trace_gpio_value(desc_to_gpio(desc), 0, value);
2912 chip->set(chip, gpio_chip_hwgpio(desc), value);
2913}
2914
2915/*
2916 * set multiple outputs on the same chip;
2917 * use the chip's set_multiple function if available;
2918 * otherwise set the outputs sequentially;
2919 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2920 * defines which outputs are to be changed
2921 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2922 * defines the values the outputs specified by mask are to be set to
2923 */
2924static void gpio_chip_set_multiple(struct gpio_chip *chip,
2925 unsigned long *mask, unsigned long *bits)
2926{
2927 if (chip->set_multiple) {
2928 chip->set_multiple(chip, mask, bits);
2929 } else {
2930 unsigned int i;
2931
2932 /* set outputs if the corresponding mask bit is set */
2933 for_each_set_bit(i, mask, chip->ngpio)
2934 chip->set(chip, i, test_bit(i, bits));
2935 }
2936}
2937
2938void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2939 unsigned int array_size,
2940 struct gpio_desc **desc_array,
2941 int *value_array)
2942{
2943 int i = 0;
2944
2945 while (i < array_size) {
2946 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2947 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2948 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2949 int count = 0;
2950
2951 if (!can_sleep)
2952 WARN_ON(chip->can_sleep);
2953
2954 memset(mask, 0, sizeof(mask));
2955 do {
2956 struct gpio_desc *desc = desc_array[i];
2957 int hwgpio = gpio_chip_hwgpio(desc);
2958 int value = value_array[i];
2959
2960 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2961 value = !value;
2962 trace_gpio_value(desc_to_gpio(desc), 0, value);
2963 /*
2964 * collect all normal outputs belonging to the same chip
2965 * open drain and open source outputs are set individually
2966 */
2967 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2968 gpio_set_open_drain_value_commit(desc, value);
2969 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2970 gpio_set_open_source_value_commit(desc, value);
2971 } else {
2972 __set_bit(hwgpio, mask);
2973 if (value)
2974 __set_bit(hwgpio, bits);
2975 else
2976 __clear_bit(hwgpio, bits);
2977 count++;
2978 }
2979 i++;
2980 } while ((i < array_size) &&
2981 (desc_array[i]->gdev->chip == chip));
2982 /* push collected bits to outputs */
2983 if (count != 0)
2984 gpio_chip_set_multiple(chip, mask, bits);
2985 }
2986}
2987
2988/**
2989 * gpiod_set_raw_value() - assign a gpio's raw value
2990 * @desc: gpio whose value will be assigned
2991 * @value: value to assign
2992 *
2993 * Set the raw value of the GPIO, i.e. the value of its physical line without
2994 * regard for its ACTIVE_LOW status.
2995 *
2996 * This function should be called from contexts where we cannot sleep, and will
2997 * complain if the GPIO chip functions potentially sleep.
2998 */
2999void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3000{
3001 VALIDATE_DESC_VOID(desc);
3002 /* Should be using gpiod_set_value_cansleep() */
3003 WARN_ON(desc->gdev->chip->can_sleep);
3004 gpiod_set_raw_value_commit(desc, value);
3005}
3006EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3007
3008/**
3009 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3010 * @desc: the descriptor to set the value on
3011 * @value: value to set
3012 *
3013 * This sets the value of a GPIO line backing a descriptor, applying
3014 * different semantic quirks like active low and open drain/source
3015 * handling.
3016 */
3017static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3018{
3019 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3020 value = !value;
3021 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3022 gpio_set_open_drain_value_commit(desc, value);
3023 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3024 gpio_set_open_source_value_commit(desc, value);
3025 else
3026 gpiod_set_raw_value_commit(desc, value);
3027}
3028
3029/**
3030 * gpiod_set_value() - assign a gpio's value
3031 * @desc: gpio whose value will be assigned
3032 * @value: value to assign
3033 *
3034 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3035 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3036 *
3037 * This function should be called from contexts where we cannot sleep, and will
3038 * complain if the GPIO chip functions potentially sleep.
3039 */
3040void gpiod_set_value(struct gpio_desc *desc, int value)
3041{
3042 VALIDATE_DESC_VOID(desc);
3043 WARN_ON(desc->gdev->chip->can_sleep);
3044 gpiod_set_value_nocheck(desc, value);
3045}
3046EXPORT_SYMBOL_GPL(gpiod_set_value);
3047
3048/**
3049 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3050 * @array_size: number of elements in the descriptor / value arrays
3051 * @desc_array: array of GPIO descriptors whose values will be assigned
3052 * @value_array: array of values to assign
3053 *
3054 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3055 * without regard for their ACTIVE_LOW status.
3056 *
3057 * This function should be called from contexts where we cannot sleep, and will
3058 * complain if the GPIO chip functions potentially sleep.
3059 */
3060void gpiod_set_raw_array_value(unsigned int array_size,
3061 struct gpio_desc **desc_array, int *value_array)
3062{
3063 if (!desc_array)
3064 return;
3065 gpiod_set_array_value_complex(true, false, array_size, desc_array,
3066 value_array);
3067}
3068EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3069
3070/**
3071 * gpiod_set_array_value() - assign values to an array of GPIOs
3072 * @array_size: number of elements in the descriptor / value arrays
3073 * @desc_array: array of GPIO descriptors whose values will be assigned
3074 * @value_array: array of values to assign
3075 *
3076 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3077 * into account.
3078 *
3079 * This function should be called from contexts where we cannot sleep, and will
3080 * complain if the GPIO chip functions potentially sleep.
3081 */
3082void gpiod_set_array_value(unsigned int array_size,
3083 struct gpio_desc **desc_array, int *value_array)
3084{
3085 if (!desc_array)
3086 return;
3087 gpiod_set_array_value_complex(false, false, array_size, desc_array,
3088 value_array);
3089}
3090EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3091
3092/**
3093 * gpiod_cansleep() - report whether gpio value access may sleep
3094 * @desc: gpio to check
3095 *
3096 */
3097int gpiod_cansleep(const struct gpio_desc *desc)
3098{
3099 VALIDATE_DESC(desc);
3100 return desc->gdev->chip->can_sleep;
3101}
3102EXPORT_SYMBOL_GPL(gpiod_cansleep);
3103
3104/**
3105 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3106 * @desc: gpio whose IRQ will be returned (already requested)
3107 *
3108 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3109 * error.
3110 */
3111int gpiod_to_irq(const struct gpio_desc *desc)
3112{
3113 struct gpio_chip *chip;
3114 int offset;
3115
3116 /*
3117 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3118 * requires this function to not return zero on an invalid descriptor
3119 * but rather a negative error number.
3120 */
3121 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3122 return -EINVAL;
3123
3124 chip = desc->gdev->chip;
3125 offset = gpio_chip_hwgpio(desc);
3126 if (chip->to_irq) {
3127 int retirq = chip->to_irq(chip, offset);
3128
3129 /* Zero means NO_IRQ */
3130 if (!retirq)
3131 return -ENXIO;
3132
3133 return retirq;
3134 }
3135 return -ENXIO;
3136}
3137EXPORT_SYMBOL_GPL(gpiod_to_irq);
3138
3139/**
3140 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3141 * @chip: the chip the GPIO to lock belongs to
3142 * @offset: the offset of the GPIO to lock as IRQ
3143 *
3144 * This is used directly by GPIO drivers that want to lock down
3145 * a certain GPIO line to be used for IRQs.
3146 */
3147int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3148{
3149 struct gpio_desc *desc;
3150
3151 desc = gpiochip_get_desc(chip, offset);
3152 if (IS_ERR(desc))
3153 return PTR_ERR(desc);
3154
3155 /*
3156 * If it's fast: flush the direction setting if something changed
3157 * behind our back
3158 */
3159 if (!chip->can_sleep && chip->get_direction) {
3160 int dir = chip->get_direction(chip, offset);
3161
3162 if (dir)
3163 clear_bit(FLAG_IS_OUT, &desc->flags);
3164 else
3165 set_bit(FLAG_IS_OUT, &desc->flags);
3166 }
3167
3168 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3169 chip_err(chip,
3170 "%s: tried to flag a GPIO set as output for IRQ\n",
3171 __func__);
3172 return -EIO;
3173 }
3174
3175 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3176
3177 /*
3178 * If the consumer has not set up a label (such as when the
3179 * IRQ is referenced from .to_irq()) we set up a label here
3180 * so it is clear this is used as an interrupt.
3181 */
3182 if (!desc->label)
3183 desc_set_label(desc, "interrupt");
3184
3185 return 0;
3186}
3187EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3188
3189/**
3190 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3191 * @chip: the chip the GPIO to lock belongs to
3192 * @offset: the offset of the GPIO to lock as IRQ
3193 *
3194 * This is used directly by GPIO drivers that want to indicate
3195 * that a certain GPIO is no longer used exclusively for IRQ.
3196 */
3197void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3198{
3199 struct gpio_desc *desc;
3200
3201 desc = gpiochip_get_desc(chip, offset);
3202 if (IS_ERR(desc))
3203 return;
3204
3205 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3206
3207 /* If we only had this marking, erase it */
3208 if (desc->label && !strcmp(desc->label, "interrupt"))
3209 desc_set_label(desc, NULL);
3210}
3211EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3212
3213bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3214{
3215 if (offset >= chip->ngpio)
3216 return false;
3217
3218 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3219}
3220EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3221
3222bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3223{
3224 if (offset >= chip->ngpio)
3225 return false;
3226
3227 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3228}
3229EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3230
3231bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3232{
3233 if (offset >= chip->ngpio)
3234 return false;
3235
3236 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3237}
3238EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3239
3240bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3241{
3242 if (offset >= chip->ngpio)
3243 return false;
3244
3245 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3246}
3247EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3248
3249/**
3250 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3251 * @desc: gpio whose value will be returned
3252 *
3253 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3254 * its ACTIVE_LOW status, or negative errno on failure.
3255 *
3256 * This function is to be called from contexts that can sleep.
3257 */
3258int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3259{
3260 might_sleep_if(extra_checks);
3261 VALIDATE_DESC(desc);
3262 return gpiod_get_raw_value_commit(desc);
3263}
3264EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3265
3266/**
3267 * gpiod_get_value_cansleep() - return a gpio's value
3268 * @desc: gpio whose value will be returned
3269 *
3270 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3271 * account, or negative errno on failure.
3272 *
3273 * This function is to be called from contexts that can sleep.
3274 */
3275int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3276{
3277 int value;
3278
3279 might_sleep_if(extra_checks);
3280 VALIDATE_DESC(desc);
3281 value = gpiod_get_raw_value_commit(desc);
3282 if (value < 0)
3283 return value;
3284
3285 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3286 value = !value;
3287
3288 return value;
3289}
3290EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3291
3292/**
3293 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3294 * @array_size: number of elements in the descriptor / value arrays
3295 * @desc_array: array of GPIO descriptors whose values will be read
3296 * @value_array: array to store the read values
3297 *
3298 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3299 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3300 * else an error code.
3301 *
3302 * This function is to be called from contexts that can sleep.
3303 */
3304int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3305 struct gpio_desc **desc_array,
3306 int *value_array)
3307{
3308 might_sleep_if(extra_checks);
3309 if (!desc_array)
3310 return -EINVAL;
3311 return gpiod_get_array_value_complex(true, true, array_size,
3312 desc_array, value_array);
3313}
3314EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3315
3316/**
3317 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3318 * @array_size: number of elements in the descriptor / value arrays
3319 * @desc_array: array of GPIO descriptors whose values will be read
3320 * @value_array: array to store the read values
3321 *
3322 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3323 * into account. Return 0 in case of success, else an error code.
3324 *
3325 * This function is to be called from contexts that can sleep.
3326 */
3327int gpiod_get_array_value_cansleep(unsigned int array_size,
3328 struct gpio_desc **desc_array,
3329 int *value_array)
3330{
3331 might_sleep_if(extra_checks);
3332 if (!desc_array)
3333 return -EINVAL;
3334 return gpiod_get_array_value_complex(false, true, array_size,
3335 desc_array, value_array);
3336}
3337EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3338
3339/**
3340 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3341 * @desc: gpio whose value will be assigned
3342 * @value: value to assign
3343 *
3344 * Set the raw value of the GPIO, i.e. the value of its physical line without
3345 * regard for its ACTIVE_LOW status.
3346 *
3347 * This function is to be called from contexts that can sleep.
3348 */
3349void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3350{
3351 might_sleep_if(extra_checks);
3352 VALIDATE_DESC_VOID(desc);
3353 gpiod_set_raw_value_commit(desc, value);
3354}
3355EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3356
3357/**
3358 * gpiod_set_value_cansleep() - assign a gpio's value
3359 * @desc: gpio whose value will be assigned
3360 * @value: value to assign
3361 *
3362 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3363 * account
3364 *
3365 * This function is to be called from contexts that can sleep.
3366 */
3367void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3368{
3369 might_sleep_if(extra_checks);
3370 VALIDATE_DESC_VOID(desc);
3371 gpiod_set_value_nocheck(desc, value);
3372}
3373EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3374
3375/**
3376 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3377 * @array_size: number of elements in the descriptor / value arrays
3378 * @desc_array: array of GPIO descriptors whose values will be assigned
3379 * @value_array: array of values to assign
3380 *
3381 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3382 * without regard for their ACTIVE_LOW status.
3383 *
3384 * This function is to be called from contexts that can sleep.
3385 */
3386void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3387 struct gpio_desc **desc_array,
3388 int *value_array)
3389{
3390 might_sleep_if(extra_checks);
3391 if (!desc_array)
3392 return;
3393 gpiod_set_array_value_complex(true, true, array_size, desc_array,
3394 value_array);
3395}
3396EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3397
3398/**
3399 * gpiod_add_lookup_tables() - register GPIO device consumers
3400 * @tables: list of tables of consumers to register
3401 * @n: number of tables in the list
3402 */
3403void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3404{
3405 unsigned int i;
3406
3407 mutex_lock(&gpio_lookup_lock);
3408
3409 for (i = 0; i < n; i++)
3410 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3411
3412 mutex_unlock(&gpio_lookup_lock);
3413}
3414
3415/**
3416 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3417 * @array_size: number of elements in the descriptor / value arrays
3418 * @desc_array: array of GPIO descriptors whose values will be assigned
3419 * @value_array: array of values to assign
3420 *
3421 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3422 * into account.
3423 *
3424 * This function is to be called from contexts that can sleep.
3425 */
3426void gpiod_set_array_value_cansleep(unsigned int array_size,
3427 struct gpio_desc **desc_array,
3428 int *value_array)
3429{
3430 might_sleep_if(extra_checks);
3431 if (!desc_array)
3432 return;
3433 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3434 value_array);
3435}
3436EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3437
3438/**
3439 * gpiod_add_lookup_table() - register GPIO device consumers
3440 * @table: table of consumers to register
3441 */
3442void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3443{
3444 mutex_lock(&gpio_lookup_lock);
3445
3446 list_add_tail(&table->list, &gpio_lookup_list);
3447
3448 mutex_unlock(&gpio_lookup_lock);
3449}
3450EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3451
3452/**
3453 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3454 * @table: table of consumers to unregister
3455 */
3456void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3457{
3458 mutex_lock(&gpio_lookup_lock);
3459
3460 list_del(&table->list);
3461
3462 mutex_unlock(&gpio_lookup_lock);
3463}
3464EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3465
3466static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3467{
3468 const char *dev_id = dev ? dev_name(dev) : NULL;
3469 struct gpiod_lookup_table *table;
3470
3471 mutex_lock(&gpio_lookup_lock);
3472
3473 list_for_each_entry(table, &gpio_lookup_list, list) {
3474 if (table->dev_id && dev_id) {
3475 /*
3476 * Valid strings on both ends, must be identical to have
3477 * a match
3478 */
3479 if (!strcmp(table->dev_id, dev_id))
3480 goto found;
3481 } else {
3482 /*
3483 * One of the pointers is NULL, so both must be to have
3484 * a match
3485 */
3486 if (dev_id == table->dev_id)
3487 goto found;
3488 }
3489 }
3490 table = NULL;
3491
3492found:
3493 mutex_unlock(&gpio_lookup_lock);
3494 return table;
3495}
3496
3497static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3498 unsigned int idx,
3499 enum gpio_lookup_flags *flags)
3500{
3501 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3502 struct gpiod_lookup_table *table;
3503 struct gpiod_lookup *p;
3504
3505 table = gpiod_find_lookup_table(dev);
3506 if (!table)
3507 return desc;
3508
3509 for (p = &table->table[0]; p->chip_label; p++) {
3510 struct gpio_chip *chip;
3511
3512 /* idx must always match exactly */
3513 if (p->idx != idx)
3514 continue;
3515
3516 /* If the lookup entry has a con_id, require exact match */
3517 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3518 continue;
3519
3520 chip = find_chip_by_name(p->chip_label);
3521
3522 if (!chip) {
3523 dev_err(dev, "cannot find GPIO chip %s\n",
3524 p->chip_label);
3525 return ERR_PTR(-ENODEV);
3526 }
3527
3528 if (chip->ngpio <= p->chip_hwnum) {
3529 dev_err(dev,
3530 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3531 idx, chip->ngpio, chip->label);
3532 return ERR_PTR(-EINVAL);
3533 }
3534
3535 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3536 *flags = p->flags;
3537
3538 return desc;
3539 }
3540
3541 return desc;
3542}
3543
3544static int dt_gpio_count(struct device *dev, const char *con_id)
3545{
3546 int ret;
3547 char propname[32];
3548 unsigned int i;
3549
3550 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3551 if (con_id)
3552 snprintf(propname, sizeof(propname), "%s-%s",
3553 con_id, gpio_suffixes[i]);
3554 else
3555 snprintf(propname, sizeof(propname), "%s",
3556 gpio_suffixes[i]);
3557
3558 ret = of_gpio_named_count(dev->of_node, propname);
3559 if (ret > 0)
3560 break;
3561 }
3562 return ret ? ret : -ENOENT;
3563}
3564
3565static int platform_gpio_count(struct device *dev, const char *con_id)
3566{
3567 struct gpiod_lookup_table *table;
3568 struct gpiod_lookup *p;
3569 unsigned int count = 0;
3570
3571 table = gpiod_find_lookup_table(dev);
3572 if (!table)
3573 return -ENOENT;
3574
3575 for (p = &table->table[0]; p->chip_label; p++) {
3576 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3577 (!con_id && !p->con_id))
3578 count++;
3579 }
3580 if (!count)
3581 return -ENOENT;
3582
3583 return count;
3584}
3585
3586/**
3587 * gpiod_count - return the number of GPIOs associated with a device / function
3588 * or -ENOENT if no GPIO has been assigned to the requested function
3589 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3590 * @con_id: function within the GPIO consumer
3591 */
3592int gpiod_count(struct device *dev, const char *con_id)
3593{
3594 int count = -ENOENT;
3595
3596 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3597 count = dt_gpio_count(dev, con_id);
3598 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3599 count = acpi_gpio_count(dev, con_id);
3600
3601 if (count < 0)
3602 count = platform_gpio_count(dev, con_id);
3603
3604 return count;
3605}
3606EXPORT_SYMBOL_GPL(gpiod_count);
3607
3608/**
3609 * gpiod_get - obtain a GPIO for a given GPIO function
3610 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3611 * @con_id: function within the GPIO consumer
3612 * @flags: optional GPIO initialization flags
3613 *
3614 * Return the GPIO descriptor corresponding to the function con_id of device
3615 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3616 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3617 */
3618struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3619 enum gpiod_flags flags)
3620{
3621 return gpiod_get_index(dev, con_id, 0, flags);
3622}
3623EXPORT_SYMBOL_GPL(gpiod_get);
3624
3625/**
3626 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3627 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3628 * @con_id: function within the GPIO consumer
3629 * @flags: optional GPIO initialization flags
3630 *
3631 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3632 * the requested function it will return NULL. This is convenient for drivers
3633 * that need to handle optional GPIOs.
3634 */
3635struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3636 const char *con_id,
3637 enum gpiod_flags flags)
3638{
3639 return gpiod_get_index_optional(dev, con_id, 0, flags);
3640}
3641EXPORT_SYMBOL_GPL(gpiod_get_optional);
3642
3643
3644/**
3645 * gpiod_configure_flags - helper function to configure a given GPIO
3646 * @desc: gpio whose value will be assigned
3647 * @con_id: function within the GPIO consumer
3648 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3649 * of_get_gpio_hog()
3650 * @dflags: gpiod_flags - optional GPIO initialization flags
3651 *
3652 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3653 * requested function and/or index, or another IS_ERR() code if an error
3654 * occurred while trying to acquire the GPIO.
3655 */
3656int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3657 unsigned long lflags, enum gpiod_flags dflags)
3658{
3659 int status;
3660
3661 if (lflags & GPIO_ACTIVE_LOW)
3662 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3663
3664 if (lflags & GPIO_OPEN_DRAIN)
3665 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3666 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3667 /*
3668 * This enforces open drain mode from the consumer side.
3669 * This is necessary for some busses like I2C, but the lookup
3670 * should *REALLY* have specified them as open drain in the
3671 * first place, so print a little warning here.
3672 */
3673 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3674 gpiod_warn(desc,
3675 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3676 }
3677
3678 if (lflags & GPIO_OPEN_SOURCE)
3679 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3680
3681 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3682 if (status < 0)
3683 return status;
3684
3685 /* No particular flag request, return here... */
3686 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3687 pr_debug("no flags found for %s\n", con_id);
3688 return 0;
3689 }
3690
3691 /* Process flags */
3692 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3693 status = gpiod_direction_output(desc,
3694 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3695 else
3696 status = gpiod_direction_input(desc);
3697
3698 return status;
3699}
3700
3701/**
3702 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3703 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3704 * @con_id: function within the GPIO consumer
3705 * @idx: index of the GPIO to obtain in the consumer
3706 * @flags: optional GPIO initialization flags
3707 *
3708 * This variant of gpiod_get() allows to access GPIOs other than the first
3709 * defined one for functions that define several GPIOs.
3710 *
3711 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3712 * requested function and/or index, or another IS_ERR() code if an error
3713 * occurred while trying to acquire the GPIO.
3714 */
3715struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3716 const char *con_id,
3717 unsigned int idx,
3718 enum gpiod_flags flags)
3719{
3720 struct gpio_desc *desc = NULL;
3721 int status;
3722 enum gpio_lookup_flags lookupflags = 0;
3723 /* Maybe we have a device name, maybe not */
3724 const char *devname = dev ? dev_name(dev) : "?";
3725
3726 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3727
3728 if (dev) {
3729 /* Using device tree? */
3730 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3731 dev_dbg(dev, "using device tree for GPIO lookup\n");
3732 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3733 } else if (ACPI_COMPANION(dev)) {
3734 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3735 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3736 }
3737 }
3738
3739 /*
3740 * Either we are not using DT or ACPI, or their lookup did not return
3741 * a result. In that case, use platform lookup as a fallback.
3742 */
3743 if (!desc || desc == ERR_PTR(-ENOENT)) {
3744 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3745 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3746 }
3747
3748 if (IS_ERR(desc)) {
3749 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3750 return desc;
3751 }
3752
3753 /*
3754 * If a connection label was passed use that, else attempt to use
3755 * the device name as label
3756 */
3757 status = gpiod_request(desc, con_id ? con_id : devname);
3758 if (status < 0)
3759 return ERR_PTR(status);
3760
3761 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3762 if (status < 0) {
3763 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3764 gpiod_put(desc);
3765 return ERR_PTR(status);
3766 }
3767
3768 return desc;
3769}
3770EXPORT_SYMBOL_GPL(gpiod_get_index);
3771
3772/**
3773 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
3774 * @node: handle of the OF node
3775 * @propname: name of the DT property representing the GPIO
3776 * @index: index of the GPIO to obtain for the consumer
3777 * @dflags: GPIO initialization flags
3778 * @label: label to attach to the requested GPIO
3779 *
3780 * Returns:
3781 * On successful request the GPIO pin is configured in accordance with
3782 * provided @dflags. If the node does not have the requested GPIO
3783 * property, NULL is returned.
3784 *
3785 * In case of error an ERR_PTR() is returned.
3786 */
3787struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
3788 const char *propname, int index,
3789 enum gpiod_flags dflags,
3790 const char *label)
3791{
3792 struct gpio_desc *desc;
3793 unsigned long lflags = 0;
3794 enum of_gpio_flags flags;
3795 bool active_low = false;
3796 bool single_ended = false;
3797 bool open_drain = false;
3798 bool transitory = false;
3799 int ret;
3800
3801 desc = of_get_named_gpiod_flags(node, propname,
3802 index, &flags);
3803
3804 if (!desc || IS_ERR(desc)) {
3805 /* If it is not there, just return NULL */
3806 if (PTR_ERR(desc) == -ENOENT)
3807 return NULL;
3808 return desc;
3809 }
3810
3811 active_low = flags & OF_GPIO_ACTIVE_LOW;
3812 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3813 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3814 transitory = flags & OF_GPIO_TRANSITORY;
3815
3816 ret = gpiod_request(desc, label);
3817 if (ret)
3818 return ERR_PTR(ret);
3819
3820 if (active_low)
3821 lflags |= GPIO_ACTIVE_LOW;
3822
3823 if (single_ended) {
3824 if (open_drain)
3825 lflags |= GPIO_OPEN_DRAIN;
3826 else
3827 lflags |= GPIO_OPEN_SOURCE;
3828 }
3829
3830 if (transitory)
3831 lflags |= GPIO_TRANSITORY;
3832
3833 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3834 if (ret < 0) {
3835 gpiod_put(desc);
3836 return ERR_PTR(ret);
3837 }
3838
3839 return desc;
3840}
3841EXPORT_SYMBOL(gpiod_get_from_of_node);
3842
3843/**
3844 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3845 * @fwnode: handle of the firmware node
3846 * @propname: name of the firmware property representing the GPIO
3847 * @index: index of the GPIO to obtain for the consumer
3848 * @dflags: GPIO initialization flags
3849 * @label: label to attach to the requested GPIO
3850 *
3851 * This function can be used for drivers that get their configuration
3852 * from opaque firmware.
3853 *
3854 * The function properly finds the corresponding GPIO using whatever is the
3855 * underlying firmware interface and then makes sure that the GPIO
3856 * descriptor is requested before it is returned to the caller.
3857 *
3858 * Returns:
3859 * On successful request the GPIO pin is configured in accordance with
3860 * provided @dflags.
3861 *
3862 * In case of error an ERR_PTR() is returned.
3863 */
3864struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3865 const char *propname, int index,
3866 enum gpiod_flags dflags,
3867 const char *label)
3868{
3869 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3870 unsigned long lflags = 0;
3871 int ret;
3872
3873 if (!fwnode)
3874 return ERR_PTR(-EINVAL);
3875
3876 if (is_of_node(fwnode)) {
3877 desc = gpiod_get_from_of_node(to_of_node(fwnode),
3878 propname, index,
3879 dflags,
3880 label);
3881 return desc;
3882 } else if (is_acpi_node(fwnode)) {
3883 struct acpi_gpio_info info;
3884
3885 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
3886 if (IS_ERR(desc))
3887 return desc;
3888
3889 acpi_gpio_update_gpiod_flags(&dflags, &info);
3890
3891 if (info.polarity == GPIO_ACTIVE_LOW)
3892 lflags |= GPIO_ACTIVE_LOW;
3893 }
3894
3895 /* Currently only ACPI takes this path */
3896 ret = gpiod_request(desc, label);
3897 if (ret)
3898 return ERR_PTR(ret);
3899
3900 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3901 if (ret < 0) {
3902 gpiod_put(desc);
3903 return ERR_PTR(ret);
3904 }
3905
3906 return desc;
3907}
3908EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3909
3910/**
3911 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3912 * function
3913 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3914 * @con_id: function within the GPIO consumer
3915 * @index: index of the GPIO to obtain in the consumer
3916 * @flags: optional GPIO initialization flags
3917 *
3918 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3919 * specified index was assigned to the requested function it will return NULL.
3920 * This is convenient for drivers that need to handle optional GPIOs.
3921 */
3922struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3923 const char *con_id,
3924 unsigned int index,
3925 enum gpiod_flags flags)
3926{
3927 struct gpio_desc *desc;
3928
3929 desc = gpiod_get_index(dev, con_id, index, flags);
3930 if (IS_ERR(desc)) {
3931 if (PTR_ERR(desc) == -ENOENT)
3932 return NULL;
3933 }
3934
3935 return desc;
3936}
3937EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3938
3939/**
3940 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3941 * @desc: gpio whose value will be assigned
3942 * @name: gpio line name
3943 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3944 * of_get_gpio_hog()
3945 * @dflags: gpiod_flags - optional GPIO initialization flags
3946 */
3947int gpiod_hog(struct gpio_desc *desc, const char *name,
3948 unsigned long lflags, enum gpiod_flags dflags)
3949{
3950 struct gpio_chip *chip;
3951 struct gpio_desc *local_desc;
3952 int hwnum;
3953 int status;
3954
3955 chip = gpiod_to_chip(desc);
3956 hwnum = gpio_chip_hwgpio(desc);
3957
3958 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3959 if (IS_ERR(local_desc)) {
3960 status = PTR_ERR(local_desc);
3961 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3962 name, chip->label, hwnum, status);
3963 return status;
3964 }
3965
3966 status = gpiod_configure_flags(desc, name, lflags, dflags);
3967 if (status < 0) {
3968 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3969 name, chip->label, hwnum, status);
3970 gpiochip_free_own_desc(desc);
3971 return status;
3972 }
3973
3974 /* Mark GPIO as hogged so it can be identified and removed later */
3975 set_bit(FLAG_IS_HOGGED, &desc->flags);
3976
3977 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3978 desc_to_gpio(desc), name,
3979 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3980 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3981 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3982
3983 return 0;
3984}
3985
3986/**
3987 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3988 * @chip: gpio chip to act on
3989 *
3990 * This is only used by of_gpiochip_remove to free hogged gpios
3991 */
3992static void gpiochip_free_hogs(struct gpio_chip *chip)
3993{
3994 int id;
3995
3996 for (id = 0; id < chip->ngpio; id++) {
3997 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3998 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3999 }
4000}
4001
4002/**
4003 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4004 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4005 * @con_id: function within the GPIO consumer
4006 * @flags: optional GPIO initialization flags
4007 *
4008 * This function acquires all the GPIOs defined under a given function.
4009 *
4010 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4011 * no GPIO has been assigned to the requested function, or another IS_ERR()
4012 * code if an error occurred while trying to acquire the GPIOs.
4013 */
4014struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4015 const char *con_id,
4016 enum gpiod_flags flags)
4017{
4018 struct gpio_desc *desc;
4019 struct gpio_descs *descs;
4020 int count;
4021
4022 count = gpiod_count(dev, con_id);
4023 if (count < 0)
4024 return ERR_PTR(count);
4025
4026 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
4027 GFP_KERNEL);
4028 if (!descs)
4029 return ERR_PTR(-ENOMEM);
4030
4031 for (descs->ndescs = 0; descs->ndescs < count; ) {
4032 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4033 if (IS_ERR(desc)) {
4034 gpiod_put_array(descs);
4035 return ERR_CAST(desc);
4036 }
4037 descs->desc[descs->ndescs] = desc;
4038 descs->ndescs++;
4039 }
4040 return descs;
4041}
4042EXPORT_SYMBOL_GPL(gpiod_get_array);
4043
4044/**
4045 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4046 * function
4047 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4048 * @con_id: function within the GPIO consumer
4049 * @flags: optional GPIO initialization flags
4050 *
4051 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4052 * assigned to the requested function it will return NULL.
4053 */
4054struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4055 const char *con_id,
4056 enum gpiod_flags flags)
4057{
4058 struct gpio_descs *descs;
4059
4060 descs = gpiod_get_array(dev, con_id, flags);
4061 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4062 return NULL;
4063
4064 return descs;
4065}
4066EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4067
4068/**
4069 * gpiod_put - dispose of a GPIO descriptor
4070 * @desc: GPIO descriptor to dispose of
4071 *
4072 * No descriptor can be used after gpiod_put() has been called on it.
4073 */
4074void gpiod_put(struct gpio_desc *desc)
4075{
4076 gpiod_free(desc);
4077}
4078EXPORT_SYMBOL_GPL(gpiod_put);
4079
4080/**
4081 * gpiod_put_array - dispose of multiple GPIO descriptors
4082 * @descs: struct gpio_descs containing an array of descriptors
4083 */
4084void gpiod_put_array(struct gpio_descs *descs)
4085{
4086 unsigned int i;
4087
4088 for (i = 0; i < descs->ndescs; i++)
4089 gpiod_put(descs->desc[i]);
4090
4091 kfree(descs);
4092}
4093EXPORT_SYMBOL_GPL(gpiod_put_array);
4094
4095static int __init gpiolib_dev_init(void)
4096{
4097 int ret;
4098
4099 /* Register GPIO sysfs bus */
4100 ret = bus_register(&gpio_bus_type);
4101 if (ret < 0) {
4102 pr_err("gpiolib: could not register GPIO bus type\n");
4103 return ret;
4104 }
4105
4106 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4107 if (ret < 0) {
4108 pr_err("gpiolib: failed to allocate char dev region\n");
4109 bus_unregister(&gpio_bus_type);
4110 } else {
4111 gpiolib_initialized = true;
4112 gpiochip_setup_devs();
4113 }
4114 return ret;
4115}
4116core_initcall(gpiolib_dev_init);
4117
4118#ifdef CONFIG_DEBUG_FS
4119
4120static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4121{
4122 unsigned i;
4123 struct gpio_chip *chip = gdev->chip;
4124 unsigned gpio = gdev->base;
4125 struct gpio_desc *gdesc = &gdev->descs[0];
4126 int is_out;
4127 int is_irq;
4128
4129 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4130 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4131 if (gdesc->name) {
4132 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4133 gpio, gdesc->name);
4134 }
4135 continue;
4136 }
4137
4138 gpiod_get_direction(gdesc);
4139 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4140 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4141 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
4142 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4143 is_out ? "out" : "in ",
4144 chip->get
4145 ? (chip->get(chip, i) ? "hi" : "lo")
4146 : "? ",
4147 is_irq ? "IRQ" : " ");
4148 seq_printf(s, "\n");
4149 }
4150}
4151
4152static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4153{
4154 unsigned long flags;
4155 struct gpio_device *gdev = NULL;
4156 loff_t index = *pos;
4157
4158 s->private = "";
4159
4160 spin_lock_irqsave(&gpio_lock, flags);
4161 list_for_each_entry(gdev, &gpio_devices, list)
4162 if (index-- == 0) {
4163 spin_unlock_irqrestore(&gpio_lock, flags);
4164 return gdev;
4165 }
4166 spin_unlock_irqrestore(&gpio_lock, flags);
4167
4168 return NULL;
4169}
4170
4171static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4172{
4173 unsigned long flags;
4174 struct gpio_device *gdev = v;
4175 void *ret = NULL;
4176
4177 spin_lock_irqsave(&gpio_lock, flags);
4178 if (list_is_last(&gdev->list, &gpio_devices))
4179 ret = NULL;
4180 else
4181 ret = list_entry(gdev->list.next, struct gpio_device, list);
4182 spin_unlock_irqrestore(&gpio_lock, flags);
4183
4184 s->private = "\n";
4185 ++*pos;
4186
4187 return ret;
4188}
4189
4190static void gpiolib_seq_stop(struct seq_file *s, void *v)
4191{
4192}
4193
4194static int gpiolib_seq_show(struct seq_file *s, void *v)
4195{
4196 struct gpio_device *gdev = v;
4197 struct gpio_chip *chip = gdev->chip;
4198 struct device *parent;
4199
4200 if (!chip) {
4201 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4202 dev_name(&gdev->dev));
4203 return 0;
4204 }
4205
4206 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4207 dev_name(&gdev->dev),
4208 gdev->base, gdev->base + gdev->ngpio - 1);
4209 parent = chip->parent;
4210 if (parent)
4211 seq_printf(s, ", parent: %s/%s",
4212 parent->bus ? parent->bus->name : "no-bus",
4213 dev_name(parent));
4214 if (chip->label)
4215 seq_printf(s, ", %s", chip->label);
4216 if (chip->can_sleep)
4217 seq_printf(s, ", can sleep");
4218 seq_printf(s, ":\n");
4219
4220 if (chip->dbg_show)
4221 chip->dbg_show(s, chip);
4222 else
4223 gpiolib_dbg_show(s, gdev);
4224
4225 return 0;
4226}
4227
4228static const struct seq_operations gpiolib_seq_ops = {
4229 .start = gpiolib_seq_start,
4230 .next = gpiolib_seq_next,
4231 .stop = gpiolib_seq_stop,
4232 .show = gpiolib_seq_show,
4233};
4234
4235static int gpiolib_open(struct inode *inode, struct file *file)
4236{
4237 return seq_open(file, &gpiolib_seq_ops);
4238}
4239
4240static const struct file_operations gpiolib_operations = {
4241 .owner = THIS_MODULE,
4242 .open = gpiolib_open,
4243 .read = seq_read,
4244 .llseek = seq_lseek,
4245 .release = seq_release,
4246};
4247
4248static int __init gpiolib_debugfs_init(void)
4249{
4250 /* /sys/kernel/debug/gpio */
4251 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4252 NULL, NULL, &gpiolib_operations);
4253 return 0;
4254}
4255subsys_initcall(gpiolib_debugfs_init);
4256
4257#endif /* DEBUG_FS */