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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/kernel.h>
2#include <linux/module.h>
3#include <linux/interrupt.h>
4#include <linux/irq.h>
5#include <linux/spinlock.h>
6#include <linux/device.h>
7#include <linux/err.h>
8#include <linux/debugfs.h>
9#include <linux/seq_file.h>
10#include <linux/gpio.h>
11#include <linux/of_gpio.h>
12#include <linux/idr.h>
13#include <linux/slab.h>
14
15#define CREATE_TRACE_POINTS
16#include <trace/events/gpio.h>
17
18/* Optional implementation infrastructure for GPIO interfaces.
19 *
20 * Platforms may want to use this if they tend to use very many GPIOs
21 * that aren't part of a System-On-Chip core; or across I2C/SPI/etc.
22 *
23 * When kernel footprint or instruction count is an issue, simpler
24 * implementations may be preferred. The GPIO programming interface
25 * allows for inlining speed-critical get/set operations for common
26 * cases, so that access to SOC-integrated GPIOs can sometimes cost
27 * only an instruction or two per bit.
28 */
29
30
31/* When debugging, extend minimal trust to callers and platform code.
32 * Also emit diagnostic messages that may help initial bringup, when
33 * board setup or driver bugs are most common.
34 *
35 * Otherwise, minimize overhead in what may be bitbanging codepaths.
36 */
37#ifdef DEBUG
38#define extra_checks 1
39#else
40#define extra_checks 0
41#endif
42
43/* gpio_lock prevents conflicts during gpio_desc[] table updates.
44 * While any GPIO is requested, its gpio_chip is not removable;
45 * each GPIO's "requested" flag serves as a lock and refcount.
46 */
47static DEFINE_SPINLOCK(gpio_lock);
48
49struct gpio_desc {
50 struct gpio_chip *chip;
51 unsigned long flags;
52/* flag symbols are bit numbers */
53#define FLAG_REQUESTED 0
54#define FLAG_IS_OUT 1
55#define FLAG_RESERVED 2
56#define FLAG_EXPORT 3 /* protected by sysfs_lock */
57#define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */
58#define FLAG_TRIG_FALL 5 /* trigger on falling edge */
59#define FLAG_TRIG_RISE 6 /* trigger on rising edge */
60#define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */
61
62#define ID_SHIFT 16 /* add new flags before this one */
63
64#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1)
65#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
66
67#ifdef CONFIG_DEBUG_FS
68 const char *label;
69#endif
70};
71static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
72
73#ifdef CONFIG_GPIO_SYSFS
74static DEFINE_IDR(dirent_idr);
75#endif
76
77static inline void desc_set_label(struct gpio_desc *d, const char *label)
78{
79#ifdef CONFIG_DEBUG_FS
80 d->label = label;
81#endif
82}
83
84/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
85 * when setting direction, and otherwise illegal. Until board setup code
86 * and drivers use explicit requests everywhere (which won't happen when
87 * those calls have no teeth) we can't avoid autorequesting. This nag
88 * message should motivate switching to explicit requests... so should
89 * the weaker cleanup after faults, compared to gpio_request().
90 *
91 * NOTE: the autorequest mechanism is going away; at this point it's
92 * only "legal" in the sense that (old) code using it won't break yet,
93 * but instead only triggers a WARN() stack dump.
94 */
95static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset)
96{
97 const struct gpio_chip *chip = desc->chip;
98 const int gpio = chip->base + offset;
99
100 if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,
101 "autorequest GPIO-%d\n", gpio)) {
102 if (!try_module_get(chip->owner)) {
103 pr_err("GPIO-%d: module can't be gotten \n", gpio);
104 clear_bit(FLAG_REQUESTED, &desc->flags);
105 /* lose */
106 return -EIO;
107 }
108 desc_set_label(desc, "[auto]");
109 /* caller must chip->request() w/o spinlock */
110 if (chip->request)
111 return 1;
112 }
113 return 0;
114}
115
116/* caller holds gpio_lock *OR* gpio is marked as requested */
117static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
118{
119 return gpio_desc[gpio].chip;
120}
121
122/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
123static int gpiochip_find_base(int ngpio)
124{
125 int i;
126 int spare = 0;
127 int base = -ENOSPC;
128
129 for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) {
130 struct gpio_desc *desc = &gpio_desc[i];
131 struct gpio_chip *chip = desc->chip;
132
133 if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) {
134 spare++;
135 if (spare == ngpio) {
136 base = i;
137 break;
138 }
139 } else {
140 spare = 0;
141 if (chip)
142 i -= chip->ngpio - 1;
143 }
144 }
145
146 if (gpio_is_valid(base))
147 pr_debug("%s: found new base at %d\n", __func__, base);
148 return base;
149}
150
151/**
152 * gpiochip_reserve() - reserve range of gpios to use with platform code only
153 * @start: starting gpio number
154 * @ngpio: number of gpios to reserve
155 * Context: platform init, potentially before irqs or kmalloc will work
156 *
157 * Returns a negative errno if any gpio within the range is already reserved
158 * or registered, else returns zero as a success code. Use this function
159 * to mark a range of gpios as unavailable for dynamic gpio number allocation,
160 * for example because its driver support is not yet loaded.
161 */
162int __init gpiochip_reserve(int start, int ngpio)
163{
164 int ret = 0;
165 unsigned long flags;
166 int i;
167
168 if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1))
169 return -EINVAL;
170
171 spin_lock_irqsave(&gpio_lock, flags);
172
173 for (i = start; i < start + ngpio; i++) {
174 struct gpio_desc *desc = &gpio_desc[i];
175
176 if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) {
177 ret = -EBUSY;
178 goto err;
179 }
180
181 set_bit(FLAG_RESERVED, &desc->flags);
182 }
183
184 pr_debug("%s: reserved gpios from %d to %d\n",
185 __func__, start, start + ngpio - 1);
186err:
187 spin_unlock_irqrestore(&gpio_lock, flags);
188
189 return ret;
190}
191
192#ifdef CONFIG_GPIO_SYSFS
193
194/* lock protects against unexport_gpio() being called while
195 * sysfs files are active.
196 */
197static DEFINE_MUTEX(sysfs_lock);
198
199/*
200 * /sys/class/gpio/gpioN... only for GPIOs that are exported
201 * /direction
202 * * MAY BE OMITTED if kernel won't allow direction changes
203 * * is read/write as "in" or "out"
204 * * may also be written as "high" or "low", initializing
205 * output value as specified ("out" implies "low")
206 * /value
207 * * always readable, subject to hardware behavior
208 * * may be writable, as zero/nonzero
209 * /edge
210 * * configures behavior of poll(2) on /value
211 * * available only if pin can generate IRQs on input
212 * * is read/write as "none", "falling", "rising", or "both"
213 * /active_low
214 * * configures polarity of /value
215 * * is read/write as zero/nonzero
216 * * also affects existing and subsequent "falling" and "rising"
217 * /edge configuration
218 */
219
220static ssize_t gpio_direction_show(struct device *dev,
221 struct device_attribute *attr, char *buf)
222{
223 const struct gpio_desc *desc = dev_get_drvdata(dev);
224 ssize_t status;
225
226 mutex_lock(&sysfs_lock);
227
228 if (!test_bit(FLAG_EXPORT, &desc->flags))
229 status = -EIO;
230 else
231 status = sprintf(buf, "%s\n",
232 test_bit(FLAG_IS_OUT, &desc->flags)
233 ? "out" : "in");
234
235 mutex_unlock(&sysfs_lock);
236 return status;
237}
238
239static ssize_t gpio_direction_store(struct device *dev,
240 struct device_attribute *attr, const char *buf, size_t size)
241{
242 const struct gpio_desc *desc = dev_get_drvdata(dev);
243 unsigned gpio = desc - gpio_desc;
244 ssize_t status;
245
246 mutex_lock(&sysfs_lock);
247
248 if (!test_bit(FLAG_EXPORT, &desc->flags))
249 status = -EIO;
250 else if (sysfs_streq(buf, "high"))
251 status = gpio_direction_output(gpio, 1);
252 else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
253 status = gpio_direction_output(gpio, 0);
254 else if (sysfs_streq(buf, "in"))
255 status = gpio_direction_input(gpio);
256 else
257 status = -EINVAL;
258
259 mutex_unlock(&sysfs_lock);
260 return status ? : size;
261}
262
263static /* const */ DEVICE_ATTR(direction, 0644,
264 gpio_direction_show, gpio_direction_store);
265
266static ssize_t gpio_value_show(struct device *dev,
267 struct device_attribute *attr, char *buf)
268{
269 const struct gpio_desc *desc = dev_get_drvdata(dev);
270 unsigned gpio = desc - gpio_desc;
271 ssize_t status;
272
273 mutex_lock(&sysfs_lock);
274
275 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
276 status = -EIO;
277 } else {
278 int value;
279
280 value = !!gpio_get_value_cansleep(gpio);
281 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
282 value = !value;
283
284 status = sprintf(buf, "%d\n", value);
285 }
286
287 mutex_unlock(&sysfs_lock);
288 return status;
289}
290
291static ssize_t gpio_value_store(struct device *dev,
292 struct device_attribute *attr, const char *buf, size_t size)
293{
294 const struct gpio_desc *desc = dev_get_drvdata(dev);
295 unsigned gpio = desc - gpio_desc;
296 ssize_t status;
297
298 mutex_lock(&sysfs_lock);
299
300 if (!test_bit(FLAG_EXPORT, &desc->flags))
301 status = -EIO;
302 else if (!test_bit(FLAG_IS_OUT, &desc->flags))
303 status = -EPERM;
304 else {
305 long value;
306
307 status = strict_strtol(buf, 0, &value);
308 if (status == 0) {
309 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
310 value = !value;
311 gpio_set_value_cansleep(gpio, value != 0);
312 status = size;
313 }
314 }
315
316 mutex_unlock(&sysfs_lock);
317 return status;
318}
319
320static const DEVICE_ATTR(value, 0644,
321 gpio_value_show, gpio_value_store);
322
323static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
324{
325 struct sysfs_dirent *value_sd = priv;
326
327 sysfs_notify_dirent(value_sd);
328 return IRQ_HANDLED;
329}
330
331static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
332 unsigned long gpio_flags)
333{
334 struct sysfs_dirent *value_sd;
335 unsigned long irq_flags;
336 int ret, irq, id;
337
338 if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
339 return 0;
340
341 irq = gpio_to_irq(desc - gpio_desc);
342 if (irq < 0)
343 return -EIO;
344
345 id = desc->flags >> ID_SHIFT;
346 value_sd = idr_find(&dirent_idr, id);
347 if (value_sd)
348 free_irq(irq, value_sd);
349
350 desc->flags &= ~GPIO_TRIGGER_MASK;
351
352 if (!gpio_flags) {
353 ret = 0;
354 goto free_id;
355 }
356
357 irq_flags = IRQF_SHARED;
358 if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
359 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
360 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
361 if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
362 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
363 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
364
365 if (!value_sd) {
366 value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value");
367 if (!value_sd) {
368 ret = -ENODEV;
369 goto err_out;
370 }
371
372 do {
373 ret = -ENOMEM;
374 if (idr_pre_get(&dirent_idr, GFP_KERNEL))
375 ret = idr_get_new_above(&dirent_idr, value_sd,
376 1, &id);
377 } while (ret == -EAGAIN);
378
379 if (ret)
380 goto free_sd;
381
382 desc->flags &= GPIO_FLAGS_MASK;
383 desc->flags |= (unsigned long)id << ID_SHIFT;
384
385 if (desc->flags >> ID_SHIFT != id) {
386 ret = -ERANGE;
387 goto free_id;
388 }
389 }
390
391 ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
392 "gpiolib", value_sd);
393 if (ret < 0)
394 goto free_id;
395
396 desc->flags |= gpio_flags;
397 return 0;
398
399free_id:
400 idr_remove(&dirent_idr, id);
401 desc->flags &= GPIO_FLAGS_MASK;
402free_sd:
403 if (value_sd)
404 sysfs_put(value_sd);
405err_out:
406 return ret;
407}
408
409static const struct {
410 const char *name;
411 unsigned long flags;
412} trigger_types[] = {
413 { "none", 0 },
414 { "falling", BIT(FLAG_TRIG_FALL) },
415 { "rising", BIT(FLAG_TRIG_RISE) },
416 { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
417};
418
419static ssize_t gpio_edge_show(struct device *dev,
420 struct device_attribute *attr, char *buf)
421{
422 const struct gpio_desc *desc = dev_get_drvdata(dev);
423 ssize_t status;
424
425 mutex_lock(&sysfs_lock);
426
427 if (!test_bit(FLAG_EXPORT, &desc->flags))
428 status = -EIO;
429 else {
430 int i;
431
432 status = 0;
433 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
434 if ((desc->flags & GPIO_TRIGGER_MASK)
435 == trigger_types[i].flags) {
436 status = sprintf(buf, "%s\n",
437 trigger_types[i].name);
438 break;
439 }
440 }
441
442 mutex_unlock(&sysfs_lock);
443 return status;
444}
445
446static ssize_t gpio_edge_store(struct device *dev,
447 struct device_attribute *attr, const char *buf, size_t size)
448{
449 struct gpio_desc *desc = dev_get_drvdata(dev);
450 ssize_t status;
451 int i;
452
453 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
454 if (sysfs_streq(trigger_types[i].name, buf))
455 goto found;
456 return -EINVAL;
457
458found:
459 mutex_lock(&sysfs_lock);
460
461 if (!test_bit(FLAG_EXPORT, &desc->flags))
462 status = -EIO;
463 else {
464 status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
465 if (!status)
466 status = size;
467 }
468
469 mutex_unlock(&sysfs_lock);
470
471 return status;
472}
473
474static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
475
476static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
477 int value)
478{
479 int status = 0;
480
481 if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
482 return 0;
483
484 if (value)
485 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
486 else
487 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
488
489 /* reconfigure poll(2) support if enabled on one edge only */
490 if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^
491 !!test_bit(FLAG_TRIG_FALL, &desc->flags))) {
492 unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK;
493
494 gpio_setup_irq(desc, dev, 0);
495 status = gpio_setup_irq(desc, dev, trigger_flags);
496 }
497
498 return status;
499}
500
501static ssize_t gpio_active_low_show(struct device *dev,
502 struct device_attribute *attr, char *buf)
503{
504 const struct gpio_desc *desc = dev_get_drvdata(dev);
505 ssize_t status;
506
507 mutex_lock(&sysfs_lock);
508
509 if (!test_bit(FLAG_EXPORT, &desc->flags))
510 status = -EIO;
511 else
512 status = sprintf(buf, "%d\n",
513 !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
514
515 mutex_unlock(&sysfs_lock);
516
517 return status;
518}
519
520static ssize_t gpio_active_low_store(struct device *dev,
521 struct device_attribute *attr, const char *buf, size_t size)
522{
523 struct gpio_desc *desc = dev_get_drvdata(dev);
524 ssize_t status;
525
526 mutex_lock(&sysfs_lock);
527
528 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
529 status = -EIO;
530 } else {
531 long value;
532
533 status = strict_strtol(buf, 0, &value);
534 if (status == 0)
535 status = sysfs_set_active_low(desc, dev, value != 0);
536 }
537
538 mutex_unlock(&sysfs_lock);
539
540 return status ? : size;
541}
542
543static const DEVICE_ATTR(active_low, 0644,
544 gpio_active_low_show, gpio_active_low_store);
545
546static const struct attribute *gpio_attrs[] = {
547 &dev_attr_value.attr,
548 &dev_attr_active_low.attr,
549 NULL,
550};
551
552static const struct attribute_group gpio_attr_group = {
553 .attrs = (struct attribute **) gpio_attrs,
554};
555
556/*
557 * /sys/class/gpio/gpiochipN/
558 * /base ... matching gpio_chip.base (N)
559 * /label ... matching gpio_chip.label
560 * /ngpio ... matching gpio_chip.ngpio
561 */
562
563static ssize_t chip_base_show(struct device *dev,
564 struct device_attribute *attr, char *buf)
565{
566 const struct gpio_chip *chip = dev_get_drvdata(dev);
567
568 return sprintf(buf, "%d\n", chip->base);
569}
570static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
571
572static ssize_t chip_label_show(struct device *dev,
573 struct device_attribute *attr, char *buf)
574{
575 const struct gpio_chip *chip = dev_get_drvdata(dev);
576
577 return sprintf(buf, "%s\n", chip->label ? : "");
578}
579static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
580
581static ssize_t chip_ngpio_show(struct device *dev,
582 struct device_attribute *attr, char *buf)
583{
584 const struct gpio_chip *chip = dev_get_drvdata(dev);
585
586 return sprintf(buf, "%u\n", chip->ngpio);
587}
588static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
589
590static const struct attribute *gpiochip_attrs[] = {
591 &dev_attr_base.attr,
592 &dev_attr_label.attr,
593 &dev_attr_ngpio.attr,
594 NULL,
595};
596
597static const struct attribute_group gpiochip_attr_group = {
598 .attrs = (struct attribute **) gpiochip_attrs,
599};
600
601/*
602 * /sys/class/gpio/export ... write-only
603 * integer N ... number of GPIO to export (full access)
604 * /sys/class/gpio/unexport ... write-only
605 * integer N ... number of GPIO to unexport
606 */
607static ssize_t export_store(struct class *class,
608 struct class_attribute *attr,
609 const char *buf, size_t len)
610{
611 long gpio;
612 int status;
613
614 status = strict_strtol(buf, 0, &gpio);
615 if (status < 0)
616 goto done;
617
618 /* No extra locking here; FLAG_SYSFS just signifies that the
619 * request and export were done by on behalf of userspace, so
620 * they may be undone on its behalf too.
621 */
622
623 status = gpio_request(gpio, "sysfs");
624 if (status < 0)
625 goto done;
626
627 status = gpio_export(gpio, true);
628 if (status < 0)
629 gpio_free(gpio);
630 else
631 set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags);
632
633done:
634 if (status)
635 pr_debug("%s: status %d\n", __func__, status);
636 return status ? : len;
637}
638
639static ssize_t unexport_store(struct class *class,
640 struct class_attribute *attr,
641 const char *buf, size_t len)
642{
643 long gpio;
644 int status;
645
646 status = strict_strtol(buf, 0, &gpio);
647 if (status < 0)
648 goto done;
649
650 status = -EINVAL;
651
652 /* reject bogus commands (gpio_unexport ignores them) */
653 if (!gpio_is_valid(gpio))
654 goto done;
655
656 /* No extra locking here; FLAG_SYSFS just signifies that the
657 * request and export were done by on behalf of userspace, so
658 * they may be undone on its behalf too.
659 */
660 if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) {
661 status = 0;
662 gpio_free(gpio);
663 }
664done:
665 if (status)
666 pr_debug("%s: status %d\n", __func__, status);
667 return status ? : len;
668}
669
670static struct class_attribute gpio_class_attrs[] = {
671 __ATTR(export, 0200, NULL, export_store),
672 __ATTR(unexport, 0200, NULL, unexport_store),
673 __ATTR_NULL,
674};
675
676static struct class gpio_class = {
677 .name = "gpio",
678 .owner = THIS_MODULE,
679
680 .class_attrs = gpio_class_attrs,
681};
682
683
684/**
685 * gpio_export - export a GPIO through sysfs
686 * @gpio: gpio to make available, already requested
687 * @direction_may_change: true if userspace may change gpio direction
688 * Context: arch_initcall or later
689 *
690 * When drivers want to make a GPIO accessible to userspace after they
691 * have requested it -- perhaps while debugging, or as part of their
692 * public interface -- they may use this routine. If the GPIO can
693 * change direction (some can't) and the caller allows it, userspace
694 * will see "direction" sysfs attribute which may be used to change
695 * the gpio's direction. A "value" attribute will always be provided.
696 *
697 * Returns zero on success, else an error.
698 */
699int gpio_export(unsigned gpio, bool direction_may_change)
700{
701 unsigned long flags;
702 struct gpio_desc *desc;
703 int status = -EINVAL;
704 const char *ioname = NULL;
705
706 /* can't export until sysfs is available ... */
707 if (!gpio_class.p) {
708 pr_debug("%s: called too early!\n", __func__);
709 return -ENOENT;
710 }
711
712 if (!gpio_is_valid(gpio))
713 goto done;
714
715 mutex_lock(&sysfs_lock);
716
717 spin_lock_irqsave(&gpio_lock, flags);
718 desc = &gpio_desc[gpio];
719 if (test_bit(FLAG_REQUESTED, &desc->flags)
720 && !test_bit(FLAG_EXPORT, &desc->flags)) {
721 status = 0;
722 if (!desc->chip->direction_input
723 || !desc->chip->direction_output)
724 direction_may_change = false;
725 }
726 spin_unlock_irqrestore(&gpio_lock, flags);
727
728 if (desc->chip->names && desc->chip->names[gpio - desc->chip->base])
729 ioname = desc->chip->names[gpio - desc->chip->base];
730
731 if (status == 0) {
732 struct device *dev;
733
734 dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
735 desc, ioname ? ioname : "gpio%u", gpio);
736 if (!IS_ERR(dev)) {
737 status = sysfs_create_group(&dev->kobj,
738 &gpio_attr_group);
739
740 if (!status && direction_may_change)
741 status = device_create_file(dev,
742 &dev_attr_direction);
743
744 if (!status && gpio_to_irq(gpio) >= 0
745 && (direction_may_change
746 || !test_bit(FLAG_IS_OUT,
747 &desc->flags)))
748 status = device_create_file(dev,
749 &dev_attr_edge);
750
751 if (status != 0)
752 device_unregister(dev);
753 } else
754 status = PTR_ERR(dev);
755 if (status == 0)
756 set_bit(FLAG_EXPORT, &desc->flags);
757 }
758
759 mutex_unlock(&sysfs_lock);
760
761done:
762 if (status)
763 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
764
765 return status;
766}
767EXPORT_SYMBOL_GPL(gpio_export);
768
769static int match_export(struct device *dev, void *data)
770{
771 return dev_get_drvdata(dev) == data;
772}
773
774/**
775 * gpio_export_link - create a sysfs link to an exported GPIO node
776 * @dev: device under which to create symlink
777 * @name: name of the symlink
778 * @gpio: gpio to create symlink to, already exported
779 *
780 * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
781 * node. Caller is responsible for unlinking.
782 *
783 * Returns zero on success, else an error.
784 */
785int gpio_export_link(struct device *dev, const char *name, unsigned gpio)
786{
787 struct gpio_desc *desc;
788 int status = -EINVAL;
789
790 if (!gpio_is_valid(gpio))
791 goto done;
792
793 mutex_lock(&sysfs_lock);
794
795 desc = &gpio_desc[gpio];
796
797 if (test_bit(FLAG_EXPORT, &desc->flags)) {
798 struct device *tdev;
799
800 tdev = class_find_device(&gpio_class, NULL, desc, match_export);
801 if (tdev != NULL) {
802 status = sysfs_create_link(&dev->kobj, &tdev->kobj,
803 name);
804 } else {
805 status = -ENODEV;
806 }
807 }
808
809 mutex_unlock(&sysfs_lock);
810
811done:
812 if (status)
813 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
814
815 return status;
816}
817EXPORT_SYMBOL_GPL(gpio_export_link);
818
819
820/**
821 * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value
822 * @gpio: gpio to change
823 * @value: non-zero to use active low, i.e. inverted values
824 *
825 * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute.
826 * The GPIO does not have to be exported yet. If poll(2) support has
827 * been enabled for either rising or falling edge, it will be
828 * reconfigured to follow the new polarity.
829 *
830 * Returns zero on success, else an error.
831 */
832int gpio_sysfs_set_active_low(unsigned gpio, int value)
833{
834 struct gpio_desc *desc;
835 struct device *dev = NULL;
836 int status = -EINVAL;
837
838 if (!gpio_is_valid(gpio))
839 goto done;
840
841 mutex_lock(&sysfs_lock);
842
843 desc = &gpio_desc[gpio];
844
845 if (test_bit(FLAG_EXPORT, &desc->flags)) {
846 dev = class_find_device(&gpio_class, NULL, desc, match_export);
847 if (dev == NULL) {
848 status = -ENODEV;
849 goto unlock;
850 }
851 }
852
853 status = sysfs_set_active_low(desc, dev, value);
854
855unlock:
856 mutex_unlock(&sysfs_lock);
857
858done:
859 if (status)
860 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
861
862 return status;
863}
864EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low);
865
866/**
867 * gpio_unexport - reverse effect of gpio_export()
868 * @gpio: gpio to make unavailable
869 *
870 * This is implicit on gpio_free().
871 */
872void gpio_unexport(unsigned gpio)
873{
874 struct gpio_desc *desc;
875 int status = 0;
876
877 if (!gpio_is_valid(gpio)) {
878 status = -EINVAL;
879 goto done;
880 }
881
882 mutex_lock(&sysfs_lock);
883
884 desc = &gpio_desc[gpio];
885
886 if (test_bit(FLAG_EXPORT, &desc->flags)) {
887 struct device *dev = NULL;
888
889 dev = class_find_device(&gpio_class, NULL, desc, match_export);
890 if (dev) {
891 gpio_setup_irq(desc, dev, 0);
892 clear_bit(FLAG_EXPORT, &desc->flags);
893 put_device(dev);
894 device_unregister(dev);
895 } else
896 status = -ENODEV;
897 }
898
899 mutex_unlock(&sysfs_lock);
900done:
901 if (status)
902 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
903}
904EXPORT_SYMBOL_GPL(gpio_unexport);
905
906static int gpiochip_export(struct gpio_chip *chip)
907{
908 int status;
909 struct device *dev;
910
911 /* Many systems register gpio chips for SOC support very early,
912 * before driver model support is available. In those cases we
913 * export this later, in gpiolib_sysfs_init() ... here we just
914 * verify that _some_ field of gpio_class got initialized.
915 */
916 if (!gpio_class.p)
917 return 0;
918
919 /* use chip->base for the ID; it's already known to be unique */
920 mutex_lock(&sysfs_lock);
921 dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip,
922 "gpiochip%d", chip->base);
923 if (!IS_ERR(dev)) {
924 status = sysfs_create_group(&dev->kobj,
925 &gpiochip_attr_group);
926 } else
927 status = PTR_ERR(dev);
928 chip->exported = (status == 0);
929 mutex_unlock(&sysfs_lock);
930
931 if (status) {
932 unsigned long flags;
933 unsigned gpio;
934
935 spin_lock_irqsave(&gpio_lock, flags);
936 gpio = chip->base;
937 while (gpio_desc[gpio].chip == chip)
938 gpio_desc[gpio++].chip = NULL;
939 spin_unlock_irqrestore(&gpio_lock, flags);
940
941 pr_debug("%s: chip %s status %d\n", __func__,
942 chip->label, status);
943 }
944
945 return status;
946}
947
948static void gpiochip_unexport(struct gpio_chip *chip)
949{
950 int status;
951 struct device *dev;
952
953 mutex_lock(&sysfs_lock);
954 dev = class_find_device(&gpio_class, NULL, chip, match_export);
955 if (dev) {
956 put_device(dev);
957 device_unregister(dev);
958 chip->exported = 0;
959 status = 0;
960 } else
961 status = -ENODEV;
962 mutex_unlock(&sysfs_lock);
963
964 if (status)
965 pr_debug("%s: chip %s status %d\n", __func__,
966 chip->label, status);
967}
968
969static int __init gpiolib_sysfs_init(void)
970{
971 int status;
972 unsigned long flags;
973 unsigned gpio;
974
975 status = class_register(&gpio_class);
976 if (status < 0)
977 return status;
978
979 /* Scan and register the gpio_chips which registered very
980 * early (e.g. before the class_register above was called).
981 *
982 * We run before arch_initcall() so chip->dev nodes can have
983 * registered, and so arch_initcall() can always gpio_export().
984 */
985 spin_lock_irqsave(&gpio_lock, flags);
986 for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) {
987 struct gpio_chip *chip;
988
989 chip = gpio_desc[gpio].chip;
990 if (!chip || chip->exported)
991 continue;
992
993 spin_unlock_irqrestore(&gpio_lock, flags);
994 status = gpiochip_export(chip);
995 spin_lock_irqsave(&gpio_lock, flags);
996 }
997 spin_unlock_irqrestore(&gpio_lock, flags);
998
999
1000 return status;
1001}
1002postcore_initcall(gpiolib_sysfs_init);
1003
1004#else
1005static inline int gpiochip_export(struct gpio_chip *chip)
1006{
1007 return 0;
1008}
1009
1010static inline void gpiochip_unexport(struct gpio_chip *chip)
1011{
1012}
1013
1014#endif /* CONFIG_GPIO_SYSFS */
1015
1016/**
1017 * gpiochip_add() - register a gpio_chip
1018 * @chip: the chip to register, with chip->base initialized
1019 * Context: potentially before irqs or kmalloc will work
1020 *
1021 * Returns a negative errno if the chip can't be registered, such as
1022 * because the chip->base is invalid or already associated with a
1023 * different chip. Otherwise it returns zero as a success code.
1024 *
1025 * When gpiochip_add() is called very early during boot, so that GPIOs
1026 * can be freely used, the chip->dev device must be registered before
1027 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1028 * for GPIOs will fail rudely.
1029 *
1030 * If chip->base is negative, this requests dynamic assignment of
1031 * a range of valid GPIOs.
1032 */
1033int gpiochip_add(struct gpio_chip *chip)
1034{
1035 unsigned long flags;
1036 int status = 0;
1037 unsigned id;
1038 int base = chip->base;
1039
1040 if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
1041 && base >= 0) {
1042 status = -EINVAL;
1043 goto fail;
1044 }
1045
1046 spin_lock_irqsave(&gpio_lock, flags);
1047
1048 if (base < 0) {
1049 base = gpiochip_find_base(chip->ngpio);
1050 if (base < 0) {
1051 status = base;
1052 goto unlock;
1053 }
1054 chip->base = base;
1055 }
1056
1057 /* these GPIO numbers must not be managed by another gpio_chip */
1058 for (id = base; id < base + chip->ngpio; id++) {
1059 if (gpio_desc[id].chip != NULL) {
1060 status = -EBUSY;
1061 break;
1062 }
1063 }
1064 if (status == 0) {
1065 for (id = base; id < base + chip->ngpio; id++) {
1066 gpio_desc[id].chip = chip;
1067
1068 /* REVISIT: most hardware initializes GPIOs as
1069 * inputs (often with pullups enabled) so power
1070 * usage is minimized. Linux code should set the
1071 * gpio direction first thing; but until it does,
1072 * we may expose the wrong direction in sysfs.
1073 */
1074 gpio_desc[id].flags = !chip->direction_input
1075 ? (1 << FLAG_IS_OUT)
1076 : 0;
1077 }
1078 }
1079
1080 of_gpiochip_add(chip);
1081
1082unlock:
1083 spin_unlock_irqrestore(&gpio_lock, flags);
1084
1085 if (status)
1086 goto fail;
1087
1088 status = gpiochip_export(chip);
1089 if (status)
1090 goto fail;
1091
1092 return 0;
1093fail:
1094 /* failures here can mean systems won't boot... */
1095 pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n",
1096 chip->base, chip->base + chip->ngpio - 1,
1097 chip->label ? : "generic");
1098 return status;
1099}
1100EXPORT_SYMBOL_GPL(gpiochip_add);
1101
1102/**
1103 * gpiochip_remove() - unregister a gpio_chip
1104 * @chip: the chip to unregister
1105 *
1106 * A gpio_chip with any GPIOs still requested may not be removed.
1107 */
1108int gpiochip_remove(struct gpio_chip *chip)
1109{
1110 unsigned long flags;
1111 int status = 0;
1112 unsigned id;
1113
1114 spin_lock_irqsave(&gpio_lock, flags);
1115
1116 of_gpiochip_remove(chip);
1117
1118 for (id = chip->base; id < chip->base + chip->ngpio; id++) {
1119 if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {
1120 status = -EBUSY;
1121 break;
1122 }
1123 }
1124 if (status == 0) {
1125 for (id = chip->base; id < chip->base + chip->ngpio; id++)
1126 gpio_desc[id].chip = NULL;
1127 }
1128
1129 spin_unlock_irqrestore(&gpio_lock, flags);
1130
1131 if (status == 0)
1132 gpiochip_unexport(chip);
1133
1134 return status;
1135}
1136EXPORT_SYMBOL_GPL(gpiochip_remove);
1137
1138/**
1139 * gpiochip_find() - iterator for locating a specific gpio_chip
1140 * @data: data to pass to match function
1141 * @callback: Callback function to check gpio_chip
1142 *
1143 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1144 * determined by a user supplied @match callback. The callback should return
1145 * 0 if the device doesn't match and non-zero if it does. If the callback is
1146 * non-zero, this function will return to the caller and not iterate over any
1147 * more gpio_chips.
1148 */
1149struct gpio_chip *gpiochip_find(void *data,
1150 int (*match)(struct gpio_chip *chip, void *data))
1151{
1152 struct gpio_chip *chip = NULL;
1153 unsigned long flags;
1154 int i;
1155
1156 spin_lock_irqsave(&gpio_lock, flags);
1157 for (i = 0; i < ARCH_NR_GPIOS; i++) {
1158 if (!gpio_desc[i].chip)
1159 continue;
1160
1161 if (match(gpio_desc[i].chip, data)) {
1162 chip = gpio_desc[i].chip;
1163 break;
1164 }
1165 }
1166 spin_unlock_irqrestore(&gpio_lock, flags);
1167
1168 return chip;
1169}
1170EXPORT_SYMBOL_GPL(gpiochip_find);
1171
1172/* These "optional" allocation calls help prevent drivers from stomping
1173 * on each other, and help provide better diagnostics in debugfs.
1174 * They're called even less than the "set direction" calls.
1175 */
1176int gpio_request(unsigned gpio, const char *label)
1177{
1178 struct gpio_desc *desc;
1179 struct gpio_chip *chip;
1180 int status = -EINVAL;
1181 unsigned long flags;
1182
1183 spin_lock_irqsave(&gpio_lock, flags);
1184
1185 if (!gpio_is_valid(gpio))
1186 goto done;
1187 desc = &gpio_desc[gpio];
1188 chip = desc->chip;
1189 if (chip == NULL)
1190 goto done;
1191
1192 if (!try_module_get(chip->owner))
1193 goto done;
1194
1195 /* NOTE: gpio_request() can be called in early boot,
1196 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1197 */
1198
1199 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1200 desc_set_label(desc, label ? : "?");
1201 status = 0;
1202 } else {
1203 status = -EBUSY;
1204 module_put(chip->owner);
1205 goto done;
1206 }
1207
1208 if (chip->request) {
1209 /* chip->request may sleep */
1210 spin_unlock_irqrestore(&gpio_lock, flags);
1211 status = chip->request(chip, gpio - chip->base);
1212 spin_lock_irqsave(&gpio_lock, flags);
1213
1214 if (status < 0) {
1215 desc_set_label(desc, NULL);
1216 module_put(chip->owner);
1217 clear_bit(FLAG_REQUESTED, &desc->flags);
1218 }
1219 }
1220
1221done:
1222 if (status)
1223 pr_debug("gpio_request: gpio-%d (%s) status %d\n",
1224 gpio, label ? : "?", status);
1225 spin_unlock_irqrestore(&gpio_lock, flags);
1226 return status;
1227}
1228EXPORT_SYMBOL_GPL(gpio_request);
1229
1230void gpio_free(unsigned gpio)
1231{
1232 unsigned long flags;
1233 struct gpio_desc *desc;
1234 struct gpio_chip *chip;
1235
1236 might_sleep();
1237
1238 if (!gpio_is_valid(gpio)) {
1239 WARN_ON(extra_checks);
1240 return;
1241 }
1242
1243 gpio_unexport(gpio);
1244
1245 spin_lock_irqsave(&gpio_lock, flags);
1246
1247 desc = &gpio_desc[gpio];
1248 chip = desc->chip;
1249 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1250 if (chip->free) {
1251 spin_unlock_irqrestore(&gpio_lock, flags);
1252 might_sleep_if(chip->can_sleep);
1253 chip->free(chip, gpio - chip->base);
1254 spin_lock_irqsave(&gpio_lock, flags);
1255 }
1256 desc_set_label(desc, NULL);
1257 module_put(desc->chip->owner);
1258 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1259 clear_bit(FLAG_REQUESTED, &desc->flags);
1260 } else
1261 WARN_ON(extra_checks);
1262
1263 spin_unlock_irqrestore(&gpio_lock, flags);
1264}
1265EXPORT_SYMBOL_GPL(gpio_free);
1266
1267/**
1268 * gpio_request_one - request a single GPIO with initial configuration
1269 * @gpio: the GPIO number
1270 * @flags: GPIO configuration as specified by GPIOF_*
1271 * @label: a literal description string of this GPIO
1272 */
1273int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
1274{
1275 int err;
1276
1277 err = gpio_request(gpio, label);
1278 if (err)
1279 return err;
1280
1281 if (flags & GPIOF_DIR_IN)
1282 err = gpio_direction_input(gpio);
1283 else
1284 err = gpio_direction_output(gpio,
1285 (flags & GPIOF_INIT_HIGH) ? 1 : 0);
1286
1287 if (err)
1288 gpio_free(gpio);
1289
1290 return err;
1291}
1292EXPORT_SYMBOL_GPL(gpio_request_one);
1293
1294/**
1295 * gpio_request_array - request multiple GPIOs in a single call
1296 * @array: array of the 'struct gpio'
1297 * @num: how many GPIOs in the array
1298 */
1299int gpio_request_array(const struct gpio *array, size_t num)
1300{
1301 int i, err;
1302
1303 for (i = 0; i < num; i++, array++) {
1304 err = gpio_request_one(array->gpio, array->flags, array->label);
1305 if (err)
1306 goto err_free;
1307 }
1308 return 0;
1309
1310err_free:
1311 while (i--)
1312 gpio_free((--array)->gpio);
1313 return err;
1314}
1315EXPORT_SYMBOL_GPL(gpio_request_array);
1316
1317/**
1318 * gpio_free_array - release multiple GPIOs in a single call
1319 * @array: array of the 'struct gpio'
1320 * @num: how many GPIOs in the array
1321 */
1322void gpio_free_array(const struct gpio *array, size_t num)
1323{
1324 while (num--)
1325 gpio_free((array++)->gpio);
1326}
1327EXPORT_SYMBOL_GPL(gpio_free_array);
1328
1329/**
1330 * gpiochip_is_requested - return string iff signal was requested
1331 * @chip: controller managing the signal
1332 * @offset: of signal within controller's 0..(ngpio - 1) range
1333 *
1334 * Returns NULL if the GPIO is not currently requested, else a string.
1335 * If debugfs support is enabled, the string returned is the label passed
1336 * to gpio_request(); otherwise it is a meaningless constant.
1337 *
1338 * This function is for use by GPIO controller drivers. The label can
1339 * help with diagnostics, and knowing that the signal is used as a GPIO
1340 * can help avoid accidentally multiplexing it to another controller.
1341 */
1342const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1343{
1344 unsigned gpio = chip->base + offset;
1345
1346 if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip)
1347 return NULL;
1348 if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0)
1349 return NULL;
1350#ifdef CONFIG_DEBUG_FS
1351 return gpio_desc[gpio].label;
1352#else
1353 return "?";
1354#endif
1355}
1356EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1357
1358
1359/* Drivers MUST set GPIO direction before making get/set calls. In
1360 * some cases this is done in early boot, before IRQs are enabled.
1361 *
1362 * As a rule these aren't called more than once (except for drivers
1363 * using the open-drain emulation idiom) so these are natural places
1364 * to accumulate extra debugging checks. Note that we can't (yet)
1365 * rely on gpio_request() having been called beforehand.
1366 */
1367
1368int gpio_direction_input(unsigned gpio)
1369{
1370 unsigned long flags;
1371 struct gpio_chip *chip;
1372 struct gpio_desc *desc = &gpio_desc[gpio];
1373 int status = -EINVAL;
1374
1375 spin_lock_irqsave(&gpio_lock, flags);
1376
1377 if (!gpio_is_valid(gpio))
1378 goto fail;
1379 chip = desc->chip;
1380 if (!chip || !chip->get || !chip->direction_input)
1381 goto fail;
1382 gpio -= chip->base;
1383 if (gpio >= chip->ngpio)
1384 goto fail;
1385 status = gpio_ensure_requested(desc, gpio);
1386 if (status < 0)
1387 goto fail;
1388
1389 /* now we know the gpio is valid and chip won't vanish */
1390
1391 spin_unlock_irqrestore(&gpio_lock, flags);
1392
1393 might_sleep_if(chip->can_sleep);
1394
1395 if (status) {
1396 status = chip->request(chip, gpio);
1397 if (status < 0) {
1398 pr_debug("GPIO-%d: chip request fail, %d\n",
1399 chip->base + gpio, status);
1400 /* and it's not available to anyone else ...
1401 * gpio_request() is the fully clean solution.
1402 */
1403 goto lose;
1404 }
1405 }
1406
1407 status = chip->direction_input(chip, gpio);
1408 if (status == 0)
1409 clear_bit(FLAG_IS_OUT, &desc->flags);
1410
1411 trace_gpio_direction(chip->base + gpio, 1, status);
1412lose:
1413 return status;
1414fail:
1415 spin_unlock_irqrestore(&gpio_lock, flags);
1416 if (status)
1417 pr_debug("%s: gpio-%d status %d\n",
1418 __func__, gpio, status);
1419 return status;
1420}
1421EXPORT_SYMBOL_GPL(gpio_direction_input);
1422
1423int gpio_direction_output(unsigned gpio, int value)
1424{
1425 unsigned long flags;
1426 struct gpio_chip *chip;
1427 struct gpio_desc *desc = &gpio_desc[gpio];
1428 int status = -EINVAL;
1429
1430 spin_lock_irqsave(&gpio_lock, flags);
1431
1432 if (!gpio_is_valid(gpio))
1433 goto fail;
1434 chip = desc->chip;
1435 if (!chip || !chip->set || !chip->direction_output)
1436 goto fail;
1437 gpio -= chip->base;
1438 if (gpio >= chip->ngpio)
1439 goto fail;
1440 status = gpio_ensure_requested(desc, gpio);
1441 if (status < 0)
1442 goto fail;
1443
1444 /* now we know the gpio is valid and chip won't vanish */
1445
1446 spin_unlock_irqrestore(&gpio_lock, flags);
1447
1448 might_sleep_if(chip->can_sleep);
1449
1450 if (status) {
1451 status = chip->request(chip, gpio);
1452 if (status < 0) {
1453 pr_debug("GPIO-%d: chip request fail, %d\n",
1454 chip->base + gpio, status);
1455 /* and it's not available to anyone else ...
1456 * gpio_request() is the fully clean solution.
1457 */
1458 goto lose;
1459 }
1460 }
1461
1462 status = chip->direction_output(chip, gpio, value);
1463 if (status == 0)
1464 set_bit(FLAG_IS_OUT, &desc->flags);
1465 trace_gpio_value(chip->base + gpio, 0, value);
1466 trace_gpio_direction(chip->base + gpio, 0, status);
1467lose:
1468 return status;
1469fail:
1470 spin_unlock_irqrestore(&gpio_lock, flags);
1471 if (status)
1472 pr_debug("%s: gpio-%d status %d\n",
1473 __func__, gpio, status);
1474 return status;
1475}
1476EXPORT_SYMBOL_GPL(gpio_direction_output);
1477
1478/**
1479 * gpio_set_debounce - sets @debounce time for a @gpio
1480 * @gpio: the gpio to set debounce time
1481 * @debounce: debounce time is microseconds
1482 */
1483int gpio_set_debounce(unsigned gpio, unsigned debounce)
1484{
1485 unsigned long flags;
1486 struct gpio_chip *chip;
1487 struct gpio_desc *desc = &gpio_desc[gpio];
1488 int status = -EINVAL;
1489
1490 spin_lock_irqsave(&gpio_lock, flags);
1491
1492 if (!gpio_is_valid(gpio))
1493 goto fail;
1494 chip = desc->chip;
1495 if (!chip || !chip->set || !chip->set_debounce)
1496 goto fail;
1497 gpio -= chip->base;
1498 if (gpio >= chip->ngpio)
1499 goto fail;
1500 status = gpio_ensure_requested(desc, gpio);
1501 if (status < 0)
1502 goto fail;
1503
1504 /* now we know the gpio is valid and chip won't vanish */
1505
1506 spin_unlock_irqrestore(&gpio_lock, flags);
1507
1508 might_sleep_if(chip->can_sleep);
1509
1510 return chip->set_debounce(chip, gpio, debounce);
1511
1512fail:
1513 spin_unlock_irqrestore(&gpio_lock, flags);
1514 if (status)
1515 pr_debug("%s: gpio-%d status %d\n",
1516 __func__, gpio, status);
1517
1518 return status;
1519}
1520EXPORT_SYMBOL_GPL(gpio_set_debounce);
1521
1522/* I/O calls are only valid after configuration completed; the relevant
1523 * "is this a valid GPIO" error checks should already have been done.
1524 *
1525 * "Get" operations are often inlinable as reading a pin value register,
1526 * and masking the relevant bit in that register.
1527 *
1528 * When "set" operations are inlinable, they involve writing that mask to
1529 * one register to set a low value, or a different register to set it high.
1530 * Otherwise locking is needed, so there may be little value to inlining.
1531 *
1532 *------------------------------------------------------------------------
1533 *
1534 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1535 * have requested the GPIO. That can include implicit requesting by
1536 * a direction setting call. Marking a gpio as requested locks its chip
1537 * in memory, guaranteeing that these table lookups need no more locking
1538 * and that gpiochip_remove() will fail.
1539 *
1540 * REVISIT when debugging, consider adding some instrumentation to ensure
1541 * that the GPIO was actually requested.
1542 */
1543
1544/**
1545 * __gpio_get_value() - return a gpio's value
1546 * @gpio: gpio whose value will be returned
1547 * Context: any
1548 *
1549 * This is used directly or indirectly to implement gpio_get_value().
1550 * It returns the zero or nonzero value provided by the associated
1551 * gpio_chip.get() method; or zero if no such method is provided.
1552 */
1553int __gpio_get_value(unsigned gpio)
1554{
1555 struct gpio_chip *chip;
1556 int value;
1557
1558 chip = gpio_to_chip(gpio);
1559 WARN_ON(chip->can_sleep);
1560 value = chip->get ? chip->get(chip, gpio - chip->base) : 0;
1561 trace_gpio_value(gpio, 1, value);
1562 return value;
1563}
1564EXPORT_SYMBOL_GPL(__gpio_get_value);
1565
1566/**
1567 * __gpio_set_value() - assign a gpio's value
1568 * @gpio: gpio whose value will be assigned
1569 * @value: value to assign
1570 * Context: any
1571 *
1572 * This is used directly or indirectly to implement gpio_set_value().
1573 * It invokes the associated gpio_chip.set() method.
1574 */
1575void __gpio_set_value(unsigned gpio, int value)
1576{
1577 struct gpio_chip *chip;
1578
1579 chip = gpio_to_chip(gpio);
1580 WARN_ON(chip->can_sleep);
1581 trace_gpio_value(gpio, 0, value);
1582 chip->set(chip, gpio - chip->base, value);
1583}
1584EXPORT_SYMBOL_GPL(__gpio_set_value);
1585
1586/**
1587 * __gpio_cansleep() - report whether gpio value access will sleep
1588 * @gpio: gpio in question
1589 * Context: any
1590 *
1591 * This is used directly or indirectly to implement gpio_cansleep(). It
1592 * returns nonzero if access reading or writing the GPIO value can sleep.
1593 */
1594int __gpio_cansleep(unsigned gpio)
1595{
1596 struct gpio_chip *chip;
1597
1598 /* only call this on GPIOs that are valid! */
1599 chip = gpio_to_chip(gpio);
1600
1601 return chip->can_sleep;
1602}
1603EXPORT_SYMBOL_GPL(__gpio_cansleep);
1604
1605/**
1606 * __gpio_to_irq() - return the IRQ corresponding to a GPIO
1607 * @gpio: gpio whose IRQ will be returned (already requested)
1608 * Context: any
1609 *
1610 * This is used directly or indirectly to implement gpio_to_irq().
1611 * It returns the number of the IRQ signaled by this (input) GPIO,
1612 * or a negative errno.
1613 */
1614int __gpio_to_irq(unsigned gpio)
1615{
1616 struct gpio_chip *chip;
1617
1618 chip = gpio_to_chip(gpio);
1619 return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO;
1620}
1621EXPORT_SYMBOL_GPL(__gpio_to_irq);
1622
1623
1624
1625/* There's no value in making it easy to inline GPIO calls that may sleep.
1626 * Common examples include ones connected to I2C or SPI chips.
1627 */
1628
1629int gpio_get_value_cansleep(unsigned gpio)
1630{
1631 struct gpio_chip *chip;
1632 int value;
1633
1634 might_sleep_if(extra_checks);
1635 chip = gpio_to_chip(gpio);
1636 value = chip->get ? chip->get(chip, gpio - chip->base) : 0;
1637 trace_gpio_value(gpio, 1, value);
1638 return value;
1639}
1640EXPORT_SYMBOL_GPL(gpio_get_value_cansleep);
1641
1642void gpio_set_value_cansleep(unsigned gpio, int value)
1643{
1644 struct gpio_chip *chip;
1645
1646 might_sleep_if(extra_checks);
1647 chip = gpio_to_chip(gpio);
1648 trace_gpio_value(gpio, 0, value);
1649 chip->set(chip, gpio - chip->base, value);
1650}
1651EXPORT_SYMBOL_GPL(gpio_set_value_cansleep);
1652
1653
1654#ifdef CONFIG_DEBUG_FS
1655
1656static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
1657{
1658 unsigned i;
1659 unsigned gpio = chip->base;
1660 struct gpio_desc *gdesc = &gpio_desc[gpio];
1661 int is_out;
1662
1663 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
1664 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
1665 continue;
1666
1667 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
1668 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s",
1669 gpio, gdesc->label,
1670 is_out ? "out" : "in ",
1671 chip->get
1672 ? (chip->get(chip, i) ? "hi" : "lo")
1673 : "? ");
1674 seq_printf(s, "\n");
1675 }
1676}
1677
1678static int gpiolib_show(struct seq_file *s, void *unused)
1679{
1680 struct gpio_chip *chip = NULL;
1681 unsigned gpio;
1682 int started = 0;
1683
1684 /* REVISIT this isn't locked against gpio_chip removal ... */
1685
1686 for (gpio = 0; gpio_is_valid(gpio); gpio++) {
1687 struct device *dev;
1688
1689 if (chip == gpio_desc[gpio].chip)
1690 continue;
1691 chip = gpio_desc[gpio].chip;
1692 if (!chip)
1693 continue;
1694
1695 seq_printf(s, "%sGPIOs %d-%d",
1696 started ? "\n" : "",
1697 chip->base, chip->base + chip->ngpio - 1);
1698 dev = chip->dev;
1699 if (dev)
1700 seq_printf(s, ", %s/%s",
1701 dev->bus ? dev->bus->name : "no-bus",
1702 dev_name(dev));
1703 if (chip->label)
1704 seq_printf(s, ", %s", chip->label);
1705 if (chip->can_sleep)
1706 seq_printf(s, ", can sleep");
1707 seq_printf(s, ":\n");
1708
1709 started = 1;
1710 if (chip->dbg_show)
1711 chip->dbg_show(s, chip);
1712 else
1713 gpiolib_dbg_show(s, chip);
1714 }
1715 return 0;
1716}
1717
1718static int gpiolib_open(struct inode *inode, struct file *file)
1719{
1720 return single_open(file, gpiolib_show, NULL);
1721}
1722
1723static const struct file_operations gpiolib_operations = {
1724 .open = gpiolib_open,
1725 .read = seq_read,
1726 .llseek = seq_lseek,
1727 .release = single_release,
1728};
1729
1730static int __init gpiolib_debugfs_init(void)
1731{
1732 /* /sys/kernel/debug/gpio */
1733 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
1734 NULL, NULL, &gpiolib_operations);
1735 return 0;
1736}
1737subsys_initcall(gpiolib_debugfs_init);
1738
1739#endif /* DEBUG_FS */