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