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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 */
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/cdev.h>
21#include <linux/fs.h>
22#include <linux/uaccess.h>
23#include <linux/compat.h>
24#include <linux/anon_inodes.h>
25#include <linux/file.h>
26#include <linux/kfifo.h>
27#include <linux/poll.h>
28#include <linux/timekeeping.h>
29#include <uapi/linux/gpio.h>
30
31#include "gpiolib.h"
32#include "gpiolib-of.h"
33#include "gpiolib-acpi.h"
34
35#define CREATE_TRACE_POINTS
36#include <trace/events/gpio.h>
37
38/* Implementation infrastructure for GPIO interfaces.
39 *
40 * The GPIO programming interface allows for inlining speed-critical
41 * get/set operations for common cases, so that access to SOC-integrated
42 * GPIOs can sometimes cost only an instruction or two per bit.
43 */
44
45
46/* When debugging, extend minimal trust to callers and platform code.
47 * Also emit diagnostic messages that may help initial bringup, when
48 * board setup or driver bugs are most common.
49 *
50 * Otherwise, minimize overhead in what may be bitbanging codepaths.
51 */
52#ifdef DEBUG
53#define extra_checks 1
54#else
55#define extra_checks 0
56#endif
57
58/* Device and char device-related information */
59static DEFINE_IDA(gpio_ida);
60static dev_t gpio_devt;
61#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
62static struct bus_type gpio_bus_type = {
63 .name = "gpio",
64};
65
66/*
67 * Number of GPIOs to use for the fast path in set array
68 */
69#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
70
71/* gpio_lock prevents conflicts during gpio_desc[] table updates.
72 * While any GPIO is requested, its gpio_chip is not removable;
73 * each GPIO's "requested" flag serves as a lock and refcount.
74 */
75DEFINE_SPINLOCK(gpio_lock);
76
77static DEFINE_MUTEX(gpio_lookup_lock);
78static LIST_HEAD(gpio_lookup_list);
79LIST_HEAD(gpio_devices);
80
81static DEFINE_MUTEX(gpio_machine_hogs_mutex);
82static LIST_HEAD(gpio_machine_hogs);
83
84static void gpiochip_free_hogs(struct gpio_chip *chip);
85static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
86 struct lock_class_key *lock_key,
87 struct lock_class_key *request_key);
88static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
89static int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip);
90static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
91static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
92
93static bool gpiolib_initialized;
94
95static inline void desc_set_label(struct gpio_desc *d, const char *label)
96{
97 d->label = label;
98}
99
100/**
101 * gpio_to_desc - Convert a GPIO number to its descriptor
102 * @gpio: global GPIO number
103 *
104 * Returns:
105 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
106 * with the given number exists in the system.
107 */
108struct gpio_desc *gpio_to_desc(unsigned gpio)
109{
110 struct gpio_device *gdev;
111 unsigned long flags;
112
113 spin_lock_irqsave(&gpio_lock, flags);
114
115 list_for_each_entry(gdev, &gpio_devices, list) {
116 if (gdev->base <= gpio &&
117 gdev->base + gdev->ngpio > gpio) {
118 spin_unlock_irqrestore(&gpio_lock, flags);
119 return &gdev->descs[gpio - gdev->base];
120 }
121 }
122
123 spin_unlock_irqrestore(&gpio_lock, flags);
124
125 if (!gpio_is_valid(gpio))
126 WARN(1, "invalid GPIO %d\n", gpio);
127
128 return NULL;
129}
130EXPORT_SYMBOL_GPL(gpio_to_desc);
131
132/**
133 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
134 * hardware number for this chip
135 * @chip: GPIO chip
136 * @hwnum: hardware number of the GPIO for this chip
137 *
138 * Returns:
139 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
140 * in the given chip for the specified hardware number.
141 */
142struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
143 u16 hwnum)
144{
145 struct gpio_device *gdev = chip->gpiodev;
146
147 if (hwnum >= gdev->ngpio)
148 return ERR_PTR(-EINVAL);
149
150 return &gdev->descs[hwnum];
151}
152
153/**
154 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
155 * @desc: GPIO descriptor
156 *
157 * This should disappear in the future but is needed since we still
158 * use GPIO numbers for error messages and sysfs nodes.
159 *
160 * Returns:
161 * The global GPIO number for the GPIO specified by its descriptor.
162 */
163int desc_to_gpio(const struct gpio_desc *desc)
164{
165 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
166}
167EXPORT_SYMBOL_GPL(desc_to_gpio);
168
169
170/**
171 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
172 * @desc: descriptor to return the chip of
173 */
174struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
175{
176 if (!desc || !desc->gdev)
177 return NULL;
178 return desc->gdev->chip;
179}
180EXPORT_SYMBOL_GPL(gpiod_to_chip);
181
182/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
183static int gpiochip_find_base(int ngpio)
184{
185 struct gpio_device *gdev;
186 int base = ARCH_NR_GPIOS - ngpio;
187
188 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
189 /* found a free space? */
190 if (gdev->base + gdev->ngpio <= base)
191 break;
192 else
193 /* nope, check the space right before the chip */
194 base = gdev->base - ngpio;
195 }
196
197 if (gpio_is_valid(base)) {
198 pr_debug("%s: found new base at %d\n", __func__, base);
199 return base;
200 } else {
201 pr_err("%s: cannot find free range\n", __func__);
202 return -ENOSPC;
203 }
204}
205
206/**
207 * gpiod_get_direction - return the current direction of a GPIO
208 * @desc: GPIO to get the direction of
209 *
210 * Returns 0 for output, 1 for input, or an error code in case of error.
211 *
212 * This function may sleep if gpiod_cansleep() is true.
213 */
214int gpiod_get_direction(struct gpio_desc *desc)
215{
216 struct gpio_chip *chip;
217 unsigned offset;
218 int ret;
219
220 chip = gpiod_to_chip(desc);
221 offset = gpio_chip_hwgpio(desc);
222
223 if (!chip->get_direction)
224 return -ENOTSUPP;
225
226 ret = chip->get_direction(chip, offset);
227 if (ret > 0) {
228 /* GPIOF_DIR_IN, or other positive */
229 ret = 1;
230 clear_bit(FLAG_IS_OUT, &desc->flags);
231 }
232 if (ret == 0) {
233 /* GPIOF_DIR_OUT */
234 set_bit(FLAG_IS_OUT, &desc->flags);
235 }
236 return ret;
237}
238EXPORT_SYMBOL_GPL(gpiod_get_direction);
239
240/*
241 * Add a new chip to the global chips list, keeping the list of chips sorted
242 * by range(means [base, base + ngpio - 1]) order.
243 *
244 * Return -EBUSY if the new chip overlaps with some other chip's integer
245 * space.
246 */
247static int gpiodev_add_to_list(struct gpio_device *gdev)
248{
249 struct gpio_device *prev, *next;
250
251 if (list_empty(&gpio_devices)) {
252 /* initial entry in list */
253 list_add_tail(&gdev->list, &gpio_devices);
254 return 0;
255 }
256
257 next = list_entry(gpio_devices.next, struct gpio_device, list);
258 if (gdev->base + gdev->ngpio <= next->base) {
259 /* add before first entry */
260 list_add(&gdev->list, &gpio_devices);
261 return 0;
262 }
263
264 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
265 if (prev->base + prev->ngpio <= gdev->base) {
266 /* add behind last entry */
267 list_add_tail(&gdev->list, &gpio_devices);
268 return 0;
269 }
270
271 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
272 /* at the end of the list */
273 if (&next->list == &gpio_devices)
274 break;
275
276 /* add between prev and next */
277 if (prev->base + prev->ngpio <= gdev->base
278 && gdev->base + gdev->ngpio <= next->base) {
279 list_add(&gdev->list, &prev->list);
280 return 0;
281 }
282 }
283
284 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
285 return -EBUSY;
286}
287
288/*
289 * Convert a GPIO name to its descriptor
290 */
291static struct gpio_desc *gpio_name_to_desc(const char * const name)
292{
293 struct gpio_device *gdev;
294 unsigned long flags;
295
296 spin_lock_irqsave(&gpio_lock, flags);
297
298 list_for_each_entry(gdev, &gpio_devices, list) {
299 int i;
300
301 for (i = 0; i != gdev->ngpio; ++i) {
302 struct gpio_desc *desc = &gdev->descs[i];
303
304 if (!desc->name || !name)
305 continue;
306
307 if (!strcmp(desc->name, name)) {
308 spin_unlock_irqrestore(&gpio_lock, flags);
309 return desc;
310 }
311 }
312 }
313
314 spin_unlock_irqrestore(&gpio_lock, flags);
315
316 return NULL;
317}
318
319/*
320 * Takes the names from gc->names and checks if they are all unique. If they
321 * are, they are assigned to their gpio descriptors.
322 *
323 * Warning if one of the names is already used for a different GPIO.
324 */
325static int gpiochip_set_desc_names(struct gpio_chip *gc)
326{
327 struct gpio_device *gdev = gc->gpiodev;
328 int i;
329
330 if (!gc->names)
331 return 0;
332
333 /* First check all names if they are unique */
334 for (i = 0; i != gc->ngpio; ++i) {
335 struct gpio_desc *gpio;
336
337 gpio = gpio_name_to_desc(gc->names[i]);
338 if (gpio)
339 dev_warn(&gdev->dev,
340 "Detected name collision for GPIO name '%s'\n",
341 gc->names[i]);
342 }
343
344 /* Then add all names to the GPIO descriptors */
345 for (i = 0; i != gc->ngpio; ++i)
346 gdev->descs[i].name = gc->names[i];
347
348 return 0;
349}
350
351static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
352{
353 unsigned long *p;
354
355 p = bitmap_alloc(chip->ngpio, GFP_KERNEL);
356 if (!p)
357 return NULL;
358
359 /* Assume by default all GPIOs are valid */
360 bitmap_fill(p, chip->ngpio);
361
362 return p;
363}
364
365static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
366{
367 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
368 return 0;
369
370 gc->valid_mask = gpiochip_allocate_mask(gc);
371 if (!gc->valid_mask)
372 return -ENOMEM;
373
374 return 0;
375}
376
377static int gpiochip_init_valid_mask(struct gpio_chip *gc)
378{
379 if (gc->init_valid_mask)
380 return gc->init_valid_mask(gc,
381 gc->valid_mask,
382 gc->ngpio);
383
384 return 0;
385}
386
387static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
388{
389 bitmap_free(gpiochip->valid_mask);
390 gpiochip->valid_mask = NULL;
391}
392
393bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
394 unsigned int offset)
395{
396 /* No mask means all valid */
397 if (likely(!gpiochip->valid_mask))
398 return true;
399 return test_bit(offset, gpiochip->valid_mask);
400}
401EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
402
403/*
404 * GPIO line handle management
405 */
406
407/**
408 * struct linehandle_state - contains the state of a userspace handle
409 * @gdev: the GPIO device the handle pertains to
410 * @label: consumer label used to tag descriptors
411 * @descs: the GPIO descriptors held by this handle
412 * @numdescs: the number of descriptors held in the descs array
413 */
414struct linehandle_state {
415 struct gpio_device *gdev;
416 const char *label;
417 struct gpio_desc *descs[GPIOHANDLES_MAX];
418 u32 numdescs;
419};
420
421#define GPIOHANDLE_REQUEST_VALID_FLAGS \
422 (GPIOHANDLE_REQUEST_INPUT | \
423 GPIOHANDLE_REQUEST_OUTPUT | \
424 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
425 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
426 GPIOHANDLE_REQUEST_OPEN_SOURCE)
427
428static long linehandle_ioctl(struct file *filep, unsigned int cmd,
429 unsigned long arg)
430{
431 struct linehandle_state *lh = filep->private_data;
432 void __user *ip = (void __user *)arg;
433 struct gpiohandle_data ghd;
434 DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
435 int i;
436
437 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
438 /* NOTE: It's ok to read values of output lines. */
439 int ret = gpiod_get_array_value_complex(false,
440 true,
441 lh->numdescs,
442 lh->descs,
443 NULL,
444 vals);
445 if (ret)
446 return ret;
447
448 memset(&ghd, 0, sizeof(ghd));
449 for (i = 0; i < lh->numdescs; i++)
450 ghd.values[i] = test_bit(i, vals);
451
452 if (copy_to_user(ip, &ghd, sizeof(ghd)))
453 return -EFAULT;
454
455 return 0;
456 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
457 /*
458 * All line descriptors were created at once with the same
459 * flags so just check if the first one is really output.
460 */
461 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
462 return -EPERM;
463
464 if (copy_from_user(&ghd, ip, sizeof(ghd)))
465 return -EFAULT;
466
467 /* Clamp all values to [0,1] */
468 for (i = 0; i < lh->numdescs; i++)
469 __assign_bit(i, vals, ghd.values[i]);
470
471 /* Reuse the array setting function */
472 return gpiod_set_array_value_complex(false,
473 true,
474 lh->numdescs,
475 lh->descs,
476 NULL,
477 vals);
478 }
479 return -EINVAL;
480}
481
482#ifdef CONFIG_COMPAT
483static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
484 unsigned long arg)
485{
486 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
487}
488#endif
489
490static int linehandle_release(struct inode *inode, struct file *filep)
491{
492 struct linehandle_state *lh = filep->private_data;
493 struct gpio_device *gdev = lh->gdev;
494 int i;
495
496 for (i = 0; i < lh->numdescs; i++)
497 gpiod_free(lh->descs[i]);
498 kfree(lh->label);
499 kfree(lh);
500 put_device(&gdev->dev);
501 return 0;
502}
503
504static const struct file_operations linehandle_fileops = {
505 .release = linehandle_release,
506 .owner = THIS_MODULE,
507 .llseek = noop_llseek,
508 .unlocked_ioctl = linehandle_ioctl,
509#ifdef CONFIG_COMPAT
510 .compat_ioctl = linehandle_ioctl_compat,
511#endif
512};
513
514static int linehandle_create(struct gpio_device *gdev, void __user *ip)
515{
516 struct gpiohandle_request handlereq;
517 struct linehandle_state *lh;
518 struct file *file;
519 int fd, i, count = 0, ret;
520 u32 lflags;
521
522 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
523 return -EFAULT;
524 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
525 return -EINVAL;
526
527 lflags = handlereq.flags;
528
529 /* Return an error if an unknown flag is set */
530 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
531 return -EINVAL;
532
533 /*
534 * Do not allow both INPUT & OUTPUT flags to be set as they are
535 * contradictory.
536 */
537 if ((lflags & GPIOHANDLE_REQUEST_INPUT) &&
538 (lflags & GPIOHANDLE_REQUEST_OUTPUT))
539 return -EINVAL;
540
541 /*
542 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
543 * the hardware actually supports enabling both at the same time the
544 * electrical result would be disastrous.
545 */
546 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
547 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
548 return -EINVAL;
549
550 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
551 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
552 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
553 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
554 return -EINVAL;
555
556 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
557 if (!lh)
558 return -ENOMEM;
559 lh->gdev = gdev;
560 get_device(&gdev->dev);
561
562 /* Make sure this is terminated */
563 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
564 if (strlen(handlereq.consumer_label)) {
565 lh->label = kstrdup(handlereq.consumer_label,
566 GFP_KERNEL);
567 if (!lh->label) {
568 ret = -ENOMEM;
569 goto out_free_lh;
570 }
571 }
572
573 /* Request each GPIO */
574 for (i = 0; i < handlereq.lines; i++) {
575 u32 offset = handlereq.lineoffsets[i];
576 struct gpio_desc *desc;
577
578 if (offset >= gdev->ngpio) {
579 ret = -EINVAL;
580 goto out_free_descs;
581 }
582
583 desc = &gdev->descs[offset];
584 ret = gpiod_request(desc, lh->label);
585 if (ret)
586 goto out_free_descs;
587 lh->descs[i] = desc;
588 count = i + 1;
589
590 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
591 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
592 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
593 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
594 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
595 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
596
597 ret = gpiod_set_transitory(desc, false);
598 if (ret < 0)
599 goto out_free_descs;
600
601 /*
602 * Lines have to be requested explicitly for input
603 * or output, else the line will be treated "as is".
604 */
605 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
606 int val = !!handlereq.default_values[i];
607
608 ret = gpiod_direction_output(desc, val);
609 if (ret)
610 goto out_free_descs;
611 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
612 ret = gpiod_direction_input(desc);
613 if (ret)
614 goto out_free_descs;
615 }
616 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
617 offset);
618 }
619 /* Let i point at the last handle */
620 i--;
621 lh->numdescs = handlereq.lines;
622
623 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
624 if (fd < 0) {
625 ret = fd;
626 goto out_free_descs;
627 }
628
629 file = anon_inode_getfile("gpio-linehandle",
630 &linehandle_fileops,
631 lh,
632 O_RDONLY | O_CLOEXEC);
633 if (IS_ERR(file)) {
634 ret = PTR_ERR(file);
635 goto out_put_unused_fd;
636 }
637
638 handlereq.fd = fd;
639 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
640 /*
641 * fput() will trigger the release() callback, so do not go onto
642 * the regular error cleanup path here.
643 */
644 fput(file);
645 put_unused_fd(fd);
646 return -EFAULT;
647 }
648
649 fd_install(fd, file);
650
651 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
652 lh->numdescs);
653
654 return 0;
655
656out_put_unused_fd:
657 put_unused_fd(fd);
658out_free_descs:
659 for (i = 0; i < count; i++)
660 gpiod_free(lh->descs[i]);
661 kfree(lh->label);
662out_free_lh:
663 kfree(lh);
664 put_device(&gdev->dev);
665 return ret;
666}
667
668/*
669 * GPIO line event management
670 */
671
672/**
673 * struct lineevent_state - contains the state of a userspace event
674 * @gdev: the GPIO device the event pertains to
675 * @label: consumer label used to tag descriptors
676 * @desc: the GPIO descriptor held by this event
677 * @eflags: the event flags this line was requested with
678 * @irq: the interrupt that trigger in response to events on this GPIO
679 * @wait: wait queue that handles blocking reads of events
680 * @events: KFIFO for the GPIO events
681 * @read_lock: mutex lock to protect reads from colliding with adding
682 * new events to the FIFO
683 * @timestamp: cache for the timestamp storing it between hardirq
684 * and IRQ thread, used to bring the timestamp close to the actual
685 * event
686 */
687struct lineevent_state {
688 struct gpio_device *gdev;
689 const char *label;
690 struct gpio_desc *desc;
691 u32 eflags;
692 int irq;
693 wait_queue_head_t wait;
694 DECLARE_KFIFO(events, struct gpioevent_data, 16);
695 struct mutex read_lock;
696 u64 timestamp;
697};
698
699#define GPIOEVENT_REQUEST_VALID_FLAGS \
700 (GPIOEVENT_REQUEST_RISING_EDGE | \
701 GPIOEVENT_REQUEST_FALLING_EDGE)
702
703static __poll_t lineevent_poll(struct file *filep,
704 struct poll_table_struct *wait)
705{
706 struct lineevent_state *le = filep->private_data;
707 __poll_t events = 0;
708
709 poll_wait(filep, &le->wait, wait);
710
711 if (!kfifo_is_empty(&le->events))
712 events = EPOLLIN | EPOLLRDNORM;
713
714 return events;
715}
716
717
718static ssize_t lineevent_read(struct file *filep,
719 char __user *buf,
720 size_t count,
721 loff_t *f_ps)
722{
723 struct lineevent_state *le = filep->private_data;
724 unsigned int copied;
725 int ret;
726
727 if (count < sizeof(struct gpioevent_data))
728 return -EINVAL;
729
730 do {
731 if (kfifo_is_empty(&le->events)) {
732 if (filep->f_flags & O_NONBLOCK)
733 return -EAGAIN;
734
735 ret = wait_event_interruptible(le->wait,
736 !kfifo_is_empty(&le->events));
737 if (ret)
738 return ret;
739 }
740
741 if (mutex_lock_interruptible(&le->read_lock))
742 return -ERESTARTSYS;
743 ret = kfifo_to_user(&le->events, buf, count, &copied);
744 mutex_unlock(&le->read_lock);
745
746 if (ret)
747 return ret;
748
749 /*
750 * If we couldn't read anything from the fifo (a different
751 * thread might have been faster) we either return -EAGAIN if
752 * the file descriptor is non-blocking, otherwise we go back to
753 * sleep and wait for more data to arrive.
754 */
755 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
756 return -EAGAIN;
757
758 } while (copied == 0);
759
760 return copied;
761}
762
763static int lineevent_release(struct inode *inode, struct file *filep)
764{
765 struct lineevent_state *le = filep->private_data;
766 struct gpio_device *gdev = le->gdev;
767
768 free_irq(le->irq, le);
769 gpiod_free(le->desc);
770 kfree(le->label);
771 kfree(le);
772 put_device(&gdev->dev);
773 return 0;
774}
775
776static long lineevent_ioctl(struct file *filep, unsigned int cmd,
777 unsigned long arg)
778{
779 struct lineevent_state *le = filep->private_data;
780 void __user *ip = (void __user *)arg;
781 struct gpiohandle_data ghd;
782
783 /*
784 * We can get the value for an event line but not set it,
785 * because it is input by definition.
786 */
787 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
788 int val;
789
790 memset(&ghd, 0, sizeof(ghd));
791
792 val = gpiod_get_value_cansleep(le->desc);
793 if (val < 0)
794 return val;
795 ghd.values[0] = val;
796
797 if (copy_to_user(ip, &ghd, sizeof(ghd)))
798 return -EFAULT;
799
800 return 0;
801 }
802 return -EINVAL;
803}
804
805#ifdef CONFIG_COMPAT
806static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
807 unsigned long arg)
808{
809 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
810}
811#endif
812
813static const struct file_operations lineevent_fileops = {
814 .release = lineevent_release,
815 .read = lineevent_read,
816 .poll = lineevent_poll,
817 .owner = THIS_MODULE,
818 .llseek = noop_llseek,
819 .unlocked_ioctl = lineevent_ioctl,
820#ifdef CONFIG_COMPAT
821 .compat_ioctl = lineevent_ioctl_compat,
822#endif
823};
824
825static irqreturn_t lineevent_irq_thread(int irq, void *p)
826{
827 struct lineevent_state *le = p;
828 struct gpioevent_data ge;
829 int ret;
830
831 /* Do not leak kernel stack to userspace */
832 memset(&ge, 0, sizeof(ge));
833
834 /*
835 * We may be running from a nested threaded interrupt in which case
836 * we didn't get the timestamp from lineevent_irq_handler().
837 */
838 if (!le->timestamp)
839 ge.timestamp = ktime_get_real_ns();
840 else
841 ge.timestamp = le->timestamp;
842
843 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
844 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
845 int level = gpiod_get_value_cansleep(le->desc);
846 if (level)
847 /* Emit low-to-high event */
848 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
849 else
850 /* Emit high-to-low event */
851 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
852 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
853 /* Emit low-to-high event */
854 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
855 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
856 /* Emit high-to-low event */
857 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
858 } else {
859 return IRQ_NONE;
860 }
861
862 ret = kfifo_put(&le->events, ge);
863 if (ret)
864 wake_up_poll(&le->wait, EPOLLIN);
865
866 return IRQ_HANDLED;
867}
868
869static irqreturn_t lineevent_irq_handler(int irq, void *p)
870{
871 struct lineevent_state *le = p;
872
873 /*
874 * Just store the timestamp in hardirq context so we get it as
875 * close in time as possible to the actual event.
876 */
877 le->timestamp = ktime_get_real_ns();
878
879 return IRQ_WAKE_THREAD;
880}
881
882static int lineevent_create(struct gpio_device *gdev, void __user *ip)
883{
884 struct gpioevent_request eventreq;
885 struct lineevent_state *le;
886 struct gpio_desc *desc;
887 struct file *file;
888 u32 offset;
889 u32 lflags;
890 u32 eflags;
891 int fd;
892 int ret;
893 int irqflags = 0;
894
895 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
896 return -EFAULT;
897
898 le = kzalloc(sizeof(*le), GFP_KERNEL);
899 if (!le)
900 return -ENOMEM;
901 le->gdev = gdev;
902 get_device(&gdev->dev);
903
904 /* Make sure this is terminated */
905 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
906 if (strlen(eventreq.consumer_label)) {
907 le->label = kstrdup(eventreq.consumer_label,
908 GFP_KERNEL);
909 if (!le->label) {
910 ret = -ENOMEM;
911 goto out_free_le;
912 }
913 }
914
915 offset = eventreq.lineoffset;
916 lflags = eventreq.handleflags;
917 eflags = eventreq.eventflags;
918
919 if (offset >= gdev->ngpio) {
920 ret = -EINVAL;
921 goto out_free_label;
922 }
923
924 /* Return an error if a unknown flag is set */
925 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
926 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
927 ret = -EINVAL;
928 goto out_free_label;
929 }
930
931 /* This is just wrong: we don't look for events on output lines */
932 if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
933 (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
934 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
935 ret = -EINVAL;
936 goto out_free_label;
937 }
938
939 desc = &gdev->descs[offset];
940 ret = gpiod_request(desc, le->label);
941 if (ret)
942 goto out_free_label;
943 le->desc = desc;
944 le->eflags = eflags;
945
946 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
947 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
948
949 ret = gpiod_direction_input(desc);
950 if (ret)
951 goto out_free_desc;
952
953 le->irq = gpiod_to_irq(desc);
954 if (le->irq <= 0) {
955 ret = -ENODEV;
956 goto out_free_desc;
957 }
958
959 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
960 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
961 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
962 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
963 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
964 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
965 irqflags |= IRQF_ONESHOT;
966
967 INIT_KFIFO(le->events);
968 init_waitqueue_head(&le->wait);
969 mutex_init(&le->read_lock);
970
971 /* Request a thread to read the events */
972 ret = request_threaded_irq(le->irq,
973 lineevent_irq_handler,
974 lineevent_irq_thread,
975 irqflags,
976 le->label,
977 le);
978 if (ret)
979 goto out_free_desc;
980
981 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
982 if (fd < 0) {
983 ret = fd;
984 goto out_free_irq;
985 }
986
987 file = anon_inode_getfile("gpio-event",
988 &lineevent_fileops,
989 le,
990 O_RDONLY | O_CLOEXEC);
991 if (IS_ERR(file)) {
992 ret = PTR_ERR(file);
993 goto out_put_unused_fd;
994 }
995
996 eventreq.fd = fd;
997 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
998 /*
999 * fput() will trigger the release() callback, so do not go onto
1000 * the regular error cleanup path here.
1001 */
1002 fput(file);
1003 put_unused_fd(fd);
1004 return -EFAULT;
1005 }
1006
1007 fd_install(fd, file);
1008
1009 return 0;
1010
1011out_put_unused_fd:
1012 put_unused_fd(fd);
1013out_free_irq:
1014 free_irq(le->irq, le);
1015out_free_desc:
1016 gpiod_free(le->desc);
1017out_free_label:
1018 kfree(le->label);
1019out_free_le:
1020 kfree(le);
1021 put_device(&gdev->dev);
1022 return ret;
1023}
1024
1025/*
1026 * gpio_ioctl() - ioctl handler for the GPIO chardev
1027 */
1028static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1029{
1030 struct gpio_device *gdev = filp->private_data;
1031 struct gpio_chip *chip = gdev->chip;
1032 void __user *ip = (void __user *)arg;
1033
1034 /* We fail any subsequent ioctl():s when the chip is gone */
1035 if (!chip)
1036 return -ENODEV;
1037
1038 /* Fill in the struct and pass to userspace */
1039 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1040 struct gpiochip_info chipinfo;
1041
1042 memset(&chipinfo, 0, sizeof(chipinfo));
1043
1044 strncpy(chipinfo.name, dev_name(&gdev->dev),
1045 sizeof(chipinfo.name));
1046 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1047 strncpy(chipinfo.label, gdev->label,
1048 sizeof(chipinfo.label));
1049 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1050 chipinfo.lines = gdev->ngpio;
1051 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1052 return -EFAULT;
1053 return 0;
1054 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1055 struct gpioline_info lineinfo;
1056 struct gpio_desc *desc;
1057
1058 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1059 return -EFAULT;
1060 if (lineinfo.line_offset >= gdev->ngpio)
1061 return -EINVAL;
1062
1063 desc = &gdev->descs[lineinfo.line_offset];
1064 if (desc->name) {
1065 strncpy(lineinfo.name, desc->name,
1066 sizeof(lineinfo.name));
1067 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1068 } else {
1069 lineinfo.name[0] = '\0';
1070 }
1071 if (desc->label) {
1072 strncpy(lineinfo.consumer, desc->label,
1073 sizeof(lineinfo.consumer));
1074 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1075 } else {
1076 lineinfo.consumer[0] = '\0';
1077 }
1078
1079 /*
1080 * Userspace only need to know that the kernel is using
1081 * this GPIO so it can't use it.
1082 */
1083 lineinfo.flags = 0;
1084 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1085 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1086 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1087 test_bit(FLAG_EXPORT, &desc->flags) ||
1088 test_bit(FLAG_SYSFS, &desc->flags) ||
1089 !pinctrl_gpio_can_use_line(chip->base + lineinfo.line_offset))
1090 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1091 if (test_bit(FLAG_IS_OUT, &desc->flags))
1092 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1093 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1094 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1095 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1096 lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
1097 GPIOLINE_FLAG_IS_OUT);
1098 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1099 lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
1100 GPIOLINE_FLAG_IS_OUT);
1101
1102 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1103 return -EFAULT;
1104 return 0;
1105 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1106 return linehandle_create(gdev, ip);
1107 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1108 return lineevent_create(gdev, ip);
1109 }
1110 return -EINVAL;
1111}
1112
1113#ifdef CONFIG_COMPAT
1114static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1115 unsigned long arg)
1116{
1117 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1118}
1119#endif
1120
1121/**
1122 * gpio_chrdev_open() - open the chardev for ioctl operations
1123 * @inode: inode for this chardev
1124 * @filp: file struct for storing private data
1125 * Returns 0 on success
1126 */
1127static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1128{
1129 struct gpio_device *gdev = container_of(inode->i_cdev,
1130 struct gpio_device, chrdev);
1131
1132 /* Fail on open if the backing gpiochip is gone */
1133 if (!gdev->chip)
1134 return -ENODEV;
1135 get_device(&gdev->dev);
1136 filp->private_data = gdev;
1137
1138 return nonseekable_open(inode, filp);
1139}
1140
1141/**
1142 * gpio_chrdev_release() - close chardev after ioctl operations
1143 * @inode: inode for this chardev
1144 * @filp: file struct for storing private data
1145 * Returns 0 on success
1146 */
1147static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1148{
1149 struct gpio_device *gdev = container_of(inode->i_cdev,
1150 struct gpio_device, chrdev);
1151
1152 put_device(&gdev->dev);
1153 return 0;
1154}
1155
1156
1157static const struct file_operations gpio_fileops = {
1158 .release = gpio_chrdev_release,
1159 .open = gpio_chrdev_open,
1160 .owner = THIS_MODULE,
1161 .llseek = no_llseek,
1162 .unlocked_ioctl = gpio_ioctl,
1163#ifdef CONFIG_COMPAT
1164 .compat_ioctl = gpio_ioctl_compat,
1165#endif
1166};
1167
1168static void gpiodevice_release(struct device *dev)
1169{
1170 struct gpio_device *gdev = dev_get_drvdata(dev);
1171
1172 list_del(&gdev->list);
1173 ida_simple_remove(&gpio_ida, gdev->id);
1174 kfree_const(gdev->label);
1175 kfree(gdev->descs);
1176 kfree(gdev);
1177}
1178
1179static int gpiochip_setup_dev(struct gpio_device *gdev)
1180{
1181 int ret;
1182
1183 cdev_init(&gdev->chrdev, &gpio_fileops);
1184 gdev->chrdev.owner = THIS_MODULE;
1185 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1186
1187 ret = cdev_device_add(&gdev->chrdev, &gdev->dev);
1188 if (ret)
1189 return ret;
1190
1191 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1192 MAJOR(gpio_devt), gdev->id);
1193
1194 ret = gpiochip_sysfs_register(gdev);
1195 if (ret)
1196 goto err_remove_device;
1197
1198 /* From this point, the .release() function cleans up gpio_device */
1199 gdev->dev.release = gpiodevice_release;
1200 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1201 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1202 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1203
1204 return 0;
1205
1206err_remove_device:
1207 cdev_device_del(&gdev->chrdev, &gdev->dev);
1208 return ret;
1209}
1210
1211static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1212{
1213 struct gpio_desc *desc;
1214 int rv;
1215
1216 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1217 if (IS_ERR(desc)) {
1218 pr_err("%s: unable to get GPIO desc: %ld\n",
1219 __func__, PTR_ERR(desc));
1220 return;
1221 }
1222
1223 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1224 return;
1225
1226 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1227 if (rv)
1228 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1229 __func__, chip->label, hog->chip_hwnum, rv);
1230}
1231
1232static void machine_gpiochip_add(struct gpio_chip *chip)
1233{
1234 struct gpiod_hog *hog;
1235
1236 mutex_lock(&gpio_machine_hogs_mutex);
1237
1238 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1239 if (!strcmp(chip->label, hog->chip_label))
1240 gpiochip_machine_hog(chip, hog);
1241 }
1242
1243 mutex_unlock(&gpio_machine_hogs_mutex);
1244}
1245
1246static void gpiochip_setup_devs(void)
1247{
1248 struct gpio_device *gdev;
1249 int ret;
1250
1251 list_for_each_entry(gdev, &gpio_devices, list) {
1252 ret = gpiochip_setup_dev(gdev);
1253 if (ret)
1254 pr_err("%s: Failed to initialize gpio device (%d)\n",
1255 dev_name(&gdev->dev), ret);
1256 }
1257}
1258
1259int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1260 struct lock_class_key *lock_key,
1261 struct lock_class_key *request_key)
1262{
1263 unsigned long flags;
1264 int ret = 0;
1265 unsigned i;
1266 int base = chip->base;
1267 struct gpio_device *gdev;
1268
1269 /*
1270 * First: allocate and populate the internal stat container, and
1271 * set up the struct device.
1272 */
1273 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1274 if (!gdev)
1275 return -ENOMEM;
1276 gdev->dev.bus = &gpio_bus_type;
1277 gdev->chip = chip;
1278 chip->gpiodev = gdev;
1279 if (chip->parent) {
1280 gdev->dev.parent = chip->parent;
1281 gdev->dev.of_node = chip->parent->of_node;
1282 }
1283
1284#ifdef CONFIG_OF_GPIO
1285 /* If the gpiochip has an assigned OF node this takes precedence */
1286 if (chip->of_node)
1287 gdev->dev.of_node = chip->of_node;
1288 else
1289 chip->of_node = gdev->dev.of_node;
1290#endif
1291
1292 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1293 if (gdev->id < 0) {
1294 ret = gdev->id;
1295 goto err_free_gdev;
1296 }
1297 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1298 device_initialize(&gdev->dev);
1299 dev_set_drvdata(&gdev->dev, gdev);
1300 if (chip->parent && chip->parent->driver)
1301 gdev->owner = chip->parent->driver->owner;
1302 else if (chip->owner)
1303 /* TODO: remove chip->owner */
1304 gdev->owner = chip->owner;
1305 else
1306 gdev->owner = THIS_MODULE;
1307
1308 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1309 if (!gdev->descs) {
1310 ret = -ENOMEM;
1311 goto err_free_ida;
1312 }
1313
1314 if (chip->ngpio == 0) {
1315 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1316 ret = -EINVAL;
1317 goto err_free_descs;
1318 }
1319
1320 if (chip->ngpio > FASTPATH_NGPIO)
1321 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1322 chip->ngpio, FASTPATH_NGPIO);
1323
1324 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1325 if (!gdev->label) {
1326 ret = -ENOMEM;
1327 goto err_free_descs;
1328 }
1329
1330 gdev->ngpio = chip->ngpio;
1331 gdev->data = data;
1332
1333 spin_lock_irqsave(&gpio_lock, flags);
1334
1335 /*
1336 * TODO: this allocates a Linux GPIO number base in the global
1337 * GPIO numberspace for this chip. In the long run we want to
1338 * get *rid* of this numberspace and use only descriptors, but
1339 * it may be a pipe dream. It will not happen before we get rid
1340 * of the sysfs interface anyways.
1341 */
1342 if (base < 0) {
1343 base = gpiochip_find_base(chip->ngpio);
1344 if (base < 0) {
1345 ret = base;
1346 spin_unlock_irqrestore(&gpio_lock, flags);
1347 goto err_free_label;
1348 }
1349 /*
1350 * TODO: it should not be necessary to reflect the assigned
1351 * base outside of the GPIO subsystem. Go over drivers and
1352 * see if anyone makes use of this, else drop this and assign
1353 * a poison instead.
1354 */
1355 chip->base = base;
1356 }
1357 gdev->base = base;
1358
1359 ret = gpiodev_add_to_list(gdev);
1360 if (ret) {
1361 spin_unlock_irqrestore(&gpio_lock, flags);
1362 goto err_free_label;
1363 }
1364
1365 spin_unlock_irqrestore(&gpio_lock, flags);
1366
1367 for (i = 0; i < chip->ngpio; i++)
1368 gdev->descs[i].gdev = gdev;
1369
1370#ifdef CONFIG_PINCTRL
1371 INIT_LIST_HEAD(&gdev->pin_ranges);
1372#endif
1373
1374 ret = gpiochip_set_desc_names(chip);
1375 if (ret)
1376 goto err_remove_from_list;
1377
1378 ret = gpiochip_alloc_valid_mask(chip);
1379 if (ret)
1380 goto err_remove_from_list;
1381
1382 ret = of_gpiochip_add(chip);
1383 if (ret)
1384 goto err_free_gpiochip_mask;
1385
1386 ret = gpiochip_init_valid_mask(chip);
1387 if (ret)
1388 goto err_remove_of_chip;
1389
1390 for (i = 0; i < chip->ngpio; i++) {
1391 struct gpio_desc *desc = &gdev->descs[i];
1392
1393 if (chip->get_direction && gpiochip_line_is_valid(chip, i)) {
1394 if (!chip->get_direction(chip, i))
1395 set_bit(FLAG_IS_OUT, &desc->flags);
1396 else
1397 clear_bit(FLAG_IS_OUT, &desc->flags);
1398 } else {
1399 if (!chip->direction_input)
1400 set_bit(FLAG_IS_OUT, &desc->flags);
1401 else
1402 clear_bit(FLAG_IS_OUT, &desc->flags);
1403 }
1404 }
1405
1406 acpi_gpiochip_add(chip);
1407
1408 machine_gpiochip_add(chip);
1409
1410 ret = gpiochip_irqchip_init_hw(chip);
1411 if (ret)
1412 goto err_remove_acpi_chip;
1413
1414 ret = gpiochip_irqchip_init_valid_mask(chip);
1415 if (ret)
1416 goto err_remove_acpi_chip;
1417
1418 ret = gpiochip_add_irqchip(chip, lock_key, request_key);
1419 if (ret)
1420 goto err_remove_irqchip_mask;
1421
1422 /*
1423 * By first adding the chardev, and then adding the device,
1424 * we get a device node entry in sysfs under
1425 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1426 * coldplug of device nodes and other udev business.
1427 * We can do this only if gpiolib has been initialized.
1428 * Otherwise, defer until later.
1429 */
1430 if (gpiolib_initialized) {
1431 ret = gpiochip_setup_dev(gdev);
1432 if (ret)
1433 goto err_remove_irqchip;
1434 }
1435 return 0;
1436
1437err_remove_irqchip:
1438 gpiochip_irqchip_remove(chip);
1439err_remove_irqchip_mask:
1440 gpiochip_irqchip_free_valid_mask(chip);
1441err_remove_acpi_chip:
1442 acpi_gpiochip_remove(chip);
1443err_remove_of_chip:
1444 gpiochip_free_hogs(chip);
1445 of_gpiochip_remove(chip);
1446err_free_gpiochip_mask:
1447 gpiochip_free_valid_mask(chip);
1448err_remove_from_list:
1449 spin_lock_irqsave(&gpio_lock, flags);
1450 list_del(&gdev->list);
1451 spin_unlock_irqrestore(&gpio_lock, flags);
1452err_free_label:
1453 kfree_const(gdev->label);
1454err_free_descs:
1455 kfree(gdev->descs);
1456err_free_ida:
1457 ida_simple_remove(&gpio_ida, gdev->id);
1458err_free_gdev:
1459 /* failures here can mean systems won't boot... */
1460 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1461 gdev->base, gdev->base + gdev->ngpio - 1,
1462 chip->label ? : "generic", ret);
1463 kfree(gdev);
1464 return ret;
1465}
1466EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1467
1468/**
1469 * gpiochip_get_data() - get per-subdriver data for the chip
1470 * @chip: GPIO chip
1471 *
1472 * Returns:
1473 * The per-subdriver data for the chip.
1474 */
1475void *gpiochip_get_data(struct gpio_chip *chip)
1476{
1477 return chip->gpiodev->data;
1478}
1479EXPORT_SYMBOL_GPL(gpiochip_get_data);
1480
1481/**
1482 * gpiochip_remove() - unregister a gpio_chip
1483 * @chip: the chip to unregister
1484 *
1485 * A gpio_chip with any GPIOs still requested may not be removed.
1486 */
1487void gpiochip_remove(struct gpio_chip *chip)
1488{
1489 struct gpio_device *gdev = chip->gpiodev;
1490 struct gpio_desc *desc;
1491 unsigned long flags;
1492 unsigned i;
1493 bool requested = false;
1494
1495 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1496 gpiochip_sysfs_unregister(gdev);
1497 gpiochip_free_hogs(chip);
1498 /* Numb the device, cancelling all outstanding operations */
1499 gdev->chip = NULL;
1500 gpiochip_irqchip_remove(chip);
1501 acpi_gpiochip_remove(chip);
1502 gpiochip_remove_pin_ranges(chip);
1503 of_gpiochip_remove(chip);
1504 gpiochip_free_valid_mask(chip);
1505 /*
1506 * We accept no more calls into the driver from this point, so
1507 * NULL the driver data pointer
1508 */
1509 gdev->data = NULL;
1510
1511 spin_lock_irqsave(&gpio_lock, flags);
1512 for (i = 0; i < gdev->ngpio; i++) {
1513 desc = &gdev->descs[i];
1514 if (test_bit(FLAG_REQUESTED, &desc->flags))
1515 requested = true;
1516 }
1517 spin_unlock_irqrestore(&gpio_lock, flags);
1518
1519 if (requested)
1520 dev_crit(&gdev->dev,
1521 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1522
1523 /*
1524 * The gpiochip side puts its use of the device to rest here:
1525 * if there are no userspace clients, the chardev and device will
1526 * be removed, else it will be dangling until the last user is
1527 * gone.
1528 */
1529 cdev_device_del(&gdev->chrdev, &gdev->dev);
1530 put_device(&gdev->dev);
1531}
1532EXPORT_SYMBOL_GPL(gpiochip_remove);
1533
1534static void devm_gpio_chip_release(struct device *dev, void *res)
1535{
1536 struct gpio_chip *chip = *(struct gpio_chip **)res;
1537
1538 gpiochip_remove(chip);
1539}
1540
1541/**
1542 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1543 * @dev: pointer to the device that gpio_chip belongs to.
1544 * @chip: the chip to register, with chip->base initialized
1545 * @data: driver-private data associated with this chip
1546 *
1547 * Context: potentially before irqs will work
1548 *
1549 * The gpio chip automatically be released when the device is unbound.
1550 *
1551 * Returns:
1552 * A negative errno if the chip can't be registered, such as because the
1553 * chip->base is invalid or already associated with a different chip.
1554 * Otherwise it returns zero as a success code.
1555 */
1556int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1557 void *data)
1558{
1559 struct gpio_chip **ptr;
1560 int ret;
1561
1562 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1563 GFP_KERNEL);
1564 if (!ptr)
1565 return -ENOMEM;
1566
1567 ret = gpiochip_add_data(chip, data);
1568 if (ret < 0) {
1569 devres_free(ptr);
1570 return ret;
1571 }
1572
1573 *ptr = chip;
1574 devres_add(dev, ptr);
1575
1576 return 0;
1577}
1578EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1579
1580/**
1581 * gpiochip_find() - iterator for locating a specific gpio_chip
1582 * @data: data to pass to match function
1583 * @match: Callback function to check gpio_chip
1584 *
1585 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1586 * determined by a user supplied @match callback. The callback should return
1587 * 0 if the device doesn't match and non-zero if it does. If the callback is
1588 * non-zero, this function will return to the caller and not iterate over any
1589 * more gpio_chips.
1590 */
1591struct gpio_chip *gpiochip_find(void *data,
1592 int (*match)(struct gpio_chip *chip,
1593 void *data))
1594{
1595 struct gpio_device *gdev;
1596 struct gpio_chip *chip = NULL;
1597 unsigned long flags;
1598
1599 spin_lock_irqsave(&gpio_lock, flags);
1600 list_for_each_entry(gdev, &gpio_devices, list)
1601 if (gdev->chip && match(gdev->chip, data)) {
1602 chip = gdev->chip;
1603 break;
1604 }
1605
1606 spin_unlock_irqrestore(&gpio_lock, flags);
1607
1608 return chip;
1609}
1610EXPORT_SYMBOL_GPL(gpiochip_find);
1611
1612static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1613{
1614 const char *name = data;
1615
1616 return !strcmp(chip->label, name);
1617}
1618
1619static struct gpio_chip *find_chip_by_name(const char *name)
1620{
1621 return gpiochip_find((void *)name, gpiochip_match_name);
1622}
1623
1624#ifdef CONFIG_GPIOLIB_IRQCHIP
1625
1626/*
1627 * The following is irqchip helper code for gpiochips.
1628 */
1629
1630static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1631{
1632 struct gpio_irq_chip *girq = &gc->irq;
1633
1634 if (!girq->init_hw)
1635 return 0;
1636
1637 return girq->init_hw(gc);
1638}
1639
1640static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1641{
1642 struct gpio_irq_chip *girq = &gc->irq;
1643
1644 if (!girq->init_valid_mask)
1645 return 0;
1646
1647 girq->valid_mask = gpiochip_allocate_mask(gc);
1648 if (!girq->valid_mask)
1649 return -ENOMEM;
1650
1651 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1652
1653 return 0;
1654}
1655
1656static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1657{
1658 bitmap_free(gpiochip->irq.valid_mask);
1659 gpiochip->irq.valid_mask = NULL;
1660}
1661
1662bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1663 unsigned int offset)
1664{
1665 if (!gpiochip_line_is_valid(gpiochip, offset))
1666 return false;
1667 /* No mask means all valid */
1668 if (likely(!gpiochip->irq.valid_mask))
1669 return true;
1670 return test_bit(offset, gpiochip->irq.valid_mask);
1671}
1672EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1673
1674/**
1675 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1676 * @gc: the gpiochip to set the irqchip chain to
1677 * @parent_irq: the irq number corresponding to the parent IRQ for this
1678 * chained irqchip
1679 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1680 * coming out of the gpiochip. If the interrupt is nested rather than
1681 * cascaded, pass NULL in this handler argument
1682 */
1683static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gc,
1684 unsigned int parent_irq,
1685 irq_flow_handler_t parent_handler)
1686{
1687 struct gpio_irq_chip *girq = &gc->irq;
1688 struct device *dev = &gc->gpiodev->dev;
1689
1690 if (!girq->domain) {
1691 chip_err(gc, "called %s before setting up irqchip\n",
1692 __func__);
1693 return;
1694 }
1695
1696 if (parent_handler) {
1697 if (gc->can_sleep) {
1698 chip_err(gc,
1699 "you cannot have chained interrupts on a chip that may sleep\n");
1700 return;
1701 }
1702 girq->parents = devm_kcalloc(dev, 1,
1703 sizeof(*girq->parents),
1704 GFP_KERNEL);
1705 if (!girq->parents) {
1706 chip_err(gc, "out of memory allocating parent IRQ\n");
1707 return;
1708 }
1709 girq->parents[0] = parent_irq;
1710 girq->num_parents = 1;
1711 /*
1712 * The parent irqchip is already using the chip_data for this
1713 * irqchip, so our callbacks simply use the handler_data.
1714 */
1715 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1716 gc);
1717 }
1718}
1719
1720/**
1721 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1722 * @gpiochip: the gpiochip to set the irqchip chain to
1723 * @irqchip: the irqchip to chain to the gpiochip
1724 * @parent_irq: the irq number corresponding to the parent IRQ for this
1725 * chained irqchip
1726 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1727 * coming out of the gpiochip.
1728 */
1729void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1730 struct irq_chip *irqchip,
1731 unsigned int parent_irq,
1732 irq_flow_handler_t parent_handler)
1733{
1734 if (gpiochip->irq.threaded) {
1735 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1736 return;
1737 }
1738
1739 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1740}
1741EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1742
1743/**
1744 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1745 * @gpiochip: the gpiochip to set the irqchip nested handler to
1746 * @irqchip: the irqchip to nest to the gpiochip
1747 * @parent_irq: the irq number corresponding to the parent IRQ for this
1748 * nested irqchip
1749 */
1750void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1751 struct irq_chip *irqchip,
1752 unsigned int parent_irq)
1753{
1754 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1755}
1756EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1757
1758#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1759
1760/**
1761 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1762 * to a gpiochip
1763 * @gc: the gpiochip to set the irqchip hierarchical handler to
1764 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1765 * will then percolate up to the parent
1766 */
1767static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1768 struct irq_chip *irqchip)
1769{
1770 /* DT will deal with mapping each IRQ as we go along */
1771 if (is_of_node(gc->irq.fwnode))
1772 return;
1773
1774 /*
1775 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1776 * irqs upfront instead of dynamically since we don't have the
1777 * dynamic type of allocation that hardware description languages
1778 * provide. Once all GPIO drivers using board files are gone from
1779 * the kernel we can delete this code, but for a transitional period
1780 * it is necessary to keep this around.
1781 */
1782 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1783 int i;
1784 int ret;
1785
1786 for (i = 0; i < gc->ngpio; i++) {
1787 struct irq_fwspec fwspec;
1788 unsigned int parent_hwirq;
1789 unsigned int parent_type;
1790 struct gpio_irq_chip *girq = &gc->irq;
1791
1792 /*
1793 * We call the child to parent translation function
1794 * only to check if the child IRQ is valid or not.
1795 * Just pick the rising edge type here as that is what
1796 * we likely need to support.
1797 */
1798 ret = girq->child_to_parent_hwirq(gc, i,
1799 IRQ_TYPE_EDGE_RISING,
1800 &parent_hwirq,
1801 &parent_type);
1802 if (ret) {
1803 chip_err(gc, "skip set-up on hwirq %d\n",
1804 i);
1805 continue;
1806 }
1807
1808 fwspec.fwnode = gc->irq.fwnode;
1809 /* This is the hwirq for the GPIO line side of things */
1810 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1811 /* Just pick something */
1812 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1813 fwspec.param_count = 2;
1814 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1815 /* just pick something */
1816 -1,
1817 1,
1818 NUMA_NO_NODE,
1819 &fwspec,
1820 false,
1821 NULL);
1822 if (ret < 0) {
1823 chip_err(gc,
1824 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1825 i, parent_hwirq,
1826 ret);
1827 }
1828 }
1829 }
1830
1831 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1832
1833 return;
1834}
1835
1836static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1837 struct irq_fwspec *fwspec,
1838 unsigned long *hwirq,
1839 unsigned int *type)
1840{
1841 /* We support standard DT translation */
1842 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1843 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1844 }
1845
1846 /* This is for board files and others not using DT */
1847 if (is_fwnode_irqchip(fwspec->fwnode)) {
1848 int ret;
1849
1850 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1851 if (ret)
1852 return ret;
1853 WARN_ON(*type == IRQ_TYPE_NONE);
1854 return 0;
1855 }
1856 return -EINVAL;
1857}
1858
1859static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1860 unsigned int irq,
1861 unsigned int nr_irqs,
1862 void *data)
1863{
1864 struct gpio_chip *gc = d->host_data;
1865 irq_hw_number_t hwirq;
1866 unsigned int type = IRQ_TYPE_NONE;
1867 struct irq_fwspec *fwspec = data;
1868 struct irq_fwspec parent_fwspec;
1869 unsigned int parent_hwirq;
1870 unsigned int parent_type;
1871 struct gpio_irq_chip *girq = &gc->irq;
1872 int ret;
1873
1874 /*
1875 * The nr_irqs parameter is always one except for PCI multi-MSI
1876 * so this should not happen.
1877 */
1878 WARN_ON(nr_irqs != 1);
1879
1880 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1881 if (ret)
1882 return ret;
1883
1884 chip_info(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1885
1886 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1887 &parent_hwirq, &parent_type);
1888 if (ret) {
1889 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1890 return ret;
1891 }
1892 chip_info(gc, "found parent hwirq %u\n", parent_hwirq);
1893
1894 /*
1895 * We set handle_bad_irq because the .set_type() should
1896 * always be invoked and set the right type of handler.
1897 */
1898 irq_domain_set_info(d,
1899 irq,
1900 hwirq,
1901 gc->irq.chip,
1902 gc,
1903 girq->handler,
1904 NULL, NULL);
1905 irq_set_probe(irq);
1906
1907 /*
1908 * Create a IRQ fwspec to send up to the parent irqdomain:
1909 * specify the hwirq we address on the parent and tie it
1910 * all together up the chain.
1911 */
1912 parent_fwspec.fwnode = d->parent->fwnode;
1913 /* This parent only handles asserted level IRQs */
1914 girq->populate_parent_fwspec(gc, &parent_fwspec, parent_hwirq,
1915 parent_type);
1916 chip_info(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1917 irq, parent_hwirq);
1918 ret = irq_domain_alloc_irqs_parent(d, irq, 1, &parent_fwspec);
1919 if (ret)
1920 chip_err(gc,
1921 "failed to allocate parent hwirq %d for hwirq %lu\n",
1922 parent_hwirq, hwirq);
1923
1924 return ret;
1925}
1926
1927static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *chip,
1928 unsigned int offset)
1929{
1930 return offset;
1931}
1932
1933static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1934{
1935 ops->activate = gpiochip_irq_domain_activate;
1936 ops->deactivate = gpiochip_irq_domain_deactivate;
1937 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1938 ops->free = irq_domain_free_irqs_common;
1939
1940 /*
1941 * We only allow overriding the translate() function for
1942 * hierarchical chips, and this should only be done if the user
1943 * really need something other than 1:1 translation.
1944 */
1945 if (!ops->translate)
1946 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1947}
1948
1949static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1950{
1951 if (!gc->irq.child_to_parent_hwirq ||
1952 !gc->irq.fwnode) {
1953 chip_err(gc, "missing irqdomain vital data\n");
1954 return -EINVAL;
1955 }
1956
1957 if (!gc->irq.child_offset_to_irq)
1958 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1959
1960 if (!gc->irq.populate_parent_fwspec)
1961 gc->irq.populate_parent_fwspec =
1962 gpiochip_populate_parent_fwspec_twocell;
1963
1964 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1965
1966 gc->irq.domain = irq_domain_create_hierarchy(
1967 gc->irq.parent_domain,
1968 0,
1969 gc->ngpio,
1970 gc->irq.fwnode,
1971 &gc->irq.child_irq_domain_ops,
1972 gc);
1973
1974 if (!gc->irq.domain)
1975 return -ENOMEM;
1976
1977 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1978
1979 return 0;
1980}
1981
1982static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1983{
1984 return !!gc->irq.parent_domain;
1985}
1986
1987void gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *chip,
1988 struct irq_fwspec *fwspec,
1989 unsigned int parent_hwirq,
1990 unsigned int parent_type)
1991{
1992 fwspec->param_count = 2;
1993 fwspec->param[0] = parent_hwirq;
1994 fwspec->param[1] = parent_type;
1995}
1996EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1997
1998void gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *chip,
1999 struct irq_fwspec *fwspec,
2000 unsigned int parent_hwirq,
2001 unsigned int parent_type)
2002{
2003 fwspec->param_count = 4;
2004 fwspec->param[0] = 0;
2005 fwspec->param[1] = parent_hwirq;
2006 fwspec->param[2] = 0;
2007 fwspec->param[3] = parent_type;
2008}
2009EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
2010
2011#else
2012
2013static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
2014{
2015 return -EINVAL;
2016}
2017
2018static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
2019{
2020 return false;
2021}
2022
2023#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
2024
2025/**
2026 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
2027 * @d: the irqdomain used by this irqchip
2028 * @irq: the global irq number used by this GPIO irqchip irq
2029 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
2030 *
2031 * This function will set up the mapping for a certain IRQ line on a
2032 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
2033 * stored inside the gpiochip.
2034 */
2035int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
2036 irq_hw_number_t hwirq)
2037{
2038 struct gpio_chip *chip = d->host_data;
2039 int ret = 0;
2040
2041 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
2042 return -ENXIO;
2043
2044 irq_set_chip_data(irq, chip);
2045 /*
2046 * This lock class tells lockdep that GPIO irqs are in a different
2047 * category than their parents, so it won't report false recursion.
2048 */
2049 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
2050 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
2051 /* Chips that use nested thread handlers have them marked */
2052 if (chip->irq.threaded)
2053 irq_set_nested_thread(irq, 1);
2054 irq_set_noprobe(irq);
2055
2056 if (chip->irq.num_parents == 1)
2057 ret = irq_set_parent(irq, chip->irq.parents[0]);
2058 else if (chip->irq.map)
2059 ret = irq_set_parent(irq, chip->irq.map[hwirq]);
2060
2061 if (ret < 0)
2062 return ret;
2063
2064 /*
2065 * No set-up of the hardware will happen if IRQ_TYPE_NONE
2066 * is passed as default type.
2067 */
2068 if (chip->irq.default_type != IRQ_TYPE_NONE)
2069 irq_set_irq_type(irq, chip->irq.default_type);
2070
2071 return 0;
2072}
2073EXPORT_SYMBOL_GPL(gpiochip_irq_map);
2074
2075void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
2076{
2077 struct gpio_chip *chip = d->host_data;
2078
2079 if (chip->irq.threaded)
2080 irq_set_nested_thread(irq, 0);
2081 irq_set_chip_and_handler(irq, NULL, NULL);
2082 irq_set_chip_data(irq, NULL);
2083}
2084EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
2085
2086static const struct irq_domain_ops gpiochip_domain_ops = {
2087 .map = gpiochip_irq_map,
2088 .unmap = gpiochip_irq_unmap,
2089 /* Virtually all GPIO irqchips are twocell:ed */
2090 .xlate = irq_domain_xlate_twocell,
2091};
2092
2093/*
2094 * TODO: move these activate/deactivate in under the hierarchicial
2095 * irqchip implementation as static once SPMI and SSBI (all external
2096 * users) are phased over.
2097 */
2098/**
2099 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
2100 * @domain: The IRQ domain used by this IRQ chip
2101 * @data: Outermost irq_data associated with the IRQ
2102 * @reserve: If set, only reserve an interrupt vector instead of assigning one
2103 *
2104 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
2105 * used as the activate function for the &struct irq_domain_ops. The host_data
2106 * for the IRQ domain must be the &struct gpio_chip.
2107 */
2108int gpiochip_irq_domain_activate(struct irq_domain *domain,
2109 struct irq_data *data, bool reserve)
2110{
2111 struct gpio_chip *chip = domain->host_data;
2112
2113 return gpiochip_lock_as_irq(chip, data->hwirq);
2114}
2115EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
2116
2117/**
2118 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
2119 * @domain: The IRQ domain used by this IRQ chip
2120 * @data: Outermost irq_data associated with the IRQ
2121 *
2122 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
2123 * be used as the deactivate function for the &struct irq_domain_ops. The
2124 * host_data for the IRQ domain must be the &struct gpio_chip.
2125 */
2126void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
2127 struct irq_data *data)
2128{
2129 struct gpio_chip *chip = domain->host_data;
2130
2131 return gpiochip_unlock_as_irq(chip, data->hwirq);
2132}
2133EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
2134
2135static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
2136{
2137 struct irq_domain *domain = chip->irq.domain;
2138
2139 if (!gpiochip_irqchip_irq_valid(chip, offset))
2140 return -ENXIO;
2141
2142#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2143 if (irq_domain_is_hierarchy(domain)) {
2144 struct irq_fwspec spec;
2145
2146 spec.fwnode = domain->fwnode;
2147 spec.param_count = 2;
2148 spec.param[0] = chip->irq.child_offset_to_irq(chip, offset);
2149 spec.param[1] = IRQ_TYPE_NONE;
2150
2151 return irq_create_fwspec_mapping(&spec);
2152 }
2153#endif
2154
2155 return irq_create_mapping(domain, offset);
2156}
2157
2158static int gpiochip_irq_reqres(struct irq_data *d)
2159{
2160 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2161
2162 return gpiochip_reqres_irq(chip, d->hwirq);
2163}
2164
2165static void gpiochip_irq_relres(struct irq_data *d)
2166{
2167 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2168
2169 gpiochip_relres_irq(chip, d->hwirq);
2170}
2171
2172static void gpiochip_irq_enable(struct irq_data *d)
2173{
2174 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2175
2176 gpiochip_enable_irq(chip, d->hwirq);
2177 if (chip->irq.irq_enable)
2178 chip->irq.irq_enable(d);
2179 else
2180 chip->irq.chip->irq_unmask(d);
2181}
2182
2183static void gpiochip_irq_disable(struct irq_data *d)
2184{
2185 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2186
2187 if (chip->irq.irq_disable)
2188 chip->irq.irq_disable(d);
2189 else
2190 chip->irq.chip->irq_mask(d);
2191 gpiochip_disable_irq(chip, d->hwirq);
2192}
2193
2194static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
2195{
2196 struct irq_chip *irqchip = gpiochip->irq.chip;
2197
2198 if (!irqchip->irq_request_resources &&
2199 !irqchip->irq_release_resources) {
2200 irqchip->irq_request_resources = gpiochip_irq_reqres;
2201 irqchip->irq_release_resources = gpiochip_irq_relres;
2202 }
2203 if (WARN_ON(gpiochip->irq.irq_enable))
2204 return;
2205 /* Check if the irqchip already has this hook... */
2206 if (irqchip->irq_enable == gpiochip_irq_enable) {
2207 /*
2208 * ...and if so, give a gentle warning that this is bad
2209 * practice.
2210 */
2211 chip_info(gpiochip,
2212 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
2213 return;
2214 }
2215 gpiochip->irq.irq_enable = irqchip->irq_enable;
2216 gpiochip->irq.irq_disable = irqchip->irq_disable;
2217 irqchip->irq_enable = gpiochip_irq_enable;
2218 irqchip->irq_disable = gpiochip_irq_disable;
2219}
2220
2221/**
2222 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
2223 * @gpiochip: the GPIO chip to add the IRQ chip to
2224 * @lock_key: lockdep class for IRQ lock
2225 * @request_key: lockdep class for IRQ request
2226 */
2227static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2228 struct lock_class_key *lock_key,
2229 struct lock_class_key *request_key)
2230{
2231 struct irq_chip *irqchip = gpiochip->irq.chip;
2232 const struct irq_domain_ops *ops = NULL;
2233 struct device_node *np;
2234 unsigned int type;
2235 unsigned int i;
2236
2237 if (!irqchip)
2238 return 0;
2239
2240 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
2241 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
2242 return -EINVAL;
2243 }
2244
2245 np = gpiochip->gpiodev->dev.of_node;
2246 type = gpiochip->irq.default_type;
2247
2248 /*
2249 * Specifying a default trigger is a terrible idea if DT or ACPI is
2250 * used to configure the interrupts, as you may end up with
2251 * conflicting triggers. Tell the user, and reset to NONE.
2252 */
2253 if (WARN(np && type != IRQ_TYPE_NONE,
2254 "%s: Ignoring %u default trigger\n", np->full_name, type))
2255 type = IRQ_TYPE_NONE;
2256
2257 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2258 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2259 "Ignoring %u default trigger\n", type);
2260 type = IRQ_TYPE_NONE;
2261 }
2262
2263 gpiochip->to_irq = gpiochip_to_irq;
2264 gpiochip->irq.default_type = type;
2265 gpiochip->irq.lock_key = lock_key;
2266 gpiochip->irq.request_key = request_key;
2267
2268 /* If a parent irqdomain is provided, let's build a hierarchy */
2269 if (gpiochip_hierarchy_is_hierarchical(gpiochip)) {
2270 int ret = gpiochip_hierarchy_add_domain(gpiochip);
2271 if (ret)
2272 return ret;
2273 } else {
2274 /* Some drivers provide custom irqdomain ops */
2275 if (gpiochip->irq.domain_ops)
2276 ops = gpiochip->irq.domain_ops;
2277
2278 if (!ops)
2279 ops = &gpiochip_domain_ops;
2280 gpiochip->irq.domain = irq_domain_add_simple(np,
2281 gpiochip->ngpio,
2282 gpiochip->irq.first,
2283 ops, gpiochip);
2284 if (!gpiochip->irq.domain)
2285 return -EINVAL;
2286 }
2287
2288 if (gpiochip->irq.parent_handler) {
2289 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
2290
2291 for (i = 0; i < gpiochip->irq.num_parents; i++) {
2292 /*
2293 * The parent IRQ chip is already using the chip_data
2294 * for this IRQ chip, so our callbacks simply use the
2295 * handler_data.
2296 */
2297 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
2298 gpiochip->irq.parent_handler,
2299 data);
2300 }
2301 }
2302
2303 gpiochip_set_irq_hooks(gpiochip);
2304
2305 acpi_gpiochip_request_interrupts(gpiochip);
2306
2307 return 0;
2308}
2309
2310/**
2311 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
2312 * @gpiochip: the gpiochip to remove the irqchip from
2313 *
2314 * This is called only from gpiochip_remove()
2315 */
2316static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
2317{
2318 struct irq_chip *irqchip = gpiochip->irq.chip;
2319 unsigned int offset;
2320
2321 acpi_gpiochip_free_interrupts(gpiochip);
2322
2323 if (irqchip && gpiochip->irq.parent_handler) {
2324 struct gpio_irq_chip *irq = &gpiochip->irq;
2325 unsigned int i;
2326
2327 for (i = 0; i < irq->num_parents; i++)
2328 irq_set_chained_handler_and_data(irq->parents[i],
2329 NULL, NULL);
2330 }
2331
2332 /* Remove all IRQ mappings and delete the domain */
2333 if (gpiochip->irq.domain) {
2334 unsigned int irq;
2335
2336 for (offset = 0; offset < gpiochip->ngpio; offset++) {
2337 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
2338 continue;
2339
2340 irq = irq_find_mapping(gpiochip->irq.domain, offset);
2341 irq_dispose_mapping(irq);
2342 }
2343
2344 irq_domain_remove(gpiochip->irq.domain);
2345 }
2346
2347 if (irqchip) {
2348 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2349 irqchip->irq_request_resources = NULL;
2350 irqchip->irq_release_resources = NULL;
2351 }
2352 if (irqchip->irq_enable == gpiochip_irq_enable) {
2353 irqchip->irq_enable = gpiochip->irq.irq_enable;
2354 irqchip->irq_disable = gpiochip->irq.irq_disable;
2355 }
2356 }
2357 gpiochip->irq.irq_enable = NULL;
2358 gpiochip->irq.irq_disable = NULL;
2359 gpiochip->irq.chip = NULL;
2360
2361 gpiochip_irqchip_free_valid_mask(gpiochip);
2362}
2363
2364/**
2365 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2366 * @gpiochip: the gpiochip to add the irqchip to
2367 * @irqchip: the irqchip to add to the gpiochip
2368 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2369 * allocate gpiochip irqs from
2370 * @handler: the irq handler to use (often a predefined irq core function)
2371 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2372 * to have the core avoid setting up any default type in the hardware.
2373 * @threaded: whether this irqchip uses a nested thread handler
2374 * @lock_key: lockdep class for IRQ lock
2375 * @request_key: lockdep class for IRQ request
2376 *
2377 * This function closely associates a certain irqchip with a certain
2378 * gpiochip, providing an irq domain to translate the local IRQs to
2379 * global irqs in the gpiolib core, and making sure that the gpiochip
2380 * is passed as chip data to all related functions. Driver callbacks
2381 * need to use gpiochip_get_data() to get their local state containers back
2382 * from the gpiochip passed as chip data. An irqdomain will be stored
2383 * in the gpiochip that shall be used by the driver to handle IRQ number
2384 * translation. The gpiochip will need to be initialized and registered
2385 * before calling this function.
2386 *
2387 * This function will handle two cell:ed simple IRQs and assumes all
2388 * the pins on the gpiochip can generate a unique IRQ. Everything else
2389 * need to be open coded.
2390 */
2391int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2392 struct irq_chip *irqchip,
2393 unsigned int first_irq,
2394 irq_flow_handler_t handler,
2395 unsigned int type,
2396 bool threaded,
2397 struct lock_class_key *lock_key,
2398 struct lock_class_key *request_key)
2399{
2400 struct device_node *of_node;
2401
2402 if (!gpiochip || !irqchip)
2403 return -EINVAL;
2404
2405 if (!gpiochip->parent) {
2406 pr_err("missing gpiochip .dev parent pointer\n");
2407 return -EINVAL;
2408 }
2409 gpiochip->irq.threaded = threaded;
2410 of_node = gpiochip->parent->of_node;
2411#ifdef CONFIG_OF_GPIO
2412 /*
2413 * If the gpiochip has an assigned OF node this takes precedence
2414 * FIXME: get rid of this and use gpiochip->parent->of_node
2415 * everywhere
2416 */
2417 if (gpiochip->of_node)
2418 of_node = gpiochip->of_node;
2419#endif
2420 /*
2421 * Specifying a default trigger is a terrible idea if DT or ACPI is
2422 * used to configure the interrupts, as you may end-up with
2423 * conflicting triggers. Tell the user, and reset to NONE.
2424 */
2425 if (WARN(of_node && type != IRQ_TYPE_NONE,
2426 "%pOF: Ignoring %d default trigger\n", of_node, type))
2427 type = IRQ_TYPE_NONE;
2428 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2429 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2430 "Ignoring %d default trigger\n", type);
2431 type = IRQ_TYPE_NONE;
2432 }
2433
2434 gpiochip->irq.chip = irqchip;
2435 gpiochip->irq.handler = handler;
2436 gpiochip->irq.default_type = type;
2437 gpiochip->to_irq = gpiochip_to_irq;
2438 gpiochip->irq.lock_key = lock_key;
2439 gpiochip->irq.request_key = request_key;
2440 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2441 gpiochip->ngpio, first_irq,
2442 &gpiochip_domain_ops, gpiochip);
2443 if (!gpiochip->irq.domain) {
2444 gpiochip->irq.chip = NULL;
2445 return -EINVAL;
2446 }
2447
2448 gpiochip_set_irq_hooks(gpiochip);
2449
2450 acpi_gpiochip_request_interrupts(gpiochip);
2451
2452 return 0;
2453}
2454EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2455
2456#else /* CONFIG_GPIOLIB_IRQCHIP */
2457
2458static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2459 struct lock_class_key *lock_key,
2460 struct lock_class_key *request_key)
2461{
2462 return 0;
2463}
2464static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2465
2466static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip)
2467{
2468 return 0;
2469}
2470
2471static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2472{
2473 return 0;
2474}
2475static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2476{ }
2477
2478#endif /* CONFIG_GPIOLIB_IRQCHIP */
2479
2480/**
2481 * gpiochip_generic_request() - request the gpio function for a pin
2482 * @chip: the gpiochip owning the GPIO
2483 * @offset: the offset of the GPIO to request for GPIO function
2484 */
2485int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2486{
2487 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2488}
2489EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2490
2491/**
2492 * gpiochip_generic_free() - free the gpio function from a pin
2493 * @chip: the gpiochip to request the gpio function for
2494 * @offset: the offset of the GPIO to free from GPIO function
2495 */
2496void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2497{
2498 pinctrl_gpio_free(chip->gpiodev->base + offset);
2499}
2500EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2501
2502/**
2503 * gpiochip_generic_config() - apply configuration for a pin
2504 * @chip: the gpiochip owning the GPIO
2505 * @offset: the offset of the GPIO to apply the configuration
2506 * @config: the configuration to be applied
2507 */
2508int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2509 unsigned long config)
2510{
2511 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2512}
2513EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2514
2515#ifdef CONFIG_PINCTRL
2516
2517/**
2518 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2519 * @chip: the gpiochip to add the range for
2520 * @pctldev: the pin controller to map to
2521 * @gpio_offset: the start offset in the current gpio_chip number space
2522 * @pin_group: name of the pin group inside the pin controller
2523 *
2524 * Calling this function directly from a DeviceTree-supported
2525 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2526 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2527 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2528 */
2529int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2530 struct pinctrl_dev *pctldev,
2531 unsigned int gpio_offset, const char *pin_group)
2532{
2533 struct gpio_pin_range *pin_range;
2534 struct gpio_device *gdev = chip->gpiodev;
2535 int ret;
2536
2537 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2538 if (!pin_range) {
2539 chip_err(chip, "failed to allocate pin ranges\n");
2540 return -ENOMEM;
2541 }
2542
2543 /* Use local offset as range ID */
2544 pin_range->range.id = gpio_offset;
2545 pin_range->range.gc = chip;
2546 pin_range->range.name = chip->label;
2547 pin_range->range.base = gdev->base + gpio_offset;
2548 pin_range->pctldev = pctldev;
2549
2550 ret = pinctrl_get_group_pins(pctldev, pin_group,
2551 &pin_range->range.pins,
2552 &pin_range->range.npins);
2553 if (ret < 0) {
2554 kfree(pin_range);
2555 return ret;
2556 }
2557
2558 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2559
2560 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2561 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2562 pinctrl_dev_get_devname(pctldev), pin_group);
2563
2564 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2565
2566 return 0;
2567}
2568EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2569
2570/**
2571 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2572 * @chip: the gpiochip to add the range for
2573 * @pinctl_name: the dev_name() of the pin controller to map to
2574 * @gpio_offset: the start offset in the current gpio_chip number space
2575 * @pin_offset: the start offset in the pin controller number space
2576 * @npins: the number of pins from the offset of each pin space (GPIO and
2577 * pin controller) to accumulate in this range
2578 *
2579 * Returns:
2580 * 0 on success, or a negative error-code on failure.
2581 *
2582 * Calling this function directly from a DeviceTree-supported
2583 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2584 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2585 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2586 */
2587int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2588 unsigned int gpio_offset, unsigned int pin_offset,
2589 unsigned int npins)
2590{
2591 struct gpio_pin_range *pin_range;
2592 struct gpio_device *gdev = chip->gpiodev;
2593 int ret;
2594
2595 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2596 if (!pin_range) {
2597 chip_err(chip, "failed to allocate pin ranges\n");
2598 return -ENOMEM;
2599 }
2600
2601 /* Use local offset as range ID */
2602 pin_range->range.id = gpio_offset;
2603 pin_range->range.gc = chip;
2604 pin_range->range.name = chip->label;
2605 pin_range->range.base = gdev->base + gpio_offset;
2606 pin_range->range.pin_base = pin_offset;
2607 pin_range->range.npins = npins;
2608 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2609 &pin_range->range);
2610 if (IS_ERR(pin_range->pctldev)) {
2611 ret = PTR_ERR(pin_range->pctldev);
2612 chip_err(chip, "could not create pin range\n");
2613 kfree(pin_range);
2614 return ret;
2615 }
2616 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2617 gpio_offset, gpio_offset + npins - 1,
2618 pinctl_name,
2619 pin_offset, pin_offset + npins - 1);
2620
2621 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2622
2623 return 0;
2624}
2625EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2626
2627/**
2628 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2629 * @chip: the chip to remove all the mappings for
2630 */
2631void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2632{
2633 struct gpio_pin_range *pin_range, *tmp;
2634 struct gpio_device *gdev = chip->gpiodev;
2635
2636 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2637 list_del(&pin_range->node);
2638 pinctrl_remove_gpio_range(pin_range->pctldev,
2639 &pin_range->range);
2640 kfree(pin_range);
2641 }
2642}
2643EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2644
2645#endif /* CONFIG_PINCTRL */
2646
2647/* These "optional" allocation calls help prevent drivers from stomping
2648 * on each other, and help provide better diagnostics in debugfs.
2649 * They're called even less than the "set direction" calls.
2650 */
2651static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2652{
2653 struct gpio_chip *chip = desc->gdev->chip;
2654 int ret;
2655 unsigned long flags;
2656 unsigned offset;
2657
2658 if (label) {
2659 label = kstrdup_const(label, GFP_KERNEL);
2660 if (!label)
2661 return -ENOMEM;
2662 }
2663
2664 spin_lock_irqsave(&gpio_lock, flags);
2665
2666 /* NOTE: gpio_request() can be called in early boot,
2667 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2668 */
2669
2670 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2671 desc_set_label(desc, label ? : "?");
2672 ret = 0;
2673 } else {
2674 kfree_const(label);
2675 ret = -EBUSY;
2676 goto done;
2677 }
2678
2679 if (chip->request) {
2680 /* chip->request may sleep */
2681 spin_unlock_irqrestore(&gpio_lock, flags);
2682 offset = gpio_chip_hwgpio(desc);
2683 if (gpiochip_line_is_valid(chip, offset))
2684 ret = chip->request(chip, offset);
2685 else
2686 ret = -EINVAL;
2687 spin_lock_irqsave(&gpio_lock, flags);
2688
2689 if (ret < 0) {
2690 desc_set_label(desc, NULL);
2691 kfree_const(label);
2692 clear_bit(FLAG_REQUESTED, &desc->flags);
2693 goto done;
2694 }
2695 }
2696 if (chip->get_direction) {
2697 /* chip->get_direction may sleep */
2698 spin_unlock_irqrestore(&gpio_lock, flags);
2699 gpiod_get_direction(desc);
2700 spin_lock_irqsave(&gpio_lock, flags);
2701 }
2702done:
2703 spin_unlock_irqrestore(&gpio_lock, flags);
2704 return ret;
2705}
2706
2707/*
2708 * This descriptor validation needs to be inserted verbatim into each
2709 * function taking a descriptor, so we need to use a preprocessor
2710 * macro to avoid endless duplication. If the desc is NULL it is an
2711 * optional GPIO and calls should just bail out.
2712 */
2713static int validate_desc(const struct gpio_desc *desc, const char *func)
2714{
2715 if (!desc)
2716 return 0;
2717 if (IS_ERR(desc)) {
2718 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2719 return PTR_ERR(desc);
2720 }
2721 if (!desc->gdev) {
2722 pr_warn("%s: invalid GPIO (no device)\n", func);
2723 return -EINVAL;
2724 }
2725 if (!desc->gdev->chip) {
2726 dev_warn(&desc->gdev->dev,
2727 "%s: backing chip is gone\n", func);
2728 return 0;
2729 }
2730 return 1;
2731}
2732
2733#define VALIDATE_DESC(desc) do { \
2734 int __valid = validate_desc(desc, __func__); \
2735 if (__valid <= 0) \
2736 return __valid; \
2737 } while (0)
2738
2739#define VALIDATE_DESC_VOID(desc) do { \
2740 int __valid = validate_desc(desc, __func__); \
2741 if (__valid <= 0) \
2742 return; \
2743 } while (0)
2744
2745int gpiod_request(struct gpio_desc *desc, const char *label)
2746{
2747 int ret = -EPROBE_DEFER;
2748 struct gpio_device *gdev;
2749
2750 VALIDATE_DESC(desc);
2751 gdev = desc->gdev;
2752
2753 if (try_module_get(gdev->owner)) {
2754 ret = gpiod_request_commit(desc, label);
2755 if (ret < 0)
2756 module_put(gdev->owner);
2757 else
2758 get_device(&gdev->dev);
2759 }
2760
2761 if (ret)
2762 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2763
2764 return ret;
2765}
2766
2767static bool gpiod_free_commit(struct gpio_desc *desc)
2768{
2769 bool ret = false;
2770 unsigned long flags;
2771 struct gpio_chip *chip;
2772
2773 might_sleep();
2774
2775 gpiod_unexport(desc);
2776
2777 spin_lock_irqsave(&gpio_lock, flags);
2778
2779 chip = desc->gdev->chip;
2780 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2781 if (chip->free) {
2782 spin_unlock_irqrestore(&gpio_lock, flags);
2783 might_sleep_if(chip->can_sleep);
2784 chip->free(chip, gpio_chip_hwgpio(desc));
2785 spin_lock_irqsave(&gpio_lock, flags);
2786 }
2787 kfree_const(desc->label);
2788 desc_set_label(desc, NULL);
2789 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2790 clear_bit(FLAG_REQUESTED, &desc->flags);
2791 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2792 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2793 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2794 ret = true;
2795 }
2796
2797 spin_unlock_irqrestore(&gpio_lock, flags);
2798 return ret;
2799}
2800
2801void gpiod_free(struct gpio_desc *desc)
2802{
2803 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2804 module_put(desc->gdev->owner);
2805 put_device(&desc->gdev->dev);
2806 } else {
2807 WARN_ON(extra_checks);
2808 }
2809}
2810
2811/**
2812 * gpiochip_is_requested - return string iff signal was requested
2813 * @chip: controller managing the signal
2814 * @offset: of signal within controller's 0..(ngpio - 1) range
2815 *
2816 * Returns NULL if the GPIO is not currently requested, else a string.
2817 * The string returned is the label passed to gpio_request(); if none has been
2818 * passed it is a meaningless, non-NULL constant.
2819 *
2820 * This function is for use by GPIO controller drivers. The label can
2821 * help with diagnostics, and knowing that the signal is used as a GPIO
2822 * can help avoid accidentally multiplexing it to another controller.
2823 */
2824const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2825{
2826 struct gpio_desc *desc;
2827
2828 if (offset >= chip->ngpio)
2829 return NULL;
2830
2831 desc = &chip->gpiodev->descs[offset];
2832
2833 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2834 return NULL;
2835 return desc->label;
2836}
2837EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2838
2839/**
2840 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2841 * @chip: GPIO chip
2842 * @hwnum: hardware number of the GPIO for which to request the descriptor
2843 * @label: label for the GPIO
2844 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2845 * specify things like line inversion semantics with the machine flags
2846 * such as GPIO_OUT_LOW
2847 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2848 * can be used to specify consumer semantics such as open drain
2849 *
2850 * Function allows GPIO chip drivers to request and use their own GPIO
2851 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2852 * function will not increase reference count of the GPIO chip module. This
2853 * allows the GPIO chip module to be unloaded as needed (we assume that the
2854 * GPIO chip driver handles freeing the GPIOs it has requested).
2855 *
2856 * Returns:
2857 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2858 * code on failure.
2859 */
2860struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2861 const char *label,
2862 enum gpio_lookup_flags lflags,
2863 enum gpiod_flags dflags)
2864{
2865 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2866 int ret;
2867
2868 if (IS_ERR(desc)) {
2869 chip_err(chip, "failed to get GPIO descriptor\n");
2870 return desc;
2871 }
2872
2873 ret = gpiod_request_commit(desc, label);
2874 if (ret < 0)
2875 return ERR_PTR(ret);
2876
2877 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2878 if (ret) {
2879 chip_err(chip, "setup of own GPIO %s failed\n", label);
2880 gpiod_free_commit(desc);
2881 return ERR_PTR(ret);
2882 }
2883
2884 return desc;
2885}
2886EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2887
2888/**
2889 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2890 * @desc: GPIO descriptor to free
2891 *
2892 * Function frees the given GPIO requested previously with
2893 * gpiochip_request_own_desc().
2894 */
2895void gpiochip_free_own_desc(struct gpio_desc *desc)
2896{
2897 if (desc)
2898 gpiod_free_commit(desc);
2899}
2900EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2901
2902/*
2903 * Drivers MUST set GPIO direction before making get/set calls. In
2904 * some cases this is done in early boot, before IRQs are enabled.
2905 *
2906 * As a rule these aren't called more than once (except for drivers
2907 * using the open-drain emulation idiom) so these are natural places
2908 * to accumulate extra debugging checks. Note that we can't (yet)
2909 * rely on gpio_request() having been called beforehand.
2910 */
2911
2912static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
2913 enum pin_config_param mode)
2914{
2915 unsigned long config;
2916 unsigned arg;
2917
2918 switch (mode) {
2919 case PIN_CONFIG_BIAS_PULL_DOWN:
2920 case PIN_CONFIG_BIAS_PULL_UP:
2921 arg = 1;
2922 break;
2923
2924 default:
2925 arg = 0;
2926 }
2927
2928 config = PIN_CONF_PACKED(mode, arg);
2929 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2930}
2931
2932/**
2933 * gpiod_direction_input - set the GPIO direction to input
2934 * @desc: GPIO to set to input
2935 *
2936 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2937 * be called safely on it.
2938 *
2939 * Return 0 in case of success, else an error code.
2940 */
2941int gpiod_direction_input(struct gpio_desc *desc)
2942{
2943 struct gpio_chip *chip;
2944 int ret = 0;
2945
2946 VALIDATE_DESC(desc);
2947 chip = desc->gdev->chip;
2948
2949 /*
2950 * It is legal to have no .get() and .direction_input() specified if
2951 * the chip is output-only, but you can't specify .direction_input()
2952 * and not support the .get() operation, that doesn't make sense.
2953 */
2954 if (!chip->get && chip->direction_input) {
2955 gpiod_warn(desc,
2956 "%s: missing get() but have direction_input()\n",
2957 __func__);
2958 return -EIO;
2959 }
2960
2961 /*
2962 * If we have a .direction_input() callback, things are simple,
2963 * just call it. Else we are some input-only chip so try to check the
2964 * direction (if .get_direction() is supported) else we silently
2965 * assume we are in input mode after this.
2966 */
2967 if (chip->direction_input) {
2968 ret = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2969 } else if (chip->get_direction &&
2970 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2971 gpiod_warn(desc,
2972 "%s: missing direction_input() operation and line is output\n",
2973 __func__);
2974 return -EIO;
2975 }
2976 if (ret == 0)
2977 clear_bit(FLAG_IS_OUT, &desc->flags);
2978
2979 if (test_bit(FLAG_PULL_UP, &desc->flags))
2980 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2981 PIN_CONFIG_BIAS_PULL_UP);
2982 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2983 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2984 PIN_CONFIG_BIAS_PULL_DOWN);
2985
2986 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2987
2988 return ret;
2989}
2990EXPORT_SYMBOL_GPL(gpiod_direction_input);
2991
2992static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2993{
2994 struct gpio_chip *gc = desc->gdev->chip;
2995 int val = !!value;
2996 int ret = 0;
2997
2998 /*
2999 * It's OK not to specify .direction_output() if the gpiochip is
3000 * output-only, but if there is then not even a .set() operation it
3001 * is pretty tricky to drive the output line.
3002 */
3003 if (!gc->set && !gc->direction_output) {
3004 gpiod_warn(desc,
3005 "%s: missing set() and direction_output() operations\n",
3006 __func__);
3007 return -EIO;
3008 }
3009
3010 if (gc->direction_output) {
3011 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
3012 } else {
3013 /* Check that we are in output mode if we can */
3014 if (gc->get_direction &&
3015 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
3016 gpiod_warn(desc,
3017 "%s: missing direction_output() operation\n",
3018 __func__);
3019 return -EIO;
3020 }
3021 /*
3022 * If we can't actively set the direction, we are some
3023 * output-only chip, so just drive the output as desired.
3024 */
3025 gc->set(gc, gpio_chip_hwgpio(desc), val);
3026 }
3027
3028 if (!ret)
3029 set_bit(FLAG_IS_OUT, &desc->flags);
3030 trace_gpio_value(desc_to_gpio(desc), 0, val);
3031 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
3032 return ret;
3033}
3034
3035/**
3036 * gpiod_direction_output_raw - set the GPIO direction to output
3037 * @desc: GPIO to set to output
3038 * @value: initial output value of the GPIO
3039 *
3040 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
3041 * be called safely on it. The initial value of the output must be specified
3042 * as raw value on the physical line without regard for the ACTIVE_LOW status.
3043 *
3044 * Return 0 in case of success, else an error code.
3045 */
3046int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
3047{
3048 VALIDATE_DESC(desc);
3049 return gpiod_direction_output_raw_commit(desc, value);
3050}
3051EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
3052
3053/**
3054 * gpiod_direction_output - set the GPIO direction to output
3055 * @desc: GPIO to set to output
3056 * @value: initial output value of the GPIO
3057 *
3058 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
3059 * be called safely on it. The initial value of the output must be specified
3060 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3061 * account.
3062 *
3063 * Return 0 in case of success, else an error code.
3064 */
3065int gpiod_direction_output(struct gpio_desc *desc, int value)
3066{
3067 struct gpio_chip *gc;
3068 int ret;
3069
3070 VALIDATE_DESC(desc);
3071 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3072 value = !value;
3073 else
3074 value = !!value;
3075
3076 /* GPIOs used for enabled IRQs shall not be set as output */
3077 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
3078 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
3079 gpiod_err(desc,
3080 "%s: tried to set a GPIO tied to an IRQ as output\n",
3081 __func__);
3082 return -EIO;
3083 }
3084
3085 gc = desc->gdev->chip;
3086 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3087 /* First see if we can enable open drain in hardware */
3088 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
3089 PIN_CONFIG_DRIVE_OPEN_DRAIN);
3090 if (!ret)
3091 goto set_output_value;
3092 /* Emulate open drain by not actively driving the line high */
3093 if (value) {
3094 ret = gpiod_direction_input(desc);
3095 goto set_output_flag;
3096 }
3097 }
3098 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
3099 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
3100 PIN_CONFIG_DRIVE_OPEN_SOURCE);
3101 if (!ret)
3102 goto set_output_value;
3103 /* Emulate open source by not actively driving the line low */
3104 if (!value) {
3105 ret = gpiod_direction_input(desc);
3106 goto set_output_flag;
3107 }
3108 } else {
3109 gpio_set_config(gc, gpio_chip_hwgpio(desc),
3110 PIN_CONFIG_DRIVE_PUSH_PULL);
3111 }
3112
3113set_output_value:
3114 return gpiod_direction_output_raw_commit(desc, value);
3115
3116set_output_flag:
3117 /*
3118 * When emulating open-source or open-drain functionalities by not
3119 * actively driving the line (setting mode to input) we still need to
3120 * set the IS_OUT flag or otherwise we won't be able to set the line
3121 * value anymore.
3122 */
3123 if (ret == 0)
3124 set_bit(FLAG_IS_OUT, &desc->flags);
3125 return ret;
3126}
3127EXPORT_SYMBOL_GPL(gpiod_direction_output);
3128
3129/**
3130 * gpiod_set_debounce - sets @debounce time for a GPIO
3131 * @desc: descriptor of the GPIO for which to set debounce time
3132 * @debounce: debounce time in microseconds
3133 *
3134 * Returns:
3135 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3136 * debounce time.
3137 */
3138int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
3139{
3140 struct gpio_chip *chip;
3141 unsigned long config;
3142
3143 VALIDATE_DESC(desc);
3144 chip = desc->gdev->chip;
3145 if (!chip->set || !chip->set_config) {
3146 gpiod_dbg(desc,
3147 "%s: missing set() or set_config() operations\n",
3148 __func__);
3149 return -ENOTSUPP;
3150 }
3151
3152 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
3153 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
3154}
3155EXPORT_SYMBOL_GPL(gpiod_set_debounce);
3156
3157/**
3158 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
3159 * @desc: descriptor of the GPIO for which to configure persistence
3160 * @transitory: True to lose state on suspend or reset, false for persistence
3161 *
3162 * Returns:
3163 * 0 on success, otherwise a negative error code.
3164 */
3165int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
3166{
3167 struct gpio_chip *chip;
3168 unsigned long packed;
3169 int gpio;
3170 int rc;
3171
3172 VALIDATE_DESC(desc);
3173 /*
3174 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
3175 * persistence state.
3176 */
3177 if (transitory)
3178 set_bit(FLAG_TRANSITORY, &desc->flags);
3179 else
3180 clear_bit(FLAG_TRANSITORY, &desc->flags);
3181
3182 /* If the driver supports it, set the persistence state now */
3183 chip = desc->gdev->chip;
3184 if (!chip->set_config)
3185 return 0;
3186
3187 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
3188 !transitory);
3189 gpio = gpio_chip_hwgpio(desc);
3190 rc = chip->set_config(chip, gpio, packed);
3191 if (rc == -ENOTSUPP) {
3192 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
3193 gpio);
3194 return 0;
3195 }
3196
3197 return rc;
3198}
3199EXPORT_SYMBOL_GPL(gpiod_set_transitory);
3200
3201/**
3202 * gpiod_is_active_low - test whether a GPIO is active-low or not
3203 * @desc: the gpio descriptor to test
3204 *
3205 * Returns 1 if the GPIO is active-low, 0 otherwise.
3206 */
3207int gpiod_is_active_low(const struct gpio_desc *desc)
3208{
3209 VALIDATE_DESC(desc);
3210 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
3211}
3212EXPORT_SYMBOL_GPL(gpiod_is_active_low);
3213
3214/* I/O calls are only valid after configuration completed; the relevant
3215 * "is this a valid GPIO" error checks should already have been done.
3216 *
3217 * "Get" operations are often inlinable as reading a pin value register,
3218 * and masking the relevant bit in that register.
3219 *
3220 * When "set" operations are inlinable, they involve writing that mask to
3221 * one register to set a low value, or a different register to set it high.
3222 * Otherwise locking is needed, so there may be little value to inlining.
3223 *
3224 *------------------------------------------------------------------------
3225 *
3226 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
3227 * have requested the GPIO. That can include implicit requesting by
3228 * a direction setting call. Marking a gpio as requested locks its chip
3229 * in memory, guaranteeing that these table lookups need no more locking
3230 * and that gpiochip_remove() will fail.
3231 *
3232 * REVISIT when debugging, consider adding some instrumentation to ensure
3233 * that the GPIO was actually requested.
3234 */
3235
3236static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
3237{
3238 struct gpio_chip *chip;
3239 int offset;
3240 int value;
3241
3242 chip = desc->gdev->chip;
3243 offset = gpio_chip_hwgpio(desc);
3244 value = chip->get ? chip->get(chip, offset) : -EIO;
3245 value = value < 0 ? value : !!value;
3246 trace_gpio_value(desc_to_gpio(desc), 1, value);
3247 return value;
3248}
3249
3250static int gpio_chip_get_multiple(struct gpio_chip *chip,
3251 unsigned long *mask, unsigned long *bits)
3252{
3253 if (chip->get_multiple) {
3254 return chip->get_multiple(chip, mask, bits);
3255 } else if (chip->get) {
3256 int i, value;
3257
3258 for_each_set_bit(i, mask, chip->ngpio) {
3259 value = chip->get(chip, i);
3260 if (value < 0)
3261 return value;
3262 __assign_bit(i, bits, value);
3263 }
3264 return 0;
3265 }
3266 return -EIO;
3267}
3268
3269int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3270 unsigned int array_size,
3271 struct gpio_desc **desc_array,
3272 struct gpio_array *array_info,
3273 unsigned long *value_bitmap)
3274{
3275 int ret, i = 0;
3276
3277 /*
3278 * Validate array_info against desc_array and its size.
3279 * It should immediately follow desc_array if both
3280 * have been obtained from the same gpiod_get_array() call.
3281 */
3282 if (array_info && array_info->desc == desc_array &&
3283 array_size <= array_info->size &&
3284 (void *)array_info == desc_array + array_info->size) {
3285 if (!can_sleep)
3286 WARN_ON(array_info->chip->can_sleep);
3287
3288 ret = gpio_chip_get_multiple(array_info->chip,
3289 array_info->get_mask,
3290 value_bitmap);
3291 if (ret)
3292 return ret;
3293
3294 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3295 bitmap_xor(value_bitmap, value_bitmap,
3296 array_info->invert_mask, array_size);
3297
3298 if (bitmap_full(array_info->get_mask, array_size))
3299 return 0;
3300
3301 i = find_first_zero_bit(array_info->get_mask, array_size);
3302 } else {
3303 array_info = NULL;
3304 }
3305
3306 while (i < array_size) {
3307 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3308 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3309 unsigned long *mask, *bits;
3310 int first, j, ret;
3311
3312 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3313 mask = fastpath;
3314 } else {
3315 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3316 sizeof(*mask),
3317 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3318 if (!mask)
3319 return -ENOMEM;
3320 }
3321
3322 bits = mask + BITS_TO_LONGS(chip->ngpio);
3323 bitmap_zero(mask, chip->ngpio);
3324
3325 if (!can_sleep)
3326 WARN_ON(chip->can_sleep);
3327
3328 /* collect all inputs belonging to the same chip */
3329 first = i;
3330 do {
3331 const struct gpio_desc *desc = desc_array[i];
3332 int hwgpio = gpio_chip_hwgpio(desc);
3333
3334 __set_bit(hwgpio, mask);
3335 i++;
3336
3337 if (array_info)
3338 i = find_next_zero_bit(array_info->get_mask,
3339 array_size, i);
3340 } while ((i < array_size) &&
3341 (desc_array[i]->gdev->chip == chip));
3342
3343 ret = gpio_chip_get_multiple(chip, mask, bits);
3344 if (ret) {
3345 if (mask != fastpath)
3346 kfree(mask);
3347 return ret;
3348 }
3349
3350 for (j = first; j < i; ) {
3351 const struct gpio_desc *desc = desc_array[j];
3352 int hwgpio = gpio_chip_hwgpio(desc);
3353 int value = test_bit(hwgpio, bits);
3354
3355 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3356 value = !value;
3357 __assign_bit(j, value_bitmap, value);
3358 trace_gpio_value(desc_to_gpio(desc), 1, value);
3359 j++;
3360
3361 if (array_info)
3362 j = find_next_zero_bit(array_info->get_mask, i,
3363 j);
3364 }
3365
3366 if (mask != fastpath)
3367 kfree(mask);
3368 }
3369 return 0;
3370}
3371
3372/**
3373 * gpiod_get_raw_value() - return a gpio's raw value
3374 * @desc: gpio whose value will be returned
3375 *
3376 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3377 * its ACTIVE_LOW status, or negative errno on failure.
3378 *
3379 * This function can be called from contexts where we cannot sleep, and will
3380 * complain if the GPIO chip functions potentially sleep.
3381 */
3382int gpiod_get_raw_value(const struct gpio_desc *desc)
3383{
3384 VALIDATE_DESC(desc);
3385 /* Should be using gpiod_get_raw_value_cansleep() */
3386 WARN_ON(desc->gdev->chip->can_sleep);
3387 return gpiod_get_raw_value_commit(desc);
3388}
3389EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3390
3391/**
3392 * gpiod_get_value() - return a gpio's value
3393 * @desc: gpio whose value will be returned
3394 *
3395 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3396 * account, or negative errno on failure.
3397 *
3398 * This function can be called from contexts where we cannot sleep, and will
3399 * complain if the GPIO chip functions potentially sleep.
3400 */
3401int gpiod_get_value(const struct gpio_desc *desc)
3402{
3403 int value;
3404
3405 VALIDATE_DESC(desc);
3406 /* Should be using gpiod_get_value_cansleep() */
3407 WARN_ON(desc->gdev->chip->can_sleep);
3408
3409 value = gpiod_get_raw_value_commit(desc);
3410 if (value < 0)
3411 return value;
3412
3413 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3414 value = !value;
3415
3416 return value;
3417}
3418EXPORT_SYMBOL_GPL(gpiod_get_value);
3419
3420/**
3421 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3422 * @array_size: number of elements in the descriptor array / value bitmap
3423 * @desc_array: array of GPIO descriptors whose values will be read
3424 * @array_info: information on applicability of fast bitmap processing path
3425 * @value_bitmap: bitmap to store the read values
3426 *
3427 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3428 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3429 * else an error code.
3430 *
3431 * This function can be called from contexts where we cannot sleep,
3432 * and it will complain if the GPIO chip functions potentially sleep.
3433 */
3434int gpiod_get_raw_array_value(unsigned int array_size,
3435 struct gpio_desc **desc_array,
3436 struct gpio_array *array_info,
3437 unsigned long *value_bitmap)
3438{
3439 if (!desc_array)
3440 return -EINVAL;
3441 return gpiod_get_array_value_complex(true, false, array_size,
3442 desc_array, array_info,
3443 value_bitmap);
3444}
3445EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3446
3447/**
3448 * gpiod_get_array_value() - read values from an array of GPIOs
3449 * @array_size: number of elements in the descriptor array / value bitmap
3450 * @desc_array: array of GPIO descriptors whose values will be read
3451 * @array_info: information on applicability of fast bitmap processing path
3452 * @value_bitmap: bitmap to store the read values
3453 *
3454 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3455 * into account. Return 0 in case of success, else an error code.
3456 *
3457 * This function can be called from contexts where we cannot sleep,
3458 * and it will complain if the GPIO chip functions potentially sleep.
3459 */
3460int gpiod_get_array_value(unsigned int array_size,
3461 struct gpio_desc **desc_array,
3462 struct gpio_array *array_info,
3463 unsigned long *value_bitmap)
3464{
3465 if (!desc_array)
3466 return -EINVAL;
3467 return gpiod_get_array_value_complex(false, false, array_size,
3468 desc_array, array_info,
3469 value_bitmap);
3470}
3471EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3472
3473/*
3474 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3475 * @desc: gpio descriptor whose state need to be set.
3476 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3477 */
3478static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3479{
3480 int ret = 0;
3481 struct gpio_chip *chip = desc->gdev->chip;
3482 int offset = gpio_chip_hwgpio(desc);
3483
3484 if (value) {
3485 ret = chip->direction_input(chip, offset);
3486 } else {
3487 ret = chip->direction_output(chip, offset, 0);
3488 if (!ret)
3489 set_bit(FLAG_IS_OUT, &desc->flags);
3490 }
3491 trace_gpio_direction(desc_to_gpio(desc), value, ret);
3492 if (ret < 0)
3493 gpiod_err(desc,
3494 "%s: Error in set_value for open drain err %d\n",
3495 __func__, ret);
3496}
3497
3498/*
3499 * _gpio_set_open_source_value() - Set the open source gpio's value.
3500 * @desc: gpio descriptor whose state need to be set.
3501 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3502 */
3503static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3504{
3505 int ret = 0;
3506 struct gpio_chip *chip = desc->gdev->chip;
3507 int offset = gpio_chip_hwgpio(desc);
3508
3509 if (value) {
3510 ret = chip->direction_output(chip, offset, 1);
3511 if (!ret)
3512 set_bit(FLAG_IS_OUT, &desc->flags);
3513 } else {
3514 ret = chip->direction_input(chip, offset);
3515 }
3516 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3517 if (ret < 0)
3518 gpiod_err(desc,
3519 "%s: Error in set_value for open source err %d\n",
3520 __func__, ret);
3521}
3522
3523static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3524{
3525 struct gpio_chip *chip;
3526
3527 chip = desc->gdev->chip;
3528 trace_gpio_value(desc_to_gpio(desc), 0, value);
3529 chip->set(chip, gpio_chip_hwgpio(desc), value);
3530}
3531
3532/*
3533 * set multiple outputs on the same chip;
3534 * use the chip's set_multiple function if available;
3535 * otherwise set the outputs sequentially;
3536 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3537 * defines which outputs are to be changed
3538 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3539 * defines the values the outputs specified by mask are to be set to
3540 */
3541static void gpio_chip_set_multiple(struct gpio_chip *chip,
3542 unsigned long *mask, unsigned long *bits)
3543{
3544 if (chip->set_multiple) {
3545 chip->set_multiple(chip, mask, bits);
3546 } else {
3547 unsigned int i;
3548
3549 /* set outputs if the corresponding mask bit is set */
3550 for_each_set_bit(i, mask, chip->ngpio)
3551 chip->set(chip, i, test_bit(i, bits));
3552 }
3553}
3554
3555int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3556 unsigned int array_size,
3557 struct gpio_desc **desc_array,
3558 struct gpio_array *array_info,
3559 unsigned long *value_bitmap)
3560{
3561 int i = 0;
3562
3563 /*
3564 * Validate array_info against desc_array and its size.
3565 * It should immediately follow desc_array if both
3566 * have been obtained from the same gpiod_get_array() call.
3567 */
3568 if (array_info && array_info->desc == desc_array &&
3569 array_size <= array_info->size &&
3570 (void *)array_info == desc_array + array_info->size) {
3571 if (!can_sleep)
3572 WARN_ON(array_info->chip->can_sleep);
3573
3574 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3575 bitmap_xor(value_bitmap, value_bitmap,
3576 array_info->invert_mask, array_size);
3577
3578 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3579 value_bitmap);
3580
3581 if (bitmap_full(array_info->set_mask, array_size))
3582 return 0;
3583
3584 i = find_first_zero_bit(array_info->set_mask, array_size);
3585 } else {
3586 array_info = NULL;
3587 }
3588
3589 while (i < array_size) {
3590 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3591 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3592 unsigned long *mask, *bits;
3593 int count = 0;
3594
3595 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3596 mask = fastpath;
3597 } else {
3598 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3599 sizeof(*mask),
3600 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3601 if (!mask)
3602 return -ENOMEM;
3603 }
3604
3605 bits = mask + BITS_TO_LONGS(chip->ngpio);
3606 bitmap_zero(mask, chip->ngpio);
3607
3608 if (!can_sleep)
3609 WARN_ON(chip->can_sleep);
3610
3611 do {
3612 struct gpio_desc *desc = desc_array[i];
3613 int hwgpio = gpio_chip_hwgpio(desc);
3614 int value = test_bit(i, value_bitmap);
3615
3616 /*
3617 * Pins applicable for fast input but not for
3618 * fast output processing may have been already
3619 * inverted inside the fast path, skip them.
3620 */
3621 if (!raw && !(array_info &&
3622 test_bit(i, array_info->invert_mask)) &&
3623 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3624 value = !value;
3625 trace_gpio_value(desc_to_gpio(desc), 0, value);
3626 /*
3627 * collect all normal outputs belonging to the same chip
3628 * open drain and open source outputs are set individually
3629 */
3630 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3631 gpio_set_open_drain_value_commit(desc, value);
3632 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3633 gpio_set_open_source_value_commit(desc, value);
3634 } else {
3635 __set_bit(hwgpio, mask);
3636 if (value)
3637 __set_bit(hwgpio, bits);
3638 else
3639 __clear_bit(hwgpio, bits);
3640 count++;
3641 }
3642 i++;
3643
3644 if (array_info)
3645 i = find_next_zero_bit(array_info->set_mask,
3646 array_size, i);
3647 } while ((i < array_size) &&
3648 (desc_array[i]->gdev->chip == chip));
3649 /* push collected bits to outputs */
3650 if (count != 0)
3651 gpio_chip_set_multiple(chip, mask, bits);
3652
3653 if (mask != fastpath)
3654 kfree(mask);
3655 }
3656 return 0;
3657}
3658
3659/**
3660 * gpiod_set_raw_value() - assign a gpio's raw value
3661 * @desc: gpio whose value will be assigned
3662 * @value: value to assign
3663 *
3664 * Set the raw value of the GPIO, i.e. the value of its physical line without
3665 * regard for its ACTIVE_LOW status.
3666 *
3667 * This function can be called from contexts where we cannot sleep, and will
3668 * complain if the GPIO chip functions potentially sleep.
3669 */
3670void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3671{
3672 VALIDATE_DESC_VOID(desc);
3673 /* Should be using gpiod_set_raw_value_cansleep() */
3674 WARN_ON(desc->gdev->chip->can_sleep);
3675 gpiod_set_raw_value_commit(desc, value);
3676}
3677EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3678
3679/**
3680 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3681 * @desc: the descriptor to set the value on
3682 * @value: value to set
3683 *
3684 * This sets the value of a GPIO line backing a descriptor, applying
3685 * different semantic quirks like active low and open drain/source
3686 * handling.
3687 */
3688static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3689{
3690 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3691 value = !value;
3692 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3693 gpio_set_open_drain_value_commit(desc, value);
3694 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3695 gpio_set_open_source_value_commit(desc, value);
3696 else
3697 gpiod_set_raw_value_commit(desc, value);
3698}
3699
3700/**
3701 * gpiod_set_value() - assign a gpio's value
3702 * @desc: gpio whose value will be assigned
3703 * @value: value to assign
3704 *
3705 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3706 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3707 *
3708 * This function can be called from contexts where we cannot sleep, and will
3709 * complain if the GPIO chip functions potentially sleep.
3710 */
3711void gpiod_set_value(struct gpio_desc *desc, int value)
3712{
3713 VALIDATE_DESC_VOID(desc);
3714 /* Should be using gpiod_set_value_cansleep() */
3715 WARN_ON(desc->gdev->chip->can_sleep);
3716 gpiod_set_value_nocheck(desc, value);
3717}
3718EXPORT_SYMBOL_GPL(gpiod_set_value);
3719
3720/**
3721 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3722 * @array_size: number of elements in the descriptor array / value bitmap
3723 * @desc_array: array of GPIO descriptors whose values will be assigned
3724 * @array_info: information on applicability of fast bitmap processing path
3725 * @value_bitmap: bitmap of values to assign
3726 *
3727 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3728 * without regard for their ACTIVE_LOW status.
3729 *
3730 * This function can be called from contexts where we cannot sleep, and will
3731 * complain if the GPIO chip functions potentially sleep.
3732 */
3733int gpiod_set_raw_array_value(unsigned int array_size,
3734 struct gpio_desc **desc_array,
3735 struct gpio_array *array_info,
3736 unsigned long *value_bitmap)
3737{
3738 if (!desc_array)
3739 return -EINVAL;
3740 return gpiod_set_array_value_complex(true, false, array_size,
3741 desc_array, array_info, value_bitmap);
3742}
3743EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3744
3745/**
3746 * gpiod_set_array_value() - assign values to an array of GPIOs
3747 * @array_size: number of elements in the descriptor array / value bitmap
3748 * @desc_array: array of GPIO descriptors whose values will be assigned
3749 * @array_info: information on applicability of fast bitmap processing path
3750 * @value_bitmap: bitmap of values to assign
3751 *
3752 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3753 * into account.
3754 *
3755 * This function can be called from contexts where we cannot sleep, and will
3756 * complain if the GPIO chip functions potentially sleep.
3757 */
3758int gpiod_set_array_value(unsigned int array_size,
3759 struct gpio_desc **desc_array,
3760 struct gpio_array *array_info,
3761 unsigned long *value_bitmap)
3762{
3763 if (!desc_array)
3764 return -EINVAL;
3765 return gpiod_set_array_value_complex(false, false, array_size,
3766 desc_array, array_info,
3767 value_bitmap);
3768}
3769EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3770
3771/**
3772 * gpiod_cansleep() - report whether gpio value access may sleep
3773 * @desc: gpio to check
3774 *
3775 */
3776int gpiod_cansleep(const struct gpio_desc *desc)
3777{
3778 VALIDATE_DESC(desc);
3779 return desc->gdev->chip->can_sleep;
3780}
3781EXPORT_SYMBOL_GPL(gpiod_cansleep);
3782
3783/**
3784 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3785 * @desc: gpio to set the consumer name on
3786 * @name: the new consumer name
3787 */
3788int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3789{
3790 VALIDATE_DESC(desc);
3791 if (name) {
3792 name = kstrdup_const(name, GFP_KERNEL);
3793 if (!name)
3794 return -ENOMEM;
3795 }
3796
3797 kfree_const(desc->label);
3798 desc_set_label(desc, name);
3799
3800 return 0;
3801}
3802EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3803
3804/**
3805 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3806 * @desc: gpio whose IRQ will be returned (already requested)
3807 *
3808 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3809 * error.
3810 */
3811int gpiod_to_irq(const struct gpio_desc *desc)
3812{
3813 struct gpio_chip *chip;
3814 int offset;
3815
3816 /*
3817 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3818 * requires this function to not return zero on an invalid descriptor
3819 * but rather a negative error number.
3820 */
3821 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3822 return -EINVAL;
3823
3824 chip = desc->gdev->chip;
3825 offset = gpio_chip_hwgpio(desc);
3826 if (chip->to_irq) {
3827 int retirq = chip->to_irq(chip, offset);
3828
3829 /* Zero means NO_IRQ */
3830 if (!retirq)
3831 return -ENXIO;
3832
3833 return retirq;
3834 }
3835 return -ENXIO;
3836}
3837EXPORT_SYMBOL_GPL(gpiod_to_irq);
3838
3839/**
3840 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3841 * @chip: the chip the GPIO to lock belongs to
3842 * @offset: the offset of the GPIO to lock as IRQ
3843 *
3844 * This is used directly by GPIO drivers that want to lock down
3845 * a certain GPIO line to be used for IRQs.
3846 */
3847int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3848{
3849 struct gpio_desc *desc;
3850
3851 desc = gpiochip_get_desc(chip, offset);
3852 if (IS_ERR(desc))
3853 return PTR_ERR(desc);
3854
3855 /*
3856 * If it's fast: flush the direction setting if something changed
3857 * behind our back
3858 */
3859 if (!chip->can_sleep && chip->get_direction) {
3860 int dir = gpiod_get_direction(desc);
3861
3862 if (dir < 0) {
3863 chip_err(chip, "%s: cannot get GPIO direction\n",
3864 __func__);
3865 return dir;
3866 }
3867 }
3868
3869 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3870 chip_err(chip,
3871 "%s: tried to flag a GPIO set as output for IRQ\n",
3872 __func__);
3873 return -EIO;
3874 }
3875
3876 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3877 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3878
3879 /*
3880 * If the consumer has not set up a label (such as when the
3881 * IRQ is referenced from .to_irq()) we set up a label here
3882 * so it is clear this is used as an interrupt.
3883 */
3884 if (!desc->label)
3885 desc_set_label(desc, "interrupt");
3886
3887 return 0;
3888}
3889EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3890
3891/**
3892 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3893 * @chip: the chip the GPIO to lock belongs to
3894 * @offset: the offset of the GPIO to lock as IRQ
3895 *
3896 * This is used directly by GPIO drivers that want to indicate
3897 * that a certain GPIO is no longer used exclusively for IRQ.
3898 */
3899void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3900{
3901 struct gpio_desc *desc;
3902
3903 desc = gpiochip_get_desc(chip, offset);
3904 if (IS_ERR(desc))
3905 return;
3906
3907 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3908 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3909
3910 /* If we only had this marking, erase it */
3911 if (desc->label && !strcmp(desc->label, "interrupt"))
3912 desc_set_label(desc, NULL);
3913}
3914EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3915
3916void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3917{
3918 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3919
3920 if (!IS_ERR(desc) &&
3921 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3922 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3923}
3924EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3925
3926void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3927{
3928 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3929
3930 if (!IS_ERR(desc) &&
3931 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3932 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags));
3933 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3934 }
3935}
3936EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3937
3938bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3939{
3940 if (offset >= chip->ngpio)
3941 return false;
3942
3943 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3944}
3945EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3946
3947int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset)
3948{
3949 int ret;
3950
3951 if (!try_module_get(chip->gpiodev->owner))
3952 return -ENODEV;
3953
3954 ret = gpiochip_lock_as_irq(chip, offset);
3955 if (ret) {
3956 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset);
3957 module_put(chip->gpiodev->owner);
3958 return ret;
3959 }
3960 return 0;
3961}
3962EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3963
3964void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset)
3965{
3966 gpiochip_unlock_as_irq(chip, offset);
3967 module_put(chip->gpiodev->owner);
3968}
3969EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3970
3971bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3972{
3973 if (offset >= chip->ngpio)
3974 return false;
3975
3976 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3977}
3978EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3979
3980bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3981{
3982 if (offset >= chip->ngpio)
3983 return false;
3984
3985 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3986}
3987EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3988
3989bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3990{
3991 if (offset >= chip->ngpio)
3992 return false;
3993
3994 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3995}
3996EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3997
3998/**
3999 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
4000 * @desc: gpio whose value will be returned
4001 *
4002 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
4003 * its ACTIVE_LOW status, or negative errno on failure.
4004 *
4005 * This function is to be called from contexts that can sleep.
4006 */
4007int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
4008{
4009 might_sleep_if(extra_checks);
4010 VALIDATE_DESC(desc);
4011 return gpiod_get_raw_value_commit(desc);
4012}
4013EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
4014
4015/**
4016 * gpiod_get_value_cansleep() - return a gpio's value
4017 * @desc: gpio whose value will be returned
4018 *
4019 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
4020 * account, or negative errno on failure.
4021 *
4022 * This function is to be called from contexts that can sleep.
4023 */
4024int gpiod_get_value_cansleep(const struct gpio_desc *desc)
4025{
4026 int value;
4027
4028 might_sleep_if(extra_checks);
4029 VALIDATE_DESC(desc);
4030 value = gpiod_get_raw_value_commit(desc);
4031 if (value < 0)
4032 return value;
4033
4034 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
4035 value = !value;
4036
4037 return value;
4038}
4039EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
4040
4041/**
4042 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
4043 * @array_size: number of elements in the descriptor array / value bitmap
4044 * @desc_array: array of GPIO descriptors whose values will be read
4045 * @array_info: information on applicability of fast bitmap processing path
4046 * @value_bitmap: bitmap to store the read values
4047 *
4048 * Read the raw values of the GPIOs, i.e. the values of the physical lines
4049 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
4050 * else an error code.
4051 *
4052 * This function is to be called from contexts that can sleep.
4053 */
4054int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
4055 struct gpio_desc **desc_array,
4056 struct gpio_array *array_info,
4057 unsigned long *value_bitmap)
4058{
4059 might_sleep_if(extra_checks);
4060 if (!desc_array)
4061 return -EINVAL;
4062 return gpiod_get_array_value_complex(true, true, array_size,
4063 desc_array, array_info,
4064 value_bitmap);
4065}
4066EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
4067
4068/**
4069 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
4070 * @array_size: number of elements in the descriptor array / value bitmap
4071 * @desc_array: array of GPIO descriptors whose values will be read
4072 * @array_info: information on applicability of fast bitmap processing path
4073 * @value_bitmap: bitmap to store the read values
4074 *
4075 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4076 * into account. Return 0 in case of success, else an error code.
4077 *
4078 * This function is to be called from contexts that can sleep.
4079 */
4080int gpiod_get_array_value_cansleep(unsigned int array_size,
4081 struct gpio_desc **desc_array,
4082 struct gpio_array *array_info,
4083 unsigned long *value_bitmap)
4084{
4085 might_sleep_if(extra_checks);
4086 if (!desc_array)
4087 return -EINVAL;
4088 return gpiod_get_array_value_complex(false, true, array_size,
4089 desc_array, array_info,
4090 value_bitmap);
4091}
4092EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
4093
4094/**
4095 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
4096 * @desc: gpio whose value will be assigned
4097 * @value: value to assign
4098 *
4099 * Set the raw value of the GPIO, i.e. the value of its physical line without
4100 * regard for its ACTIVE_LOW status.
4101 *
4102 * This function is to be called from contexts that can sleep.
4103 */
4104void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
4105{
4106 might_sleep_if(extra_checks);
4107 VALIDATE_DESC_VOID(desc);
4108 gpiod_set_raw_value_commit(desc, value);
4109}
4110EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
4111
4112/**
4113 * gpiod_set_value_cansleep() - assign a gpio's value
4114 * @desc: gpio whose value will be assigned
4115 * @value: value to assign
4116 *
4117 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
4118 * account
4119 *
4120 * This function is to be called from contexts that can sleep.
4121 */
4122void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
4123{
4124 might_sleep_if(extra_checks);
4125 VALIDATE_DESC_VOID(desc);
4126 gpiod_set_value_nocheck(desc, value);
4127}
4128EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
4129
4130/**
4131 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
4132 * @array_size: number of elements in the descriptor array / value bitmap
4133 * @desc_array: array of GPIO descriptors whose values will be assigned
4134 * @array_info: information on applicability of fast bitmap processing path
4135 * @value_bitmap: bitmap of values to assign
4136 *
4137 * Set the raw values of the GPIOs, i.e. the values of the physical lines
4138 * without regard for their ACTIVE_LOW status.
4139 *
4140 * This function is to be called from contexts that can sleep.
4141 */
4142int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
4143 struct gpio_desc **desc_array,
4144 struct gpio_array *array_info,
4145 unsigned long *value_bitmap)
4146{
4147 might_sleep_if(extra_checks);
4148 if (!desc_array)
4149 return -EINVAL;
4150 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
4151 array_info, value_bitmap);
4152}
4153EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
4154
4155/**
4156 * gpiod_add_lookup_tables() - register GPIO device consumers
4157 * @tables: list of tables of consumers to register
4158 * @n: number of tables in the list
4159 */
4160void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
4161{
4162 unsigned int i;
4163
4164 mutex_lock(&gpio_lookup_lock);
4165
4166 for (i = 0; i < n; i++)
4167 list_add_tail(&tables[i]->list, &gpio_lookup_list);
4168
4169 mutex_unlock(&gpio_lookup_lock);
4170}
4171
4172/**
4173 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
4174 * @array_size: number of elements in the descriptor array / value bitmap
4175 * @desc_array: array of GPIO descriptors whose values will be assigned
4176 * @array_info: information on applicability of fast bitmap processing path
4177 * @value_bitmap: bitmap of values to assign
4178 *
4179 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4180 * into account.
4181 *
4182 * This function is to be called from contexts that can sleep.
4183 */
4184int gpiod_set_array_value_cansleep(unsigned int array_size,
4185 struct gpio_desc **desc_array,
4186 struct gpio_array *array_info,
4187 unsigned long *value_bitmap)
4188{
4189 might_sleep_if(extra_checks);
4190 if (!desc_array)
4191 return -EINVAL;
4192 return gpiod_set_array_value_complex(false, true, array_size,
4193 desc_array, array_info,
4194 value_bitmap);
4195}
4196EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
4197
4198/**
4199 * gpiod_add_lookup_table() - register GPIO device consumers
4200 * @table: table of consumers to register
4201 */
4202void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
4203{
4204 mutex_lock(&gpio_lookup_lock);
4205
4206 list_add_tail(&table->list, &gpio_lookup_list);
4207
4208 mutex_unlock(&gpio_lookup_lock);
4209}
4210EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
4211
4212/**
4213 * gpiod_remove_lookup_table() - unregister GPIO device consumers
4214 * @table: table of consumers to unregister
4215 */
4216void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4217{
4218 mutex_lock(&gpio_lookup_lock);
4219
4220 list_del(&table->list);
4221
4222 mutex_unlock(&gpio_lookup_lock);
4223}
4224EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4225
4226/**
4227 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4228 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4229 */
4230void gpiod_add_hogs(struct gpiod_hog *hogs)
4231{
4232 struct gpio_chip *chip;
4233 struct gpiod_hog *hog;
4234
4235 mutex_lock(&gpio_machine_hogs_mutex);
4236
4237 for (hog = &hogs[0]; hog->chip_label; hog++) {
4238 list_add_tail(&hog->list, &gpio_machine_hogs);
4239
4240 /*
4241 * The chip may have been registered earlier, so check if it
4242 * exists and, if so, try to hog the line now.
4243 */
4244 chip = find_chip_by_name(hog->chip_label);
4245 if (chip)
4246 gpiochip_machine_hog(chip, hog);
4247 }
4248
4249 mutex_unlock(&gpio_machine_hogs_mutex);
4250}
4251EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4252
4253static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4254{
4255 const char *dev_id = dev ? dev_name(dev) : NULL;
4256 struct gpiod_lookup_table *table;
4257
4258 mutex_lock(&gpio_lookup_lock);
4259
4260 list_for_each_entry(table, &gpio_lookup_list, list) {
4261 if (table->dev_id && dev_id) {
4262 /*
4263 * Valid strings on both ends, must be identical to have
4264 * a match
4265 */
4266 if (!strcmp(table->dev_id, dev_id))
4267 goto found;
4268 } else {
4269 /*
4270 * One of the pointers is NULL, so both must be to have
4271 * a match
4272 */
4273 if (dev_id == table->dev_id)
4274 goto found;
4275 }
4276 }
4277 table = NULL;
4278
4279found:
4280 mutex_unlock(&gpio_lookup_lock);
4281 return table;
4282}
4283
4284static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4285 unsigned int idx, unsigned long *flags)
4286{
4287 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4288 struct gpiod_lookup_table *table;
4289 struct gpiod_lookup *p;
4290
4291 table = gpiod_find_lookup_table(dev);
4292 if (!table)
4293 return desc;
4294
4295 for (p = &table->table[0]; p->chip_label; p++) {
4296 struct gpio_chip *chip;
4297
4298 /* idx must always match exactly */
4299 if (p->idx != idx)
4300 continue;
4301
4302 /* If the lookup entry has a con_id, require exact match */
4303 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4304 continue;
4305
4306 chip = find_chip_by_name(p->chip_label);
4307
4308 if (!chip) {
4309 /*
4310 * As the lookup table indicates a chip with
4311 * p->chip_label should exist, assume it may
4312 * still appear later and let the interested
4313 * consumer be probed again or let the Deferred
4314 * Probe infrastructure handle the error.
4315 */
4316 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4317 p->chip_label);
4318 return ERR_PTR(-EPROBE_DEFER);
4319 }
4320
4321 if (chip->ngpio <= p->chip_hwnum) {
4322 dev_err(dev,
4323 "requested GPIO %d is out of range [0..%d] for chip %s\n",
4324 idx, chip->ngpio, chip->label);
4325 return ERR_PTR(-EINVAL);
4326 }
4327
4328 desc = gpiochip_get_desc(chip, p->chip_hwnum);
4329 *flags = p->flags;
4330
4331 return desc;
4332 }
4333
4334 return desc;
4335}
4336
4337static int platform_gpio_count(struct device *dev, const char *con_id)
4338{
4339 struct gpiod_lookup_table *table;
4340 struct gpiod_lookup *p;
4341 unsigned int count = 0;
4342
4343 table = gpiod_find_lookup_table(dev);
4344 if (!table)
4345 return -ENOENT;
4346
4347 for (p = &table->table[0]; p->chip_label; p++) {
4348 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4349 (!con_id && !p->con_id))
4350 count++;
4351 }
4352 if (!count)
4353 return -ENOENT;
4354
4355 return count;
4356}
4357
4358/**
4359 * gpiod_count - return the number of GPIOs associated with a device / function
4360 * or -ENOENT if no GPIO has been assigned to the requested function
4361 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4362 * @con_id: function within the GPIO consumer
4363 */
4364int gpiod_count(struct device *dev, const char *con_id)
4365{
4366 int count = -ENOENT;
4367
4368 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
4369 count = of_gpio_get_count(dev, con_id);
4370 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
4371 count = acpi_gpio_count(dev, con_id);
4372
4373 if (count < 0)
4374 count = platform_gpio_count(dev, con_id);
4375
4376 return count;
4377}
4378EXPORT_SYMBOL_GPL(gpiod_count);
4379
4380/**
4381 * gpiod_get - obtain a GPIO for a given GPIO function
4382 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4383 * @con_id: function within the GPIO consumer
4384 * @flags: optional GPIO initialization flags
4385 *
4386 * Return the GPIO descriptor corresponding to the function con_id of device
4387 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4388 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4389 */
4390struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4391 enum gpiod_flags flags)
4392{
4393 return gpiod_get_index(dev, con_id, 0, flags);
4394}
4395EXPORT_SYMBOL_GPL(gpiod_get);
4396
4397/**
4398 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4399 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4400 * @con_id: function within the GPIO consumer
4401 * @flags: optional GPIO initialization flags
4402 *
4403 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4404 * the requested function it will return NULL. This is convenient for drivers
4405 * that need to handle optional GPIOs.
4406 */
4407struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4408 const char *con_id,
4409 enum gpiod_flags flags)
4410{
4411 return gpiod_get_index_optional(dev, con_id, 0, flags);
4412}
4413EXPORT_SYMBOL_GPL(gpiod_get_optional);
4414
4415
4416/**
4417 * gpiod_configure_flags - helper function to configure a given GPIO
4418 * @desc: gpio whose value will be assigned
4419 * @con_id: function within the GPIO consumer
4420 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4421 * of_find_gpio() or of_get_gpio_hog()
4422 * @dflags: gpiod_flags - optional GPIO initialization flags
4423 *
4424 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4425 * requested function and/or index, or another IS_ERR() code if an error
4426 * occurred while trying to acquire the GPIO.
4427 */
4428int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4429 unsigned long lflags, enum gpiod_flags dflags)
4430{
4431 int ret;
4432
4433 if (lflags & GPIO_ACTIVE_LOW)
4434 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4435
4436 if (lflags & GPIO_OPEN_DRAIN)
4437 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4438 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4439 /*
4440 * This enforces open drain mode from the consumer side.
4441 * This is necessary for some busses like I2C, but the lookup
4442 * should *REALLY* have specified them as open drain in the
4443 * first place, so print a little warning here.
4444 */
4445 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4446 gpiod_warn(desc,
4447 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4448 }
4449
4450 if (lflags & GPIO_OPEN_SOURCE)
4451 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4452
4453 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
4454 gpiod_err(desc,
4455 "both pull-up and pull-down enabled, invalid configuration\n");
4456 return -EINVAL;
4457 }
4458
4459 if (lflags & GPIO_PULL_UP)
4460 set_bit(FLAG_PULL_UP, &desc->flags);
4461 else if (lflags & GPIO_PULL_DOWN)
4462 set_bit(FLAG_PULL_DOWN, &desc->flags);
4463
4464 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4465 if (ret < 0)
4466 return ret;
4467
4468 /* No particular flag request, return here... */
4469 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4470 pr_debug("no flags found for %s\n", con_id);
4471 return 0;
4472 }
4473
4474 /* Process flags */
4475 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4476 ret = gpiod_direction_output(desc,
4477 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4478 else
4479 ret = gpiod_direction_input(desc);
4480
4481 return ret;
4482}
4483
4484/**
4485 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4486 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4487 * @con_id: function within the GPIO consumer
4488 * @idx: index of the GPIO to obtain in the consumer
4489 * @flags: optional GPIO initialization flags
4490 *
4491 * This variant of gpiod_get() allows to access GPIOs other than the first
4492 * defined one for functions that define several GPIOs.
4493 *
4494 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4495 * requested function and/or index, or another IS_ERR() code if an error
4496 * occurred while trying to acquire the GPIO.
4497 */
4498struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4499 const char *con_id,
4500 unsigned int idx,
4501 enum gpiod_flags flags)
4502{
4503 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4504 struct gpio_desc *desc = NULL;
4505 int ret;
4506 /* Maybe we have a device name, maybe not */
4507 const char *devname = dev ? dev_name(dev) : "?";
4508
4509 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4510
4511 if (dev) {
4512 /* Using device tree? */
4513 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4514 dev_dbg(dev, "using device tree for GPIO lookup\n");
4515 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4516 } else if (ACPI_COMPANION(dev)) {
4517 dev_dbg(dev, "using ACPI for GPIO lookup\n");
4518 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4519 }
4520 }
4521
4522 /*
4523 * Either we are not using DT or ACPI, or their lookup did not return
4524 * a result. In that case, use platform lookup as a fallback.
4525 */
4526 if (!desc || desc == ERR_PTR(-ENOENT)) {
4527 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4528 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4529 }
4530
4531 if (IS_ERR(desc)) {
4532 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4533 return desc;
4534 }
4535
4536 /*
4537 * If a connection label was passed use that, else attempt to use
4538 * the device name as label
4539 */
4540 ret = gpiod_request(desc, con_id ? con_id : devname);
4541 if (ret < 0) {
4542 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4543 /*
4544 * This happens when there are several consumers for
4545 * the same GPIO line: we just return here without
4546 * further initialization. It is a bit if a hack.
4547 * This is necessary to support fixed regulators.
4548 *
4549 * FIXME: Make this more sane and safe.
4550 */
4551 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4552 con_id ? con_id : devname);
4553 return desc;
4554 } else {
4555 return ERR_PTR(ret);
4556 }
4557 }
4558
4559 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4560 if (ret < 0) {
4561 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4562 gpiod_put(desc);
4563 return ERR_PTR(ret);
4564 }
4565
4566 return desc;
4567}
4568EXPORT_SYMBOL_GPL(gpiod_get_index);
4569
4570/**
4571 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4572 * @fwnode: handle of the firmware node
4573 * @propname: name of the firmware property representing the GPIO
4574 * @index: index of the GPIO to obtain for the consumer
4575 * @dflags: GPIO initialization flags
4576 * @label: label to attach to the requested GPIO
4577 *
4578 * This function can be used for drivers that get their configuration
4579 * from opaque firmware.
4580 *
4581 * The function properly finds the corresponding GPIO using whatever is the
4582 * underlying firmware interface and then makes sure that the GPIO
4583 * descriptor is requested before it is returned to the caller.
4584 *
4585 * Returns:
4586 * On successful request the GPIO pin is configured in accordance with
4587 * provided @dflags.
4588 *
4589 * In case of error an ERR_PTR() is returned.
4590 */
4591struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4592 const char *propname, int index,
4593 enum gpiod_flags dflags,
4594 const char *label)
4595{
4596 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4597 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4598 int ret;
4599
4600 if (!fwnode)
4601 return ERR_PTR(-EINVAL);
4602
4603 if (is_of_node(fwnode)) {
4604 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4605 propname, index,
4606 dflags,
4607 label);
4608 return desc;
4609 } else if (is_acpi_node(fwnode)) {
4610 struct acpi_gpio_info info;
4611
4612 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4613 if (IS_ERR(desc))
4614 return desc;
4615
4616 acpi_gpio_update_gpiod_flags(&dflags, &info);
4617 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4618 }
4619
4620 /* Currently only ACPI takes this path */
4621 ret = gpiod_request(desc, label);
4622 if (ret)
4623 return ERR_PTR(ret);
4624
4625 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4626 if (ret < 0) {
4627 gpiod_put(desc);
4628 return ERR_PTR(ret);
4629 }
4630
4631 return desc;
4632}
4633EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4634
4635/**
4636 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4637 * function
4638 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4639 * @con_id: function within the GPIO consumer
4640 * @index: index of the GPIO to obtain in the consumer
4641 * @flags: optional GPIO initialization flags
4642 *
4643 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4644 * specified index was assigned to the requested function it will return NULL.
4645 * This is convenient for drivers that need to handle optional GPIOs.
4646 */
4647struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4648 const char *con_id,
4649 unsigned int index,
4650 enum gpiod_flags flags)
4651{
4652 struct gpio_desc *desc;
4653
4654 desc = gpiod_get_index(dev, con_id, index, flags);
4655 if (IS_ERR(desc)) {
4656 if (PTR_ERR(desc) == -ENOENT)
4657 return NULL;
4658 }
4659
4660 return desc;
4661}
4662EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4663
4664/**
4665 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4666 * @desc: gpio whose value will be assigned
4667 * @name: gpio line name
4668 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4669 * of_find_gpio() or of_get_gpio_hog()
4670 * @dflags: gpiod_flags - optional GPIO initialization flags
4671 */
4672int gpiod_hog(struct gpio_desc *desc, const char *name,
4673 unsigned long lflags, enum gpiod_flags dflags)
4674{
4675 struct gpio_chip *chip;
4676 struct gpio_desc *local_desc;
4677 int hwnum;
4678 int ret;
4679
4680 chip = gpiod_to_chip(desc);
4681 hwnum = gpio_chip_hwgpio(desc);
4682
4683 local_desc = gpiochip_request_own_desc(chip, hwnum, name,
4684 lflags, dflags);
4685 if (IS_ERR(local_desc)) {
4686 ret = PTR_ERR(local_desc);
4687 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4688 name, chip->label, hwnum, ret);
4689 return ret;
4690 }
4691
4692 /* Mark GPIO as hogged so it can be identified and removed later */
4693 set_bit(FLAG_IS_HOGGED, &desc->flags);
4694
4695 pr_info("GPIO line %d (%s) hogged as %s%s\n",
4696 desc_to_gpio(desc), name,
4697 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4698 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4699 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4700
4701 return 0;
4702}
4703
4704/**
4705 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4706 * @chip: gpio chip to act on
4707 */
4708static void gpiochip_free_hogs(struct gpio_chip *chip)
4709{
4710 int id;
4711
4712 for (id = 0; id < chip->ngpio; id++) {
4713 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4714 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4715 }
4716}
4717
4718/**
4719 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4720 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4721 * @con_id: function within the GPIO consumer
4722 * @flags: optional GPIO initialization flags
4723 *
4724 * This function acquires all the GPIOs defined under a given function.
4725 *
4726 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4727 * no GPIO has been assigned to the requested function, or another IS_ERR()
4728 * code if an error occurred while trying to acquire the GPIOs.
4729 */
4730struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4731 const char *con_id,
4732 enum gpiod_flags flags)
4733{
4734 struct gpio_desc *desc;
4735 struct gpio_descs *descs;
4736 struct gpio_array *array_info = NULL;
4737 struct gpio_chip *chip;
4738 int count, bitmap_size;
4739
4740 count = gpiod_count(dev, con_id);
4741 if (count < 0)
4742 return ERR_PTR(count);
4743
4744 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4745 if (!descs)
4746 return ERR_PTR(-ENOMEM);
4747
4748 for (descs->ndescs = 0; descs->ndescs < count; ) {
4749 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4750 if (IS_ERR(desc)) {
4751 gpiod_put_array(descs);
4752 return ERR_CAST(desc);
4753 }
4754
4755 descs->desc[descs->ndescs] = desc;
4756
4757 chip = gpiod_to_chip(desc);
4758 /*
4759 * If pin hardware number of array member 0 is also 0, select
4760 * its chip as a candidate for fast bitmap processing path.
4761 */
4762 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4763 struct gpio_descs *array;
4764
4765 bitmap_size = BITS_TO_LONGS(chip->ngpio > count ?
4766 chip->ngpio : count);
4767
4768 array = kzalloc(struct_size(descs, desc, count) +
4769 struct_size(array_info, invert_mask,
4770 3 * bitmap_size), GFP_KERNEL);
4771 if (!array) {
4772 gpiod_put_array(descs);
4773 return ERR_PTR(-ENOMEM);
4774 }
4775
4776 memcpy(array, descs,
4777 struct_size(descs, desc, descs->ndescs + 1));
4778 kfree(descs);
4779
4780 descs = array;
4781 array_info = (void *)(descs->desc + count);
4782 array_info->get_mask = array_info->invert_mask +
4783 bitmap_size;
4784 array_info->set_mask = array_info->get_mask +
4785 bitmap_size;
4786
4787 array_info->desc = descs->desc;
4788 array_info->size = count;
4789 array_info->chip = chip;
4790 bitmap_set(array_info->get_mask, descs->ndescs,
4791 count - descs->ndescs);
4792 bitmap_set(array_info->set_mask, descs->ndescs,
4793 count - descs->ndescs);
4794 descs->info = array_info;
4795 }
4796 /* Unmark array members which don't belong to the 'fast' chip */
4797 if (array_info && array_info->chip != chip) {
4798 __clear_bit(descs->ndescs, array_info->get_mask);
4799 __clear_bit(descs->ndescs, array_info->set_mask);
4800 }
4801 /*
4802 * Detect array members which belong to the 'fast' chip
4803 * but their pins are not in hardware order.
4804 */
4805 else if (array_info &&
4806 gpio_chip_hwgpio(desc) != descs->ndescs) {
4807 /*
4808 * Don't use fast path if all array members processed so
4809 * far belong to the same chip as this one but its pin
4810 * hardware number is different from its array index.
4811 */
4812 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4813 array_info = NULL;
4814 } else {
4815 __clear_bit(descs->ndescs,
4816 array_info->get_mask);
4817 __clear_bit(descs->ndescs,
4818 array_info->set_mask);
4819 }
4820 } else if (array_info) {
4821 /* Exclude open drain or open source from fast output */
4822 if (gpiochip_line_is_open_drain(chip, descs->ndescs) ||
4823 gpiochip_line_is_open_source(chip, descs->ndescs))
4824 __clear_bit(descs->ndescs,
4825 array_info->set_mask);
4826 /* Identify 'fast' pins which require invertion */
4827 if (gpiod_is_active_low(desc))
4828 __set_bit(descs->ndescs,
4829 array_info->invert_mask);
4830 }
4831
4832 descs->ndescs++;
4833 }
4834 if (array_info)
4835 dev_dbg(dev,
4836 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4837 array_info->chip->label, array_info->size,
4838 *array_info->get_mask, *array_info->set_mask,
4839 *array_info->invert_mask);
4840 return descs;
4841}
4842EXPORT_SYMBOL_GPL(gpiod_get_array);
4843
4844/**
4845 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4846 * function
4847 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4848 * @con_id: function within the GPIO consumer
4849 * @flags: optional GPIO initialization flags
4850 *
4851 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4852 * assigned to the requested function it will return NULL.
4853 */
4854struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4855 const char *con_id,
4856 enum gpiod_flags flags)
4857{
4858 struct gpio_descs *descs;
4859
4860 descs = gpiod_get_array(dev, con_id, flags);
4861 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4862 return NULL;
4863
4864 return descs;
4865}
4866EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4867
4868/**
4869 * gpiod_put - dispose of a GPIO descriptor
4870 * @desc: GPIO descriptor to dispose of
4871 *
4872 * No descriptor can be used after gpiod_put() has been called on it.
4873 */
4874void gpiod_put(struct gpio_desc *desc)
4875{
4876 if (desc)
4877 gpiod_free(desc);
4878}
4879EXPORT_SYMBOL_GPL(gpiod_put);
4880
4881/**
4882 * gpiod_put_array - dispose of multiple GPIO descriptors
4883 * @descs: struct gpio_descs containing an array of descriptors
4884 */
4885void gpiod_put_array(struct gpio_descs *descs)
4886{
4887 unsigned int i;
4888
4889 for (i = 0; i < descs->ndescs; i++)
4890 gpiod_put(descs->desc[i]);
4891
4892 kfree(descs);
4893}
4894EXPORT_SYMBOL_GPL(gpiod_put_array);
4895
4896static int __init gpiolib_dev_init(void)
4897{
4898 int ret;
4899
4900 /* Register GPIO sysfs bus */
4901 ret = bus_register(&gpio_bus_type);
4902 if (ret < 0) {
4903 pr_err("gpiolib: could not register GPIO bus type\n");
4904 return ret;
4905 }
4906
4907 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4908 if (ret < 0) {
4909 pr_err("gpiolib: failed to allocate char dev region\n");
4910 bus_unregister(&gpio_bus_type);
4911 } else {
4912 gpiolib_initialized = true;
4913 gpiochip_setup_devs();
4914 }
4915 return ret;
4916}
4917core_initcall(gpiolib_dev_init);
4918
4919#ifdef CONFIG_DEBUG_FS
4920
4921static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4922{
4923 unsigned i;
4924 struct gpio_chip *chip = gdev->chip;
4925 unsigned gpio = gdev->base;
4926 struct gpio_desc *gdesc = &gdev->descs[0];
4927 bool is_out;
4928 bool is_irq;
4929 bool active_low;
4930
4931 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4932 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4933 if (gdesc->name) {
4934 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4935 gpio, gdesc->name);
4936 }
4937 continue;
4938 }
4939
4940 gpiod_get_direction(gdesc);
4941 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4942 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4943 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4944 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4945 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4946 is_out ? "out" : "in ",
4947 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ",
4948 is_irq ? "IRQ " : "",
4949 active_low ? "ACTIVE LOW" : "");
4950 seq_printf(s, "\n");
4951 }
4952}
4953
4954static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4955{
4956 unsigned long flags;
4957 struct gpio_device *gdev = NULL;
4958 loff_t index = *pos;
4959
4960 s->private = "";
4961
4962 spin_lock_irqsave(&gpio_lock, flags);
4963 list_for_each_entry(gdev, &gpio_devices, list)
4964 if (index-- == 0) {
4965 spin_unlock_irqrestore(&gpio_lock, flags);
4966 return gdev;
4967 }
4968 spin_unlock_irqrestore(&gpio_lock, flags);
4969
4970 return NULL;
4971}
4972
4973static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4974{
4975 unsigned long flags;
4976 struct gpio_device *gdev = v;
4977 void *ret = NULL;
4978
4979 spin_lock_irqsave(&gpio_lock, flags);
4980 if (list_is_last(&gdev->list, &gpio_devices))
4981 ret = NULL;
4982 else
4983 ret = list_entry(gdev->list.next, struct gpio_device, list);
4984 spin_unlock_irqrestore(&gpio_lock, flags);
4985
4986 s->private = "\n";
4987 ++*pos;
4988
4989 return ret;
4990}
4991
4992static void gpiolib_seq_stop(struct seq_file *s, void *v)
4993{
4994}
4995
4996static int gpiolib_seq_show(struct seq_file *s, void *v)
4997{
4998 struct gpio_device *gdev = v;
4999 struct gpio_chip *chip = gdev->chip;
5000 struct device *parent;
5001
5002 if (!chip) {
5003 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
5004 dev_name(&gdev->dev));
5005 return 0;
5006 }
5007
5008 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
5009 dev_name(&gdev->dev),
5010 gdev->base, gdev->base + gdev->ngpio - 1);
5011 parent = chip->parent;
5012 if (parent)
5013 seq_printf(s, ", parent: %s/%s",
5014 parent->bus ? parent->bus->name : "no-bus",
5015 dev_name(parent));
5016 if (chip->label)
5017 seq_printf(s, ", %s", chip->label);
5018 if (chip->can_sleep)
5019 seq_printf(s, ", can sleep");
5020 seq_printf(s, ":\n");
5021
5022 if (chip->dbg_show)
5023 chip->dbg_show(s, chip);
5024 else
5025 gpiolib_dbg_show(s, gdev);
5026
5027 return 0;
5028}
5029
5030static const struct seq_operations gpiolib_seq_ops = {
5031 .start = gpiolib_seq_start,
5032 .next = gpiolib_seq_next,
5033 .stop = gpiolib_seq_stop,
5034 .show = gpiolib_seq_show,
5035};
5036
5037static int gpiolib_open(struct inode *inode, struct file *file)
5038{
5039 return seq_open(file, &gpiolib_seq_ops);
5040}
5041
5042static const struct file_operations gpiolib_operations = {
5043 .owner = THIS_MODULE,
5044 .open = gpiolib_open,
5045 .read = seq_read,
5046 .llseek = seq_lseek,
5047 .release = seq_release,
5048};
5049
5050static int __init gpiolib_debugfs_init(void)
5051{
5052 /* /sys/kernel/debug/gpio */
5053 debugfs_create_file("gpio", S_IFREG | S_IRUGO, NULL, NULL,
5054 &gpiolib_operations);
5055 return 0;
5056}
5057subsys_initcall(gpiolib_debugfs_init);
5058
5059#endif /* DEBUG_FS */