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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#define FLAG_OPEN_DRAIN 8 /* Gpio is open drain type */
62#define FLAG_OPEN_SOURCE 9 /* Gpio is open source type */
63
64#define ID_SHIFT 16 /* add new flags before this one */
65
66#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1)
67#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
68
69#ifdef CONFIG_DEBUG_FS
70 const char *label;
71#endif
72};
73static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
74
75#ifdef CONFIG_GPIO_SYSFS
76static DEFINE_IDR(dirent_idr);
77#endif
78
79static inline void desc_set_label(struct gpio_desc *d, const char *label)
80{
81#ifdef CONFIG_DEBUG_FS
82 d->label = label;
83#endif
84}
85
86/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
87 * when setting direction, and otherwise illegal. Until board setup code
88 * and drivers use explicit requests everywhere (which won't happen when
89 * those calls have no teeth) we can't avoid autorequesting. This nag
90 * message should motivate switching to explicit requests... so should
91 * the weaker cleanup after faults, compared to gpio_request().
92 *
93 * NOTE: the autorequest mechanism is going away; at this point it's
94 * only "legal" in the sense that (old) code using it won't break yet,
95 * but instead only triggers a WARN() stack dump.
96 */
97static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset)
98{
99 const struct gpio_chip *chip = desc->chip;
100 const int gpio = chip->base + offset;
101
102 if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,
103 "autorequest GPIO-%d\n", gpio)) {
104 if (!try_module_get(chip->owner)) {
105 pr_err("GPIO-%d: module can't be gotten \n", gpio);
106 clear_bit(FLAG_REQUESTED, &desc->flags);
107 /* lose */
108 return -EIO;
109 }
110 desc_set_label(desc, "[auto]");
111 /* caller must chip->request() w/o spinlock */
112 if (chip->request)
113 return 1;
114 }
115 return 0;
116}
117
118/* caller holds gpio_lock *OR* gpio is marked as requested */
119struct gpio_chip *gpio_to_chip(unsigned gpio)
120{
121 return gpio_desc[gpio].chip;
122}
123
124/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
125static int gpiochip_find_base(int ngpio)
126{
127 int i;
128 int spare = 0;
129 int base = -ENOSPC;
130
131 for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) {
132 struct gpio_desc *desc = &gpio_desc[i];
133 struct gpio_chip *chip = desc->chip;
134
135 if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) {
136 spare++;
137 if (spare == ngpio) {
138 base = i;
139 break;
140 }
141 } else {
142 spare = 0;
143 if (chip)
144 i -= chip->ngpio - 1;
145 }
146 }
147
148 if (gpio_is_valid(base))
149 pr_debug("%s: found new base at %d\n", __func__, base);
150 return base;
151}
152
153/**
154 * gpiochip_reserve() - reserve range of gpios to use with platform code only
155 * @start: starting gpio number
156 * @ngpio: number of gpios to reserve
157 * Context: platform init, potentially before irqs or kmalloc will work
158 *
159 * Returns a negative errno if any gpio within the range is already reserved
160 * or registered, else returns zero as a success code. Use this function
161 * to mark a range of gpios as unavailable for dynamic gpio number allocation,
162 * for example because its driver support is not yet loaded.
163 */
164int __init gpiochip_reserve(int start, int ngpio)
165{
166 int ret = 0;
167 unsigned long flags;
168 int i;
169
170 if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1))
171 return -EINVAL;
172
173 spin_lock_irqsave(&gpio_lock, flags);
174
175 for (i = start; i < start + ngpio; i++) {
176 struct gpio_desc *desc = &gpio_desc[i];
177
178 if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) {
179 ret = -EBUSY;
180 goto err;
181 }
182
183 set_bit(FLAG_RESERVED, &desc->flags);
184 }
185
186 pr_debug("%s: reserved gpios from %d to %d\n",
187 __func__, start, start + ngpio - 1);
188err:
189 spin_unlock_irqrestore(&gpio_lock, flags);
190
191 return ret;
192}
193
194#ifdef CONFIG_GPIO_SYSFS
195
196/* lock protects against unexport_gpio() being called while
197 * sysfs files are active.
198 */
199static DEFINE_MUTEX(sysfs_lock);
200
201/*
202 * /sys/class/gpio/gpioN... only for GPIOs that are exported
203 * /direction
204 * * MAY BE OMITTED if kernel won't allow direction changes
205 * * is read/write as "in" or "out"
206 * * may also be written as "high" or "low", initializing
207 * output value as specified ("out" implies "low")
208 * /value
209 * * always readable, subject to hardware behavior
210 * * may be writable, as zero/nonzero
211 * /edge
212 * * configures behavior of poll(2) on /value
213 * * available only if pin can generate IRQs on input
214 * * is read/write as "none", "falling", "rising", or "both"
215 * /active_low
216 * * configures polarity of /value
217 * * is read/write as zero/nonzero
218 * * also affects existing and subsequent "falling" and "rising"
219 * /edge configuration
220 */
221
222static ssize_t gpio_direction_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
225 const struct gpio_desc *desc = dev_get_drvdata(dev);
226 ssize_t status;
227
228 mutex_lock(&sysfs_lock);
229
230 if (!test_bit(FLAG_EXPORT, &desc->flags))
231 status = -EIO;
232 else
233 status = sprintf(buf, "%s\n",
234 test_bit(FLAG_IS_OUT, &desc->flags)
235 ? "out" : "in");
236
237 mutex_unlock(&sysfs_lock);
238 return status;
239}
240
241static ssize_t gpio_direction_store(struct device *dev,
242 struct device_attribute *attr, const char *buf, size_t size)
243{
244 const struct gpio_desc *desc = dev_get_drvdata(dev);
245 unsigned gpio = desc - gpio_desc;
246 ssize_t status;
247
248 mutex_lock(&sysfs_lock);
249
250 if (!test_bit(FLAG_EXPORT, &desc->flags))
251 status = -EIO;
252 else if (sysfs_streq(buf, "high"))
253 status = gpio_direction_output(gpio, 1);
254 else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
255 status = gpio_direction_output(gpio, 0);
256 else if (sysfs_streq(buf, "in"))
257 status = gpio_direction_input(gpio);
258 else
259 status = -EINVAL;
260
261 mutex_unlock(&sysfs_lock);
262 return status ? : size;
263}
264
265static /* const */ DEVICE_ATTR(direction, 0644,
266 gpio_direction_show, gpio_direction_store);
267
268static ssize_t gpio_value_show(struct device *dev,
269 struct device_attribute *attr, char *buf)
270{
271 const struct gpio_desc *desc = dev_get_drvdata(dev);
272 unsigned gpio = desc - gpio_desc;
273 ssize_t status;
274
275 mutex_lock(&sysfs_lock);
276
277 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
278 status = -EIO;
279 } else {
280 int value;
281
282 value = !!gpio_get_value_cansleep(gpio);
283 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
284 value = !value;
285
286 status = sprintf(buf, "%d\n", value);
287 }
288
289 mutex_unlock(&sysfs_lock);
290 return status;
291}
292
293static ssize_t gpio_value_store(struct device *dev,
294 struct device_attribute *attr, const char *buf, size_t size)
295{
296 const struct gpio_desc *desc = dev_get_drvdata(dev);
297 unsigned gpio = desc - gpio_desc;
298 ssize_t status;
299
300 mutex_lock(&sysfs_lock);
301
302 if (!test_bit(FLAG_EXPORT, &desc->flags))
303 status = -EIO;
304 else if (!test_bit(FLAG_IS_OUT, &desc->flags))
305 status = -EPERM;
306 else {
307 long value;
308
309 status = strict_strtol(buf, 0, &value);
310 if (status == 0) {
311 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
312 value = !value;
313 gpio_set_value_cansleep(gpio, value != 0);
314 status = size;
315 }
316 }
317
318 mutex_unlock(&sysfs_lock);
319 return status;
320}
321
322static const DEVICE_ATTR(value, 0644,
323 gpio_value_show, gpio_value_store);
324
325static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
326{
327 struct sysfs_dirent *value_sd = priv;
328
329 sysfs_notify_dirent(value_sd);
330 return IRQ_HANDLED;
331}
332
333static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
334 unsigned long gpio_flags)
335{
336 struct sysfs_dirent *value_sd;
337 unsigned long irq_flags;
338 int ret, irq, id;
339
340 if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
341 return 0;
342
343 irq = gpio_to_irq(desc - gpio_desc);
344 if (irq < 0)
345 return -EIO;
346
347 id = desc->flags >> ID_SHIFT;
348 value_sd = idr_find(&dirent_idr, id);
349 if (value_sd)
350 free_irq(irq, value_sd);
351
352 desc->flags &= ~GPIO_TRIGGER_MASK;
353
354 if (!gpio_flags) {
355 ret = 0;
356 goto free_id;
357 }
358
359 irq_flags = IRQF_SHARED;
360 if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
361 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
362 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
363 if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
364 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
365 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
366
367 if (!value_sd) {
368 value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value");
369 if (!value_sd) {
370 ret = -ENODEV;
371 goto err_out;
372 }
373
374 do {
375 ret = -ENOMEM;
376 if (idr_pre_get(&dirent_idr, GFP_KERNEL))
377 ret = idr_get_new_above(&dirent_idr, value_sd,
378 1, &id);
379 } while (ret == -EAGAIN);
380
381 if (ret)
382 goto free_sd;
383
384 desc->flags &= GPIO_FLAGS_MASK;
385 desc->flags |= (unsigned long)id << ID_SHIFT;
386
387 if (desc->flags >> ID_SHIFT != id) {
388 ret = -ERANGE;
389 goto free_id;
390 }
391 }
392
393 ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
394 "gpiolib", value_sd);
395 if (ret < 0)
396 goto free_id;
397
398 desc->flags |= gpio_flags;
399 return 0;
400
401free_id:
402 idr_remove(&dirent_idr, id);
403 desc->flags &= GPIO_FLAGS_MASK;
404free_sd:
405 if (value_sd)
406 sysfs_put(value_sd);
407err_out:
408 return ret;
409}
410
411static const struct {
412 const char *name;
413 unsigned long flags;
414} trigger_types[] = {
415 { "none", 0 },
416 { "falling", BIT(FLAG_TRIG_FALL) },
417 { "rising", BIT(FLAG_TRIG_RISE) },
418 { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
419};
420
421static ssize_t gpio_edge_show(struct device *dev,
422 struct device_attribute *attr, char *buf)
423{
424 const struct gpio_desc *desc = dev_get_drvdata(dev);
425 ssize_t status;
426
427 mutex_lock(&sysfs_lock);
428
429 if (!test_bit(FLAG_EXPORT, &desc->flags))
430 status = -EIO;
431 else {
432 int i;
433
434 status = 0;
435 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
436 if ((desc->flags & GPIO_TRIGGER_MASK)
437 == trigger_types[i].flags) {
438 status = sprintf(buf, "%s\n",
439 trigger_types[i].name);
440 break;
441 }
442 }
443
444 mutex_unlock(&sysfs_lock);
445 return status;
446}
447
448static ssize_t gpio_edge_store(struct device *dev,
449 struct device_attribute *attr, const char *buf, size_t size)
450{
451 struct gpio_desc *desc = dev_get_drvdata(dev);
452 ssize_t status;
453 int i;
454
455 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
456 if (sysfs_streq(trigger_types[i].name, buf))
457 goto found;
458 return -EINVAL;
459
460found:
461 mutex_lock(&sysfs_lock);
462
463 if (!test_bit(FLAG_EXPORT, &desc->flags))
464 status = -EIO;
465 else {
466 status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
467 if (!status)
468 status = size;
469 }
470
471 mutex_unlock(&sysfs_lock);
472
473 return status;
474}
475
476static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
477
478static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
479 int value)
480{
481 int status = 0;
482
483 if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
484 return 0;
485
486 if (value)
487 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
488 else
489 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
490
491 /* reconfigure poll(2) support if enabled on one edge only */
492 if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^
493 !!test_bit(FLAG_TRIG_FALL, &desc->flags))) {
494 unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK;
495
496 gpio_setup_irq(desc, dev, 0);
497 status = gpio_setup_irq(desc, dev, trigger_flags);
498 }
499
500 return status;
501}
502
503static ssize_t gpio_active_low_show(struct device *dev,
504 struct device_attribute *attr, char *buf)
505{
506 const struct gpio_desc *desc = dev_get_drvdata(dev);
507 ssize_t status;
508
509 mutex_lock(&sysfs_lock);
510
511 if (!test_bit(FLAG_EXPORT, &desc->flags))
512 status = -EIO;
513 else
514 status = sprintf(buf, "%d\n",
515 !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
516
517 mutex_unlock(&sysfs_lock);
518
519 return status;
520}
521
522static ssize_t gpio_active_low_store(struct device *dev,
523 struct device_attribute *attr, const char *buf, size_t size)
524{
525 struct gpio_desc *desc = dev_get_drvdata(dev);
526 ssize_t status;
527
528 mutex_lock(&sysfs_lock);
529
530 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
531 status = -EIO;
532 } else {
533 long value;
534
535 status = strict_strtol(buf, 0, &value);
536 if (status == 0)
537 status = sysfs_set_active_low(desc, dev, value != 0);
538 }
539
540 mutex_unlock(&sysfs_lock);
541
542 return status ? : size;
543}
544
545static const DEVICE_ATTR(active_low, 0644,
546 gpio_active_low_show, gpio_active_low_store);
547
548static const struct attribute *gpio_attrs[] = {
549 &dev_attr_value.attr,
550 &dev_attr_active_low.attr,
551 NULL,
552};
553
554static const struct attribute_group gpio_attr_group = {
555 .attrs = (struct attribute **) gpio_attrs,
556};
557
558/*
559 * /sys/class/gpio/gpiochipN/
560 * /base ... matching gpio_chip.base (N)
561 * /label ... matching gpio_chip.label
562 * /ngpio ... matching gpio_chip.ngpio
563 */
564
565static ssize_t chip_base_show(struct device *dev,
566 struct device_attribute *attr, char *buf)
567{
568 const struct gpio_chip *chip = dev_get_drvdata(dev);
569
570 return sprintf(buf, "%d\n", chip->base);
571}
572static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
573
574static ssize_t chip_label_show(struct device *dev,
575 struct device_attribute *attr, char *buf)
576{
577 const struct gpio_chip *chip = dev_get_drvdata(dev);
578
579 return sprintf(buf, "%s\n", chip->label ? : "");
580}
581static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
582
583static ssize_t chip_ngpio_show(struct device *dev,
584 struct device_attribute *attr, char *buf)
585{
586 const struct gpio_chip *chip = dev_get_drvdata(dev);
587
588 return sprintf(buf, "%u\n", chip->ngpio);
589}
590static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
591
592static const struct attribute *gpiochip_attrs[] = {
593 &dev_attr_base.attr,
594 &dev_attr_label.attr,
595 &dev_attr_ngpio.attr,
596 NULL,
597};
598
599static const struct attribute_group gpiochip_attr_group = {
600 .attrs = (struct attribute **) gpiochip_attrs,
601};
602
603/*
604 * /sys/class/gpio/export ... write-only
605 * integer N ... number of GPIO to export (full access)
606 * /sys/class/gpio/unexport ... write-only
607 * integer N ... number of GPIO to unexport
608 */
609static ssize_t export_store(struct class *class,
610 struct class_attribute *attr,
611 const char *buf, size_t len)
612{
613 long gpio;
614 int status;
615
616 status = strict_strtol(buf, 0, &gpio);
617 if (status < 0)
618 goto done;
619
620 /* No extra locking here; FLAG_SYSFS just signifies that the
621 * request and export were done by on behalf of userspace, so
622 * they may be undone on its behalf too.
623 */
624
625 status = gpio_request(gpio, "sysfs");
626 if (status < 0)
627 goto done;
628
629 status = gpio_export(gpio, true);
630 if (status < 0)
631 gpio_free(gpio);
632 else
633 set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags);
634
635done:
636 if (status)
637 pr_debug("%s: status %d\n", __func__, status);
638 return status ? : len;
639}
640
641static ssize_t unexport_store(struct class *class,
642 struct class_attribute *attr,
643 const char *buf, size_t len)
644{
645 long gpio;
646 int status;
647
648 status = strict_strtol(buf, 0, &gpio);
649 if (status < 0)
650 goto done;
651
652 status = -EINVAL;
653
654 /* reject bogus commands (gpio_unexport ignores them) */
655 if (!gpio_is_valid(gpio))
656 goto done;
657
658 /* No extra locking here; FLAG_SYSFS just signifies that the
659 * request and export were done by on behalf of userspace, so
660 * they may be undone on its behalf too.
661 */
662 if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) {
663 status = 0;
664 gpio_free(gpio);
665 }
666done:
667 if (status)
668 pr_debug("%s: status %d\n", __func__, status);
669 return status ? : len;
670}
671
672static struct class_attribute gpio_class_attrs[] = {
673 __ATTR(export, 0200, NULL, export_store),
674 __ATTR(unexport, 0200, NULL, unexport_store),
675 __ATTR_NULL,
676};
677
678static struct class gpio_class = {
679 .name = "gpio",
680 .owner = THIS_MODULE,
681
682 .class_attrs = gpio_class_attrs,
683};
684
685
686/**
687 * gpio_export - export a GPIO through sysfs
688 * @gpio: gpio to make available, already requested
689 * @direction_may_change: true if userspace may change gpio direction
690 * Context: arch_initcall or later
691 *
692 * When drivers want to make a GPIO accessible to userspace after they
693 * have requested it -- perhaps while debugging, or as part of their
694 * public interface -- they may use this routine. If the GPIO can
695 * change direction (some can't) and the caller allows it, userspace
696 * will see "direction" sysfs attribute which may be used to change
697 * the gpio's direction. A "value" attribute will always be provided.
698 *
699 * Returns zero on success, else an error.
700 */
701int gpio_export(unsigned gpio, bool direction_may_change)
702{
703 unsigned long flags;
704 struct gpio_desc *desc;
705 int status = -EINVAL;
706 const char *ioname = NULL;
707
708 /* can't export until sysfs is available ... */
709 if (!gpio_class.p) {
710 pr_debug("%s: called too early!\n", __func__);
711 return -ENOENT;
712 }
713
714 if (!gpio_is_valid(gpio))
715 goto done;
716
717 mutex_lock(&sysfs_lock);
718
719 spin_lock_irqsave(&gpio_lock, flags);
720 desc = &gpio_desc[gpio];
721 if (test_bit(FLAG_REQUESTED, &desc->flags)
722 && !test_bit(FLAG_EXPORT, &desc->flags)) {
723 status = 0;
724 if (!desc->chip->direction_input
725 || !desc->chip->direction_output)
726 direction_may_change = false;
727 }
728 spin_unlock_irqrestore(&gpio_lock, flags);
729
730 if (desc->chip->names && desc->chip->names[gpio - desc->chip->base])
731 ioname = desc->chip->names[gpio - desc->chip->base];
732
733 if (status == 0) {
734 struct device *dev;
735
736 dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
737 desc, ioname ? ioname : "gpio%u", gpio);
738 if (!IS_ERR(dev)) {
739 status = sysfs_create_group(&dev->kobj,
740 &gpio_attr_group);
741
742 if (!status && direction_may_change)
743 status = device_create_file(dev,
744 &dev_attr_direction);
745
746 if (!status && gpio_to_irq(gpio) >= 0
747 && (direction_may_change
748 || !test_bit(FLAG_IS_OUT,
749 &desc->flags)))
750 status = device_create_file(dev,
751 &dev_attr_edge);
752
753 if (status != 0)
754 device_unregister(dev);
755 } else
756 status = PTR_ERR(dev);
757 if (status == 0)
758 set_bit(FLAG_EXPORT, &desc->flags);
759 }
760
761 mutex_unlock(&sysfs_lock);
762
763done:
764 if (status)
765 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
766
767 return status;
768}
769EXPORT_SYMBOL_GPL(gpio_export);
770
771static int match_export(struct device *dev, void *data)
772{
773 return dev_get_drvdata(dev) == data;
774}
775
776/**
777 * gpio_export_link - create a sysfs link to an exported GPIO node
778 * @dev: device under which to create symlink
779 * @name: name of the symlink
780 * @gpio: gpio to create symlink to, already exported
781 *
782 * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
783 * node. Caller is responsible for unlinking.
784 *
785 * Returns zero on success, else an error.
786 */
787int gpio_export_link(struct device *dev, const char *name, unsigned gpio)
788{
789 struct gpio_desc *desc;
790 int status = -EINVAL;
791
792 if (!gpio_is_valid(gpio))
793 goto done;
794
795 mutex_lock(&sysfs_lock);
796
797 desc = &gpio_desc[gpio];
798
799 if (test_bit(FLAG_EXPORT, &desc->flags)) {
800 struct device *tdev;
801
802 tdev = class_find_device(&gpio_class, NULL, desc, match_export);
803 if (tdev != NULL) {
804 status = sysfs_create_link(&dev->kobj, &tdev->kobj,
805 name);
806 } else {
807 status = -ENODEV;
808 }
809 }
810
811 mutex_unlock(&sysfs_lock);
812
813done:
814 if (status)
815 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
816
817 return status;
818}
819EXPORT_SYMBOL_GPL(gpio_export_link);
820
821
822/**
823 * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value
824 * @gpio: gpio to change
825 * @value: non-zero to use active low, i.e. inverted values
826 *
827 * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute.
828 * The GPIO does not have to be exported yet. If poll(2) support has
829 * been enabled for either rising or falling edge, it will be
830 * reconfigured to follow the new polarity.
831 *
832 * Returns zero on success, else an error.
833 */
834int gpio_sysfs_set_active_low(unsigned gpio, int value)
835{
836 struct gpio_desc *desc;
837 struct device *dev = NULL;
838 int status = -EINVAL;
839
840 if (!gpio_is_valid(gpio))
841 goto done;
842
843 mutex_lock(&sysfs_lock);
844
845 desc = &gpio_desc[gpio];
846
847 if (test_bit(FLAG_EXPORT, &desc->flags)) {
848 dev = class_find_device(&gpio_class, NULL, desc, match_export);
849 if (dev == NULL) {
850 status = -ENODEV;
851 goto unlock;
852 }
853 }
854
855 status = sysfs_set_active_low(desc, dev, value);
856
857unlock:
858 mutex_unlock(&sysfs_lock);
859
860done:
861 if (status)
862 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
863
864 return status;
865}
866EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low);
867
868/**
869 * gpio_unexport - reverse effect of gpio_export()
870 * @gpio: gpio to make unavailable
871 *
872 * This is implicit on gpio_free().
873 */
874void gpio_unexport(unsigned gpio)
875{
876 struct gpio_desc *desc;
877 int status = 0;
878 struct device *dev = NULL;
879
880 if (!gpio_is_valid(gpio)) {
881 status = -EINVAL;
882 goto done;
883 }
884
885 mutex_lock(&sysfs_lock);
886
887 desc = &gpio_desc[gpio];
888
889 if (test_bit(FLAG_EXPORT, &desc->flags)) {
890
891 dev = class_find_device(&gpio_class, NULL, desc, match_export);
892 if (dev) {
893 gpio_setup_irq(desc, dev, 0);
894 clear_bit(FLAG_EXPORT, &desc->flags);
895 } else
896 status = -ENODEV;
897 }
898
899 mutex_unlock(&sysfs_lock);
900 if (dev) {
901 device_unregister(dev);
902 put_device(dev);
903 }
904done:
905 if (status)
906 pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
907}
908EXPORT_SYMBOL_GPL(gpio_unexport);
909
910static int gpiochip_export(struct gpio_chip *chip)
911{
912 int status;
913 struct device *dev;
914
915 /* Many systems register gpio chips for SOC support very early,
916 * before driver model support is available. In those cases we
917 * export this later, in gpiolib_sysfs_init() ... here we just
918 * verify that _some_ field of gpio_class got initialized.
919 */
920 if (!gpio_class.p)
921 return 0;
922
923 /* use chip->base for the ID; it's already known to be unique */
924 mutex_lock(&sysfs_lock);
925 dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip,
926 "gpiochip%d", chip->base);
927 if (!IS_ERR(dev)) {
928 status = sysfs_create_group(&dev->kobj,
929 &gpiochip_attr_group);
930 } else
931 status = PTR_ERR(dev);
932 chip->exported = (status == 0);
933 mutex_unlock(&sysfs_lock);
934
935 if (status) {
936 unsigned long flags;
937 unsigned gpio;
938
939 spin_lock_irqsave(&gpio_lock, flags);
940 gpio = chip->base;
941 while (gpio_desc[gpio].chip == chip)
942 gpio_desc[gpio++].chip = NULL;
943 spin_unlock_irqrestore(&gpio_lock, flags);
944
945 pr_debug("%s: chip %s status %d\n", __func__,
946 chip->label, status);
947 }
948
949 return status;
950}
951
952static void gpiochip_unexport(struct gpio_chip *chip)
953{
954 int status;
955 struct device *dev;
956
957 mutex_lock(&sysfs_lock);
958 dev = class_find_device(&gpio_class, NULL, chip, match_export);
959 if (dev) {
960 put_device(dev);
961 device_unregister(dev);
962 chip->exported = 0;
963 status = 0;
964 } else
965 status = -ENODEV;
966 mutex_unlock(&sysfs_lock);
967
968 if (status)
969 pr_debug("%s: chip %s status %d\n", __func__,
970 chip->label, status);
971}
972
973static int __init gpiolib_sysfs_init(void)
974{
975 int status;
976 unsigned long flags;
977 unsigned gpio;
978
979 status = class_register(&gpio_class);
980 if (status < 0)
981 return status;
982
983 /* Scan and register the gpio_chips which registered very
984 * early (e.g. before the class_register above was called).
985 *
986 * We run before arch_initcall() so chip->dev nodes can have
987 * registered, and so arch_initcall() can always gpio_export().
988 */
989 spin_lock_irqsave(&gpio_lock, flags);
990 for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) {
991 struct gpio_chip *chip;
992
993 chip = gpio_desc[gpio].chip;
994 if (!chip || chip->exported)
995 continue;
996
997 spin_unlock_irqrestore(&gpio_lock, flags);
998 status = gpiochip_export(chip);
999 spin_lock_irqsave(&gpio_lock, flags);
1000 }
1001 spin_unlock_irqrestore(&gpio_lock, flags);
1002
1003
1004 return status;
1005}
1006postcore_initcall(gpiolib_sysfs_init);
1007
1008#else
1009static inline int gpiochip_export(struct gpio_chip *chip)
1010{
1011 return 0;
1012}
1013
1014static inline void gpiochip_unexport(struct gpio_chip *chip)
1015{
1016}
1017
1018#endif /* CONFIG_GPIO_SYSFS */
1019
1020/**
1021 * gpiochip_add() - register a gpio_chip
1022 * @chip: the chip to register, with chip->base initialized
1023 * Context: potentially before irqs or kmalloc will work
1024 *
1025 * Returns a negative errno if the chip can't be registered, such as
1026 * because the chip->base is invalid or already associated with a
1027 * different chip. Otherwise it returns zero as a success code.
1028 *
1029 * When gpiochip_add() is called very early during boot, so that GPIOs
1030 * can be freely used, the chip->dev device must be registered before
1031 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1032 * for GPIOs will fail rudely.
1033 *
1034 * If chip->base is negative, this requests dynamic assignment of
1035 * a range of valid GPIOs.
1036 */
1037int gpiochip_add(struct gpio_chip *chip)
1038{
1039 unsigned long flags;
1040 int status = 0;
1041 unsigned id;
1042 int base = chip->base;
1043
1044 if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
1045 && base >= 0) {
1046 status = -EINVAL;
1047 goto fail;
1048 }
1049
1050 spin_lock_irqsave(&gpio_lock, flags);
1051
1052 if (base < 0) {
1053 base = gpiochip_find_base(chip->ngpio);
1054 if (base < 0) {
1055 status = base;
1056 goto unlock;
1057 }
1058 chip->base = base;
1059 }
1060
1061 /* these GPIO numbers must not be managed by another gpio_chip */
1062 for (id = base; id < base + chip->ngpio; id++) {
1063 if (gpio_desc[id].chip != NULL) {
1064 status = -EBUSY;
1065 break;
1066 }
1067 }
1068 if (status == 0) {
1069 for (id = base; id < base + chip->ngpio; id++) {
1070 gpio_desc[id].chip = chip;
1071
1072 /* REVISIT: most hardware initializes GPIOs as
1073 * inputs (often with pullups enabled) so power
1074 * usage is minimized. Linux code should set the
1075 * gpio direction first thing; but until it does,
1076 * we may expose the wrong direction in sysfs.
1077 */
1078 gpio_desc[id].flags = !chip->direction_input
1079 ? (1 << FLAG_IS_OUT)
1080 : 0;
1081 }
1082 }
1083
1084 of_gpiochip_add(chip);
1085
1086unlock:
1087 spin_unlock_irqrestore(&gpio_lock, flags);
1088
1089 if (status)
1090 goto fail;
1091
1092 status = gpiochip_export(chip);
1093 if (status)
1094 goto fail;
1095
1096 pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n",
1097 chip->base, chip->base + chip->ngpio - 1,
1098 chip->label ? : "generic");
1099
1100 return 0;
1101fail:
1102 /* failures here can mean systems won't boot... */
1103 pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n",
1104 chip->base, chip->base + chip->ngpio - 1,
1105 chip->label ? : "generic");
1106 return status;
1107}
1108EXPORT_SYMBOL_GPL(gpiochip_add);
1109
1110/**
1111 * gpiochip_remove() - unregister a gpio_chip
1112 * @chip: the chip to unregister
1113 *
1114 * A gpio_chip with any GPIOs still requested may not be removed.
1115 */
1116int gpiochip_remove(struct gpio_chip *chip)
1117{
1118 unsigned long flags;
1119 int status = 0;
1120 unsigned id;
1121
1122 spin_lock_irqsave(&gpio_lock, flags);
1123
1124 of_gpiochip_remove(chip);
1125
1126 for (id = chip->base; id < chip->base + chip->ngpio; id++) {
1127 if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {
1128 status = -EBUSY;
1129 break;
1130 }
1131 }
1132 if (status == 0) {
1133 for (id = chip->base; id < chip->base + chip->ngpio; id++)
1134 gpio_desc[id].chip = NULL;
1135 }
1136
1137 spin_unlock_irqrestore(&gpio_lock, flags);
1138
1139 if (status == 0)
1140 gpiochip_unexport(chip);
1141
1142 return status;
1143}
1144EXPORT_SYMBOL_GPL(gpiochip_remove);
1145
1146/**
1147 * gpiochip_find() - iterator for locating a specific gpio_chip
1148 * @data: data to pass to match function
1149 * @callback: Callback function to check gpio_chip
1150 *
1151 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1152 * determined by a user supplied @match callback. The callback should return
1153 * 0 if the device doesn't match and non-zero if it does. If the callback is
1154 * non-zero, this function will return to the caller and not iterate over any
1155 * more gpio_chips.
1156 */
1157struct gpio_chip *gpiochip_find(void *data,
1158 int (*match)(struct gpio_chip *chip,
1159 void *data))
1160{
1161 struct gpio_chip *chip = NULL;
1162 unsigned long flags;
1163 int i;
1164
1165 spin_lock_irqsave(&gpio_lock, flags);
1166 for (i = 0; i < ARCH_NR_GPIOS; i++) {
1167 if (!gpio_desc[i].chip)
1168 continue;
1169
1170 if (match(gpio_desc[i].chip, data)) {
1171 chip = gpio_desc[i].chip;
1172 break;
1173 }
1174 }
1175 spin_unlock_irqrestore(&gpio_lock, flags);
1176
1177 return chip;
1178}
1179EXPORT_SYMBOL_GPL(gpiochip_find);
1180
1181/* These "optional" allocation calls help prevent drivers from stomping
1182 * on each other, and help provide better diagnostics in debugfs.
1183 * They're called even less than the "set direction" calls.
1184 */
1185int gpio_request(unsigned gpio, const char *label)
1186{
1187 struct gpio_desc *desc;
1188 struct gpio_chip *chip;
1189 int status = -EINVAL;
1190 unsigned long flags;
1191
1192 spin_lock_irqsave(&gpio_lock, flags);
1193
1194 if (!gpio_is_valid(gpio))
1195 goto done;
1196 desc = &gpio_desc[gpio];
1197 chip = desc->chip;
1198 if (chip == NULL)
1199 goto done;
1200
1201 if (!try_module_get(chip->owner))
1202 goto done;
1203
1204 /* NOTE: gpio_request() can be called in early boot,
1205 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1206 */
1207
1208 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1209 desc_set_label(desc, label ? : "?");
1210 status = 0;
1211 } else {
1212 status = -EBUSY;
1213 module_put(chip->owner);
1214 goto done;
1215 }
1216
1217 if (chip->request) {
1218 /* chip->request may sleep */
1219 spin_unlock_irqrestore(&gpio_lock, flags);
1220 status = chip->request(chip, gpio - chip->base);
1221 spin_lock_irqsave(&gpio_lock, flags);
1222
1223 if (status < 0) {
1224 desc_set_label(desc, NULL);
1225 module_put(chip->owner);
1226 clear_bit(FLAG_REQUESTED, &desc->flags);
1227 }
1228 }
1229
1230done:
1231 if (status)
1232 pr_debug("gpio_request: gpio-%d (%s) status %d\n",
1233 gpio, label ? : "?", status);
1234 spin_unlock_irqrestore(&gpio_lock, flags);
1235 return status;
1236}
1237EXPORT_SYMBOL_GPL(gpio_request);
1238
1239void gpio_free(unsigned gpio)
1240{
1241 unsigned long flags;
1242 struct gpio_desc *desc;
1243 struct gpio_chip *chip;
1244
1245 might_sleep();
1246
1247 if (!gpio_is_valid(gpio)) {
1248 WARN_ON(extra_checks);
1249 return;
1250 }
1251
1252 gpio_unexport(gpio);
1253
1254 spin_lock_irqsave(&gpio_lock, flags);
1255
1256 desc = &gpio_desc[gpio];
1257 chip = desc->chip;
1258 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1259 if (chip->free) {
1260 spin_unlock_irqrestore(&gpio_lock, flags);
1261 might_sleep_if(chip->can_sleep);
1262 chip->free(chip, gpio - chip->base);
1263 spin_lock_irqsave(&gpio_lock, flags);
1264 }
1265 desc_set_label(desc, NULL);
1266 module_put(desc->chip->owner);
1267 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1268 clear_bit(FLAG_REQUESTED, &desc->flags);
1269 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1270 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1271 } else
1272 WARN_ON(extra_checks);
1273
1274 spin_unlock_irqrestore(&gpio_lock, flags);
1275}
1276EXPORT_SYMBOL_GPL(gpio_free);
1277
1278/**
1279 * gpio_request_one - request a single GPIO with initial configuration
1280 * @gpio: the GPIO number
1281 * @flags: GPIO configuration as specified by GPIOF_*
1282 * @label: a literal description string of this GPIO
1283 */
1284int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
1285{
1286 int err;
1287
1288 err = gpio_request(gpio, label);
1289 if (err)
1290 return err;
1291
1292 if (flags & GPIOF_OPEN_DRAIN)
1293 set_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags);
1294
1295 if (flags & GPIOF_OPEN_SOURCE)
1296 set_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags);
1297
1298 if (flags & GPIOF_DIR_IN)
1299 err = gpio_direction_input(gpio);
1300 else
1301 err = gpio_direction_output(gpio,
1302 (flags & GPIOF_INIT_HIGH) ? 1 : 0);
1303
1304 if (err)
1305 goto free_gpio;
1306
1307 if (flags & GPIOF_EXPORT) {
1308 err = gpio_export(gpio, flags & GPIOF_EXPORT_CHANGEABLE);
1309 if (err)
1310 goto free_gpio;
1311 }
1312
1313 return 0;
1314
1315 free_gpio:
1316 gpio_free(gpio);
1317 return err;
1318}
1319EXPORT_SYMBOL_GPL(gpio_request_one);
1320
1321/**
1322 * gpio_request_array - request multiple GPIOs in a single call
1323 * @array: array of the 'struct gpio'
1324 * @num: how many GPIOs in the array
1325 */
1326int gpio_request_array(const struct gpio *array, size_t num)
1327{
1328 int i, err;
1329
1330 for (i = 0; i < num; i++, array++) {
1331 err = gpio_request_one(array->gpio, array->flags, array->label);
1332 if (err)
1333 goto err_free;
1334 }
1335 return 0;
1336
1337err_free:
1338 while (i--)
1339 gpio_free((--array)->gpio);
1340 return err;
1341}
1342EXPORT_SYMBOL_GPL(gpio_request_array);
1343
1344/**
1345 * gpio_free_array - release multiple GPIOs in a single call
1346 * @array: array of the 'struct gpio'
1347 * @num: how many GPIOs in the array
1348 */
1349void gpio_free_array(const struct gpio *array, size_t num)
1350{
1351 while (num--)
1352 gpio_free((array++)->gpio);
1353}
1354EXPORT_SYMBOL_GPL(gpio_free_array);
1355
1356/**
1357 * gpiochip_is_requested - return string iff signal was requested
1358 * @chip: controller managing the signal
1359 * @offset: of signal within controller's 0..(ngpio - 1) range
1360 *
1361 * Returns NULL if the GPIO is not currently requested, else a string.
1362 * If debugfs support is enabled, the string returned is the label passed
1363 * to gpio_request(); otherwise it is a meaningless constant.
1364 *
1365 * This function is for use by GPIO controller drivers. The label can
1366 * help with diagnostics, and knowing that the signal is used as a GPIO
1367 * can help avoid accidentally multiplexing it to another controller.
1368 */
1369const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1370{
1371 unsigned gpio = chip->base + offset;
1372
1373 if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip)
1374 return NULL;
1375 if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0)
1376 return NULL;
1377#ifdef CONFIG_DEBUG_FS
1378 return gpio_desc[gpio].label;
1379#else
1380 return "?";
1381#endif
1382}
1383EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1384
1385
1386/* Drivers MUST set GPIO direction before making get/set calls. In
1387 * some cases this is done in early boot, before IRQs are enabled.
1388 *
1389 * As a rule these aren't called more than once (except for drivers
1390 * using the open-drain emulation idiom) so these are natural places
1391 * to accumulate extra debugging checks. Note that we can't (yet)
1392 * rely on gpio_request() having been called beforehand.
1393 */
1394
1395int gpio_direction_input(unsigned gpio)
1396{
1397 unsigned long flags;
1398 struct gpio_chip *chip;
1399 struct gpio_desc *desc = &gpio_desc[gpio];
1400 int status = -EINVAL;
1401
1402 spin_lock_irqsave(&gpio_lock, flags);
1403
1404 if (!gpio_is_valid(gpio))
1405 goto fail;
1406 chip = desc->chip;
1407 if (!chip || !chip->get || !chip->direction_input)
1408 goto fail;
1409 gpio -= chip->base;
1410 if (gpio >= chip->ngpio)
1411 goto fail;
1412 status = gpio_ensure_requested(desc, gpio);
1413 if (status < 0)
1414 goto fail;
1415
1416 /* now we know the gpio is valid and chip won't vanish */
1417
1418 spin_unlock_irqrestore(&gpio_lock, flags);
1419
1420 might_sleep_if(chip->can_sleep);
1421
1422 if (status) {
1423 status = chip->request(chip, gpio);
1424 if (status < 0) {
1425 pr_debug("GPIO-%d: chip request fail, %d\n",
1426 chip->base + gpio, status);
1427 /* and it's not available to anyone else ...
1428 * gpio_request() is the fully clean solution.
1429 */
1430 goto lose;
1431 }
1432 }
1433
1434 status = chip->direction_input(chip, gpio);
1435 if (status == 0)
1436 clear_bit(FLAG_IS_OUT, &desc->flags);
1437
1438 trace_gpio_direction(chip->base + gpio, 1, status);
1439lose:
1440 return status;
1441fail:
1442 spin_unlock_irqrestore(&gpio_lock, flags);
1443 if (status)
1444 pr_debug("%s: gpio-%d status %d\n",
1445 __func__, gpio, status);
1446 return status;
1447}
1448EXPORT_SYMBOL_GPL(gpio_direction_input);
1449
1450int gpio_direction_output(unsigned gpio, int value)
1451{
1452 unsigned long flags;
1453 struct gpio_chip *chip;
1454 struct gpio_desc *desc = &gpio_desc[gpio];
1455 int status = -EINVAL;
1456
1457 /* Open drain pin should not be driven to 1 */
1458 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1459 return gpio_direction_input(gpio);
1460
1461 /* Open source pin should not be driven to 0 */
1462 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1463 return gpio_direction_input(gpio);
1464
1465 spin_lock_irqsave(&gpio_lock, flags);
1466
1467 if (!gpio_is_valid(gpio))
1468 goto fail;
1469 chip = desc->chip;
1470 if (!chip || !chip->set || !chip->direction_output)
1471 goto fail;
1472 gpio -= chip->base;
1473 if (gpio >= chip->ngpio)
1474 goto fail;
1475 status = gpio_ensure_requested(desc, gpio);
1476 if (status < 0)
1477 goto fail;
1478
1479 /* now we know the gpio is valid and chip won't vanish */
1480
1481 spin_unlock_irqrestore(&gpio_lock, flags);
1482
1483 might_sleep_if(chip->can_sleep);
1484
1485 if (status) {
1486 status = chip->request(chip, gpio);
1487 if (status < 0) {
1488 pr_debug("GPIO-%d: chip request fail, %d\n",
1489 chip->base + gpio, status);
1490 /* and it's not available to anyone else ...
1491 * gpio_request() is the fully clean solution.
1492 */
1493 goto lose;
1494 }
1495 }
1496
1497 status = chip->direction_output(chip, gpio, value);
1498 if (status == 0)
1499 set_bit(FLAG_IS_OUT, &desc->flags);
1500 trace_gpio_value(chip->base + gpio, 0, value);
1501 trace_gpio_direction(chip->base + gpio, 0, status);
1502lose:
1503 return status;
1504fail:
1505 spin_unlock_irqrestore(&gpio_lock, flags);
1506 if (status)
1507 pr_debug("%s: gpio-%d status %d\n",
1508 __func__, gpio, status);
1509 return status;
1510}
1511EXPORT_SYMBOL_GPL(gpio_direction_output);
1512
1513/**
1514 * gpio_set_debounce - sets @debounce time for a @gpio
1515 * @gpio: the gpio to set debounce time
1516 * @debounce: debounce time is microseconds
1517 */
1518int gpio_set_debounce(unsigned gpio, unsigned debounce)
1519{
1520 unsigned long flags;
1521 struct gpio_chip *chip;
1522 struct gpio_desc *desc = &gpio_desc[gpio];
1523 int status = -EINVAL;
1524
1525 spin_lock_irqsave(&gpio_lock, flags);
1526
1527 if (!gpio_is_valid(gpio))
1528 goto fail;
1529 chip = desc->chip;
1530 if (!chip || !chip->set || !chip->set_debounce)
1531 goto fail;
1532 gpio -= chip->base;
1533 if (gpio >= chip->ngpio)
1534 goto fail;
1535 status = gpio_ensure_requested(desc, gpio);
1536 if (status < 0)
1537 goto fail;
1538
1539 /* now we know the gpio is valid and chip won't vanish */
1540
1541 spin_unlock_irqrestore(&gpio_lock, flags);
1542
1543 might_sleep_if(chip->can_sleep);
1544
1545 return chip->set_debounce(chip, gpio, debounce);
1546
1547fail:
1548 spin_unlock_irqrestore(&gpio_lock, flags);
1549 if (status)
1550 pr_debug("%s: gpio-%d status %d\n",
1551 __func__, gpio, status);
1552
1553 return status;
1554}
1555EXPORT_SYMBOL_GPL(gpio_set_debounce);
1556
1557/* I/O calls are only valid after configuration completed; the relevant
1558 * "is this a valid GPIO" error checks should already have been done.
1559 *
1560 * "Get" operations are often inlinable as reading a pin value register,
1561 * and masking the relevant bit in that register.
1562 *
1563 * When "set" operations are inlinable, they involve writing that mask to
1564 * one register to set a low value, or a different register to set it high.
1565 * Otherwise locking is needed, so there may be little value to inlining.
1566 *
1567 *------------------------------------------------------------------------
1568 *
1569 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
1570 * have requested the GPIO. That can include implicit requesting by
1571 * a direction setting call. Marking a gpio as requested locks its chip
1572 * in memory, guaranteeing that these table lookups need no more locking
1573 * and that gpiochip_remove() will fail.
1574 *
1575 * REVISIT when debugging, consider adding some instrumentation to ensure
1576 * that the GPIO was actually requested.
1577 */
1578
1579/**
1580 * __gpio_get_value() - return a gpio's value
1581 * @gpio: gpio whose value will be returned
1582 * Context: any
1583 *
1584 * This is used directly or indirectly to implement gpio_get_value().
1585 * It returns the zero or nonzero value provided by the associated
1586 * gpio_chip.get() method; or zero if no such method is provided.
1587 */
1588int __gpio_get_value(unsigned gpio)
1589{
1590 struct gpio_chip *chip;
1591 int value;
1592
1593 chip = gpio_to_chip(gpio);
1594 /* Should be using gpio_get_value_cansleep() */
1595 WARN_ON(chip->can_sleep);
1596 value = chip->get ? chip->get(chip, gpio - chip->base) : 0;
1597 trace_gpio_value(gpio, 1, value);
1598 return value;
1599}
1600EXPORT_SYMBOL_GPL(__gpio_get_value);
1601
1602/*
1603 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
1604 * @gpio: Gpio whose state need to be set.
1605 * @chip: Gpio chip.
1606 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
1607 */
1608static void _gpio_set_open_drain_value(unsigned gpio,
1609 struct gpio_chip *chip, int value)
1610{
1611 int err = 0;
1612 if (value) {
1613 err = chip->direction_input(chip, gpio - chip->base);
1614 if (!err)
1615 clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
1616 } else {
1617 err = chip->direction_output(chip, gpio - chip->base, 0);
1618 if (!err)
1619 set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
1620 }
1621 trace_gpio_direction(gpio, value, err);
1622 if (err < 0)
1623 pr_err("%s: Error in set_value for open drain gpio%d err %d\n",
1624 __func__, gpio, err);
1625}
1626
1627/*
1628 * _gpio_set_open_source() - Set the open source gpio's value.
1629 * @gpio: Gpio whose state need to be set.
1630 * @chip: Gpio chip.
1631 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
1632 */
1633static void _gpio_set_open_source_value(unsigned gpio,
1634 struct gpio_chip *chip, int value)
1635{
1636 int err = 0;
1637 if (value) {
1638 err = chip->direction_output(chip, gpio - chip->base, 1);
1639 if (!err)
1640 set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
1641 } else {
1642 err = chip->direction_input(chip, gpio - chip->base);
1643 if (!err)
1644 clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
1645 }
1646 trace_gpio_direction(gpio, !value, err);
1647 if (err < 0)
1648 pr_err("%s: Error in set_value for open source gpio%d err %d\n",
1649 __func__, gpio, err);
1650}
1651
1652
1653/**
1654 * __gpio_set_value() - assign a gpio's value
1655 * @gpio: gpio whose value will be assigned
1656 * @value: value to assign
1657 * Context: any
1658 *
1659 * This is used directly or indirectly to implement gpio_set_value().
1660 * It invokes the associated gpio_chip.set() method.
1661 */
1662void __gpio_set_value(unsigned gpio, int value)
1663{
1664 struct gpio_chip *chip;
1665
1666 chip = gpio_to_chip(gpio);
1667 /* Should be using gpio_set_value_cansleep() */
1668 WARN_ON(chip->can_sleep);
1669 trace_gpio_value(gpio, 0, value);
1670 if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags))
1671 _gpio_set_open_drain_value(gpio, chip, value);
1672 else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags))
1673 _gpio_set_open_source_value(gpio, chip, value);
1674 else
1675 chip->set(chip, gpio - chip->base, value);
1676}
1677EXPORT_SYMBOL_GPL(__gpio_set_value);
1678
1679/**
1680 * __gpio_cansleep() - report whether gpio value access will sleep
1681 * @gpio: gpio in question
1682 * Context: any
1683 *
1684 * This is used directly or indirectly to implement gpio_cansleep(). It
1685 * returns nonzero if access reading or writing the GPIO value can sleep.
1686 */
1687int __gpio_cansleep(unsigned gpio)
1688{
1689 struct gpio_chip *chip;
1690
1691 /* only call this on GPIOs that are valid! */
1692 chip = gpio_to_chip(gpio);
1693
1694 return chip->can_sleep;
1695}
1696EXPORT_SYMBOL_GPL(__gpio_cansleep);
1697
1698/**
1699 * __gpio_to_irq() - return the IRQ corresponding to a GPIO
1700 * @gpio: gpio whose IRQ will be returned (already requested)
1701 * Context: any
1702 *
1703 * This is used directly or indirectly to implement gpio_to_irq().
1704 * It returns the number of the IRQ signaled by this (input) GPIO,
1705 * or a negative errno.
1706 */
1707int __gpio_to_irq(unsigned gpio)
1708{
1709 struct gpio_chip *chip;
1710
1711 chip = gpio_to_chip(gpio);
1712 return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO;
1713}
1714EXPORT_SYMBOL_GPL(__gpio_to_irq);
1715
1716
1717
1718/* There's no value in making it easy to inline GPIO calls that may sleep.
1719 * Common examples include ones connected to I2C or SPI chips.
1720 */
1721
1722int gpio_get_value_cansleep(unsigned gpio)
1723{
1724 struct gpio_chip *chip;
1725 int value;
1726
1727 might_sleep_if(extra_checks);
1728 chip = gpio_to_chip(gpio);
1729 value = chip->get ? chip->get(chip, gpio - chip->base) : 0;
1730 trace_gpio_value(gpio, 1, value);
1731 return value;
1732}
1733EXPORT_SYMBOL_GPL(gpio_get_value_cansleep);
1734
1735void gpio_set_value_cansleep(unsigned gpio, int value)
1736{
1737 struct gpio_chip *chip;
1738
1739 might_sleep_if(extra_checks);
1740 chip = gpio_to_chip(gpio);
1741 trace_gpio_value(gpio, 0, value);
1742 if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags))
1743 _gpio_set_open_drain_value(gpio, chip, value);
1744 else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags))
1745 _gpio_set_open_source_value(gpio, chip, value);
1746 else
1747 chip->set(chip, gpio - chip->base, value);
1748}
1749EXPORT_SYMBOL_GPL(gpio_set_value_cansleep);
1750
1751
1752#ifdef CONFIG_DEBUG_FS
1753
1754static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
1755{
1756 unsigned i;
1757 unsigned gpio = chip->base;
1758 struct gpio_desc *gdesc = &gpio_desc[gpio];
1759 int is_out;
1760
1761 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
1762 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
1763 continue;
1764
1765 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
1766 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s",
1767 gpio, gdesc->label,
1768 is_out ? "out" : "in ",
1769 chip->get
1770 ? (chip->get(chip, i) ? "hi" : "lo")
1771 : "? ");
1772 seq_printf(s, "\n");
1773 }
1774}
1775
1776static int gpiolib_show(struct seq_file *s, void *unused)
1777{
1778 struct gpio_chip *chip = NULL;
1779 unsigned gpio;
1780 int started = 0;
1781
1782 /* REVISIT this isn't locked against gpio_chip removal ... */
1783
1784 for (gpio = 0; gpio_is_valid(gpio); gpio++) {
1785 struct device *dev;
1786
1787 if (chip == gpio_desc[gpio].chip)
1788 continue;
1789 chip = gpio_desc[gpio].chip;
1790 if (!chip)
1791 continue;
1792
1793 seq_printf(s, "%sGPIOs %d-%d",
1794 started ? "\n" : "",
1795 chip->base, chip->base + chip->ngpio - 1);
1796 dev = chip->dev;
1797 if (dev)
1798 seq_printf(s, ", %s/%s",
1799 dev->bus ? dev->bus->name : "no-bus",
1800 dev_name(dev));
1801 if (chip->label)
1802 seq_printf(s, ", %s", chip->label);
1803 if (chip->can_sleep)
1804 seq_printf(s, ", can sleep");
1805 seq_printf(s, ":\n");
1806
1807 started = 1;
1808 if (chip->dbg_show)
1809 chip->dbg_show(s, chip);
1810 else
1811 gpiolib_dbg_show(s, chip);
1812 }
1813 return 0;
1814}
1815
1816static int gpiolib_open(struct inode *inode, struct file *file)
1817{
1818 return single_open(file, gpiolib_show, NULL);
1819}
1820
1821static const struct file_operations gpiolib_operations = {
1822 .open = gpiolib_open,
1823 .read = seq_read,
1824 .llseek = seq_lseek,
1825 .release = single_release,
1826};
1827
1828static int __init gpiolib_debugfs_init(void)
1829{
1830 /* /sys/kernel/debug/gpio */
1831 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
1832 NULL, NULL, &gpiolib_operations);
1833 return 0;
1834}
1835subsys_initcall(gpiolib_debugfs_init);
1836
1837#endif /* DEBUG_FS */
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/bitmap.h>
4#include <linux/kernel.h>
5#include <linux/module.h>
6#include <linux/interrupt.h>
7#include <linux/irq.h>
8#include <linux/spinlock.h>
9#include <linux/list.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/debugfs.h>
13#include <linux/seq_file.h>
14#include <linux/gpio.h>
15#include <linux/idr.h>
16#include <linux/slab.h>
17#include <linux/acpi.h>
18#include <linux/gpio/driver.h>
19#include <linux/gpio/machine.h>
20#include <linux/pinctrl/consumer.h>
21#include <linux/fs.h>
22#include <linux/compat.h>
23#include <linux/file.h>
24#include <uapi/linux/gpio.h>
25
26#include "gpiolib.h"
27#include "gpiolib-of.h"
28#include "gpiolib-acpi.h"
29#include "gpiolib-cdev.h"
30#include "gpiolib-sysfs.h"
31
32#define CREATE_TRACE_POINTS
33#include <trace/events/gpio.h>
34
35/* Implementation infrastructure for GPIO interfaces.
36 *
37 * The GPIO programming interface allows for inlining speed-critical
38 * get/set operations for common cases, so that access to SOC-integrated
39 * GPIOs can sometimes cost only an instruction or two per bit.
40 */
41
42
43/* When debugging, extend minimal trust to callers and platform code.
44 * Also emit diagnostic messages that may help initial bringup, when
45 * board setup or driver bugs are most common.
46 *
47 * Otherwise, minimize overhead in what may be bitbanging codepaths.
48 */
49#ifdef DEBUG
50#define extra_checks 1
51#else
52#define extra_checks 0
53#endif
54
55/* Device and char device-related information */
56static DEFINE_IDA(gpio_ida);
57static dev_t gpio_devt;
58#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
59static int gpio_bus_match(struct device *dev, struct device_driver *drv);
60static struct bus_type gpio_bus_type = {
61 .name = "gpio",
62 .match = gpio_bus_match,
63};
64
65/*
66 * Number of GPIOs to use for the fast path in set array
67 */
68#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
69
70/* gpio_lock prevents conflicts during gpio_desc[] table updates.
71 * While any GPIO is requested, its gpio_chip is not removable;
72 * each GPIO's "requested" flag serves as a lock and refcount.
73 */
74DEFINE_SPINLOCK(gpio_lock);
75
76static DEFINE_MUTEX(gpio_lookup_lock);
77static LIST_HEAD(gpio_lookup_list);
78LIST_HEAD(gpio_devices);
79
80static DEFINE_MUTEX(gpio_machine_hogs_mutex);
81static LIST_HEAD(gpio_machine_hogs);
82
83static void gpiochip_free_hogs(struct gpio_chip *gc);
84static int gpiochip_add_irqchip(struct gpio_chip *gc,
85 struct lock_class_key *lock_key,
86 struct lock_class_key *request_key);
87static void gpiochip_irqchip_remove(struct gpio_chip *gc);
88static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
89static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
90static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
91
92static bool gpiolib_initialized;
93
94static inline void desc_set_label(struct gpio_desc *d, const char *label)
95{
96 d->label = label;
97}
98
99/**
100 * gpio_to_desc - Convert a GPIO number to its descriptor
101 * @gpio: global GPIO number
102 *
103 * Returns:
104 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
105 * with the given number exists in the system.
106 */
107struct gpio_desc *gpio_to_desc(unsigned gpio)
108{
109 struct gpio_device *gdev;
110 unsigned long flags;
111
112 spin_lock_irqsave(&gpio_lock, flags);
113
114 list_for_each_entry(gdev, &gpio_devices, list) {
115 if (gdev->base <= gpio &&
116 gdev->base + gdev->ngpio > gpio) {
117 spin_unlock_irqrestore(&gpio_lock, flags);
118 return &gdev->descs[gpio - gdev->base];
119 }
120 }
121
122 spin_unlock_irqrestore(&gpio_lock, flags);
123
124 if (!gpio_is_valid(gpio))
125 pr_warn("invalid GPIO %d\n", gpio);
126
127 return NULL;
128}
129EXPORT_SYMBOL_GPL(gpio_to_desc);
130
131/**
132 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
133 * hardware number for this chip
134 * @gc: GPIO chip
135 * @hwnum: hardware number of the GPIO for this chip
136 *
137 * Returns:
138 * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
139 * in the given chip for the specified hardware number.
140 */
141struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
142 unsigned int hwnum)
143{
144 struct gpio_device *gdev = gc->gpiodev;
145
146 if (hwnum >= gdev->ngpio)
147 return ERR_PTR(-EINVAL);
148
149 return &gdev->descs[hwnum];
150}
151EXPORT_SYMBOL_GPL(gpiochip_get_desc);
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 *gc;
217 unsigned int offset;
218 int ret;
219
220 gc = gpiod_to_chip(desc);
221 offset = gpio_chip_hwgpio(desc);
222
223 /*
224 * Open drain emulation using input mode may incorrectly report
225 * input here, fix that up.
226 */
227 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
228 test_bit(FLAG_IS_OUT, &desc->flags))
229 return 0;
230
231 if (!gc->get_direction)
232 return -ENOTSUPP;
233
234 ret = gc->get_direction(gc, offset);
235 if (ret < 0)
236 return ret;
237
238 /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
239 if (ret > 0)
240 ret = 1;
241
242 assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
243
244 return ret;
245}
246EXPORT_SYMBOL_GPL(gpiod_get_direction);
247
248/*
249 * Add a new chip to the global chips list, keeping the list of chips sorted
250 * by range(means [base, base + ngpio - 1]) order.
251 *
252 * Return -EBUSY if the new chip overlaps with some other chip's integer
253 * space.
254 */
255static int gpiodev_add_to_list(struct gpio_device *gdev)
256{
257 struct gpio_device *prev, *next;
258
259 if (list_empty(&gpio_devices)) {
260 /* initial entry in list */
261 list_add_tail(&gdev->list, &gpio_devices);
262 return 0;
263 }
264
265 next = list_entry(gpio_devices.next, struct gpio_device, list);
266 if (gdev->base + gdev->ngpio <= next->base) {
267 /* add before first entry */
268 list_add(&gdev->list, &gpio_devices);
269 return 0;
270 }
271
272 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
273 if (prev->base + prev->ngpio <= gdev->base) {
274 /* add behind last entry */
275 list_add_tail(&gdev->list, &gpio_devices);
276 return 0;
277 }
278
279 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
280 /* at the end of the list */
281 if (&next->list == &gpio_devices)
282 break;
283
284 /* add between prev and next */
285 if (prev->base + prev->ngpio <= gdev->base
286 && gdev->base + gdev->ngpio <= next->base) {
287 list_add(&gdev->list, &prev->list);
288 return 0;
289 }
290 }
291
292 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
293 return -EBUSY;
294}
295
296/*
297 * Convert a GPIO name to its descriptor
298 * Note that there is no guarantee that GPIO names are globally unique!
299 * Hence this function will return, if it exists, a reference to the first GPIO
300 * line found that matches the given name.
301 */
302static struct gpio_desc *gpio_name_to_desc(const char * const name)
303{
304 struct gpio_device *gdev;
305 unsigned long flags;
306
307 if (!name)
308 return NULL;
309
310 spin_lock_irqsave(&gpio_lock, flags);
311
312 list_for_each_entry(gdev, &gpio_devices, list) {
313 int i;
314
315 for (i = 0; i != gdev->ngpio; ++i) {
316 struct gpio_desc *desc = &gdev->descs[i];
317
318 if (!desc->name)
319 continue;
320
321 if (!strcmp(desc->name, name)) {
322 spin_unlock_irqrestore(&gpio_lock, flags);
323 return desc;
324 }
325 }
326 }
327
328 spin_unlock_irqrestore(&gpio_lock, flags);
329
330 return NULL;
331}
332
333/*
334 * Take the names from gc->names and assign them to their GPIO descriptors.
335 * Warn if a name is already used for a GPIO line on a different GPIO chip.
336 *
337 * Note that:
338 * 1. Non-unique names are still accepted,
339 * 2. Name collisions within the same GPIO chip are not reported.
340 */
341static int gpiochip_set_desc_names(struct gpio_chip *gc)
342{
343 struct gpio_device *gdev = gc->gpiodev;
344 int i;
345
346 /* First check all names if they are unique */
347 for (i = 0; i != gc->ngpio; ++i) {
348 struct gpio_desc *gpio;
349
350 gpio = gpio_name_to_desc(gc->names[i]);
351 if (gpio)
352 dev_warn(&gdev->dev,
353 "Detected name collision for GPIO name '%s'\n",
354 gc->names[i]);
355 }
356
357 /* Then add all names to the GPIO descriptors */
358 for (i = 0; i != gc->ngpio; ++i)
359 gdev->descs[i].name = gc->names[i];
360
361 return 0;
362}
363
364/*
365 * devprop_gpiochip_set_names - Set GPIO line names using device properties
366 * @chip: GPIO chip whose lines should be named, if possible
367 *
368 * Looks for device property "gpio-line-names" and if it exists assigns
369 * GPIO line names for the chip. The memory allocated for the assigned
370 * names belong to the underlying firmware node and should not be released
371 * by the caller.
372 */
373static int devprop_gpiochip_set_names(struct gpio_chip *chip)
374{
375 struct gpio_device *gdev = chip->gpiodev;
376 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
377 const char **names;
378 int ret, i;
379 int count;
380
381 count = fwnode_property_string_array_count(fwnode, "gpio-line-names");
382 if (count < 0)
383 return 0;
384
385 if (count > gdev->ngpio) {
386 dev_warn(&gdev->dev, "gpio-line-names is length %d but should be at most length %d",
387 count, gdev->ngpio);
388 count = gdev->ngpio;
389 }
390
391 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
392 if (!names)
393 return -ENOMEM;
394
395 ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
396 names, count);
397 if (ret < 0) {
398 dev_warn(&gdev->dev, "failed to read GPIO line names\n");
399 kfree(names);
400 return ret;
401 }
402
403 for (i = 0; i < count; i++)
404 gdev->descs[i].name = names[i];
405
406 kfree(names);
407
408 return 0;
409}
410
411static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
412{
413 unsigned long *p;
414
415 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
416 if (!p)
417 return NULL;
418
419 /* Assume by default all GPIOs are valid */
420 bitmap_fill(p, gc->ngpio);
421
422 return p;
423}
424
425static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
426{
427 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
428 return 0;
429
430 gc->valid_mask = gpiochip_allocate_mask(gc);
431 if (!gc->valid_mask)
432 return -ENOMEM;
433
434 return 0;
435}
436
437static int gpiochip_init_valid_mask(struct gpio_chip *gc)
438{
439 if (gc->init_valid_mask)
440 return gc->init_valid_mask(gc,
441 gc->valid_mask,
442 gc->ngpio);
443
444 return 0;
445}
446
447static void gpiochip_free_valid_mask(struct gpio_chip *gc)
448{
449 bitmap_free(gc->valid_mask);
450 gc->valid_mask = NULL;
451}
452
453static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
454{
455 if (gc->add_pin_ranges)
456 return gc->add_pin_ranges(gc);
457
458 return 0;
459}
460
461bool gpiochip_line_is_valid(const struct gpio_chip *gc,
462 unsigned int offset)
463{
464 /* No mask means all valid */
465 if (likely(!gc->valid_mask))
466 return true;
467 return test_bit(offset, gc->valid_mask);
468}
469EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
470
471static void gpiodevice_release(struct device *dev)
472{
473 struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
474 unsigned long flags;
475
476 spin_lock_irqsave(&gpio_lock, flags);
477 list_del(&gdev->list);
478 spin_unlock_irqrestore(&gpio_lock, flags);
479
480 ida_free(&gpio_ida, gdev->id);
481 kfree_const(gdev->label);
482 kfree(gdev->descs);
483 kfree(gdev);
484}
485
486#ifdef CONFIG_GPIO_CDEV
487#define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
488#define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
489#else
490/*
491 * gpiolib_cdev_register() indirectly calls device_add(), which is still
492 * required even when cdev is not selected.
493 */
494#define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
495#define gcdev_unregister(gdev) device_del(&(gdev)->dev)
496#endif
497
498static int gpiochip_setup_dev(struct gpio_device *gdev)
499{
500 int ret;
501
502 ret = gcdev_register(gdev, gpio_devt);
503 if (ret)
504 return ret;
505
506 ret = gpiochip_sysfs_register(gdev);
507 if (ret)
508 goto err_remove_device;
509
510 /* From this point, the .release() function cleans up gpio_device */
511 gdev->dev.release = gpiodevice_release;
512 dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
513 gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
514
515 return 0;
516
517err_remove_device:
518 gcdev_unregister(gdev);
519 return ret;
520}
521
522static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
523{
524 struct gpio_desc *desc;
525 int rv;
526
527 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
528 if (IS_ERR(desc)) {
529 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
530 PTR_ERR(desc));
531 return;
532 }
533
534 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
535 return;
536
537 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
538 if (rv)
539 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
540 __func__, gc->label, hog->chip_hwnum, rv);
541}
542
543static void machine_gpiochip_add(struct gpio_chip *gc)
544{
545 struct gpiod_hog *hog;
546
547 mutex_lock(&gpio_machine_hogs_mutex);
548
549 list_for_each_entry(hog, &gpio_machine_hogs, list) {
550 if (!strcmp(gc->label, hog->chip_label))
551 gpiochip_machine_hog(gc, hog);
552 }
553
554 mutex_unlock(&gpio_machine_hogs_mutex);
555}
556
557static void gpiochip_setup_devs(void)
558{
559 struct gpio_device *gdev;
560 int ret;
561
562 list_for_each_entry(gdev, &gpio_devices, list) {
563 ret = gpiochip_setup_dev(gdev);
564 if (ret)
565 dev_err(&gdev->dev,
566 "Failed to initialize gpio device (%d)\n", ret);
567 }
568}
569
570int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
571 struct lock_class_key *lock_key,
572 struct lock_class_key *request_key)
573{
574 struct fwnode_handle *fwnode = gc->parent ? dev_fwnode(gc->parent) : NULL;
575 unsigned long flags;
576 int ret = 0;
577 unsigned i;
578 int base = gc->base;
579 struct gpio_device *gdev;
580
581 /*
582 * First: allocate and populate the internal stat container, and
583 * set up the struct device.
584 */
585 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
586 if (!gdev)
587 return -ENOMEM;
588 gdev->dev.bus = &gpio_bus_type;
589 gdev->dev.parent = gc->parent;
590 gdev->chip = gc;
591 gc->gpiodev = gdev;
592
593 of_gpio_dev_init(gc, gdev);
594 acpi_gpio_dev_init(gc, gdev);
595
596 /*
597 * Assign fwnode depending on the result of the previous calls,
598 * if none of them succeed, assign it to the parent's one.
599 */
600 gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
601
602 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
603 if (gdev->id < 0) {
604 ret = gdev->id;
605 goto err_free_gdev;
606 }
607
608 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
609 if (ret)
610 goto err_free_ida;
611
612 device_initialize(&gdev->dev);
613 if (gc->parent && gc->parent->driver)
614 gdev->owner = gc->parent->driver->owner;
615 else if (gc->owner)
616 /* TODO: remove chip->owner */
617 gdev->owner = gc->owner;
618 else
619 gdev->owner = THIS_MODULE;
620
621 gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
622 if (!gdev->descs) {
623 ret = -ENOMEM;
624 goto err_free_dev_name;
625 }
626
627 if (gc->ngpio == 0) {
628 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
629 ret = -EINVAL;
630 goto err_free_descs;
631 }
632
633 if (gc->ngpio > FASTPATH_NGPIO)
634 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
635 gc->ngpio, FASTPATH_NGPIO);
636
637 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
638 if (!gdev->label) {
639 ret = -ENOMEM;
640 goto err_free_descs;
641 }
642
643 gdev->ngpio = gc->ngpio;
644 gdev->data = data;
645
646 spin_lock_irqsave(&gpio_lock, flags);
647
648 /*
649 * TODO: this allocates a Linux GPIO number base in the global
650 * GPIO numberspace for this chip. In the long run we want to
651 * get *rid* of this numberspace and use only descriptors, but
652 * it may be a pipe dream. It will not happen before we get rid
653 * of the sysfs interface anyways.
654 */
655 if (base < 0) {
656 base = gpiochip_find_base(gc->ngpio);
657 if (base < 0) {
658 ret = base;
659 spin_unlock_irqrestore(&gpio_lock, flags);
660 goto err_free_label;
661 }
662 /*
663 * TODO: it should not be necessary to reflect the assigned
664 * base outside of the GPIO subsystem. Go over drivers and
665 * see if anyone makes use of this, else drop this and assign
666 * a poison instead.
667 */
668 gc->base = base;
669 }
670 gdev->base = base;
671
672 ret = gpiodev_add_to_list(gdev);
673 if (ret) {
674 spin_unlock_irqrestore(&gpio_lock, flags);
675 goto err_free_label;
676 }
677
678 for (i = 0; i < gc->ngpio; i++)
679 gdev->descs[i].gdev = gdev;
680
681 spin_unlock_irqrestore(&gpio_lock, flags);
682
683 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
684
685#ifdef CONFIG_PINCTRL
686 INIT_LIST_HEAD(&gdev->pin_ranges);
687#endif
688
689 if (gc->names)
690 ret = gpiochip_set_desc_names(gc);
691 else
692 ret = devprop_gpiochip_set_names(gc);
693 if (ret)
694 goto err_remove_from_list;
695
696 ret = gpiochip_alloc_valid_mask(gc);
697 if (ret)
698 goto err_remove_from_list;
699
700 ret = of_gpiochip_add(gc);
701 if (ret)
702 goto err_free_gpiochip_mask;
703
704 ret = gpiochip_init_valid_mask(gc);
705 if (ret)
706 goto err_remove_of_chip;
707
708 for (i = 0; i < gc->ngpio; i++) {
709 struct gpio_desc *desc = &gdev->descs[i];
710
711 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
712 assign_bit(FLAG_IS_OUT,
713 &desc->flags, !gc->get_direction(gc, i));
714 } else {
715 assign_bit(FLAG_IS_OUT,
716 &desc->flags, !gc->direction_input);
717 }
718 }
719
720 ret = gpiochip_add_pin_ranges(gc);
721 if (ret)
722 goto err_remove_of_chip;
723
724 acpi_gpiochip_add(gc);
725
726 machine_gpiochip_add(gc);
727
728 ret = gpiochip_irqchip_init_valid_mask(gc);
729 if (ret)
730 goto err_remove_acpi_chip;
731
732 ret = gpiochip_irqchip_init_hw(gc);
733 if (ret)
734 goto err_remove_acpi_chip;
735
736 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
737 if (ret)
738 goto err_remove_irqchip_mask;
739
740 /*
741 * By first adding the chardev, and then adding the device,
742 * we get a device node entry in sysfs under
743 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
744 * coldplug of device nodes and other udev business.
745 * We can do this only if gpiolib has been initialized.
746 * Otherwise, defer until later.
747 */
748 if (gpiolib_initialized) {
749 ret = gpiochip_setup_dev(gdev);
750 if (ret)
751 goto err_remove_irqchip;
752 }
753 return 0;
754
755err_remove_irqchip:
756 gpiochip_irqchip_remove(gc);
757err_remove_irqchip_mask:
758 gpiochip_irqchip_free_valid_mask(gc);
759err_remove_acpi_chip:
760 acpi_gpiochip_remove(gc);
761err_remove_of_chip:
762 gpiochip_free_hogs(gc);
763 of_gpiochip_remove(gc);
764err_free_gpiochip_mask:
765 gpiochip_remove_pin_ranges(gc);
766 gpiochip_free_valid_mask(gc);
767err_remove_from_list:
768 spin_lock_irqsave(&gpio_lock, flags);
769 list_del(&gdev->list);
770 spin_unlock_irqrestore(&gpio_lock, flags);
771err_free_label:
772 kfree_const(gdev->label);
773err_free_descs:
774 kfree(gdev->descs);
775err_free_dev_name:
776 kfree(dev_name(&gdev->dev));
777err_free_ida:
778 ida_free(&gpio_ida, gdev->id);
779err_free_gdev:
780 /* failures here can mean systems won't boot... */
781 if (ret != -EPROBE_DEFER) {
782 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
783 gdev->base, gdev->base + gdev->ngpio - 1,
784 gc->label ? : "generic", ret);
785 }
786 kfree(gdev);
787 return ret;
788}
789EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
790
791/**
792 * gpiochip_get_data() - get per-subdriver data for the chip
793 * @gc: GPIO chip
794 *
795 * Returns:
796 * The per-subdriver data for the chip.
797 */
798void *gpiochip_get_data(struct gpio_chip *gc)
799{
800 return gc->gpiodev->data;
801}
802EXPORT_SYMBOL_GPL(gpiochip_get_data);
803
804/**
805 * gpiochip_remove() - unregister a gpio_chip
806 * @gc: the chip to unregister
807 *
808 * A gpio_chip with any GPIOs still requested may not be removed.
809 */
810void gpiochip_remove(struct gpio_chip *gc)
811{
812 struct gpio_device *gdev = gc->gpiodev;
813 unsigned long flags;
814 unsigned int i;
815
816 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
817 gpiochip_sysfs_unregister(gdev);
818 gpiochip_free_hogs(gc);
819 /* Numb the device, cancelling all outstanding operations */
820 gdev->chip = NULL;
821 gpiochip_irqchip_remove(gc);
822 acpi_gpiochip_remove(gc);
823 of_gpiochip_remove(gc);
824 gpiochip_remove_pin_ranges(gc);
825 gpiochip_free_valid_mask(gc);
826 /*
827 * We accept no more calls into the driver from this point, so
828 * NULL the driver data pointer
829 */
830 gdev->data = NULL;
831
832 spin_lock_irqsave(&gpio_lock, flags);
833 for (i = 0; i < gdev->ngpio; i++) {
834 if (gpiochip_is_requested(gc, i))
835 break;
836 }
837 spin_unlock_irqrestore(&gpio_lock, flags);
838
839 if (i != gdev->ngpio)
840 dev_crit(&gdev->dev,
841 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
842
843 /*
844 * The gpiochip side puts its use of the device to rest here:
845 * if there are no userspace clients, the chardev and device will
846 * be removed, else it will be dangling until the last user is
847 * gone.
848 */
849 gcdev_unregister(gdev);
850 put_device(&gdev->dev);
851}
852EXPORT_SYMBOL_GPL(gpiochip_remove);
853
854/**
855 * gpiochip_find() - iterator for locating a specific gpio_chip
856 * @data: data to pass to match function
857 * @match: Callback function to check gpio_chip
858 *
859 * Similar to bus_find_device. It returns a reference to a gpio_chip as
860 * determined by a user supplied @match callback. The callback should return
861 * 0 if the device doesn't match and non-zero if it does. If the callback is
862 * non-zero, this function will return to the caller and not iterate over any
863 * more gpio_chips.
864 */
865struct gpio_chip *gpiochip_find(void *data,
866 int (*match)(struct gpio_chip *gc,
867 void *data))
868{
869 struct gpio_device *gdev;
870 struct gpio_chip *gc = NULL;
871 unsigned long flags;
872
873 spin_lock_irqsave(&gpio_lock, flags);
874 list_for_each_entry(gdev, &gpio_devices, list)
875 if (gdev->chip && match(gdev->chip, data)) {
876 gc = gdev->chip;
877 break;
878 }
879
880 spin_unlock_irqrestore(&gpio_lock, flags);
881
882 return gc;
883}
884EXPORT_SYMBOL_GPL(gpiochip_find);
885
886static int gpiochip_match_name(struct gpio_chip *gc, void *data)
887{
888 const char *name = data;
889
890 return !strcmp(gc->label, name);
891}
892
893static struct gpio_chip *find_chip_by_name(const char *name)
894{
895 return gpiochip_find((void *)name, gpiochip_match_name);
896}
897
898#ifdef CONFIG_GPIOLIB_IRQCHIP
899
900/*
901 * The following is irqchip helper code for gpiochips.
902 */
903
904static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
905{
906 struct gpio_irq_chip *girq = &gc->irq;
907
908 if (!girq->init_hw)
909 return 0;
910
911 return girq->init_hw(gc);
912}
913
914static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
915{
916 struct gpio_irq_chip *girq = &gc->irq;
917
918 if (!girq->init_valid_mask)
919 return 0;
920
921 girq->valid_mask = gpiochip_allocate_mask(gc);
922 if (!girq->valid_mask)
923 return -ENOMEM;
924
925 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
926
927 return 0;
928}
929
930static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
931{
932 bitmap_free(gc->irq.valid_mask);
933 gc->irq.valid_mask = NULL;
934}
935
936bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
937 unsigned int offset)
938{
939 if (!gpiochip_line_is_valid(gc, offset))
940 return false;
941 /* No mask means all valid */
942 if (likely(!gc->irq.valid_mask))
943 return true;
944 return test_bit(offset, gc->irq.valid_mask);
945}
946EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
947
948#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
949
950/**
951 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
952 * to a gpiochip
953 * @gc: the gpiochip to set the irqchip hierarchical handler to
954 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
955 * will then percolate up to the parent
956 */
957static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
958 struct irq_chip *irqchip)
959{
960 /* DT will deal with mapping each IRQ as we go along */
961 if (is_of_node(gc->irq.fwnode))
962 return;
963
964 /*
965 * This is for legacy and boardfile "irqchip" fwnodes: allocate
966 * irqs upfront instead of dynamically since we don't have the
967 * dynamic type of allocation that hardware description languages
968 * provide. Once all GPIO drivers using board files are gone from
969 * the kernel we can delete this code, but for a transitional period
970 * it is necessary to keep this around.
971 */
972 if (is_fwnode_irqchip(gc->irq.fwnode)) {
973 int i;
974 int ret;
975
976 for (i = 0; i < gc->ngpio; i++) {
977 struct irq_fwspec fwspec;
978 unsigned int parent_hwirq;
979 unsigned int parent_type;
980 struct gpio_irq_chip *girq = &gc->irq;
981
982 /*
983 * We call the child to parent translation function
984 * only to check if the child IRQ is valid or not.
985 * Just pick the rising edge type here as that is what
986 * we likely need to support.
987 */
988 ret = girq->child_to_parent_hwirq(gc, i,
989 IRQ_TYPE_EDGE_RISING,
990 &parent_hwirq,
991 &parent_type);
992 if (ret) {
993 chip_err(gc, "skip set-up on hwirq %d\n",
994 i);
995 continue;
996 }
997
998 fwspec.fwnode = gc->irq.fwnode;
999 /* This is the hwirq for the GPIO line side of things */
1000 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1001 /* Just pick something */
1002 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1003 fwspec.param_count = 2;
1004 ret = __irq_domain_alloc_irqs(gc->irq.domain,
1005 /* just pick something */
1006 -1,
1007 1,
1008 NUMA_NO_NODE,
1009 &fwspec,
1010 false,
1011 NULL);
1012 if (ret < 0) {
1013 chip_err(gc,
1014 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1015 i, parent_hwirq,
1016 ret);
1017 }
1018 }
1019 }
1020
1021 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1022
1023 return;
1024}
1025
1026static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1027 struct irq_fwspec *fwspec,
1028 unsigned long *hwirq,
1029 unsigned int *type)
1030{
1031 /* We support standard DT translation */
1032 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1033 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1034 }
1035
1036 /* This is for board files and others not using DT */
1037 if (is_fwnode_irqchip(fwspec->fwnode)) {
1038 int ret;
1039
1040 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1041 if (ret)
1042 return ret;
1043 WARN_ON(*type == IRQ_TYPE_NONE);
1044 return 0;
1045 }
1046 return -EINVAL;
1047}
1048
1049static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1050 unsigned int irq,
1051 unsigned int nr_irqs,
1052 void *data)
1053{
1054 struct gpio_chip *gc = d->host_data;
1055 irq_hw_number_t hwirq;
1056 unsigned int type = IRQ_TYPE_NONE;
1057 struct irq_fwspec *fwspec = data;
1058 void *parent_arg;
1059 unsigned int parent_hwirq;
1060 unsigned int parent_type;
1061 struct gpio_irq_chip *girq = &gc->irq;
1062 int ret;
1063
1064 /*
1065 * The nr_irqs parameter is always one except for PCI multi-MSI
1066 * so this should not happen.
1067 */
1068 WARN_ON(nr_irqs != 1);
1069
1070 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1071 if (ret)
1072 return ret;
1073
1074 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1075
1076 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1077 &parent_hwirq, &parent_type);
1078 if (ret) {
1079 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1080 return ret;
1081 }
1082 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1083
1084 /*
1085 * We set handle_bad_irq because the .set_type() should
1086 * always be invoked and set the right type of handler.
1087 */
1088 irq_domain_set_info(d,
1089 irq,
1090 hwirq,
1091 gc->irq.chip,
1092 gc,
1093 girq->handler,
1094 NULL, NULL);
1095 irq_set_probe(irq);
1096
1097 /* This parent only handles asserted level IRQs */
1098 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1099 if (!parent_arg)
1100 return -ENOMEM;
1101
1102 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1103 irq, parent_hwirq);
1104 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1105 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1106 /*
1107 * If the parent irqdomain is msi, the interrupts have already
1108 * been allocated, so the EEXIST is good.
1109 */
1110 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1111 ret = 0;
1112 if (ret)
1113 chip_err(gc,
1114 "failed to allocate parent hwirq %d for hwirq %lu\n",
1115 parent_hwirq, hwirq);
1116
1117 kfree(parent_arg);
1118 return ret;
1119}
1120
1121static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1122 unsigned int offset)
1123{
1124 return offset;
1125}
1126
1127static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1128{
1129 ops->activate = gpiochip_irq_domain_activate;
1130 ops->deactivate = gpiochip_irq_domain_deactivate;
1131 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1132 ops->free = irq_domain_free_irqs_common;
1133
1134 /*
1135 * We only allow overriding the translate() function for
1136 * hierarchical chips, and this should only be done if the user
1137 * really need something other than 1:1 translation.
1138 */
1139 if (!ops->translate)
1140 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1141}
1142
1143static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1144{
1145 if (!gc->irq.child_to_parent_hwirq ||
1146 !gc->irq.fwnode) {
1147 chip_err(gc, "missing irqdomain vital data\n");
1148 return -EINVAL;
1149 }
1150
1151 if (!gc->irq.child_offset_to_irq)
1152 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1153
1154 if (!gc->irq.populate_parent_alloc_arg)
1155 gc->irq.populate_parent_alloc_arg =
1156 gpiochip_populate_parent_fwspec_twocell;
1157
1158 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1159
1160 gc->irq.domain = irq_domain_create_hierarchy(
1161 gc->irq.parent_domain,
1162 0,
1163 gc->ngpio,
1164 gc->irq.fwnode,
1165 &gc->irq.child_irq_domain_ops,
1166 gc);
1167
1168 if (!gc->irq.domain)
1169 return -ENOMEM;
1170
1171 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1172
1173 return 0;
1174}
1175
1176static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1177{
1178 return !!gc->irq.parent_domain;
1179}
1180
1181void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1182 unsigned int parent_hwirq,
1183 unsigned int parent_type)
1184{
1185 struct irq_fwspec *fwspec;
1186
1187 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1188 if (!fwspec)
1189 return NULL;
1190
1191 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1192 fwspec->param_count = 2;
1193 fwspec->param[0] = parent_hwirq;
1194 fwspec->param[1] = parent_type;
1195
1196 return fwspec;
1197}
1198EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1199
1200void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1201 unsigned int parent_hwirq,
1202 unsigned int parent_type)
1203{
1204 struct irq_fwspec *fwspec;
1205
1206 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1207 if (!fwspec)
1208 return NULL;
1209
1210 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1211 fwspec->param_count = 4;
1212 fwspec->param[0] = 0;
1213 fwspec->param[1] = parent_hwirq;
1214 fwspec->param[2] = 0;
1215 fwspec->param[3] = parent_type;
1216
1217 return fwspec;
1218}
1219EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1220
1221#else
1222
1223static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1224{
1225 return -EINVAL;
1226}
1227
1228static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1229{
1230 return false;
1231}
1232
1233#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1234
1235/**
1236 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1237 * @d: the irqdomain used by this irqchip
1238 * @irq: the global irq number used by this GPIO irqchip irq
1239 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1240 *
1241 * This function will set up the mapping for a certain IRQ line on a
1242 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1243 * stored inside the gpiochip.
1244 */
1245int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1246 irq_hw_number_t hwirq)
1247{
1248 struct gpio_chip *gc = d->host_data;
1249 int ret = 0;
1250
1251 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1252 return -ENXIO;
1253
1254 irq_set_chip_data(irq, gc);
1255 /*
1256 * This lock class tells lockdep that GPIO irqs are in a different
1257 * category than their parents, so it won't report false recursion.
1258 */
1259 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1260 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1261 /* Chips that use nested thread handlers have them marked */
1262 if (gc->irq.threaded)
1263 irq_set_nested_thread(irq, 1);
1264 irq_set_noprobe(irq);
1265
1266 if (gc->irq.num_parents == 1)
1267 ret = irq_set_parent(irq, gc->irq.parents[0]);
1268 else if (gc->irq.map)
1269 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1270
1271 if (ret < 0)
1272 return ret;
1273
1274 /*
1275 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1276 * is passed as default type.
1277 */
1278 if (gc->irq.default_type != IRQ_TYPE_NONE)
1279 irq_set_irq_type(irq, gc->irq.default_type);
1280
1281 return 0;
1282}
1283EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1284
1285void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1286{
1287 struct gpio_chip *gc = d->host_data;
1288
1289 if (gc->irq.threaded)
1290 irq_set_nested_thread(irq, 0);
1291 irq_set_chip_and_handler(irq, NULL, NULL);
1292 irq_set_chip_data(irq, NULL);
1293}
1294EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1295
1296static const struct irq_domain_ops gpiochip_domain_ops = {
1297 .map = gpiochip_irq_map,
1298 .unmap = gpiochip_irq_unmap,
1299 /* Virtually all GPIO irqchips are twocell:ed */
1300 .xlate = irq_domain_xlate_twocell,
1301};
1302
1303/*
1304 * TODO: move these activate/deactivate in under the hierarchicial
1305 * irqchip implementation as static once SPMI and SSBI (all external
1306 * users) are phased over.
1307 */
1308/**
1309 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1310 * @domain: The IRQ domain used by this IRQ chip
1311 * @data: Outermost irq_data associated with the IRQ
1312 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1313 *
1314 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1315 * used as the activate function for the &struct irq_domain_ops. The host_data
1316 * for the IRQ domain must be the &struct gpio_chip.
1317 */
1318int gpiochip_irq_domain_activate(struct irq_domain *domain,
1319 struct irq_data *data, bool reserve)
1320{
1321 struct gpio_chip *gc = domain->host_data;
1322
1323 return gpiochip_lock_as_irq(gc, data->hwirq);
1324}
1325EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1326
1327/**
1328 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1329 * @domain: The IRQ domain used by this IRQ chip
1330 * @data: Outermost irq_data associated with the IRQ
1331 *
1332 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1333 * be used as the deactivate function for the &struct irq_domain_ops. The
1334 * host_data for the IRQ domain must be the &struct gpio_chip.
1335 */
1336void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1337 struct irq_data *data)
1338{
1339 struct gpio_chip *gc = domain->host_data;
1340
1341 return gpiochip_unlock_as_irq(gc, data->hwirq);
1342}
1343EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1344
1345static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1346{
1347 struct irq_domain *domain = gc->irq.domain;
1348
1349 if (!gpiochip_irqchip_irq_valid(gc, offset))
1350 return -ENXIO;
1351
1352#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1353 if (irq_domain_is_hierarchy(domain)) {
1354 struct irq_fwspec spec;
1355
1356 spec.fwnode = domain->fwnode;
1357 spec.param_count = 2;
1358 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1359 spec.param[1] = IRQ_TYPE_NONE;
1360
1361 return irq_create_fwspec_mapping(&spec);
1362 }
1363#endif
1364
1365 return irq_create_mapping(domain, offset);
1366}
1367
1368static int gpiochip_irq_reqres(struct irq_data *d)
1369{
1370 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1371
1372 return gpiochip_reqres_irq(gc, d->hwirq);
1373}
1374
1375static void gpiochip_irq_relres(struct irq_data *d)
1376{
1377 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1378
1379 gpiochip_relres_irq(gc, d->hwirq);
1380}
1381
1382static void gpiochip_irq_mask(struct irq_data *d)
1383{
1384 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1385
1386 if (gc->irq.irq_mask)
1387 gc->irq.irq_mask(d);
1388 gpiochip_disable_irq(gc, d->hwirq);
1389}
1390
1391static void gpiochip_irq_unmask(struct irq_data *d)
1392{
1393 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1394
1395 gpiochip_enable_irq(gc, d->hwirq);
1396 if (gc->irq.irq_unmask)
1397 gc->irq.irq_unmask(d);
1398}
1399
1400static void gpiochip_irq_enable(struct irq_data *d)
1401{
1402 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1403
1404 gpiochip_enable_irq(gc, d->hwirq);
1405 gc->irq.irq_enable(d);
1406}
1407
1408static void gpiochip_irq_disable(struct irq_data *d)
1409{
1410 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1411
1412 gc->irq.irq_disable(d);
1413 gpiochip_disable_irq(gc, d->hwirq);
1414}
1415
1416static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1417{
1418 struct irq_chip *irqchip = gc->irq.chip;
1419
1420 if (!irqchip->irq_request_resources &&
1421 !irqchip->irq_release_resources) {
1422 irqchip->irq_request_resources = gpiochip_irq_reqres;
1423 irqchip->irq_release_resources = gpiochip_irq_relres;
1424 }
1425 if (WARN_ON(gc->irq.irq_enable))
1426 return;
1427 /* Check if the irqchip already has this hook... */
1428 if (irqchip->irq_enable == gpiochip_irq_enable ||
1429 irqchip->irq_mask == gpiochip_irq_mask) {
1430 /*
1431 * ...and if so, give a gentle warning that this is bad
1432 * practice.
1433 */
1434 chip_info(gc,
1435 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1436 return;
1437 }
1438
1439 if (irqchip->irq_disable) {
1440 gc->irq.irq_disable = irqchip->irq_disable;
1441 irqchip->irq_disable = gpiochip_irq_disable;
1442 } else {
1443 gc->irq.irq_mask = irqchip->irq_mask;
1444 irqchip->irq_mask = gpiochip_irq_mask;
1445 }
1446
1447 if (irqchip->irq_enable) {
1448 gc->irq.irq_enable = irqchip->irq_enable;
1449 irqchip->irq_enable = gpiochip_irq_enable;
1450 } else {
1451 gc->irq.irq_unmask = irqchip->irq_unmask;
1452 irqchip->irq_unmask = gpiochip_irq_unmask;
1453 }
1454}
1455
1456/**
1457 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1458 * @gc: the GPIO chip to add the IRQ chip to
1459 * @lock_key: lockdep class for IRQ lock
1460 * @request_key: lockdep class for IRQ request
1461 */
1462static int gpiochip_add_irqchip(struct gpio_chip *gc,
1463 struct lock_class_key *lock_key,
1464 struct lock_class_key *request_key)
1465{
1466 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1467 struct irq_chip *irqchip = gc->irq.chip;
1468 unsigned int type;
1469 unsigned int i;
1470
1471 if (!irqchip)
1472 return 0;
1473
1474 if (gc->irq.parent_handler && gc->can_sleep) {
1475 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1476 return -EINVAL;
1477 }
1478
1479 type = gc->irq.default_type;
1480
1481 /*
1482 * Specifying a default trigger is a terrible idea if DT or ACPI is
1483 * used to configure the interrupts, as you may end up with
1484 * conflicting triggers. Tell the user, and reset to NONE.
1485 */
1486 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1487 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1488 type = IRQ_TYPE_NONE;
1489
1490 if (gc->to_irq)
1491 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1492
1493 gc->to_irq = gpiochip_to_irq;
1494 gc->irq.default_type = type;
1495 gc->irq.lock_key = lock_key;
1496 gc->irq.request_key = request_key;
1497
1498 /* If a parent irqdomain is provided, let's build a hierarchy */
1499 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1500 int ret = gpiochip_hierarchy_add_domain(gc);
1501 if (ret)
1502 return ret;
1503 } else {
1504 /* Some drivers provide custom irqdomain ops */
1505 gc->irq.domain = irq_domain_create_simple(fwnode,
1506 gc->ngpio,
1507 gc->irq.first,
1508 gc->irq.domain_ops ?: &gpiochip_domain_ops,
1509 gc);
1510 if (!gc->irq.domain)
1511 return -EINVAL;
1512 }
1513
1514 if (gc->irq.parent_handler) {
1515 void *data = gc->irq.parent_handler_data ?: gc;
1516
1517 for (i = 0; i < gc->irq.num_parents; i++) {
1518 /*
1519 * The parent IRQ chip is already using the chip_data
1520 * for this IRQ chip, so our callbacks simply use the
1521 * handler_data.
1522 */
1523 irq_set_chained_handler_and_data(gc->irq.parents[i],
1524 gc->irq.parent_handler,
1525 data);
1526 }
1527 }
1528
1529 gpiochip_set_irq_hooks(gc);
1530
1531 acpi_gpiochip_request_interrupts(gc);
1532
1533 return 0;
1534}
1535
1536/**
1537 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1538 * @gc: the gpiochip to remove the irqchip from
1539 *
1540 * This is called only from gpiochip_remove()
1541 */
1542static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1543{
1544 struct irq_chip *irqchip = gc->irq.chip;
1545 unsigned int offset;
1546
1547 acpi_gpiochip_free_interrupts(gc);
1548
1549 if (irqchip && gc->irq.parent_handler) {
1550 struct gpio_irq_chip *irq = &gc->irq;
1551 unsigned int i;
1552
1553 for (i = 0; i < irq->num_parents; i++)
1554 irq_set_chained_handler_and_data(irq->parents[i],
1555 NULL, NULL);
1556 }
1557
1558 /* Remove all IRQ mappings and delete the domain */
1559 if (gc->irq.domain) {
1560 unsigned int irq;
1561
1562 for (offset = 0; offset < gc->ngpio; offset++) {
1563 if (!gpiochip_irqchip_irq_valid(gc, offset))
1564 continue;
1565
1566 irq = irq_find_mapping(gc->irq.domain, offset);
1567 irq_dispose_mapping(irq);
1568 }
1569
1570 irq_domain_remove(gc->irq.domain);
1571 }
1572
1573 if (irqchip) {
1574 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1575 irqchip->irq_request_resources = NULL;
1576 irqchip->irq_release_resources = NULL;
1577 }
1578 if (irqchip->irq_enable == gpiochip_irq_enable) {
1579 irqchip->irq_enable = gc->irq.irq_enable;
1580 irqchip->irq_disable = gc->irq.irq_disable;
1581 }
1582 }
1583 gc->irq.irq_enable = NULL;
1584 gc->irq.irq_disable = NULL;
1585 gc->irq.chip = NULL;
1586
1587 gpiochip_irqchip_free_valid_mask(gc);
1588}
1589
1590/**
1591 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1592 * @gc: the gpiochip to add the irqchip to
1593 * @domain: the irqdomain to add to the gpiochip
1594 *
1595 * This function adds an IRQ domain to the gpiochip.
1596 */
1597int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1598 struct irq_domain *domain)
1599{
1600 if (!domain)
1601 return -EINVAL;
1602
1603 gc->to_irq = gpiochip_to_irq;
1604 gc->irq.domain = domain;
1605
1606 return 0;
1607}
1608EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1609
1610#else /* CONFIG_GPIOLIB_IRQCHIP */
1611
1612static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1613 struct lock_class_key *lock_key,
1614 struct lock_class_key *request_key)
1615{
1616 return 0;
1617}
1618static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1619
1620static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1621{
1622 return 0;
1623}
1624
1625static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1626{
1627 return 0;
1628}
1629static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1630{ }
1631
1632#endif /* CONFIG_GPIOLIB_IRQCHIP */
1633
1634/**
1635 * gpiochip_generic_request() - request the gpio function for a pin
1636 * @gc: the gpiochip owning the GPIO
1637 * @offset: the offset of the GPIO to request for GPIO function
1638 */
1639int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
1640{
1641#ifdef CONFIG_PINCTRL
1642 if (list_empty(&gc->gpiodev->pin_ranges))
1643 return 0;
1644#endif
1645
1646 return pinctrl_gpio_request(gc->gpiodev->base + offset);
1647}
1648EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1649
1650/**
1651 * gpiochip_generic_free() - free the gpio function from a pin
1652 * @gc: the gpiochip to request the gpio function for
1653 * @offset: the offset of the GPIO to free from GPIO function
1654 */
1655void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
1656{
1657#ifdef CONFIG_PINCTRL
1658 if (list_empty(&gc->gpiodev->pin_ranges))
1659 return;
1660#endif
1661
1662 pinctrl_gpio_free(gc->gpiodev->base + offset);
1663}
1664EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1665
1666/**
1667 * gpiochip_generic_config() - apply configuration for a pin
1668 * @gc: the gpiochip owning the GPIO
1669 * @offset: the offset of the GPIO to apply the configuration
1670 * @config: the configuration to be applied
1671 */
1672int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
1673 unsigned long config)
1674{
1675 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1676}
1677EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1678
1679#ifdef CONFIG_PINCTRL
1680
1681/**
1682 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1683 * @gc: the gpiochip to add the range for
1684 * @pctldev: the pin controller to map to
1685 * @gpio_offset: the start offset in the current gpio_chip number space
1686 * @pin_group: name of the pin group inside the pin controller
1687 *
1688 * Calling this function directly from a DeviceTree-supported
1689 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1690 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1691 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1692 */
1693int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1694 struct pinctrl_dev *pctldev,
1695 unsigned int gpio_offset, const char *pin_group)
1696{
1697 struct gpio_pin_range *pin_range;
1698 struct gpio_device *gdev = gc->gpiodev;
1699 int ret;
1700
1701 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1702 if (!pin_range) {
1703 chip_err(gc, "failed to allocate pin ranges\n");
1704 return -ENOMEM;
1705 }
1706
1707 /* Use local offset as range ID */
1708 pin_range->range.id = gpio_offset;
1709 pin_range->range.gc = gc;
1710 pin_range->range.name = gc->label;
1711 pin_range->range.base = gdev->base + gpio_offset;
1712 pin_range->pctldev = pctldev;
1713
1714 ret = pinctrl_get_group_pins(pctldev, pin_group,
1715 &pin_range->range.pins,
1716 &pin_range->range.npins);
1717 if (ret < 0) {
1718 kfree(pin_range);
1719 return ret;
1720 }
1721
1722 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1723
1724 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1725 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1726 pinctrl_dev_get_devname(pctldev), pin_group);
1727
1728 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1729
1730 return 0;
1731}
1732EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1733
1734/**
1735 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1736 * @gc: the gpiochip to add the range for
1737 * @pinctl_name: the dev_name() of the pin controller to map to
1738 * @gpio_offset: the start offset in the current gpio_chip number space
1739 * @pin_offset: the start offset in the pin controller number space
1740 * @npins: the number of pins from the offset of each pin space (GPIO and
1741 * pin controller) to accumulate in this range
1742 *
1743 * Returns:
1744 * 0 on success, or a negative error-code on failure.
1745 *
1746 * Calling this function directly from a DeviceTree-supported
1747 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1748 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1749 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1750 */
1751int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1752 unsigned int gpio_offset, unsigned int pin_offset,
1753 unsigned int npins)
1754{
1755 struct gpio_pin_range *pin_range;
1756 struct gpio_device *gdev = gc->gpiodev;
1757 int ret;
1758
1759 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1760 if (!pin_range) {
1761 chip_err(gc, "failed to allocate pin ranges\n");
1762 return -ENOMEM;
1763 }
1764
1765 /* Use local offset as range ID */
1766 pin_range->range.id = gpio_offset;
1767 pin_range->range.gc = gc;
1768 pin_range->range.name = gc->label;
1769 pin_range->range.base = gdev->base + gpio_offset;
1770 pin_range->range.pin_base = pin_offset;
1771 pin_range->range.npins = npins;
1772 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1773 &pin_range->range);
1774 if (IS_ERR(pin_range->pctldev)) {
1775 ret = PTR_ERR(pin_range->pctldev);
1776 chip_err(gc, "could not create pin range\n");
1777 kfree(pin_range);
1778 return ret;
1779 }
1780 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1781 gpio_offset, gpio_offset + npins - 1,
1782 pinctl_name,
1783 pin_offset, pin_offset + npins - 1);
1784
1785 list_add_tail(&pin_range->node, &gdev->pin_ranges);
1786
1787 return 0;
1788}
1789EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1790
1791/**
1792 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1793 * @gc: the chip to remove all the mappings for
1794 */
1795void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1796{
1797 struct gpio_pin_range *pin_range, *tmp;
1798 struct gpio_device *gdev = gc->gpiodev;
1799
1800 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1801 list_del(&pin_range->node);
1802 pinctrl_remove_gpio_range(pin_range->pctldev,
1803 &pin_range->range);
1804 kfree(pin_range);
1805 }
1806}
1807EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1808
1809#endif /* CONFIG_PINCTRL */
1810
1811/* These "optional" allocation calls help prevent drivers from stomping
1812 * on each other, and help provide better diagnostics in debugfs.
1813 * They're called even less than the "set direction" calls.
1814 */
1815static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
1816{
1817 struct gpio_chip *gc = desc->gdev->chip;
1818 int ret;
1819 unsigned long flags;
1820 unsigned offset;
1821
1822 if (label) {
1823 label = kstrdup_const(label, GFP_KERNEL);
1824 if (!label)
1825 return -ENOMEM;
1826 }
1827
1828 spin_lock_irqsave(&gpio_lock, flags);
1829
1830 /* NOTE: gpio_request() can be called in early boot,
1831 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1832 */
1833
1834 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1835 desc_set_label(desc, label ? : "?");
1836 } else {
1837 ret = -EBUSY;
1838 goto out_free_unlock;
1839 }
1840
1841 if (gc->request) {
1842 /* gc->request may sleep */
1843 spin_unlock_irqrestore(&gpio_lock, flags);
1844 offset = gpio_chip_hwgpio(desc);
1845 if (gpiochip_line_is_valid(gc, offset))
1846 ret = gc->request(gc, offset);
1847 else
1848 ret = -EINVAL;
1849 spin_lock_irqsave(&gpio_lock, flags);
1850
1851 if (ret) {
1852 desc_set_label(desc, NULL);
1853 clear_bit(FLAG_REQUESTED, &desc->flags);
1854 goto out_free_unlock;
1855 }
1856 }
1857 if (gc->get_direction) {
1858 /* gc->get_direction may sleep */
1859 spin_unlock_irqrestore(&gpio_lock, flags);
1860 gpiod_get_direction(desc);
1861 spin_lock_irqsave(&gpio_lock, flags);
1862 }
1863 spin_unlock_irqrestore(&gpio_lock, flags);
1864 return 0;
1865
1866out_free_unlock:
1867 spin_unlock_irqrestore(&gpio_lock, flags);
1868 kfree_const(label);
1869 return ret;
1870}
1871
1872/*
1873 * This descriptor validation needs to be inserted verbatim into each
1874 * function taking a descriptor, so we need to use a preprocessor
1875 * macro to avoid endless duplication. If the desc is NULL it is an
1876 * optional GPIO and calls should just bail out.
1877 */
1878static int validate_desc(const struct gpio_desc *desc, const char *func)
1879{
1880 if (!desc)
1881 return 0;
1882 if (IS_ERR(desc)) {
1883 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
1884 return PTR_ERR(desc);
1885 }
1886 if (!desc->gdev) {
1887 pr_warn("%s: invalid GPIO (no device)\n", func);
1888 return -EINVAL;
1889 }
1890 if (!desc->gdev->chip) {
1891 dev_warn(&desc->gdev->dev,
1892 "%s: backing chip is gone\n", func);
1893 return 0;
1894 }
1895 return 1;
1896}
1897
1898#define VALIDATE_DESC(desc) do { \
1899 int __valid = validate_desc(desc, __func__); \
1900 if (__valid <= 0) \
1901 return __valid; \
1902 } while (0)
1903
1904#define VALIDATE_DESC_VOID(desc) do { \
1905 int __valid = validate_desc(desc, __func__); \
1906 if (__valid <= 0) \
1907 return; \
1908 } while (0)
1909
1910int gpiod_request(struct gpio_desc *desc, const char *label)
1911{
1912 int ret = -EPROBE_DEFER;
1913 struct gpio_device *gdev;
1914
1915 VALIDATE_DESC(desc);
1916 gdev = desc->gdev;
1917
1918 if (try_module_get(gdev->owner)) {
1919 ret = gpiod_request_commit(desc, label);
1920 if (ret)
1921 module_put(gdev->owner);
1922 else
1923 get_device(&gdev->dev);
1924 }
1925
1926 if (ret)
1927 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
1928
1929 return ret;
1930}
1931
1932static bool gpiod_free_commit(struct gpio_desc *desc)
1933{
1934 bool ret = false;
1935 unsigned long flags;
1936 struct gpio_chip *gc;
1937
1938 might_sleep();
1939
1940 gpiod_unexport(desc);
1941
1942 spin_lock_irqsave(&gpio_lock, flags);
1943
1944 gc = desc->gdev->chip;
1945 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
1946 if (gc->free) {
1947 spin_unlock_irqrestore(&gpio_lock, flags);
1948 might_sleep_if(gc->can_sleep);
1949 gc->free(gc, gpio_chip_hwgpio(desc));
1950 spin_lock_irqsave(&gpio_lock, flags);
1951 }
1952 kfree_const(desc->label);
1953 desc_set_label(desc, NULL);
1954 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1955 clear_bit(FLAG_REQUESTED, &desc->flags);
1956 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1957 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1958 clear_bit(FLAG_PULL_UP, &desc->flags);
1959 clear_bit(FLAG_PULL_DOWN, &desc->flags);
1960 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
1961 clear_bit(FLAG_EDGE_RISING, &desc->flags);
1962 clear_bit(FLAG_EDGE_FALLING, &desc->flags);
1963 clear_bit(FLAG_IS_HOGGED, &desc->flags);
1964#ifdef CONFIG_OF_DYNAMIC
1965 desc->hog = NULL;
1966#endif
1967#ifdef CONFIG_GPIO_CDEV
1968 WRITE_ONCE(desc->debounce_period_us, 0);
1969#endif
1970 ret = true;
1971 }
1972
1973 spin_unlock_irqrestore(&gpio_lock, flags);
1974 blocking_notifier_call_chain(&desc->gdev->notifier,
1975 GPIOLINE_CHANGED_RELEASED, desc);
1976
1977 return ret;
1978}
1979
1980void gpiod_free(struct gpio_desc *desc)
1981{
1982 if (desc && desc->gdev && gpiod_free_commit(desc)) {
1983 module_put(desc->gdev->owner);
1984 put_device(&desc->gdev->dev);
1985 } else {
1986 WARN_ON(extra_checks);
1987 }
1988}
1989
1990/**
1991 * gpiochip_is_requested - return string iff signal was requested
1992 * @gc: controller managing the signal
1993 * @offset: of signal within controller's 0..(ngpio - 1) range
1994 *
1995 * Returns NULL if the GPIO is not currently requested, else a string.
1996 * The string returned is the label passed to gpio_request(); if none has been
1997 * passed it is a meaningless, non-NULL constant.
1998 *
1999 * This function is for use by GPIO controller drivers. The label can
2000 * help with diagnostics, and knowing that the signal is used as a GPIO
2001 * can help avoid accidentally multiplexing it to another controller.
2002 */
2003const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
2004{
2005 struct gpio_desc *desc;
2006
2007 desc = gpiochip_get_desc(gc, offset);
2008 if (IS_ERR(desc))
2009 return NULL;
2010
2011 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2012 return NULL;
2013 return desc->label;
2014}
2015EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2016
2017/**
2018 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2019 * @gc: GPIO chip
2020 * @hwnum: hardware number of the GPIO for which to request the descriptor
2021 * @label: label for the GPIO
2022 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2023 * specify things like line inversion semantics with the machine flags
2024 * such as GPIO_OUT_LOW
2025 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2026 * can be used to specify consumer semantics such as open drain
2027 *
2028 * Function allows GPIO chip drivers to request and use their own GPIO
2029 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2030 * function will not increase reference count of the GPIO chip module. This
2031 * allows the GPIO chip module to be unloaded as needed (we assume that the
2032 * GPIO chip driver handles freeing the GPIOs it has requested).
2033 *
2034 * Returns:
2035 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2036 * code on failure.
2037 */
2038struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2039 unsigned int hwnum,
2040 const char *label,
2041 enum gpio_lookup_flags lflags,
2042 enum gpiod_flags dflags)
2043{
2044 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2045 int ret;
2046
2047 if (IS_ERR(desc)) {
2048 chip_err(gc, "failed to get GPIO descriptor\n");
2049 return desc;
2050 }
2051
2052 ret = gpiod_request_commit(desc, label);
2053 if (ret < 0)
2054 return ERR_PTR(ret);
2055
2056 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2057 if (ret) {
2058 chip_err(gc, "setup of own GPIO %s failed\n", label);
2059 gpiod_free_commit(desc);
2060 return ERR_PTR(ret);
2061 }
2062
2063 return desc;
2064}
2065EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2066
2067/**
2068 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2069 * @desc: GPIO descriptor to free
2070 *
2071 * Function frees the given GPIO requested previously with
2072 * gpiochip_request_own_desc().
2073 */
2074void gpiochip_free_own_desc(struct gpio_desc *desc)
2075{
2076 if (desc)
2077 gpiod_free_commit(desc);
2078}
2079EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2080
2081/*
2082 * Drivers MUST set GPIO direction before making get/set calls. In
2083 * some cases this is done in early boot, before IRQs are enabled.
2084 *
2085 * As a rule these aren't called more than once (except for drivers
2086 * using the open-drain emulation idiom) so these are natural places
2087 * to accumulate extra debugging checks. Note that we can't (yet)
2088 * rely on gpio_request() having been called beforehand.
2089 */
2090
2091static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2092 unsigned long config)
2093{
2094 if (!gc->set_config)
2095 return -ENOTSUPP;
2096
2097 return gc->set_config(gc, offset, config);
2098}
2099
2100static int gpio_set_config_with_argument(struct gpio_desc *desc,
2101 enum pin_config_param mode,
2102 u32 argument)
2103{
2104 struct gpio_chip *gc = desc->gdev->chip;
2105 unsigned long config;
2106
2107 config = pinconf_to_config_packed(mode, argument);
2108 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2109}
2110
2111static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2112 enum pin_config_param mode,
2113 u32 argument)
2114{
2115 struct device *dev = &desc->gdev->dev;
2116 int gpio = gpio_chip_hwgpio(desc);
2117 int ret;
2118
2119 ret = gpio_set_config_with_argument(desc, mode, argument);
2120 if (ret != -ENOTSUPP)
2121 return ret;
2122
2123 switch (mode) {
2124 case PIN_CONFIG_PERSIST_STATE:
2125 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2126 break;
2127 default:
2128 break;
2129 }
2130
2131 return 0;
2132}
2133
2134static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2135{
2136 return gpio_set_config_with_argument(desc, mode, 0);
2137}
2138
2139static int gpio_set_bias(struct gpio_desc *desc)
2140{
2141 enum pin_config_param bias;
2142 unsigned int arg;
2143
2144 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2145 bias = PIN_CONFIG_BIAS_DISABLE;
2146 else if (test_bit(FLAG_PULL_UP, &desc->flags))
2147 bias = PIN_CONFIG_BIAS_PULL_UP;
2148 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2149 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2150 else
2151 return 0;
2152
2153 switch (bias) {
2154 case PIN_CONFIG_BIAS_PULL_DOWN:
2155 case PIN_CONFIG_BIAS_PULL_UP:
2156 arg = 1;
2157 break;
2158
2159 default:
2160 arg = 0;
2161 break;
2162 }
2163
2164 return gpio_set_config_with_argument_optional(desc, bias, arg);
2165}
2166
2167int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2168{
2169 return gpio_set_config_with_argument_optional(desc,
2170 PIN_CONFIG_INPUT_DEBOUNCE,
2171 debounce);
2172}
2173
2174/**
2175 * gpiod_direction_input - set the GPIO direction to input
2176 * @desc: GPIO to set to input
2177 *
2178 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2179 * be called safely on it.
2180 *
2181 * Return 0 in case of success, else an error code.
2182 */
2183int gpiod_direction_input(struct gpio_desc *desc)
2184{
2185 struct gpio_chip *gc;
2186 int ret = 0;
2187
2188 VALIDATE_DESC(desc);
2189 gc = desc->gdev->chip;
2190
2191 /*
2192 * It is legal to have no .get() and .direction_input() specified if
2193 * the chip is output-only, but you can't specify .direction_input()
2194 * and not support the .get() operation, that doesn't make sense.
2195 */
2196 if (!gc->get && gc->direction_input) {
2197 gpiod_warn(desc,
2198 "%s: missing get() but have direction_input()\n",
2199 __func__);
2200 return -EIO;
2201 }
2202
2203 /*
2204 * If we have a .direction_input() callback, things are simple,
2205 * just call it. Else we are some input-only chip so try to check the
2206 * direction (if .get_direction() is supported) else we silently
2207 * assume we are in input mode after this.
2208 */
2209 if (gc->direction_input) {
2210 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2211 } else if (gc->get_direction &&
2212 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2213 gpiod_warn(desc,
2214 "%s: missing direction_input() operation and line is output\n",
2215 __func__);
2216 return -EIO;
2217 }
2218 if (ret == 0) {
2219 clear_bit(FLAG_IS_OUT, &desc->flags);
2220 ret = gpio_set_bias(desc);
2221 }
2222
2223 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2224
2225 return ret;
2226}
2227EXPORT_SYMBOL_GPL(gpiod_direction_input);
2228
2229static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2230{
2231 struct gpio_chip *gc = desc->gdev->chip;
2232 int val = !!value;
2233 int ret = 0;
2234
2235 /*
2236 * It's OK not to specify .direction_output() if the gpiochip is
2237 * output-only, but if there is then not even a .set() operation it
2238 * is pretty tricky to drive the output line.
2239 */
2240 if (!gc->set && !gc->direction_output) {
2241 gpiod_warn(desc,
2242 "%s: missing set() and direction_output() operations\n",
2243 __func__);
2244 return -EIO;
2245 }
2246
2247 if (gc->direction_output) {
2248 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2249 } else {
2250 /* Check that we are in output mode if we can */
2251 if (gc->get_direction &&
2252 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2253 gpiod_warn(desc,
2254 "%s: missing direction_output() operation\n",
2255 __func__);
2256 return -EIO;
2257 }
2258 /*
2259 * If we can't actively set the direction, we are some
2260 * output-only chip, so just drive the output as desired.
2261 */
2262 gc->set(gc, gpio_chip_hwgpio(desc), val);
2263 }
2264
2265 if (!ret)
2266 set_bit(FLAG_IS_OUT, &desc->flags);
2267 trace_gpio_value(desc_to_gpio(desc), 0, val);
2268 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2269 return ret;
2270}
2271
2272/**
2273 * gpiod_direction_output_raw - set the GPIO direction to output
2274 * @desc: GPIO to set to output
2275 * @value: initial output value of the GPIO
2276 *
2277 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2278 * be called safely on it. The initial value of the output must be specified
2279 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2280 *
2281 * Return 0 in case of success, else an error code.
2282 */
2283int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2284{
2285 VALIDATE_DESC(desc);
2286 return gpiod_direction_output_raw_commit(desc, value);
2287}
2288EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2289
2290/**
2291 * gpiod_direction_output - set the GPIO direction to output
2292 * @desc: GPIO to set to output
2293 * @value: initial output value of the GPIO
2294 *
2295 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2296 * be called safely on it. The initial value of the output must be specified
2297 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2298 * account.
2299 *
2300 * Return 0 in case of success, else an error code.
2301 */
2302int gpiod_direction_output(struct gpio_desc *desc, int value)
2303{
2304 int ret;
2305
2306 VALIDATE_DESC(desc);
2307 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2308 value = !value;
2309 else
2310 value = !!value;
2311
2312 /* GPIOs used for enabled IRQs shall not be set as output */
2313 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2314 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2315 gpiod_err(desc,
2316 "%s: tried to set a GPIO tied to an IRQ as output\n",
2317 __func__);
2318 return -EIO;
2319 }
2320
2321 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2322 /* First see if we can enable open drain in hardware */
2323 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2324 if (!ret)
2325 goto set_output_value;
2326 /* Emulate open drain by not actively driving the line high */
2327 if (value) {
2328 ret = gpiod_direction_input(desc);
2329 goto set_output_flag;
2330 }
2331 }
2332 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2333 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2334 if (!ret)
2335 goto set_output_value;
2336 /* Emulate open source by not actively driving the line low */
2337 if (!value) {
2338 ret = gpiod_direction_input(desc);
2339 goto set_output_flag;
2340 }
2341 } else {
2342 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2343 }
2344
2345set_output_value:
2346 ret = gpio_set_bias(desc);
2347 if (ret)
2348 return ret;
2349 return gpiod_direction_output_raw_commit(desc, value);
2350
2351set_output_flag:
2352 /*
2353 * When emulating open-source or open-drain functionalities by not
2354 * actively driving the line (setting mode to input) we still need to
2355 * set the IS_OUT flag or otherwise we won't be able to set the line
2356 * value anymore.
2357 */
2358 if (ret == 0)
2359 set_bit(FLAG_IS_OUT, &desc->flags);
2360 return ret;
2361}
2362EXPORT_SYMBOL_GPL(gpiod_direction_output);
2363
2364/**
2365 * gpiod_set_config - sets @config for a GPIO
2366 * @desc: descriptor of the GPIO for which to set the configuration
2367 * @config: Same packed config format as generic pinconf
2368 *
2369 * Returns:
2370 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2371 * configuration.
2372 */
2373int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2374{
2375 struct gpio_chip *gc;
2376
2377 VALIDATE_DESC(desc);
2378 gc = desc->gdev->chip;
2379
2380 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2381}
2382EXPORT_SYMBOL_GPL(gpiod_set_config);
2383
2384/**
2385 * gpiod_set_debounce - sets @debounce time for a GPIO
2386 * @desc: descriptor of the GPIO for which to set debounce time
2387 * @debounce: debounce time in microseconds
2388 *
2389 * Returns:
2390 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2391 * debounce time.
2392 */
2393int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2394{
2395 unsigned long config;
2396
2397 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2398 return gpiod_set_config(desc, config);
2399}
2400EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2401
2402/**
2403 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2404 * @desc: descriptor of the GPIO for which to configure persistence
2405 * @transitory: True to lose state on suspend or reset, false for persistence
2406 *
2407 * Returns:
2408 * 0 on success, otherwise a negative error code.
2409 */
2410int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2411{
2412 VALIDATE_DESC(desc);
2413 /*
2414 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2415 * persistence state.
2416 */
2417 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2418
2419 /* If the driver supports it, set the persistence state now */
2420 return gpio_set_config_with_argument_optional(desc,
2421 PIN_CONFIG_PERSIST_STATE,
2422 !transitory);
2423}
2424EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2425
2426/**
2427 * gpiod_is_active_low - test whether a GPIO is active-low or not
2428 * @desc: the gpio descriptor to test
2429 *
2430 * Returns 1 if the GPIO is active-low, 0 otherwise.
2431 */
2432int gpiod_is_active_low(const struct gpio_desc *desc)
2433{
2434 VALIDATE_DESC(desc);
2435 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2436}
2437EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2438
2439/**
2440 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2441 * @desc: the gpio descriptor to change
2442 */
2443void gpiod_toggle_active_low(struct gpio_desc *desc)
2444{
2445 VALIDATE_DESC_VOID(desc);
2446 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2447}
2448EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2449
2450/* I/O calls are only valid after configuration completed; the relevant
2451 * "is this a valid GPIO" error checks should already have been done.
2452 *
2453 * "Get" operations are often inlinable as reading a pin value register,
2454 * and masking the relevant bit in that register.
2455 *
2456 * When "set" operations are inlinable, they involve writing that mask to
2457 * one register to set a low value, or a different register to set it high.
2458 * Otherwise locking is needed, so there may be little value to inlining.
2459 *
2460 *------------------------------------------------------------------------
2461 *
2462 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2463 * have requested the GPIO. That can include implicit requesting by
2464 * a direction setting call. Marking a gpio as requested locks its chip
2465 * in memory, guaranteeing that these table lookups need no more locking
2466 * and that gpiochip_remove() will fail.
2467 *
2468 * REVISIT when debugging, consider adding some instrumentation to ensure
2469 * that the GPIO was actually requested.
2470 */
2471
2472static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2473{
2474 struct gpio_chip *gc;
2475 int offset;
2476 int value;
2477
2478 gc = desc->gdev->chip;
2479 offset = gpio_chip_hwgpio(desc);
2480 value = gc->get ? gc->get(gc, offset) : -EIO;
2481 value = value < 0 ? value : !!value;
2482 trace_gpio_value(desc_to_gpio(desc), 1, value);
2483 return value;
2484}
2485
2486static int gpio_chip_get_multiple(struct gpio_chip *gc,
2487 unsigned long *mask, unsigned long *bits)
2488{
2489 if (gc->get_multiple) {
2490 return gc->get_multiple(gc, mask, bits);
2491 } else if (gc->get) {
2492 int i, value;
2493
2494 for_each_set_bit(i, mask, gc->ngpio) {
2495 value = gc->get(gc, i);
2496 if (value < 0)
2497 return value;
2498 __assign_bit(i, bits, value);
2499 }
2500 return 0;
2501 }
2502 return -EIO;
2503}
2504
2505int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2506 unsigned int array_size,
2507 struct gpio_desc **desc_array,
2508 struct gpio_array *array_info,
2509 unsigned long *value_bitmap)
2510{
2511 int ret, i = 0;
2512
2513 /*
2514 * Validate array_info against desc_array and its size.
2515 * It should immediately follow desc_array if both
2516 * have been obtained from the same gpiod_get_array() call.
2517 */
2518 if (array_info && array_info->desc == desc_array &&
2519 array_size <= array_info->size &&
2520 (void *)array_info == desc_array + array_info->size) {
2521 if (!can_sleep)
2522 WARN_ON(array_info->chip->can_sleep);
2523
2524 ret = gpio_chip_get_multiple(array_info->chip,
2525 array_info->get_mask,
2526 value_bitmap);
2527 if (ret)
2528 return ret;
2529
2530 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2531 bitmap_xor(value_bitmap, value_bitmap,
2532 array_info->invert_mask, array_size);
2533
2534 i = find_first_zero_bit(array_info->get_mask, array_size);
2535 if (i == array_size)
2536 return 0;
2537 } else {
2538 array_info = NULL;
2539 }
2540
2541 while (i < array_size) {
2542 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2543 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2544 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2545 unsigned long *mask, *bits;
2546 int first, j;
2547
2548 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2549 mask = fastpath_mask;
2550 bits = fastpath_bits;
2551 } else {
2552 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2553
2554 mask = bitmap_alloc(gc->ngpio, flags);
2555 if (!mask)
2556 return -ENOMEM;
2557
2558 bits = bitmap_alloc(gc->ngpio, flags);
2559 if (!bits) {
2560 bitmap_free(mask);
2561 return -ENOMEM;
2562 }
2563 }
2564
2565 bitmap_zero(mask, gc->ngpio);
2566
2567 if (!can_sleep)
2568 WARN_ON(gc->can_sleep);
2569
2570 /* collect all inputs belonging to the same chip */
2571 first = i;
2572 do {
2573 const struct gpio_desc *desc = desc_array[i];
2574 int hwgpio = gpio_chip_hwgpio(desc);
2575
2576 __set_bit(hwgpio, mask);
2577 i++;
2578
2579 if (array_info)
2580 i = find_next_zero_bit(array_info->get_mask,
2581 array_size, i);
2582 } while ((i < array_size) &&
2583 (desc_array[i]->gdev->chip == gc));
2584
2585 ret = gpio_chip_get_multiple(gc, mask, bits);
2586 if (ret) {
2587 if (mask != fastpath_mask)
2588 bitmap_free(mask);
2589 if (bits != fastpath_bits)
2590 bitmap_free(bits);
2591 return ret;
2592 }
2593
2594 for (j = first; j < i; ) {
2595 const struct gpio_desc *desc = desc_array[j];
2596 int hwgpio = gpio_chip_hwgpio(desc);
2597 int value = test_bit(hwgpio, bits);
2598
2599 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2600 value = !value;
2601 __assign_bit(j, value_bitmap, value);
2602 trace_gpio_value(desc_to_gpio(desc), 1, value);
2603 j++;
2604
2605 if (array_info)
2606 j = find_next_zero_bit(array_info->get_mask, i,
2607 j);
2608 }
2609
2610 if (mask != fastpath_mask)
2611 bitmap_free(mask);
2612 if (bits != fastpath_bits)
2613 bitmap_free(bits);
2614 }
2615 return 0;
2616}
2617
2618/**
2619 * gpiod_get_raw_value() - return a gpio's raw value
2620 * @desc: gpio whose value will be returned
2621 *
2622 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2623 * its ACTIVE_LOW status, or negative errno on failure.
2624 *
2625 * This function can be called from contexts where we cannot sleep, and will
2626 * complain if the GPIO chip functions potentially sleep.
2627 */
2628int gpiod_get_raw_value(const struct gpio_desc *desc)
2629{
2630 VALIDATE_DESC(desc);
2631 /* Should be using gpiod_get_raw_value_cansleep() */
2632 WARN_ON(desc->gdev->chip->can_sleep);
2633 return gpiod_get_raw_value_commit(desc);
2634}
2635EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2636
2637/**
2638 * gpiod_get_value() - return a gpio's value
2639 * @desc: gpio whose value will be returned
2640 *
2641 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2642 * account, or negative errno on failure.
2643 *
2644 * This function can be called from contexts where we cannot sleep, and will
2645 * complain if the GPIO chip functions potentially sleep.
2646 */
2647int gpiod_get_value(const struct gpio_desc *desc)
2648{
2649 int value;
2650
2651 VALIDATE_DESC(desc);
2652 /* Should be using gpiod_get_value_cansleep() */
2653 WARN_ON(desc->gdev->chip->can_sleep);
2654
2655 value = gpiod_get_raw_value_commit(desc);
2656 if (value < 0)
2657 return value;
2658
2659 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2660 value = !value;
2661
2662 return value;
2663}
2664EXPORT_SYMBOL_GPL(gpiod_get_value);
2665
2666/**
2667 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2668 * @array_size: number of elements in the descriptor array / value bitmap
2669 * @desc_array: array of GPIO descriptors whose values will be read
2670 * @array_info: information on applicability of fast bitmap processing path
2671 * @value_bitmap: bitmap to store the read values
2672 *
2673 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2674 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2675 * else an error code.
2676 *
2677 * This function can be called from contexts where we cannot sleep,
2678 * and it will complain if the GPIO chip functions potentially sleep.
2679 */
2680int gpiod_get_raw_array_value(unsigned int array_size,
2681 struct gpio_desc **desc_array,
2682 struct gpio_array *array_info,
2683 unsigned long *value_bitmap)
2684{
2685 if (!desc_array)
2686 return -EINVAL;
2687 return gpiod_get_array_value_complex(true, false, array_size,
2688 desc_array, array_info,
2689 value_bitmap);
2690}
2691EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2692
2693/**
2694 * gpiod_get_array_value() - read values from an array of GPIOs
2695 * @array_size: number of elements in the descriptor array / value bitmap
2696 * @desc_array: array of GPIO descriptors whose values will be read
2697 * @array_info: information on applicability of fast bitmap processing path
2698 * @value_bitmap: bitmap to store the read values
2699 *
2700 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2701 * into account. Return 0 in case of success, else an error code.
2702 *
2703 * This function can be called from contexts where we cannot sleep,
2704 * and it will complain if the GPIO chip functions potentially sleep.
2705 */
2706int gpiod_get_array_value(unsigned int array_size,
2707 struct gpio_desc **desc_array,
2708 struct gpio_array *array_info,
2709 unsigned long *value_bitmap)
2710{
2711 if (!desc_array)
2712 return -EINVAL;
2713 return gpiod_get_array_value_complex(false, false, array_size,
2714 desc_array, array_info,
2715 value_bitmap);
2716}
2717EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2718
2719/*
2720 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2721 * @desc: gpio descriptor whose state need to be set.
2722 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2723 */
2724static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2725{
2726 int ret = 0;
2727 struct gpio_chip *gc = desc->gdev->chip;
2728 int offset = gpio_chip_hwgpio(desc);
2729
2730 if (value) {
2731 ret = gc->direction_input(gc, offset);
2732 } else {
2733 ret = gc->direction_output(gc, offset, 0);
2734 if (!ret)
2735 set_bit(FLAG_IS_OUT, &desc->flags);
2736 }
2737 trace_gpio_direction(desc_to_gpio(desc), value, ret);
2738 if (ret < 0)
2739 gpiod_err(desc,
2740 "%s: Error in set_value for open drain err %d\n",
2741 __func__, ret);
2742}
2743
2744/*
2745 * _gpio_set_open_source_value() - Set the open source gpio's value.
2746 * @desc: gpio descriptor whose state need to be set.
2747 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2748 */
2749static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2750{
2751 int ret = 0;
2752 struct gpio_chip *gc = desc->gdev->chip;
2753 int offset = gpio_chip_hwgpio(desc);
2754
2755 if (value) {
2756 ret = gc->direction_output(gc, offset, 1);
2757 if (!ret)
2758 set_bit(FLAG_IS_OUT, &desc->flags);
2759 } else {
2760 ret = gc->direction_input(gc, offset);
2761 }
2762 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2763 if (ret < 0)
2764 gpiod_err(desc,
2765 "%s: Error in set_value for open source err %d\n",
2766 __func__, ret);
2767}
2768
2769static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2770{
2771 struct gpio_chip *gc;
2772
2773 gc = desc->gdev->chip;
2774 trace_gpio_value(desc_to_gpio(desc), 0, value);
2775 gc->set(gc, gpio_chip_hwgpio(desc), value);
2776}
2777
2778/*
2779 * set multiple outputs on the same chip;
2780 * use the chip's set_multiple function if available;
2781 * otherwise set the outputs sequentially;
2782 * @chip: the GPIO chip we operate on
2783 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2784 * defines which outputs are to be changed
2785 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2786 * defines the values the outputs specified by mask are to be set to
2787 */
2788static void gpio_chip_set_multiple(struct gpio_chip *gc,
2789 unsigned long *mask, unsigned long *bits)
2790{
2791 if (gc->set_multiple) {
2792 gc->set_multiple(gc, mask, bits);
2793 } else {
2794 unsigned int i;
2795
2796 /* set outputs if the corresponding mask bit is set */
2797 for_each_set_bit(i, mask, gc->ngpio)
2798 gc->set(gc, i, test_bit(i, bits));
2799 }
2800}
2801
2802int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2803 unsigned int array_size,
2804 struct gpio_desc **desc_array,
2805 struct gpio_array *array_info,
2806 unsigned long *value_bitmap)
2807{
2808 int i = 0;
2809
2810 /*
2811 * Validate array_info against desc_array and its size.
2812 * It should immediately follow desc_array if both
2813 * have been obtained from the same gpiod_get_array() call.
2814 */
2815 if (array_info && array_info->desc == desc_array &&
2816 array_size <= array_info->size &&
2817 (void *)array_info == desc_array + array_info->size) {
2818 if (!can_sleep)
2819 WARN_ON(array_info->chip->can_sleep);
2820
2821 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2822 bitmap_xor(value_bitmap, value_bitmap,
2823 array_info->invert_mask, array_size);
2824
2825 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2826 value_bitmap);
2827
2828 i = find_first_zero_bit(array_info->set_mask, array_size);
2829 if (i == array_size)
2830 return 0;
2831 } else {
2832 array_info = NULL;
2833 }
2834
2835 while (i < array_size) {
2836 struct gpio_chip *gc = desc_array[i]->gdev->chip;
2837 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2838 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2839 unsigned long *mask, *bits;
2840 int count = 0;
2841
2842 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2843 mask = fastpath_mask;
2844 bits = fastpath_bits;
2845 } else {
2846 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2847
2848 mask = bitmap_alloc(gc->ngpio, flags);
2849 if (!mask)
2850 return -ENOMEM;
2851
2852 bits = bitmap_alloc(gc->ngpio, flags);
2853 if (!bits) {
2854 bitmap_free(mask);
2855 return -ENOMEM;
2856 }
2857 }
2858
2859 bitmap_zero(mask, gc->ngpio);
2860
2861 if (!can_sleep)
2862 WARN_ON(gc->can_sleep);
2863
2864 do {
2865 struct gpio_desc *desc = desc_array[i];
2866 int hwgpio = gpio_chip_hwgpio(desc);
2867 int value = test_bit(i, value_bitmap);
2868
2869 /*
2870 * Pins applicable for fast input but not for
2871 * fast output processing may have been already
2872 * inverted inside the fast path, skip them.
2873 */
2874 if (!raw && !(array_info &&
2875 test_bit(i, array_info->invert_mask)) &&
2876 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2877 value = !value;
2878 trace_gpio_value(desc_to_gpio(desc), 0, value);
2879 /*
2880 * collect all normal outputs belonging to the same chip
2881 * open drain and open source outputs are set individually
2882 */
2883 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2884 gpio_set_open_drain_value_commit(desc, value);
2885 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2886 gpio_set_open_source_value_commit(desc, value);
2887 } else {
2888 __set_bit(hwgpio, mask);
2889 __assign_bit(hwgpio, bits, value);
2890 count++;
2891 }
2892 i++;
2893
2894 if (array_info)
2895 i = find_next_zero_bit(array_info->set_mask,
2896 array_size, i);
2897 } while ((i < array_size) &&
2898 (desc_array[i]->gdev->chip == gc));
2899 /* push collected bits to outputs */
2900 if (count != 0)
2901 gpio_chip_set_multiple(gc, mask, bits);
2902
2903 if (mask != fastpath_mask)
2904 bitmap_free(mask);
2905 if (bits != fastpath_bits)
2906 bitmap_free(bits);
2907 }
2908 return 0;
2909}
2910
2911/**
2912 * gpiod_set_raw_value() - assign a gpio's raw value
2913 * @desc: gpio whose value will be assigned
2914 * @value: value to assign
2915 *
2916 * Set the raw value of the GPIO, i.e. the value of its physical line without
2917 * regard for its ACTIVE_LOW status.
2918 *
2919 * This function can be called from contexts where we cannot sleep, and will
2920 * complain if the GPIO chip functions potentially sleep.
2921 */
2922void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2923{
2924 VALIDATE_DESC_VOID(desc);
2925 /* Should be using gpiod_set_raw_value_cansleep() */
2926 WARN_ON(desc->gdev->chip->can_sleep);
2927 gpiod_set_raw_value_commit(desc, value);
2928}
2929EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2930
2931/**
2932 * gpiod_set_value_nocheck() - set a GPIO line value without checking
2933 * @desc: the descriptor to set the value on
2934 * @value: value to set
2935 *
2936 * This sets the value of a GPIO line backing a descriptor, applying
2937 * different semantic quirks like active low and open drain/source
2938 * handling.
2939 */
2940static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
2941{
2942 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2943 value = !value;
2944 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2945 gpio_set_open_drain_value_commit(desc, value);
2946 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2947 gpio_set_open_source_value_commit(desc, value);
2948 else
2949 gpiod_set_raw_value_commit(desc, value);
2950}
2951
2952/**
2953 * gpiod_set_value() - assign a gpio's value
2954 * @desc: gpio whose value will be assigned
2955 * @value: value to assign
2956 *
2957 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
2958 * OPEN_DRAIN and OPEN_SOURCE flags into account.
2959 *
2960 * This function can be called from contexts where we cannot sleep, and will
2961 * complain if the GPIO chip functions potentially sleep.
2962 */
2963void gpiod_set_value(struct gpio_desc *desc, int value)
2964{
2965 VALIDATE_DESC_VOID(desc);
2966 /* Should be using gpiod_set_value_cansleep() */
2967 WARN_ON(desc->gdev->chip->can_sleep);
2968 gpiod_set_value_nocheck(desc, value);
2969}
2970EXPORT_SYMBOL_GPL(gpiod_set_value);
2971
2972/**
2973 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
2974 * @array_size: number of elements in the descriptor array / value bitmap
2975 * @desc_array: array of GPIO descriptors whose values will be assigned
2976 * @array_info: information on applicability of fast bitmap processing path
2977 * @value_bitmap: bitmap of values to assign
2978 *
2979 * Set the raw values of the GPIOs, i.e. the values of the physical lines
2980 * without regard for their ACTIVE_LOW status.
2981 *
2982 * This function can be called from contexts where we cannot sleep, and will
2983 * complain if the GPIO chip functions potentially sleep.
2984 */
2985int gpiod_set_raw_array_value(unsigned int array_size,
2986 struct gpio_desc **desc_array,
2987 struct gpio_array *array_info,
2988 unsigned long *value_bitmap)
2989{
2990 if (!desc_array)
2991 return -EINVAL;
2992 return gpiod_set_array_value_complex(true, false, array_size,
2993 desc_array, array_info, value_bitmap);
2994}
2995EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2996
2997/**
2998 * gpiod_set_array_value() - assign values to an array of GPIOs
2999 * @array_size: number of elements in the descriptor array / value bitmap
3000 * @desc_array: array of GPIO descriptors whose values will be assigned
3001 * @array_info: information on applicability of fast bitmap processing path
3002 * @value_bitmap: bitmap of values to assign
3003 *
3004 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3005 * into account.
3006 *
3007 * This function can be called from contexts where we cannot sleep, and will
3008 * complain if the GPIO chip functions potentially sleep.
3009 */
3010int gpiod_set_array_value(unsigned int array_size,
3011 struct gpio_desc **desc_array,
3012 struct gpio_array *array_info,
3013 unsigned long *value_bitmap)
3014{
3015 if (!desc_array)
3016 return -EINVAL;
3017 return gpiod_set_array_value_complex(false, false, array_size,
3018 desc_array, array_info,
3019 value_bitmap);
3020}
3021EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3022
3023/**
3024 * gpiod_cansleep() - report whether gpio value access may sleep
3025 * @desc: gpio to check
3026 *
3027 */
3028int gpiod_cansleep(const struct gpio_desc *desc)
3029{
3030 VALIDATE_DESC(desc);
3031 return desc->gdev->chip->can_sleep;
3032}
3033EXPORT_SYMBOL_GPL(gpiod_cansleep);
3034
3035/**
3036 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3037 * @desc: gpio to set the consumer name on
3038 * @name: the new consumer name
3039 */
3040int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3041{
3042 VALIDATE_DESC(desc);
3043 if (name) {
3044 name = kstrdup_const(name, GFP_KERNEL);
3045 if (!name)
3046 return -ENOMEM;
3047 }
3048
3049 kfree_const(desc->label);
3050 desc_set_label(desc, name);
3051
3052 return 0;
3053}
3054EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3055
3056/**
3057 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3058 * @desc: gpio whose IRQ will be returned (already requested)
3059 *
3060 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3061 * error.
3062 */
3063int gpiod_to_irq(const struct gpio_desc *desc)
3064{
3065 struct gpio_chip *gc;
3066 int offset;
3067
3068 /*
3069 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3070 * requires this function to not return zero on an invalid descriptor
3071 * but rather a negative error number.
3072 */
3073 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3074 return -EINVAL;
3075
3076 gc = desc->gdev->chip;
3077 offset = gpio_chip_hwgpio(desc);
3078 if (gc->to_irq) {
3079 int retirq = gc->to_irq(gc, offset);
3080
3081 /* Zero means NO_IRQ */
3082 if (!retirq)
3083 return -ENXIO;
3084
3085 return retirq;
3086 }
3087 return -ENXIO;
3088}
3089EXPORT_SYMBOL_GPL(gpiod_to_irq);
3090
3091/**
3092 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3093 * @gc: the chip the GPIO to lock belongs to
3094 * @offset: the offset of the GPIO to lock as IRQ
3095 *
3096 * This is used directly by GPIO drivers that want to lock down
3097 * a certain GPIO line to be used for IRQs.
3098 */
3099int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3100{
3101 struct gpio_desc *desc;
3102
3103 desc = gpiochip_get_desc(gc, offset);
3104 if (IS_ERR(desc))
3105 return PTR_ERR(desc);
3106
3107 /*
3108 * If it's fast: flush the direction setting if something changed
3109 * behind our back
3110 */
3111 if (!gc->can_sleep && gc->get_direction) {
3112 int dir = gpiod_get_direction(desc);
3113
3114 if (dir < 0) {
3115 chip_err(gc, "%s: cannot get GPIO direction\n",
3116 __func__);
3117 return dir;
3118 }
3119 }
3120
3121 /* To be valid for IRQ the line needs to be input or open drain */
3122 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3123 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3124 chip_err(gc,
3125 "%s: tried to flag a GPIO set as output for IRQ\n",
3126 __func__);
3127 return -EIO;
3128 }
3129
3130 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3131 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3132
3133 /*
3134 * If the consumer has not set up a label (such as when the
3135 * IRQ is referenced from .to_irq()) we set up a label here
3136 * so it is clear this is used as an interrupt.
3137 */
3138 if (!desc->label)
3139 desc_set_label(desc, "interrupt");
3140
3141 return 0;
3142}
3143EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3144
3145/**
3146 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3147 * @gc: the chip the GPIO to lock belongs to
3148 * @offset: the offset of the GPIO to lock as IRQ
3149 *
3150 * This is used directly by GPIO drivers that want to indicate
3151 * that a certain GPIO is no longer used exclusively for IRQ.
3152 */
3153void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3154{
3155 struct gpio_desc *desc;
3156
3157 desc = gpiochip_get_desc(gc, offset);
3158 if (IS_ERR(desc))
3159 return;
3160
3161 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3162 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3163
3164 /* If we only had this marking, erase it */
3165 if (desc->label && !strcmp(desc->label, "interrupt"))
3166 desc_set_label(desc, NULL);
3167}
3168EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3169
3170void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3171{
3172 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3173
3174 if (!IS_ERR(desc) &&
3175 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3176 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3177}
3178EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3179
3180void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3181{
3182 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3183
3184 if (!IS_ERR(desc) &&
3185 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3186 /*
3187 * We must not be output when using IRQ UNLESS we are
3188 * open drain.
3189 */
3190 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3191 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3192 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3193 }
3194}
3195EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3196
3197bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3198{
3199 if (offset >= gc->ngpio)
3200 return false;
3201
3202 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3203}
3204EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3205
3206int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3207{
3208 int ret;
3209
3210 if (!try_module_get(gc->gpiodev->owner))
3211 return -ENODEV;
3212
3213 ret = gpiochip_lock_as_irq(gc, offset);
3214 if (ret) {
3215 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3216 module_put(gc->gpiodev->owner);
3217 return ret;
3218 }
3219 return 0;
3220}
3221EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3222
3223void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3224{
3225 gpiochip_unlock_as_irq(gc, offset);
3226 module_put(gc->gpiodev->owner);
3227}
3228EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3229
3230bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3231{
3232 if (offset >= gc->ngpio)
3233 return false;
3234
3235 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3236}
3237EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3238
3239bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3240{
3241 if (offset >= gc->ngpio)
3242 return false;
3243
3244 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3245}
3246EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3247
3248bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3249{
3250 if (offset >= gc->ngpio)
3251 return false;
3252
3253 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3254}
3255EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3256
3257/**
3258 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3259 * @desc: gpio whose value will be returned
3260 *
3261 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3262 * its ACTIVE_LOW status, or negative errno on failure.
3263 *
3264 * This function is to be called from contexts that can sleep.
3265 */
3266int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3267{
3268 might_sleep_if(extra_checks);
3269 VALIDATE_DESC(desc);
3270 return gpiod_get_raw_value_commit(desc);
3271}
3272EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3273
3274/**
3275 * gpiod_get_value_cansleep() - return a gpio's value
3276 * @desc: gpio whose value will be returned
3277 *
3278 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3279 * account, or negative errno on failure.
3280 *
3281 * This function is to be called from contexts that can sleep.
3282 */
3283int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3284{
3285 int value;
3286
3287 might_sleep_if(extra_checks);
3288 VALIDATE_DESC(desc);
3289 value = gpiod_get_raw_value_commit(desc);
3290 if (value < 0)
3291 return value;
3292
3293 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3294 value = !value;
3295
3296 return value;
3297}
3298EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3299
3300/**
3301 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3302 * @array_size: number of elements in the descriptor array / value bitmap
3303 * @desc_array: array of GPIO descriptors whose values will be read
3304 * @array_info: information on applicability of fast bitmap processing path
3305 * @value_bitmap: bitmap to store the read values
3306 *
3307 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3308 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3309 * else an error code.
3310 *
3311 * This function is to be called from contexts that can sleep.
3312 */
3313int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3314 struct gpio_desc **desc_array,
3315 struct gpio_array *array_info,
3316 unsigned long *value_bitmap)
3317{
3318 might_sleep_if(extra_checks);
3319 if (!desc_array)
3320 return -EINVAL;
3321 return gpiod_get_array_value_complex(true, true, array_size,
3322 desc_array, array_info,
3323 value_bitmap);
3324}
3325EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3326
3327/**
3328 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3329 * @array_size: number of elements in the descriptor array / value bitmap
3330 * @desc_array: array of GPIO descriptors whose values will be read
3331 * @array_info: information on applicability of fast bitmap processing path
3332 * @value_bitmap: bitmap to store the read values
3333 *
3334 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3335 * into account. Return 0 in case of success, else an error code.
3336 *
3337 * This function is to be called from contexts that can sleep.
3338 */
3339int gpiod_get_array_value_cansleep(unsigned int array_size,
3340 struct gpio_desc **desc_array,
3341 struct gpio_array *array_info,
3342 unsigned long *value_bitmap)
3343{
3344 might_sleep_if(extra_checks);
3345 if (!desc_array)
3346 return -EINVAL;
3347 return gpiod_get_array_value_complex(false, true, array_size,
3348 desc_array, array_info,
3349 value_bitmap);
3350}
3351EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3352
3353/**
3354 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3355 * @desc: gpio whose value will be assigned
3356 * @value: value to assign
3357 *
3358 * Set the raw value of the GPIO, i.e. the value of its physical line without
3359 * regard for its ACTIVE_LOW status.
3360 *
3361 * This function is to be called from contexts that can sleep.
3362 */
3363void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3364{
3365 might_sleep_if(extra_checks);
3366 VALIDATE_DESC_VOID(desc);
3367 gpiod_set_raw_value_commit(desc, value);
3368}
3369EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3370
3371/**
3372 * gpiod_set_value_cansleep() - assign a gpio's value
3373 * @desc: gpio whose value will be assigned
3374 * @value: value to assign
3375 *
3376 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3377 * account
3378 *
3379 * This function is to be called from contexts that can sleep.
3380 */
3381void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3382{
3383 might_sleep_if(extra_checks);
3384 VALIDATE_DESC_VOID(desc);
3385 gpiod_set_value_nocheck(desc, value);
3386}
3387EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3388
3389/**
3390 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3391 * @array_size: number of elements in the descriptor array / value bitmap
3392 * @desc_array: array of GPIO descriptors whose values will be assigned
3393 * @array_info: information on applicability of fast bitmap processing path
3394 * @value_bitmap: bitmap of values to assign
3395 *
3396 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3397 * without regard for their ACTIVE_LOW status.
3398 *
3399 * This function is to be called from contexts that can sleep.
3400 */
3401int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3402 struct gpio_desc **desc_array,
3403 struct gpio_array *array_info,
3404 unsigned long *value_bitmap)
3405{
3406 might_sleep_if(extra_checks);
3407 if (!desc_array)
3408 return -EINVAL;
3409 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3410 array_info, value_bitmap);
3411}
3412EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3413
3414/**
3415 * gpiod_add_lookup_tables() - register GPIO device consumers
3416 * @tables: list of tables of consumers to register
3417 * @n: number of tables in the list
3418 */
3419void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3420{
3421 unsigned int i;
3422
3423 mutex_lock(&gpio_lookup_lock);
3424
3425 for (i = 0; i < n; i++)
3426 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3427
3428 mutex_unlock(&gpio_lookup_lock);
3429}
3430
3431/**
3432 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3433 * @array_size: number of elements in the descriptor array / value bitmap
3434 * @desc_array: array of GPIO descriptors whose values will be assigned
3435 * @array_info: information on applicability of fast bitmap processing path
3436 * @value_bitmap: bitmap of values to assign
3437 *
3438 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3439 * into account.
3440 *
3441 * This function is to be called from contexts that can sleep.
3442 */
3443int gpiod_set_array_value_cansleep(unsigned int array_size,
3444 struct gpio_desc **desc_array,
3445 struct gpio_array *array_info,
3446 unsigned long *value_bitmap)
3447{
3448 might_sleep_if(extra_checks);
3449 if (!desc_array)
3450 return -EINVAL;
3451 return gpiod_set_array_value_complex(false, true, array_size,
3452 desc_array, array_info,
3453 value_bitmap);
3454}
3455EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3456
3457/**
3458 * gpiod_add_lookup_table() - register GPIO device consumers
3459 * @table: table of consumers to register
3460 */
3461void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3462{
3463 mutex_lock(&gpio_lookup_lock);
3464
3465 list_add_tail(&table->list, &gpio_lookup_list);
3466
3467 mutex_unlock(&gpio_lookup_lock);
3468}
3469EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3470
3471/**
3472 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3473 * @table: table of consumers to unregister
3474 */
3475void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3476{
3477 /* Nothing to remove */
3478 if (!table)
3479 return;
3480
3481 mutex_lock(&gpio_lookup_lock);
3482
3483 list_del(&table->list);
3484
3485 mutex_unlock(&gpio_lookup_lock);
3486}
3487EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3488
3489/**
3490 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3491 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3492 */
3493void gpiod_add_hogs(struct gpiod_hog *hogs)
3494{
3495 struct gpio_chip *gc;
3496 struct gpiod_hog *hog;
3497
3498 mutex_lock(&gpio_machine_hogs_mutex);
3499
3500 for (hog = &hogs[0]; hog->chip_label; hog++) {
3501 list_add_tail(&hog->list, &gpio_machine_hogs);
3502
3503 /*
3504 * The chip may have been registered earlier, so check if it
3505 * exists and, if so, try to hog the line now.
3506 */
3507 gc = find_chip_by_name(hog->chip_label);
3508 if (gc)
3509 gpiochip_machine_hog(gc, hog);
3510 }
3511
3512 mutex_unlock(&gpio_machine_hogs_mutex);
3513}
3514EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3515
3516static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3517{
3518 const char *dev_id = dev ? dev_name(dev) : NULL;
3519 struct gpiod_lookup_table *table;
3520
3521 mutex_lock(&gpio_lookup_lock);
3522
3523 list_for_each_entry(table, &gpio_lookup_list, list) {
3524 if (table->dev_id && dev_id) {
3525 /*
3526 * Valid strings on both ends, must be identical to have
3527 * a match
3528 */
3529 if (!strcmp(table->dev_id, dev_id))
3530 goto found;
3531 } else {
3532 /*
3533 * One of the pointers is NULL, so both must be to have
3534 * a match
3535 */
3536 if (dev_id == table->dev_id)
3537 goto found;
3538 }
3539 }
3540 table = NULL;
3541
3542found:
3543 mutex_unlock(&gpio_lookup_lock);
3544 return table;
3545}
3546
3547static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3548 unsigned int idx, unsigned long *flags)
3549{
3550 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3551 struct gpiod_lookup_table *table;
3552 struct gpiod_lookup *p;
3553
3554 table = gpiod_find_lookup_table(dev);
3555 if (!table)
3556 return desc;
3557
3558 for (p = &table->table[0]; p->key; p++) {
3559 struct gpio_chip *gc;
3560
3561 /* idx must always match exactly */
3562 if (p->idx != idx)
3563 continue;
3564
3565 /* If the lookup entry has a con_id, require exact match */
3566 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3567 continue;
3568
3569 if (p->chip_hwnum == U16_MAX) {
3570 desc = gpio_name_to_desc(p->key);
3571 if (desc) {
3572 *flags = p->flags;
3573 return desc;
3574 }
3575
3576 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3577 p->key);
3578 return ERR_PTR(-EPROBE_DEFER);
3579 }
3580
3581 gc = find_chip_by_name(p->key);
3582
3583 if (!gc) {
3584 /*
3585 * As the lookup table indicates a chip with
3586 * p->key should exist, assume it may
3587 * still appear later and let the interested
3588 * consumer be probed again or let the Deferred
3589 * Probe infrastructure handle the error.
3590 */
3591 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3592 p->key);
3593 return ERR_PTR(-EPROBE_DEFER);
3594 }
3595
3596 if (gc->ngpio <= p->chip_hwnum) {
3597 dev_err(dev,
3598 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3599 idx, p->chip_hwnum, gc->ngpio - 1,
3600 gc->label);
3601 return ERR_PTR(-EINVAL);
3602 }
3603
3604 desc = gpiochip_get_desc(gc, p->chip_hwnum);
3605 *flags = p->flags;
3606
3607 return desc;
3608 }
3609
3610 return desc;
3611}
3612
3613static int platform_gpio_count(struct device *dev, const char *con_id)
3614{
3615 struct gpiod_lookup_table *table;
3616 struct gpiod_lookup *p;
3617 unsigned int count = 0;
3618
3619 table = gpiod_find_lookup_table(dev);
3620 if (!table)
3621 return -ENOENT;
3622
3623 for (p = &table->table[0]; p->key; p++) {
3624 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3625 (!con_id && !p->con_id))
3626 count++;
3627 }
3628 if (!count)
3629 return -ENOENT;
3630
3631 return count;
3632}
3633
3634/**
3635 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3636 * @fwnode: handle of the firmware node
3637 * @con_id: function within the GPIO consumer
3638 * @index: index of the GPIO to obtain for the consumer
3639 * @flags: GPIO initialization flags
3640 * @label: label to attach to the requested GPIO
3641 *
3642 * This function can be used for drivers that get their configuration
3643 * from opaque firmware.
3644 *
3645 * The function properly finds the corresponding GPIO using whatever is the
3646 * underlying firmware interface and then makes sure that the GPIO
3647 * descriptor is requested before it is returned to the caller.
3648 *
3649 * Returns:
3650 * On successful request the GPIO pin is configured in accordance with
3651 * provided @flags.
3652 *
3653 * In case of error an ERR_PTR() is returned.
3654 */
3655struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3656 const char *con_id, int index,
3657 enum gpiod_flags flags,
3658 const char *label)
3659{
3660 struct gpio_desc *desc;
3661 char prop_name[32]; /* 32 is max size of property name */
3662 unsigned int i;
3663
3664 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3665 if (con_id)
3666 snprintf(prop_name, sizeof(prop_name), "%s-%s",
3667 con_id, gpio_suffixes[i]);
3668 else
3669 snprintf(prop_name, sizeof(prop_name), "%s",
3670 gpio_suffixes[i]);
3671
3672 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3673 label);
3674 if (!gpiod_not_found(desc))
3675 break;
3676 }
3677
3678 return desc;
3679}
3680EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3681
3682/**
3683 * gpiod_count - return the number of GPIOs associated with a device / function
3684 * or -ENOENT if no GPIO has been assigned to the requested function
3685 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3686 * @con_id: function within the GPIO consumer
3687 */
3688int gpiod_count(struct device *dev, const char *con_id)
3689{
3690 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3691 int count = -ENOENT;
3692
3693 if (is_of_node(fwnode))
3694 count = of_gpio_get_count(dev, con_id);
3695 else if (is_acpi_node(fwnode))
3696 count = acpi_gpio_count(dev, con_id);
3697
3698 if (count < 0)
3699 count = platform_gpio_count(dev, con_id);
3700
3701 return count;
3702}
3703EXPORT_SYMBOL_GPL(gpiod_count);
3704
3705/**
3706 * gpiod_get - obtain a GPIO for a given GPIO function
3707 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3708 * @con_id: function within the GPIO consumer
3709 * @flags: optional GPIO initialization flags
3710 *
3711 * Return the GPIO descriptor corresponding to the function con_id of device
3712 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3713 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3714 */
3715struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3716 enum gpiod_flags flags)
3717{
3718 return gpiod_get_index(dev, con_id, 0, flags);
3719}
3720EXPORT_SYMBOL_GPL(gpiod_get);
3721
3722/**
3723 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3724 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3725 * @con_id: function within the GPIO consumer
3726 * @flags: optional GPIO initialization flags
3727 *
3728 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3729 * the requested function it will return NULL. This is convenient for drivers
3730 * that need to handle optional GPIOs.
3731 */
3732struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3733 const char *con_id,
3734 enum gpiod_flags flags)
3735{
3736 return gpiod_get_index_optional(dev, con_id, 0, flags);
3737}
3738EXPORT_SYMBOL_GPL(gpiod_get_optional);
3739
3740
3741/**
3742 * gpiod_configure_flags - helper function to configure a given GPIO
3743 * @desc: gpio whose value will be assigned
3744 * @con_id: function within the GPIO consumer
3745 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3746 * of_find_gpio() or of_get_gpio_hog()
3747 * @dflags: gpiod_flags - optional GPIO initialization flags
3748 *
3749 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3750 * requested function and/or index, or another IS_ERR() code if an error
3751 * occurred while trying to acquire the GPIO.
3752 */
3753int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3754 unsigned long lflags, enum gpiod_flags dflags)
3755{
3756 int ret;
3757
3758 if (lflags & GPIO_ACTIVE_LOW)
3759 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3760
3761 if (lflags & GPIO_OPEN_DRAIN)
3762 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3763 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3764 /*
3765 * This enforces open drain mode from the consumer side.
3766 * This is necessary for some busses like I2C, but the lookup
3767 * should *REALLY* have specified them as open drain in the
3768 * first place, so print a little warning here.
3769 */
3770 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3771 gpiod_warn(desc,
3772 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3773 }
3774
3775 if (lflags & GPIO_OPEN_SOURCE)
3776 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3777
3778 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3779 gpiod_err(desc,
3780 "both pull-up and pull-down enabled, invalid configuration\n");
3781 return -EINVAL;
3782 }
3783
3784 if (lflags & GPIO_PULL_UP)
3785 set_bit(FLAG_PULL_UP, &desc->flags);
3786 else if (lflags & GPIO_PULL_DOWN)
3787 set_bit(FLAG_PULL_DOWN, &desc->flags);
3788
3789 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3790 if (ret < 0)
3791 return ret;
3792
3793 /* No particular flag request, return here... */
3794 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3795 gpiod_dbg(desc, "no flags found for %s\n", con_id);
3796 return 0;
3797 }
3798
3799 /* Process flags */
3800 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3801 ret = gpiod_direction_output(desc,
3802 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3803 else
3804 ret = gpiod_direction_input(desc);
3805
3806 return ret;
3807}
3808
3809/**
3810 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3811 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3812 * @con_id: function within the GPIO consumer
3813 * @idx: index of the GPIO to obtain in the consumer
3814 * @flags: optional GPIO initialization flags
3815 *
3816 * This variant of gpiod_get() allows to access GPIOs other than the first
3817 * defined one for functions that define several GPIOs.
3818 *
3819 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3820 * requested function and/or index, or another IS_ERR() code if an error
3821 * occurred while trying to acquire the GPIO.
3822 */
3823struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3824 const char *con_id,
3825 unsigned int idx,
3826 enum gpiod_flags flags)
3827{
3828 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3829 struct gpio_desc *desc = NULL;
3830 int ret;
3831 /* Maybe we have a device name, maybe not */
3832 const char *devname = dev ? dev_name(dev) : "?";
3833 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3834
3835 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3836
3837 /* Using device tree? */
3838 if (is_of_node(fwnode)) {
3839 dev_dbg(dev, "using device tree for GPIO lookup\n");
3840 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3841 } else if (is_acpi_node(fwnode)) {
3842 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3843 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3844 }
3845
3846 /*
3847 * Either we are not using DT or ACPI, or their lookup did not return
3848 * a result. In that case, use platform lookup as a fallback.
3849 */
3850 if (!desc || gpiod_not_found(desc)) {
3851 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3852 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3853 }
3854
3855 if (IS_ERR(desc)) {
3856 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3857 return desc;
3858 }
3859
3860 /*
3861 * If a connection label was passed use that, else attempt to use
3862 * the device name as label
3863 */
3864 ret = gpiod_request(desc, con_id ? con_id : devname);
3865 if (ret) {
3866 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
3867 /*
3868 * This happens when there are several consumers for
3869 * the same GPIO line: we just return here without
3870 * further initialization. It is a bit if a hack.
3871 * This is necessary to support fixed regulators.
3872 *
3873 * FIXME: Make this more sane and safe.
3874 */
3875 dev_info(dev, "nonexclusive access to GPIO for %s\n",
3876 con_id ? con_id : devname);
3877 return desc;
3878 } else {
3879 return ERR_PTR(ret);
3880 }
3881 }
3882
3883 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3884 if (ret < 0) {
3885 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3886 gpiod_put(desc);
3887 return ERR_PTR(ret);
3888 }
3889
3890 blocking_notifier_call_chain(&desc->gdev->notifier,
3891 GPIOLINE_CHANGED_REQUESTED, desc);
3892
3893 return desc;
3894}
3895EXPORT_SYMBOL_GPL(gpiod_get_index);
3896
3897/**
3898 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3899 * @fwnode: handle of the firmware node
3900 * @propname: name of the firmware property representing the GPIO
3901 * @index: index of the GPIO to obtain for the consumer
3902 * @dflags: GPIO initialization flags
3903 * @label: label to attach to the requested GPIO
3904 *
3905 * This function can be used for drivers that get their configuration
3906 * from opaque firmware.
3907 *
3908 * The function properly finds the corresponding GPIO using whatever is the
3909 * underlying firmware interface and then makes sure that the GPIO
3910 * descriptor is requested before it is returned to the caller.
3911 *
3912 * Returns:
3913 * On successful request the GPIO pin is configured in accordance with
3914 * provided @dflags.
3915 *
3916 * In case of error an ERR_PTR() is returned.
3917 */
3918struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3919 const char *propname, int index,
3920 enum gpiod_flags dflags,
3921 const char *label)
3922{
3923 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3924 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3925 int ret;
3926
3927 if (is_of_node(fwnode)) {
3928 desc = gpiod_get_from_of_node(to_of_node(fwnode),
3929 propname, index,
3930 dflags,
3931 label);
3932 return desc;
3933 } else if (is_acpi_node(fwnode)) {
3934 struct acpi_gpio_info info;
3935
3936 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
3937 if (IS_ERR(desc))
3938 return desc;
3939
3940 acpi_gpio_update_gpiod_flags(&dflags, &info);
3941 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
3942 } else
3943 return ERR_PTR(-EINVAL);
3944
3945 /* Currently only ACPI takes this path */
3946 ret = gpiod_request(desc, label);
3947 if (ret)
3948 return ERR_PTR(ret);
3949
3950 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3951 if (ret < 0) {
3952 gpiod_put(desc);
3953 return ERR_PTR(ret);
3954 }
3955
3956 blocking_notifier_call_chain(&desc->gdev->notifier,
3957 GPIOLINE_CHANGED_REQUESTED, desc);
3958
3959 return desc;
3960}
3961EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3962
3963/**
3964 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3965 * function
3966 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3967 * @con_id: function within the GPIO consumer
3968 * @index: index of the GPIO to obtain in the consumer
3969 * @flags: optional GPIO initialization flags
3970 *
3971 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3972 * specified index was assigned to the requested function it will return NULL.
3973 * This is convenient for drivers that need to handle optional GPIOs.
3974 */
3975struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3976 const char *con_id,
3977 unsigned int index,
3978 enum gpiod_flags flags)
3979{
3980 struct gpio_desc *desc;
3981
3982 desc = gpiod_get_index(dev, con_id, index, flags);
3983 if (gpiod_not_found(desc))
3984 return NULL;
3985
3986 return desc;
3987}
3988EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3989
3990/**
3991 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3992 * @desc: gpio whose value will be assigned
3993 * @name: gpio line name
3994 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
3995 * of_find_gpio() or of_get_gpio_hog()
3996 * @dflags: gpiod_flags - optional GPIO initialization flags
3997 */
3998int gpiod_hog(struct gpio_desc *desc, const char *name,
3999 unsigned long lflags, enum gpiod_flags dflags)
4000{
4001 struct gpio_chip *gc;
4002 struct gpio_desc *local_desc;
4003 int hwnum;
4004 int ret;
4005
4006 gc = gpiod_to_chip(desc);
4007 hwnum = gpio_chip_hwgpio(desc);
4008
4009 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4010 lflags, dflags);
4011 if (IS_ERR(local_desc)) {
4012 ret = PTR_ERR(local_desc);
4013 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4014 name, gc->label, hwnum, ret);
4015 return ret;
4016 }
4017
4018 /* Mark GPIO as hogged so it can be identified and removed later */
4019 set_bit(FLAG_IS_HOGGED, &desc->flags);
4020
4021 gpiod_info(desc, "hogged as %s%s\n",
4022 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4023 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4024 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4025
4026 return 0;
4027}
4028
4029/**
4030 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4031 * @gc: gpio chip to act on
4032 */
4033static void gpiochip_free_hogs(struct gpio_chip *gc)
4034{
4035 int id;
4036
4037 for (id = 0; id < gc->ngpio; id++) {
4038 if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
4039 gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
4040 }
4041}
4042
4043/**
4044 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4045 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4046 * @con_id: function within the GPIO consumer
4047 * @flags: optional GPIO initialization flags
4048 *
4049 * This function acquires all the GPIOs defined under a given function.
4050 *
4051 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4052 * no GPIO has been assigned to the requested function, or another IS_ERR()
4053 * code if an error occurred while trying to acquire the GPIOs.
4054 */
4055struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4056 const char *con_id,
4057 enum gpiod_flags flags)
4058{
4059 struct gpio_desc *desc;
4060 struct gpio_descs *descs;
4061 struct gpio_array *array_info = NULL;
4062 struct gpio_chip *gc;
4063 int count, bitmap_size;
4064
4065 count = gpiod_count(dev, con_id);
4066 if (count < 0)
4067 return ERR_PTR(count);
4068
4069 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4070 if (!descs)
4071 return ERR_PTR(-ENOMEM);
4072
4073 for (descs->ndescs = 0; descs->ndescs < count; ) {
4074 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4075 if (IS_ERR(desc)) {
4076 gpiod_put_array(descs);
4077 return ERR_CAST(desc);
4078 }
4079
4080 descs->desc[descs->ndescs] = desc;
4081
4082 gc = gpiod_to_chip(desc);
4083 /*
4084 * If pin hardware number of array member 0 is also 0, select
4085 * its chip as a candidate for fast bitmap processing path.
4086 */
4087 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4088 struct gpio_descs *array;
4089
4090 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4091 gc->ngpio : count);
4092
4093 array = kzalloc(struct_size(descs, desc, count) +
4094 struct_size(array_info, invert_mask,
4095 3 * bitmap_size), GFP_KERNEL);
4096 if (!array) {
4097 gpiod_put_array(descs);
4098 return ERR_PTR(-ENOMEM);
4099 }
4100
4101 memcpy(array, descs,
4102 struct_size(descs, desc, descs->ndescs + 1));
4103 kfree(descs);
4104
4105 descs = array;
4106 array_info = (void *)(descs->desc + count);
4107 array_info->get_mask = array_info->invert_mask +
4108 bitmap_size;
4109 array_info->set_mask = array_info->get_mask +
4110 bitmap_size;
4111
4112 array_info->desc = descs->desc;
4113 array_info->size = count;
4114 array_info->chip = gc;
4115 bitmap_set(array_info->get_mask, descs->ndescs,
4116 count - descs->ndescs);
4117 bitmap_set(array_info->set_mask, descs->ndescs,
4118 count - descs->ndescs);
4119 descs->info = array_info;
4120 }
4121 /* Unmark array members which don't belong to the 'fast' chip */
4122 if (array_info && array_info->chip != gc) {
4123 __clear_bit(descs->ndescs, array_info->get_mask);
4124 __clear_bit(descs->ndescs, array_info->set_mask);
4125 }
4126 /*
4127 * Detect array members which belong to the 'fast' chip
4128 * but their pins are not in hardware order.
4129 */
4130 else if (array_info &&
4131 gpio_chip_hwgpio(desc) != descs->ndescs) {
4132 /*
4133 * Don't use fast path if all array members processed so
4134 * far belong to the same chip as this one but its pin
4135 * hardware number is different from its array index.
4136 */
4137 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4138 array_info = NULL;
4139 } else {
4140 __clear_bit(descs->ndescs,
4141 array_info->get_mask);
4142 __clear_bit(descs->ndescs,
4143 array_info->set_mask);
4144 }
4145 } else if (array_info) {
4146 /* Exclude open drain or open source from fast output */
4147 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4148 gpiochip_line_is_open_source(gc, descs->ndescs))
4149 __clear_bit(descs->ndescs,
4150 array_info->set_mask);
4151 /* Identify 'fast' pins which require invertion */
4152 if (gpiod_is_active_low(desc))
4153 __set_bit(descs->ndescs,
4154 array_info->invert_mask);
4155 }
4156
4157 descs->ndescs++;
4158 }
4159 if (array_info)
4160 dev_dbg(dev,
4161 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4162 array_info->chip->label, array_info->size,
4163 *array_info->get_mask, *array_info->set_mask,
4164 *array_info->invert_mask);
4165 return descs;
4166}
4167EXPORT_SYMBOL_GPL(gpiod_get_array);
4168
4169/**
4170 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4171 * function
4172 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4173 * @con_id: function within the GPIO consumer
4174 * @flags: optional GPIO initialization flags
4175 *
4176 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4177 * assigned to the requested function it will return NULL.
4178 */
4179struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4180 const char *con_id,
4181 enum gpiod_flags flags)
4182{
4183 struct gpio_descs *descs;
4184
4185 descs = gpiod_get_array(dev, con_id, flags);
4186 if (gpiod_not_found(descs))
4187 return NULL;
4188
4189 return descs;
4190}
4191EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4192
4193/**
4194 * gpiod_put - dispose of a GPIO descriptor
4195 * @desc: GPIO descriptor to dispose of
4196 *
4197 * No descriptor can be used after gpiod_put() has been called on it.
4198 */
4199void gpiod_put(struct gpio_desc *desc)
4200{
4201 if (desc)
4202 gpiod_free(desc);
4203}
4204EXPORT_SYMBOL_GPL(gpiod_put);
4205
4206/**
4207 * gpiod_put_array - dispose of multiple GPIO descriptors
4208 * @descs: struct gpio_descs containing an array of descriptors
4209 */
4210void gpiod_put_array(struct gpio_descs *descs)
4211{
4212 unsigned int i;
4213
4214 for (i = 0; i < descs->ndescs; i++)
4215 gpiod_put(descs->desc[i]);
4216
4217 kfree(descs);
4218}
4219EXPORT_SYMBOL_GPL(gpiod_put_array);
4220
4221
4222static int gpio_bus_match(struct device *dev, struct device_driver *drv)
4223{
4224 struct fwnode_handle *fwnode = dev_fwnode(dev);
4225
4226 /*
4227 * Only match if the fwnode doesn't already have a proper struct device
4228 * created for it.
4229 */
4230 if (fwnode && fwnode->dev != dev)
4231 return 0;
4232 return 1;
4233}
4234
4235static int gpio_stub_drv_probe(struct device *dev)
4236{
4237 /*
4238 * The DT node of some GPIO chips have a "compatible" property, but
4239 * never have a struct device added and probed by a driver to register
4240 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4241 * the consumers of the GPIO chip to get probe deferred forever because
4242 * they will be waiting for a device associated with the GPIO chip
4243 * firmware node to get added and bound to a driver.
4244 *
4245 * To allow these consumers to probe, we associate the struct
4246 * gpio_device of the GPIO chip with the firmware node and then simply
4247 * bind it to this stub driver.
4248 */
4249 return 0;
4250}
4251
4252static struct device_driver gpio_stub_drv = {
4253 .name = "gpio_stub_drv",
4254 .bus = &gpio_bus_type,
4255 .probe = gpio_stub_drv_probe,
4256};
4257
4258static int __init gpiolib_dev_init(void)
4259{
4260 int ret;
4261
4262 /* Register GPIO sysfs bus */
4263 ret = bus_register(&gpio_bus_type);
4264 if (ret < 0) {
4265 pr_err("gpiolib: could not register GPIO bus type\n");
4266 return ret;
4267 }
4268
4269 ret = driver_register(&gpio_stub_drv);
4270 if (ret < 0) {
4271 pr_err("gpiolib: could not register GPIO stub driver\n");
4272 bus_unregister(&gpio_bus_type);
4273 return ret;
4274 }
4275
4276 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4277 if (ret < 0) {
4278 pr_err("gpiolib: failed to allocate char dev region\n");
4279 driver_unregister(&gpio_stub_drv);
4280 bus_unregister(&gpio_bus_type);
4281 return ret;
4282 }
4283
4284 gpiolib_initialized = true;
4285 gpiochip_setup_devs();
4286
4287#if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4288 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4289#endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4290
4291 return ret;
4292}
4293core_initcall(gpiolib_dev_init);
4294
4295#ifdef CONFIG_DEBUG_FS
4296
4297static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4298{
4299 unsigned i;
4300 struct gpio_chip *gc = gdev->chip;
4301 unsigned gpio = gdev->base;
4302 struct gpio_desc *gdesc = &gdev->descs[0];
4303 bool is_out;
4304 bool is_irq;
4305 bool active_low;
4306
4307 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4308 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4309 if (gdesc->name) {
4310 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4311 gpio, gdesc->name);
4312 }
4313 continue;
4314 }
4315
4316 gpiod_get_direction(gdesc);
4317 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4318 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4319 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4320 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4321 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4322 is_out ? "out" : "in ",
4323 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
4324 is_irq ? "IRQ " : "",
4325 active_low ? "ACTIVE LOW" : "");
4326 seq_printf(s, "\n");
4327 }
4328}
4329
4330static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4331{
4332 unsigned long flags;
4333 struct gpio_device *gdev = NULL;
4334 loff_t index = *pos;
4335
4336 s->private = "";
4337
4338 spin_lock_irqsave(&gpio_lock, flags);
4339 list_for_each_entry(gdev, &gpio_devices, list)
4340 if (index-- == 0) {
4341 spin_unlock_irqrestore(&gpio_lock, flags);
4342 return gdev;
4343 }
4344 spin_unlock_irqrestore(&gpio_lock, flags);
4345
4346 return NULL;
4347}
4348
4349static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4350{
4351 unsigned long flags;
4352 struct gpio_device *gdev = v;
4353 void *ret = NULL;
4354
4355 spin_lock_irqsave(&gpio_lock, flags);
4356 if (list_is_last(&gdev->list, &gpio_devices))
4357 ret = NULL;
4358 else
4359 ret = list_entry(gdev->list.next, struct gpio_device, list);
4360 spin_unlock_irqrestore(&gpio_lock, flags);
4361
4362 s->private = "\n";
4363 ++*pos;
4364
4365 return ret;
4366}
4367
4368static void gpiolib_seq_stop(struct seq_file *s, void *v)
4369{
4370}
4371
4372static int gpiolib_seq_show(struct seq_file *s, void *v)
4373{
4374 struct gpio_device *gdev = v;
4375 struct gpio_chip *gc = gdev->chip;
4376 struct device *parent;
4377
4378 if (!gc) {
4379 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4380 dev_name(&gdev->dev));
4381 return 0;
4382 }
4383
4384 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4385 dev_name(&gdev->dev),
4386 gdev->base, gdev->base + gdev->ngpio - 1);
4387 parent = gc->parent;
4388 if (parent)
4389 seq_printf(s, ", parent: %s/%s",
4390 parent->bus ? parent->bus->name : "no-bus",
4391 dev_name(parent));
4392 if (gc->label)
4393 seq_printf(s, ", %s", gc->label);
4394 if (gc->can_sleep)
4395 seq_printf(s, ", can sleep");
4396 seq_printf(s, ":\n");
4397
4398 if (gc->dbg_show)
4399 gc->dbg_show(s, gc);
4400 else
4401 gpiolib_dbg_show(s, gdev);
4402
4403 return 0;
4404}
4405
4406static const struct seq_operations gpiolib_sops = {
4407 .start = gpiolib_seq_start,
4408 .next = gpiolib_seq_next,
4409 .stop = gpiolib_seq_stop,
4410 .show = gpiolib_seq_show,
4411};
4412DEFINE_SEQ_ATTRIBUTE(gpiolib);
4413
4414static int __init gpiolib_debugfs_init(void)
4415{
4416 /* /sys/kernel/debug/gpio */
4417 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4418 return 0;
4419}
4420subsys_initcall(gpiolib_debugfs_init);
4421
4422#endif /* DEBUG_FS */