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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/list.h>
7#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/debugfs.h>
10#include <linux/seq_file.h>
11#include <linux/gpio.h>
12#include <linux/of_gpio.h>
13#include <linux/idr.h>
14#include <linux/slab.h>
15#include <linux/acpi.h>
16#include <linux/gpio/driver.h>
17
18#include "gpiolib.h"
19
20#define CREATE_TRACE_POINTS
21#include <trace/events/gpio.h>
22
23/* Implementation infrastructure for GPIO interfaces.
24 *
25 * The GPIO programming interface allows for inlining speed-critical
26 * get/set operations for common cases, so that access to SOC-integrated
27 * GPIOs can sometimes cost 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_EXPORT 2 /* protected by sysfs_lock */
56#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
57#define FLAG_TRIG_FALL 4 /* trigger on falling edge */
58#define FLAG_TRIG_RISE 5 /* trigger on rising edge */
59#define FLAG_ACTIVE_LOW 6 /* value has active low */
60#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
61#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
62#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
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#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
76
77static DEFINE_MUTEX(gpio_lookup_lock);
78static LIST_HEAD(gpio_lookup_list);
79static LIST_HEAD(gpio_chips);
80
81#ifdef CONFIG_GPIO_SYSFS
82static DEFINE_IDR(dirent_idr);
83#endif
84
85static int gpiod_request(struct gpio_desc *desc, const char *label);
86static void gpiod_free(struct gpio_desc *desc);
87
88/* With descriptor prefix */
89
90#ifdef CONFIG_DEBUG_FS
91#define gpiod_emerg(desc, fmt, ...) \
92 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
93 ##__VA_ARGS__)
94#define gpiod_crit(desc, fmt, ...) \
95 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
96 ##__VA_ARGS__)
97#define gpiod_err(desc, fmt, ...) \
98 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
99 ##__VA_ARGS__)
100#define gpiod_warn(desc, fmt, ...) \
101 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
102 ##__VA_ARGS__)
103#define gpiod_info(desc, fmt, ...) \
104 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
105 ##__VA_ARGS__)
106#define gpiod_dbg(desc, fmt, ...) \
107 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
108 ##__VA_ARGS__)
109#else
110#define gpiod_emerg(desc, fmt, ...) \
111 pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
112#define gpiod_crit(desc, fmt, ...) \
113 pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
114#define gpiod_err(desc, fmt, ...) \
115 pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
116#define gpiod_warn(desc, fmt, ...) \
117 pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
118#define gpiod_info(desc, fmt, ...) \
119 pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
120#define gpiod_dbg(desc, fmt, ...) \
121 pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
122#endif
123
124/* With chip prefix */
125
126#define chip_emerg(chip, fmt, ...) \
127 pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
128#define chip_crit(chip, fmt, ...) \
129 pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
130#define chip_err(chip, fmt, ...) \
131 pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
132#define chip_warn(chip, fmt, ...) \
133 pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
134#define chip_info(chip, fmt, ...) \
135 pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
136#define chip_dbg(chip, fmt, ...) \
137 pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
138
139static inline void desc_set_label(struct gpio_desc *d, const char *label)
140{
141#ifdef CONFIG_DEBUG_FS
142 d->label = label;
143#endif
144}
145
146/*
147 * Return the GPIO number of the passed descriptor relative to its chip
148 */
149static int gpio_chip_hwgpio(const struct gpio_desc *desc)
150{
151 return desc - &desc->chip->desc[0];
152}
153
154/**
155 * Convert a GPIO number to its descriptor
156 */
157struct gpio_desc *gpio_to_desc(unsigned gpio)
158{
159 if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio))
160 return NULL;
161 else
162 return &gpio_desc[gpio];
163}
164EXPORT_SYMBOL_GPL(gpio_to_desc);
165
166/**
167 * Get the GPIO descriptor corresponding to the given hw number for this chip.
168 */
169struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
170 u16 hwnum)
171{
172 if (hwnum >= chip->ngpio)
173 return ERR_PTR(-EINVAL);
174
175 return &chip->desc[hwnum];
176}
177EXPORT_SYMBOL_GPL(gpiochip_get_desc);
178
179/**
180 * Convert a GPIO descriptor to the integer namespace.
181 * This should disappear in the future but is needed since we still
182 * use GPIO numbers for error messages and sysfs nodes
183 */
184int desc_to_gpio(const struct gpio_desc *desc)
185{
186 return desc - &gpio_desc[0];
187}
188EXPORT_SYMBOL_GPL(desc_to_gpio);
189
190
191/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
192 * when setting direction, and otherwise illegal. Until board setup code
193 * and drivers use explicit requests everywhere (which won't happen when
194 * those calls have no teeth) we can't avoid autorequesting. This nag
195 * message should motivate switching to explicit requests... so should
196 * the weaker cleanup after faults, compared to gpio_request().
197 *
198 * NOTE: the autorequest mechanism is going away; at this point it's
199 * only "legal" in the sense that (old) code using it won't break yet,
200 * but instead only triggers a WARN() stack dump.
201 */
202static int gpio_ensure_requested(struct gpio_desc *desc)
203{
204 const struct gpio_chip *chip = desc->chip;
205 const int gpio = desc_to_gpio(desc);
206
207 if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,
208 "autorequest GPIO-%d\n", gpio)) {
209 if (!try_module_get(chip->owner)) {
210 gpiod_err(desc, "%s: module can't be gotten\n",
211 __func__);
212 clear_bit(FLAG_REQUESTED, &desc->flags);
213 /* lose */
214 return -EIO;
215 }
216 desc_set_label(desc, "[auto]");
217 /* caller must chip->request() w/o spinlock */
218 if (chip->request)
219 return 1;
220 }
221 return 0;
222}
223
224/**
225 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
226 * @desc: descriptor to return the chip of
227 */
228struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
229{
230 return desc ? desc->chip : NULL;
231}
232EXPORT_SYMBOL_GPL(gpiod_to_chip);
233
234/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
235static int gpiochip_find_base(int ngpio)
236{
237 struct gpio_chip *chip;
238 int base = ARCH_NR_GPIOS - ngpio;
239
240 list_for_each_entry_reverse(chip, &gpio_chips, list) {
241 /* found a free space? */
242 if (chip->base + chip->ngpio <= base)
243 break;
244 else
245 /* nope, check the space right before the chip */
246 base = chip->base - ngpio;
247 }
248
249 if (gpio_is_valid(base)) {
250 pr_debug("%s: found new base at %d\n", __func__, base);
251 return base;
252 } else {
253 pr_err("%s: cannot find free range\n", __func__);
254 return -ENOSPC;
255 }
256}
257
258/**
259 * gpiod_get_direction - return the current direction of a GPIO
260 * @desc: GPIO to get the direction of
261 *
262 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
263 *
264 * This function may sleep if gpiod_cansleep() is true.
265 */
266int gpiod_get_direction(const struct gpio_desc *desc)
267{
268 struct gpio_chip *chip;
269 unsigned offset;
270 int status = -EINVAL;
271
272 chip = gpiod_to_chip(desc);
273 offset = gpio_chip_hwgpio(desc);
274
275 if (!chip->get_direction)
276 return status;
277
278 status = chip->get_direction(chip, offset);
279 if (status > 0) {
280 /* GPIOF_DIR_IN, or other positive */
281 status = 1;
282 /* FLAG_IS_OUT is just a cache of the result of get_direction(),
283 * so it does not affect constness per se */
284 clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
285 }
286 if (status == 0) {
287 /* GPIOF_DIR_OUT */
288 set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
289 }
290 return status;
291}
292EXPORT_SYMBOL_GPL(gpiod_get_direction);
293
294#ifdef CONFIG_GPIO_SYSFS
295
296/* lock protects against unexport_gpio() being called while
297 * sysfs files are active.
298 */
299static DEFINE_MUTEX(sysfs_lock);
300
301/*
302 * /sys/class/gpio/gpioN... only for GPIOs that are exported
303 * /direction
304 * * MAY BE OMITTED if kernel won't allow direction changes
305 * * is read/write as "in" or "out"
306 * * may also be written as "high" or "low", initializing
307 * output value as specified ("out" implies "low")
308 * /value
309 * * always readable, subject to hardware behavior
310 * * may be writable, as zero/nonzero
311 * /edge
312 * * configures behavior of poll(2) on /value
313 * * available only if pin can generate IRQs on input
314 * * is read/write as "none", "falling", "rising", or "both"
315 * /active_low
316 * * configures polarity of /value
317 * * is read/write as zero/nonzero
318 * * also affects existing and subsequent "falling" and "rising"
319 * /edge configuration
320 */
321
322static ssize_t gpio_direction_show(struct device *dev,
323 struct device_attribute *attr, char *buf)
324{
325 const struct gpio_desc *desc = dev_get_drvdata(dev);
326 ssize_t status;
327
328 mutex_lock(&sysfs_lock);
329
330 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
331 status = -EIO;
332 } else {
333 gpiod_get_direction(desc);
334 status = sprintf(buf, "%s\n",
335 test_bit(FLAG_IS_OUT, &desc->flags)
336 ? "out" : "in");
337 }
338
339 mutex_unlock(&sysfs_lock);
340 return status;
341}
342
343static ssize_t gpio_direction_store(struct device *dev,
344 struct device_attribute *attr, const char *buf, size_t size)
345{
346 struct gpio_desc *desc = dev_get_drvdata(dev);
347 ssize_t status;
348
349 mutex_lock(&sysfs_lock);
350
351 if (!test_bit(FLAG_EXPORT, &desc->flags))
352 status = -EIO;
353 else if (sysfs_streq(buf, "high"))
354 status = gpiod_direction_output_raw(desc, 1);
355 else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
356 status = gpiod_direction_output_raw(desc, 0);
357 else if (sysfs_streq(buf, "in"))
358 status = gpiod_direction_input(desc);
359 else
360 status = -EINVAL;
361
362 mutex_unlock(&sysfs_lock);
363 return status ? : size;
364}
365
366static /* const */ DEVICE_ATTR(direction, 0644,
367 gpio_direction_show, gpio_direction_store);
368
369static ssize_t gpio_value_show(struct device *dev,
370 struct device_attribute *attr, char *buf)
371{
372 struct gpio_desc *desc = dev_get_drvdata(dev);
373 ssize_t status;
374
375 mutex_lock(&sysfs_lock);
376
377 if (!test_bit(FLAG_EXPORT, &desc->flags))
378 status = -EIO;
379 else
380 status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
381
382 mutex_unlock(&sysfs_lock);
383 return status;
384}
385
386static ssize_t gpio_value_store(struct device *dev,
387 struct device_attribute *attr, const char *buf, size_t size)
388{
389 struct gpio_desc *desc = dev_get_drvdata(dev);
390 ssize_t status;
391
392 mutex_lock(&sysfs_lock);
393
394 if (!test_bit(FLAG_EXPORT, &desc->flags))
395 status = -EIO;
396 else if (!test_bit(FLAG_IS_OUT, &desc->flags))
397 status = -EPERM;
398 else {
399 long value;
400
401 status = kstrtol(buf, 0, &value);
402 if (status == 0) {
403 gpiod_set_value_cansleep(desc, value);
404 status = size;
405 }
406 }
407
408 mutex_unlock(&sysfs_lock);
409 return status;
410}
411
412static const DEVICE_ATTR(value, 0644,
413 gpio_value_show, gpio_value_store);
414
415static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
416{
417 struct kernfs_node *value_sd = priv;
418
419 sysfs_notify_dirent(value_sd);
420 return IRQ_HANDLED;
421}
422
423static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
424 unsigned long gpio_flags)
425{
426 struct kernfs_node *value_sd;
427 unsigned long irq_flags;
428 int ret, irq, id;
429
430 if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
431 return 0;
432
433 irq = gpiod_to_irq(desc);
434 if (irq < 0)
435 return -EIO;
436
437 id = desc->flags >> ID_SHIFT;
438 value_sd = idr_find(&dirent_idr, id);
439 if (value_sd)
440 free_irq(irq, value_sd);
441
442 desc->flags &= ~GPIO_TRIGGER_MASK;
443
444 if (!gpio_flags) {
445 gpiod_unlock_as_irq(desc);
446 ret = 0;
447 goto free_id;
448 }
449
450 irq_flags = IRQF_SHARED;
451 if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
452 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
453 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
454 if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
455 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
456 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
457
458 if (!value_sd) {
459 value_sd = sysfs_get_dirent(dev->kobj.sd, "value");
460 if (!value_sd) {
461 ret = -ENODEV;
462 goto err_out;
463 }
464
465 ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL);
466 if (ret < 0)
467 goto free_sd;
468 id = ret;
469
470 desc->flags &= GPIO_FLAGS_MASK;
471 desc->flags |= (unsigned long)id << ID_SHIFT;
472
473 if (desc->flags >> ID_SHIFT != id) {
474 ret = -ERANGE;
475 goto free_id;
476 }
477 }
478
479 ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
480 "gpiolib", value_sd);
481 if (ret < 0)
482 goto free_id;
483
484 ret = gpiod_lock_as_irq(desc);
485 if (ret < 0) {
486 gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
487 goto free_id;
488 }
489
490 desc->flags |= gpio_flags;
491 return 0;
492
493free_id:
494 idr_remove(&dirent_idr, id);
495 desc->flags &= GPIO_FLAGS_MASK;
496free_sd:
497 if (value_sd)
498 sysfs_put(value_sd);
499err_out:
500 return ret;
501}
502
503static const struct {
504 const char *name;
505 unsigned long flags;
506} trigger_types[] = {
507 { "none", 0 },
508 { "falling", BIT(FLAG_TRIG_FALL) },
509 { "rising", BIT(FLAG_TRIG_RISE) },
510 { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
511};
512
513static ssize_t gpio_edge_show(struct device *dev,
514 struct device_attribute *attr, char *buf)
515{
516 const struct gpio_desc *desc = dev_get_drvdata(dev);
517 ssize_t status;
518
519 mutex_lock(&sysfs_lock);
520
521 if (!test_bit(FLAG_EXPORT, &desc->flags))
522 status = -EIO;
523 else {
524 int i;
525
526 status = 0;
527 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
528 if ((desc->flags & GPIO_TRIGGER_MASK)
529 == trigger_types[i].flags) {
530 status = sprintf(buf, "%s\n",
531 trigger_types[i].name);
532 break;
533 }
534 }
535
536 mutex_unlock(&sysfs_lock);
537 return status;
538}
539
540static ssize_t gpio_edge_store(struct device *dev,
541 struct device_attribute *attr, const char *buf, size_t size)
542{
543 struct gpio_desc *desc = dev_get_drvdata(dev);
544 ssize_t status;
545 int i;
546
547 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
548 if (sysfs_streq(trigger_types[i].name, buf))
549 goto found;
550 return -EINVAL;
551
552found:
553 mutex_lock(&sysfs_lock);
554
555 if (!test_bit(FLAG_EXPORT, &desc->flags))
556 status = -EIO;
557 else {
558 status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
559 if (!status)
560 status = size;
561 }
562
563 mutex_unlock(&sysfs_lock);
564
565 return status;
566}
567
568static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
569
570static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
571 int value)
572{
573 int status = 0;
574
575 if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
576 return 0;
577
578 if (value)
579 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
580 else
581 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
582
583 /* reconfigure poll(2) support if enabled on one edge only */
584 if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^
585 !!test_bit(FLAG_TRIG_FALL, &desc->flags))) {
586 unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK;
587
588 gpio_setup_irq(desc, dev, 0);
589 status = gpio_setup_irq(desc, dev, trigger_flags);
590 }
591
592 return status;
593}
594
595static ssize_t gpio_active_low_show(struct device *dev,
596 struct device_attribute *attr, char *buf)
597{
598 const struct gpio_desc *desc = dev_get_drvdata(dev);
599 ssize_t status;
600
601 mutex_lock(&sysfs_lock);
602
603 if (!test_bit(FLAG_EXPORT, &desc->flags))
604 status = -EIO;
605 else
606 status = sprintf(buf, "%d\n",
607 !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
608
609 mutex_unlock(&sysfs_lock);
610
611 return status;
612}
613
614static ssize_t gpio_active_low_store(struct device *dev,
615 struct device_attribute *attr, const char *buf, size_t size)
616{
617 struct gpio_desc *desc = dev_get_drvdata(dev);
618 ssize_t status;
619
620 mutex_lock(&sysfs_lock);
621
622 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
623 status = -EIO;
624 } else {
625 long value;
626
627 status = kstrtol(buf, 0, &value);
628 if (status == 0)
629 status = sysfs_set_active_low(desc, dev, value != 0);
630 }
631
632 mutex_unlock(&sysfs_lock);
633
634 return status ? : size;
635}
636
637static const DEVICE_ATTR(active_low, 0644,
638 gpio_active_low_show, gpio_active_low_store);
639
640static const struct attribute *gpio_attrs[] = {
641 &dev_attr_value.attr,
642 &dev_attr_active_low.attr,
643 NULL,
644};
645
646static const struct attribute_group gpio_attr_group = {
647 .attrs = (struct attribute **) gpio_attrs,
648};
649
650/*
651 * /sys/class/gpio/gpiochipN/
652 * /base ... matching gpio_chip.base (N)
653 * /label ... matching gpio_chip.label
654 * /ngpio ... matching gpio_chip.ngpio
655 */
656
657static ssize_t chip_base_show(struct device *dev,
658 struct device_attribute *attr, char *buf)
659{
660 const struct gpio_chip *chip = dev_get_drvdata(dev);
661
662 return sprintf(buf, "%d\n", chip->base);
663}
664static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
665
666static ssize_t chip_label_show(struct device *dev,
667 struct device_attribute *attr, char *buf)
668{
669 const struct gpio_chip *chip = dev_get_drvdata(dev);
670
671 return sprintf(buf, "%s\n", chip->label ? : "");
672}
673static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
674
675static ssize_t chip_ngpio_show(struct device *dev,
676 struct device_attribute *attr, char *buf)
677{
678 const struct gpio_chip *chip = dev_get_drvdata(dev);
679
680 return sprintf(buf, "%u\n", chip->ngpio);
681}
682static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
683
684static const struct attribute *gpiochip_attrs[] = {
685 &dev_attr_base.attr,
686 &dev_attr_label.attr,
687 &dev_attr_ngpio.attr,
688 NULL,
689};
690
691static const struct attribute_group gpiochip_attr_group = {
692 .attrs = (struct attribute **) gpiochip_attrs,
693};
694
695/*
696 * /sys/class/gpio/export ... write-only
697 * integer N ... number of GPIO to export (full access)
698 * /sys/class/gpio/unexport ... write-only
699 * integer N ... number of GPIO to unexport
700 */
701static ssize_t export_store(struct class *class,
702 struct class_attribute *attr,
703 const char *buf, size_t len)
704{
705 long gpio;
706 struct gpio_desc *desc;
707 int status;
708
709 status = kstrtol(buf, 0, &gpio);
710 if (status < 0)
711 goto done;
712
713 desc = gpio_to_desc(gpio);
714 /* reject invalid GPIOs */
715 if (!desc) {
716 pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
717 return -EINVAL;
718 }
719
720 /* No extra locking here; FLAG_SYSFS just signifies that the
721 * request and export were done by on behalf of userspace, so
722 * they may be undone on its behalf too.
723 */
724
725 status = gpiod_request(desc, "sysfs");
726 if (status < 0) {
727 if (status == -EPROBE_DEFER)
728 status = -ENODEV;
729 goto done;
730 }
731 status = gpiod_export(desc, true);
732 if (status < 0)
733 gpiod_free(desc);
734 else
735 set_bit(FLAG_SYSFS, &desc->flags);
736
737done:
738 if (status)
739 pr_debug("%s: status %d\n", __func__, status);
740 return status ? : len;
741}
742
743static ssize_t unexport_store(struct class *class,
744 struct class_attribute *attr,
745 const char *buf, size_t len)
746{
747 long gpio;
748 struct gpio_desc *desc;
749 int status;
750
751 status = kstrtol(buf, 0, &gpio);
752 if (status < 0)
753 goto done;
754
755 desc = gpio_to_desc(gpio);
756 /* reject bogus commands (gpio_unexport ignores them) */
757 if (!desc) {
758 pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
759 return -EINVAL;
760 }
761
762 status = -EINVAL;
763
764 /* No extra locking here; FLAG_SYSFS just signifies that the
765 * request and export were done by on behalf of userspace, so
766 * they may be undone on its behalf too.
767 */
768 if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) {
769 status = 0;
770 gpiod_free(desc);
771 }
772done:
773 if (status)
774 pr_debug("%s: status %d\n", __func__, status);
775 return status ? : len;
776}
777
778static struct class_attribute gpio_class_attrs[] = {
779 __ATTR(export, 0200, NULL, export_store),
780 __ATTR(unexport, 0200, NULL, unexport_store),
781 __ATTR_NULL,
782};
783
784static struct class gpio_class = {
785 .name = "gpio",
786 .owner = THIS_MODULE,
787
788 .class_attrs = gpio_class_attrs,
789};
790
791
792/**
793 * gpiod_export - export a GPIO through sysfs
794 * @gpio: gpio to make available, already requested
795 * @direction_may_change: true if userspace may change gpio direction
796 * Context: arch_initcall or later
797 *
798 * When drivers want to make a GPIO accessible to userspace after they
799 * have requested it -- perhaps while debugging, or as part of their
800 * public interface -- they may use this routine. If the GPIO can
801 * change direction (some can't) and the caller allows it, userspace
802 * will see "direction" sysfs attribute which may be used to change
803 * the gpio's direction. A "value" attribute will always be provided.
804 *
805 * Returns zero on success, else an error.
806 */
807int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
808{
809 unsigned long flags;
810 int status;
811 const char *ioname = NULL;
812 struct device *dev;
813 int offset;
814
815 /* can't export until sysfs is available ... */
816 if (!gpio_class.p) {
817 pr_debug("%s: called too early!\n", __func__);
818 return -ENOENT;
819 }
820
821 if (!desc) {
822 pr_debug("%s: invalid gpio descriptor\n", __func__);
823 return -EINVAL;
824 }
825
826 mutex_lock(&sysfs_lock);
827
828 spin_lock_irqsave(&gpio_lock, flags);
829 if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
830 test_bit(FLAG_EXPORT, &desc->flags)) {
831 spin_unlock_irqrestore(&gpio_lock, flags);
832 gpiod_dbg(desc, "%s: unavailable (requested=%d, exported=%d)\n",
833 __func__,
834 test_bit(FLAG_REQUESTED, &desc->flags),
835 test_bit(FLAG_EXPORT, &desc->flags));
836 status = -EPERM;
837 goto fail_unlock;
838 }
839
840 if (!desc->chip->direction_input || !desc->chip->direction_output)
841 direction_may_change = false;
842 spin_unlock_irqrestore(&gpio_lock, flags);
843
844 offset = gpio_chip_hwgpio(desc);
845 if (desc->chip->names && desc->chip->names[offset])
846 ioname = desc->chip->names[offset];
847
848 dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
849 desc, ioname ? ioname : "gpio%u",
850 desc_to_gpio(desc));
851 if (IS_ERR(dev)) {
852 status = PTR_ERR(dev);
853 goto fail_unlock;
854 }
855
856 status = sysfs_create_group(&dev->kobj, &gpio_attr_group);
857 if (status)
858 goto fail_unregister_device;
859
860 if (direction_may_change) {
861 status = device_create_file(dev, &dev_attr_direction);
862 if (status)
863 goto fail_unregister_device;
864 }
865
866 if (gpiod_to_irq(desc) >= 0 && (direction_may_change ||
867 !test_bit(FLAG_IS_OUT, &desc->flags))) {
868 status = device_create_file(dev, &dev_attr_edge);
869 if (status)
870 goto fail_unregister_device;
871 }
872
873 set_bit(FLAG_EXPORT, &desc->flags);
874 mutex_unlock(&sysfs_lock);
875 return 0;
876
877fail_unregister_device:
878 device_unregister(dev);
879fail_unlock:
880 mutex_unlock(&sysfs_lock);
881 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
882 return status;
883}
884EXPORT_SYMBOL_GPL(gpiod_export);
885
886static int match_export(struct device *dev, const void *data)
887{
888 return dev_get_drvdata(dev) == data;
889}
890
891/**
892 * gpiod_export_link - create a sysfs link to an exported GPIO node
893 * @dev: device under which to create symlink
894 * @name: name of the symlink
895 * @gpio: gpio to create symlink to, already exported
896 *
897 * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
898 * node. Caller is responsible for unlinking.
899 *
900 * Returns zero on success, else an error.
901 */
902int gpiod_export_link(struct device *dev, const char *name,
903 struct gpio_desc *desc)
904{
905 int status = -EINVAL;
906
907 if (!desc) {
908 pr_warn("%s: invalid GPIO\n", __func__);
909 return -EINVAL;
910 }
911
912 mutex_lock(&sysfs_lock);
913
914 if (test_bit(FLAG_EXPORT, &desc->flags)) {
915 struct device *tdev;
916
917 tdev = class_find_device(&gpio_class, NULL, desc, match_export);
918 if (tdev != NULL) {
919 status = sysfs_create_link(&dev->kobj, &tdev->kobj,
920 name);
921 } else {
922 status = -ENODEV;
923 }
924 }
925
926 mutex_unlock(&sysfs_lock);
927
928 if (status)
929 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
930
931 return status;
932}
933EXPORT_SYMBOL_GPL(gpiod_export_link);
934
935/**
936 * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value
937 * @gpio: gpio to change
938 * @value: non-zero to use active low, i.e. inverted values
939 *
940 * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute.
941 * The GPIO does not have to be exported yet. If poll(2) support has
942 * been enabled for either rising or falling edge, it will be
943 * reconfigured to follow the new polarity.
944 *
945 * Returns zero on success, else an error.
946 */
947int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
948{
949 struct device *dev = NULL;
950 int status = -EINVAL;
951
952 if (!desc) {
953 pr_warn("%s: invalid GPIO\n", __func__);
954 return -EINVAL;
955 }
956
957 mutex_lock(&sysfs_lock);
958
959 if (test_bit(FLAG_EXPORT, &desc->flags)) {
960 dev = class_find_device(&gpio_class, NULL, desc, match_export);
961 if (dev == NULL) {
962 status = -ENODEV;
963 goto unlock;
964 }
965 }
966
967 status = sysfs_set_active_low(desc, dev, value);
968
969unlock:
970 mutex_unlock(&sysfs_lock);
971
972 if (status)
973 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
974
975 return status;
976}
977EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low);
978
979/**
980 * gpiod_unexport - reverse effect of gpio_export()
981 * @gpio: gpio to make unavailable
982 *
983 * This is implicit on gpio_free().
984 */
985void gpiod_unexport(struct gpio_desc *desc)
986{
987 int status = 0;
988 struct device *dev = NULL;
989
990 if (!desc) {
991 pr_warn("%s: invalid GPIO\n", __func__);
992 return;
993 }
994
995 mutex_lock(&sysfs_lock);
996
997 if (test_bit(FLAG_EXPORT, &desc->flags)) {
998
999 dev = class_find_device(&gpio_class, NULL, desc, match_export);
1000 if (dev) {
1001 gpio_setup_irq(desc, dev, 0);
1002 clear_bit(FLAG_EXPORT, &desc->flags);
1003 } else
1004 status = -ENODEV;
1005 }
1006
1007 mutex_unlock(&sysfs_lock);
1008
1009 if (dev) {
1010 device_unregister(dev);
1011 put_device(dev);
1012 }
1013
1014 if (status)
1015 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
1016}
1017EXPORT_SYMBOL_GPL(gpiod_unexport);
1018
1019static int gpiochip_export(struct gpio_chip *chip)
1020{
1021 int status;
1022 struct device *dev;
1023
1024 /* Many systems register gpio chips for SOC support very early,
1025 * before driver model support is available. In those cases we
1026 * export this later, in gpiolib_sysfs_init() ... here we just
1027 * verify that _some_ field of gpio_class got initialized.
1028 */
1029 if (!gpio_class.p)
1030 return 0;
1031
1032 /* use chip->base for the ID; it's already known to be unique */
1033 mutex_lock(&sysfs_lock);
1034 dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip,
1035 "gpiochip%d", chip->base);
1036 if (!IS_ERR(dev)) {
1037 status = sysfs_create_group(&dev->kobj,
1038 &gpiochip_attr_group);
1039 } else
1040 status = PTR_ERR(dev);
1041 chip->exported = (status == 0);
1042 mutex_unlock(&sysfs_lock);
1043
1044 if (status) {
1045 unsigned long flags;
1046 unsigned gpio;
1047
1048 spin_lock_irqsave(&gpio_lock, flags);
1049 gpio = 0;
1050 while (gpio < chip->ngpio)
1051 chip->desc[gpio++].chip = NULL;
1052 spin_unlock_irqrestore(&gpio_lock, flags);
1053
1054 chip_dbg(chip, "%s: status %d\n", __func__, status);
1055 }
1056
1057 return status;
1058}
1059
1060static void gpiochip_unexport(struct gpio_chip *chip)
1061{
1062 int status;
1063 struct device *dev;
1064
1065 mutex_lock(&sysfs_lock);
1066 dev = class_find_device(&gpio_class, NULL, chip, match_export);
1067 if (dev) {
1068 put_device(dev);
1069 device_unregister(dev);
1070 chip->exported = false;
1071 status = 0;
1072 } else
1073 status = -ENODEV;
1074 mutex_unlock(&sysfs_lock);
1075
1076 if (status)
1077 chip_dbg(chip, "%s: status %d\n", __func__, status);
1078}
1079
1080static int __init gpiolib_sysfs_init(void)
1081{
1082 int status;
1083 unsigned long flags;
1084 struct gpio_chip *chip;
1085
1086 status = class_register(&gpio_class);
1087 if (status < 0)
1088 return status;
1089
1090 /* Scan and register the gpio_chips which registered very
1091 * early (e.g. before the class_register above was called).
1092 *
1093 * We run before arch_initcall() so chip->dev nodes can have
1094 * registered, and so arch_initcall() can always gpio_export().
1095 */
1096 spin_lock_irqsave(&gpio_lock, flags);
1097 list_for_each_entry(chip, &gpio_chips, list) {
1098 if (!chip || chip->exported)
1099 continue;
1100
1101 spin_unlock_irqrestore(&gpio_lock, flags);
1102 status = gpiochip_export(chip);
1103 spin_lock_irqsave(&gpio_lock, flags);
1104 }
1105 spin_unlock_irqrestore(&gpio_lock, flags);
1106
1107
1108 return status;
1109}
1110postcore_initcall(gpiolib_sysfs_init);
1111
1112#else
1113static inline int gpiochip_export(struct gpio_chip *chip)
1114{
1115 return 0;
1116}
1117
1118static inline void gpiochip_unexport(struct gpio_chip *chip)
1119{
1120}
1121
1122#endif /* CONFIG_GPIO_SYSFS */
1123
1124/*
1125 * Add a new chip to the global chips list, keeping the list of chips sorted
1126 * by base order.
1127 *
1128 * Return -EBUSY if the new chip overlaps with some other chip's integer
1129 * space.
1130 */
1131static int gpiochip_add_to_list(struct gpio_chip *chip)
1132{
1133 struct list_head *pos = &gpio_chips;
1134 struct gpio_chip *_chip;
1135 int err = 0;
1136
1137 /* find where to insert our chip */
1138 list_for_each(pos, &gpio_chips) {
1139 _chip = list_entry(pos, struct gpio_chip, list);
1140 /* shall we insert before _chip? */
1141 if (_chip->base >= chip->base + chip->ngpio)
1142 break;
1143 }
1144
1145 /* are we stepping on the chip right before? */
1146 if (pos != &gpio_chips && pos->prev != &gpio_chips) {
1147 _chip = list_entry(pos->prev, struct gpio_chip, list);
1148 if (_chip->base + _chip->ngpio > chip->base) {
1149 dev_err(chip->dev,
1150 "GPIO integer space overlap, cannot add chip\n");
1151 err = -EBUSY;
1152 }
1153 }
1154
1155 if (!err)
1156 list_add_tail(&chip->list, pos);
1157
1158 return err;
1159}
1160
1161/**
1162 * gpiochip_add() - register a gpio_chip
1163 * @chip: the chip to register, with chip->base initialized
1164 * Context: potentially before irqs or kmalloc will work
1165 *
1166 * Returns a negative errno if the chip can't be registered, such as
1167 * because the chip->base is invalid or already associated with a
1168 * different chip. Otherwise it returns zero as a success code.
1169 *
1170 * When gpiochip_add() is called very early during boot, so that GPIOs
1171 * can be freely used, the chip->dev device must be registered before
1172 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1173 * for GPIOs will fail rudely.
1174 *
1175 * If chip->base is negative, this requests dynamic assignment of
1176 * a range of valid GPIOs.
1177 */
1178int gpiochip_add(struct gpio_chip *chip)
1179{
1180 unsigned long flags;
1181 int status = 0;
1182 unsigned id;
1183 int base = chip->base;
1184
1185 if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
1186 && base >= 0) {
1187 status = -EINVAL;
1188 goto fail;
1189 }
1190
1191 spin_lock_irqsave(&gpio_lock, flags);
1192
1193 if (base < 0) {
1194 base = gpiochip_find_base(chip->ngpio);
1195 if (base < 0) {
1196 status = base;
1197 goto unlock;
1198 }
1199 chip->base = base;
1200 }
1201
1202 status = gpiochip_add_to_list(chip);
1203
1204 if (status == 0) {
1205 chip->desc = &gpio_desc[chip->base];
1206
1207 for (id = 0; id < chip->ngpio; id++) {
1208 struct gpio_desc *desc = &chip->desc[id];
1209 desc->chip = chip;
1210
1211 /* REVISIT: most hardware initializes GPIOs as
1212 * inputs (often with pullups enabled) so power
1213 * usage is minimized. Linux code should set the
1214 * gpio direction first thing; but until it does,
1215 * and in case chip->get_direction is not set,
1216 * we may expose the wrong direction in sysfs.
1217 */
1218 desc->flags = !chip->direction_input
1219 ? (1 << FLAG_IS_OUT)
1220 : 0;
1221 }
1222 }
1223
1224 spin_unlock_irqrestore(&gpio_lock, flags);
1225
1226#ifdef CONFIG_PINCTRL
1227 INIT_LIST_HEAD(&chip->pin_ranges);
1228#endif
1229
1230 of_gpiochip_add(chip);
1231 acpi_gpiochip_add(chip);
1232
1233 if (status)
1234 goto fail;
1235
1236 status = gpiochip_export(chip);
1237 if (status)
1238 goto fail;
1239
1240 pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
1241 chip->base, chip->base + chip->ngpio - 1,
1242 chip->label ? : "generic");
1243
1244 return 0;
1245
1246unlock:
1247 spin_unlock_irqrestore(&gpio_lock, flags);
1248fail:
1249 /* failures here can mean systems won't boot... */
1250 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1251 chip->base, chip->base + chip->ngpio - 1,
1252 chip->label ? : "generic");
1253 return status;
1254}
1255EXPORT_SYMBOL_GPL(gpiochip_add);
1256
1257/* Forward-declaration */
1258static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
1259
1260/**
1261 * gpiochip_remove() - unregister a gpio_chip
1262 * @chip: the chip to unregister
1263 *
1264 * A gpio_chip with any GPIOs still requested may not be removed.
1265 */
1266int gpiochip_remove(struct gpio_chip *chip)
1267{
1268 unsigned long flags;
1269 int status = 0;
1270 unsigned id;
1271
1272 acpi_gpiochip_remove(chip);
1273
1274 spin_lock_irqsave(&gpio_lock, flags);
1275
1276 gpiochip_irqchip_remove(chip);
1277 gpiochip_remove_pin_ranges(chip);
1278 of_gpiochip_remove(chip);
1279
1280 for (id = 0; id < chip->ngpio; id++) {
1281 if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
1282 status = -EBUSY;
1283 break;
1284 }
1285 }
1286 if (status == 0) {
1287 for (id = 0; id < chip->ngpio; id++)
1288 chip->desc[id].chip = NULL;
1289
1290 list_del(&chip->list);
1291 }
1292
1293 spin_unlock_irqrestore(&gpio_lock, flags);
1294
1295 if (status == 0)
1296 gpiochip_unexport(chip);
1297
1298 return status;
1299}
1300EXPORT_SYMBOL_GPL(gpiochip_remove);
1301
1302/**
1303 * gpiochip_find() - iterator for locating a specific gpio_chip
1304 * @data: data to pass to match function
1305 * @callback: Callback function to check gpio_chip
1306 *
1307 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1308 * determined by a user supplied @match callback. The callback should return
1309 * 0 if the device doesn't match and non-zero if it does. If the callback is
1310 * non-zero, this function will return to the caller and not iterate over any
1311 * more gpio_chips.
1312 */
1313struct gpio_chip *gpiochip_find(void *data,
1314 int (*match)(struct gpio_chip *chip,
1315 void *data))
1316{
1317 struct gpio_chip *chip;
1318 unsigned long flags;
1319
1320 spin_lock_irqsave(&gpio_lock, flags);
1321 list_for_each_entry(chip, &gpio_chips, list)
1322 if (match(chip, data))
1323 break;
1324
1325 /* No match? */
1326 if (&chip->list == &gpio_chips)
1327 chip = NULL;
1328 spin_unlock_irqrestore(&gpio_lock, flags);
1329
1330 return chip;
1331}
1332EXPORT_SYMBOL_GPL(gpiochip_find);
1333
1334static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1335{
1336 const char *name = data;
1337
1338 return !strcmp(chip->label, name);
1339}
1340
1341static struct gpio_chip *find_chip_by_name(const char *name)
1342{
1343 return gpiochip_find((void *)name, gpiochip_match_name);
1344}
1345
1346#ifdef CONFIG_GPIOLIB_IRQCHIP
1347
1348/*
1349 * The following is irqchip helper code for gpiochips.
1350 */
1351
1352/**
1353 * gpiochip_add_chained_irqchip() - adds a chained irqchip to a gpiochip
1354 * @gpiochip: the gpiochip to add the irqchip to
1355 * @irqchip: the irqchip to add to the gpiochip
1356 * @parent_irq: the irq number corresponding to the parent IRQ for this
1357 * chained irqchip
1358 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1359 * coming out of the gpiochip
1360 */
1361void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1362 struct irq_chip *irqchip,
1363 int parent_irq,
1364 irq_flow_handler_t parent_handler)
1365{
1366 irq_set_chained_handler(parent_irq, parent_handler);
1367 /*
1368 * The parent irqchip is already using the chip_data for this
1369 * irqchip, so our callbacks simply use the handler_data.
1370 */
1371 irq_set_handler_data(parent_irq, gpiochip);
1372}
1373EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1374
1375/**
1376 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1377 * @d: the irqdomain used by this irqchip
1378 * @irq: the global irq number used by this GPIO irqchip irq
1379 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1380 *
1381 * This function will set up the mapping for a certain IRQ line on a
1382 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1383 * stored inside the gpiochip.
1384 */
1385static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1386 irq_hw_number_t hwirq)
1387{
1388 struct gpio_chip *chip = d->host_data;
1389
1390 irq_set_chip_data(irq, chip);
1391 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1392#ifdef CONFIG_ARM
1393 set_irq_flags(irq, IRQF_VALID);
1394#else
1395 irq_set_noprobe(irq);
1396#endif
1397 irq_set_irq_type(irq, chip->irq_default_type);
1398
1399 return 0;
1400}
1401
1402static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1403{
1404#ifdef CONFIG_ARM
1405 set_irq_flags(irq, 0);
1406#endif
1407 irq_set_chip_and_handler(irq, NULL, NULL);
1408 irq_set_chip_data(irq, NULL);
1409}
1410
1411static const struct irq_domain_ops gpiochip_domain_ops = {
1412 .map = gpiochip_irq_map,
1413 .unmap = gpiochip_irq_unmap,
1414 /* Virtually all GPIO irqchips are twocell:ed */
1415 .xlate = irq_domain_xlate_twocell,
1416};
1417
1418static int gpiochip_irq_reqres(struct irq_data *d)
1419{
1420 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1421
1422 if (gpio_lock_as_irq(chip, d->hwirq)) {
1423 chip_err(chip,
1424 "unable to lock HW IRQ %lu for IRQ\n",
1425 d->hwirq);
1426 return -EINVAL;
1427 }
1428 return 0;
1429}
1430
1431static void gpiochip_irq_relres(struct irq_data *d)
1432{
1433 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1434
1435 gpio_unlock_as_irq(chip, d->hwirq);
1436}
1437
1438static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1439{
1440 return irq_find_mapping(chip->irqdomain, offset);
1441}
1442
1443/**
1444 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1445 * @gpiochip: the gpiochip to remove the irqchip from
1446 *
1447 * This is called only from gpiochip_remove()
1448 */
1449static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1450{
1451 unsigned int offset;
1452
1453 /* Remove all IRQ mappings and delete the domain */
1454 if (gpiochip->irqdomain) {
1455 for (offset = 0; offset < gpiochip->ngpio; offset++)
1456 irq_dispose_mapping(gpiochip->irq_base + offset);
1457 irq_domain_remove(gpiochip->irqdomain);
1458 }
1459
1460 if (gpiochip->irqchip) {
1461 gpiochip->irqchip->irq_request_resources = NULL;
1462 gpiochip->irqchip->irq_release_resources = NULL;
1463 gpiochip->irqchip = NULL;
1464 }
1465}
1466
1467/**
1468 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1469 * @gpiochip: the gpiochip to add the irqchip to
1470 * @irqchip: the irqchip to add to the gpiochip
1471 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1472 * allocate gpiochip irqs from
1473 * @handler: the irq handler to use (often a predefined irq core function)
1474 * @type: the default type for IRQs on this irqchip
1475 *
1476 * This function closely associates a certain irqchip with a certain
1477 * gpiochip, providing an irq domain to translate the local IRQs to
1478 * global irqs in the gpiolib core, and making sure that the gpiochip
1479 * is passed as chip data to all related functions. Driver callbacks
1480 * need to use container_of() to get their local state containers back
1481 * from the gpiochip passed as chip data. An irqdomain will be stored
1482 * in the gpiochip that shall be used by the driver to handle IRQ number
1483 * translation. The gpiochip will need to be initialized and registered
1484 * before calling this function.
1485 *
1486 * This function will handle two cell:ed simple IRQs and assumes all
1487 * the pins on the gpiochip can generate a unique IRQ. Everything else
1488 * need to be open coded.
1489 */
1490int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1491 struct irq_chip *irqchip,
1492 unsigned int first_irq,
1493 irq_flow_handler_t handler,
1494 unsigned int type)
1495{
1496 struct device_node *of_node;
1497 unsigned int offset;
1498 unsigned irq_base = 0;
1499
1500 if (!gpiochip || !irqchip)
1501 return -EINVAL;
1502
1503 if (!gpiochip->dev) {
1504 pr_err("missing gpiochip .dev parent pointer\n");
1505 return -EINVAL;
1506 }
1507 of_node = gpiochip->dev->of_node;
1508#ifdef CONFIG_OF_GPIO
1509 /*
1510 * If the gpiochip has an assigned OF node this takes precendence
1511 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
1512 */
1513 if (gpiochip->of_node)
1514 of_node = gpiochip->of_node;
1515#endif
1516 gpiochip->irqchip = irqchip;
1517 gpiochip->irq_handler = handler;
1518 gpiochip->irq_default_type = type;
1519 gpiochip->to_irq = gpiochip_to_irq;
1520 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1521 gpiochip->ngpio, first_irq,
1522 &gpiochip_domain_ops, gpiochip);
1523 if (!gpiochip->irqdomain) {
1524 gpiochip->irqchip = NULL;
1525 return -EINVAL;
1526 }
1527 irqchip->irq_request_resources = gpiochip_irq_reqres;
1528 irqchip->irq_release_resources = gpiochip_irq_relres;
1529
1530 /*
1531 * Prepare the mapping since the irqchip shall be orthogonal to
1532 * any gpiochip calls. If the first_irq was zero, this is
1533 * necessary to allocate descriptors for all IRQs.
1534 */
1535 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1536 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1537 if (offset == 0)
1538 /*
1539 * Store the base into the gpiochip to be used when
1540 * unmapping the irqs.
1541 */
1542 gpiochip->irq_base = irq_base;
1543 }
1544
1545 return 0;
1546}
1547EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
1548
1549#else /* CONFIG_GPIOLIB_IRQCHIP */
1550
1551static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1552
1553#endif /* CONFIG_GPIOLIB_IRQCHIP */
1554
1555#ifdef CONFIG_PINCTRL
1556
1557/**
1558 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1559 * @chip: the gpiochip to add the range for
1560 * @pinctrl: the dev_name() of the pin controller to map to
1561 * @gpio_offset: the start offset in the current gpio_chip number space
1562 * @pin_group: name of the pin group inside the pin controller
1563 */
1564int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1565 struct pinctrl_dev *pctldev,
1566 unsigned int gpio_offset, const char *pin_group)
1567{
1568 struct gpio_pin_range *pin_range;
1569 int ret;
1570
1571 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1572 if (!pin_range) {
1573 chip_err(chip, "failed to allocate pin ranges\n");
1574 return -ENOMEM;
1575 }
1576
1577 /* Use local offset as range ID */
1578 pin_range->range.id = gpio_offset;
1579 pin_range->range.gc = chip;
1580 pin_range->range.name = chip->label;
1581 pin_range->range.base = chip->base + gpio_offset;
1582 pin_range->pctldev = pctldev;
1583
1584 ret = pinctrl_get_group_pins(pctldev, pin_group,
1585 &pin_range->range.pins,
1586 &pin_range->range.npins);
1587 if (ret < 0) {
1588 kfree(pin_range);
1589 return ret;
1590 }
1591
1592 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1593
1594 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1595 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1596 pinctrl_dev_get_devname(pctldev), pin_group);
1597
1598 list_add_tail(&pin_range->node, &chip->pin_ranges);
1599
1600 return 0;
1601}
1602EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1603
1604/**
1605 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1606 * @chip: the gpiochip to add the range for
1607 * @pinctrl_name: the dev_name() of the pin controller to map to
1608 * @gpio_offset: the start offset in the current gpio_chip number space
1609 * @pin_offset: the start offset in the pin controller number space
1610 * @npins: the number of pins from the offset of each pin space (GPIO and
1611 * pin controller) to accumulate in this range
1612 */
1613int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1614 unsigned int gpio_offset, unsigned int pin_offset,
1615 unsigned int npins)
1616{
1617 struct gpio_pin_range *pin_range;
1618 int ret;
1619
1620 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1621 if (!pin_range) {
1622 chip_err(chip, "failed to allocate pin ranges\n");
1623 return -ENOMEM;
1624 }
1625
1626 /* Use local offset as range ID */
1627 pin_range->range.id = gpio_offset;
1628 pin_range->range.gc = chip;
1629 pin_range->range.name = chip->label;
1630 pin_range->range.base = chip->base + gpio_offset;
1631 pin_range->range.pin_base = pin_offset;
1632 pin_range->range.npins = npins;
1633 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1634 &pin_range->range);
1635 if (IS_ERR(pin_range->pctldev)) {
1636 ret = PTR_ERR(pin_range->pctldev);
1637 chip_err(chip, "could not create pin range\n");
1638 kfree(pin_range);
1639 return ret;
1640 }
1641 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1642 gpio_offset, gpio_offset + npins - 1,
1643 pinctl_name,
1644 pin_offset, pin_offset + npins - 1);
1645
1646 list_add_tail(&pin_range->node, &chip->pin_ranges);
1647
1648 return 0;
1649}
1650EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1651
1652/**
1653 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1654 * @chip: the chip to remove all the mappings for
1655 */
1656void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1657{
1658 struct gpio_pin_range *pin_range, *tmp;
1659
1660 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
1661 list_del(&pin_range->node);
1662 pinctrl_remove_gpio_range(pin_range->pctldev,
1663 &pin_range->range);
1664 kfree(pin_range);
1665 }
1666}
1667EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1668
1669#endif /* CONFIG_PINCTRL */
1670
1671/* These "optional" allocation calls help prevent drivers from stomping
1672 * on each other, and help provide better diagnostics in debugfs.
1673 * They're called even less than the "set direction" calls.
1674 */
1675static int __gpiod_request(struct gpio_desc *desc, const char *label)
1676{
1677 struct gpio_chip *chip = desc->chip;
1678 int status;
1679 unsigned long flags;
1680
1681 spin_lock_irqsave(&gpio_lock, flags);
1682
1683 /* NOTE: gpio_request() can be called in early boot,
1684 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1685 */
1686
1687 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1688 desc_set_label(desc, label ? : "?");
1689 status = 0;
1690 } else {
1691 status = -EBUSY;
1692 goto done;
1693 }
1694
1695 if (chip->request) {
1696 /* chip->request may sleep */
1697 spin_unlock_irqrestore(&gpio_lock, flags);
1698 status = chip->request(chip, gpio_chip_hwgpio(desc));
1699 spin_lock_irqsave(&gpio_lock, flags);
1700
1701 if (status < 0) {
1702 desc_set_label(desc, NULL);
1703 clear_bit(FLAG_REQUESTED, &desc->flags);
1704 goto done;
1705 }
1706 }
1707 if (chip->get_direction) {
1708 /* chip->get_direction may sleep */
1709 spin_unlock_irqrestore(&gpio_lock, flags);
1710 gpiod_get_direction(desc);
1711 spin_lock_irqsave(&gpio_lock, flags);
1712 }
1713done:
1714 spin_unlock_irqrestore(&gpio_lock, flags);
1715 return status;
1716}
1717
1718static int gpiod_request(struct gpio_desc *desc, const char *label)
1719{
1720 int status = -EPROBE_DEFER;
1721 struct gpio_chip *chip;
1722
1723 if (!desc) {
1724 pr_warn("%s: invalid GPIO\n", __func__);
1725 return -EINVAL;
1726 }
1727
1728 chip = desc->chip;
1729 if (!chip)
1730 goto done;
1731
1732 if (try_module_get(chip->owner)) {
1733 status = __gpiod_request(desc, label);
1734 if (status < 0)
1735 module_put(chip->owner);
1736 }
1737
1738done:
1739 if (status)
1740 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
1741
1742 return status;
1743}
1744
1745int gpio_request(unsigned gpio, const char *label)
1746{
1747 return gpiod_request(gpio_to_desc(gpio), label);
1748}
1749EXPORT_SYMBOL_GPL(gpio_request);
1750
1751static bool __gpiod_free(struct gpio_desc *desc)
1752{
1753 bool ret = false;
1754 unsigned long flags;
1755 struct gpio_chip *chip;
1756
1757 might_sleep();
1758
1759 gpiod_unexport(desc);
1760
1761 spin_lock_irqsave(&gpio_lock, flags);
1762
1763 chip = desc->chip;
1764 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1765 if (chip->free) {
1766 spin_unlock_irqrestore(&gpio_lock, flags);
1767 might_sleep_if(chip->can_sleep);
1768 chip->free(chip, gpio_chip_hwgpio(desc));
1769 spin_lock_irqsave(&gpio_lock, flags);
1770 }
1771 desc_set_label(desc, NULL);
1772 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1773 clear_bit(FLAG_REQUESTED, &desc->flags);
1774 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1775 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1776 ret = true;
1777 }
1778
1779 spin_unlock_irqrestore(&gpio_lock, flags);
1780 return ret;
1781}
1782
1783static void gpiod_free(struct gpio_desc *desc)
1784{
1785 if (desc && __gpiod_free(desc))
1786 module_put(desc->chip->owner);
1787 else
1788 WARN_ON(extra_checks);
1789}
1790
1791void gpio_free(unsigned gpio)
1792{
1793 gpiod_free(gpio_to_desc(gpio));
1794}
1795EXPORT_SYMBOL_GPL(gpio_free);
1796
1797/**
1798 * gpio_request_one - request a single GPIO with initial configuration
1799 * @gpio: the GPIO number
1800 * @flags: GPIO configuration as specified by GPIOF_*
1801 * @label: a literal description string of this GPIO
1802 */
1803int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
1804{
1805 struct gpio_desc *desc;
1806 int err;
1807
1808 desc = gpio_to_desc(gpio);
1809
1810 err = gpiod_request(desc, label);
1811 if (err)
1812 return err;
1813
1814 if (flags & GPIOF_OPEN_DRAIN)
1815 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
1816
1817 if (flags & GPIOF_OPEN_SOURCE)
1818 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
1819
1820 if (flags & GPIOF_DIR_IN)
1821 err = gpiod_direction_input(desc);
1822 else
1823 err = gpiod_direction_output_raw(desc,
1824 (flags & GPIOF_INIT_HIGH) ? 1 : 0);
1825
1826 if (err)
1827 goto free_gpio;
1828
1829 if (flags & GPIOF_EXPORT) {
1830 err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE);
1831 if (err)
1832 goto free_gpio;
1833 }
1834
1835 return 0;
1836
1837 free_gpio:
1838 gpiod_free(desc);
1839 return err;
1840}
1841EXPORT_SYMBOL_GPL(gpio_request_one);
1842
1843/**
1844 * gpio_request_array - request multiple GPIOs in a single call
1845 * @array: array of the 'struct gpio'
1846 * @num: how many GPIOs in the array
1847 */
1848int gpio_request_array(const struct gpio *array, size_t num)
1849{
1850 int i, err;
1851
1852 for (i = 0; i < num; i++, array++) {
1853 err = gpio_request_one(array->gpio, array->flags, array->label);
1854 if (err)
1855 goto err_free;
1856 }
1857 return 0;
1858
1859err_free:
1860 while (i--)
1861 gpio_free((--array)->gpio);
1862 return err;
1863}
1864EXPORT_SYMBOL_GPL(gpio_request_array);
1865
1866/**
1867 * gpio_free_array - release multiple GPIOs in a single call
1868 * @array: array of the 'struct gpio'
1869 * @num: how many GPIOs in the array
1870 */
1871void gpio_free_array(const struct gpio *array, size_t num)
1872{
1873 while (num--)
1874 gpio_free((array++)->gpio);
1875}
1876EXPORT_SYMBOL_GPL(gpio_free_array);
1877
1878/**
1879 * gpiochip_is_requested - return string iff signal was requested
1880 * @chip: controller managing the signal
1881 * @offset: of signal within controller's 0..(ngpio - 1) range
1882 *
1883 * Returns NULL if the GPIO is not currently requested, else a string.
1884 * If debugfs support is enabled, the string returned is the label passed
1885 * to gpio_request(); otherwise it is a meaningless constant.
1886 *
1887 * This function is for use by GPIO controller drivers. The label can
1888 * help with diagnostics, and knowing that the signal is used as a GPIO
1889 * can help avoid accidentally multiplexing it to another controller.
1890 */
1891const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1892{
1893 struct gpio_desc *desc;
1894
1895 if (!GPIO_OFFSET_VALID(chip, offset))
1896 return NULL;
1897
1898 desc = &chip->desc[offset];
1899
1900 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
1901 return NULL;
1902#ifdef CONFIG_DEBUG_FS
1903 return desc->label;
1904#else
1905 return "?";
1906#endif
1907}
1908EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1909
1910/**
1911 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1912 * @desc: GPIO descriptor to request
1913 * @label: label for the GPIO
1914 *
1915 * Function allows GPIO chip drivers to request and use their own GPIO
1916 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1917 * function will not increase reference count of the GPIO chip module. This
1918 * allows the GPIO chip module to be unloaded as needed (we assume that the
1919 * GPIO chip driver handles freeing the GPIOs it has requested).
1920 */
1921int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
1922{
1923 if (!desc || !desc->chip)
1924 return -EINVAL;
1925
1926 return __gpiod_request(desc, label);
1927}
1928
1929/**
1930 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1931 * @desc: GPIO descriptor to free
1932 *
1933 * Function frees the given GPIO requested previously with
1934 * gpiochip_request_own_desc().
1935 */
1936void gpiochip_free_own_desc(struct gpio_desc *desc)
1937{
1938 if (desc)
1939 __gpiod_free(desc);
1940}
1941
1942/* Drivers MUST set GPIO direction before making get/set calls. In
1943 * some cases this is done in early boot, before IRQs are enabled.
1944 *
1945 * As a rule these aren't called more than once (except for drivers
1946 * using the open-drain emulation idiom) so these are natural places
1947 * to accumulate extra debugging checks. Note that we can't (yet)
1948 * rely on gpio_request() having been called beforehand.
1949 */
1950
1951/**
1952 * gpiod_direction_input - set the GPIO direction to input
1953 * @desc: GPIO to set to input
1954 *
1955 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1956 * be called safely on it.
1957 *
1958 * Return 0 in case of success, else an error code.
1959 */
1960int gpiod_direction_input(struct gpio_desc *desc)
1961{
1962 unsigned long flags;
1963 struct gpio_chip *chip;
1964 int status = -EINVAL;
1965 int offset;
1966
1967 if (!desc || !desc->chip) {
1968 pr_warn("%s: invalid GPIO\n", __func__);
1969 return -EINVAL;
1970 }
1971
1972 chip = desc->chip;
1973 if (!chip->get || !chip->direction_input) {
1974 gpiod_warn(desc,
1975 "%s: missing get() or direction_input() operations\n",
1976 __func__);
1977 return -EIO;
1978 }
1979
1980 spin_lock_irqsave(&gpio_lock, flags);
1981
1982 status = gpio_ensure_requested(desc);
1983 if (status < 0)
1984 goto fail;
1985
1986 /* now we know the gpio is valid and chip won't vanish */
1987
1988 spin_unlock_irqrestore(&gpio_lock, flags);
1989
1990 might_sleep_if(chip->can_sleep);
1991
1992 offset = gpio_chip_hwgpio(desc);
1993 if (status) {
1994 status = chip->request(chip, offset);
1995 if (status < 0) {
1996 gpiod_dbg(desc, "%s: chip request fail, %d\n",
1997 __func__, status);
1998 /* and it's not available to anyone else ...
1999 * gpio_request() is the fully clean solution.
2000 */
2001 goto lose;
2002 }
2003 }
2004
2005 status = chip->direction_input(chip, offset);
2006 if (status == 0)
2007 clear_bit(FLAG_IS_OUT, &desc->flags);
2008
2009 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2010lose:
2011 return status;
2012fail:
2013 spin_unlock_irqrestore(&gpio_lock, flags);
2014 if (status)
2015 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2016 return status;
2017}
2018EXPORT_SYMBOL_GPL(gpiod_direction_input);
2019
2020static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2021{
2022 unsigned long flags;
2023 struct gpio_chip *chip;
2024 int status = -EINVAL;
2025 int offset;
2026
2027 /* GPIOs used for IRQs shall not be set as output */
2028 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2029 gpiod_err(desc,
2030 "%s: tried to set a GPIO tied to an IRQ as output\n",
2031 __func__);
2032 return -EIO;
2033 }
2034
2035 /* Open drain pin should not be driven to 1 */
2036 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2037 return gpiod_direction_input(desc);
2038
2039 /* Open source pin should not be driven to 0 */
2040 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2041 return gpiod_direction_input(desc);
2042
2043 chip = desc->chip;
2044 if (!chip->set || !chip->direction_output) {
2045 gpiod_warn(desc,
2046 "%s: missing set() or direction_output() operations\n",
2047 __func__);
2048 return -EIO;
2049 }
2050
2051 spin_lock_irqsave(&gpio_lock, flags);
2052
2053 status = gpio_ensure_requested(desc);
2054 if (status < 0)
2055 goto fail;
2056
2057 /* now we know the gpio is valid and chip won't vanish */
2058
2059 spin_unlock_irqrestore(&gpio_lock, flags);
2060
2061 might_sleep_if(chip->can_sleep);
2062
2063 offset = gpio_chip_hwgpio(desc);
2064 if (status) {
2065 status = chip->request(chip, offset);
2066 if (status < 0) {
2067 gpiod_dbg(desc, "%s: chip request fail, %d\n",
2068 __func__, status);
2069 /* and it's not available to anyone else ...
2070 * gpio_request() is the fully clean solution.
2071 */
2072 goto lose;
2073 }
2074 }
2075
2076 status = chip->direction_output(chip, offset, value);
2077 if (status == 0)
2078 set_bit(FLAG_IS_OUT, &desc->flags);
2079 trace_gpio_value(desc_to_gpio(desc), 0, value);
2080 trace_gpio_direction(desc_to_gpio(desc), 0, status);
2081lose:
2082 return status;
2083fail:
2084 spin_unlock_irqrestore(&gpio_lock, flags);
2085 if (status)
2086 gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);
2087 return status;
2088}
2089
2090/**
2091 * gpiod_direction_output_raw - set the GPIO direction to output
2092 * @desc: GPIO to set to output
2093 * @value: initial output value of the GPIO
2094 *
2095 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2096 * be called safely on it. The initial value of the output must be specified
2097 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2098 *
2099 * Return 0 in case of success, else an error code.
2100 */
2101int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2102{
2103 if (!desc || !desc->chip) {
2104 pr_warn("%s: invalid GPIO\n", __func__);
2105 return -EINVAL;
2106 }
2107 return _gpiod_direction_output_raw(desc, value);
2108}
2109EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2110
2111/**
2112 * gpiod_direction_output - set the GPIO direction to output
2113 * @desc: GPIO to set to output
2114 * @value: initial output value of the GPIO
2115 *
2116 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2117 * be called safely on it. The initial value of the output must be specified
2118 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2119 * account.
2120 *
2121 * Return 0 in case of success, else an error code.
2122 */
2123int gpiod_direction_output(struct gpio_desc *desc, int value)
2124{
2125 if (!desc || !desc->chip) {
2126 pr_warn("%s: invalid GPIO\n", __func__);
2127 return -EINVAL;
2128 }
2129 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2130 value = !value;
2131 return _gpiod_direction_output_raw(desc, value);
2132}
2133EXPORT_SYMBOL_GPL(gpiod_direction_output);
2134
2135/**
2136 * gpiod_set_debounce - sets @debounce time for a @gpio
2137 * @gpio: the gpio to set debounce time
2138 * @debounce: debounce time is microseconds
2139 *
2140 * returns -ENOTSUPP if the controller does not support setting
2141 * debounce.
2142 */
2143int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2144{
2145 unsigned long flags;
2146 struct gpio_chip *chip;
2147 int status = -EINVAL;
2148 int offset;
2149
2150 if (!desc || !desc->chip) {
2151 pr_warn("%s: invalid GPIO\n", __func__);
2152 return -EINVAL;
2153 }
2154
2155 chip = desc->chip;
2156 if (!chip->set || !chip->set_debounce) {
2157 gpiod_dbg(desc,
2158 "%s: missing set() or set_debounce() operations\n",
2159 __func__);
2160 return -ENOTSUPP;
2161 }
2162
2163 spin_lock_irqsave(&gpio_lock, flags);
2164
2165 status = gpio_ensure_requested(desc);
2166 if (status < 0)
2167 goto fail;
2168
2169 /* now we know the gpio is valid and chip won't vanish */
2170
2171 spin_unlock_irqrestore(&gpio_lock, flags);
2172
2173 might_sleep_if(chip->can_sleep);
2174
2175 offset = gpio_chip_hwgpio(desc);
2176 return chip->set_debounce(chip, offset, debounce);
2177
2178fail:
2179 spin_unlock_irqrestore(&gpio_lock, flags);
2180 if (status)
2181 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2182
2183 return status;
2184}
2185EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2186
2187/**
2188 * gpiod_is_active_low - test whether a GPIO is active-low or not
2189 * @desc: the gpio descriptor to test
2190 *
2191 * Returns 1 if the GPIO is active-low, 0 otherwise.
2192 */
2193int gpiod_is_active_low(const struct gpio_desc *desc)
2194{
2195 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2196}
2197EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2198
2199/* I/O calls are only valid after configuration completed; the relevant
2200 * "is this a valid GPIO" error checks should already have been done.
2201 *
2202 * "Get" operations are often inlinable as reading a pin value register,
2203 * and masking the relevant bit in that register.
2204 *
2205 * When "set" operations are inlinable, they involve writing that mask to
2206 * one register to set a low value, or a different register to set it high.
2207 * Otherwise locking is needed, so there may be little value to inlining.
2208 *
2209 *------------------------------------------------------------------------
2210 *
2211 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2212 * have requested the GPIO. That can include implicit requesting by
2213 * a direction setting call. Marking a gpio as requested locks its chip
2214 * in memory, guaranteeing that these table lookups need no more locking
2215 * and that gpiochip_remove() will fail.
2216 *
2217 * REVISIT when debugging, consider adding some instrumentation to ensure
2218 * that the GPIO was actually requested.
2219 */
2220
2221static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
2222{
2223 struct gpio_chip *chip;
2224 bool value;
2225 int offset;
2226
2227 chip = desc->chip;
2228 offset = gpio_chip_hwgpio(desc);
2229 value = chip->get ? chip->get(chip, offset) : false;
2230 trace_gpio_value(desc_to_gpio(desc), 1, value);
2231 return value;
2232}
2233
2234/**
2235 * gpiod_get_raw_value() - return a gpio's raw value
2236 * @desc: gpio whose value will be returned
2237 *
2238 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2239 * its ACTIVE_LOW status.
2240 *
2241 * This function should be called from contexts where we cannot sleep, and will
2242 * complain if the GPIO chip functions potentially sleep.
2243 */
2244int gpiod_get_raw_value(const struct gpio_desc *desc)
2245{
2246 if (!desc)
2247 return 0;
2248 /* Should be using gpio_get_value_cansleep() */
2249 WARN_ON(desc->chip->can_sleep);
2250 return _gpiod_get_raw_value(desc);
2251}
2252EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2253
2254/**
2255 * gpiod_get_value() - return a gpio's value
2256 * @desc: gpio whose value will be returned
2257 *
2258 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2259 * account.
2260 *
2261 * This function should be called from contexts where we cannot sleep, and will
2262 * complain if the GPIO chip functions potentially sleep.
2263 */
2264int gpiod_get_value(const struct gpio_desc *desc)
2265{
2266 int value;
2267 if (!desc)
2268 return 0;
2269 /* Should be using gpio_get_value_cansleep() */
2270 WARN_ON(desc->chip->can_sleep);
2271
2272 value = _gpiod_get_raw_value(desc);
2273 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2274 value = !value;
2275
2276 return value;
2277}
2278EXPORT_SYMBOL_GPL(gpiod_get_value);
2279
2280/*
2281 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
2282 * @desc: gpio descriptor whose state need to be set.
2283 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
2284 */
2285static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
2286{
2287 int err = 0;
2288 struct gpio_chip *chip = desc->chip;
2289 int offset = gpio_chip_hwgpio(desc);
2290
2291 if (value) {
2292 err = chip->direction_input(chip, offset);
2293 if (!err)
2294 clear_bit(FLAG_IS_OUT, &desc->flags);
2295 } else {
2296 err = chip->direction_output(chip, offset, 0);
2297 if (!err)
2298 set_bit(FLAG_IS_OUT, &desc->flags);
2299 }
2300 trace_gpio_direction(desc_to_gpio(desc), value, err);
2301 if (err < 0)
2302 gpiod_err(desc,
2303 "%s: Error in set_value for open drain err %d\n",
2304 __func__, err);
2305}
2306
2307/*
2308 * _gpio_set_open_source_value() - Set the open source gpio's value.
2309 * @desc: gpio descriptor whose state need to be set.
2310 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
2311 */
2312static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
2313{
2314 int err = 0;
2315 struct gpio_chip *chip = desc->chip;
2316 int offset = gpio_chip_hwgpio(desc);
2317
2318 if (value) {
2319 err = chip->direction_output(chip, offset, 1);
2320 if (!err)
2321 set_bit(FLAG_IS_OUT, &desc->flags);
2322 } else {
2323 err = chip->direction_input(chip, offset);
2324 if (!err)
2325 clear_bit(FLAG_IS_OUT, &desc->flags);
2326 }
2327 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2328 if (err < 0)
2329 gpiod_err(desc,
2330 "%s: Error in set_value for open source err %d\n",
2331 __func__, err);
2332}
2333
2334static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
2335{
2336 struct gpio_chip *chip;
2337
2338 chip = desc->chip;
2339 trace_gpio_value(desc_to_gpio(desc), 0, value);
2340 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2341 _gpio_set_open_drain_value(desc, value);
2342 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2343 _gpio_set_open_source_value(desc, value);
2344 else
2345 chip->set(chip, gpio_chip_hwgpio(desc), value);
2346}
2347
2348/**
2349 * gpiod_set_raw_value() - assign a gpio's raw value
2350 * @desc: gpio whose value will be assigned
2351 * @value: value to assign
2352 *
2353 * Set the raw value of the GPIO, i.e. the value of its physical line without
2354 * regard for its ACTIVE_LOW status.
2355 *
2356 * This function should be called from contexts where we cannot sleep, and will
2357 * complain if the GPIO chip functions potentially sleep.
2358 */
2359void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2360{
2361 if (!desc)
2362 return;
2363 /* Should be using gpio_set_value_cansleep() */
2364 WARN_ON(desc->chip->can_sleep);
2365 _gpiod_set_raw_value(desc, value);
2366}
2367EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
2368
2369/**
2370 * gpiod_set_value() - assign a gpio's value
2371 * @desc: gpio whose value will be assigned
2372 * @value: value to assign
2373 *
2374 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2375 * account
2376 *
2377 * This function should be called from contexts where we cannot sleep, and will
2378 * complain if the GPIO chip functions potentially sleep.
2379 */
2380void gpiod_set_value(struct gpio_desc *desc, int value)
2381{
2382 if (!desc)
2383 return;
2384 /* Should be using gpio_set_value_cansleep() */
2385 WARN_ON(desc->chip->can_sleep);
2386 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2387 value = !value;
2388 _gpiod_set_raw_value(desc, value);
2389}
2390EXPORT_SYMBOL_GPL(gpiod_set_value);
2391
2392/**
2393 * gpiod_cansleep() - report whether gpio value access may sleep
2394 * @desc: gpio to check
2395 *
2396 */
2397int gpiod_cansleep(const struct gpio_desc *desc)
2398{
2399 if (!desc)
2400 return 0;
2401 return desc->chip->can_sleep;
2402}
2403EXPORT_SYMBOL_GPL(gpiod_cansleep);
2404
2405/**
2406 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2407 * @desc: gpio whose IRQ will be returned (already requested)
2408 *
2409 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2410 * error.
2411 */
2412int gpiod_to_irq(const struct gpio_desc *desc)
2413{
2414 struct gpio_chip *chip;
2415 int offset;
2416
2417 if (!desc)
2418 return -EINVAL;
2419 chip = desc->chip;
2420 offset = gpio_chip_hwgpio(desc);
2421 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
2422}
2423EXPORT_SYMBOL_GPL(gpiod_to_irq);
2424
2425/**
2426 * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ
2427 * @gpio: the GPIO line to lock as used for IRQ
2428 *
2429 * This is used directly by GPIO drivers that want to lock down
2430 * a certain GPIO line to be used for IRQs.
2431 */
2432int gpiod_lock_as_irq(struct gpio_desc *desc)
2433{
2434 if (!desc)
2435 return -EINVAL;
2436
2437 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2438 gpiod_err(desc,
2439 "%s: tried to flag a GPIO set as output for IRQ\n",
2440 __func__);
2441 return -EIO;
2442 }
2443
2444 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2445 return 0;
2446}
2447EXPORT_SYMBOL_GPL(gpiod_lock_as_irq);
2448
2449int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2450{
2451 return gpiod_lock_as_irq(gpiochip_get_desc(chip, offset));
2452}
2453EXPORT_SYMBOL_GPL(gpio_lock_as_irq);
2454
2455/**
2456 * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ
2457 * @gpio: the GPIO line to unlock from IRQ usage
2458 *
2459 * This is used directly by GPIO drivers that want to indicate
2460 * that a certain GPIO is no longer used exclusively for IRQ.
2461 */
2462void gpiod_unlock_as_irq(struct gpio_desc *desc)
2463{
2464 if (!desc)
2465 return;
2466
2467 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
2468}
2469EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq);
2470
2471void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2472{
2473 return gpiod_unlock_as_irq(gpiochip_get_desc(chip, offset));
2474}
2475EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
2476
2477/**
2478 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2479 * @desc: gpio whose value will be returned
2480 *
2481 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2482 * its ACTIVE_LOW status.
2483 *
2484 * This function is to be called from contexts that can sleep.
2485 */
2486int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2487{
2488 might_sleep_if(extra_checks);
2489 if (!desc)
2490 return 0;
2491 return _gpiod_get_raw_value(desc);
2492}
2493EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2494
2495/**
2496 * gpiod_get_value_cansleep() - return a gpio's value
2497 * @desc: gpio whose value will be returned
2498 *
2499 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2500 * account.
2501 *
2502 * This function is to be called from contexts that can sleep.
2503 */
2504int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2505{
2506 int value;
2507
2508 might_sleep_if(extra_checks);
2509 if (!desc)
2510 return 0;
2511
2512 value = _gpiod_get_raw_value(desc);
2513 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2514 value = !value;
2515
2516 return value;
2517}
2518EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2519
2520/**
2521 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2522 * @desc: gpio whose value will be assigned
2523 * @value: value to assign
2524 *
2525 * Set the raw value of the GPIO, i.e. the value of its physical line without
2526 * regard for its ACTIVE_LOW status.
2527 *
2528 * This function is to be called from contexts that can sleep.
2529 */
2530void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2531{
2532 might_sleep_if(extra_checks);
2533 if (!desc)
2534 return;
2535 _gpiod_set_raw_value(desc, value);
2536}
2537EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2538
2539/**
2540 * gpiod_set_value_cansleep() - assign a gpio's value
2541 * @desc: gpio whose value will be assigned
2542 * @value: value to assign
2543 *
2544 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2545 * account
2546 *
2547 * This function is to be called from contexts that can sleep.
2548 */
2549void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2550{
2551 might_sleep_if(extra_checks);
2552 if (!desc)
2553 return;
2554
2555 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2556 value = !value;
2557 _gpiod_set_raw_value(desc, value);
2558}
2559EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2560
2561/**
2562 * gpiod_add_lookup_table() - register GPIO device consumers
2563 * @table: table of consumers to register
2564 */
2565void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2566{
2567 mutex_lock(&gpio_lookup_lock);
2568
2569 list_add_tail(&table->list, &gpio_lookup_list);
2570
2571 mutex_unlock(&gpio_lookup_lock);
2572}
2573
2574#ifdef CONFIG_OF
2575static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
2576 unsigned int idx,
2577 enum gpio_lookup_flags *flags)
2578{
2579 char prop_name[32]; /* 32 is max size of property name */
2580 enum of_gpio_flags of_flags;
2581 struct gpio_desc *desc;
2582
2583 if (con_id)
2584 snprintf(prop_name, 32, "%s-gpios", con_id);
2585 else
2586 snprintf(prop_name, 32, "gpios");
2587
2588 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
2589 &of_flags);
2590
2591 if (IS_ERR(desc))
2592 return desc;
2593
2594 if (of_flags & OF_GPIO_ACTIVE_LOW)
2595 *flags |= GPIO_ACTIVE_LOW;
2596
2597 return desc;
2598}
2599#else
2600static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
2601 unsigned int idx,
2602 enum gpio_lookup_flags *flags)
2603{
2604 return ERR_PTR(-ENODEV);
2605}
2606#endif
2607
2608static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
2609 unsigned int idx,
2610 enum gpio_lookup_flags *flags)
2611{
2612 struct acpi_gpio_info info;
2613 struct gpio_desc *desc;
2614
2615 desc = acpi_get_gpiod_by_index(dev, idx, &info);
2616 if (IS_ERR(desc))
2617 return desc;
2618
2619 if (info.gpioint && info.active_low)
2620 *flags |= GPIO_ACTIVE_LOW;
2621
2622 return desc;
2623}
2624
2625static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2626{
2627 const char *dev_id = dev ? dev_name(dev) : NULL;
2628 struct gpiod_lookup_table *table;
2629
2630 mutex_lock(&gpio_lookup_lock);
2631
2632 list_for_each_entry(table, &gpio_lookup_list, list) {
2633 if (table->dev_id && dev_id) {
2634 /*
2635 * Valid strings on both ends, must be identical to have
2636 * a match
2637 */
2638 if (!strcmp(table->dev_id, dev_id))
2639 goto found;
2640 } else {
2641 /*
2642 * One of the pointers is NULL, so both must be to have
2643 * a match
2644 */
2645 if (dev_id == table->dev_id)
2646 goto found;
2647 }
2648 }
2649 table = NULL;
2650
2651found:
2652 mutex_unlock(&gpio_lookup_lock);
2653 return table;
2654}
2655
2656static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2657 unsigned int idx,
2658 enum gpio_lookup_flags *flags)
2659{
2660 struct gpio_desc *desc = ERR_PTR(-ENOENT);
2661 struct gpiod_lookup_table *table;
2662 struct gpiod_lookup *p;
2663
2664 table = gpiod_find_lookup_table(dev);
2665 if (!table)
2666 return desc;
2667
2668 for (p = &table->table[0]; p->chip_label; p++) {
2669 struct gpio_chip *chip;
2670
2671 /* idx must always match exactly */
2672 if (p->idx != idx)
2673 continue;
2674
2675 /* If the lookup entry has a con_id, require exact match */
2676 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2677 continue;
2678
2679 chip = find_chip_by_name(p->chip_label);
2680
2681 if (!chip) {
2682 dev_err(dev, "cannot find GPIO chip %s\n",
2683 p->chip_label);
2684 return ERR_PTR(-ENODEV);
2685 }
2686
2687 if (chip->ngpio <= p->chip_hwnum) {
2688 dev_err(dev,
2689 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2690 idx, chip->ngpio, chip->label);
2691 return ERR_PTR(-EINVAL);
2692 }
2693
2694 desc = gpiochip_get_desc(chip, p->chip_hwnum);
2695 *flags = p->flags;
2696
2697 return desc;
2698 }
2699
2700 return desc;
2701}
2702
2703/**
2704 * gpio_get - obtain a GPIO for a given GPIO function
2705 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2706 * @con_id: function within the GPIO consumer
2707 *
2708 * Return the GPIO descriptor corresponding to the function con_id of device
2709 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2710 * another IS_ERR() code if an error occured while trying to acquire the GPIO.
2711 */
2712struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id)
2713{
2714 return gpiod_get_index(dev, con_id, 0);
2715}
2716EXPORT_SYMBOL_GPL(gpiod_get);
2717
2718/**
2719 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2720 * @dev: GPIO consumer, can be NULL for system-global GPIOs
2721 * @con_id: function within the GPIO consumer
2722 * @idx: index of the GPIO to obtain in the consumer
2723 *
2724 * This variant of gpiod_get() allows to access GPIOs other than the first
2725 * defined one for functions that define several GPIOs.
2726 *
2727 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2728 * requested function and/or index, or another IS_ERR() code if an error
2729 * occured while trying to acquire the GPIO.
2730 */
2731struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2732 const char *con_id,
2733 unsigned int idx)
2734{
2735 struct gpio_desc *desc = NULL;
2736 int status;
2737 enum gpio_lookup_flags flags = 0;
2738
2739 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2740
2741 /* Using device tree? */
2742 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) {
2743 dev_dbg(dev, "using device tree for GPIO lookup\n");
2744 desc = of_find_gpio(dev, con_id, idx, &flags);
2745 } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
2746 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2747 desc = acpi_find_gpio(dev, con_id, idx, &flags);
2748 }
2749
2750 /*
2751 * Either we are not using DT or ACPI, or their lookup did not return
2752 * a result. In that case, use platform lookup as a fallback.
2753 */
2754 if (!desc || desc == ERR_PTR(-ENOENT)) {
2755 dev_dbg(dev, "using lookup tables for GPIO lookup");
2756 desc = gpiod_find(dev, con_id, idx, &flags);
2757 }
2758
2759 if (IS_ERR(desc)) {
2760 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2761 return desc;
2762 }
2763
2764 status = gpiod_request(desc, con_id);
2765
2766 if (status < 0)
2767 return ERR_PTR(status);
2768
2769 if (flags & GPIO_ACTIVE_LOW)
2770 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2771 if (flags & GPIO_OPEN_DRAIN)
2772 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2773 if (flags & GPIO_OPEN_SOURCE)
2774 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2775
2776 return desc;
2777}
2778EXPORT_SYMBOL_GPL(gpiod_get_index);
2779
2780/**
2781 * gpiod_put - dispose of a GPIO descriptor
2782 * @desc: GPIO descriptor to dispose of
2783 *
2784 * No descriptor can be used after gpiod_put() has been called on it.
2785 */
2786void gpiod_put(struct gpio_desc *desc)
2787{
2788 gpiod_free(desc);
2789}
2790EXPORT_SYMBOL_GPL(gpiod_put);
2791
2792#ifdef CONFIG_DEBUG_FS
2793
2794static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2795{
2796 unsigned i;
2797 unsigned gpio = chip->base;
2798 struct gpio_desc *gdesc = &chip->desc[0];
2799 int is_out;
2800 int is_irq;
2801
2802 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2803 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
2804 continue;
2805
2806 gpiod_get_direction(gdesc);
2807 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2808 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2809 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
2810 gpio, gdesc->label,
2811 is_out ? "out" : "in ",
2812 chip->get
2813 ? (chip->get(chip, i) ? "hi" : "lo")
2814 : "? ",
2815 is_irq ? "IRQ" : " ");
2816 seq_printf(s, "\n");
2817 }
2818}
2819
2820static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2821{
2822 unsigned long flags;
2823 struct gpio_chip *chip = NULL;
2824 loff_t index = *pos;
2825
2826 s->private = "";
2827
2828 spin_lock_irqsave(&gpio_lock, flags);
2829 list_for_each_entry(chip, &gpio_chips, list)
2830 if (index-- == 0) {
2831 spin_unlock_irqrestore(&gpio_lock, flags);
2832 return chip;
2833 }
2834 spin_unlock_irqrestore(&gpio_lock, flags);
2835
2836 return NULL;
2837}
2838
2839static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2840{
2841 unsigned long flags;
2842 struct gpio_chip *chip = v;
2843 void *ret = NULL;
2844
2845 spin_lock_irqsave(&gpio_lock, flags);
2846 if (list_is_last(&chip->list, &gpio_chips))
2847 ret = NULL;
2848 else
2849 ret = list_entry(chip->list.next, struct gpio_chip, list);
2850 spin_unlock_irqrestore(&gpio_lock, flags);
2851
2852 s->private = "\n";
2853 ++*pos;
2854
2855 return ret;
2856}
2857
2858static void gpiolib_seq_stop(struct seq_file *s, void *v)
2859{
2860}
2861
2862static int gpiolib_seq_show(struct seq_file *s, void *v)
2863{
2864 struct gpio_chip *chip = v;
2865 struct device *dev;
2866
2867 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2868 chip->base, chip->base + chip->ngpio - 1);
2869 dev = chip->dev;
2870 if (dev)
2871 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2872 dev_name(dev));
2873 if (chip->label)
2874 seq_printf(s, ", %s", chip->label);
2875 if (chip->can_sleep)
2876 seq_printf(s, ", can sleep");
2877 seq_printf(s, ":\n");
2878
2879 if (chip->dbg_show)
2880 chip->dbg_show(s, chip);
2881 else
2882 gpiolib_dbg_show(s, chip);
2883
2884 return 0;
2885}
2886
2887static const struct seq_operations gpiolib_seq_ops = {
2888 .start = gpiolib_seq_start,
2889 .next = gpiolib_seq_next,
2890 .stop = gpiolib_seq_stop,
2891 .show = gpiolib_seq_show,
2892};
2893
2894static int gpiolib_open(struct inode *inode, struct file *file)
2895{
2896 return seq_open(file, &gpiolib_seq_ops);
2897}
2898
2899static const struct file_operations gpiolib_operations = {
2900 .owner = THIS_MODULE,
2901 .open = gpiolib_open,
2902 .read = seq_read,
2903 .llseek = seq_lseek,
2904 .release = seq_release,
2905};
2906
2907static int __init gpiolib_debugfs_init(void)
2908{
2909 /* /sys/kernel/debug/gpio */
2910 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2911 NULL, NULL, &gpiolib_operations);
2912 return 0;
2913}
2914subsys_initcall(gpiolib_debugfs_init);
2915
2916#endif /* DEBUG_FS */
1#include <linux/bitmap.h>
2#include <linux/kernel.h>
3#include <linux/module.h>
4#include <linux/interrupt.h>
5#include <linux/irq.h>
6#include <linux/spinlock.h>
7#include <linux/list.h>
8#include <linux/device.h>
9#include <linux/err.h>
10#include <linux/debugfs.h>
11#include <linux/seq_file.h>
12#include <linux/gpio.h>
13#include <linux/of_gpio.h>
14#include <linux/idr.h>
15#include <linux/slab.h>
16#include <linux/acpi.h>
17#include <linux/gpio/driver.h>
18#include <linux/gpio/machine.h>
19#include <linux/pinctrl/consumer.h>
20#include <linux/cdev.h>
21#include <linux/fs.h>
22#include <linux/uaccess.h>
23#include <linux/compat.h>
24#include <linux/anon_inodes.h>
25#include <linux/file.h>
26#include <linux/kfifo.h>
27#include <linux/poll.h>
28#include <linux/timekeeping.h>
29#include <uapi/linux/gpio.h>
30
31#include "gpiolib.h"
32
33#define CREATE_TRACE_POINTS
34#include <trace/events/gpio.h>
35
36/* Implementation infrastructure for GPIO interfaces.
37 *
38 * The GPIO programming interface allows for inlining speed-critical
39 * get/set operations for common cases, so that access to SOC-integrated
40 * GPIOs can sometimes cost only an instruction or two per bit.
41 */
42
43
44/* When debugging, extend minimal trust to callers and platform code.
45 * Also emit diagnostic messages that may help initial bringup, when
46 * board setup or driver bugs are most common.
47 *
48 * Otherwise, minimize overhead in what may be bitbanging codepaths.
49 */
50#ifdef DEBUG
51#define extra_checks 1
52#else
53#define extra_checks 0
54#endif
55
56/* Device and char device-related information */
57static DEFINE_IDA(gpio_ida);
58static dev_t gpio_devt;
59#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
60static struct bus_type gpio_bus_type = {
61 .name = "gpio",
62};
63
64/* gpio_lock prevents conflicts during gpio_desc[] table updates.
65 * While any GPIO is requested, its gpio_chip is not removable;
66 * each GPIO's "requested" flag serves as a lock and refcount.
67 */
68DEFINE_SPINLOCK(gpio_lock);
69
70static DEFINE_MUTEX(gpio_lookup_lock);
71static LIST_HEAD(gpio_lookup_list);
72LIST_HEAD(gpio_devices);
73
74static void gpiochip_free_hogs(struct gpio_chip *chip);
75static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
76 struct lock_class_key *lock_key,
77 struct lock_class_key *request_key);
78static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
79static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
80static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
81
82static bool gpiolib_initialized;
83
84static inline void desc_set_label(struct gpio_desc *d, const char *label)
85{
86 d->label = label;
87}
88
89/**
90 * gpio_to_desc - Convert a GPIO number to its descriptor
91 * @gpio: global GPIO number
92 *
93 * Returns:
94 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
95 * with the given number exists in the system.
96 */
97struct gpio_desc *gpio_to_desc(unsigned gpio)
98{
99 struct gpio_device *gdev;
100 unsigned long flags;
101
102 spin_lock_irqsave(&gpio_lock, flags);
103
104 list_for_each_entry(gdev, &gpio_devices, list) {
105 if (gdev->base <= gpio &&
106 gdev->base + gdev->ngpio > gpio) {
107 spin_unlock_irqrestore(&gpio_lock, flags);
108 return &gdev->descs[gpio - gdev->base];
109 }
110 }
111
112 spin_unlock_irqrestore(&gpio_lock, flags);
113
114 if (!gpio_is_valid(gpio))
115 WARN(1, "invalid GPIO %d\n", gpio);
116
117 return NULL;
118}
119EXPORT_SYMBOL_GPL(gpio_to_desc);
120
121/**
122 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
123 * hardware number for this chip
124 * @chip: GPIO chip
125 * @hwnum: hardware number of the GPIO for this chip
126 *
127 * Returns:
128 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
129 * in the given chip for the specified hardware number.
130 */
131struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
132 u16 hwnum)
133{
134 struct gpio_device *gdev = chip->gpiodev;
135
136 if (hwnum >= gdev->ngpio)
137 return ERR_PTR(-EINVAL);
138
139 return &gdev->descs[hwnum];
140}
141
142/**
143 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
144 * @desc: GPIO descriptor
145 *
146 * This should disappear in the future but is needed since we still
147 * use GPIO numbers for error messages and sysfs nodes.
148 *
149 * Returns:
150 * The global GPIO number for the GPIO specified by its descriptor.
151 */
152int desc_to_gpio(const struct gpio_desc *desc)
153{
154 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
155}
156EXPORT_SYMBOL_GPL(desc_to_gpio);
157
158
159/**
160 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
161 * @desc: descriptor to return the chip of
162 */
163struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
164{
165 if (!desc || !desc->gdev)
166 return NULL;
167 return desc->gdev->chip;
168}
169EXPORT_SYMBOL_GPL(gpiod_to_chip);
170
171/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
172static int gpiochip_find_base(int ngpio)
173{
174 struct gpio_device *gdev;
175 int base = ARCH_NR_GPIOS - ngpio;
176
177 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
178 /* found a free space? */
179 if (gdev->base + gdev->ngpio <= base)
180 break;
181 else
182 /* nope, check the space right before the chip */
183 base = gdev->base - ngpio;
184 }
185
186 if (gpio_is_valid(base)) {
187 pr_debug("%s: found new base at %d\n", __func__, base);
188 return base;
189 } else {
190 pr_err("%s: cannot find free range\n", __func__);
191 return -ENOSPC;
192 }
193}
194
195/**
196 * gpiod_get_direction - return the current direction of a GPIO
197 * @desc: GPIO to get the direction of
198 *
199 * Returns 0 for output, 1 for input, or an error code in case of error.
200 *
201 * This function may sleep if gpiod_cansleep() is true.
202 */
203int gpiod_get_direction(struct gpio_desc *desc)
204{
205 struct gpio_chip *chip;
206 unsigned offset;
207 int status = -EINVAL;
208
209 chip = gpiod_to_chip(desc);
210 offset = gpio_chip_hwgpio(desc);
211
212 if (!chip->get_direction)
213 return status;
214
215 status = chip->get_direction(chip, offset);
216 if (status > 0) {
217 /* GPIOF_DIR_IN, or other positive */
218 status = 1;
219 clear_bit(FLAG_IS_OUT, &desc->flags);
220 }
221 if (status == 0) {
222 /* GPIOF_DIR_OUT */
223 set_bit(FLAG_IS_OUT, &desc->flags);
224 }
225 return status;
226}
227EXPORT_SYMBOL_GPL(gpiod_get_direction);
228
229/*
230 * Add a new chip to the global chips list, keeping the list of chips sorted
231 * by range(means [base, base + ngpio - 1]) order.
232 *
233 * Return -EBUSY if the new chip overlaps with some other chip's integer
234 * space.
235 */
236static int gpiodev_add_to_list(struct gpio_device *gdev)
237{
238 struct gpio_device *prev, *next;
239
240 if (list_empty(&gpio_devices)) {
241 /* initial entry in list */
242 list_add_tail(&gdev->list, &gpio_devices);
243 return 0;
244 }
245
246 next = list_entry(gpio_devices.next, struct gpio_device, list);
247 if (gdev->base + gdev->ngpio <= next->base) {
248 /* add before first entry */
249 list_add(&gdev->list, &gpio_devices);
250 return 0;
251 }
252
253 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
254 if (prev->base + prev->ngpio <= gdev->base) {
255 /* add behind last entry */
256 list_add_tail(&gdev->list, &gpio_devices);
257 return 0;
258 }
259
260 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
261 /* at the end of the list */
262 if (&next->list == &gpio_devices)
263 break;
264
265 /* add between prev and next */
266 if (prev->base + prev->ngpio <= gdev->base
267 && gdev->base + gdev->ngpio <= next->base) {
268 list_add(&gdev->list, &prev->list);
269 return 0;
270 }
271 }
272
273 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
274 return -EBUSY;
275}
276
277/*
278 * Convert a GPIO name to its descriptor
279 */
280static struct gpio_desc *gpio_name_to_desc(const char * const name)
281{
282 struct gpio_device *gdev;
283 unsigned long flags;
284
285 spin_lock_irqsave(&gpio_lock, flags);
286
287 list_for_each_entry(gdev, &gpio_devices, list) {
288 int i;
289
290 for (i = 0; i != gdev->ngpio; ++i) {
291 struct gpio_desc *desc = &gdev->descs[i];
292
293 if (!desc->name || !name)
294 continue;
295
296 if (!strcmp(desc->name, name)) {
297 spin_unlock_irqrestore(&gpio_lock, flags);
298 return desc;
299 }
300 }
301 }
302
303 spin_unlock_irqrestore(&gpio_lock, flags);
304
305 return NULL;
306}
307
308/*
309 * Takes the names from gc->names and checks if they are all unique. If they
310 * are, they are assigned to their gpio descriptors.
311 *
312 * Warning if one of the names is already used for a different GPIO.
313 */
314static int gpiochip_set_desc_names(struct gpio_chip *gc)
315{
316 struct gpio_device *gdev = gc->gpiodev;
317 int i;
318
319 if (!gc->names)
320 return 0;
321
322 /* First check all names if they are unique */
323 for (i = 0; i != gc->ngpio; ++i) {
324 struct gpio_desc *gpio;
325
326 gpio = gpio_name_to_desc(gc->names[i]);
327 if (gpio)
328 dev_warn(&gdev->dev,
329 "Detected name collision for GPIO name '%s'\n",
330 gc->names[i]);
331 }
332
333 /* Then add all names to the GPIO descriptors */
334 for (i = 0; i != gc->ngpio; ++i)
335 gdev->descs[i].name = gc->names[i];
336
337 return 0;
338}
339
340static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
341{
342 unsigned long *p;
343
344 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
345 if (!p)
346 return NULL;
347
348 /* Assume by default all GPIOs are valid */
349 bitmap_fill(p, chip->ngpio);
350
351 return p;
352}
353
354static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
355{
356#ifdef CONFIG_OF_GPIO
357 int size;
358 struct device_node *np = gpiochip->of_node;
359
360 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
361 if (size > 0 && size % 2 == 0)
362 gpiochip->need_valid_mask = true;
363#endif
364
365 if (!gpiochip->need_valid_mask)
366 return 0;
367
368 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
369 if (!gpiochip->valid_mask)
370 return -ENOMEM;
371
372 return 0;
373}
374
375static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
376{
377 kfree(gpiochip->valid_mask);
378 gpiochip->valid_mask = NULL;
379}
380
381bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
382 unsigned int offset)
383{
384 /* No mask means all valid */
385 if (likely(!gpiochip->valid_mask))
386 return true;
387 return test_bit(offset, gpiochip->valid_mask);
388}
389EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
390
391/*
392 * GPIO line handle management
393 */
394
395/**
396 * struct linehandle_state - contains the state of a userspace handle
397 * @gdev: the GPIO device the handle pertains to
398 * @label: consumer label used to tag descriptors
399 * @descs: the GPIO descriptors held by this handle
400 * @numdescs: the number of descriptors held in the descs array
401 */
402struct linehandle_state {
403 struct gpio_device *gdev;
404 const char *label;
405 struct gpio_desc *descs[GPIOHANDLES_MAX];
406 u32 numdescs;
407};
408
409#define GPIOHANDLE_REQUEST_VALID_FLAGS \
410 (GPIOHANDLE_REQUEST_INPUT | \
411 GPIOHANDLE_REQUEST_OUTPUT | \
412 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
413 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
414 GPIOHANDLE_REQUEST_OPEN_SOURCE)
415
416static long linehandle_ioctl(struct file *filep, unsigned int cmd,
417 unsigned long arg)
418{
419 struct linehandle_state *lh = filep->private_data;
420 void __user *ip = (void __user *)arg;
421 struct gpiohandle_data ghd;
422 int vals[GPIOHANDLES_MAX];
423 int i;
424
425 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
426 /* TODO: check if descriptors are really input */
427 int ret = gpiod_get_array_value_complex(false,
428 true,
429 lh->numdescs,
430 lh->descs,
431 vals);
432 if (ret)
433 return ret;
434
435 memset(&ghd, 0, sizeof(ghd));
436 for (i = 0; i < lh->numdescs; i++)
437 ghd.values[i] = vals[i];
438
439 if (copy_to_user(ip, &ghd, sizeof(ghd)))
440 return -EFAULT;
441
442 return 0;
443 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
444 /* TODO: check if descriptors are really output */
445 if (copy_from_user(&ghd, ip, sizeof(ghd)))
446 return -EFAULT;
447
448 /* Clamp all values to [0,1] */
449 for (i = 0; i < lh->numdescs; i++)
450 vals[i] = !!ghd.values[i];
451
452 /* Reuse the array setting function */
453 gpiod_set_array_value_complex(false,
454 true,
455 lh->numdescs,
456 lh->descs,
457 vals);
458 return 0;
459 }
460 return -EINVAL;
461}
462
463#ifdef CONFIG_COMPAT
464static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
465 unsigned long arg)
466{
467 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
468}
469#endif
470
471static int linehandle_release(struct inode *inode, struct file *filep)
472{
473 struct linehandle_state *lh = filep->private_data;
474 struct gpio_device *gdev = lh->gdev;
475 int i;
476
477 for (i = 0; i < lh->numdescs; i++)
478 gpiod_free(lh->descs[i]);
479 kfree(lh->label);
480 kfree(lh);
481 put_device(&gdev->dev);
482 return 0;
483}
484
485static const struct file_operations linehandle_fileops = {
486 .release = linehandle_release,
487 .owner = THIS_MODULE,
488 .llseek = noop_llseek,
489 .unlocked_ioctl = linehandle_ioctl,
490#ifdef CONFIG_COMPAT
491 .compat_ioctl = linehandle_ioctl_compat,
492#endif
493};
494
495static int linehandle_create(struct gpio_device *gdev, void __user *ip)
496{
497 struct gpiohandle_request handlereq;
498 struct linehandle_state *lh;
499 struct file *file;
500 int fd, i, count = 0, ret;
501 u32 lflags;
502
503 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
504 return -EFAULT;
505 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
506 return -EINVAL;
507
508 lflags = handlereq.flags;
509
510 /* Return an error if an unknown flag is set */
511 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
512 return -EINVAL;
513
514 /*
515 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
516 * the hardware actually supports enabling both at the same time the
517 * electrical result would be disastrous.
518 */
519 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
520 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
521 return -EINVAL;
522
523 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
524 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
525 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
526 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
527 return -EINVAL;
528
529 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
530 if (!lh)
531 return -ENOMEM;
532 lh->gdev = gdev;
533 get_device(&gdev->dev);
534
535 /* Make sure this is terminated */
536 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
537 if (strlen(handlereq.consumer_label)) {
538 lh->label = kstrdup(handlereq.consumer_label,
539 GFP_KERNEL);
540 if (!lh->label) {
541 ret = -ENOMEM;
542 goto out_free_lh;
543 }
544 }
545
546 /* Request each GPIO */
547 for (i = 0; i < handlereq.lines; i++) {
548 u32 offset = handlereq.lineoffsets[i];
549 struct gpio_desc *desc;
550
551 if (offset >= gdev->ngpio) {
552 ret = -EINVAL;
553 goto out_free_descs;
554 }
555
556 desc = &gdev->descs[offset];
557 ret = gpiod_request(desc, lh->label);
558 if (ret)
559 goto out_free_descs;
560 lh->descs[i] = desc;
561 count = i;
562
563 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
564 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
565 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
566 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
567 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
568 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
569
570 ret = gpiod_set_transitory(desc, false);
571 if (ret < 0)
572 goto out_free_descs;
573
574 /*
575 * Lines have to be requested explicitly for input
576 * or output, else the line will be treated "as is".
577 */
578 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
579 int val = !!handlereq.default_values[i];
580
581 ret = gpiod_direction_output(desc, val);
582 if (ret)
583 goto out_free_descs;
584 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
585 ret = gpiod_direction_input(desc);
586 if (ret)
587 goto out_free_descs;
588 }
589 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
590 offset);
591 }
592 /* Let i point at the last handle */
593 i--;
594 lh->numdescs = handlereq.lines;
595
596 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
597 if (fd < 0) {
598 ret = fd;
599 goto out_free_descs;
600 }
601
602 file = anon_inode_getfile("gpio-linehandle",
603 &linehandle_fileops,
604 lh,
605 O_RDONLY | O_CLOEXEC);
606 if (IS_ERR(file)) {
607 ret = PTR_ERR(file);
608 goto out_put_unused_fd;
609 }
610
611 handlereq.fd = fd;
612 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
613 /*
614 * fput() will trigger the release() callback, so do not go onto
615 * the regular error cleanup path here.
616 */
617 fput(file);
618 put_unused_fd(fd);
619 return -EFAULT;
620 }
621
622 fd_install(fd, file);
623
624 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
625 lh->numdescs);
626
627 return 0;
628
629out_put_unused_fd:
630 put_unused_fd(fd);
631out_free_descs:
632 for (i = 0; i < count; i++)
633 gpiod_free(lh->descs[i]);
634 kfree(lh->label);
635out_free_lh:
636 kfree(lh);
637 put_device(&gdev->dev);
638 return ret;
639}
640
641/*
642 * GPIO line event management
643 */
644
645/**
646 * struct lineevent_state - contains the state of a userspace event
647 * @gdev: the GPIO device the event pertains to
648 * @label: consumer label used to tag descriptors
649 * @desc: the GPIO descriptor held by this event
650 * @eflags: the event flags this line was requested with
651 * @irq: the interrupt that trigger in response to events on this GPIO
652 * @wait: wait queue that handles blocking reads of events
653 * @events: KFIFO for the GPIO events
654 * @read_lock: mutex lock to protect reads from colliding with adding
655 * new events to the FIFO
656 * @timestamp: cache for the timestamp storing it between hardirq
657 * and IRQ thread, used to bring the timestamp close to the actual
658 * event
659 */
660struct lineevent_state {
661 struct gpio_device *gdev;
662 const char *label;
663 struct gpio_desc *desc;
664 u32 eflags;
665 int irq;
666 wait_queue_head_t wait;
667 DECLARE_KFIFO(events, struct gpioevent_data, 16);
668 struct mutex read_lock;
669 u64 timestamp;
670};
671
672#define GPIOEVENT_REQUEST_VALID_FLAGS \
673 (GPIOEVENT_REQUEST_RISING_EDGE | \
674 GPIOEVENT_REQUEST_FALLING_EDGE)
675
676static __poll_t lineevent_poll(struct file *filep,
677 struct poll_table_struct *wait)
678{
679 struct lineevent_state *le = filep->private_data;
680 __poll_t events = 0;
681
682 poll_wait(filep, &le->wait, wait);
683
684 if (!kfifo_is_empty(&le->events))
685 events = EPOLLIN | EPOLLRDNORM;
686
687 return events;
688}
689
690
691static ssize_t lineevent_read(struct file *filep,
692 char __user *buf,
693 size_t count,
694 loff_t *f_ps)
695{
696 struct lineevent_state *le = filep->private_data;
697 unsigned int copied;
698 int ret;
699
700 if (count < sizeof(struct gpioevent_data))
701 return -EINVAL;
702
703 do {
704 if (kfifo_is_empty(&le->events)) {
705 if (filep->f_flags & O_NONBLOCK)
706 return -EAGAIN;
707
708 ret = wait_event_interruptible(le->wait,
709 !kfifo_is_empty(&le->events));
710 if (ret)
711 return ret;
712 }
713
714 if (mutex_lock_interruptible(&le->read_lock))
715 return -ERESTARTSYS;
716 ret = kfifo_to_user(&le->events, buf, count, &copied);
717 mutex_unlock(&le->read_lock);
718
719 if (ret)
720 return ret;
721
722 /*
723 * If we couldn't read anything from the fifo (a different
724 * thread might have been faster) we either return -EAGAIN if
725 * the file descriptor is non-blocking, otherwise we go back to
726 * sleep and wait for more data to arrive.
727 */
728 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
729 return -EAGAIN;
730
731 } while (copied == 0);
732
733 return copied;
734}
735
736static int lineevent_release(struct inode *inode, struct file *filep)
737{
738 struct lineevent_state *le = filep->private_data;
739 struct gpio_device *gdev = le->gdev;
740
741 free_irq(le->irq, le);
742 gpiod_free(le->desc);
743 kfree(le->label);
744 kfree(le);
745 put_device(&gdev->dev);
746 return 0;
747}
748
749static long lineevent_ioctl(struct file *filep, unsigned int cmd,
750 unsigned long arg)
751{
752 struct lineevent_state *le = filep->private_data;
753 void __user *ip = (void __user *)arg;
754 struct gpiohandle_data ghd;
755
756 /*
757 * We can get the value for an event line but not set it,
758 * because it is input by definition.
759 */
760 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
761 int val;
762
763 memset(&ghd, 0, sizeof(ghd));
764
765 val = gpiod_get_value_cansleep(le->desc);
766 if (val < 0)
767 return val;
768 ghd.values[0] = val;
769
770 if (copy_to_user(ip, &ghd, sizeof(ghd)))
771 return -EFAULT;
772
773 return 0;
774 }
775 return -EINVAL;
776}
777
778#ifdef CONFIG_COMPAT
779static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
780 unsigned long arg)
781{
782 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
783}
784#endif
785
786static const struct file_operations lineevent_fileops = {
787 .release = lineevent_release,
788 .read = lineevent_read,
789 .poll = lineevent_poll,
790 .owner = THIS_MODULE,
791 .llseek = noop_llseek,
792 .unlocked_ioctl = lineevent_ioctl,
793#ifdef CONFIG_COMPAT
794 .compat_ioctl = lineevent_ioctl_compat,
795#endif
796};
797
798static irqreturn_t lineevent_irq_thread(int irq, void *p)
799{
800 struct lineevent_state *le = p;
801 struct gpioevent_data ge;
802 int ret, level;
803
804 /* Do not leak kernel stack to userspace */
805 memset(&ge, 0, sizeof(ge));
806
807 ge.timestamp = le->timestamp;
808 level = gpiod_get_value_cansleep(le->desc);
809
810 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
811 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
812 if (level)
813 /* Emit low-to-high event */
814 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
815 else
816 /* Emit high-to-low event */
817 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
818 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
819 /* Emit low-to-high event */
820 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
821 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
822 /* Emit high-to-low event */
823 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
824 } else {
825 return IRQ_NONE;
826 }
827
828 ret = kfifo_put(&le->events, ge);
829 if (ret != 0)
830 wake_up_poll(&le->wait, EPOLLIN);
831
832 return IRQ_HANDLED;
833}
834
835static irqreturn_t lineevent_irq_handler(int irq, void *p)
836{
837 struct lineevent_state *le = p;
838
839 /*
840 * Just store the timestamp in hardirq context so we get it as
841 * close in time as possible to the actual event.
842 */
843 le->timestamp = ktime_get_real_ns();
844
845 return IRQ_WAKE_THREAD;
846}
847
848static int lineevent_create(struct gpio_device *gdev, void __user *ip)
849{
850 struct gpioevent_request eventreq;
851 struct lineevent_state *le;
852 struct gpio_desc *desc;
853 struct file *file;
854 u32 offset;
855 u32 lflags;
856 u32 eflags;
857 int fd;
858 int ret;
859 int irqflags = 0;
860
861 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
862 return -EFAULT;
863
864 le = kzalloc(sizeof(*le), GFP_KERNEL);
865 if (!le)
866 return -ENOMEM;
867 le->gdev = gdev;
868 get_device(&gdev->dev);
869
870 /* Make sure this is terminated */
871 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
872 if (strlen(eventreq.consumer_label)) {
873 le->label = kstrdup(eventreq.consumer_label,
874 GFP_KERNEL);
875 if (!le->label) {
876 ret = -ENOMEM;
877 goto out_free_le;
878 }
879 }
880
881 offset = eventreq.lineoffset;
882 lflags = eventreq.handleflags;
883 eflags = eventreq.eventflags;
884
885 if (offset >= gdev->ngpio) {
886 ret = -EINVAL;
887 goto out_free_label;
888 }
889
890 /* Return an error if a unknown flag is set */
891 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
892 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
893 ret = -EINVAL;
894 goto out_free_label;
895 }
896
897 /* This is just wrong: we don't look for events on output lines */
898 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
899 ret = -EINVAL;
900 goto out_free_label;
901 }
902
903 desc = &gdev->descs[offset];
904 ret = gpiod_request(desc, le->label);
905 if (ret)
906 goto out_free_label;
907 le->desc = desc;
908 le->eflags = eflags;
909
910 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
911 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
912 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
913 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
914 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
915 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
916
917 ret = gpiod_direction_input(desc);
918 if (ret)
919 goto out_free_desc;
920
921 le->irq = gpiod_to_irq(desc);
922 if (le->irq <= 0) {
923 ret = -ENODEV;
924 goto out_free_desc;
925 }
926
927 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
928 irqflags |= IRQF_TRIGGER_RISING;
929 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
930 irqflags |= IRQF_TRIGGER_FALLING;
931 irqflags |= IRQF_ONESHOT;
932 irqflags |= IRQF_SHARED;
933
934 INIT_KFIFO(le->events);
935 init_waitqueue_head(&le->wait);
936 mutex_init(&le->read_lock);
937
938 /* Request a thread to read the events */
939 ret = request_threaded_irq(le->irq,
940 lineevent_irq_handler,
941 lineevent_irq_thread,
942 irqflags,
943 le->label,
944 le);
945 if (ret)
946 goto out_free_desc;
947
948 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
949 if (fd < 0) {
950 ret = fd;
951 goto out_free_irq;
952 }
953
954 file = anon_inode_getfile("gpio-event",
955 &lineevent_fileops,
956 le,
957 O_RDONLY | O_CLOEXEC);
958 if (IS_ERR(file)) {
959 ret = PTR_ERR(file);
960 goto out_put_unused_fd;
961 }
962
963 eventreq.fd = fd;
964 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
965 /*
966 * fput() will trigger the release() callback, so do not go onto
967 * the regular error cleanup path here.
968 */
969 fput(file);
970 put_unused_fd(fd);
971 return -EFAULT;
972 }
973
974 fd_install(fd, file);
975
976 return 0;
977
978out_put_unused_fd:
979 put_unused_fd(fd);
980out_free_irq:
981 free_irq(le->irq, le);
982out_free_desc:
983 gpiod_free(le->desc);
984out_free_label:
985 kfree(le->label);
986out_free_le:
987 kfree(le);
988 put_device(&gdev->dev);
989 return ret;
990}
991
992/*
993 * gpio_ioctl() - ioctl handler for the GPIO chardev
994 */
995static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
996{
997 struct gpio_device *gdev = filp->private_data;
998 struct gpio_chip *chip = gdev->chip;
999 void __user *ip = (void __user *)arg;
1000
1001 /* We fail any subsequent ioctl():s when the chip is gone */
1002 if (!chip)
1003 return -ENODEV;
1004
1005 /* Fill in the struct and pass to userspace */
1006 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1007 struct gpiochip_info chipinfo;
1008
1009 memset(&chipinfo, 0, sizeof(chipinfo));
1010
1011 strncpy(chipinfo.name, dev_name(&gdev->dev),
1012 sizeof(chipinfo.name));
1013 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1014 strncpy(chipinfo.label, gdev->label,
1015 sizeof(chipinfo.label));
1016 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1017 chipinfo.lines = gdev->ngpio;
1018 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1019 return -EFAULT;
1020 return 0;
1021 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1022 struct gpioline_info lineinfo;
1023 struct gpio_desc *desc;
1024
1025 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1026 return -EFAULT;
1027 if (lineinfo.line_offset >= gdev->ngpio)
1028 return -EINVAL;
1029
1030 desc = &gdev->descs[lineinfo.line_offset];
1031 if (desc->name) {
1032 strncpy(lineinfo.name, desc->name,
1033 sizeof(lineinfo.name));
1034 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1035 } else {
1036 lineinfo.name[0] = '\0';
1037 }
1038 if (desc->label) {
1039 strncpy(lineinfo.consumer, desc->label,
1040 sizeof(lineinfo.consumer));
1041 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1042 } else {
1043 lineinfo.consumer[0] = '\0';
1044 }
1045
1046 /*
1047 * Userspace only need to know that the kernel is using
1048 * this GPIO so it can't use it.
1049 */
1050 lineinfo.flags = 0;
1051 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1052 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1053 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1054 test_bit(FLAG_EXPORT, &desc->flags) ||
1055 test_bit(FLAG_SYSFS, &desc->flags))
1056 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1057 if (test_bit(FLAG_IS_OUT, &desc->flags))
1058 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1059 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1060 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1061 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1062 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1063 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1064 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1065
1066 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1067 return -EFAULT;
1068 return 0;
1069 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1070 return linehandle_create(gdev, ip);
1071 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1072 return lineevent_create(gdev, ip);
1073 }
1074 return -EINVAL;
1075}
1076
1077#ifdef CONFIG_COMPAT
1078static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1079 unsigned long arg)
1080{
1081 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1082}
1083#endif
1084
1085/**
1086 * gpio_chrdev_open() - open the chardev for ioctl operations
1087 * @inode: inode for this chardev
1088 * @filp: file struct for storing private data
1089 * Returns 0 on success
1090 */
1091static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1092{
1093 struct gpio_device *gdev = container_of(inode->i_cdev,
1094 struct gpio_device, chrdev);
1095
1096 /* Fail on open if the backing gpiochip is gone */
1097 if (!gdev->chip)
1098 return -ENODEV;
1099 get_device(&gdev->dev);
1100 filp->private_data = gdev;
1101
1102 return nonseekable_open(inode, filp);
1103}
1104
1105/**
1106 * gpio_chrdev_release() - close chardev after ioctl operations
1107 * @inode: inode for this chardev
1108 * @filp: file struct for storing private data
1109 * Returns 0 on success
1110 */
1111static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1112{
1113 struct gpio_device *gdev = container_of(inode->i_cdev,
1114 struct gpio_device, chrdev);
1115
1116 put_device(&gdev->dev);
1117 return 0;
1118}
1119
1120
1121static const struct file_operations gpio_fileops = {
1122 .release = gpio_chrdev_release,
1123 .open = gpio_chrdev_open,
1124 .owner = THIS_MODULE,
1125 .llseek = no_llseek,
1126 .unlocked_ioctl = gpio_ioctl,
1127#ifdef CONFIG_COMPAT
1128 .compat_ioctl = gpio_ioctl_compat,
1129#endif
1130};
1131
1132static void gpiodevice_release(struct device *dev)
1133{
1134 struct gpio_device *gdev = dev_get_drvdata(dev);
1135
1136 list_del(&gdev->list);
1137 ida_simple_remove(&gpio_ida, gdev->id);
1138 kfree_const(gdev->label);
1139 kfree(gdev->descs);
1140 kfree(gdev);
1141}
1142
1143static int gpiochip_setup_dev(struct gpio_device *gdev)
1144{
1145 int status;
1146
1147 cdev_init(&gdev->chrdev, &gpio_fileops);
1148 gdev->chrdev.owner = THIS_MODULE;
1149 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1150
1151 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1152 if (status)
1153 return status;
1154
1155 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1156 MAJOR(gpio_devt), gdev->id);
1157
1158 status = gpiochip_sysfs_register(gdev);
1159 if (status)
1160 goto err_remove_device;
1161
1162 /* From this point, the .release() function cleans up gpio_device */
1163 gdev->dev.release = gpiodevice_release;
1164 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1165 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1166 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1167
1168 return 0;
1169
1170err_remove_device:
1171 cdev_device_del(&gdev->chrdev, &gdev->dev);
1172 return status;
1173}
1174
1175static void gpiochip_setup_devs(void)
1176{
1177 struct gpio_device *gdev;
1178 int err;
1179
1180 list_for_each_entry(gdev, &gpio_devices, list) {
1181 err = gpiochip_setup_dev(gdev);
1182 if (err)
1183 pr_err("%s: Failed to initialize gpio device (%d)\n",
1184 dev_name(&gdev->dev), err);
1185 }
1186}
1187
1188int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1189 struct lock_class_key *lock_key,
1190 struct lock_class_key *request_key)
1191{
1192 unsigned long flags;
1193 int status = 0;
1194 unsigned i;
1195 int base = chip->base;
1196 struct gpio_device *gdev;
1197
1198 /*
1199 * First: allocate and populate the internal stat container, and
1200 * set up the struct device.
1201 */
1202 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1203 if (!gdev)
1204 return -ENOMEM;
1205 gdev->dev.bus = &gpio_bus_type;
1206 gdev->chip = chip;
1207 chip->gpiodev = gdev;
1208 if (chip->parent) {
1209 gdev->dev.parent = chip->parent;
1210 gdev->dev.of_node = chip->parent->of_node;
1211 }
1212
1213#ifdef CONFIG_OF_GPIO
1214 /* If the gpiochip has an assigned OF node this takes precedence */
1215 if (chip->of_node)
1216 gdev->dev.of_node = chip->of_node;
1217#endif
1218
1219 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1220 if (gdev->id < 0) {
1221 status = gdev->id;
1222 goto err_free_gdev;
1223 }
1224 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1225 device_initialize(&gdev->dev);
1226 dev_set_drvdata(&gdev->dev, gdev);
1227 if (chip->parent && chip->parent->driver)
1228 gdev->owner = chip->parent->driver->owner;
1229 else if (chip->owner)
1230 /* TODO: remove chip->owner */
1231 gdev->owner = chip->owner;
1232 else
1233 gdev->owner = THIS_MODULE;
1234
1235 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1236 if (!gdev->descs) {
1237 status = -ENOMEM;
1238 goto err_free_gdev;
1239 }
1240
1241 if (chip->ngpio == 0) {
1242 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1243 status = -EINVAL;
1244 goto err_free_descs;
1245 }
1246
1247 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1248 if (!gdev->label) {
1249 status = -ENOMEM;
1250 goto err_free_descs;
1251 }
1252
1253 gdev->ngpio = chip->ngpio;
1254 gdev->data = data;
1255
1256 spin_lock_irqsave(&gpio_lock, flags);
1257
1258 /*
1259 * TODO: this allocates a Linux GPIO number base in the global
1260 * GPIO numberspace for this chip. In the long run we want to
1261 * get *rid* of this numberspace and use only descriptors, but
1262 * it may be a pipe dream. It will not happen before we get rid
1263 * of the sysfs interface anyways.
1264 */
1265 if (base < 0) {
1266 base = gpiochip_find_base(chip->ngpio);
1267 if (base < 0) {
1268 status = base;
1269 spin_unlock_irqrestore(&gpio_lock, flags);
1270 goto err_free_label;
1271 }
1272 /*
1273 * TODO: it should not be necessary to reflect the assigned
1274 * base outside of the GPIO subsystem. Go over drivers and
1275 * see if anyone makes use of this, else drop this and assign
1276 * a poison instead.
1277 */
1278 chip->base = base;
1279 }
1280 gdev->base = base;
1281
1282 status = gpiodev_add_to_list(gdev);
1283 if (status) {
1284 spin_unlock_irqrestore(&gpio_lock, flags);
1285 goto err_free_label;
1286 }
1287
1288 spin_unlock_irqrestore(&gpio_lock, flags);
1289
1290 for (i = 0; i < chip->ngpio; i++) {
1291 struct gpio_desc *desc = &gdev->descs[i];
1292
1293 desc->gdev = gdev;
1294
1295 /* REVISIT: most hardware initializes GPIOs as inputs (often
1296 * with pullups enabled) so power usage is minimized. Linux
1297 * code should set the gpio direction first thing; but until
1298 * it does, and in case chip->get_direction is not set, we may
1299 * expose the wrong direction in sysfs.
1300 */
1301 desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
1302 }
1303
1304#ifdef CONFIG_PINCTRL
1305 INIT_LIST_HEAD(&gdev->pin_ranges);
1306#endif
1307
1308 status = gpiochip_set_desc_names(chip);
1309 if (status)
1310 goto err_remove_from_list;
1311
1312 status = gpiochip_irqchip_init_valid_mask(chip);
1313 if (status)
1314 goto err_remove_from_list;
1315
1316 status = gpiochip_init_valid_mask(chip);
1317 if (status)
1318 goto err_remove_irqchip_mask;
1319
1320 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1321 if (status)
1322 goto err_remove_chip;
1323
1324 status = of_gpiochip_add(chip);
1325 if (status)
1326 goto err_remove_chip;
1327
1328 acpi_gpiochip_add(chip);
1329
1330 /*
1331 * By first adding the chardev, and then adding the device,
1332 * we get a device node entry in sysfs under
1333 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1334 * coldplug of device nodes and other udev business.
1335 * We can do this only if gpiolib has been initialized.
1336 * Otherwise, defer until later.
1337 */
1338 if (gpiolib_initialized) {
1339 status = gpiochip_setup_dev(gdev);
1340 if (status)
1341 goto err_remove_chip;
1342 }
1343 return 0;
1344
1345err_remove_chip:
1346 acpi_gpiochip_remove(chip);
1347 gpiochip_free_hogs(chip);
1348 of_gpiochip_remove(chip);
1349 gpiochip_free_valid_mask(chip);
1350err_remove_irqchip_mask:
1351 gpiochip_irqchip_free_valid_mask(chip);
1352err_remove_from_list:
1353 spin_lock_irqsave(&gpio_lock, flags);
1354 list_del(&gdev->list);
1355 spin_unlock_irqrestore(&gpio_lock, flags);
1356err_free_label:
1357 kfree_const(gdev->label);
1358err_free_descs:
1359 kfree(gdev->descs);
1360err_free_gdev:
1361 ida_simple_remove(&gpio_ida, gdev->id);
1362 /* failures here can mean systems won't boot... */
1363 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
1364 gdev->base, gdev->base + gdev->ngpio - 1,
1365 chip->label ? : "generic");
1366 kfree(gdev);
1367 return status;
1368}
1369EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1370
1371/**
1372 * gpiochip_get_data() - get per-subdriver data for the chip
1373 * @chip: GPIO chip
1374 *
1375 * Returns:
1376 * The per-subdriver data for the chip.
1377 */
1378void *gpiochip_get_data(struct gpio_chip *chip)
1379{
1380 return chip->gpiodev->data;
1381}
1382EXPORT_SYMBOL_GPL(gpiochip_get_data);
1383
1384/**
1385 * gpiochip_remove() - unregister a gpio_chip
1386 * @chip: the chip to unregister
1387 *
1388 * A gpio_chip with any GPIOs still requested may not be removed.
1389 */
1390void gpiochip_remove(struct gpio_chip *chip)
1391{
1392 struct gpio_device *gdev = chip->gpiodev;
1393 struct gpio_desc *desc;
1394 unsigned long flags;
1395 unsigned i;
1396 bool requested = false;
1397
1398 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1399 gpiochip_sysfs_unregister(gdev);
1400 gpiochip_free_hogs(chip);
1401 /* Numb the device, cancelling all outstanding operations */
1402 gdev->chip = NULL;
1403 gpiochip_irqchip_remove(chip);
1404 acpi_gpiochip_remove(chip);
1405 gpiochip_remove_pin_ranges(chip);
1406 of_gpiochip_remove(chip);
1407 gpiochip_free_valid_mask(chip);
1408 /*
1409 * We accept no more calls into the driver from this point, so
1410 * NULL the driver data pointer
1411 */
1412 gdev->data = NULL;
1413
1414 spin_lock_irqsave(&gpio_lock, flags);
1415 for (i = 0; i < gdev->ngpio; i++) {
1416 desc = &gdev->descs[i];
1417 if (test_bit(FLAG_REQUESTED, &desc->flags))
1418 requested = true;
1419 }
1420 spin_unlock_irqrestore(&gpio_lock, flags);
1421
1422 if (requested)
1423 dev_crit(&gdev->dev,
1424 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1425
1426 /*
1427 * The gpiochip side puts its use of the device to rest here:
1428 * if there are no userspace clients, the chardev and device will
1429 * be removed, else it will be dangling until the last user is
1430 * gone.
1431 */
1432 cdev_device_del(&gdev->chrdev, &gdev->dev);
1433 put_device(&gdev->dev);
1434}
1435EXPORT_SYMBOL_GPL(gpiochip_remove);
1436
1437static void devm_gpio_chip_release(struct device *dev, void *res)
1438{
1439 struct gpio_chip *chip = *(struct gpio_chip **)res;
1440
1441 gpiochip_remove(chip);
1442}
1443
1444static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
1445
1446{
1447 struct gpio_chip **r = res;
1448
1449 if (!r || !*r) {
1450 WARN_ON(!r || !*r);
1451 return 0;
1452 }
1453
1454 return *r == data;
1455}
1456
1457/**
1458 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1459 * @dev: the device pointer on which irq_chip belongs to.
1460 * @chip: the chip to register, with chip->base initialized
1461 * @data: driver-private data associated with this chip
1462 *
1463 * Context: potentially before irqs will work
1464 *
1465 * The gpio chip automatically be released when the device is unbound.
1466 *
1467 * Returns:
1468 * A negative errno if the chip can't be registered, such as because the
1469 * chip->base is invalid or already associated with a different chip.
1470 * Otherwise it returns zero as a success code.
1471 */
1472int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1473 void *data)
1474{
1475 struct gpio_chip **ptr;
1476 int ret;
1477
1478 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1479 GFP_KERNEL);
1480 if (!ptr)
1481 return -ENOMEM;
1482
1483 ret = gpiochip_add_data(chip, data);
1484 if (ret < 0) {
1485 devres_free(ptr);
1486 return ret;
1487 }
1488
1489 *ptr = chip;
1490 devres_add(dev, ptr);
1491
1492 return 0;
1493}
1494EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1495
1496/**
1497 * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
1498 * @dev: device for which which resource was allocated
1499 * @chip: the chip to remove
1500 *
1501 * A gpio_chip with any GPIOs still requested may not be removed.
1502 */
1503void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
1504{
1505 int ret;
1506
1507 ret = devres_release(dev, devm_gpio_chip_release,
1508 devm_gpio_chip_match, chip);
1509 WARN_ON(ret);
1510}
1511EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
1512
1513/**
1514 * gpiochip_find() - iterator for locating a specific gpio_chip
1515 * @data: data to pass to match function
1516 * @match: Callback function to check gpio_chip
1517 *
1518 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1519 * determined by a user supplied @match callback. The callback should return
1520 * 0 if the device doesn't match and non-zero if it does. If the callback is
1521 * non-zero, this function will return to the caller and not iterate over any
1522 * more gpio_chips.
1523 */
1524struct gpio_chip *gpiochip_find(void *data,
1525 int (*match)(struct gpio_chip *chip,
1526 void *data))
1527{
1528 struct gpio_device *gdev;
1529 struct gpio_chip *chip = NULL;
1530 unsigned long flags;
1531
1532 spin_lock_irqsave(&gpio_lock, flags);
1533 list_for_each_entry(gdev, &gpio_devices, list)
1534 if (gdev->chip && match(gdev->chip, data)) {
1535 chip = gdev->chip;
1536 break;
1537 }
1538
1539 spin_unlock_irqrestore(&gpio_lock, flags);
1540
1541 return chip;
1542}
1543EXPORT_SYMBOL_GPL(gpiochip_find);
1544
1545static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1546{
1547 const char *name = data;
1548
1549 return !strcmp(chip->label, name);
1550}
1551
1552static struct gpio_chip *find_chip_by_name(const char *name)
1553{
1554 return gpiochip_find((void *)name, gpiochip_match_name);
1555}
1556
1557#ifdef CONFIG_GPIOLIB_IRQCHIP
1558
1559/*
1560 * The following is irqchip helper code for gpiochips.
1561 */
1562
1563static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1564{
1565 if (!gpiochip->irq.need_valid_mask)
1566 return 0;
1567
1568 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1569 if (!gpiochip->irq.valid_mask)
1570 return -ENOMEM;
1571
1572 return 0;
1573}
1574
1575static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1576{
1577 kfree(gpiochip->irq.valid_mask);
1578 gpiochip->irq.valid_mask = NULL;
1579}
1580
1581bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1582 unsigned int offset)
1583{
1584 if (!gpiochip_line_is_valid(gpiochip, offset))
1585 return false;
1586 /* No mask means all valid */
1587 if (likely(!gpiochip->irq.valid_mask))
1588 return true;
1589 return test_bit(offset, gpiochip->irq.valid_mask);
1590}
1591EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1592
1593/**
1594 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1595 * @gpiochip: the gpiochip to set the irqchip chain to
1596 * @irqchip: the irqchip to chain to the gpiochip
1597 * @parent_irq: the irq number corresponding to the parent IRQ for this
1598 * chained irqchip
1599 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1600 * coming out of the gpiochip. If the interrupt is nested rather than
1601 * cascaded, pass NULL in this handler argument
1602 */
1603static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1604 struct irq_chip *irqchip,
1605 unsigned int parent_irq,
1606 irq_flow_handler_t parent_handler)
1607{
1608 unsigned int offset;
1609
1610 if (!gpiochip->irq.domain) {
1611 chip_err(gpiochip, "called %s before setting up irqchip\n",
1612 __func__);
1613 return;
1614 }
1615
1616 if (parent_handler) {
1617 if (gpiochip->can_sleep) {
1618 chip_err(gpiochip,
1619 "you cannot have chained interrupts on a "
1620 "chip that may sleep\n");
1621 return;
1622 }
1623 /*
1624 * The parent irqchip is already using the chip_data for this
1625 * irqchip, so our callbacks simply use the handler_data.
1626 */
1627 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1628 gpiochip);
1629
1630 gpiochip->irq.parents = &parent_irq;
1631 gpiochip->irq.num_parents = 1;
1632 }
1633
1634 /* Set the parent IRQ for all affected IRQs */
1635 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1636 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1637 continue;
1638 irq_set_parent(irq_find_mapping(gpiochip->irq.domain, offset),
1639 parent_irq);
1640 }
1641}
1642
1643/**
1644 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1645 * @gpiochip: the gpiochip to set the irqchip chain to
1646 * @irqchip: the irqchip to chain to the gpiochip
1647 * @parent_irq: the irq number corresponding to the parent IRQ for this
1648 * chained irqchip
1649 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1650 * coming out of the gpiochip. If the interrupt is nested rather than
1651 * cascaded, pass NULL in this handler argument
1652 */
1653void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1654 struct irq_chip *irqchip,
1655 unsigned int parent_irq,
1656 irq_flow_handler_t parent_handler)
1657{
1658 if (gpiochip->irq.threaded) {
1659 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1660 return;
1661 }
1662
1663 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1664 parent_handler);
1665}
1666EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1667
1668/**
1669 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1670 * @gpiochip: the gpiochip to set the irqchip nested handler to
1671 * @irqchip: the irqchip to nest to the gpiochip
1672 * @parent_irq: the irq number corresponding to the parent IRQ for this
1673 * nested irqchip
1674 */
1675void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1676 struct irq_chip *irqchip,
1677 unsigned int parent_irq)
1678{
1679 gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
1680 NULL);
1681}
1682EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1683
1684/**
1685 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1686 * @d: the irqdomain used by this irqchip
1687 * @irq: the global irq number used by this GPIO irqchip irq
1688 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1689 *
1690 * This function will set up the mapping for a certain IRQ line on a
1691 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1692 * stored inside the gpiochip.
1693 */
1694int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1695 irq_hw_number_t hwirq)
1696{
1697 struct gpio_chip *chip = d->host_data;
1698 int err = 0;
1699
1700 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1701 return -ENXIO;
1702
1703 irq_set_chip_data(irq, chip);
1704 /*
1705 * This lock class tells lockdep that GPIO irqs are in a different
1706 * category than their parents, so it won't report false recursion.
1707 */
1708 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1709 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1710 /* Chips that use nested thread handlers have them marked */
1711 if (chip->irq.threaded)
1712 irq_set_nested_thread(irq, 1);
1713 irq_set_noprobe(irq);
1714
1715 if (chip->irq.num_parents == 1)
1716 err = irq_set_parent(irq, chip->irq.parents[0]);
1717 else if (chip->irq.map)
1718 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1719
1720 if (err < 0)
1721 return err;
1722
1723 /*
1724 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1725 * is passed as default type.
1726 */
1727 if (chip->irq.default_type != IRQ_TYPE_NONE)
1728 irq_set_irq_type(irq, chip->irq.default_type);
1729
1730 return 0;
1731}
1732EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1733
1734void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1735{
1736 struct gpio_chip *chip = d->host_data;
1737
1738 if (chip->irq.threaded)
1739 irq_set_nested_thread(irq, 0);
1740 irq_set_chip_and_handler(irq, NULL, NULL);
1741 irq_set_chip_data(irq, NULL);
1742}
1743EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1744
1745static const struct irq_domain_ops gpiochip_domain_ops = {
1746 .map = gpiochip_irq_map,
1747 .unmap = gpiochip_irq_unmap,
1748 /* Virtually all GPIO irqchips are twocell:ed */
1749 .xlate = irq_domain_xlate_twocell,
1750};
1751
1752static int gpiochip_irq_reqres(struct irq_data *d)
1753{
1754 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1755
1756 if (!try_module_get(chip->gpiodev->owner))
1757 return -ENODEV;
1758
1759 if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1760 chip_err(chip,
1761 "unable to lock HW IRQ %lu for IRQ\n",
1762 d->hwirq);
1763 module_put(chip->gpiodev->owner);
1764 return -EINVAL;
1765 }
1766 return 0;
1767}
1768
1769static void gpiochip_irq_relres(struct irq_data *d)
1770{
1771 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1772
1773 gpiochip_unlock_as_irq(chip, d->hwirq);
1774 module_put(chip->gpiodev->owner);
1775}
1776
1777static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1778{
1779 if (!gpiochip_irqchip_irq_valid(chip, offset))
1780 return -ENXIO;
1781
1782 return irq_create_mapping(chip->irq.domain, offset);
1783}
1784
1785/**
1786 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1787 * @gpiochip: the GPIO chip to add the IRQ chip to
1788 * @lock_key: lockdep class for IRQ lock
1789 * @request_key: lockdep class for IRQ request
1790 */
1791static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1792 struct lock_class_key *lock_key,
1793 struct lock_class_key *request_key)
1794{
1795 struct irq_chip *irqchip = gpiochip->irq.chip;
1796 const struct irq_domain_ops *ops;
1797 struct device_node *np;
1798 unsigned int type;
1799 unsigned int i;
1800
1801 if (!irqchip)
1802 return 0;
1803
1804 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1805 chip_err(gpiochip, "you cannot have chained interrupts on a "
1806 "chip that may sleep\n");
1807 return -EINVAL;
1808 }
1809
1810 np = gpiochip->gpiodev->dev.of_node;
1811 type = gpiochip->irq.default_type;
1812
1813 /*
1814 * Specifying a default trigger is a terrible idea if DT or ACPI is
1815 * used to configure the interrupts, as you may end up with
1816 * conflicting triggers. Tell the user, and reset to NONE.
1817 */
1818 if (WARN(np && type != IRQ_TYPE_NONE,
1819 "%s: Ignoring %u default trigger\n", np->full_name, type))
1820 type = IRQ_TYPE_NONE;
1821
1822 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1823 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1824 "Ignoring %u default trigger\n", type);
1825 type = IRQ_TYPE_NONE;
1826 }
1827
1828 gpiochip->to_irq = gpiochip_to_irq;
1829 gpiochip->irq.default_type = type;
1830 gpiochip->irq.lock_key = lock_key;
1831 gpiochip->irq.request_key = request_key;
1832
1833 if (gpiochip->irq.domain_ops)
1834 ops = gpiochip->irq.domain_ops;
1835 else
1836 ops = &gpiochip_domain_ops;
1837
1838 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1839 gpiochip->irq.first,
1840 ops, gpiochip);
1841 if (!gpiochip->irq.domain)
1842 return -EINVAL;
1843
1844 /*
1845 * It is possible for a driver to override this, but only if the
1846 * alternative functions are both implemented.
1847 */
1848 if (!irqchip->irq_request_resources &&
1849 !irqchip->irq_release_resources) {
1850 irqchip->irq_request_resources = gpiochip_irq_reqres;
1851 irqchip->irq_release_resources = gpiochip_irq_relres;
1852 }
1853
1854 if (gpiochip->irq.parent_handler) {
1855 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1856
1857 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1858 /*
1859 * The parent IRQ chip is already using the chip_data
1860 * for this IRQ chip, so our callbacks simply use the
1861 * handler_data.
1862 */
1863 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1864 gpiochip->irq.parent_handler,
1865 data);
1866 }
1867 }
1868
1869 acpi_gpiochip_request_interrupts(gpiochip);
1870
1871 return 0;
1872}
1873
1874/**
1875 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1876 * @gpiochip: the gpiochip to remove the irqchip from
1877 *
1878 * This is called only from gpiochip_remove()
1879 */
1880static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1881{
1882 unsigned int offset;
1883
1884 acpi_gpiochip_free_interrupts(gpiochip);
1885
1886 if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
1887 struct gpio_irq_chip *irq = &gpiochip->irq;
1888 unsigned int i;
1889
1890 for (i = 0; i < irq->num_parents; i++)
1891 irq_set_chained_handler_and_data(irq->parents[i],
1892 NULL, NULL);
1893 }
1894
1895 /* Remove all IRQ mappings and delete the domain */
1896 if (gpiochip->irq.domain) {
1897 unsigned int irq;
1898
1899 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1900 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
1901 continue;
1902
1903 irq = irq_find_mapping(gpiochip->irq.domain, offset);
1904 irq_dispose_mapping(irq);
1905 }
1906
1907 irq_domain_remove(gpiochip->irq.domain);
1908 }
1909
1910 if (gpiochip->irq.chip) {
1911 gpiochip->irq.chip->irq_request_resources = NULL;
1912 gpiochip->irq.chip->irq_release_resources = NULL;
1913 gpiochip->irq.chip = NULL;
1914 }
1915
1916 gpiochip_irqchip_free_valid_mask(gpiochip);
1917}
1918
1919/**
1920 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
1921 * @gpiochip: the gpiochip to add the irqchip to
1922 * @irqchip: the irqchip to add to the gpiochip
1923 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1924 * allocate gpiochip irqs from
1925 * @handler: the irq handler to use (often a predefined irq core function)
1926 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1927 * to have the core avoid setting up any default type in the hardware.
1928 * @threaded: whether this irqchip uses a nested thread handler
1929 * @lock_key: lockdep class for IRQ lock
1930 * @request_key: lockdep class for IRQ request
1931 *
1932 * This function closely associates a certain irqchip with a certain
1933 * gpiochip, providing an irq domain to translate the local IRQs to
1934 * global irqs in the gpiolib core, and making sure that the gpiochip
1935 * is passed as chip data to all related functions. Driver callbacks
1936 * need to use gpiochip_get_data() to get their local state containers back
1937 * from the gpiochip passed as chip data. An irqdomain will be stored
1938 * in the gpiochip that shall be used by the driver to handle IRQ number
1939 * translation. The gpiochip will need to be initialized and registered
1940 * before calling this function.
1941 *
1942 * This function will handle two cell:ed simple IRQs and assumes all
1943 * the pins on the gpiochip can generate a unique IRQ. Everything else
1944 * need to be open coded.
1945 */
1946int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
1947 struct irq_chip *irqchip,
1948 unsigned int first_irq,
1949 irq_flow_handler_t handler,
1950 unsigned int type,
1951 bool threaded,
1952 struct lock_class_key *lock_key,
1953 struct lock_class_key *request_key)
1954{
1955 struct device_node *of_node;
1956
1957 if (!gpiochip || !irqchip)
1958 return -EINVAL;
1959
1960 if (!gpiochip->parent) {
1961 pr_err("missing gpiochip .dev parent pointer\n");
1962 return -EINVAL;
1963 }
1964 gpiochip->irq.threaded = threaded;
1965 of_node = gpiochip->parent->of_node;
1966#ifdef CONFIG_OF_GPIO
1967 /*
1968 * If the gpiochip has an assigned OF node this takes precedence
1969 * FIXME: get rid of this and use gpiochip->parent->of_node
1970 * everywhere
1971 */
1972 if (gpiochip->of_node)
1973 of_node = gpiochip->of_node;
1974#endif
1975 /*
1976 * Specifying a default trigger is a terrible idea if DT or ACPI is
1977 * used to configure the interrupts, as you may end-up with
1978 * conflicting triggers. Tell the user, and reset to NONE.
1979 */
1980 if (WARN(of_node && type != IRQ_TYPE_NONE,
1981 "%pOF: Ignoring %d default trigger\n", of_node, type))
1982 type = IRQ_TYPE_NONE;
1983 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1984 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1985 "Ignoring %d default trigger\n", type);
1986 type = IRQ_TYPE_NONE;
1987 }
1988
1989 gpiochip->irq.chip = irqchip;
1990 gpiochip->irq.handler = handler;
1991 gpiochip->irq.default_type = type;
1992 gpiochip->to_irq = gpiochip_to_irq;
1993 gpiochip->irq.lock_key = lock_key;
1994 gpiochip->irq.request_key = request_key;
1995 gpiochip->irq.domain = irq_domain_add_simple(of_node,
1996 gpiochip->ngpio, first_irq,
1997 &gpiochip_domain_ops, gpiochip);
1998 if (!gpiochip->irq.domain) {
1999 gpiochip->irq.chip = NULL;
2000 return -EINVAL;
2001 }
2002
2003 /*
2004 * It is possible for a driver to override this, but only if the
2005 * alternative functions are both implemented.
2006 */
2007 if (!irqchip->irq_request_resources &&
2008 !irqchip->irq_release_resources) {
2009 irqchip->irq_request_resources = gpiochip_irq_reqres;
2010 irqchip->irq_release_resources = gpiochip_irq_relres;
2011 }
2012
2013 acpi_gpiochip_request_interrupts(gpiochip);
2014
2015 return 0;
2016}
2017EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2018
2019#else /* CONFIG_GPIOLIB_IRQCHIP */
2020
2021static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2022 struct lock_class_key *lock_key,
2023 struct lock_class_key *request_key)
2024{
2025 return 0;
2026}
2027
2028static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2029static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2030{
2031 return 0;
2032}
2033static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2034{ }
2035
2036#endif /* CONFIG_GPIOLIB_IRQCHIP */
2037
2038/**
2039 * gpiochip_generic_request() - request the gpio function for a pin
2040 * @chip: the gpiochip owning the GPIO
2041 * @offset: the offset of the GPIO to request for GPIO function
2042 */
2043int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2044{
2045 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2046}
2047EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2048
2049/**
2050 * gpiochip_generic_free() - free the gpio function from a pin
2051 * @chip: the gpiochip to request the gpio function for
2052 * @offset: the offset of the GPIO to free from GPIO function
2053 */
2054void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2055{
2056 pinctrl_gpio_free(chip->gpiodev->base + offset);
2057}
2058EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2059
2060/**
2061 * gpiochip_generic_config() - apply configuration for a pin
2062 * @chip: the gpiochip owning the GPIO
2063 * @offset: the offset of the GPIO to apply the configuration
2064 * @config: the configuration to be applied
2065 */
2066int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2067 unsigned long config)
2068{
2069 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2070}
2071EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2072
2073#ifdef CONFIG_PINCTRL
2074
2075/**
2076 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2077 * @chip: the gpiochip to add the range for
2078 * @pctldev: the pin controller to map to
2079 * @gpio_offset: the start offset in the current gpio_chip number space
2080 * @pin_group: name of the pin group inside the pin controller
2081 */
2082int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2083 struct pinctrl_dev *pctldev,
2084 unsigned int gpio_offset, const char *pin_group)
2085{
2086 struct gpio_pin_range *pin_range;
2087 struct gpio_device *gdev = chip->gpiodev;
2088 int ret;
2089
2090 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2091 if (!pin_range) {
2092 chip_err(chip, "failed to allocate pin ranges\n");
2093 return -ENOMEM;
2094 }
2095
2096 /* Use local offset as range ID */
2097 pin_range->range.id = gpio_offset;
2098 pin_range->range.gc = chip;
2099 pin_range->range.name = chip->label;
2100 pin_range->range.base = gdev->base + gpio_offset;
2101 pin_range->pctldev = pctldev;
2102
2103 ret = pinctrl_get_group_pins(pctldev, pin_group,
2104 &pin_range->range.pins,
2105 &pin_range->range.npins);
2106 if (ret < 0) {
2107 kfree(pin_range);
2108 return ret;
2109 }
2110
2111 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2112
2113 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2114 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2115 pinctrl_dev_get_devname(pctldev), pin_group);
2116
2117 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2118
2119 return 0;
2120}
2121EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2122
2123/**
2124 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2125 * @chip: the gpiochip to add the range for
2126 * @pinctl_name: the dev_name() of the pin controller to map to
2127 * @gpio_offset: the start offset in the current gpio_chip number space
2128 * @pin_offset: the start offset in the pin controller number space
2129 * @npins: the number of pins from the offset of each pin space (GPIO and
2130 * pin controller) to accumulate in this range
2131 *
2132 * Returns:
2133 * 0 on success, or a negative error-code on failure.
2134 */
2135int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2136 unsigned int gpio_offset, unsigned int pin_offset,
2137 unsigned int npins)
2138{
2139 struct gpio_pin_range *pin_range;
2140 struct gpio_device *gdev = chip->gpiodev;
2141 int ret;
2142
2143 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2144 if (!pin_range) {
2145 chip_err(chip, "failed to allocate pin ranges\n");
2146 return -ENOMEM;
2147 }
2148
2149 /* Use local offset as range ID */
2150 pin_range->range.id = gpio_offset;
2151 pin_range->range.gc = chip;
2152 pin_range->range.name = chip->label;
2153 pin_range->range.base = gdev->base + gpio_offset;
2154 pin_range->range.pin_base = pin_offset;
2155 pin_range->range.npins = npins;
2156 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2157 &pin_range->range);
2158 if (IS_ERR(pin_range->pctldev)) {
2159 ret = PTR_ERR(pin_range->pctldev);
2160 chip_err(chip, "could not create pin range\n");
2161 kfree(pin_range);
2162 return ret;
2163 }
2164 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2165 gpio_offset, gpio_offset + npins - 1,
2166 pinctl_name,
2167 pin_offset, pin_offset + npins - 1);
2168
2169 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2170
2171 return 0;
2172}
2173EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2174
2175/**
2176 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2177 * @chip: the chip to remove all the mappings for
2178 */
2179void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2180{
2181 struct gpio_pin_range *pin_range, *tmp;
2182 struct gpio_device *gdev = chip->gpiodev;
2183
2184 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2185 list_del(&pin_range->node);
2186 pinctrl_remove_gpio_range(pin_range->pctldev,
2187 &pin_range->range);
2188 kfree(pin_range);
2189 }
2190}
2191EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2192
2193#endif /* CONFIG_PINCTRL */
2194
2195/* These "optional" allocation calls help prevent drivers from stomping
2196 * on each other, and help provide better diagnostics in debugfs.
2197 * They're called even less than the "set direction" calls.
2198 */
2199static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2200{
2201 struct gpio_chip *chip = desc->gdev->chip;
2202 int status;
2203 unsigned long flags;
2204
2205 spin_lock_irqsave(&gpio_lock, flags);
2206
2207 /* NOTE: gpio_request() can be called in early boot,
2208 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2209 */
2210
2211 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2212 desc_set_label(desc, label ? : "?");
2213 status = 0;
2214 } else {
2215 status = -EBUSY;
2216 goto done;
2217 }
2218
2219 if (chip->request) {
2220 /* chip->request may sleep */
2221 spin_unlock_irqrestore(&gpio_lock, flags);
2222 status = chip->request(chip, gpio_chip_hwgpio(desc));
2223 spin_lock_irqsave(&gpio_lock, flags);
2224
2225 if (status < 0) {
2226 desc_set_label(desc, NULL);
2227 clear_bit(FLAG_REQUESTED, &desc->flags);
2228 goto done;
2229 }
2230 }
2231 if (chip->get_direction) {
2232 /* chip->get_direction may sleep */
2233 spin_unlock_irqrestore(&gpio_lock, flags);
2234 gpiod_get_direction(desc);
2235 spin_lock_irqsave(&gpio_lock, flags);
2236 }
2237done:
2238 spin_unlock_irqrestore(&gpio_lock, flags);
2239 return status;
2240}
2241
2242/*
2243 * This descriptor validation needs to be inserted verbatim into each
2244 * function taking a descriptor, so we need to use a preprocessor
2245 * macro to avoid endless duplication. If the desc is NULL it is an
2246 * optional GPIO and calls should just bail out.
2247 */
2248static int validate_desc(const struct gpio_desc *desc, const char *func)
2249{
2250 if (!desc)
2251 return 0;
2252 if (IS_ERR(desc)) {
2253 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2254 return PTR_ERR(desc);
2255 }
2256 if (!desc->gdev) {
2257 pr_warn("%s: invalid GPIO (no device)\n", func);
2258 return -EINVAL;
2259 }
2260 if (!desc->gdev->chip) {
2261 dev_warn(&desc->gdev->dev,
2262 "%s: backing chip is gone\n", func);
2263 return 0;
2264 }
2265 return 1;
2266}
2267
2268#define VALIDATE_DESC(desc) do { \
2269 int __valid = validate_desc(desc, __func__); \
2270 if (__valid <= 0) \
2271 return __valid; \
2272 } while (0)
2273
2274#define VALIDATE_DESC_VOID(desc) do { \
2275 int __valid = validate_desc(desc, __func__); \
2276 if (__valid <= 0) \
2277 return; \
2278 } while (0)
2279
2280int gpiod_request(struct gpio_desc *desc, const char *label)
2281{
2282 int status = -EPROBE_DEFER;
2283 struct gpio_device *gdev;
2284
2285 VALIDATE_DESC(desc);
2286 gdev = desc->gdev;
2287
2288 if (try_module_get(gdev->owner)) {
2289 status = gpiod_request_commit(desc, label);
2290 if (status < 0)
2291 module_put(gdev->owner);
2292 else
2293 get_device(&gdev->dev);
2294 }
2295
2296 if (status)
2297 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2298
2299 return status;
2300}
2301
2302static bool gpiod_free_commit(struct gpio_desc *desc)
2303{
2304 bool ret = false;
2305 unsigned long flags;
2306 struct gpio_chip *chip;
2307
2308 might_sleep();
2309
2310 gpiod_unexport(desc);
2311
2312 spin_lock_irqsave(&gpio_lock, flags);
2313
2314 chip = desc->gdev->chip;
2315 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2316 if (chip->free) {
2317 spin_unlock_irqrestore(&gpio_lock, flags);
2318 might_sleep_if(chip->can_sleep);
2319 chip->free(chip, gpio_chip_hwgpio(desc));
2320 spin_lock_irqsave(&gpio_lock, flags);
2321 }
2322 desc_set_label(desc, NULL);
2323 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2324 clear_bit(FLAG_REQUESTED, &desc->flags);
2325 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2326 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2327 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2328 ret = true;
2329 }
2330
2331 spin_unlock_irqrestore(&gpio_lock, flags);
2332 return ret;
2333}
2334
2335void gpiod_free(struct gpio_desc *desc)
2336{
2337 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2338 module_put(desc->gdev->owner);
2339 put_device(&desc->gdev->dev);
2340 } else {
2341 WARN_ON(extra_checks);
2342 }
2343}
2344
2345/**
2346 * gpiochip_is_requested - return string iff signal was requested
2347 * @chip: controller managing the signal
2348 * @offset: of signal within controller's 0..(ngpio - 1) range
2349 *
2350 * Returns NULL if the GPIO is not currently requested, else a string.
2351 * The string returned is the label passed to gpio_request(); if none has been
2352 * passed it is a meaningless, non-NULL constant.
2353 *
2354 * This function is for use by GPIO controller drivers. The label can
2355 * help with diagnostics, and knowing that the signal is used as a GPIO
2356 * can help avoid accidentally multiplexing it to another controller.
2357 */
2358const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2359{
2360 struct gpio_desc *desc;
2361
2362 if (offset >= chip->ngpio)
2363 return NULL;
2364
2365 desc = &chip->gpiodev->descs[offset];
2366
2367 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2368 return NULL;
2369 return desc->label;
2370}
2371EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2372
2373/**
2374 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2375 * @chip: GPIO chip
2376 * @hwnum: hardware number of the GPIO for which to request the descriptor
2377 * @label: label for the GPIO
2378 *
2379 * Function allows GPIO chip drivers to request and use their own GPIO
2380 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2381 * function will not increase reference count of the GPIO chip module. This
2382 * allows the GPIO chip module to be unloaded as needed (we assume that the
2383 * GPIO chip driver handles freeing the GPIOs it has requested).
2384 *
2385 * Returns:
2386 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2387 * code on failure.
2388 */
2389struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2390 const char *label)
2391{
2392 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2393 int err;
2394
2395 if (IS_ERR(desc)) {
2396 chip_err(chip, "failed to get GPIO descriptor\n");
2397 return desc;
2398 }
2399
2400 err = gpiod_request_commit(desc, label);
2401 if (err < 0)
2402 return ERR_PTR(err);
2403
2404 return desc;
2405}
2406EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2407
2408/**
2409 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2410 * @desc: GPIO descriptor to free
2411 *
2412 * Function frees the given GPIO requested previously with
2413 * gpiochip_request_own_desc().
2414 */
2415void gpiochip_free_own_desc(struct gpio_desc *desc)
2416{
2417 if (desc)
2418 gpiod_free_commit(desc);
2419}
2420EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2421
2422/*
2423 * Drivers MUST set GPIO direction before making get/set calls. In
2424 * some cases this is done in early boot, before IRQs are enabled.
2425 *
2426 * As a rule these aren't called more than once (except for drivers
2427 * using the open-drain emulation idiom) so these are natural places
2428 * to accumulate extra debugging checks. Note that we can't (yet)
2429 * rely on gpio_request() having been called beforehand.
2430 */
2431
2432/**
2433 * gpiod_direction_input - set the GPIO direction to input
2434 * @desc: GPIO to set to input
2435 *
2436 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2437 * be called safely on it.
2438 *
2439 * Return 0 in case of success, else an error code.
2440 */
2441int gpiod_direction_input(struct gpio_desc *desc)
2442{
2443 struct gpio_chip *chip;
2444 int status = -EINVAL;
2445
2446 VALIDATE_DESC(desc);
2447 chip = desc->gdev->chip;
2448
2449 if (!chip->get || !chip->direction_input) {
2450 gpiod_warn(desc,
2451 "%s: missing get() or direction_input() operations\n",
2452 __func__);
2453 return -EIO;
2454 }
2455
2456 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2457 if (status == 0)
2458 clear_bit(FLAG_IS_OUT, &desc->flags);
2459
2460 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2461
2462 return status;
2463}
2464EXPORT_SYMBOL_GPL(gpiod_direction_input);
2465
2466static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
2467 enum pin_config_param mode)
2468{
2469 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2470
2471 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2472}
2473
2474static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2475{
2476 struct gpio_chip *gc = desc->gdev->chip;
2477 int val = !!value;
2478 int ret;
2479
2480 if (!gc->set || !gc->direction_output) {
2481 gpiod_warn(desc,
2482 "%s: missing set() or direction_output() operations\n",
2483 __func__);
2484 return -EIO;
2485 }
2486
2487 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2488 if (!ret)
2489 set_bit(FLAG_IS_OUT, &desc->flags);
2490 trace_gpio_value(desc_to_gpio(desc), 0, val);
2491 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2492 return ret;
2493}
2494
2495/**
2496 * gpiod_direction_output_raw - set the GPIO direction to output
2497 * @desc: GPIO to set to output
2498 * @value: initial output value of the GPIO
2499 *
2500 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2501 * be called safely on it. The initial value of the output must be specified
2502 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2503 *
2504 * Return 0 in case of success, else an error code.
2505 */
2506int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2507{
2508 VALIDATE_DESC(desc);
2509 return gpiod_direction_output_raw_commit(desc, value);
2510}
2511EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2512
2513/**
2514 * gpiod_direction_output - set the GPIO direction to output
2515 * @desc: GPIO to set to output
2516 * @value: initial output value of the GPIO
2517 *
2518 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2519 * be called safely on it. The initial value of the output must be specified
2520 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2521 * account.
2522 *
2523 * Return 0 in case of success, else an error code.
2524 */
2525int gpiod_direction_output(struct gpio_desc *desc, int value)
2526{
2527 struct gpio_chip *gc;
2528 int ret;
2529
2530 VALIDATE_DESC(desc);
2531 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2532 value = !value;
2533 else
2534 value = !!value;
2535
2536 /* GPIOs used for IRQs shall not be set as output */
2537 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2538 gpiod_err(desc,
2539 "%s: tried to set a GPIO tied to an IRQ as output\n",
2540 __func__);
2541 return -EIO;
2542 }
2543
2544 gc = desc->gdev->chip;
2545 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2546 /* First see if we can enable open drain in hardware */
2547 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2548 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2549 if (!ret)
2550 goto set_output_value;
2551 /* Emulate open drain by not actively driving the line high */
2552 if (value)
2553 return gpiod_direction_input(desc);
2554 }
2555 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2556 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2557 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2558 if (!ret)
2559 goto set_output_value;
2560 /* Emulate open source by not actively driving the line low */
2561 if (!value)
2562 return gpiod_direction_input(desc);
2563 } else {
2564 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
2565 PIN_CONFIG_DRIVE_PUSH_PULL);
2566 }
2567
2568set_output_value:
2569 return gpiod_direction_output_raw_commit(desc, value);
2570}
2571EXPORT_SYMBOL_GPL(gpiod_direction_output);
2572
2573/**
2574 * gpiod_set_debounce - sets @debounce time for a GPIO
2575 * @desc: descriptor of the GPIO for which to set debounce time
2576 * @debounce: debounce time in microseconds
2577 *
2578 * Returns:
2579 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2580 * debounce time.
2581 */
2582int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2583{
2584 struct gpio_chip *chip;
2585 unsigned long config;
2586
2587 VALIDATE_DESC(desc);
2588 chip = desc->gdev->chip;
2589 if (!chip->set || !chip->set_config) {
2590 gpiod_dbg(desc,
2591 "%s: missing set() or set_config() operations\n",
2592 __func__);
2593 return -ENOTSUPP;
2594 }
2595
2596 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2597 return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
2598}
2599EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2600
2601/**
2602 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2603 * @desc: descriptor of the GPIO for which to configure persistence
2604 * @transitory: True to lose state on suspend or reset, false for persistence
2605 *
2606 * Returns:
2607 * 0 on success, otherwise a negative error code.
2608 */
2609int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2610{
2611 struct gpio_chip *chip;
2612 unsigned long packed;
2613 int gpio;
2614 int rc;
2615
2616 VALIDATE_DESC(desc);
2617 /*
2618 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2619 * persistence state.
2620 */
2621 if (transitory)
2622 set_bit(FLAG_TRANSITORY, &desc->flags);
2623 else
2624 clear_bit(FLAG_TRANSITORY, &desc->flags);
2625
2626 /* If the driver supports it, set the persistence state now */
2627 chip = desc->gdev->chip;
2628 if (!chip->set_config)
2629 return 0;
2630
2631 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2632 !transitory);
2633 gpio = gpio_chip_hwgpio(desc);
2634 rc = chip->set_config(chip, gpio, packed);
2635 if (rc == -ENOTSUPP) {
2636 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2637 gpio);
2638 return 0;
2639 }
2640
2641 return rc;
2642}
2643EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2644
2645/**
2646 * gpiod_is_active_low - test whether a GPIO is active-low or not
2647 * @desc: the gpio descriptor to test
2648 *
2649 * Returns 1 if the GPIO is active-low, 0 otherwise.
2650 */
2651int gpiod_is_active_low(const struct gpio_desc *desc)
2652{
2653 VALIDATE_DESC(desc);
2654 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2655}
2656EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2657
2658/* I/O calls are only valid after configuration completed; the relevant
2659 * "is this a valid GPIO" error checks should already have been done.
2660 *
2661 * "Get" operations are often inlinable as reading a pin value register,
2662 * and masking the relevant bit in that register.
2663 *
2664 * When "set" operations are inlinable, they involve writing that mask to
2665 * one register to set a low value, or a different register to set it high.
2666 * Otherwise locking is needed, so there may be little value to inlining.
2667 *
2668 *------------------------------------------------------------------------
2669 *
2670 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2671 * have requested the GPIO. That can include implicit requesting by
2672 * a direction setting call. Marking a gpio as requested locks its chip
2673 * in memory, guaranteeing that these table lookups need no more locking
2674 * and that gpiochip_remove() will fail.
2675 *
2676 * REVISIT when debugging, consider adding some instrumentation to ensure
2677 * that the GPIO was actually requested.
2678 */
2679
2680static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2681{
2682 struct gpio_chip *chip;
2683 int offset;
2684 int value;
2685
2686 chip = desc->gdev->chip;
2687 offset = gpio_chip_hwgpio(desc);
2688 value = chip->get ? chip->get(chip, offset) : -EIO;
2689 value = value < 0 ? value : !!value;
2690 trace_gpio_value(desc_to_gpio(desc), 1, value);
2691 return value;
2692}
2693
2694static int gpio_chip_get_multiple(struct gpio_chip *chip,
2695 unsigned long *mask, unsigned long *bits)
2696{
2697 if (chip->get_multiple) {
2698 return chip->get_multiple(chip, mask, bits);
2699 } else if (chip->get) {
2700 int i, value;
2701
2702 for_each_set_bit(i, mask, chip->ngpio) {
2703 value = chip->get(chip, i);
2704 if (value < 0)
2705 return value;
2706 __assign_bit(i, bits, value);
2707 }
2708 return 0;
2709 }
2710 return -EIO;
2711}
2712
2713int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2714 unsigned int array_size,
2715 struct gpio_desc **desc_array,
2716 int *value_array)
2717{
2718 int i = 0;
2719
2720 while (i < array_size) {
2721 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2722 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2723 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2724 int first, j, ret;
2725
2726 if (!can_sleep)
2727 WARN_ON(chip->can_sleep);
2728
2729 /* collect all inputs belonging to the same chip */
2730 first = i;
2731 memset(mask, 0, sizeof(mask));
2732 do {
2733 const struct gpio_desc *desc = desc_array[i];
2734 int hwgpio = gpio_chip_hwgpio(desc);
2735
2736 __set_bit(hwgpio, mask);
2737 i++;
2738 } while ((i < array_size) &&
2739 (desc_array[i]->gdev->chip == chip));
2740
2741 ret = gpio_chip_get_multiple(chip, mask, bits);
2742 if (ret)
2743 return ret;
2744
2745 for (j = first; j < i; j++) {
2746 const struct gpio_desc *desc = desc_array[j];
2747 int hwgpio = gpio_chip_hwgpio(desc);
2748 int value = test_bit(hwgpio, bits);
2749
2750 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2751 value = !value;
2752 value_array[j] = value;
2753 trace_gpio_value(desc_to_gpio(desc), 1, value);
2754 }
2755 }
2756 return 0;
2757}
2758
2759/**
2760 * gpiod_get_raw_value() - return a gpio's raw value
2761 * @desc: gpio whose value will be returned
2762 *
2763 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2764 * its ACTIVE_LOW status, or negative errno on failure.
2765 *
2766 * This function should be called from contexts where we cannot sleep, and will
2767 * complain if the GPIO chip functions potentially sleep.
2768 */
2769int gpiod_get_raw_value(const struct gpio_desc *desc)
2770{
2771 VALIDATE_DESC(desc);
2772 /* Should be using gpio_get_value_cansleep() */
2773 WARN_ON(desc->gdev->chip->can_sleep);
2774 return gpiod_get_raw_value_commit(desc);
2775}
2776EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2777
2778/**
2779 * gpiod_get_value() - return a gpio's value
2780 * @desc: gpio whose value will be returned
2781 *
2782 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2783 * account, or negative errno on failure.
2784 *
2785 * This function should be called from contexts where we cannot sleep, and will
2786 * complain if the GPIO chip functions potentially sleep.
2787 */
2788int gpiod_get_value(const struct gpio_desc *desc)
2789{
2790 int value;
2791
2792 VALIDATE_DESC(desc);
2793 /* Should be using gpio_get_value_cansleep() */
2794 WARN_ON(desc->gdev->chip->can_sleep);
2795
2796 value = gpiod_get_raw_value_commit(desc);
2797 if (value < 0)
2798 return value;
2799
2800 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2801 value = !value;
2802
2803 return value;
2804}
2805EXPORT_SYMBOL_GPL(gpiod_get_value);
2806
2807/**
2808 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2809 * @array_size: number of elements in the descriptor / value arrays
2810 * @desc_array: array of GPIO descriptors whose values will be read
2811 * @value_array: array to store the read values
2812 *
2813 * Read the raw values of the GPIOs, i.e. the values of the physical lines
2814 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
2815 * else an error code.
2816 *
2817 * This function should be called from contexts where we cannot sleep,
2818 * and it will complain if the GPIO chip functions potentially sleep.
2819 */
2820int gpiod_get_raw_array_value(unsigned int array_size,
2821 struct gpio_desc **desc_array, int *value_array)
2822{
2823 if (!desc_array)
2824 return -EINVAL;
2825 return gpiod_get_array_value_complex(true, false, array_size,
2826 desc_array, value_array);
2827}
2828EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2829
2830/**
2831 * gpiod_get_array_value() - read values from an array of GPIOs
2832 * @array_size: number of elements in the descriptor / value arrays
2833 * @desc_array: array of GPIO descriptors whose values will be read
2834 * @value_array: array to store the read values
2835 *
2836 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2837 * into account. Return 0 in case of success, else an error code.
2838 *
2839 * This function should be called from contexts where we cannot sleep,
2840 * and it will complain if the GPIO chip functions potentially sleep.
2841 */
2842int gpiod_get_array_value(unsigned int array_size,
2843 struct gpio_desc **desc_array, int *value_array)
2844{
2845 if (!desc_array)
2846 return -EINVAL;
2847 return gpiod_get_array_value_complex(false, false, array_size,
2848 desc_array, value_array);
2849}
2850EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2851
2852/*
2853 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2854 * @desc: gpio descriptor whose state need to be set.
2855 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2856 */
2857static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2858{
2859 int err = 0;
2860 struct gpio_chip *chip = desc->gdev->chip;
2861 int offset = gpio_chip_hwgpio(desc);
2862
2863 if (value) {
2864 err = chip->direction_input(chip, offset);
2865 if (!err)
2866 clear_bit(FLAG_IS_OUT, &desc->flags);
2867 } else {
2868 err = chip->direction_output(chip, offset, 0);
2869 if (!err)
2870 set_bit(FLAG_IS_OUT, &desc->flags);
2871 }
2872 trace_gpio_direction(desc_to_gpio(desc), value, err);
2873 if (err < 0)
2874 gpiod_err(desc,
2875 "%s: Error in set_value for open drain err %d\n",
2876 __func__, err);
2877}
2878
2879/*
2880 * _gpio_set_open_source_value() - Set the open source gpio's value.
2881 * @desc: gpio descriptor whose state need to be set.
2882 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2883 */
2884static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2885{
2886 int err = 0;
2887 struct gpio_chip *chip = desc->gdev->chip;
2888 int offset = gpio_chip_hwgpio(desc);
2889
2890 if (value) {
2891 err = chip->direction_output(chip, offset, 1);
2892 if (!err)
2893 set_bit(FLAG_IS_OUT, &desc->flags);
2894 } else {
2895 err = chip->direction_input(chip, offset);
2896 if (!err)
2897 clear_bit(FLAG_IS_OUT, &desc->flags);
2898 }
2899 trace_gpio_direction(desc_to_gpio(desc), !value, err);
2900 if (err < 0)
2901 gpiod_err(desc,
2902 "%s: Error in set_value for open source err %d\n",
2903 __func__, err);
2904}
2905
2906static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2907{
2908 struct gpio_chip *chip;
2909
2910 chip = desc->gdev->chip;
2911 trace_gpio_value(desc_to_gpio(desc), 0, value);
2912 chip->set(chip, gpio_chip_hwgpio(desc), value);
2913}
2914
2915/*
2916 * set multiple outputs on the same chip;
2917 * use the chip's set_multiple function if available;
2918 * otherwise set the outputs sequentially;
2919 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2920 * defines which outputs are to be changed
2921 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2922 * defines the values the outputs specified by mask are to be set to
2923 */
2924static void gpio_chip_set_multiple(struct gpio_chip *chip,
2925 unsigned long *mask, unsigned long *bits)
2926{
2927 if (chip->set_multiple) {
2928 chip->set_multiple(chip, mask, bits);
2929 } else {
2930 unsigned int i;
2931
2932 /* set outputs if the corresponding mask bit is set */
2933 for_each_set_bit(i, mask, chip->ngpio)
2934 chip->set(chip, i, test_bit(i, bits));
2935 }
2936}
2937
2938void gpiod_set_array_value_complex(bool raw, bool can_sleep,
2939 unsigned int array_size,
2940 struct gpio_desc **desc_array,
2941 int *value_array)
2942{
2943 int i = 0;
2944
2945 while (i < array_size) {
2946 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2947 unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
2948 unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
2949 int count = 0;
2950
2951 if (!can_sleep)
2952 WARN_ON(chip->can_sleep);
2953
2954 memset(mask, 0, sizeof(mask));
2955 do {
2956 struct gpio_desc *desc = desc_array[i];
2957 int hwgpio = gpio_chip_hwgpio(desc);
2958 int value = value_array[i];
2959
2960 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2961 value = !value;
2962 trace_gpio_value(desc_to_gpio(desc), 0, value);
2963 /*
2964 * collect all normal outputs belonging to the same chip
2965 * open drain and open source outputs are set individually
2966 */
2967 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2968 gpio_set_open_drain_value_commit(desc, value);
2969 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2970 gpio_set_open_source_value_commit(desc, value);
2971 } else {
2972 __set_bit(hwgpio, mask);
2973 if (value)
2974 __set_bit(hwgpio, bits);
2975 else
2976 __clear_bit(hwgpio, bits);
2977 count++;
2978 }
2979 i++;
2980 } while ((i < array_size) &&
2981 (desc_array[i]->gdev->chip == chip));
2982 /* push collected bits to outputs */
2983 if (count != 0)
2984 gpio_chip_set_multiple(chip, mask, bits);
2985 }
2986}
2987
2988/**
2989 * gpiod_set_raw_value() - assign a gpio's raw value
2990 * @desc: gpio whose value will be assigned
2991 * @value: value to assign
2992 *
2993 * Set the raw value of the GPIO, i.e. the value of its physical line without
2994 * regard for its ACTIVE_LOW status.
2995 *
2996 * This function should be called from contexts where we cannot sleep, and will
2997 * complain if the GPIO chip functions potentially sleep.
2998 */
2999void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3000{
3001 VALIDATE_DESC_VOID(desc);
3002 /* Should be using gpiod_set_value_cansleep() */
3003 WARN_ON(desc->gdev->chip->can_sleep);
3004 gpiod_set_raw_value_commit(desc, value);
3005}
3006EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3007
3008/**
3009 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3010 * @desc: the descriptor to set the value on
3011 * @value: value to set
3012 *
3013 * This sets the value of a GPIO line backing a descriptor, applying
3014 * different semantic quirks like active low and open drain/source
3015 * handling.
3016 */
3017static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3018{
3019 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3020 value = !value;
3021 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3022 gpio_set_open_drain_value_commit(desc, value);
3023 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3024 gpio_set_open_source_value_commit(desc, value);
3025 else
3026 gpiod_set_raw_value_commit(desc, value);
3027}
3028
3029/**
3030 * gpiod_set_value() - assign a gpio's value
3031 * @desc: gpio whose value will be assigned
3032 * @value: value to assign
3033 *
3034 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3035 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3036 *
3037 * This function should be called from contexts where we cannot sleep, and will
3038 * complain if the GPIO chip functions potentially sleep.
3039 */
3040void gpiod_set_value(struct gpio_desc *desc, int value)
3041{
3042 VALIDATE_DESC_VOID(desc);
3043 WARN_ON(desc->gdev->chip->can_sleep);
3044 gpiod_set_value_nocheck(desc, value);
3045}
3046EXPORT_SYMBOL_GPL(gpiod_set_value);
3047
3048/**
3049 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3050 * @array_size: number of elements in the descriptor / value arrays
3051 * @desc_array: array of GPIO descriptors whose values will be assigned
3052 * @value_array: array of values to assign
3053 *
3054 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3055 * without regard for their ACTIVE_LOW status.
3056 *
3057 * This function should be called from contexts where we cannot sleep, and will
3058 * complain if the GPIO chip functions potentially sleep.
3059 */
3060void gpiod_set_raw_array_value(unsigned int array_size,
3061 struct gpio_desc **desc_array, int *value_array)
3062{
3063 if (!desc_array)
3064 return;
3065 gpiod_set_array_value_complex(true, false, array_size, desc_array,
3066 value_array);
3067}
3068EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3069
3070/**
3071 * gpiod_set_array_value() - assign values to an array of GPIOs
3072 * @array_size: number of elements in the descriptor / value arrays
3073 * @desc_array: array of GPIO descriptors whose values will be assigned
3074 * @value_array: array of values to assign
3075 *
3076 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3077 * into account.
3078 *
3079 * This function should be called from contexts where we cannot sleep, and will
3080 * complain if the GPIO chip functions potentially sleep.
3081 */
3082void gpiod_set_array_value(unsigned int array_size,
3083 struct gpio_desc **desc_array, int *value_array)
3084{
3085 if (!desc_array)
3086 return;
3087 gpiod_set_array_value_complex(false, false, array_size, desc_array,
3088 value_array);
3089}
3090EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3091
3092/**
3093 * gpiod_cansleep() - report whether gpio value access may sleep
3094 * @desc: gpio to check
3095 *
3096 */
3097int gpiod_cansleep(const struct gpio_desc *desc)
3098{
3099 VALIDATE_DESC(desc);
3100 return desc->gdev->chip->can_sleep;
3101}
3102EXPORT_SYMBOL_GPL(gpiod_cansleep);
3103
3104/**
3105 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3106 * @desc: gpio whose IRQ will be returned (already requested)
3107 *
3108 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3109 * error.
3110 */
3111int gpiod_to_irq(const struct gpio_desc *desc)
3112{
3113 struct gpio_chip *chip;
3114 int offset;
3115
3116 /*
3117 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3118 * requires this function to not return zero on an invalid descriptor
3119 * but rather a negative error number.
3120 */
3121 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3122 return -EINVAL;
3123
3124 chip = desc->gdev->chip;
3125 offset = gpio_chip_hwgpio(desc);
3126 if (chip->to_irq) {
3127 int retirq = chip->to_irq(chip, offset);
3128
3129 /* Zero means NO_IRQ */
3130 if (!retirq)
3131 return -ENXIO;
3132
3133 return retirq;
3134 }
3135 return -ENXIO;
3136}
3137EXPORT_SYMBOL_GPL(gpiod_to_irq);
3138
3139/**
3140 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3141 * @chip: the chip the GPIO to lock belongs to
3142 * @offset: the offset of the GPIO to lock as IRQ
3143 *
3144 * This is used directly by GPIO drivers that want to lock down
3145 * a certain GPIO line to be used for IRQs.
3146 */
3147int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3148{
3149 struct gpio_desc *desc;
3150
3151 desc = gpiochip_get_desc(chip, offset);
3152 if (IS_ERR(desc))
3153 return PTR_ERR(desc);
3154
3155 /*
3156 * If it's fast: flush the direction setting if something changed
3157 * behind our back
3158 */
3159 if (!chip->can_sleep && chip->get_direction) {
3160 int dir = chip->get_direction(chip, offset);
3161
3162 if (dir)
3163 clear_bit(FLAG_IS_OUT, &desc->flags);
3164 else
3165 set_bit(FLAG_IS_OUT, &desc->flags);
3166 }
3167
3168 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3169 chip_err(chip,
3170 "%s: tried to flag a GPIO set as output for IRQ\n",
3171 __func__);
3172 return -EIO;
3173 }
3174
3175 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3176
3177 /*
3178 * If the consumer has not set up a label (such as when the
3179 * IRQ is referenced from .to_irq()) we set up a label here
3180 * so it is clear this is used as an interrupt.
3181 */
3182 if (!desc->label)
3183 desc_set_label(desc, "interrupt");
3184
3185 return 0;
3186}
3187EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3188
3189/**
3190 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3191 * @chip: the chip the GPIO to lock belongs to
3192 * @offset: the offset of the GPIO to lock as IRQ
3193 *
3194 * This is used directly by GPIO drivers that want to indicate
3195 * that a certain GPIO is no longer used exclusively for IRQ.
3196 */
3197void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3198{
3199 struct gpio_desc *desc;
3200
3201 desc = gpiochip_get_desc(chip, offset);
3202 if (IS_ERR(desc))
3203 return;
3204
3205 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3206
3207 /* If we only had this marking, erase it */
3208 if (desc->label && !strcmp(desc->label, "interrupt"))
3209 desc_set_label(desc, NULL);
3210}
3211EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3212
3213bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3214{
3215 if (offset >= chip->ngpio)
3216 return false;
3217
3218 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3219}
3220EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3221
3222bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
3223{
3224 if (offset >= chip->ngpio)
3225 return false;
3226
3227 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
3228}
3229EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3230
3231bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
3232{
3233 if (offset >= chip->ngpio)
3234 return false;
3235
3236 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
3237}
3238EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3239
3240bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
3241{
3242 if (offset >= chip->ngpio)
3243 return false;
3244
3245 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
3246}
3247EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3248
3249/**
3250 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3251 * @desc: gpio whose value will be returned
3252 *
3253 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3254 * its ACTIVE_LOW status, or negative errno on failure.
3255 *
3256 * This function is to be called from contexts that can sleep.
3257 */
3258int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3259{
3260 might_sleep_if(extra_checks);
3261 VALIDATE_DESC(desc);
3262 return gpiod_get_raw_value_commit(desc);
3263}
3264EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3265
3266/**
3267 * gpiod_get_value_cansleep() - return a gpio's value
3268 * @desc: gpio whose value will be returned
3269 *
3270 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3271 * account, or negative errno on failure.
3272 *
3273 * This function is to be called from contexts that can sleep.
3274 */
3275int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3276{
3277 int value;
3278
3279 might_sleep_if(extra_checks);
3280 VALIDATE_DESC(desc);
3281 value = gpiod_get_raw_value_commit(desc);
3282 if (value < 0)
3283 return value;
3284
3285 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3286 value = !value;
3287
3288 return value;
3289}
3290EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3291
3292/**
3293 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3294 * @array_size: number of elements in the descriptor / value arrays
3295 * @desc_array: array of GPIO descriptors whose values will be read
3296 * @value_array: array to store the read values
3297 *
3298 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3299 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3300 * else an error code.
3301 *
3302 * This function is to be called from contexts that can sleep.
3303 */
3304int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3305 struct gpio_desc **desc_array,
3306 int *value_array)
3307{
3308 might_sleep_if(extra_checks);
3309 if (!desc_array)
3310 return -EINVAL;
3311 return gpiod_get_array_value_complex(true, true, array_size,
3312 desc_array, value_array);
3313}
3314EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3315
3316/**
3317 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3318 * @array_size: number of elements in the descriptor / value arrays
3319 * @desc_array: array of GPIO descriptors whose values will be read
3320 * @value_array: array to store the read values
3321 *
3322 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3323 * into account. Return 0 in case of success, else an error code.
3324 *
3325 * This function is to be called from contexts that can sleep.
3326 */
3327int gpiod_get_array_value_cansleep(unsigned int array_size,
3328 struct gpio_desc **desc_array,
3329 int *value_array)
3330{
3331 might_sleep_if(extra_checks);
3332 if (!desc_array)
3333 return -EINVAL;
3334 return gpiod_get_array_value_complex(false, true, array_size,
3335 desc_array, value_array);
3336}
3337EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3338
3339/**
3340 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3341 * @desc: gpio whose value will be assigned
3342 * @value: value to assign
3343 *
3344 * Set the raw value of the GPIO, i.e. the value of its physical line without
3345 * regard for its ACTIVE_LOW status.
3346 *
3347 * This function is to be called from contexts that can sleep.
3348 */
3349void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3350{
3351 might_sleep_if(extra_checks);
3352 VALIDATE_DESC_VOID(desc);
3353 gpiod_set_raw_value_commit(desc, value);
3354}
3355EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3356
3357/**
3358 * gpiod_set_value_cansleep() - assign a gpio's value
3359 * @desc: gpio whose value will be assigned
3360 * @value: value to assign
3361 *
3362 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3363 * account
3364 *
3365 * This function is to be called from contexts that can sleep.
3366 */
3367void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3368{
3369 might_sleep_if(extra_checks);
3370 VALIDATE_DESC_VOID(desc);
3371 gpiod_set_value_nocheck(desc, value);
3372}
3373EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3374
3375/**
3376 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3377 * @array_size: number of elements in the descriptor / value arrays
3378 * @desc_array: array of GPIO descriptors whose values will be assigned
3379 * @value_array: array of values to assign
3380 *
3381 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3382 * without regard for their ACTIVE_LOW status.
3383 *
3384 * This function is to be called from contexts that can sleep.
3385 */
3386void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3387 struct gpio_desc **desc_array,
3388 int *value_array)
3389{
3390 might_sleep_if(extra_checks);
3391 if (!desc_array)
3392 return;
3393 gpiod_set_array_value_complex(true, true, array_size, desc_array,
3394 value_array);
3395}
3396EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3397
3398/**
3399 * gpiod_add_lookup_tables() - register GPIO device consumers
3400 * @tables: list of tables of consumers to register
3401 * @n: number of tables in the list
3402 */
3403void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3404{
3405 unsigned int i;
3406
3407 mutex_lock(&gpio_lookup_lock);
3408
3409 for (i = 0; i < n; i++)
3410 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3411
3412 mutex_unlock(&gpio_lookup_lock);
3413}
3414
3415/**
3416 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3417 * @array_size: number of elements in the descriptor / value arrays
3418 * @desc_array: array of GPIO descriptors whose values will be assigned
3419 * @value_array: array of values to assign
3420 *
3421 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3422 * into account.
3423 *
3424 * This function is to be called from contexts that can sleep.
3425 */
3426void gpiod_set_array_value_cansleep(unsigned int array_size,
3427 struct gpio_desc **desc_array,
3428 int *value_array)
3429{
3430 might_sleep_if(extra_checks);
3431 if (!desc_array)
3432 return;
3433 gpiod_set_array_value_complex(false, true, array_size, desc_array,
3434 value_array);
3435}
3436EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3437
3438/**
3439 * gpiod_add_lookup_table() - register GPIO device consumers
3440 * @table: table of consumers to register
3441 */
3442void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3443{
3444 mutex_lock(&gpio_lookup_lock);
3445
3446 list_add_tail(&table->list, &gpio_lookup_list);
3447
3448 mutex_unlock(&gpio_lookup_lock);
3449}
3450EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3451
3452/**
3453 * gpiod_remove_lookup_table() - unregister GPIO device consumers
3454 * @table: table of consumers to unregister
3455 */
3456void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3457{
3458 mutex_lock(&gpio_lookup_lock);
3459
3460 list_del(&table->list);
3461
3462 mutex_unlock(&gpio_lookup_lock);
3463}
3464EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3465
3466static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3467{
3468 const char *dev_id = dev ? dev_name(dev) : NULL;
3469 struct gpiod_lookup_table *table;
3470
3471 mutex_lock(&gpio_lookup_lock);
3472
3473 list_for_each_entry(table, &gpio_lookup_list, list) {
3474 if (table->dev_id && dev_id) {
3475 /*
3476 * Valid strings on both ends, must be identical to have
3477 * a match
3478 */
3479 if (!strcmp(table->dev_id, dev_id))
3480 goto found;
3481 } else {
3482 /*
3483 * One of the pointers is NULL, so both must be to have
3484 * a match
3485 */
3486 if (dev_id == table->dev_id)
3487 goto found;
3488 }
3489 }
3490 table = NULL;
3491
3492found:
3493 mutex_unlock(&gpio_lookup_lock);
3494 return table;
3495}
3496
3497static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3498 unsigned int idx,
3499 enum gpio_lookup_flags *flags)
3500{
3501 struct gpio_desc *desc = ERR_PTR(-ENOENT);
3502 struct gpiod_lookup_table *table;
3503 struct gpiod_lookup *p;
3504
3505 table = gpiod_find_lookup_table(dev);
3506 if (!table)
3507 return desc;
3508
3509 for (p = &table->table[0]; p->chip_label; p++) {
3510 struct gpio_chip *chip;
3511
3512 /* idx must always match exactly */
3513 if (p->idx != idx)
3514 continue;
3515
3516 /* If the lookup entry has a con_id, require exact match */
3517 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3518 continue;
3519
3520 chip = find_chip_by_name(p->chip_label);
3521
3522 if (!chip) {
3523 dev_err(dev, "cannot find GPIO chip %s\n",
3524 p->chip_label);
3525 return ERR_PTR(-ENODEV);
3526 }
3527
3528 if (chip->ngpio <= p->chip_hwnum) {
3529 dev_err(dev,
3530 "requested GPIO %d is out of range [0..%d] for chip %s\n",
3531 idx, chip->ngpio, chip->label);
3532 return ERR_PTR(-EINVAL);
3533 }
3534
3535 desc = gpiochip_get_desc(chip, p->chip_hwnum);
3536 *flags = p->flags;
3537
3538 return desc;
3539 }
3540
3541 return desc;
3542}
3543
3544static int dt_gpio_count(struct device *dev, const char *con_id)
3545{
3546 int ret;
3547 char propname[32];
3548 unsigned int i;
3549
3550 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3551 if (con_id)
3552 snprintf(propname, sizeof(propname), "%s-%s",
3553 con_id, gpio_suffixes[i]);
3554 else
3555 snprintf(propname, sizeof(propname), "%s",
3556 gpio_suffixes[i]);
3557
3558 ret = of_gpio_named_count(dev->of_node, propname);
3559 if (ret > 0)
3560 break;
3561 }
3562 return ret ? ret : -ENOENT;
3563}
3564
3565static int platform_gpio_count(struct device *dev, const char *con_id)
3566{
3567 struct gpiod_lookup_table *table;
3568 struct gpiod_lookup *p;
3569 unsigned int count = 0;
3570
3571 table = gpiod_find_lookup_table(dev);
3572 if (!table)
3573 return -ENOENT;
3574
3575 for (p = &table->table[0]; p->chip_label; p++) {
3576 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3577 (!con_id && !p->con_id))
3578 count++;
3579 }
3580 if (!count)
3581 return -ENOENT;
3582
3583 return count;
3584}
3585
3586/**
3587 * gpiod_count - return the number of GPIOs associated with a device / function
3588 * or -ENOENT if no GPIO has been assigned to the requested function
3589 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3590 * @con_id: function within the GPIO consumer
3591 */
3592int gpiod_count(struct device *dev, const char *con_id)
3593{
3594 int count = -ENOENT;
3595
3596 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
3597 count = dt_gpio_count(dev, con_id);
3598 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
3599 count = acpi_gpio_count(dev, con_id);
3600
3601 if (count < 0)
3602 count = platform_gpio_count(dev, con_id);
3603
3604 return count;
3605}
3606EXPORT_SYMBOL_GPL(gpiod_count);
3607
3608/**
3609 * gpiod_get - obtain a GPIO for a given GPIO function
3610 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3611 * @con_id: function within the GPIO consumer
3612 * @flags: optional GPIO initialization flags
3613 *
3614 * Return the GPIO descriptor corresponding to the function con_id of device
3615 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3616 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3617 */
3618struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3619 enum gpiod_flags flags)
3620{
3621 return gpiod_get_index(dev, con_id, 0, flags);
3622}
3623EXPORT_SYMBOL_GPL(gpiod_get);
3624
3625/**
3626 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3627 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3628 * @con_id: function within the GPIO consumer
3629 * @flags: optional GPIO initialization flags
3630 *
3631 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3632 * the requested function it will return NULL. This is convenient for drivers
3633 * that need to handle optional GPIOs.
3634 */
3635struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3636 const char *con_id,
3637 enum gpiod_flags flags)
3638{
3639 return gpiod_get_index_optional(dev, con_id, 0, flags);
3640}
3641EXPORT_SYMBOL_GPL(gpiod_get_optional);
3642
3643
3644/**
3645 * gpiod_configure_flags - helper function to configure a given GPIO
3646 * @desc: gpio whose value will be assigned
3647 * @con_id: function within the GPIO consumer
3648 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3649 * of_get_gpio_hog()
3650 * @dflags: gpiod_flags - optional GPIO initialization flags
3651 *
3652 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3653 * requested function and/or index, or another IS_ERR() code if an error
3654 * occurred while trying to acquire the GPIO.
3655 */
3656int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3657 unsigned long lflags, enum gpiod_flags dflags)
3658{
3659 int status;
3660
3661 if (lflags & GPIO_ACTIVE_LOW)
3662 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3663
3664 if (lflags & GPIO_OPEN_DRAIN)
3665 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3666 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3667 /*
3668 * This enforces open drain mode from the consumer side.
3669 * This is necessary for some busses like I2C, but the lookup
3670 * should *REALLY* have specified them as open drain in the
3671 * first place, so print a little warning here.
3672 */
3673 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3674 gpiod_warn(desc,
3675 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3676 }
3677
3678 if (lflags & GPIO_OPEN_SOURCE)
3679 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3680
3681 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3682 if (status < 0)
3683 return status;
3684
3685 /* No particular flag request, return here... */
3686 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3687 pr_debug("no flags found for %s\n", con_id);
3688 return 0;
3689 }
3690
3691 /* Process flags */
3692 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3693 status = gpiod_direction_output(desc,
3694 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3695 else
3696 status = gpiod_direction_input(desc);
3697
3698 return status;
3699}
3700
3701/**
3702 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3703 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3704 * @con_id: function within the GPIO consumer
3705 * @idx: index of the GPIO to obtain in the consumer
3706 * @flags: optional GPIO initialization flags
3707 *
3708 * This variant of gpiod_get() allows to access GPIOs other than the first
3709 * defined one for functions that define several GPIOs.
3710 *
3711 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3712 * requested function and/or index, or another IS_ERR() code if an error
3713 * occurred while trying to acquire the GPIO.
3714 */
3715struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3716 const char *con_id,
3717 unsigned int idx,
3718 enum gpiod_flags flags)
3719{
3720 struct gpio_desc *desc = NULL;
3721 int status;
3722 enum gpio_lookup_flags lookupflags = 0;
3723 /* Maybe we have a device name, maybe not */
3724 const char *devname = dev ? dev_name(dev) : "?";
3725
3726 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3727
3728 if (dev) {
3729 /* Using device tree? */
3730 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
3731 dev_dbg(dev, "using device tree for GPIO lookup\n");
3732 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3733 } else if (ACPI_COMPANION(dev)) {
3734 dev_dbg(dev, "using ACPI for GPIO lookup\n");
3735 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3736 }
3737 }
3738
3739 /*
3740 * Either we are not using DT or ACPI, or their lookup did not return
3741 * a result. In that case, use platform lookup as a fallback.
3742 */
3743 if (!desc || desc == ERR_PTR(-ENOENT)) {
3744 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3745 desc = gpiod_find(dev, con_id, idx, &lookupflags);
3746 }
3747
3748 if (IS_ERR(desc)) {
3749 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3750 return desc;
3751 }
3752
3753 /*
3754 * If a connection label was passed use that, else attempt to use
3755 * the device name as label
3756 */
3757 status = gpiod_request(desc, con_id ? con_id : devname);
3758 if (status < 0)
3759 return ERR_PTR(status);
3760
3761 status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3762 if (status < 0) {
3763 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3764 gpiod_put(desc);
3765 return ERR_PTR(status);
3766 }
3767
3768 return desc;
3769}
3770EXPORT_SYMBOL_GPL(gpiod_get_index);
3771
3772/**
3773 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
3774 * @node: handle of the OF node
3775 * @propname: name of the DT property representing the GPIO
3776 * @index: index of the GPIO to obtain for the consumer
3777 * @dflags: GPIO initialization flags
3778 * @label: label to attach to the requested GPIO
3779 *
3780 * Returns:
3781 * On successful request the GPIO pin is configured in accordance with
3782 * provided @dflags. If the node does not have the requested GPIO
3783 * property, NULL is returned.
3784 *
3785 * In case of error an ERR_PTR() is returned.
3786 */
3787struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
3788 const char *propname, int index,
3789 enum gpiod_flags dflags,
3790 const char *label)
3791{
3792 struct gpio_desc *desc;
3793 unsigned long lflags = 0;
3794 enum of_gpio_flags flags;
3795 bool active_low = false;
3796 bool single_ended = false;
3797 bool open_drain = false;
3798 bool transitory = false;
3799 int ret;
3800
3801 desc = of_get_named_gpiod_flags(node, propname,
3802 index, &flags);
3803
3804 if (!desc || IS_ERR(desc)) {
3805 /* If it is not there, just return NULL */
3806 if (PTR_ERR(desc) == -ENOENT)
3807 return NULL;
3808 return desc;
3809 }
3810
3811 active_low = flags & OF_GPIO_ACTIVE_LOW;
3812 single_ended = flags & OF_GPIO_SINGLE_ENDED;
3813 open_drain = flags & OF_GPIO_OPEN_DRAIN;
3814 transitory = flags & OF_GPIO_TRANSITORY;
3815
3816 ret = gpiod_request(desc, label);
3817 if (ret)
3818 return ERR_PTR(ret);
3819
3820 if (active_low)
3821 lflags |= GPIO_ACTIVE_LOW;
3822
3823 if (single_ended) {
3824 if (open_drain)
3825 lflags |= GPIO_OPEN_DRAIN;
3826 else
3827 lflags |= GPIO_OPEN_SOURCE;
3828 }
3829
3830 if (transitory)
3831 lflags |= GPIO_TRANSITORY;
3832
3833 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3834 if (ret < 0) {
3835 gpiod_put(desc);
3836 return ERR_PTR(ret);
3837 }
3838
3839 return desc;
3840}
3841EXPORT_SYMBOL(gpiod_get_from_of_node);
3842
3843/**
3844 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3845 * @fwnode: handle of the firmware node
3846 * @propname: name of the firmware property representing the GPIO
3847 * @index: index of the GPIO to obtain for the consumer
3848 * @dflags: GPIO initialization flags
3849 * @label: label to attach to the requested GPIO
3850 *
3851 * This function can be used for drivers that get their configuration
3852 * from opaque firmware.
3853 *
3854 * The function properly finds the corresponding GPIO using whatever is the
3855 * underlying firmware interface and then makes sure that the GPIO
3856 * descriptor is requested before it is returned to the caller.
3857 *
3858 * Returns:
3859 * On successful request the GPIO pin is configured in accordance with
3860 * provided @dflags.
3861 *
3862 * In case of error an ERR_PTR() is returned.
3863 */
3864struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
3865 const char *propname, int index,
3866 enum gpiod_flags dflags,
3867 const char *label)
3868{
3869 struct gpio_desc *desc = ERR_PTR(-ENODEV);
3870 unsigned long lflags = 0;
3871 int ret;
3872
3873 if (!fwnode)
3874 return ERR_PTR(-EINVAL);
3875
3876 if (is_of_node(fwnode)) {
3877 desc = gpiod_get_from_of_node(to_of_node(fwnode),
3878 propname, index,
3879 dflags,
3880 label);
3881 return desc;
3882 } else if (is_acpi_node(fwnode)) {
3883 struct acpi_gpio_info info;
3884
3885 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
3886 if (IS_ERR(desc))
3887 return desc;
3888
3889 acpi_gpio_update_gpiod_flags(&dflags, &info);
3890
3891 if (info.polarity == GPIO_ACTIVE_LOW)
3892 lflags |= GPIO_ACTIVE_LOW;
3893 }
3894
3895 /* Currently only ACPI takes this path */
3896 ret = gpiod_request(desc, label);
3897 if (ret)
3898 return ERR_PTR(ret);
3899
3900 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
3901 if (ret < 0) {
3902 gpiod_put(desc);
3903 return ERR_PTR(ret);
3904 }
3905
3906 return desc;
3907}
3908EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
3909
3910/**
3911 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
3912 * function
3913 * @dev: GPIO consumer, can be NULL for system-global GPIOs
3914 * @con_id: function within the GPIO consumer
3915 * @index: index of the GPIO to obtain in the consumer
3916 * @flags: optional GPIO initialization flags
3917 *
3918 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
3919 * specified index was assigned to the requested function it will return NULL.
3920 * This is convenient for drivers that need to handle optional GPIOs.
3921 */
3922struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
3923 const char *con_id,
3924 unsigned int index,
3925 enum gpiod_flags flags)
3926{
3927 struct gpio_desc *desc;
3928
3929 desc = gpiod_get_index(dev, con_id, index, flags);
3930 if (IS_ERR(desc)) {
3931 if (PTR_ERR(desc) == -ENOENT)
3932 return NULL;
3933 }
3934
3935 return desc;
3936}
3937EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
3938
3939/**
3940 * gpiod_hog - Hog the specified GPIO desc given the provided flags
3941 * @desc: gpio whose value will be assigned
3942 * @name: gpio line name
3943 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or
3944 * of_get_gpio_hog()
3945 * @dflags: gpiod_flags - optional GPIO initialization flags
3946 */
3947int gpiod_hog(struct gpio_desc *desc, const char *name,
3948 unsigned long lflags, enum gpiod_flags dflags)
3949{
3950 struct gpio_chip *chip;
3951 struct gpio_desc *local_desc;
3952 int hwnum;
3953 int status;
3954
3955 chip = gpiod_to_chip(desc);
3956 hwnum = gpio_chip_hwgpio(desc);
3957
3958 local_desc = gpiochip_request_own_desc(chip, hwnum, name);
3959 if (IS_ERR(local_desc)) {
3960 status = PTR_ERR(local_desc);
3961 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
3962 name, chip->label, hwnum, status);
3963 return status;
3964 }
3965
3966 status = gpiod_configure_flags(desc, name, lflags, dflags);
3967 if (status < 0) {
3968 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
3969 name, chip->label, hwnum, status);
3970 gpiochip_free_own_desc(desc);
3971 return status;
3972 }
3973
3974 /* Mark GPIO as hogged so it can be identified and removed later */
3975 set_bit(FLAG_IS_HOGGED, &desc->flags);
3976
3977 pr_info("GPIO line %d (%s) hogged as %s%s\n",
3978 desc_to_gpio(desc), name,
3979 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
3980 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
3981 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
3982
3983 return 0;
3984}
3985
3986/**
3987 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
3988 * @chip: gpio chip to act on
3989 *
3990 * This is only used by of_gpiochip_remove to free hogged gpios
3991 */
3992static void gpiochip_free_hogs(struct gpio_chip *chip)
3993{
3994 int id;
3995
3996 for (id = 0; id < chip->ngpio; id++) {
3997 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
3998 gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
3999 }
4000}
4001
4002/**
4003 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4004 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4005 * @con_id: function within the GPIO consumer
4006 * @flags: optional GPIO initialization flags
4007 *
4008 * This function acquires all the GPIOs defined under a given function.
4009 *
4010 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4011 * no GPIO has been assigned to the requested function, or another IS_ERR()
4012 * code if an error occurred while trying to acquire the GPIOs.
4013 */
4014struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4015 const char *con_id,
4016 enum gpiod_flags flags)
4017{
4018 struct gpio_desc *desc;
4019 struct gpio_descs *descs;
4020 int count;
4021
4022 count = gpiod_count(dev, con_id);
4023 if (count < 0)
4024 return ERR_PTR(count);
4025
4026 descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
4027 GFP_KERNEL);
4028 if (!descs)
4029 return ERR_PTR(-ENOMEM);
4030
4031 for (descs->ndescs = 0; descs->ndescs < count; ) {
4032 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4033 if (IS_ERR(desc)) {
4034 gpiod_put_array(descs);
4035 return ERR_CAST(desc);
4036 }
4037 descs->desc[descs->ndescs] = desc;
4038 descs->ndescs++;
4039 }
4040 return descs;
4041}
4042EXPORT_SYMBOL_GPL(gpiod_get_array);
4043
4044/**
4045 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4046 * function
4047 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4048 * @con_id: function within the GPIO consumer
4049 * @flags: optional GPIO initialization flags
4050 *
4051 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4052 * assigned to the requested function it will return NULL.
4053 */
4054struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4055 const char *con_id,
4056 enum gpiod_flags flags)
4057{
4058 struct gpio_descs *descs;
4059
4060 descs = gpiod_get_array(dev, con_id, flags);
4061 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4062 return NULL;
4063
4064 return descs;
4065}
4066EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4067
4068/**
4069 * gpiod_put - dispose of a GPIO descriptor
4070 * @desc: GPIO descriptor to dispose of
4071 *
4072 * No descriptor can be used after gpiod_put() has been called on it.
4073 */
4074void gpiod_put(struct gpio_desc *desc)
4075{
4076 gpiod_free(desc);
4077}
4078EXPORT_SYMBOL_GPL(gpiod_put);
4079
4080/**
4081 * gpiod_put_array - dispose of multiple GPIO descriptors
4082 * @descs: struct gpio_descs containing an array of descriptors
4083 */
4084void gpiod_put_array(struct gpio_descs *descs)
4085{
4086 unsigned int i;
4087
4088 for (i = 0; i < descs->ndescs; i++)
4089 gpiod_put(descs->desc[i]);
4090
4091 kfree(descs);
4092}
4093EXPORT_SYMBOL_GPL(gpiod_put_array);
4094
4095static int __init gpiolib_dev_init(void)
4096{
4097 int ret;
4098
4099 /* Register GPIO sysfs bus */
4100 ret = bus_register(&gpio_bus_type);
4101 if (ret < 0) {
4102 pr_err("gpiolib: could not register GPIO bus type\n");
4103 return ret;
4104 }
4105
4106 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4107 if (ret < 0) {
4108 pr_err("gpiolib: failed to allocate char dev region\n");
4109 bus_unregister(&gpio_bus_type);
4110 } else {
4111 gpiolib_initialized = true;
4112 gpiochip_setup_devs();
4113 }
4114 return ret;
4115}
4116core_initcall(gpiolib_dev_init);
4117
4118#ifdef CONFIG_DEBUG_FS
4119
4120static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4121{
4122 unsigned i;
4123 struct gpio_chip *chip = gdev->chip;
4124 unsigned gpio = gdev->base;
4125 struct gpio_desc *gdesc = &gdev->descs[0];
4126 int is_out;
4127 int is_irq;
4128
4129 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4130 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4131 if (gdesc->name) {
4132 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4133 gpio, gdesc->name);
4134 }
4135 continue;
4136 }
4137
4138 gpiod_get_direction(gdesc);
4139 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4140 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4141 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
4142 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4143 is_out ? "out" : "in ",
4144 chip->get
4145 ? (chip->get(chip, i) ? "hi" : "lo")
4146 : "? ",
4147 is_irq ? "IRQ" : " ");
4148 seq_printf(s, "\n");
4149 }
4150}
4151
4152static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4153{
4154 unsigned long flags;
4155 struct gpio_device *gdev = NULL;
4156 loff_t index = *pos;
4157
4158 s->private = "";
4159
4160 spin_lock_irqsave(&gpio_lock, flags);
4161 list_for_each_entry(gdev, &gpio_devices, list)
4162 if (index-- == 0) {
4163 spin_unlock_irqrestore(&gpio_lock, flags);
4164 return gdev;
4165 }
4166 spin_unlock_irqrestore(&gpio_lock, flags);
4167
4168 return NULL;
4169}
4170
4171static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4172{
4173 unsigned long flags;
4174 struct gpio_device *gdev = v;
4175 void *ret = NULL;
4176
4177 spin_lock_irqsave(&gpio_lock, flags);
4178 if (list_is_last(&gdev->list, &gpio_devices))
4179 ret = NULL;
4180 else
4181 ret = list_entry(gdev->list.next, struct gpio_device, list);
4182 spin_unlock_irqrestore(&gpio_lock, flags);
4183
4184 s->private = "\n";
4185 ++*pos;
4186
4187 return ret;
4188}
4189
4190static void gpiolib_seq_stop(struct seq_file *s, void *v)
4191{
4192}
4193
4194static int gpiolib_seq_show(struct seq_file *s, void *v)
4195{
4196 struct gpio_device *gdev = v;
4197 struct gpio_chip *chip = gdev->chip;
4198 struct device *parent;
4199
4200 if (!chip) {
4201 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4202 dev_name(&gdev->dev));
4203 return 0;
4204 }
4205
4206 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4207 dev_name(&gdev->dev),
4208 gdev->base, gdev->base + gdev->ngpio - 1);
4209 parent = chip->parent;
4210 if (parent)
4211 seq_printf(s, ", parent: %s/%s",
4212 parent->bus ? parent->bus->name : "no-bus",
4213 dev_name(parent));
4214 if (chip->label)
4215 seq_printf(s, ", %s", chip->label);
4216 if (chip->can_sleep)
4217 seq_printf(s, ", can sleep");
4218 seq_printf(s, ":\n");
4219
4220 if (chip->dbg_show)
4221 chip->dbg_show(s, chip);
4222 else
4223 gpiolib_dbg_show(s, gdev);
4224
4225 return 0;
4226}
4227
4228static const struct seq_operations gpiolib_seq_ops = {
4229 .start = gpiolib_seq_start,
4230 .next = gpiolib_seq_next,
4231 .stop = gpiolib_seq_stop,
4232 .show = gpiolib_seq_show,
4233};
4234
4235static int gpiolib_open(struct inode *inode, struct file *file)
4236{
4237 return seq_open(file, &gpiolib_seq_ops);
4238}
4239
4240static const struct file_operations gpiolib_operations = {
4241 .owner = THIS_MODULE,
4242 .open = gpiolib_open,
4243 .read = seq_read,
4244 .llseek = seq_lseek,
4245 .release = seq_release,
4246};
4247
4248static int __init gpiolib_debugfs_init(void)
4249{
4250 /* /sys/kernel/debug/gpio */
4251 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
4252 NULL, NULL, &gpiolib_operations);
4253 return 0;
4254}
4255subsys_initcall(gpiolib_debugfs_init);
4256
4257#endif /* DEBUG_FS */