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