1// SPDX-License-Identifier: GPL-2.0
2#include <linux/bitmap.h>
3#include <linux/kernel.h>
4#include <linux/module.h>
5#include <linux/interrupt.h>
6#include <linux/irq.h>
7#include <linux/spinlock.h>
8#include <linux/list.h>
9#include <linux/device.h>
10#include <linux/err.h>
11#include <linux/debugfs.h>
12#include <linux/seq_file.h>
13#include <linux/gpio.h>
14#include <linux/of_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/cdev.h>
22#include <linux/fs.h>
23#include <linux/uaccess.h>
24#include <linux/compat.h>
25#include <linux/anon_inodes.h>
26#include <linux/file.h>
27#include <linux/kfifo.h>
28#include <linux/poll.h>
29#include <linux/timekeeping.h>
30#include <uapi/linux/gpio.h>
31
32#include "gpiolib.h"
33
34#define CREATE_TRACE_POINTS
35#include <trace/events/gpio.h>
36
37/* Implementation infrastructure for GPIO interfaces.
38 *
39 * The GPIO programming interface allows for inlining speed-critical
40 * get/set operations for common cases, so that access to SOC-integrated
41 * GPIOs can sometimes cost only an instruction or two per bit.
42 */
43
44
45/* When debugging, extend minimal trust to callers and platform code.
46 * Also emit diagnostic messages that may help initial bringup, when
47 * board setup or driver bugs are most common.
48 *
49 * Otherwise, minimize overhead in what may be bitbanging codepaths.
50 */
51#ifdef DEBUG
52#define extra_checks 1
53#else
54#define extra_checks 0
55#endif
56
57/* Device and char device-related information */
58static DEFINE_IDA(gpio_ida);
59static dev_t gpio_devt;
60#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
61static struct bus_type gpio_bus_type = {
62 .name = "gpio",
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 *chip);
84static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
85 struct lock_class_key *lock_key,
86 struct lock_class_key *request_key);
87static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
88static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
89static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
90
91static bool gpiolib_initialized;
92
93static inline void desc_set_label(struct gpio_desc *d, const char *label)
94{
95 d->label = label;
96}
97
98/**
99 * gpio_to_desc - Convert a GPIO number to its descriptor
100 * @gpio: global GPIO number
101 *
102 * Returns:
103 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
104 * with the given number exists in the system.
105 */
106struct gpio_desc *gpio_to_desc(unsigned gpio)
107{
108 struct gpio_device *gdev;
109 unsigned long flags;
110
111 spin_lock_irqsave(&gpio_lock, flags);
112
113 list_for_each_entry(gdev, &gpio_devices, list) {
114 if (gdev->base <= gpio &&
115 gdev->base + gdev->ngpio > gpio) {
116 spin_unlock_irqrestore(&gpio_lock, flags);
117 return &gdev->descs[gpio - gdev->base];
118 }
119 }
120
121 spin_unlock_irqrestore(&gpio_lock, flags);
122
123 if (!gpio_is_valid(gpio))
124 WARN(1, "invalid GPIO %d\n", gpio);
125
126 return NULL;
127}
128EXPORT_SYMBOL_GPL(gpio_to_desc);
129
130/**
131 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
132 * hardware number for this chip
133 * @chip: GPIO chip
134 * @hwnum: hardware number of the GPIO for this chip
135 *
136 * Returns:
137 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
138 * in the given chip for the specified hardware number.
139 */
140struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
141 u16 hwnum)
142{
143 struct gpio_device *gdev = chip->gpiodev;
144
145 if (hwnum >= gdev->ngpio)
146 return ERR_PTR(-EINVAL);
147
148 return &gdev->descs[hwnum];
149}
150
151/**
152 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
153 * @desc: GPIO descriptor
154 *
155 * This should disappear in the future but is needed since we still
156 * use GPIO numbers for error messages and sysfs nodes.
157 *
158 * Returns:
159 * The global GPIO number for the GPIO specified by its descriptor.
160 */
161int desc_to_gpio(const struct gpio_desc *desc)
162{
163 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
164}
165EXPORT_SYMBOL_GPL(desc_to_gpio);
166
167
168/**
169 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
170 * @desc: descriptor to return the chip of
171 */
172struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
173{
174 if (!desc || !desc->gdev)
175 return NULL;
176 return desc->gdev->chip;
177}
178EXPORT_SYMBOL_GPL(gpiod_to_chip);
179
180/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
181static int gpiochip_find_base(int ngpio)
182{
183 struct gpio_device *gdev;
184 int base = ARCH_NR_GPIOS - ngpio;
185
186 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
187 /* found a free space? */
188 if (gdev->base + gdev->ngpio <= base)
189 break;
190 else
191 /* nope, check the space right before the chip */
192 base = gdev->base - ngpio;
193 }
194
195 if (gpio_is_valid(base)) {
196 pr_debug("%s: found new base at %d\n", __func__, base);
197 return base;
198 } else {
199 pr_err("%s: cannot find free range\n", __func__);
200 return -ENOSPC;
201 }
202}
203
204/**
205 * gpiod_get_direction - return the current direction of a GPIO
206 * @desc: GPIO to get the direction of
207 *
208 * Returns 0 for output, 1 for input, or an error code in case of error.
209 *
210 * This function may sleep if gpiod_cansleep() is true.
211 */
212int gpiod_get_direction(struct gpio_desc *desc)
213{
214 struct gpio_chip *chip;
215 unsigned offset;
216 int status;
217
218 chip = gpiod_to_chip(desc);
219 offset = gpio_chip_hwgpio(desc);
220
221 if (!chip->get_direction)
222 return -ENOTSUPP;
223
224 status = chip->get_direction(chip, offset);
225 if (status > 0) {
226 /* GPIOF_DIR_IN, or other positive */
227 status = 1;
228 clear_bit(FLAG_IS_OUT, &desc->flags);
229 }
230 if (status == 0) {
231 /* GPIOF_DIR_OUT */
232 set_bit(FLAG_IS_OUT, &desc->flags);
233 }
234 return status;
235}
236EXPORT_SYMBOL_GPL(gpiod_get_direction);
237
238/*
239 * Add a new chip to the global chips list, keeping the list of chips sorted
240 * by range(means [base, base + ngpio - 1]) order.
241 *
242 * Return -EBUSY if the new chip overlaps with some other chip's integer
243 * space.
244 */
245static int gpiodev_add_to_list(struct gpio_device *gdev)
246{
247 struct gpio_device *prev, *next;
248
249 if (list_empty(&gpio_devices)) {
250 /* initial entry in list */
251 list_add_tail(&gdev->list, &gpio_devices);
252 return 0;
253 }
254
255 next = list_entry(gpio_devices.next, struct gpio_device, list);
256 if (gdev->base + gdev->ngpio <= next->base) {
257 /* add before first entry */
258 list_add(&gdev->list, &gpio_devices);
259 return 0;
260 }
261
262 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
263 if (prev->base + prev->ngpio <= gdev->base) {
264 /* add behind last entry */
265 list_add_tail(&gdev->list, &gpio_devices);
266 return 0;
267 }
268
269 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
270 /* at the end of the list */
271 if (&next->list == &gpio_devices)
272 break;
273
274 /* add between prev and next */
275 if (prev->base + prev->ngpio <= gdev->base
276 && gdev->base + gdev->ngpio <= next->base) {
277 list_add(&gdev->list, &prev->list);
278 return 0;
279 }
280 }
281
282 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
283 return -EBUSY;
284}
285
286/*
287 * Convert a GPIO name to its descriptor
288 */
289static struct gpio_desc *gpio_name_to_desc(const char * const name)
290{
291 struct gpio_device *gdev;
292 unsigned long flags;
293
294 spin_lock_irqsave(&gpio_lock, flags);
295
296 list_for_each_entry(gdev, &gpio_devices, list) {
297 int i;
298
299 for (i = 0; i != gdev->ngpio; ++i) {
300 struct gpio_desc *desc = &gdev->descs[i];
301
302 if (!desc->name || !name)
303 continue;
304
305 if (!strcmp(desc->name, name)) {
306 spin_unlock_irqrestore(&gpio_lock, flags);
307 return desc;
308 }
309 }
310 }
311
312 spin_unlock_irqrestore(&gpio_lock, flags);
313
314 return NULL;
315}
316
317/*
318 * Takes the names from gc->names and checks if they are all unique. If they
319 * are, they are assigned to their gpio descriptors.
320 *
321 * Warning if one of the names is already used for a different GPIO.
322 */
323static int gpiochip_set_desc_names(struct gpio_chip *gc)
324{
325 struct gpio_device *gdev = gc->gpiodev;
326 int i;
327
328 if (!gc->names)
329 return 0;
330
331 /* First check all names if they are unique */
332 for (i = 0; i != gc->ngpio; ++i) {
333 struct gpio_desc *gpio;
334
335 gpio = gpio_name_to_desc(gc->names[i]);
336 if (gpio)
337 dev_warn(&gdev->dev,
338 "Detected name collision for GPIO name '%s'\n",
339 gc->names[i]);
340 }
341
342 /* Then add all names to the GPIO descriptors */
343 for (i = 0; i != gc->ngpio; ++i)
344 gdev->descs[i].name = gc->names[i];
345
346 return 0;
347}
348
349static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
350{
351 unsigned long *p;
352
353 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
354 if (!p)
355 return NULL;
356
357 /* Assume by default all GPIOs are valid */
358 bitmap_fill(p, chip->ngpio);
359
360 return p;
361}
362
363static int gpiochip_alloc_valid_mask(struct gpio_chip *gpiochip)
364{
365#ifdef CONFIG_OF_GPIO
366 int size;
367 struct device_node *np = gpiochip->of_node;
368
369 size = of_property_count_u32_elems(np, "gpio-reserved-ranges");
370 if (size > 0 && size % 2 == 0)
371 gpiochip->need_valid_mask = true;
372#endif
373
374 if (!gpiochip->need_valid_mask)
375 return 0;
376
377 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
378 if (!gpiochip->valid_mask)
379 return -ENOMEM;
380
381 return 0;
382}
383
384static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
385{
386 if (gpiochip->init_valid_mask)
387 return gpiochip->init_valid_mask(gpiochip);
388
389 return 0;
390}
391
392static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
393{
394 kfree(gpiochip->valid_mask);
395 gpiochip->valid_mask = NULL;
396}
397
398bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
399 unsigned int offset)
400{
401 /* No mask means all valid */
402 if (likely(!gpiochip->valid_mask))
403 return true;
404 return test_bit(offset, gpiochip->valid_mask);
405}
406EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
407
408/*
409 * GPIO line handle management
410 */
411
412/**
413 * struct linehandle_state - contains the state of a userspace handle
414 * @gdev: the GPIO device the handle pertains to
415 * @label: consumer label used to tag descriptors
416 * @descs: the GPIO descriptors held by this handle
417 * @numdescs: the number of descriptors held in the descs array
418 */
419struct linehandle_state {
420 struct gpio_device *gdev;
421 const char *label;
422 struct gpio_desc *descs[GPIOHANDLES_MAX];
423 u32 numdescs;
424};
425
426#define GPIOHANDLE_REQUEST_VALID_FLAGS \
427 (GPIOHANDLE_REQUEST_INPUT | \
428 GPIOHANDLE_REQUEST_OUTPUT | \
429 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
430 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
431 GPIOHANDLE_REQUEST_OPEN_SOURCE)
432
433static long linehandle_ioctl(struct file *filep, unsigned int cmd,
434 unsigned long arg)
435{
436 struct linehandle_state *lh = filep->private_data;
437 void __user *ip = (void __user *)arg;
438 struct gpiohandle_data ghd;
439 DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
440 int i;
441
442 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
443 /* NOTE: It's ok to read values of output lines. */
444 int ret = gpiod_get_array_value_complex(false,
445 true,
446 lh->numdescs,
447 lh->descs,
448 NULL,
449 vals);
450 if (ret)
451 return ret;
452
453 memset(&ghd, 0, sizeof(ghd));
454 for (i = 0; i < lh->numdescs; i++)
455 ghd.values[i] = test_bit(i, vals);
456
457 if (copy_to_user(ip, &ghd, sizeof(ghd)))
458 return -EFAULT;
459
460 return 0;
461 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
462 /*
463 * All line descriptors were created at once with the same
464 * flags so just check if the first one is really output.
465 */
466 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
467 return -EPERM;
468
469 if (copy_from_user(&ghd, ip, sizeof(ghd)))
470 return -EFAULT;
471
472 /* Clamp all values to [0,1] */
473 for (i = 0; i < lh->numdescs; i++)
474 __assign_bit(i, vals, ghd.values[i]);
475
476 /* Reuse the array setting function */
477 return gpiod_set_array_value_complex(false,
478 true,
479 lh->numdescs,
480 lh->descs,
481 NULL,
482 vals);
483 }
484 return -EINVAL;
485}
486
487#ifdef CONFIG_COMPAT
488static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
489 unsigned long arg)
490{
491 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
492}
493#endif
494
495static int linehandle_release(struct inode *inode, struct file *filep)
496{
497 struct linehandle_state *lh = filep->private_data;
498 struct gpio_device *gdev = lh->gdev;
499 int i;
500
501 for (i = 0; i < lh->numdescs; i++)
502 gpiod_free(lh->descs[i]);
503 kfree(lh->label);
504 kfree(lh);
505 put_device(&gdev->dev);
506 return 0;
507}
508
509static const struct file_operations linehandle_fileops = {
510 .release = linehandle_release,
511 .owner = THIS_MODULE,
512 .llseek = noop_llseek,
513 .unlocked_ioctl = linehandle_ioctl,
514#ifdef CONFIG_COMPAT
515 .compat_ioctl = linehandle_ioctl_compat,
516#endif
517};
518
519static int linehandle_create(struct gpio_device *gdev, void __user *ip)
520{
521 struct gpiohandle_request handlereq;
522 struct linehandle_state *lh;
523 struct file *file;
524 int fd, i, count = 0, ret;
525 u32 lflags;
526
527 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
528 return -EFAULT;
529 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
530 return -EINVAL;
531
532 lflags = handlereq.flags;
533
534 /* Return an error if an unknown flag is set */
535 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
536 return -EINVAL;
537
538 /*
539 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
540 * the hardware actually supports enabling both at the same time the
541 * electrical result would be disastrous.
542 */
543 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
544 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
545 return -EINVAL;
546
547 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
548 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
549 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
550 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
551 return -EINVAL;
552
553 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
554 if (!lh)
555 return -ENOMEM;
556 lh->gdev = gdev;
557 get_device(&gdev->dev);
558
559 /* Make sure this is terminated */
560 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
561 if (strlen(handlereq.consumer_label)) {
562 lh->label = kstrdup(handlereq.consumer_label,
563 GFP_KERNEL);
564 if (!lh->label) {
565 ret = -ENOMEM;
566 goto out_free_lh;
567 }
568 }
569
570 /* Request each GPIO */
571 for (i = 0; i < handlereq.lines; i++) {
572 u32 offset = handlereq.lineoffsets[i];
573 struct gpio_desc *desc;
574
575 if (offset >= gdev->ngpio) {
576 ret = -EINVAL;
577 goto out_free_descs;
578 }
579
580 desc = &gdev->descs[offset];
581 ret = gpiod_request(desc, lh->label);
582 if (ret)
583 goto out_free_descs;
584 lh->descs[i] = desc;
585 count = i + 1;
586
587 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
588 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
589 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
590 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
591 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
592 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
593
594 ret = gpiod_set_transitory(desc, false);
595 if (ret < 0)
596 goto out_free_descs;
597
598 /*
599 * Lines have to be requested explicitly for input
600 * or output, else the line will be treated "as is".
601 */
602 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
603 int val = !!handlereq.default_values[i];
604
605 ret = gpiod_direction_output(desc, val);
606 if (ret)
607 goto out_free_descs;
608 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
609 ret = gpiod_direction_input(desc);
610 if (ret)
611 goto out_free_descs;
612 }
613 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
614 offset);
615 }
616 /* Let i point at the last handle */
617 i--;
618 lh->numdescs = handlereq.lines;
619
620 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
621 if (fd < 0) {
622 ret = fd;
623 goto out_free_descs;
624 }
625
626 file = anon_inode_getfile("gpio-linehandle",
627 &linehandle_fileops,
628 lh,
629 O_RDONLY | O_CLOEXEC);
630 if (IS_ERR(file)) {
631 ret = PTR_ERR(file);
632 goto out_put_unused_fd;
633 }
634
635 handlereq.fd = fd;
636 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
637 /*
638 * fput() will trigger the release() callback, so do not go onto
639 * the regular error cleanup path here.
640 */
641 fput(file);
642 put_unused_fd(fd);
643 return -EFAULT;
644 }
645
646 fd_install(fd, file);
647
648 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
649 lh->numdescs);
650
651 return 0;
652
653out_put_unused_fd:
654 put_unused_fd(fd);
655out_free_descs:
656 for (i = 0; i < count; i++)
657 gpiod_free(lh->descs[i]);
658 kfree(lh->label);
659out_free_lh:
660 kfree(lh);
661 put_device(&gdev->dev);
662 return ret;
663}
664
665/*
666 * GPIO line event management
667 */
668
669/**
670 * struct lineevent_state - contains the state of a userspace event
671 * @gdev: the GPIO device the event pertains to
672 * @label: consumer label used to tag descriptors
673 * @desc: the GPIO descriptor held by this event
674 * @eflags: the event flags this line was requested with
675 * @irq: the interrupt that trigger in response to events on this GPIO
676 * @wait: wait queue that handles blocking reads of events
677 * @events: KFIFO for the GPIO events
678 * @read_lock: mutex lock to protect reads from colliding with adding
679 * new events to the FIFO
680 * @timestamp: cache for the timestamp storing it between hardirq
681 * and IRQ thread, used to bring the timestamp close to the actual
682 * event
683 */
684struct lineevent_state {
685 struct gpio_device *gdev;
686 const char *label;
687 struct gpio_desc *desc;
688 u32 eflags;
689 int irq;
690 wait_queue_head_t wait;
691 DECLARE_KFIFO(events, struct gpioevent_data, 16);
692 struct mutex read_lock;
693 u64 timestamp;
694};
695
696#define GPIOEVENT_REQUEST_VALID_FLAGS \
697 (GPIOEVENT_REQUEST_RISING_EDGE | \
698 GPIOEVENT_REQUEST_FALLING_EDGE)
699
700static __poll_t lineevent_poll(struct file *filep,
701 struct poll_table_struct *wait)
702{
703 struct lineevent_state *le = filep->private_data;
704 __poll_t events = 0;
705
706 poll_wait(filep, &le->wait, wait);
707
708 if (!kfifo_is_empty(&le->events))
709 events = EPOLLIN | EPOLLRDNORM;
710
711 return events;
712}
713
714
715static ssize_t lineevent_read(struct file *filep,
716 char __user *buf,
717 size_t count,
718 loff_t *f_ps)
719{
720 struct lineevent_state *le = filep->private_data;
721 unsigned int copied;
722 int ret;
723
724 if (count < sizeof(struct gpioevent_data))
725 return -EINVAL;
726
727 do {
728 if (kfifo_is_empty(&le->events)) {
729 if (filep->f_flags & O_NONBLOCK)
730 return -EAGAIN;
731
732 ret = wait_event_interruptible(le->wait,
733 !kfifo_is_empty(&le->events));
734 if (ret)
735 return ret;
736 }
737
738 if (mutex_lock_interruptible(&le->read_lock))
739 return -ERESTARTSYS;
740 ret = kfifo_to_user(&le->events, buf, count, &copied);
741 mutex_unlock(&le->read_lock);
742
743 if (ret)
744 return ret;
745
746 /*
747 * If we couldn't read anything from the fifo (a different
748 * thread might have been faster) we either return -EAGAIN if
749 * the file descriptor is non-blocking, otherwise we go back to
750 * sleep and wait for more data to arrive.
751 */
752 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
753 return -EAGAIN;
754
755 } while (copied == 0);
756
757 return copied;
758}
759
760static int lineevent_release(struct inode *inode, struct file *filep)
761{
762 struct lineevent_state *le = filep->private_data;
763 struct gpio_device *gdev = le->gdev;
764
765 free_irq(le->irq, le);
766 gpiod_free(le->desc);
767 kfree(le->label);
768 kfree(le);
769 put_device(&gdev->dev);
770 return 0;
771}
772
773static long lineevent_ioctl(struct file *filep, unsigned int cmd,
774 unsigned long arg)
775{
776 struct lineevent_state *le = filep->private_data;
777 void __user *ip = (void __user *)arg;
778 struct gpiohandle_data ghd;
779
780 /*
781 * We can get the value for an event line but not set it,
782 * because it is input by definition.
783 */
784 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
785 int val;
786
787 memset(&ghd, 0, sizeof(ghd));
788
789 val = gpiod_get_value_cansleep(le->desc);
790 if (val < 0)
791 return val;
792 ghd.values[0] = val;
793
794 if (copy_to_user(ip, &ghd, sizeof(ghd)))
795 return -EFAULT;
796
797 return 0;
798 }
799 return -EINVAL;
800}
801
802#ifdef CONFIG_COMPAT
803static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
804 unsigned long arg)
805{
806 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
807}
808#endif
809
810static const struct file_operations lineevent_fileops = {
811 .release = lineevent_release,
812 .read = lineevent_read,
813 .poll = lineevent_poll,
814 .owner = THIS_MODULE,
815 .llseek = noop_llseek,
816 .unlocked_ioctl = lineevent_ioctl,
817#ifdef CONFIG_COMPAT
818 .compat_ioctl = lineevent_ioctl_compat,
819#endif
820};
821
822static irqreturn_t lineevent_irq_thread(int irq, void *p)
823{
824 struct lineevent_state *le = p;
825 struct gpioevent_data ge;
826 int ret;
827
828 /* Do not leak kernel stack to userspace */
829 memset(&ge, 0, sizeof(ge));
830
831 /*
832 * We may be running from a nested threaded interrupt in which case
833 * we didn't get the timestamp from lineevent_irq_handler().
834 */
835 if (!le->timestamp)
836 ge.timestamp = ktime_get_real_ns();
837 else
838 ge.timestamp = le->timestamp;
839
840 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
841 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
842 int level = gpiod_get_value_cansleep(le->desc);
843 if (level)
844 /* Emit low-to-high event */
845 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
846 else
847 /* Emit high-to-low event */
848 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
849 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
850 /* Emit low-to-high event */
851 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
852 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
853 /* Emit high-to-low event */
854 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
855 } else {
856 return IRQ_NONE;
857 }
858
859 ret = kfifo_put(&le->events, ge);
860 if (ret != 0)
861 wake_up_poll(&le->wait, EPOLLIN);
862
863 return IRQ_HANDLED;
864}
865
866static irqreturn_t lineevent_irq_handler(int irq, void *p)
867{
868 struct lineevent_state *le = p;
869
870 /*
871 * Just store the timestamp in hardirq context so we get it as
872 * close in time as possible to the actual event.
873 */
874 le->timestamp = ktime_get_real_ns();
875
876 return IRQ_WAKE_THREAD;
877}
878
879static int lineevent_create(struct gpio_device *gdev, void __user *ip)
880{
881 struct gpioevent_request eventreq;
882 struct lineevent_state *le;
883 struct gpio_desc *desc;
884 struct file *file;
885 u32 offset;
886 u32 lflags;
887 u32 eflags;
888 int fd;
889 int ret;
890 int irqflags = 0;
891
892 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
893 return -EFAULT;
894
895 le = kzalloc(sizeof(*le), GFP_KERNEL);
896 if (!le)
897 return -ENOMEM;
898 le->gdev = gdev;
899 get_device(&gdev->dev);
900
901 /* Make sure this is terminated */
902 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
903 if (strlen(eventreq.consumer_label)) {
904 le->label = kstrdup(eventreq.consumer_label,
905 GFP_KERNEL);
906 if (!le->label) {
907 ret = -ENOMEM;
908 goto out_free_le;
909 }
910 }
911
912 offset = eventreq.lineoffset;
913 lflags = eventreq.handleflags;
914 eflags = eventreq.eventflags;
915
916 if (offset >= gdev->ngpio) {
917 ret = -EINVAL;
918 goto out_free_label;
919 }
920
921 /* Return an error if a unknown flag is set */
922 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
923 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
924 ret = -EINVAL;
925 goto out_free_label;
926 }
927
928 /* This is just wrong: we don't look for events on output lines */
929 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
930 ret = -EINVAL;
931 goto out_free_label;
932 }
933
934 desc = &gdev->descs[offset];
935 ret = gpiod_request(desc, le->label);
936 if (ret)
937 goto out_free_label;
938 le->desc = desc;
939 le->eflags = eflags;
940
941 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
942 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
943 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
944 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
945 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
946 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
947
948 ret = gpiod_direction_input(desc);
949 if (ret)
950 goto out_free_desc;
951
952 le->irq = gpiod_to_irq(desc);
953 if (le->irq <= 0) {
954 ret = -ENODEV;
955 goto out_free_desc;
956 }
957
958 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
959 irqflags |= IRQF_TRIGGER_RISING;
960 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
961 irqflags |= IRQF_TRIGGER_FALLING;
962 irqflags |= IRQF_ONESHOT;
963
964 INIT_KFIFO(le->events);
965 init_waitqueue_head(&le->wait);
966 mutex_init(&le->read_lock);
967
968 /* Request a thread to read the events */
969 ret = request_threaded_irq(le->irq,
970 lineevent_irq_handler,
971 lineevent_irq_thread,
972 irqflags,
973 le->label,
974 le);
975 if (ret)
976 goto out_free_desc;
977
978 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
979 if (fd < 0) {
980 ret = fd;
981 goto out_free_irq;
982 }
983
984 file = anon_inode_getfile("gpio-event",
985 &lineevent_fileops,
986 le,
987 O_RDONLY | O_CLOEXEC);
988 if (IS_ERR(file)) {
989 ret = PTR_ERR(file);
990 goto out_put_unused_fd;
991 }
992
993 eventreq.fd = fd;
994 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
995 /*
996 * fput() will trigger the release() callback, so do not go onto
997 * the regular error cleanup path here.
998 */
999 fput(file);
1000 put_unused_fd(fd);
1001 return -EFAULT;
1002 }
1003
1004 fd_install(fd, file);
1005
1006 return 0;
1007
1008out_put_unused_fd:
1009 put_unused_fd(fd);
1010out_free_irq:
1011 free_irq(le->irq, le);
1012out_free_desc:
1013 gpiod_free(le->desc);
1014out_free_label:
1015 kfree(le->label);
1016out_free_le:
1017 kfree(le);
1018 put_device(&gdev->dev);
1019 return ret;
1020}
1021
1022/*
1023 * gpio_ioctl() - ioctl handler for the GPIO chardev
1024 */
1025static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1026{
1027 struct gpio_device *gdev = filp->private_data;
1028 struct gpio_chip *chip = gdev->chip;
1029 void __user *ip = (void __user *)arg;
1030
1031 /* We fail any subsequent ioctl():s when the chip is gone */
1032 if (!chip)
1033 return -ENODEV;
1034
1035 /* Fill in the struct and pass to userspace */
1036 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1037 struct gpiochip_info chipinfo;
1038
1039 memset(&chipinfo, 0, sizeof(chipinfo));
1040
1041 strncpy(chipinfo.name, dev_name(&gdev->dev),
1042 sizeof(chipinfo.name));
1043 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1044 strncpy(chipinfo.label, gdev->label,
1045 sizeof(chipinfo.label));
1046 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1047 chipinfo.lines = gdev->ngpio;
1048 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1049 return -EFAULT;
1050 return 0;
1051 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1052 struct gpioline_info lineinfo;
1053 struct gpio_desc *desc;
1054
1055 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1056 return -EFAULT;
1057 if (lineinfo.line_offset >= gdev->ngpio)
1058 return -EINVAL;
1059
1060 desc = &gdev->descs[lineinfo.line_offset];
1061 if (desc->name) {
1062 strncpy(lineinfo.name, desc->name,
1063 sizeof(lineinfo.name));
1064 lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1065 } else {
1066 lineinfo.name[0] = '\0';
1067 }
1068 if (desc->label) {
1069 strncpy(lineinfo.consumer, desc->label,
1070 sizeof(lineinfo.consumer));
1071 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1072 } else {
1073 lineinfo.consumer[0] = '\0';
1074 }
1075
1076 /*
1077 * Userspace only need to know that the kernel is using
1078 * this GPIO so it can't use it.
1079 */
1080 lineinfo.flags = 0;
1081 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1082 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1083 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1084 test_bit(FLAG_EXPORT, &desc->flags) ||
1085 test_bit(FLAG_SYSFS, &desc->flags))
1086 lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1087 if (test_bit(FLAG_IS_OUT, &desc->flags))
1088 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1089 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1090 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1091 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1092 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
1093 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1094 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
1095
1096 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1097 return -EFAULT;
1098 return 0;
1099 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1100 return linehandle_create(gdev, ip);
1101 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1102 return lineevent_create(gdev, ip);
1103 }
1104 return -EINVAL;
1105}
1106
1107#ifdef CONFIG_COMPAT
1108static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1109 unsigned long arg)
1110{
1111 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1112}
1113#endif
1114
1115/**
1116 * gpio_chrdev_open() - open the chardev for ioctl operations
1117 * @inode: inode for this chardev
1118 * @filp: file struct for storing private data
1119 * Returns 0 on success
1120 */
1121static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1122{
1123 struct gpio_device *gdev = container_of(inode->i_cdev,
1124 struct gpio_device, chrdev);
1125
1126 /* Fail on open if the backing gpiochip is gone */
1127 if (!gdev->chip)
1128 return -ENODEV;
1129 get_device(&gdev->dev);
1130 filp->private_data = gdev;
1131
1132 return nonseekable_open(inode, filp);
1133}
1134
1135/**
1136 * gpio_chrdev_release() - close chardev after ioctl operations
1137 * @inode: inode for this chardev
1138 * @filp: file struct for storing private data
1139 * Returns 0 on success
1140 */
1141static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1142{
1143 struct gpio_device *gdev = container_of(inode->i_cdev,
1144 struct gpio_device, chrdev);
1145
1146 put_device(&gdev->dev);
1147 return 0;
1148}
1149
1150
1151static const struct file_operations gpio_fileops = {
1152 .release = gpio_chrdev_release,
1153 .open = gpio_chrdev_open,
1154 .owner = THIS_MODULE,
1155 .llseek = no_llseek,
1156 .unlocked_ioctl = gpio_ioctl,
1157#ifdef CONFIG_COMPAT
1158 .compat_ioctl = gpio_ioctl_compat,
1159#endif
1160};
1161
1162static void gpiodevice_release(struct device *dev)
1163{
1164 struct gpio_device *gdev = dev_get_drvdata(dev);
1165
1166 list_del(&gdev->list);
1167 ida_simple_remove(&gpio_ida, gdev->id);
1168 kfree_const(gdev->label);
1169 kfree(gdev->descs);
1170 kfree(gdev);
1171}
1172
1173static int gpiochip_setup_dev(struct gpio_device *gdev)
1174{
1175 int status;
1176
1177 cdev_init(&gdev->chrdev, &gpio_fileops);
1178 gdev->chrdev.owner = THIS_MODULE;
1179 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1180
1181 status = cdev_device_add(&gdev->chrdev, &gdev->dev);
1182 if (status)
1183 return status;
1184
1185 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1186 MAJOR(gpio_devt), gdev->id);
1187
1188 status = gpiochip_sysfs_register(gdev);
1189 if (status)
1190 goto err_remove_device;
1191
1192 /* From this point, the .release() function cleans up gpio_device */
1193 gdev->dev.release = gpiodevice_release;
1194 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1195 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1196 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1197
1198 return 0;
1199
1200err_remove_device:
1201 cdev_device_del(&gdev->chrdev, &gdev->dev);
1202 return status;
1203}
1204
1205static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1206{
1207 struct gpio_desc *desc;
1208 int rv;
1209
1210 desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1211 if (IS_ERR(desc)) {
1212 pr_err("%s: unable to get GPIO desc: %ld\n",
1213 __func__, PTR_ERR(desc));
1214 return;
1215 }
1216
1217 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1218 return;
1219
1220 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1221 if (rv)
1222 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1223 __func__, chip->label, hog->chip_hwnum, rv);
1224}
1225
1226static void machine_gpiochip_add(struct gpio_chip *chip)
1227{
1228 struct gpiod_hog *hog;
1229
1230 mutex_lock(&gpio_machine_hogs_mutex);
1231
1232 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1233 if (!strcmp(chip->label, hog->chip_label))
1234 gpiochip_machine_hog(chip, hog);
1235 }
1236
1237 mutex_unlock(&gpio_machine_hogs_mutex);
1238}
1239
1240static void gpiochip_setup_devs(void)
1241{
1242 struct gpio_device *gdev;
1243 int err;
1244
1245 list_for_each_entry(gdev, &gpio_devices, list) {
1246 err = gpiochip_setup_dev(gdev);
1247 if (err)
1248 pr_err("%s: Failed to initialize gpio device (%d)\n",
1249 dev_name(&gdev->dev), err);
1250 }
1251}
1252
1253int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1254 struct lock_class_key *lock_key,
1255 struct lock_class_key *request_key)
1256{
1257 unsigned long flags;
1258 int status = 0;
1259 unsigned i;
1260 int base = chip->base;
1261 struct gpio_device *gdev;
1262
1263 /*
1264 * First: allocate and populate the internal stat container, and
1265 * set up the struct device.
1266 */
1267 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1268 if (!gdev)
1269 return -ENOMEM;
1270 gdev->dev.bus = &gpio_bus_type;
1271 gdev->chip = chip;
1272 chip->gpiodev = gdev;
1273 if (chip->parent) {
1274 gdev->dev.parent = chip->parent;
1275 gdev->dev.of_node = chip->parent->of_node;
1276 }
1277
1278#ifdef CONFIG_OF_GPIO
1279 /* If the gpiochip has an assigned OF node this takes precedence */
1280 if (chip->of_node)
1281 gdev->dev.of_node = chip->of_node;
1282 else
1283 chip->of_node = gdev->dev.of_node;
1284#endif
1285
1286 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1287 if (gdev->id < 0) {
1288 status = gdev->id;
1289 goto err_free_gdev;
1290 }
1291 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1292 device_initialize(&gdev->dev);
1293 dev_set_drvdata(&gdev->dev, gdev);
1294 if (chip->parent && chip->parent->driver)
1295 gdev->owner = chip->parent->driver->owner;
1296 else if (chip->owner)
1297 /* TODO: remove chip->owner */
1298 gdev->owner = chip->owner;
1299 else
1300 gdev->owner = THIS_MODULE;
1301
1302 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1303 if (!gdev->descs) {
1304 status = -ENOMEM;
1305 goto err_free_ida;
1306 }
1307
1308 if (chip->ngpio == 0) {
1309 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1310 status = -EINVAL;
1311 goto err_free_descs;
1312 }
1313
1314 if (chip->ngpio > FASTPATH_NGPIO)
1315 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1316 chip->ngpio, FASTPATH_NGPIO);
1317
1318 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1319 if (!gdev->label) {
1320 status = -ENOMEM;
1321 goto err_free_descs;
1322 }
1323
1324 gdev->ngpio = chip->ngpio;
1325 gdev->data = data;
1326
1327 spin_lock_irqsave(&gpio_lock, flags);
1328
1329 /*
1330 * TODO: this allocates a Linux GPIO number base in the global
1331 * GPIO numberspace for this chip. In the long run we want to
1332 * get *rid* of this numberspace and use only descriptors, but
1333 * it may be a pipe dream. It will not happen before we get rid
1334 * of the sysfs interface anyways.
1335 */
1336 if (base < 0) {
1337 base = gpiochip_find_base(chip->ngpio);
1338 if (base < 0) {
1339 status = base;
1340 spin_unlock_irqrestore(&gpio_lock, flags);
1341 goto err_free_label;
1342 }
1343 /*
1344 * TODO: it should not be necessary to reflect the assigned
1345 * base outside of the GPIO subsystem. Go over drivers and
1346 * see if anyone makes use of this, else drop this and assign
1347 * a poison instead.
1348 */
1349 chip->base = base;
1350 }
1351 gdev->base = base;
1352
1353 status = gpiodev_add_to_list(gdev);
1354 if (status) {
1355 spin_unlock_irqrestore(&gpio_lock, flags);
1356 goto err_free_label;
1357 }
1358
1359 spin_unlock_irqrestore(&gpio_lock, flags);
1360
1361 for (i = 0; i < chip->ngpio; i++)
1362 gdev->descs[i].gdev = gdev;
1363
1364#ifdef CONFIG_PINCTRL
1365 INIT_LIST_HEAD(&gdev->pin_ranges);
1366#endif
1367
1368 status = gpiochip_set_desc_names(chip);
1369 if (status)
1370 goto err_remove_from_list;
1371
1372 status = gpiochip_irqchip_init_valid_mask(chip);
1373 if (status)
1374 goto err_remove_from_list;
1375
1376 status = gpiochip_alloc_valid_mask(chip);
1377 if (status)
1378 goto err_remove_irqchip_mask;
1379
1380 status = gpiochip_add_irqchip(chip, lock_key, request_key);
1381 if (status)
1382 goto err_remove_chip;
1383
1384 status = of_gpiochip_add(chip);
1385 if (status)
1386 goto err_remove_chip;
1387
1388 status = gpiochip_init_valid_mask(chip);
1389 if (status)
1390 goto err_remove_chip;
1391
1392 for (i = 0; i < chip->ngpio; i++) {
1393 struct gpio_desc *desc = &gdev->descs[i];
1394
1395 if (chip->get_direction && gpiochip_line_is_valid(chip, i))
1396 desc->flags = !chip->get_direction(chip, i) ?
1397 (1 << FLAG_IS_OUT) : 0;
1398 else
1399 desc->flags = !chip->direction_input ?
1400 (1 << FLAG_IS_OUT) : 0;
1401 }
1402
1403 acpi_gpiochip_add(chip);
1404
1405 machine_gpiochip_add(chip);
1406
1407 /*
1408 * By first adding the chardev, and then adding the device,
1409 * we get a device node entry in sysfs under
1410 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1411 * coldplug of device nodes and other udev business.
1412 * We can do this only if gpiolib has been initialized.
1413 * Otherwise, defer until later.
1414 */
1415 if (gpiolib_initialized) {
1416 status = gpiochip_setup_dev(gdev);
1417 if (status)
1418 goto err_remove_chip;
1419 }
1420 return 0;
1421
1422err_remove_chip:
1423 acpi_gpiochip_remove(chip);
1424 gpiochip_free_hogs(chip);
1425 of_gpiochip_remove(chip);
1426 gpiochip_free_valid_mask(chip);
1427err_remove_irqchip_mask:
1428 gpiochip_irqchip_free_valid_mask(chip);
1429err_remove_from_list:
1430 spin_lock_irqsave(&gpio_lock, flags);
1431 list_del(&gdev->list);
1432 spin_unlock_irqrestore(&gpio_lock, flags);
1433err_free_label:
1434 kfree_const(gdev->label);
1435err_free_descs:
1436 kfree(gdev->descs);
1437err_free_ida:
1438 ida_simple_remove(&gpio_ida, gdev->id);
1439err_free_gdev:
1440 /* failures here can mean systems won't boot... */
1441 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1442 gdev->base, gdev->base + gdev->ngpio - 1,
1443 chip->label ? : "generic", status);
1444 kfree(gdev);
1445 return status;
1446}
1447EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1448
1449/**
1450 * gpiochip_get_data() - get per-subdriver data for the chip
1451 * @chip: GPIO chip
1452 *
1453 * Returns:
1454 * The per-subdriver data for the chip.
1455 */
1456void *gpiochip_get_data(struct gpio_chip *chip)
1457{
1458 return chip->gpiodev->data;
1459}
1460EXPORT_SYMBOL_GPL(gpiochip_get_data);
1461
1462/**
1463 * gpiochip_remove() - unregister a gpio_chip
1464 * @chip: the chip to unregister
1465 *
1466 * A gpio_chip with any GPIOs still requested may not be removed.
1467 */
1468void gpiochip_remove(struct gpio_chip *chip)
1469{
1470 struct gpio_device *gdev = chip->gpiodev;
1471 struct gpio_desc *desc;
1472 unsigned long flags;
1473 unsigned i;
1474 bool requested = false;
1475
1476 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1477 gpiochip_sysfs_unregister(gdev);
1478 gpiochip_free_hogs(chip);
1479 /* Numb the device, cancelling all outstanding operations */
1480 gdev->chip = NULL;
1481 gpiochip_irqchip_remove(chip);
1482 acpi_gpiochip_remove(chip);
1483 gpiochip_remove_pin_ranges(chip);
1484 of_gpiochip_remove(chip);
1485 gpiochip_free_valid_mask(chip);
1486 /*
1487 * We accept no more calls into the driver from this point, so
1488 * NULL the driver data pointer
1489 */
1490 gdev->data = NULL;
1491
1492 spin_lock_irqsave(&gpio_lock, flags);
1493 for (i = 0; i < gdev->ngpio; i++) {
1494 desc = &gdev->descs[i];
1495 if (test_bit(FLAG_REQUESTED, &desc->flags))
1496 requested = true;
1497 }
1498 spin_unlock_irqrestore(&gpio_lock, flags);
1499
1500 if (requested)
1501 dev_crit(&gdev->dev,
1502 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1503
1504 /*
1505 * The gpiochip side puts its use of the device to rest here:
1506 * if there are no userspace clients, the chardev and device will
1507 * be removed, else it will be dangling until the last user is
1508 * gone.
1509 */
1510 cdev_device_del(&gdev->chrdev, &gdev->dev);
1511 put_device(&gdev->dev);
1512}
1513EXPORT_SYMBOL_GPL(gpiochip_remove);
1514
1515static void devm_gpio_chip_release(struct device *dev, void *res)
1516{
1517 struct gpio_chip *chip = *(struct gpio_chip **)res;
1518
1519 gpiochip_remove(chip);
1520}
1521
1522/**
1523 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1524 * @dev: pointer to the device that gpio_chip belongs to.
1525 * @chip: the chip to register, with chip->base initialized
1526 * @data: driver-private data associated with this chip
1527 *
1528 * Context: potentially before irqs will work
1529 *
1530 * The gpio chip automatically be released when the device is unbound.
1531 *
1532 * Returns:
1533 * A negative errno if the chip can't be registered, such as because the
1534 * chip->base is invalid or already associated with a different chip.
1535 * Otherwise it returns zero as a success code.
1536 */
1537int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1538 void *data)
1539{
1540 struct gpio_chip **ptr;
1541 int ret;
1542
1543 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1544 GFP_KERNEL);
1545 if (!ptr)
1546 return -ENOMEM;
1547
1548 ret = gpiochip_add_data(chip, data);
1549 if (ret < 0) {
1550 devres_free(ptr);
1551 return ret;
1552 }
1553
1554 *ptr = chip;
1555 devres_add(dev, ptr);
1556
1557 return 0;
1558}
1559EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1560
1561/**
1562 * gpiochip_find() - iterator for locating a specific gpio_chip
1563 * @data: data to pass to match function
1564 * @match: Callback function to check gpio_chip
1565 *
1566 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1567 * determined by a user supplied @match callback. The callback should return
1568 * 0 if the device doesn't match and non-zero if it does. If the callback is
1569 * non-zero, this function will return to the caller and not iterate over any
1570 * more gpio_chips.
1571 */
1572struct gpio_chip *gpiochip_find(void *data,
1573 int (*match)(struct gpio_chip *chip,
1574 void *data))
1575{
1576 struct gpio_device *gdev;
1577 struct gpio_chip *chip = NULL;
1578 unsigned long flags;
1579
1580 spin_lock_irqsave(&gpio_lock, flags);
1581 list_for_each_entry(gdev, &gpio_devices, list)
1582 if (gdev->chip && match(gdev->chip, data)) {
1583 chip = gdev->chip;
1584 break;
1585 }
1586
1587 spin_unlock_irqrestore(&gpio_lock, flags);
1588
1589 return chip;
1590}
1591EXPORT_SYMBOL_GPL(gpiochip_find);
1592
1593static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1594{
1595 const char *name = data;
1596
1597 return !strcmp(chip->label, name);
1598}
1599
1600static struct gpio_chip *find_chip_by_name(const char *name)
1601{
1602 return gpiochip_find((void *)name, gpiochip_match_name);
1603}
1604
1605#ifdef CONFIG_GPIOLIB_IRQCHIP
1606
1607/*
1608 * The following is irqchip helper code for gpiochips.
1609 */
1610
1611static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
1612{
1613 if (!gpiochip->irq.need_valid_mask)
1614 return 0;
1615
1616 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
1617 if (!gpiochip->irq.valid_mask)
1618 return -ENOMEM;
1619
1620 return 0;
1621}
1622
1623static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1624{
1625 kfree(gpiochip->irq.valid_mask);
1626 gpiochip->irq.valid_mask = NULL;
1627}
1628
1629bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1630 unsigned int offset)
1631{
1632 if (!gpiochip_line_is_valid(gpiochip, offset))
1633 return false;
1634 /* No mask means all valid */
1635 if (likely(!gpiochip->irq.valid_mask))
1636 return true;
1637 return test_bit(offset, gpiochip->irq.valid_mask);
1638}
1639EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1640
1641/**
1642 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1643 * @gpiochip: the gpiochip to set the irqchip chain to
1644 * @parent_irq: the irq number corresponding to the parent IRQ for this
1645 * chained irqchip
1646 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1647 * coming out of the gpiochip. If the interrupt is nested rather than
1648 * cascaded, pass NULL in this handler argument
1649 */
1650static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
1651 unsigned int parent_irq,
1652 irq_flow_handler_t parent_handler)
1653{
1654 if (!gpiochip->irq.domain) {
1655 chip_err(gpiochip, "called %s before setting up irqchip\n",
1656 __func__);
1657 return;
1658 }
1659
1660 if (parent_handler) {
1661 if (gpiochip->can_sleep) {
1662 chip_err(gpiochip,
1663 "you cannot have chained interrupts on a chip that may sleep\n");
1664 return;
1665 }
1666 /*
1667 * The parent irqchip is already using the chip_data for this
1668 * irqchip, so our callbacks simply use the handler_data.
1669 */
1670 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1671 gpiochip);
1672
1673 gpiochip->irq.parent_irq = parent_irq;
1674 gpiochip->irq.parents = &gpiochip->irq.parent_irq;
1675 gpiochip->irq.num_parents = 1;
1676 }
1677}
1678
1679/**
1680 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1681 * @gpiochip: the gpiochip to set the irqchip chain to
1682 * @irqchip: the irqchip to chain to the gpiochip
1683 * @parent_irq: the irq number corresponding to the parent IRQ for this
1684 * chained irqchip
1685 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1686 * coming out of the gpiochip.
1687 */
1688void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1689 struct irq_chip *irqchip,
1690 unsigned int parent_irq,
1691 irq_flow_handler_t parent_handler)
1692{
1693 if (gpiochip->irq.threaded) {
1694 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1695 return;
1696 }
1697
1698 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1699}
1700EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1701
1702/**
1703 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1704 * @gpiochip: the gpiochip to set the irqchip nested handler to
1705 * @irqchip: the irqchip to nest to the gpiochip
1706 * @parent_irq: the irq number corresponding to the parent IRQ for this
1707 * nested irqchip
1708 */
1709void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1710 struct irq_chip *irqchip,
1711 unsigned int parent_irq)
1712{
1713 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1714}
1715EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1716
1717/**
1718 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1719 * @d: the irqdomain used by this irqchip
1720 * @irq: the global irq number used by this GPIO irqchip irq
1721 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1722 *
1723 * This function will set up the mapping for a certain IRQ line on a
1724 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1725 * stored inside the gpiochip.
1726 */
1727int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1728 irq_hw_number_t hwirq)
1729{
1730 struct gpio_chip *chip = d->host_data;
1731 int err = 0;
1732
1733 if (!gpiochip_irqchip_irq_valid(chip, hwirq))
1734 return -ENXIO;
1735
1736 irq_set_chip_data(irq, chip);
1737 /*
1738 * This lock class tells lockdep that GPIO irqs are in a different
1739 * category than their parents, so it won't report false recursion.
1740 */
1741 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
1742 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
1743 /* Chips that use nested thread handlers have them marked */
1744 if (chip->irq.threaded)
1745 irq_set_nested_thread(irq, 1);
1746 irq_set_noprobe(irq);
1747
1748 if (chip->irq.num_parents == 1)
1749 err = irq_set_parent(irq, chip->irq.parents[0]);
1750 else if (chip->irq.map)
1751 err = irq_set_parent(irq, chip->irq.map[hwirq]);
1752
1753 if (err < 0)
1754 return err;
1755
1756 /*
1757 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1758 * is passed as default type.
1759 */
1760 if (chip->irq.default_type != IRQ_TYPE_NONE)
1761 irq_set_irq_type(irq, chip->irq.default_type);
1762
1763 return 0;
1764}
1765EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1766
1767void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1768{
1769 struct gpio_chip *chip = d->host_data;
1770
1771 if (chip->irq.threaded)
1772 irq_set_nested_thread(irq, 0);
1773 irq_set_chip_and_handler(irq, NULL, NULL);
1774 irq_set_chip_data(irq, NULL);
1775}
1776EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1777
1778static const struct irq_domain_ops gpiochip_domain_ops = {
1779 .map = gpiochip_irq_map,
1780 .unmap = gpiochip_irq_unmap,
1781 /* Virtually all GPIO irqchips are twocell:ed */
1782 .xlate = irq_domain_xlate_twocell,
1783};
1784
1785/**
1786 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1787 * @domain: The IRQ domain used by this IRQ chip
1788 * @data: Outermost irq_data associated with the IRQ
1789 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1790 *
1791 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1792 * used as the activate function for the &struct irq_domain_ops. The host_data
1793 * for the IRQ domain must be the &struct gpio_chip.
1794 */
1795int gpiochip_irq_domain_activate(struct irq_domain *domain,
1796 struct irq_data *data, bool reserve)
1797{
1798 struct gpio_chip *chip = domain->host_data;
1799
1800 return gpiochip_lock_as_irq(chip, data->hwirq);
1801}
1802EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1803
1804/**
1805 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1806 * @domain: The IRQ domain used by this IRQ chip
1807 * @data: Outermost irq_data associated with the IRQ
1808 *
1809 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1810 * be used as the deactivate function for the &struct irq_domain_ops. The
1811 * host_data for the IRQ domain must be the &struct gpio_chip.
1812 */
1813void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1814 struct irq_data *data)
1815{
1816 struct gpio_chip *chip = domain->host_data;
1817
1818 return gpiochip_unlock_as_irq(chip, data->hwirq);
1819}
1820EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1821
1822static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1823{
1824 if (!gpiochip_irqchip_irq_valid(chip, offset))
1825 return -ENXIO;
1826
1827 return irq_create_mapping(chip->irq.domain, offset);
1828}
1829
1830static int gpiochip_irq_reqres(struct irq_data *d)
1831{
1832 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1833
1834 return gpiochip_reqres_irq(chip, d->hwirq);
1835}
1836
1837static void gpiochip_irq_relres(struct irq_data *d)
1838{
1839 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1840
1841 gpiochip_relres_irq(chip, d->hwirq);
1842}
1843
1844static void gpiochip_irq_enable(struct irq_data *d)
1845{
1846 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1847
1848 gpiochip_enable_irq(chip, d->hwirq);
1849 if (chip->irq.irq_enable)
1850 chip->irq.irq_enable(d);
1851 else
1852 chip->irq.chip->irq_unmask(d);
1853}
1854
1855static void gpiochip_irq_disable(struct irq_data *d)
1856{
1857 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1858
1859 if (chip->irq.irq_disable)
1860 chip->irq.irq_disable(d);
1861 else
1862 chip->irq.chip->irq_mask(d);
1863 gpiochip_disable_irq(chip, d->hwirq);
1864}
1865
1866static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
1867{
1868 struct irq_chip *irqchip = gpiochip->irq.chip;
1869
1870 if (!irqchip->irq_request_resources &&
1871 !irqchip->irq_release_resources) {
1872 irqchip->irq_request_resources = gpiochip_irq_reqres;
1873 irqchip->irq_release_resources = gpiochip_irq_relres;
1874 }
1875 if (WARN_ON(gpiochip->irq.irq_enable))
1876 return;
1877 /* Check if the irqchip already has this hook... */
1878 if (irqchip->irq_enable == gpiochip_irq_enable) {
1879 /*
1880 * ...and if so, give a gentle warning that this is bad
1881 * practice.
1882 */
1883 chip_info(gpiochip,
1884 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1885 return;
1886 }
1887 gpiochip->irq.irq_enable = irqchip->irq_enable;
1888 gpiochip->irq.irq_disable = irqchip->irq_disable;
1889 irqchip->irq_enable = gpiochip_irq_enable;
1890 irqchip->irq_disable = gpiochip_irq_disable;
1891}
1892
1893/**
1894 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1895 * @gpiochip: the GPIO chip to add the IRQ chip to
1896 * @lock_key: lockdep class for IRQ lock
1897 * @request_key: lockdep class for IRQ request
1898 */
1899static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
1900 struct lock_class_key *lock_key,
1901 struct lock_class_key *request_key)
1902{
1903 struct irq_chip *irqchip = gpiochip->irq.chip;
1904 const struct irq_domain_ops *ops;
1905 struct device_node *np;
1906 unsigned int type;
1907 unsigned int i;
1908
1909 if (!irqchip)
1910 return 0;
1911
1912 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
1913 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
1914 return -EINVAL;
1915 }
1916
1917 np = gpiochip->gpiodev->dev.of_node;
1918 type = gpiochip->irq.default_type;
1919
1920 /*
1921 * Specifying a default trigger is a terrible idea if DT or ACPI is
1922 * used to configure the interrupts, as you may end up with
1923 * conflicting triggers. Tell the user, and reset to NONE.
1924 */
1925 if (WARN(np && type != IRQ_TYPE_NONE,
1926 "%s: Ignoring %u default trigger\n", np->full_name, type))
1927 type = IRQ_TYPE_NONE;
1928
1929 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
1930 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
1931 "Ignoring %u default trigger\n", type);
1932 type = IRQ_TYPE_NONE;
1933 }
1934
1935 gpiochip->to_irq = gpiochip_to_irq;
1936 gpiochip->irq.default_type = type;
1937 gpiochip->irq.lock_key = lock_key;
1938 gpiochip->irq.request_key = request_key;
1939
1940 if (gpiochip->irq.domain_ops)
1941 ops = gpiochip->irq.domain_ops;
1942 else
1943 ops = &gpiochip_domain_ops;
1944
1945 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
1946 gpiochip->irq.first,
1947 ops, gpiochip);
1948 if (!gpiochip->irq.domain)
1949 return -EINVAL;
1950
1951 if (gpiochip->irq.parent_handler) {
1952 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
1953
1954 for (i = 0; i < gpiochip->irq.num_parents; i++) {
1955 /*
1956 * The parent IRQ chip is already using the chip_data
1957 * for this IRQ chip, so our callbacks simply use the
1958 * handler_data.
1959 */
1960 irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
1961 gpiochip->irq.parent_handler,
1962 data);
1963 }
1964 }
1965
1966 gpiochip_set_irq_hooks(gpiochip);
1967
1968 acpi_gpiochip_request_interrupts(gpiochip);
1969
1970 return 0;
1971}
1972
1973/**
1974 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1975 * @gpiochip: the gpiochip to remove the irqchip from
1976 *
1977 * This is called only from gpiochip_remove()
1978 */
1979static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1980{
1981 struct irq_chip *irqchip = gpiochip->irq.chip;
1982 unsigned int offset;
1983
1984 acpi_gpiochip_free_interrupts(gpiochip);
1985
1986 if (irqchip && gpiochip->irq.parent_handler) {
1987 struct gpio_irq_chip *irq = &gpiochip->irq;
1988 unsigned int i;
1989
1990 for (i = 0; i < irq->num_parents; i++)
1991 irq_set_chained_handler_and_data(irq->parents[i],
1992 NULL, NULL);
1993 }
1994
1995 /* Remove all IRQ mappings and delete the domain */
1996 if (gpiochip->irq.domain) {
1997 unsigned int irq;
1998
1999 for (offset = 0; offset < gpiochip->ngpio; offset++) {
2000 if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
2001 continue;
2002
2003 irq = irq_find_mapping(gpiochip->irq.domain, offset);
2004 irq_dispose_mapping(irq);
2005 }
2006
2007 irq_domain_remove(gpiochip->irq.domain);
2008 }
2009
2010 if (irqchip) {
2011 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2012 irqchip->irq_request_resources = NULL;
2013 irqchip->irq_release_resources = NULL;
2014 }
2015 if (irqchip->irq_enable == gpiochip_irq_enable) {
2016 irqchip->irq_enable = gpiochip->irq.irq_enable;
2017 irqchip->irq_disable = gpiochip->irq.irq_disable;
2018 }
2019 }
2020 gpiochip->irq.irq_enable = NULL;
2021 gpiochip->irq.irq_disable = NULL;
2022 gpiochip->irq.chip = NULL;
2023
2024 gpiochip_irqchip_free_valid_mask(gpiochip);
2025}
2026
2027/**
2028 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2029 * @gpiochip: the gpiochip to add the irqchip to
2030 * @irqchip: the irqchip to add to the gpiochip
2031 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2032 * allocate gpiochip irqs from
2033 * @handler: the irq handler to use (often a predefined irq core function)
2034 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2035 * to have the core avoid setting up any default type in the hardware.
2036 * @threaded: whether this irqchip uses a nested thread handler
2037 * @lock_key: lockdep class for IRQ lock
2038 * @request_key: lockdep class for IRQ request
2039 *
2040 * This function closely associates a certain irqchip with a certain
2041 * gpiochip, providing an irq domain to translate the local IRQs to
2042 * global irqs in the gpiolib core, and making sure that the gpiochip
2043 * is passed as chip data to all related functions. Driver callbacks
2044 * need to use gpiochip_get_data() to get their local state containers back
2045 * from the gpiochip passed as chip data. An irqdomain will be stored
2046 * in the gpiochip that shall be used by the driver to handle IRQ number
2047 * translation. The gpiochip will need to be initialized and registered
2048 * before calling this function.
2049 *
2050 * This function will handle two cell:ed simple IRQs and assumes all
2051 * the pins on the gpiochip can generate a unique IRQ. Everything else
2052 * need to be open coded.
2053 */
2054int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2055 struct irq_chip *irqchip,
2056 unsigned int first_irq,
2057 irq_flow_handler_t handler,
2058 unsigned int type,
2059 bool threaded,
2060 struct lock_class_key *lock_key,
2061 struct lock_class_key *request_key)
2062{
2063 struct device_node *of_node;
2064
2065 if (!gpiochip || !irqchip)
2066 return -EINVAL;
2067
2068 if (!gpiochip->parent) {
2069 pr_err("missing gpiochip .dev parent pointer\n");
2070 return -EINVAL;
2071 }
2072 gpiochip->irq.threaded = threaded;
2073 of_node = gpiochip->parent->of_node;
2074#ifdef CONFIG_OF_GPIO
2075 /*
2076 * If the gpiochip has an assigned OF node this takes precedence
2077 * FIXME: get rid of this and use gpiochip->parent->of_node
2078 * everywhere
2079 */
2080 if (gpiochip->of_node)
2081 of_node = gpiochip->of_node;
2082#endif
2083 /*
2084 * Specifying a default trigger is a terrible idea if DT or ACPI is
2085 * used to configure the interrupts, as you may end-up with
2086 * conflicting triggers. Tell the user, and reset to NONE.
2087 */
2088 if (WARN(of_node && type != IRQ_TYPE_NONE,
2089 "%pOF: Ignoring %d default trigger\n", of_node, type))
2090 type = IRQ_TYPE_NONE;
2091 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2092 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2093 "Ignoring %d default trigger\n", type);
2094 type = IRQ_TYPE_NONE;
2095 }
2096
2097 gpiochip->irq.chip = irqchip;
2098 gpiochip->irq.handler = handler;
2099 gpiochip->irq.default_type = type;
2100 gpiochip->to_irq = gpiochip_to_irq;
2101 gpiochip->irq.lock_key = lock_key;
2102 gpiochip->irq.request_key = request_key;
2103 gpiochip->irq.domain = irq_domain_add_simple(of_node,
2104 gpiochip->ngpio, first_irq,
2105 &gpiochip_domain_ops, gpiochip);
2106 if (!gpiochip->irq.domain) {
2107 gpiochip->irq.chip = NULL;
2108 return -EINVAL;
2109 }
2110
2111 gpiochip_set_irq_hooks(gpiochip);
2112
2113 acpi_gpiochip_request_interrupts(gpiochip);
2114
2115 return 0;
2116}
2117EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2118
2119#else /* CONFIG_GPIOLIB_IRQCHIP */
2120
2121static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2122 struct lock_class_key *lock_key,
2123 struct lock_class_key *request_key)
2124{
2125 return 0;
2126}
2127
2128static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2129static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2130{
2131 return 0;
2132}
2133static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2134{ }
2135
2136#endif /* CONFIG_GPIOLIB_IRQCHIP */
2137
2138/**
2139 * gpiochip_generic_request() - request the gpio function for a pin
2140 * @chip: the gpiochip owning the GPIO
2141 * @offset: the offset of the GPIO to request for GPIO function
2142 */
2143int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2144{
2145 return pinctrl_gpio_request(chip->gpiodev->base + offset);
2146}
2147EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2148
2149/**
2150 * gpiochip_generic_free() - free the gpio function from a pin
2151 * @chip: the gpiochip to request the gpio function for
2152 * @offset: the offset of the GPIO to free from GPIO function
2153 */
2154void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2155{
2156 pinctrl_gpio_free(chip->gpiodev->base + offset);
2157}
2158EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2159
2160/**
2161 * gpiochip_generic_config() - apply configuration for a pin
2162 * @chip: the gpiochip owning the GPIO
2163 * @offset: the offset of the GPIO to apply the configuration
2164 * @config: the configuration to be applied
2165 */
2166int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2167 unsigned long config)
2168{
2169 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2170}
2171EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2172
2173#ifdef CONFIG_PINCTRL
2174
2175/**
2176 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2177 * @chip: the gpiochip to add the range for
2178 * @pctldev: the pin controller to map to
2179 * @gpio_offset: the start offset in the current gpio_chip number space
2180 * @pin_group: name of the pin group inside the pin controller
2181 *
2182 * Calling this function directly from a DeviceTree-supported
2183 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2184 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2185 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2186 */
2187int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2188 struct pinctrl_dev *pctldev,
2189 unsigned int gpio_offset, const char *pin_group)
2190{
2191 struct gpio_pin_range *pin_range;
2192 struct gpio_device *gdev = chip->gpiodev;
2193 int ret;
2194
2195 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2196 if (!pin_range) {
2197 chip_err(chip, "failed to allocate pin ranges\n");
2198 return -ENOMEM;
2199 }
2200
2201 /* Use local offset as range ID */
2202 pin_range->range.id = gpio_offset;
2203 pin_range->range.gc = chip;
2204 pin_range->range.name = chip->label;
2205 pin_range->range.base = gdev->base + gpio_offset;
2206 pin_range->pctldev = pctldev;
2207
2208 ret = pinctrl_get_group_pins(pctldev, pin_group,
2209 &pin_range->range.pins,
2210 &pin_range->range.npins);
2211 if (ret < 0) {
2212 kfree(pin_range);
2213 return ret;
2214 }
2215
2216 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2217
2218 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2219 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2220 pinctrl_dev_get_devname(pctldev), pin_group);
2221
2222 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2223
2224 return 0;
2225}
2226EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2227
2228/**
2229 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2230 * @chip: the gpiochip to add the range for
2231 * @pinctl_name: the dev_name() of the pin controller to map to
2232 * @gpio_offset: the start offset in the current gpio_chip number space
2233 * @pin_offset: the start offset in the pin controller number space
2234 * @npins: the number of pins from the offset of each pin space (GPIO and
2235 * pin controller) to accumulate in this range
2236 *
2237 * Returns:
2238 * 0 on success, or a negative error-code on failure.
2239 *
2240 * Calling this function directly from a DeviceTree-supported
2241 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2242 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2243 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2244 */
2245int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2246 unsigned int gpio_offset, unsigned int pin_offset,
2247 unsigned int npins)
2248{
2249 struct gpio_pin_range *pin_range;
2250 struct gpio_device *gdev = chip->gpiodev;
2251 int ret;
2252
2253 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2254 if (!pin_range) {
2255 chip_err(chip, "failed to allocate pin ranges\n");
2256 return -ENOMEM;
2257 }
2258
2259 /* Use local offset as range ID */
2260 pin_range->range.id = gpio_offset;
2261 pin_range->range.gc = chip;
2262 pin_range->range.name = chip->label;
2263 pin_range->range.base = gdev->base + gpio_offset;
2264 pin_range->range.pin_base = pin_offset;
2265 pin_range->range.npins = npins;
2266 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2267 &pin_range->range);
2268 if (IS_ERR(pin_range->pctldev)) {
2269 ret = PTR_ERR(pin_range->pctldev);
2270 chip_err(chip, "could not create pin range\n");
2271 kfree(pin_range);
2272 return ret;
2273 }
2274 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2275 gpio_offset, gpio_offset + npins - 1,
2276 pinctl_name,
2277 pin_offset, pin_offset + npins - 1);
2278
2279 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2280
2281 return 0;
2282}
2283EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2284
2285/**
2286 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2287 * @chip: the chip to remove all the mappings for
2288 */
2289void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2290{
2291 struct gpio_pin_range *pin_range, *tmp;
2292 struct gpio_device *gdev = chip->gpiodev;
2293
2294 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2295 list_del(&pin_range->node);
2296 pinctrl_remove_gpio_range(pin_range->pctldev,
2297 &pin_range->range);
2298 kfree(pin_range);
2299 }
2300}
2301EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2302
2303#endif /* CONFIG_PINCTRL */
2304
2305/* These "optional" allocation calls help prevent drivers from stomping
2306 * on each other, and help provide better diagnostics in debugfs.
2307 * They're called even less than the "set direction" calls.
2308 */
2309static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2310{
2311 struct gpio_chip *chip = desc->gdev->chip;
2312 int status;
2313 unsigned long flags;
2314 unsigned offset;
2315
2316 if (label) {
2317 label = kstrdup_const(label, GFP_KERNEL);
2318 if (!label)
2319 return -ENOMEM;
2320 }
2321
2322 spin_lock_irqsave(&gpio_lock, flags);
2323
2324 /* NOTE: gpio_request() can be called in early boot,
2325 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2326 */
2327
2328 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2329 desc_set_label(desc, label ? : "?");
2330 status = 0;
2331 } else {
2332 kfree_const(label);
2333 status = -EBUSY;
2334 goto done;
2335 }
2336
2337 if (chip->request) {
2338 /* chip->request may sleep */
2339 spin_unlock_irqrestore(&gpio_lock, flags);
2340 offset = gpio_chip_hwgpio(desc);
2341 if (gpiochip_line_is_valid(chip, offset))
2342 status = chip->request(chip, offset);
2343 else
2344 status = -EINVAL;
2345 spin_lock_irqsave(&gpio_lock, flags);
2346
2347 if (status < 0) {
2348 desc_set_label(desc, NULL);
2349 kfree_const(label);
2350 clear_bit(FLAG_REQUESTED, &desc->flags);
2351 goto done;
2352 }
2353 }
2354 if (chip->get_direction) {
2355 /* chip->get_direction may sleep */
2356 spin_unlock_irqrestore(&gpio_lock, flags);
2357 gpiod_get_direction(desc);
2358 spin_lock_irqsave(&gpio_lock, flags);
2359 }
2360done:
2361 spin_unlock_irqrestore(&gpio_lock, flags);
2362 return status;
2363}
2364
2365/*
2366 * This descriptor validation needs to be inserted verbatim into each
2367 * function taking a descriptor, so we need to use a preprocessor
2368 * macro to avoid endless duplication. If the desc is NULL it is an
2369 * optional GPIO and calls should just bail out.
2370 */
2371static int validate_desc(const struct gpio_desc *desc, const char *func)
2372{
2373 if (!desc)
2374 return 0;
2375 if (IS_ERR(desc)) {
2376 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2377 return PTR_ERR(desc);
2378 }
2379 if (!desc->gdev) {
2380 pr_warn("%s: invalid GPIO (no device)\n", func);
2381 return -EINVAL;
2382 }
2383 if (!desc->gdev->chip) {
2384 dev_warn(&desc->gdev->dev,
2385 "%s: backing chip is gone\n", func);
2386 return 0;
2387 }
2388 return 1;
2389}
2390
2391#define VALIDATE_DESC(desc) do { \
2392 int __valid = validate_desc(desc, __func__); \
2393 if (__valid <= 0) \
2394 return __valid; \
2395 } while (0)
2396
2397#define VALIDATE_DESC_VOID(desc) do { \
2398 int __valid = validate_desc(desc, __func__); \
2399 if (__valid <= 0) \
2400 return; \
2401 } while (0)
2402
2403int gpiod_request(struct gpio_desc *desc, const char *label)
2404{
2405 int status = -EPROBE_DEFER;
2406 struct gpio_device *gdev;
2407
2408 VALIDATE_DESC(desc);
2409 gdev = desc->gdev;
2410
2411 if (try_module_get(gdev->owner)) {
2412 status = gpiod_request_commit(desc, label);
2413 if (status < 0)
2414 module_put(gdev->owner);
2415 else
2416 get_device(&gdev->dev);
2417 }
2418
2419 if (status)
2420 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
2421
2422 return status;
2423}
2424
2425static bool gpiod_free_commit(struct gpio_desc *desc)
2426{
2427 bool ret = false;
2428 unsigned long flags;
2429 struct gpio_chip *chip;
2430
2431 might_sleep();
2432
2433 gpiod_unexport(desc);
2434
2435 spin_lock_irqsave(&gpio_lock, flags);
2436
2437 chip = desc->gdev->chip;
2438 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2439 if (chip->free) {
2440 spin_unlock_irqrestore(&gpio_lock, flags);
2441 might_sleep_if(chip->can_sleep);
2442 chip->free(chip, gpio_chip_hwgpio(desc));
2443 spin_lock_irqsave(&gpio_lock, flags);
2444 }
2445 kfree_const(desc->label);
2446 desc_set_label(desc, NULL);
2447 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2448 clear_bit(FLAG_REQUESTED, &desc->flags);
2449 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2450 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2451 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2452 ret = true;
2453 }
2454
2455 spin_unlock_irqrestore(&gpio_lock, flags);
2456 return ret;
2457}
2458
2459void gpiod_free(struct gpio_desc *desc)
2460{
2461 if (desc && desc->gdev && gpiod_free_commit(desc)) {
2462 module_put(desc->gdev->owner);
2463 put_device(&desc->gdev->dev);
2464 } else {
2465 WARN_ON(extra_checks);
2466 }
2467}
2468
2469/**
2470 * gpiochip_is_requested - return string iff signal was requested
2471 * @chip: controller managing the signal
2472 * @offset: of signal within controller's 0..(ngpio - 1) range
2473 *
2474 * Returns NULL if the GPIO is not currently requested, else a string.
2475 * The string returned is the label passed to gpio_request(); if none has been
2476 * passed it is a meaningless, non-NULL constant.
2477 *
2478 * This function is for use by GPIO controller drivers. The label can
2479 * help with diagnostics, and knowing that the signal is used as a GPIO
2480 * can help avoid accidentally multiplexing it to another controller.
2481 */
2482const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2483{
2484 struct gpio_desc *desc;
2485
2486 if (offset >= chip->ngpio)
2487 return NULL;
2488
2489 desc = &chip->gpiodev->descs[offset];
2490
2491 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2492 return NULL;
2493 return desc->label;
2494}
2495EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2496
2497/**
2498 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2499 * @chip: GPIO chip
2500 * @hwnum: hardware number of the GPIO for which to request the descriptor
2501 * @label: label for the GPIO
2502 * @flags: flags for this GPIO or 0 if default
2503 *
2504 * Function allows GPIO chip drivers to request and use their own GPIO
2505 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2506 * function will not increase reference count of the GPIO chip module. This
2507 * allows the GPIO chip module to be unloaded as needed (we assume that the
2508 * GPIO chip driver handles freeing the GPIOs it has requested).
2509 *
2510 * Returns:
2511 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2512 * code on failure.
2513 */
2514struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2515 const char *label,
2516 enum gpiod_flags flags)
2517{
2518 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2519 int err;
2520
2521 if (IS_ERR(desc)) {
2522 chip_err(chip, "failed to get GPIO descriptor\n");
2523 return desc;
2524 }
2525
2526 err = gpiod_request_commit(desc, label);
2527 if (err < 0)
2528 return ERR_PTR(err);
2529
2530 err = gpiod_configure_flags(desc, label, 0, flags);
2531 if (err) {
2532 chip_err(chip, "setup of own GPIO %s failed\n", label);
2533 gpiod_free_commit(desc);
2534 return ERR_PTR(err);
2535 }
2536
2537 return desc;
2538}
2539EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2540
2541/**
2542 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2543 * @desc: GPIO descriptor to free
2544 *
2545 * Function frees the given GPIO requested previously with
2546 * gpiochip_request_own_desc().
2547 */
2548void gpiochip_free_own_desc(struct gpio_desc *desc)
2549{
2550 if (desc)
2551 gpiod_free_commit(desc);
2552}
2553EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2554
2555/*
2556 * Drivers MUST set GPIO direction before making get/set calls. In
2557 * some cases this is done in early boot, before IRQs are enabled.
2558 *
2559 * As a rule these aren't called more than once (except for drivers
2560 * using the open-drain emulation idiom) so these are natural places
2561 * to accumulate extra debugging checks. Note that we can't (yet)
2562 * rely on gpio_request() having been called beforehand.
2563 */
2564
2565static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
2566 enum pin_config_param mode)
2567{
2568 unsigned long config = { PIN_CONF_PACKED(mode, 0) };
2569
2570 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2571}
2572
2573/**
2574 * gpiod_direction_input - set the GPIO direction to input
2575 * @desc: GPIO to set to input
2576 *
2577 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2578 * be called safely on it.
2579 *
2580 * Return 0 in case of success, else an error code.
2581 */
2582int gpiod_direction_input(struct gpio_desc *desc)
2583{
2584 struct gpio_chip *chip;
2585 int status = 0;
2586
2587 VALIDATE_DESC(desc);
2588 chip = desc->gdev->chip;
2589
2590 /*
2591 * It is legal to have no .get() and .direction_input() specified if
2592 * the chip is output-only, but you can't specify .direction_input()
2593 * and not support the .get() operation, that doesn't make sense.
2594 */
2595 if (!chip->get && chip->direction_input) {
2596 gpiod_warn(desc,
2597 "%s: missing get() but have direction_input()\n",
2598 __func__);
2599 return -EIO;
2600 }
2601
2602 /*
2603 * If we have a .direction_input() callback, things are simple,
2604 * just call it. Else we are some input-only chip so try to check the
2605 * direction (if .get_direction() is supported) else we silently
2606 * assume we are in input mode after this.
2607 */
2608 if (chip->direction_input) {
2609 status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2610 } else if (chip->get_direction &&
2611 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2612 gpiod_warn(desc,
2613 "%s: missing direction_input() operation and line is output\n",
2614 __func__);
2615 return -EIO;
2616 }
2617 if (status == 0)
2618 clear_bit(FLAG_IS_OUT, &desc->flags);
2619
2620 if (test_bit(FLAG_PULL_UP, &desc->flags))
2621 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2622 PIN_CONFIG_BIAS_PULL_UP);
2623 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2624 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2625 PIN_CONFIG_BIAS_PULL_DOWN);
2626
2627 trace_gpio_direction(desc_to_gpio(desc), 1, status);
2628
2629 return status;
2630}
2631EXPORT_SYMBOL_GPL(gpiod_direction_input);
2632
2633static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2634{
2635 struct gpio_chip *gc = desc->gdev->chip;
2636 int val = !!value;
2637 int ret = 0;
2638
2639 /*
2640 * It's OK not to specify .direction_output() if the gpiochip is
2641 * output-only, but if there is then not even a .set() operation it
2642 * is pretty tricky to drive the output line.
2643 */
2644 if (!gc->set && !gc->direction_output) {
2645 gpiod_warn(desc,
2646 "%s: missing set() and direction_output() operations\n",
2647 __func__);
2648 return -EIO;
2649 }
2650
2651 if (gc->direction_output) {
2652 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2653 } else {
2654 /* Check that we are in output mode if we can */
2655 if (gc->get_direction &&
2656 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2657 gpiod_warn(desc,
2658 "%s: missing direction_output() operation\n",
2659 __func__);
2660 return -EIO;
2661 }
2662 /*
2663 * If we can't actively set the direction, we are some
2664 * output-only chip, so just drive the output as desired.
2665 */
2666 gc->set(gc, gpio_chip_hwgpio(desc), val);
2667 }
2668
2669 if (!ret)
2670 set_bit(FLAG_IS_OUT, &desc->flags);
2671 trace_gpio_value(desc_to_gpio(desc), 0, val);
2672 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2673 return ret;
2674}
2675
2676/**
2677 * gpiod_direction_output_raw - set the GPIO direction to output
2678 * @desc: GPIO to set to output
2679 * @value: initial output value of the GPIO
2680 *
2681 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2682 * be called safely on it. The initial value of the output must be specified
2683 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2684 *
2685 * Return 0 in case of success, else an error code.
2686 */
2687int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2688{
2689 VALIDATE_DESC(desc);
2690 return gpiod_direction_output_raw_commit(desc, value);
2691}
2692EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2693
2694/**
2695 * gpiod_direction_output - set the GPIO direction to output
2696 * @desc: GPIO to set to output
2697 * @value: initial output value of the GPIO
2698 *
2699 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2700 * be called safely on it. The initial value of the output must be specified
2701 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2702 * account.
2703 *
2704 * Return 0 in case of success, else an error code.
2705 */
2706int gpiod_direction_output(struct gpio_desc *desc, int value)
2707{
2708 struct gpio_chip *gc;
2709 int ret;
2710
2711 VALIDATE_DESC(desc);
2712 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2713 value = !value;
2714 else
2715 value = !!value;
2716
2717 /* GPIOs used for enabled IRQs shall not be set as output */
2718 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2719 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2720 gpiod_err(desc,
2721 "%s: tried to set a GPIO tied to an IRQ as output\n",
2722 __func__);
2723 return -EIO;
2724 }
2725
2726 gc = desc->gdev->chip;
2727 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2728 /* First see if we can enable open drain in hardware */
2729 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2730 PIN_CONFIG_DRIVE_OPEN_DRAIN);
2731 if (!ret)
2732 goto set_output_value;
2733 /* Emulate open drain by not actively driving the line high */
2734 if (value)
2735 return gpiod_direction_input(desc);
2736 }
2737 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2738 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
2739 PIN_CONFIG_DRIVE_OPEN_SOURCE);
2740 if (!ret)
2741 goto set_output_value;
2742 /* Emulate open source by not actively driving the line low */
2743 if (!value)
2744 return gpiod_direction_input(desc);
2745 } else {
2746 gpio_set_config(gc, gpio_chip_hwgpio(desc),
2747 PIN_CONFIG_DRIVE_PUSH_PULL);
2748 }
2749
2750set_output_value:
2751 return gpiod_direction_output_raw_commit(desc, value);
2752}
2753EXPORT_SYMBOL_GPL(gpiod_direction_output);
2754
2755/**
2756 * gpiod_set_debounce - sets @debounce time for a GPIO
2757 * @desc: descriptor of the GPIO for which to set debounce time
2758 * @debounce: debounce time in microseconds
2759 *
2760 * Returns:
2761 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2762 * debounce time.
2763 */
2764int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
2765{
2766 struct gpio_chip *chip;
2767 unsigned long config;
2768
2769 VALIDATE_DESC(desc);
2770 chip = desc->gdev->chip;
2771 if (!chip->set || !chip->set_config) {
2772 gpiod_dbg(desc,
2773 "%s: missing set() or set_config() operations\n",
2774 __func__);
2775 return -ENOTSUPP;
2776 }
2777
2778 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2779 return gpio_set_config(chip, gpio_chip_hwgpio(desc), config);
2780}
2781EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2782
2783/**
2784 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2785 * @desc: descriptor of the GPIO for which to configure persistence
2786 * @transitory: True to lose state on suspend or reset, false for persistence
2787 *
2788 * Returns:
2789 * 0 on success, otherwise a negative error code.
2790 */
2791int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2792{
2793 struct gpio_chip *chip;
2794 unsigned long packed;
2795 int gpio;
2796 int rc;
2797
2798 VALIDATE_DESC(desc);
2799 /*
2800 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2801 * persistence state.
2802 */
2803 if (transitory)
2804 set_bit(FLAG_TRANSITORY, &desc->flags);
2805 else
2806 clear_bit(FLAG_TRANSITORY, &desc->flags);
2807
2808 /* If the driver supports it, set the persistence state now */
2809 chip = desc->gdev->chip;
2810 if (!chip->set_config)
2811 return 0;
2812
2813 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
2814 !transitory);
2815 gpio = gpio_chip_hwgpio(desc);
2816 rc = gpio_set_config(chip, gpio, packed);
2817 if (rc == -ENOTSUPP) {
2818 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
2819 gpio);
2820 return 0;
2821 }
2822
2823 return rc;
2824}
2825EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2826
2827/**
2828 * gpiod_is_active_low - test whether a GPIO is active-low or not
2829 * @desc: the gpio descriptor to test
2830 *
2831 * Returns 1 if the GPIO is active-low, 0 otherwise.
2832 */
2833int gpiod_is_active_low(const struct gpio_desc *desc)
2834{
2835 VALIDATE_DESC(desc);
2836 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2837}
2838EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2839
2840/* I/O calls are only valid after configuration completed; the relevant
2841 * "is this a valid GPIO" error checks should already have been done.
2842 *
2843 * "Get" operations are often inlinable as reading a pin value register,
2844 * and masking the relevant bit in that register.
2845 *
2846 * When "set" operations are inlinable, they involve writing that mask to
2847 * one register to set a low value, or a different register to set it high.
2848 * Otherwise locking is needed, so there may be little value to inlining.
2849 *
2850 *------------------------------------------------------------------------
2851 *
2852 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2853 * have requested the GPIO. That can include implicit requesting by
2854 * a direction setting call. Marking a gpio as requested locks its chip
2855 * in memory, guaranteeing that these table lookups need no more locking
2856 * and that gpiochip_remove() will fail.
2857 *
2858 * REVISIT when debugging, consider adding some instrumentation to ensure
2859 * that the GPIO was actually requested.
2860 */
2861
2862static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2863{
2864 struct gpio_chip *chip;
2865 int offset;
2866 int value;
2867
2868 chip = desc->gdev->chip;
2869 offset = gpio_chip_hwgpio(desc);
2870 value = chip->get ? chip->get(chip, offset) : -EIO;
2871 value = value < 0 ? value : !!value;
2872 trace_gpio_value(desc_to_gpio(desc), 1, value);
2873 return value;
2874}
2875
2876static int gpio_chip_get_multiple(struct gpio_chip *chip,
2877 unsigned long *mask, unsigned long *bits)
2878{
2879 if (chip->get_multiple) {
2880 return chip->get_multiple(chip, mask, bits);
2881 } else if (chip->get) {
2882 int i, value;
2883
2884 for_each_set_bit(i, mask, chip->ngpio) {
2885 value = chip->get(chip, i);
2886 if (value < 0)
2887 return value;
2888 __assign_bit(i, bits, value);
2889 }
2890 return 0;
2891 }
2892 return -EIO;
2893}
2894
2895int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2896 unsigned int array_size,
2897 struct gpio_desc **desc_array,
2898 struct gpio_array *array_info,
2899 unsigned long *value_bitmap)
2900{
2901 int err, i = 0;
2902
2903 /*
2904 * Validate array_info against desc_array and its size.
2905 * It should immediately follow desc_array if both
2906 * have been obtained from the same gpiod_get_array() call.
2907 */
2908 if (array_info && array_info->desc == desc_array &&
2909 array_size <= array_info->size &&
2910 (void *)array_info == desc_array + array_info->size) {
2911 if (!can_sleep)
2912 WARN_ON(array_info->chip->can_sleep);
2913
2914 err = gpio_chip_get_multiple(array_info->chip,
2915 array_info->get_mask,
2916 value_bitmap);
2917 if (err)
2918 return err;
2919
2920 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2921 bitmap_xor(value_bitmap, value_bitmap,
2922 array_info->invert_mask, array_size);
2923
2924 if (bitmap_full(array_info->get_mask, array_size))
2925 return 0;
2926
2927 i = find_first_zero_bit(array_info->get_mask, array_size);
2928 } else {
2929 array_info = NULL;
2930 }
2931
2932 while (i < array_size) {
2933 struct gpio_chip *chip = desc_array[i]->gdev->chip;
2934 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
2935 unsigned long *mask, *bits;
2936 int first, j, ret;
2937
2938 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
2939 mask = fastpath;
2940 } else {
2941 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
2942 sizeof(*mask),
2943 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
2944 if (!mask)
2945 return -ENOMEM;
2946 }
2947
2948 bits = mask + BITS_TO_LONGS(chip->ngpio);
2949 bitmap_zero(mask, chip->ngpio);
2950
2951 if (!can_sleep)
2952 WARN_ON(chip->can_sleep);
2953
2954 /* collect all inputs belonging to the same chip */
2955 first = i;
2956 do {
2957 const struct gpio_desc *desc = desc_array[i];
2958 int hwgpio = gpio_chip_hwgpio(desc);
2959
2960 __set_bit(hwgpio, mask);
2961 i++;
2962
2963 if (array_info)
2964 i = find_next_zero_bit(array_info->get_mask,
2965 array_size, i);
2966 } while ((i < array_size) &&
2967 (desc_array[i]->gdev->chip == chip));
2968
2969 ret = gpio_chip_get_multiple(chip, mask, bits);
2970 if (ret) {
2971 if (mask != fastpath)
2972 kfree(mask);
2973 return ret;
2974 }
2975
2976 for (j = first; j < i; ) {
2977 const struct gpio_desc *desc = desc_array[j];
2978 int hwgpio = gpio_chip_hwgpio(desc);
2979 int value = test_bit(hwgpio, bits);
2980
2981 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2982 value = !value;
2983 __assign_bit(j, value_bitmap, value);
2984 trace_gpio_value(desc_to_gpio(desc), 1, value);
2985 j++;
2986
2987 if (array_info)
2988 j = find_next_zero_bit(array_info->get_mask, i,
2989 j);
2990 }
2991
2992 if (mask != fastpath)
2993 kfree(mask);
2994 }
2995 return 0;
2996}
2997
2998/**
2999 * gpiod_get_raw_value() - return a gpio's raw value
3000 * @desc: gpio whose value will be returned
3001 *
3002 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3003 * its ACTIVE_LOW status, or negative errno on failure.
3004 *
3005 * This function should be called from contexts where we cannot sleep, and will
3006 * complain if the GPIO chip functions potentially sleep.
3007 */
3008int gpiod_get_raw_value(const struct gpio_desc *desc)
3009{
3010 VALIDATE_DESC(desc);
3011 /* Should be using gpio_get_value_cansleep() */
3012 WARN_ON(desc->gdev->chip->can_sleep);
3013 return gpiod_get_raw_value_commit(desc);
3014}
3015EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3016
3017/**
3018 * gpiod_get_value() - return a gpio's value
3019 * @desc: gpio whose value will be returned
3020 *
3021 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3022 * account, or negative errno on failure.
3023 *
3024 * This function should be called from contexts where we cannot sleep, and will
3025 * complain if the GPIO chip functions potentially sleep.
3026 */
3027int gpiod_get_value(const struct gpio_desc *desc)
3028{
3029 int value;
3030
3031 VALIDATE_DESC(desc);
3032 /* Should be using gpio_get_value_cansleep() */
3033 WARN_ON(desc->gdev->chip->can_sleep);
3034
3035 value = gpiod_get_raw_value_commit(desc);
3036 if (value < 0)
3037 return value;
3038
3039 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3040 value = !value;
3041
3042 return value;
3043}
3044EXPORT_SYMBOL_GPL(gpiod_get_value);
3045
3046/**
3047 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3048 * @array_size: number of elements in the descriptor array / value bitmap
3049 * @desc_array: array of GPIO descriptors whose values will be read
3050 * @array_info: information on applicability of fast bitmap processing path
3051 * @value_bitmap: bitmap to store the read values
3052 *
3053 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3054 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3055 * else an error code.
3056 *
3057 * This function should be called from contexts where we cannot sleep,
3058 * and it will complain if the GPIO chip functions potentially sleep.
3059 */
3060int gpiod_get_raw_array_value(unsigned int array_size,
3061 struct gpio_desc **desc_array,
3062 struct gpio_array *array_info,
3063 unsigned long *value_bitmap)
3064{
3065 if (!desc_array)
3066 return -EINVAL;
3067 return gpiod_get_array_value_complex(true, false, array_size,
3068 desc_array, array_info,
3069 value_bitmap);
3070}
3071EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3072
3073/**
3074 * gpiod_get_array_value() - read values from an array of GPIOs
3075 * @array_size: number of elements in the descriptor array / value bitmap
3076 * @desc_array: array of GPIO descriptors whose values will be read
3077 * @array_info: information on applicability of fast bitmap processing path
3078 * @value_bitmap: bitmap to store the read values
3079 *
3080 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3081 * into account. Return 0 in case of success, else an error code.
3082 *
3083 * This function should be called from contexts where we cannot sleep,
3084 * and it will complain if the GPIO chip functions potentially sleep.
3085 */
3086int gpiod_get_array_value(unsigned int array_size,
3087 struct gpio_desc **desc_array,
3088 struct gpio_array *array_info,
3089 unsigned long *value_bitmap)
3090{
3091 if (!desc_array)
3092 return -EINVAL;
3093 return gpiod_get_array_value_complex(false, false, array_size,
3094 desc_array, array_info,
3095 value_bitmap);
3096}
3097EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3098
3099/*
3100 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3101 * @desc: gpio descriptor whose state need to be set.
3102 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3103 */
3104static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3105{
3106 int err = 0;
3107 struct gpio_chip *chip = desc->gdev->chip;
3108 int offset = gpio_chip_hwgpio(desc);
3109
3110 if (value) {
3111 err = chip->direction_input(chip, offset);
3112 if (!err)
3113 clear_bit(FLAG_IS_OUT, &desc->flags);
3114 } else {
3115 err = chip->direction_output(chip, offset, 0);
3116 if (!err)
3117 set_bit(FLAG_IS_OUT, &desc->flags);
3118 }
3119 trace_gpio_direction(desc_to_gpio(desc), value, err);
3120 if (err < 0)
3121 gpiod_err(desc,
3122 "%s: Error in set_value for open drain err %d\n",
3123 __func__, err);
3124}
3125
3126/*
3127 * _gpio_set_open_source_value() - Set the open source gpio's value.
3128 * @desc: gpio descriptor whose state need to be set.
3129 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3130 */
3131static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3132{
3133 int err = 0;
3134 struct gpio_chip *chip = desc->gdev->chip;
3135 int offset = gpio_chip_hwgpio(desc);
3136
3137 if (value) {
3138 err = chip->direction_output(chip, offset, 1);
3139 if (!err)
3140 set_bit(FLAG_IS_OUT, &desc->flags);
3141 } else {
3142 err = chip->direction_input(chip, offset);
3143 if (!err)
3144 clear_bit(FLAG_IS_OUT, &desc->flags);
3145 }
3146 trace_gpio_direction(desc_to_gpio(desc), !value, err);
3147 if (err < 0)
3148 gpiod_err(desc,
3149 "%s: Error in set_value for open source err %d\n",
3150 __func__, err);
3151}
3152
3153static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3154{
3155 struct gpio_chip *chip;
3156
3157 chip = desc->gdev->chip;
3158 trace_gpio_value(desc_to_gpio(desc), 0, value);
3159 chip->set(chip, gpio_chip_hwgpio(desc), value);
3160}
3161
3162/*
3163 * set multiple outputs on the same chip;
3164 * use the chip's set_multiple function if available;
3165 * otherwise set the outputs sequentially;
3166 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3167 * defines which outputs are to be changed
3168 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3169 * defines the values the outputs specified by mask are to be set to
3170 */
3171static void gpio_chip_set_multiple(struct gpio_chip *chip,
3172 unsigned long *mask, unsigned long *bits)
3173{
3174 if (chip->set_multiple) {
3175 chip->set_multiple(chip, mask, bits);
3176 } else {
3177 unsigned int i;
3178
3179 /* set outputs if the corresponding mask bit is set */
3180 for_each_set_bit(i, mask, chip->ngpio)
3181 chip->set(chip, i, test_bit(i, bits));
3182 }
3183}
3184
3185int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3186 unsigned int array_size,
3187 struct gpio_desc **desc_array,
3188 struct gpio_array *array_info,
3189 unsigned long *value_bitmap)
3190{
3191 int i = 0;
3192
3193 /*
3194 * Validate array_info against desc_array and its size.
3195 * It should immediately follow desc_array if both
3196 * have been obtained from the same gpiod_get_array() call.
3197 */
3198 if (array_info && array_info->desc == desc_array &&
3199 array_size <= array_info->size &&
3200 (void *)array_info == desc_array + array_info->size) {
3201 if (!can_sleep)
3202 WARN_ON(array_info->chip->can_sleep);
3203
3204 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3205 bitmap_xor(value_bitmap, value_bitmap,
3206 array_info->invert_mask, array_size);
3207
3208 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3209 value_bitmap);
3210
3211 if (bitmap_full(array_info->set_mask, array_size))
3212 return 0;
3213
3214 i = find_first_zero_bit(array_info->set_mask, array_size);
3215 } else {
3216 array_info = NULL;
3217 }
3218
3219 while (i < array_size) {
3220 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3221 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3222 unsigned long *mask, *bits;
3223 int count = 0;
3224
3225 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3226 mask = fastpath;
3227 } else {
3228 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3229 sizeof(*mask),
3230 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3231 if (!mask)
3232 return -ENOMEM;
3233 }
3234
3235 bits = mask + BITS_TO_LONGS(chip->ngpio);
3236 bitmap_zero(mask, chip->ngpio);
3237
3238 if (!can_sleep)
3239 WARN_ON(chip->can_sleep);
3240
3241 do {
3242 struct gpio_desc *desc = desc_array[i];
3243 int hwgpio = gpio_chip_hwgpio(desc);
3244 int value = test_bit(i, value_bitmap);
3245
3246 /*
3247 * Pins applicable for fast input but not for
3248 * fast output processing may have been already
3249 * inverted inside the fast path, skip them.
3250 */
3251 if (!raw && !(array_info &&
3252 test_bit(i, array_info->invert_mask)) &&
3253 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3254 value = !value;
3255 trace_gpio_value(desc_to_gpio(desc), 0, value);
3256 /*
3257 * collect all normal outputs belonging to the same chip
3258 * open drain and open source outputs are set individually
3259 */
3260 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3261 gpio_set_open_drain_value_commit(desc, value);
3262 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3263 gpio_set_open_source_value_commit(desc, value);
3264 } else {
3265 __set_bit(hwgpio, mask);
3266 if (value)
3267 __set_bit(hwgpio, bits);
3268 else
3269 __clear_bit(hwgpio, bits);
3270 count++;
3271 }
3272 i++;
3273
3274 if (array_info)
3275 i = find_next_zero_bit(array_info->set_mask,
3276 array_size, i);
3277 } while ((i < array_size) &&
3278 (desc_array[i]->gdev->chip == chip));
3279 /* push collected bits to outputs */
3280 if (count != 0)
3281 gpio_chip_set_multiple(chip, mask, bits);
3282
3283 if (mask != fastpath)
3284 kfree(mask);
3285 }
3286 return 0;
3287}
3288
3289/**
3290 * gpiod_set_raw_value() - assign a gpio's raw value
3291 * @desc: gpio whose value will be assigned
3292 * @value: value to assign
3293 *
3294 * Set the raw value of the GPIO, i.e. the value of its physical line without
3295 * regard for its ACTIVE_LOW status.
3296 *
3297 * This function should be called from contexts where we cannot sleep, and will
3298 * complain if the GPIO chip functions potentially sleep.
3299 */
3300void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3301{
3302 VALIDATE_DESC_VOID(desc);
3303 /* Should be using gpiod_set_value_cansleep() */
3304 WARN_ON(desc->gdev->chip->can_sleep);
3305 gpiod_set_raw_value_commit(desc, value);
3306}
3307EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3308
3309/**
3310 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3311 * @desc: the descriptor to set the value on
3312 * @value: value to set
3313 *
3314 * This sets the value of a GPIO line backing a descriptor, applying
3315 * different semantic quirks like active low and open drain/source
3316 * handling.
3317 */
3318static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3319{
3320 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3321 value = !value;
3322 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3323 gpio_set_open_drain_value_commit(desc, value);
3324 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3325 gpio_set_open_source_value_commit(desc, value);
3326 else
3327 gpiod_set_raw_value_commit(desc, value);
3328}
3329
3330/**
3331 * gpiod_set_value() - assign a gpio's value
3332 * @desc: gpio whose value will be assigned
3333 * @value: value to assign
3334 *
3335 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3336 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3337 *
3338 * This function should be called from contexts where we cannot sleep, and will
3339 * complain if the GPIO chip functions potentially sleep.
3340 */
3341void gpiod_set_value(struct gpio_desc *desc, int value)
3342{
3343 VALIDATE_DESC_VOID(desc);
3344 WARN_ON(desc->gdev->chip->can_sleep);
3345 gpiod_set_value_nocheck(desc, value);
3346}
3347EXPORT_SYMBOL_GPL(gpiod_set_value);
3348
3349/**
3350 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3351 * @array_size: number of elements in the descriptor array / value bitmap
3352 * @desc_array: array of GPIO descriptors whose values will be assigned
3353 * @array_info: information on applicability of fast bitmap processing path
3354 * @value_bitmap: bitmap of values to assign
3355 *
3356 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3357 * without regard for their ACTIVE_LOW status.
3358 *
3359 * This function should be called from contexts where we cannot sleep, and will
3360 * complain if the GPIO chip functions potentially sleep.
3361 */
3362int gpiod_set_raw_array_value(unsigned int array_size,
3363 struct gpio_desc **desc_array,
3364 struct gpio_array *array_info,
3365 unsigned long *value_bitmap)
3366{
3367 if (!desc_array)
3368 return -EINVAL;
3369 return gpiod_set_array_value_complex(true, false, array_size,
3370 desc_array, array_info, value_bitmap);
3371}
3372EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3373
3374/**
3375 * gpiod_set_array_value() - assign values to an array of GPIOs
3376 * @array_size: number of elements in the descriptor array / value bitmap
3377 * @desc_array: array of GPIO descriptors whose values will be assigned
3378 * @array_info: information on applicability of fast bitmap processing path
3379 * @value_bitmap: bitmap of values to assign
3380 *
3381 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3382 * into account.
3383 *
3384 * This function should be called from contexts where we cannot sleep, and will
3385 * complain if the GPIO chip functions potentially sleep.
3386 */
3387int gpiod_set_array_value(unsigned int array_size,
3388 struct gpio_desc **desc_array,
3389 struct gpio_array *array_info,
3390 unsigned long *value_bitmap)
3391{
3392 if (!desc_array)
3393 return -EINVAL;
3394 return gpiod_set_array_value_complex(false, false, array_size,
3395 desc_array, array_info,
3396 value_bitmap);
3397}
3398EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3399
3400/**
3401 * gpiod_cansleep() - report whether gpio value access may sleep
3402 * @desc: gpio to check
3403 *
3404 */
3405int gpiod_cansleep(const struct gpio_desc *desc)
3406{
3407 VALIDATE_DESC(desc);
3408 return desc->gdev->chip->can_sleep;
3409}
3410EXPORT_SYMBOL_GPL(gpiod_cansleep);
3411
3412/**
3413 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3414 * @desc: gpio to set the consumer name on
3415 * @name: the new consumer name
3416 */
3417int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3418{
3419 VALIDATE_DESC(desc);
3420 if (name) {
3421 name = kstrdup_const(name, GFP_KERNEL);
3422 if (!name)
3423 return -ENOMEM;
3424 }
3425
3426 kfree_const(desc->label);
3427 desc_set_label(desc, name);
3428
3429 return 0;
3430}
3431EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3432
3433/**
3434 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3435 * @desc: gpio whose IRQ will be returned (already requested)
3436 *
3437 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3438 * error.
3439 */
3440int gpiod_to_irq(const struct gpio_desc *desc)
3441{
3442 struct gpio_chip *chip;
3443 int offset;
3444
3445 /*
3446 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3447 * requires this function to not return zero on an invalid descriptor
3448 * but rather a negative error number.
3449 */
3450 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3451 return -EINVAL;
3452
3453 chip = desc->gdev->chip;
3454 offset = gpio_chip_hwgpio(desc);
3455 if (chip->to_irq) {
3456 int retirq = chip->to_irq(chip, offset);
3457
3458 /* Zero means NO_IRQ */
3459 if (!retirq)
3460 return -ENXIO;
3461
3462 return retirq;
3463 }
3464 return -ENXIO;
3465}
3466EXPORT_SYMBOL_GPL(gpiod_to_irq);
3467
3468/**
3469 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3470 * @chip: the chip the GPIO to lock belongs to
3471 * @offset: the offset of the GPIO to lock as IRQ
3472 *
3473 * This is used directly by GPIO drivers that want to lock down
3474 * a certain GPIO line to be used for IRQs.
3475 */
3476int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3477{
3478 struct gpio_desc *desc;
3479
3480 desc = gpiochip_get_desc(chip, offset);
3481 if (IS_ERR(desc))
3482 return PTR_ERR(desc);
3483
3484 /*
3485 * If it's fast: flush the direction setting if something changed
3486 * behind our back
3487 */
3488 if (!chip->can_sleep && chip->get_direction) {
3489 int dir = gpiod_get_direction(desc);
3490
3491 if (dir < 0) {
3492 chip_err(chip, "%s: cannot get GPIO direction\n",
3493 __func__);
3494 return dir;
3495 }
3496 }
3497
3498 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
3499 chip_err(chip,
3500 "%s: tried to flag a GPIO set as output for IRQ\n",
3501 __func__);
3502 return -EIO;
3503 }
3504
3505 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3506 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3507
3508 /*
3509 * If the consumer has not set up a label (such as when the
3510 * IRQ is referenced from .to_irq()) we set up a label here
3511 * so it is clear this is used as an interrupt.
3512 */
3513 if (!desc->label)
3514 desc_set_label(desc, "interrupt");
3515
3516 return 0;
3517}
3518EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3519
3520/**
3521 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3522 * @chip: the chip the GPIO to lock belongs to
3523 * @offset: the offset of the GPIO to lock as IRQ
3524 *
3525 * This is used directly by GPIO drivers that want to indicate
3526 * that a certain GPIO is no longer used exclusively for IRQ.
3527 */
3528void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3529{
3530 struct gpio_desc *desc;
3531
3532 desc = gpiochip_get_desc(chip, offset);
3533 if (IS_ERR(desc))
3534 return;
3535
3536 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3537 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3538
3539 /* If we only had this marking, erase it */
3540 if (desc->label && !strcmp(desc->label, "interrupt"))
3541 desc_set_label(desc, NULL);
3542}
3543EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3544
3545void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3546{
3547 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3548
3549 if (!IS_ERR(desc) &&
3550 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3551 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3552}
3553EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3554
3555void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3556{
3557 struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3558
3559 if (!IS_ERR(desc) &&
3560 !