]> git.ipfire.org Git - thirdparty/linux.git/blob - drivers/gpio/gpiolib.c
Merge tag 'io_uring-5.7-2020-05-22' of git://git.kernel.dk/linux-block
[thirdparty/linux.git] / drivers / gpio / gpiolib.c
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bitmap.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/interrupt.h>
6 #include <linux/irq.h>
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/debugfs.h>
12 #include <linux/seq_file.h>
13 #include <linux/gpio.h>
14 #include <linux/idr.h>
15 #include <linux/slab.h>
16 #include <linux/acpi.h>
17 #include <linux/gpio/driver.h>
18 #include <linux/gpio/machine.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/cdev.h>
21 #include <linux/fs.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <linux/anon_inodes.h>
25 #include <linux/file.h>
26 #include <linux/kfifo.h>
27 #include <linux/poll.h>
28 #include <linux/timekeeping.h>
29 #include <uapi/linux/gpio.h>
30
31 #include "gpiolib.h"
32 #include "gpiolib-of.h"
33 #include "gpiolib-acpi.h"
34
35 #define CREATE_TRACE_POINTS
36 #include <trace/events/gpio.h>
37
38 /* Implementation infrastructure for GPIO interfaces.
39 *
40 * The GPIO programming interface allows for inlining speed-critical
41 * get/set operations for common cases, so that access to SOC-integrated
42 * GPIOs can sometimes cost only an instruction or two per bit.
43 */
44
45
46 /* When debugging, extend minimal trust to callers and platform code.
47 * Also emit diagnostic messages that may help initial bringup, when
48 * board setup or driver bugs are most common.
49 *
50 * Otherwise, minimize overhead in what may be bitbanging codepaths.
51 */
52 #ifdef DEBUG
53 #define extra_checks 1
54 #else
55 #define extra_checks 0
56 #endif
57
58 /* Device and char device-related information */
59 static DEFINE_IDA(gpio_ida);
60 static dev_t gpio_devt;
61 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
62 static struct bus_type gpio_bus_type = {
63 .name = "gpio",
64 };
65
66 /*
67 * Number of GPIOs to use for the fast path in set array
68 */
69 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
70
71 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
72 * While any GPIO is requested, its gpio_chip is not removable;
73 * each GPIO's "requested" flag serves as a lock and refcount.
74 */
75 DEFINE_SPINLOCK(gpio_lock);
76
77 static DEFINE_MUTEX(gpio_lookup_lock);
78 static LIST_HEAD(gpio_lookup_list);
79 LIST_HEAD(gpio_devices);
80
81 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
82 static LIST_HEAD(gpio_machine_hogs);
83
84 static void gpiochip_free_hogs(struct gpio_chip *gc);
85 static int gpiochip_add_irqchip(struct gpio_chip *gc,
86 struct lock_class_key *lock_key,
87 struct lock_class_key *request_key);
88 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
89 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
90 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
91 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
92
93 static bool gpiolib_initialized;
94
95 static inline void desc_set_label(struct gpio_desc *d, const char *label)
96 {
97 d->label = label;
98 }
99
100 /**
101 * gpio_to_desc - Convert a GPIO number to its descriptor
102 * @gpio: global GPIO number
103 *
104 * Returns:
105 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
106 * with the given number exists in the system.
107 */
108 struct gpio_desc *gpio_to_desc(unsigned gpio)
109 {
110 struct gpio_device *gdev;
111 unsigned long flags;
112
113 spin_lock_irqsave(&gpio_lock, flags);
114
115 list_for_each_entry(gdev, &gpio_devices, list) {
116 if (gdev->base <= gpio &&
117 gdev->base + gdev->ngpio > gpio) {
118 spin_unlock_irqrestore(&gpio_lock, flags);
119 return &gdev->descs[gpio - gdev->base];
120 }
121 }
122
123 spin_unlock_irqrestore(&gpio_lock, flags);
124
125 if (!gpio_is_valid(gpio))
126 WARN(1, "invalid GPIO %d\n", gpio);
127
128 return NULL;
129 }
130 EXPORT_SYMBOL_GPL(gpio_to_desc);
131
132 /**
133 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
134 * hardware number for this chip
135 * @gc: GPIO chip
136 * @hwnum: hardware number of the GPIO for this chip
137 *
138 * Returns:
139 * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
140 * in the given chip for the specified hardware number.
141 */
142 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
143 unsigned int hwnum)
144 {
145 struct gpio_device *gdev = gc->gpiodev;
146
147 if (hwnum >= gdev->ngpio)
148 return ERR_PTR(-EINVAL);
149
150 return &gdev->descs[hwnum];
151 }
152 EXPORT_SYMBOL_GPL(gpiochip_get_desc);
153
154 /**
155 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
156 * @desc: GPIO descriptor
157 *
158 * This should disappear in the future but is needed since we still
159 * use GPIO numbers for error messages and sysfs nodes.
160 *
161 * Returns:
162 * The global GPIO number for the GPIO specified by its descriptor.
163 */
164 int desc_to_gpio(const struct gpio_desc *desc)
165 {
166 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
167 }
168 EXPORT_SYMBOL_GPL(desc_to_gpio);
169
170
171 /**
172 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
173 * @desc: descriptor to return the chip of
174 */
175 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
176 {
177 if (!desc || !desc->gdev)
178 return NULL;
179 return desc->gdev->chip;
180 }
181 EXPORT_SYMBOL_GPL(gpiod_to_chip);
182
183 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
184 static int gpiochip_find_base(int ngpio)
185 {
186 struct gpio_device *gdev;
187 int base = ARCH_NR_GPIOS - ngpio;
188
189 list_for_each_entry_reverse(gdev, &gpio_devices, list) {
190 /* found a free space? */
191 if (gdev->base + gdev->ngpio <= base)
192 break;
193 else
194 /* nope, check the space right before the chip */
195 base = gdev->base - ngpio;
196 }
197
198 if (gpio_is_valid(base)) {
199 pr_debug("%s: found new base at %d\n", __func__, base);
200 return base;
201 } else {
202 pr_err("%s: cannot find free range\n", __func__);
203 return -ENOSPC;
204 }
205 }
206
207 /**
208 * gpiod_get_direction - return the current direction of a GPIO
209 * @desc: GPIO to get the direction of
210 *
211 * Returns 0 for output, 1 for input, or an error code in case of error.
212 *
213 * This function may sleep if gpiod_cansleep() is true.
214 */
215 int gpiod_get_direction(struct gpio_desc *desc)
216 {
217 struct gpio_chip *gc;
218 unsigned offset;
219 int ret;
220
221 gc = gpiod_to_chip(desc);
222 offset = gpio_chip_hwgpio(desc);
223
224 /*
225 * Open drain emulation using input mode may incorrectly report
226 * input here, fix that up.
227 */
228 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
229 test_bit(FLAG_IS_OUT, &desc->flags))
230 return 0;
231
232 if (!gc->get_direction)
233 return -ENOTSUPP;
234
235 ret = gc->get_direction(gc, offset);
236 if (ret < 0)
237 return ret;
238
239 /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
240 if (ret > 0)
241 ret = 1;
242
243 assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
244
245 return ret;
246 }
247 EXPORT_SYMBOL_GPL(gpiod_get_direction);
248
249 /*
250 * Add a new chip to the global chips list, keeping the list of chips sorted
251 * by range(means [base, base + ngpio - 1]) order.
252 *
253 * Return -EBUSY if the new chip overlaps with some other chip's integer
254 * space.
255 */
256 static int gpiodev_add_to_list(struct gpio_device *gdev)
257 {
258 struct gpio_device *prev, *next;
259
260 if (list_empty(&gpio_devices)) {
261 /* initial entry in list */
262 list_add_tail(&gdev->list, &gpio_devices);
263 return 0;
264 }
265
266 next = list_entry(gpio_devices.next, struct gpio_device, list);
267 if (gdev->base + gdev->ngpio <= next->base) {
268 /* add before first entry */
269 list_add(&gdev->list, &gpio_devices);
270 return 0;
271 }
272
273 prev = list_entry(gpio_devices.prev, struct gpio_device, list);
274 if (prev->base + prev->ngpio <= gdev->base) {
275 /* add behind last entry */
276 list_add_tail(&gdev->list, &gpio_devices);
277 return 0;
278 }
279
280 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
281 /* at the end of the list */
282 if (&next->list == &gpio_devices)
283 break;
284
285 /* add between prev and next */
286 if (prev->base + prev->ngpio <= gdev->base
287 && gdev->base + gdev->ngpio <= next->base) {
288 list_add(&gdev->list, &prev->list);
289 return 0;
290 }
291 }
292
293 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
294 return -EBUSY;
295 }
296
297 /*
298 * Convert a GPIO name to its descriptor
299 */
300 static struct gpio_desc *gpio_name_to_desc(const char * const name)
301 {
302 struct gpio_device *gdev;
303 unsigned long flags;
304
305 if (!name)
306 return NULL;
307
308 spin_lock_irqsave(&gpio_lock, flags);
309
310 list_for_each_entry(gdev, &gpio_devices, list) {
311 int i;
312
313 for (i = 0; i != gdev->ngpio; ++i) {
314 struct gpio_desc *desc = &gdev->descs[i];
315
316 if (!desc->name)
317 continue;
318
319 if (!strcmp(desc->name, name)) {
320 spin_unlock_irqrestore(&gpio_lock, flags);
321 return desc;
322 }
323 }
324 }
325
326 spin_unlock_irqrestore(&gpio_lock, flags);
327
328 return NULL;
329 }
330
331 /*
332 * Takes the names from gc->names and checks if they are all unique. If they
333 * are, they are assigned to their gpio descriptors.
334 *
335 * Warning if one of the names is already used for a different GPIO.
336 */
337 static int gpiochip_set_desc_names(struct gpio_chip *gc)
338 {
339 struct gpio_device *gdev = gc->gpiodev;
340 int i;
341
342 if (!gc->names)
343 return 0;
344
345 /* First check all names if they are unique */
346 for (i = 0; i != gc->ngpio; ++i) {
347 struct gpio_desc *gpio;
348
349 gpio = gpio_name_to_desc(gc->names[i]);
350 if (gpio)
351 dev_warn(&gdev->dev,
352 "Detected name collision for GPIO name '%s'\n",
353 gc->names[i]);
354 }
355
356 /* Then add all names to the GPIO descriptors */
357 for (i = 0; i != gc->ngpio; ++i)
358 gdev->descs[i].name = gc->names[i];
359
360 return 0;
361 }
362
363 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
364 {
365 unsigned long *p;
366
367 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
368 if (!p)
369 return NULL;
370
371 /* Assume by default all GPIOs are valid */
372 bitmap_fill(p, gc->ngpio);
373
374 return p;
375 }
376
377 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
378 {
379 if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
380 return 0;
381
382 gc->valid_mask = gpiochip_allocate_mask(gc);
383 if (!gc->valid_mask)
384 return -ENOMEM;
385
386 return 0;
387 }
388
389 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
390 {
391 if (gc->init_valid_mask)
392 return gc->init_valid_mask(gc,
393 gc->valid_mask,
394 gc->ngpio);
395
396 return 0;
397 }
398
399 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
400 {
401 bitmap_free(gc->valid_mask);
402 gc->valid_mask = NULL;
403 }
404
405 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
406 {
407 if (gc->add_pin_ranges)
408 return gc->add_pin_ranges(gc);
409
410 return 0;
411 }
412
413 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
414 unsigned int offset)
415 {
416 /* No mask means all valid */
417 if (likely(!gc->valid_mask))
418 return true;
419 return test_bit(offset, gc->valid_mask);
420 }
421 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
422
423 /*
424 * GPIO line handle management
425 */
426
427 /**
428 * struct linehandle_state - contains the state of a userspace handle
429 * @gdev: the GPIO device the handle pertains to
430 * @label: consumer label used to tag descriptors
431 * @descs: the GPIO descriptors held by this handle
432 * @numdescs: the number of descriptors held in the descs array
433 */
434 struct linehandle_state {
435 struct gpio_device *gdev;
436 const char *label;
437 struct gpio_desc *descs[GPIOHANDLES_MAX];
438 u32 numdescs;
439 };
440
441 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
442 (GPIOHANDLE_REQUEST_INPUT | \
443 GPIOHANDLE_REQUEST_OUTPUT | \
444 GPIOHANDLE_REQUEST_ACTIVE_LOW | \
445 GPIOHANDLE_REQUEST_BIAS_PULL_UP | \
446 GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \
447 GPIOHANDLE_REQUEST_BIAS_DISABLE | \
448 GPIOHANDLE_REQUEST_OPEN_DRAIN | \
449 GPIOHANDLE_REQUEST_OPEN_SOURCE)
450
451 static int linehandle_validate_flags(u32 flags)
452 {
453 /* Return an error if an unknown flag is set */
454 if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
455 return -EINVAL;
456
457 /*
458 * Do not allow both INPUT & OUTPUT flags to be set as they are
459 * contradictory.
460 */
461 if ((flags & GPIOHANDLE_REQUEST_INPUT) &&
462 (flags & GPIOHANDLE_REQUEST_OUTPUT))
463 return -EINVAL;
464
465 /*
466 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
467 * the hardware actually supports enabling both at the same time the
468 * electrical result would be disastrous.
469 */
470 if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
471 (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
472 return -EINVAL;
473
474 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
475 if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) &&
476 ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
477 (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
478 return -EINVAL;
479
480 /* Bias flags only allowed for input or output mode. */
481 if (!((flags & GPIOHANDLE_REQUEST_INPUT) ||
482 (flags & GPIOHANDLE_REQUEST_OUTPUT)) &&
483 ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) ||
484 (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
485 (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
486 return -EINVAL;
487
488 /* Only one bias flag can be set. */
489 if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
490 (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
491 GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
492 ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
493 (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
494 return -EINVAL;
495
496 return 0;
497 }
498
499 static long linehandle_set_config(struct linehandle_state *lh,
500 void __user *ip)
501 {
502 struct gpiohandle_config gcnf;
503 struct gpio_desc *desc;
504 int i, ret;
505 u32 lflags;
506 unsigned long *flagsp;
507
508 if (copy_from_user(&gcnf, ip, sizeof(gcnf)))
509 return -EFAULT;
510
511 lflags = gcnf.flags;
512 ret = linehandle_validate_flags(lflags);
513 if (ret)
514 return ret;
515
516 for (i = 0; i < lh->numdescs; i++) {
517 desc = lh->descs[i];
518 flagsp = &desc->flags;
519
520 assign_bit(FLAG_ACTIVE_LOW, flagsp,
521 lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW);
522
523 assign_bit(FLAG_OPEN_DRAIN, flagsp,
524 lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN);
525
526 assign_bit(FLAG_OPEN_SOURCE, flagsp,
527 lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE);
528
529 assign_bit(FLAG_PULL_UP, flagsp,
530 lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP);
531
532 assign_bit(FLAG_PULL_DOWN, flagsp,
533 lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN);
534
535 assign_bit(FLAG_BIAS_DISABLE, flagsp,
536 lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE);
537
538 /*
539 * Lines have to be requested explicitly for input
540 * or output, else the line will be treated "as is".
541 */
542 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
543 int val = !!gcnf.default_values[i];
544
545 ret = gpiod_direction_output(desc, val);
546 if (ret)
547 return ret;
548 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
549 ret = gpiod_direction_input(desc);
550 if (ret)
551 return ret;
552 }
553
554 atomic_notifier_call_chain(&desc->gdev->notifier,
555 GPIOLINE_CHANGED_CONFIG, desc);
556 }
557 return 0;
558 }
559
560 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
561 unsigned long arg)
562 {
563 struct linehandle_state *lh = filep->private_data;
564 void __user *ip = (void __user *)arg;
565 struct gpiohandle_data ghd;
566 DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
567 int i;
568
569 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
570 /* NOTE: It's ok to read values of output lines. */
571 int ret = gpiod_get_array_value_complex(false,
572 true,
573 lh->numdescs,
574 lh->descs,
575 NULL,
576 vals);
577 if (ret)
578 return ret;
579
580 memset(&ghd, 0, sizeof(ghd));
581 for (i = 0; i < lh->numdescs; i++)
582 ghd.values[i] = test_bit(i, vals);
583
584 if (copy_to_user(ip, &ghd, sizeof(ghd)))
585 return -EFAULT;
586
587 return 0;
588 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
589 /*
590 * All line descriptors were created at once with the same
591 * flags so just check if the first one is really output.
592 */
593 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
594 return -EPERM;
595
596 if (copy_from_user(&ghd, ip, sizeof(ghd)))
597 return -EFAULT;
598
599 /* Clamp all values to [0,1] */
600 for (i = 0; i < lh->numdescs; i++)
601 __assign_bit(i, vals, ghd.values[i]);
602
603 /* Reuse the array setting function */
604 return gpiod_set_array_value_complex(false,
605 true,
606 lh->numdescs,
607 lh->descs,
608 NULL,
609 vals);
610 } else if (cmd == GPIOHANDLE_SET_CONFIG_IOCTL) {
611 return linehandle_set_config(lh, ip);
612 }
613 return -EINVAL;
614 }
615
616 #ifdef CONFIG_COMPAT
617 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
618 unsigned long arg)
619 {
620 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
621 }
622 #endif
623
624 static int linehandle_release(struct inode *inode, struct file *filep)
625 {
626 struct linehandle_state *lh = filep->private_data;
627 struct gpio_device *gdev = lh->gdev;
628 int i;
629
630 for (i = 0; i < lh->numdescs; i++)
631 gpiod_free(lh->descs[i]);
632 kfree(lh->label);
633 kfree(lh);
634 put_device(&gdev->dev);
635 return 0;
636 }
637
638 static const struct file_operations linehandle_fileops = {
639 .release = linehandle_release,
640 .owner = THIS_MODULE,
641 .llseek = noop_llseek,
642 .unlocked_ioctl = linehandle_ioctl,
643 #ifdef CONFIG_COMPAT
644 .compat_ioctl = linehandle_ioctl_compat,
645 #endif
646 };
647
648 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
649 {
650 struct gpiohandle_request handlereq;
651 struct linehandle_state *lh;
652 struct file *file;
653 int fd, i, count = 0, ret;
654 u32 lflags;
655
656 if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
657 return -EFAULT;
658 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
659 return -EINVAL;
660
661 lflags = handlereq.flags;
662
663 ret = linehandle_validate_flags(lflags);
664 if (ret)
665 return ret;
666
667 lh = kzalloc(sizeof(*lh), GFP_KERNEL);
668 if (!lh)
669 return -ENOMEM;
670 lh->gdev = gdev;
671 get_device(&gdev->dev);
672
673 /* Make sure this is terminated */
674 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
675 if (strlen(handlereq.consumer_label)) {
676 lh->label = kstrdup(handlereq.consumer_label,
677 GFP_KERNEL);
678 if (!lh->label) {
679 ret = -ENOMEM;
680 goto out_free_lh;
681 }
682 }
683
684 /* Request each GPIO */
685 for (i = 0; i < handlereq.lines; i++) {
686 u32 offset = handlereq.lineoffsets[i];
687 struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset);
688
689 if (IS_ERR(desc)) {
690 ret = PTR_ERR(desc);
691 goto out_free_descs;
692 }
693
694 ret = gpiod_request(desc, lh->label);
695 if (ret)
696 goto out_free_descs;
697 lh->descs[i] = desc;
698 count = i + 1;
699
700 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
701 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
702 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
703 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
704 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
705 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
706 if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE)
707 set_bit(FLAG_BIAS_DISABLE, &desc->flags);
708 if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
709 set_bit(FLAG_PULL_DOWN, &desc->flags);
710 if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
711 set_bit(FLAG_PULL_UP, &desc->flags);
712
713 ret = gpiod_set_transitory(desc, false);
714 if (ret < 0)
715 goto out_free_descs;
716
717 /*
718 * Lines have to be requested explicitly for input
719 * or output, else the line will be treated "as is".
720 */
721 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
722 int val = !!handlereq.default_values[i];
723
724 ret = gpiod_direction_output(desc, val);
725 if (ret)
726 goto out_free_descs;
727 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
728 ret = gpiod_direction_input(desc);
729 if (ret)
730 goto out_free_descs;
731 }
732 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
733 offset);
734 }
735 /* Let i point at the last handle */
736 i--;
737 lh->numdescs = handlereq.lines;
738
739 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
740 if (fd < 0) {
741 ret = fd;
742 goto out_free_descs;
743 }
744
745 file = anon_inode_getfile("gpio-linehandle",
746 &linehandle_fileops,
747 lh,
748 O_RDONLY | O_CLOEXEC);
749 if (IS_ERR(file)) {
750 ret = PTR_ERR(file);
751 goto out_put_unused_fd;
752 }
753
754 handlereq.fd = fd;
755 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
756 /*
757 * fput() will trigger the release() callback, so do not go onto
758 * the regular error cleanup path here.
759 */
760 fput(file);
761 put_unused_fd(fd);
762 return -EFAULT;
763 }
764
765 fd_install(fd, file);
766
767 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
768 lh->numdescs);
769
770 return 0;
771
772 out_put_unused_fd:
773 put_unused_fd(fd);
774 out_free_descs:
775 for (i = 0; i < count; i++)
776 gpiod_free(lh->descs[i]);
777 kfree(lh->label);
778 out_free_lh:
779 kfree(lh);
780 put_device(&gdev->dev);
781 return ret;
782 }
783
784 /*
785 * GPIO line event management
786 */
787
788 /**
789 * struct lineevent_state - contains the state of a userspace event
790 * @gdev: the GPIO device the event pertains to
791 * @label: consumer label used to tag descriptors
792 * @desc: the GPIO descriptor held by this event
793 * @eflags: the event flags this line was requested with
794 * @irq: the interrupt that trigger in response to events on this GPIO
795 * @wait: wait queue that handles blocking reads of events
796 * @events: KFIFO for the GPIO events
797 * @timestamp: cache for the timestamp storing it between hardirq
798 * and IRQ thread, used to bring the timestamp close to the actual
799 * event
800 */
801 struct lineevent_state {
802 struct gpio_device *gdev;
803 const char *label;
804 struct gpio_desc *desc;
805 u32 eflags;
806 int irq;
807 wait_queue_head_t wait;
808 DECLARE_KFIFO(events, struct gpioevent_data, 16);
809 u64 timestamp;
810 };
811
812 #define GPIOEVENT_REQUEST_VALID_FLAGS \
813 (GPIOEVENT_REQUEST_RISING_EDGE | \
814 GPIOEVENT_REQUEST_FALLING_EDGE)
815
816 static __poll_t lineevent_poll(struct file *filep,
817 struct poll_table_struct *wait)
818 {
819 struct lineevent_state *le = filep->private_data;
820 __poll_t events = 0;
821
822 poll_wait(filep, &le->wait, wait);
823
824 if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock))
825 events = EPOLLIN | EPOLLRDNORM;
826
827 return events;
828 }
829
830
831 static ssize_t lineevent_read(struct file *filep,
832 char __user *buf,
833 size_t count,
834 loff_t *f_ps)
835 {
836 struct lineevent_state *le = filep->private_data;
837 struct gpioevent_data ge;
838 ssize_t bytes_read = 0;
839 int ret;
840
841 if (count < sizeof(ge))
842 return -EINVAL;
843
844 do {
845 spin_lock(&le->wait.lock);
846 if (kfifo_is_empty(&le->events)) {
847 if (bytes_read) {
848 spin_unlock(&le->wait.lock);
849 return bytes_read;
850 }
851
852 if (filep->f_flags & O_NONBLOCK) {
853 spin_unlock(&le->wait.lock);
854 return -EAGAIN;
855 }
856
857 ret = wait_event_interruptible_locked(le->wait,
858 !kfifo_is_empty(&le->events));
859 if (ret) {
860 spin_unlock(&le->wait.lock);
861 return ret;
862 }
863 }
864
865 ret = kfifo_out(&le->events, &ge, 1);
866 spin_unlock(&le->wait.lock);
867 if (ret != 1) {
868 /*
869 * This should never happen - we were holding the lock
870 * from the moment we learned the fifo is no longer
871 * empty until now.
872 */
873 ret = -EIO;
874 break;
875 }
876
877 if (copy_to_user(buf + bytes_read, &ge, sizeof(ge)))
878 return -EFAULT;
879 bytes_read += sizeof(ge);
880 } while (count >= bytes_read + sizeof(ge));
881
882 return bytes_read;
883 }
884
885 static int lineevent_release(struct inode *inode, struct file *filep)
886 {
887 struct lineevent_state *le = filep->private_data;
888 struct gpio_device *gdev = le->gdev;
889
890 free_irq(le->irq, le);
891 gpiod_free(le->desc);
892 kfree(le->label);
893 kfree(le);
894 put_device(&gdev->dev);
895 return 0;
896 }
897
898 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
899 unsigned long arg)
900 {
901 struct lineevent_state *le = filep->private_data;
902 void __user *ip = (void __user *)arg;
903 struct gpiohandle_data ghd;
904
905 /*
906 * We can get the value for an event line but not set it,
907 * because it is input by definition.
908 */
909 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
910 int val;
911
912 memset(&ghd, 0, sizeof(ghd));
913
914 val = gpiod_get_value_cansleep(le->desc);
915 if (val < 0)
916 return val;
917 ghd.values[0] = val;
918
919 if (copy_to_user(ip, &ghd, sizeof(ghd)))
920 return -EFAULT;
921
922 return 0;
923 }
924 return -EINVAL;
925 }
926
927 #ifdef CONFIG_COMPAT
928 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
929 unsigned long arg)
930 {
931 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
932 }
933 #endif
934
935 static const struct file_operations lineevent_fileops = {
936 .release = lineevent_release,
937 .read = lineevent_read,
938 .poll = lineevent_poll,
939 .owner = THIS_MODULE,
940 .llseek = noop_llseek,
941 .unlocked_ioctl = lineevent_ioctl,
942 #ifdef CONFIG_COMPAT
943 .compat_ioctl = lineevent_ioctl_compat,
944 #endif
945 };
946
947 static irqreturn_t lineevent_irq_thread(int irq, void *p)
948 {
949 struct lineevent_state *le = p;
950 struct gpioevent_data ge;
951 int ret;
952
953 /* Do not leak kernel stack to userspace */
954 memset(&ge, 0, sizeof(ge));
955
956 /*
957 * We may be running from a nested threaded interrupt in which case
958 * we didn't get the timestamp from lineevent_irq_handler().
959 */
960 if (!le->timestamp)
961 ge.timestamp = ktime_get_ns();
962 else
963 ge.timestamp = le->timestamp;
964
965 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
966 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
967 int level = gpiod_get_value_cansleep(le->desc);
968 if (level)
969 /* Emit low-to-high event */
970 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
971 else
972 /* Emit high-to-low event */
973 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
974 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
975 /* Emit low-to-high event */
976 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
977 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
978 /* Emit high-to-low event */
979 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
980 } else {
981 return IRQ_NONE;
982 }
983
984 ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge,
985 1, &le->wait.lock);
986 if (ret)
987 wake_up_poll(&le->wait, EPOLLIN);
988 else
989 pr_debug_ratelimited("event FIFO is full - event dropped\n");
990
991 return IRQ_HANDLED;
992 }
993
994 static irqreturn_t lineevent_irq_handler(int irq, void *p)
995 {
996 struct lineevent_state *le = p;
997
998 /*
999 * Just store the timestamp in hardirq context so we get it as
1000 * close in time as possible to the actual event.
1001 */
1002 le->timestamp = ktime_get_ns();
1003
1004 return IRQ_WAKE_THREAD;
1005 }
1006
1007 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
1008 {
1009 struct gpioevent_request eventreq;
1010 struct lineevent_state *le;
1011 struct gpio_desc *desc;
1012 struct file *file;
1013 u32 offset;
1014 u32 lflags;
1015 u32 eflags;
1016 int fd;
1017 int ret;
1018 int irqflags = 0;
1019
1020 if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
1021 return -EFAULT;
1022
1023 offset = eventreq.lineoffset;
1024 lflags = eventreq.handleflags;
1025 eflags = eventreq.eventflags;
1026
1027 desc = gpiochip_get_desc(gdev->chip, offset);
1028 if (IS_ERR(desc))
1029 return PTR_ERR(desc);
1030
1031 /* Return an error if a unknown flag is set */
1032 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
1033 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS))
1034 return -EINVAL;
1035
1036 /* This is just wrong: we don't look for events on output lines */
1037 if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
1038 (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
1039 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
1040 return -EINVAL;
1041
1042 /* Only one bias flag can be set. */
1043 if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
1044 (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
1045 GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
1046 ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
1047 (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
1048 return -EINVAL;
1049
1050 le = kzalloc(sizeof(*le), GFP_KERNEL);
1051 if (!le)
1052 return -ENOMEM;
1053 le->gdev = gdev;
1054 get_device(&gdev->dev);
1055
1056 /* Make sure this is terminated */
1057 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
1058 if (strlen(eventreq.consumer_label)) {
1059 le->label = kstrdup(eventreq.consumer_label,
1060 GFP_KERNEL);
1061 if (!le->label) {
1062 ret = -ENOMEM;
1063 goto out_free_le;
1064 }
1065 }
1066
1067 ret = gpiod_request(desc, le->label);
1068 if (ret)
1069 goto out_free_label;
1070 le->desc = desc;
1071 le->eflags = eflags;
1072
1073 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
1074 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
1075 if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE)
1076 set_bit(FLAG_BIAS_DISABLE, &desc->flags);
1077 if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
1078 set_bit(FLAG_PULL_DOWN, &desc->flags);
1079 if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
1080 set_bit(FLAG_PULL_UP, &desc->flags);
1081
1082 ret = gpiod_direction_input(desc);
1083 if (ret)
1084 goto out_free_desc;
1085
1086 le->irq = gpiod_to_irq(desc);
1087 if (le->irq <= 0) {
1088 ret = -ENODEV;
1089 goto out_free_desc;
1090 }
1091
1092 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
1093 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
1094 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
1095 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
1096 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
1097 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
1098 irqflags |= IRQF_ONESHOT;
1099
1100 INIT_KFIFO(le->events);
1101 init_waitqueue_head(&le->wait);
1102
1103 /* Request a thread to read the events */
1104 ret = request_threaded_irq(le->irq,
1105 lineevent_irq_handler,
1106 lineevent_irq_thread,
1107 irqflags,
1108 le->label,
1109 le);
1110 if (ret)
1111 goto out_free_desc;
1112
1113 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
1114 if (fd < 0) {
1115 ret = fd;
1116 goto out_free_irq;
1117 }
1118
1119 file = anon_inode_getfile("gpio-event",
1120 &lineevent_fileops,
1121 le,
1122 O_RDONLY | O_CLOEXEC);
1123 if (IS_ERR(file)) {
1124 ret = PTR_ERR(file);
1125 goto out_put_unused_fd;
1126 }
1127
1128 eventreq.fd = fd;
1129 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
1130 /*
1131 * fput() will trigger the release() callback, so do not go onto
1132 * the regular error cleanup path here.
1133 */
1134 fput(file);
1135 put_unused_fd(fd);
1136 return -EFAULT;
1137 }
1138
1139 fd_install(fd, file);
1140
1141 return 0;
1142
1143 out_put_unused_fd:
1144 put_unused_fd(fd);
1145 out_free_irq:
1146 free_irq(le->irq, le);
1147 out_free_desc:
1148 gpiod_free(le->desc);
1149 out_free_label:
1150 kfree(le->label);
1151 out_free_le:
1152 kfree(le);
1153 put_device(&gdev->dev);
1154 return ret;
1155 }
1156
1157 static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
1158 struct gpioline_info *info)
1159 {
1160 struct gpio_chip *gc = desc->gdev->chip;
1161 bool ok_for_pinctrl;
1162 unsigned long flags;
1163
1164 /*
1165 * This function takes a mutex so we must check this before taking
1166 * the spinlock.
1167 *
1168 * FIXME: find a non-racy way to retrieve this information. Maybe a
1169 * lock common to both frameworks?
1170 */
1171 ok_for_pinctrl =
1172 pinctrl_gpio_can_use_line(gc->base + info->line_offset);
1173
1174 spin_lock_irqsave(&gpio_lock, flags);
1175
1176 if (desc->name) {
1177 strncpy(info->name, desc->name, sizeof(info->name));
1178 info->name[sizeof(info->name) - 1] = '\0';
1179 } else {
1180 info->name[0] = '\0';
1181 }
1182
1183 if (desc->label) {
1184 strncpy(info->consumer, desc->label, sizeof(info->consumer));
1185 info->consumer[sizeof(info->consumer) - 1] = '\0';
1186 } else {
1187 info->consumer[0] = '\0';
1188 }
1189
1190 /*
1191 * Userspace only need to know that the kernel is using this GPIO so
1192 * it can't use it.
1193 */
1194 info->flags = 0;
1195 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1196 test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1197 test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1198 test_bit(FLAG_EXPORT, &desc->flags) ||
1199 test_bit(FLAG_SYSFS, &desc->flags) ||
1200 !ok_for_pinctrl)
1201 info->flags |= GPIOLINE_FLAG_KERNEL;
1202 if (test_bit(FLAG_IS_OUT, &desc->flags))
1203 info->flags |= GPIOLINE_FLAG_IS_OUT;
1204 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1205 info->flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1206 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1207 info->flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
1208 GPIOLINE_FLAG_IS_OUT);
1209 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1210 info->flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
1211 GPIOLINE_FLAG_IS_OUT);
1212 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
1213 info->flags |= GPIOLINE_FLAG_BIAS_DISABLE;
1214 if (test_bit(FLAG_PULL_DOWN, &desc->flags))
1215 info->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
1216 if (test_bit(FLAG_PULL_UP, &desc->flags))
1217 info->flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
1218
1219 spin_unlock_irqrestore(&gpio_lock, flags);
1220 }
1221
1222 struct gpio_chardev_data {
1223 struct gpio_device *gdev;
1224 wait_queue_head_t wait;
1225 DECLARE_KFIFO(events, struct gpioline_info_changed, 32);
1226 struct notifier_block lineinfo_changed_nb;
1227 unsigned long *watched_lines;
1228 };
1229
1230 /*
1231 * gpio_ioctl() - ioctl handler for the GPIO chardev
1232 */
1233 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1234 {
1235 struct gpio_chardev_data *priv = filp->private_data;
1236 struct gpio_device *gdev = priv->gdev;
1237 struct gpio_chip *gc = gdev->chip;
1238 void __user *ip = (void __user *)arg;
1239 struct gpio_desc *desc;
1240 __u32 offset;
1241 int hwgpio;
1242
1243 /* We fail any subsequent ioctl():s when the chip is gone */
1244 if (!gc)
1245 return -ENODEV;
1246
1247 /* Fill in the struct and pass to userspace */
1248 if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1249 struct gpiochip_info chipinfo;
1250
1251 memset(&chipinfo, 0, sizeof(chipinfo));
1252
1253 strncpy(chipinfo.name, dev_name(&gdev->dev),
1254 sizeof(chipinfo.name));
1255 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1256 strncpy(chipinfo.label, gdev->label,
1257 sizeof(chipinfo.label));
1258 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1259 chipinfo.lines = gdev->ngpio;
1260 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1261 return -EFAULT;
1262 return 0;
1263 } else if (cmd == GPIO_GET_LINEINFO_IOCTL ||
1264 cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) {
1265 struct gpioline_info lineinfo;
1266
1267 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1268 return -EFAULT;
1269
1270 desc = gpiochip_get_desc(gc, lineinfo.line_offset);
1271 if (IS_ERR(desc))
1272 return PTR_ERR(desc);
1273
1274 hwgpio = gpio_chip_hwgpio(desc);
1275
1276 if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL &&
1277 test_bit(hwgpio, priv->watched_lines))
1278 return -EBUSY;
1279
1280 gpio_desc_to_lineinfo(desc, &lineinfo);
1281
1282 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1283 return -EFAULT;
1284
1285 if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL)
1286 set_bit(hwgpio, priv->watched_lines);
1287
1288 return 0;
1289 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1290 return linehandle_create(gdev, ip);
1291 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1292 return lineevent_create(gdev, ip);
1293 } else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) {
1294 if (copy_from_user(&offset, ip, sizeof(offset)))
1295 return -EFAULT;
1296
1297 desc = gpiochip_get_desc(gc, offset);
1298 if (IS_ERR(desc))
1299 return PTR_ERR(desc);
1300
1301 hwgpio = gpio_chip_hwgpio(desc);
1302
1303 if (!test_bit(hwgpio, priv->watched_lines))
1304 return -EBUSY;
1305
1306 clear_bit(hwgpio, priv->watched_lines);
1307 return 0;
1308 }
1309 return -EINVAL;
1310 }
1311
1312 #ifdef CONFIG_COMPAT
1313 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1314 unsigned long arg)
1315 {
1316 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1317 }
1318 #endif
1319
1320 static struct gpio_chardev_data *
1321 to_gpio_chardev_data(struct notifier_block *nb)
1322 {
1323 return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb);
1324 }
1325
1326 static int lineinfo_changed_notify(struct notifier_block *nb,
1327 unsigned long action, void *data)
1328 {
1329 struct gpio_chardev_data *priv = to_gpio_chardev_data(nb);
1330 struct gpioline_info_changed chg;
1331 struct gpio_desc *desc = data;
1332 int ret;
1333
1334 if (!test_bit(gpio_chip_hwgpio(desc), priv->watched_lines))
1335 return NOTIFY_DONE;
1336
1337 memset(&chg, 0, sizeof(chg));
1338 chg.info.line_offset = gpio_chip_hwgpio(desc);
1339 chg.event_type = action;
1340 chg.timestamp = ktime_get_ns();
1341 gpio_desc_to_lineinfo(desc, &chg.info);
1342
1343 ret = kfifo_in_spinlocked(&priv->events, &chg, 1, &priv->wait.lock);
1344 if (ret)
1345 wake_up_poll(&priv->wait, EPOLLIN);
1346 else
1347 pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n");
1348
1349 return NOTIFY_OK;
1350 }
1351
1352 static __poll_t lineinfo_watch_poll(struct file *filep,
1353 struct poll_table_struct *pollt)
1354 {
1355 struct gpio_chardev_data *priv = filep->private_data;
1356 __poll_t events = 0;
1357
1358 poll_wait(filep, &priv->wait, pollt);
1359
1360 if (!kfifo_is_empty_spinlocked_noirqsave(&priv->events,
1361 &priv->wait.lock))
1362 events = EPOLLIN | EPOLLRDNORM;
1363
1364 return events;
1365 }
1366
1367 static ssize_t lineinfo_watch_read(struct file *filep, char __user *buf,
1368 size_t count, loff_t *off)
1369 {
1370 struct gpio_chardev_data *priv = filep->private_data;
1371 struct gpioline_info_changed event;
1372 ssize_t bytes_read = 0;
1373 int ret;
1374
1375 if (count < sizeof(event))
1376 return -EINVAL;
1377
1378 do {
1379 spin_lock(&priv->wait.lock);
1380 if (kfifo_is_empty(&priv->events)) {
1381 if (bytes_read) {
1382 spin_unlock(&priv->wait.lock);
1383 return bytes_read;
1384 }
1385
1386 if (filep->f_flags & O_NONBLOCK) {
1387 spin_unlock(&priv->wait.lock);
1388 return -EAGAIN;
1389 }
1390
1391 ret = wait_event_interruptible_locked(priv->wait,
1392 !kfifo_is_empty(&priv->events));
1393 if (ret) {
1394 spin_unlock(&priv->wait.lock);
1395 return ret;
1396 }
1397 }
1398
1399 ret = kfifo_out(&priv->events, &event, 1);
1400 spin_unlock(&priv->wait.lock);
1401 if (ret != 1) {
1402 ret = -EIO;
1403 break;
1404 /* We should never get here. See lineevent_read(). */
1405 }
1406
1407 if (copy_to_user(buf + bytes_read, &event, sizeof(event)))
1408 return -EFAULT;
1409 bytes_read += sizeof(event);
1410 } while (count >= bytes_read + sizeof(event));
1411
1412 return bytes_read;
1413 }
1414
1415 /**
1416 * gpio_chrdev_open() - open the chardev for ioctl operations
1417 * @inode: inode for this chardev
1418 * @filp: file struct for storing private data
1419 * Returns 0 on success
1420 */
1421 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1422 {
1423 struct gpio_device *gdev = container_of(inode->i_cdev,
1424 struct gpio_device, chrdev);
1425 struct gpio_chardev_data *priv;
1426 int ret = -ENOMEM;
1427
1428 /* Fail on open if the backing gpiochip is gone */
1429 if (!gdev->chip)
1430 return -ENODEV;
1431
1432 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1433 if (!priv)
1434 return -ENOMEM;
1435
1436 priv->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL);
1437 if (!priv->watched_lines)
1438 goto out_free_priv;
1439
1440 init_waitqueue_head(&priv->wait);
1441 INIT_KFIFO(priv->events);
1442 priv->gdev = gdev;
1443
1444 priv->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
1445 ret = atomic_notifier_chain_register(&gdev->notifier,
1446 &priv->lineinfo_changed_nb);
1447 if (ret)
1448 goto out_free_bitmap;
1449
1450 get_device(&gdev->dev);
1451 filp->private_data = priv;
1452
1453 ret = nonseekable_open(inode, filp);
1454 if (ret)
1455 goto out_unregister_notifier;
1456
1457 return ret;
1458
1459 out_unregister_notifier:
1460 atomic_notifier_chain_unregister(&gdev->notifier,
1461 &priv->lineinfo_changed_nb);
1462 out_free_bitmap:
1463 bitmap_free(priv->watched_lines);
1464 out_free_priv:
1465 kfree(priv);
1466 return ret;
1467 }
1468
1469 /**
1470 * gpio_chrdev_release() - close chardev after ioctl operations
1471 * @inode: inode for this chardev
1472 * @filp: file struct for storing private data
1473 * Returns 0 on success
1474 */
1475 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1476 {
1477 struct gpio_chardev_data *priv = filp->private_data;
1478 struct gpio_device *gdev = priv->gdev;
1479
1480 bitmap_free(priv->watched_lines);
1481 atomic_notifier_chain_unregister(&gdev->notifier,
1482 &priv->lineinfo_changed_nb);
1483 put_device(&gdev->dev);
1484 kfree(priv);
1485
1486 return 0;
1487 }
1488
1489 static const struct file_operations gpio_fileops = {
1490 .release = gpio_chrdev_release,
1491 .open = gpio_chrdev_open,
1492 .poll = lineinfo_watch_poll,
1493 .read = lineinfo_watch_read,
1494 .owner = THIS_MODULE,
1495 .llseek = no_llseek,
1496 .unlocked_ioctl = gpio_ioctl,
1497 #ifdef CONFIG_COMPAT
1498 .compat_ioctl = gpio_ioctl_compat,
1499 #endif
1500 };
1501
1502 static void gpiodevice_release(struct device *dev)
1503 {
1504 struct gpio_device *gdev = dev_get_drvdata(dev);
1505
1506 list_del(&gdev->list);
1507 ida_simple_remove(&gpio_ida, gdev->id);
1508 kfree_const(gdev->label);
1509 kfree(gdev->descs);
1510 kfree(gdev);
1511 }
1512
1513 static int gpiochip_setup_dev(struct gpio_device *gdev)
1514 {
1515 int ret;
1516
1517 cdev_init(&gdev->chrdev, &gpio_fileops);
1518 gdev->chrdev.owner = THIS_MODULE;
1519 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1520
1521 ret = cdev_device_add(&gdev->chrdev, &gdev->dev);
1522 if (ret)
1523 return ret;
1524
1525 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1526 MAJOR(gpio_devt), gdev->id);
1527
1528 ret = gpiochip_sysfs_register(gdev);
1529 if (ret)
1530 goto err_remove_device;
1531
1532 /* From this point, the .release() function cleans up gpio_device */
1533 gdev->dev.release = gpiodevice_release;
1534 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1535 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1536 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1537
1538 return 0;
1539
1540 err_remove_device:
1541 cdev_device_del(&gdev->chrdev, &gdev->dev);
1542 return ret;
1543 }
1544
1545 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
1546 {
1547 struct gpio_desc *desc;
1548 int rv;
1549
1550 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
1551 if (IS_ERR(desc)) {
1552 pr_err("%s: unable to get GPIO desc: %ld\n",
1553 __func__, PTR_ERR(desc));
1554 return;
1555 }
1556
1557 if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1558 return;
1559
1560 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1561 if (rv)
1562 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1563 __func__, gc->label, hog->chip_hwnum, rv);
1564 }
1565
1566 static void machine_gpiochip_add(struct gpio_chip *gc)
1567 {
1568 struct gpiod_hog *hog;
1569
1570 mutex_lock(&gpio_machine_hogs_mutex);
1571
1572 list_for_each_entry(hog, &gpio_machine_hogs, list) {
1573 if (!strcmp(gc->label, hog->chip_label))
1574 gpiochip_machine_hog(gc, hog);
1575 }
1576
1577 mutex_unlock(&gpio_machine_hogs_mutex);
1578 }
1579
1580 static void gpiochip_setup_devs(void)
1581 {
1582 struct gpio_device *gdev;
1583 int ret;
1584
1585 list_for_each_entry(gdev, &gpio_devices, list) {
1586 ret = gpiochip_setup_dev(gdev);
1587 if (ret)
1588 pr_err("%s: Failed to initialize gpio device (%d)\n",
1589 dev_name(&gdev->dev), ret);
1590 }
1591 }
1592
1593 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
1594 struct lock_class_key *lock_key,
1595 struct lock_class_key *request_key)
1596 {
1597 unsigned long flags;
1598 int ret = 0;
1599 unsigned i;
1600 int base = gc->base;
1601 struct gpio_device *gdev;
1602
1603 /*
1604 * First: allocate and populate the internal stat container, and
1605 * set up the struct device.
1606 */
1607 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1608 if (!gdev)
1609 return -ENOMEM;
1610 gdev->dev.bus = &gpio_bus_type;
1611 gdev->chip = gc;
1612 gc->gpiodev = gdev;
1613 if (gc->parent) {
1614 gdev->dev.parent = gc->parent;
1615 gdev->dev.of_node = gc->parent->of_node;
1616 }
1617
1618 #ifdef CONFIG_OF_GPIO
1619 /* If the gpiochip has an assigned OF node this takes precedence */
1620 if (gc->of_node)
1621 gdev->dev.of_node = gc->of_node;
1622 else
1623 gc->of_node = gdev->dev.of_node;
1624 #endif
1625
1626 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1627 if (gdev->id < 0) {
1628 ret = gdev->id;
1629 goto err_free_gdev;
1630 }
1631 dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
1632 device_initialize(&gdev->dev);
1633 dev_set_drvdata(&gdev->dev, gdev);
1634 if (gc->parent && gc->parent->driver)
1635 gdev->owner = gc->parent->driver->owner;
1636 else if (gc->owner)
1637 /* TODO: remove chip->owner */
1638 gdev->owner = gc->owner;
1639 else
1640 gdev->owner = THIS_MODULE;
1641
1642 gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1643 if (!gdev->descs) {
1644 ret = -ENOMEM;
1645 goto err_free_ida;
1646 }
1647
1648 if (gc->ngpio == 0) {
1649 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
1650 ret = -EINVAL;
1651 goto err_free_descs;
1652 }
1653
1654 if (gc->ngpio > FASTPATH_NGPIO)
1655 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
1656 gc->ngpio, FASTPATH_NGPIO);
1657
1658 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
1659 if (!gdev->label) {
1660 ret = -ENOMEM;
1661 goto err_free_descs;
1662 }
1663
1664 gdev->ngpio = gc->ngpio;
1665 gdev->data = data;
1666
1667 spin_lock_irqsave(&gpio_lock, flags);
1668
1669 /*
1670 * TODO: this allocates a Linux GPIO number base in the global
1671 * GPIO numberspace for this chip. In the long run we want to
1672 * get *rid* of this numberspace and use only descriptors, but
1673 * it may be a pipe dream. It will not happen before we get rid
1674 * of the sysfs interface anyways.
1675 */
1676 if (base < 0) {
1677 base = gpiochip_find_base(gc->ngpio);
1678 if (base < 0) {
1679 ret = base;
1680 spin_unlock_irqrestore(&gpio_lock, flags);
1681 goto err_free_label;
1682 }
1683 /*
1684 * TODO: it should not be necessary to reflect the assigned
1685 * base outside of the GPIO subsystem. Go over drivers and
1686 * see if anyone makes use of this, else drop this and assign
1687 * a poison instead.
1688 */
1689 gc->base = base;
1690 }
1691 gdev->base = base;
1692
1693 ret = gpiodev_add_to_list(gdev);
1694 if (ret) {
1695 spin_unlock_irqrestore(&gpio_lock, flags);
1696 goto err_free_label;
1697 }
1698
1699 for (i = 0; i < gc->ngpio; i++)
1700 gdev->descs[i].gdev = gdev;
1701
1702 spin_unlock_irqrestore(&gpio_lock, flags);
1703
1704 ATOMIC_INIT_NOTIFIER_HEAD(&gdev->notifier);
1705
1706 #ifdef CONFIG_PINCTRL
1707 INIT_LIST_HEAD(&gdev->pin_ranges);
1708 #endif
1709
1710 ret = gpiochip_set_desc_names(gc);
1711 if (ret)
1712 goto err_remove_from_list;
1713
1714 ret = gpiochip_alloc_valid_mask(gc);
1715 if (ret)
1716 goto err_remove_from_list;
1717
1718 ret = of_gpiochip_add(gc);
1719 if (ret)
1720 goto err_free_gpiochip_mask;
1721
1722 ret = gpiochip_init_valid_mask(gc);
1723 if (ret)
1724 goto err_remove_of_chip;
1725
1726 for (i = 0; i < gc->ngpio; i++) {
1727 struct gpio_desc *desc = &gdev->descs[i];
1728
1729 if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
1730 assign_bit(FLAG_IS_OUT,
1731 &desc->flags, !gc->get_direction(gc, i));
1732 } else {
1733 assign_bit(FLAG_IS_OUT,
1734 &desc->flags, !gc->direction_input);
1735 }
1736 }
1737
1738 ret = gpiochip_add_pin_ranges(gc);
1739 if (ret)
1740 goto err_remove_of_chip;
1741
1742 acpi_gpiochip_add(gc);
1743
1744 machine_gpiochip_add(gc);
1745
1746 ret = gpiochip_irqchip_init_valid_mask(gc);
1747 if (ret)
1748 goto err_remove_acpi_chip;
1749
1750 ret = gpiochip_irqchip_init_hw(gc);
1751 if (ret)
1752 goto err_remove_acpi_chip;
1753
1754 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
1755 if (ret)
1756 goto err_remove_irqchip_mask;
1757
1758 /*
1759 * By first adding the chardev, and then adding the device,
1760 * we get a device node entry in sysfs under
1761 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1762 * coldplug of device nodes and other udev business.
1763 * We can do this only if gpiolib has been initialized.
1764 * Otherwise, defer until later.
1765 */
1766 if (gpiolib_initialized) {
1767 ret = gpiochip_setup_dev(gdev);
1768 if (ret)
1769 goto err_remove_irqchip;
1770 }
1771 return 0;
1772
1773 err_remove_irqchip:
1774 gpiochip_irqchip_remove(gc);
1775 err_remove_irqchip_mask:
1776 gpiochip_irqchip_free_valid_mask(gc);
1777 err_remove_acpi_chip:
1778 acpi_gpiochip_remove(gc);
1779 err_remove_of_chip:
1780 gpiochip_free_hogs(gc);
1781 of_gpiochip_remove(gc);
1782 err_free_gpiochip_mask:
1783 gpiochip_remove_pin_ranges(gc);
1784 gpiochip_free_valid_mask(gc);
1785 err_remove_from_list:
1786 spin_lock_irqsave(&gpio_lock, flags);
1787 list_del(&gdev->list);
1788 spin_unlock_irqrestore(&gpio_lock, flags);
1789 err_free_label:
1790 kfree_const(gdev->label);
1791 err_free_descs:
1792 kfree(gdev->descs);
1793 err_free_ida:
1794 ida_simple_remove(&gpio_ida, gdev->id);
1795 err_free_gdev:
1796 /* failures here can mean systems won't boot... */
1797 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1798 gdev->base, gdev->base + gdev->ngpio - 1,
1799 gc->label ? : "generic", ret);
1800 kfree(gdev);
1801 return ret;
1802 }
1803 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1804
1805 /**
1806 * gpiochip_get_data() - get per-subdriver data for the chip
1807 * @gc: GPIO chip
1808 *
1809 * Returns:
1810 * The per-subdriver data for the chip.
1811 */
1812 void *gpiochip_get_data(struct gpio_chip *gc)
1813 {
1814 return gc->gpiodev->data;
1815 }
1816 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1817
1818 /**
1819 * gpiochip_remove() - unregister a gpio_chip
1820 * @gc: the chip to unregister
1821 *
1822 * A gpio_chip with any GPIOs still requested may not be removed.
1823 */
1824 void gpiochip_remove(struct gpio_chip *gc)
1825 {
1826 struct gpio_device *gdev = gc->gpiodev;
1827 unsigned long flags;
1828 unsigned int i;
1829
1830 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1831 gpiochip_sysfs_unregister(gdev);
1832 gpiochip_free_hogs(gc);
1833 /* Numb the device, cancelling all outstanding operations */
1834 gdev->chip = NULL;
1835 gpiochip_irqchip_remove(gc);
1836 acpi_gpiochip_remove(gc);
1837 of_gpiochip_remove(gc);
1838 gpiochip_remove_pin_ranges(gc);
1839 gpiochip_free_valid_mask(gc);
1840 /*
1841 * We accept no more calls into the driver from this point, so
1842 * NULL the driver data pointer
1843 */
1844 gdev->data = NULL;
1845
1846 spin_lock_irqsave(&gpio_lock, flags);
1847 for (i = 0; i < gdev->ngpio; i++) {
1848 if (gpiochip_is_requested(gc, i))
1849 break;
1850 }
1851 spin_unlock_irqrestore(&gpio_lock, flags);
1852
1853 if (i != gdev->ngpio)
1854 dev_crit(&gdev->dev,
1855 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1856
1857 /*
1858 * The gpiochip side puts its use of the device to rest here:
1859 * if there are no userspace clients, the chardev and device will
1860 * be removed, else it will be dangling until the last user is
1861 * gone.
1862 */
1863 cdev_device_del(&gdev->chrdev, &gdev->dev);
1864 put_device(&gdev->dev);
1865 }
1866 EXPORT_SYMBOL_GPL(gpiochip_remove);
1867
1868 /**
1869 * gpiochip_find() - iterator for locating a specific gpio_chip
1870 * @data: data to pass to match function
1871 * @match: Callback function to check gpio_chip
1872 *
1873 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1874 * determined by a user supplied @match callback. The callback should return
1875 * 0 if the device doesn't match and non-zero if it does. If the callback is
1876 * non-zero, this function will return to the caller and not iterate over any
1877 * more gpio_chips.
1878 */
1879 struct gpio_chip *gpiochip_find(void *data,
1880 int (*match)(struct gpio_chip *gc,
1881 void *data))
1882 {
1883 struct gpio_device *gdev;
1884 struct gpio_chip *gc = NULL;
1885 unsigned long flags;
1886
1887 spin_lock_irqsave(&gpio_lock, flags);
1888 list_for_each_entry(gdev, &gpio_devices, list)
1889 if (gdev->chip && match(gdev->chip, data)) {
1890 gc = gdev->chip;
1891 break;
1892 }
1893
1894 spin_unlock_irqrestore(&gpio_lock, flags);
1895
1896 return gc;
1897 }
1898 EXPORT_SYMBOL_GPL(gpiochip_find);
1899
1900 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
1901 {
1902 const char *name = data;
1903
1904 return !strcmp(gc->label, name);
1905 }
1906
1907 static struct gpio_chip *find_chip_by_name(const char *name)
1908 {
1909 return gpiochip_find((void *)name, gpiochip_match_name);
1910 }
1911
1912 #ifdef CONFIG_GPIOLIB_IRQCHIP
1913
1914 /*
1915 * The following is irqchip helper code for gpiochips.
1916 */
1917
1918 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1919 {
1920 struct gpio_irq_chip *girq = &gc->irq;
1921
1922 if (!girq->init_hw)
1923 return 0;
1924
1925 return girq->init_hw(gc);
1926 }
1927
1928 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1929 {
1930 struct gpio_irq_chip *girq = &gc->irq;
1931
1932 if (!girq->init_valid_mask)
1933 return 0;
1934
1935 girq->valid_mask = gpiochip_allocate_mask(gc);
1936 if (!girq->valid_mask)
1937 return -ENOMEM;
1938
1939 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1940
1941 return 0;
1942 }
1943
1944 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1945 {
1946 bitmap_free(gc->irq.valid_mask);
1947 gc->irq.valid_mask = NULL;
1948 }
1949
1950 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
1951 unsigned int offset)
1952 {
1953 if (!gpiochip_line_is_valid(gc, offset))
1954 return false;
1955 /* No mask means all valid */
1956 if (likely(!gc->irq.valid_mask))
1957 return true;
1958 return test_bit(offset, gc->irq.valid_mask);
1959 }
1960 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1961
1962 /**
1963 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1964 * @gc: the gpiochip to set the irqchip chain to
1965 * @parent_irq: the irq number corresponding to the parent IRQ for this
1966 * cascaded irqchip
1967 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1968 * coming out of the gpiochip. If the interrupt is nested rather than
1969 * cascaded, pass NULL in this handler argument
1970 */
1971 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gc,
1972 unsigned int parent_irq,
1973 irq_flow_handler_t parent_handler)
1974 {
1975 struct gpio_irq_chip *girq = &gc->irq;
1976 struct device *dev = &gc->gpiodev->dev;
1977
1978 if (!girq->domain) {
1979 chip_err(gc, "called %s before setting up irqchip\n",
1980 __func__);
1981 return;
1982 }
1983
1984 if (parent_handler) {
1985 if (gc->can_sleep) {
1986 chip_err(gc,
1987 "you cannot have chained interrupts on a chip that may sleep\n");
1988 return;
1989 }
1990 girq->parents = devm_kcalloc(dev, 1,
1991 sizeof(*girq->parents),
1992 GFP_KERNEL);
1993 if (!girq->parents) {
1994 chip_err(gc, "out of memory allocating parent IRQ\n");
1995 return;
1996 }
1997 girq->parents[0] = parent_irq;
1998 girq->num_parents = 1;
1999 /*
2000 * The parent irqchip is already using the chip_data for this
2001 * irqchip, so our callbacks simply use the handler_data.
2002 */
2003 irq_set_chained_handler_and_data(parent_irq, parent_handler,
2004 gc);
2005 }
2006 }
2007
2008 /**
2009 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
2010 * @gc: the gpiochip to set the irqchip nested handler to
2011 * @irqchip: the irqchip to nest to the gpiochip
2012 * @parent_irq: the irq number corresponding to the parent IRQ for this
2013 * nested irqchip
2014 */
2015 void gpiochip_set_nested_irqchip(struct gpio_chip *gc,
2016 struct irq_chip *irqchip,
2017 unsigned int parent_irq)
2018 {
2019 gpiochip_set_cascaded_irqchip(gc, parent_irq, NULL);
2020 }
2021 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
2022
2023 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2024
2025 /**
2026 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
2027 * to a gpiochip
2028 * @gc: the gpiochip to set the irqchip hierarchical handler to
2029 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
2030 * will then percolate up to the parent
2031 */
2032 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
2033 struct irq_chip *irqchip)
2034 {
2035 /* DT will deal with mapping each IRQ as we go along */
2036 if (is_of_node(gc->irq.fwnode))
2037 return;
2038
2039 /*
2040 * This is for legacy and boardfile "irqchip" fwnodes: allocate
2041 * irqs upfront instead of dynamically since we don't have the
2042 * dynamic type of allocation that hardware description languages
2043 * provide. Once all GPIO drivers using board files are gone from
2044 * the kernel we can delete this code, but for a transitional period
2045 * it is necessary to keep this around.
2046 */
2047 if (is_fwnode_irqchip(gc->irq.fwnode)) {
2048 int i;
2049 int ret;
2050
2051 for (i = 0; i < gc->ngpio; i++) {
2052 struct irq_fwspec fwspec;
2053 unsigned int parent_hwirq;
2054 unsigned int parent_type;
2055 struct gpio_irq_chip *girq = &gc->irq;
2056
2057 /*
2058 * We call the child to parent translation function
2059 * only to check if the child IRQ is valid or not.
2060 * Just pick the rising edge type here as that is what
2061 * we likely need to support.
2062 */
2063 ret = girq->child_to_parent_hwirq(gc, i,
2064 IRQ_TYPE_EDGE_RISING,
2065 &parent_hwirq,
2066 &parent_type);
2067 if (ret) {
2068 chip_err(gc, "skip set-up on hwirq %d\n",
2069 i);
2070 continue;
2071 }
2072
2073 fwspec.fwnode = gc->irq.fwnode;
2074 /* This is the hwirq for the GPIO line side of things */
2075 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
2076 /* Just pick something */
2077 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
2078 fwspec.param_count = 2;
2079 ret = __irq_domain_alloc_irqs(gc->irq.domain,
2080 /* just pick something */
2081 -1,
2082 1,
2083 NUMA_NO_NODE,
2084 &fwspec,
2085 false,
2086 NULL);
2087 if (ret < 0) {
2088 chip_err(gc,
2089 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
2090 i, parent_hwirq,
2091 ret);
2092 }
2093 }
2094 }
2095
2096 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
2097
2098 return;
2099 }
2100
2101 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
2102 struct irq_fwspec *fwspec,
2103 unsigned long *hwirq,
2104 unsigned int *type)
2105 {
2106 /* We support standard DT translation */
2107 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
2108 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
2109 }
2110
2111 /* This is for board files and others not using DT */
2112 if (is_fwnode_irqchip(fwspec->fwnode)) {
2113 int ret;
2114
2115 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
2116 if (ret)
2117 return ret;
2118 WARN_ON(*type == IRQ_TYPE_NONE);
2119 return 0;
2120 }
2121 return -EINVAL;
2122 }
2123
2124 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
2125 unsigned int irq,
2126 unsigned int nr_irqs,
2127 void *data)
2128 {
2129 struct gpio_chip *gc = d->host_data;
2130 irq_hw_number_t hwirq;
2131 unsigned int type = IRQ_TYPE_NONE;
2132 struct irq_fwspec *fwspec = data;
2133 void *parent_arg;
2134 unsigned int parent_hwirq;
2135 unsigned int parent_type;
2136 struct gpio_irq_chip *girq = &gc->irq;
2137 int ret;
2138
2139 /*
2140 * The nr_irqs parameter is always one except for PCI multi-MSI
2141 * so this should not happen.
2142 */
2143 WARN_ON(nr_irqs != 1);
2144
2145 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
2146 if (ret)
2147 return ret;
2148
2149 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
2150
2151 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
2152 &parent_hwirq, &parent_type);
2153 if (ret) {
2154 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
2155 return ret;
2156 }
2157 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
2158
2159 /*
2160 * We set handle_bad_irq because the .set_type() should
2161 * always be invoked and set the right type of handler.
2162 */
2163 irq_domain_set_info(d,
2164 irq,
2165 hwirq,
2166 gc->irq.chip,
2167 gc,
2168 girq->handler,
2169 NULL, NULL);
2170 irq_set_probe(irq);
2171
2172 /* This parent only handles asserted level IRQs */
2173 parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
2174 if (!parent_arg)
2175 return -ENOMEM;
2176
2177 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
2178 irq, parent_hwirq);
2179 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
2180 ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
2181 /*
2182 * If the parent irqdomain is msi, the interrupts have already
2183 * been allocated, so the EEXIST is good.
2184 */
2185 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
2186 ret = 0;
2187 if (ret)
2188 chip_err(gc,
2189 "failed to allocate parent hwirq %d for hwirq %lu\n",
2190 parent_hwirq, hwirq);
2191
2192 kfree(parent_arg);
2193 return ret;
2194 }
2195
2196 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
2197 unsigned int offset)
2198 {
2199 return offset;
2200 }
2201
2202 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
2203 {
2204 ops->activate = gpiochip_irq_domain_activate;
2205 ops->deactivate = gpiochip_irq_domain_deactivate;
2206 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
2207 ops->free = irq_domain_free_irqs_common;
2208
2209 /*
2210 * We only allow overriding the translate() function for
2211 * hierarchical chips, and this should only be done if the user
2212 * really need something other than 1:1 translation.
2213 */
2214 if (!ops->translate)
2215 ops->translate = gpiochip_hierarchy_irq_domain_translate;
2216 }
2217
2218 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
2219 {
2220 if (!gc->irq.child_to_parent_hwirq ||
2221 !gc->irq.fwnode) {
2222 chip_err(gc, "missing irqdomain vital data\n");
2223 return -EINVAL;
2224 }
2225
2226 if (!gc->irq.child_offset_to_irq)
2227 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
2228
2229 if (!gc->irq.populate_parent_alloc_arg)
2230 gc->irq.populate_parent_alloc_arg =
2231 gpiochip_populate_parent_fwspec_twocell;
2232
2233 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
2234
2235 gc->irq.domain = irq_domain_create_hierarchy(
2236 gc->irq.parent_domain,
2237 0,
2238 gc->ngpio,
2239 gc->irq.fwnode,
2240 &gc->irq.child_irq_domain_ops,
2241 gc);
2242
2243 if (!gc->irq.domain)
2244 return -ENOMEM;
2245
2246 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
2247
2248 return 0;
2249 }
2250
2251 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
2252 {
2253 return !!gc->irq.parent_domain;
2254 }
2255
2256 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
2257 unsigned int parent_hwirq,
2258 unsigned int parent_type)
2259 {
2260 struct irq_fwspec *fwspec;
2261
2262 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
2263 if (!fwspec)
2264 return NULL;
2265
2266 fwspec->fwnode = gc->irq.parent_domain->fwnode;
2267 fwspec->param_count = 2;
2268 fwspec->param[0] = parent_hwirq;
2269 fwspec->param[1] = parent_type;
2270
2271 return fwspec;
2272 }
2273 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
2274
2275 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
2276 unsigned int parent_hwirq,
2277 unsigned int parent_type)
2278 {
2279 struct irq_fwspec *fwspec;
2280
2281 fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
2282 if (!fwspec)
2283 return NULL;
2284
2285 fwspec->fwnode = gc->irq.parent_domain->fwnode;
2286 fwspec->param_count = 4;
2287 fwspec->param[0] = 0;
2288 fwspec->param[1] = parent_hwirq;
2289 fwspec->param[2] = 0;
2290 fwspec->param[3] = parent_type;
2291
2292 return fwspec;
2293 }
2294 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
2295
2296 #else
2297
2298 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
2299 {
2300 return -EINVAL;
2301 }
2302
2303 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
2304 {
2305 return false;
2306 }
2307
2308 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
2309
2310 /**
2311 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
2312 * @d: the irqdomain used by this irqchip
2313 * @irq: the global irq number used by this GPIO irqchip irq
2314 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
2315 *
2316 * This function will set up the mapping for a certain IRQ line on a
2317 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
2318 * stored inside the gpiochip.
2319 */
2320 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
2321 irq_hw_number_t hwirq)
2322 {
2323 struct gpio_chip *gc = d->host_data;
2324 int ret = 0;
2325
2326 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
2327 return -ENXIO;
2328
2329 irq_set_chip_data(irq, gc);
2330 /*
2331 * This lock class tells lockdep that GPIO irqs are in a different
2332 * category than their parents, so it won't report false recursion.
2333 */
2334 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
2335 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
2336 /* Chips that use nested thread handlers have them marked */
2337 if (gc->irq.threaded)
2338 irq_set_nested_thread(irq, 1);
2339 irq_set_noprobe(irq);
2340
2341 if (gc->irq.num_parents == 1)
2342 ret = irq_set_parent(irq, gc->irq.parents[0]);
2343 else if (gc->irq.map)
2344 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
2345
2346 if (ret < 0)
2347 return ret;
2348
2349 /*
2350 * No set-up of the hardware will happen if IRQ_TYPE_NONE
2351 * is passed as default type.
2352 */
2353 if (gc->irq.default_type != IRQ_TYPE_NONE)
2354 irq_set_irq_type(irq, gc->irq.default_type);
2355
2356 return 0;
2357 }
2358 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
2359
2360 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
2361 {
2362 struct gpio_chip *gc = d->host_data;
2363
2364 if (gc->irq.threaded)
2365 irq_set_nested_thread(irq, 0);
2366 irq_set_chip_and_handler(irq, NULL, NULL);
2367 irq_set_chip_data(irq, NULL);
2368 }
2369 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
2370
2371 static const struct irq_domain_ops gpiochip_domain_ops = {
2372 .map = gpiochip_irq_map,
2373 .unmap = gpiochip_irq_unmap,
2374 /* Virtually all GPIO irqchips are twocell:ed */
2375 .xlate = irq_domain_xlate_twocell,
2376 };
2377
2378 /*
2379 * TODO: move these activate/deactivate in under the hierarchicial
2380 * irqchip implementation as static once SPMI and SSBI (all external
2381 * users) are phased over.
2382 */
2383 /**
2384 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
2385 * @domain: The IRQ domain used by this IRQ chip
2386 * @data: Outermost irq_data associated with the IRQ
2387 * @reserve: If set, only reserve an interrupt vector instead of assigning one
2388 *
2389 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
2390 * used as the activate function for the &struct irq_domain_ops. The host_data
2391 * for the IRQ domain must be the &struct gpio_chip.
2392 */
2393 int gpiochip_irq_domain_activate(struct irq_domain *domain,
2394 struct irq_data *data, bool reserve)
2395 {
2396 struct gpio_chip *gc = domain->host_data;
2397
2398 return gpiochip_lock_as_irq(gc, data->hwirq);
2399 }
2400 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
2401
2402 /**
2403 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
2404 * @domain: The IRQ domain used by this IRQ chip
2405 * @data: Outermost irq_data associated with the IRQ
2406 *
2407 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
2408 * be used as the deactivate function for the &struct irq_domain_ops. The
2409 * host_data for the IRQ domain must be the &struct gpio_chip.
2410 */
2411 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
2412 struct irq_data *data)
2413 {
2414 struct gpio_chip *gc = domain->host_data;
2415
2416 return gpiochip_unlock_as_irq(gc, data->hwirq);
2417 }
2418 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
2419
2420 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned offset)
2421 {
2422 struct irq_domain *domain = gc->irq.domain;
2423
2424 if (!gpiochip_irqchip_irq_valid(gc, offset))
2425 return -ENXIO;
2426
2427 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2428 if (irq_domain_is_hierarchy(domain)) {
2429 struct irq_fwspec spec;
2430
2431 spec.fwnode = domain->fwnode;
2432 spec.param_count = 2;
2433 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
2434 spec.param[1] = IRQ_TYPE_NONE;
2435
2436 return irq_create_fwspec_mapping(&spec);
2437 }
2438 #endif
2439
2440 return irq_create_mapping(domain, offset);
2441 }
2442
2443 static int gpiochip_irq_reqres(struct irq_data *d)
2444 {
2445 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
2446
2447 return gpiochip_reqres_irq(gc, d->hwirq);
2448 }
2449
2450 static void gpiochip_irq_relres(struct irq_data *d)
2451 {
2452 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
2453
2454 gpiochip_relres_irq(gc, d->hwirq);
2455 }
2456
2457 static void gpiochip_irq_enable(struct irq_data *d)
2458 {
2459 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
2460
2461 gpiochip_enable_irq(gc, d->hwirq);
2462 if (gc->irq.irq_enable)
2463 gc->irq.irq_enable(d);
2464 else
2465 gc->irq.chip->irq_unmask(d);
2466 }
2467
2468 static void gpiochip_irq_disable(struct irq_data *d)
2469 {
2470 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
2471
2472 /*
2473 * Since we override .irq_disable() we need to mimic the
2474 * behaviour of __irq_disable() in irq/chip.c.
2475 * First call .irq_disable() if it exists, else mimic the
2476 * behaviour of mask_irq() which calls .irq_mask() if
2477 * it exists.
2478 */
2479 if (gc->irq.irq_disable)
2480 gc->irq.irq_disable(d);
2481 else if (gc->irq.chip->irq_mask)
2482 gc->irq.chip->irq_mask(d);
2483 gpiochip_disable_irq(gc, d->hwirq);
2484 }
2485
2486 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
2487 {
2488 struct irq_chip *irqchip = gc->irq.chip;
2489
2490 if (!irqchip->irq_request_resources &&
2491 !irqchip->irq_release_resources) {
2492 irqchip->irq_request_resources = gpiochip_irq_reqres;
2493 irqchip->irq_release_resources = gpiochip_irq_relres;
2494 }
2495 if (WARN_ON(gc->irq.irq_enable))
2496 return;
2497 /* Check if the irqchip already has this hook... */
2498 if (irqchip->irq_enable == gpiochip_irq_enable) {
2499 /*
2500 * ...and if so, give a gentle warning that this is bad
2501 * practice.
2502 */
2503 chip_info(gc,
2504 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
2505 return;
2506 }
2507 gc->irq.irq_enable = irqchip->irq_enable;
2508 gc->irq.irq_disable = irqchip->irq_disable;
2509 irqchip->irq_enable = gpiochip_irq_enable;
2510 irqchip->irq_disable = gpiochip_irq_disable;
2511 }
2512
2513 /**
2514 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
2515 * @gc: the GPIO chip to add the IRQ chip to
2516 * @lock_key: lockdep class for IRQ lock
2517 * @request_key: lockdep class for IRQ request
2518 */
2519 static int gpiochip_add_irqchip(struct gpio_chip *gc,
2520 struct lock_class_key *lock_key,
2521 struct lock_class_key *request_key)
2522 {
2523 struct irq_chip *irqchip = gc->irq.chip;
2524 const struct irq_domain_ops *ops = NULL;
2525 struct device_node *np;
2526 unsigned int type;
2527 unsigned int i;
2528
2529 if (!irqchip)
2530 return 0;
2531
2532 if (gc->irq.parent_handler && gc->can_sleep) {
2533 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
2534 return -EINVAL;
2535 }
2536
2537 np = gc->gpiodev->dev.of_node;
2538 type = gc->irq.default_type;
2539
2540 /*
2541 * Specifying a default trigger is a terrible idea if DT or ACPI is
2542 * used to configure the interrupts, as you may end up with
2543 * conflicting triggers. Tell the user, and reset to NONE.
2544 */
2545 if (WARN(np && type != IRQ_TYPE_NONE,
2546 "%s: Ignoring %u default trigger\n", np->full_name, type))
2547 type = IRQ_TYPE_NONE;
2548
2549 if (has_acpi_companion(gc->parent) && type != IRQ_TYPE_NONE) {
2550 acpi_handle_warn(ACPI_HANDLE(gc->parent),
2551 "Ignoring %u default trigger\n", type);
2552 type = IRQ_TYPE_NONE;
2553 }
2554
2555 gc->to_irq = gpiochip_to_irq;
2556 gc->irq.default_type = type;
2557 gc->irq.lock_key = lock_key;
2558 gc->irq.request_key = request_key;
2559
2560 /* If a parent irqdomain is provided, let's build a hierarchy */
2561 if (gpiochip_hierarchy_is_hierarchical(gc)) {
2562 int ret = gpiochip_hierarchy_add_domain(gc);
2563 if (ret)
2564 return ret;
2565 } else {
2566 /* Some drivers provide custom irqdomain ops */
2567 if (gc->irq.domain_ops)
2568 ops = gc->irq.domain_ops;
2569
2570 if (!ops)
2571 ops = &gpiochip_domain_ops;
2572 gc->irq.domain = irq_domain_add_simple(np,
2573 gc->ngpio,
2574 gc->irq.first,
2575 ops, gc);
2576 if (!gc->irq.domain)
2577 return -EINVAL;
2578 }
2579
2580 if (gc->irq.parent_handler) {
2581 void *data = gc->irq.parent_handler_data ?: gc;
2582
2583 for (i = 0; i < gc->irq.num_parents; i++) {
2584 /*
2585 * The parent IRQ chip is already using the chip_data
2586 * for this IRQ chip, so our callbacks simply use the
2587 * handler_data.
2588 */
2589 irq_set_chained_handler_and_data(gc->irq.parents[i],
2590 gc->irq.parent_handler,
2591 data);
2592 }
2593 }
2594
2595 gpiochip_set_irq_hooks(gc);
2596
2597 acpi_gpiochip_request_interrupts(gc);
2598
2599 return 0;
2600 }
2601
2602 /**
2603 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
2604 * @gc: the gpiochip to remove the irqchip from
2605 *
2606 * This is called only from gpiochip_remove()
2607 */
2608 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
2609 {
2610 struct irq_chip *irqchip = gc->irq.chip;
2611 unsigned int offset;
2612
2613 acpi_gpiochip_free_interrupts(gc);
2614
2615 if (irqchip && gc->irq.parent_handler) {
2616 struct gpio_irq_chip *irq = &gc->irq;
2617 unsigned int i;
2618
2619 for (i = 0; i < irq->num_parents; i++)
2620 irq_set_chained_handler_and_data(irq->parents[i],
2621 NULL, NULL);
2622 }
2623
2624 /* Remove all IRQ mappings and delete the domain */
2625 if (gc->irq.domain) {
2626 unsigned int irq;
2627
2628 for (offset = 0; offset < gc->ngpio; offset++) {
2629 if (!gpiochip_irqchip_irq_valid(gc, offset))
2630 continue;
2631
2632 irq = irq_find_mapping(gc->irq.domain, offset);
2633 irq_dispose_mapping(irq);
2634 }
2635
2636 irq_domain_remove(gc->irq.domain);
2637 }
2638
2639 if (irqchip) {
2640 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2641 irqchip->irq_request_resources = NULL;
2642 irqchip->irq_release_resources = NULL;
2643 }
2644 if (irqchip->irq_enable == gpiochip_irq_enable) {
2645 irqchip->irq_enable = gc->irq.irq_enable;
2646 irqchip->irq_disable = gc->irq.irq_disable;
2647 }
2648 }
2649 gc->irq.irq_enable = NULL;
2650 gc->irq.irq_disable = NULL;
2651 gc->irq.chip = NULL;
2652
2653 gpiochip_irqchip_free_valid_mask(gc);
2654 }
2655
2656 /**
2657 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2658 * @gc: the gpiochip to add the irqchip to
2659 * @irqchip: the irqchip to add to the gpiochip
2660 * @first_irq: if not dynamically assigned, the base (first) IRQ to
2661 * allocate gpiochip irqs from
2662 * @handler: the irq handler to use (often a predefined irq core function)
2663 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2664 * to have the core avoid setting up any default type in the hardware.
2665 * @threaded: whether this irqchip uses a nested thread handler
2666 * @lock_key: lockdep class for IRQ lock
2667 * @request_key: lockdep class for IRQ request
2668 *
2669 * This function closely associates a certain irqchip with a certain
2670 * gpiochip, providing an irq domain to translate the local IRQs to
2671 * global irqs in the gpiolib core, and making sure that the gpiochip
2672 * is passed as chip data to all related functions. Driver callbacks
2673 * need to use gpiochip_get_data() to get their local state containers back
2674 * from the gpiochip passed as chip data. An irqdomain will be stored
2675 * in the gpiochip that shall be used by the driver to handle IRQ number
2676 * translation. The gpiochip will need to be initialized and registered
2677 * before calling this function.
2678 *
2679 * This function will handle two cell:ed simple IRQs and assumes all
2680 * the pins on the gpiochip can generate a unique IRQ. Everything else
2681 * need to be open coded.
2682 */
2683 int gpiochip_irqchip_add_key(struct gpio_chip *gc,
2684 struct irq_chip *irqchip,
2685 unsigned int first_irq,
2686 irq_flow_handler_t handler,
2687 unsigned int type,
2688 bool threaded,
2689 struct lock_class_key *lock_key,
2690 struct lock_class_key *request_key)
2691 {
2692 struct device_node *of_node;
2693
2694 if (!gc || !irqchip)
2695 return -EINVAL;
2696
2697 if (!gc->parent) {
2698 pr_err("missing gpiochip .dev parent pointer\n");
2699 return -EINVAL;
2700 }
2701 gc->irq.threaded = threaded;
2702 of_node = gc->parent->of_node;
2703 #ifdef CONFIG_OF_GPIO
2704 /*
2705 * If the gpiochip has an assigned OF node this takes precedence
2706 * FIXME: get rid of this and use gc->parent->of_node
2707 * everywhere
2708 */
2709 if (gc->of_node)
2710 of_node = gc->of_node;
2711 #endif
2712 /*
2713 * Specifying a default trigger is a terrible idea if DT or ACPI is
2714 * used to configure the interrupts, as you may end-up with
2715 * conflicting triggers. Tell the user, and reset to NONE.
2716 */
2717 if (WARN(of_node && type != IRQ_TYPE_NONE,
2718 "%pOF: Ignoring %d default trigger\n", of_node, type))
2719 type = IRQ_TYPE_NONE;
2720 if (has_acpi_companion(gc->parent) && type != IRQ_TYPE_NONE) {
2721 acpi_handle_warn(ACPI_HANDLE(gc->parent),
2722 "Ignoring %d default trigger\n", type);
2723 type = IRQ_TYPE_NONE;
2724 }
2725
2726 gc->irq.chip = irqchip;
2727 gc->irq.handler = handler;
2728 gc->irq.default_type = type;
2729 gc->to_irq = gpiochip_to_irq;
2730 gc->irq.lock_key = lock_key;
2731 gc->irq.request_key = request_key;
2732 gc->irq.domain = irq_domain_add_simple(of_node,
2733 gc->ngpio, first_irq,
2734 &gpiochip_domain_ops, gc);
2735 if (!gc->irq.domain) {
2736 gc->irq.chip = NULL;
2737 return -EINVAL;
2738 }
2739
2740 gpiochip_set_irq_hooks(gc);
2741
2742 acpi_gpiochip_request_interrupts(gc);
2743
2744 return 0;
2745 }
2746 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2747
2748 #else /* CONFIG_GPIOLIB_IRQCHIP */
2749
2750 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
2751 struct lock_class_key *lock_key,
2752 struct lock_class_key *request_key)
2753 {
2754 return 0;
2755 }
2756 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
2757
2758 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
2759 {
2760 return 0;
2761 }
2762
2763 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
2764 {
2765 return 0;
2766 }
2767 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
2768 { }
2769
2770 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2771
2772 /**
2773 * gpiochip_generic_request() - request the gpio function for a pin
2774 * @gc: the gpiochip owning the GPIO
2775 * @offset: the offset of the GPIO to request for GPIO function
2776 */
2777 int gpiochip_generic_request(struct gpio_chip *gc, unsigned offset)
2778 {
2779 #ifdef CONFIG_PINCTRL
2780 if (list_empty(&gc->gpiodev->pin_ranges))
2781 return 0;
2782 #endif
2783
2784 return pinctrl_gpio_request(gc->gpiodev->base + offset);
2785 }
2786 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2787
2788 /**
2789 * gpiochip_generic_free() - free the gpio function from a pin
2790 * @gc: the gpiochip to request the gpio function for
2791 * @offset: the offset of the GPIO to free from GPIO function
2792 */
2793 void gpiochip_generic_free(struct gpio_chip *gc, unsigned offset)
2794 {
2795 pinctrl_gpio_free(gc->gpiodev->base + offset);
2796 }
2797 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2798
2799 /**
2800 * gpiochip_generic_config() - apply configuration for a pin
2801 * @gc: the gpiochip owning the GPIO
2802 * @offset: the offset of the GPIO to apply the configuration
2803 * @config: the configuration to be applied
2804 */
2805 int gpiochip_generic_config(struct gpio_chip *gc, unsigned offset,
2806 unsigned long config)
2807 {
2808 return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
2809 }
2810 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2811
2812 #ifdef CONFIG_PINCTRL
2813
2814 /**
2815 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2816 * @gc: the gpiochip to add the range for
2817 * @pctldev: the pin controller to map to
2818 * @gpio_offset: the start offset in the current gpio_chip number space
2819 * @pin_group: name of the pin group inside the pin controller
2820 *
2821 * Calling this function directly from a DeviceTree-supported
2822 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2823 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2824 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2825 */
2826 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
2827 struct pinctrl_dev *pctldev,
2828 unsigned int gpio_offset, const char *pin_group)
2829 {
2830 struct gpio_pin_range *pin_range;
2831 struct gpio_device *gdev = gc->gpiodev;
2832 int ret;
2833
2834 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2835 if (!pin_range) {
2836 chip_err(gc, "failed to allocate pin ranges\n");
2837 return -ENOMEM;
2838 }
2839
2840 /* Use local offset as range ID */
2841 pin_range->range.id = gpio_offset;
2842 pin_range->range.gc = gc;
2843 pin_range->range.name = gc->label;
2844 pin_range->range.base = gdev->base + gpio_offset;
2845 pin_range->pctldev = pctldev;
2846
2847 ret = pinctrl_get_group_pins(pctldev, pin_group,
2848 &pin_range->range.pins,
2849 &pin_range->range.npins);
2850 if (ret < 0) {
2851 kfree(pin_range);
2852 return ret;
2853 }
2854
2855 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2856
2857 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2858 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2859 pinctrl_dev_get_devname(pctldev), pin_group);
2860
2861 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2862
2863 return 0;
2864 }
2865 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2866
2867 /**
2868 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2869 * @gc: the gpiochip to add the range for
2870 * @pinctl_name: the dev_name() of the pin controller to map to
2871 * @gpio_offset: the start offset in the current gpio_chip number space
2872 * @pin_offset: the start offset in the pin controller number space
2873 * @npins: the number of pins from the offset of each pin space (GPIO and
2874 * pin controller) to accumulate in this range
2875 *
2876 * Returns:
2877 * 0 on success, or a negative error-code on failure.
2878 *
2879 * Calling this function directly from a DeviceTree-supported
2880 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2881 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2882 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2883 */
2884 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
2885 unsigned int gpio_offset, unsigned int pin_offset,
2886 unsigned int npins)
2887 {
2888 struct gpio_pin_range *pin_range;
2889 struct gpio_device *gdev = gc->gpiodev;
2890 int ret;
2891
2892 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2893 if (!pin_range) {
2894 chip_err(gc, "failed to allocate pin ranges\n");
2895 return -ENOMEM;
2896 }
2897
2898 /* Use local offset as range ID */
2899 pin_range->range.id = gpio_offset;
2900 pin_range->range.gc = gc;
2901 pin_range->range.name = gc->label;
2902 pin_range->range.base = gdev->base + gpio_offset;
2903 pin_range->range.pin_base = pin_offset;
2904 pin_range->range.npins = npins;
2905 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2906 &pin_range->range);
2907 if (IS_ERR(pin_range->pctldev)) {
2908 ret = PTR_ERR(pin_range->pctldev);
2909 chip_err(gc, "could not create pin range\n");
2910 kfree(pin_range);
2911 return ret;
2912 }
2913 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2914 gpio_offset, gpio_offset + npins - 1,
2915 pinctl_name,
2916 pin_offset, pin_offset + npins - 1);
2917
2918 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2919
2920 return 0;
2921 }
2922 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2923
2924 /**
2925 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2926 * @gc: the chip to remove all the mappings for
2927 */
2928 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
2929 {
2930 struct gpio_pin_range *pin_range, *tmp;
2931 struct gpio_device *gdev = gc->gpiodev;
2932
2933 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2934 list_del(&pin_range->node);
2935 pinctrl_remove_gpio_range(pin_range->pctldev,
2936 &pin_range->range);
2937 kfree(pin_range);
2938 }
2939 }
2940 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2941
2942 #endif /* CONFIG_PINCTRL */
2943
2944 /* These "optional" allocation calls help prevent drivers from stomping
2945 * on each other, and help provide better diagnostics in debugfs.
2946 * They're called even less than the "set direction" calls.
2947 */
2948 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2949 {
2950 struct gpio_chip *gc = desc->gdev->chip;
2951 int ret;
2952 unsigned long flags;
2953 unsigned offset;
2954
2955 if (label) {
2956 label = kstrdup_const(label, GFP_KERNEL);
2957 if (!label)
2958 return -ENOMEM;
2959 }
2960
2961 spin_lock_irqsave(&gpio_lock, flags);
2962
2963 /* NOTE: gpio_request() can be called in early boot,
2964 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2965 */
2966
2967 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2968 desc_set_label(desc, label ? : "?");
2969 ret = 0;
2970 } else {
2971 kfree_const(label);
2972 ret = -EBUSY;
2973 goto done;
2974 }
2975
2976 if (gc->request) {
2977 /* gc->request may sleep */
2978 spin_unlock_irqrestore(&gpio_lock, flags);
2979 offset = gpio_chip_hwgpio(desc);
2980 if (gpiochip_line_is_valid(gc, offset))
2981 ret = gc->request(gc, offset);
2982 else
2983 ret = -EINVAL;
2984 spin_lock_irqsave(&gpio_lock, flags);
2985
2986 if (ret < 0) {
2987 desc_set_label(desc, NULL);
2988 kfree_const(label);
2989 clear_bit(FLAG_REQUESTED, &desc->flags);
2990 goto done;
2991 }
2992 }
2993 if (gc->get_direction) {
2994 /* gc->get_direction may sleep */
2995 spin_unlock_irqrestore(&gpio_lock, flags);
2996 gpiod_get_direction(desc);
2997 spin_lock_irqsave(&gpio_lock, flags);
2998 }
2999 done:
3000 spin_unlock_irqrestore(&gpio_lock, flags);
3001 atomic_notifier_call_chain(&desc->gdev->notifier,
3002 GPIOLINE_CHANGED_REQUESTED, desc);
3003 return ret;
3004 }
3005
3006 /*
3007 * This descriptor validation needs to be inserted verbatim into each
3008 * function taking a descriptor, so we need to use a preprocessor
3009 * macro to avoid endless duplication. If the desc is NULL it is an
3010 * optional GPIO and calls should just bail out.
3011 */
3012 static int validate_desc(const struct gpio_desc *desc, const char *func)
3013 {
3014 if (!desc)
3015 return 0;
3016 if (IS_ERR(desc)) {
3017 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
3018 return PTR_ERR(desc);
3019 }
3020 if (!desc->gdev) {
3021 pr_warn("%s: invalid GPIO (no device)\n", func);
3022 return -EINVAL;
3023 }
3024 if (!desc->gdev->chip) {
3025 dev_warn(&desc->gdev->dev,
3026 "%s: backing chip is gone\n", func);
3027 return 0;
3028 }
3029 return 1;
3030 }
3031
3032 #define VALIDATE_DESC(desc) do { \
3033 int __valid = validate_desc(desc, __func__); \
3034 if (__valid <= 0) \
3035 return __valid; \
3036 } while (0)
3037
3038 #define VALIDATE_DESC_VOID(desc) do { \
3039 int __valid = validate_desc(desc, __func__); \
3040 if (__valid <= 0) \
3041 return; \
3042 } while (0)
3043
3044 int gpiod_request(struct gpio_desc *desc, const char *label)
3045 {
3046 int ret = -EPROBE_DEFER;
3047 struct gpio_device *gdev;
3048
3049 VALIDATE_DESC(desc);
3050 gdev = desc->gdev;
3051
3052 if (try_module_get(gdev->owner)) {
3053 ret = gpiod_request_commit(desc, label);
3054 if (ret < 0)
3055 module_put(gdev->owner);
3056 else
3057 get_device(&gdev->dev);
3058 }
3059
3060 if (ret)
3061 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
3062
3063 return ret;
3064 }
3065
3066 static bool gpiod_free_commit(struct gpio_desc *desc)
3067 {
3068 bool ret = false;
3069 unsigned long flags;
3070 struct gpio_chip *gc;
3071
3072 might_sleep();
3073
3074 gpiod_unexport(desc);
3075
3076 spin_lock_irqsave(&gpio_lock, flags);
3077
3078 gc = desc->gdev->chip;
3079 if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
3080 if (gc->free) {
3081 spin_unlock_irqrestore(&gpio_lock, flags);
3082 might_sleep_if(gc->can_sleep);
3083 gc->free(gc, gpio_chip_hwgpio(desc));
3084 spin_lock_irqsave(&gpio_lock, flags);
3085 }
3086 kfree_const(desc->label);
3087 desc_set_label(desc, NULL);
3088 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
3089 clear_bit(FLAG_REQUESTED, &desc->flags);
3090 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
3091 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
3092 clear_bit(FLAG_PULL_UP, &desc->flags);
3093 clear_bit(FLAG_PULL_DOWN, &desc->flags);
3094 clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
3095 clear_bit(FLAG_IS_HOGGED, &desc->flags);
3096 #ifdef CONFIG_OF_DYNAMIC
3097 desc->hog = NULL;
3098 #endif
3099 ret = true;
3100 }
3101
3102 spin_unlock_irqrestore(&gpio_lock, flags);
3103 atomic_notifier_call_chain(&desc->gdev->notifier,
3104 GPIOLINE_CHANGED_RELEASED, desc);
3105
3106 return ret;
3107 }
3108
3109 void gpiod_free(struct gpio_desc *desc)
3110 {
3111 if (desc && desc->gdev && gpiod_free_commit(desc)) {
3112 module_put(desc->gdev->owner);
3113 put_device(&desc->gdev->dev);
3114 } else {
3115 WARN_ON(extra_checks);
3116 }
3117 }
3118
3119 /**
3120 * gpiochip_is_requested - return string iff signal was requested
3121 * @gc: controller managing the signal
3122 * @offset: of signal within controller's 0..(ngpio - 1) range
3123 *
3124 * Returns NULL if the GPIO is not currently requested, else a string.
3125 * The string returned is the label passed to gpio_request(); if none has been
3126 * passed it is a meaningless, non-NULL constant.
3127 *
3128 * This function is for use by GPIO controller drivers. The label can
3129 * help with diagnostics, and knowing that the signal is used as a GPIO
3130 * can help avoid accidentally multiplexing it to another controller.
3131 */
3132 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned offset)
3133 {
3134 struct gpio_desc *desc;
3135
3136 if (offset >= gc->ngpio)
3137 return NULL;
3138
3139 desc = gpiochip_get_desc(gc, offset);
3140 if (IS_ERR(desc))
3141 return NULL;
3142
3143 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
3144 return NULL;
3145 return desc->label;
3146 }
3147 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
3148
3149 /**
3150 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
3151 * @gc: GPIO chip
3152 * @hwnum: hardware number of the GPIO for which to request the descriptor
3153 * @label: label for the GPIO
3154 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
3155 * specify things like line inversion semantics with the machine flags
3156 * such as GPIO_OUT_LOW
3157 * @dflags: descriptor request flags for this GPIO or 0 if default, this
3158 * can be used to specify consumer semantics such as open drain
3159 *
3160 * Function allows GPIO chip drivers to request and use their own GPIO
3161 * descriptors via gpiolib API. Difference to gpiod_request() is that this
3162 * function will not increase reference count of the GPIO chip module. This
3163 * allows the GPIO chip module to be unloaded as needed (we assume that the
3164 * GPIO chip driver handles freeing the GPIOs it has requested).
3165 *
3166 * Returns:
3167 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
3168 * code on failure.
3169 */
3170 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
3171 unsigned int hwnum,
3172 const char *label,
3173 enum gpio_lookup_flags lflags,
3174 enum gpiod_flags dflags)
3175 {
3176 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
3177 int ret;
3178
3179 if (IS_ERR(desc)) {
3180 chip_err(gc, "failed to get GPIO descriptor\n");
3181 return desc;
3182 }
3183
3184 ret = gpiod_request_commit(desc, label);
3185 if (ret < 0)
3186 return ERR_PTR(ret);
3187
3188 ret = gpiod_configure_flags(desc, label, lflags, dflags);
3189 if (ret) {
3190 chip_err(gc, "setup of own GPIO %s failed\n", label);
3191 gpiod_free_commit(desc);
3192 return ERR_PTR(ret);
3193 }
3194
3195 return desc;
3196 }
3197 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
3198
3199 /**
3200 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
3201 * @desc: GPIO descriptor to free
3202 *
3203 * Function frees the given GPIO requested previously with
3204 * gpiochip_request_own_desc().
3205 */
3206 void gpiochip_free_own_desc(struct gpio_desc *desc)
3207 {
3208 if (desc)
3209 gpiod_free_commit(desc);
3210 }
3211 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
3212
3213 /*
3214 * Drivers MUST set GPIO direction before making get/set calls. In
3215 * some cases this is done in early boot, before IRQs are enabled.
3216 *
3217 * As a rule these aren't called more than once (except for drivers
3218 * using the open-drain emulation idiom) so these are natural places
3219 * to accumulate extra debugging checks. Note that we can't (yet)
3220 * rely on gpio_request() having been called beforehand.
3221 */
3222
3223 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
3224 unsigned long config)
3225 {
3226 if (!gc->set_config)
3227 return -ENOTSUPP;
3228
3229 return gc->set_config(gc, offset, config);
3230 }
3231
3232 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
3233 {
3234 struct gpio_chip *gc = desc->gdev->chip;
3235 unsigned long config;
3236 unsigned arg;
3237
3238 switch (mode) {
3239 case PIN_CONFIG_BIAS_PULL_DOWN:
3240 case PIN_CONFIG_BIAS_PULL_UP:
3241 arg = 1;
3242 break;
3243
3244 default:
3245 arg = 0;
3246 }
3247
3248 config = PIN_CONF_PACKED(mode, arg);
3249 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
3250 }
3251
3252 static int gpio_set_bias(struct gpio_desc *desc)
3253 {
3254 int bias = 0;
3255 int ret = 0;
3256
3257 if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
3258 bias = PIN_CONFIG_BIAS_DISABLE;
3259 else if (test_bit(FLAG_PULL_UP, &desc->flags))
3260 bias = PIN_CONFIG_BIAS_PULL_UP;
3261 else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
3262 bias = PIN_CONFIG_BIAS_PULL_DOWN;
3263
3264 if (bias) {
3265 ret = gpio_set_config(desc, bias);
3266 if (ret != -ENOTSUPP)
3267 return ret;
3268 }
3269 return 0;
3270 }
3271
3272 /**
3273 * gpiod_direction_input - set the GPIO direction to input
3274 * @desc: GPIO to set to input
3275 *
3276 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
3277 * be called safely on it.
3278 *
3279 * Return 0 in case of success, else an error code.
3280 */
3281 int gpiod_direction_input(struct gpio_desc *desc)
3282 {
3283 struct gpio_chip *gc;
3284 int ret = 0;
3285
3286 VALIDATE_DESC(desc);
3287 gc = desc->gdev->chip;
3288
3289 /*
3290 * It is legal to have no .get() and .direction_input() specified if
3291 * the chip is output-only, but you can't specify .direction_input()
3292 * and not support the .get() operation, that doesn't make sense.
3293 */
3294 if (!gc->get && gc->direction_input) {
3295 gpiod_warn(desc,
3296 "%s: missing get() but have direction_input()\n",
3297 __func__);
3298 return -EIO;
3299 }
3300
3301 /*
3302 * If we have a .direction_input() callback, things are simple,
3303 * just call it. Else we are some input-only chip so try to check the
3304 * direction (if .get_direction() is supported) else we silently
3305 * assume we are in input mode after this.
3306 */
3307 if (gc->direction_input) {
3308 ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
3309 } else if (gc->get_direction &&
3310 (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
3311 gpiod_warn(desc,
3312 "%s: missing direction_input() operation and line is output\n",
3313 __func__);
3314 return -EIO;
3315 }
3316 if (ret == 0) {
3317 clear_bit(FLAG_IS_OUT, &desc->flags);
3318 ret = gpio_set_bias(desc);
3319 }
3320
3321 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
3322
3323 return ret;
3324 }
3325 EXPORT_SYMBOL_GPL(gpiod_direction_input);
3326
3327 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
3328 {
3329 struct gpio_chip *gc = desc->gdev->chip;
3330 int val = !!value;
3331 int ret = 0;
3332
3333 /*
3334 * It's OK not to specify .direction_output() if the gpiochip is
3335 * output-only, but if there is then not even a .set() operation it
3336 * is pretty tricky to drive the output line.
3337 */
3338 if (!gc->set && !gc->direction_output) {
3339 gpiod_warn(desc,
3340 "%s: missing set() and direction_output() operations\n",
3341 __func__);
3342 return -EIO;
3343 }
3344
3345 if (gc->direction_output) {
3346 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
3347 } else {
3348 /* Check that we are in output mode if we can */
3349 if (gc->get_direction &&
3350 gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
3351 gpiod_warn(desc,
3352 "%s: missing direction_output() operation\n",
3353 __func__);
3354 return -EIO;
3355 }
3356 /*
3357 * If we can't actively set the direction, we are some
3358 * output-only chip, so just drive the output as desired.
3359 */
3360 gc->set(gc, gpio_chip_hwgpio(desc), val);
3361 }
3362
3363 if (!ret)
3364 set_bit(FLAG_IS_OUT, &desc->flags);
3365 trace_gpio_value(desc_to_gpio(desc), 0, val);
3366 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
3367 return ret;
3368 }
3369
3370 /**
3371 * gpiod_direction_output_raw - set the GPIO direction to output
3372 * @desc: GPIO to set to output
3373 * @value: initial output value of the GPIO
3374 *
3375 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
3376 * be called safely on it. The initial value of the output must be specified
3377 * as raw value on the physical line without regard for the ACTIVE_LOW status.
3378 *
3379 * Return 0 in case of success, else an error code.
3380 */
3381 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
3382 {
3383 VALIDATE_DESC(desc);
3384 return gpiod_direction_output_raw_commit(desc, value);
3385 }
3386 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
3387
3388 /**
3389 * gpiod_direction_output - set the GPIO direction to output
3390 * @desc: GPIO to set to output
3391 * @value: initial output value of the GPIO
3392 *
3393 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
3394 * be called safely on it. The initial value of the output must be specified
3395 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3396 * account.
3397 *
3398 * Return 0 in case of success, else an error code.
3399 */
3400 int gpiod_direction_output(struct gpio_desc *desc, int value)
3401 {
3402 int ret;
3403
3404 VALIDATE_DESC(desc);
3405 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3406 value = !value;
3407 else
3408 value = !!value;
3409
3410 /* GPIOs used for enabled IRQs shall not be set as output */
3411 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
3412 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
3413 gpiod_err(desc,
3414 "%s: tried to set a GPIO tied to an IRQ as output\n",
3415 __func__);
3416 return -EIO;
3417 }
3418
3419 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3420 /* First see if we can enable open drain in hardware */
3421 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
3422 if (!ret)
3423 goto set_output_value;
3424 /* Emulate open drain by not actively driving the line high */
3425 if (value) {
3426 ret = gpiod_direction_input(desc);
3427 goto set_output_flag;
3428 }
3429 }
3430 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
3431 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
3432 if (!ret)
3433 goto set_output_value;
3434 /* Emulate open source by not actively driving the line low */
3435 if (!value) {
3436 ret = gpiod_direction_input(desc);
3437 goto set_output_flag;
3438 }
3439 } else {
3440 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
3441 }
3442
3443 set_output_value:
3444 ret = gpio_set_bias(desc);
3445 if (ret)
3446 return ret;
3447 return gpiod_direction_output_raw_commit(desc, value);
3448
3449 set_output_flag:
3450 /*
3451 * When emulating open-source or open-drain functionalities by not
3452 * actively driving the line (setting mode to input) we still need to
3453 * set the IS_OUT flag or otherwise we won't be able to set the line
3454 * value anymore.
3455 */
3456 if (ret == 0)
3457 set_bit(FLAG_IS_OUT, &desc->flags);
3458 return ret;
3459 }
3460 EXPORT_SYMBOL_GPL(gpiod_direction_output);
3461
3462 /**
3463 * gpiod_set_config - sets @config for a GPIO
3464 * @desc: descriptor of the GPIO for which to set the configuration
3465 * @config: Same packed config format as generic pinconf
3466 *
3467 * Returns:
3468 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3469 * configuration.
3470 */
3471 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
3472 {
3473 struct gpio_chip *gc;
3474
3475 VALIDATE_DESC(desc);
3476 gc = desc->gdev->chip;
3477
3478 return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
3479 }
3480 EXPORT_SYMBOL_GPL(gpiod_set_config);
3481
3482 /**
3483 * gpiod_set_debounce - sets @debounce time for a GPIO
3484 * @desc: descriptor of the GPIO for which to set debounce time
3485 * @debounce: debounce time in microseconds
3486 *
3487 * Returns:
3488 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3489 * debounce time.
3490 */
3491 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
3492 {
3493 unsigned long config;
3494
3495 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
3496 return gpiod_set_config(desc, config);
3497 }
3498 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
3499
3500 /**
3501 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
3502 * @desc: descriptor of the GPIO for which to configure persistence
3503 * @transitory: True to lose state on suspend or reset, false for persistence
3504 *
3505 * Returns:
3506 * 0 on success, otherwise a negative error code.
3507 */
3508 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
3509 {
3510 struct gpio_chip *gc;
3511 unsigned long packed;
3512 int gpio;
3513 int rc;
3514
3515 VALIDATE_DESC(desc);
3516 /*
3517 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
3518 * persistence state.
3519 */
3520 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
3521
3522 /* If the driver supports it, set the persistence state now */
3523 gc = desc->gdev->chip;
3524 if (!gc->set_config)
3525 return 0;
3526
3527 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
3528 !transitory);
3529 gpio = gpio_chip_hwgpio(desc);
3530 rc = gpio_do_set_config(gc, gpio, packed);
3531 if (rc == -ENOTSUPP) {
3532 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
3533 gpio);
3534 return 0;
3535 }
3536
3537 return rc;
3538 }
3539 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
3540
3541 /**
3542 * gpiod_is_active_low - test whether a GPIO is active-low or not
3543 * @desc: the gpio descriptor to test
3544 *
3545 * Returns 1 if the GPIO is active-low, 0 otherwise.
3546 */
3547 int gpiod_is_active_low(const struct gpio_desc *desc)
3548 {
3549 VALIDATE_DESC(desc);
3550 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
3551 }
3552 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
3553
3554 /**
3555 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
3556 * @desc: the gpio descriptor to change
3557 */
3558 void gpiod_toggle_active_low(struct gpio_desc *desc)
3559 {
3560 VALIDATE_DESC_VOID(desc);
3561 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
3562 }
3563 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
3564
3565 /* I/O calls are only valid after configuration completed; the relevant
3566 * "is this a valid GPIO" error checks should already have been done.
3567 *
3568 * "Get" operations are often inlinable as reading a pin value register,
3569 * and masking the relevant bit in that register.
3570 *
3571 * When "set" operations are inlinable, they involve writing that mask to
3572 * one register to set a low value, or a different register to set it high.
3573 * Otherwise locking is needed, so there may be little value to inlining.
3574 *
3575 *------------------------------------------------------------------------
3576 *
3577 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
3578 * have requested the GPIO. That can include implicit requesting by
3579 * a direction setting call. Marking a gpio as requested locks its chip
3580 * in memory, guaranteeing that these table lookups need no more locking
3581 * and that gpiochip_remove() will fail.
3582 *
3583 * REVISIT when debugging, consider adding some instrumentation to ensure
3584 * that the GPIO was actually requested.
3585 */
3586
3587 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
3588 {
3589 struct gpio_chip *gc;
3590 int offset;
3591 int value;
3592
3593 gc = desc->gdev->chip;
3594 offset = gpio_chip_hwgpio(desc);
3595 value = gc->get ? gc->get(gc, offset) : -EIO;
3596 value = value < 0 ? value : !!value;
3597 trace_gpio_value(desc_to_gpio(desc), 1, value);
3598 return value;
3599 }
3600
3601 static int gpio_chip_get_multiple(struct gpio_chip *gc,
3602 unsigned long *mask, unsigned long *bits)
3603 {
3604 if (gc->get_multiple) {
3605 return gc->get_multiple(gc, mask, bits);
3606 } else if (gc->get) {
3607 int i, value;
3608
3609 for_each_set_bit(i, mask, gc->ngpio) {
3610 value = gc->get(gc, i);
3611 if (value < 0)
3612 return value;
3613 __assign_bit(i, bits, value);
3614 }
3615 return 0;
3616 }
3617 return -EIO;
3618 }
3619
3620 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3621 unsigned int array_size,
3622 struct gpio_desc **desc_array,
3623 struct gpio_array *array_info,
3624 unsigned long *value_bitmap)
3625 {
3626 int ret, i = 0;
3627
3628 /*
3629 * Validate array_info against desc_array and its size.
3630 * It should immediately follow desc_array if both
3631 * have been obtained from the same gpiod_get_array() call.
3632 */
3633 if (array_info && array_info->desc == desc_array &&
3634 array_size <= array_info->size &&
3635 (void *)array_info == desc_array + array_info->size) {
3636 if (!can_sleep)
3637 WARN_ON(array_info->chip->can_sleep);
3638
3639 ret = gpio_chip_get_multiple(array_info->chip,
3640 array_info->get_mask,
3641 value_bitmap);
3642 if (ret)
3643 return ret;
3644
3645 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3646 bitmap_xor(value_bitmap, value_bitmap,
3647 array_info->invert_mask, array_size);
3648
3649 if (bitmap_full(array_info->get_mask, array_size))
3650 return 0;
3651
3652 i = find_first_zero_bit(array_info->get_mask, array_size);
3653 } else {
3654 array_info = NULL;
3655 }
3656
3657 while (i < array_size) {
3658 struct gpio_chip *gc = desc_array[i]->gdev->chip;
3659 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3660 unsigned long *mask, *bits;
3661 int first, j, ret;
3662
3663 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
3664 mask = fastpath;
3665 } else {
3666 mask = kmalloc_array(2 * BITS_TO_LONGS(gc->ngpio),
3667 sizeof(*mask),
3668 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3669 if (!mask)
3670 return -ENOMEM;
3671 }
3672
3673 bits = mask + BITS_TO_LONGS(gc->ngpio);
3674 bitmap_zero(mask, gc->ngpio);
3675
3676 if (!can_sleep)
3677 WARN_ON(gc->can_sleep);
3678
3679 /* collect all inputs belonging to the same chip */
3680 first = i;
3681 do {
3682 const struct gpio_desc *desc = desc_array[i];
3683 int hwgpio = gpio_chip_hwgpio(desc);
3684
3685 __set_bit(hwgpio, mask);
3686 i++;
3687
3688 if (array_info)
3689 i = find_next_zero_bit(array_info->get_mask,
3690 array_size, i);
3691 } while ((i < array_size) &&
3692 (desc_array[i]->gdev->chip == gc));
3693
3694 ret = gpio_chip_get_multiple(gc, mask, bits);
3695 if (ret) {
3696 if (mask != fastpath)
3697 kfree(mask);
3698 return ret;
3699 }
3700
3701 for (j = first; j < i; ) {
3702 const struct gpio_desc *desc = desc_array[j];
3703 int hwgpio = gpio_chip_hwgpio(desc);
3704 int value = test_bit(hwgpio, bits);
3705
3706 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3707 value = !value;
3708 __assign_bit(j, value_bitmap, value);
3709 trace_gpio_value(desc_to_gpio(desc), 1, value);
3710 j++;
3711
3712 if (array_info)
3713 j = find_next_zero_bit(array_info->get_mask, i,
3714 j);
3715 }
3716
3717 if (mask != fastpath)
3718 kfree(mask);
3719 }
3720 return 0;
3721 }
3722
3723 /**
3724 * gpiod_get_raw_value() - return a gpio's raw value
3725 * @desc: gpio whose value will be returned
3726 *
3727 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3728 * its ACTIVE_LOW status, or negative errno on failure.
3729 *
3730 * This function can be called from contexts where we cannot sleep, and will
3731 * complain if the GPIO chip functions potentially sleep.
3732 */
3733 int gpiod_get_raw_value(const struct gpio_desc *desc)
3734 {
3735 VALIDATE_DESC(desc);
3736 /* Should be using gpiod_get_raw_value_cansleep() */
3737 WARN_ON(desc->gdev->chip->can_sleep);
3738 return gpiod_get_raw_value_commit(desc);
3739 }
3740 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3741
3742 /**
3743 * gpiod_get_value() - return a gpio's value
3744 * @desc: gpio whose value will be returned
3745 *
3746 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3747 * account, or negative errno on failure.
3748 *
3749 * This function can be called from contexts where we cannot sleep, and will
3750 * complain if the GPIO chip functions potentially sleep.
3751 */
3752 int gpiod_get_value(const struct gpio_desc *desc)
3753 {
3754 int value;
3755
3756 VALIDATE_DESC(desc);
3757 /* Should be using gpiod_get_value_cansleep() */
3758 WARN_ON(desc->gdev->chip->can_sleep);
3759
3760 value = gpiod_get_raw_value_commit(desc);
3761 if (value < 0)
3762 return value;
3763
3764 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3765 value = !value;
3766
3767 return value;
3768 }
3769 EXPORT_SYMBOL_GPL(gpiod_get_value);
3770
3771 /**
3772 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3773 * @array_size: number of elements in the descriptor array / value bitmap
3774 * @desc_array: array of GPIO descriptors whose values will be read
3775 * @array_info: information on applicability of fast bitmap processing path
3776 * @value_bitmap: bitmap to store the read values
3777 *
3778 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3779 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3780 * else an error code.
3781 *
3782 * This function can be called from contexts where we cannot sleep,
3783 * and it will complain if the GPIO chip functions potentially sleep.
3784 */
3785 int gpiod_get_raw_array_value(unsigned int array_size,
3786 struct gpio_desc **desc_array,
3787 struct gpio_array *array_info,
3788 unsigned long *value_bitmap)
3789 {
3790 if (!desc_array)
3791 return -EINVAL;
3792 return gpiod_get_array_value_complex(true, false, array_size,
3793 desc_array, array_info,
3794 value_bitmap);
3795 }
3796 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3797
3798 /**
3799 * gpiod_get_array_value() - read values from an array of GPIOs
3800 * @array_size: number of elements in the descriptor array / value bitmap
3801 * @desc_array: array of GPIO descriptors whose values will be read
3802 * @array_info: information on applicability of fast bitmap processing path
3803 * @value_bitmap: bitmap to store the read values
3804 *
3805 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3806 * into account. Return 0 in case of success, else an error code.
3807 *
3808 * This function can be called from contexts where we cannot sleep,
3809 * and it will complain if the GPIO chip functions potentially sleep.
3810 */
3811 int gpiod_get_array_value(unsigned int array_size,
3812 struct gpio_desc **desc_array,
3813 struct gpio_array *array_info,
3814 unsigned long *value_bitmap)
3815 {
3816 if (!desc_array)
3817 return -EINVAL;
3818 return gpiod_get_array_value_complex(false, false, array_size,
3819 desc_array, array_info,
3820 value_bitmap);
3821 }
3822 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3823
3824 /*
3825 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3826 * @desc: gpio descriptor whose state need to be set.
3827 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3828 */
3829 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3830 {
3831 int ret = 0;
3832 struct gpio_chip *gc = desc->gdev->chip;
3833 int offset = gpio_chip_hwgpio(desc);
3834
3835 if (value) {
3836 ret = gc->direction_input(gc, offset);
3837 } else {
3838 ret = gc->direction_output(gc, offset, 0);
3839 if (!ret)
3840 set_bit(FLAG_IS_OUT, &desc->flags);
3841 }
3842 trace_gpio_direction(desc_to_gpio(desc), value, ret);
3843 if (ret < 0)
3844 gpiod_err(desc,
3845 "%s: Error in set_value for open drain err %d\n",
3846 __func__, ret);
3847 }
3848
3849 /*
3850 * _gpio_set_open_source_value() - Set the open source gpio's value.
3851 * @desc: gpio descriptor whose state need to be set.
3852 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3853 */
3854 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3855 {
3856 int ret = 0;
3857 struct gpio_chip *gc = desc->gdev->chip;
3858 int offset = gpio_chip_hwgpio(desc);
3859
3860 if (value) {
3861 ret = gc->direction_output(gc, offset, 1);
3862 if (!ret)
3863 set_bit(FLAG_IS_OUT, &desc->flags);
3864 } else {
3865 ret = gc->direction_input(gc, offset);
3866 }
3867 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3868 if (ret < 0)
3869 gpiod_err(desc,
3870 "%s: Error in set_value for open source err %d\n",
3871 __func__, ret);
3872 }
3873
3874 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3875 {
3876 struct gpio_chip *gc;
3877
3878 gc = desc->gdev->chip;
3879 trace_gpio_value(desc_to_gpio(desc), 0, value);
3880 gc->set(gc, gpio_chip_hwgpio(desc), value);
3881 }
3882
3883 /*
3884 * set multiple outputs on the same chip;
3885 * use the chip's set_multiple function if available;
3886 * otherwise set the outputs sequentially;
3887 * @chip: the GPIO chip we operate on
3888 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3889 * defines which outputs are to be changed
3890 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3891 * defines the values the outputs specified by mask are to be set to
3892 */
3893 static void gpio_chip_set_multiple(struct gpio_chip *gc,
3894 unsigned long *mask, unsigned long *bits)
3895 {
3896 if (gc->set_multiple) {
3897 gc->set_multiple(gc, mask, bits);
3898 } else {
3899 unsigned int i;
3900
3901 /* set outputs if the corresponding mask bit is set */
3902 for_each_set_bit(i, mask, gc->ngpio)
3903 gc->set(gc, i, test_bit(i, bits));
3904 }
3905 }
3906
3907 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3908 unsigned int array_size,
3909 struct gpio_desc **desc_array,
3910 struct gpio_array *array_info,
3911 unsigned long *value_bitmap)
3912 {
3913 int i = 0;
3914
3915 /*
3916 * Validate array_info against desc_array and its size.
3917 * It should immediately follow desc_array if both
3918 * have been obtained from the same gpiod_get_array() call.
3919 */
3920 if (array_info && array_info->desc == desc_array &&
3921 array_size <= array_info->size &&
3922 (void *)array_info == desc_array + array_info->size) {
3923 if (!can_sleep)
3924 WARN_ON(array_info->chip->can_sleep);
3925
3926 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3927 bitmap_xor(value_bitmap, value_bitmap,
3928 array_info->invert_mask, array_size);
3929
3930 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3931 value_bitmap);
3932
3933 if (bitmap_full(array_info->set_mask, array_size))
3934 return 0;
3935
3936 i = find_first_zero_bit(array_info->set_mask, array_size);
3937 } else {
3938 array_info = NULL;
3939 }
3940
3941 while (i < array_size) {
3942 struct gpio_chip *gc = desc_array[i]->gdev->chip;
3943 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3944 unsigned long *mask, *bits;
3945 int count = 0;
3946
3947 if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
3948 mask = fastpath;
3949 } else {
3950 mask = kmalloc_array(2 * BITS_TO_LONGS(gc->ngpio),
3951 sizeof(*mask),
3952 can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3953 if (!mask)
3954 return -ENOMEM;
3955 }
3956
3957 bits = mask + BITS_TO_LONGS(gc->ngpio);
3958 bitmap_zero(mask, gc->ngpio);
3959
3960 if (!can_sleep)
3961 WARN_ON(gc->can_sleep);
3962
3963 do {
3964 struct gpio_desc *desc = desc_array[i];
3965 int hwgpio = gpio_chip_hwgpio(desc);
3966 int value = test_bit(i, value_bitmap);
3967
3968 /*
3969 * Pins applicable for fast input but not for
3970 * fast output processing may have been already
3971 * inverted inside the fast path, skip them.
3972 */
3973 if (!raw && !(array_info &&
3974 test_bit(i, array_info->invert_mask)) &&
3975 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3976 value = !value;
3977 trace_gpio_value(desc_to_gpio(desc), 0, value);
3978 /*
3979 * collect all normal outputs belonging to the same chip
3980 * open drain and open source outputs are set individually
3981 */
3982 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3983 gpio_set_open_drain_value_commit(desc, value);
3984 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3985 gpio_set_open_source_value_commit(desc, value);
3986 } else {
3987 __set_bit(hwgpio, mask);
3988 __assign_bit(hwgpio, bits, value);
3989 count++;
3990 }
3991 i++;
3992
3993 if (array_info)
3994 i = find_next_zero_bit(array_info->set_mask,
3995 array_size, i);
3996 } while ((i < array_size) &&
3997 (desc_array[i]->gdev->chip == gc));
3998 /* push collected bits to outputs */
3999 if (count != 0)
4000 gpio_chip_set_multiple(gc, mask, bits);
4001
4002 if (mask != fastpath)
4003 kfree(mask);
4004 }
4005 return 0;
4006 }
4007
4008 /**
4009 * gpiod_set_raw_value() - assign a gpio's raw value
4010 * @desc: gpio whose value will be assigned
4011 * @value: value to assign
4012 *
4013 * Set the raw value of the GPIO, i.e. the value of its physical line without
4014 * regard for its ACTIVE_LOW status.
4015 *
4016 * This function can be called from contexts where we cannot sleep, and will
4017 * complain if the GPIO chip functions potentially sleep.
4018 */
4019 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
4020 {
4021 VALIDATE_DESC_VOID(desc);
4022 /* Should be using gpiod_set_raw_value_cansleep() */
4023 WARN_ON(desc->gdev->chip->can_sleep);
4024 gpiod_set_raw_value_commit(desc, value);
4025 }
4026 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
4027
4028 /**
4029 * gpiod_set_value_nocheck() - set a GPIO line value without checking
4030 * @desc: the descriptor to set the value on
4031 * @value: value to set
4032 *
4033 * This sets the value of a GPIO line backing a descriptor, applying
4034 * different semantic quirks like active low and open drain/source
4035 * handling.
4036 */
4037 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
4038 {
4039 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
4040 value = !value;
4041 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
4042 gpio_set_open_drain_value_commit(desc, value);
4043 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
4044 gpio_set_open_source_value_commit(desc, value);
4045 else
4046 gpiod_set_raw_value_commit(desc, value);
4047 }
4048
4049 /**
4050 * gpiod_set_value() - assign a gpio's value
4051 * @desc: gpio whose value will be assigned
4052 * @value: value to assign
4053 *
4054 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
4055 * OPEN_DRAIN and OPEN_SOURCE flags into account.
4056 *
4057 * This function can be called from contexts where we cannot sleep, and will
4058 * complain if the GPIO chip functions potentially sleep.
4059 */
4060 void gpiod_set_value(struct gpio_desc *desc, int value)
4061 {
4062 VALIDATE_DESC_VOID(desc);
4063 /* Should be using gpiod_set_value_cansleep() */
4064 WARN_ON(desc->gdev->chip->can_sleep);
4065 gpiod_set_value_nocheck(desc, value);
4066 }
4067 EXPORT_SYMBOL_GPL(gpiod_set_value);
4068
4069 /**
4070 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
4071 * @array_size: number of elements in the descriptor array / value bitmap
4072 * @desc_array: array of GPIO descriptors whose values will be assigned
4073 * @array_info: information on applicability of fast bitmap processing path
4074 * @value_bitmap: bitmap of values to assign
4075 *
4076 * Set the raw values of the GPIOs, i.e. the values of the physical lines
4077 * without regard for their ACTIVE_LOW status.
4078 *
4079 * This function can be called from contexts where we cannot sleep, and will
4080 * complain if the GPIO chip functions potentially sleep.
4081 */
4082 int gpiod_set_raw_array_value(unsigned int array_size,
4083 struct gpio_desc **desc_array,
4084 struct gpio_array *array_info,
4085 unsigned long *value_bitmap)
4086 {
4087 if (!desc_array)
4088 return -EINVAL;
4089 return gpiod_set_array_value_complex(true, false, array_size,
4090 desc_array, array_info, value_bitmap);
4091 }
4092 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
4093
4094 /**
4095 * gpiod_set_array_value() - assign values to an array of GPIOs
4096 * @array_size: number of elements in the descriptor array / value bitmap
4097 * @desc_array: array of GPIO descriptors whose values will be assigned
4098 * @array_info: information on applicability of fast bitmap processing path
4099 * @value_bitmap: bitmap of values to assign
4100 *
4101 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4102 * into account.
4103 *
4104 * This function can be called from contexts where we cannot sleep, and will
4105 * complain if the GPIO chip functions potentially sleep.
4106 */
4107 int gpiod_set_array_value(unsigned int array_size,
4108 struct gpio_desc **desc_array,
4109 struct gpio_array *array_info,
4110 unsigned long *value_bitmap)
4111 {
4112 if (!desc_array)
4113 return -EINVAL;
4114 return gpiod_set_array_value_complex(false, false, array_size,
4115 desc_array, array_info,
4116 value_bitmap);
4117 }
4118 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
4119
4120 /**
4121 * gpiod_cansleep() - report whether gpio value access may sleep
4122 * @desc: gpio to check
4123 *
4124 */
4125 int gpiod_cansleep(const struct gpio_desc *desc)
4126 {
4127 VALIDATE_DESC(desc);
4128 return desc->gdev->chip->can_sleep;
4129 }
4130 EXPORT_SYMBOL_GPL(gpiod_cansleep);
4131
4132 /**
4133 * gpiod_set_consumer_name() - set the consumer name for the descriptor
4134 * @desc: gpio to set the consumer name on
4135 * @name: the new consumer name
4136 */
4137 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
4138 {
4139 VALIDATE_DESC(desc);
4140 if (name) {
4141 name = kstrdup_const(name, GFP_KERNEL);
4142 if (!name)
4143 return -ENOMEM;
4144 }
4145
4146 kfree_const(desc->label);
4147 desc_set_label(desc, name);
4148
4149 return 0;
4150 }
4151 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
4152
4153 /**
4154 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
4155 * @desc: gpio whose IRQ will be returned (already requested)
4156 *
4157 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
4158 * error.
4159 */
4160 int gpiod_to_irq(const struct gpio_desc *desc)
4161 {
4162 struct gpio_chip *gc;
4163 int offset;
4164
4165 /*
4166 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
4167 * requires this function to not return zero on an invalid descriptor
4168 * but rather a negative error number.
4169 */
4170 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
4171 return -EINVAL;
4172
4173 gc = desc->gdev->chip;
4174 offset = gpio_chip_hwgpio(desc);
4175 if (gc->to_irq) {
4176 int retirq = gc->to_irq(gc, offset);
4177
4178 /* Zero means NO_IRQ */
4179 if (!retirq)
4180 return -ENXIO;
4181
4182 return retirq;
4183 }
4184 return -ENXIO;
4185 }
4186 EXPORT_SYMBOL_GPL(gpiod_to_irq);
4187
4188 /**
4189 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
4190 * @gc: the chip the GPIO to lock belongs to
4191 * @offset: the offset of the GPIO to lock as IRQ
4192 *
4193 * This is used directly by GPIO drivers that want to lock down
4194 * a certain GPIO line to be used for IRQs.
4195 */
4196 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
4197 {
4198 struct gpio_desc *desc;
4199
4200 desc = gpiochip_get_desc(gc, offset);
4201 if (IS_ERR(desc))
4202 return PTR_ERR(desc);
4203
4204 /*
4205 * If it's fast: flush the direction setting if something changed
4206 * behind our back
4207 */
4208 if (!gc->can_sleep && gc->get_direction) {
4209 int dir = gpiod_get_direction(desc);
4210
4211 if (dir < 0) {
4212 chip_err(gc, "%s: cannot get GPIO direction\n",
4213 __func__);
4214 return dir;
4215 }
4216 }
4217
4218 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
4219 chip_err(gc,
4220 "%s: tried to flag a GPIO set as output for IRQ\n",
4221 __func__);
4222 return -EIO;
4223 }
4224
4225 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
4226 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4227
4228 /*
4229 * If the consumer has not set up a label (such as when the
4230 * IRQ is referenced from .to_irq()) we set up a label here
4231 * so it is clear this is used as an interrupt.
4232 */
4233 if (!desc->label)
4234 desc_set_label(desc, "interrupt");
4235
4236 return 0;
4237 }
4238 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
4239
4240 /**
4241 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
4242 * @gc: the chip the GPIO to lock belongs to
4243 * @offset: the offset of the GPIO to lock as IRQ
4244 *
4245 * This is used directly by GPIO drivers that want to indicate
4246 * that a certain GPIO is no longer used exclusively for IRQ.
4247 */
4248 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
4249 {
4250 struct gpio_desc *desc;
4251
4252 desc = gpiochip_get_desc(gc, offset);
4253 if (IS_ERR(desc))
4254 return;
4255
4256 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
4257 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4258
4259 /* If we only had this marking, erase it */
4260 if (desc->label && !strcmp(desc->label, "interrupt"))
4261 desc_set_label(desc, NULL);
4262 }
4263 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
4264
4265 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
4266 {
4267 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4268
4269 if (!IS_ERR(desc) &&
4270 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
4271 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4272 }
4273 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
4274
4275 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
4276 {
4277 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4278
4279 if (!IS_ERR(desc) &&
4280 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
4281 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags));
4282 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4283 }
4284 }
4285 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
4286
4287 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
4288 {
4289 if (offset >= gc->ngpio)
4290 return false;
4291
4292 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
4293 }
4294 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
4295
4296 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
4297 {
4298 int ret;
4299
4300 if (!try_module_get(gc->gpiodev->owner))
4301 return -ENODEV;
4302
4303 ret = gpiochip_lock_as_irq(gc, offset);
4304 if (ret) {
4305 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
4306 module_put(gc->gpiodev->owner);
4307 return ret;
4308 }
4309 return 0;
4310 }
4311 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
4312
4313 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
4314 {
4315 gpiochip_unlock_as_irq(gc, offset);
4316 module_put(gc->gpiodev->owner);
4317 }
4318 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
4319
4320 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
4321 {
4322 if (offset >= gc->ngpio)
4323 return false;
4324
4325 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
4326 }
4327 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
4328
4329 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
4330 {
4331 if (offset >= gc->ngpio)
4332 return false;
4333
4334 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
4335 }
4336 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
4337
4338 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
4339 {
4340 if (offset >= gc->ngpio)
4341 return false;
4342
4343 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
4344 }
4345 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
4346
4347 /**
4348 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
4349 * @desc: gpio whose value will be returned
4350 *
4351 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
4352 * its ACTIVE_LOW status, or negative errno on failure.
4353 *
4354 * This function is to be called from contexts that can sleep.
4355 */
4356 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
4357 {
4358 might_sleep_if(extra_checks);
4359 VALIDATE_DESC(desc);
4360 return gpiod_get_raw_value_commit(desc);
4361 }
4362 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
4363
4364 /**
4365 * gpiod_get_value_cansleep() - return a gpio's value
4366 * @desc: gpio whose value will be returned
4367 *
4368 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
4369 * account, or negative errno on failure.
4370 *
4371 * This function is to be called from contexts that can sleep.
4372 */
4373 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
4374 {
4375 int value;
4376
4377 might_sleep_if(extra_checks);
4378 VALIDATE_DESC(desc);
4379 value = gpiod_get_raw_value_commit(desc);
4380 if (value < 0)
4381 return value;
4382
4383 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
4384 value = !value;
4385
4386 return value;
4387 }
4388 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
4389
4390 /**
4391 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
4392 * @array_size: number of elements in the descriptor array / value bitmap
4393 * @desc_array: array of GPIO descriptors whose values will be read
4394 * @array_info: information on applicability of fast bitmap processing path
4395 * @value_bitmap: bitmap to store the read values
4396 *
4397 * Read the raw values of the GPIOs, i.e. the values of the physical lines
4398 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
4399 * else an error code.
4400 *
4401 * This function is to be called from contexts that can sleep.
4402 */
4403 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
4404 struct gpio_desc **desc_array,
4405 struct gpio_array *array_info,
4406 unsigned long *value_bitmap)
4407 {
4408 might_sleep_if(extra_checks);
4409 if (!desc_array)
4410 return -EINVAL;
4411 return gpiod_get_array_value_complex(true, true, array_size,
4412 desc_array, array_info,
4413 value_bitmap);
4414 }
4415 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
4416
4417 /**
4418 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
4419 * @array_size: number of elements in the descriptor array / value bitmap
4420 * @desc_array: array of GPIO descriptors whose values will be read
4421 * @array_info: information on applicability of fast bitmap processing path
4422 * @value_bitmap: bitmap to store the read values
4423 *
4424 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4425 * into account. Return 0 in case of success, else an error code.
4426 *
4427 * This function is to be called from contexts that can sleep.
4428 */
4429 int gpiod_get_array_value_cansleep(unsigned int array_size,
4430 struct gpio_desc **desc_array,
4431 struct gpio_array *array_info,
4432 unsigned long *value_bitmap)
4433 {
4434 might_sleep_if(extra_checks);
4435 if (!desc_array)
4436 return -EINVAL;
4437 return gpiod_get_array_value_complex(false, true, array_size,
4438 desc_array, array_info,
4439 value_bitmap);
4440 }
4441 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
4442
4443 /**
4444 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
4445 * @desc: gpio whose value will be assigned
4446 * @value: value to assign
4447 *
4448 * Set the raw value of the GPIO, i.e. the value of its physical line without
4449 * regard for its ACTIVE_LOW status.
4450 *
4451 * This function is to be called from contexts that can sleep.
4452 */
4453 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
4454 {
4455 might_sleep_if(extra_checks);
4456 VALIDATE_DESC_VOID(desc);
4457 gpiod_set_raw_value_commit(desc, value);
4458 }
4459 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
4460
4461 /**
4462 * gpiod_set_value_cansleep() - assign a gpio's value
4463 * @desc: gpio whose value will be assigned
4464 * @value: value to assign
4465 *
4466 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
4467 * account
4468 *
4469 * This function is to be called from contexts that can sleep.
4470 */
4471 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
4472 {
4473 might_sleep_if(extra_checks);
4474 VALIDATE_DESC_VOID(desc);
4475 gpiod_set_value_nocheck(desc, value);
4476 }
4477 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
4478
4479 /**
4480 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
4481 * @array_size: number of elements in the descriptor array / value bitmap
4482 * @desc_array: array of GPIO descriptors whose values will be assigned
4483 * @array_info: information on applicability of fast bitmap processing path
4484 * @value_bitmap: bitmap of values to assign
4485 *
4486 * Set the raw values of the GPIOs, i.e. the values of the physical lines
4487 * without regard for their ACTIVE_LOW status.
4488 *
4489 * This function is to be called from contexts that can sleep.
4490 */
4491 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
4492 struct gpio_desc **desc_array,
4493 struct gpio_array *array_info,
4494 unsigned long *value_bitmap)
4495 {
4496 might_sleep_if(extra_checks);
4497 if (!desc_array)
4498 return -EINVAL;
4499 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
4500 array_info, value_bitmap);
4501 }
4502 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
4503
4504 /**
4505 * gpiod_add_lookup_tables() - register GPIO device consumers
4506 * @tables: list of tables of consumers to register
4507 * @n: number of tables in the list
4508 */
4509 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
4510 {
4511 unsigned int i;
4512
4513 mutex_lock(&gpio_lookup_lock);
4514
4515 for (i = 0; i < n; i++)
4516 list_add_tail(&tables[i]->list, &gpio_lookup_list);
4517
4518 mutex_unlock(&gpio_lookup_lock);
4519 }
4520
4521 /**
4522 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
4523 * @array_size: number of elements in the descriptor array / value bitmap
4524 * @desc_array: array of GPIO descriptors whose values will be assigned
4525 * @array_info: information on applicability of fast bitmap processing path
4526 * @value_bitmap: bitmap of values to assign
4527 *
4528 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4529 * into account.
4530 *
4531 * This function is to be called from contexts that can sleep.
4532 */
4533 int gpiod_set_array_value_cansleep(unsigned int array_size,
4534 struct gpio_desc **desc_array,
4535 struct gpio_array *array_info,
4536 unsigned long *value_bitmap)
4537 {
4538 might_sleep_if(extra_checks);
4539 if (!desc_array)
4540 return -EINVAL;
4541 return gpiod_set_array_value_complex(false, true, array_size,
4542 desc_array, array_info,
4543 value_bitmap);
4544 }
4545 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
4546
4547 /**
4548 * gpiod_add_lookup_table() - register GPIO device consumers
4549 * @table: table of consumers to register
4550 */
4551 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
4552 {
4553 mutex_lock(&gpio_lookup_lock);
4554
4555 list_add_tail(&table->list, &gpio_lookup_list);
4556
4557 mutex_unlock(&gpio_lookup_lock);
4558 }
4559 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
4560
4561 /**
4562 * gpiod_remove_lookup_table() - unregister GPIO device consumers
4563 * @table: table of consumers to unregister
4564 */
4565 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4566 {
4567 mutex_lock(&gpio_lookup_lock);
4568
4569 list_del(&table->list);
4570
4571 mutex_unlock(&gpio_lookup_lock);
4572 }
4573 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4574
4575 /**
4576 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4577 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4578 */
4579 void gpiod_add_hogs(struct gpiod_hog *hogs)
4580 {
4581 struct gpio_chip *gc;
4582 struct gpiod_hog *hog;
4583
4584 mutex_lock(&gpio_machine_hogs_mutex);
4585
4586 for (hog = &hogs[0]; hog->chip_label; hog++) {
4587 list_add_tail(&hog->list, &gpio_machine_hogs);
4588
4589 /*
4590 * The chip may have been registered earlier, so check if it
4591 * exists and, if so, try to hog the line now.
4592 */
4593 gc = find_chip_by_name(hog->chip_label);
4594 if (gc)
4595 gpiochip_machine_hog(gc, hog);
4596 }
4597
4598 mutex_unlock(&gpio_machine_hogs_mutex);
4599 }
4600 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4601
4602 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4603 {
4604 const char *dev_id = dev ? dev_name(dev) : NULL;
4605 struct gpiod_lookup_table *table;
4606
4607 mutex_lock(&gpio_lookup_lock);
4608
4609 list_for_each_entry(table, &gpio_lookup_list, list) {
4610 if (table->dev_id && dev_id) {
4611 /*
4612 * Valid strings on both ends, must be identical to have
4613 * a match
4614 */
4615 if (!strcmp(table->dev_id, dev_id))
4616 goto found;
4617 } else {
4618 /*
4619 * One of the pointers is NULL, so both must be to have
4620 * a match
4621 */
4622 if (dev_id == table->dev_id)
4623 goto found;
4624 }
4625 }
4626 table = NULL;
4627
4628 found:
4629 mutex_unlock(&gpio_lookup_lock);
4630 return table;
4631 }
4632
4633 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4634 unsigned int idx, unsigned long *flags)
4635 {
4636 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4637 struct gpiod_lookup_table *table;
4638 struct gpiod_lookup *p;
4639
4640 table = gpiod_find_lookup_table(dev);
4641 if (!table)
4642 return desc;
4643
4644 for (p = &table->table[0]; p->chip_label; p++) {
4645 struct gpio_chip *gc;
4646
4647 /* idx must always match exactly */
4648 if (p->idx != idx)
4649 continue;
4650
4651 /* If the lookup entry has a con_id, require exact match */
4652 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4653 continue;
4654
4655 gc = find_chip_by_name(p->chip_label);
4656
4657 if (!gc) {
4658 /*
4659 * As the lookup table indicates a chip with
4660 * p->chip_label should exist, assume it may
4661 * still appear later and let the interested
4662 * consumer be probed again or let the Deferred
4663 * Probe infrastructure handle the error.
4664 */
4665 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4666 p->chip_label);
4667 return ERR_PTR(-EPROBE_DEFER);
4668 }
4669
4670 if (gc->ngpio <= p->chip_hwnum) {
4671 dev_err(dev,
4672 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4673 idx, p->chip_hwnum, gc->ngpio - 1,
4674 gc->label);
4675 return ERR_PTR(-EINVAL);
4676 }
4677
4678 desc = gpiochip_get_desc(gc, p->chip_hwnum);
4679 *flags = p->flags;
4680
4681 return desc;
4682 }
4683
4684 return desc;
4685 }
4686
4687 static int platform_gpio_count(struct device *dev, const char *con_id)
4688 {
4689 struct gpiod_lookup_table *table;
4690 struct gpiod_lookup *p;
4691 unsigned int count = 0;
4692
4693 table = gpiod_find_lookup_table(dev);
4694 if (!table)
4695 return -ENOENT;
4696
4697 for (p = &table->table[0]; p->chip_label; p++) {
4698 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4699 (!con_id && !p->con_id))
4700 count++;
4701 }
4702 if (!count)
4703 return -ENOENT;
4704
4705 return count;
4706 }
4707
4708 /**
4709 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
4710 * @fwnode: handle of the firmware node
4711 * @con_id: function within the GPIO consumer
4712 * @index: index of the GPIO to obtain for the consumer
4713 * @flags: GPIO initialization flags
4714 * @label: label to attach to the requested GPIO
4715 *
4716 * This function can be used for drivers that get their configuration
4717 * from opaque firmware.
4718 *
4719 * The function properly finds the corresponding GPIO using whatever is the
4720 * underlying firmware interface and then makes sure that the GPIO
4721 * descriptor is requested before it is returned to the caller.
4722 *
4723 * Returns:
4724 * On successful request the GPIO pin is configured in accordance with
4725 * provided @flags.
4726 *
4727 * In case of error an ERR_PTR() is returned.
4728 */
4729 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
4730 const char *con_id, int index,
4731 enum gpiod_flags flags,
4732 const char *label)
4733 {
4734 struct gpio_desc *desc;
4735 char prop_name[32]; /* 32 is max size of property name */
4736 unsigned int i;
4737
4738 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
4739 if (con_id)
4740 snprintf(prop_name, sizeof(prop_name), "%s-%s",
4741 con_id, gpio_suffixes[i]);
4742 else
4743 snprintf(prop_name, sizeof(prop_name), "%s",
4744 gpio_suffixes[i]);
4745
4746 desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
4747 label);
4748 if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
4749 break;
4750 }
4751
4752 return desc;
4753 }
4754 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
4755
4756 /**
4757 * gpiod_count - return the number of GPIOs associated with a device / function
4758 * or -ENOENT if no GPIO has been assigned to the requested function
4759 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4760 * @con_id: function within the GPIO consumer
4761 */
4762 int gpiod_count(struct device *dev, const char *con_id)
4763 {
4764 int count = -ENOENT;
4765
4766 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
4767 count = of_gpio_get_count(dev, con_id);
4768 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
4769 count = acpi_gpio_count(dev, con_id);
4770
4771 if (count < 0)
4772 count = platform_gpio_count(dev, con_id);
4773
4774 return count;
4775 }
4776 EXPORT_SYMBOL_GPL(gpiod_count);
4777
4778 /**
4779 * gpiod_get - obtain a GPIO for a given GPIO function
4780 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4781 * @con_id: function within the GPIO consumer
4782 * @flags: optional GPIO initialization flags
4783 *
4784 * Return the GPIO descriptor corresponding to the function con_id of device
4785 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4786 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4787 */
4788 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4789 enum gpiod_flags flags)
4790 {
4791 return gpiod_get_index(dev, con_id, 0, flags);
4792 }
4793 EXPORT_SYMBOL_GPL(gpiod_get);
4794
4795 /**
4796 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4797 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4798 * @con_id: function within the GPIO consumer
4799 * @flags: optional GPIO initialization flags
4800 *
4801 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4802 * the requested function it will return NULL. This is convenient for drivers
4803 * that need to handle optional GPIOs.
4804 */
4805 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4806 const char *con_id,
4807 enum gpiod_flags flags)
4808 {
4809 return gpiod_get_index_optional(dev, con_id, 0, flags);
4810 }
4811 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4812
4813
4814 /**
4815 * gpiod_configure_flags - helper function to configure a given GPIO
4816 * @desc: gpio whose value will be assigned
4817 * @con_id: function within the GPIO consumer
4818 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4819 * of_find_gpio() or of_get_gpio_hog()
4820 * @dflags: gpiod_flags - optional GPIO initialization flags
4821 *
4822 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4823 * requested function and/or index, or another IS_ERR() code if an error
4824 * occurred while trying to acquire the GPIO.
4825 */
4826 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4827 unsigned long lflags, enum gpiod_flags dflags)
4828 {
4829 int ret;
4830
4831 if (lflags & GPIO_ACTIVE_LOW)
4832 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4833
4834 if (lflags & GPIO_OPEN_DRAIN)
4835 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4836 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4837 /*
4838 * This enforces open drain mode from the consumer side.
4839 * This is necessary for some busses like I2C, but the lookup
4840 * should *REALLY* have specified them as open drain in the
4841 * first place, so print a little warning here.
4842 */
4843 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4844 gpiod_warn(desc,
4845 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4846 }
4847
4848 if (lflags & GPIO_OPEN_SOURCE)
4849 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4850
4851 if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
4852 gpiod_err(desc,
4853 "both pull-up and pull-down enabled, invalid configuration\n");
4854 return -EINVAL;
4855 }
4856
4857 if (lflags & GPIO_PULL_UP)
4858 set_bit(FLAG_PULL_UP, &desc->flags);
4859 else if (lflags & GPIO_PULL_DOWN)
4860 set_bit(FLAG_PULL_DOWN, &desc->flags);
4861
4862 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4863 if (ret < 0)
4864 return ret;
4865
4866 /* No particular flag request, return here... */
4867 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4868 pr_debug("no flags found for %s\n", con_id);
4869 return 0;
4870 }
4871
4872 /* Process flags */
4873 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4874 ret = gpiod_direction_output(desc,
4875 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4876 else
4877 ret = gpiod_direction_input(desc);
4878
4879 return ret;
4880 }
4881
4882 /**
4883 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4884 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4885 * @con_id: function within the GPIO consumer
4886 * @idx: index of the GPIO to obtain in the consumer
4887 * @flags: optional GPIO initialization flags
4888 *
4889 * This variant of gpiod_get() allows to access GPIOs other than the first
4890 * defined one for functions that define several GPIOs.
4891 *
4892 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4893 * requested function and/or index, or another IS_ERR() code if an error
4894 * occurred while trying to acquire the GPIO.
4895 */
4896 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4897 const char *con_id,
4898 unsigned int idx,
4899 enum gpiod_flags flags)
4900 {
4901 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4902 struct gpio_desc *desc = NULL;
4903 int ret;
4904 /* Maybe we have a device name, maybe not */
4905 const char *devname = dev ? dev_name(dev) : "?";
4906
4907 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4908
4909 if (dev) {
4910 /* Using device tree? */
4911 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4912 dev_dbg(dev, "using device tree for GPIO lookup\n");
4913 desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4914 } else if (ACPI_COMPANION(dev)) {
4915 dev_dbg(dev, "using ACPI for GPIO lookup\n");
4916 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4917 }
4918 }
4919
4920 /*
4921 * Either we are not using DT or ACPI, or their lookup did not return
4922 * a result. In that case, use platform lookup as a fallback.
4923 */
4924 if (!desc || desc == ERR_PTR(-ENOENT)) {
4925 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4926 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4927 }
4928
4929 if (IS_ERR(desc)) {
4930 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4931 return desc;
4932 }
4933
4934 /*
4935 * If a connection label was passed use that, else attempt to use
4936 * the device name as label
4937 */
4938 ret = gpiod_request(desc, con_id ? con_id : devname);
4939 if (ret < 0) {
4940 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4941 /*
4942 * This happens when there are several consumers for
4943 * the same GPIO line: we just return here without
4944 * further initialization. It is a bit if a hack.
4945 * This is necessary to support fixed regulators.
4946 *
4947 * FIXME: Make this more sane and safe.
4948 */
4949 dev_info(dev, "nonexclusive access to GPIO for %s\n",
4950 con_id ? con_id : devname);
4951 return desc;
4952 } else {
4953 return ERR_PTR(ret);
4954 }
4955 }
4956
4957 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4958 if (ret < 0) {
4959 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4960 gpiod_put(desc);
4961 return ERR_PTR(ret);
4962 }
4963
4964 return desc;
4965 }
4966 EXPORT_SYMBOL_GPL(gpiod_get_index);
4967
4968 /**
4969 * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4970 * @fwnode: handle of the firmware node
4971 * @propname: name of the firmware property representing the GPIO
4972 * @index: index of the GPIO to obtain for the consumer
4973 * @dflags: GPIO initialization flags
4974 * @label: label to attach to the requested GPIO
4975 *
4976 * This function can be used for drivers that get their configuration
4977 * from opaque firmware.
4978 *
4979 * The function properly finds the corresponding GPIO using whatever is the
4980 * underlying firmware interface and then makes sure that the GPIO
4981 * descriptor is requested before it is returned to the caller.
4982 *
4983 * Returns:
4984 * On successful request the GPIO pin is configured in accordance with
4985 * provided @dflags.
4986 *
4987 * In case of error an ERR_PTR() is returned.
4988 */
4989 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4990 const char *propname, int index,
4991 enum gpiod_flags dflags,
4992 const char *label)
4993 {
4994 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4995 struct gpio_desc *desc = ERR_PTR(-ENODEV);
4996 int ret;
4997
4998 if (!fwnode)
4999 return ERR_PTR(-EINVAL);
5000
5001 if (is_of_node(fwnode)) {
5002 desc = gpiod_get_from_of_node(to_of_node(fwnode),
5003 propname, index,
5004 dflags,
5005 label);
5006 return desc;
5007 } else if (is_acpi_node(fwnode)) {
5008 struct acpi_gpio_info info;
5009
5010 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
5011 if (IS_ERR(desc))
5012 return desc;
5013
5014 acpi_gpio_update_gpiod_flags(&dflags, &info);
5015 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
5016 }
5017
5018 /* Currently only ACPI takes this path */
5019 ret = gpiod_request(desc, label);
5020 if (ret)
5021 return ERR_PTR(ret);
5022
5023 ret = gpiod_configure_flags(desc, propname, lflags, dflags);
5024 if (ret < 0) {
5025 gpiod_put(desc);
5026 return ERR_PTR(ret);
5027 }
5028
5029 return desc;
5030 }
5031 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
5032
5033 /**
5034 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
5035 * function
5036 * @dev: GPIO consumer, can be NULL for system-global GPIOs
5037 * @con_id: function within the GPIO consumer
5038 * @index: index of the GPIO to obtain in the consumer
5039 * @flags: optional GPIO initialization flags
5040 *
5041 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
5042 * specified index was assigned to the requested function it will return NULL.
5043 * This is convenient for drivers that need to handle optional GPIOs.
5044 */
5045 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
5046 const char *con_id,
5047 unsigned int index,
5048 enum gpiod_flags flags)
5049 {
5050 struct gpio_desc *desc;
5051
5052 desc = gpiod_get_index(dev, con_id, index, flags);
5053 if (IS_ERR(desc)) {
5054 if (PTR_ERR(desc) == -ENOENT)
5055 return NULL;
5056 }
5057
5058 return desc;
5059 }
5060 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
5061
5062 /**
5063 * gpiod_hog - Hog the specified GPIO desc given the provided flags
5064 * @desc: gpio whose value will be assigned
5065 * @name: gpio line name
5066 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
5067 * of_find_gpio() or of_get_gpio_hog()
5068 * @dflags: gpiod_flags - optional GPIO initialization flags
5069 */
5070 int gpiod_hog(struct gpio_desc *desc, const char *name,
5071 unsigned long lflags, enum gpiod_flags dflags)
5072 {
5073 struct gpio_chip *gc;
5074 struct gpio_desc *local_desc;
5075 int hwnum;
5076 int ret;
5077
5078 gc = gpiod_to_chip(desc);
5079 hwnum = gpio_chip_hwgpio(desc);
5080
5081 local_desc = gpiochip_request_own_desc(gc, hwnum, name,
5082 lflags, dflags);
5083 if (IS_ERR(local_desc)) {
5084 ret = PTR_ERR(local_desc);
5085 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
5086 name, gc->label, hwnum, ret);
5087 return ret;
5088 }
5089
5090 /* Mark GPIO as hogged so it can be identified and removed later */
5091 set_bit(FLAG_IS_HOGGED, &desc->flags);
5092
5093 pr_info("GPIO line %d (%s) hogged as %s%s\n",
5094 desc_to_gpio(desc), name,
5095 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
5096 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
5097 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
5098
5099 return 0;
5100 }
5101
5102 /**
5103 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
5104 * @gc: gpio chip to act on
5105 */
5106 static void gpiochip_free_hogs(struct gpio_chip *gc)
5107 {
5108 int id;
5109
5110 for (id = 0; id < gc->ngpio; id++) {
5111 if (test_bit(FLAG_IS_HOGGED, &gc->gpiodev->descs[id].flags))
5112 gpiochip_free_own_desc(&gc->gpiodev->descs[id]);
5113 }
5114 }
5115
5116 /**
5117 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
5118 * @dev: GPIO consumer, can be NULL for system-global GPIOs
5119 * @con_id: function within the GPIO consumer
5120 * @flags: optional GPIO initialization flags
5121 *
5122 * This function acquires all the GPIOs defined under a given function.
5123 *
5124 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
5125 * no GPIO has been assigned to the requested function, or another IS_ERR()
5126 * code if an error occurred while trying to acquire the GPIOs.
5127 */
5128 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
5129 const char *con_id,
5130 enum gpiod_flags flags)
5131 {
5132 struct gpio_desc *desc;
5133 struct gpio_descs *descs;
5134 struct gpio_array *array_info = NULL;
5135 struct gpio_chip *gc;
5136 int count, bitmap_size;
5137
5138 count = gpiod_count(dev, con_id);
5139 if (count < 0)
5140 return ERR_PTR(count);
5141
5142 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
5143 if (!descs)
5144 return ERR_PTR(-ENOMEM);
5145
5146 for (descs->ndescs = 0; descs->ndescs < count; ) {
5147 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
5148 if (IS_ERR(desc)) {
5149 gpiod_put_array(descs);
5150 return ERR_CAST(desc);
5151 }
5152
5153 descs->desc[descs->ndescs] = desc;
5154
5155 gc = gpiod_to_chip(desc);
5156 /*
5157 * If pin hardware number of array member 0 is also 0, select
5158 * its chip as a candidate for fast bitmap processing path.
5159 */
5160 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
5161 struct gpio_descs *array;
5162
5163 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
5164 gc->ngpio : count);
5165
5166 array = kzalloc(struct_size(descs, desc, count) +
5167 struct_size(array_info, invert_mask,
5168 3 * bitmap_size), GFP_KERNEL);
5169 if (!array) {
5170 gpiod_put_array(descs);
5171 return ERR_PTR(-ENOMEM);
5172 }
5173
5174 memcpy(array, descs,
5175 struct_size(descs, desc, descs->ndescs + 1));
5176 kfree(descs);
5177
5178 descs = array;
5179 array_info = (void *)(descs->desc + count);
5180 array_info->get_mask = array_info->invert_mask +
5181 bitmap_size;
5182 array_info->set_mask = array_info->get_mask +
5183 bitmap_size;
5184
5185 array_info->desc = descs->desc;
5186 array_info->size = count;
5187 array_info->chip = gc;
5188 bitmap_set(array_info->get_mask, descs->ndescs,
5189 count - descs->ndescs);
5190 bitmap_set(array_info->set_mask, descs->ndescs,
5191 count - descs->ndescs);
5192 descs->info = array_info;
5193 }
5194 /* Unmark array members which don't belong to the 'fast' chip */
5195 if (array_info && array_info->chip != gc) {
5196 __clear_bit(descs->ndescs, array_info->get_mask);
5197 __clear_bit(descs->ndescs, array_info->set_mask);
5198 }
5199 /*
5200 * Detect array members which belong to the 'fast' chip
5201 * but their pins are not in hardware order.
5202 */
5203 else if (array_info &&
5204 gpio_chip_hwgpio(desc) != descs->ndescs) {
5205 /*
5206 * Don't use fast path if all array members processed so
5207 * far belong to the same chip as this one but its pin
5208 * hardware number is different from its array index.
5209 */
5210 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
5211 array_info = NULL;
5212 } else {
5213 __clear_bit(descs->ndescs,
5214 array_info->get_mask);
5215 __clear_bit(descs->ndescs,
5216 array_info->set_mask);
5217 }
5218 } else if (array_info) {
5219 /* Exclude open drain or open source from fast output */
5220 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
5221 gpiochip_line_is_open_source(gc, descs->ndescs))
5222 __clear_bit(descs->ndescs,
5223 array_info->set_mask);
5224 /* Identify 'fast' pins which require invertion */
5225 if (gpiod_is_active_low(desc))
5226 __set_bit(descs->ndescs,
5227 array_info->invert_mask);
5228 }
5229
5230 descs->ndescs++;
5231 }
5232 if (array_info)
5233 dev_dbg(dev,
5234 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
5235 array_info->chip->label, array_info->size,
5236 *array_info->get_mask, *array_info->set_mask,
5237 *array_info->invert_mask);
5238 return descs;
5239 }
5240 EXPORT_SYMBOL_GPL(gpiod_get_array);
5241
5242 /**
5243 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
5244 * function
5245 * @dev: GPIO consumer, can be NULL for system-global GPIOs
5246 * @con_id: function within the GPIO consumer
5247 * @flags: optional GPIO initialization flags
5248 *
5249 * This is equivalent to gpiod_get_array(), except that when no GPIO was
5250 * assigned to the requested function it will return NULL.
5251 */
5252 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
5253 const char *con_id,
5254 enum gpiod_flags flags)
5255 {
5256 struct gpio_descs *descs;
5257
5258 descs = gpiod_get_array(dev, con_id, flags);
5259 if (PTR_ERR(descs) == -ENOENT)
5260 return NULL;
5261
5262 return descs;
5263 }
5264 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
5265
5266 /**
5267 * gpiod_put - dispose of a GPIO descriptor
5268 * @desc: GPIO descriptor to dispose of
5269 *
5270 * No descriptor can be used after gpiod_put() has been called on it.
5271 */
5272 void gpiod_put(struct gpio_desc *desc)
5273 {
5274 if (desc)
5275 gpiod_free(desc);
5276 }
5277 EXPORT_SYMBOL_GPL(gpiod_put);
5278
5279 /**
5280 * gpiod_put_array - dispose of multiple GPIO descriptors
5281 * @descs: struct gpio_descs containing an array of descriptors
5282 */
5283 void gpiod_put_array(struct gpio_descs *descs)
5284 {
5285 unsigned int i;
5286
5287 for (i = 0; i < descs->ndescs; i++)
5288 gpiod_put(descs->desc[i]);
5289
5290 kfree(descs);
5291 }
5292 EXPORT_SYMBOL_GPL(gpiod_put_array);
5293
5294 static int __init gpiolib_dev_init(void)
5295 {
5296 int ret;
5297
5298 /* Register GPIO sysfs bus */
5299 ret = bus_register(&gpio_bus_type);
5300 if (ret < 0) {
5301 pr_err("gpiolib: could not register GPIO bus type\n");
5302 return ret;
5303 }
5304
5305 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
5306 if (ret < 0) {
5307 pr_err("gpiolib: failed to allocate char dev region\n");
5308 bus_unregister(&gpio_bus_type);
5309 return ret;
5310 }
5311
5312 gpiolib_initialized = true;
5313 gpiochip_setup_devs();
5314
5315 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
5316 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
5317 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
5318
5319 return ret;
5320 }
5321 core_initcall(gpiolib_dev_init);
5322
5323 #ifdef CONFIG_DEBUG_FS
5324
5325 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
5326 {
5327 unsigned i;
5328 struct gpio_chip *gc = gdev->chip;
5329 unsigned gpio = gdev->base;
5330 struct gpio_desc *gdesc = &gdev->descs[0];
5331 bool is_out;
5332 bool is_irq;
5333 bool active_low;
5334
5335 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
5336 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
5337 if (gdesc->name) {
5338 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
5339 gpio, gdesc->name);
5340 }
5341 continue;
5342 }
5343
5344 gpiod_get_direction(gdesc);
5345 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
5346 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
5347 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
5348 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
5349 gpio, gdesc->name ? gdesc->name : "", gdesc->label,
5350 is_out ? "out" : "in ",
5351 gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "? ",
5352 is_irq ? "IRQ " : "",
5353 active_low ? "ACTIVE LOW" : "");
5354 seq_printf(s, "\n");
5355 }
5356 }
5357
5358 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
5359 {
5360 unsigned long flags;
5361 struct gpio_device *gdev = NULL;
5362 loff_t index = *pos;
5363
5364 s->private = "";
5365
5366 spin_lock_irqsave(&gpio_lock, flags);
5367 list_for_each_entry(gdev, &gpio_devices, list)
5368 if (index-- == 0) {
5369 spin_unlock_irqrestore(&gpio_lock, flags);
5370 return gdev;
5371 }
5372 spin_unlock_irqrestore(&gpio_lock, flags);
5373
5374 return NULL;
5375 }
5376
5377 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
5378 {
5379 unsigned long flags;
5380 struct gpio_device *gdev = v;
5381 void *ret = NULL;
5382
5383 spin_lock_irqsave(&gpio_lock, flags);
5384 if (list_is_last(&gdev->list, &gpio_devices))
5385 ret = NULL;
5386 else
5387 ret = list_entry(gdev->list.next, struct gpio_device, list);
5388 spin_unlock_irqrestore(&gpio_lock, flags);
5389
5390 s->private = "\n";
5391 ++*pos;
5392
5393 return ret;
5394 }
5395
5396 static void gpiolib_seq_stop(struct seq_file *s, void *v)
5397 {
5398 }
5399
5400 static int gpiolib_seq_show(struct seq_file *s, void *v)
5401 {
5402 struct gpio_device *gdev = v;
5403 struct gpio_chip *gc = gdev->chip;
5404 struct device *parent;
5405
5406 if (!gc) {
5407 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
5408 dev_name(&gdev->dev));
5409 return 0;
5410 }
5411
5412 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
5413 dev_name(&gdev->dev),
5414 gdev->base, gdev->base + gdev->ngpio - 1);
5415 parent = gc->parent;
5416 if (parent)
5417 seq_printf(s, ", parent: %s/%s",
5418 parent->bus ? parent->bus->name : "no-bus",
5419 dev_name(parent));
5420 if (gc->label)
5421 seq_printf(s, ", %s", gc->label);
5422 if (gc->can_sleep)
5423 seq_printf(s, ", can sleep");
5424 seq_printf(s, ":\n");
5425
5426 if (gc->dbg_show)
5427 gc->dbg_show(s, gc);
5428 else
5429 gpiolib_dbg_show(s, gdev);
5430
5431 return 0;
5432 }
5433
5434 static const struct seq_operations gpiolib_seq_ops = {
5435 .start = gpiolib_seq_start,
5436 .next = gpiolib_seq_next,
5437 .stop = gpiolib_seq_stop,
5438 .show = gpiolib_seq_show,
5439 };
5440
5441 static int gpiolib_open(struct inode *inode, struct file *file)
5442 {
5443 return seq_open(file, &gpiolib_seq_ops);
5444 }
5445
5446 static const struct file_operations gpiolib_operations = {
5447 .owner = THIS_MODULE,
5448 .open = gpiolib_open,
5449 .read = seq_read,
5450 .llseek = seq_lseek,
5451 .release = seq_release,
5452 };
5453
5454 static int __init gpiolib_debugfs_init(void)
5455 {
5456 /* /sys/kernel/debug/gpio */
5457 debugfs_create_file("gpio", S_IFREG | S_IRUGO, NULL, NULL,
5458 &gpiolib_operations);
5459 return 0;
5460 }
5461 subsys_initcall(gpiolib_debugfs_init);
5462
5463 #endif /* DEBUG_FS */