1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/acpi.h>
4 #include <linux/array_size.h>
5 #include <linux/bitmap.h>
6 #include <linux/cleanup.h>
7 #include <linux/compat.h>
8 #include <linux/debugfs.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/errno.h>
12 #include <linux/file.h>
13 #include <linux/fs.h>
14 #include <linux/idr.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/irqdesc.h>
18 #include <linux/kernel.h>
19 #include <linux/list.h>
20 #include <linux/lockdep.h>
21 #include <linux/module.h>
22 #include <linux/nospec.h>
23 #include <linux/of.h>
24 #include <linux/pinctrl/consumer.h>
25 #include <linux/seq_file.h>
26 #include <linux/slab.h>
27 #include <linux/srcu.h>
28 #include <linux/string.h>
29 #include <linux/string_choices.h>
30
31 #include <linux/gpio.h>
32 #include <linux/gpio/driver.h>
33 #include <linux/gpio/machine.h>
34
35 #include <uapi/linux/gpio.h>
36
37 #include "gpiolib-acpi.h"
38 #include "gpiolib-cdev.h"
39 #include "gpiolib-of.h"
40 #include "gpiolib-swnode.h"
41 #include "gpiolib-sysfs.h"
42 #include "gpiolib.h"
43
44 #define CREATE_TRACE_POINTS
45 #include <trace/events/gpio.h>
46
47 /* Implementation infrastructure for GPIO interfaces.
48 *
49 * The GPIO programming interface allows for inlining speed-critical
50 * get/set operations for common cases, so that access to SOC-integrated
51 * GPIOs can sometimes cost only an instruction or two per bit.
52 */
53
54 /* Device and char device-related information */
55 static DEFINE_IDA(gpio_ida);
56 static dev_t gpio_devt;
57 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
58
gpio_bus_match(struct device * dev,const struct device_driver * drv)59 static int gpio_bus_match(struct device *dev, const struct device_driver *drv)
60 {
61 struct fwnode_handle *fwnode = dev_fwnode(dev);
62
63 /*
64 * Only match if the fwnode doesn't already have a proper struct device
65 * created for it.
66 */
67 if (fwnode && fwnode->dev != dev)
68 return 0;
69 return 1;
70 }
71
72 static const struct bus_type gpio_bus_type = {
73 .name = "gpio",
74 .match = gpio_bus_match,
75 };
76
77 /*
78 * Number of GPIOs to use for the fast path in set array
79 */
80 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
81
82 static DEFINE_MUTEX(gpio_lookup_lock);
83 static LIST_HEAD(gpio_lookup_list);
84
85 static LIST_HEAD(gpio_devices);
86 /* Protects the GPIO device list against concurrent modifications. */
87 static DEFINE_MUTEX(gpio_devices_lock);
88 /* Ensures coherence during read-only accesses to the list of GPIO devices. */
89 DEFINE_STATIC_SRCU(gpio_devices_srcu);
90
91 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
92 static LIST_HEAD(gpio_machine_hogs);
93
94 const char *const gpio_suffixes[] = { "gpios", "gpio", NULL };
95
96 static void gpiochip_free_hogs(struct gpio_chip *gc);
97 static int gpiochip_add_irqchip(struct gpio_chip *gc,
98 struct lock_class_key *lock_key,
99 struct lock_class_key *request_key);
100 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
101 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
102 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
103 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
104
105 static bool gpiolib_initialized;
106
gpiod_get_label(struct gpio_desc * desc)107 const char *gpiod_get_label(struct gpio_desc *desc)
108 {
109 struct gpio_desc_label *label;
110 unsigned long flags;
111
112 flags = READ_ONCE(desc->flags);
113
114 label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu,
115 srcu_read_lock_held(&desc->gdev->desc_srcu));
116
117 if (test_bit(FLAG_USED_AS_IRQ, &flags))
118 return label ? label->str : "interrupt";
119
120 if (!test_bit(FLAG_REQUESTED, &flags))
121 return NULL;
122
123 return label ? label->str : NULL;
124 }
125
desc_free_label(struct rcu_head * rh)126 static void desc_free_label(struct rcu_head *rh)
127 {
128 kfree(container_of(rh, struct gpio_desc_label, rh));
129 }
130
desc_set_label(struct gpio_desc * desc,const char * label)131 static int desc_set_label(struct gpio_desc *desc, const char *label)
132 {
133 struct gpio_desc_label *new = NULL, *old;
134
135 if (label) {
136 new = kzalloc(struct_size(new, str, strlen(label) + 1),
137 GFP_KERNEL);
138 if (!new)
139 return -ENOMEM;
140
141 strcpy(new->str, label);
142 }
143
144 old = rcu_replace_pointer(desc->label, new, 1);
145 if (old)
146 call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label);
147
148 return 0;
149 }
150
151 /**
152 * gpio_to_desc - Convert a GPIO number to its descriptor
153 * @gpio: global GPIO number
154 *
155 * Returns:
156 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
157 * with the given number exists in the system.
158 */
gpio_to_desc(unsigned gpio)159 struct gpio_desc *gpio_to_desc(unsigned gpio)
160 {
161 struct gpio_device *gdev;
162
163 scoped_guard(srcu, &gpio_devices_srcu) {
164 list_for_each_entry_srcu(gdev, &gpio_devices, list,
165 srcu_read_lock_held(&gpio_devices_srcu)) {
166 if (gdev->base <= gpio &&
167 gdev->base + gdev->ngpio > gpio)
168 return &gdev->descs[gpio - gdev->base];
169 }
170 }
171
172 return NULL;
173 }
174 EXPORT_SYMBOL_GPL(gpio_to_desc);
175
176 /* This function is deprecated and will be removed soon, don't use. */
gpiochip_get_desc(struct gpio_chip * gc,unsigned int hwnum)177 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
178 unsigned int hwnum)
179 {
180 return gpio_device_get_desc(gc->gpiodev, hwnum);
181 }
182
183 /**
184 * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given
185 * hardware number for this GPIO device
186 * @gdev: GPIO device to get the descriptor from
187 * @hwnum: hardware number of the GPIO for this chip
188 *
189 * Returns:
190 * A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given
191 * chip for the specified hardware number or %ENODEV if the underlying chip
192 * already vanished.
193 *
194 * The reference count of struct gpio_device is *NOT* increased like when the
195 * GPIO is being requested for exclusive usage. It's up to the caller to make
196 * sure the GPIO device will stay alive together with the descriptor returned
197 * by this function.
198 */
199 struct gpio_desc *
gpio_device_get_desc(struct gpio_device * gdev,unsigned int hwnum)200 gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum)
201 {
202 if (hwnum >= gdev->ngpio)
203 return ERR_PTR(-EINVAL);
204
205 return &gdev->descs[array_index_nospec(hwnum, gdev->ngpio)];
206 }
207 EXPORT_SYMBOL_GPL(gpio_device_get_desc);
208
209 /**
210 * desc_to_gpio - convert a GPIO descriptor to the integer namespace
211 * @desc: GPIO descriptor
212 *
213 * This should disappear in the future but is needed since we still
214 * use GPIO numbers for error messages and sysfs nodes.
215 *
216 * Returns:
217 * The global GPIO number for the GPIO specified by its descriptor.
218 */
desc_to_gpio(const struct gpio_desc * desc)219 int desc_to_gpio(const struct gpio_desc *desc)
220 {
221 return desc->gdev->base + (desc - &desc->gdev->descs[0]);
222 }
223 EXPORT_SYMBOL_GPL(desc_to_gpio);
224
225
226 /**
227 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
228 * @desc: descriptor to return the chip of
229 *
230 * *DEPRECATED*
231 * This function is unsafe and should not be used. Using the chip address
232 * without taking the SRCU read lock may result in dereferencing a dangling
233 * pointer.
234 *
235 * Returns:
236 * Address of the GPIO chip backing this device.
237 */
gpiod_to_chip(const struct gpio_desc * desc)238 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
239 {
240 if (!desc)
241 return NULL;
242
243 return gpio_device_get_chip(desc->gdev);
244 }
245 EXPORT_SYMBOL_GPL(gpiod_to_chip);
246
247 /**
248 * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor
249 * belongs.
250 * @desc: Descriptor for which to return the GPIO device.
251 *
252 * This *DOES NOT* increase the reference count of the GPIO device as it's
253 * expected that the descriptor is requested and the users already holds a
254 * reference to the device.
255 *
256 * Returns:
257 * Address of the GPIO device owning this descriptor.
258 */
gpiod_to_gpio_device(struct gpio_desc * desc)259 struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc)
260 {
261 if (!desc)
262 return NULL;
263
264 return desc->gdev;
265 }
266 EXPORT_SYMBOL_GPL(gpiod_to_gpio_device);
267
268 /**
269 * gpio_device_get_base() - Get the base GPIO number allocated by this device
270 * @gdev: GPIO device
271 *
272 * Returns:
273 * First GPIO number in the global GPIO numberspace for this device.
274 */
gpio_device_get_base(struct gpio_device * gdev)275 int gpio_device_get_base(struct gpio_device *gdev)
276 {
277 return gdev->base;
278 }
279 EXPORT_SYMBOL_GPL(gpio_device_get_base);
280
281 /**
282 * gpio_device_get_label() - Get the label of this GPIO device
283 * @gdev: GPIO device
284 *
285 * Returns:
286 * Pointer to the string containing the GPIO device label. The string's
287 * lifetime is tied to that of the underlying GPIO device.
288 */
gpio_device_get_label(struct gpio_device * gdev)289 const char *gpio_device_get_label(struct gpio_device *gdev)
290 {
291 return gdev->label;
292 }
293 EXPORT_SYMBOL(gpio_device_get_label);
294
295 /**
296 * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device
297 * @gdev: GPIO device
298 *
299 * Returns:
300 * Address of the GPIO chip backing this device.
301 *
302 * *DEPRECATED*
303 * Until we can get rid of all non-driver users of struct gpio_chip, we must
304 * provide a way of retrieving the pointer to it from struct gpio_device. This
305 * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the
306 * chip can dissapear at any moment (unlike reference-counted struct
307 * gpio_device).
308 *
309 * Use at your own risk.
310 */
gpio_device_get_chip(struct gpio_device * gdev)311 struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)
312 {
313 return rcu_dereference_check(gdev->chip, 1);
314 }
315 EXPORT_SYMBOL_GPL(gpio_device_get_chip);
316
317 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
gpiochip_find_base_unlocked(u16 ngpio)318 static int gpiochip_find_base_unlocked(u16 ngpio)
319 {
320 unsigned int base = GPIO_DYNAMIC_BASE;
321 struct gpio_device *gdev;
322
323 list_for_each_entry_srcu(gdev, &gpio_devices, list,
324 lockdep_is_held(&gpio_devices_lock)) {
325 /* found a free space? */
326 if (gdev->base >= base + ngpio)
327 break;
328 /* nope, check the space right after the chip */
329 base = gdev->base + gdev->ngpio;
330 if (base < GPIO_DYNAMIC_BASE)
331 base = GPIO_DYNAMIC_BASE;
332 if (base > GPIO_DYNAMIC_MAX - ngpio)
333 break;
334 }
335
336 if (base <= GPIO_DYNAMIC_MAX - ngpio) {
337 pr_debug("%s: found new base at %d\n", __func__, base);
338 return base;
339 } else {
340 pr_err("%s: cannot find free range\n", __func__);
341 return -ENOSPC;
342 }
343 }
344
gpiochip_get_direction(struct gpio_chip * gc,unsigned int offset)345 static int gpiochip_get_direction(struct gpio_chip *gc, unsigned int offset)
346 {
347 int ret;
348
349 lockdep_assert_held(&gc->gpiodev->srcu);
350
351 if (WARN_ON(!gc->get_direction))
352 return -EOPNOTSUPP;
353
354 ret = gc->get_direction(gc, offset);
355 if (ret < 0)
356 return ret;
357
358 if (ret != GPIO_LINE_DIRECTION_OUT && ret != GPIO_LINE_DIRECTION_IN)
359 ret = -EBADE;
360
361 return ret;
362 }
363
364 /**
365 * gpiod_get_direction - return the current direction of a GPIO
366 * @desc: GPIO to get the direction of
367 *
368 * Returns:
369 * 0 for output, 1 for input, or an error code in case of error.
370 *
371 * This function may sleep if gpiod_cansleep() is true.
372 */
gpiod_get_direction(struct gpio_desc * desc)373 int gpiod_get_direction(struct gpio_desc *desc)
374 {
375 unsigned long flags;
376 unsigned int offset;
377 int ret;
378
379 /*
380 * We cannot use VALIDATE_DESC() as we must not return 0 for a NULL
381 * descriptor like we usually do.
382 */
383 if (IS_ERR_OR_NULL(desc))
384 return -EINVAL;
385
386 CLASS(gpio_chip_guard, guard)(desc);
387 if (!guard.gc)
388 return -ENODEV;
389
390 offset = gpio_chip_hwgpio(desc);
391 flags = READ_ONCE(desc->flags);
392
393 /*
394 * Open drain emulation using input mode may incorrectly report
395 * input here, fix that up.
396 */
397 if (test_bit(FLAG_OPEN_DRAIN, &flags) &&
398 test_bit(FLAG_IS_OUT, &flags))
399 return 0;
400
401 if (!guard.gc->get_direction)
402 return -ENOTSUPP;
403
404 ret = gpiochip_get_direction(guard.gc, offset);
405 if (ret < 0)
406 return ret;
407
408 /*
409 * GPIO_LINE_DIRECTION_IN or other positive,
410 * otherwise GPIO_LINE_DIRECTION_OUT.
411 */
412 if (ret > 0)
413 ret = 1;
414
415 assign_bit(FLAG_IS_OUT, &flags, !ret);
416 WRITE_ONCE(desc->flags, flags);
417
418 return ret;
419 }
420 EXPORT_SYMBOL_GPL(gpiod_get_direction);
421
422 /*
423 * Add a new chip to the global chips list, keeping the list of chips sorted
424 * by range(means [base, base + ngpio - 1]) order.
425 *
426 * Returns:
427 * -EBUSY if the new chip overlaps with some other chip's integer space.
428 */
gpiodev_add_to_list_unlocked(struct gpio_device * gdev)429 static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)
430 {
431 struct gpio_device *prev, *next;
432
433 lockdep_assert_held(&gpio_devices_lock);
434
435 if (list_empty(&gpio_devices)) {
436 /* initial entry in list */
437 list_add_tail_rcu(&gdev->list, &gpio_devices);
438 return 0;
439 }
440
441 next = list_first_entry(&gpio_devices, struct gpio_device, list);
442 if (gdev->base + gdev->ngpio <= next->base) {
443 /* add before first entry */
444 list_add_rcu(&gdev->list, &gpio_devices);
445 return 0;
446 }
447
448 prev = list_last_entry(&gpio_devices, struct gpio_device, list);
449 if (prev->base + prev->ngpio <= gdev->base) {
450 /* add behind last entry */
451 list_add_tail_rcu(&gdev->list, &gpio_devices);
452 return 0;
453 }
454
455 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
456 /* at the end of the list */
457 if (&next->list == &gpio_devices)
458 break;
459
460 /* add between prev and next */
461 if (prev->base + prev->ngpio <= gdev->base
462 && gdev->base + gdev->ngpio <= next->base) {
463 list_add_rcu(&gdev->list, &prev->list);
464 return 0;
465 }
466 }
467
468 synchronize_srcu(&gpio_devices_srcu);
469
470 return -EBUSY;
471 }
472
473 /*
474 * Convert a GPIO name to its descriptor
475 * Note that there is no guarantee that GPIO names are globally unique!
476 * Hence this function will return, if it exists, a reference to the first GPIO
477 * line found that matches the given name.
478 */
gpio_name_to_desc(const char * const name)479 static struct gpio_desc *gpio_name_to_desc(const char * const name)
480 {
481 struct gpio_device *gdev;
482 struct gpio_desc *desc;
483 struct gpio_chip *gc;
484
485 if (!name)
486 return NULL;
487
488 guard(srcu)(&gpio_devices_srcu);
489
490 list_for_each_entry_srcu(gdev, &gpio_devices, list,
491 srcu_read_lock_held(&gpio_devices_srcu)) {
492 guard(srcu)(&gdev->srcu);
493
494 gc = srcu_dereference(gdev->chip, &gdev->srcu);
495 if (!gc)
496 continue;
497
498 for_each_gpio_desc(gc, desc) {
499 if (desc->name && !strcmp(desc->name, name))
500 return desc;
501 }
502 }
503
504 return NULL;
505 }
506
507 /*
508 * Take the names from gc->names and assign them to their GPIO descriptors.
509 * Warn if a name is already used for a GPIO line on a different GPIO chip.
510 *
511 * Note that:
512 * 1. Non-unique names are still accepted,
513 * 2. Name collisions within the same GPIO chip are not reported.
514 */
gpiochip_set_desc_names(struct gpio_chip * gc)515 static void gpiochip_set_desc_names(struct gpio_chip *gc)
516 {
517 struct gpio_device *gdev = gc->gpiodev;
518 int i;
519
520 /* First check all names if they are unique */
521 for (i = 0; i != gc->ngpio; ++i) {
522 struct gpio_desc *gpio;
523
524 gpio = gpio_name_to_desc(gc->names[i]);
525 if (gpio)
526 dev_warn(&gdev->dev,
527 "Detected name collision for GPIO name '%s'\n",
528 gc->names[i]);
529 }
530
531 /* Then add all names to the GPIO descriptors */
532 for (i = 0; i != gc->ngpio; ++i)
533 gdev->descs[i].name = gc->names[i];
534 }
535
536 /*
537 * gpiochip_set_names - Set GPIO line names using device properties
538 * @chip: GPIO chip whose lines should be named, if possible
539 *
540 * Looks for device property "gpio-line-names" and if it exists assigns
541 * GPIO line names for the chip. The memory allocated for the assigned
542 * names belong to the underlying firmware node and should not be released
543 * by the caller.
544 */
gpiochip_set_names(struct gpio_chip * chip)545 static int gpiochip_set_names(struct gpio_chip *chip)
546 {
547 struct gpio_device *gdev = chip->gpiodev;
548 struct device *dev = &gdev->dev;
549 const char **names;
550 int ret, i;
551 int count;
552
553 count = device_property_string_array_count(dev, "gpio-line-names");
554 if (count < 0)
555 return 0;
556
557 /*
558 * When offset is set in the driver side we assume the driver internally
559 * is using more than one gpiochip per the same device. We have to stop
560 * setting friendly names if the specified ones with 'gpio-line-names'
561 * are less than the offset in the device itself. This means all the
562 * lines are not present for every single pin within all the internal
563 * gpiochips.
564 */
565 if (count <= chip->offset) {
566 dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
567 count, chip->offset);
568 return 0;
569 }
570
571 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
572 if (!names)
573 return -ENOMEM;
574
575 ret = device_property_read_string_array(dev, "gpio-line-names",
576 names, count);
577 if (ret < 0) {
578 dev_warn(dev, "failed to read GPIO line names\n");
579 kfree(names);
580 return ret;
581 }
582
583 /*
584 * When more that one gpiochip per device is used, 'count' can
585 * contain at most number gpiochips x chip->ngpio. We have to
586 * correctly distribute all defined lines taking into account
587 * chip->offset as starting point from where we will assign
588 * the names to pins from the 'names' array. Since property
589 * 'gpio-line-names' cannot contains gaps, we have to be sure
590 * we only assign those pins that really exists since chip->ngpio
591 * can be different of the chip->offset.
592 */
593 count = (count > chip->offset) ? count - chip->offset : count;
594 if (count > chip->ngpio)
595 count = chip->ngpio;
596
597 for (i = 0; i < count; i++) {
598 /*
599 * Allow overriding "fixed" names provided by the GPIO
600 * provider. The "fixed" names are more often than not
601 * generic and less informative than the names given in
602 * device properties.
603 */
604 if (names[chip->offset + i] && names[chip->offset + i][0])
605 gdev->descs[i].name = names[chip->offset + i];
606 }
607
608 kfree(names);
609
610 return 0;
611 }
612
gpiochip_allocate_mask(struct gpio_chip * gc)613 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
614 {
615 unsigned long *p;
616
617 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
618 if (!p)
619 return NULL;
620
621 /* Assume by default all GPIOs are valid */
622 bitmap_fill(p, gc->ngpio);
623
624 return p;
625 }
626
gpiochip_free_mask(unsigned long ** p)627 static void gpiochip_free_mask(unsigned long **p)
628 {
629 bitmap_free(*p);
630 *p = NULL;
631 }
632
gpiochip_count_reserved_ranges(struct gpio_chip * gc)633 static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc)
634 {
635 struct device *dev = &gc->gpiodev->dev;
636 int size;
637
638 /* Format is "start, count, ..." */
639 size = device_property_count_u32(dev, "gpio-reserved-ranges");
640 if (size > 0 && size % 2 == 0)
641 return size;
642
643 return 0;
644 }
645
gpiochip_apply_reserved_ranges(struct gpio_chip * gc)646 static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc)
647 {
648 struct device *dev = &gc->gpiodev->dev;
649 unsigned int size;
650 u32 *ranges;
651 int ret;
652
653 size = gpiochip_count_reserved_ranges(gc);
654 if (size == 0)
655 return 0;
656
657 ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL);
658 if (!ranges)
659 return -ENOMEM;
660
661 ret = device_property_read_u32_array(dev, "gpio-reserved-ranges",
662 ranges, size);
663 if (ret) {
664 kfree(ranges);
665 return ret;
666 }
667
668 while (size) {
669 u32 count = ranges[--size];
670 u32 start = ranges[--size];
671
672 if (start >= gc->ngpio || start + count > gc->ngpio)
673 continue;
674
675 bitmap_clear(gc->gpiodev->valid_mask, start, count);
676 }
677
678 kfree(ranges);
679 return 0;
680 }
681
gpiochip_init_valid_mask(struct gpio_chip * gc)682 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
683 {
684 int ret;
685
686 if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask))
687 return 0;
688
689 gc->gpiodev->valid_mask = gpiochip_allocate_mask(gc);
690 if (!gc->gpiodev->valid_mask)
691 return -ENOMEM;
692
693 ret = gpiochip_apply_reserved_ranges(gc);
694 if (ret)
695 return ret;
696
697 if (gc->init_valid_mask)
698 return gc->init_valid_mask(gc,
699 gc->gpiodev->valid_mask,
700 gc->ngpio);
701
702 return 0;
703 }
704
gpiochip_free_valid_mask(struct gpio_chip * gc)705 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
706 {
707 gpiochip_free_mask(&gc->gpiodev->valid_mask);
708 }
709
gpiochip_add_pin_ranges(struct gpio_chip * gc)710 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
711 {
712 /*
713 * Device Tree platforms are supposed to use "gpio-ranges"
714 * property. This check ensures that the ->add_pin_ranges()
715 * won't be called for them.
716 */
717 if (device_property_present(&gc->gpiodev->dev, "gpio-ranges"))
718 return 0;
719
720 if (gc->add_pin_ranges)
721 return gc->add_pin_ranges(gc);
722
723 return 0;
724 }
725
726 /**
727 * gpiochip_query_valid_mask - return the GPIO validity information
728 * @gc: gpio chip which validity information is queried
729 *
730 * Returns: bitmap representing valid GPIOs or NULL if all GPIOs are valid
731 *
732 * Some GPIO chips may support configurations where some of the pins aren't
733 * available. These chips can have valid_mask set to represent the valid
734 * GPIOs. This function can be used to retrieve this information.
735 */
gpiochip_query_valid_mask(const struct gpio_chip * gc)736 const unsigned long *gpiochip_query_valid_mask(const struct gpio_chip *gc)
737 {
738 return gc->gpiodev->valid_mask;
739 }
740 EXPORT_SYMBOL_GPL(gpiochip_query_valid_mask);
741
gpiochip_line_is_valid(const struct gpio_chip * gc,unsigned int offset)742 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
743 unsigned int offset)
744 {
745 /* No mask means all valid */
746 if (likely(!gc->gpiodev->valid_mask))
747 return true;
748 return test_bit(offset, gc->gpiodev->valid_mask);
749 }
750 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
751
gpiod_free_irqs(struct gpio_desc * desc)752 static void gpiod_free_irqs(struct gpio_desc *desc)
753 {
754 int irq = gpiod_to_irq(desc);
755 struct irq_desc *irqd = irq_to_desc(irq);
756 void *cookie;
757
758 for (;;) {
759 /*
760 * Make sure the action doesn't go away while we're
761 * dereferencing it. Retrieve and store the cookie value.
762 * If the irq is freed after we release the lock, that's
763 * alright - the underlying maple tree lookup will return NULL
764 * and nothing will happen in free_irq().
765 */
766 scoped_guard(mutex, &irqd->request_mutex) {
767 if (!irq_desc_has_action(irqd))
768 return;
769
770 cookie = irqd->action->dev_id;
771 }
772
773 free_irq(irq, cookie);
774 }
775 }
776
777 /*
778 * The chip is going away but there may be users who had requested interrupts
779 * on its GPIO lines who have no idea about its removal and have no way of
780 * being notified about it. We need to free any interrupts still in use here or
781 * we'll leak memory and resources (like procfs files).
782 */
gpiochip_free_remaining_irqs(struct gpio_chip * gc)783 static void gpiochip_free_remaining_irqs(struct gpio_chip *gc)
784 {
785 struct gpio_desc *desc;
786
787 for_each_gpio_desc_with_flag(gc, desc, FLAG_USED_AS_IRQ)
788 gpiod_free_irqs(desc);
789 }
790
gpiodev_release(struct device * dev)791 static void gpiodev_release(struct device *dev)
792 {
793 struct gpio_device *gdev = to_gpio_device(dev);
794
795 /* Call pending kfree()s for descriptor labels. */
796 synchronize_srcu(&gdev->desc_srcu);
797 cleanup_srcu_struct(&gdev->desc_srcu);
798
799 ida_free(&gpio_ida, gdev->id);
800 kfree_const(gdev->label);
801 kfree(gdev->descs);
802 cleanup_srcu_struct(&gdev->srcu);
803 kfree(gdev);
804 }
805
806 static const struct device_type gpio_dev_type = {
807 .name = "gpio_chip",
808 .release = gpiodev_release,
809 };
810
811 #ifdef CONFIG_GPIO_CDEV
812 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
813 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
814 #else
815 /*
816 * gpiolib_cdev_register() indirectly calls device_add(), which is still
817 * required even when cdev is not selected.
818 */
819 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
820 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
821 #endif
822
gpiochip_setup_dev(struct gpio_device * gdev)823 static int gpiochip_setup_dev(struct gpio_device *gdev)
824 {
825 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
826 int ret;
827
828 device_initialize(&gdev->dev);
829
830 /*
831 * If fwnode doesn't belong to another device, it's safe to clear its
832 * initialized flag.
833 */
834 if (fwnode && !fwnode->dev)
835 fwnode_dev_initialized(fwnode, false);
836
837 ret = gcdev_register(gdev, gpio_devt);
838 if (ret)
839 return ret;
840
841 ret = gpiochip_sysfs_register(gdev);
842 if (ret)
843 goto err_remove_device;
844
845 dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base,
846 gdev->base + gdev->ngpio - 1, gdev->label);
847
848 return 0;
849
850 err_remove_device:
851 gcdev_unregister(gdev);
852 return ret;
853 }
854
gpiochip_machine_hog(struct gpio_chip * gc,struct gpiod_hog * hog)855 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
856 {
857 struct gpio_desc *desc;
858 int rv;
859
860 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
861 if (IS_ERR(desc)) {
862 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
863 PTR_ERR(desc));
864 return;
865 }
866
867 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
868 if (rv)
869 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
870 __func__, gc->label, hog->chip_hwnum, rv);
871 }
872
machine_gpiochip_add(struct gpio_chip * gc)873 static void machine_gpiochip_add(struct gpio_chip *gc)
874 {
875 struct gpiod_hog *hog;
876
877 mutex_lock(&gpio_machine_hogs_mutex);
878
879 list_for_each_entry(hog, &gpio_machine_hogs, list) {
880 if (!strcmp(gc->label, hog->chip_label))
881 gpiochip_machine_hog(gc, hog);
882 }
883
884 mutex_unlock(&gpio_machine_hogs_mutex);
885 }
886
gpiochip_setup_devs(void)887 static void gpiochip_setup_devs(void)
888 {
889 struct gpio_device *gdev;
890 int ret;
891
892 guard(srcu)(&gpio_devices_srcu);
893
894 list_for_each_entry_srcu(gdev, &gpio_devices, list,
895 srcu_read_lock_held(&gpio_devices_srcu)) {
896 ret = gpiochip_setup_dev(gdev);
897 if (ret)
898 dev_err(&gdev->dev,
899 "Failed to initialize gpio device (%d)\n", ret);
900 }
901 }
902
gpiochip_set_data(struct gpio_chip * gc,void * data)903 static void gpiochip_set_data(struct gpio_chip *gc, void *data)
904 {
905 gc->gpiodev->data = data;
906 }
907
908 /**
909 * gpiochip_get_data() - get per-subdriver data for the chip
910 * @gc: GPIO chip
911 *
912 * Returns:
913 * The per-subdriver data for the chip.
914 */
gpiochip_get_data(struct gpio_chip * gc)915 void *gpiochip_get_data(struct gpio_chip *gc)
916 {
917 return gc->gpiodev->data;
918 }
919 EXPORT_SYMBOL_GPL(gpiochip_get_data);
920
921 /*
922 * If the calling driver provides the specific firmware node,
923 * use it. Otherwise use the one from the parent device, if any.
924 */
gpiochip_choose_fwnode(struct gpio_chip * gc)925 static struct fwnode_handle *gpiochip_choose_fwnode(struct gpio_chip *gc)
926 {
927 if (gc->fwnode)
928 return gc->fwnode;
929
930 if (gc->parent)
931 return dev_fwnode(gc->parent);
932
933 return NULL;
934 }
935
gpiochip_get_ngpios(struct gpio_chip * gc,struct device * dev)936 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
937 {
938 struct fwnode_handle *fwnode = gpiochip_choose_fwnode(gc);
939 u32 ngpios = gc->ngpio;
940 int ret;
941
942 if (ngpios == 0) {
943 ret = fwnode_property_read_u32(fwnode, "ngpios", &ngpios);
944 if (ret == -ENODATA)
945 /*
946 * -ENODATA means that there is no property found and
947 * we want to issue the error message to the user.
948 * Besides that, we want to return different error code
949 * to state that supplied value is not valid.
950 */
951 ngpios = 0;
952 else if (ret)
953 return ret;
954
955 gc->ngpio = ngpios;
956 }
957
958 if (gc->ngpio == 0) {
959 dev_err(dev, "tried to insert a GPIO chip with zero lines\n");
960 return -EINVAL;
961 }
962
963 if (gc->ngpio > FASTPATH_NGPIO)
964 dev_warn(dev, "line cnt %u is greater than fast path cnt %u\n",
965 gc->ngpio, FASTPATH_NGPIO);
966
967 return 0;
968 }
969 EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);
970
gpiochip_add_data_with_key(struct gpio_chip * gc,void * data,struct lock_class_key * lock_key,struct lock_class_key * request_key)971 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
972 struct lock_class_key *lock_key,
973 struct lock_class_key *request_key)
974 {
975 struct gpio_device *gdev;
976 unsigned int desc_index;
977 int base = 0;
978 int ret = 0;
979
980 /* Only allow one set() and one set_multiple(). */
981 if ((gc->set && gc->set_rv) ||
982 (gc->set_multiple && gc->set_multiple_rv))
983 return -EINVAL;
984
985 /*
986 * First: allocate and populate the internal stat container, and
987 * set up the struct device.
988 */
989 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
990 if (!gdev)
991 return -ENOMEM;
992
993 gdev->dev.type = &gpio_dev_type;
994 gdev->dev.bus = &gpio_bus_type;
995 gdev->dev.parent = gc->parent;
996 rcu_assign_pointer(gdev->chip, gc);
997
998 gc->gpiodev = gdev;
999 gpiochip_set_data(gc, data);
1000
1001 device_set_node(&gdev->dev, gpiochip_choose_fwnode(gc));
1002
1003 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
1004 if (gdev->id < 0) {
1005 ret = gdev->id;
1006 goto err_free_gdev;
1007 }
1008
1009 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
1010 if (ret)
1011 goto err_free_ida;
1012
1013 if (gc->parent && gc->parent->driver)
1014 gdev->owner = gc->parent->driver->owner;
1015 else if (gc->owner)
1016 /* TODO: remove chip->owner */
1017 gdev->owner = gc->owner;
1018 else
1019 gdev->owner = THIS_MODULE;
1020
1021 ret = gpiochip_get_ngpios(gc, &gdev->dev);
1022 if (ret)
1023 goto err_free_dev_name;
1024
1025 gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
1026 if (!gdev->descs) {
1027 ret = -ENOMEM;
1028 goto err_free_dev_name;
1029 }
1030
1031 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
1032 if (!gdev->label) {
1033 ret = -ENOMEM;
1034 goto err_free_descs;
1035 }
1036
1037 gdev->ngpio = gc->ngpio;
1038 gdev->can_sleep = gc->can_sleep;
1039
1040 scoped_guard(mutex, &gpio_devices_lock) {
1041 /*
1042 * TODO: this allocates a Linux GPIO number base in the global
1043 * GPIO numberspace for this chip. In the long run we want to
1044 * get *rid* of this numberspace and use only descriptors, but
1045 * it may be a pipe dream. It will not happen before we get rid
1046 * of the sysfs interface anyways.
1047 */
1048 base = gc->base;
1049 if (base < 0) {
1050 base = gpiochip_find_base_unlocked(gc->ngpio);
1051 if (base < 0) {
1052 ret = base;
1053 base = 0;
1054 goto err_free_label;
1055 }
1056
1057 /*
1058 * TODO: it should not be necessary to reflect the
1059 * assigned base outside of the GPIO subsystem. Go over
1060 * drivers and see if anyone makes use of this, else
1061 * drop this and assign a poison instead.
1062 */
1063 gc->base = base;
1064 } else {
1065 dev_warn(&gdev->dev,
1066 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
1067 }
1068
1069 gdev->base = base;
1070
1071 ret = gpiodev_add_to_list_unlocked(gdev);
1072 if (ret) {
1073 chip_err(gc, "GPIO integer space overlap, cannot add chip\n");
1074 goto err_free_label;
1075 }
1076 }
1077
1078 rwlock_init(&gdev->line_state_lock);
1079 RAW_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
1080 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
1081
1082 ret = init_srcu_struct(&gdev->srcu);
1083 if (ret)
1084 goto err_remove_from_list;
1085
1086 ret = init_srcu_struct(&gdev->desc_srcu);
1087 if (ret)
1088 goto err_cleanup_gdev_srcu;
1089
1090 #ifdef CONFIG_PINCTRL
1091 INIT_LIST_HEAD(&gdev->pin_ranges);
1092 #endif
1093
1094 if (gc->names)
1095 gpiochip_set_desc_names(gc);
1096
1097 ret = gpiochip_set_names(gc);
1098 if (ret)
1099 goto err_cleanup_desc_srcu;
1100
1101 ret = gpiochip_init_valid_mask(gc);
1102 if (ret)
1103 goto err_cleanup_desc_srcu;
1104
1105 for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
1106 struct gpio_desc *desc = &gdev->descs[desc_index];
1107
1108 desc->gdev = gdev;
1109
1110 /*
1111 * We would typically want to use gpiochip_get_direction() here
1112 * but we must not check the return value and bail-out as pin
1113 * controllers can have pins configured to alternate functions
1114 * and return -EINVAL. Also: there's no need to take the SRCU
1115 * lock here.
1116 */
1117 if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index))
1118 assign_bit(FLAG_IS_OUT, &desc->flags,
1119 !gc->get_direction(gc, desc_index));
1120 else
1121 assign_bit(FLAG_IS_OUT,
1122 &desc->flags, !gc->direction_input);
1123 }
1124
1125 ret = of_gpiochip_add(gc);
1126 if (ret)
1127 goto err_free_valid_mask;
1128
1129 ret = gpiochip_add_pin_ranges(gc);
1130 if (ret)
1131 goto err_remove_of_chip;
1132
1133 acpi_gpiochip_add(gc);
1134
1135 machine_gpiochip_add(gc);
1136
1137 ret = gpiochip_irqchip_init_valid_mask(gc);
1138 if (ret)
1139 goto err_free_hogs;
1140
1141 ret = gpiochip_irqchip_init_hw(gc);
1142 if (ret)
1143 goto err_remove_irqchip_mask;
1144
1145 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
1146 if (ret)
1147 goto err_remove_irqchip_mask;
1148
1149 /*
1150 * By first adding the chardev, and then adding the device,
1151 * we get a device node entry in sysfs under
1152 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1153 * coldplug of device nodes and other udev business.
1154 * We can do this only if gpiolib has been initialized.
1155 * Otherwise, defer until later.
1156 */
1157 if (gpiolib_initialized) {
1158 ret = gpiochip_setup_dev(gdev);
1159 if (ret)
1160 goto err_remove_irqchip;
1161 }
1162 return 0;
1163
1164 err_remove_irqchip:
1165 gpiochip_irqchip_remove(gc);
1166 err_remove_irqchip_mask:
1167 gpiochip_irqchip_free_valid_mask(gc);
1168 err_free_hogs:
1169 gpiochip_free_hogs(gc);
1170 acpi_gpiochip_remove(gc);
1171 gpiochip_remove_pin_ranges(gc);
1172 err_remove_of_chip:
1173 of_gpiochip_remove(gc);
1174 err_free_valid_mask:
1175 gpiochip_free_valid_mask(gc);
1176 err_cleanup_desc_srcu:
1177 cleanup_srcu_struct(&gdev->desc_srcu);
1178 err_cleanup_gdev_srcu:
1179 cleanup_srcu_struct(&gdev->srcu);
1180 err_remove_from_list:
1181 scoped_guard(mutex, &gpio_devices_lock)
1182 list_del_rcu(&gdev->list);
1183 synchronize_srcu(&gpio_devices_srcu);
1184 if (gdev->dev.release) {
1185 /* release() has been registered by gpiochip_setup_dev() */
1186 gpio_device_put(gdev);
1187 goto err_print_message;
1188 }
1189 err_free_label:
1190 kfree_const(gdev->label);
1191 err_free_descs:
1192 kfree(gdev->descs);
1193 err_free_dev_name:
1194 kfree(dev_name(&gdev->dev));
1195 err_free_ida:
1196 ida_free(&gpio_ida, gdev->id);
1197 err_free_gdev:
1198 kfree(gdev);
1199 err_print_message:
1200 /* failures here can mean systems won't boot... */
1201 if (ret != -EPROBE_DEFER) {
1202 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1203 base, base + (int)gc->ngpio - 1,
1204 gc->label ? : "generic", ret);
1205 }
1206 return ret;
1207 }
1208 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1209
1210 /**
1211 * gpiochip_remove() - unregister a gpio_chip
1212 * @gc: the chip to unregister
1213 *
1214 * A gpio_chip with any GPIOs still requested may not be removed.
1215 */
gpiochip_remove(struct gpio_chip * gc)1216 void gpiochip_remove(struct gpio_chip *gc)
1217 {
1218 struct gpio_device *gdev = gc->gpiodev;
1219
1220 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1221 gpiochip_sysfs_unregister(gdev);
1222 gpiochip_free_hogs(gc);
1223 gpiochip_free_remaining_irqs(gc);
1224
1225 scoped_guard(mutex, &gpio_devices_lock)
1226 list_del_rcu(&gdev->list);
1227 synchronize_srcu(&gpio_devices_srcu);
1228
1229 /* Numb the device, cancelling all outstanding operations */
1230 rcu_assign_pointer(gdev->chip, NULL);
1231 synchronize_srcu(&gdev->srcu);
1232 gpiochip_irqchip_remove(gc);
1233 acpi_gpiochip_remove(gc);
1234 of_gpiochip_remove(gc);
1235 gpiochip_remove_pin_ranges(gc);
1236 gpiochip_free_valid_mask(gc);
1237 /*
1238 * We accept no more calls into the driver from this point, so
1239 * NULL the driver data pointer.
1240 */
1241 gpiochip_set_data(gc, NULL);
1242
1243 /*
1244 * The gpiochip side puts its use of the device to rest here:
1245 * if there are no userspace clients, the chardev and device will
1246 * be removed, else it will be dangling until the last user is
1247 * gone.
1248 */
1249 gcdev_unregister(gdev);
1250 gpio_device_put(gdev);
1251 }
1252 EXPORT_SYMBOL_GPL(gpiochip_remove);
1253
1254 /**
1255 * gpio_device_find() - find a specific GPIO device
1256 * @data: data to pass to match function
1257 * @match: Callback function to check gpio_chip
1258 *
1259 * Returns:
1260 * New reference to struct gpio_device.
1261 *
1262 * Similar to bus_find_device(). It returns a reference to a gpio_device as
1263 * determined by a user supplied @match callback. The callback should return
1264 * 0 if the device doesn't match and non-zero if it does. If the callback
1265 * returns non-zero, this function will return to the caller and not iterate
1266 * over any more gpio_devices.
1267 *
1268 * The callback takes the GPIO chip structure as argument. During the execution
1269 * of the callback function the chip is protected from being freed. TODO: This
1270 * actually has yet to be implemented.
1271 *
1272 * If the function returns non-NULL, the returned reference must be freed by
1273 * the caller using gpio_device_put().
1274 */
gpio_device_find(const void * data,int (* match)(struct gpio_chip * gc,const void * data))1275 struct gpio_device *gpio_device_find(const void *data,
1276 int (*match)(struct gpio_chip *gc,
1277 const void *data))
1278 {
1279 struct gpio_device *gdev;
1280 struct gpio_chip *gc;
1281
1282 might_sleep();
1283
1284 guard(srcu)(&gpio_devices_srcu);
1285
1286 list_for_each_entry_srcu(gdev, &gpio_devices, list,
1287 srcu_read_lock_held(&gpio_devices_srcu)) {
1288 if (!device_is_registered(&gdev->dev))
1289 continue;
1290
1291 guard(srcu)(&gdev->srcu);
1292
1293 gc = srcu_dereference(gdev->chip, &gdev->srcu);
1294
1295 if (gc && match(gc, data))
1296 return gpio_device_get(gdev);
1297 }
1298
1299 return NULL;
1300 }
1301 EXPORT_SYMBOL_GPL(gpio_device_find);
1302
gpio_chip_match_by_label(struct gpio_chip * gc,const void * label)1303 static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)
1304 {
1305 return gc->label && !strcmp(gc->label, label);
1306 }
1307
1308 /**
1309 * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the
1310 * GPIO device by its backing chip's label
1311 * @label: Label to lookup
1312 *
1313 * Returns:
1314 * Reference to the GPIO device or NULL. Reference must be released with
1315 * gpio_device_put().
1316 */
gpio_device_find_by_label(const char * label)1317 struct gpio_device *gpio_device_find_by_label(const char *label)
1318 {
1319 return gpio_device_find((void *)label, gpio_chip_match_by_label);
1320 }
1321 EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
1322
gpio_chip_match_by_fwnode(struct gpio_chip * gc,const void * fwnode)1323 static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)
1324 {
1325 return device_match_fwnode(&gc->gpiodev->dev, fwnode);
1326 }
1327
1328 /**
1329 * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
1330 * the GPIO device by its fwnode
1331 * @fwnode: Firmware node to lookup
1332 *
1333 * Returns:
1334 * Reference to the GPIO device or NULL. Reference must be released with
1335 * gpio_device_put().
1336 */
gpio_device_find_by_fwnode(const struct fwnode_handle * fwnode)1337 struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
1338 {
1339 return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
1340 }
1341 EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
1342
1343 /**
1344 * gpio_device_get() - Increase the reference count of this GPIO device
1345 * @gdev: GPIO device to increase the refcount for
1346 *
1347 * Returns:
1348 * Pointer to @gdev.
1349 */
gpio_device_get(struct gpio_device * gdev)1350 struct gpio_device *gpio_device_get(struct gpio_device *gdev)
1351 {
1352 return to_gpio_device(get_device(&gdev->dev));
1353 }
1354 EXPORT_SYMBOL_GPL(gpio_device_get);
1355
1356 /**
1357 * gpio_device_put() - Decrease the reference count of this GPIO device and
1358 * possibly free all resources associated with it.
1359 * @gdev: GPIO device to decrease the reference count for
1360 */
gpio_device_put(struct gpio_device * gdev)1361 void gpio_device_put(struct gpio_device *gdev)
1362 {
1363 put_device(&gdev->dev);
1364 }
1365 EXPORT_SYMBOL_GPL(gpio_device_put);
1366
1367 /**
1368 * gpio_device_to_device() - Retrieve the address of the underlying struct
1369 * device.
1370 * @gdev: GPIO device for which to return the address.
1371 *
1372 * This does not increase the reference count of the GPIO device nor the
1373 * underlying struct device.
1374 *
1375 * Returns:
1376 * Address of struct device backing this GPIO device.
1377 */
gpio_device_to_device(struct gpio_device * gdev)1378 struct device *gpio_device_to_device(struct gpio_device *gdev)
1379 {
1380 return &gdev->dev;
1381 }
1382 EXPORT_SYMBOL_GPL(gpio_device_to_device);
1383
1384 #ifdef CONFIG_GPIOLIB_IRQCHIP
1385
1386 /*
1387 * The following is irqchip helper code for gpiochips.
1388 */
1389
gpiochip_irqchip_init_hw(struct gpio_chip * gc)1390 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1391 {
1392 struct gpio_irq_chip *girq = &gc->irq;
1393
1394 if (!girq->init_hw)
1395 return 0;
1396
1397 return girq->init_hw(gc);
1398 }
1399
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)1400 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1401 {
1402 struct gpio_irq_chip *girq = &gc->irq;
1403
1404 if (!girq->init_valid_mask)
1405 return 0;
1406
1407 girq->valid_mask = gpiochip_allocate_mask(gc);
1408 if (!girq->valid_mask)
1409 return -ENOMEM;
1410
1411 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1412
1413 return 0;
1414 }
1415
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)1416 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1417 {
1418 gpiochip_free_mask(&gc->irq.valid_mask);
1419 }
1420
gpiochip_irqchip_irq_valid(const struct gpio_chip * gc,unsigned int offset)1421 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
1422 unsigned int offset)
1423 {
1424 if (!gpiochip_line_is_valid(gc, offset))
1425 return false;
1426 /* No mask means all valid */
1427 if (likely(!gc->irq.valid_mask))
1428 return true;
1429 return test_bit(offset, gc->irq.valid_mask);
1430 }
1431
1432 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1433
1434 /**
1435 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1436 * to a gpiochip
1437 * @gc: the gpiochip to set the irqchip hierarchical handler to
1438 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1439 * will then percolate up to the parent
1440 */
gpiochip_set_hierarchical_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip)1441 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1442 struct irq_chip *irqchip)
1443 {
1444 /* DT will deal with mapping each IRQ as we go along */
1445 if (is_of_node(gc->irq.fwnode))
1446 return;
1447
1448 /*
1449 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1450 * irqs upfront instead of dynamically since we don't have the
1451 * dynamic type of allocation that hardware description languages
1452 * provide. Once all GPIO drivers using board files are gone from
1453 * the kernel we can delete this code, but for a transitional period
1454 * it is necessary to keep this around.
1455 */
1456 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1457 int i;
1458 int ret;
1459
1460 for (i = 0; i < gc->ngpio; i++) {
1461 struct irq_fwspec fwspec;
1462 unsigned int parent_hwirq;
1463 unsigned int parent_type;
1464 struct gpio_irq_chip *girq = &gc->irq;
1465
1466 /*
1467 * We call the child to parent translation function
1468 * only to check if the child IRQ is valid or not.
1469 * Just pick the rising edge type here as that is what
1470 * we likely need to support.
1471 */
1472 ret = girq->child_to_parent_hwirq(gc, i,
1473 IRQ_TYPE_EDGE_RISING,
1474 &parent_hwirq,
1475 &parent_type);
1476 if (ret) {
1477 chip_err(gc, "skip set-up on hwirq %d\n",
1478 i);
1479 continue;
1480 }
1481
1482 fwspec.fwnode = gc->irq.fwnode;
1483 /* This is the hwirq for the GPIO line side of things */
1484 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1485 /* Just pick something */
1486 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1487 fwspec.param_count = 2;
1488 ret = irq_domain_alloc_irqs(gc->irq.domain, 1,
1489 NUMA_NO_NODE, &fwspec);
1490 if (ret < 0) {
1491 chip_err(gc,
1492 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1493 i, parent_hwirq,
1494 ret);
1495 }
1496 }
1497 }
1498
1499 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1500
1501 return;
1502 }
1503
gpiochip_hierarchy_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1504 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1505 struct irq_fwspec *fwspec,
1506 unsigned long *hwirq,
1507 unsigned int *type)
1508 {
1509 /* We support standard DT translation */
1510 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1511 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1512 }
1513
1514 /* This is for board files and others not using DT */
1515 if (is_fwnode_irqchip(fwspec->fwnode)) {
1516 int ret;
1517
1518 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1519 if (ret)
1520 return ret;
1521 WARN_ON(*type == IRQ_TYPE_NONE);
1522 return 0;
1523 }
1524 return -EINVAL;
1525 }
1526
gpiochip_hierarchy_irq_domain_alloc(struct irq_domain * d,unsigned int irq,unsigned int nr_irqs,void * data)1527 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1528 unsigned int irq,
1529 unsigned int nr_irqs,
1530 void *data)
1531 {
1532 struct gpio_chip *gc = d->host_data;
1533 irq_hw_number_t hwirq;
1534 unsigned int type = IRQ_TYPE_NONE;
1535 struct irq_fwspec *fwspec = data;
1536 union gpio_irq_fwspec gpio_parent_fwspec = {};
1537 unsigned int parent_hwirq;
1538 unsigned int parent_type;
1539 struct gpio_irq_chip *girq = &gc->irq;
1540 int ret;
1541
1542 /*
1543 * The nr_irqs parameter is always one except for PCI multi-MSI
1544 * so this should not happen.
1545 */
1546 WARN_ON(nr_irqs != 1);
1547
1548 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1549 if (ret)
1550 return ret;
1551
1552 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1553
1554 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1555 &parent_hwirq, &parent_type);
1556 if (ret) {
1557 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1558 return ret;
1559 }
1560 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1561
1562 /*
1563 * We set handle_bad_irq because the .set_type() should
1564 * always be invoked and set the right type of handler.
1565 */
1566 irq_domain_set_info(d,
1567 irq,
1568 hwirq,
1569 gc->irq.chip,
1570 gc,
1571 girq->handler,
1572 NULL, NULL);
1573 irq_set_probe(irq);
1574
1575 /* This parent only handles asserted level IRQs */
1576 ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,
1577 parent_hwirq, parent_type);
1578 if (ret)
1579 return ret;
1580
1581 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1582 irq, parent_hwirq);
1583 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1584 ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);
1585 /*
1586 * If the parent irqdomain is msi, the interrupts have already
1587 * been allocated, so the EEXIST is good.
1588 */
1589 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1590 ret = 0;
1591 if (ret)
1592 chip_err(gc,
1593 "failed to allocate parent hwirq %d for hwirq %lu\n",
1594 parent_hwirq, hwirq);
1595
1596 return ret;
1597 }
1598
gpiochip_child_offset_to_irq_noop(struct gpio_chip * gc,unsigned int offset)1599 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1600 unsigned int offset)
1601 {
1602 return offset;
1603 }
1604
1605 /**
1606 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1607 * @domain: The IRQ domain used by this IRQ chip
1608 * @data: Outermost irq_data associated with the IRQ
1609 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1610 *
1611 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1612 * used as the activate function for the &struct irq_domain_ops. The host_data
1613 * for the IRQ domain must be the &struct gpio_chip.
1614 *
1615 * Returns:
1616 * 0 on success, or negative errno on failure.
1617 */
gpiochip_irq_domain_activate(struct irq_domain * domain,struct irq_data * data,bool reserve)1618 static int gpiochip_irq_domain_activate(struct irq_domain *domain,
1619 struct irq_data *data, bool reserve)
1620 {
1621 struct gpio_chip *gc = domain->host_data;
1622 unsigned int hwirq = irqd_to_hwirq(data);
1623
1624 return gpiochip_lock_as_irq(gc, hwirq);
1625 }
1626
1627 /**
1628 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1629 * @domain: The IRQ domain used by this IRQ chip
1630 * @data: Outermost irq_data associated with the IRQ
1631 *
1632 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1633 * be used as the deactivate function for the &struct irq_domain_ops. The
1634 * host_data for the IRQ domain must be the &struct gpio_chip.
1635 */
gpiochip_irq_domain_deactivate(struct irq_domain * domain,struct irq_data * data)1636 static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1637 struct irq_data *data)
1638 {
1639 struct gpio_chip *gc = domain->host_data;
1640 unsigned int hwirq = irqd_to_hwirq(data);
1641
1642 return gpiochip_unlock_as_irq(gc, hwirq);
1643 }
1644
gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops * ops)1645 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1646 {
1647 ops->activate = gpiochip_irq_domain_activate;
1648 ops->deactivate = gpiochip_irq_domain_deactivate;
1649 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1650
1651 /*
1652 * We only allow overriding the translate() and free() functions for
1653 * hierarchical chips, and this should only be done if the user
1654 * really need something other than 1:1 translation for translate()
1655 * callback and free if user wants to free up any resources which
1656 * were allocated during callbacks, for example populate_parent_alloc_arg.
1657 */
1658 if (!ops->translate)
1659 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1660 if (!ops->free)
1661 ops->free = irq_domain_free_irqs_common;
1662 }
1663
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1664 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1665 {
1666 struct irq_domain *domain;
1667
1668 if (!gc->irq.child_to_parent_hwirq ||
1669 !gc->irq.fwnode) {
1670 chip_err(gc, "missing irqdomain vital data\n");
1671 return ERR_PTR(-EINVAL);
1672 }
1673
1674 if (!gc->irq.child_offset_to_irq)
1675 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1676
1677 if (!gc->irq.populate_parent_alloc_arg)
1678 gc->irq.populate_parent_alloc_arg =
1679 gpiochip_populate_parent_fwspec_twocell;
1680
1681 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1682
1683 domain = irq_domain_create_hierarchy(
1684 gc->irq.parent_domain,
1685 0,
1686 gc->ngpio,
1687 gc->irq.fwnode,
1688 &gc->irq.child_irq_domain_ops,
1689 gc);
1690
1691 if (!domain)
1692 return ERR_PTR(-ENOMEM);
1693
1694 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1695
1696 return domain;
1697 }
1698
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1699 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1700 {
1701 return !!gc->irq.parent_domain;
1702 }
1703
gpiochip_populate_parent_fwspec_twocell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1704 int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1705 union gpio_irq_fwspec *gfwspec,
1706 unsigned int parent_hwirq,
1707 unsigned int parent_type)
1708 {
1709 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1710
1711 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1712 fwspec->param_count = 2;
1713 fwspec->param[0] = parent_hwirq;
1714 fwspec->param[1] = parent_type;
1715
1716 return 0;
1717 }
1718 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1719
gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1720 int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1721 union gpio_irq_fwspec *gfwspec,
1722 unsigned int parent_hwirq,
1723 unsigned int parent_type)
1724 {
1725 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1726
1727 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1728 fwspec->param_count = 4;
1729 fwspec->param[0] = 0;
1730 fwspec->param[1] = parent_hwirq;
1731 fwspec->param[2] = 0;
1732 fwspec->param[3] = parent_type;
1733
1734 return 0;
1735 }
1736 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1737
1738 #else
1739
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1740 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1741 {
1742 return ERR_PTR(-EINVAL);
1743 }
1744
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1745 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1746 {
1747 return false;
1748 }
1749
1750 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1751
1752 /**
1753 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1754 * @d: the irqdomain used by this irqchip
1755 * @irq: the global irq number used by this GPIO irqchip irq
1756 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1757 *
1758 * This function will set up the mapping for a certain IRQ line on a
1759 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1760 * stored inside the gpiochip.
1761 *
1762 * Returns:
1763 * 0 on success, or negative errno on failure.
1764 */
gpiochip_irq_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)1765 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1766 irq_hw_number_t hwirq)
1767 {
1768 struct gpio_chip *gc = d->host_data;
1769 int ret = 0;
1770
1771 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1772 return -ENXIO;
1773
1774 irq_set_chip_data(irq, gc);
1775 /*
1776 * This lock class tells lockdep that GPIO irqs are in a different
1777 * category than their parents, so it won't report false recursion.
1778 */
1779 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1780 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1781 /* Chips that use nested thread handlers have them marked */
1782 if (gc->irq.threaded)
1783 irq_set_nested_thread(irq, 1);
1784 irq_set_noprobe(irq);
1785
1786 if (gc->irq.num_parents == 1)
1787 ret = irq_set_parent(irq, gc->irq.parents[0]);
1788 else if (gc->irq.map)
1789 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1790
1791 if (ret < 0)
1792 return ret;
1793
1794 /*
1795 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1796 * is passed as default type.
1797 */
1798 if (gc->irq.default_type != IRQ_TYPE_NONE)
1799 irq_set_irq_type(irq, gc->irq.default_type);
1800
1801 return 0;
1802 }
1803
gpiochip_irq_unmap(struct irq_domain * d,unsigned int irq)1804 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1805 {
1806 struct gpio_chip *gc = d->host_data;
1807
1808 if (gc->irq.threaded)
1809 irq_set_nested_thread(irq, 0);
1810 irq_set_chip_and_handler(irq, NULL, NULL);
1811 irq_set_chip_data(irq, NULL);
1812 }
1813
1814 static const struct irq_domain_ops gpiochip_domain_ops = {
1815 .map = gpiochip_irq_map,
1816 .unmap = gpiochip_irq_unmap,
1817 /* Virtually all GPIO irqchips are twocell:ed */
1818 .xlate = irq_domain_xlate_twocell,
1819 };
1820
gpiochip_simple_create_domain(struct gpio_chip * gc)1821 static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
1822 {
1823 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1824 struct irq_domain *domain;
1825
1826 domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,
1827 &gpiochip_domain_ops, gc);
1828 if (!domain)
1829 return ERR_PTR(-EINVAL);
1830
1831 return domain;
1832 }
1833
gpiochip_to_irq(struct gpio_chip * gc,unsigned int offset)1834 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1835 {
1836 struct irq_domain *domain = gc->irq.domain;
1837
1838 #ifdef CONFIG_GPIOLIB_IRQCHIP
1839 /*
1840 * Avoid race condition with other code, which tries to lookup
1841 * an IRQ before the irqchip has been properly registered,
1842 * i.e. while gpiochip is still being brought up.
1843 */
1844 if (!gc->irq.initialized)
1845 return -EPROBE_DEFER;
1846 #endif
1847
1848 if (!gpiochip_irqchip_irq_valid(gc, offset))
1849 return -ENXIO;
1850
1851 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1852 if (irq_domain_is_hierarchy(domain)) {
1853 struct irq_fwspec spec;
1854
1855 spec.fwnode = domain->fwnode;
1856 spec.param_count = 2;
1857 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1858 spec.param[1] = IRQ_TYPE_NONE;
1859
1860 return irq_create_fwspec_mapping(&spec);
1861 }
1862 #endif
1863
1864 return irq_create_mapping(domain, offset);
1865 }
1866
gpiochip_irq_reqres(struct irq_data * d)1867 int gpiochip_irq_reqres(struct irq_data *d)
1868 {
1869 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1870 unsigned int hwirq = irqd_to_hwirq(d);
1871
1872 return gpiochip_reqres_irq(gc, hwirq);
1873 }
1874 EXPORT_SYMBOL(gpiochip_irq_reqres);
1875
gpiochip_irq_relres(struct irq_data * d)1876 void gpiochip_irq_relres(struct irq_data *d)
1877 {
1878 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1879 unsigned int hwirq = irqd_to_hwirq(d);
1880
1881 gpiochip_relres_irq(gc, hwirq);
1882 }
1883 EXPORT_SYMBOL(gpiochip_irq_relres);
1884
gpiochip_irq_mask(struct irq_data * d)1885 static void gpiochip_irq_mask(struct irq_data *d)
1886 {
1887 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1888 unsigned int hwirq = irqd_to_hwirq(d);
1889
1890 if (gc->irq.irq_mask)
1891 gc->irq.irq_mask(d);
1892 gpiochip_disable_irq(gc, hwirq);
1893 }
1894
gpiochip_irq_unmask(struct irq_data * d)1895 static void gpiochip_irq_unmask(struct irq_data *d)
1896 {
1897 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1898 unsigned int hwirq = irqd_to_hwirq(d);
1899
1900 gpiochip_enable_irq(gc, hwirq);
1901 if (gc->irq.irq_unmask)
1902 gc->irq.irq_unmask(d);
1903 }
1904
gpiochip_irq_enable(struct irq_data * d)1905 static void gpiochip_irq_enable(struct irq_data *d)
1906 {
1907 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1908 unsigned int hwirq = irqd_to_hwirq(d);
1909
1910 gpiochip_enable_irq(gc, hwirq);
1911 gc->irq.irq_enable(d);
1912 }
1913
gpiochip_irq_disable(struct irq_data * d)1914 static void gpiochip_irq_disable(struct irq_data *d)
1915 {
1916 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1917 unsigned int hwirq = irqd_to_hwirq(d);
1918
1919 gc->irq.irq_disable(d);
1920 gpiochip_disable_irq(gc, hwirq);
1921 }
1922
gpiochip_set_irq_hooks(struct gpio_chip * gc)1923 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1924 {
1925 struct irq_chip *irqchip = gc->irq.chip;
1926
1927 if (irqchip->flags & IRQCHIP_IMMUTABLE)
1928 return;
1929
1930 chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
1931
1932 if (!irqchip->irq_request_resources &&
1933 !irqchip->irq_release_resources) {
1934 irqchip->irq_request_resources = gpiochip_irq_reqres;
1935 irqchip->irq_release_resources = gpiochip_irq_relres;
1936 }
1937 if (WARN_ON(gc->irq.irq_enable))
1938 return;
1939 /* Check if the irqchip already has this hook... */
1940 if (irqchip->irq_enable == gpiochip_irq_enable ||
1941 irqchip->irq_mask == gpiochip_irq_mask) {
1942 /*
1943 * ...and if so, give a gentle warning that this is bad
1944 * practice.
1945 */
1946 chip_info(gc,
1947 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1948 return;
1949 }
1950
1951 if (irqchip->irq_disable) {
1952 gc->irq.irq_disable = irqchip->irq_disable;
1953 irqchip->irq_disable = gpiochip_irq_disable;
1954 } else {
1955 gc->irq.irq_mask = irqchip->irq_mask;
1956 irqchip->irq_mask = gpiochip_irq_mask;
1957 }
1958
1959 if (irqchip->irq_enable) {
1960 gc->irq.irq_enable = irqchip->irq_enable;
1961 irqchip->irq_enable = gpiochip_irq_enable;
1962 } else {
1963 gc->irq.irq_unmask = irqchip->irq_unmask;
1964 irqchip->irq_unmask = gpiochip_irq_unmask;
1965 }
1966 }
1967
gpiochip_irqchip_add_allocated_domain(struct gpio_chip * gc,struct irq_domain * domain,bool allocated_externally)1968 static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
1969 struct irq_domain *domain,
1970 bool allocated_externally)
1971 {
1972 if (!domain)
1973 return -EINVAL;
1974
1975 if (gc->to_irq)
1976 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1977
1978 gc->to_irq = gpiochip_to_irq;
1979 gc->irq.domain = domain;
1980 gc->irq.domain_is_allocated_externally = allocated_externally;
1981
1982 /*
1983 * Using barrier() here to prevent compiler from reordering
1984 * gc->irq.initialized before adding irqdomain.
1985 */
1986 barrier();
1987
1988 gc->irq.initialized = true;
1989
1990 return 0;
1991 }
1992
1993 /**
1994 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1995 * @gc: the GPIO chip to add the IRQ chip to
1996 * @lock_key: lockdep class for IRQ lock
1997 * @request_key: lockdep class for IRQ request
1998 *
1999 * Returns:
2000 * 0 on success, or a negative errno on failure.
2001 */
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)2002 static int gpiochip_add_irqchip(struct gpio_chip *gc,
2003 struct lock_class_key *lock_key,
2004 struct lock_class_key *request_key)
2005 {
2006 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
2007 struct irq_chip *irqchip = gc->irq.chip;
2008 struct irq_domain *domain;
2009 unsigned int type;
2010 unsigned int i;
2011 int ret;
2012
2013 if (!irqchip)
2014 return 0;
2015
2016 if (gc->irq.parent_handler && gc->can_sleep) {
2017 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
2018 return -EINVAL;
2019 }
2020
2021 type = gc->irq.default_type;
2022
2023 /*
2024 * Specifying a default trigger is a terrible idea if DT or ACPI is
2025 * used to configure the interrupts, as you may end up with
2026 * conflicting triggers. Tell the user, and reset to NONE.
2027 */
2028 if (WARN(fwnode && type != IRQ_TYPE_NONE,
2029 "%pfw: Ignoring %u default trigger\n", fwnode, type))
2030 type = IRQ_TYPE_NONE;
2031
2032 gc->irq.default_type = type;
2033 gc->irq.lock_key = lock_key;
2034 gc->irq.request_key = request_key;
2035
2036 /* If a parent irqdomain is provided, let's build a hierarchy */
2037 if (gpiochip_hierarchy_is_hierarchical(gc)) {
2038 domain = gpiochip_hierarchy_create_domain(gc);
2039 } else {
2040 domain = gpiochip_simple_create_domain(gc);
2041 }
2042 if (IS_ERR(domain))
2043 return PTR_ERR(domain);
2044
2045 if (gc->irq.parent_handler) {
2046 for (i = 0; i < gc->irq.num_parents; i++) {
2047 void *data;
2048
2049 if (gc->irq.per_parent_data)
2050 data = gc->irq.parent_handler_data_array[i];
2051 else
2052 data = gc->irq.parent_handler_data ?: gc;
2053
2054 /*
2055 * The parent IRQ chip is already using the chip_data
2056 * for this IRQ chip, so our callbacks simply use the
2057 * handler_data.
2058 */
2059 irq_set_chained_handler_and_data(gc->irq.parents[i],
2060 gc->irq.parent_handler,
2061 data);
2062 }
2063 }
2064
2065 gpiochip_set_irq_hooks(gc);
2066
2067 ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);
2068 if (ret)
2069 return ret;
2070
2071 acpi_gpiochip_request_interrupts(gc);
2072
2073 return 0;
2074 }
2075
2076 /**
2077 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
2078 * @gc: the gpiochip to remove the irqchip from
2079 *
2080 * This is called only from gpiochip_remove()
2081 */
gpiochip_irqchip_remove(struct gpio_chip * gc)2082 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
2083 {
2084 struct irq_chip *irqchip = gc->irq.chip;
2085 unsigned int offset;
2086
2087 acpi_gpiochip_free_interrupts(gc);
2088
2089 if (irqchip && gc->irq.parent_handler) {
2090 struct gpio_irq_chip *irq = &gc->irq;
2091 unsigned int i;
2092
2093 for (i = 0; i < irq->num_parents; i++)
2094 irq_set_chained_handler_and_data(irq->parents[i],
2095 NULL, NULL);
2096 }
2097
2098 /* Remove all IRQ mappings and delete the domain */
2099 if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
2100 unsigned int irq;
2101
2102 for (offset = 0; offset < gc->ngpio; offset++) {
2103 if (!gpiochip_irqchip_irq_valid(gc, offset))
2104 continue;
2105
2106 irq = irq_find_mapping(gc->irq.domain, offset);
2107 irq_dispose_mapping(irq);
2108 }
2109
2110 irq_domain_remove(gc->irq.domain);
2111 }
2112
2113 if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
2114 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2115 irqchip->irq_request_resources = NULL;
2116 irqchip->irq_release_resources = NULL;
2117 }
2118 if (irqchip->irq_enable == gpiochip_irq_enable) {
2119 irqchip->irq_enable = gc->irq.irq_enable;
2120 irqchip->irq_disable = gc->irq.irq_disable;
2121 }
2122 }
2123 gc->irq.irq_enable = NULL;
2124 gc->irq.irq_disable = NULL;
2125 gc->irq.chip = NULL;
2126
2127 gpiochip_irqchip_free_valid_mask(gc);
2128 }
2129
2130 /**
2131 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
2132 * @gc: the gpiochip to add the irqchip to
2133 * @domain: the irqdomain to add to the gpiochip
2134 *
2135 * This function adds an IRQ domain to the gpiochip.
2136 *
2137 * Returns:
2138 * 0 on success, or negative errno on failure.
2139 */
gpiochip_irqchip_add_domain(struct gpio_chip * gc,struct irq_domain * domain)2140 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
2141 struct irq_domain *domain)
2142 {
2143 return gpiochip_irqchip_add_allocated_domain(gc, domain, true);
2144 }
2145 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
2146
2147 #else /* CONFIG_GPIOLIB_IRQCHIP */
2148
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)2149 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
2150 struct lock_class_key *lock_key,
2151 struct lock_class_key *request_key)
2152 {
2153 return 0;
2154 }
gpiochip_irqchip_remove(struct gpio_chip * gc)2155 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
2156
gpiochip_irqchip_init_hw(struct gpio_chip * gc)2157 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
2158 {
2159 return 0;
2160 }
2161
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)2162 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
2163 {
2164 return 0;
2165 }
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)2166 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
2167 { }
2168
2169 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2170
2171 /**
2172 * gpiochip_generic_request() - request the gpio function for a pin
2173 * @gc: the gpiochip owning the GPIO
2174 * @offset: the offset of the GPIO to request for GPIO function
2175 *
2176 * Returns:
2177 * 0 on success, or negative errno on failure.
2178 */
gpiochip_generic_request(struct gpio_chip * gc,unsigned int offset)2179 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
2180 {
2181 #ifdef CONFIG_PINCTRL
2182 if (list_empty(&gc->gpiodev->pin_ranges))
2183 return 0;
2184 #endif
2185
2186 return pinctrl_gpio_request(gc, offset);
2187 }
2188 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2189
2190 /**
2191 * gpiochip_generic_free() - free the gpio function from a pin
2192 * @gc: the gpiochip to request the gpio function for
2193 * @offset: the offset of the GPIO to free from GPIO function
2194 */
gpiochip_generic_free(struct gpio_chip * gc,unsigned int offset)2195 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
2196 {
2197 #ifdef CONFIG_PINCTRL
2198 if (list_empty(&gc->gpiodev->pin_ranges))
2199 return;
2200 #endif
2201
2202 pinctrl_gpio_free(gc, offset);
2203 }
2204 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2205
2206 /**
2207 * gpiochip_generic_config() - apply configuration for a pin
2208 * @gc: the gpiochip owning the GPIO
2209 * @offset: the offset of the GPIO to apply the configuration
2210 * @config: the configuration to be applied
2211 *
2212 * Returns:
2213 * 0 on success, or negative errno on failure.
2214 */
gpiochip_generic_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2215 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
2216 unsigned long config)
2217 {
2218 #ifdef CONFIG_PINCTRL
2219 if (list_empty(&gc->gpiodev->pin_ranges))
2220 return -ENOTSUPP;
2221 #endif
2222
2223 return pinctrl_gpio_set_config(gc, offset, config);
2224 }
2225 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2226
2227 #ifdef CONFIG_PINCTRL
2228
2229 /**
2230 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2231 * @gc: the gpiochip to add the range for
2232 * @pctldev: the pin controller to map to
2233 * @gpio_offset: the start offset in the current gpio_chip number space
2234 * @pin_group: name of the pin group inside the pin controller
2235 *
2236 * Calling this function directly from a DeviceTree-supported
2237 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2238 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2239 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2240 *
2241 * Returns:
2242 * 0 on success, or negative errno on failure.
2243 */
gpiochip_add_pingroup_range(struct gpio_chip * gc,struct pinctrl_dev * pctldev,unsigned int gpio_offset,const char * pin_group)2244 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
2245 struct pinctrl_dev *pctldev,
2246 unsigned int gpio_offset, const char *pin_group)
2247 {
2248 struct gpio_pin_range *pin_range;
2249 struct gpio_device *gdev = gc->gpiodev;
2250 int ret;
2251
2252 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2253 if (!pin_range) {
2254 chip_err(gc, "failed to allocate pin ranges\n");
2255 return -ENOMEM;
2256 }
2257
2258 /* Use local offset as range ID */
2259 pin_range->range.id = gpio_offset;
2260 pin_range->range.gc = gc;
2261 pin_range->range.name = gc->label;
2262 pin_range->range.base = gdev->base + gpio_offset;
2263 pin_range->pctldev = pctldev;
2264
2265 ret = pinctrl_get_group_pins(pctldev, pin_group,
2266 &pin_range->range.pins,
2267 &pin_range->range.npins);
2268 if (ret < 0) {
2269 kfree(pin_range);
2270 return ret;
2271 }
2272
2273 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2274
2275 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2276 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2277 pinctrl_dev_get_devname(pctldev), pin_group);
2278
2279 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2280
2281 return 0;
2282 }
2283 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2284
2285 /**
2286 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2287 * @gc: the gpiochip to add the range for
2288 * @pinctl_name: the dev_name() of the pin controller to map to
2289 * @gpio_offset: the start offset in the current gpio_chip number space
2290 * @pin_offset: the start offset in the pin controller number space
2291 * @npins: the number of pins from the offset of each pin space (GPIO and
2292 * pin controller) to accumulate in this range
2293 *
2294 * Calling this function directly from a DeviceTree-supported
2295 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2296 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2297 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2298 *
2299 * Returns:
2300 * 0 on success, or a negative errno on failure.
2301 */
gpiochip_add_pin_range(struct gpio_chip * gc,const char * pinctl_name,unsigned int gpio_offset,unsigned int pin_offset,unsigned int npins)2302 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
2303 unsigned int gpio_offset, unsigned int pin_offset,
2304 unsigned int npins)
2305 {
2306 struct gpio_pin_range *pin_range;
2307 struct gpio_device *gdev = gc->gpiodev;
2308 int ret;
2309
2310 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2311 if (!pin_range) {
2312 chip_err(gc, "failed to allocate pin ranges\n");
2313 return -ENOMEM;
2314 }
2315
2316 /* Use local offset as range ID */
2317 pin_range->range.id = gpio_offset;
2318 pin_range->range.gc = gc;
2319 pin_range->range.name = gc->label;
2320 pin_range->range.base = gdev->base + gpio_offset;
2321 pin_range->range.pin_base = pin_offset;
2322 pin_range->range.npins = npins;
2323 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2324 &pin_range->range);
2325 if (IS_ERR(pin_range->pctldev)) {
2326 ret = PTR_ERR(pin_range->pctldev);
2327 chip_err(gc, "could not create pin range\n");
2328 kfree(pin_range);
2329 return ret;
2330 }
2331 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2332 gpio_offset, gpio_offset + npins - 1,
2333 pinctl_name,
2334 pin_offset, pin_offset + npins - 1);
2335
2336 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2337
2338 return 0;
2339 }
2340 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2341
2342 /**
2343 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2344 * @gc: the chip to remove all the mappings for
2345 */
gpiochip_remove_pin_ranges(struct gpio_chip * gc)2346 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
2347 {
2348 struct gpio_pin_range *pin_range, *tmp;
2349 struct gpio_device *gdev = gc->gpiodev;
2350
2351 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2352 list_del(&pin_range->node);
2353 pinctrl_remove_gpio_range(pin_range->pctldev,
2354 &pin_range->range);
2355 kfree(pin_range);
2356 }
2357 }
2358 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2359
2360 #endif /* CONFIG_PINCTRL */
2361
2362 /* These "optional" allocation calls help prevent drivers from stomping
2363 * on each other, and help provide better diagnostics in debugfs.
2364 * They're called even less than the "set direction" calls.
2365 */
gpiod_request_commit(struct gpio_desc * desc,const char * label)2366 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2367 {
2368 unsigned int offset;
2369 int ret;
2370
2371 CLASS(gpio_chip_guard, guard)(desc);
2372 if (!guard.gc)
2373 return -ENODEV;
2374
2375 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
2376 return -EBUSY;
2377
2378 offset = gpio_chip_hwgpio(desc);
2379 if (!gpiochip_line_is_valid(guard.gc, offset))
2380 return -EINVAL;
2381
2382 /* NOTE: gpio_request() can be called in early boot,
2383 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2384 */
2385
2386 if (guard.gc->request) {
2387 ret = guard.gc->request(guard.gc, offset);
2388 if (ret > 0)
2389 ret = -EBADE;
2390 if (ret)
2391 goto out_clear_bit;
2392 }
2393
2394 if (guard.gc->get_direction)
2395 gpiod_get_direction(desc);
2396
2397 ret = desc_set_label(desc, label ? : "?");
2398 if (ret)
2399 goto out_clear_bit;
2400
2401 return 0;
2402
2403 out_clear_bit:
2404 clear_bit(FLAG_REQUESTED, &desc->flags);
2405 return ret;
2406 }
2407
2408 /*
2409 * This descriptor validation needs to be inserted verbatim into each
2410 * function taking a descriptor, so we need to use a preprocessor
2411 * macro to avoid endless duplication. If the desc is NULL it is an
2412 * optional GPIO and calls should just bail out.
2413 */
validate_desc(const struct gpio_desc * desc,const char * func)2414 static int validate_desc(const struct gpio_desc *desc, const char *func)
2415 {
2416 if (!desc)
2417 return 0;
2418
2419 if (IS_ERR(desc)) {
2420 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2421 return PTR_ERR(desc);
2422 }
2423
2424 return 1;
2425 }
2426
2427 #define VALIDATE_DESC(desc) do { \
2428 int __valid = validate_desc(desc, __func__); \
2429 if (__valid <= 0) \
2430 return __valid; \
2431 } while (0)
2432
2433 #define VALIDATE_DESC_VOID(desc) do { \
2434 int __valid = validate_desc(desc, __func__); \
2435 if (__valid <= 0) \
2436 return; \
2437 } while (0)
2438
gpiod_request(struct gpio_desc * desc,const char * label)2439 int gpiod_request(struct gpio_desc *desc, const char *label)
2440 {
2441 int ret = -EPROBE_DEFER;
2442
2443 VALIDATE_DESC(desc);
2444
2445 if (try_module_get(desc->gdev->owner)) {
2446 ret = gpiod_request_commit(desc, label);
2447 if (ret)
2448 module_put(desc->gdev->owner);
2449 else
2450 gpio_device_get(desc->gdev);
2451 }
2452
2453 if (ret)
2454 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2455
2456 return ret;
2457 }
2458
gpiod_free_commit(struct gpio_desc * desc)2459 static void gpiod_free_commit(struct gpio_desc *desc)
2460 {
2461 unsigned long flags;
2462
2463 might_sleep();
2464
2465 CLASS(gpio_chip_guard, guard)(desc);
2466
2467 flags = READ_ONCE(desc->flags);
2468
2469 if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {
2470 if (guard.gc->free)
2471 guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));
2472
2473 clear_bit(FLAG_ACTIVE_LOW, &flags);
2474 clear_bit(FLAG_REQUESTED, &flags);
2475 clear_bit(FLAG_OPEN_DRAIN, &flags);
2476 clear_bit(FLAG_OPEN_SOURCE, &flags);
2477 clear_bit(FLAG_PULL_UP, &flags);
2478 clear_bit(FLAG_PULL_DOWN, &flags);
2479 clear_bit(FLAG_BIAS_DISABLE, &flags);
2480 clear_bit(FLAG_EDGE_RISING, &flags);
2481 clear_bit(FLAG_EDGE_FALLING, &flags);
2482 clear_bit(FLAG_IS_HOGGED, &flags);
2483 #ifdef CONFIG_OF_DYNAMIC
2484 WRITE_ONCE(desc->hog, NULL);
2485 #endif
2486 desc_set_label(desc, NULL);
2487 WRITE_ONCE(desc->flags, flags);
2488 #ifdef CONFIG_GPIO_CDEV
2489 WRITE_ONCE(desc->debounce_period_us, 0);
2490 #endif
2491 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_RELEASED);
2492 }
2493 }
2494
gpiod_free(struct gpio_desc * desc)2495 void gpiod_free(struct gpio_desc *desc)
2496 {
2497 VALIDATE_DESC_VOID(desc);
2498
2499 gpiod_free_commit(desc);
2500 module_put(desc->gdev->owner);
2501 gpio_device_put(desc->gdev);
2502 }
2503
2504 /**
2505 * gpiochip_dup_line_label - Get a copy of the consumer label.
2506 * @gc: GPIO chip controlling this line.
2507 * @offset: Hardware offset of the line.
2508 *
2509 * Returns:
2510 * Pointer to a copy of the consumer label if the line is requested or NULL
2511 * if it's not. If a valid pointer was returned, it must be freed using
2512 * kfree(). In case of a memory allocation error, the function returns %ENOMEM.
2513 *
2514 * Must not be called from atomic context.
2515 */
gpiochip_dup_line_label(struct gpio_chip * gc,unsigned int offset)2516 char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
2517 {
2518 struct gpio_desc *desc;
2519 char *label;
2520
2521 desc = gpiochip_get_desc(gc, offset);
2522 if (IS_ERR(desc))
2523 return NULL;
2524
2525 if (!test_bit(FLAG_REQUESTED, &desc->flags))
2526 return NULL;
2527
2528 guard(srcu)(&desc->gdev->desc_srcu);
2529
2530 label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);
2531 if (!label)
2532 return ERR_PTR(-ENOMEM);
2533
2534 return label;
2535 }
2536 EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
2537
function_name_or_default(const char * con_id)2538 static inline const char *function_name_or_default(const char *con_id)
2539 {
2540 return con_id ?: "(default)";
2541 }
2542
2543 /**
2544 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2545 * @gc: GPIO chip
2546 * @hwnum: hardware number of the GPIO for which to request the descriptor
2547 * @label: label for the GPIO
2548 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2549 * specify things like line inversion semantics with the machine flags
2550 * such as GPIO_OUT_LOW
2551 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2552 * can be used to specify consumer semantics such as open drain
2553 *
2554 * Function allows GPIO chip drivers to request and use their own GPIO
2555 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2556 * function will not increase reference count of the GPIO chip module. This
2557 * allows the GPIO chip module to be unloaded as needed (we assume that the
2558 * GPIO chip driver handles freeing the GPIOs it has requested).
2559 *
2560 * Returns:
2561 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2562 * code on failure.
2563 */
gpiochip_request_own_desc(struct gpio_chip * gc,unsigned int hwnum,const char * label,enum gpio_lookup_flags lflags,enum gpiod_flags dflags)2564 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2565 unsigned int hwnum,
2566 const char *label,
2567 enum gpio_lookup_flags lflags,
2568 enum gpiod_flags dflags)
2569 {
2570 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2571 const char *name = function_name_or_default(label);
2572 int ret;
2573
2574 if (IS_ERR(desc)) {
2575 chip_err(gc, "failed to get GPIO %s descriptor\n", name);
2576 return desc;
2577 }
2578
2579 ret = gpiod_request_commit(desc, label);
2580 if (ret < 0)
2581 return ERR_PTR(ret);
2582
2583 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2584 if (ret) {
2585 gpiod_free_commit(desc);
2586 chip_err(gc, "setup of own GPIO %s failed\n", name);
2587 return ERR_PTR(ret);
2588 }
2589
2590 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
2591
2592 return desc;
2593 }
2594 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2595
2596 /**
2597 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2598 * @desc: GPIO descriptor to free
2599 *
2600 * Function frees the given GPIO requested previously with
2601 * gpiochip_request_own_desc().
2602 */
gpiochip_free_own_desc(struct gpio_desc * desc)2603 void gpiochip_free_own_desc(struct gpio_desc *desc)
2604 {
2605 if (desc)
2606 gpiod_free_commit(desc);
2607 }
2608 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2609
2610 /*
2611 * Drivers MUST set GPIO direction before making get/set calls. In
2612 * some cases this is done in early boot, before IRQs are enabled.
2613 *
2614 * As a rule these aren't called more than once (except for drivers
2615 * using the open-drain emulation idiom) so these are natural places
2616 * to accumulate extra debugging checks. Note that we can't (yet)
2617 * rely on gpio_request() having been called beforehand.
2618 */
2619
gpio_do_set_config(struct gpio_desc * desc,unsigned long config)2620 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config)
2621 {
2622 int ret;
2623
2624 CLASS(gpio_chip_guard, guard)(desc);
2625 if (!guard.gc)
2626 return -ENODEV;
2627
2628 if (!guard.gc->set_config)
2629 return -ENOTSUPP;
2630
2631 ret = guard.gc->set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2632 if (ret > 0)
2633 ret = -EBADE;
2634
2635 #ifdef CONFIG_GPIO_CDEV
2636 /*
2637 * Special case - if we're setting debounce period, we need to store
2638 * it in the descriptor in case user-space wants to know it.
2639 */
2640 if (!ret && pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE)
2641 WRITE_ONCE(desc->debounce_period_us,
2642 pinconf_to_config_argument(config));
2643 #endif
2644 return ret;
2645 }
2646
gpio_set_config_with_argument(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2647 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2648 enum pin_config_param mode,
2649 u32 argument)
2650 {
2651 unsigned long config;
2652
2653 config = pinconf_to_config_packed(mode, argument);
2654 return gpio_do_set_config(desc, config);
2655 }
2656
gpio_set_config_with_argument_optional(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2657 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2658 enum pin_config_param mode,
2659 u32 argument)
2660 {
2661 struct device *dev = &desc->gdev->dev;
2662 int gpio = gpio_chip_hwgpio(desc);
2663 int ret;
2664
2665 ret = gpio_set_config_with_argument(desc, mode, argument);
2666 if (ret != -ENOTSUPP)
2667 return ret;
2668
2669 switch (mode) {
2670 case PIN_CONFIG_PERSIST_STATE:
2671 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2672 break;
2673 default:
2674 break;
2675 }
2676
2677 return 0;
2678 }
2679
gpio_set_config(struct gpio_desc * desc,enum pin_config_param mode)2680 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2681 {
2682 return gpio_set_config_with_argument(desc, mode, 0);
2683 }
2684
gpio_set_bias(struct gpio_desc * desc)2685 static int gpio_set_bias(struct gpio_desc *desc)
2686 {
2687 enum pin_config_param bias;
2688 unsigned long flags;
2689 unsigned int arg;
2690
2691 flags = READ_ONCE(desc->flags);
2692
2693 if (test_bit(FLAG_BIAS_DISABLE, &flags))
2694 bias = PIN_CONFIG_BIAS_DISABLE;
2695 else if (test_bit(FLAG_PULL_UP, &flags))
2696 bias = PIN_CONFIG_BIAS_PULL_UP;
2697 else if (test_bit(FLAG_PULL_DOWN, &flags))
2698 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2699 else
2700 return 0;
2701
2702 switch (bias) {
2703 case PIN_CONFIG_BIAS_PULL_DOWN:
2704 case PIN_CONFIG_BIAS_PULL_UP:
2705 arg = 1;
2706 break;
2707
2708 default:
2709 arg = 0;
2710 break;
2711 }
2712
2713 return gpio_set_config_with_argument_optional(desc, bias, arg);
2714 }
2715
2716 /**
2717 * gpio_set_debounce_timeout() - Set debounce timeout
2718 * @desc: GPIO descriptor to set the debounce timeout
2719 * @debounce: Debounce timeout in microseconds
2720 *
2721 * The function calls the certain GPIO driver to set debounce timeout
2722 * in the hardware.
2723 *
2724 * Returns:
2725 * 0 on success, or negative errno on failure.
2726 */
gpio_set_debounce_timeout(struct gpio_desc * desc,unsigned int debounce)2727 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2728 {
2729 int ret;
2730
2731 ret = gpio_set_config_with_argument_optional(desc,
2732 PIN_CONFIG_INPUT_DEBOUNCE,
2733 debounce);
2734 if (!ret)
2735 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2736
2737 return ret;
2738 }
2739
gpiochip_direction_input(struct gpio_chip * gc,unsigned int offset)2740 static int gpiochip_direction_input(struct gpio_chip *gc, unsigned int offset)
2741 {
2742 int ret;
2743
2744 lockdep_assert_held(&gc->gpiodev->srcu);
2745
2746 if (WARN_ON(!gc->direction_input))
2747 return -EOPNOTSUPP;
2748
2749 ret = gc->direction_input(gc, offset);
2750 if (ret > 0)
2751 ret = -EBADE;
2752
2753 return ret;
2754 }
2755
gpiochip_direction_output(struct gpio_chip * gc,unsigned int offset,int value)2756 static int gpiochip_direction_output(struct gpio_chip *gc, unsigned int offset,
2757 int value)
2758 {
2759 int ret;
2760
2761 lockdep_assert_held(&gc->gpiodev->srcu);
2762
2763 if (WARN_ON(!gc->direction_output))
2764 return -EOPNOTSUPP;
2765
2766 ret = gc->direction_output(gc, offset, value);
2767 if (ret > 0)
2768 ret = -EBADE;
2769
2770 return ret;
2771 }
2772
2773 /**
2774 * gpiod_direction_input - set the GPIO direction to input
2775 * @desc: GPIO to set to input
2776 *
2777 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2778 * be called safely on it.
2779 *
2780 * Returns:
2781 * 0 on success, or negative errno on failure.
2782 */
gpiod_direction_input(struct gpio_desc * desc)2783 int gpiod_direction_input(struct gpio_desc *desc)
2784 {
2785 int ret;
2786
2787 VALIDATE_DESC(desc);
2788
2789 ret = gpiod_direction_input_nonotify(desc);
2790 if (ret == 0)
2791 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2792
2793 return ret;
2794 }
2795 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2796
gpiod_direction_input_nonotify(struct gpio_desc * desc)2797 int gpiod_direction_input_nonotify(struct gpio_desc *desc)
2798 {
2799 int ret = 0, dir;
2800
2801 CLASS(gpio_chip_guard, guard)(desc);
2802 if (!guard.gc)
2803 return -ENODEV;
2804
2805 /*
2806 * It is legal to have no .get() and .direction_input() specified if
2807 * the chip is output-only, but you can't specify .direction_input()
2808 * and not support the .get() operation, that doesn't make sense.
2809 */
2810 if (!guard.gc->get && guard.gc->direction_input) {
2811 gpiod_warn(desc,
2812 "%s: missing get() but have direction_input()\n",
2813 __func__);
2814 return -EIO;
2815 }
2816
2817 /*
2818 * If we have a .direction_input() callback, things are simple,
2819 * just call it. Else we are some input-only chip so try to check the
2820 * direction (if .get_direction() is supported) else we silently
2821 * assume we are in input mode after this.
2822 */
2823 if (guard.gc->direction_input) {
2824 ret = gpiochip_direction_input(guard.gc,
2825 gpio_chip_hwgpio(desc));
2826 } else if (guard.gc->get_direction) {
2827 dir = gpiochip_get_direction(guard.gc, gpio_chip_hwgpio(desc));
2828 if (dir < 0)
2829 return dir;
2830
2831 if (dir != GPIO_LINE_DIRECTION_IN) {
2832 gpiod_warn(desc,
2833 "%s: missing direction_input() operation and line is output\n",
2834 __func__);
2835 return -EIO;
2836 }
2837 }
2838 if (ret == 0) {
2839 clear_bit(FLAG_IS_OUT, &desc->flags);
2840 ret = gpio_set_bias(desc);
2841 }
2842
2843 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2844
2845 return ret;
2846 }
2847
gpiochip_set(struct gpio_chip * gc,unsigned int offset,int value)2848 static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value)
2849 {
2850 int ret;
2851
2852 lockdep_assert_held(&gc->gpiodev->srcu);
2853
2854 if (WARN_ON(unlikely(!gc->set && !gc->set_rv)))
2855 return -EOPNOTSUPP;
2856
2857 if (gc->set_rv) {
2858 ret = gc->set_rv(gc, offset, value);
2859 if (ret > 0)
2860 ret = -EBADE;
2861
2862 return ret;
2863 }
2864
2865 gc->set(gc, offset, value);
2866 return 0;
2867 }
2868
gpiod_direction_output_raw_commit(struct gpio_desc * desc,int value)2869 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2870 {
2871 int val = !!value, ret = 0, dir;
2872
2873 CLASS(gpio_chip_guard, guard)(desc);
2874 if (!guard.gc)
2875 return -ENODEV;
2876
2877 /*
2878 * It's OK not to specify .direction_output() if the gpiochip is
2879 * output-only, but if there is then not even a .set() operation it
2880 * is pretty tricky to drive the output line.
2881 */
2882 if (!guard.gc->set && !guard.gc->direction_output) {
2883 gpiod_warn(desc,
2884 "%s: missing set() and direction_output() operations\n",
2885 __func__);
2886 return -EIO;
2887 }
2888
2889 if (guard.gc->direction_output) {
2890 ret = gpiochip_direction_output(guard.gc,
2891 gpio_chip_hwgpio(desc), val);
2892 } else {
2893 /* Check that we are in output mode if we can */
2894 if (guard.gc->get_direction) {
2895 dir = gpiochip_get_direction(guard.gc,
2896 gpio_chip_hwgpio(desc));
2897 if (dir < 0)
2898 return dir;
2899
2900 if (dir != GPIO_LINE_DIRECTION_OUT) {
2901 gpiod_warn(desc,
2902 "%s: missing direction_output() operation\n",
2903 __func__);
2904 return -EIO;
2905 }
2906 }
2907 /*
2908 * If we can't actively set the direction, we are some
2909 * output-only chip, so just drive the output as desired.
2910 */
2911 ret = gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), val);
2912 if (ret)
2913 return ret;
2914 }
2915
2916 if (!ret)
2917 set_bit(FLAG_IS_OUT, &desc->flags);
2918 trace_gpio_value(desc_to_gpio(desc), 0, val);
2919 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2920 return ret;
2921 }
2922
2923 /**
2924 * gpiod_direction_output_raw - set the GPIO direction to output
2925 * @desc: GPIO to set to output
2926 * @value: initial output value of the GPIO
2927 *
2928 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2929 * be called safely on it. The initial value of the output must be specified
2930 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2931 *
2932 * Returns:
2933 * 0 on success, or negative errno on failure.
2934 */
gpiod_direction_output_raw(struct gpio_desc * desc,int value)2935 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2936 {
2937 int ret;
2938
2939 VALIDATE_DESC(desc);
2940
2941 ret = gpiod_direction_output_raw_commit(desc, value);
2942 if (ret == 0)
2943 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2944
2945 return ret;
2946 }
2947 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2948
2949 /**
2950 * gpiod_direction_output - set the GPIO direction to output
2951 * @desc: GPIO to set to output
2952 * @value: initial output value of the GPIO
2953 *
2954 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2955 * be called safely on it. The initial value of the output must be specified
2956 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2957 * account.
2958 *
2959 * Returns:
2960 * 0 on success, or negative errno on failure.
2961 */
gpiod_direction_output(struct gpio_desc * desc,int value)2962 int gpiod_direction_output(struct gpio_desc *desc, int value)
2963 {
2964 int ret;
2965
2966 VALIDATE_DESC(desc);
2967
2968 ret = gpiod_direction_output_nonotify(desc, value);
2969 if (ret == 0)
2970 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2971
2972 return ret;
2973 }
2974 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2975
gpiod_direction_output_nonotify(struct gpio_desc * desc,int value)2976 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value)
2977 {
2978 unsigned long flags;
2979 int ret;
2980
2981 flags = READ_ONCE(desc->flags);
2982
2983 if (test_bit(FLAG_ACTIVE_LOW, &flags))
2984 value = !value;
2985 else
2986 value = !!value;
2987
2988 /* GPIOs used for enabled IRQs shall not be set as output */
2989 if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
2990 test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {
2991 gpiod_err(desc,
2992 "%s: tried to set a GPIO tied to an IRQ as output\n",
2993 __func__);
2994 return -EIO;
2995 }
2996
2997 if (test_bit(FLAG_OPEN_DRAIN, &flags)) {
2998 /* First see if we can enable open drain in hardware */
2999 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
3000 if (!ret)
3001 goto set_output_value;
3002 /* Emulate open drain by not actively driving the line high */
3003 if (value)
3004 goto set_output_flag;
3005 } else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {
3006 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
3007 if (!ret)
3008 goto set_output_value;
3009 /* Emulate open source by not actively driving the line low */
3010 if (!value)
3011 goto set_output_flag;
3012 } else {
3013 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
3014 }
3015
3016 set_output_value:
3017 ret = gpio_set_bias(desc);
3018 if (ret)
3019 return ret;
3020 return gpiod_direction_output_raw_commit(desc, value);
3021
3022 set_output_flag:
3023 ret = gpiod_direction_input_nonotify(desc);
3024 if (ret)
3025 return ret;
3026 /*
3027 * When emulating open-source or open-drain functionalities by not
3028 * actively driving the line (setting mode to input) we still need to
3029 * set the IS_OUT flag or otherwise we won't be able to set the line
3030 * value anymore.
3031 */
3032 set_bit(FLAG_IS_OUT, &desc->flags);
3033 return 0;
3034 }
3035
3036 #if IS_ENABLED(CONFIG_HTE)
3037 /**
3038 * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
3039 *
3040 * @desc: GPIO to enable.
3041 * @flags: Flags related to GPIO edge.
3042 *
3043 * Returns:
3044 * 0 on success, or negative errno on failure.
3045 */
gpiod_enable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)3046 int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
3047 {
3048 int ret = 0;
3049
3050 VALIDATE_DESC(desc);
3051
3052 CLASS(gpio_chip_guard, guard)(desc);
3053 if (!guard.gc)
3054 return -ENODEV;
3055
3056 if (!guard.gc->en_hw_timestamp) {
3057 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
3058 return -ENOTSUPP;
3059 }
3060
3061 ret = guard.gc->en_hw_timestamp(guard.gc,
3062 gpio_chip_hwgpio(desc), flags);
3063 if (ret)
3064 gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
3065
3066 return ret;
3067 }
3068 EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
3069
3070 /**
3071 * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
3072 *
3073 * @desc: GPIO to disable.
3074 * @flags: Flags related to GPIO edge, same value as used during enable call.
3075 *
3076 * Returns:
3077 * 0 on success, or negative errno on failure.
3078 */
gpiod_disable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)3079 int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
3080 {
3081 int ret = 0;
3082
3083 VALIDATE_DESC(desc);
3084
3085 CLASS(gpio_chip_guard, guard)(desc);
3086 if (!guard.gc)
3087 return -ENODEV;
3088
3089 if (!guard.gc->dis_hw_timestamp) {
3090 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
3091 return -ENOTSUPP;
3092 }
3093
3094 ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),
3095 flags);
3096 if (ret)
3097 gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
3098
3099 return ret;
3100 }
3101 EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
3102 #endif /* CONFIG_HTE */
3103
3104 /**
3105 * gpiod_set_config - sets @config for a GPIO
3106 * @desc: descriptor of the GPIO for which to set the configuration
3107 * @config: Same packed config format as generic pinconf
3108 *
3109 * Returns:
3110 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3111 * configuration.
3112 */
gpiod_set_config(struct gpio_desc * desc,unsigned long config)3113 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
3114 {
3115 int ret;
3116
3117 VALIDATE_DESC(desc);
3118
3119 ret = gpio_do_set_config(desc, config);
3120 if (!ret) {
3121 /* These are the only options we notify the userspace about. */
3122 switch (pinconf_to_config_param(config)) {
3123 case PIN_CONFIG_BIAS_DISABLE:
3124 case PIN_CONFIG_BIAS_PULL_DOWN:
3125 case PIN_CONFIG_BIAS_PULL_UP:
3126 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
3127 case PIN_CONFIG_DRIVE_OPEN_SOURCE:
3128 case PIN_CONFIG_DRIVE_PUSH_PULL:
3129 case PIN_CONFIG_INPUT_DEBOUNCE:
3130 gpiod_line_state_notify(desc,
3131 GPIO_V2_LINE_CHANGED_CONFIG);
3132 break;
3133 default:
3134 break;
3135 }
3136 }
3137
3138 return ret;
3139 }
3140 EXPORT_SYMBOL_GPL(gpiod_set_config);
3141
3142 /**
3143 * gpiod_set_debounce - sets @debounce time for a GPIO
3144 * @desc: descriptor of the GPIO for which to set debounce time
3145 * @debounce: debounce time in microseconds
3146 *
3147 * Returns:
3148 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3149 * debounce time.
3150 */
gpiod_set_debounce(struct gpio_desc * desc,unsigned int debounce)3151 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
3152 {
3153 unsigned long config;
3154
3155 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
3156 return gpiod_set_config(desc, config);
3157 }
3158 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
3159
3160 /**
3161 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
3162 * @desc: descriptor of the GPIO for which to configure persistence
3163 * @transitory: True to lose state on suspend or reset, false for persistence
3164 *
3165 * Returns:
3166 * 0 on success, otherwise a negative error code.
3167 */
gpiod_set_transitory(struct gpio_desc * desc,bool transitory)3168 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
3169 {
3170 VALIDATE_DESC(desc);
3171 /*
3172 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
3173 * persistence state.
3174 */
3175 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
3176
3177 /* If the driver supports it, set the persistence state now */
3178 return gpio_set_config_with_argument_optional(desc,
3179 PIN_CONFIG_PERSIST_STATE,
3180 !transitory);
3181 }
3182
3183 /**
3184 * gpiod_is_active_low - test whether a GPIO is active-low or not
3185 * @desc: the gpio descriptor to test
3186 *
3187 * Returns:
3188 * 1 if the GPIO is active-low, 0 otherwise.
3189 */
gpiod_is_active_low(const struct gpio_desc * desc)3190 int gpiod_is_active_low(const struct gpio_desc *desc)
3191 {
3192 VALIDATE_DESC(desc);
3193 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
3194 }
3195 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
3196
3197 /**
3198 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
3199 * @desc: the gpio descriptor to change
3200 */
gpiod_toggle_active_low(struct gpio_desc * desc)3201 void gpiod_toggle_active_low(struct gpio_desc *desc)
3202 {
3203 VALIDATE_DESC_VOID(desc);
3204 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
3205 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3206 }
3207 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
3208
gpiochip_get(struct gpio_chip * gc,unsigned int offset)3209 static int gpiochip_get(struct gpio_chip *gc, unsigned int offset)
3210 {
3211 int ret;
3212
3213 lockdep_assert_held(&gc->gpiodev->srcu);
3214
3215 /* Make sure this is called after checking for gc->get(). */
3216 ret = gc->get(gc, offset);
3217 if (ret > 1)
3218 ret = -EBADE;
3219
3220 return ret;
3221 }
3222
gpio_chip_get_value(struct gpio_chip * gc,const struct gpio_desc * desc)3223 static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)
3224 {
3225 return gc->get ? gpiochip_get(gc, gpio_chip_hwgpio(desc)) : -EIO;
3226 }
3227
3228 /* I/O calls are only valid after configuration completed; the relevant
3229 * "is this a valid GPIO" error checks should already have been done.
3230 *
3231 * "Get" operations are often inlinable as reading a pin value register,
3232 * and masking the relevant bit in that register.
3233 *
3234 * When "set" operations are inlinable, they involve writing that mask to
3235 * one register to set a low value, or a different register to set it high.
3236 * Otherwise locking is needed, so there may be little value to inlining.
3237 *
3238 *------------------------------------------------------------------------
3239 *
3240 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
3241 * have requested the GPIO. That can include implicit requesting by
3242 * a direction setting call. Marking a gpio as requested locks its chip
3243 * in memory, guaranteeing that these table lookups need no more locking
3244 * and that gpiochip_remove() will fail.
3245 *
3246 * REVISIT when debugging, consider adding some instrumentation to ensure
3247 * that the GPIO was actually requested.
3248 */
3249
gpiod_get_raw_value_commit(const struct gpio_desc * desc)3250 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
3251 {
3252 struct gpio_device *gdev;
3253 struct gpio_chip *gc;
3254 int value;
3255
3256 /* FIXME Unable to use gpio_chip_guard due to const desc. */
3257 gdev = desc->gdev;
3258
3259 guard(srcu)(&gdev->srcu);
3260
3261 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3262 if (!gc)
3263 return -ENODEV;
3264
3265 value = gpio_chip_get_value(gc, desc);
3266 value = value < 0 ? value : !!value;
3267 trace_gpio_value(desc_to_gpio(desc), 1, value);
3268 return value;
3269 }
3270
gpio_chip_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)3271 static int gpio_chip_get_multiple(struct gpio_chip *gc,
3272 unsigned long *mask, unsigned long *bits)
3273 {
3274 int ret;
3275
3276 lockdep_assert_held(&gc->gpiodev->srcu);
3277
3278 if (gc->get_multiple) {
3279 ret = gc->get_multiple(gc, mask, bits);
3280 if (ret > 0)
3281 return -EBADE;
3282 }
3283
3284 if (gc->get) {
3285 int i, value;
3286
3287 for_each_set_bit(i, mask, gc->ngpio) {
3288 value = gpiochip_get(gc, i);
3289 if (value < 0)
3290 return value;
3291 __assign_bit(i, bits, value);
3292 }
3293 return 0;
3294 }
3295 return -EIO;
3296 }
3297
3298 /* The 'other' chip must be protected with its GPIO device's SRCU. */
gpio_device_chip_cmp(struct gpio_device * gdev,struct gpio_chip * gc)3299 static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
3300 {
3301 guard(srcu)(&gdev->srcu);
3302
3303 return gc == srcu_dereference(gdev->chip, &gdev->srcu);
3304 }
3305
gpiod_get_array_value_complex(bool raw,bool can_sleep,unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3306 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3307 unsigned int array_size,
3308 struct gpio_desc **desc_array,
3309 struct gpio_array *array_info,
3310 unsigned long *value_bitmap)
3311 {
3312 struct gpio_chip *gc;
3313 int ret, i = 0;
3314
3315 /*
3316 * Validate array_info against desc_array and its size.
3317 * It should immediately follow desc_array if both
3318 * have been obtained from the same gpiod_get_array() call.
3319 */
3320 if (array_info && array_info->desc == desc_array &&
3321 array_size <= array_info->size &&
3322 (void *)array_info == desc_array + array_info->size) {
3323 if (!can_sleep)
3324 WARN_ON(array_info->gdev->can_sleep);
3325
3326 guard(srcu)(&array_info->gdev->srcu);
3327 gc = srcu_dereference(array_info->gdev->chip,
3328 &array_info->gdev->srcu);
3329 if (!gc)
3330 return -ENODEV;
3331
3332 ret = gpio_chip_get_multiple(gc, array_info->get_mask,
3333 value_bitmap);
3334 if (ret)
3335 return ret;
3336
3337 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3338 bitmap_xor(value_bitmap, value_bitmap,
3339 array_info->invert_mask, array_size);
3340
3341 i = find_first_zero_bit(array_info->get_mask, array_size);
3342 if (i == array_size)
3343 return 0;
3344 } else {
3345 array_info = NULL;
3346 }
3347
3348 while (i < array_size) {
3349 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3350 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3351 unsigned long *mask, *bits;
3352 int first, j;
3353
3354 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3355 if (!guard.gc)
3356 return -ENODEV;
3357
3358 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3359 mask = fastpath_mask;
3360 bits = fastpath_bits;
3361 } else {
3362 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3363
3364 mask = bitmap_alloc(guard.gc->ngpio, flags);
3365 if (!mask)
3366 return -ENOMEM;
3367
3368 bits = bitmap_alloc(guard.gc->ngpio, flags);
3369 if (!bits) {
3370 bitmap_free(mask);
3371 return -ENOMEM;
3372 }
3373 }
3374
3375 bitmap_zero(mask, guard.gc->ngpio);
3376
3377 if (!can_sleep)
3378 WARN_ON(guard.gc->can_sleep);
3379
3380 /* collect all inputs belonging to the same chip */
3381 first = i;
3382 do {
3383 const struct gpio_desc *desc = desc_array[i];
3384 int hwgpio = gpio_chip_hwgpio(desc);
3385
3386 __set_bit(hwgpio, mask);
3387 i++;
3388
3389 if (array_info)
3390 i = find_next_zero_bit(array_info->get_mask,
3391 array_size, i);
3392 } while ((i < array_size) &&
3393 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3394
3395 ret = gpio_chip_get_multiple(guard.gc, mask, bits);
3396 if (ret) {
3397 if (mask != fastpath_mask)
3398 bitmap_free(mask);
3399 if (bits != fastpath_bits)
3400 bitmap_free(bits);
3401 return ret;
3402 }
3403
3404 for (j = first; j < i; ) {
3405 const struct gpio_desc *desc = desc_array[j];
3406 int hwgpio = gpio_chip_hwgpio(desc);
3407 int value = test_bit(hwgpio, bits);
3408
3409 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3410 value = !value;
3411 __assign_bit(j, value_bitmap, value);
3412 trace_gpio_value(desc_to_gpio(desc), 1, value);
3413 j++;
3414
3415 if (array_info)
3416 j = find_next_zero_bit(array_info->get_mask, i,
3417 j);
3418 }
3419
3420 if (mask != fastpath_mask)
3421 bitmap_free(mask);
3422 if (bits != fastpath_bits)
3423 bitmap_free(bits);
3424 }
3425 return 0;
3426 }
3427
3428 /**
3429 * gpiod_get_raw_value() - return a gpio's raw value
3430 * @desc: gpio whose value will be returned
3431 *
3432 * Returns:
3433 * The GPIO's raw value, i.e. the value of the physical line disregarding
3434 * its ACTIVE_LOW status, or negative errno on failure.
3435 *
3436 * This function can be called from contexts where we cannot sleep, and will
3437 * complain if the GPIO chip functions potentially sleep.
3438 */
gpiod_get_raw_value(const struct gpio_desc * desc)3439 int gpiod_get_raw_value(const struct gpio_desc *desc)
3440 {
3441 VALIDATE_DESC(desc);
3442 /* Should be using gpiod_get_raw_value_cansleep() */
3443 WARN_ON(desc->gdev->can_sleep);
3444 return gpiod_get_raw_value_commit(desc);
3445 }
3446 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3447
3448 /**
3449 * gpiod_get_value() - return a gpio's value
3450 * @desc: gpio whose value will be returned
3451 *
3452 * Returns:
3453 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3454 * account, or negative errno on failure.
3455 *
3456 * This function can be called from contexts where we cannot sleep, and will
3457 * complain if the GPIO chip functions potentially sleep.
3458 */
gpiod_get_value(const struct gpio_desc * desc)3459 int gpiod_get_value(const struct gpio_desc *desc)
3460 {
3461 int value;
3462
3463 VALIDATE_DESC(desc);
3464 /* Should be using gpiod_get_value_cansleep() */
3465 WARN_ON(desc->gdev->can_sleep);
3466
3467 value = gpiod_get_raw_value_commit(desc);
3468 if (value < 0)
3469 return value;
3470
3471 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3472 value = !value;
3473
3474 return value;
3475 }
3476 EXPORT_SYMBOL_GPL(gpiod_get_value);
3477
3478 /**
3479 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3480 * @array_size: number of elements in the descriptor array / value bitmap
3481 * @desc_array: array of GPIO descriptors whose values will be read
3482 * @array_info: information on applicability of fast bitmap processing path
3483 * @value_bitmap: bitmap to store the read values
3484 *
3485 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3486 * without regard for their ACTIVE_LOW status.
3487 *
3488 * This function can be called from contexts where we cannot sleep,
3489 * and it will complain if the GPIO chip functions potentially sleep.
3490 *
3491 * Returns:
3492 * 0 on success, or negative errno on failure.
3493 */
gpiod_get_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3494 int gpiod_get_raw_array_value(unsigned int array_size,
3495 struct gpio_desc **desc_array,
3496 struct gpio_array *array_info,
3497 unsigned long *value_bitmap)
3498 {
3499 if (!desc_array)
3500 return -EINVAL;
3501 return gpiod_get_array_value_complex(true, false, array_size,
3502 desc_array, array_info,
3503 value_bitmap);
3504 }
3505 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3506
3507 /**
3508 * gpiod_get_array_value() - read values from an array of GPIOs
3509 * @array_size: number of elements in the descriptor array / value bitmap
3510 * @desc_array: array of GPIO descriptors whose values will be read
3511 * @array_info: information on applicability of fast bitmap processing path
3512 * @value_bitmap: bitmap to store the read values
3513 *
3514 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3515 * into account.
3516 *
3517 * This function can be called from contexts where we cannot sleep,
3518 * and it will complain if the GPIO chip functions potentially sleep.
3519 *
3520 * Returns:
3521 * 0 on success, or negative errno on failure.
3522 */
gpiod_get_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3523 int gpiod_get_array_value(unsigned int array_size,
3524 struct gpio_desc **desc_array,
3525 struct gpio_array *array_info,
3526 unsigned long *value_bitmap)
3527 {
3528 if (!desc_array)
3529 return -EINVAL;
3530 return gpiod_get_array_value_complex(false, false, array_size,
3531 desc_array, array_info,
3532 value_bitmap);
3533 }
3534 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3535
3536 /*
3537 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3538 * @desc: gpio descriptor whose state need to be set.
3539 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3540 */
gpio_set_open_drain_value_commit(struct gpio_desc * desc,bool value)3541 static int gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3542 {
3543 int ret = 0, offset = gpio_chip_hwgpio(desc);
3544
3545 CLASS(gpio_chip_guard, guard)(desc);
3546 if (!guard.gc)
3547 return -ENODEV;
3548
3549 if (value) {
3550 ret = gpiochip_direction_input(guard.gc, offset);
3551 } else {
3552 ret = gpiochip_direction_output(guard.gc, offset, 0);
3553 if (!ret)
3554 set_bit(FLAG_IS_OUT, &desc->flags);
3555 }
3556 trace_gpio_direction(desc_to_gpio(desc), value, ret);
3557 if (ret < 0)
3558 gpiod_err(desc,
3559 "%s: Error in set_value for open drain err %d\n",
3560 __func__, ret);
3561
3562 return ret;
3563 }
3564
3565 /*
3566 * _gpio_set_open_source_value() - Set the open source gpio's value.
3567 * @desc: gpio descriptor whose state need to be set.
3568 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3569 */
gpio_set_open_source_value_commit(struct gpio_desc * desc,bool value)3570 static int gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3571 {
3572 int ret = 0, offset = gpio_chip_hwgpio(desc);
3573
3574 CLASS(gpio_chip_guard, guard)(desc);
3575 if (!guard.gc)
3576 return -ENODEV;
3577
3578 if (value) {
3579 ret = gpiochip_direction_output(guard.gc, offset, 1);
3580 if (!ret)
3581 set_bit(FLAG_IS_OUT, &desc->flags);
3582 } else {
3583 ret = gpiochip_direction_input(guard.gc, offset);
3584 }
3585 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3586 if (ret < 0)
3587 gpiod_err(desc,
3588 "%s: Error in set_value for open source err %d\n",
3589 __func__, ret);
3590
3591 return ret;
3592 }
3593
gpiod_set_raw_value_commit(struct gpio_desc * desc,bool value)3594 static int gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3595 {
3596 CLASS(gpio_chip_guard, guard)(desc);
3597 if (!guard.gc)
3598 return -ENODEV;
3599
3600 trace_gpio_value(desc_to_gpio(desc), 0, value);
3601 return gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), value);
3602 }
3603
3604 /*
3605 * set multiple outputs on the same chip;
3606 * use the chip's set_multiple function if available;
3607 * otherwise set the outputs sequentially;
3608 * @chip: the GPIO chip we operate on
3609 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3610 * defines which outputs are to be changed
3611 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3612 * defines the values the outputs specified by mask are to be set to
3613 *
3614 * Returns: 0 on success, negative error number on failure.
3615 */
gpiochip_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)3616 static int gpiochip_set_multiple(struct gpio_chip *gc,
3617 unsigned long *mask, unsigned long *bits)
3618 {
3619 unsigned int i;
3620 int ret;
3621
3622 lockdep_assert_held(&gc->gpiodev->srcu);
3623
3624 if (gc->set_multiple_rv) {
3625 ret = gc->set_multiple_rv(gc, mask, bits);
3626 if (ret > 0)
3627 ret = -EBADE;
3628
3629 return ret;
3630 }
3631
3632 if (gc->set_multiple) {
3633 gc->set_multiple(gc, mask, bits);
3634 return 0;
3635 }
3636
3637 /* set outputs if the corresponding mask bit is set */
3638 for_each_set_bit(i, mask, gc->ngpio) {
3639 ret = gpiochip_set(gc, i, test_bit(i, bits));
3640 if (ret)
3641 break;
3642 }
3643
3644 return ret;
3645 }
3646
gpiod_set_array_value_complex(bool raw,bool can_sleep,unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3647 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3648 unsigned int array_size,
3649 struct gpio_desc **desc_array,
3650 struct gpio_array *array_info,
3651 unsigned long *value_bitmap)
3652 {
3653 struct gpio_chip *gc;
3654 int i = 0, ret;
3655
3656 /*
3657 * Validate array_info against desc_array and its size.
3658 * It should immediately follow desc_array if both
3659 * have been obtained from the same gpiod_get_array() call.
3660 */
3661 if (array_info && array_info->desc == desc_array &&
3662 array_size <= array_info->size &&
3663 (void *)array_info == desc_array + array_info->size) {
3664 if (!can_sleep)
3665 WARN_ON(array_info->gdev->can_sleep);
3666
3667 guard(srcu)(&array_info->gdev->srcu);
3668 gc = srcu_dereference(array_info->gdev->chip,
3669 &array_info->gdev->srcu);
3670 if (!gc)
3671 return -ENODEV;
3672
3673 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3674 bitmap_xor(value_bitmap, value_bitmap,
3675 array_info->invert_mask, array_size);
3676
3677 ret = gpiochip_set_multiple(gc, array_info->set_mask,
3678 value_bitmap);
3679 if (ret)
3680 return ret;
3681
3682 i = find_first_zero_bit(array_info->set_mask, array_size);
3683 if (i == array_size)
3684 return 0;
3685 } else {
3686 array_info = NULL;
3687 }
3688
3689 while (i < array_size) {
3690 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3691 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3692 unsigned long *mask, *bits;
3693 int count = 0;
3694
3695 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3696 if (!guard.gc)
3697 return -ENODEV;
3698
3699 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3700 mask = fastpath_mask;
3701 bits = fastpath_bits;
3702 } else {
3703 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3704
3705 mask = bitmap_alloc(guard.gc->ngpio, flags);
3706 if (!mask)
3707 return -ENOMEM;
3708
3709 bits = bitmap_alloc(guard.gc->ngpio, flags);
3710 if (!bits) {
3711 bitmap_free(mask);
3712 return -ENOMEM;
3713 }
3714 }
3715
3716 bitmap_zero(mask, guard.gc->ngpio);
3717
3718 if (!can_sleep)
3719 WARN_ON(guard.gc->can_sleep);
3720
3721 do {
3722 struct gpio_desc *desc = desc_array[i];
3723 int hwgpio = gpio_chip_hwgpio(desc);
3724 int value = test_bit(i, value_bitmap);
3725
3726 /*
3727 * Pins applicable for fast input but not for
3728 * fast output processing may have been already
3729 * inverted inside the fast path, skip them.
3730 */
3731 if (!raw && !(array_info &&
3732 test_bit(i, array_info->invert_mask)) &&
3733 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3734 value = !value;
3735 trace_gpio_value(desc_to_gpio(desc), 0, value);
3736 /*
3737 * collect all normal outputs belonging to the same chip
3738 * open drain and open source outputs are set individually
3739 */
3740 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3741 gpio_set_open_drain_value_commit(desc, value);
3742 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3743 gpio_set_open_source_value_commit(desc, value);
3744 } else {
3745 __set_bit(hwgpio, mask);
3746 __assign_bit(hwgpio, bits, value);
3747 count++;
3748 }
3749 i++;
3750
3751 if (array_info)
3752 i = find_next_zero_bit(array_info->set_mask,
3753 array_size, i);
3754 } while ((i < array_size) &&
3755 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3756 /* push collected bits to outputs */
3757 if (count != 0) {
3758 ret = gpiochip_set_multiple(guard.gc, mask, bits);
3759 if (ret)
3760 return ret;
3761 }
3762
3763 if (mask != fastpath_mask)
3764 bitmap_free(mask);
3765 if (bits != fastpath_bits)
3766 bitmap_free(bits);
3767 }
3768 return 0;
3769 }
3770
3771 /**
3772 * gpiod_set_raw_value() - assign a gpio's raw value
3773 * @desc: gpio whose value will be assigned
3774 * @value: value to assign
3775 *
3776 * Set the raw value of the GPIO, i.e. the value of its physical line without
3777 * regard for its ACTIVE_LOW status.
3778 *
3779 * This function can be called from contexts where we cannot sleep, and will
3780 * complain if the GPIO chip functions potentially sleep.
3781 *
3782 * Returns:
3783 * 0 on success, negative error number on failure.
3784 */
gpiod_set_raw_value(struct gpio_desc * desc,int value)3785 int gpiod_set_raw_value(struct gpio_desc *desc, int value)
3786 {
3787 VALIDATE_DESC(desc);
3788 /* Should be using gpiod_set_raw_value_cansleep() */
3789 WARN_ON(desc->gdev->can_sleep);
3790 return gpiod_set_raw_value_commit(desc, value);
3791 }
3792 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3793
3794 /**
3795 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3796 * @desc: the descriptor to set the value on
3797 * @value: value to set
3798 *
3799 * This sets the value of a GPIO line backing a descriptor, applying
3800 * different semantic quirks like active low and open drain/source
3801 * handling.
3802 *
3803 * Returns:
3804 * 0 on success, negative error number on failure.
3805 */
gpiod_set_value_nocheck(struct gpio_desc * desc,int value)3806 static int gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3807 {
3808 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3809 value = !value;
3810
3811 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3812 return gpio_set_open_drain_value_commit(desc, value);
3813 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3814 return gpio_set_open_source_value_commit(desc, value);
3815
3816 return gpiod_set_raw_value_commit(desc, value);
3817 }
3818
3819 /**
3820 * gpiod_set_value() - assign a gpio's value
3821 * @desc: gpio whose value will be assigned
3822 * @value: value to assign
3823 *
3824 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3825 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3826 *
3827 * This function can be called from contexts where we cannot sleep, and will
3828 * complain if the GPIO chip functions potentially sleep.
3829 *
3830 * Returns:
3831 * 0 on success, negative error number on failure.
3832 */
gpiod_set_value(struct gpio_desc * desc,int value)3833 int gpiod_set_value(struct gpio_desc *desc, int value)
3834 {
3835 VALIDATE_DESC(desc);
3836 /* Should be using gpiod_set_value_cansleep() */
3837 WARN_ON(desc->gdev->can_sleep);
3838 return gpiod_set_value_nocheck(desc, value);
3839 }
3840 EXPORT_SYMBOL_GPL(gpiod_set_value);
3841
3842 /**
3843 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3844 * @array_size: number of elements in the descriptor array / value bitmap
3845 * @desc_array: array of GPIO descriptors whose values will be assigned
3846 * @array_info: information on applicability of fast bitmap processing path
3847 * @value_bitmap: bitmap of values to assign
3848 *
3849 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3850 * without regard for their ACTIVE_LOW status.
3851 *
3852 * This function can be called from contexts where we cannot sleep, and will
3853 * complain if the GPIO chip functions potentially sleep.
3854 *
3855 * Returns:
3856 * 0 on success, or negative errno on failure.
3857 */
gpiod_set_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3858 int gpiod_set_raw_array_value(unsigned int array_size,
3859 struct gpio_desc **desc_array,
3860 struct gpio_array *array_info,
3861 unsigned long *value_bitmap)
3862 {
3863 if (!desc_array)
3864 return -EINVAL;
3865 return gpiod_set_array_value_complex(true, false, array_size,
3866 desc_array, array_info, value_bitmap);
3867 }
3868 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3869
3870 /**
3871 * gpiod_set_array_value() - assign values to an array of GPIOs
3872 * @array_size: number of elements in the descriptor array / value bitmap
3873 * @desc_array: array of GPIO descriptors whose values will be assigned
3874 * @array_info: information on applicability of fast bitmap processing path
3875 * @value_bitmap: bitmap of values to assign
3876 *
3877 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3878 * into account.
3879 *
3880 * This function can be called from contexts where we cannot sleep, and will
3881 * complain if the GPIO chip functions potentially sleep.
3882 *
3883 * Returns:
3884 * 0 on success, or negative errno on failure.
3885 */
gpiod_set_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3886 int gpiod_set_array_value(unsigned int array_size,
3887 struct gpio_desc **desc_array,
3888 struct gpio_array *array_info,
3889 unsigned long *value_bitmap)
3890 {
3891 if (!desc_array)
3892 return -EINVAL;
3893 return gpiod_set_array_value_complex(false, false, array_size,
3894 desc_array, array_info,
3895 value_bitmap);
3896 }
3897 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3898
3899 /**
3900 * gpiod_cansleep() - report whether gpio value access may sleep
3901 * @desc: gpio to check
3902 *
3903 * Returns:
3904 * 0 for non-sleepable, 1 for sleepable, or an error code in case of error.
3905 */
gpiod_cansleep(const struct gpio_desc * desc)3906 int gpiod_cansleep(const struct gpio_desc *desc)
3907 {
3908 VALIDATE_DESC(desc);
3909 return desc->gdev->can_sleep;
3910 }
3911 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3912
3913 /**
3914 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3915 * @desc: gpio to set the consumer name on
3916 * @name: the new consumer name
3917 *
3918 * Returns:
3919 * 0 on success, or negative errno on failure.
3920 */
gpiod_set_consumer_name(struct gpio_desc * desc,const char * name)3921 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3922 {
3923 int ret;
3924
3925 VALIDATE_DESC(desc);
3926
3927 ret = desc_set_label(desc, name);
3928 if (ret == 0)
3929 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3930
3931 return ret;
3932 }
3933 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3934
3935 /**
3936 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3937 * @desc: gpio whose IRQ will be returned (already requested)
3938 *
3939 * Returns:
3940 * The IRQ corresponding to the passed GPIO, or an error code in case of error.
3941 */
gpiod_to_irq(const struct gpio_desc * desc)3942 int gpiod_to_irq(const struct gpio_desc *desc)
3943 {
3944 struct gpio_device *gdev;
3945 struct gpio_chip *gc;
3946 int offset;
3947
3948 /*
3949 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3950 * requires this function to not return zero on an invalid descriptor
3951 * but rather a negative error number.
3952 */
3953 if (IS_ERR_OR_NULL(desc))
3954 return -EINVAL;
3955
3956 gdev = desc->gdev;
3957 /* FIXME Cannot use gpio_chip_guard due to const desc. */
3958 guard(srcu)(&gdev->srcu);
3959 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3960 if (!gc)
3961 return -ENODEV;
3962
3963 offset = gpio_chip_hwgpio(desc);
3964 if (gc->to_irq) {
3965 int retirq = gc->to_irq(gc, offset);
3966
3967 /* Zero means NO_IRQ */
3968 if (!retirq)
3969 return -ENXIO;
3970
3971 return retirq;
3972 }
3973 #ifdef CONFIG_GPIOLIB_IRQCHIP
3974 if (gc->irq.chip) {
3975 /*
3976 * Avoid race condition with other code, which tries to lookup
3977 * an IRQ before the irqchip has been properly registered,
3978 * i.e. while gpiochip is still being brought up.
3979 */
3980 return -EPROBE_DEFER;
3981 }
3982 #endif
3983 return -ENXIO;
3984 }
3985 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3986
3987 /**
3988 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3989 * @gc: the chip the GPIO to lock belongs to
3990 * @offset: the offset of the GPIO to lock as IRQ
3991 *
3992 * This is used directly by GPIO drivers that want to lock down
3993 * a certain GPIO line to be used for IRQs.
3994 *
3995 * Returns:
3996 * 0 on success, or negative errno on failure.
3997 */
gpiochip_lock_as_irq(struct gpio_chip * gc,unsigned int offset)3998 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3999 {
4000 struct gpio_desc *desc;
4001
4002 desc = gpiochip_get_desc(gc, offset);
4003 if (IS_ERR(desc))
4004 return PTR_ERR(desc);
4005
4006 /*
4007 * If it's fast: flush the direction setting if something changed
4008 * behind our back
4009 */
4010 if (!gc->can_sleep && gc->get_direction) {
4011 int dir = gpiod_get_direction(desc);
4012
4013 if (dir < 0) {
4014 chip_err(gc, "%s: cannot get GPIO direction\n",
4015 __func__);
4016 return dir;
4017 }
4018 }
4019
4020 /* To be valid for IRQ the line needs to be input or open drain */
4021 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
4022 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
4023 chip_err(gc,
4024 "%s: tried to flag a GPIO set as output for IRQ\n",
4025 __func__);
4026 return -EIO;
4027 }
4028
4029 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
4030 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4031
4032 return 0;
4033 }
4034 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
4035
4036 /**
4037 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
4038 * @gc: the chip the GPIO to lock belongs to
4039 * @offset: the offset of the GPIO to lock as IRQ
4040 *
4041 * This is used directly by GPIO drivers that want to indicate
4042 * that a certain GPIO is no longer used exclusively for IRQ.
4043 */
gpiochip_unlock_as_irq(struct gpio_chip * gc,unsigned int offset)4044 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
4045 {
4046 struct gpio_desc *desc;
4047
4048 desc = gpiochip_get_desc(gc, offset);
4049 if (IS_ERR(desc))
4050 return;
4051
4052 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
4053 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4054 }
4055 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
4056
gpiochip_disable_irq(struct gpio_chip * gc,unsigned int offset)4057 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
4058 {
4059 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4060
4061 if (!IS_ERR(desc) &&
4062 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
4063 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4064 }
4065 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
4066
gpiochip_enable_irq(struct gpio_chip * gc,unsigned int offset)4067 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
4068 {
4069 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4070
4071 if (!IS_ERR(desc) &&
4072 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
4073 /*
4074 * We must not be output when using IRQ UNLESS we are
4075 * open drain.
4076 */
4077 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
4078 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
4079 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4080 }
4081 }
4082 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
4083
gpiochip_line_is_irq(struct gpio_chip * gc,unsigned int offset)4084 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
4085 {
4086 if (offset >= gc->ngpio)
4087 return false;
4088
4089 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
4090 }
4091 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
4092
gpiochip_reqres_irq(struct gpio_chip * gc,unsigned int offset)4093 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
4094 {
4095 int ret;
4096
4097 if (!try_module_get(gc->gpiodev->owner))
4098 return -ENODEV;
4099
4100 ret = gpiochip_lock_as_irq(gc, offset);
4101 if (ret) {
4102 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
4103 module_put(gc->gpiodev->owner);
4104 return ret;
4105 }
4106 return 0;
4107 }
4108 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
4109
gpiochip_relres_irq(struct gpio_chip * gc,unsigned int offset)4110 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
4111 {
4112 gpiochip_unlock_as_irq(gc, offset);
4113 module_put(gc->gpiodev->owner);
4114 }
4115 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
4116
gpiochip_line_is_open_drain(struct gpio_chip * gc,unsigned int offset)4117 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
4118 {
4119 if (offset >= gc->ngpio)
4120 return false;
4121
4122 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
4123 }
4124 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
4125
gpiochip_line_is_open_source(struct gpio_chip * gc,unsigned int offset)4126 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
4127 {
4128 if (offset >= gc->ngpio)
4129 return false;
4130
4131 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
4132 }
4133 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
4134
gpiochip_line_is_persistent(struct gpio_chip * gc,unsigned int offset)4135 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
4136 {
4137 if (offset >= gc->ngpio)
4138 return false;
4139
4140 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
4141 }
4142 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
4143
4144 /**
4145 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
4146 * @desc: gpio whose value will be returned
4147 *
4148 * Returns:
4149 * The GPIO's raw value, i.e. the value of the physical line disregarding
4150 * its ACTIVE_LOW status, or negative errno on failure.
4151 *
4152 * This function is to be called from contexts that can sleep.
4153 */
gpiod_get_raw_value_cansleep(const struct gpio_desc * desc)4154 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
4155 {
4156 might_sleep();
4157 VALIDATE_DESC(desc);
4158 return gpiod_get_raw_value_commit(desc);
4159 }
4160 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
4161
4162 /**
4163 * gpiod_get_value_cansleep() - return a gpio's value
4164 * @desc: gpio whose value will be returned
4165 *
4166 * Returns:
4167 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
4168 * account, or negative errno on failure.
4169 *
4170 * This function is to be called from contexts that can sleep.
4171 */
gpiod_get_value_cansleep(const struct gpio_desc * desc)4172 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
4173 {
4174 int value;
4175
4176 might_sleep();
4177 VALIDATE_DESC(desc);
4178 value = gpiod_get_raw_value_commit(desc);
4179 if (value < 0)
4180 return value;
4181
4182 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
4183 value = !value;
4184
4185 return value;
4186 }
4187 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
4188
4189 /**
4190 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
4191 * @array_size: number of elements in the descriptor array / value bitmap
4192 * @desc_array: array of GPIO descriptors whose values will be read
4193 * @array_info: information on applicability of fast bitmap processing path
4194 * @value_bitmap: bitmap to store the read values
4195 *
4196 * Read the raw values of the GPIOs, i.e. the values of the physical lines
4197 * without regard for their ACTIVE_LOW status.
4198 *
4199 * This function is to be called from contexts that can sleep.
4200 *
4201 * Returns:
4202 * 0 on success, or negative errno on failure.
4203 */
gpiod_get_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4204 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
4205 struct gpio_desc **desc_array,
4206 struct gpio_array *array_info,
4207 unsigned long *value_bitmap)
4208 {
4209 might_sleep();
4210 if (!desc_array)
4211 return -EINVAL;
4212 return gpiod_get_array_value_complex(true, true, array_size,
4213 desc_array, array_info,
4214 value_bitmap);
4215 }
4216 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
4217
4218 /**
4219 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
4220 * @array_size: number of elements in the descriptor array / value bitmap
4221 * @desc_array: array of GPIO descriptors whose values will be read
4222 * @array_info: information on applicability of fast bitmap processing path
4223 * @value_bitmap: bitmap to store the read values
4224 *
4225 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4226 * into account.
4227 *
4228 * This function is to be called from contexts that can sleep.
4229 *
4230 * Returns:
4231 * 0 on success, or negative errno on failure.
4232 */
gpiod_get_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4233 int gpiod_get_array_value_cansleep(unsigned int array_size,
4234 struct gpio_desc **desc_array,
4235 struct gpio_array *array_info,
4236 unsigned long *value_bitmap)
4237 {
4238 might_sleep();
4239 if (!desc_array)
4240 return -EINVAL;
4241 return gpiod_get_array_value_complex(false, true, array_size,
4242 desc_array, array_info,
4243 value_bitmap);
4244 }
4245 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
4246
4247 /**
4248 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
4249 * @desc: gpio whose value will be assigned
4250 * @value: value to assign
4251 *
4252 * Set the raw value of the GPIO, i.e. the value of its physical line without
4253 * regard for its ACTIVE_LOW status.
4254 *
4255 * This function is to be called from contexts that can sleep.
4256 *
4257 * Returns:
4258 * 0 on success, negative error number on failure.
4259 */
gpiod_set_raw_value_cansleep(struct gpio_desc * desc,int value)4260 int gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
4261 {
4262 might_sleep();
4263 VALIDATE_DESC(desc);
4264 return gpiod_set_raw_value_commit(desc, value);
4265 }
4266 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
4267
4268 /**
4269 * gpiod_set_value_cansleep() - assign a gpio's value
4270 * @desc: gpio whose value will be assigned
4271 * @value: value to assign
4272 *
4273 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
4274 * account
4275 *
4276 * This function is to be called from contexts that can sleep.
4277 *
4278 * Returns:
4279 * 0 on success, negative error number on failure.
4280 */
gpiod_set_value_cansleep(struct gpio_desc * desc,int value)4281 int gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
4282 {
4283 might_sleep();
4284 VALIDATE_DESC(desc);
4285 return gpiod_set_value_nocheck(desc, value);
4286 }
4287 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
4288
4289 /**
4290 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
4291 * @array_size: number of elements in the descriptor array / value bitmap
4292 * @desc_array: array of GPIO descriptors whose values will be assigned
4293 * @array_info: information on applicability of fast bitmap processing path
4294 * @value_bitmap: bitmap of values to assign
4295 *
4296 * Set the raw values of the GPIOs, i.e. the values of the physical lines
4297 * without regard for their ACTIVE_LOW status.
4298 *
4299 * This function is to be called from contexts that can sleep.
4300 *
4301 * Returns:
4302 * 0 on success, or negative errno on failure.
4303 */
gpiod_set_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4304 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
4305 struct gpio_desc **desc_array,
4306 struct gpio_array *array_info,
4307 unsigned long *value_bitmap)
4308 {
4309 might_sleep();
4310 if (!desc_array)
4311 return -EINVAL;
4312 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
4313 array_info, value_bitmap);
4314 }
4315 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
4316
4317 /**
4318 * gpiod_add_lookup_tables() - register GPIO device consumers
4319 * @tables: list of tables of consumers to register
4320 * @n: number of tables in the list
4321 */
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)4322 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
4323 {
4324 unsigned int i;
4325
4326 mutex_lock(&gpio_lookup_lock);
4327
4328 for (i = 0; i < n; i++)
4329 list_add_tail(&tables[i]->list, &gpio_lookup_list);
4330
4331 mutex_unlock(&gpio_lookup_lock);
4332 }
4333
4334 /**
4335 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
4336 * @array_size: number of elements in the descriptor array / value bitmap
4337 * @desc_array: array of GPIO descriptors whose values will be assigned
4338 * @array_info: information on applicability of fast bitmap processing path
4339 * @value_bitmap: bitmap of values to assign
4340 *
4341 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4342 * into account.
4343 *
4344 * This function is to be called from contexts that can sleep.
4345 *
4346 * Returns:
4347 * 0 on success, or negative errno on failure.
4348 */
gpiod_set_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4349 int gpiod_set_array_value_cansleep(unsigned int array_size,
4350 struct gpio_desc **desc_array,
4351 struct gpio_array *array_info,
4352 unsigned long *value_bitmap)
4353 {
4354 might_sleep();
4355 if (!desc_array)
4356 return -EINVAL;
4357 return gpiod_set_array_value_complex(false, true, array_size,
4358 desc_array, array_info,
4359 value_bitmap);
4360 }
4361 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
4362
gpiod_line_state_notify(struct gpio_desc * desc,unsigned long action)4363 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
4364 {
4365 guard(read_lock_irqsave)(&desc->gdev->line_state_lock);
4366
4367 raw_notifier_call_chain(&desc->gdev->line_state_notifier, action, desc);
4368 }
4369
4370 /**
4371 * gpiod_add_lookup_table() - register GPIO device consumers
4372 * @table: table of consumers to register
4373 */
gpiod_add_lookup_table(struct gpiod_lookup_table * table)4374 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
4375 {
4376 gpiod_add_lookup_tables(&table, 1);
4377 }
4378 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
4379
4380 /**
4381 * gpiod_remove_lookup_table() - unregister GPIO device consumers
4382 * @table: table of consumers to unregister
4383 */
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)4384 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4385 {
4386 /* Nothing to remove */
4387 if (!table)
4388 return;
4389
4390 mutex_lock(&gpio_lookup_lock);
4391
4392 list_del(&table->list);
4393
4394 mutex_unlock(&gpio_lookup_lock);
4395 }
4396 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4397
4398 /**
4399 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4400 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4401 */
gpiod_add_hogs(struct gpiod_hog * hogs)4402 void gpiod_add_hogs(struct gpiod_hog *hogs)
4403 {
4404 struct gpiod_hog *hog;
4405
4406 mutex_lock(&gpio_machine_hogs_mutex);
4407
4408 for (hog = &hogs[0]; hog->chip_label; hog++) {
4409 list_add_tail(&hog->list, &gpio_machine_hogs);
4410
4411 /*
4412 * The chip may have been registered earlier, so check if it
4413 * exists and, if so, try to hog the line now.
4414 */
4415 struct gpio_device *gdev __free(gpio_device_put) =
4416 gpio_device_find_by_label(hog->chip_label);
4417 if (gdev)
4418 gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);
4419 }
4420
4421 mutex_unlock(&gpio_machine_hogs_mutex);
4422 }
4423 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4424
gpiod_remove_hogs(struct gpiod_hog * hogs)4425 void gpiod_remove_hogs(struct gpiod_hog *hogs)
4426 {
4427 struct gpiod_hog *hog;
4428
4429 mutex_lock(&gpio_machine_hogs_mutex);
4430 for (hog = &hogs[0]; hog->chip_label; hog++)
4431 list_del(&hog->list);
4432 mutex_unlock(&gpio_machine_hogs_mutex);
4433 }
4434 EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
4435
gpiod_find_lookup_table(struct device * dev)4436 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4437 {
4438 const char *dev_id = dev ? dev_name(dev) : NULL;
4439 struct gpiod_lookup_table *table;
4440
4441 list_for_each_entry(table, &gpio_lookup_list, list) {
4442 if (table->dev_id && dev_id) {
4443 /*
4444 * Valid strings on both ends, must be identical to have
4445 * a match
4446 */
4447 if (!strcmp(table->dev_id, dev_id))
4448 return table;
4449 } else {
4450 /*
4451 * One of the pointers is NULL, so both must be to have
4452 * a match
4453 */
4454 if (dev_id == table->dev_id)
4455 return table;
4456 }
4457 }
4458
4459 return NULL;
4460 }
4461
gpiod_find(struct device * dev,const char * con_id,unsigned int idx,unsigned long * flags)4462 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4463 unsigned int idx, unsigned long *flags)
4464 {
4465 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4466 struct gpiod_lookup_table *table;
4467 struct gpiod_lookup *p;
4468 struct gpio_chip *gc;
4469
4470 guard(mutex)(&gpio_lookup_lock);
4471
4472 table = gpiod_find_lookup_table(dev);
4473 if (!table)
4474 return desc;
4475
4476 for (p = &table->table[0]; p->key; p++) {
4477 /* idx must always match exactly */
4478 if (p->idx != idx)
4479 continue;
4480
4481 /* If the lookup entry has a con_id, require exact match */
4482 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4483 continue;
4484
4485 if (p->chip_hwnum == U16_MAX) {
4486 desc = gpio_name_to_desc(p->key);
4487 if (desc) {
4488 *flags = p->flags;
4489 return desc;
4490 }
4491
4492 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
4493 p->key);
4494 return ERR_PTR(-EPROBE_DEFER);
4495 }
4496
4497 struct gpio_device *gdev __free(gpio_device_put) =
4498 gpio_device_find_by_label(p->key);
4499 if (!gdev) {
4500 /*
4501 * As the lookup table indicates a chip with
4502 * p->key should exist, assume it may
4503 * still appear later and let the interested
4504 * consumer be probed again or let the Deferred
4505 * Probe infrastructure handle the error.
4506 */
4507 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4508 p->key);
4509 return ERR_PTR(-EPROBE_DEFER);
4510 }
4511
4512 gc = gpio_device_get_chip(gdev);
4513
4514 if (gc->ngpio <= p->chip_hwnum) {
4515 dev_err(dev,
4516 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4517 idx, p->chip_hwnum, gc->ngpio - 1,
4518 gc->label);
4519 return ERR_PTR(-EINVAL);
4520 }
4521
4522 desc = gpio_device_get_desc(gdev, p->chip_hwnum);
4523 *flags = p->flags;
4524
4525 return desc;
4526 }
4527
4528 return desc;
4529 }
4530
platform_gpio_count(struct device * dev,const char * con_id)4531 static int platform_gpio_count(struct device *dev, const char *con_id)
4532 {
4533 struct gpiod_lookup_table *table;
4534 struct gpiod_lookup *p;
4535 unsigned int count = 0;
4536
4537 scoped_guard(mutex, &gpio_lookup_lock) {
4538 table = gpiod_find_lookup_table(dev);
4539 if (!table)
4540 return -ENOENT;
4541
4542 for (p = &table->table[0]; p->key; p++) {
4543 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4544 (!con_id && !p->con_id))
4545 count++;
4546 }
4547 }
4548
4549 if (!count)
4550 return -ENOENT;
4551
4552 return count;
4553 }
4554
gpiod_find_by_fwnode(struct fwnode_handle * fwnode,struct device * consumer,const char * con_id,unsigned int idx,enum gpiod_flags * flags,unsigned long * lookupflags)4555 static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
4556 struct device *consumer,
4557 const char *con_id,
4558 unsigned int idx,
4559 enum gpiod_flags *flags,
4560 unsigned long *lookupflags)
4561 {
4562 const char *name = function_name_or_default(con_id);
4563 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4564
4565 if (is_of_node(fwnode)) {
4566 dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4567 desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
4568 } else if (is_acpi_node(fwnode)) {
4569 dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4570 desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
4571 } else if (is_software_node(fwnode)) {
4572 dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4573 desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
4574 }
4575
4576 return desc;
4577 }
4578
gpiod_find_and_request(struct device * consumer,struct fwnode_handle * fwnode,const char * con_id,unsigned int idx,enum gpiod_flags flags,const char * label,bool platform_lookup_allowed)4579 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
4580 struct fwnode_handle *fwnode,
4581 const char *con_id,
4582 unsigned int idx,
4583 enum gpiod_flags flags,
4584 const char *label,
4585 bool platform_lookup_allowed)
4586 {
4587 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4588 const char *name = function_name_or_default(con_id);
4589 /*
4590 * scoped_guard() is implemented as a for loop, meaning static
4591 * analyzers will complain about these two not being initialized.
4592 */
4593 struct gpio_desc *desc = NULL;
4594 int ret = 0;
4595
4596 scoped_guard(srcu, &gpio_devices_srcu) {
4597 desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
4598 &flags, &lookupflags);
4599 if (gpiod_not_found(desc) && platform_lookup_allowed) {
4600 /*
4601 * Either we are not using DT or ACPI, or their lookup
4602 * did not return a result. In that case, use platform
4603 * lookup as a fallback.
4604 */
4605 dev_dbg(consumer,
4606 "using lookup tables for GPIO lookup\n");
4607 desc = gpiod_find(consumer, con_id, idx, &lookupflags);
4608 }
4609
4610 if (IS_ERR(desc)) {
4611 dev_dbg(consumer, "No GPIO consumer %s found\n", name);
4612 return desc;
4613 }
4614
4615 /*
4616 * If a connection label was passed use that, else attempt to use
4617 * the device name as label
4618 */
4619 ret = gpiod_request(desc, label);
4620 }
4621 if (ret) {
4622 if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4623 return ERR_PTR(ret);
4624
4625 /*
4626 * This happens when there are several consumers for
4627 * the same GPIO line: we just return here without
4628 * further initialization. It is a bit of a hack.
4629 * This is necessary to support fixed regulators.
4630 *
4631 * FIXME: Make this more sane and safe.
4632 */
4633 dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
4634 return desc;
4635 }
4636
4637 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4638 if (ret < 0) {
4639 gpiod_put(desc);
4640 dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret);
4641 return ERR_PTR(ret);
4642 }
4643
4644 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
4645
4646 return desc;
4647 }
4648
4649 /**
4650 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
4651 * @fwnode: handle of the firmware node
4652 * @con_id: function within the GPIO consumer
4653 * @index: index of the GPIO to obtain for the consumer
4654 * @flags: GPIO initialization flags
4655 * @label: label to attach to the requested GPIO
4656 *
4657 * This function can be used for drivers that get their configuration
4658 * from opaque firmware.
4659 *
4660 * The function properly finds the corresponding GPIO using whatever is the
4661 * underlying firmware interface and then makes sure that the GPIO
4662 * descriptor is requested before it is returned to the caller.
4663 *
4664 * Returns:
4665 * On successful request the GPIO pin is configured in accordance with
4666 * provided @flags.
4667 *
4668 * In case of error an ERR_PTR() is returned.
4669 */
fwnode_gpiod_get_index(struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)4670 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
4671 const char *con_id,
4672 int index,
4673 enum gpiod_flags flags,
4674 const char *label)
4675 {
4676 return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
4677 }
4678 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
4679
4680 /**
4681 * gpiod_count - return the number of GPIOs associated with a device / function
4682 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4683 * @con_id: function within the GPIO consumer
4684 *
4685 * Returns:
4686 * The number of GPIOs associated with a device / function or -ENOENT if no
4687 * GPIO has been assigned to the requested function.
4688 */
gpiod_count(struct device * dev,const char * con_id)4689 int gpiod_count(struct device *dev, const char *con_id)
4690 {
4691 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4692 int count = -ENOENT;
4693
4694 if (is_of_node(fwnode))
4695 count = of_gpio_count(fwnode, con_id);
4696 else if (is_acpi_node(fwnode))
4697 count = acpi_gpio_count(fwnode, con_id);
4698 else if (is_software_node(fwnode))
4699 count = swnode_gpio_count(fwnode, con_id);
4700
4701 if (count < 0)
4702 count = platform_gpio_count(dev, con_id);
4703
4704 return count;
4705 }
4706 EXPORT_SYMBOL_GPL(gpiod_count);
4707
4708 /**
4709 * gpiod_get - obtain a GPIO for a given GPIO function
4710 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4711 * @con_id: function within the GPIO consumer
4712 * @flags: optional GPIO initialization flags
4713 *
4714 * Returns:
4715 * The GPIO descriptor corresponding to the function @con_id of device
4716 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4717 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4718 */
gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)4719 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4720 enum gpiod_flags flags)
4721 {
4722 return gpiod_get_index(dev, con_id, 0, flags);
4723 }
4724 EXPORT_SYMBOL_GPL(gpiod_get);
4725
4726 /**
4727 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4728 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4729 * @con_id: function within the GPIO consumer
4730 * @flags: optional GPIO initialization flags
4731 *
4732 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4733 * the requested function it will return NULL. This is convenient for drivers
4734 * that need to handle optional GPIOs.
4735 *
4736 * Returns:
4737 * The GPIO descriptor corresponding to the function @con_id of device
4738 * dev, NULL if no GPIO has been assigned to the requested function, or
4739 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4740 */
gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4741 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4742 const char *con_id,
4743 enum gpiod_flags flags)
4744 {
4745 return gpiod_get_index_optional(dev, con_id, 0, flags);
4746 }
4747 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4748
4749
4750 /**
4751 * gpiod_configure_flags - helper function to configure a given GPIO
4752 * @desc: gpio whose value will be assigned
4753 * @con_id: function within the GPIO consumer
4754 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4755 * of_find_gpio() or of_get_gpio_hog()
4756 * @dflags: gpiod_flags - optional GPIO initialization flags
4757 *
4758 * Returns:
4759 * 0 on success, -ENOENT if no GPIO has been assigned to the
4760 * requested function and/or index, or another IS_ERR() code if an error
4761 * occurred while trying to acquire the GPIO.
4762 */
gpiod_configure_flags(struct gpio_desc * desc,const char * con_id,unsigned long lflags,enum gpiod_flags dflags)4763 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4764 unsigned long lflags, enum gpiod_flags dflags)
4765 {
4766 const char *name = function_name_or_default(con_id);
4767 int ret;
4768
4769 if (lflags & GPIO_ACTIVE_LOW)
4770 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4771
4772 if (lflags & GPIO_OPEN_DRAIN)
4773 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4774 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4775 /*
4776 * This enforces open drain mode from the consumer side.
4777 * This is necessary for some busses like I2C, but the lookup
4778 * should *REALLY* have specified them as open drain in the
4779 * first place, so print a little warning here.
4780 */
4781 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4782 gpiod_warn(desc,
4783 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4784 }
4785
4786 if (lflags & GPIO_OPEN_SOURCE)
4787 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4788
4789 if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
4790 ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
4791 ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
4792 gpiod_err(desc,
4793 "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
4794 return -EINVAL;
4795 }
4796
4797 if (lflags & GPIO_PULL_UP)
4798 set_bit(FLAG_PULL_UP, &desc->flags);
4799 else if (lflags & GPIO_PULL_DOWN)
4800 set_bit(FLAG_PULL_DOWN, &desc->flags);
4801 else if (lflags & GPIO_PULL_DISABLE)
4802 set_bit(FLAG_BIAS_DISABLE, &desc->flags);
4803
4804 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4805 if (ret < 0)
4806 return ret;
4807
4808 /* No particular flag request, return here... */
4809 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4810 gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
4811 return 0;
4812 }
4813
4814 /* Process flags */
4815 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4816 ret = gpiod_direction_output_nonotify(desc,
4817 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4818 else
4819 ret = gpiod_direction_input_nonotify(desc);
4820
4821 return ret;
4822 }
4823
4824 /**
4825 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4826 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4827 * @con_id: function within the GPIO consumer
4828 * @idx: index of the GPIO to obtain in the consumer
4829 * @flags: optional GPIO initialization flags
4830 *
4831 * This variant of gpiod_get() allows to access GPIOs other than the first
4832 * defined one for functions that define several GPIOs.
4833 *
4834 * Returns:
4835 * A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4836 * requested function and/or index, or another IS_ERR() code if an error
4837 * occurred while trying to acquire the GPIO.
4838 */
gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)4839 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4840 const char *con_id,
4841 unsigned int idx,
4842 enum gpiod_flags flags)
4843 {
4844 struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4845 const char *devname = dev ? dev_name(dev) : "?";
4846 const char *label = con_id ?: devname;
4847
4848 return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
4849 }
4850 EXPORT_SYMBOL_GPL(gpiod_get_index);
4851
4852 /**
4853 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4854 * function
4855 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4856 * @con_id: function within the GPIO consumer
4857 * @index: index of the GPIO to obtain in the consumer
4858 * @flags: optional GPIO initialization flags
4859 *
4860 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4861 * specified index was assigned to the requested function it will return NULL.
4862 * This is convenient for drivers that need to handle optional GPIOs.
4863 *
4864 * Returns:
4865 * A valid GPIO descriptor, NULL if no GPIO has been assigned to the
4866 * requested function and/or index, or another IS_ERR() code if an error
4867 * occurred while trying to acquire the GPIO.
4868 */
gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)4869 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4870 const char *con_id,
4871 unsigned int index,
4872 enum gpiod_flags flags)
4873 {
4874 struct gpio_desc *desc;
4875
4876 desc = gpiod_get_index(dev, con_id, index, flags);
4877 if (gpiod_not_found(desc))
4878 return NULL;
4879
4880 return desc;
4881 }
4882 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4883
4884 /**
4885 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4886 * @desc: gpio whose value will be assigned
4887 * @name: gpio line name
4888 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4889 * of_find_gpio() or of_get_gpio_hog()
4890 * @dflags: gpiod_flags - optional GPIO initialization flags
4891 *
4892 * Returns:
4893 * 0 on success, or negative errno on failure.
4894 */
gpiod_hog(struct gpio_desc * desc,const char * name,unsigned long lflags,enum gpiod_flags dflags)4895 int gpiod_hog(struct gpio_desc *desc, const char *name,
4896 unsigned long lflags, enum gpiod_flags dflags)
4897 {
4898 struct gpio_device *gdev = desc->gdev;
4899 struct gpio_desc *local_desc;
4900 int hwnum;
4901 int ret;
4902
4903 CLASS(gpio_chip_guard, guard)(desc);
4904 if (!guard.gc)
4905 return -ENODEV;
4906
4907 if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))
4908 return 0;
4909
4910 hwnum = gpio_chip_hwgpio(desc);
4911
4912 local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
4913 lflags, dflags);
4914 if (IS_ERR(local_desc)) {
4915 clear_bit(FLAG_IS_HOGGED, &desc->flags);
4916 ret = PTR_ERR(local_desc);
4917 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4918 name, gdev->label, hwnum, ret);
4919 return ret;
4920 }
4921
4922 gpiod_dbg(desc, "hogged as %s/%s\n",
4923 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4924 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4925 str_high_low(dflags & GPIOD_FLAGS_BIT_DIR_VAL) : "?");
4926
4927 return 0;
4928 }
4929
4930 /**
4931 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4932 * @gc: gpio chip to act on
4933 */
gpiochip_free_hogs(struct gpio_chip * gc)4934 static void gpiochip_free_hogs(struct gpio_chip *gc)
4935 {
4936 struct gpio_desc *desc;
4937
4938 for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)
4939 gpiochip_free_own_desc(desc);
4940 }
4941
4942 /**
4943 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4944 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4945 * @con_id: function within the GPIO consumer
4946 * @flags: optional GPIO initialization flags
4947 *
4948 * This function acquires all the GPIOs defined under a given function.
4949 *
4950 * Returns:
4951 * The GPIO descriptors corresponding to the function @con_id of device
4952 * dev, -ENOENT if no GPIO has been assigned to the requested function,
4953 * or another IS_ERR() code if an error occurred while trying to acquire
4954 * the GPIOs.
4955 */
gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)4956 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4957 const char *con_id,
4958 enum gpiod_flags flags)
4959 {
4960 struct gpio_desc *desc;
4961 struct gpio_descs *descs;
4962 struct gpio_device *gdev;
4963 struct gpio_array *array_info = NULL;
4964 int count, bitmap_size;
4965 unsigned long dflags;
4966 size_t descs_size;
4967
4968 count = gpiod_count(dev, con_id);
4969 if (count < 0)
4970 return ERR_PTR(count);
4971
4972 descs_size = struct_size(descs, desc, count);
4973 descs = kzalloc(descs_size, GFP_KERNEL);
4974 if (!descs)
4975 return ERR_PTR(-ENOMEM);
4976
4977 for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
4978 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4979 if (IS_ERR(desc)) {
4980 gpiod_put_array(descs);
4981 return ERR_CAST(desc);
4982 }
4983
4984 descs->desc[descs->ndescs] = desc;
4985
4986 gdev = gpiod_to_gpio_device(desc);
4987 /*
4988 * If pin hardware number of array member 0 is also 0, select
4989 * its chip as a candidate for fast bitmap processing path.
4990 */
4991 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4992 struct gpio_descs *array;
4993
4994 bitmap_size = BITS_TO_LONGS(gdev->ngpio > count ?
4995 gdev->ngpio : count);
4996
4997 array = krealloc(descs, descs_size +
4998 struct_size(array_info, invert_mask, 3 * bitmap_size),
4999 GFP_KERNEL | __GFP_ZERO);
5000 if (!array) {
5001 gpiod_put_array(descs);
5002 return ERR_PTR(-ENOMEM);
5003 }
5004
5005 descs = array;
5006
5007 array_info = (void *)descs + descs_size;
5008 array_info->get_mask = array_info->invert_mask +
5009 bitmap_size;
5010 array_info->set_mask = array_info->get_mask +
5011 bitmap_size;
5012
5013 array_info->desc = descs->desc;
5014 array_info->size = count;
5015 array_info->gdev = gdev;
5016 bitmap_set(array_info->get_mask, descs->ndescs,
5017 count - descs->ndescs);
5018 bitmap_set(array_info->set_mask, descs->ndescs,
5019 count - descs->ndescs);
5020 descs->info = array_info;
5021 }
5022
5023 /* If there is no cache for fast bitmap processing path, continue */
5024 if (!array_info)
5025 continue;
5026
5027 /* Unmark array members which don't belong to the 'fast' chip */
5028 if (array_info->gdev != gdev) {
5029 __clear_bit(descs->ndescs, array_info->get_mask);
5030 __clear_bit(descs->ndescs, array_info->set_mask);
5031 }
5032 /*
5033 * Detect array members which belong to the 'fast' chip
5034 * but their pins are not in hardware order.
5035 */
5036 else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
5037 /*
5038 * Don't use fast path if all array members processed so
5039 * far belong to the same chip as this one but its pin
5040 * hardware number is different from its array index.
5041 */
5042 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
5043 array_info = NULL;
5044 } else {
5045 __clear_bit(descs->ndescs,
5046 array_info->get_mask);
5047 __clear_bit(descs->ndescs,
5048 array_info->set_mask);
5049 }
5050 } else {
5051 dflags = READ_ONCE(desc->flags);
5052 /* Exclude open drain or open source from fast output */
5053 if (test_bit(FLAG_OPEN_DRAIN, &dflags) ||
5054 test_bit(FLAG_OPEN_SOURCE, &dflags))
5055 __clear_bit(descs->ndescs,
5056 array_info->set_mask);
5057 /* Identify 'fast' pins which require invertion */
5058 if (gpiod_is_active_low(desc))
5059 __set_bit(descs->ndescs,
5060 array_info->invert_mask);
5061 }
5062 }
5063 if (array_info)
5064 dev_dbg(dev,
5065 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
5066 array_info->gdev->label, array_info->size,
5067 *array_info->get_mask, *array_info->set_mask,
5068 *array_info->invert_mask);
5069 return descs;
5070 }
5071 EXPORT_SYMBOL_GPL(gpiod_get_array);
5072
5073 /**
5074 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
5075 * function
5076 * @dev: GPIO consumer, can be NULL for system-global GPIOs
5077 * @con_id: function within the GPIO consumer
5078 * @flags: optional GPIO initialization flags
5079 *
5080 * This is equivalent to gpiod_get_array(), except that when no GPIO was
5081 * assigned to the requested function it will return NULL.
5082 *
5083 * Returns:
5084 * The GPIO descriptors corresponding to the function @con_id of device
5085 * dev, NULL if no GPIO has been assigned to the requested function,
5086 * or another IS_ERR() code if an error occurred while trying to acquire
5087 * the GPIOs.
5088 */
gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)5089 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
5090 const char *con_id,
5091 enum gpiod_flags flags)
5092 {
5093 struct gpio_descs *descs;
5094
5095 descs = gpiod_get_array(dev, con_id, flags);
5096 if (gpiod_not_found(descs))
5097 return NULL;
5098
5099 return descs;
5100 }
5101 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
5102
5103 /**
5104 * gpiod_put - dispose of a GPIO descriptor
5105 * @desc: GPIO descriptor to dispose of
5106 *
5107 * No descriptor can be used after gpiod_put() has been called on it.
5108 */
gpiod_put(struct gpio_desc * desc)5109 void gpiod_put(struct gpio_desc *desc)
5110 {
5111 if (desc)
5112 gpiod_free(desc);
5113 }
5114 EXPORT_SYMBOL_GPL(gpiod_put);
5115
5116 /**
5117 * gpiod_put_array - dispose of multiple GPIO descriptors
5118 * @descs: struct gpio_descs containing an array of descriptors
5119 */
gpiod_put_array(struct gpio_descs * descs)5120 void gpiod_put_array(struct gpio_descs *descs)
5121 {
5122 unsigned int i;
5123
5124 for (i = 0; i < descs->ndescs; i++)
5125 gpiod_put(descs->desc[i]);
5126
5127 kfree(descs);
5128 }
5129 EXPORT_SYMBOL_GPL(gpiod_put_array);
5130
gpio_stub_drv_probe(struct device * dev)5131 static int gpio_stub_drv_probe(struct device *dev)
5132 {
5133 /*
5134 * The DT node of some GPIO chips have a "compatible" property, but
5135 * never have a struct device added and probed by a driver to register
5136 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
5137 * the consumers of the GPIO chip to get probe deferred forever because
5138 * they will be waiting for a device associated with the GPIO chip
5139 * firmware node to get added and bound to a driver.
5140 *
5141 * To allow these consumers to probe, we associate the struct
5142 * gpio_device of the GPIO chip with the firmware node and then simply
5143 * bind it to this stub driver.
5144 */
5145 return 0;
5146 }
5147
5148 static struct device_driver gpio_stub_drv = {
5149 .name = "gpio_stub_drv",
5150 .bus = &gpio_bus_type,
5151 .probe = gpio_stub_drv_probe,
5152 };
5153
gpiolib_dev_init(void)5154 static int __init gpiolib_dev_init(void)
5155 {
5156 int ret;
5157
5158 /* Register GPIO sysfs bus */
5159 ret = bus_register(&gpio_bus_type);
5160 if (ret < 0) {
5161 pr_err("gpiolib: could not register GPIO bus type\n");
5162 return ret;
5163 }
5164
5165 ret = driver_register(&gpio_stub_drv);
5166 if (ret < 0) {
5167 pr_err("gpiolib: could not register GPIO stub driver\n");
5168 bus_unregister(&gpio_bus_type);
5169 return ret;
5170 }
5171
5172 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
5173 if (ret < 0) {
5174 pr_err("gpiolib: failed to allocate char dev region\n");
5175 driver_unregister(&gpio_stub_drv);
5176 bus_unregister(&gpio_bus_type);
5177 return ret;
5178 }
5179
5180 gpiolib_initialized = true;
5181 gpiochip_setup_devs();
5182
5183 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
5184 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
5185 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
5186
5187 return ret;
5188 }
5189 core_initcall(gpiolib_dev_init);
5190
5191 #ifdef CONFIG_DEBUG_FS
5192
gpiolib_dbg_show(struct seq_file * s,struct gpio_device * gdev)5193 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
5194 {
5195 bool active_low, is_irq, is_out;
5196 unsigned int gpio = gdev->base;
5197 struct gpio_desc *desc;
5198 struct gpio_chip *gc;
5199 unsigned long flags;
5200 int value;
5201
5202 guard(srcu)(&gdev->srcu);
5203
5204 gc = srcu_dereference(gdev->chip, &gdev->srcu);
5205 if (!gc) {
5206 seq_puts(s, "Underlying GPIO chip is gone\n");
5207 return;
5208 }
5209
5210 for_each_gpio_desc(gc, desc) {
5211 guard(srcu)(&desc->gdev->desc_srcu);
5212 flags = READ_ONCE(desc->flags);
5213 is_irq = test_bit(FLAG_USED_AS_IRQ, &flags);
5214 if (is_irq || test_bit(FLAG_REQUESTED, &flags)) {
5215 gpiod_get_direction(desc);
5216 is_out = test_bit(FLAG_IS_OUT, &flags);
5217 value = gpio_chip_get_value(gc, desc);
5218 active_low = test_bit(FLAG_ACTIVE_LOW, &flags);
5219 seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
5220 gpio, desc->name ?: "", gpiod_get_label(desc),
5221 is_out ? "out" : "in ",
5222 value >= 0 ? str_hi_lo(value) : "? ",
5223 is_irq ? "IRQ " : "",
5224 active_low ? "ACTIVE LOW" : "");
5225 } else if (desc->name) {
5226 seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name);
5227 }
5228
5229 gpio++;
5230 }
5231 }
5232
5233 struct gpiolib_seq_priv {
5234 bool newline;
5235 int idx;
5236 };
5237
gpiolib_seq_start(struct seq_file * s,loff_t * pos)5238 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
5239 {
5240 struct gpiolib_seq_priv *priv;
5241 struct gpio_device *gdev;
5242 loff_t index = *pos;
5243
5244 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
5245 if (!priv)
5246 return NULL;
5247
5248 s->private = priv;
5249 if (*pos > 0)
5250 priv->newline = true;
5251 priv->idx = srcu_read_lock(&gpio_devices_srcu);
5252
5253 list_for_each_entry_srcu(gdev, &gpio_devices, list,
5254 srcu_read_lock_held(&gpio_devices_srcu)) {
5255 if (index-- == 0)
5256 return gdev;
5257 }
5258
5259 return NULL;
5260 }
5261
gpiolib_seq_next(struct seq_file * s,void * v,loff_t * pos)5262 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
5263 {
5264 struct gpiolib_seq_priv *priv = s->private;
5265 struct gpio_device *gdev = v, *next;
5266
5267 next = list_entry_rcu(gdev->list.next, struct gpio_device, list);
5268 gdev = &next->list == &gpio_devices ? NULL : next;
5269 priv->newline = true;
5270 ++*pos;
5271
5272 return gdev;
5273 }
5274
gpiolib_seq_stop(struct seq_file * s,void * v)5275 static void gpiolib_seq_stop(struct seq_file *s, void *v)
5276 {
5277 struct gpiolib_seq_priv *priv = s->private;
5278
5279 srcu_read_unlock(&gpio_devices_srcu, priv->idx);
5280 kfree(priv);
5281 }
5282
gpiolib_seq_show(struct seq_file * s,void * v)5283 static int gpiolib_seq_show(struct seq_file *s, void *v)
5284 {
5285 struct gpiolib_seq_priv *priv = s->private;
5286 struct gpio_device *gdev = v;
5287 struct gpio_chip *gc;
5288 struct device *parent;
5289
5290 if (priv->newline)
5291 seq_putc(s, '\n');
5292
5293 guard(srcu)(&gdev->srcu);
5294
5295 gc = srcu_dereference(gdev->chip, &gdev->srcu);
5296 if (!gc) {
5297 seq_printf(s, "%s: (dangling chip)\n", dev_name(&gdev->dev));
5298 return 0;
5299 }
5300
5301 seq_printf(s, "%s: GPIOs %u-%u", dev_name(&gdev->dev), gdev->base,
5302 gdev->base + gdev->ngpio - 1);
5303 parent = gc->parent;
5304 if (parent)
5305 seq_printf(s, ", parent: %s/%s",
5306 parent->bus ? parent->bus->name : "no-bus",
5307 dev_name(parent));
5308 if (gc->label)
5309 seq_printf(s, ", %s", gc->label);
5310 if (gc->can_sleep)
5311 seq_printf(s, ", can sleep");
5312 seq_printf(s, ":\n");
5313
5314 if (gc->dbg_show)
5315 gc->dbg_show(s, gc);
5316 else
5317 gpiolib_dbg_show(s, gdev);
5318
5319 return 0;
5320 }
5321
5322 static const struct seq_operations gpiolib_sops = {
5323 .start = gpiolib_seq_start,
5324 .next = gpiolib_seq_next,
5325 .stop = gpiolib_seq_stop,
5326 .show = gpiolib_seq_show,
5327 };
5328 DEFINE_SEQ_ATTRIBUTE(gpiolib);
5329
gpiolib_debugfs_init(void)5330 static int __init gpiolib_debugfs_init(void)
5331 {
5332 /* /sys/kernel/debug/gpio */
5333 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
5334 return 0;
5335 }
5336 subsys_initcall(gpiolib_debugfs_init);
5337
5338 #endif /* DEBUG_FS */
5339