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 /*
746 * hog pins are requested before registering GPIO chip
747 */
748 if (!gc->gpiodev)
749 return true;
750
751 /* No mask means all valid */
752 if (likely(!gc->gpiodev->valid_mask))
753 return true;
754 return test_bit(offset, gc->gpiodev->valid_mask);
755 }
756 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
757
gpiod_free_irqs(struct gpio_desc * desc)758 static void gpiod_free_irqs(struct gpio_desc *desc)
759 {
760 int irq = gpiod_to_irq(desc);
761 struct irq_desc *irqd = irq_to_desc(irq);
762 void *cookie;
763
764 for (;;) {
765 /*
766 * Make sure the action doesn't go away while we're
767 * dereferencing it. Retrieve and store the cookie value.
768 * If the irq is freed after we release the lock, that's
769 * alright - the underlying maple tree lookup will return NULL
770 * and nothing will happen in free_irq().
771 */
772 scoped_guard(mutex, &irqd->request_mutex) {
773 if (!irq_desc_has_action(irqd))
774 return;
775
776 cookie = irqd->action->dev_id;
777 }
778
779 free_irq(irq, cookie);
780 }
781 }
782
783 /*
784 * The chip is going away but there may be users who had requested interrupts
785 * on its GPIO lines who have no idea about its removal and have no way of
786 * being notified about it. We need to free any interrupts still in use here or
787 * we'll leak memory and resources (like procfs files).
788 */
gpiochip_free_remaining_irqs(struct gpio_chip * gc)789 static void gpiochip_free_remaining_irqs(struct gpio_chip *gc)
790 {
791 struct gpio_desc *desc;
792
793 for_each_gpio_desc_with_flag(gc, desc, FLAG_USED_AS_IRQ)
794 gpiod_free_irqs(desc);
795 }
796
gpiodev_release(struct device * dev)797 static void gpiodev_release(struct device *dev)
798 {
799 struct gpio_device *gdev = to_gpio_device(dev);
800
801 /* Call pending kfree()s for descriptor labels. */
802 synchronize_srcu(&gdev->desc_srcu);
803 cleanup_srcu_struct(&gdev->desc_srcu);
804
805 ida_free(&gpio_ida, gdev->id);
806 kfree_const(gdev->label);
807 kfree(gdev->descs);
808 cleanup_srcu_struct(&gdev->srcu);
809 kfree(gdev);
810 }
811
812 static const struct device_type gpio_dev_type = {
813 .name = "gpio_chip",
814 .release = gpiodev_release,
815 };
816
817 #ifdef CONFIG_GPIO_CDEV
818 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
819 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
820 #else
821 /*
822 * gpiolib_cdev_register() indirectly calls device_add(), which is still
823 * required even when cdev is not selected.
824 */
825 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
826 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
827 #endif
828
gpiochip_setup_dev(struct gpio_device * gdev)829 static int gpiochip_setup_dev(struct gpio_device *gdev)
830 {
831 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
832 int ret;
833
834 device_initialize(&gdev->dev);
835
836 /*
837 * If fwnode doesn't belong to another device, it's safe to clear its
838 * initialized flag.
839 */
840 if (fwnode && !fwnode->dev)
841 fwnode_dev_initialized(fwnode, false);
842
843 ret = gcdev_register(gdev, gpio_devt);
844 if (ret)
845 return ret;
846
847 ret = gpiochip_sysfs_register(gdev);
848 if (ret)
849 goto err_remove_device;
850
851 dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base,
852 gdev->base + gdev->ngpio - 1, gdev->label);
853
854 return 0;
855
856 err_remove_device:
857 gcdev_unregister(gdev);
858 return ret;
859 }
860
gpiochip_machine_hog(struct gpio_chip * gc,struct gpiod_hog * hog)861 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
862 {
863 struct gpio_desc *desc;
864 int rv;
865
866 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
867 if (IS_ERR(desc)) {
868 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
869 PTR_ERR(desc));
870 return;
871 }
872
873 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
874 if (rv)
875 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
876 __func__, gc->label, hog->chip_hwnum, rv);
877 }
878
machine_gpiochip_add(struct gpio_chip * gc)879 static void machine_gpiochip_add(struct gpio_chip *gc)
880 {
881 struct gpiod_hog *hog;
882
883 mutex_lock(&gpio_machine_hogs_mutex);
884
885 list_for_each_entry(hog, &gpio_machine_hogs, list) {
886 if (!strcmp(gc->label, hog->chip_label))
887 gpiochip_machine_hog(gc, hog);
888 }
889
890 mutex_unlock(&gpio_machine_hogs_mutex);
891 }
892
gpiochip_setup_devs(void)893 static void gpiochip_setup_devs(void)
894 {
895 struct gpio_device *gdev;
896 int ret;
897
898 guard(srcu)(&gpio_devices_srcu);
899
900 list_for_each_entry_srcu(gdev, &gpio_devices, list,
901 srcu_read_lock_held(&gpio_devices_srcu)) {
902 ret = gpiochip_setup_dev(gdev);
903 if (ret)
904 dev_err(&gdev->dev,
905 "Failed to initialize gpio device (%d)\n", ret);
906 }
907 }
908
gpiochip_set_data(struct gpio_chip * gc,void * data)909 static void gpiochip_set_data(struct gpio_chip *gc, void *data)
910 {
911 gc->gpiodev->data = data;
912 }
913
914 /**
915 * gpiochip_get_data() - get per-subdriver data for the chip
916 * @gc: GPIO chip
917 *
918 * Returns:
919 * The per-subdriver data for the chip.
920 */
gpiochip_get_data(struct gpio_chip * gc)921 void *gpiochip_get_data(struct gpio_chip *gc)
922 {
923 return gc->gpiodev->data;
924 }
925 EXPORT_SYMBOL_GPL(gpiochip_get_data);
926
927 /*
928 * If the calling driver provides the specific firmware node,
929 * use it. Otherwise use the one from the parent device, if any.
930 */
gpiochip_choose_fwnode(struct gpio_chip * gc)931 static struct fwnode_handle *gpiochip_choose_fwnode(struct gpio_chip *gc)
932 {
933 if (gc->fwnode)
934 return gc->fwnode;
935
936 if (gc->parent)
937 return dev_fwnode(gc->parent);
938
939 return NULL;
940 }
941
gpiochip_get_ngpios(struct gpio_chip * gc,struct device * dev)942 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
943 {
944 struct fwnode_handle *fwnode = gpiochip_choose_fwnode(gc);
945 u32 ngpios = gc->ngpio;
946 int ret;
947
948 if (ngpios == 0) {
949 ret = fwnode_property_read_u32(fwnode, "ngpios", &ngpios);
950 if (ret == -ENODATA)
951 /*
952 * -ENODATA means that there is no property found and
953 * we want to issue the error message to the user.
954 * Besides that, we want to return different error code
955 * to state that supplied value is not valid.
956 */
957 ngpios = 0;
958 else if (ret)
959 return ret;
960
961 gc->ngpio = ngpios;
962 }
963
964 if (gc->ngpio == 0) {
965 dev_err(dev, "tried to insert a GPIO chip with zero lines\n");
966 return -EINVAL;
967 }
968
969 if (gc->ngpio > FASTPATH_NGPIO)
970 dev_warn(dev, "line cnt %u is greater than fast path cnt %u\n",
971 gc->ngpio, FASTPATH_NGPIO);
972
973 return 0;
974 }
975 EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);
976
gpiochip_add_data_with_key(struct gpio_chip * gc,void * data,struct lock_class_key * lock_key,struct lock_class_key * request_key)977 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
978 struct lock_class_key *lock_key,
979 struct lock_class_key *request_key)
980 {
981 struct gpio_device *gdev;
982 unsigned int desc_index;
983 int base = 0;
984 int ret = 0;
985
986 /* Only allow one set() and one set_multiple(). */
987 if ((gc->set && gc->set_rv) ||
988 (gc->set_multiple && gc->set_multiple_rv))
989 return -EINVAL;
990
991 /*
992 * First: allocate and populate the internal stat container, and
993 * set up the struct device.
994 */
995 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
996 if (!gdev)
997 return -ENOMEM;
998
999 gdev->dev.type = &gpio_dev_type;
1000 gdev->dev.bus = &gpio_bus_type;
1001 gdev->dev.parent = gc->parent;
1002 rcu_assign_pointer(gdev->chip, gc);
1003
1004 gc->gpiodev = gdev;
1005 gpiochip_set_data(gc, data);
1006
1007 device_set_node(&gdev->dev, gpiochip_choose_fwnode(gc));
1008
1009 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
1010 if (gdev->id < 0) {
1011 ret = gdev->id;
1012 goto err_free_gdev;
1013 }
1014
1015 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
1016 if (ret)
1017 goto err_free_ida;
1018
1019 if (gc->parent && gc->parent->driver)
1020 gdev->owner = gc->parent->driver->owner;
1021 else if (gc->owner)
1022 /* TODO: remove chip->owner */
1023 gdev->owner = gc->owner;
1024 else
1025 gdev->owner = THIS_MODULE;
1026
1027 ret = gpiochip_get_ngpios(gc, &gdev->dev);
1028 if (ret)
1029 goto err_free_dev_name;
1030
1031 gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
1032 if (!gdev->descs) {
1033 ret = -ENOMEM;
1034 goto err_free_dev_name;
1035 }
1036
1037 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
1038 if (!gdev->label) {
1039 ret = -ENOMEM;
1040 goto err_free_descs;
1041 }
1042
1043 gdev->ngpio = gc->ngpio;
1044 gdev->can_sleep = gc->can_sleep;
1045
1046 scoped_guard(mutex, &gpio_devices_lock) {
1047 /*
1048 * TODO: this allocates a Linux GPIO number base in the global
1049 * GPIO numberspace for this chip. In the long run we want to
1050 * get *rid* of this numberspace and use only descriptors, but
1051 * it may be a pipe dream. It will not happen before we get rid
1052 * of the sysfs interface anyways.
1053 */
1054 base = gc->base;
1055 if (base < 0) {
1056 base = gpiochip_find_base_unlocked(gc->ngpio);
1057 if (base < 0) {
1058 ret = base;
1059 base = 0;
1060 goto err_free_label;
1061 }
1062
1063 /*
1064 * TODO: it should not be necessary to reflect the
1065 * assigned base outside of the GPIO subsystem. Go over
1066 * drivers and see if anyone makes use of this, else
1067 * drop this and assign a poison instead.
1068 */
1069 gc->base = base;
1070 } else {
1071 dev_warn(&gdev->dev,
1072 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
1073 }
1074
1075 gdev->base = base;
1076
1077 ret = gpiodev_add_to_list_unlocked(gdev);
1078 if (ret) {
1079 chip_err(gc, "GPIO integer space overlap, cannot add chip\n");
1080 goto err_free_label;
1081 }
1082 }
1083
1084 rwlock_init(&gdev->line_state_lock);
1085 RAW_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
1086 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
1087
1088 ret = init_srcu_struct(&gdev->srcu);
1089 if (ret)
1090 goto err_remove_from_list;
1091
1092 ret = init_srcu_struct(&gdev->desc_srcu);
1093 if (ret)
1094 goto err_cleanup_gdev_srcu;
1095
1096 #ifdef CONFIG_PINCTRL
1097 INIT_LIST_HEAD(&gdev->pin_ranges);
1098 #endif
1099
1100 if (gc->names)
1101 gpiochip_set_desc_names(gc);
1102
1103 ret = gpiochip_set_names(gc);
1104 if (ret)
1105 goto err_cleanup_desc_srcu;
1106
1107 ret = gpiochip_init_valid_mask(gc);
1108 if (ret)
1109 goto err_cleanup_desc_srcu;
1110
1111 for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
1112 struct gpio_desc *desc = &gdev->descs[desc_index];
1113
1114 desc->gdev = gdev;
1115
1116 /*
1117 * We would typically want to use gpiochip_get_direction() here
1118 * but we must not check the return value and bail-out as pin
1119 * controllers can have pins configured to alternate functions
1120 * and return -EINVAL. Also: there's no need to take the SRCU
1121 * lock here.
1122 */
1123 if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index))
1124 assign_bit(FLAG_IS_OUT, &desc->flags,
1125 !gc->get_direction(gc, desc_index));
1126 else
1127 assign_bit(FLAG_IS_OUT,
1128 &desc->flags, !gc->direction_input);
1129 }
1130
1131 ret = of_gpiochip_add(gc);
1132 if (ret)
1133 goto err_free_valid_mask;
1134
1135 ret = gpiochip_add_pin_ranges(gc);
1136 if (ret)
1137 goto err_remove_of_chip;
1138
1139 acpi_gpiochip_add(gc);
1140
1141 machine_gpiochip_add(gc);
1142
1143 ret = gpiochip_irqchip_init_valid_mask(gc);
1144 if (ret)
1145 goto err_free_hogs;
1146
1147 ret = gpiochip_irqchip_init_hw(gc);
1148 if (ret)
1149 goto err_remove_irqchip_mask;
1150
1151 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
1152 if (ret)
1153 goto err_remove_irqchip_mask;
1154
1155 /*
1156 * By first adding the chardev, and then adding the device,
1157 * we get a device node entry in sysfs under
1158 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1159 * coldplug of device nodes and other udev business.
1160 * We can do this only if gpiolib has been initialized.
1161 * Otherwise, defer until later.
1162 */
1163 if (gpiolib_initialized) {
1164 ret = gpiochip_setup_dev(gdev);
1165 if (ret)
1166 goto err_remove_irqchip;
1167 }
1168 return 0;
1169
1170 err_remove_irqchip:
1171 gpiochip_irqchip_remove(gc);
1172 err_remove_irqchip_mask:
1173 gpiochip_irqchip_free_valid_mask(gc);
1174 err_free_hogs:
1175 gpiochip_free_hogs(gc);
1176 acpi_gpiochip_remove(gc);
1177 gpiochip_remove_pin_ranges(gc);
1178 err_remove_of_chip:
1179 of_gpiochip_remove(gc);
1180 err_free_valid_mask:
1181 gpiochip_free_valid_mask(gc);
1182 err_cleanup_desc_srcu:
1183 cleanup_srcu_struct(&gdev->desc_srcu);
1184 err_cleanup_gdev_srcu:
1185 cleanup_srcu_struct(&gdev->srcu);
1186 err_remove_from_list:
1187 scoped_guard(mutex, &gpio_devices_lock)
1188 list_del_rcu(&gdev->list);
1189 synchronize_srcu(&gpio_devices_srcu);
1190 if (gdev->dev.release) {
1191 /* release() has been registered by gpiochip_setup_dev() */
1192 gpio_device_put(gdev);
1193 goto err_print_message;
1194 }
1195 err_free_label:
1196 kfree_const(gdev->label);
1197 err_free_descs:
1198 kfree(gdev->descs);
1199 err_free_dev_name:
1200 kfree(dev_name(&gdev->dev));
1201 err_free_ida:
1202 ida_free(&gpio_ida, gdev->id);
1203 err_free_gdev:
1204 kfree(gdev);
1205 err_print_message:
1206 /* failures here can mean systems won't boot... */
1207 if (ret != -EPROBE_DEFER) {
1208 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1209 base, base + (int)gc->ngpio - 1,
1210 gc->label ? : "generic", ret);
1211 }
1212 return ret;
1213 }
1214 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1215
1216 /**
1217 * gpiochip_remove() - unregister a gpio_chip
1218 * @gc: the chip to unregister
1219 *
1220 * A gpio_chip with any GPIOs still requested may not be removed.
1221 */
gpiochip_remove(struct gpio_chip * gc)1222 void gpiochip_remove(struct gpio_chip *gc)
1223 {
1224 struct gpio_device *gdev = gc->gpiodev;
1225
1226 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1227 gpiochip_sysfs_unregister(gdev);
1228 gpiochip_free_hogs(gc);
1229 gpiochip_free_remaining_irqs(gc);
1230
1231 scoped_guard(mutex, &gpio_devices_lock)
1232 list_del_rcu(&gdev->list);
1233 synchronize_srcu(&gpio_devices_srcu);
1234
1235 /* Numb the device, cancelling all outstanding operations */
1236 rcu_assign_pointer(gdev->chip, NULL);
1237 synchronize_srcu(&gdev->srcu);
1238 gpiochip_irqchip_remove(gc);
1239 acpi_gpiochip_remove(gc);
1240 of_gpiochip_remove(gc);
1241 gpiochip_remove_pin_ranges(gc);
1242 gpiochip_free_valid_mask(gc);
1243 /*
1244 * We accept no more calls into the driver from this point, so
1245 * NULL the driver data pointer.
1246 */
1247 gpiochip_set_data(gc, NULL);
1248
1249 /*
1250 * The gpiochip side puts its use of the device to rest here:
1251 * if there are no userspace clients, the chardev and device will
1252 * be removed, else it will be dangling until the last user is
1253 * gone.
1254 */
1255 gcdev_unregister(gdev);
1256 gpio_device_put(gdev);
1257 }
1258 EXPORT_SYMBOL_GPL(gpiochip_remove);
1259
1260 /**
1261 * gpio_device_find() - find a specific GPIO device
1262 * @data: data to pass to match function
1263 * @match: Callback function to check gpio_chip
1264 *
1265 * Returns:
1266 * New reference to struct gpio_device.
1267 *
1268 * Similar to bus_find_device(). It returns a reference to a gpio_device as
1269 * determined by a user supplied @match callback. The callback should return
1270 * 0 if the device doesn't match and non-zero if it does. If the callback
1271 * returns non-zero, this function will return to the caller and not iterate
1272 * over any more gpio_devices.
1273 *
1274 * The callback takes the GPIO chip structure as argument. During the execution
1275 * of the callback function the chip is protected from being freed. TODO: This
1276 * actually has yet to be implemented.
1277 *
1278 * If the function returns non-NULL, the returned reference must be freed by
1279 * the caller using gpio_device_put().
1280 */
gpio_device_find(const void * data,int (* match)(struct gpio_chip * gc,const void * data))1281 struct gpio_device *gpio_device_find(const void *data,
1282 int (*match)(struct gpio_chip *gc,
1283 const void *data))
1284 {
1285 struct gpio_device *gdev;
1286 struct gpio_chip *gc;
1287
1288 might_sleep();
1289
1290 guard(srcu)(&gpio_devices_srcu);
1291
1292 list_for_each_entry_srcu(gdev, &gpio_devices, list,
1293 srcu_read_lock_held(&gpio_devices_srcu)) {
1294 if (!device_is_registered(&gdev->dev))
1295 continue;
1296
1297 guard(srcu)(&gdev->srcu);
1298
1299 gc = srcu_dereference(gdev->chip, &gdev->srcu);
1300
1301 if (gc && match(gc, data))
1302 return gpio_device_get(gdev);
1303 }
1304
1305 return NULL;
1306 }
1307 EXPORT_SYMBOL_GPL(gpio_device_find);
1308
gpio_chip_match_by_label(struct gpio_chip * gc,const void * label)1309 static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)
1310 {
1311 return gc->label && !strcmp(gc->label, label);
1312 }
1313
1314 /**
1315 * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the
1316 * GPIO device by its backing chip's label
1317 * @label: Label to lookup
1318 *
1319 * Returns:
1320 * Reference to the GPIO device or NULL. Reference must be released with
1321 * gpio_device_put().
1322 */
gpio_device_find_by_label(const char * label)1323 struct gpio_device *gpio_device_find_by_label(const char *label)
1324 {
1325 return gpio_device_find((void *)label, gpio_chip_match_by_label);
1326 }
1327 EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
1328
gpio_chip_match_by_fwnode(struct gpio_chip * gc,const void * fwnode)1329 static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)
1330 {
1331 return device_match_fwnode(&gc->gpiodev->dev, fwnode);
1332 }
1333
1334 /**
1335 * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
1336 * the GPIO device by its fwnode
1337 * @fwnode: Firmware node to lookup
1338 *
1339 * Returns:
1340 * Reference to the GPIO device or NULL. Reference must be released with
1341 * gpio_device_put().
1342 */
gpio_device_find_by_fwnode(const struct fwnode_handle * fwnode)1343 struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
1344 {
1345 return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
1346 }
1347 EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
1348
1349 /**
1350 * gpio_device_get() - Increase the reference count of this GPIO device
1351 * @gdev: GPIO device to increase the refcount for
1352 *
1353 * Returns:
1354 * Pointer to @gdev.
1355 */
gpio_device_get(struct gpio_device * gdev)1356 struct gpio_device *gpio_device_get(struct gpio_device *gdev)
1357 {
1358 return to_gpio_device(get_device(&gdev->dev));
1359 }
1360 EXPORT_SYMBOL_GPL(gpio_device_get);
1361
1362 /**
1363 * gpio_device_put() - Decrease the reference count of this GPIO device and
1364 * possibly free all resources associated with it.
1365 * @gdev: GPIO device to decrease the reference count for
1366 */
gpio_device_put(struct gpio_device * gdev)1367 void gpio_device_put(struct gpio_device *gdev)
1368 {
1369 put_device(&gdev->dev);
1370 }
1371 EXPORT_SYMBOL_GPL(gpio_device_put);
1372
1373 /**
1374 * gpio_device_to_device() - Retrieve the address of the underlying struct
1375 * device.
1376 * @gdev: GPIO device for which to return the address.
1377 *
1378 * This does not increase the reference count of the GPIO device nor the
1379 * underlying struct device.
1380 *
1381 * Returns:
1382 * Address of struct device backing this GPIO device.
1383 */
gpio_device_to_device(struct gpio_device * gdev)1384 struct device *gpio_device_to_device(struct gpio_device *gdev)
1385 {
1386 return &gdev->dev;
1387 }
1388 EXPORT_SYMBOL_GPL(gpio_device_to_device);
1389
1390 #ifdef CONFIG_GPIOLIB_IRQCHIP
1391
1392 /*
1393 * The following is irqchip helper code for gpiochips.
1394 */
1395
gpiochip_irqchip_init_hw(struct gpio_chip * gc)1396 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1397 {
1398 struct gpio_irq_chip *girq = &gc->irq;
1399
1400 if (!girq->init_hw)
1401 return 0;
1402
1403 return girq->init_hw(gc);
1404 }
1405
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)1406 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1407 {
1408 struct gpio_irq_chip *girq = &gc->irq;
1409
1410 if (!girq->init_valid_mask)
1411 return 0;
1412
1413 girq->valid_mask = gpiochip_allocate_mask(gc);
1414 if (!girq->valid_mask)
1415 return -ENOMEM;
1416
1417 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1418
1419 return 0;
1420 }
1421
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)1422 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1423 {
1424 gpiochip_free_mask(&gc->irq.valid_mask);
1425 }
1426
gpiochip_irqchip_irq_valid(const struct gpio_chip * gc,unsigned int offset)1427 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
1428 unsigned int offset)
1429 {
1430 if (!gpiochip_line_is_valid(gc, offset))
1431 return false;
1432 /* No mask means all valid */
1433 if (likely(!gc->irq.valid_mask))
1434 return true;
1435 return test_bit(offset, gc->irq.valid_mask);
1436 }
1437
1438 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1439
1440 /**
1441 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1442 * to a gpiochip
1443 * @gc: the gpiochip to set the irqchip hierarchical handler to
1444 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1445 * will then percolate up to the parent
1446 */
gpiochip_set_hierarchical_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip)1447 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1448 struct irq_chip *irqchip)
1449 {
1450 /* DT will deal with mapping each IRQ as we go along */
1451 if (is_of_node(gc->irq.fwnode))
1452 return;
1453
1454 /*
1455 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1456 * irqs upfront instead of dynamically since we don't have the
1457 * dynamic type of allocation that hardware description languages
1458 * provide. Once all GPIO drivers using board files are gone from
1459 * the kernel we can delete this code, but for a transitional period
1460 * it is necessary to keep this around.
1461 */
1462 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1463 int i;
1464 int ret;
1465
1466 for (i = 0; i < gc->ngpio; i++) {
1467 struct irq_fwspec fwspec;
1468 unsigned int parent_hwirq;
1469 unsigned int parent_type;
1470 struct gpio_irq_chip *girq = &gc->irq;
1471
1472 /*
1473 * We call the child to parent translation function
1474 * only to check if the child IRQ is valid or not.
1475 * Just pick the rising edge type here as that is what
1476 * we likely need to support.
1477 */
1478 ret = girq->child_to_parent_hwirq(gc, i,
1479 IRQ_TYPE_EDGE_RISING,
1480 &parent_hwirq,
1481 &parent_type);
1482 if (ret) {
1483 chip_err(gc, "skip set-up on hwirq %d\n",
1484 i);
1485 continue;
1486 }
1487
1488 fwspec.fwnode = gc->irq.fwnode;
1489 /* This is the hwirq for the GPIO line side of things */
1490 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1491 /* Just pick something */
1492 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1493 fwspec.param_count = 2;
1494 ret = irq_domain_alloc_irqs(gc->irq.domain, 1,
1495 NUMA_NO_NODE, &fwspec);
1496 if (ret < 0) {
1497 chip_err(gc,
1498 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1499 i, parent_hwirq,
1500 ret);
1501 }
1502 }
1503 }
1504
1505 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1506
1507 return;
1508 }
1509
gpiochip_hierarchy_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1510 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1511 struct irq_fwspec *fwspec,
1512 unsigned long *hwirq,
1513 unsigned int *type)
1514 {
1515 /* We support standard DT translation */
1516 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1517 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1518 }
1519
1520 /* This is for board files and others not using DT */
1521 if (is_fwnode_irqchip(fwspec->fwnode)) {
1522 int ret;
1523
1524 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1525 if (ret)
1526 return ret;
1527 WARN_ON(*type == IRQ_TYPE_NONE);
1528 return 0;
1529 }
1530 return -EINVAL;
1531 }
1532
gpiochip_hierarchy_irq_domain_alloc(struct irq_domain * d,unsigned int irq,unsigned int nr_irqs,void * data)1533 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1534 unsigned int irq,
1535 unsigned int nr_irqs,
1536 void *data)
1537 {
1538 struct gpio_chip *gc = d->host_data;
1539 irq_hw_number_t hwirq;
1540 unsigned int type = IRQ_TYPE_NONE;
1541 struct irq_fwspec *fwspec = data;
1542 union gpio_irq_fwspec gpio_parent_fwspec = {};
1543 unsigned int parent_hwirq;
1544 unsigned int parent_type;
1545 struct gpio_irq_chip *girq = &gc->irq;
1546 int ret;
1547
1548 /*
1549 * The nr_irqs parameter is always one except for PCI multi-MSI
1550 * so this should not happen.
1551 */
1552 WARN_ON(nr_irqs != 1);
1553
1554 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1555 if (ret)
1556 return ret;
1557
1558 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1559
1560 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1561 &parent_hwirq, &parent_type);
1562 if (ret) {
1563 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1564 return ret;
1565 }
1566 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1567
1568 /*
1569 * We set handle_bad_irq because the .set_type() should
1570 * always be invoked and set the right type of handler.
1571 */
1572 irq_domain_set_info(d,
1573 irq,
1574 hwirq,
1575 gc->irq.chip,
1576 gc,
1577 girq->handler,
1578 NULL, NULL);
1579 irq_set_probe(irq);
1580
1581 /* This parent only handles asserted level IRQs */
1582 ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,
1583 parent_hwirq, parent_type);
1584 if (ret)
1585 return ret;
1586
1587 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1588 irq, parent_hwirq);
1589 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1590 ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);
1591 /*
1592 * If the parent irqdomain is msi, the interrupts have already
1593 * been allocated, so the EEXIST is good.
1594 */
1595 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1596 ret = 0;
1597 if (ret)
1598 chip_err(gc,
1599 "failed to allocate parent hwirq %d for hwirq %lu\n",
1600 parent_hwirq, hwirq);
1601
1602 return ret;
1603 }
1604
gpiochip_child_offset_to_irq_noop(struct gpio_chip * gc,unsigned int offset)1605 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1606 unsigned int offset)
1607 {
1608 return offset;
1609 }
1610
1611 /**
1612 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1613 * @domain: The IRQ domain used by this IRQ chip
1614 * @data: Outermost irq_data associated with the IRQ
1615 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1616 *
1617 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1618 * used as the activate function for the &struct irq_domain_ops. The host_data
1619 * for the IRQ domain must be the &struct gpio_chip.
1620 *
1621 * Returns:
1622 * 0 on success, or negative errno on failure.
1623 */
gpiochip_irq_domain_activate(struct irq_domain * domain,struct irq_data * data,bool reserve)1624 static int gpiochip_irq_domain_activate(struct irq_domain *domain,
1625 struct irq_data *data, bool reserve)
1626 {
1627 struct gpio_chip *gc = domain->host_data;
1628 unsigned int hwirq = irqd_to_hwirq(data);
1629
1630 return gpiochip_lock_as_irq(gc, hwirq);
1631 }
1632
1633 /**
1634 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1635 * @domain: The IRQ domain used by this IRQ chip
1636 * @data: Outermost irq_data associated with the IRQ
1637 *
1638 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1639 * be used as the deactivate function for the &struct irq_domain_ops. The
1640 * host_data for the IRQ domain must be the &struct gpio_chip.
1641 */
gpiochip_irq_domain_deactivate(struct irq_domain * domain,struct irq_data * data)1642 static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1643 struct irq_data *data)
1644 {
1645 struct gpio_chip *gc = domain->host_data;
1646 unsigned int hwirq = irqd_to_hwirq(data);
1647
1648 return gpiochip_unlock_as_irq(gc, hwirq);
1649 }
1650
gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops * ops)1651 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1652 {
1653 ops->activate = gpiochip_irq_domain_activate;
1654 ops->deactivate = gpiochip_irq_domain_deactivate;
1655 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1656
1657 /*
1658 * We only allow overriding the translate() and free() functions for
1659 * hierarchical chips, and this should only be done if the user
1660 * really need something other than 1:1 translation for translate()
1661 * callback and free if user wants to free up any resources which
1662 * were allocated during callbacks, for example populate_parent_alloc_arg.
1663 */
1664 if (!ops->translate)
1665 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1666 if (!ops->free)
1667 ops->free = irq_domain_free_irqs_common;
1668 }
1669
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1670 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1671 {
1672 struct irq_domain *domain;
1673
1674 if (!gc->irq.child_to_parent_hwirq ||
1675 !gc->irq.fwnode) {
1676 chip_err(gc, "missing irqdomain vital data\n");
1677 return ERR_PTR(-EINVAL);
1678 }
1679
1680 if (!gc->irq.child_offset_to_irq)
1681 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1682
1683 if (!gc->irq.populate_parent_alloc_arg)
1684 gc->irq.populate_parent_alloc_arg =
1685 gpiochip_populate_parent_fwspec_twocell;
1686
1687 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1688
1689 domain = irq_domain_create_hierarchy(
1690 gc->irq.parent_domain,
1691 0,
1692 gc->ngpio,
1693 gc->irq.fwnode,
1694 &gc->irq.child_irq_domain_ops,
1695 gc);
1696
1697 if (!domain)
1698 return ERR_PTR(-ENOMEM);
1699
1700 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1701
1702 return domain;
1703 }
1704
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1705 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1706 {
1707 return !!gc->irq.parent_domain;
1708 }
1709
gpiochip_populate_parent_fwspec_twocell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1710 int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1711 union gpio_irq_fwspec *gfwspec,
1712 unsigned int parent_hwirq,
1713 unsigned int parent_type)
1714 {
1715 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1716
1717 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1718 fwspec->param_count = 2;
1719 fwspec->param[0] = parent_hwirq;
1720 fwspec->param[1] = parent_type;
1721
1722 return 0;
1723 }
1724 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1725
gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1726 int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1727 union gpio_irq_fwspec *gfwspec,
1728 unsigned int parent_hwirq,
1729 unsigned int parent_type)
1730 {
1731 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1732
1733 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1734 fwspec->param_count = 4;
1735 fwspec->param[0] = 0;
1736 fwspec->param[1] = parent_hwirq;
1737 fwspec->param[2] = 0;
1738 fwspec->param[3] = parent_type;
1739
1740 return 0;
1741 }
1742 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1743
1744 #else
1745
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1746 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1747 {
1748 return ERR_PTR(-EINVAL);
1749 }
1750
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1751 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1752 {
1753 return false;
1754 }
1755
1756 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1757
1758 /**
1759 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1760 * @d: the irqdomain used by this irqchip
1761 * @irq: the global irq number used by this GPIO irqchip irq
1762 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1763 *
1764 * This function will set up the mapping for a certain IRQ line on a
1765 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1766 * stored inside the gpiochip.
1767 *
1768 * Returns:
1769 * 0 on success, or negative errno on failure.
1770 */
gpiochip_irq_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)1771 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1772 irq_hw_number_t hwirq)
1773 {
1774 struct gpio_chip *gc = d->host_data;
1775 int ret = 0;
1776
1777 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1778 return -ENXIO;
1779
1780 irq_set_chip_data(irq, gc);
1781 /*
1782 * This lock class tells lockdep that GPIO irqs are in a different
1783 * category than their parents, so it won't report false recursion.
1784 */
1785 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1786 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1787 /* Chips that use nested thread handlers have them marked */
1788 if (gc->irq.threaded)
1789 irq_set_nested_thread(irq, 1);
1790 irq_set_noprobe(irq);
1791
1792 if (gc->irq.num_parents == 1)
1793 ret = irq_set_parent(irq, gc->irq.parents[0]);
1794 else if (gc->irq.map)
1795 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1796
1797 if (ret < 0)
1798 return ret;
1799
1800 /*
1801 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1802 * is passed as default type.
1803 */
1804 if (gc->irq.default_type != IRQ_TYPE_NONE)
1805 irq_set_irq_type(irq, gc->irq.default_type);
1806
1807 return 0;
1808 }
1809
gpiochip_irq_unmap(struct irq_domain * d,unsigned int irq)1810 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1811 {
1812 struct gpio_chip *gc = d->host_data;
1813
1814 if (gc->irq.threaded)
1815 irq_set_nested_thread(irq, 0);
1816 irq_set_chip_and_handler(irq, NULL, NULL);
1817 irq_set_chip_data(irq, NULL);
1818 }
1819
1820 static const struct irq_domain_ops gpiochip_domain_ops = {
1821 .map = gpiochip_irq_map,
1822 .unmap = gpiochip_irq_unmap,
1823 /* Virtually all GPIO irqchips are twocell:ed */
1824 .xlate = irq_domain_xlate_twocell,
1825 };
1826
gpiochip_simple_create_domain(struct gpio_chip * gc)1827 static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
1828 {
1829 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1830 struct irq_domain *domain;
1831
1832 domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,
1833 &gpiochip_domain_ops, gc);
1834 if (!domain)
1835 return ERR_PTR(-EINVAL);
1836
1837 return domain;
1838 }
1839
gpiochip_to_irq(struct gpio_chip * gc,unsigned int offset)1840 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1841 {
1842 struct irq_domain *domain = gc->irq.domain;
1843
1844 #ifdef CONFIG_GPIOLIB_IRQCHIP
1845 /*
1846 * Avoid race condition with other code, which tries to lookup
1847 * an IRQ before the irqchip has been properly registered,
1848 * i.e. while gpiochip is still being brought up.
1849 */
1850 if (!gc->irq.initialized)
1851 return -EPROBE_DEFER;
1852 #endif
1853
1854 if (!gpiochip_irqchip_irq_valid(gc, offset))
1855 return -ENXIO;
1856
1857 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1858 if (irq_domain_is_hierarchy(domain)) {
1859 struct irq_fwspec spec;
1860
1861 spec.fwnode = domain->fwnode;
1862 spec.param_count = 2;
1863 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1864 spec.param[1] = IRQ_TYPE_NONE;
1865
1866 return irq_create_fwspec_mapping(&spec);
1867 }
1868 #endif
1869
1870 return irq_create_mapping(domain, offset);
1871 }
1872
gpiochip_irq_reqres(struct irq_data * d)1873 int gpiochip_irq_reqres(struct irq_data *d)
1874 {
1875 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1876 unsigned int hwirq = irqd_to_hwirq(d);
1877
1878 return gpiochip_reqres_irq(gc, hwirq);
1879 }
1880 EXPORT_SYMBOL(gpiochip_irq_reqres);
1881
gpiochip_irq_relres(struct irq_data * d)1882 void gpiochip_irq_relres(struct irq_data *d)
1883 {
1884 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1885 unsigned int hwirq = irqd_to_hwirq(d);
1886
1887 gpiochip_relres_irq(gc, hwirq);
1888 }
1889 EXPORT_SYMBOL(gpiochip_irq_relres);
1890
gpiochip_irq_mask(struct irq_data * d)1891 static void gpiochip_irq_mask(struct irq_data *d)
1892 {
1893 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1894 unsigned int hwirq = irqd_to_hwirq(d);
1895
1896 if (gc->irq.irq_mask)
1897 gc->irq.irq_mask(d);
1898 gpiochip_disable_irq(gc, hwirq);
1899 }
1900
gpiochip_irq_unmask(struct irq_data * d)1901 static void gpiochip_irq_unmask(struct irq_data *d)
1902 {
1903 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1904 unsigned int hwirq = irqd_to_hwirq(d);
1905
1906 gpiochip_enable_irq(gc, hwirq);
1907 if (gc->irq.irq_unmask)
1908 gc->irq.irq_unmask(d);
1909 }
1910
gpiochip_irq_enable(struct irq_data * d)1911 static void gpiochip_irq_enable(struct irq_data *d)
1912 {
1913 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1914 unsigned int hwirq = irqd_to_hwirq(d);
1915
1916 gpiochip_enable_irq(gc, hwirq);
1917 gc->irq.irq_enable(d);
1918 }
1919
gpiochip_irq_disable(struct irq_data * d)1920 static void gpiochip_irq_disable(struct irq_data *d)
1921 {
1922 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1923 unsigned int hwirq = irqd_to_hwirq(d);
1924
1925 gc->irq.irq_disable(d);
1926 gpiochip_disable_irq(gc, hwirq);
1927 }
1928
gpiochip_set_irq_hooks(struct gpio_chip * gc)1929 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1930 {
1931 struct irq_chip *irqchip = gc->irq.chip;
1932
1933 if (irqchip->flags & IRQCHIP_IMMUTABLE)
1934 return;
1935
1936 chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
1937
1938 if (!irqchip->irq_request_resources &&
1939 !irqchip->irq_release_resources) {
1940 irqchip->irq_request_resources = gpiochip_irq_reqres;
1941 irqchip->irq_release_resources = gpiochip_irq_relres;
1942 }
1943 if (WARN_ON(gc->irq.irq_enable))
1944 return;
1945 /* Check if the irqchip already has this hook... */
1946 if (irqchip->irq_enable == gpiochip_irq_enable ||
1947 irqchip->irq_mask == gpiochip_irq_mask) {
1948 /*
1949 * ...and if so, give a gentle warning that this is bad
1950 * practice.
1951 */
1952 chip_info(gc,
1953 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1954 return;
1955 }
1956
1957 if (irqchip->irq_disable) {
1958 gc->irq.irq_disable = irqchip->irq_disable;
1959 irqchip->irq_disable = gpiochip_irq_disable;
1960 } else {
1961 gc->irq.irq_mask = irqchip->irq_mask;
1962 irqchip->irq_mask = gpiochip_irq_mask;
1963 }
1964
1965 if (irqchip->irq_enable) {
1966 gc->irq.irq_enable = irqchip->irq_enable;
1967 irqchip->irq_enable = gpiochip_irq_enable;
1968 } else {
1969 gc->irq.irq_unmask = irqchip->irq_unmask;
1970 irqchip->irq_unmask = gpiochip_irq_unmask;
1971 }
1972 }
1973
gpiochip_irqchip_add_allocated_domain(struct gpio_chip * gc,struct irq_domain * domain,bool allocated_externally)1974 static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
1975 struct irq_domain *domain,
1976 bool allocated_externally)
1977 {
1978 if (!domain)
1979 return -EINVAL;
1980
1981 if (gc->to_irq)
1982 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1983
1984 gc->to_irq = gpiochip_to_irq;
1985 gc->irq.domain = domain;
1986 gc->irq.domain_is_allocated_externally = allocated_externally;
1987
1988 /*
1989 * Using barrier() here to prevent compiler from reordering
1990 * gc->irq.initialized before adding irqdomain.
1991 */
1992 barrier();
1993
1994 gc->irq.initialized = true;
1995
1996 return 0;
1997 }
1998
1999 /**
2000 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
2001 * @gc: the GPIO chip to add the IRQ chip to
2002 * @lock_key: lockdep class for IRQ lock
2003 * @request_key: lockdep class for IRQ request
2004 *
2005 * Returns:
2006 * 0 on success, or a negative errno on failure.
2007 */
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)2008 static int gpiochip_add_irqchip(struct gpio_chip *gc,
2009 struct lock_class_key *lock_key,
2010 struct lock_class_key *request_key)
2011 {
2012 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
2013 struct irq_chip *irqchip = gc->irq.chip;
2014 struct irq_domain *domain;
2015 unsigned int type;
2016 unsigned int i;
2017 int ret;
2018
2019 if (!irqchip)
2020 return 0;
2021
2022 if (gc->irq.parent_handler && gc->can_sleep) {
2023 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
2024 return -EINVAL;
2025 }
2026
2027 type = gc->irq.default_type;
2028
2029 /*
2030 * Specifying a default trigger is a terrible idea if DT or ACPI is
2031 * used to configure the interrupts, as you may end up with
2032 * conflicting triggers. Tell the user, and reset to NONE.
2033 */
2034 if (WARN(fwnode && type != IRQ_TYPE_NONE,
2035 "%pfw: Ignoring %u default trigger\n", fwnode, type))
2036 type = IRQ_TYPE_NONE;
2037
2038 gc->irq.default_type = type;
2039 gc->irq.lock_key = lock_key;
2040 gc->irq.request_key = request_key;
2041
2042 /* If a parent irqdomain is provided, let's build a hierarchy */
2043 if (gpiochip_hierarchy_is_hierarchical(gc)) {
2044 domain = gpiochip_hierarchy_create_domain(gc);
2045 } else {
2046 domain = gpiochip_simple_create_domain(gc);
2047 }
2048 if (IS_ERR(domain))
2049 return PTR_ERR(domain);
2050
2051 if (gc->irq.parent_handler) {
2052 for (i = 0; i < gc->irq.num_parents; i++) {
2053 void *data;
2054
2055 if (gc->irq.per_parent_data)
2056 data = gc->irq.parent_handler_data_array[i];
2057 else
2058 data = gc->irq.parent_handler_data ?: gc;
2059
2060 /*
2061 * The parent IRQ chip is already using the chip_data
2062 * for this IRQ chip, so our callbacks simply use the
2063 * handler_data.
2064 */
2065 irq_set_chained_handler_and_data(gc->irq.parents[i],
2066 gc->irq.parent_handler,
2067 data);
2068 }
2069 }
2070
2071 gpiochip_set_irq_hooks(gc);
2072
2073 ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);
2074 if (ret)
2075 return ret;
2076
2077 acpi_gpiochip_request_interrupts(gc);
2078
2079 return 0;
2080 }
2081
2082 /**
2083 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
2084 * @gc: the gpiochip to remove the irqchip from
2085 *
2086 * This is called only from gpiochip_remove()
2087 */
gpiochip_irqchip_remove(struct gpio_chip * gc)2088 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
2089 {
2090 struct irq_chip *irqchip = gc->irq.chip;
2091 unsigned int offset;
2092
2093 acpi_gpiochip_free_interrupts(gc);
2094
2095 if (irqchip && gc->irq.parent_handler) {
2096 struct gpio_irq_chip *irq = &gc->irq;
2097 unsigned int i;
2098
2099 for (i = 0; i < irq->num_parents; i++)
2100 irq_set_chained_handler_and_data(irq->parents[i],
2101 NULL, NULL);
2102 }
2103
2104 /* Remove all IRQ mappings and delete the domain */
2105 if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
2106 unsigned int irq;
2107
2108 for (offset = 0; offset < gc->ngpio; offset++) {
2109 if (!gpiochip_irqchip_irq_valid(gc, offset))
2110 continue;
2111
2112 irq = irq_find_mapping(gc->irq.domain, offset);
2113 irq_dispose_mapping(irq);
2114 }
2115
2116 irq_domain_remove(gc->irq.domain);
2117 }
2118
2119 if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
2120 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2121 irqchip->irq_request_resources = NULL;
2122 irqchip->irq_release_resources = NULL;
2123 }
2124 if (irqchip->irq_enable == gpiochip_irq_enable) {
2125 irqchip->irq_enable = gc->irq.irq_enable;
2126 irqchip->irq_disable = gc->irq.irq_disable;
2127 }
2128 }
2129 gc->irq.irq_enable = NULL;
2130 gc->irq.irq_disable = NULL;
2131 gc->irq.chip = NULL;
2132
2133 gpiochip_irqchip_free_valid_mask(gc);
2134 }
2135
2136 /**
2137 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
2138 * @gc: the gpiochip to add the irqchip to
2139 * @domain: the irqdomain to add to the gpiochip
2140 *
2141 * This function adds an IRQ domain to the gpiochip.
2142 *
2143 * Returns:
2144 * 0 on success, or negative errno on failure.
2145 */
gpiochip_irqchip_add_domain(struct gpio_chip * gc,struct irq_domain * domain)2146 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
2147 struct irq_domain *domain)
2148 {
2149 return gpiochip_irqchip_add_allocated_domain(gc, domain, true);
2150 }
2151 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
2152
2153 #else /* CONFIG_GPIOLIB_IRQCHIP */
2154
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)2155 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
2156 struct lock_class_key *lock_key,
2157 struct lock_class_key *request_key)
2158 {
2159 return 0;
2160 }
gpiochip_irqchip_remove(struct gpio_chip * gc)2161 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
2162
gpiochip_irqchip_init_hw(struct gpio_chip * gc)2163 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
2164 {
2165 return 0;
2166 }
2167
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)2168 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
2169 {
2170 return 0;
2171 }
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)2172 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
2173 { }
2174
2175 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2176
2177 /**
2178 * gpiochip_generic_request() - request the gpio function for a pin
2179 * @gc: the gpiochip owning the GPIO
2180 * @offset: the offset of the GPIO to request for GPIO function
2181 *
2182 * Returns:
2183 * 0 on success, or negative errno on failure.
2184 */
gpiochip_generic_request(struct gpio_chip * gc,unsigned int offset)2185 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
2186 {
2187 #ifdef CONFIG_PINCTRL
2188 if (list_empty(&gc->gpiodev->pin_ranges))
2189 return 0;
2190 #endif
2191
2192 return pinctrl_gpio_request(gc, offset);
2193 }
2194 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2195
2196 /**
2197 * gpiochip_generic_free() - free the gpio function from a pin
2198 * @gc: the gpiochip to request the gpio function for
2199 * @offset: the offset of the GPIO to free from GPIO function
2200 */
gpiochip_generic_free(struct gpio_chip * gc,unsigned int offset)2201 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
2202 {
2203 #ifdef CONFIG_PINCTRL
2204 if (list_empty(&gc->gpiodev->pin_ranges))
2205 return;
2206 #endif
2207
2208 pinctrl_gpio_free(gc, offset);
2209 }
2210 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2211
2212 /**
2213 * gpiochip_generic_config() - apply configuration for a pin
2214 * @gc: the gpiochip owning the GPIO
2215 * @offset: the offset of the GPIO to apply the configuration
2216 * @config: the configuration to be applied
2217 *
2218 * Returns:
2219 * 0 on success, or negative errno on failure.
2220 */
gpiochip_generic_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2221 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
2222 unsigned long config)
2223 {
2224 #ifdef CONFIG_PINCTRL
2225 if (list_empty(&gc->gpiodev->pin_ranges))
2226 return -ENOTSUPP;
2227 #endif
2228
2229 return pinctrl_gpio_set_config(gc, offset, config);
2230 }
2231 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2232
2233 #ifdef CONFIG_PINCTRL
2234
2235 /**
2236 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2237 * @gc: the gpiochip to add the range for
2238 * @pctldev: the pin controller to map to
2239 * @gpio_offset: the start offset in the current gpio_chip number space
2240 * @pin_group: name of the pin group inside the pin controller
2241 *
2242 * Calling this function directly from a DeviceTree-supported
2243 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2244 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2245 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2246 *
2247 * Returns:
2248 * 0 on success, or negative errno on failure.
2249 */
gpiochip_add_pingroup_range(struct gpio_chip * gc,struct pinctrl_dev * pctldev,unsigned int gpio_offset,const char * pin_group)2250 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
2251 struct pinctrl_dev *pctldev,
2252 unsigned int gpio_offset, const char *pin_group)
2253 {
2254 struct gpio_pin_range *pin_range;
2255 struct gpio_device *gdev = gc->gpiodev;
2256 int ret;
2257
2258 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2259 if (!pin_range) {
2260 chip_err(gc, "failed to allocate pin ranges\n");
2261 return -ENOMEM;
2262 }
2263
2264 /* Use local offset as range ID */
2265 pin_range->range.id = gpio_offset;
2266 pin_range->range.gc = gc;
2267 pin_range->range.name = gc->label;
2268 pin_range->range.base = gdev->base + gpio_offset;
2269 pin_range->pctldev = pctldev;
2270
2271 ret = pinctrl_get_group_pins(pctldev, pin_group,
2272 &pin_range->range.pins,
2273 &pin_range->range.npins);
2274 if (ret < 0) {
2275 kfree(pin_range);
2276 return ret;
2277 }
2278
2279 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2280
2281 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2282 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2283 pinctrl_dev_get_devname(pctldev), pin_group);
2284
2285 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2286
2287 return 0;
2288 }
2289 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2290
2291 /**
2292 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2293 * @gc: the gpiochip to add the range for
2294 * @pinctl_name: the dev_name() of the pin controller to map to
2295 * @gpio_offset: the start offset in the current gpio_chip number space
2296 * @pin_offset: the start offset in the pin controller number space
2297 * @npins: the number of pins from the offset of each pin space (GPIO and
2298 * pin controller) to accumulate in this range
2299 *
2300 * Calling this function directly from a DeviceTree-supported
2301 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2302 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2303 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2304 *
2305 * Returns:
2306 * 0 on success, or a negative errno on failure.
2307 */
gpiochip_add_pin_range(struct gpio_chip * gc,const char * pinctl_name,unsigned int gpio_offset,unsigned int pin_offset,unsigned int npins)2308 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
2309 unsigned int gpio_offset, unsigned int pin_offset,
2310 unsigned int npins)
2311 {
2312 struct gpio_pin_range *pin_range;
2313 struct gpio_device *gdev = gc->gpiodev;
2314 int ret;
2315
2316 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2317 if (!pin_range) {
2318 chip_err(gc, "failed to allocate pin ranges\n");
2319 return -ENOMEM;
2320 }
2321
2322 /* Use local offset as range ID */
2323 pin_range->range.id = gpio_offset;
2324 pin_range->range.gc = gc;
2325 pin_range->range.name = gc->label;
2326 pin_range->range.base = gdev->base + gpio_offset;
2327 pin_range->range.pin_base = pin_offset;
2328 pin_range->range.npins = npins;
2329 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2330 &pin_range->range);
2331 if (IS_ERR(pin_range->pctldev)) {
2332 ret = PTR_ERR(pin_range->pctldev);
2333 chip_err(gc, "could not create pin range\n");
2334 kfree(pin_range);
2335 return ret;
2336 }
2337 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2338 gpio_offset, gpio_offset + npins - 1,
2339 pinctl_name,
2340 pin_offset, pin_offset + npins - 1);
2341
2342 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2343
2344 return 0;
2345 }
2346 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2347
2348 /**
2349 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2350 * @gc: the chip to remove all the mappings for
2351 */
gpiochip_remove_pin_ranges(struct gpio_chip * gc)2352 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
2353 {
2354 struct gpio_pin_range *pin_range, *tmp;
2355 struct gpio_device *gdev = gc->gpiodev;
2356
2357 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2358 list_del(&pin_range->node);
2359 pinctrl_remove_gpio_range(pin_range->pctldev,
2360 &pin_range->range);
2361 kfree(pin_range);
2362 }
2363 }
2364 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2365
2366 #endif /* CONFIG_PINCTRL */
2367
2368 /* These "optional" allocation calls help prevent drivers from stomping
2369 * on each other, and help provide better diagnostics in debugfs.
2370 * They're called even less than the "set direction" calls.
2371 */
gpiod_request_commit(struct gpio_desc * desc,const char * label)2372 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2373 {
2374 unsigned int offset;
2375 int ret;
2376
2377 CLASS(gpio_chip_guard, guard)(desc);
2378 if (!guard.gc)
2379 return -ENODEV;
2380
2381 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
2382 return -EBUSY;
2383
2384 offset = gpio_chip_hwgpio(desc);
2385 if (!gpiochip_line_is_valid(guard.gc, offset))
2386 return -EINVAL;
2387
2388 /* NOTE: gpio_request() can be called in early boot,
2389 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2390 */
2391
2392 if (guard.gc->request) {
2393 ret = guard.gc->request(guard.gc, offset);
2394 if (ret > 0)
2395 ret = -EBADE;
2396 if (ret)
2397 goto out_clear_bit;
2398 }
2399
2400 if (guard.gc->get_direction)
2401 gpiod_get_direction(desc);
2402
2403 ret = desc_set_label(desc, label ? : "?");
2404 if (ret)
2405 goto out_clear_bit;
2406
2407 return 0;
2408
2409 out_clear_bit:
2410 clear_bit(FLAG_REQUESTED, &desc->flags);
2411 return ret;
2412 }
2413
2414 /*
2415 * This descriptor validation needs to be inserted verbatim into each
2416 * function taking a descriptor, so we need to use a preprocessor
2417 * macro to avoid endless duplication. If the desc is NULL it is an
2418 * optional GPIO and calls should just bail out.
2419 */
validate_desc(const struct gpio_desc * desc,const char * func)2420 static int validate_desc(const struct gpio_desc *desc, const char *func)
2421 {
2422 if (!desc)
2423 return 0;
2424
2425 if (IS_ERR(desc)) {
2426 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2427 return PTR_ERR(desc);
2428 }
2429
2430 return 1;
2431 }
2432
2433 #define VALIDATE_DESC(desc) do { \
2434 int __valid = validate_desc(desc, __func__); \
2435 if (__valid <= 0) \
2436 return __valid; \
2437 } while (0)
2438
2439 #define VALIDATE_DESC_VOID(desc) do { \
2440 int __valid = validate_desc(desc, __func__); \
2441 if (__valid <= 0) \
2442 return; \
2443 } while (0)
2444
gpiod_request(struct gpio_desc * desc,const char * label)2445 int gpiod_request(struct gpio_desc *desc, const char *label)
2446 {
2447 int ret = -EPROBE_DEFER;
2448
2449 VALIDATE_DESC(desc);
2450
2451 if (try_module_get(desc->gdev->owner)) {
2452 ret = gpiod_request_commit(desc, label);
2453 if (ret)
2454 module_put(desc->gdev->owner);
2455 else
2456 gpio_device_get(desc->gdev);
2457 }
2458
2459 if (ret)
2460 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2461
2462 return ret;
2463 }
2464
gpiod_free_commit(struct gpio_desc * desc)2465 static void gpiod_free_commit(struct gpio_desc *desc)
2466 {
2467 unsigned long flags;
2468
2469 might_sleep();
2470
2471 CLASS(gpio_chip_guard, guard)(desc);
2472
2473 flags = READ_ONCE(desc->flags);
2474
2475 if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {
2476 if (guard.gc->free)
2477 guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));
2478
2479 clear_bit(FLAG_ACTIVE_LOW, &flags);
2480 clear_bit(FLAG_REQUESTED, &flags);
2481 clear_bit(FLAG_OPEN_DRAIN, &flags);
2482 clear_bit(FLAG_OPEN_SOURCE, &flags);
2483 clear_bit(FLAG_PULL_UP, &flags);
2484 clear_bit(FLAG_PULL_DOWN, &flags);
2485 clear_bit(FLAG_BIAS_DISABLE, &flags);
2486 clear_bit(FLAG_EDGE_RISING, &flags);
2487 clear_bit(FLAG_EDGE_FALLING, &flags);
2488 clear_bit(FLAG_IS_HOGGED, &flags);
2489 #ifdef CONFIG_OF_DYNAMIC
2490 WRITE_ONCE(desc->hog, NULL);
2491 #endif
2492 desc_set_label(desc, NULL);
2493 WRITE_ONCE(desc->flags, flags);
2494 #ifdef CONFIG_GPIO_CDEV
2495 WRITE_ONCE(desc->debounce_period_us, 0);
2496 #endif
2497 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_RELEASED);
2498 }
2499 }
2500
gpiod_free(struct gpio_desc * desc)2501 void gpiod_free(struct gpio_desc *desc)
2502 {
2503 VALIDATE_DESC_VOID(desc);
2504
2505 gpiod_free_commit(desc);
2506 module_put(desc->gdev->owner);
2507 gpio_device_put(desc->gdev);
2508 }
2509
2510 /**
2511 * gpiochip_dup_line_label - Get a copy of the consumer label.
2512 * @gc: GPIO chip controlling this line.
2513 * @offset: Hardware offset of the line.
2514 *
2515 * Returns:
2516 * Pointer to a copy of the consumer label if the line is requested or NULL
2517 * if it's not. If a valid pointer was returned, it must be freed using
2518 * kfree(). In case of a memory allocation error, the function returns %ENOMEM.
2519 *
2520 * Must not be called from atomic context.
2521 */
gpiochip_dup_line_label(struct gpio_chip * gc,unsigned int offset)2522 char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
2523 {
2524 struct gpio_desc *desc;
2525 char *label;
2526
2527 desc = gpiochip_get_desc(gc, offset);
2528 if (IS_ERR(desc))
2529 return NULL;
2530
2531 if (!test_bit(FLAG_REQUESTED, &desc->flags))
2532 return NULL;
2533
2534 guard(srcu)(&desc->gdev->desc_srcu);
2535
2536 label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);
2537 if (!label)
2538 return ERR_PTR(-ENOMEM);
2539
2540 return label;
2541 }
2542 EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
2543
function_name_or_default(const char * con_id)2544 static inline const char *function_name_or_default(const char *con_id)
2545 {
2546 return con_id ?: "(default)";
2547 }
2548
2549 /**
2550 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2551 * @gc: GPIO chip
2552 * @hwnum: hardware number of the GPIO for which to request the descriptor
2553 * @label: label for the GPIO
2554 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2555 * specify things like line inversion semantics with the machine flags
2556 * such as GPIO_OUT_LOW
2557 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2558 * can be used to specify consumer semantics such as open drain
2559 *
2560 * Function allows GPIO chip drivers to request and use their own GPIO
2561 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2562 * function will not increase reference count of the GPIO chip module. This
2563 * allows the GPIO chip module to be unloaded as needed (we assume that the
2564 * GPIO chip driver handles freeing the GPIOs it has requested).
2565 *
2566 * Returns:
2567 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2568 * code on failure.
2569 */
gpiochip_request_own_desc(struct gpio_chip * gc,unsigned int hwnum,const char * label,enum gpio_lookup_flags lflags,enum gpiod_flags dflags)2570 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2571 unsigned int hwnum,
2572 const char *label,
2573 enum gpio_lookup_flags lflags,
2574 enum gpiod_flags dflags)
2575 {
2576 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2577 const char *name = function_name_or_default(label);
2578 int ret;
2579
2580 if (IS_ERR(desc)) {
2581 chip_err(gc, "failed to get GPIO %s descriptor\n", name);
2582 return desc;
2583 }
2584
2585 ret = gpiod_request_commit(desc, label);
2586 if (ret < 0)
2587 return ERR_PTR(ret);
2588
2589 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2590 if (ret) {
2591 gpiod_free_commit(desc);
2592 chip_err(gc, "setup of own GPIO %s failed\n", name);
2593 return ERR_PTR(ret);
2594 }
2595
2596 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
2597
2598 return desc;
2599 }
2600 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2601
2602 /**
2603 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2604 * @desc: GPIO descriptor to free
2605 *
2606 * Function frees the given GPIO requested previously with
2607 * gpiochip_request_own_desc().
2608 */
gpiochip_free_own_desc(struct gpio_desc * desc)2609 void gpiochip_free_own_desc(struct gpio_desc *desc)
2610 {
2611 if (desc)
2612 gpiod_free_commit(desc);
2613 }
2614 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2615
2616 /*
2617 * Drivers MUST set GPIO direction before making get/set calls. In
2618 * some cases this is done in early boot, before IRQs are enabled.
2619 *
2620 * As a rule these aren't called more than once (except for drivers
2621 * using the open-drain emulation idiom) so these are natural places
2622 * to accumulate extra debugging checks. Note that we can't (yet)
2623 * rely on gpio_request() having been called beforehand.
2624 */
2625
gpio_do_set_config(struct gpio_desc * desc,unsigned long config)2626 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config)
2627 {
2628 int ret;
2629
2630 CLASS(gpio_chip_guard, guard)(desc);
2631 if (!guard.gc)
2632 return -ENODEV;
2633
2634 if (!guard.gc->set_config)
2635 return -ENOTSUPP;
2636
2637 ret = guard.gc->set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2638 if (ret > 0)
2639 ret = -EBADE;
2640
2641 #ifdef CONFIG_GPIO_CDEV
2642 /*
2643 * Special case - if we're setting debounce period, we need to store
2644 * it in the descriptor in case user-space wants to know it.
2645 */
2646 if (!ret && pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE)
2647 WRITE_ONCE(desc->debounce_period_us,
2648 pinconf_to_config_argument(config));
2649 #endif
2650 return ret;
2651 }
2652
gpio_set_config_with_argument(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2653 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2654 enum pin_config_param mode,
2655 u32 argument)
2656 {
2657 unsigned long config;
2658
2659 config = pinconf_to_config_packed(mode, argument);
2660 return gpio_do_set_config(desc, config);
2661 }
2662
gpio_set_config_with_argument_optional(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2663 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2664 enum pin_config_param mode,
2665 u32 argument)
2666 {
2667 struct device *dev = &desc->gdev->dev;
2668 int gpio = gpio_chip_hwgpio(desc);
2669 int ret;
2670
2671 ret = gpio_set_config_with_argument(desc, mode, argument);
2672 if (ret != -ENOTSUPP)
2673 return ret;
2674
2675 switch (mode) {
2676 case PIN_CONFIG_PERSIST_STATE:
2677 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2678 break;
2679 default:
2680 break;
2681 }
2682
2683 return 0;
2684 }
2685
gpio_set_config(struct gpio_desc * desc,enum pin_config_param mode)2686 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2687 {
2688 return gpio_set_config_with_argument(desc, mode, 0);
2689 }
2690
gpio_set_bias(struct gpio_desc * desc)2691 static int gpio_set_bias(struct gpio_desc *desc)
2692 {
2693 enum pin_config_param bias;
2694 unsigned long flags;
2695 unsigned int arg;
2696
2697 flags = READ_ONCE(desc->flags);
2698
2699 if (test_bit(FLAG_BIAS_DISABLE, &flags))
2700 bias = PIN_CONFIG_BIAS_DISABLE;
2701 else if (test_bit(FLAG_PULL_UP, &flags))
2702 bias = PIN_CONFIG_BIAS_PULL_UP;
2703 else if (test_bit(FLAG_PULL_DOWN, &flags))
2704 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2705 else
2706 return 0;
2707
2708 switch (bias) {
2709 case PIN_CONFIG_BIAS_PULL_DOWN:
2710 case PIN_CONFIG_BIAS_PULL_UP:
2711 arg = 1;
2712 break;
2713
2714 default:
2715 arg = 0;
2716 break;
2717 }
2718
2719 return gpio_set_config_with_argument_optional(desc, bias, arg);
2720 }
2721
2722 /**
2723 * gpio_set_debounce_timeout() - Set debounce timeout
2724 * @desc: GPIO descriptor to set the debounce timeout
2725 * @debounce: Debounce timeout in microseconds
2726 *
2727 * The function calls the certain GPIO driver to set debounce timeout
2728 * in the hardware.
2729 *
2730 * Returns:
2731 * 0 on success, or negative errno on failure.
2732 */
gpio_set_debounce_timeout(struct gpio_desc * desc,unsigned int debounce)2733 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2734 {
2735 int ret;
2736
2737 ret = gpio_set_config_with_argument_optional(desc,
2738 PIN_CONFIG_INPUT_DEBOUNCE,
2739 debounce);
2740 if (!ret)
2741 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2742
2743 return ret;
2744 }
2745
gpiochip_direction_input(struct gpio_chip * gc,unsigned int offset)2746 static int gpiochip_direction_input(struct gpio_chip *gc, unsigned int offset)
2747 {
2748 int ret;
2749
2750 lockdep_assert_held(&gc->gpiodev->srcu);
2751
2752 if (WARN_ON(!gc->direction_input))
2753 return -EOPNOTSUPP;
2754
2755 ret = gc->direction_input(gc, offset);
2756 if (ret > 0)
2757 ret = -EBADE;
2758
2759 return ret;
2760 }
2761
gpiochip_direction_output(struct gpio_chip * gc,unsigned int offset,int value)2762 static int gpiochip_direction_output(struct gpio_chip *gc, unsigned int offset,
2763 int value)
2764 {
2765 int ret;
2766
2767 lockdep_assert_held(&gc->gpiodev->srcu);
2768
2769 if (WARN_ON(!gc->direction_output))
2770 return -EOPNOTSUPP;
2771
2772 ret = gc->direction_output(gc, offset, value);
2773 if (ret > 0)
2774 ret = -EBADE;
2775
2776 return ret;
2777 }
2778
2779 /**
2780 * gpiod_direction_input - set the GPIO direction to input
2781 * @desc: GPIO to set to input
2782 *
2783 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2784 * be called safely on it.
2785 *
2786 * Returns:
2787 * 0 on success, or negative errno on failure.
2788 */
gpiod_direction_input(struct gpio_desc * desc)2789 int gpiod_direction_input(struct gpio_desc *desc)
2790 {
2791 int ret;
2792
2793 VALIDATE_DESC(desc);
2794
2795 ret = gpiod_direction_input_nonotify(desc);
2796 if (ret == 0)
2797 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2798
2799 return ret;
2800 }
2801 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2802
gpiod_direction_input_nonotify(struct gpio_desc * desc)2803 int gpiod_direction_input_nonotify(struct gpio_desc *desc)
2804 {
2805 int ret = 0, dir;
2806
2807 CLASS(gpio_chip_guard, guard)(desc);
2808 if (!guard.gc)
2809 return -ENODEV;
2810
2811 /*
2812 * It is legal to have no .get() and .direction_input() specified if
2813 * the chip is output-only, but you can't specify .direction_input()
2814 * and not support the .get() operation, that doesn't make sense.
2815 */
2816 if (!guard.gc->get && guard.gc->direction_input) {
2817 gpiod_warn(desc,
2818 "%s: missing get() but have direction_input()\n",
2819 __func__);
2820 return -EIO;
2821 }
2822
2823 /*
2824 * If we have a .direction_input() callback, things are simple,
2825 * just call it. Else we are some input-only chip so try to check the
2826 * direction (if .get_direction() is supported) else we silently
2827 * assume we are in input mode after this.
2828 */
2829 if (guard.gc->direction_input) {
2830 ret = gpiochip_direction_input(guard.gc,
2831 gpio_chip_hwgpio(desc));
2832 } else if (guard.gc->get_direction) {
2833 dir = gpiochip_get_direction(guard.gc, gpio_chip_hwgpio(desc));
2834 if (dir < 0)
2835 return dir;
2836
2837 if (dir != GPIO_LINE_DIRECTION_IN) {
2838 gpiod_warn(desc,
2839 "%s: missing direction_input() operation and line is output\n",
2840 __func__);
2841 return -EIO;
2842 }
2843 }
2844 if (ret == 0) {
2845 clear_bit(FLAG_IS_OUT, &desc->flags);
2846 ret = gpio_set_bias(desc);
2847 }
2848
2849 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2850
2851 return ret;
2852 }
2853
gpiochip_set(struct gpio_chip * gc,unsigned int offset,int value)2854 static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value)
2855 {
2856 int ret;
2857
2858 lockdep_assert_held(&gc->gpiodev->srcu);
2859
2860 if (WARN_ON(unlikely(!gc->set && !gc->set_rv)))
2861 return -EOPNOTSUPP;
2862
2863 if (gc->set_rv) {
2864 ret = gc->set_rv(gc, offset, value);
2865 if (ret > 0)
2866 ret = -EBADE;
2867
2868 return ret;
2869 }
2870
2871 gc->set(gc, offset, value);
2872 return 0;
2873 }
2874
gpiod_direction_output_raw_commit(struct gpio_desc * desc,int value)2875 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2876 {
2877 int val = !!value, ret = 0, dir;
2878
2879 CLASS(gpio_chip_guard, guard)(desc);
2880 if (!guard.gc)
2881 return -ENODEV;
2882
2883 /*
2884 * It's OK not to specify .direction_output() if the gpiochip is
2885 * output-only, but if there is then not even a .set() operation it
2886 * is pretty tricky to drive the output line.
2887 */
2888 if (!guard.gc->set && !guard.gc->set_rv && !guard.gc->direction_output) {
2889 gpiod_warn(desc,
2890 "%s: missing set() and direction_output() operations\n",
2891 __func__);
2892 return -EIO;
2893 }
2894
2895 if (guard.gc->direction_output) {
2896 ret = gpiochip_direction_output(guard.gc,
2897 gpio_chip_hwgpio(desc), val);
2898 } else {
2899 /* Check that we are in output mode if we can */
2900 if (guard.gc->get_direction) {
2901 dir = gpiochip_get_direction(guard.gc,
2902 gpio_chip_hwgpio(desc));
2903 if (dir < 0)
2904 return dir;
2905
2906 if (dir != GPIO_LINE_DIRECTION_OUT) {
2907 gpiod_warn(desc,
2908 "%s: missing direction_output() operation\n",
2909 __func__);
2910 return -EIO;
2911 }
2912 }
2913 /*
2914 * If we can't actively set the direction, we are some
2915 * output-only chip, so just drive the output as desired.
2916 */
2917 ret = gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), val);
2918 if (ret)
2919 return ret;
2920 }
2921
2922 if (!ret)
2923 set_bit(FLAG_IS_OUT, &desc->flags);
2924 trace_gpio_value(desc_to_gpio(desc), 0, val);
2925 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2926 return ret;
2927 }
2928
2929 /**
2930 * gpiod_direction_output_raw - set the GPIO direction to output
2931 * @desc: GPIO to set to output
2932 * @value: initial output value of the GPIO
2933 *
2934 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2935 * be called safely on it. The initial value of the output must be specified
2936 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2937 *
2938 * Returns:
2939 * 0 on success, or negative errno on failure.
2940 */
gpiod_direction_output_raw(struct gpio_desc * desc,int value)2941 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2942 {
2943 int ret;
2944
2945 VALIDATE_DESC(desc);
2946
2947 ret = gpiod_direction_output_raw_commit(desc, value);
2948 if (ret == 0)
2949 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2950
2951 return ret;
2952 }
2953 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2954
2955 /**
2956 * gpiod_direction_output - set the GPIO direction to output
2957 * @desc: GPIO to set to output
2958 * @value: initial output value of the GPIO
2959 *
2960 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2961 * be called safely on it. The initial value of the output must be specified
2962 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2963 * account.
2964 *
2965 * Returns:
2966 * 0 on success, or negative errno on failure.
2967 */
gpiod_direction_output(struct gpio_desc * desc,int value)2968 int gpiod_direction_output(struct gpio_desc *desc, int value)
2969 {
2970 int ret;
2971
2972 VALIDATE_DESC(desc);
2973
2974 ret = gpiod_direction_output_nonotify(desc, value);
2975 if (ret == 0)
2976 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2977
2978 return ret;
2979 }
2980 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2981
gpiod_direction_output_nonotify(struct gpio_desc * desc,int value)2982 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value)
2983 {
2984 unsigned long flags;
2985 int ret;
2986
2987 flags = READ_ONCE(desc->flags);
2988
2989 if (test_bit(FLAG_ACTIVE_LOW, &flags))
2990 value = !value;
2991 else
2992 value = !!value;
2993
2994 /* GPIOs used for enabled IRQs shall not be set as output */
2995 if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
2996 test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {
2997 gpiod_err(desc,
2998 "%s: tried to set a GPIO tied to an IRQ as output\n",
2999 __func__);
3000 return -EIO;
3001 }
3002
3003 if (test_bit(FLAG_OPEN_DRAIN, &flags)) {
3004 /* First see if we can enable open drain in hardware */
3005 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
3006 if (!ret)
3007 goto set_output_value;
3008 /* Emulate open drain by not actively driving the line high */
3009 if (value)
3010 goto set_output_flag;
3011 } else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {
3012 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
3013 if (!ret)
3014 goto set_output_value;
3015 /* Emulate open source by not actively driving the line low */
3016 if (!value)
3017 goto set_output_flag;
3018 } else {
3019 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
3020 }
3021
3022 set_output_value:
3023 ret = gpio_set_bias(desc);
3024 if (ret)
3025 return ret;
3026 return gpiod_direction_output_raw_commit(desc, value);
3027
3028 set_output_flag:
3029 ret = gpiod_direction_input_nonotify(desc);
3030 if (ret)
3031 return ret;
3032 /*
3033 * When emulating open-source or open-drain functionalities by not
3034 * actively driving the line (setting mode to input) we still need to
3035 * set the IS_OUT flag or otherwise we won't be able to set the line
3036 * value anymore.
3037 */
3038 set_bit(FLAG_IS_OUT, &desc->flags);
3039 return 0;
3040 }
3041
3042 #if IS_ENABLED(CONFIG_HTE)
3043 /**
3044 * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
3045 *
3046 * @desc: GPIO to enable.
3047 * @flags: Flags related to GPIO edge.
3048 *
3049 * Returns:
3050 * 0 on success, or negative errno on failure.
3051 */
gpiod_enable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)3052 int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
3053 {
3054 int ret = 0;
3055
3056 VALIDATE_DESC(desc);
3057
3058 CLASS(gpio_chip_guard, guard)(desc);
3059 if (!guard.gc)
3060 return -ENODEV;
3061
3062 if (!guard.gc->en_hw_timestamp) {
3063 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
3064 return -ENOTSUPP;
3065 }
3066
3067 ret = guard.gc->en_hw_timestamp(guard.gc,
3068 gpio_chip_hwgpio(desc), flags);
3069 if (ret)
3070 gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
3071
3072 return ret;
3073 }
3074 EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
3075
3076 /**
3077 * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
3078 *
3079 * @desc: GPIO to disable.
3080 * @flags: Flags related to GPIO edge, same value as used during enable call.
3081 *
3082 * Returns:
3083 * 0 on success, or negative errno on failure.
3084 */
gpiod_disable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)3085 int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
3086 {
3087 int ret = 0;
3088
3089 VALIDATE_DESC(desc);
3090
3091 CLASS(gpio_chip_guard, guard)(desc);
3092 if (!guard.gc)
3093 return -ENODEV;
3094
3095 if (!guard.gc->dis_hw_timestamp) {
3096 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
3097 return -ENOTSUPP;
3098 }
3099
3100 ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),
3101 flags);
3102 if (ret)
3103 gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
3104
3105 return ret;
3106 }
3107 EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
3108 #endif /* CONFIG_HTE */
3109
3110 /**
3111 * gpiod_set_config - sets @config for a GPIO
3112 * @desc: descriptor of the GPIO for which to set the configuration
3113 * @config: Same packed config format as generic pinconf
3114 *
3115 * Returns:
3116 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3117 * configuration.
3118 */
gpiod_set_config(struct gpio_desc * desc,unsigned long config)3119 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
3120 {
3121 int ret;
3122
3123 VALIDATE_DESC(desc);
3124
3125 ret = gpio_do_set_config(desc, config);
3126 if (!ret) {
3127 /* These are the only options we notify the userspace about. */
3128 switch (pinconf_to_config_param(config)) {
3129 case PIN_CONFIG_BIAS_DISABLE:
3130 case PIN_CONFIG_BIAS_PULL_DOWN:
3131 case PIN_CONFIG_BIAS_PULL_UP:
3132 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
3133 case PIN_CONFIG_DRIVE_OPEN_SOURCE:
3134 case PIN_CONFIG_DRIVE_PUSH_PULL:
3135 case PIN_CONFIG_INPUT_DEBOUNCE:
3136 gpiod_line_state_notify(desc,
3137 GPIO_V2_LINE_CHANGED_CONFIG);
3138 break;
3139 default:
3140 break;
3141 }
3142 }
3143
3144 return ret;
3145 }
3146 EXPORT_SYMBOL_GPL(gpiod_set_config);
3147
3148 /**
3149 * gpiod_set_debounce - sets @debounce time for a GPIO
3150 * @desc: descriptor of the GPIO for which to set debounce time
3151 * @debounce: debounce time in microseconds
3152 *
3153 * Returns:
3154 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3155 * debounce time.
3156 */
gpiod_set_debounce(struct gpio_desc * desc,unsigned int debounce)3157 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
3158 {
3159 unsigned long config;
3160
3161 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
3162 return gpiod_set_config(desc, config);
3163 }
3164 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
3165
3166 /**
3167 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
3168 * @desc: descriptor of the GPIO for which to configure persistence
3169 * @transitory: True to lose state on suspend or reset, false for persistence
3170 *
3171 * Returns:
3172 * 0 on success, otherwise a negative error code.
3173 */
gpiod_set_transitory(struct gpio_desc * desc,bool transitory)3174 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
3175 {
3176 VALIDATE_DESC(desc);
3177 /*
3178 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
3179 * persistence state.
3180 */
3181 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
3182
3183 /* If the driver supports it, set the persistence state now */
3184 return gpio_set_config_with_argument_optional(desc,
3185 PIN_CONFIG_PERSIST_STATE,
3186 !transitory);
3187 }
3188
3189 /**
3190 * gpiod_is_active_low - test whether a GPIO is active-low or not
3191 * @desc: the gpio descriptor to test
3192 *
3193 * Returns:
3194 * 1 if the GPIO is active-low, 0 otherwise.
3195 */
gpiod_is_active_low(const struct gpio_desc * desc)3196 int gpiod_is_active_low(const struct gpio_desc *desc)
3197 {
3198 VALIDATE_DESC(desc);
3199 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
3200 }
3201 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
3202
3203 /**
3204 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
3205 * @desc: the gpio descriptor to change
3206 */
gpiod_toggle_active_low(struct gpio_desc * desc)3207 void gpiod_toggle_active_low(struct gpio_desc *desc)
3208 {
3209 VALIDATE_DESC_VOID(desc);
3210 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
3211 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3212 }
3213 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
3214
gpiochip_get(struct gpio_chip * gc,unsigned int offset)3215 static int gpiochip_get(struct gpio_chip *gc, unsigned int offset)
3216 {
3217 int ret;
3218
3219 lockdep_assert_held(&gc->gpiodev->srcu);
3220
3221 /* Make sure this is called after checking for gc->get(). */
3222 ret = gc->get(gc, offset);
3223 if (ret > 1)
3224 ret = -EBADE;
3225
3226 return ret;
3227 }
3228
gpio_chip_get_value(struct gpio_chip * gc,const struct gpio_desc * desc)3229 static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)
3230 {
3231 return gc->get ? gpiochip_get(gc, gpio_chip_hwgpio(desc)) : -EIO;
3232 }
3233
3234 /* I/O calls are only valid after configuration completed; the relevant
3235 * "is this a valid GPIO" error checks should already have been done.
3236 *
3237 * "Get" operations are often inlinable as reading a pin value register,
3238 * and masking the relevant bit in that register.
3239 *
3240 * When "set" operations are inlinable, they involve writing that mask to
3241 * one register to set a low value, or a different register to set it high.
3242 * Otherwise locking is needed, so there may be little value to inlining.
3243 *
3244 *------------------------------------------------------------------------
3245 *
3246 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
3247 * have requested the GPIO. That can include implicit requesting by
3248 * a direction setting call. Marking a gpio as requested locks its chip
3249 * in memory, guaranteeing that these table lookups need no more locking
3250 * and that gpiochip_remove() will fail.
3251 *
3252 * REVISIT when debugging, consider adding some instrumentation to ensure
3253 * that the GPIO was actually requested.
3254 */
3255
gpiod_get_raw_value_commit(const struct gpio_desc * desc)3256 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
3257 {
3258 struct gpio_device *gdev;
3259 struct gpio_chip *gc;
3260 int value;
3261
3262 /* FIXME Unable to use gpio_chip_guard due to const desc. */
3263 gdev = desc->gdev;
3264
3265 guard(srcu)(&gdev->srcu);
3266
3267 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3268 if (!gc)
3269 return -ENODEV;
3270
3271 value = gpio_chip_get_value(gc, desc);
3272 value = value < 0 ? value : !!value;
3273 trace_gpio_value(desc_to_gpio(desc), 1, value);
3274 return value;
3275 }
3276
gpio_chip_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)3277 static int gpio_chip_get_multiple(struct gpio_chip *gc,
3278 unsigned long *mask, unsigned long *bits)
3279 {
3280 int ret;
3281
3282 lockdep_assert_held(&gc->gpiodev->srcu);
3283
3284 if (gc->get_multiple) {
3285 ret = gc->get_multiple(gc, mask, bits);
3286 if (ret > 0)
3287 return -EBADE;
3288 }
3289
3290 if (gc->get) {
3291 int i, value;
3292
3293 for_each_set_bit(i, mask, gc->ngpio) {
3294 value = gpiochip_get(gc, i);
3295 if (value < 0)
3296 return value;
3297 __assign_bit(i, bits, value);
3298 }
3299 return 0;
3300 }
3301 return -EIO;
3302 }
3303
3304 /* The 'other' chip must be protected with its GPIO device's SRCU. */
gpio_device_chip_cmp(struct gpio_device * gdev,struct gpio_chip * gc)3305 static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
3306 {
3307 guard(srcu)(&gdev->srcu);
3308
3309 return gc == srcu_dereference(gdev->chip, &gdev->srcu);
3310 }
3311
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)3312 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3313 unsigned int array_size,
3314 struct gpio_desc **desc_array,
3315 struct gpio_array *array_info,
3316 unsigned long *value_bitmap)
3317 {
3318 struct gpio_chip *gc;
3319 int ret, i = 0;
3320
3321 /*
3322 * Validate array_info against desc_array and its size.
3323 * It should immediately follow desc_array if both
3324 * have been obtained from the same gpiod_get_array() call.
3325 */
3326 if (array_info && array_info->desc == desc_array &&
3327 array_size <= array_info->size &&
3328 (void *)array_info == desc_array + array_info->size) {
3329 if (!can_sleep)
3330 WARN_ON(array_info->gdev->can_sleep);
3331
3332 guard(srcu)(&array_info->gdev->srcu);
3333 gc = srcu_dereference(array_info->gdev->chip,
3334 &array_info->gdev->srcu);
3335 if (!gc)
3336 return -ENODEV;
3337
3338 ret = gpio_chip_get_multiple(gc, array_info->get_mask,
3339 value_bitmap);
3340 if (ret)
3341 return ret;
3342
3343 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3344 bitmap_xor(value_bitmap, value_bitmap,
3345 array_info->invert_mask, array_size);
3346
3347 i = find_first_zero_bit(array_info->get_mask, array_size);
3348 if (i == array_size)
3349 return 0;
3350 } else {
3351 array_info = NULL;
3352 }
3353
3354 while (i < array_size) {
3355 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3356 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3357 unsigned long *mask, *bits;
3358 int first, j;
3359
3360 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3361 if (!guard.gc)
3362 return -ENODEV;
3363
3364 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3365 mask = fastpath_mask;
3366 bits = fastpath_bits;
3367 } else {
3368 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3369
3370 mask = bitmap_alloc(guard.gc->ngpio, flags);
3371 if (!mask)
3372 return -ENOMEM;
3373
3374 bits = bitmap_alloc(guard.gc->ngpio, flags);
3375 if (!bits) {
3376 bitmap_free(mask);
3377 return -ENOMEM;
3378 }
3379 }
3380
3381 bitmap_zero(mask, guard.gc->ngpio);
3382
3383 if (!can_sleep)
3384 WARN_ON(guard.gc->can_sleep);
3385
3386 /* collect all inputs belonging to the same chip */
3387 first = i;
3388 do {
3389 const struct gpio_desc *desc = desc_array[i];
3390 int hwgpio = gpio_chip_hwgpio(desc);
3391
3392 __set_bit(hwgpio, mask);
3393 i++;
3394
3395 if (array_info)
3396 i = find_next_zero_bit(array_info->get_mask,
3397 array_size, i);
3398 } while ((i < array_size) &&
3399 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3400
3401 ret = gpio_chip_get_multiple(guard.gc, mask, bits);
3402 if (ret) {
3403 if (mask != fastpath_mask)
3404 bitmap_free(mask);
3405 if (bits != fastpath_bits)
3406 bitmap_free(bits);
3407 return ret;
3408 }
3409
3410 for (j = first; j < i; ) {
3411 const struct gpio_desc *desc = desc_array[j];
3412 int hwgpio = gpio_chip_hwgpio(desc);
3413 int value = test_bit(hwgpio, bits);
3414
3415 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3416 value = !value;
3417 __assign_bit(j, value_bitmap, value);
3418 trace_gpio_value(desc_to_gpio(desc), 1, value);
3419 j++;
3420
3421 if (array_info)
3422 j = find_next_zero_bit(array_info->get_mask, i,
3423 j);
3424 }
3425
3426 if (mask != fastpath_mask)
3427 bitmap_free(mask);
3428 if (bits != fastpath_bits)
3429 bitmap_free(bits);
3430 }
3431 return 0;
3432 }
3433
3434 /**
3435 * gpiod_get_raw_value() - return a gpio's raw value
3436 * @desc: gpio whose value will be returned
3437 *
3438 * Returns:
3439 * The GPIO's raw value, i.e. the value of the physical line disregarding
3440 * its ACTIVE_LOW status, or negative errno on failure.
3441 *
3442 * This function can be called from contexts where we cannot sleep, and will
3443 * complain if the GPIO chip functions potentially sleep.
3444 */
gpiod_get_raw_value(const struct gpio_desc * desc)3445 int gpiod_get_raw_value(const struct gpio_desc *desc)
3446 {
3447 VALIDATE_DESC(desc);
3448 /* Should be using gpiod_get_raw_value_cansleep() */
3449 WARN_ON(desc->gdev->can_sleep);
3450 return gpiod_get_raw_value_commit(desc);
3451 }
3452 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3453
3454 /**
3455 * gpiod_get_value() - return a gpio's value
3456 * @desc: gpio whose value will be returned
3457 *
3458 * Returns:
3459 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3460 * account, or negative errno on failure.
3461 *
3462 * This function can be called from contexts where we cannot sleep, and will
3463 * complain if the GPIO chip functions potentially sleep.
3464 */
gpiod_get_value(const struct gpio_desc * desc)3465 int gpiod_get_value(const struct gpio_desc *desc)
3466 {
3467 int value;
3468
3469 VALIDATE_DESC(desc);
3470 /* Should be using gpiod_get_value_cansleep() */
3471 WARN_ON(desc->gdev->can_sleep);
3472
3473 value = gpiod_get_raw_value_commit(desc);
3474 if (value < 0)
3475 return value;
3476
3477 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3478 value = !value;
3479
3480 return value;
3481 }
3482 EXPORT_SYMBOL_GPL(gpiod_get_value);
3483
3484 /**
3485 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3486 * @array_size: number of elements in the descriptor array / value bitmap
3487 * @desc_array: array of GPIO descriptors whose values will be read
3488 * @array_info: information on applicability of fast bitmap processing path
3489 * @value_bitmap: bitmap to store the read values
3490 *
3491 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3492 * without regard for their ACTIVE_LOW status.
3493 *
3494 * This function can be called from contexts where we cannot sleep,
3495 * and it will complain if the GPIO chip functions potentially sleep.
3496 *
3497 * Returns:
3498 * 0 on success, or negative errno on failure.
3499 */
gpiod_get_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3500 int gpiod_get_raw_array_value(unsigned int array_size,
3501 struct gpio_desc **desc_array,
3502 struct gpio_array *array_info,
3503 unsigned long *value_bitmap)
3504 {
3505 if (!desc_array)
3506 return -EINVAL;
3507 return gpiod_get_array_value_complex(true, false, array_size,
3508 desc_array, array_info,
3509 value_bitmap);
3510 }
3511 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3512
3513 /**
3514 * gpiod_get_array_value() - read values from an array of GPIOs
3515 * @array_size: number of elements in the descriptor array / value bitmap
3516 * @desc_array: array of GPIO descriptors whose values will be read
3517 * @array_info: information on applicability of fast bitmap processing path
3518 * @value_bitmap: bitmap to store the read values
3519 *
3520 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3521 * into account.
3522 *
3523 * This function can be called from contexts where we cannot sleep,
3524 * and it will complain if the GPIO chip functions potentially sleep.
3525 *
3526 * Returns:
3527 * 0 on success, or negative errno on failure.
3528 */
gpiod_get_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3529 int gpiod_get_array_value(unsigned int array_size,
3530 struct gpio_desc **desc_array,
3531 struct gpio_array *array_info,
3532 unsigned long *value_bitmap)
3533 {
3534 if (!desc_array)
3535 return -EINVAL;
3536 return gpiod_get_array_value_complex(false, false, array_size,
3537 desc_array, array_info,
3538 value_bitmap);
3539 }
3540 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3541
3542 /*
3543 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3544 * @desc: gpio descriptor whose state need to be set.
3545 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3546 */
gpio_set_open_drain_value_commit(struct gpio_desc * desc,bool value)3547 static int gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3548 {
3549 int ret = 0, offset = gpio_chip_hwgpio(desc);
3550
3551 CLASS(gpio_chip_guard, guard)(desc);
3552 if (!guard.gc)
3553 return -ENODEV;
3554
3555 if (value) {
3556 ret = gpiochip_direction_input(guard.gc, offset);
3557 } else {
3558 ret = gpiochip_direction_output(guard.gc, offset, 0);
3559 if (!ret)
3560 set_bit(FLAG_IS_OUT, &desc->flags);
3561 }
3562 trace_gpio_direction(desc_to_gpio(desc), value, ret);
3563 if (ret < 0)
3564 gpiod_err(desc,
3565 "%s: Error in set_value for open drain err %d\n",
3566 __func__, ret);
3567
3568 return ret;
3569 }
3570
3571 /*
3572 * _gpio_set_open_source_value() - Set the open source gpio's value.
3573 * @desc: gpio descriptor whose state need to be set.
3574 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3575 */
gpio_set_open_source_value_commit(struct gpio_desc * desc,bool value)3576 static int gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3577 {
3578 int ret = 0, offset = gpio_chip_hwgpio(desc);
3579
3580 CLASS(gpio_chip_guard, guard)(desc);
3581 if (!guard.gc)
3582 return -ENODEV;
3583
3584 if (value) {
3585 ret = gpiochip_direction_output(guard.gc, offset, 1);
3586 if (!ret)
3587 set_bit(FLAG_IS_OUT, &desc->flags);
3588 } else {
3589 ret = gpiochip_direction_input(guard.gc, offset);
3590 }
3591 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3592 if (ret < 0)
3593 gpiod_err(desc,
3594 "%s: Error in set_value for open source err %d\n",
3595 __func__, ret);
3596
3597 return ret;
3598 }
3599
gpiod_set_raw_value_commit(struct gpio_desc * desc,bool value)3600 static int gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3601 {
3602 CLASS(gpio_chip_guard, guard)(desc);
3603 if (!guard.gc)
3604 return -ENODEV;
3605
3606 trace_gpio_value(desc_to_gpio(desc), 0, value);
3607 return gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), value);
3608 }
3609
3610 /*
3611 * set multiple outputs on the same chip;
3612 * use the chip's set_multiple function if available;
3613 * otherwise set the outputs sequentially;
3614 * @chip: the GPIO chip we operate on
3615 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3616 * defines which outputs are to be changed
3617 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3618 * defines the values the outputs specified by mask are to be set to
3619 *
3620 * Returns: 0 on success, negative error number on failure.
3621 */
gpiochip_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)3622 static int gpiochip_set_multiple(struct gpio_chip *gc,
3623 unsigned long *mask, unsigned long *bits)
3624 {
3625 unsigned int i;
3626 int ret;
3627
3628 lockdep_assert_held(&gc->gpiodev->srcu);
3629
3630 if (gc->set_multiple_rv) {
3631 ret = gc->set_multiple_rv(gc, mask, bits);
3632 if (ret > 0)
3633 ret = -EBADE;
3634
3635 return ret;
3636 }
3637
3638 if (gc->set_multiple) {
3639 gc->set_multiple(gc, mask, bits);
3640 return 0;
3641 }
3642
3643 /* set outputs if the corresponding mask bit is set */
3644 for_each_set_bit(i, mask, gc->ngpio) {
3645 ret = gpiochip_set(gc, i, test_bit(i, bits));
3646 if (ret)
3647 break;
3648 }
3649
3650 return ret;
3651 }
3652
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)3653 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3654 unsigned int array_size,
3655 struct gpio_desc **desc_array,
3656 struct gpio_array *array_info,
3657 unsigned long *value_bitmap)
3658 {
3659 struct gpio_chip *gc;
3660 int i = 0, ret;
3661
3662 /*
3663 * Validate array_info against desc_array and its size.
3664 * It should immediately follow desc_array if both
3665 * have been obtained from the same gpiod_get_array() call.
3666 */
3667 if (array_info && array_info->desc == desc_array &&
3668 array_size <= array_info->size &&
3669 (void *)array_info == desc_array + array_info->size) {
3670 if (!can_sleep)
3671 WARN_ON(array_info->gdev->can_sleep);
3672
3673 guard(srcu)(&array_info->gdev->srcu);
3674 gc = srcu_dereference(array_info->gdev->chip,
3675 &array_info->gdev->srcu);
3676 if (!gc)
3677 return -ENODEV;
3678
3679 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3680 bitmap_xor(value_bitmap, value_bitmap,
3681 array_info->invert_mask, array_size);
3682
3683 ret = gpiochip_set_multiple(gc, array_info->set_mask,
3684 value_bitmap);
3685 if (ret)
3686 return ret;
3687
3688 i = find_first_zero_bit(array_info->set_mask, array_size);
3689 if (i == array_size)
3690 return 0;
3691 } else {
3692 array_info = NULL;
3693 }
3694
3695 while (i < array_size) {
3696 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3697 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3698 unsigned long *mask, *bits;
3699 int count = 0;
3700
3701 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3702 if (!guard.gc)
3703 return -ENODEV;
3704
3705 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3706 mask = fastpath_mask;
3707 bits = fastpath_bits;
3708 } else {
3709 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3710
3711 mask = bitmap_alloc(guard.gc->ngpio, flags);
3712 if (!mask)
3713 return -ENOMEM;
3714
3715 bits = bitmap_alloc(guard.gc->ngpio, flags);
3716 if (!bits) {
3717 bitmap_free(mask);
3718 return -ENOMEM;
3719 }
3720 }
3721
3722 bitmap_zero(mask, guard.gc->ngpio);
3723
3724 if (!can_sleep)
3725 WARN_ON(guard.gc->can_sleep);
3726
3727 do {
3728 struct gpio_desc *desc = desc_array[i];
3729 int hwgpio = gpio_chip_hwgpio(desc);
3730 int value = test_bit(i, value_bitmap);
3731
3732 /*
3733 * Pins applicable for fast input but not for
3734 * fast output processing may have been already
3735 * inverted inside the fast path, skip them.
3736 */
3737 if (!raw && !(array_info &&
3738 test_bit(i, array_info->invert_mask)) &&
3739 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3740 value = !value;
3741 trace_gpio_value(desc_to_gpio(desc), 0, value);
3742 /*
3743 * collect all normal outputs belonging to the same chip
3744 * open drain and open source outputs are set individually
3745 */
3746 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3747 gpio_set_open_drain_value_commit(desc, value);
3748 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3749 gpio_set_open_source_value_commit(desc, value);
3750 } else {
3751 __set_bit(hwgpio, mask);
3752 __assign_bit(hwgpio, bits, value);
3753 count++;
3754 }
3755 i++;
3756
3757 if (array_info)
3758 i = find_next_zero_bit(array_info->set_mask,
3759 array_size, i);
3760 } while ((i < array_size) &&
3761 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3762 /* push collected bits to outputs */
3763 if (count != 0) {
3764 ret = gpiochip_set_multiple(guard.gc, mask, bits);
3765 if (ret)
3766 return ret;
3767 }
3768
3769 if (mask != fastpath_mask)
3770 bitmap_free(mask);
3771 if (bits != fastpath_bits)
3772 bitmap_free(bits);
3773 }
3774 return 0;
3775 }
3776
3777 /**
3778 * gpiod_set_raw_value() - assign a gpio's raw value
3779 * @desc: gpio whose value will be assigned
3780 * @value: value to assign
3781 *
3782 * Set the raw value of the GPIO, i.e. the value of its physical line without
3783 * regard for its ACTIVE_LOW status.
3784 *
3785 * This function can be called from contexts where we cannot sleep, and will
3786 * complain if the GPIO chip functions potentially sleep.
3787 *
3788 * Returns:
3789 * 0 on success, negative error number on failure.
3790 */
gpiod_set_raw_value(struct gpio_desc * desc,int value)3791 int gpiod_set_raw_value(struct gpio_desc *desc, int value)
3792 {
3793 VALIDATE_DESC(desc);
3794 /* Should be using gpiod_set_raw_value_cansleep() */
3795 WARN_ON(desc->gdev->can_sleep);
3796 return gpiod_set_raw_value_commit(desc, value);
3797 }
3798 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3799
3800 /**
3801 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3802 * @desc: the descriptor to set the value on
3803 * @value: value to set
3804 *
3805 * This sets the value of a GPIO line backing a descriptor, applying
3806 * different semantic quirks like active low and open drain/source
3807 * handling.
3808 *
3809 * Returns:
3810 * 0 on success, negative error number on failure.
3811 */
gpiod_set_value_nocheck(struct gpio_desc * desc,int value)3812 static int gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3813 {
3814 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3815 value = !value;
3816
3817 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3818 return gpio_set_open_drain_value_commit(desc, value);
3819 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3820 return gpio_set_open_source_value_commit(desc, value);
3821
3822 return gpiod_set_raw_value_commit(desc, value);
3823 }
3824
3825 /**
3826 * gpiod_set_value() - assign a gpio's value
3827 * @desc: gpio whose value will be assigned
3828 * @value: value to assign
3829 *
3830 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3831 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3832 *
3833 * This function can be called from contexts where we cannot sleep, and will
3834 * complain if the GPIO chip functions potentially sleep.
3835 *
3836 * Returns:
3837 * 0 on success, negative error number on failure.
3838 */
gpiod_set_value(struct gpio_desc * desc,int value)3839 int gpiod_set_value(struct gpio_desc *desc, int value)
3840 {
3841 VALIDATE_DESC(desc);
3842 /* Should be using gpiod_set_value_cansleep() */
3843 WARN_ON(desc->gdev->can_sleep);
3844 return gpiod_set_value_nocheck(desc, value);
3845 }
3846 EXPORT_SYMBOL_GPL(gpiod_set_value);
3847
3848 /**
3849 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3850 * @array_size: number of elements in the descriptor array / value bitmap
3851 * @desc_array: array of GPIO descriptors whose values will be assigned
3852 * @array_info: information on applicability of fast bitmap processing path
3853 * @value_bitmap: bitmap of values to assign
3854 *
3855 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3856 * without regard for their ACTIVE_LOW status.
3857 *
3858 * This function can be called from contexts where we cannot sleep, and will
3859 * complain if the GPIO chip functions potentially sleep.
3860 *
3861 * Returns:
3862 * 0 on success, or negative errno on failure.
3863 */
gpiod_set_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3864 int gpiod_set_raw_array_value(unsigned int array_size,
3865 struct gpio_desc **desc_array,
3866 struct gpio_array *array_info,
3867 unsigned long *value_bitmap)
3868 {
3869 if (!desc_array)
3870 return -EINVAL;
3871 return gpiod_set_array_value_complex(true, false, array_size,
3872 desc_array, array_info, value_bitmap);
3873 }
3874 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3875
3876 /**
3877 * gpiod_set_array_value() - assign values to an array of GPIOs
3878 * @array_size: number of elements in the descriptor array / value bitmap
3879 * @desc_array: array of GPIO descriptors whose values will be assigned
3880 * @array_info: information on applicability of fast bitmap processing path
3881 * @value_bitmap: bitmap of values to assign
3882 *
3883 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3884 * into account.
3885 *
3886 * This function can be called from contexts where we cannot sleep, and will
3887 * complain if the GPIO chip functions potentially sleep.
3888 *
3889 * Returns:
3890 * 0 on success, or negative errno on failure.
3891 */
gpiod_set_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3892 int gpiod_set_array_value(unsigned int array_size,
3893 struct gpio_desc **desc_array,
3894 struct gpio_array *array_info,
3895 unsigned long *value_bitmap)
3896 {
3897 if (!desc_array)
3898 return -EINVAL;
3899 return gpiod_set_array_value_complex(false, false, array_size,
3900 desc_array, array_info,
3901 value_bitmap);
3902 }
3903 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3904
3905 /**
3906 * gpiod_cansleep() - report whether gpio value access may sleep
3907 * @desc: gpio to check
3908 *
3909 * Returns:
3910 * 0 for non-sleepable, 1 for sleepable, or an error code in case of error.
3911 */
gpiod_cansleep(const struct gpio_desc * desc)3912 int gpiod_cansleep(const struct gpio_desc *desc)
3913 {
3914 VALIDATE_DESC(desc);
3915 return desc->gdev->can_sleep;
3916 }
3917 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3918
3919 /**
3920 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3921 * @desc: gpio to set the consumer name on
3922 * @name: the new consumer name
3923 *
3924 * Returns:
3925 * 0 on success, or negative errno on failure.
3926 */
gpiod_set_consumer_name(struct gpio_desc * desc,const char * name)3927 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3928 {
3929 int ret;
3930
3931 VALIDATE_DESC(desc);
3932
3933 ret = desc_set_label(desc, name);
3934 if (ret == 0)
3935 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3936
3937 return ret;
3938 }
3939 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3940
3941 /**
3942 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3943 * @desc: gpio whose IRQ will be returned (already requested)
3944 *
3945 * Returns:
3946 * The IRQ corresponding to the passed GPIO, or an error code in case of error.
3947 */
gpiod_to_irq(const struct gpio_desc * desc)3948 int gpiod_to_irq(const struct gpio_desc *desc)
3949 {
3950 struct gpio_device *gdev;
3951 struct gpio_chip *gc;
3952 int offset;
3953
3954 /*
3955 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3956 * requires this function to not return zero on an invalid descriptor
3957 * but rather a negative error number.
3958 */
3959 if (IS_ERR_OR_NULL(desc))
3960 return -EINVAL;
3961
3962 gdev = desc->gdev;
3963 /* FIXME Cannot use gpio_chip_guard due to const desc. */
3964 guard(srcu)(&gdev->srcu);
3965 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3966 if (!gc)
3967 return -ENODEV;
3968
3969 offset = gpio_chip_hwgpio(desc);
3970 if (gc->to_irq) {
3971 int retirq = gc->to_irq(gc, offset);
3972
3973 /* Zero means NO_IRQ */
3974 if (!retirq)
3975 return -ENXIO;
3976
3977 return retirq;
3978 }
3979 #ifdef CONFIG_GPIOLIB_IRQCHIP
3980 if (gc->irq.chip) {
3981 /*
3982 * Avoid race condition with other code, which tries to lookup
3983 * an IRQ before the irqchip has been properly registered,
3984 * i.e. while gpiochip is still being brought up.
3985 */
3986 return -EPROBE_DEFER;
3987 }
3988 #endif
3989 return -ENXIO;
3990 }
3991 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3992
3993 /**
3994 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3995 * @gc: the chip the GPIO to lock belongs to
3996 * @offset: the offset of the GPIO to lock as IRQ
3997 *
3998 * This is used directly by GPIO drivers that want to lock down
3999 * a certain GPIO line to be used for IRQs.
4000 *
4001 * Returns:
4002 * 0 on success, or negative errno on failure.
4003 */
gpiochip_lock_as_irq(struct gpio_chip * gc,unsigned int offset)4004 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
4005 {
4006 struct gpio_desc *desc;
4007
4008 desc = gpiochip_get_desc(gc, offset);
4009 if (IS_ERR(desc))
4010 return PTR_ERR(desc);
4011
4012 /*
4013 * If it's fast: flush the direction setting if something changed
4014 * behind our back
4015 */
4016 if (!gc->can_sleep && gc->get_direction) {
4017 int dir = gpiod_get_direction(desc);
4018
4019 if (dir < 0) {
4020 chip_err(gc, "%s: cannot get GPIO direction\n",
4021 __func__);
4022 return dir;
4023 }
4024 }
4025
4026 /* To be valid for IRQ the line needs to be input or open drain */
4027 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
4028 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
4029 chip_err(gc,
4030 "%s: tried to flag a GPIO set as output for IRQ\n",
4031 __func__);
4032 return -EIO;
4033 }
4034
4035 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
4036 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4037
4038 return 0;
4039 }
4040 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
4041
4042 /**
4043 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
4044 * @gc: the chip the GPIO to lock belongs to
4045 * @offset: the offset of the GPIO to lock as IRQ
4046 *
4047 * This is used directly by GPIO drivers that want to indicate
4048 * that a certain GPIO is no longer used exclusively for IRQ.
4049 */
gpiochip_unlock_as_irq(struct gpio_chip * gc,unsigned int offset)4050 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
4051 {
4052 struct gpio_desc *desc;
4053
4054 desc = gpiochip_get_desc(gc, offset);
4055 if (IS_ERR(desc))
4056 return;
4057
4058 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
4059 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4060 }
4061 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
4062
gpiochip_disable_irq(struct gpio_chip * gc,unsigned int offset)4063 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
4064 {
4065 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4066
4067 if (!IS_ERR(desc) &&
4068 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
4069 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4070 }
4071 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
4072
gpiochip_enable_irq(struct gpio_chip * gc,unsigned int offset)4073 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
4074 {
4075 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4076
4077 if (!IS_ERR(desc) &&
4078 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
4079 /*
4080 * We must not be output when using IRQ UNLESS we are
4081 * open drain.
4082 */
4083 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
4084 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
4085 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4086 }
4087 }
4088 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
4089
gpiochip_line_is_irq(struct gpio_chip * gc,unsigned int offset)4090 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
4091 {
4092 if (offset >= gc->ngpio)
4093 return false;
4094
4095 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
4096 }
4097 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
4098
gpiochip_reqres_irq(struct gpio_chip * gc,unsigned int offset)4099 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
4100 {
4101 int ret;
4102
4103 if (!try_module_get(gc->gpiodev->owner))
4104 return -ENODEV;
4105
4106 ret = gpiochip_lock_as_irq(gc, offset);
4107 if (ret) {
4108 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
4109 module_put(gc->gpiodev->owner);
4110 return ret;
4111 }
4112 return 0;
4113 }
4114 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
4115
gpiochip_relres_irq(struct gpio_chip * gc,unsigned int offset)4116 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
4117 {
4118 gpiochip_unlock_as_irq(gc, offset);
4119 module_put(gc->gpiodev->owner);
4120 }
4121 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
4122
gpiochip_line_is_open_drain(struct gpio_chip * gc,unsigned int offset)4123 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
4124 {
4125 if (offset >= gc->ngpio)
4126 return false;
4127
4128 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
4129 }
4130 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
4131
gpiochip_line_is_open_source(struct gpio_chip * gc,unsigned int offset)4132 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
4133 {
4134 if (offset >= gc->ngpio)
4135 return false;
4136
4137 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
4138 }
4139 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
4140
gpiochip_line_is_persistent(struct gpio_chip * gc,unsigned int offset)4141 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
4142 {
4143 if (offset >= gc->ngpio)
4144 return false;
4145
4146 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
4147 }
4148 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
4149
4150 /**
4151 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
4152 * @desc: gpio whose value will be returned
4153 *
4154 * Returns:
4155 * The GPIO's raw value, i.e. the value of the physical line disregarding
4156 * its ACTIVE_LOW status, or negative errno on failure.
4157 *
4158 * This function is to be called from contexts that can sleep.
4159 */
gpiod_get_raw_value_cansleep(const struct gpio_desc * desc)4160 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
4161 {
4162 might_sleep();
4163 VALIDATE_DESC(desc);
4164 return gpiod_get_raw_value_commit(desc);
4165 }
4166 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
4167
4168 /**
4169 * gpiod_get_value_cansleep() - return a gpio's value
4170 * @desc: gpio whose value will be returned
4171 *
4172 * Returns:
4173 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
4174 * account, or negative errno on failure.
4175 *
4176 * This function is to be called from contexts that can sleep.
4177 */
gpiod_get_value_cansleep(const struct gpio_desc * desc)4178 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
4179 {
4180 int value;
4181
4182 might_sleep();
4183 VALIDATE_DESC(desc);
4184 value = gpiod_get_raw_value_commit(desc);
4185 if (value < 0)
4186 return value;
4187
4188 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
4189 value = !value;
4190
4191 return value;
4192 }
4193 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
4194
4195 /**
4196 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
4197 * @array_size: number of elements in the descriptor array / value bitmap
4198 * @desc_array: array of GPIO descriptors whose values will be read
4199 * @array_info: information on applicability of fast bitmap processing path
4200 * @value_bitmap: bitmap to store the read values
4201 *
4202 * Read the raw values of the GPIOs, i.e. the values of the physical lines
4203 * without regard for their ACTIVE_LOW status.
4204 *
4205 * This function is to be called from contexts that can sleep.
4206 *
4207 * Returns:
4208 * 0 on success, or negative errno on failure.
4209 */
gpiod_get_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4210 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
4211 struct gpio_desc **desc_array,
4212 struct gpio_array *array_info,
4213 unsigned long *value_bitmap)
4214 {
4215 might_sleep();
4216 if (!desc_array)
4217 return -EINVAL;
4218 return gpiod_get_array_value_complex(true, true, array_size,
4219 desc_array, array_info,
4220 value_bitmap);
4221 }
4222 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
4223
4224 /**
4225 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
4226 * @array_size: number of elements in the descriptor array / value bitmap
4227 * @desc_array: array of GPIO descriptors whose values will be read
4228 * @array_info: information on applicability of fast bitmap processing path
4229 * @value_bitmap: bitmap to store the read values
4230 *
4231 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4232 * into account.
4233 *
4234 * This function is to be called from contexts that can sleep.
4235 *
4236 * Returns:
4237 * 0 on success, or negative errno on failure.
4238 */
gpiod_get_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4239 int gpiod_get_array_value_cansleep(unsigned int array_size,
4240 struct gpio_desc **desc_array,
4241 struct gpio_array *array_info,
4242 unsigned long *value_bitmap)
4243 {
4244 might_sleep();
4245 if (!desc_array)
4246 return -EINVAL;
4247 return gpiod_get_array_value_complex(false, true, array_size,
4248 desc_array, array_info,
4249 value_bitmap);
4250 }
4251 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
4252
4253 /**
4254 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
4255 * @desc: gpio whose value will be assigned
4256 * @value: value to assign
4257 *
4258 * Set the raw value of the GPIO, i.e. the value of its physical line without
4259 * regard for its ACTIVE_LOW status.
4260 *
4261 * This function is to be called from contexts that can sleep.
4262 *
4263 * Returns:
4264 * 0 on success, negative error number on failure.
4265 */
gpiod_set_raw_value_cansleep(struct gpio_desc * desc,int value)4266 int gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
4267 {
4268 might_sleep();
4269 VALIDATE_DESC(desc);
4270 return gpiod_set_raw_value_commit(desc, value);
4271 }
4272 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
4273
4274 /**
4275 * gpiod_set_value_cansleep() - assign a gpio's value
4276 * @desc: gpio whose value will be assigned
4277 * @value: value to assign
4278 *
4279 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
4280 * account
4281 *
4282 * This function is to be called from contexts that can sleep.
4283 *
4284 * Returns:
4285 * 0 on success, negative error number on failure.
4286 */
gpiod_set_value_cansleep(struct gpio_desc * desc,int value)4287 int gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
4288 {
4289 might_sleep();
4290 VALIDATE_DESC(desc);
4291 return gpiod_set_value_nocheck(desc, value);
4292 }
4293 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
4294
4295 /**
4296 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
4297 * @array_size: number of elements in the descriptor array / value bitmap
4298 * @desc_array: array of GPIO descriptors whose values will be assigned
4299 * @array_info: information on applicability of fast bitmap processing path
4300 * @value_bitmap: bitmap of values to assign
4301 *
4302 * Set the raw values of the GPIOs, i.e. the values of the physical lines
4303 * without regard for their ACTIVE_LOW status.
4304 *
4305 * This function is to be called from contexts that can sleep.
4306 *
4307 * Returns:
4308 * 0 on success, or negative errno on failure.
4309 */
gpiod_set_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4310 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
4311 struct gpio_desc **desc_array,
4312 struct gpio_array *array_info,
4313 unsigned long *value_bitmap)
4314 {
4315 might_sleep();
4316 if (!desc_array)
4317 return -EINVAL;
4318 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
4319 array_info, value_bitmap);
4320 }
4321 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
4322
4323 /**
4324 * gpiod_add_lookup_tables() - register GPIO device consumers
4325 * @tables: list of tables of consumers to register
4326 * @n: number of tables in the list
4327 */
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)4328 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
4329 {
4330 unsigned int i;
4331
4332 mutex_lock(&gpio_lookup_lock);
4333
4334 for (i = 0; i < n; i++)
4335 list_add_tail(&tables[i]->list, &gpio_lookup_list);
4336
4337 mutex_unlock(&gpio_lookup_lock);
4338 }
4339
4340 /**
4341 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
4342 * @array_size: number of elements in the descriptor array / value bitmap
4343 * @desc_array: array of GPIO descriptors whose values will be assigned
4344 * @array_info: information on applicability of fast bitmap processing path
4345 * @value_bitmap: bitmap of values to assign
4346 *
4347 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4348 * into account.
4349 *
4350 * This function is to be called from contexts that can sleep.
4351 *
4352 * Returns:
4353 * 0 on success, or negative errno on failure.
4354 */
gpiod_set_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4355 int gpiod_set_array_value_cansleep(unsigned int array_size,
4356 struct gpio_desc **desc_array,
4357 struct gpio_array *array_info,
4358 unsigned long *value_bitmap)
4359 {
4360 might_sleep();
4361 if (!desc_array)
4362 return -EINVAL;
4363 return gpiod_set_array_value_complex(false, true, array_size,
4364 desc_array, array_info,
4365 value_bitmap);
4366 }
4367 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
4368
gpiod_line_state_notify(struct gpio_desc * desc,unsigned long action)4369 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
4370 {
4371 guard(read_lock_irqsave)(&desc->gdev->line_state_lock);
4372
4373 raw_notifier_call_chain(&desc->gdev->line_state_notifier, action, desc);
4374 }
4375
4376 /**
4377 * gpiod_add_lookup_table() - register GPIO device consumers
4378 * @table: table of consumers to register
4379 */
gpiod_add_lookup_table(struct gpiod_lookup_table * table)4380 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
4381 {
4382 gpiod_add_lookup_tables(&table, 1);
4383 }
4384 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
4385
4386 /**
4387 * gpiod_remove_lookup_table() - unregister GPIO device consumers
4388 * @table: table of consumers to unregister
4389 */
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)4390 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4391 {
4392 /* Nothing to remove */
4393 if (!table)
4394 return;
4395
4396 mutex_lock(&gpio_lookup_lock);
4397
4398 list_del(&table->list);
4399
4400 mutex_unlock(&gpio_lookup_lock);
4401 }
4402 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4403
4404 /**
4405 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4406 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4407 */
gpiod_add_hogs(struct gpiod_hog * hogs)4408 void gpiod_add_hogs(struct gpiod_hog *hogs)
4409 {
4410 struct gpiod_hog *hog;
4411
4412 mutex_lock(&gpio_machine_hogs_mutex);
4413
4414 for (hog = &hogs[0]; hog->chip_label; hog++) {
4415 list_add_tail(&hog->list, &gpio_machine_hogs);
4416
4417 /*
4418 * The chip may have been registered earlier, so check if it
4419 * exists and, if so, try to hog the line now.
4420 */
4421 struct gpio_device *gdev __free(gpio_device_put) =
4422 gpio_device_find_by_label(hog->chip_label);
4423 if (gdev)
4424 gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);
4425 }
4426
4427 mutex_unlock(&gpio_machine_hogs_mutex);
4428 }
4429 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4430
gpiod_remove_hogs(struct gpiod_hog * hogs)4431 void gpiod_remove_hogs(struct gpiod_hog *hogs)
4432 {
4433 struct gpiod_hog *hog;
4434
4435 mutex_lock(&gpio_machine_hogs_mutex);
4436 for (hog = &hogs[0]; hog->chip_label; hog++)
4437 list_del(&hog->list);
4438 mutex_unlock(&gpio_machine_hogs_mutex);
4439 }
4440 EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
4441
gpiod_find_lookup_table(struct device * dev)4442 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4443 {
4444 const char *dev_id = dev ? dev_name(dev) : NULL;
4445 struct gpiod_lookup_table *table;
4446
4447 list_for_each_entry(table, &gpio_lookup_list, list) {
4448 if (table->dev_id && dev_id) {
4449 /*
4450 * Valid strings on both ends, must be identical to have
4451 * a match
4452 */
4453 if (!strcmp(table->dev_id, dev_id))
4454 return table;
4455 } else {
4456 /*
4457 * One of the pointers is NULL, so both must be to have
4458 * a match
4459 */
4460 if (dev_id == table->dev_id)
4461 return table;
4462 }
4463 }
4464
4465 return NULL;
4466 }
4467
gpiod_find(struct device * dev,const char * con_id,unsigned int idx,unsigned long * flags)4468 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4469 unsigned int idx, unsigned long *flags)
4470 {
4471 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4472 struct gpiod_lookup_table *table;
4473 struct gpiod_lookup *p;
4474 struct gpio_chip *gc;
4475
4476 guard(mutex)(&gpio_lookup_lock);
4477
4478 table = gpiod_find_lookup_table(dev);
4479 if (!table)
4480 return desc;
4481
4482 for (p = &table->table[0]; p->key; p++) {
4483 /* idx must always match exactly */
4484 if (p->idx != idx)
4485 continue;
4486
4487 /* If the lookup entry has a con_id, require exact match */
4488 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4489 continue;
4490
4491 if (p->chip_hwnum == U16_MAX) {
4492 desc = gpio_name_to_desc(p->key);
4493 if (desc) {
4494 *flags = p->flags;
4495 return desc;
4496 }
4497
4498 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
4499 p->key);
4500 return ERR_PTR(-EPROBE_DEFER);
4501 }
4502
4503 struct gpio_device *gdev __free(gpio_device_put) =
4504 gpio_device_find_by_label(p->key);
4505 if (!gdev) {
4506 /*
4507 * As the lookup table indicates a chip with
4508 * p->key should exist, assume it may
4509 * still appear later and let the interested
4510 * consumer be probed again or let the Deferred
4511 * Probe infrastructure handle the error.
4512 */
4513 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4514 p->key);
4515 return ERR_PTR(-EPROBE_DEFER);
4516 }
4517
4518 gc = gpio_device_get_chip(gdev);
4519
4520 if (gc->ngpio <= p->chip_hwnum) {
4521 dev_err(dev,
4522 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4523 idx, p->chip_hwnum, gc->ngpio - 1,
4524 gc->label);
4525 return ERR_PTR(-EINVAL);
4526 }
4527
4528 desc = gpio_device_get_desc(gdev, p->chip_hwnum);
4529 *flags = p->flags;
4530
4531 return desc;
4532 }
4533
4534 return desc;
4535 }
4536
platform_gpio_count(struct device * dev,const char * con_id)4537 static int platform_gpio_count(struct device *dev, const char *con_id)
4538 {
4539 struct gpiod_lookup_table *table;
4540 struct gpiod_lookup *p;
4541 unsigned int count = 0;
4542
4543 scoped_guard(mutex, &gpio_lookup_lock) {
4544 table = gpiod_find_lookup_table(dev);
4545 if (!table)
4546 return -ENOENT;
4547
4548 for (p = &table->table[0]; p->key; p++) {
4549 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4550 (!con_id && !p->con_id))
4551 count++;
4552 }
4553 }
4554
4555 if (!count)
4556 return -ENOENT;
4557
4558 return count;
4559 }
4560
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)4561 static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
4562 struct device *consumer,
4563 const char *con_id,
4564 unsigned int idx,
4565 enum gpiod_flags *flags,
4566 unsigned long *lookupflags)
4567 {
4568 const char *name = function_name_or_default(con_id);
4569 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4570
4571 if (is_of_node(fwnode)) {
4572 dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4573 desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
4574 } else if (is_acpi_node(fwnode)) {
4575 dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4576 desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
4577 } else if (is_software_node(fwnode)) {
4578 dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4579 desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
4580 }
4581
4582 return desc;
4583 }
4584
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)4585 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
4586 struct fwnode_handle *fwnode,
4587 const char *con_id,
4588 unsigned int idx,
4589 enum gpiod_flags flags,
4590 const char *label,
4591 bool platform_lookup_allowed)
4592 {
4593 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4594 const char *name = function_name_or_default(con_id);
4595 /*
4596 * scoped_guard() is implemented as a for loop, meaning static
4597 * analyzers will complain about these two not being initialized.
4598 */
4599 struct gpio_desc *desc = NULL;
4600 int ret = 0;
4601
4602 scoped_guard(srcu, &gpio_devices_srcu) {
4603 desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
4604 &flags, &lookupflags);
4605 if (gpiod_not_found(desc) && platform_lookup_allowed) {
4606 /*
4607 * Either we are not using DT or ACPI, or their lookup
4608 * did not return a result. In that case, use platform
4609 * lookup as a fallback.
4610 */
4611 dev_dbg(consumer,
4612 "using lookup tables for GPIO lookup\n");
4613 desc = gpiod_find(consumer, con_id, idx, &lookupflags);
4614 }
4615
4616 if (IS_ERR(desc)) {
4617 dev_dbg(consumer, "No GPIO consumer %s found\n", name);
4618 return desc;
4619 }
4620
4621 /*
4622 * If a connection label was passed use that, else attempt to use
4623 * the device name as label
4624 */
4625 ret = gpiod_request(desc, label);
4626 }
4627 if (ret) {
4628 if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4629 return ERR_PTR(ret);
4630
4631 /*
4632 * This happens when there are several consumers for
4633 * the same GPIO line: we just return here without
4634 * further initialization. It is a bit of a hack.
4635 * This is necessary to support fixed regulators.
4636 *
4637 * FIXME: Make this more sane and safe.
4638 */
4639 dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
4640 return desc;
4641 }
4642
4643 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4644 if (ret < 0) {
4645 gpiod_put(desc);
4646 dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret);
4647 return ERR_PTR(ret);
4648 }
4649
4650 gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
4651
4652 return desc;
4653 }
4654
4655 /**
4656 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
4657 * @fwnode: handle of the firmware node
4658 * @con_id: function within the GPIO consumer
4659 * @index: index of the GPIO to obtain for the consumer
4660 * @flags: GPIO initialization flags
4661 * @label: label to attach to the requested GPIO
4662 *
4663 * This function can be used for drivers that get their configuration
4664 * from opaque firmware.
4665 *
4666 * The function properly finds the corresponding GPIO using whatever is the
4667 * underlying firmware interface and then makes sure that the GPIO
4668 * descriptor is requested before it is returned to the caller.
4669 *
4670 * Returns:
4671 * On successful request the GPIO pin is configured in accordance with
4672 * provided @flags.
4673 *
4674 * In case of error an ERR_PTR() is returned.
4675 */
fwnode_gpiod_get_index(struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)4676 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
4677 const char *con_id,
4678 int index,
4679 enum gpiod_flags flags,
4680 const char *label)
4681 {
4682 return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
4683 }
4684 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
4685
4686 /**
4687 * gpiod_count - return the number of GPIOs associated with a device / function
4688 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4689 * @con_id: function within the GPIO consumer
4690 *
4691 * Returns:
4692 * The number of GPIOs associated with a device / function or -ENOENT if no
4693 * GPIO has been assigned to the requested function.
4694 */
gpiod_count(struct device * dev,const char * con_id)4695 int gpiod_count(struct device *dev, const char *con_id)
4696 {
4697 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4698 int count = -ENOENT;
4699
4700 if (is_of_node(fwnode))
4701 count = of_gpio_count(fwnode, con_id);
4702 else if (is_acpi_node(fwnode))
4703 count = acpi_gpio_count(fwnode, con_id);
4704 else if (is_software_node(fwnode))
4705 count = swnode_gpio_count(fwnode, con_id);
4706
4707 if (count < 0)
4708 count = platform_gpio_count(dev, con_id);
4709
4710 return count;
4711 }
4712 EXPORT_SYMBOL_GPL(gpiod_count);
4713
4714 /**
4715 * gpiod_get - obtain a GPIO for a given GPIO function
4716 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4717 * @con_id: function within the GPIO consumer
4718 * @flags: optional GPIO initialization flags
4719 *
4720 * Returns:
4721 * The GPIO descriptor corresponding to the function @con_id of device
4722 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4723 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4724 */
gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)4725 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4726 enum gpiod_flags flags)
4727 {
4728 return gpiod_get_index(dev, con_id, 0, flags);
4729 }
4730 EXPORT_SYMBOL_GPL(gpiod_get);
4731
4732 /**
4733 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4734 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4735 * @con_id: function within the GPIO consumer
4736 * @flags: optional GPIO initialization flags
4737 *
4738 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4739 * the requested function it will return NULL. This is convenient for drivers
4740 * that need to handle optional GPIOs.
4741 *
4742 * Returns:
4743 * The GPIO descriptor corresponding to the function @con_id of device
4744 * dev, NULL if no GPIO has been assigned to the requested function, or
4745 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4746 */
gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4747 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4748 const char *con_id,
4749 enum gpiod_flags flags)
4750 {
4751 return gpiod_get_index_optional(dev, con_id, 0, flags);
4752 }
4753 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4754
4755
4756 /**
4757 * gpiod_configure_flags - helper function to configure a given GPIO
4758 * @desc: gpio whose value will be assigned
4759 * @con_id: function within the GPIO consumer
4760 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4761 * of_find_gpio() or of_get_gpio_hog()
4762 * @dflags: gpiod_flags - optional GPIO initialization flags
4763 *
4764 * Returns:
4765 * 0 on success, -ENOENT if no GPIO has been assigned to the
4766 * requested function and/or index, or another IS_ERR() code if an error
4767 * occurred while trying to acquire the GPIO.
4768 */
gpiod_configure_flags(struct gpio_desc * desc,const char * con_id,unsigned long lflags,enum gpiod_flags dflags)4769 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4770 unsigned long lflags, enum gpiod_flags dflags)
4771 {
4772 const char *name = function_name_or_default(con_id);
4773 int ret;
4774
4775 if (lflags & GPIO_ACTIVE_LOW)
4776 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4777
4778 if (lflags & GPIO_OPEN_DRAIN)
4779 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4780 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4781 /*
4782 * This enforces open drain mode from the consumer side.
4783 * This is necessary for some busses like I2C, but the lookup
4784 * should *REALLY* have specified them as open drain in the
4785 * first place, so print a little warning here.
4786 */
4787 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4788 gpiod_warn(desc,
4789 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4790 }
4791
4792 if (lflags & GPIO_OPEN_SOURCE)
4793 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4794
4795 if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
4796 ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
4797 ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
4798 gpiod_err(desc,
4799 "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
4800 return -EINVAL;
4801 }
4802
4803 if (lflags & GPIO_PULL_UP)
4804 set_bit(FLAG_PULL_UP, &desc->flags);
4805 else if (lflags & GPIO_PULL_DOWN)
4806 set_bit(FLAG_PULL_DOWN, &desc->flags);
4807 else if (lflags & GPIO_PULL_DISABLE)
4808 set_bit(FLAG_BIAS_DISABLE, &desc->flags);
4809
4810 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4811 if (ret < 0)
4812 return ret;
4813
4814 /* No particular flag request, return here... */
4815 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4816 gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
4817 return 0;
4818 }
4819
4820 /* Process flags */
4821 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4822 ret = gpiod_direction_output_nonotify(desc,
4823 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4824 else
4825 ret = gpiod_direction_input_nonotify(desc);
4826
4827 return ret;
4828 }
4829
4830 /**
4831 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4832 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4833 * @con_id: function within the GPIO consumer
4834 * @idx: index of the GPIO to obtain in the consumer
4835 * @flags: optional GPIO initialization flags
4836 *
4837 * This variant of gpiod_get() allows to access GPIOs other than the first
4838 * defined one for functions that define several GPIOs.
4839 *
4840 * Returns:
4841 * A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4842 * requested function and/or index, or another IS_ERR() code if an error
4843 * occurred while trying to acquire the GPIO.
4844 */
gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)4845 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4846 const char *con_id,
4847 unsigned int idx,
4848 enum gpiod_flags flags)
4849 {
4850 struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4851 const char *devname = dev ? dev_name(dev) : "?";
4852 const char *label = con_id ?: devname;
4853
4854 return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
4855 }
4856 EXPORT_SYMBOL_GPL(gpiod_get_index);
4857
4858 /**
4859 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4860 * function
4861 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4862 * @con_id: function within the GPIO consumer
4863 * @index: index of the GPIO to obtain in the consumer
4864 * @flags: optional GPIO initialization flags
4865 *
4866 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4867 * specified index was assigned to the requested function it will return NULL.
4868 * This is convenient for drivers that need to handle optional GPIOs.
4869 *
4870 * Returns:
4871 * A valid GPIO descriptor, NULL if no GPIO has been assigned to the
4872 * requested function and/or index, or another IS_ERR() code if an error
4873 * occurred while trying to acquire the GPIO.
4874 */
gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)4875 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4876 const char *con_id,
4877 unsigned int index,
4878 enum gpiod_flags flags)
4879 {
4880 struct gpio_desc *desc;
4881
4882 desc = gpiod_get_index(dev, con_id, index, flags);
4883 if (gpiod_not_found(desc))
4884 return NULL;
4885
4886 return desc;
4887 }
4888 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4889
4890 /**
4891 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4892 * @desc: gpio whose value will be assigned
4893 * @name: gpio line name
4894 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4895 * of_find_gpio() or of_get_gpio_hog()
4896 * @dflags: gpiod_flags - optional GPIO initialization flags
4897 *
4898 * Returns:
4899 * 0 on success, or negative errno on failure.
4900 */
gpiod_hog(struct gpio_desc * desc,const char * name,unsigned long lflags,enum gpiod_flags dflags)4901 int gpiod_hog(struct gpio_desc *desc, const char *name,
4902 unsigned long lflags, enum gpiod_flags dflags)
4903 {
4904 struct gpio_device *gdev = desc->gdev;
4905 struct gpio_desc *local_desc;
4906 int hwnum;
4907 int ret;
4908
4909 CLASS(gpio_chip_guard, guard)(desc);
4910 if (!guard.gc)
4911 return -ENODEV;
4912
4913 if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))
4914 return 0;
4915
4916 hwnum = gpio_chip_hwgpio(desc);
4917
4918 local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
4919 lflags, dflags);
4920 if (IS_ERR(local_desc)) {
4921 clear_bit(FLAG_IS_HOGGED, &desc->flags);
4922 ret = PTR_ERR(local_desc);
4923 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4924 name, gdev->label, hwnum, ret);
4925 return ret;
4926 }
4927
4928 gpiod_dbg(desc, "hogged as %s/%s\n",
4929 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4930 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4931 str_high_low(dflags & GPIOD_FLAGS_BIT_DIR_VAL) : "?");
4932
4933 return 0;
4934 }
4935
4936 /**
4937 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4938 * @gc: gpio chip to act on
4939 */
gpiochip_free_hogs(struct gpio_chip * gc)4940 static void gpiochip_free_hogs(struct gpio_chip *gc)
4941 {
4942 struct gpio_desc *desc;
4943
4944 for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)
4945 gpiochip_free_own_desc(desc);
4946 }
4947
4948 /**
4949 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4950 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4951 * @con_id: function within the GPIO consumer
4952 * @flags: optional GPIO initialization flags
4953 *
4954 * This function acquires all the GPIOs defined under a given function.
4955 *
4956 * Returns:
4957 * The GPIO descriptors corresponding to the function @con_id of device
4958 * dev, -ENOENT if no GPIO has been assigned to the requested function,
4959 * or another IS_ERR() code if an error occurred while trying to acquire
4960 * the GPIOs.
4961 */
gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)4962 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4963 const char *con_id,
4964 enum gpiod_flags flags)
4965 {
4966 struct gpio_desc *desc;
4967 struct gpio_descs *descs;
4968 struct gpio_device *gdev;
4969 struct gpio_array *array_info = NULL;
4970 int count, bitmap_size;
4971 unsigned long dflags;
4972 size_t descs_size;
4973
4974 count = gpiod_count(dev, con_id);
4975 if (count < 0)
4976 return ERR_PTR(count);
4977
4978 descs_size = struct_size(descs, desc, count);
4979 descs = kzalloc(descs_size, GFP_KERNEL);
4980 if (!descs)
4981 return ERR_PTR(-ENOMEM);
4982
4983 for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
4984 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4985 if (IS_ERR(desc)) {
4986 gpiod_put_array(descs);
4987 return ERR_CAST(desc);
4988 }
4989
4990 descs->desc[descs->ndescs] = desc;
4991
4992 gdev = gpiod_to_gpio_device(desc);
4993 /*
4994 * If pin hardware number of array member 0 is also 0, select
4995 * its chip as a candidate for fast bitmap processing path.
4996 */
4997 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4998 struct gpio_descs *array;
4999
5000 bitmap_size = BITS_TO_LONGS(gdev->ngpio > count ?
5001 gdev->ngpio : count);
5002
5003 array = krealloc(descs, descs_size +
5004 struct_size(array_info, invert_mask, 3 * bitmap_size),
5005 GFP_KERNEL | __GFP_ZERO);
5006 if (!array) {
5007 gpiod_put_array(descs);
5008 return ERR_PTR(-ENOMEM);
5009 }
5010
5011 descs = array;
5012
5013 array_info = (void *)descs + descs_size;
5014 array_info->get_mask = array_info->invert_mask +
5015 bitmap_size;
5016 array_info->set_mask = array_info->get_mask +
5017 bitmap_size;
5018
5019 array_info->desc = descs->desc;
5020 array_info->size = count;
5021 array_info->gdev = gdev;
5022 bitmap_set(array_info->get_mask, descs->ndescs,
5023 count - descs->ndescs);
5024 bitmap_set(array_info->set_mask, descs->ndescs,
5025 count - descs->ndescs);
5026 descs->info = array_info;
5027 }
5028
5029 /* If there is no cache for fast bitmap processing path, continue */
5030 if (!array_info)
5031 continue;
5032
5033 /* Unmark array members which don't belong to the 'fast' chip */
5034 if (array_info->gdev != gdev) {
5035 __clear_bit(descs->ndescs, array_info->get_mask);
5036 __clear_bit(descs->ndescs, array_info->set_mask);
5037 }
5038 /*
5039 * Detect array members which belong to the 'fast' chip
5040 * but their pins are not in hardware order.
5041 */
5042 else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
5043 /*
5044 * Don't use fast path if all array members processed so
5045 * far belong to the same chip as this one but its pin
5046 * hardware number is different from its array index.
5047 */
5048 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
5049 array_info = NULL;
5050 } else {
5051 __clear_bit(descs->ndescs,
5052 array_info->get_mask);
5053 __clear_bit(descs->ndescs,
5054 array_info->set_mask);
5055 }
5056 } else {
5057 dflags = READ_ONCE(desc->flags);
5058 /* Exclude open drain or open source from fast output */
5059 if (test_bit(FLAG_OPEN_DRAIN, &dflags) ||
5060 test_bit(FLAG_OPEN_SOURCE, &dflags))
5061 __clear_bit(descs->ndescs,
5062 array_info->set_mask);
5063 /* Identify 'fast' pins which require invertion */
5064 if (gpiod_is_active_low(desc))
5065 __set_bit(descs->ndescs,
5066 array_info->invert_mask);
5067 }
5068 }
5069 if (array_info)
5070 dev_dbg(dev,
5071 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
5072 array_info->gdev->label, array_info->size,
5073 *array_info->get_mask, *array_info->set_mask,
5074 *array_info->invert_mask);
5075 return descs;
5076 }
5077 EXPORT_SYMBOL_GPL(gpiod_get_array);
5078
5079 /**
5080 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
5081 * function
5082 * @dev: GPIO consumer, can be NULL for system-global GPIOs
5083 * @con_id: function within the GPIO consumer
5084 * @flags: optional GPIO initialization flags
5085 *
5086 * This is equivalent to gpiod_get_array(), except that when no GPIO was
5087 * assigned to the requested function it will return NULL.
5088 *
5089 * Returns:
5090 * The GPIO descriptors corresponding to the function @con_id of device
5091 * dev, NULL if no GPIO has been assigned to the requested function,
5092 * or another IS_ERR() code if an error occurred while trying to acquire
5093 * the GPIOs.
5094 */
gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)5095 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
5096 const char *con_id,
5097 enum gpiod_flags flags)
5098 {
5099 struct gpio_descs *descs;
5100
5101 descs = gpiod_get_array(dev, con_id, flags);
5102 if (gpiod_not_found(descs))
5103 return NULL;
5104
5105 return descs;
5106 }
5107 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
5108
5109 /**
5110 * gpiod_put - dispose of a GPIO descriptor
5111 * @desc: GPIO descriptor to dispose of
5112 *
5113 * No descriptor can be used after gpiod_put() has been called on it.
5114 */
gpiod_put(struct gpio_desc * desc)5115 void gpiod_put(struct gpio_desc *desc)
5116 {
5117 if (desc)
5118 gpiod_free(desc);
5119 }
5120 EXPORT_SYMBOL_GPL(gpiod_put);
5121
5122 /**
5123 * gpiod_put_array - dispose of multiple GPIO descriptors
5124 * @descs: struct gpio_descs containing an array of descriptors
5125 */
gpiod_put_array(struct gpio_descs * descs)5126 void gpiod_put_array(struct gpio_descs *descs)
5127 {
5128 unsigned int i;
5129
5130 for (i = 0; i < descs->ndescs; i++)
5131 gpiod_put(descs->desc[i]);
5132
5133 kfree(descs);
5134 }
5135 EXPORT_SYMBOL_GPL(gpiod_put_array);
5136
gpio_stub_drv_probe(struct device * dev)5137 static int gpio_stub_drv_probe(struct device *dev)
5138 {
5139 /*
5140 * The DT node of some GPIO chips have a "compatible" property, but
5141 * never have a struct device added and probed by a driver to register
5142 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
5143 * the consumers of the GPIO chip to get probe deferred forever because
5144 * they will be waiting for a device associated with the GPIO chip
5145 * firmware node to get added and bound to a driver.
5146 *
5147 * To allow these consumers to probe, we associate the struct
5148 * gpio_device of the GPIO chip with the firmware node and then simply
5149 * bind it to this stub driver.
5150 */
5151 return 0;
5152 }
5153
5154 static struct device_driver gpio_stub_drv = {
5155 .name = "gpio_stub_drv",
5156 .bus = &gpio_bus_type,
5157 .probe = gpio_stub_drv_probe,
5158 };
5159
gpiolib_dev_init(void)5160 static int __init gpiolib_dev_init(void)
5161 {
5162 int ret;
5163
5164 /* Register GPIO sysfs bus */
5165 ret = bus_register(&gpio_bus_type);
5166 if (ret < 0) {
5167 pr_err("gpiolib: could not register GPIO bus type\n");
5168 return ret;
5169 }
5170
5171 ret = driver_register(&gpio_stub_drv);
5172 if (ret < 0) {
5173 pr_err("gpiolib: could not register GPIO stub driver\n");
5174 bus_unregister(&gpio_bus_type);
5175 return ret;
5176 }
5177
5178 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
5179 if (ret < 0) {
5180 pr_err("gpiolib: failed to allocate char dev region\n");
5181 driver_unregister(&gpio_stub_drv);
5182 bus_unregister(&gpio_bus_type);
5183 return ret;
5184 }
5185
5186 gpiolib_initialized = true;
5187 gpiochip_setup_devs();
5188
5189 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
5190 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
5191 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
5192
5193 return ret;
5194 }
5195 core_initcall(gpiolib_dev_init);
5196
5197 #ifdef CONFIG_DEBUG_FS
5198
gpiolib_dbg_show(struct seq_file * s,struct gpio_device * gdev)5199 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
5200 {
5201 bool active_low, is_irq, is_out;
5202 unsigned int gpio = gdev->base;
5203 struct gpio_desc *desc;
5204 struct gpio_chip *gc;
5205 unsigned long flags;
5206 int value;
5207
5208 guard(srcu)(&gdev->srcu);
5209
5210 gc = srcu_dereference(gdev->chip, &gdev->srcu);
5211 if (!gc) {
5212 seq_puts(s, "Underlying GPIO chip is gone\n");
5213 return;
5214 }
5215
5216 for_each_gpio_desc(gc, desc) {
5217 guard(srcu)(&desc->gdev->desc_srcu);
5218 flags = READ_ONCE(desc->flags);
5219 is_irq = test_bit(FLAG_USED_AS_IRQ, &flags);
5220 if (is_irq || test_bit(FLAG_REQUESTED, &flags)) {
5221 gpiod_get_direction(desc);
5222 is_out = test_bit(FLAG_IS_OUT, &flags);
5223 value = gpio_chip_get_value(gc, desc);
5224 active_low = test_bit(FLAG_ACTIVE_LOW, &flags);
5225 seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
5226 gpio, desc->name ?: "", gpiod_get_label(desc),
5227 is_out ? "out" : "in ",
5228 value >= 0 ? str_hi_lo(value) : "? ",
5229 is_irq ? "IRQ " : "",
5230 active_low ? "ACTIVE LOW" : "");
5231 } else if (desc->name) {
5232 seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name);
5233 }
5234
5235 gpio++;
5236 }
5237 }
5238
5239 struct gpiolib_seq_priv {
5240 bool newline;
5241 int idx;
5242 };
5243
gpiolib_seq_start(struct seq_file * s,loff_t * pos)5244 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
5245 {
5246 struct gpiolib_seq_priv *priv;
5247 struct gpio_device *gdev;
5248 loff_t index = *pos;
5249
5250 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
5251 if (!priv)
5252 return NULL;
5253
5254 s->private = priv;
5255 if (*pos > 0)
5256 priv->newline = true;
5257 priv->idx = srcu_read_lock(&gpio_devices_srcu);
5258
5259 list_for_each_entry_srcu(gdev, &gpio_devices, list,
5260 srcu_read_lock_held(&gpio_devices_srcu)) {
5261 if (index-- == 0)
5262 return gdev;
5263 }
5264
5265 return NULL;
5266 }
5267
gpiolib_seq_next(struct seq_file * s,void * v,loff_t * pos)5268 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
5269 {
5270 struct gpiolib_seq_priv *priv = s->private;
5271 struct gpio_device *gdev = v, *next;
5272
5273 next = list_entry_rcu(gdev->list.next, struct gpio_device, list);
5274 gdev = &next->list == &gpio_devices ? NULL : next;
5275 priv->newline = true;
5276 ++*pos;
5277
5278 return gdev;
5279 }
5280
gpiolib_seq_stop(struct seq_file * s,void * v)5281 static void gpiolib_seq_stop(struct seq_file *s, void *v)
5282 {
5283 struct gpiolib_seq_priv *priv = s->private;
5284
5285 srcu_read_unlock(&gpio_devices_srcu, priv->idx);
5286 kfree(priv);
5287 }
5288
gpiolib_seq_show(struct seq_file * s,void * v)5289 static int gpiolib_seq_show(struct seq_file *s, void *v)
5290 {
5291 struct gpiolib_seq_priv *priv = s->private;
5292 struct gpio_device *gdev = v;
5293 struct gpio_chip *gc;
5294 struct device *parent;
5295
5296 if (priv->newline)
5297 seq_putc(s, '\n');
5298
5299 guard(srcu)(&gdev->srcu);
5300
5301 gc = srcu_dereference(gdev->chip, &gdev->srcu);
5302 if (!gc) {
5303 seq_printf(s, "%s: (dangling chip)\n", dev_name(&gdev->dev));
5304 return 0;
5305 }
5306
5307 seq_printf(s, "%s: GPIOs %u-%u", dev_name(&gdev->dev), gdev->base,
5308 gdev->base + gdev->ngpio - 1);
5309 parent = gc->parent;
5310 if (parent)
5311 seq_printf(s, ", parent: %s/%s",
5312 parent->bus ? parent->bus->name : "no-bus",
5313 dev_name(parent));
5314 if (gc->label)
5315 seq_printf(s, ", %s", gc->label);
5316 if (gc->can_sleep)
5317 seq_printf(s, ", can sleep");
5318 seq_printf(s, ":\n");
5319
5320 if (gc->dbg_show)
5321 gc->dbg_show(s, gc);
5322 else
5323 gpiolib_dbg_show(s, gdev);
5324
5325 return 0;
5326 }
5327
5328 static const struct seq_operations gpiolib_sops = {
5329 .start = gpiolib_seq_start,
5330 .next = gpiolib_seq_next,
5331 .stop = gpiolib_seq_stop,
5332 .show = gpiolib_seq_show,
5333 };
5334 DEFINE_SEQ_ATTRIBUTE(gpiolib);
5335
gpiolib_debugfs_init(void)5336 static int __init gpiolib_debugfs_init(void)
5337 {
5338 /* /sys/kernel/debug/gpio */
5339 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
5340 return 0;
5341 }
5342 subsys_initcall(gpiolib_debugfs_init);
5343
5344 #endif /* DEBUG_FS */
5345