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/kernel.h>
18 #include <linux/list.h>
19 #include <linux/lockdep.h>
20 #include <linux/module.h>
21 #include <linux/nospec.h>
22 #include <linux/of.h>
23 #include <linux/pinctrl/consumer.h>
24 #include <linux/seq_file.h>
25 #include <linux/slab.h>
26 #include <linux/spinlock.h>
27 #include <linux/srcu.h>
28 #include <linux/string.h>
29
30 #include <linux/gpio.h>
31 #include <linux/gpio/driver.h>
32 #include <linux/gpio/machine.h>
33
34 #include <uapi/linux/gpio.h>
35
36 #include "gpiolib-acpi.h"
37 #include "gpiolib-cdev.h"
38 #include "gpiolib-of.h"
39 #include "gpiolib-swnode.h"
40 #include "gpiolib-sysfs.h"
41 #include "gpiolib.h"
42
43 #define CREATE_TRACE_POINTS
44 #include <trace/events/gpio.h>
45
46 /* Implementation infrastructure for GPIO interfaces.
47 *
48 * The GPIO programming interface allows for inlining speed-critical
49 * get/set operations for common cases, so that access to SOC-integrated
50 * GPIOs can sometimes cost only an instruction or two per bit.
51 */
52
53 /* Device and char device-related information */
54 static DEFINE_IDA(gpio_ida);
55 static dev_t gpio_devt;
56 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
57
gpio_bus_match(struct device * dev,const struct device_driver * drv)58 static int gpio_bus_match(struct device *dev, const struct device_driver *drv)
59 {
60 struct fwnode_handle *fwnode = dev_fwnode(dev);
61
62 /*
63 * Only match if the fwnode doesn't already have a proper struct device
64 * created for it.
65 */
66 if (fwnode && fwnode->dev != dev)
67 return 0;
68 return 1;
69 }
70
71 static const struct bus_type gpio_bus_type = {
72 .name = "gpio",
73 .match = gpio_bus_match,
74 };
75
76 /*
77 * Number of GPIOs to use for the fast path in set array
78 */
79 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
80
81 static DEFINE_MUTEX(gpio_lookup_lock);
82 static LIST_HEAD(gpio_lookup_list);
83
84 static LIST_HEAD(gpio_devices);
85 /* Protects the GPIO device list against concurrent modifications. */
86 static DEFINE_MUTEX(gpio_devices_lock);
87 /* Ensures coherence during read-only accesses to the list of GPIO devices. */
88 DEFINE_STATIC_SRCU(gpio_devices_srcu);
89
90 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
91 static LIST_HEAD(gpio_machine_hogs);
92
93 const char *const gpio_suffixes[] = { "gpios", "gpio" };
94 const size_t gpio_suffix_count = ARRAY_SIZE(gpio_suffixes);
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->str ?: "interrupt";
119
120 if (!test_bit(FLAG_REQUESTED, &flags))
121 return NULL;
122
123 return label->str;
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 */
gpiod_to_chip(const struct gpio_desc * desc)235 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
236 {
237 if (!desc)
238 return NULL;
239
240 return gpio_device_get_chip(desc->gdev);
241 }
242 EXPORT_SYMBOL_GPL(gpiod_to_chip);
243
244 /**
245 * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor
246 * belongs.
247 * @desc: Descriptor for which to return the GPIO device.
248 *
249 * This *DOES NOT* increase the reference count of the GPIO device as it's
250 * expected that the descriptor is requested and the users already holds a
251 * reference to the device.
252 *
253 * Returns:
254 * Address of the GPIO device owning this descriptor.
255 */
gpiod_to_gpio_device(struct gpio_desc * desc)256 struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc)
257 {
258 if (!desc)
259 return NULL;
260
261 return desc->gdev;
262 }
263 EXPORT_SYMBOL_GPL(gpiod_to_gpio_device);
264
265 /**
266 * gpio_device_get_base() - Get the base GPIO number allocated by this device
267 * @gdev: GPIO device
268 *
269 * Returns:
270 * First GPIO number in the global GPIO numberspace for this device.
271 */
gpio_device_get_base(struct gpio_device * gdev)272 int gpio_device_get_base(struct gpio_device *gdev)
273 {
274 return gdev->base;
275 }
276 EXPORT_SYMBOL_GPL(gpio_device_get_base);
277
278 /**
279 * gpio_device_get_label() - Get the label of this GPIO device
280 * @gdev: GPIO device
281 *
282 * Returns:
283 * Pointer to the string containing the GPIO device label. The string's
284 * lifetime is tied to that of the underlying GPIO device.
285 */
gpio_device_get_label(struct gpio_device * gdev)286 const char *gpio_device_get_label(struct gpio_device *gdev)
287 {
288 return gdev->label;
289 }
290 EXPORT_SYMBOL(gpio_device_get_label);
291
292 /**
293 * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device
294 * @gdev: GPIO device
295 *
296 * Returns:
297 * Address of the GPIO chip backing this device.
298 *
299 * *DEPRECATED*
300 * Until we can get rid of all non-driver users of struct gpio_chip, we must
301 * provide a way of retrieving the pointer to it from struct gpio_device. This
302 * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the
303 * chip can dissapear at any moment (unlike reference-counted struct
304 * gpio_device).
305 *
306 * Use at your own risk.
307 */
gpio_device_get_chip(struct gpio_device * gdev)308 struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)
309 {
310 return rcu_dereference_check(gdev->chip, 1);
311 }
312 EXPORT_SYMBOL_GPL(gpio_device_get_chip);
313
314 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
gpiochip_find_base_unlocked(u16 ngpio)315 static int gpiochip_find_base_unlocked(u16 ngpio)
316 {
317 unsigned int base = GPIO_DYNAMIC_BASE;
318 struct gpio_device *gdev;
319
320 list_for_each_entry_srcu(gdev, &gpio_devices, list,
321 lockdep_is_held(&gpio_devices_lock)) {
322 /* found a free space? */
323 if (gdev->base >= base + ngpio)
324 break;
325 /* nope, check the space right after the chip */
326 base = gdev->base + gdev->ngpio;
327 if (base < GPIO_DYNAMIC_BASE)
328 base = GPIO_DYNAMIC_BASE;
329 if (base > GPIO_DYNAMIC_MAX - ngpio)
330 break;
331 }
332
333 if (base <= GPIO_DYNAMIC_MAX - ngpio) {
334 pr_debug("%s: found new base at %d\n", __func__, base);
335 return base;
336 } else {
337 pr_err("%s: cannot find free range\n", __func__);
338 return -ENOSPC;
339 }
340 }
341
342 /**
343 * gpiod_get_direction - return the current direction of a GPIO
344 * @desc: GPIO to get the direction of
345 *
346 * Returns 0 for output, 1 for input, or an error code in case of error.
347 *
348 * This function may sleep if gpiod_cansleep() is true.
349 */
gpiod_get_direction(struct gpio_desc * desc)350 int gpiod_get_direction(struct gpio_desc *desc)
351 {
352 unsigned long flags;
353 unsigned int offset;
354 int ret;
355
356 /*
357 * We cannot use VALIDATE_DESC() as we must not return 0 for a NULL
358 * descriptor like we usually do.
359 */
360 if (!desc || IS_ERR(desc))
361 return -EINVAL;
362
363 CLASS(gpio_chip_guard, guard)(desc);
364 if (!guard.gc)
365 return -ENODEV;
366
367 offset = gpio_chip_hwgpio(desc);
368 flags = READ_ONCE(desc->flags);
369
370 /*
371 * Open drain emulation using input mode may incorrectly report
372 * input here, fix that up.
373 */
374 if (test_bit(FLAG_OPEN_DRAIN, &flags) &&
375 test_bit(FLAG_IS_OUT, &flags))
376 return 0;
377
378 if (!guard.gc->get_direction)
379 return -ENOTSUPP;
380
381 ret = guard.gc->get_direction(guard.gc, offset);
382 if (ret < 0)
383 return ret;
384
385 /*
386 * GPIO_LINE_DIRECTION_IN or other positive,
387 * otherwise GPIO_LINE_DIRECTION_OUT.
388 */
389 if (ret > 0)
390 ret = 1;
391
392 assign_bit(FLAG_IS_OUT, &flags, !ret);
393 WRITE_ONCE(desc->flags, flags);
394
395 return ret;
396 }
397 EXPORT_SYMBOL_GPL(gpiod_get_direction);
398
399 /*
400 * Add a new chip to the global chips list, keeping the list of chips sorted
401 * by range(means [base, base + ngpio - 1]) order.
402 *
403 * Return -EBUSY if the new chip overlaps with some other chip's integer
404 * space.
405 */
gpiodev_add_to_list_unlocked(struct gpio_device * gdev)406 static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)
407 {
408 struct gpio_device *prev, *next;
409
410 lockdep_assert_held(&gpio_devices_lock);
411
412 if (list_empty(&gpio_devices)) {
413 /* initial entry in list */
414 list_add_tail_rcu(&gdev->list, &gpio_devices);
415 return 0;
416 }
417
418 next = list_first_entry(&gpio_devices, struct gpio_device, list);
419 if (gdev->base + gdev->ngpio <= next->base) {
420 /* add before first entry */
421 list_add_rcu(&gdev->list, &gpio_devices);
422 return 0;
423 }
424
425 prev = list_last_entry(&gpio_devices, struct gpio_device, list);
426 if (prev->base + prev->ngpio <= gdev->base) {
427 /* add behind last entry */
428 list_add_tail_rcu(&gdev->list, &gpio_devices);
429 return 0;
430 }
431
432 list_for_each_entry_safe(prev, next, &gpio_devices, list) {
433 /* at the end of the list */
434 if (&next->list == &gpio_devices)
435 break;
436
437 /* add between prev and next */
438 if (prev->base + prev->ngpio <= gdev->base
439 && gdev->base + gdev->ngpio <= next->base) {
440 list_add_rcu(&gdev->list, &prev->list);
441 return 0;
442 }
443 }
444
445 synchronize_srcu(&gpio_devices_srcu);
446
447 return -EBUSY;
448 }
449
450 /*
451 * Convert a GPIO name to its descriptor
452 * Note that there is no guarantee that GPIO names are globally unique!
453 * Hence this function will return, if it exists, a reference to the first GPIO
454 * line found that matches the given name.
455 */
gpio_name_to_desc(const char * const name)456 static struct gpio_desc *gpio_name_to_desc(const char * const name)
457 {
458 struct gpio_device *gdev;
459 struct gpio_desc *desc;
460 struct gpio_chip *gc;
461
462 if (!name)
463 return NULL;
464
465 guard(srcu)(&gpio_devices_srcu);
466
467 list_for_each_entry_srcu(gdev, &gpio_devices, list,
468 srcu_read_lock_held(&gpio_devices_srcu)) {
469 guard(srcu)(&gdev->srcu);
470
471 gc = srcu_dereference(gdev->chip, &gdev->srcu);
472 if (!gc)
473 continue;
474
475 for_each_gpio_desc(gc, desc) {
476 if (desc->name && !strcmp(desc->name, name))
477 return desc;
478 }
479 }
480
481 return NULL;
482 }
483
484 /*
485 * Take the names from gc->names and assign them to their GPIO descriptors.
486 * Warn if a name is already used for a GPIO line on a different GPIO chip.
487 *
488 * Note that:
489 * 1. Non-unique names are still accepted,
490 * 2. Name collisions within the same GPIO chip are not reported.
491 */
gpiochip_set_desc_names(struct gpio_chip * gc)492 static void gpiochip_set_desc_names(struct gpio_chip *gc)
493 {
494 struct gpio_device *gdev = gc->gpiodev;
495 int i;
496
497 /* First check all names if they are unique */
498 for (i = 0; i != gc->ngpio; ++i) {
499 struct gpio_desc *gpio;
500
501 gpio = gpio_name_to_desc(gc->names[i]);
502 if (gpio)
503 dev_warn(&gdev->dev,
504 "Detected name collision for GPIO name '%s'\n",
505 gc->names[i]);
506 }
507
508 /* Then add all names to the GPIO descriptors */
509 for (i = 0; i != gc->ngpio; ++i)
510 gdev->descs[i].name = gc->names[i];
511 }
512
513 /*
514 * gpiochip_set_names - Set GPIO line names using device properties
515 * @chip: GPIO chip whose lines should be named, if possible
516 *
517 * Looks for device property "gpio-line-names" and if it exists assigns
518 * GPIO line names for the chip. The memory allocated for the assigned
519 * names belong to the underlying firmware node and should not be released
520 * by the caller.
521 */
gpiochip_set_names(struct gpio_chip * chip)522 static int gpiochip_set_names(struct gpio_chip *chip)
523 {
524 struct gpio_device *gdev = chip->gpiodev;
525 struct device *dev = &gdev->dev;
526 const char **names;
527 int ret, i;
528 int count;
529
530 count = device_property_string_array_count(dev, "gpio-line-names");
531 if (count < 0)
532 return 0;
533
534 /*
535 * When offset is set in the driver side we assume the driver internally
536 * is using more than one gpiochip per the same device. We have to stop
537 * setting friendly names if the specified ones with 'gpio-line-names'
538 * are less than the offset in the device itself. This means all the
539 * lines are not present for every single pin within all the internal
540 * gpiochips.
541 */
542 if (count <= chip->offset) {
543 dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
544 count, chip->offset);
545 return 0;
546 }
547
548 names = kcalloc(count, sizeof(*names), GFP_KERNEL);
549 if (!names)
550 return -ENOMEM;
551
552 ret = device_property_read_string_array(dev, "gpio-line-names",
553 names, count);
554 if (ret < 0) {
555 dev_warn(dev, "failed to read GPIO line names\n");
556 kfree(names);
557 return ret;
558 }
559
560 /*
561 * When more that one gpiochip per device is used, 'count' can
562 * contain at most number gpiochips x chip->ngpio. We have to
563 * correctly distribute all defined lines taking into account
564 * chip->offset as starting point from where we will assign
565 * the names to pins from the 'names' array. Since property
566 * 'gpio-line-names' cannot contains gaps, we have to be sure
567 * we only assign those pins that really exists since chip->ngpio
568 * can be different of the chip->offset.
569 */
570 count = (count > chip->offset) ? count - chip->offset : count;
571 if (count > chip->ngpio)
572 count = chip->ngpio;
573
574 for (i = 0; i < count; i++) {
575 /*
576 * Allow overriding "fixed" names provided by the GPIO
577 * provider. The "fixed" names are more often than not
578 * generic and less informative than the names given in
579 * device properties.
580 */
581 if (names[chip->offset + i] && names[chip->offset + i][0])
582 gdev->descs[i].name = names[chip->offset + i];
583 }
584
585 kfree(names);
586
587 return 0;
588 }
589
gpiochip_allocate_mask(struct gpio_chip * gc)590 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
591 {
592 unsigned long *p;
593
594 p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
595 if (!p)
596 return NULL;
597
598 /* Assume by default all GPIOs are valid */
599 bitmap_fill(p, gc->ngpio);
600
601 return p;
602 }
603
gpiochip_free_mask(unsigned long ** p)604 static void gpiochip_free_mask(unsigned long **p)
605 {
606 bitmap_free(*p);
607 *p = NULL;
608 }
609
gpiochip_count_reserved_ranges(struct gpio_chip * gc)610 static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc)
611 {
612 struct device *dev = &gc->gpiodev->dev;
613 int size;
614
615 /* Format is "start, count, ..." */
616 size = device_property_count_u32(dev, "gpio-reserved-ranges");
617 if (size > 0 && size % 2 == 0)
618 return size;
619
620 return 0;
621 }
622
gpiochip_apply_reserved_ranges(struct gpio_chip * gc)623 static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc)
624 {
625 struct device *dev = &gc->gpiodev->dev;
626 unsigned int size;
627 u32 *ranges;
628 int ret;
629
630 size = gpiochip_count_reserved_ranges(gc);
631 if (size == 0)
632 return 0;
633
634 ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL);
635 if (!ranges)
636 return -ENOMEM;
637
638 ret = device_property_read_u32_array(dev, "gpio-reserved-ranges",
639 ranges, size);
640 if (ret) {
641 kfree(ranges);
642 return ret;
643 }
644
645 while (size) {
646 u32 count = ranges[--size];
647 u32 start = ranges[--size];
648
649 if (start >= gc->ngpio || start + count > gc->ngpio)
650 continue;
651
652 bitmap_clear(gc->valid_mask, start, count);
653 }
654
655 kfree(ranges);
656 return 0;
657 }
658
gpiochip_init_valid_mask(struct gpio_chip * gc)659 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
660 {
661 int ret;
662
663 if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask))
664 return 0;
665
666 gc->valid_mask = gpiochip_allocate_mask(gc);
667 if (!gc->valid_mask)
668 return -ENOMEM;
669
670 ret = gpiochip_apply_reserved_ranges(gc);
671 if (ret)
672 return ret;
673
674 if (gc->init_valid_mask)
675 return gc->init_valid_mask(gc,
676 gc->valid_mask,
677 gc->ngpio);
678
679 return 0;
680 }
681
gpiochip_free_valid_mask(struct gpio_chip * gc)682 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
683 {
684 gpiochip_free_mask(&gc->valid_mask);
685 }
686
gpiochip_add_pin_ranges(struct gpio_chip * gc)687 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
688 {
689 /*
690 * Device Tree platforms are supposed to use "gpio-ranges"
691 * property. This check ensures that the ->add_pin_ranges()
692 * won't be called for them.
693 */
694 if (device_property_present(&gc->gpiodev->dev, "gpio-ranges"))
695 return 0;
696
697 if (gc->add_pin_ranges)
698 return gc->add_pin_ranges(gc);
699
700 return 0;
701 }
702
gpiochip_line_is_valid(const struct gpio_chip * gc,unsigned int offset)703 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
704 unsigned int offset)
705 {
706 /* No mask means all valid */
707 if (likely(!gc->valid_mask))
708 return true;
709 return test_bit(offset, gc->valid_mask);
710 }
711 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
712
gpiodev_release(struct device * dev)713 static void gpiodev_release(struct device *dev)
714 {
715 struct gpio_device *gdev = to_gpio_device(dev);
716
717 /* Call pending kfree()s for descriptor labels. */
718 synchronize_srcu(&gdev->desc_srcu);
719 cleanup_srcu_struct(&gdev->desc_srcu);
720
721 ida_free(&gpio_ida, gdev->id);
722 kfree_const(gdev->label);
723 kfree(gdev->descs);
724 cleanup_srcu_struct(&gdev->srcu);
725 kfree(gdev);
726 }
727
728 static const struct device_type gpio_dev_type = {
729 .name = "gpio_chip",
730 .release = gpiodev_release,
731 };
732
733 #ifdef CONFIG_GPIO_CDEV
734 #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
735 #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
736 #else
737 /*
738 * gpiolib_cdev_register() indirectly calls device_add(), which is still
739 * required even when cdev is not selected.
740 */
741 #define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
742 #define gcdev_unregister(gdev) device_del(&(gdev)->dev)
743 #endif
744
gpiochip_setup_dev(struct gpio_device * gdev)745 static int gpiochip_setup_dev(struct gpio_device *gdev)
746 {
747 struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
748 int ret;
749
750 device_initialize(&gdev->dev);
751
752 /*
753 * If fwnode doesn't belong to another device, it's safe to clear its
754 * initialized flag.
755 */
756 if (fwnode && !fwnode->dev)
757 fwnode_dev_initialized(fwnode, false);
758
759 ret = gcdev_register(gdev, gpio_devt);
760 if (ret)
761 return ret;
762
763 ret = gpiochip_sysfs_register(gdev);
764 if (ret)
765 goto err_remove_device;
766
767 dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base,
768 gdev->base + gdev->ngpio - 1, gdev->label);
769
770 return 0;
771
772 err_remove_device:
773 gcdev_unregister(gdev);
774 return ret;
775 }
776
gpiochip_machine_hog(struct gpio_chip * gc,struct gpiod_hog * hog)777 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
778 {
779 struct gpio_desc *desc;
780 int rv;
781
782 desc = gpiochip_get_desc(gc, hog->chip_hwnum);
783 if (IS_ERR(desc)) {
784 chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
785 PTR_ERR(desc));
786 return;
787 }
788
789 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
790 if (rv)
791 gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
792 __func__, gc->label, hog->chip_hwnum, rv);
793 }
794
machine_gpiochip_add(struct gpio_chip * gc)795 static void machine_gpiochip_add(struct gpio_chip *gc)
796 {
797 struct gpiod_hog *hog;
798
799 mutex_lock(&gpio_machine_hogs_mutex);
800
801 list_for_each_entry(hog, &gpio_machine_hogs, list) {
802 if (!strcmp(gc->label, hog->chip_label))
803 gpiochip_machine_hog(gc, hog);
804 }
805
806 mutex_unlock(&gpio_machine_hogs_mutex);
807 }
808
gpiochip_setup_devs(void)809 static void gpiochip_setup_devs(void)
810 {
811 struct gpio_device *gdev;
812 int ret;
813
814 guard(srcu)(&gpio_devices_srcu);
815
816 list_for_each_entry_srcu(gdev, &gpio_devices, list,
817 srcu_read_lock_held(&gpio_devices_srcu)) {
818 ret = gpiochip_setup_dev(gdev);
819 if (ret)
820 dev_err(&gdev->dev,
821 "Failed to initialize gpio device (%d)\n", ret);
822 }
823 }
824
gpiochip_set_data(struct gpio_chip * gc,void * data)825 static void gpiochip_set_data(struct gpio_chip *gc, void *data)
826 {
827 gc->gpiodev->data = data;
828 }
829
830 /**
831 * gpiochip_get_data() - get per-subdriver data for the chip
832 * @gc: GPIO chip
833 *
834 * Returns:
835 * The per-subdriver data for the chip.
836 */
gpiochip_get_data(struct gpio_chip * gc)837 void *gpiochip_get_data(struct gpio_chip *gc)
838 {
839 return gc->gpiodev->data;
840 }
841 EXPORT_SYMBOL_GPL(gpiochip_get_data);
842
gpiochip_get_ngpios(struct gpio_chip * gc,struct device * dev)843 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
844 {
845 u32 ngpios = gc->ngpio;
846 int ret;
847
848 if (ngpios == 0) {
849 ret = device_property_read_u32(dev, "ngpios", &ngpios);
850 if (ret == -ENODATA)
851 /*
852 * -ENODATA means that there is no property found and
853 * we want to issue the error message to the user.
854 * Besides that, we want to return different error code
855 * to state that supplied value is not valid.
856 */
857 ngpios = 0;
858 else if (ret)
859 return ret;
860
861 gc->ngpio = ngpios;
862 }
863
864 if (gc->ngpio == 0) {
865 chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
866 return -EINVAL;
867 }
868
869 if (gc->ngpio > FASTPATH_NGPIO)
870 chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
871 gc->ngpio, FASTPATH_NGPIO);
872
873 return 0;
874 }
875 EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);
876
gpiochip_add_data_with_key(struct gpio_chip * gc,void * data,struct lock_class_key * lock_key,struct lock_class_key * request_key)877 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
878 struct lock_class_key *lock_key,
879 struct lock_class_key *request_key)
880 {
881 struct gpio_device *gdev;
882 unsigned int desc_index;
883 int base = 0;
884 int ret = 0;
885
886 /*
887 * First: allocate and populate the internal stat container, and
888 * set up the struct device.
889 */
890 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
891 if (!gdev)
892 return -ENOMEM;
893
894 gdev->dev.type = &gpio_dev_type;
895 gdev->dev.bus = &gpio_bus_type;
896 gdev->dev.parent = gc->parent;
897 rcu_assign_pointer(gdev->chip, gc);
898
899 gc->gpiodev = gdev;
900 gpiochip_set_data(gc, data);
901
902 /*
903 * If the calling driver did not initialize firmware node,
904 * do it here using the parent device, if any.
905 */
906 if (gc->fwnode)
907 device_set_node(&gdev->dev, gc->fwnode);
908 else if (gc->parent)
909 device_set_node(&gdev->dev, dev_fwnode(gc->parent));
910
911 gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
912 if (gdev->id < 0) {
913 ret = gdev->id;
914 goto err_free_gdev;
915 }
916
917 ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
918 if (ret)
919 goto err_free_ida;
920
921 if (gc->parent && gc->parent->driver)
922 gdev->owner = gc->parent->driver->owner;
923 else if (gc->owner)
924 /* TODO: remove chip->owner */
925 gdev->owner = gc->owner;
926 else
927 gdev->owner = THIS_MODULE;
928
929 ret = gpiochip_get_ngpios(gc, &gdev->dev);
930 if (ret)
931 goto err_free_dev_name;
932
933 gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
934 if (!gdev->descs) {
935 ret = -ENOMEM;
936 goto err_free_dev_name;
937 }
938
939 gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
940 if (!gdev->label) {
941 ret = -ENOMEM;
942 goto err_free_descs;
943 }
944
945 gdev->ngpio = gc->ngpio;
946 gdev->can_sleep = gc->can_sleep;
947
948 scoped_guard(mutex, &gpio_devices_lock) {
949 /*
950 * TODO: this allocates a Linux GPIO number base in the global
951 * GPIO numberspace for this chip. In the long run we want to
952 * get *rid* of this numberspace and use only descriptors, but
953 * it may be a pipe dream. It will not happen before we get rid
954 * of the sysfs interface anyways.
955 */
956 base = gc->base;
957 if (base < 0) {
958 base = gpiochip_find_base_unlocked(gc->ngpio);
959 if (base < 0) {
960 ret = base;
961 base = 0;
962 goto err_free_label;
963 }
964
965 /*
966 * TODO: it should not be necessary to reflect the
967 * assigned base outside of the GPIO subsystem. Go over
968 * drivers and see if anyone makes use of this, else
969 * drop this and assign a poison instead.
970 */
971 gc->base = base;
972 } else {
973 dev_warn(&gdev->dev,
974 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
975 }
976
977 gdev->base = base;
978
979 ret = gpiodev_add_to_list_unlocked(gdev);
980 if (ret) {
981 chip_err(gc, "GPIO integer space overlap, cannot add chip\n");
982 goto err_free_label;
983 }
984 }
985
986 for (desc_index = 0; desc_index < gc->ngpio; desc_index++)
987 gdev->descs[desc_index].gdev = gdev;
988
989 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
990 BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
991
992 ret = init_srcu_struct(&gdev->srcu);
993 if (ret)
994 goto err_remove_from_list;
995
996 ret = init_srcu_struct(&gdev->desc_srcu);
997 if (ret)
998 goto err_cleanup_gdev_srcu;
999
1000 #ifdef CONFIG_PINCTRL
1001 INIT_LIST_HEAD(&gdev->pin_ranges);
1002 #endif
1003
1004 if (gc->names)
1005 gpiochip_set_desc_names(gc);
1006
1007 ret = gpiochip_set_names(gc);
1008 if (ret)
1009 goto err_cleanup_desc_srcu;
1010
1011 ret = gpiochip_init_valid_mask(gc);
1012 if (ret)
1013 goto err_cleanup_desc_srcu;
1014
1015 for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
1016 struct gpio_desc *desc = &gdev->descs[desc_index];
1017
1018 if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {
1019 assign_bit(FLAG_IS_OUT,
1020 &desc->flags, !gc->get_direction(gc, desc_index));
1021 } else {
1022 assign_bit(FLAG_IS_OUT,
1023 &desc->flags, !gc->direction_input);
1024 }
1025 }
1026
1027 ret = of_gpiochip_add(gc);
1028 if (ret)
1029 goto err_free_valid_mask;
1030
1031 ret = gpiochip_add_pin_ranges(gc);
1032 if (ret)
1033 goto err_remove_of_chip;
1034
1035 acpi_gpiochip_add(gc);
1036
1037 machine_gpiochip_add(gc);
1038
1039 ret = gpiochip_irqchip_init_valid_mask(gc);
1040 if (ret)
1041 goto err_free_hogs;
1042
1043 ret = gpiochip_irqchip_init_hw(gc);
1044 if (ret)
1045 goto err_remove_irqchip_mask;
1046
1047 ret = gpiochip_add_irqchip(gc, lock_key, request_key);
1048 if (ret)
1049 goto err_remove_irqchip_mask;
1050
1051 /*
1052 * By first adding the chardev, and then adding the device,
1053 * we get a device node entry in sysfs under
1054 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1055 * coldplug of device nodes and other udev business.
1056 * We can do this only if gpiolib has been initialized.
1057 * Otherwise, defer until later.
1058 */
1059 if (gpiolib_initialized) {
1060 ret = gpiochip_setup_dev(gdev);
1061 if (ret)
1062 goto err_remove_irqchip;
1063 }
1064 return 0;
1065
1066 err_remove_irqchip:
1067 gpiochip_irqchip_remove(gc);
1068 err_remove_irqchip_mask:
1069 gpiochip_irqchip_free_valid_mask(gc);
1070 err_free_hogs:
1071 gpiochip_free_hogs(gc);
1072 acpi_gpiochip_remove(gc);
1073 gpiochip_remove_pin_ranges(gc);
1074 err_remove_of_chip:
1075 of_gpiochip_remove(gc);
1076 err_free_valid_mask:
1077 gpiochip_free_valid_mask(gc);
1078 err_cleanup_desc_srcu:
1079 cleanup_srcu_struct(&gdev->desc_srcu);
1080 err_cleanup_gdev_srcu:
1081 cleanup_srcu_struct(&gdev->srcu);
1082 err_remove_from_list:
1083 scoped_guard(mutex, &gpio_devices_lock)
1084 list_del_rcu(&gdev->list);
1085 synchronize_srcu(&gpio_devices_srcu);
1086 if (gdev->dev.release) {
1087 /* release() has been registered by gpiochip_setup_dev() */
1088 gpio_device_put(gdev);
1089 goto err_print_message;
1090 }
1091 err_free_label:
1092 kfree_const(gdev->label);
1093 err_free_descs:
1094 kfree(gdev->descs);
1095 err_free_dev_name:
1096 kfree(dev_name(&gdev->dev));
1097 err_free_ida:
1098 ida_free(&gpio_ida, gdev->id);
1099 err_free_gdev:
1100 kfree(gdev);
1101 err_print_message:
1102 /* failures here can mean systems won't boot... */
1103 if (ret != -EPROBE_DEFER) {
1104 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1105 base, base + (int)gc->ngpio - 1,
1106 gc->label ? : "generic", ret);
1107 }
1108 return ret;
1109 }
1110 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1111
1112 /**
1113 * gpiochip_remove() - unregister a gpio_chip
1114 * @gc: the chip to unregister
1115 *
1116 * A gpio_chip with any GPIOs still requested may not be removed.
1117 */
gpiochip_remove(struct gpio_chip * gc)1118 void gpiochip_remove(struct gpio_chip *gc)
1119 {
1120 struct gpio_device *gdev = gc->gpiodev;
1121
1122 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1123 gpiochip_sysfs_unregister(gdev);
1124 gpiochip_free_hogs(gc);
1125
1126 scoped_guard(mutex, &gpio_devices_lock)
1127 list_del_rcu(&gdev->list);
1128 synchronize_srcu(&gpio_devices_srcu);
1129
1130 /* Numb the device, cancelling all outstanding operations */
1131 rcu_assign_pointer(gdev->chip, NULL);
1132 synchronize_srcu(&gdev->srcu);
1133 gpiochip_irqchip_remove(gc);
1134 acpi_gpiochip_remove(gc);
1135 of_gpiochip_remove(gc);
1136 gpiochip_remove_pin_ranges(gc);
1137 gpiochip_free_valid_mask(gc);
1138 /*
1139 * We accept no more calls into the driver from this point, so
1140 * NULL the driver data pointer.
1141 */
1142 gpiochip_set_data(gc, NULL);
1143
1144 /*
1145 * The gpiochip side puts its use of the device to rest here:
1146 * if there are no userspace clients, the chardev and device will
1147 * be removed, else it will be dangling until the last user is
1148 * gone.
1149 */
1150 gcdev_unregister(gdev);
1151 gpio_device_put(gdev);
1152 }
1153 EXPORT_SYMBOL_GPL(gpiochip_remove);
1154
1155 /**
1156 * gpio_device_find() - find a specific GPIO device
1157 * @data: data to pass to match function
1158 * @match: Callback function to check gpio_chip
1159 *
1160 * Returns:
1161 * New reference to struct gpio_device.
1162 *
1163 * Similar to bus_find_device(). It returns a reference to a gpio_device as
1164 * determined by a user supplied @match callback. The callback should return
1165 * 0 if the device doesn't match and non-zero if it does. If the callback
1166 * returns non-zero, this function will return to the caller and not iterate
1167 * over any more gpio_devices.
1168 *
1169 * The callback takes the GPIO chip structure as argument. During the execution
1170 * of the callback function the chip is protected from being freed. TODO: This
1171 * actually has yet to be implemented.
1172 *
1173 * If the function returns non-NULL, the returned reference must be freed by
1174 * the caller using gpio_device_put().
1175 */
gpio_device_find(const void * data,int (* match)(struct gpio_chip * gc,const void * data))1176 struct gpio_device *gpio_device_find(const void *data,
1177 int (*match)(struct gpio_chip *gc,
1178 const void *data))
1179 {
1180 struct gpio_device *gdev;
1181 struct gpio_chip *gc;
1182
1183 /*
1184 * Not yet but in the future the spinlock below will become a mutex.
1185 * Annotate this function before anyone tries to use it in interrupt
1186 * context like it happened with gpiochip_find().
1187 */
1188 might_sleep();
1189
1190 guard(srcu)(&gpio_devices_srcu);
1191
1192 list_for_each_entry_srcu(gdev, &gpio_devices, list,
1193 srcu_read_lock_held(&gpio_devices_srcu)) {
1194 if (!device_is_registered(&gdev->dev))
1195 continue;
1196
1197 guard(srcu)(&gdev->srcu);
1198
1199 gc = srcu_dereference(gdev->chip, &gdev->srcu);
1200
1201 if (gc && match(gc, data))
1202 return gpio_device_get(gdev);
1203 }
1204
1205 return NULL;
1206 }
1207 EXPORT_SYMBOL_GPL(gpio_device_find);
1208
gpio_chip_match_by_label(struct gpio_chip * gc,const void * label)1209 static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)
1210 {
1211 return gc->label && !strcmp(gc->label, label);
1212 }
1213
1214 /**
1215 * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the
1216 * GPIO device by its backing chip's label
1217 * @label: Label to lookup
1218 *
1219 * Returns:
1220 * Reference to the GPIO device or NULL. Reference must be released with
1221 * gpio_device_put().
1222 */
gpio_device_find_by_label(const char * label)1223 struct gpio_device *gpio_device_find_by_label(const char *label)
1224 {
1225 return gpio_device_find((void *)label, gpio_chip_match_by_label);
1226 }
1227 EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
1228
gpio_chip_match_by_fwnode(struct gpio_chip * gc,const void * fwnode)1229 static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)
1230 {
1231 return device_match_fwnode(&gc->gpiodev->dev, fwnode);
1232 }
1233
1234 /**
1235 * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
1236 * the GPIO device by its fwnode
1237 * @fwnode: Firmware node to lookup
1238 *
1239 * Returns:
1240 * Reference to the GPIO device or NULL. Reference must be released with
1241 * gpio_device_put().
1242 */
gpio_device_find_by_fwnode(const struct fwnode_handle * fwnode)1243 struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
1244 {
1245 return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
1246 }
1247 EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
1248
1249 /**
1250 * gpio_device_get() - Increase the reference count of this GPIO device
1251 * @gdev: GPIO device to increase the refcount for
1252 *
1253 * Returns:
1254 * Pointer to @gdev.
1255 */
gpio_device_get(struct gpio_device * gdev)1256 struct gpio_device *gpio_device_get(struct gpio_device *gdev)
1257 {
1258 return to_gpio_device(get_device(&gdev->dev));
1259 }
1260 EXPORT_SYMBOL_GPL(gpio_device_get);
1261
1262 /**
1263 * gpio_device_put() - Decrease the reference count of this GPIO device and
1264 * possibly free all resources associated with it.
1265 * @gdev: GPIO device to decrease the reference count for
1266 */
gpio_device_put(struct gpio_device * gdev)1267 void gpio_device_put(struct gpio_device *gdev)
1268 {
1269 put_device(&gdev->dev);
1270 }
1271 EXPORT_SYMBOL_GPL(gpio_device_put);
1272
1273 /**
1274 * gpio_device_to_device() - Retrieve the address of the underlying struct
1275 * device.
1276 * @gdev: GPIO device for which to return the address.
1277 *
1278 * This does not increase the reference count of the GPIO device nor the
1279 * underlying struct device.
1280 *
1281 * Returns:
1282 * Address of struct device backing this GPIO device.
1283 */
gpio_device_to_device(struct gpio_device * gdev)1284 struct device *gpio_device_to_device(struct gpio_device *gdev)
1285 {
1286 return &gdev->dev;
1287 }
1288 EXPORT_SYMBOL_GPL(gpio_device_to_device);
1289
1290 #ifdef CONFIG_GPIOLIB_IRQCHIP
1291
1292 /*
1293 * The following is irqchip helper code for gpiochips.
1294 */
1295
gpiochip_irqchip_init_hw(struct gpio_chip * gc)1296 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1297 {
1298 struct gpio_irq_chip *girq = &gc->irq;
1299
1300 if (!girq->init_hw)
1301 return 0;
1302
1303 return girq->init_hw(gc);
1304 }
1305
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)1306 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1307 {
1308 struct gpio_irq_chip *girq = &gc->irq;
1309
1310 if (!girq->init_valid_mask)
1311 return 0;
1312
1313 girq->valid_mask = gpiochip_allocate_mask(gc);
1314 if (!girq->valid_mask)
1315 return -ENOMEM;
1316
1317 girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1318
1319 return 0;
1320 }
1321
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)1322 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1323 {
1324 gpiochip_free_mask(&gc->irq.valid_mask);
1325 }
1326
gpiochip_irqchip_irq_valid(const struct gpio_chip * gc,unsigned int offset)1327 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
1328 unsigned int offset)
1329 {
1330 if (!gpiochip_line_is_valid(gc, offset))
1331 return false;
1332 /* No mask means all valid */
1333 if (likely(!gc->irq.valid_mask))
1334 return true;
1335 return test_bit(offset, gc->irq.valid_mask);
1336 }
1337
1338 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1339
1340 /**
1341 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1342 * to a gpiochip
1343 * @gc: the gpiochip to set the irqchip hierarchical handler to
1344 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1345 * will then percolate up to the parent
1346 */
gpiochip_set_hierarchical_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip)1347 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1348 struct irq_chip *irqchip)
1349 {
1350 /* DT will deal with mapping each IRQ as we go along */
1351 if (is_of_node(gc->irq.fwnode))
1352 return;
1353
1354 /*
1355 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1356 * irqs upfront instead of dynamically since we don't have the
1357 * dynamic type of allocation that hardware description languages
1358 * provide. Once all GPIO drivers using board files are gone from
1359 * the kernel we can delete this code, but for a transitional period
1360 * it is necessary to keep this around.
1361 */
1362 if (is_fwnode_irqchip(gc->irq.fwnode)) {
1363 int i;
1364 int ret;
1365
1366 for (i = 0; i < gc->ngpio; i++) {
1367 struct irq_fwspec fwspec;
1368 unsigned int parent_hwirq;
1369 unsigned int parent_type;
1370 struct gpio_irq_chip *girq = &gc->irq;
1371
1372 /*
1373 * We call the child to parent translation function
1374 * only to check if the child IRQ is valid or not.
1375 * Just pick the rising edge type here as that is what
1376 * we likely need to support.
1377 */
1378 ret = girq->child_to_parent_hwirq(gc, i,
1379 IRQ_TYPE_EDGE_RISING,
1380 &parent_hwirq,
1381 &parent_type);
1382 if (ret) {
1383 chip_err(gc, "skip set-up on hwirq %d\n",
1384 i);
1385 continue;
1386 }
1387
1388 fwspec.fwnode = gc->irq.fwnode;
1389 /* This is the hwirq for the GPIO line side of things */
1390 fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1391 /* Just pick something */
1392 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1393 fwspec.param_count = 2;
1394 ret = irq_domain_alloc_irqs(gc->irq.domain, 1,
1395 NUMA_NO_NODE, &fwspec);
1396 if (ret < 0) {
1397 chip_err(gc,
1398 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1399 i, parent_hwirq,
1400 ret);
1401 }
1402 }
1403 }
1404
1405 chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1406
1407 return;
1408 }
1409
gpiochip_hierarchy_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1410 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1411 struct irq_fwspec *fwspec,
1412 unsigned long *hwirq,
1413 unsigned int *type)
1414 {
1415 /* We support standard DT translation */
1416 if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1417 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1418 }
1419
1420 /* This is for board files and others not using DT */
1421 if (is_fwnode_irqchip(fwspec->fwnode)) {
1422 int ret;
1423
1424 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1425 if (ret)
1426 return ret;
1427 WARN_ON(*type == IRQ_TYPE_NONE);
1428 return 0;
1429 }
1430 return -EINVAL;
1431 }
1432
gpiochip_hierarchy_irq_domain_alloc(struct irq_domain * d,unsigned int irq,unsigned int nr_irqs,void * data)1433 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1434 unsigned int irq,
1435 unsigned int nr_irqs,
1436 void *data)
1437 {
1438 struct gpio_chip *gc = d->host_data;
1439 irq_hw_number_t hwirq;
1440 unsigned int type = IRQ_TYPE_NONE;
1441 struct irq_fwspec *fwspec = data;
1442 union gpio_irq_fwspec gpio_parent_fwspec = {};
1443 unsigned int parent_hwirq;
1444 unsigned int parent_type;
1445 struct gpio_irq_chip *girq = &gc->irq;
1446 int ret;
1447
1448 /*
1449 * The nr_irqs parameter is always one except for PCI multi-MSI
1450 * so this should not happen.
1451 */
1452 WARN_ON(nr_irqs != 1);
1453
1454 ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1455 if (ret)
1456 return ret;
1457
1458 chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1459
1460 ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1461 &parent_hwirq, &parent_type);
1462 if (ret) {
1463 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1464 return ret;
1465 }
1466 chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1467
1468 /*
1469 * We set handle_bad_irq because the .set_type() should
1470 * always be invoked and set the right type of handler.
1471 */
1472 irq_domain_set_info(d,
1473 irq,
1474 hwirq,
1475 gc->irq.chip,
1476 gc,
1477 girq->handler,
1478 NULL, NULL);
1479 irq_set_probe(irq);
1480
1481 /* This parent only handles asserted level IRQs */
1482 ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,
1483 parent_hwirq, parent_type);
1484 if (ret)
1485 return ret;
1486
1487 chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1488 irq, parent_hwirq);
1489 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1490 ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);
1491 /*
1492 * If the parent irqdomain is msi, the interrupts have already
1493 * been allocated, so the EEXIST is good.
1494 */
1495 if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1496 ret = 0;
1497 if (ret)
1498 chip_err(gc,
1499 "failed to allocate parent hwirq %d for hwirq %lu\n",
1500 parent_hwirq, hwirq);
1501
1502 return ret;
1503 }
1504
gpiochip_child_offset_to_irq_noop(struct gpio_chip * gc,unsigned int offset)1505 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1506 unsigned int offset)
1507 {
1508 return offset;
1509 }
1510
1511 /**
1512 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1513 * @domain: The IRQ domain used by this IRQ chip
1514 * @data: Outermost irq_data associated with the IRQ
1515 * @reserve: If set, only reserve an interrupt vector instead of assigning one
1516 *
1517 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1518 * used as the activate function for the &struct irq_domain_ops. The host_data
1519 * for the IRQ domain must be the &struct gpio_chip.
1520 */
gpiochip_irq_domain_activate(struct irq_domain * domain,struct irq_data * data,bool reserve)1521 static int gpiochip_irq_domain_activate(struct irq_domain *domain,
1522 struct irq_data *data, bool reserve)
1523 {
1524 struct gpio_chip *gc = domain->host_data;
1525 unsigned int hwirq = irqd_to_hwirq(data);
1526
1527 return gpiochip_lock_as_irq(gc, hwirq);
1528 }
1529
1530 /**
1531 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1532 * @domain: The IRQ domain used by this IRQ chip
1533 * @data: Outermost irq_data associated with the IRQ
1534 *
1535 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1536 * be used as the deactivate function for the &struct irq_domain_ops. The
1537 * host_data for the IRQ domain must be the &struct gpio_chip.
1538 */
gpiochip_irq_domain_deactivate(struct irq_domain * domain,struct irq_data * data)1539 static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1540 struct irq_data *data)
1541 {
1542 struct gpio_chip *gc = domain->host_data;
1543 unsigned int hwirq = irqd_to_hwirq(data);
1544
1545 return gpiochip_unlock_as_irq(gc, hwirq);
1546 }
1547
gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops * ops)1548 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1549 {
1550 ops->activate = gpiochip_irq_domain_activate;
1551 ops->deactivate = gpiochip_irq_domain_deactivate;
1552 ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1553
1554 /*
1555 * We only allow overriding the translate() and free() functions for
1556 * hierarchical chips, and this should only be done if the user
1557 * really need something other than 1:1 translation for translate()
1558 * callback and free if user wants to free up any resources which
1559 * were allocated during callbacks, for example populate_parent_alloc_arg.
1560 */
1561 if (!ops->translate)
1562 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1563 if (!ops->free)
1564 ops->free = irq_domain_free_irqs_common;
1565 }
1566
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1567 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1568 {
1569 struct irq_domain *domain;
1570
1571 if (!gc->irq.child_to_parent_hwirq ||
1572 !gc->irq.fwnode) {
1573 chip_err(gc, "missing irqdomain vital data\n");
1574 return ERR_PTR(-EINVAL);
1575 }
1576
1577 if (!gc->irq.child_offset_to_irq)
1578 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1579
1580 if (!gc->irq.populate_parent_alloc_arg)
1581 gc->irq.populate_parent_alloc_arg =
1582 gpiochip_populate_parent_fwspec_twocell;
1583
1584 gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1585
1586 domain = irq_domain_create_hierarchy(
1587 gc->irq.parent_domain,
1588 0,
1589 gc->ngpio,
1590 gc->irq.fwnode,
1591 &gc->irq.child_irq_domain_ops,
1592 gc);
1593
1594 if (!domain)
1595 return ERR_PTR(-ENOMEM);
1596
1597 gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1598
1599 return domain;
1600 }
1601
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1602 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1603 {
1604 return !!gc->irq.parent_domain;
1605 }
1606
gpiochip_populate_parent_fwspec_twocell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1607 int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1608 union gpio_irq_fwspec *gfwspec,
1609 unsigned int parent_hwirq,
1610 unsigned int parent_type)
1611 {
1612 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1613
1614 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1615 fwspec->param_count = 2;
1616 fwspec->param[0] = parent_hwirq;
1617 fwspec->param[1] = parent_type;
1618
1619 return 0;
1620 }
1621 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1622
gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1623 int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1624 union gpio_irq_fwspec *gfwspec,
1625 unsigned int parent_hwirq,
1626 unsigned int parent_type)
1627 {
1628 struct irq_fwspec *fwspec = &gfwspec->fwspec;
1629
1630 fwspec->fwnode = gc->irq.parent_domain->fwnode;
1631 fwspec->param_count = 4;
1632 fwspec->param[0] = 0;
1633 fwspec->param[1] = parent_hwirq;
1634 fwspec->param[2] = 0;
1635 fwspec->param[3] = parent_type;
1636
1637 return 0;
1638 }
1639 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1640
1641 #else
1642
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1643 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1644 {
1645 return ERR_PTR(-EINVAL);
1646 }
1647
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1648 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1649 {
1650 return false;
1651 }
1652
1653 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1654
1655 /**
1656 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1657 * @d: the irqdomain used by this irqchip
1658 * @irq: the global irq number used by this GPIO irqchip irq
1659 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1660 *
1661 * This function will set up the mapping for a certain IRQ line on a
1662 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1663 * stored inside the gpiochip.
1664 */
gpiochip_irq_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)1665 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1666 irq_hw_number_t hwirq)
1667 {
1668 struct gpio_chip *gc = d->host_data;
1669 int ret = 0;
1670
1671 if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1672 return -ENXIO;
1673
1674 irq_set_chip_data(irq, gc);
1675 /*
1676 * This lock class tells lockdep that GPIO irqs are in a different
1677 * category than their parents, so it won't report false recursion.
1678 */
1679 irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1680 irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1681 /* Chips that use nested thread handlers have them marked */
1682 if (gc->irq.threaded)
1683 irq_set_nested_thread(irq, 1);
1684 irq_set_noprobe(irq);
1685
1686 if (gc->irq.num_parents == 1)
1687 ret = irq_set_parent(irq, gc->irq.parents[0]);
1688 else if (gc->irq.map)
1689 ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1690
1691 if (ret < 0)
1692 return ret;
1693
1694 /*
1695 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1696 * is passed as default type.
1697 */
1698 if (gc->irq.default_type != IRQ_TYPE_NONE)
1699 irq_set_irq_type(irq, gc->irq.default_type);
1700
1701 return 0;
1702 }
1703
gpiochip_irq_unmap(struct irq_domain * d,unsigned int irq)1704 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1705 {
1706 struct gpio_chip *gc = d->host_data;
1707
1708 if (gc->irq.threaded)
1709 irq_set_nested_thread(irq, 0);
1710 irq_set_chip_and_handler(irq, NULL, NULL);
1711 irq_set_chip_data(irq, NULL);
1712 }
1713
1714 static const struct irq_domain_ops gpiochip_domain_ops = {
1715 .map = gpiochip_irq_map,
1716 .unmap = gpiochip_irq_unmap,
1717 /* Virtually all GPIO irqchips are twocell:ed */
1718 .xlate = irq_domain_xlate_twocell,
1719 };
1720
gpiochip_simple_create_domain(struct gpio_chip * gc)1721 static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
1722 {
1723 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1724 struct irq_domain *domain;
1725
1726 domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,
1727 &gpiochip_domain_ops, gc);
1728 if (!domain)
1729 return ERR_PTR(-EINVAL);
1730
1731 return domain;
1732 }
1733
gpiochip_to_irq(struct gpio_chip * gc,unsigned int offset)1734 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1735 {
1736 struct irq_domain *domain = gc->irq.domain;
1737
1738 #ifdef CONFIG_GPIOLIB_IRQCHIP
1739 /*
1740 * Avoid race condition with other code, which tries to lookup
1741 * an IRQ before the irqchip has been properly registered,
1742 * i.e. while gpiochip is still being brought up.
1743 */
1744 if (!gc->irq.initialized)
1745 return -EPROBE_DEFER;
1746 #endif
1747
1748 if (!gpiochip_irqchip_irq_valid(gc, offset))
1749 return -ENXIO;
1750
1751 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1752 if (irq_domain_is_hierarchy(domain)) {
1753 struct irq_fwspec spec;
1754
1755 spec.fwnode = domain->fwnode;
1756 spec.param_count = 2;
1757 spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1758 spec.param[1] = IRQ_TYPE_NONE;
1759
1760 return irq_create_fwspec_mapping(&spec);
1761 }
1762 #endif
1763
1764 return irq_create_mapping(domain, offset);
1765 }
1766
gpiochip_irq_reqres(struct irq_data * d)1767 int gpiochip_irq_reqres(struct irq_data *d)
1768 {
1769 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1770 unsigned int hwirq = irqd_to_hwirq(d);
1771
1772 return gpiochip_reqres_irq(gc, hwirq);
1773 }
1774 EXPORT_SYMBOL(gpiochip_irq_reqres);
1775
gpiochip_irq_relres(struct irq_data * d)1776 void gpiochip_irq_relres(struct irq_data *d)
1777 {
1778 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1779 unsigned int hwirq = irqd_to_hwirq(d);
1780
1781 gpiochip_relres_irq(gc, hwirq);
1782 }
1783 EXPORT_SYMBOL(gpiochip_irq_relres);
1784
gpiochip_irq_mask(struct irq_data * d)1785 static void gpiochip_irq_mask(struct irq_data *d)
1786 {
1787 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1788 unsigned int hwirq = irqd_to_hwirq(d);
1789
1790 if (gc->irq.irq_mask)
1791 gc->irq.irq_mask(d);
1792 gpiochip_disable_irq(gc, hwirq);
1793 }
1794
gpiochip_irq_unmask(struct irq_data * d)1795 static void gpiochip_irq_unmask(struct irq_data *d)
1796 {
1797 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1798 unsigned int hwirq = irqd_to_hwirq(d);
1799
1800 gpiochip_enable_irq(gc, hwirq);
1801 if (gc->irq.irq_unmask)
1802 gc->irq.irq_unmask(d);
1803 }
1804
gpiochip_irq_enable(struct irq_data * d)1805 static void gpiochip_irq_enable(struct irq_data *d)
1806 {
1807 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1808 unsigned int hwirq = irqd_to_hwirq(d);
1809
1810 gpiochip_enable_irq(gc, hwirq);
1811 gc->irq.irq_enable(d);
1812 }
1813
gpiochip_irq_disable(struct irq_data * d)1814 static void gpiochip_irq_disable(struct irq_data *d)
1815 {
1816 struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1817 unsigned int hwirq = irqd_to_hwirq(d);
1818
1819 gc->irq.irq_disable(d);
1820 gpiochip_disable_irq(gc, hwirq);
1821 }
1822
gpiochip_set_irq_hooks(struct gpio_chip * gc)1823 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1824 {
1825 struct irq_chip *irqchip = gc->irq.chip;
1826
1827 if (irqchip->flags & IRQCHIP_IMMUTABLE)
1828 return;
1829
1830 chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
1831
1832 if (!irqchip->irq_request_resources &&
1833 !irqchip->irq_release_resources) {
1834 irqchip->irq_request_resources = gpiochip_irq_reqres;
1835 irqchip->irq_release_resources = gpiochip_irq_relres;
1836 }
1837 if (WARN_ON(gc->irq.irq_enable))
1838 return;
1839 /* Check if the irqchip already has this hook... */
1840 if (irqchip->irq_enable == gpiochip_irq_enable ||
1841 irqchip->irq_mask == gpiochip_irq_mask) {
1842 /*
1843 * ...and if so, give a gentle warning that this is bad
1844 * practice.
1845 */
1846 chip_info(gc,
1847 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1848 return;
1849 }
1850
1851 if (irqchip->irq_disable) {
1852 gc->irq.irq_disable = irqchip->irq_disable;
1853 irqchip->irq_disable = gpiochip_irq_disable;
1854 } else {
1855 gc->irq.irq_mask = irqchip->irq_mask;
1856 irqchip->irq_mask = gpiochip_irq_mask;
1857 }
1858
1859 if (irqchip->irq_enable) {
1860 gc->irq.irq_enable = irqchip->irq_enable;
1861 irqchip->irq_enable = gpiochip_irq_enable;
1862 } else {
1863 gc->irq.irq_unmask = irqchip->irq_unmask;
1864 irqchip->irq_unmask = gpiochip_irq_unmask;
1865 }
1866 }
1867
gpiochip_irqchip_add_allocated_domain(struct gpio_chip * gc,struct irq_domain * domain,bool allocated_externally)1868 static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
1869 struct irq_domain *domain,
1870 bool allocated_externally)
1871 {
1872 if (!domain)
1873 return -EINVAL;
1874
1875 if (gc->to_irq)
1876 chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1877
1878 gc->to_irq = gpiochip_to_irq;
1879 gc->irq.domain = domain;
1880 gc->irq.domain_is_allocated_externally = allocated_externally;
1881
1882 /*
1883 * Using barrier() here to prevent compiler from reordering
1884 * gc->irq.initialized before adding irqdomain.
1885 */
1886 barrier();
1887
1888 gc->irq.initialized = true;
1889
1890 return 0;
1891 }
1892
1893 /**
1894 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1895 * @gc: the GPIO chip to add the IRQ chip to
1896 * @lock_key: lockdep class for IRQ lock
1897 * @request_key: lockdep class for IRQ request
1898 */
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)1899 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1900 struct lock_class_key *lock_key,
1901 struct lock_class_key *request_key)
1902 {
1903 struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1904 struct irq_chip *irqchip = gc->irq.chip;
1905 struct irq_domain *domain;
1906 unsigned int type;
1907 unsigned int i;
1908 int ret;
1909
1910 if (!irqchip)
1911 return 0;
1912
1913 if (gc->irq.parent_handler && gc->can_sleep) {
1914 chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1915 return -EINVAL;
1916 }
1917
1918 type = gc->irq.default_type;
1919
1920 /*
1921 * Specifying a default trigger is a terrible idea if DT or ACPI is
1922 * used to configure the interrupts, as you may end up with
1923 * conflicting triggers. Tell the user, and reset to NONE.
1924 */
1925 if (WARN(fwnode && type != IRQ_TYPE_NONE,
1926 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1927 type = IRQ_TYPE_NONE;
1928
1929 gc->irq.default_type = type;
1930 gc->irq.lock_key = lock_key;
1931 gc->irq.request_key = request_key;
1932
1933 /* If a parent irqdomain is provided, let's build a hierarchy */
1934 if (gpiochip_hierarchy_is_hierarchical(gc)) {
1935 domain = gpiochip_hierarchy_create_domain(gc);
1936 } else {
1937 domain = gpiochip_simple_create_domain(gc);
1938 }
1939 if (IS_ERR(domain))
1940 return PTR_ERR(domain);
1941
1942 if (gc->irq.parent_handler) {
1943 for (i = 0; i < gc->irq.num_parents; i++) {
1944 void *data;
1945
1946 if (gc->irq.per_parent_data)
1947 data = gc->irq.parent_handler_data_array[i];
1948 else
1949 data = gc->irq.parent_handler_data ?: gc;
1950
1951 /*
1952 * The parent IRQ chip is already using the chip_data
1953 * for this IRQ chip, so our callbacks simply use the
1954 * handler_data.
1955 */
1956 irq_set_chained_handler_and_data(gc->irq.parents[i],
1957 gc->irq.parent_handler,
1958 data);
1959 }
1960 }
1961
1962 gpiochip_set_irq_hooks(gc);
1963
1964 ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);
1965 if (ret)
1966 return ret;
1967
1968 acpi_gpiochip_request_interrupts(gc);
1969
1970 return 0;
1971 }
1972
1973 /**
1974 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1975 * @gc: the gpiochip to remove the irqchip from
1976 *
1977 * This is called only from gpiochip_remove()
1978 */
gpiochip_irqchip_remove(struct gpio_chip * gc)1979 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1980 {
1981 struct irq_chip *irqchip = gc->irq.chip;
1982 unsigned int offset;
1983
1984 acpi_gpiochip_free_interrupts(gc);
1985
1986 if (irqchip && gc->irq.parent_handler) {
1987 struct gpio_irq_chip *irq = &gc->irq;
1988 unsigned int i;
1989
1990 for (i = 0; i < irq->num_parents; i++)
1991 irq_set_chained_handler_and_data(irq->parents[i],
1992 NULL, NULL);
1993 }
1994
1995 /* Remove all IRQ mappings and delete the domain */
1996 if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
1997 unsigned int irq;
1998
1999 for (offset = 0; offset < gc->ngpio; offset++) {
2000 if (!gpiochip_irqchip_irq_valid(gc, offset))
2001 continue;
2002
2003 irq = irq_find_mapping(gc->irq.domain, offset);
2004 irq_dispose_mapping(irq);
2005 }
2006
2007 irq_domain_remove(gc->irq.domain);
2008 }
2009
2010 if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
2011 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2012 irqchip->irq_request_resources = NULL;
2013 irqchip->irq_release_resources = NULL;
2014 }
2015 if (irqchip->irq_enable == gpiochip_irq_enable) {
2016 irqchip->irq_enable = gc->irq.irq_enable;
2017 irqchip->irq_disable = gc->irq.irq_disable;
2018 }
2019 }
2020 gc->irq.irq_enable = NULL;
2021 gc->irq.irq_disable = NULL;
2022 gc->irq.chip = NULL;
2023
2024 gpiochip_irqchip_free_valid_mask(gc);
2025 }
2026
2027 /**
2028 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
2029 * @gc: the gpiochip to add the irqchip to
2030 * @domain: the irqdomain to add to the gpiochip
2031 *
2032 * This function adds an IRQ domain to the gpiochip.
2033 */
gpiochip_irqchip_add_domain(struct gpio_chip * gc,struct irq_domain * domain)2034 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
2035 struct irq_domain *domain)
2036 {
2037 return gpiochip_irqchip_add_allocated_domain(gc, domain, true);
2038 }
2039 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
2040
2041 #else /* CONFIG_GPIOLIB_IRQCHIP */
2042
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)2043 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
2044 struct lock_class_key *lock_key,
2045 struct lock_class_key *request_key)
2046 {
2047 return 0;
2048 }
gpiochip_irqchip_remove(struct gpio_chip * gc)2049 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
2050
gpiochip_irqchip_init_hw(struct gpio_chip * gc)2051 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
2052 {
2053 return 0;
2054 }
2055
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)2056 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
2057 {
2058 return 0;
2059 }
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)2060 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
2061 { }
2062
2063 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2064
2065 /**
2066 * gpiochip_generic_request() - request the gpio function for a pin
2067 * @gc: the gpiochip owning the GPIO
2068 * @offset: the offset of the GPIO to request for GPIO function
2069 */
gpiochip_generic_request(struct gpio_chip * gc,unsigned int offset)2070 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
2071 {
2072 #ifdef CONFIG_PINCTRL
2073 if (list_empty(&gc->gpiodev->pin_ranges))
2074 return 0;
2075 #endif
2076
2077 return pinctrl_gpio_request(gc, offset);
2078 }
2079 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2080
2081 /**
2082 * gpiochip_generic_free() - free the gpio function from a pin
2083 * @gc: the gpiochip to request the gpio function for
2084 * @offset: the offset of the GPIO to free from GPIO function
2085 */
gpiochip_generic_free(struct gpio_chip * gc,unsigned int offset)2086 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
2087 {
2088 #ifdef CONFIG_PINCTRL
2089 if (list_empty(&gc->gpiodev->pin_ranges))
2090 return;
2091 #endif
2092
2093 pinctrl_gpio_free(gc, offset);
2094 }
2095 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2096
2097 /**
2098 * gpiochip_generic_config() - apply configuration for a pin
2099 * @gc: the gpiochip owning the GPIO
2100 * @offset: the offset of the GPIO to apply the configuration
2101 * @config: the configuration to be applied
2102 */
gpiochip_generic_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2103 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
2104 unsigned long config)
2105 {
2106 #ifdef CONFIG_PINCTRL
2107 if (list_empty(&gc->gpiodev->pin_ranges))
2108 return -ENOTSUPP;
2109 #endif
2110
2111 return pinctrl_gpio_set_config(gc, offset, config);
2112 }
2113 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2114
2115 #ifdef CONFIG_PINCTRL
2116
2117 /**
2118 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2119 * @gc: the gpiochip to add the range for
2120 * @pctldev: the pin controller to map to
2121 * @gpio_offset: the start offset in the current gpio_chip number space
2122 * @pin_group: name of the pin group inside the pin controller
2123 *
2124 * Calling this function directly from a DeviceTree-supported
2125 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2126 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2127 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2128 */
gpiochip_add_pingroup_range(struct gpio_chip * gc,struct pinctrl_dev * pctldev,unsigned int gpio_offset,const char * pin_group)2129 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
2130 struct pinctrl_dev *pctldev,
2131 unsigned int gpio_offset, const char *pin_group)
2132 {
2133 struct gpio_pin_range *pin_range;
2134 struct gpio_device *gdev = gc->gpiodev;
2135 int ret;
2136
2137 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2138 if (!pin_range) {
2139 chip_err(gc, "failed to allocate pin ranges\n");
2140 return -ENOMEM;
2141 }
2142
2143 /* Use local offset as range ID */
2144 pin_range->range.id = gpio_offset;
2145 pin_range->range.gc = gc;
2146 pin_range->range.name = gc->label;
2147 pin_range->range.base = gdev->base + gpio_offset;
2148 pin_range->pctldev = pctldev;
2149
2150 ret = pinctrl_get_group_pins(pctldev, pin_group,
2151 &pin_range->range.pins,
2152 &pin_range->range.npins);
2153 if (ret < 0) {
2154 kfree(pin_range);
2155 return ret;
2156 }
2157
2158 pinctrl_add_gpio_range(pctldev, &pin_range->range);
2159
2160 chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2161 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2162 pinctrl_dev_get_devname(pctldev), pin_group);
2163
2164 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2165
2166 return 0;
2167 }
2168 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2169
2170 /**
2171 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2172 * @gc: the gpiochip to add the range for
2173 * @pinctl_name: the dev_name() of the pin controller to map to
2174 * @gpio_offset: the start offset in the current gpio_chip number space
2175 * @pin_offset: the start offset in the pin controller number space
2176 * @npins: the number of pins from the offset of each pin space (GPIO and
2177 * pin controller) to accumulate in this range
2178 *
2179 * Returns:
2180 * 0 on success, or a negative error-code on failure.
2181 *
2182 * Calling this function directly from a DeviceTree-supported
2183 * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2184 * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2185 * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2186 */
gpiochip_add_pin_range(struct gpio_chip * gc,const char * pinctl_name,unsigned int gpio_offset,unsigned int pin_offset,unsigned int npins)2187 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
2188 unsigned int gpio_offset, unsigned int pin_offset,
2189 unsigned int npins)
2190 {
2191 struct gpio_pin_range *pin_range;
2192 struct gpio_device *gdev = gc->gpiodev;
2193 int ret;
2194
2195 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2196 if (!pin_range) {
2197 chip_err(gc, "failed to allocate pin ranges\n");
2198 return -ENOMEM;
2199 }
2200
2201 /* Use local offset as range ID */
2202 pin_range->range.id = gpio_offset;
2203 pin_range->range.gc = gc;
2204 pin_range->range.name = gc->label;
2205 pin_range->range.base = gdev->base + gpio_offset;
2206 pin_range->range.pin_base = pin_offset;
2207 pin_range->range.npins = npins;
2208 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2209 &pin_range->range);
2210 if (IS_ERR(pin_range->pctldev)) {
2211 ret = PTR_ERR(pin_range->pctldev);
2212 chip_err(gc, "could not create pin range\n");
2213 kfree(pin_range);
2214 return ret;
2215 }
2216 chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2217 gpio_offset, gpio_offset + npins - 1,
2218 pinctl_name,
2219 pin_offset, pin_offset + npins - 1);
2220
2221 list_add_tail(&pin_range->node, &gdev->pin_ranges);
2222
2223 return 0;
2224 }
2225 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2226
2227 /**
2228 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2229 * @gc: the chip to remove all the mappings for
2230 */
gpiochip_remove_pin_ranges(struct gpio_chip * gc)2231 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
2232 {
2233 struct gpio_pin_range *pin_range, *tmp;
2234 struct gpio_device *gdev = gc->gpiodev;
2235
2236 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2237 list_del(&pin_range->node);
2238 pinctrl_remove_gpio_range(pin_range->pctldev,
2239 &pin_range->range);
2240 kfree(pin_range);
2241 }
2242 }
2243 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2244
2245 #endif /* CONFIG_PINCTRL */
2246
2247 /* These "optional" allocation calls help prevent drivers from stomping
2248 * on each other, and help provide better diagnostics in debugfs.
2249 * They're called even less than the "set direction" calls.
2250 */
gpiod_request_commit(struct gpio_desc * desc,const char * label)2251 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2252 {
2253 unsigned int offset;
2254 int ret;
2255
2256 CLASS(gpio_chip_guard, guard)(desc);
2257 if (!guard.gc)
2258 return -ENODEV;
2259
2260 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
2261 return -EBUSY;
2262
2263 /* NOTE: gpio_request() can be called in early boot,
2264 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2265 */
2266
2267 if (guard.gc->request) {
2268 offset = gpio_chip_hwgpio(desc);
2269 if (gpiochip_line_is_valid(guard.gc, offset))
2270 ret = guard.gc->request(guard.gc, offset);
2271 else
2272 ret = -EINVAL;
2273 if (ret)
2274 goto out_clear_bit;
2275 }
2276
2277 if (guard.gc->get_direction)
2278 gpiod_get_direction(desc);
2279
2280 ret = desc_set_label(desc, label ? : "?");
2281 if (ret)
2282 goto out_clear_bit;
2283
2284 return 0;
2285
2286 out_clear_bit:
2287 clear_bit(FLAG_REQUESTED, &desc->flags);
2288 return ret;
2289 }
2290
2291 /*
2292 * This descriptor validation needs to be inserted verbatim into each
2293 * function taking a descriptor, so we need to use a preprocessor
2294 * macro to avoid endless duplication. If the desc is NULL it is an
2295 * optional GPIO and calls should just bail out.
2296 */
validate_desc(const struct gpio_desc * desc,const char * func)2297 static int validate_desc(const struct gpio_desc *desc, const char *func)
2298 {
2299 if (!desc)
2300 return 0;
2301
2302 if (IS_ERR(desc)) {
2303 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2304 return PTR_ERR(desc);
2305 }
2306
2307 return 1;
2308 }
2309
2310 #define VALIDATE_DESC(desc) do { \
2311 int __valid = validate_desc(desc, __func__); \
2312 if (__valid <= 0) \
2313 return __valid; \
2314 } while (0)
2315
2316 #define VALIDATE_DESC_VOID(desc) do { \
2317 int __valid = validate_desc(desc, __func__); \
2318 if (__valid <= 0) \
2319 return; \
2320 } while (0)
2321
gpiod_request(struct gpio_desc * desc,const char * label)2322 int gpiod_request(struct gpio_desc *desc, const char *label)
2323 {
2324 int ret = -EPROBE_DEFER;
2325
2326 VALIDATE_DESC(desc);
2327
2328 if (try_module_get(desc->gdev->owner)) {
2329 ret = gpiod_request_commit(desc, label);
2330 if (ret)
2331 module_put(desc->gdev->owner);
2332 else
2333 gpio_device_get(desc->gdev);
2334 }
2335
2336 if (ret)
2337 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2338
2339 return ret;
2340 }
2341
gpiod_free_commit(struct gpio_desc * desc)2342 static void gpiod_free_commit(struct gpio_desc *desc)
2343 {
2344 unsigned long flags;
2345
2346 might_sleep();
2347
2348 CLASS(gpio_chip_guard, guard)(desc);
2349
2350 flags = READ_ONCE(desc->flags);
2351
2352 if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {
2353 if (guard.gc->free)
2354 guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));
2355
2356 clear_bit(FLAG_ACTIVE_LOW, &flags);
2357 clear_bit(FLAG_REQUESTED, &flags);
2358 clear_bit(FLAG_OPEN_DRAIN, &flags);
2359 clear_bit(FLAG_OPEN_SOURCE, &flags);
2360 clear_bit(FLAG_PULL_UP, &flags);
2361 clear_bit(FLAG_PULL_DOWN, &flags);
2362 clear_bit(FLAG_BIAS_DISABLE, &flags);
2363 clear_bit(FLAG_EDGE_RISING, &flags);
2364 clear_bit(FLAG_EDGE_FALLING, &flags);
2365 clear_bit(FLAG_IS_HOGGED, &flags);
2366 #ifdef CONFIG_OF_DYNAMIC
2367 WRITE_ONCE(desc->hog, NULL);
2368 #endif
2369 desc_set_label(desc, NULL);
2370 WRITE_ONCE(desc->flags, flags);
2371
2372 gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED);
2373 }
2374 }
2375
gpiod_free(struct gpio_desc * desc)2376 void gpiod_free(struct gpio_desc *desc)
2377 {
2378 VALIDATE_DESC_VOID(desc);
2379
2380 gpiod_free_commit(desc);
2381 module_put(desc->gdev->owner);
2382 gpio_device_put(desc->gdev);
2383 }
2384
2385 /**
2386 * gpiochip_dup_line_label - Get a copy of the consumer label.
2387 * @gc: GPIO chip controlling this line.
2388 * @offset: Hardware offset of the line.
2389 *
2390 * Returns:
2391 * Pointer to a copy of the consumer label if the line is requested or NULL
2392 * if it's not. If a valid pointer was returned, it must be freed using
2393 * kfree(). In case of a memory allocation error, the function returns %ENOMEM.
2394 *
2395 * Must not be called from atomic context.
2396 */
gpiochip_dup_line_label(struct gpio_chip * gc,unsigned int offset)2397 char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
2398 {
2399 struct gpio_desc *desc;
2400 char *label;
2401
2402 desc = gpiochip_get_desc(gc, offset);
2403 if (IS_ERR(desc))
2404 return NULL;
2405
2406 if (!test_bit(FLAG_REQUESTED, &desc->flags))
2407 return NULL;
2408
2409 guard(srcu)(&desc->gdev->desc_srcu);
2410
2411 label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);
2412 if (!label)
2413 return ERR_PTR(-ENOMEM);
2414
2415 return label;
2416 }
2417 EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
2418
function_name_or_default(const char * con_id)2419 static inline const char *function_name_or_default(const char *con_id)
2420 {
2421 return con_id ?: "(default)";
2422 }
2423
2424 /**
2425 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2426 * @gc: GPIO chip
2427 * @hwnum: hardware number of the GPIO for which to request the descriptor
2428 * @label: label for the GPIO
2429 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2430 * specify things like line inversion semantics with the machine flags
2431 * such as GPIO_OUT_LOW
2432 * @dflags: descriptor request flags for this GPIO or 0 if default, this
2433 * can be used to specify consumer semantics such as open drain
2434 *
2435 * Function allows GPIO chip drivers to request and use their own GPIO
2436 * descriptors via gpiolib API. Difference to gpiod_request() is that this
2437 * function will not increase reference count of the GPIO chip module. This
2438 * allows the GPIO chip module to be unloaded as needed (we assume that the
2439 * GPIO chip driver handles freeing the GPIOs it has requested).
2440 *
2441 * Returns:
2442 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2443 * code on failure.
2444 */
gpiochip_request_own_desc(struct gpio_chip * gc,unsigned int hwnum,const char * label,enum gpio_lookup_flags lflags,enum gpiod_flags dflags)2445 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2446 unsigned int hwnum,
2447 const char *label,
2448 enum gpio_lookup_flags lflags,
2449 enum gpiod_flags dflags)
2450 {
2451 struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2452 const char *name = function_name_or_default(label);
2453 int ret;
2454
2455 if (IS_ERR(desc)) {
2456 chip_err(gc, "failed to get GPIO %s descriptor\n", name);
2457 return desc;
2458 }
2459
2460 ret = gpiod_request_commit(desc, label);
2461 if (ret < 0)
2462 return ERR_PTR(ret);
2463
2464 ret = gpiod_configure_flags(desc, label, lflags, dflags);
2465 if (ret) {
2466 gpiod_free_commit(desc);
2467 chip_err(gc, "setup of own GPIO %s failed\n", name);
2468 return ERR_PTR(ret);
2469 }
2470
2471 return desc;
2472 }
2473 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2474
2475 /**
2476 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2477 * @desc: GPIO descriptor to free
2478 *
2479 * Function frees the given GPIO requested previously with
2480 * gpiochip_request_own_desc().
2481 */
gpiochip_free_own_desc(struct gpio_desc * desc)2482 void gpiochip_free_own_desc(struct gpio_desc *desc)
2483 {
2484 if (desc)
2485 gpiod_free_commit(desc);
2486 }
2487 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2488
2489 /*
2490 * Drivers MUST set GPIO direction before making get/set calls. In
2491 * some cases this is done in early boot, before IRQs are enabled.
2492 *
2493 * As a rule these aren't called more than once (except for drivers
2494 * using the open-drain emulation idiom) so these are natural places
2495 * to accumulate extra debugging checks. Note that we can't (yet)
2496 * rely on gpio_request() having been called beforehand.
2497 */
2498
gpio_do_set_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2499 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2500 unsigned long config)
2501 {
2502 if (!gc->set_config)
2503 return -ENOTSUPP;
2504
2505 return gc->set_config(gc, offset, config);
2506 }
2507
gpio_set_config_with_argument(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2508 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2509 enum pin_config_param mode,
2510 u32 argument)
2511 {
2512 unsigned long config;
2513
2514 CLASS(gpio_chip_guard, guard)(desc);
2515 if (!guard.gc)
2516 return -ENODEV;
2517
2518 config = pinconf_to_config_packed(mode, argument);
2519 return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2520 }
2521
gpio_set_config_with_argument_optional(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2522 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2523 enum pin_config_param mode,
2524 u32 argument)
2525 {
2526 struct device *dev = &desc->gdev->dev;
2527 int gpio = gpio_chip_hwgpio(desc);
2528 int ret;
2529
2530 ret = gpio_set_config_with_argument(desc, mode, argument);
2531 if (ret != -ENOTSUPP)
2532 return ret;
2533
2534 switch (mode) {
2535 case PIN_CONFIG_PERSIST_STATE:
2536 dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2537 break;
2538 default:
2539 break;
2540 }
2541
2542 return 0;
2543 }
2544
gpio_set_config(struct gpio_desc * desc,enum pin_config_param mode)2545 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2546 {
2547 return gpio_set_config_with_argument(desc, mode, 0);
2548 }
2549
gpio_set_bias(struct gpio_desc * desc)2550 static int gpio_set_bias(struct gpio_desc *desc)
2551 {
2552 enum pin_config_param bias;
2553 unsigned long flags;
2554 unsigned int arg;
2555
2556 flags = READ_ONCE(desc->flags);
2557
2558 if (test_bit(FLAG_BIAS_DISABLE, &flags))
2559 bias = PIN_CONFIG_BIAS_DISABLE;
2560 else if (test_bit(FLAG_PULL_UP, &flags))
2561 bias = PIN_CONFIG_BIAS_PULL_UP;
2562 else if (test_bit(FLAG_PULL_DOWN, &flags))
2563 bias = PIN_CONFIG_BIAS_PULL_DOWN;
2564 else
2565 return 0;
2566
2567 switch (bias) {
2568 case PIN_CONFIG_BIAS_PULL_DOWN:
2569 case PIN_CONFIG_BIAS_PULL_UP:
2570 arg = 1;
2571 break;
2572
2573 default:
2574 arg = 0;
2575 break;
2576 }
2577
2578 return gpio_set_config_with_argument_optional(desc, bias, arg);
2579 }
2580
2581 /**
2582 * gpio_set_debounce_timeout() - Set debounce timeout
2583 * @desc: GPIO descriptor to set the debounce timeout
2584 * @debounce: Debounce timeout in microseconds
2585 *
2586 * The function calls the certain GPIO driver to set debounce timeout
2587 * in the hardware.
2588 *
2589 * Returns 0 on success, or negative error code otherwise.
2590 */
gpio_set_debounce_timeout(struct gpio_desc * desc,unsigned int debounce)2591 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2592 {
2593 return gpio_set_config_with_argument_optional(desc,
2594 PIN_CONFIG_INPUT_DEBOUNCE,
2595 debounce);
2596 }
2597
2598 /**
2599 * gpiod_direction_input - set the GPIO direction to input
2600 * @desc: GPIO to set to input
2601 *
2602 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2603 * be called safely on it.
2604 *
2605 * Return 0 in case of success, else an error code.
2606 */
gpiod_direction_input(struct gpio_desc * desc)2607 int gpiod_direction_input(struct gpio_desc *desc)
2608 {
2609 int ret = 0;
2610
2611 VALIDATE_DESC(desc);
2612
2613 CLASS(gpio_chip_guard, guard)(desc);
2614 if (!guard.gc)
2615 return -ENODEV;
2616
2617 /*
2618 * It is legal to have no .get() and .direction_input() specified if
2619 * the chip is output-only, but you can't specify .direction_input()
2620 * and not support the .get() operation, that doesn't make sense.
2621 */
2622 if (!guard.gc->get && guard.gc->direction_input) {
2623 gpiod_warn(desc,
2624 "%s: missing get() but have direction_input()\n",
2625 __func__);
2626 return -EIO;
2627 }
2628
2629 /*
2630 * If we have a .direction_input() callback, things are simple,
2631 * just call it. Else we are some input-only chip so try to check the
2632 * direction (if .get_direction() is supported) else we silently
2633 * assume we are in input mode after this.
2634 */
2635 if (guard.gc->direction_input) {
2636 ret = guard.gc->direction_input(guard.gc,
2637 gpio_chip_hwgpio(desc));
2638 } else if (guard.gc->get_direction &&
2639 (guard.gc->get_direction(guard.gc,
2640 gpio_chip_hwgpio(desc)) != 1)) {
2641 gpiod_warn(desc,
2642 "%s: missing direction_input() operation and line is output\n",
2643 __func__);
2644 return -EIO;
2645 }
2646 if (ret == 0) {
2647 clear_bit(FLAG_IS_OUT, &desc->flags);
2648 ret = gpio_set_bias(desc);
2649 }
2650
2651 trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2652
2653 return ret;
2654 }
2655 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2656
gpiod_direction_output_raw_commit(struct gpio_desc * desc,int value)2657 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2658 {
2659 int val = !!value, ret = 0;
2660
2661 CLASS(gpio_chip_guard, guard)(desc);
2662 if (!guard.gc)
2663 return -ENODEV;
2664
2665 /*
2666 * It's OK not to specify .direction_output() if the gpiochip is
2667 * output-only, but if there is then not even a .set() operation it
2668 * is pretty tricky to drive the output line.
2669 */
2670 if (!guard.gc->set && !guard.gc->direction_output) {
2671 gpiod_warn(desc,
2672 "%s: missing set() and direction_output() operations\n",
2673 __func__);
2674 return -EIO;
2675 }
2676
2677 if (guard.gc->direction_output) {
2678 ret = guard.gc->direction_output(guard.gc,
2679 gpio_chip_hwgpio(desc), val);
2680 } else {
2681 /* Check that we are in output mode if we can */
2682 if (guard.gc->get_direction &&
2683 guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) {
2684 gpiod_warn(desc,
2685 "%s: missing direction_output() operation\n",
2686 __func__);
2687 return -EIO;
2688 }
2689 /*
2690 * If we can't actively set the direction, we are some
2691 * output-only chip, so just drive the output as desired.
2692 */
2693 guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), val);
2694 }
2695
2696 if (!ret)
2697 set_bit(FLAG_IS_OUT, &desc->flags);
2698 trace_gpio_value(desc_to_gpio(desc), 0, val);
2699 trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2700 return ret;
2701 }
2702
2703 /**
2704 * gpiod_direction_output_raw - set the GPIO direction to output
2705 * @desc: GPIO to set to output
2706 * @value: initial output value of the GPIO
2707 *
2708 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2709 * be called safely on it. The initial value of the output must be specified
2710 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2711 *
2712 * Return 0 in case of success, else an error code.
2713 */
gpiod_direction_output_raw(struct gpio_desc * desc,int value)2714 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2715 {
2716 VALIDATE_DESC(desc);
2717 return gpiod_direction_output_raw_commit(desc, value);
2718 }
2719 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2720
2721 /**
2722 * gpiod_direction_output - set the GPIO direction to output
2723 * @desc: GPIO to set to output
2724 * @value: initial output value of the GPIO
2725 *
2726 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2727 * be called safely on it. The initial value of the output must be specified
2728 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2729 * account.
2730 *
2731 * Return 0 in case of success, else an error code.
2732 */
gpiod_direction_output(struct gpio_desc * desc,int value)2733 int gpiod_direction_output(struct gpio_desc *desc, int value)
2734 {
2735 unsigned long flags;
2736 int ret;
2737
2738 VALIDATE_DESC(desc);
2739
2740 flags = READ_ONCE(desc->flags);
2741
2742 if (test_bit(FLAG_ACTIVE_LOW, &flags))
2743 value = !value;
2744 else
2745 value = !!value;
2746
2747 /* GPIOs used for enabled IRQs shall not be set as output */
2748 if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
2749 test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {
2750 gpiod_err(desc,
2751 "%s: tried to set a GPIO tied to an IRQ as output\n",
2752 __func__);
2753 return -EIO;
2754 }
2755
2756 if (test_bit(FLAG_OPEN_DRAIN, &flags)) {
2757 /* First see if we can enable open drain in hardware */
2758 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2759 if (!ret)
2760 goto set_output_value;
2761 /* Emulate open drain by not actively driving the line high */
2762 if (value) {
2763 ret = gpiod_direction_input(desc);
2764 goto set_output_flag;
2765 }
2766 } else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {
2767 ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2768 if (!ret)
2769 goto set_output_value;
2770 /* Emulate open source by not actively driving the line low */
2771 if (!value) {
2772 ret = gpiod_direction_input(desc);
2773 goto set_output_flag;
2774 }
2775 } else {
2776 gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2777 }
2778
2779 set_output_value:
2780 ret = gpio_set_bias(desc);
2781 if (ret)
2782 return ret;
2783 return gpiod_direction_output_raw_commit(desc, value);
2784
2785 set_output_flag:
2786 /*
2787 * When emulating open-source or open-drain functionalities by not
2788 * actively driving the line (setting mode to input) we still need to
2789 * set the IS_OUT flag or otherwise we won't be able to set the line
2790 * value anymore.
2791 */
2792 if (ret == 0)
2793 set_bit(FLAG_IS_OUT, &desc->flags);
2794 return ret;
2795 }
2796 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2797
2798 /**
2799 * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
2800 *
2801 * @desc: GPIO to enable.
2802 * @flags: Flags related to GPIO edge.
2803 *
2804 * Return 0 in case of success, else negative error code.
2805 */
gpiod_enable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)2806 int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
2807 {
2808 int ret = 0;
2809
2810 VALIDATE_DESC(desc);
2811
2812 CLASS(gpio_chip_guard, guard)(desc);
2813 if (!guard.gc)
2814 return -ENODEV;
2815
2816 if (!guard.gc->en_hw_timestamp) {
2817 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
2818 return -ENOTSUPP;
2819 }
2820
2821 ret = guard.gc->en_hw_timestamp(guard.gc,
2822 gpio_chip_hwgpio(desc), flags);
2823 if (ret)
2824 gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
2825
2826 return ret;
2827 }
2828 EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
2829
2830 /**
2831 * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
2832 *
2833 * @desc: GPIO to disable.
2834 * @flags: Flags related to GPIO edge, same value as used during enable call.
2835 *
2836 * Return 0 in case of success, else negative error code.
2837 */
gpiod_disable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)2838 int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
2839 {
2840 int ret = 0;
2841
2842 VALIDATE_DESC(desc);
2843
2844 CLASS(gpio_chip_guard, guard)(desc);
2845 if (!guard.gc)
2846 return -ENODEV;
2847
2848 if (!guard.gc->dis_hw_timestamp) {
2849 gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
2850 return -ENOTSUPP;
2851 }
2852
2853 ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),
2854 flags);
2855 if (ret)
2856 gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
2857
2858 return ret;
2859 }
2860 EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
2861
2862 /**
2863 * gpiod_set_config - sets @config for a GPIO
2864 * @desc: descriptor of the GPIO for which to set the configuration
2865 * @config: Same packed config format as generic pinconf
2866 *
2867 * Returns:
2868 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2869 * configuration.
2870 */
gpiod_set_config(struct gpio_desc * desc,unsigned long config)2871 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2872 {
2873 VALIDATE_DESC(desc);
2874
2875 CLASS(gpio_chip_guard, guard)(desc);
2876 if (!guard.gc)
2877 return -ENODEV;
2878
2879 return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2880 }
2881 EXPORT_SYMBOL_GPL(gpiod_set_config);
2882
2883 /**
2884 * gpiod_set_debounce - sets @debounce time for a GPIO
2885 * @desc: descriptor of the GPIO for which to set debounce time
2886 * @debounce: debounce time in microseconds
2887 *
2888 * Returns:
2889 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2890 * debounce time.
2891 */
gpiod_set_debounce(struct gpio_desc * desc,unsigned int debounce)2892 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2893 {
2894 unsigned long config;
2895
2896 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2897 return gpiod_set_config(desc, config);
2898 }
2899 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2900
2901 /**
2902 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2903 * @desc: descriptor of the GPIO for which to configure persistence
2904 * @transitory: True to lose state on suspend or reset, false for persistence
2905 *
2906 * Returns:
2907 * 0 on success, otherwise a negative error code.
2908 */
gpiod_set_transitory(struct gpio_desc * desc,bool transitory)2909 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2910 {
2911 VALIDATE_DESC(desc);
2912 /*
2913 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2914 * persistence state.
2915 */
2916 assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2917
2918 /* If the driver supports it, set the persistence state now */
2919 return gpio_set_config_with_argument_optional(desc,
2920 PIN_CONFIG_PERSIST_STATE,
2921 !transitory);
2922 }
2923
2924 /**
2925 * gpiod_is_active_low - test whether a GPIO is active-low or not
2926 * @desc: the gpio descriptor to test
2927 *
2928 * Returns 1 if the GPIO is active-low, 0 otherwise.
2929 */
gpiod_is_active_low(const struct gpio_desc * desc)2930 int gpiod_is_active_low(const struct gpio_desc *desc)
2931 {
2932 VALIDATE_DESC(desc);
2933 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2934 }
2935 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2936
2937 /**
2938 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2939 * @desc: the gpio descriptor to change
2940 */
gpiod_toggle_active_low(struct gpio_desc * desc)2941 void gpiod_toggle_active_low(struct gpio_desc *desc)
2942 {
2943 VALIDATE_DESC_VOID(desc);
2944 change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2945 }
2946 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2947
gpio_chip_get_value(struct gpio_chip * gc,const struct gpio_desc * desc)2948 static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)
2949 {
2950 return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO;
2951 }
2952
2953 /* I/O calls are only valid after configuration completed; the relevant
2954 * "is this a valid GPIO" error checks should already have been done.
2955 *
2956 * "Get" operations are often inlinable as reading a pin value register,
2957 * and masking the relevant bit in that register.
2958 *
2959 * When "set" operations are inlinable, they involve writing that mask to
2960 * one register to set a low value, or a different register to set it high.
2961 * Otherwise locking is needed, so there may be little value to inlining.
2962 *
2963 *------------------------------------------------------------------------
2964 *
2965 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2966 * have requested the GPIO. That can include implicit requesting by
2967 * a direction setting call. Marking a gpio as requested locks its chip
2968 * in memory, guaranteeing that these table lookups need no more locking
2969 * and that gpiochip_remove() will fail.
2970 *
2971 * REVISIT when debugging, consider adding some instrumentation to ensure
2972 * that the GPIO was actually requested.
2973 */
2974
gpiod_get_raw_value_commit(const struct gpio_desc * desc)2975 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2976 {
2977 struct gpio_device *gdev;
2978 struct gpio_chip *gc;
2979 int value;
2980
2981 /* FIXME Unable to use gpio_chip_guard due to const desc. */
2982 gdev = desc->gdev;
2983
2984 guard(srcu)(&gdev->srcu);
2985
2986 gc = srcu_dereference(gdev->chip, &gdev->srcu);
2987 if (!gc)
2988 return -ENODEV;
2989
2990 value = gpio_chip_get_value(gc, desc);
2991 value = value < 0 ? value : !!value;
2992 trace_gpio_value(desc_to_gpio(desc), 1, value);
2993 return value;
2994 }
2995
gpio_chip_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)2996 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2997 unsigned long *mask, unsigned long *bits)
2998 {
2999 if (gc->get_multiple)
3000 return gc->get_multiple(gc, mask, bits);
3001 if (gc->get) {
3002 int i, value;
3003
3004 for_each_set_bit(i, mask, gc->ngpio) {
3005 value = gc->get(gc, i);
3006 if (value < 0)
3007 return value;
3008 __assign_bit(i, bits, value);
3009 }
3010 return 0;
3011 }
3012 return -EIO;
3013 }
3014
3015 /* The 'other' chip must be protected with its GPIO device's SRCU. */
gpio_device_chip_cmp(struct gpio_device * gdev,struct gpio_chip * gc)3016 static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
3017 {
3018 guard(srcu)(&gdev->srcu);
3019
3020 return gc == srcu_dereference(gdev->chip, &gdev->srcu);
3021 }
3022
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)3023 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3024 unsigned int array_size,
3025 struct gpio_desc **desc_array,
3026 struct gpio_array *array_info,
3027 unsigned long *value_bitmap)
3028 {
3029 int ret, i = 0;
3030
3031 /*
3032 * Validate array_info against desc_array and its size.
3033 * It should immediately follow desc_array if both
3034 * have been obtained from the same gpiod_get_array() call.
3035 */
3036 if (array_info && array_info->desc == desc_array &&
3037 array_size <= array_info->size &&
3038 (void *)array_info == desc_array + array_info->size) {
3039 if (!can_sleep)
3040 WARN_ON(array_info->chip->can_sleep);
3041
3042 ret = gpio_chip_get_multiple(array_info->chip,
3043 array_info->get_mask,
3044 value_bitmap);
3045 if (ret)
3046 return ret;
3047
3048 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3049 bitmap_xor(value_bitmap, value_bitmap,
3050 array_info->invert_mask, array_size);
3051
3052 i = find_first_zero_bit(array_info->get_mask, array_size);
3053 if (i == array_size)
3054 return 0;
3055 } else {
3056 array_info = NULL;
3057 }
3058
3059 while (i < array_size) {
3060 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3061 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3062 unsigned long *mask, *bits;
3063 int first, j;
3064
3065 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3066 if (!guard.gc)
3067 return -ENODEV;
3068
3069 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3070 mask = fastpath_mask;
3071 bits = fastpath_bits;
3072 } else {
3073 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3074
3075 mask = bitmap_alloc(guard.gc->ngpio, flags);
3076 if (!mask)
3077 return -ENOMEM;
3078
3079 bits = bitmap_alloc(guard.gc->ngpio, flags);
3080 if (!bits) {
3081 bitmap_free(mask);
3082 return -ENOMEM;
3083 }
3084 }
3085
3086 bitmap_zero(mask, guard.gc->ngpio);
3087
3088 if (!can_sleep)
3089 WARN_ON(guard.gc->can_sleep);
3090
3091 /* collect all inputs belonging to the same chip */
3092 first = i;
3093 do {
3094 const struct gpio_desc *desc = desc_array[i];
3095 int hwgpio = gpio_chip_hwgpio(desc);
3096
3097 __set_bit(hwgpio, mask);
3098 i++;
3099
3100 if (array_info)
3101 i = find_next_zero_bit(array_info->get_mask,
3102 array_size, i);
3103 } while ((i < array_size) &&
3104 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3105
3106 ret = gpio_chip_get_multiple(guard.gc, mask, bits);
3107 if (ret) {
3108 if (mask != fastpath_mask)
3109 bitmap_free(mask);
3110 if (bits != fastpath_bits)
3111 bitmap_free(bits);
3112 return ret;
3113 }
3114
3115 for (j = first; j < i; ) {
3116 const struct gpio_desc *desc = desc_array[j];
3117 int hwgpio = gpio_chip_hwgpio(desc);
3118 int value = test_bit(hwgpio, bits);
3119
3120 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3121 value = !value;
3122 __assign_bit(j, value_bitmap, value);
3123 trace_gpio_value(desc_to_gpio(desc), 1, value);
3124 j++;
3125
3126 if (array_info)
3127 j = find_next_zero_bit(array_info->get_mask, i,
3128 j);
3129 }
3130
3131 if (mask != fastpath_mask)
3132 bitmap_free(mask);
3133 if (bits != fastpath_bits)
3134 bitmap_free(bits);
3135 }
3136 return 0;
3137 }
3138
3139 /**
3140 * gpiod_get_raw_value() - return a gpio's raw value
3141 * @desc: gpio whose value will be returned
3142 *
3143 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3144 * its ACTIVE_LOW status, or negative errno on failure.
3145 *
3146 * This function can be called from contexts where we cannot sleep, and will
3147 * complain if the GPIO chip functions potentially sleep.
3148 */
gpiod_get_raw_value(const struct gpio_desc * desc)3149 int gpiod_get_raw_value(const struct gpio_desc *desc)
3150 {
3151 VALIDATE_DESC(desc);
3152 /* Should be using gpiod_get_raw_value_cansleep() */
3153 WARN_ON(desc->gdev->can_sleep);
3154 return gpiod_get_raw_value_commit(desc);
3155 }
3156 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3157
3158 /**
3159 * gpiod_get_value() - return a gpio's value
3160 * @desc: gpio whose value will be returned
3161 *
3162 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3163 * account, or negative errno on failure.
3164 *
3165 * This function can be called from contexts where we cannot sleep, and will
3166 * complain if the GPIO chip functions potentially sleep.
3167 */
gpiod_get_value(const struct gpio_desc * desc)3168 int gpiod_get_value(const struct gpio_desc *desc)
3169 {
3170 int value;
3171
3172 VALIDATE_DESC(desc);
3173 /* Should be using gpiod_get_value_cansleep() */
3174 WARN_ON(desc->gdev->can_sleep);
3175
3176 value = gpiod_get_raw_value_commit(desc);
3177 if (value < 0)
3178 return value;
3179
3180 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3181 value = !value;
3182
3183 return value;
3184 }
3185 EXPORT_SYMBOL_GPL(gpiod_get_value);
3186
3187 /**
3188 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3189 * @array_size: number of elements in the descriptor array / value bitmap
3190 * @desc_array: array of GPIO descriptors whose values will be read
3191 * @array_info: information on applicability of fast bitmap processing path
3192 * @value_bitmap: bitmap to store the read values
3193 *
3194 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3195 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3196 * else an error code.
3197 *
3198 * This function can be called from contexts where we cannot sleep,
3199 * and it will complain if the GPIO chip functions potentially sleep.
3200 */
gpiod_get_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3201 int gpiod_get_raw_array_value(unsigned int array_size,
3202 struct gpio_desc **desc_array,
3203 struct gpio_array *array_info,
3204 unsigned long *value_bitmap)
3205 {
3206 if (!desc_array)
3207 return -EINVAL;
3208 return gpiod_get_array_value_complex(true, false, array_size,
3209 desc_array, array_info,
3210 value_bitmap);
3211 }
3212 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3213
3214 /**
3215 * gpiod_get_array_value() - read values from an array of GPIOs
3216 * @array_size: number of elements in the descriptor array / value bitmap
3217 * @desc_array: array of GPIO descriptors whose values will be read
3218 * @array_info: information on applicability of fast bitmap processing path
3219 * @value_bitmap: bitmap to store the read values
3220 *
3221 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3222 * into account. Return 0 in case of success, else an error code.
3223 *
3224 * This function can be called from contexts where we cannot sleep,
3225 * and it will complain if the GPIO chip functions potentially sleep.
3226 */
gpiod_get_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3227 int gpiod_get_array_value(unsigned int array_size,
3228 struct gpio_desc **desc_array,
3229 struct gpio_array *array_info,
3230 unsigned long *value_bitmap)
3231 {
3232 if (!desc_array)
3233 return -EINVAL;
3234 return gpiod_get_array_value_complex(false, false, array_size,
3235 desc_array, array_info,
3236 value_bitmap);
3237 }
3238 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3239
3240 /*
3241 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3242 * @desc: gpio descriptor whose state need to be set.
3243 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3244 */
gpio_set_open_drain_value_commit(struct gpio_desc * desc,bool value)3245 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3246 {
3247 int ret = 0, offset = gpio_chip_hwgpio(desc);
3248
3249 CLASS(gpio_chip_guard, guard)(desc);
3250 if (!guard.gc)
3251 return;
3252
3253 if (value) {
3254 ret = guard.gc->direction_input(guard.gc, offset);
3255 } else {
3256 ret = guard.gc->direction_output(guard.gc, offset, 0);
3257 if (!ret)
3258 set_bit(FLAG_IS_OUT, &desc->flags);
3259 }
3260 trace_gpio_direction(desc_to_gpio(desc), value, ret);
3261 if (ret < 0)
3262 gpiod_err(desc,
3263 "%s: Error in set_value for open drain err %d\n",
3264 __func__, ret);
3265 }
3266
3267 /*
3268 * _gpio_set_open_source_value() - Set the open source gpio's value.
3269 * @desc: gpio descriptor whose state need to be set.
3270 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3271 */
gpio_set_open_source_value_commit(struct gpio_desc * desc,bool value)3272 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3273 {
3274 int ret = 0, offset = gpio_chip_hwgpio(desc);
3275
3276 CLASS(gpio_chip_guard, guard)(desc);
3277 if (!guard.gc)
3278 return;
3279
3280 if (value) {
3281 ret = guard.gc->direction_output(guard.gc, offset, 1);
3282 if (!ret)
3283 set_bit(FLAG_IS_OUT, &desc->flags);
3284 } else {
3285 ret = guard.gc->direction_input(guard.gc, offset);
3286 }
3287 trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3288 if (ret < 0)
3289 gpiod_err(desc,
3290 "%s: Error in set_value for open source err %d\n",
3291 __func__, ret);
3292 }
3293
gpiod_set_raw_value_commit(struct gpio_desc * desc,bool value)3294 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3295 {
3296 CLASS(gpio_chip_guard, guard)(desc);
3297 if (!guard.gc)
3298 return;
3299
3300 trace_gpio_value(desc_to_gpio(desc), 0, value);
3301 guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), value);
3302 }
3303
3304 /*
3305 * set multiple outputs on the same chip;
3306 * use the chip's set_multiple function if available;
3307 * otherwise set the outputs sequentially;
3308 * @chip: the GPIO chip we operate on
3309 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3310 * defines which outputs are to be changed
3311 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3312 * defines the values the outputs specified by mask are to be set to
3313 */
gpio_chip_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)3314 static void gpio_chip_set_multiple(struct gpio_chip *gc,
3315 unsigned long *mask, unsigned long *bits)
3316 {
3317 if (gc->set_multiple) {
3318 gc->set_multiple(gc, mask, bits);
3319 } else {
3320 unsigned int i;
3321
3322 /* set outputs if the corresponding mask bit is set */
3323 for_each_set_bit(i, mask, gc->ngpio)
3324 gc->set(gc, i, test_bit(i, bits));
3325 }
3326 }
3327
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)3328 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3329 unsigned int array_size,
3330 struct gpio_desc **desc_array,
3331 struct gpio_array *array_info,
3332 unsigned long *value_bitmap)
3333 {
3334 int i = 0;
3335
3336 /*
3337 * Validate array_info against desc_array and its size.
3338 * It should immediately follow desc_array if both
3339 * have been obtained from the same gpiod_get_array() call.
3340 */
3341 if (array_info && array_info->desc == desc_array &&
3342 array_size <= array_info->size &&
3343 (void *)array_info == desc_array + array_info->size) {
3344 if (!can_sleep)
3345 WARN_ON(array_info->chip->can_sleep);
3346
3347 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3348 bitmap_xor(value_bitmap, value_bitmap,
3349 array_info->invert_mask, array_size);
3350
3351 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3352 value_bitmap);
3353
3354 i = find_first_zero_bit(array_info->set_mask, array_size);
3355 if (i == array_size)
3356 return 0;
3357 } else {
3358 array_info = NULL;
3359 }
3360
3361 while (i < array_size) {
3362 DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3363 DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3364 unsigned long *mask, *bits;
3365 int count = 0;
3366
3367 CLASS(gpio_chip_guard, guard)(desc_array[i]);
3368 if (!guard.gc)
3369 return -ENODEV;
3370
3371 if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3372 mask = fastpath_mask;
3373 bits = fastpath_bits;
3374 } else {
3375 gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3376
3377 mask = bitmap_alloc(guard.gc->ngpio, flags);
3378 if (!mask)
3379 return -ENOMEM;
3380
3381 bits = bitmap_alloc(guard.gc->ngpio, flags);
3382 if (!bits) {
3383 bitmap_free(mask);
3384 return -ENOMEM;
3385 }
3386 }
3387
3388 bitmap_zero(mask, guard.gc->ngpio);
3389
3390 if (!can_sleep)
3391 WARN_ON(guard.gc->can_sleep);
3392
3393 do {
3394 struct gpio_desc *desc = desc_array[i];
3395 int hwgpio = gpio_chip_hwgpio(desc);
3396 int value = test_bit(i, value_bitmap);
3397
3398 /*
3399 * Pins applicable for fast input but not for
3400 * fast output processing may have been already
3401 * inverted inside the fast path, skip them.
3402 */
3403 if (!raw && !(array_info &&
3404 test_bit(i, array_info->invert_mask)) &&
3405 test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3406 value = !value;
3407 trace_gpio_value(desc_to_gpio(desc), 0, value);
3408 /*
3409 * collect all normal outputs belonging to the same chip
3410 * open drain and open source outputs are set individually
3411 */
3412 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3413 gpio_set_open_drain_value_commit(desc, value);
3414 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3415 gpio_set_open_source_value_commit(desc, value);
3416 } else {
3417 __set_bit(hwgpio, mask);
3418 __assign_bit(hwgpio, bits, value);
3419 count++;
3420 }
3421 i++;
3422
3423 if (array_info)
3424 i = find_next_zero_bit(array_info->set_mask,
3425 array_size, i);
3426 } while ((i < array_size) &&
3427 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3428 /* push collected bits to outputs */
3429 if (count != 0)
3430 gpio_chip_set_multiple(guard.gc, mask, bits);
3431
3432 if (mask != fastpath_mask)
3433 bitmap_free(mask);
3434 if (bits != fastpath_bits)
3435 bitmap_free(bits);
3436 }
3437 return 0;
3438 }
3439
3440 /**
3441 * gpiod_set_raw_value() - assign a gpio's raw value
3442 * @desc: gpio whose value will be assigned
3443 * @value: value to assign
3444 *
3445 * Set the raw value of the GPIO, i.e. the value of its physical line without
3446 * regard for its ACTIVE_LOW status.
3447 *
3448 * This function can be called from contexts where we cannot sleep, and will
3449 * complain if the GPIO chip functions potentially sleep.
3450 */
gpiod_set_raw_value(struct gpio_desc * desc,int value)3451 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3452 {
3453 VALIDATE_DESC_VOID(desc);
3454 /* Should be using gpiod_set_raw_value_cansleep() */
3455 WARN_ON(desc->gdev->can_sleep);
3456 gpiod_set_raw_value_commit(desc, value);
3457 }
3458 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3459
3460 /**
3461 * gpiod_set_value_nocheck() - set a GPIO line value without checking
3462 * @desc: the descriptor to set the value on
3463 * @value: value to set
3464 *
3465 * This sets the value of a GPIO line backing a descriptor, applying
3466 * different semantic quirks like active low and open drain/source
3467 * handling.
3468 */
gpiod_set_value_nocheck(struct gpio_desc * desc,int value)3469 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3470 {
3471 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3472 value = !value;
3473 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3474 gpio_set_open_drain_value_commit(desc, value);
3475 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3476 gpio_set_open_source_value_commit(desc, value);
3477 else
3478 gpiod_set_raw_value_commit(desc, value);
3479 }
3480
3481 /**
3482 * gpiod_set_value() - assign a gpio's value
3483 * @desc: gpio whose value will be assigned
3484 * @value: value to assign
3485 *
3486 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3487 * OPEN_DRAIN and OPEN_SOURCE flags into account.
3488 *
3489 * This function can be called from contexts where we cannot sleep, and will
3490 * complain if the GPIO chip functions potentially sleep.
3491 */
gpiod_set_value(struct gpio_desc * desc,int value)3492 void gpiod_set_value(struct gpio_desc *desc, int value)
3493 {
3494 VALIDATE_DESC_VOID(desc);
3495 /* Should be using gpiod_set_value_cansleep() */
3496 WARN_ON(desc->gdev->can_sleep);
3497 gpiod_set_value_nocheck(desc, value);
3498 }
3499 EXPORT_SYMBOL_GPL(gpiod_set_value);
3500
3501 /**
3502 * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3503 * @array_size: number of elements in the descriptor array / value bitmap
3504 * @desc_array: array of GPIO descriptors whose values will be assigned
3505 * @array_info: information on applicability of fast bitmap processing path
3506 * @value_bitmap: bitmap of values to assign
3507 *
3508 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3509 * without regard for their ACTIVE_LOW status.
3510 *
3511 * This function can be called from contexts where we cannot sleep, and will
3512 * complain if the GPIO chip functions potentially sleep.
3513 */
gpiod_set_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3514 int gpiod_set_raw_array_value(unsigned int array_size,
3515 struct gpio_desc **desc_array,
3516 struct gpio_array *array_info,
3517 unsigned long *value_bitmap)
3518 {
3519 if (!desc_array)
3520 return -EINVAL;
3521 return gpiod_set_array_value_complex(true, false, array_size,
3522 desc_array, array_info, value_bitmap);
3523 }
3524 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3525
3526 /**
3527 * gpiod_set_array_value() - assign values to an array of GPIOs
3528 * @array_size: number of elements in the descriptor array / value bitmap
3529 * @desc_array: array of GPIO descriptors whose values will be assigned
3530 * @array_info: information on applicability of fast bitmap processing path
3531 * @value_bitmap: bitmap of values to assign
3532 *
3533 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3534 * into account.
3535 *
3536 * This function can be called from contexts where we cannot sleep, and will
3537 * complain if the GPIO chip functions potentially sleep.
3538 */
gpiod_set_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3539 int gpiod_set_array_value(unsigned int array_size,
3540 struct gpio_desc **desc_array,
3541 struct gpio_array *array_info,
3542 unsigned long *value_bitmap)
3543 {
3544 if (!desc_array)
3545 return -EINVAL;
3546 return gpiod_set_array_value_complex(false, false, array_size,
3547 desc_array, array_info,
3548 value_bitmap);
3549 }
3550 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3551
3552 /**
3553 * gpiod_cansleep() - report whether gpio value access may sleep
3554 * @desc: gpio to check
3555 *
3556 */
gpiod_cansleep(const struct gpio_desc * desc)3557 int gpiod_cansleep(const struct gpio_desc *desc)
3558 {
3559 VALIDATE_DESC(desc);
3560 return desc->gdev->can_sleep;
3561 }
3562 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3563
3564 /**
3565 * gpiod_set_consumer_name() - set the consumer name for the descriptor
3566 * @desc: gpio to set the consumer name on
3567 * @name: the new consumer name
3568 */
gpiod_set_consumer_name(struct gpio_desc * desc,const char * name)3569 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3570 {
3571 VALIDATE_DESC(desc);
3572
3573 return desc_set_label(desc, name);
3574 }
3575 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3576
3577 /**
3578 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3579 * @desc: gpio whose IRQ will be returned (already requested)
3580 *
3581 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3582 * error.
3583 */
gpiod_to_irq(const struct gpio_desc * desc)3584 int gpiod_to_irq(const struct gpio_desc *desc)
3585 {
3586 struct gpio_device *gdev;
3587 struct gpio_chip *gc;
3588 int offset;
3589
3590 /*
3591 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3592 * requires this function to not return zero on an invalid descriptor
3593 * but rather a negative error number.
3594 */
3595 if (!desc || IS_ERR(desc))
3596 return -EINVAL;
3597
3598 gdev = desc->gdev;
3599 /* FIXME Cannot use gpio_chip_guard due to const desc. */
3600 guard(srcu)(&gdev->srcu);
3601 gc = srcu_dereference(gdev->chip, &gdev->srcu);
3602 if (!gc)
3603 return -ENODEV;
3604
3605 offset = gpio_chip_hwgpio(desc);
3606 if (gc->to_irq) {
3607 int retirq = gc->to_irq(gc, offset);
3608
3609 /* Zero means NO_IRQ */
3610 if (!retirq)
3611 return -ENXIO;
3612
3613 return retirq;
3614 }
3615 #ifdef CONFIG_GPIOLIB_IRQCHIP
3616 if (gc->irq.chip) {
3617 /*
3618 * Avoid race condition with other code, which tries to lookup
3619 * an IRQ before the irqchip has been properly registered,
3620 * i.e. while gpiochip is still being brought up.
3621 */
3622 return -EPROBE_DEFER;
3623 }
3624 #endif
3625 return -ENXIO;
3626 }
3627 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3628
3629 /**
3630 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3631 * @gc: the chip the GPIO to lock belongs to
3632 * @offset: the offset of the GPIO to lock as IRQ
3633 *
3634 * This is used directly by GPIO drivers that want to lock down
3635 * a certain GPIO line to be used for IRQs.
3636 */
gpiochip_lock_as_irq(struct gpio_chip * gc,unsigned int offset)3637 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3638 {
3639 struct gpio_desc *desc;
3640
3641 desc = gpiochip_get_desc(gc, offset);
3642 if (IS_ERR(desc))
3643 return PTR_ERR(desc);
3644
3645 /*
3646 * If it's fast: flush the direction setting if something changed
3647 * behind our back
3648 */
3649 if (!gc->can_sleep && gc->get_direction) {
3650 int dir = gpiod_get_direction(desc);
3651
3652 if (dir < 0) {
3653 chip_err(gc, "%s: cannot get GPIO direction\n",
3654 __func__);
3655 return dir;
3656 }
3657 }
3658
3659 /* To be valid for IRQ the line needs to be input or open drain */
3660 if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3661 !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3662 chip_err(gc,
3663 "%s: tried to flag a GPIO set as output for IRQ\n",
3664 __func__);
3665 return -EIO;
3666 }
3667
3668 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3669 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3670
3671 return 0;
3672 }
3673 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3674
3675 /**
3676 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3677 * @gc: the chip the GPIO to lock belongs to
3678 * @offset: the offset of the GPIO to lock as IRQ
3679 *
3680 * This is used directly by GPIO drivers that want to indicate
3681 * that a certain GPIO is no longer used exclusively for IRQ.
3682 */
gpiochip_unlock_as_irq(struct gpio_chip * gc,unsigned int offset)3683 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3684 {
3685 struct gpio_desc *desc;
3686
3687 desc = gpiochip_get_desc(gc, offset);
3688 if (IS_ERR(desc))
3689 return;
3690
3691 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3692 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3693 }
3694 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3695
gpiochip_disable_irq(struct gpio_chip * gc,unsigned int offset)3696 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3697 {
3698 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3699
3700 if (!IS_ERR(desc) &&
3701 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3702 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3703 }
3704 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3705
gpiochip_enable_irq(struct gpio_chip * gc,unsigned int offset)3706 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3707 {
3708 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3709
3710 if (!IS_ERR(desc) &&
3711 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3712 /*
3713 * We must not be output when using IRQ UNLESS we are
3714 * open drain.
3715 */
3716 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3717 !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3718 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3719 }
3720 }
3721 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3722
gpiochip_line_is_irq(struct gpio_chip * gc,unsigned int offset)3723 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3724 {
3725 if (offset >= gc->ngpio)
3726 return false;
3727
3728 return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3729 }
3730 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3731
gpiochip_reqres_irq(struct gpio_chip * gc,unsigned int offset)3732 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3733 {
3734 int ret;
3735
3736 if (!try_module_get(gc->gpiodev->owner))
3737 return -ENODEV;
3738
3739 ret = gpiochip_lock_as_irq(gc, offset);
3740 if (ret) {
3741 chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3742 module_put(gc->gpiodev->owner);
3743 return ret;
3744 }
3745 return 0;
3746 }
3747 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3748
gpiochip_relres_irq(struct gpio_chip * gc,unsigned int offset)3749 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3750 {
3751 gpiochip_unlock_as_irq(gc, offset);
3752 module_put(gc->gpiodev->owner);
3753 }
3754 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3755
gpiochip_line_is_open_drain(struct gpio_chip * gc,unsigned int offset)3756 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3757 {
3758 if (offset >= gc->ngpio)
3759 return false;
3760
3761 return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3762 }
3763 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3764
gpiochip_line_is_open_source(struct gpio_chip * gc,unsigned int offset)3765 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3766 {
3767 if (offset >= gc->ngpio)
3768 return false;
3769
3770 return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3771 }
3772 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3773
gpiochip_line_is_persistent(struct gpio_chip * gc,unsigned int offset)3774 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3775 {
3776 if (offset >= gc->ngpio)
3777 return false;
3778
3779 return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3780 }
3781 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3782
3783 /**
3784 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3785 * @desc: gpio whose value will be returned
3786 *
3787 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3788 * its ACTIVE_LOW status, or negative errno on failure.
3789 *
3790 * This function is to be called from contexts that can sleep.
3791 */
gpiod_get_raw_value_cansleep(const struct gpio_desc * desc)3792 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3793 {
3794 might_sleep();
3795 VALIDATE_DESC(desc);
3796 return gpiod_get_raw_value_commit(desc);
3797 }
3798 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3799
3800 /**
3801 * gpiod_get_value_cansleep() - return a gpio's value
3802 * @desc: gpio whose value will be returned
3803 *
3804 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3805 * account, or negative errno on failure.
3806 *
3807 * This function is to be called from contexts that can sleep.
3808 */
gpiod_get_value_cansleep(const struct gpio_desc * desc)3809 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3810 {
3811 int value;
3812
3813 might_sleep();
3814 VALIDATE_DESC(desc);
3815 value = gpiod_get_raw_value_commit(desc);
3816 if (value < 0)
3817 return value;
3818
3819 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3820 value = !value;
3821
3822 return value;
3823 }
3824 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3825
3826 /**
3827 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3828 * @array_size: number of elements in the descriptor array / value bitmap
3829 * @desc_array: array of GPIO descriptors whose values will be read
3830 * @array_info: information on applicability of fast bitmap processing path
3831 * @value_bitmap: bitmap to store the read values
3832 *
3833 * Read the raw values of the GPIOs, i.e. the values of the physical lines
3834 * without regard for their ACTIVE_LOW status. Return 0 in case of success,
3835 * else an error code.
3836 *
3837 * This function is to be called from contexts that can sleep.
3838 */
gpiod_get_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3839 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3840 struct gpio_desc **desc_array,
3841 struct gpio_array *array_info,
3842 unsigned long *value_bitmap)
3843 {
3844 might_sleep();
3845 if (!desc_array)
3846 return -EINVAL;
3847 return gpiod_get_array_value_complex(true, true, array_size,
3848 desc_array, array_info,
3849 value_bitmap);
3850 }
3851 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3852
3853 /**
3854 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3855 * @array_size: number of elements in the descriptor array / value bitmap
3856 * @desc_array: array of GPIO descriptors whose values will be read
3857 * @array_info: information on applicability of fast bitmap processing path
3858 * @value_bitmap: bitmap to store the read values
3859 *
3860 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3861 * into account. Return 0 in case of success, else an error code.
3862 *
3863 * This function is to be called from contexts that can sleep.
3864 */
gpiod_get_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3865 int gpiod_get_array_value_cansleep(unsigned int array_size,
3866 struct gpio_desc **desc_array,
3867 struct gpio_array *array_info,
3868 unsigned long *value_bitmap)
3869 {
3870 might_sleep();
3871 if (!desc_array)
3872 return -EINVAL;
3873 return gpiod_get_array_value_complex(false, true, array_size,
3874 desc_array, array_info,
3875 value_bitmap);
3876 }
3877 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3878
3879 /**
3880 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3881 * @desc: gpio whose value will be assigned
3882 * @value: value to assign
3883 *
3884 * Set the raw value of the GPIO, i.e. the value of its physical line without
3885 * regard for its ACTIVE_LOW status.
3886 *
3887 * This function is to be called from contexts that can sleep.
3888 */
gpiod_set_raw_value_cansleep(struct gpio_desc * desc,int value)3889 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3890 {
3891 might_sleep();
3892 VALIDATE_DESC_VOID(desc);
3893 gpiod_set_raw_value_commit(desc, value);
3894 }
3895 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3896
3897 /**
3898 * gpiod_set_value_cansleep() - assign a gpio's value
3899 * @desc: gpio whose value will be assigned
3900 * @value: value to assign
3901 *
3902 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3903 * account
3904 *
3905 * This function is to be called from contexts that can sleep.
3906 */
gpiod_set_value_cansleep(struct gpio_desc * desc,int value)3907 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3908 {
3909 might_sleep();
3910 VALIDATE_DESC_VOID(desc);
3911 gpiod_set_value_nocheck(desc, value);
3912 }
3913 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3914
3915 /**
3916 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3917 * @array_size: number of elements in the descriptor array / value bitmap
3918 * @desc_array: array of GPIO descriptors whose values will be assigned
3919 * @array_info: information on applicability of fast bitmap processing path
3920 * @value_bitmap: bitmap of values to assign
3921 *
3922 * Set the raw values of the GPIOs, i.e. the values of the physical lines
3923 * without regard for their ACTIVE_LOW status.
3924 *
3925 * This function is to be called from contexts that can sleep.
3926 */
gpiod_set_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3927 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3928 struct gpio_desc **desc_array,
3929 struct gpio_array *array_info,
3930 unsigned long *value_bitmap)
3931 {
3932 might_sleep();
3933 if (!desc_array)
3934 return -EINVAL;
3935 return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3936 array_info, value_bitmap);
3937 }
3938 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3939
3940 /**
3941 * gpiod_add_lookup_tables() - register GPIO device consumers
3942 * @tables: list of tables of consumers to register
3943 * @n: number of tables in the list
3944 */
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)3945 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3946 {
3947 unsigned int i;
3948
3949 mutex_lock(&gpio_lookup_lock);
3950
3951 for (i = 0; i < n; i++)
3952 list_add_tail(&tables[i]->list, &gpio_lookup_list);
3953
3954 mutex_unlock(&gpio_lookup_lock);
3955 }
3956
3957 /**
3958 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3959 * @array_size: number of elements in the descriptor array / value bitmap
3960 * @desc_array: array of GPIO descriptors whose values will be assigned
3961 * @array_info: information on applicability of fast bitmap processing path
3962 * @value_bitmap: bitmap of values to assign
3963 *
3964 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3965 * into account.
3966 *
3967 * This function is to be called from contexts that can sleep.
3968 */
gpiod_set_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3969 int gpiod_set_array_value_cansleep(unsigned int array_size,
3970 struct gpio_desc **desc_array,
3971 struct gpio_array *array_info,
3972 unsigned long *value_bitmap)
3973 {
3974 might_sleep();
3975 if (!desc_array)
3976 return -EINVAL;
3977 return gpiod_set_array_value_complex(false, true, array_size,
3978 desc_array, array_info,
3979 value_bitmap);
3980 }
3981 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3982
gpiod_line_state_notify(struct gpio_desc * desc,unsigned long action)3983 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
3984 {
3985 blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
3986 action, desc);
3987 }
3988
3989 /**
3990 * gpiod_add_lookup_table() - register GPIO device consumers
3991 * @table: table of consumers to register
3992 */
gpiod_add_lookup_table(struct gpiod_lookup_table * table)3993 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3994 {
3995 gpiod_add_lookup_tables(&table, 1);
3996 }
3997 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3998
3999 /**
4000 * gpiod_remove_lookup_table() - unregister GPIO device consumers
4001 * @table: table of consumers to unregister
4002 */
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)4003 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4004 {
4005 /* Nothing to remove */
4006 if (!table)
4007 return;
4008
4009 mutex_lock(&gpio_lookup_lock);
4010
4011 list_del(&table->list);
4012
4013 mutex_unlock(&gpio_lookup_lock);
4014 }
4015 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4016
4017 /**
4018 * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4019 * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4020 */
gpiod_add_hogs(struct gpiod_hog * hogs)4021 void gpiod_add_hogs(struct gpiod_hog *hogs)
4022 {
4023 struct gpiod_hog *hog;
4024
4025 mutex_lock(&gpio_machine_hogs_mutex);
4026
4027 for (hog = &hogs[0]; hog->chip_label; hog++) {
4028 list_add_tail(&hog->list, &gpio_machine_hogs);
4029
4030 /*
4031 * The chip may have been registered earlier, so check if it
4032 * exists and, if so, try to hog the line now.
4033 */
4034 struct gpio_device *gdev __free(gpio_device_put) =
4035 gpio_device_find_by_label(hog->chip_label);
4036 if (gdev)
4037 gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);
4038 }
4039
4040 mutex_unlock(&gpio_machine_hogs_mutex);
4041 }
4042 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4043
gpiod_remove_hogs(struct gpiod_hog * hogs)4044 void gpiod_remove_hogs(struct gpiod_hog *hogs)
4045 {
4046 struct gpiod_hog *hog;
4047
4048 mutex_lock(&gpio_machine_hogs_mutex);
4049 for (hog = &hogs[0]; hog->chip_label; hog++)
4050 list_del(&hog->list);
4051 mutex_unlock(&gpio_machine_hogs_mutex);
4052 }
4053 EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
4054
gpiod_find_lookup_table(struct device * dev)4055 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4056 {
4057 const char *dev_id = dev ? dev_name(dev) : NULL;
4058 struct gpiod_lookup_table *table;
4059
4060 list_for_each_entry(table, &gpio_lookup_list, list) {
4061 if (table->dev_id && dev_id) {
4062 /*
4063 * Valid strings on both ends, must be identical to have
4064 * a match
4065 */
4066 if (!strcmp(table->dev_id, dev_id))
4067 return table;
4068 } else {
4069 /*
4070 * One of the pointers is NULL, so both must be to have
4071 * a match
4072 */
4073 if (dev_id == table->dev_id)
4074 return table;
4075 }
4076 }
4077
4078 return NULL;
4079 }
4080
gpiod_find(struct device * dev,const char * con_id,unsigned int idx,unsigned long * flags)4081 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4082 unsigned int idx, unsigned long *flags)
4083 {
4084 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4085 struct gpiod_lookup_table *table;
4086 struct gpiod_lookup *p;
4087 struct gpio_chip *gc;
4088
4089 guard(mutex)(&gpio_lookup_lock);
4090
4091 table = gpiod_find_lookup_table(dev);
4092 if (!table)
4093 return desc;
4094
4095 for (p = &table->table[0]; p->key; p++) {
4096 /* idx must always match exactly */
4097 if (p->idx != idx)
4098 continue;
4099
4100 /* If the lookup entry has a con_id, require exact match */
4101 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4102 continue;
4103
4104 if (p->chip_hwnum == U16_MAX) {
4105 desc = gpio_name_to_desc(p->key);
4106 if (desc) {
4107 *flags = p->flags;
4108 return desc;
4109 }
4110
4111 dev_warn(dev, "cannot find GPIO line %s, deferring\n",
4112 p->key);
4113 return ERR_PTR(-EPROBE_DEFER);
4114 }
4115
4116 struct gpio_device *gdev __free(gpio_device_put) =
4117 gpio_device_find_by_label(p->key);
4118 if (!gdev) {
4119 /*
4120 * As the lookup table indicates a chip with
4121 * p->key should exist, assume it may
4122 * still appear later and let the interested
4123 * consumer be probed again or let the Deferred
4124 * Probe infrastructure handle the error.
4125 */
4126 dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4127 p->key);
4128 return ERR_PTR(-EPROBE_DEFER);
4129 }
4130
4131 gc = gpio_device_get_chip(gdev);
4132
4133 if (gc->ngpio <= p->chip_hwnum) {
4134 dev_err(dev,
4135 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4136 idx, p->chip_hwnum, gc->ngpio - 1,
4137 gc->label);
4138 return ERR_PTR(-EINVAL);
4139 }
4140
4141 desc = gpio_device_get_desc(gdev, p->chip_hwnum);
4142 *flags = p->flags;
4143
4144 return desc;
4145 }
4146
4147 return desc;
4148 }
4149
platform_gpio_count(struct device * dev,const char * con_id)4150 static int platform_gpio_count(struct device *dev, const char *con_id)
4151 {
4152 struct gpiod_lookup_table *table;
4153 struct gpiod_lookup *p;
4154 unsigned int count = 0;
4155
4156 scoped_guard(mutex, &gpio_lookup_lock) {
4157 table = gpiod_find_lookup_table(dev);
4158 if (!table)
4159 return -ENOENT;
4160
4161 for (p = &table->table[0]; p->key; p++) {
4162 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4163 (!con_id && !p->con_id))
4164 count++;
4165 }
4166 }
4167
4168 if (!count)
4169 return -ENOENT;
4170
4171 return count;
4172 }
4173
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)4174 static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
4175 struct device *consumer,
4176 const char *con_id,
4177 unsigned int idx,
4178 enum gpiod_flags *flags,
4179 unsigned long *lookupflags)
4180 {
4181 const char *name = function_name_or_default(con_id);
4182 struct gpio_desc *desc = ERR_PTR(-ENOENT);
4183
4184 if (is_of_node(fwnode)) {
4185 dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4186 desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
4187 } else if (is_acpi_node(fwnode)) {
4188 dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4189 desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
4190 } else if (is_software_node(fwnode)) {
4191 dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4192 desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
4193 }
4194
4195 return desc;
4196 }
4197
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)4198 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
4199 struct fwnode_handle *fwnode,
4200 const char *con_id,
4201 unsigned int idx,
4202 enum gpiod_flags flags,
4203 const char *label,
4204 bool platform_lookup_allowed)
4205 {
4206 unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4207 const char *name = function_name_or_default(con_id);
4208 /*
4209 * scoped_guard() is implemented as a for loop, meaning static
4210 * analyzers will complain about these two not being initialized.
4211 */
4212 struct gpio_desc *desc = NULL;
4213 int ret = 0;
4214
4215 scoped_guard(srcu, &gpio_devices_srcu) {
4216 desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
4217 &flags, &lookupflags);
4218 if (gpiod_not_found(desc) && platform_lookup_allowed) {
4219 /*
4220 * Either we are not using DT or ACPI, or their lookup
4221 * did not return a result. In that case, use platform
4222 * lookup as a fallback.
4223 */
4224 dev_dbg(consumer,
4225 "using lookup tables for GPIO lookup\n");
4226 desc = gpiod_find(consumer, con_id, idx, &lookupflags);
4227 }
4228
4229 if (IS_ERR(desc)) {
4230 dev_dbg(consumer, "No GPIO consumer %s found\n", name);
4231 return desc;
4232 }
4233
4234 /*
4235 * If a connection label was passed use that, else attempt to use
4236 * the device name as label
4237 */
4238 ret = gpiod_request(desc, label);
4239 }
4240 if (ret) {
4241 if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4242 return ERR_PTR(ret);
4243
4244 /*
4245 * This happens when there are several consumers for
4246 * the same GPIO line: we just return here without
4247 * further initialization. It is a bit of a hack.
4248 * This is necessary to support fixed regulators.
4249 *
4250 * FIXME: Make this more sane and safe.
4251 */
4252 dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
4253 return desc;
4254 }
4255
4256 ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4257 if (ret < 0) {
4258 gpiod_put(desc);
4259 dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret);
4260 return ERR_PTR(ret);
4261 }
4262
4263 gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED);
4264
4265 return desc;
4266 }
4267
4268 /**
4269 * fwnode_gpiod_get_index - obtain a GPIO from firmware node
4270 * @fwnode: handle of the firmware node
4271 * @con_id: function within the GPIO consumer
4272 * @index: index of the GPIO to obtain for the consumer
4273 * @flags: GPIO initialization flags
4274 * @label: label to attach to the requested GPIO
4275 *
4276 * This function can be used for drivers that get their configuration
4277 * from opaque firmware.
4278 *
4279 * The function properly finds the corresponding GPIO using whatever is the
4280 * underlying firmware interface and then makes sure that the GPIO
4281 * descriptor is requested before it is returned to the caller.
4282 *
4283 * Returns:
4284 * On successful request the GPIO pin is configured in accordance with
4285 * provided @flags.
4286 *
4287 * In case of error an ERR_PTR() is returned.
4288 */
fwnode_gpiod_get_index(struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)4289 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
4290 const char *con_id,
4291 int index,
4292 enum gpiod_flags flags,
4293 const char *label)
4294 {
4295 return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
4296 }
4297 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
4298
4299 /**
4300 * gpiod_count - return the number of GPIOs associated with a device / function
4301 * or -ENOENT if no GPIO has been assigned to the requested function
4302 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4303 * @con_id: function within the GPIO consumer
4304 */
gpiod_count(struct device * dev,const char * con_id)4305 int gpiod_count(struct device *dev, const char *con_id)
4306 {
4307 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4308 int count = -ENOENT;
4309
4310 if (is_of_node(fwnode))
4311 count = of_gpio_count(fwnode, con_id);
4312 else if (is_acpi_node(fwnode))
4313 count = acpi_gpio_count(fwnode, con_id);
4314 else if (is_software_node(fwnode))
4315 count = swnode_gpio_count(fwnode, con_id);
4316
4317 if (count < 0)
4318 count = platform_gpio_count(dev, con_id);
4319
4320 return count;
4321 }
4322 EXPORT_SYMBOL_GPL(gpiod_count);
4323
4324 /**
4325 * gpiod_get - obtain a GPIO for a given GPIO function
4326 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4327 * @con_id: function within the GPIO consumer
4328 * @flags: optional GPIO initialization flags
4329 *
4330 * Return the GPIO descriptor corresponding to the function con_id of device
4331 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4332 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4333 */
gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)4334 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4335 enum gpiod_flags flags)
4336 {
4337 return gpiod_get_index(dev, con_id, 0, flags);
4338 }
4339 EXPORT_SYMBOL_GPL(gpiod_get);
4340
4341 /**
4342 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4343 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4344 * @con_id: function within the GPIO consumer
4345 * @flags: optional GPIO initialization flags
4346 *
4347 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4348 * the requested function it will return NULL. This is convenient for drivers
4349 * that need to handle optional GPIOs.
4350 */
gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4351 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4352 const char *con_id,
4353 enum gpiod_flags flags)
4354 {
4355 return gpiod_get_index_optional(dev, con_id, 0, flags);
4356 }
4357 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4358
4359
4360 /**
4361 * gpiod_configure_flags - helper function to configure a given GPIO
4362 * @desc: gpio whose value will be assigned
4363 * @con_id: function within the GPIO consumer
4364 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4365 * of_find_gpio() or of_get_gpio_hog()
4366 * @dflags: gpiod_flags - optional GPIO initialization flags
4367 *
4368 * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4369 * requested function and/or index, or another IS_ERR() code if an error
4370 * occurred while trying to acquire the GPIO.
4371 */
gpiod_configure_flags(struct gpio_desc * desc,const char * con_id,unsigned long lflags,enum gpiod_flags dflags)4372 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4373 unsigned long lflags, enum gpiod_flags dflags)
4374 {
4375 const char *name = function_name_or_default(con_id);
4376 int ret;
4377
4378 if (lflags & GPIO_ACTIVE_LOW)
4379 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4380
4381 if (lflags & GPIO_OPEN_DRAIN)
4382 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4383 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4384 /*
4385 * This enforces open drain mode from the consumer side.
4386 * This is necessary for some busses like I2C, but the lookup
4387 * should *REALLY* have specified them as open drain in the
4388 * first place, so print a little warning here.
4389 */
4390 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4391 gpiod_warn(desc,
4392 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4393 }
4394
4395 if (lflags & GPIO_OPEN_SOURCE)
4396 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4397
4398 if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
4399 ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
4400 ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
4401 gpiod_err(desc,
4402 "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
4403 return -EINVAL;
4404 }
4405
4406 if (lflags & GPIO_PULL_UP)
4407 set_bit(FLAG_PULL_UP, &desc->flags);
4408 else if (lflags & GPIO_PULL_DOWN)
4409 set_bit(FLAG_PULL_DOWN, &desc->flags);
4410 else if (lflags & GPIO_PULL_DISABLE)
4411 set_bit(FLAG_BIAS_DISABLE, &desc->flags);
4412
4413 ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4414 if (ret < 0)
4415 return ret;
4416
4417 /* No particular flag request, return here... */
4418 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4419 gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
4420 return 0;
4421 }
4422
4423 /* Process flags */
4424 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4425 ret = gpiod_direction_output(desc,
4426 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4427 else
4428 ret = gpiod_direction_input(desc);
4429
4430 return ret;
4431 }
4432
4433 /**
4434 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4435 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4436 * @con_id: function within the GPIO consumer
4437 * @idx: index of the GPIO to obtain in the consumer
4438 * @flags: optional GPIO initialization flags
4439 *
4440 * This variant of gpiod_get() allows to access GPIOs other than the first
4441 * defined one for functions that define several GPIOs.
4442 *
4443 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4444 * requested function and/or index, or another IS_ERR() code if an error
4445 * occurred while trying to acquire the GPIO.
4446 */
gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)4447 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4448 const char *con_id,
4449 unsigned int idx,
4450 enum gpiod_flags flags)
4451 {
4452 struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4453 const char *devname = dev ? dev_name(dev) : "?";
4454 const char *label = con_id ?: devname;
4455
4456 return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
4457 }
4458 EXPORT_SYMBOL_GPL(gpiod_get_index);
4459
4460 /**
4461 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4462 * function
4463 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4464 * @con_id: function within the GPIO consumer
4465 * @index: index of the GPIO to obtain in the consumer
4466 * @flags: optional GPIO initialization flags
4467 *
4468 * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4469 * specified index was assigned to the requested function it will return NULL.
4470 * This is convenient for drivers that need to handle optional GPIOs.
4471 */
gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)4472 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4473 const char *con_id,
4474 unsigned int index,
4475 enum gpiod_flags flags)
4476 {
4477 struct gpio_desc *desc;
4478
4479 desc = gpiod_get_index(dev, con_id, index, flags);
4480 if (gpiod_not_found(desc))
4481 return NULL;
4482
4483 return desc;
4484 }
4485 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4486
4487 /**
4488 * gpiod_hog - Hog the specified GPIO desc given the provided flags
4489 * @desc: gpio whose value will be assigned
4490 * @name: gpio line name
4491 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
4492 * of_find_gpio() or of_get_gpio_hog()
4493 * @dflags: gpiod_flags - optional GPIO initialization flags
4494 */
gpiod_hog(struct gpio_desc * desc,const char * name,unsigned long lflags,enum gpiod_flags dflags)4495 int gpiod_hog(struct gpio_desc *desc, const char *name,
4496 unsigned long lflags, enum gpiod_flags dflags)
4497 {
4498 struct gpio_device *gdev = desc->gdev;
4499 struct gpio_desc *local_desc;
4500 int hwnum;
4501 int ret;
4502
4503 CLASS(gpio_chip_guard, guard)(desc);
4504 if (!guard.gc)
4505 return -ENODEV;
4506
4507 if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))
4508 return 0;
4509
4510 hwnum = gpio_chip_hwgpio(desc);
4511
4512 local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
4513 lflags, dflags);
4514 if (IS_ERR(local_desc)) {
4515 clear_bit(FLAG_IS_HOGGED, &desc->flags);
4516 ret = PTR_ERR(local_desc);
4517 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4518 name, gdev->label, hwnum, ret);
4519 return ret;
4520 }
4521
4522 gpiod_dbg(desc, "hogged as %s%s\n",
4523 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4524 (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4525 (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4526
4527 return 0;
4528 }
4529
4530 /**
4531 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4532 * @gc: gpio chip to act on
4533 */
gpiochip_free_hogs(struct gpio_chip * gc)4534 static void gpiochip_free_hogs(struct gpio_chip *gc)
4535 {
4536 struct gpio_desc *desc;
4537
4538 for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)
4539 gpiochip_free_own_desc(desc);
4540 }
4541
4542 /**
4543 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4544 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4545 * @con_id: function within the GPIO consumer
4546 * @flags: optional GPIO initialization flags
4547 *
4548 * This function acquires all the GPIOs defined under a given function.
4549 *
4550 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4551 * no GPIO has been assigned to the requested function, or another IS_ERR()
4552 * code if an error occurred while trying to acquire the GPIOs.
4553 */
gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)4554 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4555 const char *con_id,
4556 enum gpiod_flags flags)
4557 {
4558 struct gpio_desc *desc;
4559 struct gpio_descs *descs;
4560 struct gpio_array *array_info = NULL;
4561 struct gpio_chip *gc;
4562 int count, bitmap_size;
4563 size_t descs_size;
4564
4565 count = gpiod_count(dev, con_id);
4566 if (count < 0)
4567 return ERR_PTR(count);
4568
4569 descs_size = struct_size(descs, desc, count);
4570 descs = kzalloc(descs_size, GFP_KERNEL);
4571 if (!descs)
4572 return ERR_PTR(-ENOMEM);
4573
4574 for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
4575 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4576 if (IS_ERR(desc)) {
4577 gpiod_put_array(descs);
4578 return ERR_CAST(desc);
4579 }
4580
4581 descs->desc[descs->ndescs] = desc;
4582
4583 gc = gpiod_to_chip(desc);
4584 /*
4585 * If pin hardware number of array member 0 is also 0, select
4586 * its chip as a candidate for fast bitmap processing path.
4587 */
4588 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4589 struct gpio_descs *array;
4590
4591 bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4592 gc->ngpio : count);
4593
4594 array = krealloc(descs, descs_size +
4595 struct_size(array_info, invert_mask, 3 * bitmap_size),
4596 GFP_KERNEL | __GFP_ZERO);
4597 if (!array) {
4598 gpiod_put_array(descs);
4599 return ERR_PTR(-ENOMEM);
4600 }
4601
4602 descs = array;
4603
4604 array_info = (void *)descs + descs_size;
4605 array_info->get_mask = array_info->invert_mask +
4606 bitmap_size;
4607 array_info->set_mask = array_info->get_mask +
4608 bitmap_size;
4609
4610 array_info->desc = descs->desc;
4611 array_info->size = count;
4612 array_info->chip = gc;
4613 bitmap_set(array_info->get_mask, descs->ndescs,
4614 count - descs->ndescs);
4615 bitmap_set(array_info->set_mask, descs->ndescs,
4616 count - descs->ndescs);
4617 descs->info = array_info;
4618 }
4619
4620 /* If there is no cache for fast bitmap processing path, continue */
4621 if (!array_info)
4622 continue;
4623
4624 /* Unmark array members which don't belong to the 'fast' chip */
4625 if (array_info->chip != gc) {
4626 __clear_bit(descs->ndescs, array_info->get_mask);
4627 __clear_bit(descs->ndescs, array_info->set_mask);
4628 }
4629 /*
4630 * Detect array members which belong to the 'fast' chip
4631 * but their pins are not in hardware order.
4632 */
4633 else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
4634 /*
4635 * Don't use fast path if all array members processed so
4636 * far belong to the same chip as this one but its pin
4637 * hardware number is different from its array index.
4638 */
4639 if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4640 array_info = NULL;
4641 } else {
4642 __clear_bit(descs->ndescs,
4643 array_info->get_mask);
4644 __clear_bit(descs->ndescs,
4645 array_info->set_mask);
4646 }
4647 } else {
4648 /* Exclude open drain or open source from fast output */
4649 if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4650 gpiochip_line_is_open_source(gc, descs->ndescs))
4651 __clear_bit(descs->ndescs,
4652 array_info->set_mask);
4653 /* Identify 'fast' pins which require invertion */
4654 if (gpiod_is_active_low(desc))
4655 __set_bit(descs->ndescs,
4656 array_info->invert_mask);
4657 }
4658 }
4659 if (array_info)
4660 dev_dbg(dev,
4661 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4662 array_info->chip->label, array_info->size,
4663 *array_info->get_mask, *array_info->set_mask,
4664 *array_info->invert_mask);
4665 return descs;
4666 }
4667 EXPORT_SYMBOL_GPL(gpiod_get_array);
4668
4669 /**
4670 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4671 * function
4672 * @dev: GPIO consumer, can be NULL for system-global GPIOs
4673 * @con_id: function within the GPIO consumer
4674 * @flags: optional GPIO initialization flags
4675 *
4676 * This is equivalent to gpiod_get_array(), except that when no GPIO was
4677 * assigned to the requested function it will return NULL.
4678 */
gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4679 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4680 const char *con_id,
4681 enum gpiod_flags flags)
4682 {
4683 struct gpio_descs *descs;
4684
4685 descs = gpiod_get_array(dev, con_id, flags);
4686 if (gpiod_not_found(descs))
4687 return NULL;
4688
4689 return descs;
4690 }
4691 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4692
4693 /**
4694 * gpiod_put - dispose of a GPIO descriptor
4695 * @desc: GPIO descriptor to dispose of
4696 *
4697 * No descriptor can be used after gpiod_put() has been called on it.
4698 */
gpiod_put(struct gpio_desc * desc)4699 void gpiod_put(struct gpio_desc *desc)
4700 {
4701 if (desc)
4702 gpiod_free(desc);
4703 }
4704 EXPORT_SYMBOL_GPL(gpiod_put);
4705
4706 /**
4707 * gpiod_put_array - dispose of multiple GPIO descriptors
4708 * @descs: struct gpio_descs containing an array of descriptors
4709 */
gpiod_put_array(struct gpio_descs * descs)4710 void gpiod_put_array(struct gpio_descs *descs)
4711 {
4712 unsigned int i;
4713
4714 for (i = 0; i < descs->ndescs; i++)
4715 gpiod_put(descs->desc[i]);
4716
4717 kfree(descs);
4718 }
4719 EXPORT_SYMBOL_GPL(gpiod_put_array);
4720
gpio_stub_drv_probe(struct device * dev)4721 static int gpio_stub_drv_probe(struct device *dev)
4722 {
4723 /*
4724 * The DT node of some GPIO chips have a "compatible" property, but
4725 * never have a struct device added and probed by a driver to register
4726 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4727 * the consumers of the GPIO chip to get probe deferred forever because
4728 * they will be waiting for a device associated with the GPIO chip
4729 * firmware node to get added and bound to a driver.
4730 *
4731 * To allow these consumers to probe, we associate the struct
4732 * gpio_device of the GPIO chip with the firmware node and then simply
4733 * bind it to this stub driver.
4734 */
4735 return 0;
4736 }
4737
4738 static struct device_driver gpio_stub_drv = {
4739 .name = "gpio_stub_drv",
4740 .bus = &gpio_bus_type,
4741 .probe = gpio_stub_drv_probe,
4742 };
4743
gpiolib_dev_init(void)4744 static int __init gpiolib_dev_init(void)
4745 {
4746 int ret;
4747
4748 /* Register GPIO sysfs bus */
4749 ret = bus_register(&gpio_bus_type);
4750 if (ret < 0) {
4751 pr_err("gpiolib: could not register GPIO bus type\n");
4752 return ret;
4753 }
4754
4755 ret = driver_register(&gpio_stub_drv);
4756 if (ret < 0) {
4757 pr_err("gpiolib: could not register GPIO stub driver\n");
4758 bus_unregister(&gpio_bus_type);
4759 return ret;
4760 }
4761
4762 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4763 if (ret < 0) {
4764 pr_err("gpiolib: failed to allocate char dev region\n");
4765 driver_unregister(&gpio_stub_drv);
4766 bus_unregister(&gpio_bus_type);
4767 return ret;
4768 }
4769
4770 gpiolib_initialized = true;
4771 gpiochip_setup_devs();
4772
4773 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4774 WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4775 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4776
4777 return ret;
4778 }
4779 core_initcall(gpiolib_dev_init);
4780
4781 #ifdef CONFIG_DEBUG_FS
4782
gpiolib_dbg_show(struct seq_file * s,struct gpio_device * gdev)4783 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4784 {
4785 bool active_low, is_irq, is_out;
4786 unsigned int gpio = gdev->base;
4787 struct gpio_desc *desc;
4788 struct gpio_chip *gc;
4789 int value;
4790
4791 guard(srcu)(&gdev->srcu);
4792
4793 gc = srcu_dereference(gdev->chip, &gdev->srcu);
4794 if (!gc) {
4795 seq_puts(s, "Underlying GPIO chip is gone\n");
4796 return;
4797 }
4798
4799 for_each_gpio_desc(gc, desc) {
4800 guard(srcu)(&desc->gdev->desc_srcu);
4801 is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
4802 if (is_irq || test_bit(FLAG_REQUESTED, &desc->flags)) {
4803 gpiod_get_direction(desc);
4804 is_out = test_bit(FLAG_IS_OUT, &desc->flags);
4805 value = gpio_chip_get_value(gc, desc);
4806 active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags);
4807 seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
4808 gpio, desc->name ?: "", gpiod_get_label(desc),
4809 is_out ? "out" : "in ",
4810 value >= 0 ? (value ? "hi" : "lo") : "? ",
4811 is_irq ? "IRQ " : "",
4812 active_low ? "ACTIVE LOW" : "");
4813 } else if (desc->name) {
4814 seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name);
4815 }
4816
4817 gpio++;
4818 }
4819 }
4820
4821 struct gpiolib_seq_priv {
4822 bool newline;
4823 int idx;
4824 };
4825
gpiolib_seq_start(struct seq_file * s,loff_t * pos)4826 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4827 {
4828 struct gpiolib_seq_priv *priv;
4829 struct gpio_device *gdev;
4830 loff_t index = *pos;
4831
4832 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
4833 if (!priv)
4834 return NULL;
4835
4836 s->private = priv;
4837 priv->idx = srcu_read_lock(&gpio_devices_srcu);
4838
4839 list_for_each_entry_srcu(gdev, &gpio_devices, list,
4840 srcu_read_lock_held(&gpio_devices_srcu)) {
4841 if (index-- == 0)
4842 return gdev;
4843 }
4844
4845 return NULL;
4846 }
4847
gpiolib_seq_next(struct seq_file * s,void * v,loff_t * pos)4848 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4849 {
4850 struct gpiolib_seq_priv *priv = s->private;
4851 struct gpio_device *gdev = v, *next;
4852
4853 next = list_entry_rcu(gdev->list.next, struct gpio_device, list);
4854 gdev = &next->list == &gpio_devices ? NULL : next;
4855 priv->newline = true;
4856 ++*pos;
4857
4858 return gdev;
4859 }
4860
gpiolib_seq_stop(struct seq_file * s,void * v)4861 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4862 {
4863 struct gpiolib_seq_priv *priv = s->private;
4864
4865 srcu_read_unlock(&gpio_devices_srcu, priv->idx);
4866 kfree(priv);
4867 }
4868
gpiolib_seq_show(struct seq_file * s,void * v)4869 static int gpiolib_seq_show(struct seq_file *s, void *v)
4870 {
4871 struct gpiolib_seq_priv *priv = s->private;
4872 struct gpio_device *gdev = v;
4873 struct gpio_chip *gc;
4874 struct device *parent;
4875
4876 guard(srcu)(&gdev->srcu);
4877
4878 gc = srcu_dereference(gdev->chip, &gdev->srcu);
4879 if (!gc) {
4880 seq_printf(s, "%s%s: (dangling chip)",
4881 priv->newline ? "\n" : "",
4882 dev_name(&gdev->dev));
4883 return 0;
4884 }
4885
4886 seq_printf(s, "%s%s: GPIOs %u-%u", priv->newline ? "\n" : "",
4887 dev_name(&gdev->dev),
4888 gdev->base, gdev->base + gdev->ngpio - 1);
4889 parent = gc->parent;
4890 if (parent)
4891 seq_printf(s, ", parent: %s/%s",
4892 parent->bus ? parent->bus->name : "no-bus",
4893 dev_name(parent));
4894 if (gc->label)
4895 seq_printf(s, ", %s", gc->label);
4896 if (gc->can_sleep)
4897 seq_printf(s, ", can sleep");
4898 seq_printf(s, ":\n");
4899
4900 if (gc->dbg_show)
4901 gc->dbg_show(s, gc);
4902 else
4903 gpiolib_dbg_show(s, gdev);
4904
4905 return 0;
4906 }
4907
4908 static const struct seq_operations gpiolib_sops = {
4909 .start = gpiolib_seq_start,
4910 .next = gpiolib_seq_next,
4911 .stop = gpiolib_seq_stop,
4912 .show = gpiolib_seq_show,
4913 };
4914 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4915
gpiolib_debugfs_init(void)4916 static int __init gpiolib_debugfs_init(void)
4917 {
4918 /* /sys/kernel/debug/gpio */
4919 debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4920 return 0;
4921 }
4922 subsys_initcall(gpiolib_debugfs_init);
4923
4924 #endif /* DEBUG_FS */
4925