1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/acpi.h>
4 #include <linux/array_size.h>
5 #include <linux/bitmap.h>
6 #include <linux/cleanup.h>
7 #include <linux/compat.h>
8 #include <linux/debugfs.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/errno.h>
12 #include <linux/file.h>
13 #include <linux/fs.h>
14 #include <linux/idr.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/irqdesc.h>
18 #include <linux/kernel.h>
19 #include <linux/list.h>
20 #include <linux/lockdep.h>
21 #include <linux/module.h>
22 #include <linux/nospec.h>
23 #include <linux/of.h>
24 #include <linux/pinctrl/consumer.h>
25 #include <linux/seq_file.h>
26 #include <linux/slab.h>
27 #include <linux/srcu.h>
28 #include <linux/string.h>
29 #include <linux/string_choices.h>
30 
31 #include <linux/gpio.h>
32 #include <linux/gpio/driver.h>
33 #include <linux/gpio/machine.h>
34 
35 #include <uapi/linux/gpio.h>
36 
37 #include "gpiolib-acpi.h"
38 #include "gpiolib-cdev.h"
39 #include "gpiolib-of.h"
40 #include "gpiolib-swnode.h"
41 #include "gpiolib-sysfs.h"
42 #include "gpiolib.h"
43 
44 #define CREATE_TRACE_POINTS
45 #include <trace/events/gpio.h>
46 
47 /* Implementation infrastructure for GPIO interfaces.
48  *
49  * The GPIO programming interface allows for inlining speed-critical
50  * get/set operations for common cases, so that access to SOC-integrated
51  * GPIOs can sometimes cost only an instruction or two per bit.
52  */
53 
54 /* Device and char device-related information */
55 static DEFINE_IDA(gpio_ida);
56 static dev_t gpio_devt;
57 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
58 
gpio_bus_match(struct device * dev,const struct device_driver * drv)59 static int gpio_bus_match(struct device *dev, const struct device_driver *drv)
60 {
61 	struct fwnode_handle *fwnode = dev_fwnode(dev);
62 
63 	/*
64 	 * Only match if the fwnode doesn't already have a proper struct device
65 	 * created for it.
66 	 */
67 	if (fwnode && fwnode->dev != dev)
68 		return 0;
69 	return 1;
70 }
71 
72 static const struct bus_type gpio_bus_type = {
73 	.name = "gpio",
74 	.match = gpio_bus_match,
75 };
76 
77 /*
78  * Number of GPIOs to use for the fast path in set array
79  */
80 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
81 
82 static DEFINE_MUTEX(gpio_lookup_lock);
83 static LIST_HEAD(gpio_lookup_list);
84 
85 static LIST_HEAD(gpio_devices);
86 /* Protects the GPIO device list against concurrent modifications. */
87 static DEFINE_MUTEX(gpio_devices_lock);
88 /* Ensures coherence during read-only accesses to the list of GPIO devices. */
89 DEFINE_STATIC_SRCU(gpio_devices_srcu);
90 
91 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
92 static LIST_HEAD(gpio_machine_hogs);
93 
94 const char *const gpio_suffixes[] = { "gpios", "gpio", NULL };
95 
96 static void gpiochip_free_hogs(struct gpio_chip *gc);
97 static int gpiochip_add_irqchip(struct gpio_chip *gc,
98 				struct lock_class_key *lock_key,
99 				struct lock_class_key *request_key);
100 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
101 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
102 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
103 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
104 
105 static bool gpiolib_initialized;
106 
gpiod_get_label(struct gpio_desc * desc)107 const char *gpiod_get_label(struct gpio_desc *desc)
108 {
109 	struct gpio_desc_label *label;
110 	unsigned long flags;
111 
112 	flags = READ_ONCE(desc->flags);
113 
114 	label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu,
115 				srcu_read_lock_held(&desc->gdev->desc_srcu));
116 
117 	if (test_bit(FLAG_USED_AS_IRQ, &flags))
118 		return label ? label->str : "interrupt";
119 
120 	if (!test_bit(FLAG_REQUESTED, &flags))
121 		return NULL;
122 
123 	return label ? label->str : NULL;
124 }
125 
desc_free_label(struct rcu_head * rh)126 static void desc_free_label(struct rcu_head *rh)
127 {
128 	kfree(container_of(rh, struct gpio_desc_label, rh));
129 }
130 
desc_set_label(struct gpio_desc * desc,const char * label)131 static int desc_set_label(struct gpio_desc *desc, const char *label)
132 {
133 	struct gpio_desc_label *new = NULL, *old;
134 
135 	if (label) {
136 		new = kzalloc(struct_size(new, str, strlen(label) + 1),
137 			      GFP_KERNEL);
138 		if (!new)
139 			return -ENOMEM;
140 
141 		strcpy(new->str, label);
142 	}
143 
144 	old = rcu_replace_pointer(desc->label, new, 1);
145 	if (old)
146 		call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label);
147 
148 	return 0;
149 }
150 
151 /**
152  * gpio_to_desc - Convert a GPIO number to its descriptor
153  * @gpio: global GPIO number
154  *
155  * Returns:
156  * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
157  * with the given number exists in the system.
158  */
gpio_to_desc(unsigned gpio)159 struct gpio_desc *gpio_to_desc(unsigned gpio)
160 {
161 	struct gpio_device *gdev;
162 
163 	scoped_guard(srcu, &gpio_devices_srcu) {
164 		list_for_each_entry_srcu(gdev, &gpio_devices, list,
165 				srcu_read_lock_held(&gpio_devices_srcu)) {
166 			if (gdev->base <= gpio &&
167 			    gdev->base + gdev->ngpio > gpio)
168 				return &gdev->descs[gpio - gdev->base];
169 		}
170 	}
171 
172 	return NULL;
173 }
174 EXPORT_SYMBOL_GPL(gpio_to_desc);
175 
176 /* This function is deprecated and will be removed soon, don't use. */
gpiochip_get_desc(struct gpio_chip * gc,unsigned int hwnum)177 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
178 				    unsigned int hwnum)
179 {
180 	return gpio_device_get_desc(gc->gpiodev, hwnum);
181 }
182 
183 /**
184  * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given
185  *                          hardware number for this GPIO device
186  * @gdev: GPIO device to get the descriptor from
187  * @hwnum: hardware number of the GPIO for this chip
188  *
189  * Returns:
190  * A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given
191  * chip for the specified hardware number or %ENODEV if the underlying chip
192  * already vanished.
193  *
194  * The reference count of struct gpio_device is *NOT* increased like when the
195  * GPIO is being requested for exclusive usage. It's up to the caller to make
196  * sure the GPIO device will stay alive together with the descriptor returned
197  * by this function.
198  */
199 struct gpio_desc *
gpio_device_get_desc(struct gpio_device * gdev,unsigned int hwnum)200 gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum)
201 {
202 	if (hwnum >= gdev->ngpio)
203 		return ERR_PTR(-EINVAL);
204 
205 	return &gdev->descs[array_index_nospec(hwnum, gdev->ngpio)];
206 }
207 EXPORT_SYMBOL_GPL(gpio_device_get_desc);
208 
209 /**
210  * desc_to_gpio - convert a GPIO descriptor to the integer namespace
211  * @desc: GPIO descriptor
212  *
213  * This should disappear in the future but is needed since we still
214  * use GPIO numbers for error messages and sysfs nodes.
215  *
216  * Returns:
217  * The global GPIO number for the GPIO specified by its descriptor.
218  */
desc_to_gpio(const struct gpio_desc * desc)219 int desc_to_gpio(const struct gpio_desc *desc)
220 {
221 	return desc->gdev->base + (desc - &desc->gdev->descs[0]);
222 }
223 EXPORT_SYMBOL_GPL(desc_to_gpio);
224 
225 
226 /**
227  * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
228  * @desc:	descriptor to return the chip of
229  *
230  * *DEPRECATED*
231  * This function is unsafe and should not be used. Using the chip address
232  * without taking the SRCU read lock may result in dereferencing a dangling
233  * pointer.
234  *
235  * Returns:
236  * Address of the GPIO chip backing this device.
237  */
gpiod_to_chip(const struct gpio_desc * desc)238 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
239 {
240 	if (!desc)
241 		return NULL;
242 
243 	return gpio_device_get_chip(desc->gdev);
244 }
245 EXPORT_SYMBOL_GPL(gpiod_to_chip);
246 
247 /**
248  * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor
249  *                          belongs.
250  * @desc: Descriptor for which to return the GPIO device.
251  *
252  * This *DOES NOT* increase the reference count of the GPIO device as it's
253  * expected that the descriptor is requested and the users already holds a
254  * reference to the device.
255  *
256  * Returns:
257  * Address of the GPIO device owning this descriptor.
258  */
gpiod_to_gpio_device(struct gpio_desc * desc)259 struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc)
260 {
261 	if (!desc)
262 		return NULL;
263 
264 	return desc->gdev;
265 }
266 EXPORT_SYMBOL_GPL(gpiod_to_gpio_device);
267 
268 /**
269  * gpio_device_get_base() - Get the base GPIO number allocated by this device
270  * @gdev: GPIO device
271  *
272  * Returns:
273  * First GPIO number in the global GPIO numberspace for this device.
274  */
gpio_device_get_base(struct gpio_device * gdev)275 int gpio_device_get_base(struct gpio_device *gdev)
276 {
277 	return gdev->base;
278 }
279 EXPORT_SYMBOL_GPL(gpio_device_get_base);
280 
281 /**
282  * gpio_device_get_label() - Get the label of this GPIO device
283  * @gdev: GPIO device
284  *
285  * Returns:
286  * Pointer to the string containing the GPIO device label. The string's
287  * lifetime is tied to that of the underlying GPIO device.
288  */
gpio_device_get_label(struct gpio_device * gdev)289 const char *gpio_device_get_label(struct gpio_device *gdev)
290 {
291 	return gdev->label;
292 }
293 EXPORT_SYMBOL(gpio_device_get_label);
294 
295 /**
296  * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device
297  * @gdev: GPIO device
298  *
299  * Returns:
300  * Address of the GPIO chip backing this device.
301  *
302  * *DEPRECATED*
303  * Until we can get rid of all non-driver users of struct gpio_chip, we must
304  * provide a way of retrieving the pointer to it from struct gpio_device. This
305  * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the
306  * chip can dissapear at any moment (unlike reference-counted struct
307  * gpio_device).
308  *
309  * Use at your own risk.
310  */
gpio_device_get_chip(struct gpio_device * gdev)311 struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)
312 {
313 	return rcu_dereference_check(gdev->chip, 1);
314 }
315 EXPORT_SYMBOL_GPL(gpio_device_get_chip);
316 
317 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
gpiochip_find_base_unlocked(u16 ngpio)318 static int gpiochip_find_base_unlocked(u16 ngpio)
319 {
320 	unsigned int base = GPIO_DYNAMIC_BASE;
321 	struct gpio_device *gdev;
322 
323 	list_for_each_entry_srcu(gdev, &gpio_devices, list,
324 				 lockdep_is_held(&gpio_devices_lock)) {
325 		/* found a free space? */
326 		if (gdev->base >= base + ngpio)
327 			break;
328 		/* nope, check the space right after the chip */
329 		base = gdev->base + gdev->ngpio;
330 		if (base < GPIO_DYNAMIC_BASE)
331 			base = GPIO_DYNAMIC_BASE;
332 		if (base > GPIO_DYNAMIC_MAX - ngpio)
333 			break;
334 	}
335 
336 	if (base <= GPIO_DYNAMIC_MAX - ngpio) {
337 		pr_debug("%s: found new base at %d\n", __func__, base);
338 		return base;
339 	} else {
340 		pr_err("%s: cannot find free range\n", __func__);
341 		return -ENOSPC;
342 	}
343 }
344 
gpiochip_get_direction(struct gpio_chip * gc,unsigned int offset)345 static int gpiochip_get_direction(struct gpio_chip *gc, unsigned int offset)
346 {
347 	int ret;
348 
349 	lockdep_assert_held(&gc->gpiodev->srcu);
350 
351 	if (WARN_ON(!gc->get_direction))
352 		return -EOPNOTSUPP;
353 
354 	ret = gc->get_direction(gc, offset);
355 	if (ret < 0)
356 		return ret;
357 
358 	if (ret != GPIO_LINE_DIRECTION_OUT && ret != GPIO_LINE_DIRECTION_IN)
359 		ret = -EBADE;
360 
361 	return ret;
362 }
363 
364 /**
365  * gpiod_get_direction - return the current direction of a GPIO
366  * @desc:	GPIO to get the direction of
367  *
368  * Returns:
369  * 0 for output, 1 for input, or an error code in case of error.
370  *
371  * This function may sleep if gpiod_cansleep() is true.
372  */
gpiod_get_direction(struct gpio_desc * desc)373 int gpiod_get_direction(struct gpio_desc *desc)
374 {
375 	unsigned long flags;
376 	unsigned int offset;
377 	int ret;
378 
379 	/*
380 	 * We cannot use VALIDATE_DESC() as we must not return 0 for a NULL
381 	 * descriptor like we usually do.
382 	 */
383 	if (IS_ERR_OR_NULL(desc))
384 		return -EINVAL;
385 
386 	CLASS(gpio_chip_guard, guard)(desc);
387 	if (!guard.gc)
388 		return -ENODEV;
389 
390 	offset = gpio_chip_hwgpio(desc);
391 	flags = READ_ONCE(desc->flags);
392 
393 	/*
394 	 * Open drain emulation using input mode may incorrectly report
395 	 * input here, fix that up.
396 	 */
397 	if (test_bit(FLAG_OPEN_DRAIN, &flags) &&
398 	    test_bit(FLAG_IS_OUT, &flags))
399 		return 0;
400 
401 	if (!guard.gc->get_direction)
402 		return -ENOTSUPP;
403 
404 	ret = gpiochip_get_direction(guard.gc, offset);
405 	if (ret < 0)
406 		return ret;
407 
408 	/*
409 	 * GPIO_LINE_DIRECTION_IN or other positive,
410 	 * otherwise GPIO_LINE_DIRECTION_OUT.
411 	 */
412 	if (ret > 0)
413 		ret = 1;
414 
415 	assign_bit(FLAG_IS_OUT, &flags, !ret);
416 	WRITE_ONCE(desc->flags, flags);
417 
418 	return ret;
419 }
420 EXPORT_SYMBOL_GPL(gpiod_get_direction);
421 
422 /*
423  * Add a new chip to the global chips list, keeping the list of chips sorted
424  * by range(means [base, base + ngpio - 1]) order.
425  *
426  * Returns:
427  * -EBUSY if the new chip overlaps with some other chip's integer space.
428  */
gpiodev_add_to_list_unlocked(struct gpio_device * gdev)429 static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)
430 {
431 	struct gpio_device *prev, *next;
432 
433 	lockdep_assert_held(&gpio_devices_lock);
434 
435 	if (list_empty(&gpio_devices)) {
436 		/* initial entry in list */
437 		list_add_tail_rcu(&gdev->list, &gpio_devices);
438 		return 0;
439 	}
440 
441 	next = list_first_entry(&gpio_devices, struct gpio_device, list);
442 	if (gdev->base + gdev->ngpio <= next->base) {
443 		/* add before first entry */
444 		list_add_rcu(&gdev->list, &gpio_devices);
445 		return 0;
446 	}
447 
448 	prev = list_last_entry(&gpio_devices, struct gpio_device, list);
449 	if (prev->base + prev->ngpio <= gdev->base) {
450 		/* add behind last entry */
451 		list_add_tail_rcu(&gdev->list, &gpio_devices);
452 		return 0;
453 	}
454 
455 	list_for_each_entry_safe(prev, next, &gpio_devices, list) {
456 		/* at the end of the list */
457 		if (&next->list == &gpio_devices)
458 			break;
459 
460 		/* add between prev and next */
461 		if (prev->base + prev->ngpio <= gdev->base
462 				&& gdev->base + gdev->ngpio <= next->base) {
463 			list_add_rcu(&gdev->list, &prev->list);
464 			return 0;
465 		}
466 	}
467 
468 	synchronize_srcu(&gpio_devices_srcu);
469 
470 	return -EBUSY;
471 }
472 
473 /*
474  * Convert a GPIO name to its descriptor
475  * Note that there is no guarantee that GPIO names are globally unique!
476  * Hence this function will return, if it exists, a reference to the first GPIO
477  * line found that matches the given name.
478  */
gpio_name_to_desc(const char * const name)479 static struct gpio_desc *gpio_name_to_desc(const char * const name)
480 {
481 	struct gpio_device *gdev;
482 	struct gpio_desc *desc;
483 	struct gpio_chip *gc;
484 
485 	if (!name)
486 		return NULL;
487 
488 	guard(srcu)(&gpio_devices_srcu);
489 
490 	list_for_each_entry_srcu(gdev, &gpio_devices, list,
491 				 srcu_read_lock_held(&gpio_devices_srcu)) {
492 		guard(srcu)(&gdev->srcu);
493 
494 		gc = srcu_dereference(gdev->chip, &gdev->srcu);
495 		if (!gc)
496 			continue;
497 
498 		for_each_gpio_desc(gc, desc) {
499 			if (desc->name && !strcmp(desc->name, name))
500 				return desc;
501 		}
502 	}
503 
504 	return NULL;
505 }
506 
507 /*
508  * Take the names from gc->names and assign them to their GPIO descriptors.
509  * Warn if a name is already used for a GPIO line on a different GPIO chip.
510  *
511  * Note that:
512  *   1. Non-unique names are still accepted,
513  *   2. Name collisions within the same GPIO chip are not reported.
514  */
gpiochip_set_desc_names(struct gpio_chip * gc)515 static void gpiochip_set_desc_names(struct gpio_chip *gc)
516 {
517 	struct gpio_device *gdev = gc->gpiodev;
518 	int i;
519 
520 	/* First check all names if they are unique */
521 	for (i = 0; i != gc->ngpio; ++i) {
522 		struct gpio_desc *gpio;
523 
524 		gpio = gpio_name_to_desc(gc->names[i]);
525 		if (gpio)
526 			dev_warn(&gdev->dev,
527 				 "Detected name collision for GPIO name '%s'\n",
528 				 gc->names[i]);
529 	}
530 
531 	/* Then add all names to the GPIO descriptors */
532 	for (i = 0; i != gc->ngpio; ++i)
533 		gdev->descs[i].name = gc->names[i];
534 }
535 
536 /*
537  * gpiochip_set_names - Set GPIO line names using device properties
538  * @chip: GPIO chip whose lines should be named, if possible
539  *
540  * Looks for device property "gpio-line-names" and if it exists assigns
541  * GPIO line names for the chip. The memory allocated for the assigned
542  * names belong to the underlying firmware node and should not be released
543  * by the caller.
544  */
gpiochip_set_names(struct gpio_chip * chip)545 static int gpiochip_set_names(struct gpio_chip *chip)
546 {
547 	struct gpio_device *gdev = chip->gpiodev;
548 	struct device *dev = &gdev->dev;
549 	const char **names;
550 	int ret, i;
551 	int count;
552 
553 	count = device_property_string_array_count(dev, "gpio-line-names");
554 	if (count < 0)
555 		return 0;
556 
557 	/*
558 	 * When offset is set in the driver side we assume the driver internally
559 	 * is using more than one gpiochip per the same device. We have to stop
560 	 * setting friendly names if the specified ones with 'gpio-line-names'
561 	 * are less than the offset in the device itself. This means all the
562 	 * lines are not present for every single pin within all the internal
563 	 * gpiochips.
564 	 */
565 	if (count <= chip->offset) {
566 		dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
567 			 count, chip->offset);
568 		return 0;
569 	}
570 
571 	names = kcalloc(count, sizeof(*names), GFP_KERNEL);
572 	if (!names)
573 		return -ENOMEM;
574 
575 	ret = device_property_read_string_array(dev, "gpio-line-names",
576 						names, count);
577 	if (ret < 0) {
578 		dev_warn(dev, "failed to read GPIO line names\n");
579 		kfree(names);
580 		return ret;
581 	}
582 
583 	/*
584 	 * When more that one gpiochip per device is used, 'count' can
585 	 * contain at most number gpiochips x chip->ngpio. We have to
586 	 * correctly distribute all defined lines taking into account
587 	 * chip->offset as starting point from where we will assign
588 	 * the names to pins from the 'names' array. Since property
589 	 * 'gpio-line-names' cannot contains gaps, we have to be sure
590 	 * we only assign those pins that really exists since chip->ngpio
591 	 * can be different of the chip->offset.
592 	 */
593 	count = (count > chip->offset) ? count - chip->offset : count;
594 	if (count > chip->ngpio)
595 		count = chip->ngpio;
596 
597 	for (i = 0; i < count; i++) {
598 		/*
599 		 * Allow overriding "fixed" names provided by the GPIO
600 		 * provider. The "fixed" names are more often than not
601 		 * generic and less informative than the names given in
602 		 * device properties.
603 		 */
604 		if (names[chip->offset + i] && names[chip->offset + i][0])
605 			gdev->descs[i].name = names[chip->offset + i];
606 	}
607 
608 	kfree(names);
609 
610 	return 0;
611 }
612 
gpiochip_allocate_mask(struct gpio_chip * gc)613 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
614 {
615 	unsigned long *p;
616 
617 	p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
618 	if (!p)
619 		return NULL;
620 
621 	/* Assume by default all GPIOs are valid */
622 	bitmap_fill(p, gc->ngpio);
623 
624 	return p;
625 }
626 
gpiochip_free_mask(unsigned long ** p)627 static void gpiochip_free_mask(unsigned long **p)
628 {
629 	bitmap_free(*p);
630 	*p = NULL;
631 }
632 
gpiochip_count_reserved_ranges(struct gpio_chip * gc)633 static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc)
634 {
635 	struct device *dev = &gc->gpiodev->dev;
636 	int size;
637 
638 	/* Format is "start, count, ..." */
639 	size = device_property_count_u32(dev, "gpio-reserved-ranges");
640 	if (size > 0 && size % 2 == 0)
641 		return size;
642 
643 	return 0;
644 }
645 
gpiochip_apply_reserved_ranges(struct gpio_chip * gc)646 static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc)
647 {
648 	struct device *dev = &gc->gpiodev->dev;
649 	unsigned int size;
650 	u32 *ranges;
651 	int ret;
652 
653 	size = gpiochip_count_reserved_ranges(gc);
654 	if (size == 0)
655 		return 0;
656 
657 	ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL);
658 	if (!ranges)
659 		return -ENOMEM;
660 
661 	ret = device_property_read_u32_array(dev, "gpio-reserved-ranges",
662 					     ranges, size);
663 	if (ret) {
664 		kfree(ranges);
665 		return ret;
666 	}
667 
668 	while (size) {
669 		u32 count = ranges[--size];
670 		u32 start = ranges[--size];
671 
672 		if (start >= gc->ngpio || start + count > gc->ngpio)
673 			continue;
674 
675 		bitmap_clear(gc->gpiodev->valid_mask, start, count);
676 	}
677 
678 	kfree(ranges);
679 	return 0;
680 }
681 
gpiochip_init_valid_mask(struct gpio_chip * gc)682 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
683 {
684 	int ret;
685 
686 	if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask))
687 		return 0;
688 
689 	gc->gpiodev->valid_mask = gpiochip_allocate_mask(gc);
690 	if (!gc->gpiodev->valid_mask)
691 		return -ENOMEM;
692 
693 	ret = gpiochip_apply_reserved_ranges(gc);
694 	if (ret)
695 		return ret;
696 
697 	if (gc->init_valid_mask)
698 		return gc->init_valid_mask(gc,
699 					   gc->gpiodev->valid_mask,
700 					   gc->ngpio);
701 
702 	return 0;
703 }
704 
gpiochip_free_valid_mask(struct gpio_chip * gc)705 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
706 {
707 	gpiochip_free_mask(&gc->gpiodev->valid_mask);
708 }
709 
gpiochip_add_pin_ranges(struct gpio_chip * gc)710 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
711 {
712 	/*
713 	 * Device Tree platforms are supposed to use "gpio-ranges"
714 	 * property. This check ensures that the ->add_pin_ranges()
715 	 * won't be called for them.
716 	 */
717 	if (device_property_present(&gc->gpiodev->dev, "gpio-ranges"))
718 		return 0;
719 
720 	if (gc->add_pin_ranges)
721 		return gc->add_pin_ranges(gc);
722 
723 	return 0;
724 }
725 
726 /**
727  * gpiochip_query_valid_mask - return the GPIO validity information
728  * @gc:	gpio chip which validity information is queried
729  *
730  * Returns: bitmap representing valid GPIOs or NULL if all GPIOs are valid
731  *
732  * Some GPIO chips may support configurations where some of the pins aren't
733  * available. These chips can have valid_mask set to represent the valid
734  * GPIOs. This function can be used to retrieve this information.
735  */
gpiochip_query_valid_mask(const struct gpio_chip * gc)736 const unsigned long *gpiochip_query_valid_mask(const struct gpio_chip *gc)
737 {
738 	return gc->gpiodev->valid_mask;
739 }
740 EXPORT_SYMBOL_GPL(gpiochip_query_valid_mask);
741 
gpiochip_line_is_valid(const struct gpio_chip * gc,unsigned int offset)742 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
743 				unsigned int offset)
744 {
745 	/*
746 	 * hog pins are requested before registering GPIO chip
747 	 */
748 	if (!gc->gpiodev)
749 		return true;
750 
751 	/* No mask means all valid */
752 	if (likely(!gc->gpiodev->valid_mask))
753 		return true;
754 	return test_bit(offset, gc->gpiodev->valid_mask);
755 }
756 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
757 
gpiod_free_irqs(struct gpio_desc * desc)758 static void gpiod_free_irqs(struct gpio_desc *desc)
759 {
760 	int irq = gpiod_to_irq(desc);
761 	struct irq_desc *irqd = irq_to_desc(irq);
762 	void *cookie;
763 
764 	for (;;) {
765 		/*
766 		 * Make sure the action doesn't go away while we're
767 		 * dereferencing it. Retrieve and store the cookie value.
768 		 * If the irq is freed after we release the lock, that's
769 		 * alright - the underlying maple tree lookup will return NULL
770 		 * and nothing will happen in free_irq().
771 		 */
772 		scoped_guard(mutex, &irqd->request_mutex) {
773 			if (!irq_desc_has_action(irqd))
774 				return;
775 
776 			cookie = irqd->action->dev_id;
777 		}
778 
779 		free_irq(irq, cookie);
780 	}
781 }
782 
783 /*
784  * The chip is going away but there may be users who had requested interrupts
785  * on its GPIO lines who have no idea about its removal and have no way of
786  * being notified about it. We need to free any interrupts still in use here or
787  * we'll leak memory and resources (like procfs files).
788  */
gpiochip_free_remaining_irqs(struct gpio_chip * gc)789 static void gpiochip_free_remaining_irqs(struct gpio_chip *gc)
790 {
791 	struct gpio_desc *desc;
792 
793 	for_each_gpio_desc_with_flag(gc, desc, FLAG_USED_AS_IRQ)
794 		gpiod_free_irqs(desc);
795 }
796 
gpiodev_release(struct device * dev)797 static void gpiodev_release(struct device *dev)
798 {
799 	struct gpio_device *gdev = to_gpio_device(dev);
800 
801 	/* Call pending kfree()s for descriptor labels. */
802 	synchronize_srcu(&gdev->desc_srcu);
803 	cleanup_srcu_struct(&gdev->desc_srcu);
804 
805 	ida_free(&gpio_ida, gdev->id);
806 	kfree_const(gdev->label);
807 	kfree(gdev->descs);
808 	cleanup_srcu_struct(&gdev->srcu);
809 	kfree(gdev);
810 }
811 
812 static const struct device_type gpio_dev_type = {
813 	.name = "gpio_chip",
814 	.release = gpiodev_release,
815 };
816 
817 #ifdef CONFIG_GPIO_CDEV
818 #define gcdev_register(gdev, devt)	gpiolib_cdev_register((gdev), (devt))
819 #define gcdev_unregister(gdev)		gpiolib_cdev_unregister((gdev))
820 #else
821 /*
822  * gpiolib_cdev_register() indirectly calls device_add(), which is still
823  * required even when cdev is not selected.
824  */
825 #define gcdev_register(gdev, devt)	device_add(&(gdev)->dev)
826 #define gcdev_unregister(gdev)		device_del(&(gdev)->dev)
827 #endif
828 
gpiochip_setup_dev(struct gpio_device * gdev)829 static int gpiochip_setup_dev(struct gpio_device *gdev)
830 {
831 	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
832 	int ret;
833 
834 	device_initialize(&gdev->dev);
835 
836 	/*
837 	 * If fwnode doesn't belong to another device, it's safe to clear its
838 	 * initialized flag.
839 	 */
840 	if (fwnode && !fwnode->dev)
841 		fwnode_dev_initialized(fwnode, false);
842 
843 	ret = gcdev_register(gdev, gpio_devt);
844 	if (ret)
845 		return ret;
846 
847 	ret = gpiochip_sysfs_register(gdev);
848 	if (ret)
849 		goto err_remove_device;
850 
851 	dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base,
852 		gdev->base + gdev->ngpio - 1, gdev->label);
853 
854 	return 0;
855 
856 err_remove_device:
857 	gcdev_unregister(gdev);
858 	return ret;
859 }
860 
gpiochip_machine_hog(struct gpio_chip * gc,struct gpiod_hog * hog)861 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
862 {
863 	struct gpio_desc *desc;
864 	int rv;
865 
866 	desc = gpiochip_get_desc(gc, hog->chip_hwnum);
867 	if (IS_ERR(desc)) {
868 		chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
869 			 PTR_ERR(desc));
870 		return;
871 	}
872 
873 	rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
874 	if (rv)
875 		gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
876 			  __func__, gc->label, hog->chip_hwnum, rv);
877 }
878 
machine_gpiochip_add(struct gpio_chip * gc)879 static void machine_gpiochip_add(struct gpio_chip *gc)
880 {
881 	struct gpiod_hog *hog;
882 
883 	mutex_lock(&gpio_machine_hogs_mutex);
884 
885 	list_for_each_entry(hog, &gpio_machine_hogs, list) {
886 		if (!strcmp(gc->label, hog->chip_label))
887 			gpiochip_machine_hog(gc, hog);
888 	}
889 
890 	mutex_unlock(&gpio_machine_hogs_mutex);
891 }
892 
gpiochip_setup_devs(void)893 static void gpiochip_setup_devs(void)
894 {
895 	struct gpio_device *gdev;
896 	int ret;
897 
898 	guard(srcu)(&gpio_devices_srcu);
899 
900 	list_for_each_entry_srcu(gdev, &gpio_devices, list,
901 				 srcu_read_lock_held(&gpio_devices_srcu)) {
902 		ret = gpiochip_setup_dev(gdev);
903 		if (ret)
904 			dev_err(&gdev->dev,
905 				"Failed to initialize gpio device (%d)\n", ret);
906 	}
907 }
908 
gpiochip_set_data(struct gpio_chip * gc,void * data)909 static void gpiochip_set_data(struct gpio_chip *gc, void *data)
910 {
911 	gc->gpiodev->data = data;
912 }
913 
914 /**
915  * gpiochip_get_data() - get per-subdriver data for the chip
916  * @gc: GPIO chip
917  *
918  * Returns:
919  * The per-subdriver data for the chip.
920  */
gpiochip_get_data(struct gpio_chip * gc)921 void *gpiochip_get_data(struct gpio_chip *gc)
922 {
923 	return gc->gpiodev->data;
924 }
925 EXPORT_SYMBOL_GPL(gpiochip_get_data);
926 
927 /*
928  * If the calling driver provides the specific firmware node,
929  * use it. Otherwise use the one from the parent device, if any.
930  */
gpiochip_choose_fwnode(struct gpio_chip * gc)931 static struct fwnode_handle *gpiochip_choose_fwnode(struct gpio_chip *gc)
932 {
933 	if (gc->fwnode)
934 		return gc->fwnode;
935 
936 	if (gc->parent)
937 		return dev_fwnode(gc->parent);
938 
939 	return NULL;
940 }
941 
gpiochip_get_ngpios(struct gpio_chip * gc,struct device * dev)942 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
943 {
944 	struct fwnode_handle *fwnode = gpiochip_choose_fwnode(gc);
945 	u32 ngpios = gc->ngpio;
946 	int ret;
947 
948 	if (ngpios == 0) {
949 		ret = fwnode_property_read_u32(fwnode, "ngpios", &ngpios);
950 		if (ret == -ENODATA)
951 			/*
952 			 * -ENODATA means that there is no property found and
953 			 * we want to issue the error message to the user.
954 			 * Besides that, we want to return different error code
955 			 * to state that supplied value is not valid.
956 			 */
957 			ngpios = 0;
958 		else if (ret)
959 			return ret;
960 
961 		gc->ngpio = ngpios;
962 	}
963 
964 	if (gc->ngpio == 0) {
965 		dev_err(dev, "tried to insert a GPIO chip with zero lines\n");
966 		return -EINVAL;
967 	}
968 
969 	if (gc->ngpio > FASTPATH_NGPIO)
970 		dev_warn(dev, "line cnt %u is greater than fast path cnt %u\n",
971 			 gc->ngpio, FASTPATH_NGPIO);
972 
973 	return 0;
974 }
975 EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);
976 
gpiochip_add_data_with_key(struct gpio_chip * gc,void * data,struct lock_class_key * lock_key,struct lock_class_key * request_key)977 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
978 			       struct lock_class_key *lock_key,
979 			       struct lock_class_key *request_key)
980 {
981 	struct gpio_device *gdev;
982 	unsigned int desc_index;
983 	int base = 0;
984 	int ret = 0;
985 
986 	/* Only allow one set() and one set_multiple(). */
987 	if ((gc->set && gc->set_rv) ||
988 	    (gc->set_multiple && gc->set_multiple_rv))
989 		return -EINVAL;
990 
991 	/*
992 	 * First: allocate and populate the internal stat container, and
993 	 * set up the struct device.
994 	 */
995 	gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
996 	if (!gdev)
997 		return -ENOMEM;
998 
999 	gdev->dev.type = &gpio_dev_type;
1000 	gdev->dev.bus = &gpio_bus_type;
1001 	gdev->dev.parent = gc->parent;
1002 	rcu_assign_pointer(gdev->chip, gc);
1003 
1004 	gc->gpiodev = gdev;
1005 	gpiochip_set_data(gc, data);
1006 
1007 	device_set_node(&gdev->dev, gpiochip_choose_fwnode(gc));
1008 
1009 	gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
1010 	if (gdev->id < 0) {
1011 		ret = gdev->id;
1012 		goto err_free_gdev;
1013 	}
1014 
1015 	ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
1016 	if (ret)
1017 		goto err_free_ida;
1018 
1019 	if (gc->parent && gc->parent->driver)
1020 		gdev->owner = gc->parent->driver->owner;
1021 	else if (gc->owner)
1022 		/* TODO: remove chip->owner */
1023 		gdev->owner = gc->owner;
1024 	else
1025 		gdev->owner = THIS_MODULE;
1026 
1027 	ret = gpiochip_get_ngpios(gc, &gdev->dev);
1028 	if (ret)
1029 		goto err_free_dev_name;
1030 
1031 	gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
1032 	if (!gdev->descs) {
1033 		ret = -ENOMEM;
1034 		goto err_free_dev_name;
1035 	}
1036 
1037 	gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
1038 	if (!gdev->label) {
1039 		ret = -ENOMEM;
1040 		goto err_free_descs;
1041 	}
1042 
1043 	gdev->ngpio = gc->ngpio;
1044 	gdev->can_sleep = gc->can_sleep;
1045 
1046 	scoped_guard(mutex, &gpio_devices_lock) {
1047 		/*
1048 		 * TODO: this allocates a Linux GPIO number base in the global
1049 		 * GPIO numberspace for this chip. In the long run we want to
1050 		 * get *rid* of this numberspace and use only descriptors, but
1051 		 * it may be a pipe dream. It will not happen before we get rid
1052 		 * of the sysfs interface anyways.
1053 		 */
1054 		base = gc->base;
1055 		if (base < 0) {
1056 			base = gpiochip_find_base_unlocked(gc->ngpio);
1057 			if (base < 0) {
1058 				ret = base;
1059 				base = 0;
1060 				goto err_free_label;
1061 			}
1062 
1063 			/*
1064 			 * TODO: it should not be necessary to reflect the
1065 			 * assigned base outside of the GPIO subsystem. Go over
1066 			 * drivers and see if anyone makes use of this, else
1067 			 * drop this and assign a poison instead.
1068 			 */
1069 			gc->base = base;
1070 		} else {
1071 			dev_warn(&gdev->dev,
1072 				 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
1073 		}
1074 
1075 		gdev->base = base;
1076 
1077 		ret = gpiodev_add_to_list_unlocked(gdev);
1078 		if (ret) {
1079 			chip_err(gc, "GPIO integer space overlap, cannot add chip\n");
1080 			goto err_free_label;
1081 		}
1082 	}
1083 
1084 	rwlock_init(&gdev->line_state_lock);
1085 	RAW_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
1086 	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
1087 
1088 	ret = init_srcu_struct(&gdev->srcu);
1089 	if (ret)
1090 		goto err_remove_from_list;
1091 
1092 	ret = init_srcu_struct(&gdev->desc_srcu);
1093 	if (ret)
1094 		goto err_cleanup_gdev_srcu;
1095 
1096 #ifdef CONFIG_PINCTRL
1097 	INIT_LIST_HEAD(&gdev->pin_ranges);
1098 #endif
1099 
1100 	if (gc->names)
1101 		gpiochip_set_desc_names(gc);
1102 
1103 	ret = gpiochip_set_names(gc);
1104 	if (ret)
1105 		goto err_cleanup_desc_srcu;
1106 
1107 	ret = gpiochip_init_valid_mask(gc);
1108 	if (ret)
1109 		goto err_cleanup_desc_srcu;
1110 
1111 	for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
1112 		struct gpio_desc *desc = &gdev->descs[desc_index];
1113 
1114 		desc->gdev = gdev;
1115 
1116 		/*
1117 		 * We would typically want to use gpiochip_get_direction() here
1118 		 * but we must not check the return value and bail-out as pin
1119 		 * controllers can have pins configured to alternate functions
1120 		 * and return -EINVAL. Also: there's no need to take the SRCU
1121 		 * lock here.
1122 		 */
1123 		if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index))
1124 			assign_bit(FLAG_IS_OUT, &desc->flags,
1125 				   !gc->get_direction(gc, desc_index));
1126 		else
1127 			assign_bit(FLAG_IS_OUT,
1128 				   &desc->flags, !gc->direction_input);
1129 	}
1130 
1131 	ret = of_gpiochip_add(gc);
1132 	if (ret)
1133 		goto err_free_valid_mask;
1134 
1135 	ret = gpiochip_add_pin_ranges(gc);
1136 	if (ret)
1137 		goto err_remove_of_chip;
1138 
1139 	acpi_gpiochip_add(gc);
1140 
1141 	machine_gpiochip_add(gc);
1142 
1143 	ret = gpiochip_irqchip_init_valid_mask(gc);
1144 	if (ret)
1145 		goto err_free_hogs;
1146 
1147 	ret = gpiochip_irqchip_init_hw(gc);
1148 	if (ret)
1149 		goto err_remove_irqchip_mask;
1150 
1151 	ret = gpiochip_add_irqchip(gc, lock_key, request_key);
1152 	if (ret)
1153 		goto err_remove_irqchip_mask;
1154 
1155 	/*
1156 	 * By first adding the chardev, and then adding the device,
1157 	 * we get a device node entry in sysfs under
1158 	 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1159 	 * coldplug of device nodes and other udev business.
1160 	 * We can do this only if gpiolib has been initialized.
1161 	 * Otherwise, defer until later.
1162 	 */
1163 	if (gpiolib_initialized) {
1164 		ret = gpiochip_setup_dev(gdev);
1165 		if (ret)
1166 			goto err_remove_irqchip;
1167 	}
1168 	return 0;
1169 
1170 err_remove_irqchip:
1171 	gpiochip_irqchip_remove(gc);
1172 err_remove_irqchip_mask:
1173 	gpiochip_irqchip_free_valid_mask(gc);
1174 err_free_hogs:
1175 	gpiochip_free_hogs(gc);
1176 	acpi_gpiochip_remove(gc);
1177 	gpiochip_remove_pin_ranges(gc);
1178 err_remove_of_chip:
1179 	of_gpiochip_remove(gc);
1180 err_free_valid_mask:
1181 	gpiochip_free_valid_mask(gc);
1182 err_cleanup_desc_srcu:
1183 	cleanup_srcu_struct(&gdev->desc_srcu);
1184 err_cleanup_gdev_srcu:
1185 	cleanup_srcu_struct(&gdev->srcu);
1186 err_remove_from_list:
1187 	scoped_guard(mutex, &gpio_devices_lock)
1188 		list_del_rcu(&gdev->list);
1189 	synchronize_srcu(&gpio_devices_srcu);
1190 	if (gdev->dev.release) {
1191 		/* release() has been registered by gpiochip_setup_dev() */
1192 		gpio_device_put(gdev);
1193 		goto err_print_message;
1194 	}
1195 err_free_label:
1196 	kfree_const(gdev->label);
1197 err_free_descs:
1198 	kfree(gdev->descs);
1199 err_free_dev_name:
1200 	kfree(dev_name(&gdev->dev));
1201 err_free_ida:
1202 	ida_free(&gpio_ida, gdev->id);
1203 err_free_gdev:
1204 	kfree(gdev);
1205 err_print_message:
1206 	/* failures here can mean systems won't boot... */
1207 	if (ret != -EPROBE_DEFER) {
1208 		pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1209 		       base, base + (int)gc->ngpio - 1,
1210 		       gc->label ? : "generic", ret);
1211 	}
1212 	return ret;
1213 }
1214 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1215 
1216 /**
1217  * gpiochip_remove() - unregister a gpio_chip
1218  * @gc: the chip to unregister
1219  *
1220  * A gpio_chip with any GPIOs still requested may not be removed.
1221  */
gpiochip_remove(struct gpio_chip * gc)1222 void gpiochip_remove(struct gpio_chip *gc)
1223 {
1224 	struct gpio_device *gdev = gc->gpiodev;
1225 
1226 	/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1227 	gpiochip_sysfs_unregister(gdev);
1228 	gpiochip_free_hogs(gc);
1229 	gpiochip_free_remaining_irqs(gc);
1230 
1231 	scoped_guard(mutex, &gpio_devices_lock)
1232 		list_del_rcu(&gdev->list);
1233 	synchronize_srcu(&gpio_devices_srcu);
1234 
1235 	/* Numb the device, cancelling all outstanding operations */
1236 	rcu_assign_pointer(gdev->chip, NULL);
1237 	synchronize_srcu(&gdev->srcu);
1238 	gpiochip_irqchip_remove(gc);
1239 	acpi_gpiochip_remove(gc);
1240 	of_gpiochip_remove(gc);
1241 	gpiochip_remove_pin_ranges(gc);
1242 	gpiochip_free_valid_mask(gc);
1243 	/*
1244 	 * We accept no more calls into the driver from this point, so
1245 	 * NULL the driver data pointer.
1246 	 */
1247 	gpiochip_set_data(gc, NULL);
1248 
1249 	/*
1250 	 * The gpiochip side puts its use of the device to rest here:
1251 	 * if there are no userspace clients, the chardev and device will
1252 	 * be removed, else it will be dangling until the last user is
1253 	 * gone.
1254 	 */
1255 	gcdev_unregister(gdev);
1256 	gpio_device_put(gdev);
1257 }
1258 EXPORT_SYMBOL_GPL(gpiochip_remove);
1259 
1260 /**
1261  * gpio_device_find() - find a specific GPIO device
1262  * @data: data to pass to match function
1263  * @match: Callback function to check gpio_chip
1264  *
1265  * Returns:
1266  * New reference to struct gpio_device.
1267  *
1268  * Similar to bus_find_device(). It returns a reference to a gpio_device as
1269  * determined by a user supplied @match callback. The callback should return
1270  * 0 if the device doesn't match and non-zero if it does. If the callback
1271  * returns non-zero, this function will return to the caller and not iterate
1272  * over any more gpio_devices.
1273  *
1274  * The callback takes the GPIO chip structure as argument. During the execution
1275  * of the callback function the chip is protected from being freed. TODO: This
1276  * actually has yet to be implemented.
1277  *
1278  * If the function returns non-NULL, the returned reference must be freed by
1279  * the caller using gpio_device_put().
1280  */
gpio_device_find(const void * data,int (* match)(struct gpio_chip * gc,const void * data))1281 struct gpio_device *gpio_device_find(const void *data,
1282 				     int (*match)(struct gpio_chip *gc,
1283 						  const void *data))
1284 {
1285 	struct gpio_device *gdev;
1286 	struct gpio_chip *gc;
1287 
1288 	might_sleep();
1289 
1290 	guard(srcu)(&gpio_devices_srcu);
1291 
1292 	list_for_each_entry_srcu(gdev, &gpio_devices, list,
1293 				 srcu_read_lock_held(&gpio_devices_srcu)) {
1294 		if (!device_is_registered(&gdev->dev))
1295 			continue;
1296 
1297 		guard(srcu)(&gdev->srcu);
1298 
1299 		gc = srcu_dereference(gdev->chip, &gdev->srcu);
1300 
1301 		if (gc && match(gc, data))
1302 			return gpio_device_get(gdev);
1303 	}
1304 
1305 	return NULL;
1306 }
1307 EXPORT_SYMBOL_GPL(gpio_device_find);
1308 
gpio_chip_match_by_label(struct gpio_chip * gc,const void * label)1309 static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)
1310 {
1311 	return gc->label && !strcmp(gc->label, label);
1312 }
1313 
1314 /**
1315  * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the
1316  *                               GPIO device by its backing chip's label
1317  * @label: Label to lookup
1318  *
1319  * Returns:
1320  * Reference to the GPIO device or NULL. Reference must be released with
1321  * gpio_device_put().
1322  */
gpio_device_find_by_label(const char * label)1323 struct gpio_device *gpio_device_find_by_label(const char *label)
1324 {
1325 	return gpio_device_find((void *)label, gpio_chip_match_by_label);
1326 }
1327 EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
1328 
gpio_chip_match_by_fwnode(struct gpio_chip * gc,const void * fwnode)1329 static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)
1330 {
1331 	return device_match_fwnode(&gc->gpiodev->dev, fwnode);
1332 }
1333 
1334 /**
1335  * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
1336  *                                the GPIO device by its fwnode
1337  * @fwnode: Firmware node to lookup
1338  *
1339  * Returns:
1340  * Reference to the GPIO device or NULL. Reference must be released with
1341  * gpio_device_put().
1342  */
gpio_device_find_by_fwnode(const struct fwnode_handle * fwnode)1343 struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
1344 {
1345 	return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
1346 }
1347 EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
1348 
1349 /**
1350  * gpio_device_get() - Increase the reference count of this GPIO device
1351  * @gdev: GPIO device to increase the refcount for
1352  *
1353  * Returns:
1354  * Pointer to @gdev.
1355  */
gpio_device_get(struct gpio_device * gdev)1356 struct gpio_device *gpio_device_get(struct gpio_device *gdev)
1357 {
1358 	return to_gpio_device(get_device(&gdev->dev));
1359 }
1360 EXPORT_SYMBOL_GPL(gpio_device_get);
1361 
1362 /**
1363  * gpio_device_put() - Decrease the reference count of this GPIO device and
1364  *                     possibly free all resources associated with it.
1365  * @gdev: GPIO device to decrease the reference count for
1366  */
gpio_device_put(struct gpio_device * gdev)1367 void gpio_device_put(struct gpio_device *gdev)
1368 {
1369 	put_device(&gdev->dev);
1370 }
1371 EXPORT_SYMBOL_GPL(gpio_device_put);
1372 
1373 /**
1374  * gpio_device_to_device() - Retrieve the address of the underlying struct
1375  *                           device.
1376  * @gdev: GPIO device for which to return the address.
1377  *
1378  * This does not increase the reference count of the GPIO device nor the
1379  * underlying struct device.
1380  *
1381  * Returns:
1382  * Address of struct device backing this GPIO device.
1383  */
gpio_device_to_device(struct gpio_device * gdev)1384 struct device *gpio_device_to_device(struct gpio_device *gdev)
1385 {
1386 	return &gdev->dev;
1387 }
1388 EXPORT_SYMBOL_GPL(gpio_device_to_device);
1389 
1390 #ifdef CONFIG_GPIOLIB_IRQCHIP
1391 
1392 /*
1393  * The following is irqchip helper code for gpiochips.
1394  */
1395 
gpiochip_irqchip_init_hw(struct gpio_chip * gc)1396 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1397 {
1398 	struct gpio_irq_chip *girq = &gc->irq;
1399 
1400 	if (!girq->init_hw)
1401 		return 0;
1402 
1403 	return girq->init_hw(gc);
1404 }
1405 
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)1406 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1407 {
1408 	struct gpio_irq_chip *girq = &gc->irq;
1409 
1410 	if (!girq->init_valid_mask)
1411 		return 0;
1412 
1413 	girq->valid_mask = gpiochip_allocate_mask(gc);
1414 	if (!girq->valid_mask)
1415 		return -ENOMEM;
1416 
1417 	girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1418 
1419 	return 0;
1420 }
1421 
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)1422 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1423 {
1424 	gpiochip_free_mask(&gc->irq.valid_mask);
1425 }
1426 
gpiochip_irqchip_irq_valid(const struct gpio_chip * gc,unsigned int offset)1427 static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
1428 				       unsigned int offset)
1429 {
1430 	if (!gpiochip_line_is_valid(gc, offset))
1431 		return false;
1432 	/* No mask means all valid */
1433 	if (likely(!gc->irq.valid_mask))
1434 		return true;
1435 	return test_bit(offset, gc->irq.valid_mask);
1436 }
1437 
1438 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1439 
1440 /**
1441  * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1442  * to a gpiochip
1443  * @gc: the gpiochip to set the irqchip hierarchical handler to
1444  * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1445  * will then percolate up to the parent
1446  */
gpiochip_set_hierarchical_irqchip(struct gpio_chip * gc,struct irq_chip * irqchip)1447 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1448 					      struct irq_chip *irqchip)
1449 {
1450 	/* DT will deal with mapping each IRQ as we go along */
1451 	if (is_of_node(gc->irq.fwnode))
1452 		return;
1453 
1454 	/*
1455 	 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1456 	 * irqs upfront instead of dynamically since we don't have the
1457 	 * dynamic type of allocation that hardware description languages
1458 	 * provide. Once all GPIO drivers using board files are gone from
1459 	 * the kernel we can delete this code, but for a transitional period
1460 	 * it is necessary to keep this around.
1461 	 */
1462 	if (is_fwnode_irqchip(gc->irq.fwnode)) {
1463 		int i;
1464 		int ret;
1465 
1466 		for (i = 0; i < gc->ngpio; i++) {
1467 			struct irq_fwspec fwspec;
1468 			unsigned int parent_hwirq;
1469 			unsigned int parent_type;
1470 			struct gpio_irq_chip *girq = &gc->irq;
1471 
1472 			/*
1473 			 * We call the child to parent translation function
1474 			 * only to check if the child IRQ is valid or not.
1475 			 * Just pick the rising edge type here as that is what
1476 			 * we likely need to support.
1477 			 */
1478 			ret = girq->child_to_parent_hwirq(gc, i,
1479 							  IRQ_TYPE_EDGE_RISING,
1480 							  &parent_hwirq,
1481 							  &parent_type);
1482 			if (ret) {
1483 				chip_err(gc, "skip set-up on hwirq %d\n",
1484 					 i);
1485 				continue;
1486 			}
1487 
1488 			fwspec.fwnode = gc->irq.fwnode;
1489 			/* This is the hwirq for the GPIO line side of things */
1490 			fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1491 			/* Just pick something */
1492 			fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1493 			fwspec.param_count = 2;
1494 			ret = irq_domain_alloc_irqs(gc->irq.domain, 1,
1495 						    NUMA_NO_NODE, &fwspec);
1496 			if (ret < 0) {
1497 				chip_err(gc,
1498 					 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1499 					 i, parent_hwirq,
1500 					 ret);
1501 			}
1502 		}
1503 	}
1504 
1505 	chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1506 
1507 	return;
1508 }
1509 
gpiochip_hierarchy_irq_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)1510 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1511 						   struct irq_fwspec *fwspec,
1512 						   unsigned long *hwirq,
1513 						   unsigned int *type)
1514 {
1515 	/* We support standard DT translation */
1516 	if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1517 		return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1518 	}
1519 
1520 	/* This is for board files and others not using DT */
1521 	if (is_fwnode_irqchip(fwspec->fwnode)) {
1522 		int ret;
1523 
1524 		ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1525 		if (ret)
1526 			return ret;
1527 		WARN_ON(*type == IRQ_TYPE_NONE);
1528 		return 0;
1529 	}
1530 	return -EINVAL;
1531 }
1532 
gpiochip_hierarchy_irq_domain_alloc(struct irq_domain * d,unsigned int irq,unsigned int nr_irqs,void * data)1533 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1534 					       unsigned int irq,
1535 					       unsigned int nr_irqs,
1536 					       void *data)
1537 {
1538 	struct gpio_chip *gc = d->host_data;
1539 	irq_hw_number_t hwirq;
1540 	unsigned int type = IRQ_TYPE_NONE;
1541 	struct irq_fwspec *fwspec = data;
1542 	union gpio_irq_fwspec gpio_parent_fwspec = {};
1543 	unsigned int parent_hwirq;
1544 	unsigned int parent_type;
1545 	struct gpio_irq_chip *girq = &gc->irq;
1546 	int ret;
1547 
1548 	/*
1549 	 * The nr_irqs parameter is always one except for PCI multi-MSI
1550 	 * so this should not happen.
1551 	 */
1552 	WARN_ON(nr_irqs != 1);
1553 
1554 	ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1555 	if (ret)
1556 		return ret;
1557 
1558 	chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
1559 
1560 	ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1561 					  &parent_hwirq, &parent_type);
1562 	if (ret) {
1563 		chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1564 		return ret;
1565 	}
1566 	chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1567 
1568 	/*
1569 	 * We set handle_bad_irq because the .set_type() should
1570 	 * always be invoked and set the right type of handler.
1571 	 */
1572 	irq_domain_set_info(d,
1573 			    irq,
1574 			    hwirq,
1575 			    gc->irq.chip,
1576 			    gc,
1577 			    girq->handler,
1578 			    NULL, NULL);
1579 	irq_set_probe(irq);
1580 
1581 	/* This parent only handles asserted level IRQs */
1582 	ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,
1583 					      parent_hwirq, parent_type);
1584 	if (ret)
1585 		return ret;
1586 
1587 	chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1588 		  irq, parent_hwirq);
1589 	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1590 	ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);
1591 	/*
1592 	 * If the parent irqdomain is msi, the interrupts have already
1593 	 * been allocated, so the EEXIST is good.
1594 	 */
1595 	if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1596 		ret = 0;
1597 	if (ret)
1598 		chip_err(gc,
1599 			 "failed to allocate parent hwirq %d for hwirq %lu\n",
1600 			 parent_hwirq, hwirq);
1601 
1602 	return ret;
1603 }
1604 
gpiochip_child_offset_to_irq_noop(struct gpio_chip * gc,unsigned int offset)1605 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1606 						      unsigned int offset)
1607 {
1608 	return offset;
1609 }
1610 
1611 /**
1612  * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1613  * @domain: The IRQ domain used by this IRQ chip
1614  * @data: Outermost irq_data associated with the IRQ
1615  * @reserve: If set, only reserve an interrupt vector instead of assigning one
1616  *
1617  * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1618  * used as the activate function for the &struct irq_domain_ops. The host_data
1619  * for the IRQ domain must be the &struct gpio_chip.
1620  *
1621  * Returns:
1622  * 0 on success, or negative errno on failure.
1623  */
gpiochip_irq_domain_activate(struct irq_domain * domain,struct irq_data * data,bool reserve)1624 static int gpiochip_irq_domain_activate(struct irq_domain *domain,
1625 					struct irq_data *data, bool reserve)
1626 {
1627 	struct gpio_chip *gc = domain->host_data;
1628 	unsigned int hwirq = irqd_to_hwirq(data);
1629 
1630 	return gpiochip_lock_as_irq(gc, hwirq);
1631 }
1632 
1633 /**
1634  * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1635  * @domain: The IRQ domain used by this IRQ chip
1636  * @data: Outermost irq_data associated with the IRQ
1637  *
1638  * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1639  * be used as the deactivate function for the &struct irq_domain_ops. The
1640  * host_data for the IRQ domain must be the &struct gpio_chip.
1641  */
gpiochip_irq_domain_deactivate(struct irq_domain * domain,struct irq_data * data)1642 static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1643 					   struct irq_data *data)
1644 {
1645 	struct gpio_chip *gc = domain->host_data;
1646 	unsigned int hwirq = irqd_to_hwirq(data);
1647 
1648 	return gpiochip_unlock_as_irq(gc, hwirq);
1649 }
1650 
gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops * ops)1651 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1652 {
1653 	ops->activate = gpiochip_irq_domain_activate;
1654 	ops->deactivate = gpiochip_irq_domain_deactivate;
1655 	ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1656 
1657 	/*
1658 	 * We only allow overriding the translate() and free() functions for
1659 	 * hierarchical chips, and this should only be done if the user
1660 	 * really need something other than 1:1 translation for translate()
1661 	 * callback and free if user wants to free up any resources which
1662 	 * were allocated during callbacks, for example populate_parent_alloc_arg.
1663 	 */
1664 	if (!ops->translate)
1665 		ops->translate = gpiochip_hierarchy_irq_domain_translate;
1666 	if (!ops->free)
1667 		ops->free = irq_domain_free_irqs_common;
1668 }
1669 
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1670 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1671 {
1672 	struct irq_domain *domain;
1673 
1674 	if (!gc->irq.child_to_parent_hwirq ||
1675 	    !gc->irq.fwnode) {
1676 		chip_err(gc, "missing irqdomain vital data\n");
1677 		return ERR_PTR(-EINVAL);
1678 	}
1679 
1680 	if (!gc->irq.child_offset_to_irq)
1681 		gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1682 
1683 	if (!gc->irq.populate_parent_alloc_arg)
1684 		gc->irq.populate_parent_alloc_arg =
1685 			gpiochip_populate_parent_fwspec_twocell;
1686 
1687 	gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1688 
1689 	domain = irq_domain_create_hierarchy(
1690 		gc->irq.parent_domain,
1691 		0,
1692 		gc->ngpio,
1693 		gc->irq.fwnode,
1694 		&gc->irq.child_irq_domain_ops,
1695 		gc);
1696 
1697 	if (!domain)
1698 		return ERR_PTR(-ENOMEM);
1699 
1700 	gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1701 
1702 	return domain;
1703 }
1704 
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1705 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1706 {
1707 	return !!gc->irq.parent_domain;
1708 }
1709 
gpiochip_populate_parent_fwspec_twocell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1710 int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1711 					    union gpio_irq_fwspec *gfwspec,
1712 					    unsigned int parent_hwirq,
1713 					    unsigned int parent_type)
1714 {
1715 	struct irq_fwspec *fwspec = &gfwspec->fwspec;
1716 
1717 	fwspec->fwnode = gc->irq.parent_domain->fwnode;
1718 	fwspec->param_count = 2;
1719 	fwspec->param[0] = parent_hwirq;
1720 	fwspec->param[1] = parent_type;
1721 
1722 	return 0;
1723 }
1724 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1725 
gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip * gc,union gpio_irq_fwspec * gfwspec,unsigned int parent_hwirq,unsigned int parent_type)1726 int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1727 					     union gpio_irq_fwspec *gfwspec,
1728 					     unsigned int parent_hwirq,
1729 					     unsigned int parent_type)
1730 {
1731 	struct irq_fwspec *fwspec = &gfwspec->fwspec;
1732 
1733 	fwspec->fwnode = gc->irq.parent_domain->fwnode;
1734 	fwspec->param_count = 4;
1735 	fwspec->param[0] = 0;
1736 	fwspec->param[1] = parent_hwirq;
1737 	fwspec->param[2] = 0;
1738 	fwspec->param[3] = parent_type;
1739 
1740 	return 0;
1741 }
1742 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1743 
1744 #else
1745 
gpiochip_hierarchy_create_domain(struct gpio_chip * gc)1746 static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
1747 {
1748 	return ERR_PTR(-EINVAL);
1749 }
1750 
gpiochip_hierarchy_is_hierarchical(struct gpio_chip * gc)1751 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1752 {
1753 	return false;
1754 }
1755 
1756 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1757 
1758 /**
1759  * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1760  * @d: the irqdomain used by this irqchip
1761  * @irq: the global irq number used by this GPIO irqchip irq
1762  * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1763  *
1764  * This function will set up the mapping for a certain IRQ line on a
1765  * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1766  * stored inside the gpiochip.
1767  *
1768  * Returns:
1769  * 0 on success, or negative errno on failure.
1770  */
gpiochip_irq_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)1771 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1772 			    irq_hw_number_t hwirq)
1773 {
1774 	struct gpio_chip *gc = d->host_data;
1775 	int ret = 0;
1776 
1777 	if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1778 		return -ENXIO;
1779 
1780 	irq_set_chip_data(irq, gc);
1781 	/*
1782 	 * This lock class tells lockdep that GPIO irqs are in a different
1783 	 * category than their parents, so it won't report false recursion.
1784 	 */
1785 	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1786 	irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1787 	/* Chips that use nested thread handlers have them marked */
1788 	if (gc->irq.threaded)
1789 		irq_set_nested_thread(irq, 1);
1790 	irq_set_noprobe(irq);
1791 
1792 	if (gc->irq.num_parents == 1)
1793 		ret = irq_set_parent(irq, gc->irq.parents[0]);
1794 	else if (gc->irq.map)
1795 		ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1796 
1797 	if (ret < 0)
1798 		return ret;
1799 
1800 	/*
1801 	 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1802 	 * is passed as default type.
1803 	 */
1804 	if (gc->irq.default_type != IRQ_TYPE_NONE)
1805 		irq_set_irq_type(irq, gc->irq.default_type);
1806 
1807 	return 0;
1808 }
1809 
gpiochip_irq_unmap(struct irq_domain * d,unsigned int irq)1810 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1811 {
1812 	struct gpio_chip *gc = d->host_data;
1813 
1814 	if (gc->irq.threaded)
1815 		irq_set_nested_thread(irq, 0);
1816 	irq_set_chip_and_handler(irq, NULL, NULL);
1817 	irq_set_chip_data(irq, NULL);
1818 }
1819 
1820 static const struct irq_domain_ops gpiochip_domain_ops = {
1821 	.map	= gpiochip_irq_map,
1822 	.unmap	= gpiochip_irq_unmap,
1823 	/* Virtually all GPIO irqchips are twocell:ed */
1824 	.xlate	= irq_domain_xlate_twocell,
1825 };
1826 
gpiochip_simple_create_domain(struct gpio_chip * gc)1827 static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
1828 {
1829 	struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1830 	struct irq_domain *domain;
1831 
1832 	domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,
1833 					  &gpiochip_domain_ops, gc);
1834 	if (!domain)
1835 		return ERR_PTR(-EINVAL);
1836 
1837 	return domain;
1838 }
1839 
gpiochip_to_irq(struct gpio_chip * gc,unsigned int offset)1840 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1841 {
1842 	struct irq_domain *domain = gc->irq.domain;
1843 
1844 #ifdef CONFIG_GPIOLIB_IRQCHIP
1845 	/*
1846 	 * Avoid race condition with other code, which tries to lookup
1847 	 * an IRQ before the irqchip has been properly registered,
1848 	 * i.e. while gpiochip is still being brought up.
1849 	 */
1850 	if (!gc->irq.initialized)
1851 		return -EPROBE_DEFER;
1852 #endif
1853 
1854 	if (!gpiochip_irqchip_irq_valid(gc, offset))
1855 		return -ENXIO;
1856 
1857 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1858 	if (irq_domain_is_hierarchy(domain)) {
1859 		struct irq_fwspec spec;
1860 
1861 		spec.fwnode = domain->fwnode;
1862 		spec.param_count = 2;
1863 		spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1864 		spec.param[1] = IRQ_TYPE_NONE;
1865 
1866 		return irq_create_fwspec_mapping(&spec);
1867 	}
1868 #endif
1869 
1870 	return irq_create_mapping(domain, offset);
1871 }
1872 
gpiochip_irq_reqres(struct irq_data * d)1873 int gpiochip_irq_reqres(struct irq_data *d)
1874 {
1875 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1876 	unsigned int hwirq = irqd_to_hwirq(d);
1877 
1878 	return gpiochip_reqres_irq(gc, hwirq);
1879 }
1880 EXPORT_SYMBOL(gpiochip_irq_reqres);
1881 
gpiochip_irq_relres(struct irq_data * d)1882 void gpiochip_irq_relres(struct irq_data *d)
1883 {
1884 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1885 	unsigned int hwirq = irqd_to_hwirq(d);
1886 
1887 	gpiochip_relres_irq(gc, hwirq);
1888 }
1889 EXPORT_SYMBOL(gpiochip_irq_relres);
1890 
gpiochip_irq_mask(struct irq_data * d)1891 static void gpiochip_irq_mask(struct irq_data *d)
1892 {
1893 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1894 	unsigned int hwirq = irqd_to_hwirq(d);
1895 
1896 	if (gc->irq.irq_mask)
1897 		gc->irq.irq_mask(d);
1898 	gpiochip_disable_irq(gc, hwirq);
1899 }
1900 
gpiochip_irq_unmask(struct irq_data * d)1901 static void gpiochip_irq_unmask(struct irq_data *d)
1902 {
1903 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1904 	unsigned int hwirq = irqd_to_hwirq(d);
1905 
1906 	gpiochip_enable_irq(gc, hwirq);
1907 	if (gc->irq.irq_unmask)
1908 		gc->irq.irq_unmask(d);
1909 }
1910 
gpiochip_irq_enable(struct irq_data * d)1911 static void gpiochip_irq_enable(struct irq_data *d)
1912 {
1913 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1914 	unsigned int hwirq = irqd_to_hwirq(d);
1915 
1916 	gpiochip_enable_irq(gc, hwirq);
1917 	gc->irq.irq_enable(d);
1918 }
1919 
gpiochip_irq_disable(struct irq_data * d)1920 static void gpiochip_irq_disable(struct irq_data *d)
1921 {
1922 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1923 	unsigned int hwirq = irqd_to_hwirq(d);
1924 
1925 	gc->irq.irq_disable(d);
1926 	gpiochip_disable_irq(gc, hwirq);
1927 }
1928 
gpiochip_set_irq_hooks(struct gpio_chip * gc)1929 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1930 {
1931 	struct irq_chip *irqchip = gc->irq.chip;
1932 
1933 	if (irqchip->flags & IRQCHIP_IMMUTABLE)
1934 		return;
1935 
1936 	chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
1937 
1938 	if (!irqchip->irq_request_resources &&
1939 	    !irqchip->irq_release_resources) {
1940 		irqchip->irq_request_resources = gpiochip_irq_reqres;
1941 		irqchip->irq_release_resources = gpiochip_irq_relres;
1942 	}
1943 	if (WARN_ON(gc->irq.irq_enable))
1944 		return;
1945 	/* Check if the irqchip already has this hook... */
1946 	if (irqchip->irq_enable == gpiochip_irq_enable ||
1947 		irqchip->irq_mask == gpiochip_irq_mask) {
1948 		/*
1949 		 * ...and if so, give a gentle warning that this is bad
1950 		 * practice.
1951 		 */
1952 		chip_info(gc,
1953 			  "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1954 		return;
1955 	}
1956 
1957 	if (irqchip->irq_disable) {
1958 		gc->irq.irq_disable = irqchip->irq_disable;
1959 		irqchip->irq_disable = gpiochip_irq_disable;
1960 	} else {
1961 		gc->irq.irq_mask = irqchip->irq_mask;
1962 		irqchip->irq_mask = gpiochip_irq_mask;
1963 	}
1964 
1965 	if (irqchip->irq_enable) {
1966 		gc->irq.irq_enable = irqchip->irq_enable;
1967 		irqchip->irq_enable = gpiochip_irq_enable;
1968 	} else {
1969 		gc->irq.irq_unmask = irqchip->irq_unmask;
1970 		irqchip->irq_unmask = gpiochip_irq_unmask;
1971 	}
1972 }
1973 
gpiochip_irqchip_add_allocated_domain(struct gpio_chip * gc,struct irq_domain * domain,bool allocated_externally)1974 static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
1975 						 struct irq_domain *domain,
1976 						 bool allocated_externally)
1977 {
1978 	if (!domain)
1979 		return -EINVAL;
1980 
1981 	if (gc->to_irq)
1982 		chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1983 
1984 	gc->to_irq = gpiochip_to_irq;
1985 	gc->irq.domain = domain;
1986 	gc->irq.domain_is_allocated_externally = allocated_externally;
1987 
1988 	/*
1989 	 * Using barrier() here to prevent compiler from reordering
1990 	 * gc->irq.initialized before adding irqdomain.
1991 	 */
1992 	barrier();
1993 
1994 	gc->irq.initialized = true;
1995 
1996 	return 0;
1997 }
1998 
1999 /**
2000  * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
2001  * @gc: the GPIO chip to add the IRQ chip to
2002  * @lock_key: lockdep class for IRQ lock
2003  * @request_key: lockdep class for IRQ request
2004  *
2005  * Returns:
2006  * 0 on success, or a negative errno on failure.
2007  */
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)2008 static int gpiochip_add_irqchip(struct gpio_chip *gc,
2009 				struct lock_class_key *lock_key,
2010 				struct lock_class_key *request_key)
2011 {
2012 	struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
2013 	struct irq_chip *irqchip = gc->irq.chip;
2014 	struct irq_domain *domain;
2015 	unsigned int type;
2016 	unsigned int i;
2017 	int ret;
2018 
2019 	if (!irqchip)
2020 		return 0;
2021 
2022 	if (gc->irq.parent_handler && gc->can_sleep) {
2023 		chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
2024 		return -EINVAL;
2025 	}
2026 
2027 	type = gc->irq.default_type;
2028 
2029 	/*
2030 	 * Specifying a default trigger is a terrible idea if DT or ACPI is
2031 	 * used to configure the interrupts, as you may end up with
2032 	 * conflicting triggers. Tell the user, and reset to NONE.
2033 	 */
2034 	if (WARN(fwnode && type != IRQ_TYPE_NONE,
2035 		 "%pfw: Ignoring %u default trigger\n", fwnode, type))
2036 		type = IRQ_TYPE_NONE;
2037 
2038 	gc->irq.default_type = type;
2039 	gc->irq.lock_key = lock_key;
2040 	gc->irq.request_key = request_key;
2041 
2042 	/* If a parent irqdomain is provided, let's build a hierarchy */
2043 	if (gpiochip_hierarchy_is_hierarchical(gc)) {
2044 		domain = gpiochip_hierarchy_create_domain(gc);
2045 	} else {
2046 		domain = gpiochip_simple_create_domain(gc);
2047 	}
2048 	if (IS_ERR(domain))
2049 		return PTR_ERR(domain);
2050 
2051 	if (gc->irq.parent_handler) {
2052 		for (i = 0; i < gc->irq.num_parents; i++) {
2053 			void *data;
2054 
2055 			if (gc->irq.per_parent_data)
2056 				data = gc->irq.parent_handler_data_array[i];
2057 			else
2058 				data = gc->irq.parent_handler_data ?: gc;
2059 
2060 			/*
2061 			 * The parent IRQ chip is already using the chip_data
2062 			 * for this IRQ chip, so our callbacks simply use the
2063 			 * handler_data.
2064 			 */
2065 			irq_set_chained_handler_and_data(gc->irq.parents[i],
2066 							 gc->irq.parent_handler,
2067 							 data);
2068 		}
2069 	}
2070 
2071 	gpiochip_set_irq_hooks(gc);
2072 
2073 	ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);
2074 	if (ret)
2075 		return ret;
2076 
2077 	acpi_gpiochip_request_interrupts(gc);
2078 
2079 	return 0;
2080 }
2081 
2082 /**
2083  * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
2084  * @gc: the gpiochip to remove the irqchip from
2085  *
2086  * This is called only from gpiochip_remove()
2087  */
gpiochip_irqchip_remove(struct gpio_chip * gc)2088 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
2089 {
2090 	struct irq_chip *irqchip = gc->irq.chip;
2091 	unsigned int offset;
2092 
2093 	acpi_gpiochip_free_interrupts(gc);
2094 
2095 	if (irqchip && gc->irq.parent_handler) {
2096 		struct gpio_irq_chip *irq = &gc->irq;
2097 		unsigned int i;
2098 
2099 		for (i = 0; i < irq->num_parents; i++)
2100 			irq_set_chained_handler_and_data(irq->parents[i],
2101 							 NULL, NULL);
2102 	}
2103 
2104 	/* Remove all IRQ mappings and delete the domain */
2105 	if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
2106 		unsigned int irq;
2107 
2108 		for (offset = 0; offset < gc->ngpio; offset++) {
2109 			if (!gpiochip_irqchip_irq_valid(gc, offset))
2110 				continue;
2111 
2112 			irq = irq_find_mapping(gc->irq.domain, offset);
2113 			irq_dispose_mapping(irq);
2114 		}
2115 
2116 		irq_domain_remove(gc->irq.domain);
2117 	}
2118 
2119 	if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
2120 		if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2121 			irqchip->irq_request_resources = NULL;
2122 			irqchip->irq_release_resources = NULL;
2123 		}
2124 		if (irqchip->irq_enable == gpiochip_irq_enable) {
2125 			irqchip->irq_enable = gc->irq.irq_enable;
2126 			irqchip->irq_disable = gc->irq.irq_disable;
2127 		}
2128 	}
2129 	gc->irq.irq_enable = NULL;
2130 	gc->irq.irq_disable = NULL;
2131 	gc->irq.chip = NULL;
2132 
2133 	gpiochip_irqchip_free_valid_mask(gc);
2134 }
2135 
2136 /**
2137  * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
2138  * @gc: the gpiochip to add the irqchip to
2139  * @domain: the irqdomain to add to the gpiochip
2140  *
2141  * This function adds an IRQ domain to the gpiochip.
2142  *
2143  * Returns:
2144  * 0 on success, or negative errno on failure.
2145  */
gpiochip_irqchip_add_domain(struct gpio_chip * gc,struct irq_domain * domain)2146 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
2147 				struct irq_domain *domain)
2148 {
2149 	return gpiochip_irqchip_add_allocated_domain(gc, domain, true);
2150 }
2151 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
2152 
2153 #else /* CONFIG_GPIOLIB_IRQCHIP */
2154 
gpiochip_add_irqchip(struct gpio_chip * gc,struct lock_class_key * lock_key,struct lock_class_key * request_key)2155 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
2156 				       struct lock_class_key *lock_key,
2157 				       struct lock_class_key *request_key)
2158 {
2159 	return 0;
2160 }
gpiochip_irqchip_remove(struct gpio_chip * gc)2161 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
2162 
gpiochip_irqchip_init_hw(struct gpio_chip * gc)2163 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
2164 {
2165 	return 0;
2166 }
2167 
gpiochip_irqchip_init_valid_mask(struct gpio_chip * gc)2168 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
2169 {
2170 	return 0;
2171 }
gpiochip_irqchip_free_valid_mask(struct gpio_chip * gc)2172 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
2173 { }
2174 
2175 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2176 
2177 /**
2178  * gpiochip_generic_request() - request the gpio function for a pin
2179  * @gc: the gpiochip owning the GPIO
2180  * @offset: the offset of the GPIO to request for GPIO function
2181  *
2182  * Returns:
2183  * 0 on success, or negative errno on failure.
2184  */
gpiochip_generic_request(struct gpio_chip * gc,unsigned int offset)2185 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
2186 {
2187 #ifdef CONFIG_PINCTRL
2188 	if (list_empty(&gc->gpiodev->pin_ranges))
2189 		return 0;
2190 #endif
2191 
2192 	return pinctrl_gpio_request(gc, offset);
2193 }
2194 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2195 
2196 /**
2197  * gpiochip_generic_free() - free the gpio function from a pin
2198  * @gc: the gpiochip to request the gpio function for
2199  * @offset: the offset of the GPIO to free from GPIO function
2200  */
gpiochip_generic_free(struct gpio_chip * gc,unsigned int offset)2201 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
2202 {
2203 #ifdef CONFIG_PINCTRL
2204 	if (list_empty(&gc->gpiodev->pin_ranges))
2205 		return;
2206 #endif
2207 
2208 	pinctrl_gpio_free(gc, offset);
2209 }
2210 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2211 
2212 /**
2213  * gpiochip_generic_config() - apply configuration for a pin
2214  * @gc: the gpiochip owning the GPIO
2215  * @offset: the offset of the GPIO to apply the configuration
2216  * @config: the configuration to be applied
2217  *
2218  * Returns:
2219  * 0 on success, or negative errno on failure.
2220  */
gpiochip_generic_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)2221 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
2222 			    unsigned long config)
2223 {
2224 #ifdef CONFIG_PINCTRL
2225 	if (list_empty(&gc->gpiodev->pin_ranges))
2226 		return -ENOTSUPP;
2227 #endif
2228 
2229 	return pinctrl_gpio_set_config(gc, offset, config);
2230 }
2231 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2232 
2233 #ifdef CONFIG_PINCTRL
2234 
2235 /**
2236  * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2237  * @gc: the gpiochip to add the range for
2238  * @pctldev: the pin controller to map to
2239  * @gpio_offset: the start offset in the current gpio_chip number space
2240  * @pin_group: name of the pin group inside the pin controller
2241  *
2242  * Calling this function directly from a DeviceTree-supported
2243  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2244  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2245  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2246  *
2247  * Returns:
2248  * 0 on success, or negative errno on failure.
2249  */
gpiochip_add_pingroup_range(struct gpio_chip * gc,struct pinctrl_dev * pctldev,unsigned int gpio_offset,const char * pin_group)2250 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
2251 			struct pinctrl_dev *pctldev,
2252 			unsigned int gpio_offset, const char *pin_group)
2253 {
2254 	struct gpio_pin_range *pin_range;
2255 	struct gpio_device *gdev = gc->gpiodev;
2256 	int ret;
2257 
2258 	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2259 	if (!pin_range) {
2260 		chip_err(gc, "failed to allocate pin ranges\n");
2261 		return -ENOMEM;
2262 	}
2263 
2264 	/* Use local offset as range ID */
2265 	pin_range->range.id = gpio_offset;
2266 	pin_range->range.gc = gc;
2267 	pin_range->range.name = gc->label;
2268 	pin_range->range.base = gdev->base + gpio_offset;
2269 	pin_range->pctldev = pctldev;
2270 
2271 	ret = pinctrl_get_group_pins(pctldev, pin_group,
2272 					&pin_range->range.pins,
2273 					&pin_range->range.npins);
2274 	if (ret < 0) {
2275 		kfree(pin_range);
2276 		return ret;
2277 	}
2278 
2279 	pinctrl_add_gpio_range(pctldev, &pin_range->range);
2280 
2281 	chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2282 		 gpio_offset, gpio_offset + pin_range->range.npins - 1,
2283 		 pinctrl_dev_get_devname(pctldev), pin_group);
2284 
2285 	list_add_tail(&pin_range->node, &gdev->pin_ranges);
2286 
2287 	return 0;
2288 }
2289 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2290 
2291 /**
2292  * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2293  * @gc: the gpiochip to add the range for
2294  * @pinctl_name: the dev_name() of the pin controller to map to
2295  * @gpio_offset: the start offset in the current gpio_chip number space
2296  * @pin_offset: the start offset in the pin controller number space
2297  * @npins: the number of pins from the offset of each pin space (GPIO and
2298  *	pin controller) to accumulate in this range
2299  *
2300  * Calling this function directly from a DeviceTree-supported
2301  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2302  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2303  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2304  *
2305  * Returns:
2306  * 0 on success, or a negative errno on failure.
2307  */
gpiochip_add_pin_range(struct gpio_chip * gc,const char * pinctl_name,unsigned int gpio_offset,unsigned int pin_offset,unsigned int npins)2308 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
2309 			   unsigned int gpio_offset, unsigned int pin_offset,
2310 			   unsigned int npins)
2311 {
2312 	struct gpio_pin_range *pin_range;
2313 	struct gpio_device *gdev = gc->gpiodev;
2314 	int ret;
2315 
2316 	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2317 	if (!pin_range) {
2318 		chip_err(gc, "failed to allocate pin ranges\n");
2319 		return -ENOMEM;
2320 	}
2321 
2322 	/* Use local offset as range ID */
2323 	pin_range->range.id = gpio_offset;
2324 	pin_range->range.gc = gc;
2325 	pin_range->range.name = gc->label;
2326 	pin_range->range.base = gdev->base + gpio_offset;
2327 	pin_range->range.pin_base = pin_offset;
2328 	pin_range->range.npins = npins;
2329 	pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2330 			&pin_range->range);
2331 	if (IS_ERR(pin_range->pctldev)) {
2332 		ret = PTR_ERR(pin_range->pctldev);
2333 		chip_err(gc, "could not create pin range\n");
2334 		kfree(pin_range);
2335 		return ret;
2336 	}
2337 	chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2338 		 gpio_offset, gpio_offset + npins - 1,
2339 		 pinctl_name,
2340 		 pin_offset, pin_offset + npins - 1);
2341 
2342 	list_add_tail(&pin_range->node, &gdev->pin_ranges);
2343 
2344 	return 0;
2345 }
2346 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2347 
2348 /**
2349  * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2350  * @gc: the chip to remove all the mappings for
2351  */
gpiochip_remove_pin_ranges(struct gpio_chip * gc)2352 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
2353 {
2354 	struct gpio_pin_range *pin_range, *tmp;
2355 	struct gpio_device *gdev = gc->gpiodev;
2356 
2357 	list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2358 		list_del(&pin_range->node);
2359 		pinctrl_remove_gpio_range(pin_range->pctldev,
2360 				&pin_range->range);
2361 		kfree(pin_range);
2362 	}
2363 }
2364 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2365 
2366 #endif /* CONFIG_PINCTRL */
2367 
2368 /* These "optional" allocation calls help prevent drivers from stomping
2369  * on each other, and help provide better diagnostics in debugfs.
2370  * They're called even less than the "set direction" calls.
2371  */
gpiod_request_commit(struct gpio_desc * desc,const char * label)2372 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2373 {
2374 	unsigned int offset;
2375 	int ret;
2376 
2377 	CLASS(gpio_chip_guard, guard)(desc);
2378 	if (!guard.gc)
2379 		return -ENODEV;
2380 
2381 	if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
2382 		return -EBUSY;
2383 
2384 	offset = gpio_chip_hwgpio(desc);
2385 	if (!gpiochip_line_is_valid(guard.gc, offset))
2386 		return -EINVAL;
2387 
2388 	/* NOTE:  gpio_request() can be called in early boot,
2389 	 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2390 	 */
2391 
2392 	if (guard.gc->request) {
2393 		ret = guard.gc->request(guard.gc, offset);
2394 		if (ret > 0)
2395 			ret = -EBADE;
2396 		if (ret)
2397 			goto out_clear_bit;
2398 	}
2399 
2400 	if (guard.gc->get_direction)
2401 		gpiod_get_direction(desc);
2402 
2403 	ret = desc_set_label(desc, label ? : "?");
2404 	if (ret)
2405 		goto out_clear_bit;
2406 
2407 	return 0;
2408 
2409 out_clear_bit:
2410 	clear_bit(FLAG_REQUESTED, &desc->flags);
2411 	return ret;
2412 }
2413 
2414 /*
2415  * This descriptor validation needs to be inserted verbatim into each
2416  * function taking a descriptor, so we need to use a preprocessor
2417  * macro to avoid endless duplication. If the desc is NULL it is an
2418  * optional GPIO and calls should just bail out.
2419  */
validate_desc(const struct gpio_desc * desc,const char * func)2420 static int validate_desc(const struct gpio_desc *desc, const char *func)
2421 {
2422 	if (!desc)
2423 		return 0;
2424 
2425 	if (IS_ERR(desc)) {
2426 		pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2427 		return PTR_ERR(desc);
2428 	}
2429 
2430 	return 1;
2431 }
2432 
2433 #define VALIDATE_DESC(desc) do { \
2434 	int __valid = validate_desc(desc, __func__); \
2435 	if (__valid <= 0) \
2436 		return __valid; \
2437 	} while (0)
2438 
2439 #define VALIDATE_DESC_VOID(desc) do { \
2440 	int __valid = validate_desc(desc, __func__); \
2441 	if (__valid <= 0) \
2442 		return; \
2443 	} while (0)
2444 
gpiod_request(struct gpio_desc * desc,const char * label)2445 int gpiod_request(struct gpio_desc *desc, const char *label)
2446 {
2447 	int ret = -EPROBE_DEFER;
2448 
2449 	VALIDATE_DESC(desc);
2450 
2451 	if (try_module_get(desc->gdev->owner)) {
2452 		ret = gpiod_request_commit(desc, label);
2453 		if (ret)
2454 			module_put(desc->gdev->owner);
2455 		else
2456 			gpio_device_get(desc->gdev);
2457 	}
2458 
2459 	if (ret)
2460 		gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2461 
2462 	return ret;
2463 }
2464 
gpiod_free_commit(struct gpio_desc * desc)2465 static void gpiod_free_commit(struct gpio_desc *desc)
2466 {
2467 	unsigned long flags;
2468 
2469 	might_sleep();
2470 
2471 	CLASS(gpio_chip_guard, guard)(desc);
2472 
2473 	flags = READ_ONCE(desc->flags);
2474 
2475 	if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {
2476 		if (guard.gc->free)
2477 			guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));
2478 
2479 		clear_bit(FLAG_ACTIVE_LOW, &flags);
2480 		clear_bit(FLAG_REQUESTED, &flags);
2481 		clear_bit(FLAG_OPEN_DRAIN, &flags);
2482 		clear_bit(FLAG_OPEN_SOURCE, &flags);
2483 		clear_bit(FLAG_PULL_UP, &flags);
2484 		clear_bit(FLAG_PULL_DOWN, &flags);
2485 		clear_bit(FLAG_BIAS_DISABLE, &flags);
2486 		clear_bit(FLAG_EDGE_RISING, &flags);
2487 		clear_bit(FLAG_EDGE_FALLING, &flags);
2488 		clear_bit(FLAG_IS_HOGGED, &flags);
2489 #ifdef CONFIG_OF_DYNAMIC
2490 		WRITE_ONCE(desc->hog, NULL);
2491 #endif
2492 		desc_set_label(desc, NULL);
2493 		WRITE_ONCE(desc->flags, flags);
2494 #ifdef CONFIG_GPIO_CDEV
2495 		WRITE_ONCE(desc->debounce_period_us, 0);
2496 #endif
2497 		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_RELEASED);
2498 	}
2499 }
2500 
gpiod_free(struct gpio_desc * desc)2501 void gpiod_free(struct gpio_desc *desc)
2502 {
2503 	VALIDATE_DESC_VOID(desc);
2504 
2505 	gpiod_free_commit(desc);
2506 	module_put(desc->gdev->owner);
2507 	gpio_device_put(desc->gdev);
2508 }
2509 
2510 /**
2511  * gpiochip_dup_line_label - Get a copy of the consumer label.
2512  * @gc: GPIO chip controlling this line.
2513  * @offset: Hardware offset of the line.
2514  *
2515  * Returns:
2516  * Pointer to a copy of the consumer label if the line is requested or NULL
2517  * if it's not. If a valid pointer was returned, it must be freed using
2518  * kfree(). In case of a memory allocation error, the function returns %ENOMEM.
2519  *
2520  * Must not be called from atomic context.
2521  */
gpiochip_dup_line_label(struct gpio_chip * gc,unsigned int offset)2522 char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
2523 {
2524 	struct gpio_desc *desc;
2525 	char *label;
2526 
2527 	desc = gpiochip_get_desc(gc, offset);
2528 	if (IS_ERR(desc))
2529 		return NULL;
2530 
2531 	if (!test_bit(FLAG_REQUESTED, &desc->flags))
2532 		return NULL;
2533 
2534 	guard(srcu)(&desc->gdev->desc_srcu);
2535 
2536 	label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);
2537 	if (!label)
2538 		return ERR_PTR(-ENOMEM);
2539 
2540 	return label;
2541 }
2542 EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
2543 
function_name_or_default(const char * con_id)2544 static inline const char *function_name_or_default(const char *con_id)
2545 {
2546 	return con_id ?: "(default)";
2547 }
2548 
2549 /**
2550  * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2551  * @gc: GPIO chip
2552  * @hwnum: hardware number of the GPIO for which to request the descriptor
2553  * @label: label for the GPIO
2554  * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2555  * specify things like line inversion semantics with the machine flags
2556  * such as GPIO_OUT_LOW
2557  * @dflags: descriptor request flags for this GPIO or 0 if default, this
2558  * can be used to specify consumer semantics such as open drain
2559  *
2560  * Function allows GPIO chip drivers to request and use their own GPIO
2561  * descriptors via gpiolib API. Difference to gpiod_request() is that this
2562  * function will not increase reference count of the GPIO chip module. This
2563  * allows the GPIO chip module to be unloaded as needed (we assume that the
2564  * GPIO chip driver handles freeing the GPIOs it has requested).
2565  *
2566  * Returns:
2567  * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2568  * code on failure.
2569  */
gpiochip_request_own_desc(struct gpio_chip * gc,unsigned int hwnum,const char * label,enum gpio_lookup_flags lflags,enum gpiod_flags dflags)2570 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2571 					    unsigned int hwnum,
2572 					    const char *label,
2573 					    enum gpio_lookup_flags lflags,
2574 					    enum gpiod_flags dflags)
2575 {
2576 	struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2577 	const char *name = function_name_or_default(label);
2578 	int ret;
2579 
2580 	if (IS_ERR(desc)) {
2581 		chip_err(gc, "failed to get GPIO %s descriptor\n", name);
2582 		return desc;
2583 	}
2584 
2585 	ret = gpiod_request_commit(desc, label);
2586 	if (ret < 0)
2587 		return ERR_PTR(ret);
2588 
2589 	ret = gpiod_configure_flags(desc, label, lflags, dflags);
2590 	if (ret) {
2591 		gpiod_free_commit(desc);
2592 		chip_err(gc, "setup of own GPIO %s failed\n", name);
2593 		return ERR_PTR(ret);
2594 	}
2595 
2596 	gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
2597 
2598 	return desc;
2599 }
2600 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2601 
2602 /**
2603  * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2604  * @desc: GPIO descriptor to free
2605  *
2606  * Function frees the given GPIO requested previously with
2607  * gpiochip_request_own_desc().
2608  */
gpiochip_free_own_desc(struct gpio_desc * desc)2609 void gpiochip_free_own_desc(struct gpio_desc *desc)
2610 {
2611 	if (desc)
2612 		gpiod_free_commit(desc);
2613 }
2614 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2615 
2616 /*
2617  * Drivers MUST set GPIO direction before making get/set calls.  In
2618  * some cases this is done in early boot, before IRQs are enabled.
2619  *
2620  * As a rule these aren't called more than once (except for drivers
2621  * using the open-drain emulation idiom) so these are natural places
2622  * to accumulate extra debugging checks.  Note that we can't (yet)
2623  * rely on gpio_request() having been called beforehand.
2624  */
2625 
gpio_do_set_config(struct gpio_desc * desc,unsigned long config)2626 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config)
2627 {
2628 	int ret;
2629 
2630 	CLASS(gpio_chip_guard, guard)(desc);
2631 	if (!guard.gc)
2632 		return -ENODEV;
2633 
2634 	if (!guard.gc->set_config)
2635 		return -ENOTSUPP;
2636 
2637 	ret = guard.gc->set_config(guard.gc, gpio_chip_hwgpio(desc), config);
2638 	if (ret > 0)
2639 		ret = -EBADE;
2640 
2641 #ifdef CONFIG_GPIO_CDEV
2642 	/*
2643 	 * Special case - if we're setting debounce period, we need to store
2644 	 * it in the descriptor in case user-space wants to know it.
2645 	 */
2646 	if (!ret && pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE)
2647 		WRITE_ONCE(desc->debounce_period_us,
2648 			   pinconf_to_config_argument(config));
2649 #endif
2650 	return ret;
2651 }
2652 
gpio_set_config_with_argument(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2653 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2654 					 enum pin_config_param mode,
2655 					 u32 argument)
2656 {
2657 	unsigned long config;
2658 
2659 	config = pinconf_to_config_packed(mode, argument);
2660 	return gpio_do_set_config(desc, config);
2661 }
2662 
gpio_set_config_with_argument_optional(struct gpio_desc * desc,enum pin_config_param mode,u32 argument)2663 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2664 						  enum pin_config_param mode,
2665 						  u32 argument)
2666 {
2667 	struct device *dev = &desc->gdev->dev;
2668 	int gpio = gpio_chip_hwgpio(desc);
2669 	int ret;
2670 
2671 	ret = gpio_set_config_with_argument(desc, mode, argument);
2672 	if (ret != -ENOTSUPP)
2673 		return ret;
2674 
2675 	switch (mode) {
2676 	case PIN_CONFIG_PERSIST_STATE:
2677 		dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2678 		break;
2679 	default:
2680 		break;
2681 	}
2682 
2683 	return 0;
2684 }
2685 
gpio_set_config(struct gpio_desc * desc,enum pin_config_param mode)2686 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2687 {
2688 	return gpio_set_config_with_argument(desc, mode, 0);
2689 }
2690 
gpio_set_bias(struct gpio_desc * desc)2691 static int gpio_set_bias(struct gpio_desc *desc)
2692 {
2693 	enum pin_config_param bias;
2694 	unsigned long flags;
2695 	unsigned int arg;
2696 
2697 	flags = READ_ONCE(desc->flags);
2698 
2699 	if (test_bit(FLAG_BIAS_DISABLE, &flags))
2700 		bias = PIN_CONFIG_BIAS_DISABLE;
2701 	else if (test_bit(FLAG_PULL_UP, &flags))
2702 		bias = PIN_CONFIG_BIAS_PULL_UP;
2703 	else if (test_bit(FLAG_PULL_DOWN, &flags))
2704 		bias = PIN_CONFIG_BIAS_PULL_DOWN;
2705 	else
2706 		return 0;
2707 
2708 	switch (bias) {
2709 	case PIN_CONFIG_BIAS_PULL_DOWN:
2710 	case PIN_CONFIG_BIAS_PULL_UP:
2711 		arg = 1;
2712 		break;
2713 
2714 	default:
2715 		arg = 0;
2716 		break;
2717 	}
2718 
2719 	return gpio_set_config_with_argument_optional(desc, bias, arg);
2720 }
2721 
2722 /**
2723  * gpio_set_debounce_timeout() - Set debounce timeout
2724  * @desc:	GPIO descriptor to set the debounce timeout
2725  * @debounce:	Debounce timeout in microseconds
2726  *
2727  * The function calls the certain GPIO driver to set debounce timeout
2728  * in the hardware.
2729  *
2730  * Returns:
2731  * 0 on success, or negative errno on failure.
2732  */
gpio_set_debounce_timeout(struct gpio_desc * desc,unsigned int debounce)2733 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2734 {
2735 	int ret;
2736 
2737 	ret = gpio_set_config_with_argument_optional(desc,
2738 						     PIN_CONFIG_INPUT_DEBOUNCE,
2739 						     debounce);
2740 	if (!ret)
2741 		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2742 
2743 	return ret;
2744 }
2745 
gpiochip_direction_input(struct gpio_chip * gc,unsigned int offset)2746 static int gpiochip_direction_input(struct gpio_chip *gc, unsigned int offset)
2747 {
2748 	int ret;
2749 
2750 	lockdep_assert_held(&gc->gpiodev->srcu);
2751 
2752 	if (WARN_ON(!gc->direction_input))
2753 		return -EOPNOTSUPP;
2754 
2755 	ret = gc->direction_input(gc, offset);
2756 	if (ret > 0)
2757 		ret = -EBADE;
2758 
2759 	return ret;
2760 }
2761 
gpiochip_direction_output(struct gpio_chip * gc,unsigned int offset,int value)2762 static int gpiochip_direction_output(struct gpio_chip *gc, unsigned int offset,
2763 				     int value)
2764 {
2765 	int ret;
2766 
2767 	lockdep_assert_held(&gc->gpiodev->srcu);
2768 
2769 	if (WARN_ON(!gc->direction_output))
2770 		return -EOPNOTSUPP;
2771 
2772 	ret = gc->direction_output(gc, offset, value);
2773 	if (ret > 0)
2774 		ret = -EBADE;
2775 
2776 	return ret;
2777 }
2778 
2779 /**
2780  * gpiod_direction_input - set the GPIO direction to input
2781  * @desc:	GPIO to set to input
2782  *
2783  * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2784  * be called safely on it.
2785  *
2786  * Returns:
2787  * 0 on success, or negative errno on failure.
2788  */
gpiod_direction_input(struct gpio_desc * desc)2789 int gpiod_direction_input(struct gpio_desc *desc)
2790 {
2791 	int ret;
2792 
2793 	VALIDATE_DESC(desc);
2794 
2795 	ret = gpiod_direction_input_nonotify(desc);
2796 	if (ret == 0)
2797 		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2798 
2799 	return ret;
2800 }
2801 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2802 
gpiod_direction_input_nonotify(struct gpio_desc * desc)2803 int gpiod_direction_input_nonotify(struct gpio_desc *desc)
2804 {
2805 	int ret = 0, dir;
2806 
2807 	CLASS(gpio_chip_guard, guard)(desc);
2808 	if (!guard.gc)
2809 		return -ENODEV;
2810 
2811 	/*
2812 	 * It is legal to have no .get() and .direction_input() specified if
2813 	 * the chip is output-only, but you can't specify .direction_input()
2814 	 * and not support the .get() operation, that doesn't make sense.
2815 	 */
2816 	if (!guard.gc->get && guard.gc->direction_input) {
2817 		gpiod_warn(desc,
2818 			   "%s: missing get() but have direction_input()\n",
2819 			   __func__);
2820 		return -EIO;
2821 	}
2822 
2823 	/*
2824 	 * If we have a .direction_input() callback, things are simple,
2825 	 * just call it. Else we are some input-only chip so try to check the
2826 	 * direction (if .get_direction() is supported) else we silently
2827 	 * assume we are in input mode after this.
2828 	 */
2829 	if (guard.gc->direction_input) {
2830 		ret = gpiochip_direction_input(guard.gc,
2831 					       gpio_chip_hwgpio(desc));
2832 	} else if (guard.gc->get_direction) {
2833 		dir = gpiochip_get_direction(guard.gc, gpio_chip_hwgpio(desc));
2834 		if (dir < 0)
2835 			return dir;
2836 
2837 		if (dir != GPIO_LINE_DIRECTION_IN) {
2838 			gpiod_warn(desc,
2839 				   "%s: missing direction_input() operation and line is output\n",
2840 				    __func__);
2841 			return -EIO;
2842 		}
2843 	}
2844 	if (ret == 0) {
2845 		clear_bit(FLAG_IS_OUT, &desc->flags);
2846 		ret = gpio_set_bias(desc);
2847 	}
2848 
2849 	trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2850 
2851 	return ret;
2852 }
2853 
gpiochip_set(struct gpio_chip * gc,unsigned int offset,int value)2854 static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value)
2855 {
2856 	int ret;
2857 
2858 	lockdep_assert_held(&gc->gpiodev->srcu);
2859 
2860 	if (WARN_ON(unlikely(!gc->set && !gc->set_rv)))
2861 		return -EOPNOTSUPP;
2862 
2863 	if (gc->set_rv) {
2864 		ret = gc->set_rv(gc, offset, value);
2865 		if (ret > 0)
2866 			ret = -EBADE;
2867 
2868 		return ret;
2869 	}
2870 
2871 	gc->set(gc, offset, value);
2872 	return 0;
2873 }
2874 
gpiod_direction_output_raw_commit(struct gpio_desc * desc,int value)2875 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2876 {
2877 	int val = !!value, ret = 0, dir;
2878 
2879 	CLASS(gpio_chip_guard, guard)(desc);
2880 	if (!guard.gc)
2881 		return -ENODEV;
2882 
2883 	/*
2884 	 * It's OK not to specify .direction_output() if the gpiochip is
2885 	 * output-only, but if there is then not even a .set() operation it
2886 	 * is pretty tricky to drive the output line.
2887 	 */
2888 	if (!guard.gc->set && !guard.gc->set_rv && !guard.gc->direction_output) {
2889 		gpiod_warn(desc,
2890 			   "%s: missing set() and direction_output() operations\n",
2891 			   __func__);
2892 		return -EIO;
2893 	}
2894 
2895 	if (guard.gc->direction_output) {
2896 		ret = gpiochip_direction_output(guard.gc,
2897 						gpio_chip_hwgpio(desc), val);
2898 	} else {
2899 		/* Check that we are in output mode if we can */
2900 		if (guard.gc->get_direction) {
2901 			dir = gpiochip_get_direction(guard.gc,
2902 						     gpio_chip_hwgpio(desc));
2903 			if (dir < 0)
2904 				return dir;
2905 
2906 			if (dir != GPIO_LINE_DIRECTION_OUT) {
2907 				gpiod_warn(desc,
2908 					   "%s: missing direction_output() operation\n",
2909 					   __func__);
2910 				return -EIO;
2911 			}
2912 		}
2913 		/*
2914 		 * If we can't actively set the direction, we are some
2915 		 * output-only chip, so just drive the output as desired.
2916 		 */
2917 		ret = gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), val);
2918 		if (ret)
2919 			return ret;
2920 	}
2921 
2922 	if (!ret)
2923 		set_bit(FLAG_IS_OUT, &desc->flags);
2924 	trace_gpio_value(desc_to_gpio(desc), 0, val);
2925 	trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2926 	return ret;
2927 }
2928 
2929 /**
2930  * gpiod_direction_output_raw - set the GPIO direction to output
2931  * @desc:	GPIO to set to output
2932  * @value:	initial output value of the GPIO
2933  *
2934  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2935  * be called safely on it. The initial value of the output must be specified
2936  * as raw value on the physical line without regard for the ACTIVE_LOW status.
2937  *
2938  * Returns:
2939  * 0 on success, or negative errno on failure.
2940  */
gpiod_direction_output_raw(struct gpio_desc * desc,int value)2941 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2942 {
2943 	int ret;
2944 
2945 	VALIDATE_DESC(desc);
2946 
2947 	ret = gpiod_direction_output_raw_commit(desc, value);
2948 	if (ret == 0)
2949 		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2950 
2951 	return ret;
2952 }
2953 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2954 
2955 /**
2956  * gpiod_direction_output - set the GPIO direction to output
2957  * @desc:	GPIO to set to output
2958  * @value:	initial output value of the GPIO
2959  *
2960  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2961  * be called safely on it. The initial value of the output must be specified
2962  * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2963  * account.
2964  *
2965  * Returns:
2966  * 0 on success, or negative errno on failure.
2967  */
gpiod_direction_output(struct gpio_desc * desc,int value)2968 int gpiod_direction_output(struct gpio_desc *desc, int value)
2969 {
2970 	int ret;
2971 
2972 	VALIDATE_DESC(desc);
2973 
2974 	ret = gpiod_direction_output_nonotify(desc, value);
2975 	if (ret == 0)
2976 		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
2977 
2978 	return ret;
2979 }
2980 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2981 
gpiod_direction_output_nonotify(struct gpio_desc * desc,int value)2982 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value)
2983 {
2984 	unsigned long flags;
2985 	int ret;
2986 
2987 	flags = READ_ONCE(desc->flags);
2988 
2989 	if (test_bit(FLAG_ACTIVE_LOW, &flags))
2990 		value = !value;
2991 	else
2992 		value = !!value;
2993 
2994 	/* GPIOs used for enabled IRQs shall not be set as output */
2995 	if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
2996 	    test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {
2997 		gpiod_err(desc,
2998 			  "%s: tried to set a GPIO tied to an IRQ as output\n",
2999 			  __func__);
3000 		return -EIO;
3001 	}
3002 
3003 	if (test_bit(FLAG_OPEN_DRAIN, &flags)) {
3004 		/* First see if we can enable open drain in hardware */
3005 		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
3006 		if (!ret)
3007 			goto set_output_value;
3008 		/* Emulate open drain by not actively driving the line high */
3009 		if (value)
3010 			goto set_output_flag;
3011 	} else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {
3012 		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
3013 		if (!ret)
3014 			goto set_output_value;
3015 		/* Emulate open source by not actively driving the line low */
3016 		if (!value)
3017 			goto set_output_flag;
3018 	} else {
3019 		gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
3020 	}
3021 
3022 set_output_value:
3023 	ret = gpio_set_bias(desc);
3024 	if (ret)
3025 		return ret;
3026 	return gpiod_direction_output_raw_commit(desc, value);
3027 
3028 set_output_flag:
3029 	ret = gpiod_direction_input_nonotify(desc);
3030 	if (ret)
3031 		return ret;
3032 	/*
3033 	 * When emulating open-source or open-drain functionalities by not
3034 	 * actively driving the line (setting mode to input) we still need to
3035 	 * set the IS_OUT flag or otherwise we won't be able to set the line
3036 	 * value anymore.
3037 	 */
3038 	set_bit(FLAG_IS_OUT, &desc->flags);
3039 	return 0;
3040 }
3041 
3042 #if IS_ENABLED(CONFIG_HTE)
3043 /**
3044  * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
3045  *
3046  * @desc: GPIO to enable.
3047  * @flags: Flags related to GPIO edge.
3048  *
3049  * Returns:
3050  * 0 on success, or negative errno on failure.
3051  */
gpiod_enable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)3052 int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
3053 {
3054 	int ret = 0;
3055 
3056 	VALIDATE_DESC(desc);
3057 
3058 	CLASS(gpio_chip_guard, guard)(desc);
3059 	if (!guard.gc)
3060 		return -ENODEV;
3061 
3062 	if (!guard.gc->en_hw_timestamp) {
3063 		gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
3064 		return -ENOTSUPP;
3065 	}
3066 
3067 	ret = guard.gc->en_hw_timestamp(guard.gc,
3068 					gpio_chip_hwgpio(desc), flags);
3069 	if (ret)
3070 		gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
3071 
3072 	return ret;
3073 }
3074 EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
3075 
3076 /**
3077  * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
3078  *
3079  * @desc: GPIO to disable.
3080  * @flags: Flags related to GPIO edge, same value as used during enable call.
3081  *
3082  * Returns:
3083  * 0 on success, or negative errno on failure.
3084  */
gpiod_disable_hw_timestamp_ns(struct gpio_desc * desc,unsigned long flags)3085 int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
3086 {
3087 	int ret = 0;
3088 
3089 	VALIDATE_DESC(desc);
3090 
3091 	CLASS(gpio_chip_guard, guard)(desc);
3092 	if (!guard.gc)
3093 		return -ENODEV;
3094 
3095 	if (!guard.gc->dis_hw_timestamp) {
3096 		gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
3097 		return -ENOTSUPP;
3098 	}
3099 
3100 	ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),
3101 					 flags);
3102 	if (ret)
3103 		gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
3104 
3105 	return ret;
3106 }
3107 EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
3108 #endif /* CONFIG_HTE */
3109 
3110 /**
3111  * gpiod_set_config - sets @config for a GPIO
3112  * @desc: descriptor of the GPIO for which to set the configuration
3113  * @config: Same packed config format as generic pinconf
3114  *
3115  * Returns:
3116  * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3117  * configuration.
3118  */
gpiod_set_config(struct gpio_desc * desc,unsigned long config)3119 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
3120 {
3121 	int ret;
3122 
3123 	VALIDATE_DESC(desc);
3124 
3125 	ret = gpio_do_set_config(desc, config);
3126 	if (!ret) {
3127 		/* These are the only options we notify the userspace about. */
3128 		switch (pinconf_to_config_param(config)) {
3129 		case PIN_CONFIG_BIAS_DISABLE:
3130 		case PIN_CONFIG_BIAS_PULL_DOWN:
3131 		case PIN_CONFIG_BIAS_PULL_UP:
3132 		case PIN_CONFIG_DRIVE_OPEN_DRAIN:
3133 		case PIN_CONFIG_DRIVE_OPEN_SOURCE:
3134 		case PIN_CONFIG_DRIVE_PUSH_PULL:
3135 		case PIN_CONFIG_INPUT_DEBOUNCE:
3136 			gpiod_line_state_notify(desc,
3137 						GPIO_V2_LINE_CHANGED_CONFIG);
3138 			break;
3139 		default:
3140 			break;
3141 		}
3142 	}
3143 
3144 	return ret;
3145 }
3146 EXPORT_SYMBOL_GPL(gpiod_set_config);
3147 
3148 /**
3149  * gpiod_set_debounce - sets @debounce time for a GPIO
3150  * @desc: descriptor of the GPIO for which to set debounce time
3151  * @debounce: debounce time in microseconds
3152  *
3153  * Returns:
3154  * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3155  * debounce time.
3156  */
gpiod_set_debounce(struct gpio_desc * desc,unsigned int debounce)3157 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
3158 {
3159 	unsigned long config;
3160 
3161 	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
3162 	return gpiod_set_config(desc, config);
3163 }
3164 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
3165 
3166 /**
3167  * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
3168  * @desc: descriptor of the GPIO for which to configure persistence
3169  * @transitory: True to lose state on suspend or reset, false for persistence
3170  *
3171  * Returns:
3172  * 0 on success, otherwise a negative error code.
3173  */
gpiod_set_transitory(struct gpio_desc * desc,bool transitory)3174 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
3175 {
3176 	VALIDATE_DESC(desc);
3177 	/*
3178 	 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
3179 	 * persistence state.
3180 	 */
3181 	assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
3182 
3183 	/* If the driver supports it, set the persistence state now */
3184 	return gpio_set_config_with_argument_optional(desc,
3185 						      PIN_CONFIG_PERSIST_STATE,
3186 						      !transitory);
3187 }
3188 
3189 /**
3190  * gpiod_is_active_low - test whether a GPIO is active-low or not
3191  * @desc: the gpio descriptor to test
3192  *
3193  * Returns:
3194  * 1 if the GPIO is active-low, 0 otherwise.
3195  */
gpiod_is_active_low(const struct gpio_desc * desc)3196 int gpiod_is_active_low(const struct gpio_desc *desc)
3197 {
3198 	VALIDATE_DESC(desc);
3199 	return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
3200 }
3201 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
3202 
3203 /**
3204  * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
3205  * @desc: the gpio descriptor to change
3206  */
gpiod_toggle_active_low(struct gpio_desc * desc)3207 void gpiod_toggle_active_low(struct gpio_desc *desc)
3208 {
3209 	VALIDATE_DESC_VOID(desc);
3210 	change_bit(FLAG_ACTIVE_LOW, &desc->flags);
3211 	gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3212 }
3213 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
3214 
gpiochip_get(struct gpio_chip * gc,unsigned int offset)3215 static int gpiochip_get(struct gpio_chip *gc, unsigned int offset)
3216 {
3217 	int ret;
3218 
3219 	lockdep_assert_held(&gc->gpiodev->srcu);
3220 
3221 	/* Make sure this is called after checking for gc->get(). */
3222 	ret = gc->get(gc, offset);
3223 	if (ret > 1)
3224 		ret = -EBADE;
3225 
3226 	return ret;
3227 }
3228 
gpio_chip_get_value(struct gpio_chip * gc,const struct gpio_desc * desc)3229 static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)
3230 {
3231 	return gc->get ? gpiochip_get(gc, gpio_chip_hwgpio(desc)) : -EIO;
3232 }
3233 
3234 /* I/O calls are only valid after configuration completed; the relevant
3235  * "is this a valid GPIO" error checks should already have been done.
3236  *
3237  * "Get" operations are often inlinable as reading a pin value register,
3238  * and masking the relevant bit in that register.
3239  *
3240  * When "set" operations are inlinable, they involve writing that mask to
3241  * one register to set a low value, or a different register to set it high.
3242  * Otherwise locking is needed, so there may be little value to inlining.
3243  *
3244  *------------------------------------------------------------------------
3245  *
3246  * IMPORTANT!!!  The hot paths -- get/set value -- assume that callers
3247  * have requested the GPIO.  That can include implicit requesting by
3248  * a direction setting call.  Marking a gpio as requested locks its chip
3249  * in memory, guaranteeing that these table lookups need no more locking
3250  * and that gpiochip_remove() will fail.
3251  *
3252  * REVISIT when debugging, consider adding some instrumentation to ensure
3253  * that the GPIO was actually requested.
3254  */
3255 
gpiod_get_raw_value_commit(const struct gpio_desc * desc)3256 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
3257 {
3258 	struct gpio_device *gdev;
3259 	struct gpio_chip *gc;
3260 	int value;
3261 
3262 	/* FIXME Unable to use gpio_chip_guard due to const desc. */
3263 	gdev = desc->gdev;
3264 
3265 	guard(srcu)(&gdev->srcu);
3266 
3267 	gc = srcu_dereference(gdev->chip, &gdev->srcu);
3268 	if (!gc)
3269 		return -ENODEV;
3270 
3271 	value = gpio_chip_get_value(gc, desc);
3272 	value = value < 0 ? value : !!value;
3273 	trace_gpio_value(desc_to_gpio(desc), 1, value);
3274 	return value;
3275 }
3276 
gpio_chip_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)3277 static int gpio_chip_get_multiple(struct gpio_chip *gc,
3278 				  unsigned long *mask, unsigned long *bits)
3279 {
3280 	int ret;
3281 
3282 	lockdep_assert_held(&gc->gpiodev->srcu);
3283 
3284 	if (gc->get_multiple) {
3285 		ret = gc->get_multiple(gc, mask, bits);
3286 		if (ret > 0)
3287 			return -EBADE;
3288 	}
3289 
3290 	if (gc->get) {
3291 		int i, value;
3292 
3293 		for_each_set_bit(i, mask, gc->ngpio) {
3294 			value = gpiochip_get(gc, i);
3295 			if (value < 0)
3296 				return value;
3297 			__assign_bit(i, bits, value);
3298 		}
3299 		return 0;
3300 	}
3301 	return -EIO;
3302 }
3303 
3304 /* The 'other' chip must be protected with its GPIO device's SRCU. */
gpio_device_chip_cmp(struct gpio_device * gdev,struct gpio_chip * gc)3305 static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
3306 {
3307 	guard(srcu)(&gdev->srcu);
3308 
3309 	return gc == srcu_dereference(gdev->chip, &gdev->srcu);
3310 }
3311 
gpiod_get_array_value_complex(bool raw,bool can_sleep,unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3312 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3313 				  unsigned int array_size,
3314 				  struct gpio_desc **desc_array,
3315 				  struct gpio_array *array_info,
3316 				  unsigned long *value_bitmap)
3317 {
3318 	struct gpio_chip *gc;
3319 	int ret, i = 0;
3320 
3321 	/*
3322 	 * Validate array_info against desc_array and its size.
3323 	 * It should immediately follow desc_array if both
3324 	 * have been obtained from the same gpiod_get_array() call.
3325 	 */
3326 	if (array_info && array_info->desc == desc_array &&
3327 	    array_size <= array_info->size &&
3328 	    (void *)array_info == desc_array + array_info->size) {
3329 		if (!can_sleep)
3330 			WARN_ON(array_info->gdev->can_sleep);
3331 
3332 		guard(srcu)(&array_info->gdev->srcu);
3333 		gc = srcu_dereference(array_info->gdev->chip,
3334 				      &array_info->gdev->srcu);
3335 		if (!gc)
3336 			return -ENODEV;
3337 
3338 		ret = gpio_chip_get_multiple(gc, array_info->get_mask,
3339 					     value_bitmap);
3340 		if (ret)
3341 			return ret;
3342 
3343 		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3344 			bitmap_xor(value_bitmap, value_bitmap,
3345 				   array_info->invert_mask, array_size);
3346 
3347 		i = find_first_zero_bit(array_info->get_mask, array_size);
3348 		if (i == array_size)
3349 			return 0;
3350 	} else {
3351 		array_info = NULL;
3352 	}
3353 
3354 	while (i < array_size) {
3355 		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3356 		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3357 		unsigned long *mask, *bits;
3358 		int first, j;
3359 
3360 		CLASS(gpio_chip_guard, guard)(desc_array[i]);
3361 		if (!guard.gc)
3362 			return -ENODEV;
3363 
3364 		if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3365 			mask = fastpath_mask;
3366 			bits = fastpath_bits;
3367 		} else {
3368 			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3369 
3370 			mask = bitmap_alloc(guard.gc->ngpio, flags);
3371 			if (!mask)
3372 				return -ENOMEM;
3373 
3374 			bits = bitmap_alloc(guard.gc->ngpio, flags);
3375 			if (!bits) {
3376 				bitmap_free(mask);
3377 				return -ENOMEM;
3378 			}
3379 		}
3380 
3381 		bitmap_zero(mask, guard.gc->ngpio);
3382 
3383 		if (!can_sleep)
3384 			WARN_ON(guard.gc->can_sleep);
3385 
3386 		/* collect all inputs belonging to the same chip */
3387 		first = i;
3388 		do {
3389 			const struct gpio_desc *desc = desc_array[i];
3390 			int hwgpio = gpio_chip_hwgpio(desc);
3391 
3392 			__set_bit(hwgpio, mask);
3393 			i++;
3394 
3395 			if (array_info)
3396 				i = find_next_zero_bit(array_info->get_mask,
3397 						       array_size, i);
3398 		} while ((i < array_size) &&
3399 			 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3400 
3401 		ret = gpio_chip_get_multiple(guard.gc, mask, bits);
3402 		if (ret) {
3403 			if (mask != fastpath_mask)
3404 				bitmap_free(mask);
3405 			if (bits != fastpath_bits)
3406 				bitmap_free(bits);
3407 			return ret;
3408 		}
3409 
3410 		for (j = first; j < i; ) {
3411 			const struct gpio_desc *desc = desc_array[j];
3412 			int hwgpio = gpio_chip_hwgpio(desc);
3413 			int value = test_bit(hwgpio, bits);
3414 
3415 			if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3416 				value = !value;
3417 			__assign_bit(j, value_bitmap, value);
3418 			trace_gpio_value(desc_to_gpio(desc), 1, value);
3419 			j++;
3420 
3421 			if (array_info)
3422 				j = find_next_zero_bit(array_info->get_mask, i,
3423 						       j);
3424 		}
3425 
3426 		if (mask != fastpath_mask)
3427 			bitmap_free(mask);
3428 		if (bits != fastpath_bits)
3429 			bitmap_free(bits);
3430 	}
3431 	return 0;
3432 }
3433 
3434 /**
3435  * gpiod_get_raw_value() - return a gpio's raw value
3436  * @desc: gpio whose value will be returned
3437  *
3438  * Returns:
3439  * The GPIO's raw value, i.e. the value of the physical line disregarding
3440  * its ACTIVE_LOW status, or negative errno on failure.
3441  *
3442  * This function can be called from contexts where we cannot sleep, and will
3443  * complain if the GPIO chip functions potentially sleep.
3444  */
gpiod_get_raw_value(const struct gpio_desc * desc)3445 int gpiod_get_raw_value(const struct gpio_desc *desc)
3446 {
3447 	VALIDATE_DESC(desc);
3448 	/* Should be using gpiod_get_raw_value_cansleep() */
3449 	WARN_ON(desc->gdev->can_sleep);
3450 	return gpiod_get_raw_value_commit(desc);
3451 }
3452 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3453 
3454 /**
3455  * gpiod_get_value() - return a gpio's value
3456  * @desc: gpio whose value will be returned
3457  *
3458  * Returns:
3459  * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3460  * account, or negative errno on failure.
3461  *
3462  * This function can be called from contexts where we cannot sleep, and will
3463  * complain if the GPIO chip functions potentially sleep.
3464  */
gpiod_get_value(const struct gpio_desc * desc)3465 int gpiod_get_value(const struct gpio_desc *desc)
3466 {
3467 	int value;
3468 
3469 	VALIDATE_DESC(desc);
3470 	/* Should be using gpiod_get_value_cansleep() */
3471 	WARN_ON(desc->gdev->can_sleep);
3472 
3473 	value = gpiod_get_raw_value_commit(desc);
3474 	if (value < 0)
3475 		return value;
3476 
3477 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3478 		value = !value;
3479 
3480 	return value;
3481 }
3482 EXPORT_SYMBOL_GPL(gpiod_get_value);
3483 
3484 /**
3485  * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3486  * @array_size: number of elements in the descriptor array / value bitmap
3487  * @desc_array: array of GPIO descriptors whose values will be read
3488  * @array_info: information on applicability of fast bitmap processing path
3489  * @value_bitmap: bitmap to store the read values
3490  *
3491  * Read the raw values of the GPIOs, i.e. the values of the physical lines
3492  * without regard for their ACTIVE_LOW status.
3493  *
3494  * This function can be called from contexts where we cannot sleep,
3495  * and it will complain if the GPIO chip functions potentially sleep.
3496  *
3497  * Returns:
3498  * 0 on success, or negative errno on failure.
3499  */
gpiod_get_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3500 int gpiod_get_raw_array_value(unsigned int array_size,
3501 			      struct gpio_desc **desc_array,
3502 			      struct gpio_array *array_info,
3503 			      unsigned long *value_bitmap)
3504 {
3505 	if (!desc_array)
3506 		return -EINVAL;
3507 	return gpiod_get_array_value_complex(true, false, array_size,
3508 					     desc_array, array_info,
3509 					     value_bitmap);
3510 }
3511 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3512 
3513 /**
3514  * gpiod_get_array_value() - read values from an array of GPIOs
3515  * @array_size: number of elements in the descriptor array / value bitmap
3516  * @desc_array: array of GPIO descriptors whose values will be read
3517  * @array_info: information on applicability of fast bitmap processing path
3518  * @value_bitmap: bitmap to store the read values
3519  *
3520  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3521  * into account.
3522  *
3523  * This function can be called from contexts where we cannot sleep,
3524  * and it will complain if the GPIO chip functions potentially sleep.
3525  *
3526  * Returns:
3527  * 0 on success, or negative errno on failure.
3528  */
gpiod_get_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3529 int gpiod_get_array_value(unsigned int array_size,
3530 			  struct gpio_desc **desc_array,
3531 			  struct gpio_array *array_info,
3532 			  unsigned long *value_bitmap)
3533 {
3534 	if (!desc_array)
3535 		return -EINVAL;
3536 	return gpiod_get_array_value_complex(false, false, array_size,
3537 					     desc_array, array_info,
3538 					     value_bitmap);
3539 }
3540 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3541 
3542 /*
3543  *  gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3544  * @desc: gpio descriptor whose state need to be set.
3545  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3546  */
gpio_set_open_drain_value_commit(struct gpio_desc * desc,bool value)3547 static int gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3548 {
3549 	int ret = 0, offset = gpio_chip_hwgpio(desc);
3550 
3551 	CLASS(gpio_chip_guard, guard)(desc);
3552 	if (!guard.gc)
3553 		return -ENODEV;
3554 
3555 	if (value) {
3556 		ret = gpiochip_direction_input(guard.gc, offset);
3557 	} else {
3558 		ret = gpiochip_direction_output(guard.gc, offset, 0);
3559 		if (!ret)
3560 			set_bit(FLAG_IS_OUT, &desc->flags);
3561 	}
3562 	trace_gpio_direction(desc_to_gpio(desc), value, ret);
3563 	if (ret < 0)
3564 		gpiod_err(desc,
3565 			  "%s: Error in set_value for open drain err %d\n",
3566 			  __func__, ret);
3567 
3568 	return ret;
3569 }
3570 
3571 /*
3572  *  _gpio_set_open_source_value() - Set the open source gpio's value.
3573  * @desc: gpio descriptor whose state need to be set.
3574  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3575  */
gpio_set_open_source_value_commit(struct gpio_desc * desc,bool value)3576 static int gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3577 {
3578 	int ret = 0, offset = gpio_chip_hwgpio(desc);
3579 
3580 	CLASS(gpio_chip_guard, guard)(desc);
3581 	if (!guard.gc)
3582 		return -ENODEV;
3583 
3584 	if (value) {
3585 		ret = gpiochip_direction_output(guard.gc, offset, 1);
3586 		if (!ret)
3587 			set_bit(FLAG_IS_OUT, &desc->flags);
3588 	} else {
3589 		ret = gpiochip_direction_input(guard.gc, offset);
3590 	}
3591 	trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3592 	if (ret < 0)
3593 		gpiod_err(desc,
3594 			  "%s: Error in set_value for open source err %d\n",
3595 			  __func__, ret);
3596 
3597 	return ret;
3598 }
3599 
gpiod_set_raw_value_commit(struct gpio_desc * desc,bool value)3600 static int gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3601 {
3602 	CLASS(gpio_chip_guard, guard)(desc);
3603 	if (!guard.gc)
3604 		return -ENODEV;
3605 
3606 	trace_gpio_value(desc_to_gpio(desc), 0, value);
3607 	return gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), value);
3608 }
3609 
3610 /*
3611  * set multiple outputs on the same chip;
3612  * use the chip's set_multiple function if available;
3613  * otherwise set the outputs sequentially;
3614  * @chip: the GPIO chip we operate on
3615  * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3616  *        defines which outputs are to be changed
3617  * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3618  *        defines the values the outputs specified by mask are to be set to
3619  *
3620  * Returns: 0 on success, negative error number on failure.
3621  */
gpiochip_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)3622 static int gpiochip_set_multiple(struct gpio_chip *gc,
3623 				 unsigned long *mask, unsigned long *bits)
3624 {
3625 	unsigned int i;
3626 	int ret;
3627 
3628 	lockdep_assert_held(&gc->gpiodev->srcu);
3629 
3630 	if (gc->set_multiple_rv) {
3631 		ret = gc->set_multiple_rv(gc, mask, bits);
3632 		if (ret > 0)
3633 			ret = -EBADE;
3634 
3635 		return ret;
3636 	}
3637 
3638 	if (gc->set_multiple) {
3639 		gc->set_multiple(gc, mask, bits);
3640 		return 0;
3641 	}
3642 
3643 	/* set outputs if the corresponding mask bit is set */
3644 	for_each_set_bit(i, mask, gc->ngpio) {
3645 		ret = gpiochip_set(gc, i, test_bit(i, bits));
3646 		if (ret)
3647 			break;
3648 	}
3649 
3650 	return ret;
3651 }
3652 
gpiod_set_array_value_complex(bool raw,bool can_sleep,unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3653 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3654 				  unsigned int array_size,
3655 				  struct gpio_desc **desc_array,
3656 				  struct gpio_array *array_info,
3657 				  unsigned long *value_bitmap)
3658 {
3659 	struct gpio_chip *gc;
3660 	int i = 0, ret;
3661 
3662 	/*
3663 	 * Validate array_info against desc_array and its size.
3664 	 * It should immediately follow desc_array if both
3665 	 * have been obtained from the same gpiod_get_array() call.
3666 	 */
3667 	if (array_info && array_info->desc == desc_array &&
3668 	    array_size <= array_info->size &&
3669 	    (void *)array_info == desc_array + array_info->size) {
3670 		if (!can_sleep)
3671 			WARN_ON(array_info->gdev->can_sleep);
3672 
3673 		guard(srcu)(&array_info->gdev->srcu);
3674 		gc = srcu_dereference(array_info->gdev->chip,
3675 				      &array_info->gdev->srcu);
3676 		if (!gc)
3677 			return -ENODEV;
3678 
3679 		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3680 			bitmap_xor(value_bitmap, value_bitmap,
3681 				   array_info->invert_mask, array_size);
3682 
3683 		ret = gpiochip_set_multiple(gc, array_info->set_mask,
3684 					    value_bitmap);
3685 		if (ret)
3686 			return ret;
3687 
3688 		i = find_first_zero_bit(array_info->set_mask, array_size);
3689 		if (i == array_size)
3690 			return 0;
3691 	} else {
3692 		array_info = NULL;
3693 	}
3694 
3695 	while (i < array_size) {
3696 		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
3697 		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
3698 		unsigned long *mask, *bits;
3699 		int count = 0;
3700 
3701 		CLASS(gpio_chip_guard, guard)(desc_array[i]);
3702 		if (!guard.gc)
3703 			return -ENODEV;
3704 
3705 		if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
3706 			mask = fastpath_mask;
3707 			bits = fastpath_bits;
3708 		} else {
3709 			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
3710 
3711 			mask = bitmap_alloc(guard.gc->ngpio, flags);
3712 			if (!mask)
3713 				return -ENOMEM;
3714 
3715 			bits = bitmap_alloc(guard.gc->ngpio, flags);
3716 			if (!bits) {
3717 				bitmap_free(mask);
3718 				return -ENOMEM;
3719 			}
3720 		}
3721 
3722 		bitmap_zero(mask, guard.gc->ngpio);
3723 
3724 		if (!can_sleep)
3725 			WARN_ON(guard.gc->can_sleep);
3726 
3727 		do {
3728 			struct gpio_desc *desc = desc_array[i];
3729 			int hwgpio = gpio_chip_hwgpio(desc);
3730 			int value = test_bit(i, value_bitmap);
3731 
3732 			/*
3733 			 * Pins applicable for fast input but not for
3734 			 * fast output processing may have been already
3735 			 * inverted inside the fast path, skip them.
3736 			 */
3737 			if (!raw && !(array_info &&
3738 			    test_bit(i, array_info->invert_mask)) &&
3739 			    test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3740 				value = !value;
3741 			trace_gpio_value(desc_to_gpio(desc), 0, value);
3742 			/*
3743 			 * collect all normal outputs belonging to the same chip
3744 			 * open drain and open source outputs are set individually
3745 			 */
3746 			if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3747 				gpio_set_open_drain_value_commit(desc, value);
3748 			} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3749 				gpio_set_open_source_value_commit(desc, value);
3750 			} else {
3751 				__set_bit(hwgpio, mask);
3752 				__assign_bit(hwgpio, bits, value);
3753 				count++;
3754 			}
3755 			i++;
3756 
3757 			if (array_info)
3758 				i = find_next_zero_bit(array_info->set_mask,
3759 						       array_size, i);
3760 		} while ((i < array_size) &&
3761 			 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
3762 		/* push collected bits to outputs */
3763 		if (count != 0) {
3764 			ret = gpiochip_set_multiple(guard.gc, mask, bits);
3765 			if (ret)
3766 				return ret;
3767 		}
3768 
3769 		if (mask != fastpath_mask)
3770 			bitmap_free(mask);
3771 		if (bits != fastpath_bits)
3772 			bitmap_free(bits);
3773 	}
3774 	return 0;
3775 }
3776 
3777 /**
3778  * gpiod_set_raw_value() - assign a gpio's raw value
3779  * @desc: gpio whose value will be assigned
3780  * @value: value to assign
3781  *
3782  * Set the raw value of the GPIO, i.e. the value of its physical line without
3783  * regard for its ACTIVE_LOW status.
3784  *
3785  * This function can be called from contexts where we cannot sleep, and will
3786  * complain if the GPIO chip functions potentially sleep.
3787  *
3788  * Returns:
3789  * 0 on success, negative error number on failure.
3790  */
gpiod_set_raw_value(struct gpio_desc * desc,int value)3791 int gpiod_set_raw_value(struct gpio_desc *desc, int value)
3792 {
3793 	VALIDATE_DESC(desc);
3794 	/* Should be using gpiod_set_raw_value_cansleep() */
3795 	WARN_ON(desc->gdev->can_sleep);
3796 	return gpiod_set_raw_value_commit(desc, value);
3797 }
3798 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3799 
3800 /**
3801  * gpiod_set_value_nocheck() - set a GPIO line value without checking
3802  * @desc: the descriptor to set the value on
3803  * @value: value to set
3804  *
3805  * This sets the value of a GPIO line backing a descriptor, applying
3806  * different semantic quirks like active low and open drain/source
3807  * handling.
3808  *
3809  * Returns:
3810  * 0 on success, negative error number on failure.
3811  */
gpiod_set_value_nocheck(struct gpio_desc * desc,int value)3812 static int gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3813 {
3814 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3815 		value = !value;
3816 
3817 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3818 		return gpio_set_open_drain_value_commit(desc, value);
3819 	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3820 		return gpio_set_open_source_value_commit(desc, value);
3821 
3822 	return gpiod_set_raw_value_commit(desc, value);
3823 }
3824 
3825 /**
3826  * gpiod_set_value() - assign a gpio's value
3827  * @desc: gpio whose value will be assigned
3828  * @value: value to assign
3829  *
3830  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3831  * OPEN_DRAIN and OPEN_SOURCE flags into account.
3832  *
3833  * This function can be called from contexts where we cannot sleep, and will
3834  * complain if the GPIO chip functions potentially sleep.
3835  *
3836  * Returns:
3837  * 0 on success, negative error number on failure.
3838  */
gpiod_set_value(struct gpio_desc * desc,int value)3839 int gpiod_set_value(struct gpio_desc *desc, int value)
3840 {
3841 	VALIDATE_DESC(desc);
3842 	/* Should be using gpiod_set_value_cansleep() */
3843 	WARN_ON(desc->gdev->can_sleep);
3844 	return gpiod_set_value_nocheck(desc, value);
3845 }
3846 EXPORT_SYMBOL_GPL(gpiod_set_value);
3847 
3848 /**
3849  * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3850  * @array_size: number of elements in the descriptor array / value bitmap
3851  * @desc_array: array of GPIO descriptors whose values will be assigned
3852  * @array_info: information on applicability of fast bitmap processing path
3853  * @value_bitmap: bitmap of values to assign
3854  *
3855  * Set the raw values of the GPIOs, i.e. the values of the physical lines
3856  * without regard for their ACTIVE_LOW status.
3857  *
3858  * This function can be called from contexts where we cannot sleep, and will
3859  * complain if the GPIO chip functions potentially sleep.
3860  *
3861  * Returns:
3862  * 0 on success, or negative errno on failure.
3863  */
gpiod_set_raw_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3864 int gpiod_set_raw_array_value(unsigned int array_size,
3865 			      struct gpio_desc **desc_array,
3866 			      struct gpio_array *array_info,
3867 			      unsigned long *value_bitmap)
3868 {
3869 	if (!desc_array)
3870 		return -EINVAL;
3871 	return gpiod_set_array_value_complex(true, false, array_size,
3872 					desc_array, array_info, value_bitmap);
3873 }
3874 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3875 
3876 /**
3877  * gpiod_set_array_value() - assign values to an array of GPIOs
3878  * @array_size: number of elements in the descriptor array / value bitmap
3879  * @desc_array: array of GPIO descriptors whose values will be assigned
3880  * @array_info: information on applicability of fast bitmap processing path
3881  * @value_bitmap: bitmap of values to assign
3882  *
3883  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3884  * into account.
3885  *
3886  * This function can be called from contexts where we cannot sleep, and will
3887  * complain if the GPIO chip functions potentially sleep.
3888  *
3889  * Returns:
3890  * 0 on success, or negative errno on failure.
3891  */
gpiod_set_array_value(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)3892 int gpiod_set_array_value(unsigned int array_size,
3893 			  struct gpio_desc **desc_array,
3894 			  struct gpio_array *array_info,
3895 			  unsigned long *value_bitmap)
3896 {
3897 	if (!desc_array)
3898 		return -EINVAL;
3899 	return gpiod_set_array_value_complex(false, false, array_size,
3900 					     desc_array, array_info,
3901 					     value_bitmap);
3902 }
3903 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3904 
3905 /**
3906  * gpiod_cansleep() - report whether gpio value access may sleep
3907  * @desc: gpio to check
3908  *
3909  * Returns:
3910  * 0 for non-sleepable, 1 for sleepable, or an error code in case of error.
3911  */
gpiod_cansleep(const struct gpio_desc * desc)3912 int gpiod_cansleep(const struct gpio_desc *desc)
3913 {
3914 	VALIDATE_DESC(desc);
3915 	return desc->gdev->can_sleep;
3916 }
3917 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3918 
3919 /**
3920  * gpiod_set_consumer_name() - set the consumer name for the descriptor
3921  * @desc: gpio to set the consumer name on
3922  * @name: the new consumer name
3923  *
3924  * Returns:
3925  * 0 on success, or negative errno on failure.
3926  */
gpiod_set_consumer_name(struct gpio_desc * desc,const char * name)3927 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3928 {
3929 	int ret;
3930 
3931 	VALIDATE_DESC(desc);
3932 
3933 	ret = desc_set_label(desc, name);
3934 	if (ret == 0)
3935 		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
3936 
3937 	return ret;
3938 }
3939 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3940 
3941 /**
3942  * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3943  * @desc: gpio whose IRQ will be returned (already requested)
3944  *
3945  * Returns:
3946  * The IRQ corresponding to the passed GPIO, or an error code in case of error.
3947  */
gpiod_to_irq(const struct gpio_desc * desc)3948 int gpiod_to_irq(const struct gpio_desc *desc)
3949 {
3950 	struct gpio_device *gdev;
3951 	struct gpio_chip *gc;
3952 	int offset;
3953 
3954 	/*
3955 	 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3956 	 * requires this function to not return zero on an invalid descriptor
3957 	 * but rather a negative error number.
3958 	 */
3959 	if (IS_ERR_OR_NULL(desc))
3960 		return -EINVAL;
3961 
3962 	gdev = desc->gdev;
3963 	/* FIXME Cannot use gpio_chip_guard due to const desc. */
3964 	guard(srcu)(&gdev->srcu);
3965 	gc = srcu_dereference(gdev->chip, &gdev->srcu);
3966 	if (!gc)
3967 		return -ENODEV;
3968 
3969 	offset = gpio_chip_hwgpio(desc);
3970 	if (gc->to_irq) {
3971 		int retirq = gc->to_irq(gc, offset);
3972 
3973 		/* Zero means NO_IRQ */
3974 		if (!retirq)
3975 			return -ENXIO;
3976 
3977 		return retirq;
3978 	}
3979 #ifdef CONFIG_GPIOLIB_IRQCHIP
3980 	if (gc->irq.chip) {
3981 		/*
3982 		 * Avoid race condition with other code, which tries to lookup
3983 		 * an IRQ before the irqchip has been properly registered,
3984 		 * i.e. while gpiochip is still being brought up.
3985 		 */
3986 		return -EPROBE_DEFER;
3987 	}
3988 #endif
3989 	return -ENXIO;
3990 }
3991 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3992 
3993 /**
3994  * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3995  * @gc: the chip the GPIO to lock belongs to
3996  * @offset: the offset of the GPIO to lock as IRQ
3997  *
3998  * This is used directly by GPIO drivers that want to lock down
3999  * a certain GPIO line to be used for IRQs.
4000  *
4001  * Returns:
4002  * 0 on success, or negative errno on failure.
4003  */
gpiochip_lock_as_irq(struct gpio_chip * gc,unsigned int offset)4004 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
4005 {
4006 	struct gpio_desc *desc;
4007 
4008 	desc = gpiochip_get_desc(gc, offset);
4009 	if (IS_ERR(desc))
4010 		return PTR_ERR(desc);
4011 
4012 	/*
4013 	 * If it's fast: flush the direction setting if something changed
4014 	 * behind our back
4015 	 */
4016 	if (!gc->can_sleep && gc->get_direction) {
4017 		int dir = gpiod_get_direction(desc);
4018 
4019 		if (dir < 0) {
4020 			chip_err(gc, "%s: cannot get GPIO direction\n",
4021 				 __func__);
4022 			return dir;
4023 		}
4024 	}
4025 
4026 	/* To be valid for IRQ the line needs to be input or open drain */
4027 	if (test_bit(FLAG_IS_OUT, &desc->flags) &&
4028 	    !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
4029 		chip_err(gc,
4030 			 "%s: tried to flag a GPIO set as output for IRQ\n",
4031 			 __func__);
4032 		return -EIO;
4033 	}
4034 
4035 	set_bit(FLAG_USED_AS_IRQ, &desc->flags);
4036 	set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4037 
4038 	return 0;
4039 }
4040 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
4041 
4042 /**
4043  * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
4044  * @gc: the chip the GPIO to lock belongs to
4045  * @offset: the offset of the GPIO to lock as IRQ
4046  *
4047  * This is used directly by GPIO drivers that want to indicate
4048  * that a certain GPIO is no longer used exclusively for IRQ.
4049  */
gpiochip_unlock_as_irq(struct gpio_chip * gc,unsigned int offset)4050 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
4051 {
4052 	struct gpio_desc *desc;
4053 
4054 	desc = gpiochip_get_desc(gc, offset);
4055 	if (IS_ERR(desc))
4056 		return;
4057 
4058 	clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
4059 	clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4060 }
4061 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
4062 
gpiochip_disable_irq(struct gpio_chip * gc,unsigned int offset)4063 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
4064 {
4065 	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4066 
4067 	if (!IS_ERR(desc) &&
4068 	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
4069 		clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4070 }
4071 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
4072 
gpiochip_enable_irq(struct gpio_chip * gc,unsigned int offset)4073 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
4074 {
4075 	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
4076 
4077 	if (!IS_ERR(desc) &&
4078 	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
4079 		/*
4080 		 * We must not be output when using IRQ UNLESS we are
4081 		 * open drain.
4082 		 */
4083 		WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
4084 			!test_bit(FLAG_OPEN_DRAIN, &desc->flags));
4085 		set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
4086 	}
4087 }
4088 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
4089 
gpiochip_line_is_irq(struct gpio_chip * gc,unsigned int offset)4090 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
4091 {
4092 	if (offset >= gc->ngpio)
4093 		return false;
4094 
4095 	return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
4096 }
4097 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
4098 
gpiochip_reqres_irq(struct gpio_chip * gc,unsigned int offset)4099 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
4100 {
4101 	int ret;
4102 
4103 	if (!try_module_get(gc->gpiodev->owner))
4104 		return -ENODEV;
4105 
4106 	ret = gpiochip_lock_as_irq(gc, offset);
4107 	if (ret) {
4108 		chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
4109 		module_put(gc->gpiodev->owner);
4110 		return ret;
4111 	}
4112 	return 0;
4113 }
4114 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
4115 
gpiochip_relres_irq(struct gpio_chip * gc,unsigned int offset)4116 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
4117 {
4118 	gpiochip_unlock_as_irq(gc, offset);
4119 	module_put(gc->gpiodev->owner);
4120 }
4121 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
4122 
gpiochip_line_is_open_drain(struct gpio_chip * gc,unsigned int offset)4123 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
4124 {
4125 	if (offset >= gc->ngpio)
4126 		return false;
4127 
4128 	return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
4129 }
4130 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
4131 
gpiochip_line_is_open_source(struct gpio_chip * gc,unsigned int offset)4132 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
4133 {
4134 	if (offset >= gc->ngpio)
4135 		return false;
4136 
4137 	return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
4138 }
4139 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
4140 
gpiochip_line_is_persistent(struct gpio_chip * gc,unsigned int offset)4141 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
4142 {
4143 	if (offset >= gc->ngpio)
4144 		return false;
4145 
4146 	return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
4147 }
4148 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
4149 
4150 /**
4151  * gpiod_get_raw_value_cansleep() - return a gpio's raw value
4152  * @desc: gpio whose value will be returned
4153  *
4154  * Returns:
4155  * The GPIO's raw value, i.e. the value of the physical line disregarding
4156  * its ACTIVE_LOW status, or negative errno on failure.
4157  *
4158  * This function is to be called from contexts that can sleep.
4159  */
gpiod_get_raw_value_cansleep(const struct gpio_desc * desc)4160 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
4161 {
4162 	might_sleep();
4163 	VALIDATE_DESC(desc);
4164 	return gpiod_get_raw_value_commit(desc);
4165 }
4166 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
4167 
4168 /**
4169  * gpiod_get_value_cansleep() - return a gpio's value
4170  * @desc: gpio whose value will be returned
4171  *
4172  * Returns:
4173  * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
4174  * account, or negative errno on failure.
4175  *
4176  * This function is to be called from contexts that can sleep.
4177  */
gpiod_get_value_cansleep(const struct gpio_desc * desc)4178 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
4179 {
4180 	int value;
4181 
4182 	might_sleep();
4183 	VALIDATE_DESC(desc);
4184 	value = gpiod_get_raw_value_commit(desc);
4185 	if (value < 0)
4186 		return value;
4187 
4188 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
4189 		value = !value;
4190 
4191 	return value;
4192 }
4193 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
4194 
4195 /**
4196  * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
4197  * @array_size: number of elements in the descriptor array / value bitmap
4198  * @desc_array: array of GPIO descriptors whose values will be read
4199  * @array_info: information on applicability of fast bitmap processing path
4200  * @value_bitmap: bitmap to store the read values
4201  *
4202  * Read the raw values of the GPIOs, i.e. the values of the physical lines
4203  * without regard for their ACTIVE_LOW status.
4204  *
4205  * This function is to be called from contexts that can sleep.
4206  *
4207  * Returns:
4208  * 0 on success, or negative errno on failure.
4209  */
gpiod_get_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4210 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
4211 				       struct gpio_desc **desc_array,
4212 				       struct gpio_array *array_info,
4213 				       unsigned long *value_bitmap)
4214 {
4215 	might_sleep();
4216 	if (!desc_array)
4217 		return -EINVAL;
4218 	return gpiod_get_array_value_complex(true, true, array_size,
4219 					     desc_array, array_info,
4220 					     value_bitmap);
4221 }
4222 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
4223 
4224 /**
4225  * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
4226  * @array_size: number of elements in the descriptor array / value bitmap
4227  * @desc_array: array of GPIO descriptors whose values will be read
4228  * @array_info: information on applicability of fast bitmap processing path
4229  * @value_bitmap: bitmap to store the read values
4230  *
4231  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4232  * into account.
4233  *
4234  * This function is to be called from contexts that can sleep.
4235  *
4236  * Returns:
4237  * 0 on success, or negative errno on failure.
4238  */
gpiod_get_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4239 int gpiod_get_array_value_cansleep(unsigned int array_size,
4240 				   struct gpio_desc **desc_array,
4241 				   struct gpio_array *array_info,
4242 				   unsigned long *value_bitmap)
4243 {
4244 	might_sleep();
4245 	if (!desc_array)
4246 		return -EINVAL;
4247 	return gpiod_get_array_value_complex(false, true, array_size,
4248 					     desc_array, array_info,
4249 					     value_bitmap);
4250 }
4251 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
4252 
4253 /**
4254  * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
4255  * @desc: gpio whose value will be assigned
4256  * @value: value to assign
4257  *
4258  * Set the raw value of the GPIO, i.e. the value of its physical line without
4259  * regard for its ACTIVE_LOW status.
4260  *
4261  * This function is to be called from contexts that can sleep.
4262  *
4263  * Returns:
4264  * 0 on success, negative error number on failure.
4265  */
gpiod_set_raw_value_cansleep(struct gpio_desc * desc,int value)4266 int gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
4267 {
4268 	might_sleep();
4269 	VALIDATE_DESC(desc);
4270 	return gpiod_set_raw_value_commit(desc, value);
4271 }
4272 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
4273 
4274 /**
4275  * gpiod_set_value_cansleep() - assign a gpio's value
4276  * @desc: gpio whose value will be assigned
4277  * @value: value to assign
4278  *
4279  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
4280  * account
4281  *
4282  * This function is to be called from contexts that can sleep.
4283  *
4284  * Returns:
4285  * 0 on success, negative error number on failure.
4286  */
gpiod_set_value_cansleep(struct gpio_desc * desc,int value)4287 int gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
4288 {
4289 	might_sleep();
4290 	VALIDATE_DESC(desc);
4291 	return gpiod_set_value_nocheck(desc, value);
4292 }
4293 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
4294 
4295 /**
4296  * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
4297  * @array_size: number of elements in the descriptor array / value bitmap
4298  * @desc_array: array of GPIO descriptors whose values will be assigned
4299  * @array_info: information on applicability of fast bitmap processing path
4300  * @value_bitmap: bitmap of values to assign
4301  *
4302  * Set the raw values of the GPIOs, i.e. the values of the physical lines
4303  * without regard for their ACTIVE_LOW status.
4304  *
4305  * This function is to be called from contexts that can sleep.
4306  *
4307  * Returns:
4308  * 0 on success, or negative errno on failure.
4309  */
gpiod_set_raw_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4310 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
4311 				       struct gpio_desc **desc_array,
4312 				       struct gpio_array *array_info,
4313 				       unsigned long *value_bitmap)
4314 {
4315 	might_sleep();
4316 	if (!desc_array)
4317 		return -EINVAL;
4318 	return gpiod_set_array_value_complex(true, true, array_size, desc_array,
4319 				      array_info, value_bitmap);
4320 }
4321 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
4322 
4323 /**
4324  * gpiod_add_lookup_tables() - register GPIO device consumers
4325  * @tables: list of tables of consumers to register
4326  * @n: number of tables in the list
4327  */
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)4328 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
4329 {
4330 	unsigned int i;
4331 
4332 	mutex_lock(&gpio_lookup_lock);
4333 
4334 	for (i = 0; i < n; i++)
4335 		list_add_tail(&tables[i]->list, &gpio_lookup_list);
4336 
4337 	mutex_unlock(&gpio_lookup_lock);
4338 }
4339 
4340 /**
4341  * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
4342  * @array_size: number of elements in the descriptor array / value bitmap
4343  * @desc_array: array of GPIO descriptors whose values will be assigned
4344  * @array_info: information on applicability of fast bitmap processing path
4345  * @value_bitmap: bitmap of values to assign
4346  *
4347  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4348  * into account.
4349  *
4350  * This function is to be called from contexts that can sleep.
4351  *
4352  * Returns:
4353  * 0 on success, or negative errno on failure.
4354  */
gpiod_set_array_value_cansleep(unsigned int array_size,struct gpio_desc ** desc_array,struct gpio_array * array_info,unsigned long * value_bitmap)4355 int gpiod_set_array_value_cansleep(unsigned int array_size,
4356 				   struct gpio_desc **desc_array,
4357 				   struct gpio_array *array_info,
4358 				   unsigned long *value_bitmap)
4359 {
4360 	might_sleep();
4361 	if (!desc_array)
4362 		return -EINVAL;
4363 	return gpiod_set_array_value_complex(false, true, array_size,
4364 					     desc_array, array_info,
4365 					     value_bitmap);
4366 }
4367 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
4368 
gpiod_line_state_notify(struct gpio_desc * desc,unsigned long action)4369 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
4370 {
4371 	guard(read_lock_irqsave)(&desc->gdev->line_state_lock);
4372 
4373 	raw_notifier_call_chain(&desc->gdev->line_state_notifier, action, desc);
4374 }
4375 
4376 /**
4377  * gpiod_add_lookup_table() - register GPIO device consumers
4378  * @table: table of consumers to register
4379  */
gpiod_add_lookup_table(struct gpiod_lookup_table * table)4380 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
4381 {
4382 	gpiod_add_lookup_tables(&table, 1);
4383 }
4384 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
4385 
4386 /**
4387  * gpiod_remove_lookup_table() - unregister GPIO device consumers
4388  * @table: table of consumers to unregister
4389  */
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)4390 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4391 {
4392 	/* Nothing to remove */
4393 	if (!table)
4394 		return;
4395 
4396 	mutex_lock(&gpio_lookup_lock);
4397 
4398 	list_del(&table->list);
4399 
4400 	mutex_unlock(&gpio_lookup_lock);
4401 }
4402 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4403 
4404 /**
4405  * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4406  * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4407  */
gpiod_add_hogs(struct gpiod_hog * hogs)4408 void gpiod_add_hogs(struct gpiod_hog *hogs)
4409 {
4410 	struct gpiod_hog *hog;
4411 
4412 	mutex_lock(&gpio_machine_hogs_mutex);
4413 
4414 	for (hog = &hogs[0]; hog->chip_label; hog++) {
4415 		list_add_tail(&hog->list, &gpio_machine_hogs);
4416 
4417 		/*
4418 		 * The chip may have been registered earlier, so check if it
4419 		 * exists and, if so, try to hog the line now.
4420 		 */
4421 		struct gpio_device *gdev __free(gpio_device_put) =
4422 				gpio_device_find_by_label(hog->chip_label);
4423 		if (gdev)
4424 			gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);
4425 	}
4426 
4427 	mutex_unlock(&gpio_machine_hogs_mutex);
4428 }
4429 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4430 
gpiod_remove_hogs(struct gpiod_hog * hogs)4431 void gpiod_remove_hogs(struct gpiod_hog *hogs)
4432 {
4433 	struct gpiod_hog *hog;
4434 
4435 	mutex_lock(&gpio_machine_hogs_mutex);
4436 	for (hog = &hogs[0]; hog->chip_label; hog++)
4437 		list_del(&hog->list);
4438 	mutex_unlock(&gpio_machine_hogs_mutex);
4439 }
4440 EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
4441 
gpiod_find_lookup_table(struct device * dev)4442 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4443 {
4444 	const char *dev_id = dev ? dev_name(dev) : NULL;
4445 	struct gpiod_lookup_table *table;
4446 
4447 	list_for_each_entry(table, &gpio_lookup_list, list) {
4448 		if (table->dev_id && dev_id) {
4449 			/*
4450 			 * Valid strings on both ends, must be identical to have
4451 			 * a match
4452 			 */
4453 			if (!strcmp(table->dev_id, dev_id))
4454 				return table;
4455 		} else {
4456 			/*
4457 			 * One of the pointers is NULL, so both must be to have
4458 			 * a match
4459 			 */
4460 			if (dev_id == table->dev_id)
4461 				return table;
4462 		}
4463 	}
4464 
4465 	return NULL;
4466 }
4467 
gpiod_find(struct device * dev,const char * con_id,unsigned int idx,unsigned long * flags)4468 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4469 				    unsigned int idx, unsigned long *flags)
4470 {
4471 	struct gpio_desc *desc = ERR_PTR(-ENOENT);
4472 	struct gpiod_lookup_table *table;
4473 	struct gpiod_lookup *p;
4474 	struct gpio_chip *gc;
4475 
4476 	guard(mutex)(&gpio_lookup_lock);
4477 
4478 	table = gpiod_find_lookup_table(dev);
4479 	if (!table)
4480 		return desc;
4481 
4482 	for (p = &table->table[0]; p->key; p++) {
4483 		/* idx must always match exactly */
4484 		if (p->idx != idx)
4485 			continue;
4486 
4487 		/* If the lookup entry has a con_id, require exact match */
4488 		if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4489 			continue;
4490 
4491 		if (p->chip_hwnum == U16_MAX) {
4492 			desc = gpio_name_to_desc(p->key);
4493 			if (desc) {
4494 				*flags = p->flags;
4495 				return desc;
4496 			}
4497 
4498 			dev_warn(dev, "cannot find GPIO line %s, deferring\n",
4499 				 p->key);
4500 			return ERR_PTR(-EPROBE_DEFER);
4501 		}
4502 
4503 		struct gpio_device *gdev __free(gpio_device_put) =
4504 					gpio_device_find_by_label(p->key);
4505 		if (!gdev) {
4506 			/*
4507 			 * As the lookup table indicates a chip with
4508 			 * p->key should exist, assume it may
4509 			 * still appear later and let the interested
4510 			 * consumer be probed again or let the Deferred
4511 			 * Probe infrastructure handle the error.
4512 			 */
4513 			dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4514 				 p->key);
4515 			return ERR_PTR(-EPROBE_DEFER);
4516 		}
4517 
4518 		gc = gpio_device_get_chip(gdev);
4519 
4520 		if (gc->ngpio <= p->chip_hwnum) {
4521 			dev_err(dev,
4522 				"requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4523 				idx, p->chip_hwnum, gc->ngpio - 1,
4524 				gc->label);
4525 			return ERR_PTR(-EINVAL);
4526 		}
4527 
4528 		desc = gpio_device_get_desc(gdev, p->chip_hwnum);
4529 		*flags = p->flags;
4530 
4531 		return desc;
4532 	}
4533 
4534 	return desc;
4535 }
4536 
platform_gpio_count(struct device * dev,const char * con_id)4537 static int platform_gpio_count(struct device *dev, const char *con_id)
4538 {
4539 	struct gpiod_lookup_table *table;
4540 	struct gpiod_lookup *p;
4541 	unsigned int count = 0;
4542 
4543 	scoped_guard(mutex, &gpio_lookup_lock) {
4544 		table = gpiod_find_lookup_table(dev);
4545 		if (!table)
4546 			return -ENOENT;
4547 
4548 		for (p = &table->table[0]; p->key; p++) {
4549 			if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4550 			    (!con_id && !p->con_id))
4551 				count++;
4552 		}
4553 	}
4554 
4555 	if (!count)
4556 		return -ENOENT;
4557 
4558 	return count;
4559 }
4560 
gpiod_find_by_fwnode(struct fwnode_handle * fwnode,struct device * consumer,const char * con_id,unsigned int idx,enum gpiod_flags * flags,unsigned long * lookupflags)4561 static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
4562 					      struct device *consumer,
4563 					      const char *con_id,
4564 					      unsigned int idx,
4565 					      enum gpiod_flags *flags,
4566 					      unsigned long *lookupflags)
4567 {
4568 	const char *name = function_name_or_default(con_id);
4569 	struct gpio_desc *desc = ERR_PTR(-ENOENT);
4570 
4571 	if (is_of_node(fwnode)) {
4572 		dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4573 		desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
4574 	} else if (is_acpi_node(fwnode)) {
4575 		dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4576 		desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
4577 	} else if (is_software_node(fwnode)) {
4578 		dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
4579 		desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
4580 	}
4581 
4582 	return desc;
4583 }
4584 
gpiod_find_and_request(struct device * consumer,struct fwnode_handle * fwnode,const char * con_id,unsigned int idx,enum gpiod_flags flags,const char * label,bool platform_lookup_allowed)4585 struct gpio_desc *gpiod_find_and_request(struct device *consumer,
4586 					 struct fwnode_handle *fwnode,
4587 					 const char *con_id,
4588 					 unsigned int idx,
4589 					 enum gpiod_flags flags,
4590 					 const char *label,
4591 					 bool platform_lookup_allowed)
4592 {
4593 	unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4594 	const char *name = function_name_or_default(con_id);
4595 	/*
4596 	 * scoped_guard() is implemented as a for loop, meaning static
4597 	 * analyzers will complain about these two not being initialized.
4598 	 */
4599 	struct gpio_desc *desc = NULL;
4600 	int ret = 0;
4601 
4602 	scoped_guard(srcu, &gpio_devices_srcu) {
4603 		desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
4604 					    &flags, &lookupflags);
4605 		if (gpiod_not_found(desc) && platform_lookup_allowed) {
4606 			/*
4607 			 * Either we are not using DT or ACPI, or their lookup
4608 			 * did not return a result. In that case, use platform
4609 			 * lookup as a fallback.
4610 			 */
4611 			dev_dbg(consumer,
4612 				"using lookup tables for GPIO lookup\n");
4613 			desc = gpiod_find(consumer, con_id, idx, &lookupflags);
4614 		}
4615 
4616 		if (IS_ERR(desc)) {
4617 			dev_dbg(consumer, "No GPIO consumer %s found\n", name);
4618 			return desc;
4619 		}
4620 
4621 		/*
4622 		 * If a connection label was passed use that, else attempt to use
4623 		 * the device name as label
4624 		 */
4625 		ret = gpiod_request(desc, label);
4626 	}
4627 	if (ret) {
4628 		if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
4629 			return ERR_PTR(ret);
4630 
4631 		/*
4632 		 * This happens when there are several consumers for
4633 		 * the same GPIO line: we just return here without
4634 		 * further initialization. It is a bit of a hack.
4635 		 * This is necessary to support fixed regulators.
4636 		 *
4637 		 * FIXME: Make this more sane and safe.
4638 		 */
4639 		dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
4640 		return desc;
4641 	}
4642 
4643 	ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4644 	if (ret < 0) {
4645 		gpiod_put(desc);
4646 		dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret);
4647 		return ERR_PTR(ret);
4648 	}
4649 
4650 	gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
4651 
4652 	return desc;
4653 }
4654 
4655 /**
4656  * fwnode_gpiod_get_index - obtain a GPIO from firmware node
4657  * @fwnode:	handle of the firmware node
4658  * @con_id:	function within the GPIO consumer
4659  * @index:	index of the GPIO to obtain for the consumer
4660  * @flags:	GPIO initialization flags
4661  * @label:	label to attach to the requested GPIO
4662  *
4663  * This function can be used for drivers that get their configuration
4664  * from opaque firmware.
4665  *
4666  * The function properly finds the corresponding GPIO using whatever is the
4667  * underlying firmware interface and then makes sure that the GPIO
4668  * descriptor is requested before it is returned to the caller.
4669  *
4670  * Returns:
4671  * On successful request the GPIO pin is configured in accordance with
4672  * provided @flags.
4673  *
4674  * In case of error an ERR_PTR() is returned.
4675  */
fwnode_gpiod_get_index(struct fwnode_handle * fwnode,const char * con_id,int index,enum gpiod_flags flags,const char * label)4676 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
4677 					 const char *con_id,
4678 					 int index,
4679 					 enum gpiod_flags flags,
4680 					 const char *label)
4681 {
4682 	return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
4683 }
4684 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
4685 
4686 /**
4687  * gpiod_count - return the number of GPIOs associated with a device / function
4688  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
4689  * @con_id:	function within the GPIO consumer
4690  *
4691  * Returns:
4692  * The number of GPIOs associated with a device / function or -ENOENT if no
4693  * GPIO has been assigned to the requested function.
4694  */
gpiod_count(struct device * dev,const char * con_id)4695 int gpiod_count(struct device *dev, const char *con_id)
4696 {
4697 	const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4698 	int count = -ENOENT;
4699 
4700 	if (is_of_node(fwnode))
4701 		count = of_gpio_count(fwnode, con_id);
4702 	else if (is_acpi_node(fwnode))
4703 		count = acpi_gpio_count(fwnode, con_id);
4704 	else if (is_software_node(fwnode))
4705 		count = swnode_gpio_count(fwnode, con_id);
4706 
4707 	if (count < 0)
4708 		count = platform_gpio_count(dev, con_id);
4709 
4710 	return count;
4711 }
4712 EXPORT_SYMBOL_GPL(gpiod_count);
4713 
4714 /**
4715  * gpiod_get - obtain a GPIO for a given GPIO function
4716  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
4717  * @con_id:	function within the GPIO consumer
4718  * @flags:	optional GPIO initialization flags
4719  *
4720  * Returns:
4721  * The GPIO descriptor corresponding to the function @con_id of device
4722  * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4723  * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4724  */
gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)4725 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4726 					 enum gpiod_flags flags)
4727 {
4728 	return gpiod_get_index(dev, con_id, 0, flags);
4729 }
4730 EXPORT_SYMBOL_GPL(gpiod_get);
4731 
4732 /**
4733  * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4734  * @dev: GPIO consumer, can be NULL for system-global GPIOs
4735  * @con_id: function within the GPIO consumer
4736  * @flags: optional GPIO initialization flags
4737  *
4738  * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4739  * the requested function it will return NULL. This is convenient for drivers
4740  * that need to handle optional GPIOs.
4741  *
4742  * Returns:
4743  * The GPIO descriptor corresponding to the function @con_id of device
4744  * dev, NULL if no GPIO has been assigned to the requested function, or
4745  * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4746  */
gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)4747 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4748 						  const char *con_id,
4749 						  enum gpiod_flags flags)
4750 {
4751 	return gpiod_get_index_optional(dev, con_id, 0, flags);
4752 }
4753 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4754 
4755 
4756 /**
4757  * gpiod_configure_flags - helper function to configure a given GPIO
4758  * @desc:	gpio whose value will be assigned
4759  * @con_id:	function within the GPIO consumer
4760  * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
4761  *		of_find_gpio() or of_get_gpio_hog()
4762  * @dflags:	gpiod_flags - optional GPIO initialization flags
4763  *
4764  * Returns:
4765  * 0 on success, -ENOENT if no GPIO has been assigned to the
4766  * requested function and/or index, or another IS_ERR() code if an error
4767  * occurred while trying to acquire the GPIO.
4768  */
gpiod_configure_flags(struct gpio_desc * desc,const char * con_id,unsigned long lflags,enum gpiod_flags dflags)4769 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4770 		unsigned long lflags, enum gpiod_flags dflags)
4771 {
4772 	const char *name = function_name_or_default(con_id);
4773 	int ret;
4774 
4775 	if (lflags & GPIO_ACTIVE_LOW)
4776 		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4777 
4778 	if (lflags & GPIO_OPEN_DRAIN)
4779 		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4780 	else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4781 		/*
4782 		 * This enforces open drain mode from the consumer side.
4783 		 * This is necessary for some busses like I2C, but the lookup
4784 		 * should *REALLY* have specified them as open drain in the
4785 		 * first place, so print a little warning here.
4786 		 */
4787 		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4788 		gpiod_warn(desc,
4789 			   "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4790 	}
4791 
4792 	if (lflags & GPIO_OPEN_SOURCE)
4793 		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4794 
4795 	if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
4796 	    ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
4797 	    ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
4798 		gpiod_err(desc,
4799 			  "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
4800 		return -EINVAL;
4801 	}
4802 
4803 	if (lflags & GPIO_PULL_UP)
4804 		set_bit(FLAG_PULL_UP, &desc->flags);
4805 	else if (lflags & GPIO_PULL_DOWN)
4806 		set_bit(FLAG_PULL_DOWN, &desc->flags);
4807 	else if (lflags & GPIO_PULL_DISABLE)
4808 		set_bit(FLAG_BIAS_DISABLE, &desc->flags);
4809 
4810 	ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4811 	if (ret < 0)
4812 		return ret;
4813 
4814 	/* No particular flag request, return here... */
4815 	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4816 		gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
4817 		return 0;
4818 	}
4819 
4820 	/* Process flags */
4821 	if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4822 		ret = gpiod_direction_output_nonotify(desc,
4823 				!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4824 	else
4825 		ret = gpiod_direction_input_nonotify(desc);
4826 
4827 	return ret;
4828 }
4829 
4830 /**
4831  * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4832  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
4833  * @con_id:	function within the GPIO consumer
4834  * @idx:	index of the GPIO to obtain in the consumer
4835  * @flags:	optional GPIO initialization flags
4836  *
4837  * This variant of gpiod_get() allows to access GPIOs other than the first
4838  * defined one for functions that define several GPIOs.
4839  *
4840  * Returns:
4841  * A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4842  * requested function and/or index, or another IS_ERR() code if an error
4843  * occurred while trying to acquire the GPIO.
4844  */
gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)4845 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4846 					       const char *con_id,
4847 					       unsigned int idx,
4848 					       enum gpiod_flags flags)
4849 {
4850 	struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
4851 	const char *devname = dev ? dev_name(dev) : "?";
4852 	const char *label = con_id ?: devname;
4853 
4854 	return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
4855 }
4856 EXPORT_SYMBOL_GPL(gpiod_get_index);
4857 
4858 /**
4859  * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4860  *                            function
4861  * @dev: GPIO consumer, can be NULL for system-global GPIOs
4862  * @con_id: function within the GPIO consumer
4863  * @index: index of the GPIO to obtain in the consumer
4864  * @flags: optional GPIO initialization flags
4865  *
4866  * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4867  * specified index was assigned to the requested function it will return NULL.
4868  * This is convenient for drivers that need to handle optional GPIOs.
4869  *
4870  * Returns:
4871  * A valid GPIO descriptor, NULL if no GPIO has been assigned to the
4872  * requested function and/or index, or another IS_ERR() code if an error
4873  * occurred while trying to acquire the GPIO.
4874  */
gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)4875 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4876 							const char *con_id,
4877 							unsigned int index,
4878 							enum gpiod_flags flags)
4879 {
4880 	struct gpio_desc *desc;
4881 
4882 	desc = gpiod_get_index(dev, con_id, index, flags);
4883 	if (gpiod_not_found(desc))
4884 		return NULL;
4885 
4886 	return desc;
4887 }
4888 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4889 
4890 /**
4891  * gpiod_hog - Hog the specified GPIO desc given the provided flags
4892  * @desc:	gpio whose value will be assigned
4893  * @name:	gpio line name
4894  * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
4895  *		of_find_gpio() or of_get_gpio_hog()
4896  * @dflags:	gpiod_flags - optional GPIO initialization flags
4897  *
4898  * Returns:
4899  * 0 on success, or negative errno on failure.
4900  */
gpiod_hog(struct gpio_desc * desc,const char * name,unsigned long lflags,enum gpiod_flags dflags)4901 int gpiod_hog(struct gpio_desc *desc, const char *name,
4902 	      unsigned long lflags, enum gpiod_flags dflags)
4903 {
4904 	struct gpio_device *gdev = desc->gdev;
4905 	struct gpio_desc *local_desc;
4906 	int hwnum;
4907 	int ret;
4908 
4909 	CLASS(gpio_chip_guard, guard)(desc);
4910 	if (!guard.gc)
4911 		return -ENODEV;
4912 
4913 	if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))
4914 		return 0;
4915 
4916 	hwnum = gpio_chip_hwgpio(desc);
4917 
4918 	local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
4919 					       lflags, dflags);
4920 	if (IS_ERR(local_desc)) {
4921 		clear_bit(FLAG_IS_HOGGED, &desc->flags);
4922 		ret = PTR_ERR(local_desc);
4923 		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4924 		       name, gdev->label, hwnum, ret);
4925 		return ret;
4926 	}
4927 
4928 	gpiod_dbg(desc, "hogged as %s/%s\n",
4929 		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4930 		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4931 		  str_high_low(dflags & GPIOD_FLAGS_BIT_DIR_VAL) : "?");
4932 
4933 	return 0;
4934 }
4935 
4936 /**
4937  * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4938  * @gc:	gpio chip to act on
4939  */
gpiochip_free_hogs(struct gpio_chip * gc)4940 static void gpiochip_free_hogs(struct gpio_chip *gc)
4941 {
4942 	struct gpio_desc *desc;
4943 
4944 	for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)
4945 		gpiochip_free_own_desc(desc);
4946 }
4947 
4948 /**
4949  * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4950  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
4951  * @con_id:	function within the GPIO consumer
4952  * @flags:	optional GPIO initialization flags
4953  *
4954  * This function acquires all the GPIOs defined under a given function.
4955  *
4956  * Returns:
4957  * The GPIO descriptors corresponding to the function @con_id of device
4958  * dev, -ENOENT if no GPIO has been assigned to the requested function,
4959  * or another IS_ERR() code if an error occurred while trying to acquire
4960  * the GPIOs.
4961  */
gpiod_get_array(struct device * dev,const char * con_id,enum gpiod_flags flags)4962 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4963 						const char *con_id,
4964 						enum gpiod_flags flags)
4965 {
4966 	struct gpio_desc *desc;
4967 	struct gpio_descs *descs;
4968 	struct gpio_device *gdev;
4969 	struct gpio_array *array_info = NULL;
4970 	int count, bitmap_size;
4971 	unsigned long dflags;
4972 	size_t descs_size;
4973 
4974 	count = gpiod_count(dev, con_id);
4975 	if (count < 0)
4976 		return ERR_PTR(count);
4977 
4978 	descs_size = struct_size(descs, desc, count);
4979 	descs = kzalloc(descs_size, GFP_KERNEL);
4980 	if (!descs)
4981 		return ERR_PTR(-ENOMEM);
4982 
4983 	for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
4984 		desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4985 		if (IS_ERR(desc)) {
4986 			gpiod_put_array(descs);
4987 			return ERR_CAST(desc);
4988 		}
4989 
4990 		descs->desc[descs->ndescs] = desc;
4991 
4992 		gdev = gpiod_to_gpio_device(desc);
4993 		/*
4994 		 * If pin hardware number of array member 0 is also 0, select
4995 		 * its chip as a candidate for fast bitmap processing path.
4996 		 */
4997 		if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4998 			struct gpio_descs *array;
4999 
5000 			bitmap_size = BITS_TO_LONGS(gdev->ngpio > count ?
5001 						    gdev->ngpio : count);
5002 
5003 			array = krealloc(descs, descs_size +
5004 					 struct_size(array_info, invert_mask, 3 * bitmap_size),
5005 					 GFP_KERNEL | __GFP_ZERO);
5006 			if (!array) {
5007 				gpiod_put_array(descs);
5008 				return ERR_PTR(-ENOMEM);
5009 			}
5010 
5011 			descs = array;
5012 
5013 			array_info = (void *)descs + descs_size;
5014 			array_info->get_mask = array_info->invert_mask +
5015 						  bitmap_size;
5016 			array_info->set_mask = array_info->get_mask +
5017 						  bitmap_size;
5018 
5019 			array_info->desc = descs->desc;
5020 			array_info->size = count;
5021 			array_info->gdev = gdev;
5022 			bitmap_set(array_info->get_mask, descs->ndescs,
5023 				   count - descs->ndescs);
5024 			bitmap_set(array_info->set_mask, descs->ndescs,
5025 				   count - descs->ndescs);
5026 			descs->info = array_info;
5027 		}
5028 
5029 		/* If there is no cache for fast bitmap processing path, continue */
5030 		if (!array_info)
5031 			continue;
5032 
5033 		/* Unmark array members which don't belong to the 'fast' chip */
5034 		if (array_info->gdev != gdev) {
5035 			__clear_bit(descs->ndescs, array_info->get_mask);
5036 			__clear_bit(descs->ndescs, array_info->set_mask);
5037 		}
5038 		/*
5039 		 * Detect array members which belong to the 'fast' chip
5040 		 * but their pins are not in hardware order.
5041 		 */
5042 		else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
5043 			/*
5044 			 * Don't use fast path if all array members processed so
5045 			 * far belong to the same chip as this one but its pin
5046 			 * hardware number is different from its array index.
5047 			 */
5048 			if (bitmap_full(array_info->get_mask, descs->ndescs)) {
5049 				array_info = NULL;
5050 			} else {
5051 				__clear_bit(descs->ndescs,
5052 					    array_info->get_mask);
5053 				__clear_bit(descs->ndescs,
5054 					    array_info->set_mask);
5055 			}
5056 		} else {
5057 			dflags = READ_ONCE(desc->flags);
5058 			/* Exclude open drain or open source from fast output */
5059 			if (test_bit(FLAG_OPEN_DRAIN, &dflags) ||
5060 			    test_bit(FLAG_OPEN_SOURCE, &dflags))
5061 				__clear_bit(descs->ndescs,
5062 					    array_info->set_mask);
5063 			/* Identify 'fast' pins which require invertion */
5064 			if (gpiod_is_active_low(desc))
5065 				__set_bit(descs->ndescs,
5066 					  array_info->invert_mask);
5067 		}
5068 	}
5069 	if (array_info)
5070 		dev_dbg(dev,
5071 			"GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
5072 			array_info->gdev->label, array_info->size,
5073 			*array_info->get_mask, *array_info->set_mask,
5074 			*array_info->invert_mask);
5075 	return descs;
5076 }
5077 EXPORT_SYMBOL_GPL(gpiod_get_array);
5078 
5079 /**
5080  * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
5081  *                            function
5082  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
5083  * @con_id:	function within the GPIO consumer
5084  * @flags:	optional GPIO initialization flags
5085  *
5086  * This is equivalent to gpiod_get_array(), except that when no GPIO was
5087  * assigned to the requested function it will return NULL.
5088  *
5089  * Returns:
5090  * The GPIO descriptors corresponding to the function @con_id of device
5091  * dev, NULL if no GPIO has been assigned to the requested function,
5092  * or another IS_ERR() code if an error occurred while trying to acquire
5093  * the GPIOs.
5094  */
gpiod_get_array_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)5095 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
5096 							const char *con_id,
5097 							enum gpiod_flags flags)
5098 {
5099 	struct gpio_descs *descs;
5100 
5101 	descs = gpiod_get_array(dev, con_id, flags);
5102 	if (gpiod_not_found(descs))
5103 		return NULL;
5104 
5105 	return descs;
5106 }
5107 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
5108 
5109 /**
5110  * gpiod_put - dispose of a GPIO descriptor
5111  * @desc:	GPIO descriptor to dispose of
5112  *
5113  * No descriptor can be used after gpiod_put() has been called on it.
5114  */
gpiod_put(struct gpio_desc * desc)5115 void gpiod_put(struct gpio_desc *desc)
5116 {
5117 	if (desc)
5118 		gpiod_free(desc);
5119 }
5120 EXPORT_SYMBOL_GPL(gpiod_put);
5121 
5122 /**
5123  * gpiod_put_array - dispose of multiple GPIO descriptors
5124  * @descs:	struct gpio_descs containing an array of descriptors
5125  */
gpiod_put_array(struct gpio_descs * descs)5126 void gpiod_put_array(struct gpio_descs *descs)
5127 {
5128 	unsigned int i;
5129 
5130 	for (i = 0; i < descs->ndescs; i++)
5131 		gpiod_put(descs->desc[i]);
5132 
5133 	kfree(descs);
5134 }
5135 EXPORT_SYMBOL_GPL(gpiod_put_array);
5136 
gpio_stub_drv_probe(struct device * dev)5137 static int gpio_stub_drv_probe(struct device *dev)
5138 {
5139 	/*
5140 	 * The DT node of some GPIO chips have a "compatible" property, but
5141 	 * never have a struct device added and probed by a driver to register
5142 	 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
5143 	 * the consumers of the GPIO chip to get probe deferred forever because
5144 	 * they will be waiting for a device associated with the GPIO chip
5145 	 * firmware node to get added and bound to a driver.
5146 	 *
5147 	 * To allow these consumers to probe, we associate the struct
5148 	 * gpio_device of the GPIO chip with the firmware node and then simply
5149 	 * bind it to this stub driver.
5150 	 */
5151 	return 0;
5152 }
5153 
5154 static struct device_driver gpio_stub_drv = {
5155 	.name = "gpio_stub_drv",
5156 	.bus = &gpio_bus_type,
5157 	.probe = gpio_stub_drv_probe,
5158 };
5159 
gpiolib_dev_init(void)5160 static int __init gpiolib_dev_init(void)
5161 {
5162 	int ret;
5163 
5164 	/* Register GPIO sysfs bus */
5165 	ret = bus_register(&gpio_bus_type);
5166 	if (ret < 0) {
5167 		pr_err("gpiolib: could not register GPIO bus type\n");
5168 		return ret;
5169 	}
5170 
5171 	ret = driver_register(&gpio_stub_drv);
5172 	if (ret < 0) {
5173 		pr_err("gpiolib: could not register GPIO stub driver\n");
5174 		bus_unregister(&gpio_bus_type);
5175 		return ret;
5176 	}
5177 
5178 	ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
5179 	if (ret < 0) {
5180 		pr_err("gpiolib: failed to allocate char dev region\n");
5181 		driver_unregister(&gpio_stub_drv);
5182 		bus_unregister(&gpio_bus_type);
5183 		return ret;
5184 	}
5185 
5186 	gpiolib_initialized = true;
5187 	gpiochip_setup_devs();
5188 
5189 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
5190 	WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
5191 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
5192 
5193 	return ret;
5194 }
5195 core_initcall(gpiolib_dev_init);
5196 
5197 #ifdef CONFIG_DEBUG_FS
5198 
gpiolib_dbg_show(struct seq_file * s,struct gpio_device * gdev)5199 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
5200 {
5201 	bool active_low, is_irq, is_out;
5202 	unsigned int gpio = gdev->base;
5203 	struct gpio_desc *desc;
5204 	struct gpio_chip *gc;
5205 	unsigned long flags;
5206 	int value;
5207 
5208 	guard(srcu)(&gdev->srcu);
5209 
5210 	gc = srcu_dereference(gdev->chip, &gdev->srcu);
5211 	if (!gc) {
5212 		seq_puts(s, "Underlying GPIO chip is gone\n");
5213 		return;
5214 	}
5215 
5216 	for_each_gpio_desc(gc, desc) {
5217 		guard(srcu)(&desc->gdev->desc_srcu);
5218 		flags = READ_ONCE(desc->flags);
5219 		is_irq = test_bit(FLAG_USED_AS_IRQ, &flags);
5220 		if (is_irq || test_bit(FLAG_REQUESTED, &flags)) {
5221 			gpiod_get_direction(desc);
5222 			is_out = test_bit(FLAG_IS_OUT, &flags);
5223 			value = gpio_chip_get_value(gc, desc);
5224 			active_low = test_bit(FLAG_ACTIVE_LOW, &flags);
5225 			seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
5226 				   gpio, desc->name ?: "", gpiod_get_label(desc),
5227 				   is_out ? "out" : "in ",
5228 				   value >= 0 ? str_hi_lo(value) : "?  ",
5229 				   is_irq ? "IRQ " : "",
5230 				   active_low ? "ACTIVE LOW" : "");
5231 		} else if (desc->name) {
5232 			seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name);
5233 		}
5234 
5235 		gpio++;
5236 	}
5237 }
5238 
5239 struct gpiolib_seq_priv {
5240 	bool newline;
5241 	int idx;
5242 };
5243 
gpiolib_seq_start(struct seq_file * s,loff_t * pos)5244 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
5245 {
5246 	struct gpiolib_seq_priv *priv;
5247 	struct gpio_device *gdev;
5248 	loff_t index = *pos;
5249 
5250 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
5251 	if (!priv)
5252 		return NULL;
5253 
5254 	s->private = priv;
5255 	if (*pos > 0)
5256 		priv->newline = true;
5257 	priv->idx = srcu_read_lock(&gpio_devices_srcu);
5258 
5259 	list_for_each_entry_srcu(gdev, &gpio_devices, list,
5260 				 srcu_read_lock_held(&gpio_devices_srcu)) {
5261 		if (index-- == 0)
5262 			return gdev;
5263 	}
5264 
5265 	return NULL;
5266 }
5267 
gpiolib_seq_next(struct seq_file * s,void * v,loff_t * pos)5268 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
5269 {
5270 	struct gpiolib_seq_priv *priv = s->private;
5271 	struct gpio_device *gdev = v, *next;
5272 
5273 	next = list_entry_rcu(gdev->list.next, struct gpio_device, list);
5274 	gdev = &next->list == &gpio_devices ? NULL : next;
5275 	priv->newline = true;
5276 	++*pos;
5277 
5278 	return gdev;
5279 }
5280 
gpiolib_seq_stop(struct seq_file * s,void * v)5281 static void gpiolib_seq_stop(struct seq_file *s, void *v)
5282 {
5283 	struct gpiolib_seq_priv *priv = s->private;
5284 
5285 	srcu_read_unlock(&gpio_devices_srcu, priv->idx);
5286 	kfree(priv);
5287 }
5288 
gpiolib_seq_show(struct seq_file * s,void * v)5289 static int gpiolib_seq_show(struct seq_file *s, void *v)
5290 {
5291 	struct gpiolib_seq_priv *priv = s->private;
5292 	struct gpio_device *gdev = v;
5293 	struct gpio_chip *gc;
5294 	struct device *parent;
5295 
5296 	if (priv->newline)
5297 		seq_putc(s, '\n');
5298 
5299 	guard(srcu)(&gdev->srcu);
5300 
5301 	gc = srcu_dereference(gdev->chip, &gdev->srcu);
5302 	if (!gc) {
5303 		seq_printf(s, "%s: (dangling chip)\n", dev_name(&gdev->dev));
5304 		return 0;
5305 	}
5306 
5307 	seq_printf(s, "%s: GPIOs %u-%u", dev_name(&gdev->dev), gdev->base,
5308 		   gdev->base + gdev->ngpio - 1);
5309 	parent = gc->parent;
5310 	if (parent)
5311 		seq_printf(s, ", parent: %s/%s",
5312 			   parent->bus ? parent->bus->name : "no-bus",
5313 			   dev_name(parent));
5314 	if (gc->label)
5315 		seq_printf(s, ", %s", gc->label);
5316 	if (gc->can_sleep)
5317 		seq_printf(s, ", can sleep");
5318 	seq_printf(s, ":\n");
5319 
5320 	if (gc->dbg_show)
5321 		gc->dbg_show(s, gc);
5322 	else
5323 		gpiolib_dbg_show(s, gdev);
5324 
5325 	return 0;
5326 }
5327 
5328 static const struct seq_operations gpiolib_sops = {
5329 	.start = gpiolib_seq_start,
5330 	.next = gpiolib_seq_next,
5331 	.stop = gpiolib_seq_stop,
5332 	.show = gpiolib_seq_show,
5333 };
5334 DEFINE_SEQ_ATTRIBUTE(gpiolib);
5335 
gpiolib_debugfs_init(void)5336 static int __init gpiolib_debugfs_init(void)
5337 {
5338 	/* /sys/kernel/debug/gpio */
5339 	debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
5340 	return 0;
5341 }
5342 subsys_initcall(gpiolib_debugfs_init);
5343 
5344 #endif	/* DEBUG_FS */
5345