xref: /linux/drivers/gpio/gpiolib.c (revision a93fbb002310ef04fce504dbf1510f6eb8265188)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/bitmap.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/interrupt.h>
7 #include <linux/irq.h>
8 #include <linux/spinlock.h>
9 #include <linux/list.h>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/debugfs.h>
13 #include <linux/seq_file.h>
14 #include <linux/gpio.h>
15 #include <linux/idr.h>
16 #include <linux/slab.h>
17 #include <linux/acpi.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/gpio/machine.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/fs.h>
22 #include <linux/compat.h>
23 #include <linux/file.h>
24 #include <uapi/linux/gpio.h>
25 
26 #include "gpiolib.h"
27 #include "gpiolib-of.h"
28 #include "gpiolib-acpi.h"
29 #include "gpiolib-cdev.h"
30 #include "gpiolib-sysfs.h"
31 
32 #define CREATE_TRACE_POINTS
33 #include <trace/events/gpio.h>
34 
35 /* Implementation infrastructure for GPIO interfaces.
36  *
37  * The GPIO programming interface allows for inlining speed-critical
38  * get/set operations for common cases, so that access to SOC-integrated
39  * GPIOs can sometimes cost only an instruction or two per bit.
40  */
41 
42 
43 /* When debugging, extend minimal trust to callers and platform code.
44  * Also emit diagnostic messages that may help initial bringup, when
45  * board setup or driver bugs are most common.
46  *
47  * Otherwise, minimize overhead in what may be bitbanging codepaths.
48  */
49 #ifdef	DEBUG
50 #define	extra_checks	1
51 #else
52 #define	extra_checks	0
53 #endif
54 
55 /* Device and char device-related information */
56 static DEFINE_IDA(gpio_ida);
57 static dev_t gpio_devt;
58 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
59 static int gpio_bus_match(struct device *dev, struct device_driver *drv);
60 static struct bus_type gpio_bus_type = {
61 	.name = "gpio",
62 	.match = gpio_bus_match,
63 };
64 
65 /*
66  * Number of GPIOs to use for the fast path in set array
67  */
68 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
69 
70 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
71  * While any GPIO is requested, its gpio_chip is not removable;
72  * each GPIO's "requested" flag serves as a lock and refcount.
73  */
74 DEFINE_SPINLOCK(gpio_lock);
75 
76 static DEFINE_MUTEX(gpio_lookup_lock);
77 static LIST_HEAD(gpio_lookup_list);
78 LIST_HEAD(gpio_devices);
79 
80 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
81 static LIST_HEAD(gpio_machine_hogs);
82 
83 static void gpiochip_free_hogs(struct gpio_chip *gc);
84 static int gpiochip_add_irqchip(struct gpio_chip *gc,
85 				struct lock_class_key *lock_key,
86 				struct lock_class_key *request_key);
87 static void gpiochip_irqchip_remove(struct gpio_chip *gc);
88 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
89 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
90 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
91 
92 static bool gpiolib_initialized;
93 
94 static inline void desc_set_label(struct gpio_desc *d, const char *label)
95 {
96 	d->label = label;
97 }
98 
99 /**
100  * gpio_to_desc - Convert a GPIO number to its descriptor
101  * @gpio: global GPIO number
102  *
103  * Returns:
104  * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
105  * with the given number exists in the system.
106  */
107 struct gpio_desc *gpio_to_desc(unsigned gpio)
108 {
109 	struct gpio_device *gdev;
110 	unsigned long flags;
111 
112 	spin_lock_irqsave(&gpio_lock, flags);
113 
114 	list_for_each_entry(gdev, &gpio_devices, list) {
115 		if (gdev->base <= gpio &&
116 		    gdev->base + gdev->ngpio > gpio) {
117 			spin_unlock_irqrestore(&gpio_lock, flags);
118 			return &gdev->descs[gpio - gdev->base];
119 		}
120 	}
121 
122 	spin_unlock_irqrestore(&gpio_lock, flags);
123 
124 	if (!gpio_is_valid(gpio))
125 		pr_warn("invalid GPIO %d\n", gpio);
126 
127 	return NULL;
128 }
129 EXPORT_SYMBOL_GPL(gpio_to_desc);
130 
131 /**
132  * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
133  *                     hardware number for this chip
134  * @gc: GPIO chip
135  * @hwnum: hardware number of the GPIO for this chip
136  *
137  * Returns:
138  * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
139  * in the given chip for the specified hardware number.
140  */
141 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
142 				    unsigned int hwnum)
143 {
144 	struct gpio_device *gdev = gc->gpiodev;
145 
146 	if (hwnum >= gdev->ngpio)
147 		return ERR_PTR(-EINVAL);
148 
149 	return &gdev->descs[hwnum];
150 }
151 EXPORT_SYMBOL_GPL(gpiochip_get_desc);
152 
153 /**
154  * desc_to_gpio - convert a GPIO descriptor to the integer namespace
155  * @desc: GPIO descriptor
156  *
157  * This should disappear in the future but is needed since we still
158  * use GPIO numbers for error messages and sysfs nodes.
159  *
160  * Returns:
161  * The global GPIO number for the GPIO specified by its descriptor.
162  */
163 int desc_to_gpio(const struct gpio_desc *desc)
164 {
165 	return desc->gdev->base + (desc - &desc->gdev->descs[0]);
166 }
167 EXPORT_SYMBOL_GPL(desc_to_gpio);
168 
169 
170 /**
171  * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
172  * @desc:	descriptor to return the chip of
173  */
174 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
175 {
176 	if (!desc || !desc->gdev)
177 		return NULL;
178 	return desc->gdev->chip;
179 }
180 EXPORT_SYMBOL_GPL(gpiod_to_chip);
181 
182 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
183 static int gpiochip_find_base(int ngpio)
184 {
185 	struct gpio_device *gdev;
186 	int base = ARCH_NR_GPIOS - ngpio;
187 
188 	list_for_each_entry_reverse(gdev, &gpio_devices, list) {
189 		/* found a free space? */
190 		if (gdev->base + gdev->ngpio <= base)
191 			break;
192 		else
193 			/* nope, check the space right before the chip */
194 			base = gdev->base - ngpio;
195 	}
196 
197 	if (gpio_is_valid(base)) {
198 		pr_debug("%s: found new base at %d\n", __func__, base);
199 		return base;
200 	} else {
201 		pr_err("%s: cannot find free range\n", __func__);
202 		return -ENOSPC;
203 	}
204 }
205 
206 /**
207  * gpiod_get_direction - return the current direction of a GPIO
208  * @desc:	GPIO to get the direction of
209  *
210  * Returns 0 for output, 1 for input, or an error code in case of error.
211  *
212  * This function may sleep if gpiod_cansleep() is true.
213  */
214 int gpiod_get_direction(struct gpio_desc *desc)
215 {
216 	struct gpio_chip *gc;
217 	unsigned int offset;
218 	int ret;
219 
220 	gc = gpiod_to_chip(desc);
221 	offset = gpio_chip_hwgpio(desc);
222 
223 	/*
224 	 * Open drain emulation using input mode may incorrectly report
225 	 * input here, fix that up.
226 	 */
227 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
228 	    test_bit(FLAG_IS_OUT, &desc->flags))
229 		return 0;
230 
231 	if (!gc->get_direction)
232 		return -ENOTSUPP;
233 
234 	ret = gc->get_direction(gc, offset);
235 	if (ret < 0)
236 		return ret;
237 
238 	/* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
239 	if (ret > 0)
240 		ret = 1;
241 
242 	assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
243 
244 	return ret;
245 }
246 EXPORT_SYMBOL_GPL(gpiod_get_direction);
247 
248 /*
249  * Add a new chip to the global chips list, keeping the list of chips sorted
250  * by range(means [base, base + ngpio - 1]) order.
251  *
252  * Return -EBUSY if the new chip overlaps with some other chip's integer
253  * space.
254  */
255 static int gpiodev_add_to_list(struct gpio_device *gdev)
256 {
257 	struct gpio_device *prev, *next;
258 
259 	if (list_empty(&gpio_devices)) {
260 		/* initial entry in list */
261 		list_add_tail(&gdev->list, &gpio_devices);
262 		return 0;
263 	}
264 
265 	next = list_first_entry(&gpio_devices, struct gpio_device, list);
266 	if (gdev->base + gdev->ngpio <= next->base) {
267 		/* add before first entry */
268 		list_add(&gdev->list, &gpio_devices);
269 		return 0;
270 	}
271 
272 	prev = list_last_entry(&gpio_devices, struct gpio_device, list);
273 	if (prev->base + prev->ngpio <= gdev->base) {
274 		/* add behind last entry */
275 		list_add_tail(&gdev->list, &gpio_devices);
276 		return 0;
277 	}
278 
279 	list_for_each_entry_safe(prev, next, &gpio_devices, list) {
280 		/* at the end of the list */
281 		if (&next->list == &gpio_devices)
282 			break;
283 
284 		/* add between prev and next */
285 		if (prev->base + prev->ngpio <= gdev->base
286 				&& gdev->base + gdev->ngpio <= next->base) {
287 			list_add(&gdev->list, &prev->list);
288 			return 0;
289 		}
290 	}
291 
292 	dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
293 	return -EBUSY;
294 }
295 
296 /*
297  * Convert a GPIO name to its descriptor
298  * Note that there is no guarantee that GPIO names are globally unique!
299  * Hence this function will return, if it exists, a reference to the first GPIO
300  * line found that matches the given name.
301  */
302 static struct gpio_desc *gpio_name_to_desc(const char * const name)
303 {
304 	struct gpio_device *gdev;
305 	unsigned long flags;
306 
307 	if (!name)
308 		return NULL;
309 
310 	spin_lock_irqsave(&gpio_lock, flags);
311 
312 	list_for_each_entry(gdev, &gpio_devices, list) {
313 		int i;
314 
315 		for (i = 0; i != gdev->ngpio; ++i) {
316 			struct gpio_desc *desc = &gdev->descs[i];
317 
318 			if (!desc->name)
319 				continue;
320 
321 			if (!strcmp(desc->name, name)) {
322 				spin_unlock_irqrestore(&gpio_lock, flags);
323 				return desc;
324 			}
325 		}
326 	}
327 
328 	spin_unlock_irqrestore(&gpio_lock, flags);
329 
330 	return NULL;
331 }
332 
333 /*
334  * Take the names from gc->names and assign them to their GPIO descriptors.
335  * Warn if a name is already used for a GPIO line on a different GPIO chip.
336  *
337  * Note that:
338  *   1. Non-unique names are still accepted,
339  *   2. Name collisions within the same GPIO chip are not reported.
340  */
341 static int gpiochip_set_desc_names(struct gpio_chip *gc)
342 {
343 	struct gpio_device *gdev = gc->gpiodev;
344 	int i;
345 
346 	/* First check all names if they are unique */
347 	for (i = 0; i != gc->ngpio; ++i) {
348 		struct gpio_desc *gpio;
349 
350 		gpio = gpio_name_to_desc(gc->names[i]);
351 		if (gpio)
352 			dev_warn(&gdev->dev,
353 				 "Detected name collision for GPIO name '%s'\n",
354 				 gc->names[i]);
355 	}
356 
357 	/* Then add all names to the GPIO descriptors */
358 	for (i = 0; i != gc->ngpio; ++i)
359 		gdev->descs[i].name = gc->names[i];
360 
361 	return 0;
362 }
363 
364 /*
365  * devprop_gpiochip_set_names - Set GPIO line names using device properties
366  * @chip: GPIO chip whose lines should be named, if possible
367  *
368  * Looks for device property "gpio-line-names" and if it exists assigns
369  * GPIO line names for the chip. The memory allocated for the assigned
370  * names belong to the underlying firmware node and should not be released
371  * by the caller.
372  */
373 static int devprop_gpiochip_set_names(struct gpio_chip *chip)
374 {
375 	struct gpio_device *gdev = chip->gpiodev;
376 	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
377 	const char **names;
378 	int ret, i;
379 	int count;
380 
381 	count = fwnode_property_string_array_count(fwnode, "gpio-line-names");
382 	if (count < 0)
383 		return 0;
384 
385 	/*
386 	 * When offset is set in the driver side we assume the driver internally
387 	 * is using more than one gpiochip per the same device. We have to stop
388 	 * setting friendly names if the specified ones with 'gpio-line-names'
389 	 * are less than the offset in the device itself. This means all the
390 	 * lines are not present for every single pin within all the internal
391 	 * gpiochips.
392 	 */
393 	if (count <= chip->offset) {
394 		dev_warn(&gdev->dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
395 			 count, chip->offset);
396 		return 0;
397 	}
398 
399 	names = kcalloc(count, sizeof(*names), GFP_KERNEL);
400 	if (!names)
401 		return -ENOMEM;
402 
403 	ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
404 						names, count);
405 	if (ret < 0) {
406 		dev_warn(&gdev->dev, "failed to read GPIO line names\n");
407 		kfree(names);
408 		return ret;
409 	}
410 
411 	/*
412 	 * When more that one gpiochip per device is used, 'count' can
413 	 * contain at most number gpiochips x chip->ngpio. We have to
414 	 * correctly distribute all defined lines taking into account
415 	 * chip->offset as starting point from where we will assign
416 	 * the names to pins from the 'names' array. Since property
417 	 * 'gpio-line-names' cannot contains gaps, we have to be sure
418 	 * we only assign those pins that really exists since chip->ngpio
419 	 * can be different of the chip->offset.
420 	 */
421 	count = (count > chip->offset) ? count - chip->offset : count;
422 	if (count > chip->ngpio)
423 		count = chip->ngpio;
424 
425 	for (i = 0; i < count; i++) {
426 		/*
427 		 * Allow overriding "fixed" names provided by the GPIO
428 		 * provider. The "fixed" names are more often than not
429 		 * generic and less informative than the names given in
430 		 * device properties.
431 		 */
432 		if (names[chip->offset + i] && names[chip->offset + i][0])
433 			gdev->descs[i].name = names[chip->offset + i];
434 	}
435 
436 	kfree(names);
437 
438 	return 0;
439 }
440 
441 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
442 {
443 	unsigned long *p;
444 
445 	p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
446 	if (!p)
447 		return NULL;
448 
449 	/* Assume by default all GPIOs are valid */
450 	bitmap_fill(p, gc->ngpio);
451 
452 	return p;
453 }
454 
455 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
456 {
457 	if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
458 		return 0;
459 
460 	gc->valid_mask = gpiochip_allocate_mask(gc);
461 	if (!gc->valid_mask)
462 		return -ENOMEM;
463 
464 	return 0;
465 }
466 
467 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
468 {
469 	if (gc->init_valid_mask)
470 		return gc->init_valid_mask(gc,
471 					   gc->valid_mask,
472 					   gc->ngpio);
473 
474 	return 0;
475 }
476 
477 static void gpiochip_free_valid_mask(struct gpio_chip *gc)
478 {
479 	bitmap_free(gc->valid_mask);
480 	gc->valid_mask = NULL;
481 }
482 
483 static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
484 {
485 	if (gc->add_pin_ranges)
486 		return gc->add_pin_ranges(gc);
487 
488 	return 0;
489 }
490 
491 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
492 				unsigned int offset)
493 {
494 	/* No mask means all valid */
495 	if (likely(!gc->valid_mask))
496 		return true;
497 	return test_bit(offset, gc->valid_mask);
498 }
499 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
500 
501 static void gpiodevice_release(struct device *dev)
502 {
503 	struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
504 	unsigned long flags;
505 
506 	spin_lock_irqsave(&gpio_lock, flags);
507 	list_del(&gdev->list);
508 	spin_unlock_irqrestore(&gpio_lock, flags);
509 
510 	ida_free(&gpio_ida, gdev->id);
511 	kfree_const(gdev->label);
512 	kfree(gdev->descs);
513 	kfree(gdev);
514 }
515 
516 #ifdef CONFIG_GPIO_CDEV
517 #define gcdev_register(gdev, devt)	gpiolib_cdev_register((gdev), (devt))
518 #define gcdev_unregister(gdev)		gpiolib_cdev_unregister((gdev))
519 #else
520 /*
521  * gpiolib_cdev_register() indirectly calls device_add(), which is still
522  * required even when cdev is not selected.
523  */
524 #define gcdev_register(gdev, devt)	device_add(&(gdev)->dev)
525 #define gcdev_unregister(gdev)		device_del(&(gdev)->dev)
526 #endif
527 
528 static int gpiochip_setup_dev(struct gpio_device *gdev)
529 {
530 	int ret;
531 
532 	ret = gcdev_register(gdev, gpio_devt);
533 	if (ret)
534 		return ret;
535 
536 	ret = gpiochip_sysfs_register(gdev);
537 	if (ret)
538 		goto err_remove_device;
539 
540 	/* From this point, the .release() function cleans up gpio_device */
541 	gdev->dev.release = gpiodevice_release;
542 	dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
543 		gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
544 
545 	return 0;
546 
547 err_remove_device:
548 	gcdev_unregister(gdev);
549 	return ret;
550 }
551 
552 static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
553 {
554 	struct gpio_desc *desc;
555 	int rv;
556 
557 	desc = gpiochip_get_desc(gc, hog->chip_hwnum);
558 	if (IS_ERR(desc)) {
559 		chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
560 			 PTR_ERR(desc));
561 		return;
562 	}
563 
564 	if (test_bit(FLAG_IS_HOGGED, &desc->flags))
565 		return;
566 
567 	rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
568 	if (rv)
569 		gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
570 			  __func__, gc->label, hog->chip_hwnum, rv);
571 }
572 
573 static void machine_gpiochip_add(struct gpio_chip *gc)
574 {
575 	struct gpiod_hog *hog;
576 
577 	mutex_lock(&gpio_machine_hogs_mutex);
578 
579 	list_for_each_entry(hog, &gpio_machine_hogs, list) {
580 		if (!strcmp(gc->label, hog->chip_label))
581 			gpiochip_machine_hog(gc, hog);
582 	}
583 
584 	mutex_unlock(&gpio_machine_hogs_mutex);
585 }
586 
587 static void gpiochip_setup_devs(void)
588 {
589 	struct gpio_device *gdev;
590 	int ret;
591 
592 	list_for_each_entry(gdev, &gpio_devices, list) {
593 		ret = gpiochip_setup_dev(gdev);
594 		if (ret)
595 			dev_err(&gdev->dev,
596 				"Failed to initialize gpio device (%d)\n", ret);
597 	}
598 }
599 
600 int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
601 			       struct lock_class_key *lock_key,
602 			       struct lock_class_key *request_key)
603 {
604 	struct fwnode_handle *fwnode = NULL;
605 	struct gpio_device *gdev;
606 	unsigned long flags;
607 	int base = gc->base;
608 	unsigned int i;
609 	int ret = 0;
610 	u32 ngpios;
611 
612 	if (gc->fwnode)
613 		fwnode = gc->fwnode;
614 	else if (gc->parent)
615 		fwnode = dev_fwnode(gc->parent);
616 
617 	/*
618 	 * First: allocate and populate the internal stat container, and
619 	 * set up the struct device.
620 	 */
621 	gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
622 	if (!gdev)
623 		return -ENOMEM;
624 	gdev->dev.bus = &gpio_bus_type;
625 	gdev->dev.parent = gc->parent;
626 	gdev->chip = gc;
627 	gc->gpiodev = gdev;
628 
629 	of_gpio_dev_init(gc, gdev);
630 	acpi_gpio_dev_init(gc, gdev);
631 
632 	/*
633 	 * Assign fwnode depending on the result of the previous calls,
634 	 * if none of them succeed, assign it to the parent's one.
635 	 */
636 	gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
637 
638 	gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
639 	if (gdev->id < 0) {
640 		ret = gdev->id;
641 		goto err_free_gdev;
642 	}
643 
644 	ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
645 	if (ret)
646 		goto err_free_ida;
647 
648 	device_initialize(&gdev->dev);
649 	if (gc->parent && gc->parent->driver)
650 		gdev->owner = gc->parent->driver->owner;
651 	else if (gc->owner)
652 		/* TODO: remove chip->owner */
653 		gdev->owner = gc->owner;
654 	else
655 		gdev->owner = THIS_MODULE;
656 
657 	gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
658 	if (!gdev->descs) {
659 		ret = -ENOMEM;
660 		goto err_free_dev_name;
661 	}
662 
663 	/*
664 	 * Try the device properties if the driver didn't supply the number
665 	 * of GPIO lines.
666 	 */
667 	if (gc->ngpio == 0) {
668 		ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);
669 		if (ret == -ENODATA)
670 			/*
671 			 * -ENODATA means that there is no property found and
672 			 * we want to issue the error message to the user.
673 			 * Besides that, we want to return different error code
674 			 * to state that supplied value is not valid.
675 			 */
676 			ngpios = 0;
677 		else if (ret)
678 			goto err_free_descs;
679 
680 		gc->ngpio = ngpios;
681 	}
682 
683 	if (gc->ngpio == 0) {
684 		chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
685 		ret = -EINVAL;
686 		goto err_free_descs;
687 	}
688 
689 	if (gc->ngpio > FASTPATH_NGPIO)
690 		chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
691 			  gc->ngpio, FASTPATH_NGPIO);
692 
693 	gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
694 	if (!gdev->label) {
695 		ret = -ENOMEM;
696 		goto err_free_descs;
697 	}
698 
699 	gdev->ngpio = gc->ngpio;
700 	gdev->data = data;
701 
702 	spin_lock_irqsave(&gpio_lock, flags);
703 
704 	/*
705 	 * TODO: this allocates a Linux GPIO number base in the global
706 	 * GPIO numberspace for this chip. In the long run we want to
707 	 * get *rid* of this numberspace and use only descriptors, but
708 	 * it may be a pipe dream. It will not happen before we get rid
709 	 * of the sysfs interface anyways.
710 	 */
711 	if (base < 0) {
712 		base = gpiochip_find_base(gc->ngpio);
713 		if (base < 0) {
714 			ret = base;
715 			spin_unlock_irqrestore(&gpio_lock, flags);
716 			goto err_free_label;
717 		}
718 		/*
719 		 * TODO: it should not be necessary to reflect the assigned
720 		 * base outside of the GPIO subsystem. Go over drivers and
721 		 * see if anyone makes use of this, else drop this and assign
722 		 * a poison instead.
723 		 */
724 		gc->base = base;
725 	}
726 	gdev->base = base;
727 
728 	ret = gpiodev_add_to_list(gdev);
729 	if (ret) {
730 		spin_unlock_irqrestore(&gpio_lock, flags);
731 		goto err_free_label;
732 	}
733 
734 	for (i = 0; i < gc->ngpio; i++)
735 		gdev->descs[i].gdev = gdev;
736 
737 	spin_unlock_irqrestore(&gpio_lock, flags);
738 
739 	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
740 
741 #ifdef CONFIG_PINCTRL
742 	INIT_LIST_HEAD(&gdev->pin_ranges);
743 #endif
744 
745 	if (gc->names) {
746 		ret = gpiochip_set_desc_names(gc);
747 		if (ret)
748 			goto err_remove_from_list;
749 	}
750 	ret = devprop_gpiochip_set_names(gc);
751 	if (ret)
752 		goto err_remove_from_list;
753 
754 	ret = gpiochip_alloc_valid_mask(gc);
755 	if (ret)
756 		goto err_remove_from_list;
757 
758 	ret = of_gpiochip_add(gc);
759 	if (ret)
760 		goto err_free_gpiochip_mask;
761 
762 	ret = gpiochip_init_valid_mask(gc);
763 	if (ret)
764 		goto err_remove_of_chip;
765 
766 	for (i = 0; i < gc->ngpio; i++) {
767 		struct gpio_desc *desc = &gdev->descs[i];
768 
769 		if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
770 			assign_bit(FLAG_IS_OUT,
771 				   &desc->flags, !gc->get_direction(gc, i));
772 		} else {
773 			assign_bit(FLAG_IS_OUT,
774 				   &desc->flags, !gc->direction_input);
775 		}
776 	}
777 
778 	ret = gpiochip_add_pin_ranges(gc);
779 	if (ret)
780 		goto err_remove_of_chip;
781 
782 	acpi_gpiochip_add(gc);
783 
784 	machine_gpiochip_add(gc);
785 
786 	ret = gpiochip_irqchip_init_valid_mask(gc);
787 	if (ret)
788 		goto err_remove_acpi_chip;
789 
790 	ret = gpiochip_irqchip_init_hw(gc);
791 	if (ret)
792 		goto err_remove_acpi_chip;
793 
794 	ret = gpiochip_add_irqchip(gc, lock_key, request_key);
795 	if (ret)
796 		goto err_remove_irqchip_mask;
797 
798 	/*
799 	 * By first adding the chardev, and then adding the device,
800 	 * we get a device node entry in sysfs under
801 	 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
802 	 * coldplug of device nodes and other udev business.
803 	 * We can do this only if gpiolib has been initialized.
804 	 * Otherwise, defer until later.
805 	 */
806 	if (gpiolib_initialized) {
807 		ret = gpiochip_setup_dev(gdev);
808 		if (ret)
809 			goto err_remove_irqchip;
810 	}
811 	return 0;
812 
813 err_remove_irqchip:
814 	gpiochip_irqchip_remove(gc);
815 err_remove_irqchip_mask:
816 	gpiochip_irqchip_free_valid_mask(gc);
817 err_remove_acpi_chip:
818 	acpi_gpiochip_remove(gc);
819 err_remove_of_chip:
820 	gpiochip_free_hogs(gc);
821 	of_gpiochip_remove(gc);
822 err_free_gpiochip_mask:
823 	gpiochip_remove_pin_ranges(gc);
824 	gpiochip_free_valid_mask(gc);
825 err_remove_from_list:
826 	spin_lock_irqsave(&gpio_lock, flags);
827 	list_del(&gdev->list);
828 	spin_unlock_irqrestore(&gpio_lock, flags);
829 err_free_label:
830 	kfree_const(gdev->label);
831 err_free_descs:
832 	kfree(gdev->descs);
833 err_free_dev_name:
834 	kfree(dev_name(&gdev->dev));
835 err_free_ida:
836 	ida_free(&gpio_ida, gdev->id);
837 err_free_gdev:
838 	/* failures here can mean systems won't boot... */
839 	if (ret != -EPROBE_DEFER) {
840 		pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
841 		       gdev->base, gdev->base + gdev->ngpio - 1,
842 		       gc->label ? : "generic", ret);
843 	}
844 	kfree(gdev);
845 	return ret;
846 }
847 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
848 
849 /**
850  * gpiochip_get_data() - get per-subdriver data for the chip
851  * @gc: GPIO chip
852  *
853  * Returns:
854  * The per-subdriver data for the chip.
855  */
856 void *gpiochip_get_data(struct gpio_chip *gc)
857 {
858 	return gc->gpiodev->data;
859 }
860 EXPORT_SYMBOL_GPL(gpiochip_get_data);
861 
862 /**
863  * gpiochip_remove() - unregister a gpio_chip
864  * @gc: the chip to unregister
865  *
866  * A gpio_chip with any GPIOs still requested may not be removed.
867  */
868 void gpiochip_remove(struct gpio_chip *gc)
869 {
870 	struct gpio_device *gdev = gc->gpiodev;
871 	unsigned long	flags;
872 	unsigned int	i;
873 
874 	/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
875 	gpiochip_sysfs_unregister(gdev);
876 	gpiochip_free_hogs(gc);
877 	/* Numb the device, cancelling all outstanding operations */
878 	gdev->chip = NULL;
879 	gpiochip_irqchip_remove(gc);
880 	acpi_gpiochip_remove(gc);
881 	of_gpiochip_remove(gc);
882 	gpiochip_remove_pin_ranges(gc);
883 	gpiochip_free_valid_mask(gc);
884 	/*
885 	 * We accept no more calls into the driver from this point, so
886 	 * NULL the driver data pointer
887 	 */
888 	gdev->data = NULL;
889 
890 	spin_lock_irqsave(&gpio_lock, flags);
891 	for (i = 0; i < gdev->ngpio; i++) {
892 		if (gpiochip_is_requested(gc, i))
893 			break;
894 	}
895 	spin_unlock_irqrestore(&gpio_lock, flags);
896 
897 	if (i != gdev->ngpio)
898 		dev_crit(&gdev->dev,
899 			 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
900 
901 	/*
902 	 * The gpiochip side puts its use of the device to rest here:
903 	 * if there are no userspace clients, the chardev and device will
904 	 * be removed, else it will be dangling until the last user is
905 	 * gone.
906 	 */
907 	gcdev_unregister(gdev);
908 	put_device(&gdev->dev);
909 }
910 EXPORT_SYMBOL_GPL(gpiochip_remove);
911 
912 /**
913  * gpiochip_find() - iterator for locating a specific gpio_chip
914  * @data: data to pass to match function
915  * @match: Callback function to check gpio_chip
916  *
917  * Similar to bus_find_device.  It returns a reference to a gpio_chip as
918  * determined by a user supplied @match callback.  The callback should return
919  * 0 if the device doesn't match and non-zero if it does.  If the callback is
920  * non-zero, this function will return to the caller and not iterate over any
921  * more gpio_chips.
922  */
923 struct gpio_chip *gpiochip_find(void *data,
924 				int (*match)(struct gpio_chip *gc,
925 					     void *data))
926 {
927 	struct gpio_device *gdev;
928 	struct gpio_chip *gc = NULL;
929 	unsigned long flags;
930 
931 	spin_lock_irqsave(&gpio_lock, flags);
932 	list_for_each_entry(gdev, &gpio_devices, list)
933 		if (gdev->chip && match(gdev->chip, data)) {
934 			gc = gdev->chip;
935 			break;
936 		}
937 
938 	spin_unlock_irqrestore(&gpio_lock, flags);
939 
940 	return gc;
941 }
942 EXPORT_SYMBOL_GPL(gpiochip_find);
943 
944 static int gpiochip_match_name(struct gpio_chip *gc, void *data)
945 {
946 	const char *name = data;
947 
948 	return !strcmp(gc->label, name);
949 }
950 
951 static struct gpio_chip *find_chip_by_name(const char *name)
952 {
953 	return gpiochip_find((void *)name, gpiochip_match_name);
954 }
955 
956 #ifdef CONFIG_GPIOLIB_IRQCHIP
957 
958 /*
959  * The following is irqchip helper code for gpiochips.
960  */
961 
962 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
963 {
964 	struct gpio_irq_chip *girq = &gc->irq;
965 
966 	if (!girq->init_hw)
967 		return 0;
968 
969 	return girq->init_hw(gc);
970 }
971 
972 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
973 {
974 	struct gpio_irq_chip *girq = &gc->irq;
975 
976 	if (!girq->init_valid_mask)
977 		return 0;
978 
979 	girq->valid_mask = gpiochip_allocate_mask(gc);
980 	if (!girq->valid_mask)
981 		return -ENOMEM;
982 
983 	girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
984 
985 	return 0;
986 }
987 
988 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
989 {
990 	bitmap_free(gc->irq.valid_mask);
991 	gc->irq.valid_mask = NULL;
992 }
993 
994 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
995 				unsigned int offset)
996 {
997 	if (!gpiochip_line_is_valid(gc, offset))
998 		return false;
999 	/* No mask means all valid */
1000 	if (likely(!gc->irq.valid_mask))
1001 		return true;
1002 	return test_bit(offset, gc->irq.valid_mask);
1003 }
1004 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1005 
1006 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1007 
1008 /**
1009  * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1010  * to a gpiochip
1011  * @gc: the gpiochip to set the irqchip hierarchical handler to
1012  * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1013  * will then percolate up to the parent
1014  */
1015 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1016 					      struct irq_chip *irqchip)
1017 {
1018 	/* DT will deal with mapping each IRQ as we go along */
1019 	if (is_of_node(gc->irq.fwnode))
1020 		return;
1021 
1022 	/*
1023 	 * This is for legacy and boardfile "irqchip" fwnodes: allocate
1024 	 * irqs upfront instead of dynamically since we don't have the
1025 	 * dynamic type of allocation that hardware description languages
1026 	 * provide. Once all GPIO drivers using board files are gone from
1027 	 * the kernel we can delete this code, but for a transitional period
1028 	 * it is necessary to keep this around.
1029 	 */
1030 	if (is_fwnode_irqchip(gc->irq.fwnode)) {
1031 		int i;
1032 		int ret;
1033 
1034 		for (i = 0; i < gc->ngpio; i++) {
1035 			struct irq_fwspec fwspec;
1036 			unsigned int parent_hwirq;
1037 			unsigned int parent_type;
1038 			struct gpio_irq_chip *girq = &gc->irq;
1039 
1040 			/*
1041 			 * We call the child to parent translation function
1042 			 * only to check if the child IRQ is valid or not.
1043 			 * Just pick the rising edge type here as that is what
1044 			 * we likely need to support.
1045 			 */
1046 			ret = girq->child_to_parent_hwirq(gc, i,
1047 							  IRQ_TYPE_EDGE_RISING,
1048 							  &parent_hwirq,
1049 							  &parent_type);
1050 			if (ret) {
1051 				chip_err(gc, "skip set-up on hwirq %d\n",
1052 					 i);
1053 				continue;
1054 			}
1055 
1056 			fwspec.fwnode = gc->irq.fwnode;
1057 			/* This is the hwirq for the GPIO line side of things */
1058 			fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1059 			/* Just pick something */
1060 			fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1061 			fwspec.param_count = 2;
1062 			ret = __irq_domain_alloc_irqs(gc->irq.domain,
1063 						      /* just pick something */
1064 						      -1,
1065 						      1,
1066 						      NUMA_NO_NODE,
1067 						      &fwspec,
1068 						      false,
1069 						      NULL);
1070 			if (ret < 0) {
1071 				chip_err(gc,
1072 					 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1073 					 i, parent_hwirq,
1074 					 ret);
1075 			}
1076 		}
1077 	}
1078 
1079 	chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1080 
1081 	return;
1082 }
1083 
1084 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1085 						   struct irq_fwspec *fwspec,
1086 						   unsigned long *hwirq,
1087 						   unsigned int *type)
1088 {
1089 	/* We support standard DT translation */
1090 	if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1091 		return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1092 	}
1093 
1094 	/* This is for board files and others not using DT */
1095 	if (is_fwnode_irqchip(fwspec->fwnode)) {
1096 		int ret;
1097 
1098 		ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1099 		if (ret)
1100 			return ret;
1101 		WARN_ON(*type == IRQ_TYPE_NONE);
1102 		return 0;
1103 	}
1104 	return -EINVAL;
1105 }
1106 
1107 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1108 					       unsigned int irq,
1109 					       unsigned int nr_irqs,
1110 					       void *data)
1111 {
1112 	struct gpio_chip *gc = d->host_data;
1113 	irq_hw_number_t hwirq;
1114 	unsigned int type = IRQ_TYPE_NONE;
1115 	struct irq_fwspec *fwspec = data;
1116 	void *parent_arg;
1117 	unsigned int parent_hwirq;
1118 	unsigned int parent_type;
1119 	struct gpio_irq_chip *girq = &gc->irq;
1120 	int ret;
1121 
1122 	/*
1123 	 * The nr_irqs parameter is always one except for PCI multi-MSI
1124 	 * so this should not happen.
1125 	 */
1126 	WARN_ON(nr_irqs != 1);
1127 
1128 	ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1129 	if (ret)
1130 		return ret;
1131 
1132 	chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq,  hwirq);
1133 
1134 	ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1135 					  &parent_hwirq, &parent_type);
1136 	if (ret) {
1137 		chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1138 		return ret;
1139 	}
1140 	chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
1141 
1142 	/*
1143 	 * We set handle_bad_irq because the .set_type() should
1144 	 * always be invoked and set the right type of handler.
1145 	 */
1146 	irq_domain_set_info(d,
1147 			    irq,
1148 			    hwirq,
1149 			    gc->irq.chip,
1150 			    gc,
1151 			    girq->handler,
1152 			    NULL, NULL);
1153 	irq_set_probe(irq);
1154 
1155 	/* This parent only handles asserted level IRQs */
1156 	parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
1157 	if (!parent_arg)
1158 		return -ENOMEM;
1159 
1160 	chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1161 		  irq, parent_hwirq);
1162 	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1163 	ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
1164 	/*
1165 	 * If the parent irqdomain is msi, the interrupts have already
1166 	 * been allocated, so the EEXIST is good.
1167 	 */
1168 	if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
1169 		ret = 0;
1170 	if (ret)
1171 		chip_err(gc,
1172 			 "failed to allocate parent hwirq %d for hwirq %lu\n",
1173 			 parent_hwirq, hwirq);
1174 
1175 	kfree(parent_arg);
1176 	return ret;
1177 }
1178 
1179 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
1180 						      unsigned int offset)
1181 {
1182 	return offset;
1183 }
1184 
1185 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1186 {
1187 	ops->activate = gpiochip_irq_domain_activate;
1188 	ops->deactivate = gpiochip_irq_domain_deactivate;
1189 	ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1190 	ops->free = irq_domain_free_irqs_common;
1191 
1192 	/*
1193 	 * We only allow overriding the translate() function for
1194 	 * hierarchical chips, and this should only be done if the user
1195 	 * really need something other than 1:1 translation.
1196 	 */
1197 	if (!ops->translate)
1198 		ops->translate = gpiochip_hierarchy_irq_domain_translate;
1199 }
1200 
1201 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1202 {
1203 	if (!gc->irq.child_to_parent_hwirq ||
1204 	    !gc->irq.fwnode) {
1205 		chip_err(gc, "missing irqdomain vital data\n");
1206 		return -EINVAL;
1207 	}
1208 
1209 	if (!gc->irq.child_offset_to_irq)
1210 		gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1211 
1212 	if (!gc->irq.populate_parent_alloc_arg)
1213 		gc->irq.populate_parent_alloc_arg =
1214 			gpiochip_populate_parent_fwspec_twocell;
1215 
1216 	gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1217 
1218 	gc->irq.domain = irq_domain_create_hierarchy(
1219 		gc->irq.parent_domain,
1220 		0,
1221 		gc->ngpio,
1222 		gc->irq.fwnode,
1223 		&gc->irq.child_irq_domain_ops,
1224 		gc);
1225 
1226 	if (!gc->irq.domain)
1227 		return -ENOMEM;
1228 
1229 	gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1230 
1231 	return 0;
1232 }
1233 
1234 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1235 {
1236 	return !!gc->irq.parent_domain;
1237 }
1238 
1239 void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
1240 					     unsigned int parent_hwirq,
1241 					     unsigned int parent_type)
1242 {
1243 	struct irq_fwspec *fwspec;
1244 
1245 	fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1246 	if (!fwspec)
1247 		return NULL;
1248 
1249 	fwspec->fwnode = gc->irq.parent_domain->fwnode;
1250 	fwspec->param_count = 2;
1251 	fwspec->param[0] = parent_hwirq;
1252 	fwspec->param[1] = parent_type;
1253 
1254 	return fwspec;
1255 }
1256 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
1257 
1258 void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
1259 					      unsigned int parent_hwirq,
1260 					      unsigned int parent_type)
1261 {
1262 	struct irq_fwspec *fwspec;
1263 
1264 	fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
1265 	if (!fwspec)
1266 		return NULL;
1267 
1268 	fwspec->fwnode = gc->irq.parent_domain->fwnode;
1269 	fwspec->param_count = 4;
1270 	fwspec->param[0] = 0;
1271 	fwspec->param[1] = parent_hwirq;
1272 	fwspec->param[2] = 0;
1273 	fwspec->param[3] = parent_type;
1274 
1275 	return fwspec;
1276 }
1277 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
1278 
1279 #else
1280 
1281 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1282 {
1283 	return -EINVAL;
1284 }
1285 
1286 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1287 {
1288 	return false;
1289 }
1290 
1291 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
1292 
1293 /**
1294  * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1295  * @d: the irqdomain used by this irqchip
1296  * @irq: the global irq number used by this GPIO irqchip irq
1297  * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1298  *
1299  * This function will set up the mapping for a certain IRQ line on a
1300  * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1301  * stored inside the gpiochip.
1302  */
1303 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1304 		     irq_hw_number_t hwirq)
1305 {
1306 	struct gpio_chip *gc = d->host_data;
1307 	int ret = 0;
1308 
1309 	if (!gpiochip_irqchip_irq_valid(gc, hwirq))
1310 		return -ENXIO;
1311 
1312 	irq_set_chip_data(irq, gc);
1313 	/*
1314 	 * This lock class tells lockdep that GPIO irqs are in a different
1315 	 * category than their parents, so it won't report false recursion.
1316 	 */
1317 	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1318 	irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
1319 	/* Chips that use nested thread handlers have them marked */
1320 	if (gc->irq.threaded)
1321 		irq_set_nested_thread(irq, 1);
1322 	irq_set_noprobe(irq);
1323 
1324 	if (gc->irq.num_parents == 1)
1325 		ret = irq_set_parent(irq, gc->irq.parents[0]);
1326 	else if (gc->irq.map)
1327 		ret = irq_set_parent(irq, gc->irq.map[hwirq]);
1328 
1329 	if (ret < 0)
1330 		return ret;
1331 
1332 	/*
1333 	 * No set-up of the hardware will happen if IRQ_TYPE_NONE
1334 	 * is passed as default type.
1335 	 */
1336 	if (gc->irq.default_type != IRQ_TYPE_NONE)
1337 		irq_set_irq_type(irq, gc->irq.default_type);
1338 
1339 	return 0;
1340 }
1341 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
1342 
1343 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1344 {
1345 	struct gpio_chip *gc = d->host_data;
1346 
1347 	if (gc->irq.threaded)
1348 		irq_set_nested_thread(irq, 0);
1349 	irq_set_chip_and_handler(irq, NULL, NULL);
1350 	irq_set_chip_data(irq, NULL);
1351 }
1352 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
1353 
1354 static const struct irq_domain_ops gpiochip_domain_ops = {
1355 	.map	= gpiochip_irq_map,
1356 	.unmap	= gpiochip_irq_unmap,
1357 	/* Virtually all GPIO irqchips are twocell:ed */
1358 	.xlate	= irq_domain_xlate_twocell,
1359 };
1360 
1361 /*
1362  * TODO: move these activate/deactivate in under the hierarchicial
1363  * irqchip implementation as static once SPMI and SSBI (all external
1364  * users) are phased over.
1365  */
1366 /**
1367  * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
1368  * @domain: The IRQ domain used by this IRQ chip
1369  * @data: Outermost irq_data associated with the IRQ
1370  * @reserve: If set, only reserve an interrupt vector instead of assigning one
1371  *
1372  * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
1373  * used as the activate function for the &struct irq_domain_ops. The host_data
1374  * for the IRQ domain must be the &struct gpio_chip.
1375  */
1376 int gpiochip_irq_domain_activate(struct irq_domain *domain,
1377 				 struct irq_data *data, bool reserve)
1378 {
1379 	struct gpio_chip *gc = domain->host_data;
1380 
1381 	return gpiochip_lock_as_irq(gc, data->hwirq);
1382 }
1383 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
1384 
1385 /**
1386  * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
1387  * @domain: The IRQ domain used by this IRQ chip
1388  * @data: Outermost irq_data associated with the IRQ
1389  *
1390  * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
1391  * be used as the deactivate function for the &struct irq_domain_ops. The
1392  * host_data for the IRQ domain must be the &struct gpio_chip.
1393  */
1394 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
1395 				    struct irq_data *data)
1396 {
1397 	struct gpio_chip *gc = domain->host_data;
1398 
1399 	return gpiochip_unlock_as_irq(gc, data->hwirq);
1400 }
1401 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
1402 
1403 static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
1404 {
1405 	struct irq_domain *domain = gc->irq.domain;
1406 
1407 	if (!gpiochip_irqchip_irq_valid(gc, offset))
1408 		return -ENXIO;
1409 
1410 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1411 	if (irq_domain_is_hierarchy(domain)) {
1412 		struct irq_fwspec spec;
1413 
1414 		spec.fwnode = domain->fwnode;
1415 		spec.param_count = 2;
1416 		spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
1417 		spec.param[1] = IRQ_TYPE_NONE;
1418 
1419 		return irq_create_fwspec_mapping(&spec);
1420 	}
1421 #endif
1422 
1423 	return irq_create_mapping(domain, offset);
1424 }
1425 
1426 static int gpiochip_irq_reqres(struct irq_data *d)
1427 {
1428 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1429 
1430 	return gpiochip_reqres_irq(gc, d->hwirq);
1431 }
1432 
1433 static void gpiochip_irq_relres(struct irq_data *d)
1434 {
1435 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1436 
1437 	gpiochip_relres_irq(gc, d->hwirq);
1438 }
1439 
1440 static void gpiochip_irq_mask(struct irq_data *d)
1441 {
1442 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1443 
1444 	if (gc->irq.irq_mask)
1445 		gc->irq.irq_mask(d);
1446 	gpiochip_disable_irq(gc, d->hwirq);
1447 }
1448 
1449 static void gpiochip_irq_unmask(struct irq_data *d)
1450 {
1451 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1452 
1453 	gpiochip_enable_irq(gc, d->hwirq);
1454 	if (gc->irq.irq_unmask)
1455 		gc->irq.irq_unmask(d);
1456 }
1457 
1458 static void gpiochip_irq_enable(struct irq_data *d)
1459 {
1460 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1461 
1462 	gpiochip_enable_irq(gc, d->hwirq);
1463 	gc->irq.irq_enable(d);
1464 }
1465 
1466 static void gpiochip_irq_disable(struct irq_data *d)
1467 {
1468 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1469 
1470 	gc->irq.irq_disable(d);
1471 	gpiochip_disable_irq(gc, d->hwirq);
1472 }
1473 
1474 static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
1475 {
1476 	struct irq_chip *irqchip = gc->irq.chip;
1477 
1478 	if (!irqchip->irq_request_resources &&
1479 	    !irqchip->irq_release_resources) {
1480 		irqchip->irq_request_resources = gpiochip_irq_reqres;
1481 		irqchip->irq_release_resources = gpiochip_irq_relres;
1482 	}
1483 	if (WARN_ON(gc->irq.irq_enable))
1484 		return;
1485 	/* Check if the irqchip already has this hook... */
1486 	if (irqchip->irq_enable == gpiochip_irq_enable ||
1487 		irqchip->irq_mask == gpiochip_irq_mask) {
1488 		/*
1489 		 * ...and if so, give a gentle warning that this is bad
1490 		 * practice.
1491 		 */
1492 		chip_info(gc,
1493 			  "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
1494 		return;
1495 	}
1496 
1497 	if (irqchip->irq_disable) {
1498 		gc->irq.irq_disable = irqchip->irq_disable;
1499 		irqchip->irq_disable = gpiochip_irq_disable;
1500 	} else {
1501 		gc->irq.irq_mask = irqchip->irq_mask;
1502 		irqchip->irq_mask = gpiochip_irq_mask;
1503 	}
1504 
1505 	if (irqchip->irq_enable) {
1506 		gc->irq.irq_enable = irqchip->irq_enable;
1507 		irqchip->irq_enable = gpiochip_irq_enable;
1508 	} else {
1509 		gc->irq.irq_unmask = irqchip->irq_unmask;
1510 		irqchip->irq_unmask = gpiochip_irq_unmask;
1511 	}
1512 }
1513 
1514 /**
1515  * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
1516  * @gc: the GPIO chip to add the IRQ chip to
1517  * @lock_key: lockdep class for IRQ lock
1518  * @request_key: lockdep class for IRQ request
1519  */
1520 static int gpiochip_add_irqchip(struct gpio_chip *gc,
1521 				struct lock_class_key *lock_key,
1522 				struct lock_class_key *request_key)
1523 {
1524 	struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
1525 	struct irq_chip *irqchip = gc->irq.chip;
1526 	unsigned int type;
1527 	unsigned int i;
1528 
1529 	if (!irqchip)
1530 		return 0;
1531 
1532 	if (gc->irq.parent_handler && gc->can_sleep) {
1533 		chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
1534 		return -EINVAL;
1535 	}
1536 
1537 	type = gc->irq.default_type;
1538 
1539 	/*
1540 	 * Specifying a default trigger is a terrible idea if DT or ACPI is
1541 	 * used to configure the interrupts, as you may end up with
1542 	 * conflicting triggers. Tell the user, and reset to NONE.
1543 	 */
1544 	if (WARN(fwnode && type != IRQ_TYPE_NONE,
1545 		 "%pfw: Ignoring %u default trigger\n", fwnode, type))
1546 		type = IRQ_TYPE_NONE;
1547 
1548 	if (gc->to_irq)
1549 		chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
1550 
1551 	gc->to_irq = gpiochip_to_irq;
1552 	gc->irq.default_type = type;
1553 	gc->irq.lock_key = lock_key;
1554 	gc->irq.request_key = request_key;
1555 
1556 	/* If a parent irqdomain is provided, let's build a hierarchy */
1557 	if (gpiochip_hierarchy_is_hierarchical(gc)) {
1558 		int ret = gpiochip_hierarchy_add_domain(gc);
1559 		if (ret)
1560 			return ret;
1561 	} else {
1562 		/* Some drivers provide custom irqdomain ops */
1563 		gc->irq.domain = irq_domain_create_simple(fwnode,
1564 			gc->ngpio,
1565 			gc->irq.first,
1566 			gc->irq.domain_ops ?: &gpiochip_domain_ops,
1567 			gc);
1568 		if (!gc->irq.domain)
1569 			return -EINVAL;
1570 	}
1571 
1572 	if (gc->irq.parent_handler) {
1573 		for (i = 0; i < gc->irq.num_parents; i++) {
1574 			void *data;
1575 
1576 			if (gc->irq.per_parent_data)
1577 				data = gc->irq.parent_handler_data_array[i];
1578 			else
1579 				data = gc->irq.parent_handler_data ?: gc;
1580 
1581 			/*
1582 			 * The parent IRQ chip is already using the chip_data
1583 			 * for this IRQ chip, so our callbacks simply use the
1584 			 * handler_data.
1585 			 */
1586 			irq_set_chained_handler_and_data(gc->irq.parents[i],
1587 							 gc->irq.parent_handler,
1588 							 data);
1589 		}
1590 	}
1591 
1592 	gpiochip_set_irq_hooks(gc);
1593 
1594 	acpi_gpiochip_request_interrupts(gc);
1595 
1596 	return 0;
1597 }
1598 
1599 /**
1600  * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1601  * @gc: the gpiochip to remove the irqchip from
1602  *
1603  * This is called only from gpiochip_remove()
1604  */
1605 static void gpiochip_irqchip_remove(struct gpio_chip *gc)
1606 {
1607 	struct irq_chip *irqchip = gc->irq.chip;
1608 	unsigned int offset;
1609 
1610 	acpi_gpiochip_free_interrupts(gc);
1611 
1612 	if (irqchip && gc->irq.parent_handler) {
1613 		struct gpio_irq_chip *irq = &gc->irq;
1614 		unsigned int i;
1615 
1616 		for (i = 0; i < irq->num_parents; i++)
1617 			irq_set_chained_handler_and_data(irq->parents[i],
1618 							 NULL, NULL);
1619 	}
1620 
1621 	/* Remove all IRQ mappings and delete the domain */
1622 	if (gc->irq.domain) {
1623 		unsigned int irq;
1624 
1625 		for (offset = 0; offset < gc->ngpio; offset++) {
1626 			if (!gpiochip_irqchip_irq_valid(gc, offset))
1627 				continue;
1628 
1629 			irq = irq_find_mapping(gc->irq.domain, offset);
1630 			irq_dispose_mapping(irq);
1631 		}
1632 
1633 		irq_domain_remove(gc->irq.domain);
1634 	}
1635 
1636 	if (irqchip) {
1637 		if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
1638 			irqchip->irq_request_resources = NULL;
1639 			irqchip->irq_release_resources = NULL;
1640 		}
1641 		if (irqchip->irq_enable == gpiochip_irq_enable) {
1642 			irqchip->irq_enable = gc->irq.irq_enable;
1643 			irqchip->irq_disable = gc->irq.irq_disable;
1644 		}
1645 	}
1646 	gc->irq.irq_enable = NULL;
1647 	gc->irq.irq_disable = NULL;
1648 	gc->irq.chip = NULL;
1649 
1650 	gpiochip_irqchip_free_valid_mask(gc);
1651 }
1652 
1653 /**
1654  * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
1655  * @gc: the gpiochip to add the irqchip to
1656  * @domain: the irqdomain to add to the gpiochip
1657  *
1658  * This function adds an IRQ domain to the gpiochip.
1659  */
1660 int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
1661 				struct irq_domain *domain)
1662 {
1663 	if (!domain)
1664 		return -EINVAL;
1665 
1666 	gc->to_irq = gpiochip_to_irq;
1667 	gc->irq.domain = domain;
1668 
1669 	return 0;
1670 }
1671 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
1672 
1673 #else /* CONFIG_GPIOLIB_IRQCHIP */
1674 
1675 static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
1676 				       struct lock_class_key *lock_key,
1677 				       struct lock_class_key *request_key)
1678 {
1679 	return 0;
1680 }
1681 static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
1682 
1683 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1684 {
1685 	return 0;
1686 }
1687 
1688 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1689 {
1690 	return 0;
1691 }
1692 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
1693 { }
1694 
1695 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1696 
1697 /**
1698  * gpiochip_generic_request() - request the gpio function for a pin
1699  * @gc: the gpiochip owning the GPIO
1700  * @offset: the offset of the GPIO to request for GPIO function
1701  */
1702 int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
1703 {
1704 #ifdef CONFIG_PINCTRL
1705 	if (list_empty(&gc->gpiodev->pin_ranges))
1706 		return 0;
1707 #endif
1708 
1709 	return pinctrl_gpio_request(gc->gpiodev->base + offset);
1710 }
1711 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1712 
1713 /**
1714  * gpiochip_generic_free() - free the gpio function from a pin
1715  * @gc: the gpiochip to request the gpio function for
1716  * @offset: the offset of the GPIO to free from GPIO function
1717  */
1718 void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
1719 {
1720 #ifdef CONFIG_PINCTRL
1721 	if (list_empty(&gc->gpiodev->pin_ranges))
1722 		return;
1723 #endif
1724 
1725 	pinctrl_gpio_free(gc->gpiodev->base + offset);
1726 }
1727 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1728 
1729 /**
1730  * gpiochip_generic_config() - apply configuration for a pin
1731  * @gc: the gpiochip owning the GPIO
1732  * @offset: the offset of the GPIO to apply the configuration
1733  * @config: the configuration to be applied
1734  */
1735 int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
1736 			    unsigned long config)
1737 {
1738 	return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
1739 }
1740 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
1741 
1742 #ifdef CONFIG_PINCTRL
1743 
1744 /**
1745  * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1746  * @gc: the gpiochip to add the range for
1747  * @pctldev: the pin controller to map to
1748  * @gpio_offset: the start offset in the current gpio_chip number space
1749  * @pin_group: name of the pin group inside the pin controller
1750  *
1751  * Calling this function directly from a DeviceTree-supported
1752  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1753  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1754  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1755  */
1756 int gpiochip_add_pingroup_range(struct gpio_chip *gc,
1757 			struct pinctrl_dev *pctldev,
1758 			unsigned int gpio_offset, const char *pin_group)
1759 {
1760 	struct gpio_pin_range *pin_range;
1761 	struct gpio_device *gdev = gc->gpiodev;
1762 	int ret;
1763 
1764 	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1765 	if (!pin_range) {
1766 		chip_err(gc, "failed to allocate pin ranges\n");
1767 		return -ENOMEM;
1768 	}
1769 
1770 	/* Use local offset as range ID */
1771 	pin_range->range.id = gpio_offset;
1772 	pin_range->range.gc = gc;
1773 	pin_range->range.name = gc->label;
1774 	pin_range->range.base = gdev->base + gpio_offset;
1775 	pin_range->pctldev = pctldev;
1776 
1777 	ret = pinctrl_get_group_pins(pctldev, pin_group,
1778 					&pin_range->range.pins,
1779 					&pin_range->range.npins);
1780 	if (ret < 0) {
1781 		kfree(pin_range);
1782 		return ret;
1783 	}
1784 
1785 	pinctrl_add_gpio_range(pctldev, &pin_range->range);
1786 
1787 	chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1788 		 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1789 		 pinctrl_dev_get_devname(pctldev), pin_group);
1790 
1791 	list_add_tail(&pin_range->node, &gdev->pin_ranges);
1792 
1793 	return 0;
1794 }
1795 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1796 
1797 /**
1798  * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1799  * @gc: the gpiochip to add the range for
1800  * @pinctl_name: the dev_name() of the pin controller to map to
1801  * @gpio_offset: the start offset in the current gpio_chip number space
1802  * @pin_offset: the start offset in the pin controller number space
1803  * @npins: the number of pins from the offset of each pin space (GPIO and
1804  *	pin controller) to accumulate in this range
1805  *
1806  * Returns:
1807  * 0 on success, or a negative error-code on failure.
1808  *
1809  * Calling this function directly from a DeviceTree-supported
1810  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
1811  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
1812  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
1813  */
1814 int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
1815 			   unsigned int gpio_offset, unsigned int pin_offset,
1816 			   unsigned int npins)
1817 {
1818 	struct gpio_pin_range *pin_range;
1819 	struct gpio_device *gdev = gc->gpiodev;
1820 	int ret;
1821 
1822 	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1823 	if (!pin_range) {
1824 		chip_err(gc, "failed to allocate pin ranges\n");
1825 		return -ENOMEM;
1826 	}
1827 
1828 	/* Use local offset as range ID */
1829 	pin_range->range.id = gpio_offset;
1830 	pin_range->range.gc = gc;
1831 	pin_range->range.name = gc->label;
1832 	pin_range->range.base = gdev->base + gpio_offset;
1833 	pin_range->range.pin_base = pin_offset;
1834 	pin_range->range.npins = npins;
1835 	pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1836 			&pin_range->range);
1837 	if (IS_ERR(pin_range->pctldev)) {
1838 		ret = PTR_ERR(pin_range->pctldev);
1839 		chip_err(gc, "could not create pin range\n");
1840 		kfree(pin_range);
1841 		return ret;
1842 	}
1843 	chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1844 		 gpio_offset, gpio_offset + npins - 1,
1845 		 pinctl_name,
1846 		 pin_offset, pin_offset + npins - 1);
1847 
1848 	list_add_tail(&pin_range->node, &gdev->pin_ranges);
1849 
1850 	return 0;
1851 }
1852 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1853 
1854 /**
1855  * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1856  * @gc: the chip to remove all the mappings for
1857  */
1858 void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
1859 {
1860 	struct gpio_pin_range *pin_range, *tmp;
1861 	struct gpio_device *gdev = gc->gpiodev;
1862 
1863 	list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1864 		list_del(&pin_range->node);
1865 		pinctrl_remove_gpio_range(pin_range->pctldev,
1866 				&pin_range->range);
1867 		kfree(pin_range);
1868 	}
1869 }
1870 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1871 
1872 #endif /* CONFIG_PINCTRL */
1873 
1874 /* These "optional" allocation calls help prevent drivers from stomping
1875  * on each other, and help provide better diagnostics in debugfs.
1876  * They're called even less than the "set direction" calls.
1877  */
1878 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
1879 {
1880 	struct gpio_chip	*gc = desc->gdev->chip;
1881 	int			ret;
1882 	unsigned long		flags;
1883 	unsigned		offset;
1884 
1885 	if (label) {
1886 		label = kstrdup_const(label, GFP_KERNEL);
1887 		if (!label)
1888 			return -ENOMEM;
1889 	}
1890 
1891 	spin_lock_irqsave(&gpio_lock, flags);
1892 
1893 	/* NOTE:  gpio_request() can be called in early boot,
1894 	 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1895 	 */
1896 
1897 	if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1898 		desc_set_label(desc, label ? : "?");
1899 	} else {
1900 		ret = -EBUSY;
1901 		goto out_free_unlock;
1902 	}
1903 
1904 	if (gc->request) {
1905 		/* gc->request may sleep */
1906 		spin_unlock_irqrestore(&gpio_lock, flags);
1907 		offset = gpio_chip_hwgpio(desc);
1908 		if (gpiochip_line_is_valid(gc, offset))
1909 			ret = gc->request(gc, offset);
1910 		else
1911 			ret = -EINVAL;
1912 		spin_lock_irqsave(&gpio_lock, flags);
1913 
1914 		if (ret) {
1915 			desc_set_label(desc, NULL);
1916 			clear_bit(FLAG_REQUESTED, &desc->flags);
1917 			goto out_free_unlock;
1918 		}
1919 	}
1920 	if (gc->get_direction) {
1921 		/* gc->get_direction may sleep */
1922 		spin_unlock_irqrestore(&gpio_lock, flags);
1923 		gpiod_get_direction(desc);
1924 		spin_lock_irqsave(&gpio_lock, flags);
1925 	}
1926 	spin_unlock_irqrestore(&gpio_lock, flags);
1927 	return 0;
1928 
1929 out_free_unlock:
1930 	spin_unlock_irqrestore(&gpio_lock, flags);
1931 	kfree_const(label);
1932 	return ret;
1933 }
1934 
1935 /*
1936  * This descriptor validation needs to be inserted verbatim into each
1937  * function taking a descriptor, so we need to use a preprocessor
1938  * macro to avoid endless duplication. If the desc is NULL it is an
1939  * optional GPIO and calls should just bail out.
1940  */
1941 static int validate_desc(const struct gpio_desc *desc, const char *func)
1942 {
1943 	if (!desc)
1944 		return 0;
1945 	if (IS_ERR(desc)) {
1946 		pr_warn("%s: invalid GPIO (errorpointer)\n", func);
1947 		return PTR_ERR(desc);
1948 	}
1949 	if (!desc->gdev) {
1950 		pr_warn("%s: invalid GPIO (no device)\n", func);
1951 		return -EINVAL;
1952 	}
1953 	if (!desc->gdev->chip) {
1954 		dev_warn(&desc->gdev->dev,
1955 			 "%s: backing chip is gone\n", func);
1956 		return 0;
1957 	}
1958 	return 1;
1959 }
1960 
1961 #define VALIDATE_DESC(desc) do { \
1962 	int __valid = validate_desc(desc, __func__); \
1963 	if (__valid <= 0) \
1964 		return __valid; \
1965 	} while (0)
1966 
1967 #define VALIDATE_DESC_VOID(desc) do { \
1968 	int __valid = validate_desc(desc, __func__); \
1969 	if (__valid <= 0) \
1970 		return; \
1971 	} while (0)
1972 
1973 int gpiod_request(struct gpio_desc *desc, const char *label)
1974 {
1975 	int ret = -EPROBE_DEFER;
1976 	struct gpio_device *gdev;
1977 
1978 	VALIDATE_DESC(desc);
1979 	gdev = desc->gdev;
1980 
1981 	if (try_module_get(gdev->owner)) {
1982 		ret = gpiod_request_commit(desc, label);
1983 		if (ret)
1984 			module_put(gdev->owner);
1985 		else
1986 			get_device(&gdev->dev);
1987 	}
1988 
1989 	if (ret)
1990 		gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
1991 
1992 	return ret;
1993 }
1994 
1995 static bool gpiod_free_commit(struct gpio_desc *desc)
1996 {
1997 	bool			ret = false;
1998 	unsigned long		flags;
1999 	struct gpio_chip	*gc;
2000 
2001 	might_sleep();
2002 
2003 	gpiod_unexport(desc);
2004 
2005 	spin_lock_irqsave(&gpio_lock, flags);
2006 
2007 	gc = desc->gdev->chip;
2008 	if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
2009 		if (gc->free) {
2010 			spin_unlock_irqrestore(&gpio_lock, flags);
2011 			might_sleep_if(gc->can_sleep);
2012 			gc->free(gc, gpio_chip_hwgpio(desc));
2013 			spin_lock_irqsave(&gpio_lock, flags);
2014 		}
2015 		kfree_const(desc->label);
2016 		desc_set_label(desc, NULL);
2017 		clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2018 		clear_bit(FLAG_REQUESTED, &desc->flags);
2019 		clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2020 		clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2021 		clear_bit(FLAG_PULL_UP, &desc->flags);
2022 		clear_bit(FLAG_PULL_DOWN, &desc->flags);
2023 		clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
2024 		clear_bit(FLAG_EDGE_RISING, &desc->flags);
2025 		clear_bit(FLAG_EDGE_FALLING, &desc->flags);
2026 		clear_bit(FLAG_IS_HOGGED, &desc->flags);
2027 #ifdef CONFIG_OF_DYNAMIC
2028 		desc->hog = NULL;
2029 #endif
2030 #ifdef CONFIG_GPIO_CDEV
2031 		WRITE_ONCE(desc->debounce_period_us, 0);
2032 #endif
2033 		ret = true;
2034 	}
2035 
2036 	spin_unlock_irqrestore(&gpio_lock, flags);
2037 	blocking_notifier_call_chain(&desc->gdev->notifier,
2038 				     GPIOLINE_CHANGED_RELEASED, desc);
2039 
2040 	return ret;
2041 }
2042 
2043 void gpiod_free(struct gpio_desc *desc)
2044 {
2045 	if (desc && desc->gdev && gpiod_free_commit(desc)) {
2046 		module_put(desc->gdev->owner);
2047 		put_device(&desc->gdev->dev);
2048 	} else {
2049 		WARN_ON(extra_checks);
2050 	}
2051 }
2052 
2053 /**
2054  * gpiochip_is_requested - return string iff signal was requested
2055  * @gc: controller managing the signal
2056  * @offset: of signal within controller's 0..(ngpio - 1) range
2057  *
2058  * Returns NULL if the GPIO is not currently requested, else a string.
2059  * The string returned is the label passed to gpio_request(); if none has been
2060  * passed it is a meaningless, non-NULL constant.
2061  *
2062  * This function is for use by GPIO controller drivers.  The label can
2063  * help with diagnostics, and knowing that the signal is used as a GPIO
2064  * can help avoid accidentally multiplexing it to another controller.
2065  */
2066 const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
2067 {
2068 	struct gpio_desc *desc;
2069 
2070 	desc = gpiochip_get_desc(gc, offset);
2071 	if (IS_ERR(desc))
2072 		return NULL;
2073 
2074 	if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2075 		return NULL;
2076 	return desc->label;
2077 }
2078 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2079 
2080 /**
2081  * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2082  * @gc: GPIO chip
2083  * @hwnum: hardware number of the GPIO for which to request the descriptor
2084  * @label: label for the GPIO
2085  * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2086  * specify things like line inversion semantics with the machine flags
2087  * such as GPIO_OUT_LOW
2088  * @dflags: descriptor request flags for this GPIO or 0 if default, this
2089  * can be used to specify consumer semantics such as open drain
2090  *
2091  * Function allows GPIO chip drivers to request and use their own GPIO
2092  * descriptors via gpiolib API. Difference to gpiod_request() is that this
2093  * function will not increase reference count of the GPIO chip module. This
2094  * allows the GPIO chip module to be unloaded as needed (we assume that the
2095  * GPIO chip driver handles freeing the GPIOs it has requested).
2096  *
2097  * Returns:
2098  * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2099  * code on failure.
2100  */
2101 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
2102 					    unsigned int hwnum,
2103 					    const char *label,
2104 					    enum gpio_lookup_flags lflags,
2105 					    enum gpiod_flags dflags)
2106 {
2107 	struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
2108 	int ret;
2109 
2110 	if (IS_ERR(desc)) {
2111 		chip_err(gc, "failed to get GPIO descriptor\n");
2112 		return desc;
2113 	}
2114 
2115 	ret = gpiod_request_commit(desc, label);
2116 	if (ret < 0)
2117 		return ERR_PTR(ret);
2118 
2119 	ret = gpiod_configure_flags(desc, label, lflags, dflags);
2120 	if (ret) {
2121 		chip_err(gc, "setup of own GPIO %s failed\n", label);
2122 		gpiod_free_commit(desc);
2123 		return ERR_PTR(ret);
2124 	}
2125 
2126 	return desc;
2127 }
2128 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2129 
2130 /**
2131  * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2132  * @desc: GPIO descriptor to free
2133  *
2134  * Function frees the given GPIO requested previously with
2135  * gpiochip_request_own_desc().
2136  */
2137 void gpiochip_free_own_desc(struct gpio_desc *desc)
2138 {
2139 	if (desc)
2140 		gpiod_free_commit(desc);
2141 }
2142 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2143 
2144 /*
2145  * Drivers MUST set GPIO direction before making get/set calls.  In
2146  * some cases this is done in early boot, before IRQs are enabled.
2147  *
2148  * As a rule these aren't called more than once (except for drivers
2149  * using the open-drain emulation idiom) so these are natural places
2150  * to accumulate extra debugging checks.  Note that we can't (yet)
2151  * rely on gpio_request() having been called beforehand.
2152  */
2153 
2154 static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
2155 			      unsigned long config)
2156 {
2157 	if (!gc->set_config)
2158 		return -ENOTSUPP;
2159 
2160 	return gc->set_config(gc, offset, config);
2161 }
2162 
2163 static int gpio_set_config_with_argument(struct gpio_desc *desc,
2164 					 enum pin_config_param mode,
2165 					 u32 argument)
2166 {
2167 	struct gpio_chip *gc = desc->gdev->chip;
2168 	unsigned long config;
2169 
2170 	config = pinconf_to_config_packed(mode, argument);
2171 	return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2172 }
2173 
2174 static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
2175 						  enum pin_config_param mode,
2176 						  u32 argument)
2177 {
2178 	struct device *dev = &desc->gdev->dev;
2179 	int gpio = gpio_chip_hwgpio(desc);
2180 	int ret;
2181 
2182 	ret = gpio_set_config_with_argument(desc, mode, argument);
2183 	if (ret != -ENOTSUPP)
2184 		return ret;
2185 
2186 	switch (mode) {
2187 	case PIN_CONFIG_PERSIST_STATE:
2188 		dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
2189 		break;
2190 	default:
2191 		break;
2192 	}
2193 
2194 	return 0;
2195 }
2196 
2197 static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
2198 {
2199 	return gpio_set_config_with_argument(desc, mode, 0);
2200 }
2201 
2202 static int gpio_set_bias(struct gpio_desc *desc)
2203 {
2204 	enum pin_config_param bias;
2205 	unsigned int arg;
2206 
2207 	if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
2208 		bias = PIN_CONFIG_BIAS_DISABLE;
2209 	else if (test_bit(FLAG_PULL_UP, &desc->flags))
2210 		bias = PIN_CONFIG_BIAS_PULL_UP;
2211 	else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
2212 		bias = PIN_CONFIG_BIAS_PULL_DOWN;
2213 	else
2214 		return 0;
2215 
2216 	switch (bias) {
2217 	case PIN_CONFIG_BIAS_PULL_DOWN:
2218 	case PIN_CONFIG_BIAS_PULL_UP:
2219 		arg = 1;
2220 		break;
2221 
2222 	default:
2223 		arg = 0;
2224 		break;
2225 	}
2226 
2227 	return gpio_set_config_with_argument_optional(desc, bias, arg);
2228 }
2229 
2230 /**
2231  * gpio_set_debounce_timeout() - Set debounce timeout
2232  * @desc:	GPIO descriptor to set the debounce timeout
2233  * @debounce:	Debounce timeout in microseconds
2234  *
2235  * The function calls the certain GPIO driver to set debounce timeout
2236  * in the hardware.
2237  *
2238  * Returns 0 on success, or negative error code otherwise.
2239  */
2240 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
2241 {
2242 	return gpio_set_config_with_argument_optional(desc,
2243 						      PIN_CONFIG_INPUT_DEBOUNCE,
2244 						      debounce);
2245 }
2246 
2247 /**
2248  * gpiod_direction_input - set the GPIO direction to input
2249  * @desc:	GPIO to set to input
2250  *
2251  * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2252  * be called safely on it.
2253  *
2254  * Return 0 in case of success, else an error code.
2255  */
2256 int gpiod_direction_input(struct gpio_desc *desc)
2257 {
2258 	struct gpio_chip	*gc;
2259 	int			ret = 0;
2260 
2261 	VALIDATE_DESC(desc);
2262 	gc = desc->gdev->chip;
2263 
2264 	/*
2265 	 * It is legal to have no .get() and .direction_input() specified if
2266 	 * the chip is output-only, but you can't specify .direction_input()
2267 	 * and not support the .get() operation, that doesn't make sense.
2268 	 */
2269 	if (!gc->get && gc->direction_input) {
2270 		gpiod_warn(desc,
2271 			   "%s: missing get() but have direction_input()\n",
2272 			   __func__);
2273 		return -EIO;
2274 	}
2275 
2276 	/*
2277 	 * If we have a .direction_input() callback, things are simple,
2278 	 * just call it. Else we are some input-only chip so try to check the
2279 	 * direction (if .get_direction() is supported) else we silently
2280 	 * assume we are in input mode after this.
2281 	 */
2282 	if (gc->direction_input) {
2283 		ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
2284 	} else if (gc->get_direction &&
2285 		  (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
2286 		gpiod_warn(desc,
2287 			   "%s: missing direction_input() operation and line is output\n",
2288 			   __func__);
2289 		return -EIO;
2290 	}
2291 	if (ret == 0) {
2292 		clear_bit(FLAG_IS_OUT, &desc->flags);
2293 		ret = gpio_set_bias(desc);
2294 	}
2295 
2296 	trace_gpio_direction(desc_to_gpio(desc), 1, ret);
2297 
2298 	return ret;
2299 }
2300 EXPORT_SYMBOL_GPL(gpiod_direction_input);
2301 
2302 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
2303 {
2304 	struct gpio_chip *gc = desc->gdev->chip;
2305 	int val = !!value;
2306 	int ret = 0;
2307 
2308 	/*
2309 	 * It's OK not to specify .direction_output() if the gpiochip is
2310 	 * output-only, but if there is then not even a .set() operation it
2311 	 * is pretty tricky to drive the output line.
2312 	 */
2313 	if (!gc->set && !gc->direction_output) {
2314 		gpiod_warn(desc,
2315 			   "%s: missing set() and direction_output() operations\n",
2316 			   __func__);
2317 		return -EIO;
2318 	}
2319 
2320 	if (gc->direction_output) {
2321 		ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
2322 	} else {
2323 		/* Check that we are in output mode if we can */
2324 		if (gc->get_direction &&
2325 		    gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
2326 			gpiod_warn(desc,
2327 				"%s: missing direction_output() operation\n",
2328 				__func__);
2329 			return -EIO;
2330 		}
2331 		/*
2332 		 * If we can't actively set the direction, we are some
2333 		 * output-only chip, so just drive the output as desired.
2334 		 */
2335 		gc->set(gc, gpio_chip_hwgpio(desc), val);
2336 	}
2337 
2338 	if (!ret)
2339 		set_bit(FLAG_IS_OUT, &desc->flags);
2340 	trace_gpio_value(desc_to_gpio(desc), 0, val);
2341 	trace_gpio_direction(desc_to_gpio(desc), 0, ret);
2342 	return ret;
2343 }
2344 
2345 /**
2346  * gpiod_direction_output_raw - set the GPIO direction to output
2347  * @desc:	GPIO to set to output
2348  * @value:	initial output value of the GPIO
2349  *
2350  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2351  * be called safely on it. The initial value of the output must be specified
2352  * as raw value on the physical line without regard for the ACTIVE_LOW status.
2353  *
2354  * Return 0 in case of success, else an error code.
2355  */
2356 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2357 {
2358 	VALIDATE_DESC(desc);
2359 	return gpiod_direction_output_raw_commit(desc, value);
2360 }
2361 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2362 
2363 /**
2364  * gpiod_direction_output - set the GPIO direction to output
2365  * @desc:	GPIO to set to output
2366  * @value:	initial output value of the GPIO
2367  *
2368  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2369  * be called safely on it. The initial value of the output must be specified
2370  * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2371  * account.
2372  *
2373  * Return 0 in case of success, else an error code.
2374  */
2375 int gpiod_direction_output(struct gpio_desc *desc, int value)
2376 {
2377 	int ret;
2378 
2379 	VALIDATE_DESC(desc);
2380 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2381 		value = !value;
2382 	else
2383 		value = !!value;
2384 
2385 	/* GPIOs used for enabled IRQs shall not be set as output */
2386 	if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
2387 	    test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
2388 		gpiod_err(desc,
2389 			  "%s: tried to set a GPIO tied to an IRQ as output\n",
2390 			  __func__);
2391 		return -EIO;
2392 	}
2393 
2394 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
2395 		/* First see if we can enable open drain in hardware */
2396 		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
2397 		if (!ret)
2398 			goto set_output_value;
2399 		/* Emulate open drain by not actively driving the line high */
2400 		if (value) {
2401 			ret = gpiod_direction_input(desc);
2402 			goto set_output_flag;
2403 		}
2404 	}
2405 	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
2406 		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
2407 		if (!ret)
2408 			goto set_output_value;
2409 		/* Emulate open source by not actively driving the line low */
2410 		if (!value) {
2411 			ret = gpiod_direction_input(desc);
2412 			goto set_output_flag;
2413 		}
2414 	} else {
2415 		gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
2416 	}
2417 
2418 set_output_value:
2419 	ret = gpio_set_bias(desc);
2420 	if (ret)
2421 		return ret;
2422 	return gpiod_direction_output_raw_commit(desc, value);
2423 
2424 set_output_flag:
2425 	/*
2426 	 * When emulating open-source or open-drain functionalities by not
2427 	 * actively driving the line (setting mode to input) we still need to
2428 	 * set the IS_OUT flag or otherwise we won't be able to set the line
2429 	 * value anymore.
2430 	 */
2431 	if (ret == 0)
2432 		set_bit(FLAG_IS_OUT, &desc->flags);
2433 	return ret;
2434 }
2435 EXPORT_SYMBOL_GPL(gpiod_direction_output);
2436 
2437 /**
2438  * gpiod_set_config - sets @config for a GPIO
2439  * @desc: descriptor of the GPIO for which to set the configuration
2440  * @config: Same packed config format as generic pinconf
2441  *
2442  * Returns:
2443  * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2444  * configuration.
2445  */
2446 int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
2447 {
2448 	struct gpio_chip *gc;
2449 
2450 	VALIDATE_DESC(desc);
2451 	gc = desc->gdev->chip;
2452 
2453 	return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
2454 }
2455 EXPORT_SYMBOL_GPL(gpiod_set_config);
2456 
2457 /**
2458  * gpiod_set_debounce - sets @debounce time for a GPIO
2459  * @desc: descriptor of the GPIO for which to set debounce time
2460  * @debounce: debounce time in microseconds
2461  *
2462  * Returns:
2463  * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
2464  * debounce time.
2465  */
2466 int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
2467 {
2468 	unsigned long config;
2469 
2470 	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
2471 	return gpiod_set_config(desc, config);
2472 }
2473 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
2474 
2475 /**
2476  * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
2477  * @desc: descriptor of the GPIO for which to configure persistence
2478  * @transitory: True to lose state on suspend or reset, false for persistence
2479  *
2480  * Returns:
2481  * 0 on success, otherwise a negative error code.
2482  */
2483 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
2484 {
2485 	VALIDATE_DESC(desc);
2486 	/*
2487 	 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
2488 	 * persistence state.
2489 	 */
2490 	assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
2491 
2492 	/* If the driver supports it, set the persistence state now */
2493 	return gpio_set_config_with_argument_optional(desc,
2494 						      PIN_CONFIG_PERSIST_STATE,
2495 						      !transitory);
2496 }
2497 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
2498 
2499 /**
2500  * gpiod_is_active_low - test whether a GPIO is active-low or not
2501  * @desc: the gpio descriptor to test
2502  *
2503  * Returns 1 if the GPIO is active-low, 0 otherwise.
2504  */
2505 int gpiod_is_active_low(const struct gpio_desc *desc)
2506 {
2507 	VALIDATE_DESC(desc);
2508 	return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
2509 }
2510 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
2511 
2512 /**
2513  * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
2514  * @desc: the gpio descriptor to change
2515  */
2516 void gpiod_toggle_active_low(struct gpio_desc *desc)
2517 {
2518 	VALIDATE_DESC_VOID(desc);
2519 	change_bit(FLAG_ACTIVE_LOW, &desc->flags);
2520 }
2521 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
2522 
2523 /* I/O calls are only valid after configuration completed; the relevant
2524  * "is this a valid GPIO" error checks should already have been done.
2525  *
2526  * "Get" operations are often inlinable as reading a pin value register,
2527  * and masking the relevant bit in that register.
2528  *
2529  * When "set" operations are inlinable, they involve writing that mask to
2530  * one register to set a low value, or a different register to set it high.
2531  * Otherwise locking is needed, so there may be little value to inlining.
2532  *
2533  *------------------------------------------------------------------------
2534  *
2535  * IMPORTANT!!!  The hot paths -- get/set value -- assume that callers
2536  * have requested the GPIO.  That can include implicit requesting by
2537  * a direction setting call.  Marking a gpio as requested locks its chip
2538  * in memory, guaranteeing that these table lookups need no more locking
2539  * and that gpiochip_remove() will fail.
2540  *
2541  * REVISIT when debugging, consider adding some instrumentation to ensure
2542  * that the GPIO was actually requested.
2543  */
2544 
2545 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
2546 {
2547 	struct gpio_chip	*gc;
2548 	int offset;
2549 	int value;
2550 
2551 	gc = desc->gdev->chip;
2552 	offset = gpio_chip_hwgpio(desc);
2553 	value = gc->get ? gc->get(gc, offset) : -EIO;
2554 	value = value < 0 ? value : !!value;
2555 	trace_gpio_value(desc_to_gpio(desc), 1, value);
2556 	return value;
2557 }
2558 
2559 static int gpio_chip_get_multiple(struct gpio_chip *gc,
2560 				  unsigned long *mask, unsigned long *bits)
2561 {
2562 	if (gc->get_multiple) {
2563 		return gc->get_multiple(gc, mask, bits);
2564 	} else if (gc->get) {
2565 		int i, value;
2566 
2567 		for_each_set_bit(i, mask, gc->ngpio) {
2568 			value = gc->get(gc, i);
2569 			if (value < 0)
2570 				return value;
2571 			__assign_bit(i, bits, value);
2572 		}
2573 		return 0;
2574 	}
2575 	return -EIO;
2576 }
2577 
2578 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
2579 				  unsigned int array_size,
2580 				  struct gpio_desc **desc_array,
2581 				  struct gpio_array *array_info,
2582 				  unsigned long *value_bitmap)
2583 {
2584 	int ret, i = 0;
2585 
2586 	/*
2587 	 * Validate array_info against desc_array and its size.
2588 	 * It should immediately follow desc_array if both
2589 	 * have been obtained from the same gpiod_get_array() call.
2590 	 */
2591 	if (array_info && array_info->desc == desc_array &&
2592 	    array_size <= array_info->size &&
2593 	    (void *)array_info == desc_array + array_info->size) {
2594 		if (!can_sleep)
2595 			WARN_ON(array_info->chip->can_sleep);
2596 
2597 		ret = gpio_chip_get_multiple(array_info->chip,
2598 					     array_info->get_mask,
2599 					     value_bitmap);
2600 		if (ret)
2601 			return ret;
2602 
2603 		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2604 			bitmap_xor(value_bitmap, value_bitmap,
2605 				   array_info->invert_mask, array_size);
2606 
2607 		i = find_first_zero_bit(array_info->get_mask, array_size);
2608 		if (i == array_size)
2609 			return 0;
2610 	} else {
2611 		array_info = NULL;
2612 	}
2613 
2614 	while (i < array_size) {
2615 		struct gpio_chip *gc = desc_array[i]->gdev->chip;
2616 		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2617 		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2618 		unsigned long *mask, *bits;
2619 		int first, j;
2620 
2621 		if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2622 			mask = fastpath_mask;
2623 			bits = fastpath_bits;
2624 		} else {
2625 			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2626 
2627 			mask = bitmap_alloc(gc->ngpio, flags);
2628 			if (!mask)
2629 				return -ENOMEM;
2630 
2631 			bits = bitmap_alloc(gc->ngpio, flags);
2632 			if (!bits) {
2633 				bitmap_free(mask);
2634 				return -ENOMEM;
2635 			}
2636 		}
2637 
2638 		bitmap_zero(mask, gc->ngpio);
2639 
2640 		if (!can_sleep)
2641 			WARN_ON(gc->can_sleep);
2642 
2643 		/* collect all inputs belonging to the same chip */
2644 		first = i;
2645 		do {
2646 			const struct gpio_desc *desc = desc_array[i];
2647 			int hwgpio = gpio_chip_hwgpio(desc);
2648 
2649 			__set_bit(hwgpio, mask);
2650 			i++;
2651 
2652 			if (array_info)
2653 				i = find_next_zero_bit(array_info->get_mask,
2654 						       array_size, i);
2655 		} while ((i < array_size) &&
2656 			 (desc_array[i]->gdev->chip == gc));
2657 
2658 		ret = gpio_chip_get_multiple(gc, mask, bits);
2659 		if (ret) {
2660 			if (mask != fastpath_mask)
2661 				bitmap_free(mask);
2662 			if (bits != fastpath_bits)
2663 				bitmap_free(bits);
2664 			return ret;
2665 		}
2666 
2667 		for (j = first; j < i; ) {
2668 			const struct gpio_desc *desc = desc_array[j];
2669 			int hwgpio = gpio_chip_hwgpio(desc);
2670 			int value = test_bit(hwgpio, bits);
2671 
2672 			if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2673 				value = !value;
2674 			__assign_bit(j, value_bitmap, value);
2675 			trace_gpio_value(desc_to_gpio(desc), 1, value);
2676 			j++;
2677 
2678 			if (array_info)
2679 				j = find_next_zero_bit(array_info->get_mask, i,
2680 						       j);
2681 		}
2682 
2683 		if (mask != fastpath_mask)
2684 			bitmap_free(mask);
2685 		if (bits != fastpath_bits)
2686 			bitmap_free(bits);
2687 	}
2688 	return 0;
2689 }
2690 
2691 /**
2692  * gpiod_get_raw_value() - return a gpio's raw value
2693  * @desc: gpio whose value will be returned
2694  *
2695  * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2696  * its ACTIVE_LOW status, or negative errno on failure.
2697  *
2698  * This function can be called from contexts where we cannot sleep, and will
2699  * complain if the GPIO chip functions potentially sleep.
2700  */
2701 int gpiod_get_raw_value(const struct gpio_desc *desc)
2702 {
2703 	VALIDATE_DESC(desc);
2704 	/* Should be using gpiod_get_raw_value_cansleep() */
2705 	WARN_ON(desc->gdev->chip->can_sleep);
2706 	return gpiod_get_raw_value_commit(desc);
2707 }
2708 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
2709 
2710 /**
2711  * gpiod_get_value() - return a gpio's value
2712  * @desc: gpio whose value will be returned
2713  *
2714  * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2715  * account, or negative errno on failure.
2716  *
2717  * This function can be called from contexts where we cannot sleep, and will
2718  * complain if the GPIO chip functions potentially sleep.
2719  */
2720 int gpiod_get_value(const struct gpio_desc *desc)
2721 {
2722 	int value;
2723 
2724 	VALIDATE_DESC(desc);
2725 	/* Should be using gpiod_get_value_cansleep() */
2726 	WARN_ON(desc->gdev->chip->can_sleep);
2727 
2728 	value = gpiod_get_raw_value_commit(desc);
2729 	if (value < 0)
2730 		return value;
2731 
2732 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2733 		value = !value;
2734 
2735 	return value;
2736 }
2737 EXPORT_SYMBOL_GPL(gpiod_get_value);
2738 
2739 /**
2740  * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
2741  * @array_size: number of elements in the descriptor array / value bitmap
2742  * @desc_array: array of GPIO descriptors whose values will be read
2743  * @array_info: information on applicability of fast bitmap processing path
2744  * @value_bitmap: bitmap to store the read values
2745  *
2746  * Read the raw values of the GPIOs, i.e. the values of the physical lines
2747  * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
2748  * else an error code.
2749  *
2750  * This function can be called from contexts where we cannot sleep,
2751  * and it will complain if the GPIO chip functions potentially sleep.
2752  */
2753 int gpiod_get_raw_array_value(unsigned int array_size,
2754 			      struct gpio_desc **desc_array,
2755 			      struct gpio_array *array_info,
2756 			      unsigned long *value_bitmap)
2757 {
2758 	if (!desc_array)
2759 		return -EINVAL;
2760 	return gpiod_get_array_value_complex(true, false, array_size,
2761 					     desc_array, array_info,
2762 					     value_bitmap);
2763 }
2764 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
2765 
2766 /**
2767  * gpiod_get_array_value() - read values from an array of GPIOs
2768  * @array_size: number of elements in the descriptor array / value bitmap
2769  * @desc_array: array of GPIO descriptors whose values will be read
2770  * @array_info: information on applicability of fast bitmap processing path
2771  * @value_bitmap: bitmap to store the read values
2772  *
2773  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2774  * into account.  Return 0 in case of success, else an error code.
2775  *
2776  * This function can be called from contexts where we cannot sleep,
2777  * and it will complain if the GPIO chip functions potentially sleep.
2778  */
2779 int gpiod_get_array_value(unsigned int array_size,
2780 			  struct gpio_desc **desc_array,
2781 			  struct gpio_array *array_info,
2782 			  unsigned long *value_bitmap)
2783 {
2784 	if (!desc_array)
2785 		return -EINVAL;
2786 	return gpiod_get_array_value_complex(false, false, array_size,
2787 					     desc_array, array_info,
2788 					     value_bitmap);
2789 }
2790 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
2791 
2792 /*
2793  *  gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
2794  * @desc: gpio descriptor whose state need to be set.
2795  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2796  */
2797 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
2798 {
2799 	int ret = 0;
2800 	struct gpio_chip *gc = desc->gdev->chip;
2801 	int offset = gpio_chip_hwgpio(desc);
2802 
2803 	if (value) {
2804 		ret = gc->direction_input(gc, offset);
2805 	} else {
2806 		ret = gc->direction_output(gc, offset, 0);
2807 		if (!ret)
2808 			set_bit(FLAG_IS_OUT, &desc->flags);
2809 	}
2810 	trace_gpio_direction(desc_to_gpio(desc), value, ret);
2811 	if (ret < 0)
2812 		gpiod_err(desc,
2813 			  "%s: Error in set_value for open drain err %d\n",
2814 			  __func__, ret);
2815 }
2816 
2817 /*
2818  *  _gpio_set_open_source_value() - Set the open source gpio's value.
2819  * @desc: gpio descriptor whose state need to be set.
2820  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
2821  */
2822 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
2823 {
2824 	int ret = 0;
2825 	struct gpio_chip *gc = desc->gdev->chip;
2826 	int offset = gpio_chip_hwgpio(desc);
2827 
2828 	if (value) {
2829 		ret = gc->direction_output(gc, offset, 1);
2830 		if (!ret)
2831 			set_bit(FLAG_IS_OUT, &desc->flags);
2832 	} else {
2833 		ret = gc->direction_input(gc, offset);
2834 	}
2835 	trace_gpio_direction(desc_to_gpio(desc), !value, ret);
2836 	if (ret < 0)
2837 		gpiod_err(desc,
2838 			  "%s: Error in set_value for open source err %d\n",
2839 			  __func__, ret);
2840 }
2841 
2842 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
2843 {
2844 	struct gpio_chip	*gc;
2845 
2846 	gc = desc->gdev->chip;
2847 	trace_gpio_value(desc_to_gpio(desc), 0, value);
2848 	gc->set(gc, gpio_chip_hwgpio(desc), value);
2849 }
2850 
2851 /*
2852  * set multiple outputs on the same chip;
2853  * use the chip's set_multiple function if available;
2854  * otherwise set the outputs sequentially;
2855  * @chip: the GPIO chip we operate on
2856  * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
2857  *        defines which outputs are to be changed
2858  * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
2859  *        defines the values the outputs specified by mask are to be set to
2860  */
2861 static void gpio_chip_set_multiple(struct gpio_chip *gc,
2862 				   unsigned long *mask, unsigned long *bits)
2863 {
2864 	if (gc->set_multiple) {
2865 		gc->set_multiple(gc, mask, bits);
2866 	} else {
2867 		unsigned int i;
2868 
2869 		/* set outputs if the corresponding mask bit is set */
2870 		for_each_set_bit(i, mask, gc->ngpio)
2871 			gc->set(gc, i, test_bit(i, bits));
2872 	}
2873 }
2874 
2875 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
2876 				  unsigned int array_size,
2877 				  struct gpio_desc **desc_array,
2878 				  struct gpio_array *array_info,
2879 				  unsigned long *value_bitmap)
2880 {
2881 	int i = 0;
2882 
2883 	/*
2884 	 * Validate array_info against desc_array and its size.
2885 	 * It should immediately follow desc_array if both
2886 	 * have been obtained from the same gpiod_get_array() call.
2887 	 */
2888 	if (array_info && array_info->desc == desc_array &&
2889 	    array_size <= array_info->size &&
2890 	    (void *)array_info == desc_array + array_info->size) {
2891 		if (!can_sleep)
2892 			WARN_ON(array_info->chip->can_sleep);
2893 
2894 		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
2895 			bitmap_xor(value_bitmap, value_bitmap,
2896 				   array_info->invert_mask, array_size);
2897 
2898 		gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
2899 				       value_bitmap);
2900 
2901 		i = find_first_zero_bit(array_info->set_mask, array_size);
2902 		if (i == array_size)
2903 			return 0;
2904 	} else {
2905 		array_info = NULL;
2906 	}
2907 
2908 	while (i < array_size) {
2909 		struct gpio_chip *gc = desc_array[i]->gdev->chip;
2910 		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
2911 		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
2912 		unsigned long *mask, *bits;
2913 		int count = 0;
2914 
2915 		if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
2916 			mask = fastpath_mask;
2917 			bits = fastpath_bits;
2918 		} else {
2919 			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
2920 
2921 			mask = bitmap_alloc(gc->ngpio, flags);
2922 			if (!mask)
2923 				return -ENOMEM;
2924 
2925 			bits = bitmap_alloc(gc->ngpio, flags);
2926 			if (!bits) {
2927 				bitmap_free(mask);
2928 				return -ENOMEM;
2929 			}
2930 		}
2931 
2932 		bitmap_zero(mask, gc->ngpio);
2933 
2934 		if (!can_sleep)
2935 			WARN_ON(gc->can_sleep);
2936 
2937 		do {
2938 			struct gpio_desc *desc = desc_array[i];
2939 			int hwgpio = gpio_chip_hwgpio(desc);
2940 			int value = test_bit(i, value_bitmap);
2941 
2942 			/*
2943 			 * Pins applicable for fast input but not for
2944 			 * fast output processing may have been already
2945 			 * inverted inside the fast path, skip them.
2946 			 */
2947 			if (!raw && !(array_info &&
2948 			    test_bit(i, array_info->invert_mask)) &&
2949 			    test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2950 				value = !value;
2951 			trace_gpio_value(desc_to_gpio(desc), 0, value);
2952 			/*
2953 			 * collect all normal outputs belonging to the same chip
2954 			 * open drain and open source outputs are set individually
2955 			 */
2956 			if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
2957 				gpio_set_open_drain_value_commit(desc, value);
2958 			} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
2959 				gpio_set_open_source_value_commit(desc, value);
2960 			} else {
2961 				__set_bit(hwgpio, mask);
2962 				__assign_bit(hwgpio, bits, value);
2963 				count++;
2964 			}
2965 			i++;
2966 
2967 			if (array_info)
2968 				i = find_next_zero_bit(array_info->set_mask,
2969 						       array_size, i);
2970 		} while ((i < array_size) &&
2971 			 (desc_array[i]->gdev->chip == gc));
2972 		/* push collected bits to outputs */
2973 		if (count != 0)
2974 			gpio_chip_set_multiple(gc, mask, bits);
2975 
2976 		if (mask != fastpath_mask)
2977 			bitmap_free(mask);
2978 		if (bits != fastpath_bits)
2979 			bitmap_free(bits);
2980 	}
2981 	return 0;
2982 }
2983 
2984 /**
2985  * gpiod_set_raw_value() - assign a gpio's raw value
2986  * @desc: gpio whose value will be assigned
2987  * @value: value to assign
2988  *
2989  * Set the raw value of the GPIO, i.e. the value of its physical line without
2990  * regard for its ACTIVE_LOW status.
2991  *
2992  * This function can be called from contexts where we cannot sleep, and will
2993  * complain if the GPIO chip functions potentially sleep.
2994  */
2995 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
2996 {
2997 	VALIDATE_DESC_VOID(desc);
2998 	/* Should be using gpiod_set_raw_value_cansleep() */
2999 	WARN_ON(desc->gdev->chip->can_sleep);
3000 	gpiod_set_raw_value_commit(desc, value);
3001 }
3002 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3003 
3004 /**
3005  * gpiod_set_value_nocheck() - set a GPIO line value without checking
3006  * @desc: the descriptor to set the value on
3007  * @value: value to set
3008  *
3009  * This sets the value of a GPIO line backing a descriptor, applying
3010  * different semantic quirks like active low and open drain/source
3011  * handling.
3012  */
3013 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3014 {
3015 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3016 		value = !value;
3017 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3018 		gpio_set_open_drain_value_commit(desc, value);
3019 	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3020 		gpio_set_open_source_value_commit(desc, value);
3021 	else
3022 		gpiod_set_raw_value_commit(desc, value);
3023 }
3024 
3025 /**
3026  * gpiod_set_value() - assign a gpio's value
3027  * @desc: gpio whose value will be assigned
3028  * @value: value to assign
3029  *
3030  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3031  * OPEN_DRAIN and OPEN_SOURCE flags into account.
3032  *
3033  * This function can be called from contexts where we cannot sleep, and will
3034  * complain if the GPIO chip functions potentially sleep.
3035  */
3036 void gpiod_set_value(struct gpio_desc *desc, int value)
3037 {
3038 	VALIDATE_DESC_VOID(desc);
3039 	/* Should be using gpiod_set_value_cansleep() */
3040 	WARN_ON(desc->gdev->chip->can_sleep);
3041 	gpiod_set_value_nocheck(desc, value);
3042 }
3043 EXPORT_SYMBOL_GPL(gpiod_set_value);
3044 
3045 /**
3046  * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3047  * @array_size: number of elements in the descriptor array / value bitmap
3048  * @desc_array: array of GPIO descriptors whose values will be assigned
3049  * @array_info: information on applicability of fast bitmap processing path
3050  * @value_bitmap: bitmap of values to assign
3051  *
3052  * Set the raw values of the GPIOs, i.e. the values of the physical lines
3053  * without regard for their ACTIVE_LOW status.
3054  *
3055  * This function can be called from contexts where we cannot sleep, and will
3056  * complain if the GPIO chip functions potentially sleep.
3057  */
3058 int gpiod_set_raw_array_value(unsigned int array_size,
3059 			      struct gpio_desc **desc_array,
3060 			      struct gpio_array *array_info,
3061 			      unsigned long *value_bitmap)
3062 {
3063 	if (!desc_array)
3064 		return -EINVAL;
3065 	return gpiod_set_array_value_complex(true, false, array_size,
3066 					desc_array, array_info, value_bitmap);
3067 }
3068 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3069 
3070 /**
3071  * gpiod_set_array_value() - assign values to an array of GPIOs
3072  * @array_size: number of elements in the descriptor array / value bitmap
3073  * @desc_array: array of GPIO descriptors whose values will be assigned
3074  * @array_info: information on applicability of fast bitmap processing path
3075  * @value_bitmap: bitmap of values to assign
3076  *
3077  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3078  * into account.
3079  *
3080  * This function can be called from contexts where we cannot sleep, and will
3081  * complain if the GPIO chip functions potentially sleep.
3082  */
3083 int gpiod_set_array_value(unsigned int array_size,
3084 			  struct gpio_desc **desc_array,
3085 			  struct gpio_array *array_info,
3086 			  unsigned long *value_bitmap)
3087 {
3088 	if (!desc_array)
3089 		return -EINVAL;
3090 	return gpiod_set_array_value_complex(false, false, array_size,
3091 					     desc_array, array_info,
3092 					     value_bitmap);
3093 }
3094 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3095 
3096 /**
3097  * gpiod_cansleep() - report whether gpio value access may sleep
3098  * @desc: gpio to check
3099  *
3100  */
3101 int gpiod_cansleep(const struct gpio_desc *desc)
3102 {
3103 	VALIDATE_DESC(desc);
3104 	return desc->gdev->chip->can_sleep;
3105 }
3106 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3107 
3108 /**
3109  * gpiod_set_consumer_name() - set the consumer name for the descriptor
3110  * @desc: gpio to set the consumer name on
3111  * @name: the new consumer name
3112  */
3113 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3114 {
3115 	VALIDATE_DESC(desc);
3116 	if (name) {
3117 		name = kstrdup_const(name, GFP_KERNEL);
3118 		if (!name)
3119 			return -ENOMEM;
3120 	}
3121 
3122 	kfree_const(desc->label);
3123 	desc_set_label(desc, name);
3124 
3125 	return 0;
3126 }
3127 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3128 
3129 /**
3130  * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3131  * @desc: gpio whose IRQ will be returned (already requested)
3132  *
3133  * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3134  * error.
3135  */
3136 int gpiod_to_irq(const struct gpio_desc *desc)
3137 {
3138 	struct gpio_chip *gc;
3139 	int offset;
3140 
3141 	/*
3142 	 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3143 	 * requires this function to not return zero on an invalid descriptor
3144 	 * but rather a negative error number.
3145 	 */
3146 	if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3147 		return -EINVAL;
3148 
3149 	gc = desc->gdev->chip;
3150 	offset = gpio_chip_hwgpio(desc);
3151 	if (gc->to_irq) {
3152 		int retirq = gc->to_irq(gc, offset);
3153 
3154 		/* Zero means NO_IRQ */
3155 		if (!retirq)
3156 			return -ENXIO;
3157 
3158 		return retirq;
3159 	}
3160 #ifdef CONFIG_GPIOLIB_IRQCHIP
3161 	if (gc->irq.chip) {
3162 		/*
3163 		 * Avoid race condition with other code, which tries to lookup
3164 		 * an IRQ before the irqchip has been properly registered,
3165 		 * i.e. while gpiochip is still being brought up.
3166 		 */
3167 		return -EPROBE_DEFER;
3168 	}
3169 #endif
3170 	return -ENXIO;
3171 }
3172 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3173 
3174 /**
3175  * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3176  * @gc: the chip the GPIO to lock belongs to
3177  * @offset: the offset of the GPIO to lock as IRQ
3178  *
3179  * This is used directly by GPIO drivers that want to lock down
3180  * a certain GPIO line to be used for IRQs.
3181  */
3182 int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
3183 {
3184 	struct gpio_desc *desc;
3185 
3186 	desc = gpiochip_get_desc(gc, offset);
3187 	if (IS_ERR(desc))
3188 		return PTR_ERR(desc);
3189 
3190 	/*
3191 	 * If it's fast: flush the direction setting if something changed
3192 	 * behind our back
3193 	 */
3194 	if (!gc->can_sleep && gc->get_direction) {
3195 		int dir = gpiod_get_direction(desc);
3196 
3197 		if (dir < 0) {
3198 			chip_err(gc, "%s: cannot get GPIO direction\n",
3199 				 __func__);
3200 			return dir;
3201 		}
3202 	}
3203 
3204 	/* To be valid for IRQ the line needs to be input or open drain */
3205 	if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3206 	    !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3207 		chip_err(gc,
3208 			 "%s: tried to flag a GPIO set as output for IRQ\n",
3209 			 __func__);
3210 		return -EIO;
3211 	}
3212 
3213 	set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3214 	set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3215 
3216 	/*
3217 	 * If the consumer has not set up a label (such as when the
3218 	 * IRQ is referenced from .to_irq()) we set up a label here
3219 	 * so it is clear this is used as an interrupt.
3220 	 */
3221 	if (!desc->label)
3222 		desc_set_label(desc, "interrupt");
3223 
3224 	return 0;
3225 }
3226 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3227 
3228 /**
3229  * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3230  * @gc: the chip the GPIO to lock belongs to
3231  * @offset: the offset of the GPIO to lock as IRQ
3232  *
3233  * This is used directly by GPIO drivers that want to indicate
3234  * that a certain GPIO is no longer used exclusively for IRQ.
3235  */
3236 void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
3237 {
3238 	struct gpio_desc *desc;
3239 
3240 	desc = gpiochip_get_desc(gc, offset);
3241 	if (IS_ERR(desc))
3242 		return;
3243 
3244 	clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3245 	clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3246 
3247 	/* If we only had this marking, erase it */
3248 	if (desc->label && !strcmp(desc->label, "interrupt"))
3249 		desc_set_label(desc, NULL);
3250 }
3251 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3252 
3253 void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
3254 {
3255 	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3256 
3257 	if (!IS_ERR(desc) &&
3258 	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3259 		clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3260 }
3261 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3262 
3263 void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
3264 {
3265 	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
3266 
3267 	if (!IS_ERR(desc) &&
3268 	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3269 		/*
3270 		 * We must not be output when using IRQ UNLESS we are
3271 		 * open drain.
3272 		 */
3273 		WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3274 			!test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3275 		set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3276 	}
3277 }
3278 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3279 
3280 bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
3281 {
3282 	if (offset >= gc->ngpio)
3283 		return false;
3284 
3285 	return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
3286 }
3287 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3288 
3289 int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
3290 {
3291 	int ret;
3292 
3293 	if (!try_module_get(gc->gpiodev->owner))
3294 		return -ENODEV;
3295 
3296 	ret = gpiochip_lock_as_irq(gc, offset);
3297 	if (ret) {
3298 		chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
3299 		module_put(gc->gpiodev->owner);
3300 		return ret;
3301 	}
3302 	return 0;
3303 }
3304 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3305 
3306 void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
3307 {
3308 	gpiochip_unlock_as_irq(gc, offset);
3309 	module_put(gc->gpiodev->owner);
3310 }
3311 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
3312 
3313 bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
3314 {
3315 	if (offset >= gc->ngpio)
3316 		return false;
3317 
3318 	return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
3319 }
3320 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
3321 
3322 bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
3323 {
3324 	if (offset >= gc->ngpio)
3325 		return false;
3326 
3327 	return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
3328 }
3329 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
3330 
3331 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
3332 {
3333 	if (offset >= gc->ngpio)
3334 		return false;
3335 
3336 	return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
3337 }
3338 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
3339 
3340 /**
3341  * gpiod_get_raw_value_cansleep() - return a gpio's raw value
3342  * @desc: gpio whose value will be returned
3343  *
3344  * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3345  * its ACTIVE_LOW status, or negative errno on failure.
3346  *
3347  * This function is to be called from contexts that can sleep.
3348  */
3349 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
3350 {
3351 	might_sleep_if(extra_checks);
3352 	VALIDATE_DESC(desc);
3353 	return gpiod_get_raw_value_commit(desc);
3354 }
3355 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
3356 
3357 /**
3358  * gpiod_get_value_cansleep() - return a gpio's value
3359  * @desc: gpio whose value will be returned
3360  *
3361  * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3362  * account, or negative errno on failure.
3363  *
3364  * This function is to be called from contexts that can sleep.
3365  */
3366 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
3367 {
3368 	int value;
3369 
3370 	might_sleep_if(extra_checks);
3371 	VALIDATE_DESC(desc);
3372 	value = gpiod_get_raw_value_commit(desc);
3373 	if (value < 0)
3374 		return value;
3375 
3376 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3377 		value = !value;
3378 
3379 	return value;
3380 }
3381 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
3382 
3383 /**
3384  * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
3385  * @array_size: number of elements in the descriptor array / value bitmap
3386  * @desc_array: array of GPIO descriptors whose values will be read
3387  * @array_info: information on applicability of fast bitmap processing path
3388  * @value_bitmap: bitmap to store the read values
3389  *
3390  * Read the raw values of the GPIOs, i.e. the values of the physical lines
3391  * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
3392  * else an error code.
3393  *
3394  * This function is to be called from contexts that can sleep.
3395  */
3396 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
3397 				       struct gpio_desc **desc_array,
3398 				       struct gpio_array *array_info,
3399 				       unsigned long *value_bitmap)
3400 {
3401 	might_sleep_if(extra_checks);
3402 	if (!desc_array)
3403 		return -EINVAL;
3404 	return gpiod_get_array_value_complex(true, true, array_size,
3405 					     desc_array, array_info,
3406 					     value_bitmap);
3407 }
3408 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
3409 
3410 /**
3411  * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
3412  * @array_size: number of elements in the descriptor array / value bitmap
3413  * @desc_array: array of GPIO descriptors whose values will be read
3414  * @array_info: information on applicability of fast bitmap processing path
3415  * @value_bitmap: bitmap to store the read values
3416  *
3417  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3418  * into account.  Return 0 in case of success, else an error code.
3419  *
3420  * This function is to be called from contexts that can sleep.
3421  */
3422 int gpiod_get_array_value_cansleep(unsigned int array_size,
3423 				   struct gpio_desc **desc_array,
3424 				   struct gpio_array *array_info,
3425 				   unsigned long *value_bitmap)
3426 {
3427 	might_sleep_if(extra_checks);
3428 	if (!desc_array)
3429 		return -EINVAL;
3430 	return gpiod_get_array_value_complex(false, true, array_size,
3431 					     desc_array, array_info,
3432 					     value_bitmap);
3433 }
3434 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
3435 
3436 /**
3437  * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
3438  * @desc: gpio whose value will be assigned
3439  * @value: value to assign
3440  *
3441  * Set the raw value of the GPIO, i.e. the value of its physical line without
3442  * regard for its ACTIVE_LOW status.
3443  *
3444  * This function is to be called from contexts that can sleep.
3445  */
3446 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
3447 {
3448 	might_sleep_if(extra_checks);
3449 	VALIDATE_DESC_VOID(desc);
3450 	gpiod_set_raw_value_commit(desc, value);
3451 }
3452 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
3453 
3454 /**
3455  * gpiod_set_value_cansleep() - assign a gpio's value
3456  * @desc: gpio whose value will be assigned
3457  * @value: value to assign
3458  *
3459  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3460  * account
3461  *
3462  * This function is to be called from contexts that can sleep.
3463  */
3464 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
3465 {
3466 	might_sleep_if(extra_checks);
3467 	VALIDATE_DESC_VOID(desc);
3468 	gpiod_set_value_nocheck(desc, value);
3469 }
3470 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
3471 
3472 /**
3473  * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
3474  * @array_size: number of elements in the descriptor array / value bitmap
3475  * @desc_array: array of GPIO descriptors whose values will be assigned
3476  * @array_info: information on applicability of fast bitmap processing path
3477  * @value_bitmap: bitmap of values to assign
3478  *
3479  * Set the raw values of the GPIOs, i.e. the values of the physical lines
3480  * without regard for their ACTIVE_LOW status.
3481  *
3482  * This function is to be called from contexts that can sleep.
3483  */
3484 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
3485 				       struct gpio_desc **desc_array,
3486 				       struct gpio_array *array_info,
3487 				       unsigned long *value_bitmap)
3488 {
3489 	might_sleep_if(extra_checks);
3490 	if (!desc_array)
3491 		return -EINVAL;
3492 	return gpiod_set_array_value_complex(true, true, array_size, desc_array,
3493 				      array_info, value_bitmap);
3494 }
3495 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
3496 
3497 /**
3498  * gpiod_add_lookup_tables() - register GPIO device consumers
3499  * @tables: list of tables of consumers to register
3500  * @n: number of tables in the list
3501  */
3502 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
3503 {
3504 	unsigned int i;
3505 
3506 	mutex_lock(&gpio_lookup_lock);
3507 
3508 	for (i = 0; i < n; i++)
3509 		list_add_tail(&tables[i]->list, &gpio_lookup_list);
3510 
3511 	mutex_unlock(&gpio_lookup_lock);
3512 }
3513 
3514 /**
3515  * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
3516  * @array_size: number of elements in the descriptor array / value bitmap
3517  * @desc_array: array of GPIO descriptors whose values will be assigned
3518  * @array_info: information on applicability of fast bitmap processing path
3519  * @value_bitmap: bitmap of values to assign
3520  *
3521  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3522  * into account.
3523  *
3524  * This function is to be called from contexts that can sleep.
3525  */
3526 int gpiod_set_array_value_cansleep(unsigned int array_size,
3527 				   struct gpio_desc **desc_array,
3528 				   struct gpio_array *array_info,
3529 				   unsigned long *value_bitmap)
3530 {
3531 	might_sleep_if(extra_checks);
3532 	if (!desc_array)
3533 		return -EINVAL;
3534 	return gpiod_set_array_value_complex(false, true, array_size,
3535 					     desc_array, array_info,
3536 					     value_bitmap);
3537 }
3538 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
3539 
3540 /**
3541  * gpiod_add_lookup_table() - register GPIO device consumers
3542  * @table: table of consumers to register
3543  */
3544 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
3545 {
3546 	gpiod_add_lookup_tables(&table, 1);
3547 }
3548 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
3549 
3550 /**
3551  * gpiod_remove_lookup_table() - unregister GPIO device consumers
3552  * @table: table of consumers to unregister
3553  */
3554 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
3555 {
3556 	/* Nothing to remove */
3557 	if (!table)
3558 		return;
3559 
3560 	mutex_lock(&gpio_lookup_lock);
3561 
3562 	list_del(&table->list);
3563 
3564 	mutex_unlock(&gpio_lookup_lock);
3565 }
3566 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
3567 
3568 /**
3569  * gpiod_add_hogs() - register a set of GPIO hogs from machine code
3570  * @hogs: table of gpio hog entries with a zeroed sentinel at the end
3571  */
3572 void gpiod_add_hogs(struct gpiod_hog *hogs)
3573 {
3574 	struct gpio_chip *gc;
3575 	struct gpiod_hog *hog;
3576 
3577 	mutex_lock(&gpio_machine_hogs_mutex);
3578 
3579 	for (hog = &hogs[0]; hog->chip_label; hog++) {
3580 		list_add_tail(&hog->list, &gpio_machine_hogs);
3581 
3582 		/*
3583 		 * The chip may have been registered earlier, so check if it
3584 		 * exists and, if so, try to hog the line now.
3585 		 */
3586 		gc = find_chip_by_name(hog->chip_label);
3587 		if (gc)
3588 			gpiochip_machine_hog(gc, hog);
3589 	}
3590 
3591 	mutex_unlock(&gpio_machine_hogs_mutex);
3592 }
3593 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
3594 
3595 void gpiod_remove_hogs(struct gpiod_hog *hogs)
3596 {
3597 	struct gpiod_hog *hog;
3598 
3599 	mutex_lock(&gpio_machine_hogs_mutex);
3600 	for (hog = &hogs[0]; hog->chip_label; hog++)
3601 		list_del(&hog->list);
3602 	mutex_unlock(&gpio_machine_hogs_mutex);
3603 }
3604 EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
3605 
3606 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
3607 {
3608 	const char *dev_id = dev ? dev_name(dev) : NULL;
3609 	struct gpiod_lookup_table *table;
3610 
3611 	mutex_lock(&gpio_lookup_lock);
3612 
3613 	list_for_each_entry(table, &gpio_lookup_list, list) {
3614 		if (table->dev_id && dev_id) {
3615 			/*
3616 			 * Valid strings on both ends, must be identical to have
3617 			 * a match
3618 			 */
3619 			if (!strcmp(table->dev_id, dev_id))
3620 				goto found;
3621 		} else {
3622 			/*
3623 			 * One of the pointers is NULL, so both must be to have
3624 			 * a match
3625 			 */
3626 			if (dev_id == table->dev_id)
3627 				goto found;
3628 		}
3629 	}
3630 	table = NULL;
3631 
3632 found:
3633 	mutex_unlock(&gpio_lookup_lock);
3634 	return table;
3635 }
3636 
3637 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
3638 				    unsigned int idx, unsigned long *flags)
3639 {
3640 	struct gpio_desc *desc = ERR_PTR(-ENOENT);
3641 	struct gpiod_lookup_table *table;
3642 	struct gpiod_lookup *p;
3643 
3644 	table = gpiod_find_lookup_table(dev);
3645 	if (!table)
3646 		return desc;
3647 
3648 	for (p = &table->table[0]; p->key; p++) {
3649 		struct gpio_chip *gc;
3650 
3651 		/* idx must always match exactly */
3652 		if (p->idx != idx)
3653 			continue;
3654 
3655 		/* If the lookup entry has a con_id, require exact match */
3656 		if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
3657 			continue;
3658 
3659 		if (p->chip_hwnum == U16_MAX) {
3660 			desc = gpio_name_to_desc(p->key);
3661 			if (desc) {
3662 				*flags = p->flags;
3663 				return desc;
3664 			}
3665 
3666 			dev_warn(dev, "cannot find GPIO line %s, deferring\n",
3667 				 p->key);
3668 			return ERR_PTR(-EPROBE_DEFER);
3669 		}
3670 
3671 		gc = find_chip_by_name(p->key);
3672 
3673 		if (!gc) {
3674 			/*
3675 			 * As the lookup table indicates a chip with
3676 			 * p->key should exist, assume it may
3677 			 * still appear later and let the interested
3678 			 * consumer be probed again or let the Deferred
3679 			 * Probe infrastructure handle the error.
3680 			 */
3681 			dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
3682 				 p->key);
3683 			return ERR_PTR(-EPROBE_DEFER);
3684 		}
3685 
3686 		if (gc->ngpio <= p->chip_hwnum) {
3687 			dev_err(dev,
3688 				"requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
3689 				idx, p->chip_hwnum, gc->ngpio - 1,
3690 				gc->label);
3691 			return ERR_PTR(-EINVAL);
3692 		}
3693 
3694 		desc = gpiochip_get_desc(gc, p->chip_hwnum);
3695 		*flags = p->flags;
3696 
3697 		return desc;
3698 	}
3699 
3700 	return desc;
3701 }
3702 
3703 static int platform_gpio_count(struct device *dev, const char *con_id)
3704 {
3705 	struct gpiod_lookup_table *table;
3706 	struct gpiod_lookup *p;
3707 	unsigned int count = 0;
3708 
3709 	table = gpiod_find_lookup_table(dev);
3710 	if (!table)
3711 		return -ENOENT;
3712 
3713 	for (p = &table->table[0]; p->key; p++) {
3714 		if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
3715 		    (!con_id && !p->con_id))
3716 			count++;
3717 	}
3718 	if (!count)
3719 		return -ENOENT;
3720 
3721 	return count;
3722 }
3723 
3724 /**
3725  * fwnode_gpiod_get_index - obtain a GPIO from firmware node
3726  * @fwnode:	handle of the firmware node
3727  * @con_id:	function within the GPIO consumer
3728  * @index:	index of the GPIO to obtain for the consumer
3729  * @flags:	GPIO initialization flags
3730  * @label:	label to attach to the requested GPIO
3731  *
3732  * This function can be used for drivers that get their configuration
3733  * from opaque firmware.
3734  *
3735  * The function properly finds the corresponding GPIO using whatever is the
3736  * underlying firmware interface and then makes sure that the GPIO
3737  * descriptor is requested before it is returned to the caller.
3738  *
3739  * Returns:
3740  * On successful request the GPIO pin is configured in accordance with
3741  * provided @flags.
3742  *
3743  * In case of error an ERR_PTR() is returned.
3744  */
3745 struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
3746 					 const char *con_id, int index,
3747 					 enum gpiod_flags flags,
3748 					 const char *label)
3749 {
3750 	struct gpio_desc *desc;
3751 	char prop_name[32]; /* 32 is max size of property name */
3752 	unsigned int i;
3753 
3754 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
3755 		if (con_id)
3756 			snprintf(prop_name, sizeof(prop_name), "%s-%s",
3757 					    con_id, gpio_suffixes[i]);
3758 		else
3759 			snprintf(prop_name, sizeof(prop_name), "%s",
3760 					    gpio_suffixes[i]);
3761 
3762 		desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
3763 					      label);
3764 		if (!gpiod_not_found(desc))
3765 			break;
3766 	}
3767 
3768 	return desc;
3769 }
3770 EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
3771 
3772 /**
3773  * gpiod_count - return the number of GPIOs associated with a device / function
3774  *		or -ENOENT if no GPIO has been assigned to the requested function
3775  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
3776  * @con_id:	function within the GPIO consumer
3777  */
3778 int gpiod_count(struct device *dev, const char *con_id)
3779 {
3780 	const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3781 	int count = -ENOENT;
3782 
3783 	if (is_of_node(fwnode))
3784 		count = of_gpio_get_count(dev, con_id);
3785 	else if (is_acpi_node(fwnode))
3786 		count = acpi_gpio_count(dev, con_id);
3787 
3788 	if (count < 0)
3789 		count = platform_gpio_count(dev, con_id);
3790 
3791 	return count;
3792 }
3793 EXPORT_SYMBOL_GPL(gpiod_count);
3794 
3795 /**
3796  * gpiod_get - obtain a GPIO for a given GPIO function
3797  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
3798  * @con_id:	function within the GPIO consumer
3799  * @flags:	optional GPIO initialization flags
3800  *
3801  * Return the GPIO descriptor corresponding to the function con_id of device
3802  * dev, -ENOENT if no GPIO has been assigned to the requested function, or
3803  * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
3804  */
3805 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
3806 					 enum gpiod_flags flags)
3807 {
3808 	return gpiod_get_index(dev, con_id, 0, flags);
3809 }
3810 EXPORT_SYMBOL_GPL(gpiod_get);
3811 
3812 /**
3813  * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
3814  * @dev: GPIO consumer, can be NULL for system-global GPIOs
3815  * @con_id: function within the GPIO consumer
3816  * @flags: optional GPIO initialization flags
3817  *
3818  * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
3819  * the requested function it will return NULL. This is convenient for drivers
3820  * that need to handle optional GPIOs.
3821  */
3822 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
3823 						  const char *con_id,
3824 						  enum gpiod_flags flags)
3825 {
3826 	return gpiod_get_index_optional(dev, con_id, 0, flags);
3827 }
3828 EXPORT_SYMBOL_GPL(gpiod_get_optional);
3829 
3830 
3831 /**
3832  * gpiod_configure_flags - helper function to configure a given GPIO
3833  * @desc:	gpio whose value will be assigned
3834  * @con_id:	function within the GPIO consumer
3835  * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
3836  *		of_find_gpio() or of_get_gpio_hog()
3837  * @dflags:	gpiod_flags - optional GPIO initialization flags
3838  *
3839  * Return 0 on success, -ENOENT if no GPIO has been assigned to the
3840  * requested function and/or index, or another IS_ERR() code if an error
3841  * occurred while trying to acquire the GPIO.
3842  */
3843 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
3844 		unsigned long lflags, enum gpiod_flags dflags)
3845 {
3846 	int ret;
3847 
3848 	if (lflags & GPIO_ACTIVE_LOW)
3849 		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
3850 
3851 	if (lflags & GPIO_OPEN_DRAIN)
3852 		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3853 	else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
3854 		/*
3855 		 * This enforces open drain mode from the consumer side.
3856 		 * This is necessary for some busses like I2C, but the lookup
3857 		 * should *REALLY* have specified them as open drain in the
3858 		 * first place, so print a little warning here.
3859 		 */
3860 		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
3861 		gpiod_warn(desc,
3862 			   "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
3863 	}
3864 
3865 	if (lflags & GPIO_OPEN_SOURCE)
3866 		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
3867 
3868 	if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
3869 		gpiod_err(desc,
3870 			  "both pull-up and pull-down enabled, invalid configuration\n");
3871 		return -EINVAL;
3872 	}
3873 
3874 	if (lflags & GPIO_PULL_UP)
3875 		set_bit(FLAG_PULL_UP, &desc->flags);
3876 	else if (lflags & GPIO_PULL_DOWN)
3877 		set_bit(FLAG_PULL_DOWN, &desc->flags);
3878 
3879 	ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
3880 	if (ret < 0)
3881 		return ret;
3882 
3883 	/* No particular flag request, return here... */
3884 	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
3885 		gpiod_dbg(desc, "no flags found for %s\n", con_id);
3886 		return 0;
3887 	}
3888 
3889 	/* Process flags */
3890 	if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
3891 		ret = gpiod_direction_output(desc,
3892 				!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
3893 	else
3894 		ret = gpiod_direction_input(desc);
3895 
3896 	return ret;
3897 }
3898 
3899 /**
3900  * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
3901  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
3902  * @con_id:	function within the GPIO consumer
3903  * @idx:	index of the GPIO to obtain in the consumer
3904  * @flags:	optional GPIO initialization flags
3905  *
3906  * This variant of gpiod_get() allows to access GPIOs other than the first
3907  * defined one for functions that define several GPIOs.
3908  *
3909  * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
3910  * requested function and/or index, or another IS_ERR() code if an error
3911  * occurred while trying to acquire the GPIO.
3912  */
3913 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
3914 					       const char *con_id,
3915 					       unsigned int idx,
3916 					       enum gpiod_flags flags)
3917 {
3918 	unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
3919 	struct gpio_desc *desc = NULL;
3920 	int ret;
3921 	/* Maybe we have a device name, maybe not */
3922 	const char *devname = dev ? dev_name(dev) : "?";
3923 	const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
3924 
3925 	dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
3926 
3927 	/* Using device tree? */
3928 	if (is_of_node(fwnode)) {
3929 		dev_dbg(dev, "using device tree for GPIO lookup\n");
3930 		desc = of_find_gpio(dev, con_id, idx, &lookupflags);
3931 	} else if (is_acpi_node(fwnode)) {
3932 		dev_dbg(dev, "using ACPI for GPIO lookup\n");
3933 		desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
3934 	}
3935 
3936 	/*
3937 	 * Either we are not using DT or ACPI, or their lookup did not return
3938 	 * a result. In that case, use platform lookup as a fallback.
3939 	 */
3940 	if (!desc || gpiod_not_found(desc)) {
3941 		dev_dbg(dev, "using lookup tables for GPIO lookup\n");
3942 		desc = gpiod_find(dev, con_id, idx, &lookupflags);
3943 	}
3944 
3945 	if (IS_ERR(desc)) {
3946 		dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
3947 		return desc;
3948 	}
3949 
3950 	/*
3951 	 * If a connection label was passed use that, else attempt to use
3952 	 * the device name as label
3953 	 */
3954 	ret = gpiod_request(desc, con_id ?: devname);
3955 	if (ret) {
3956 		if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
3957 			return ERR_PTR(ret);
3958 
3959 		/*
3960 		 * This happens when there are several consumers for
3961 		 * the same GPIO line: we just return here without
3962 		 * further initialization. It is a bit of a hack.
3963 		 * This is necessary to support fixed regulators.
3964 		 *
3965 		 * FIXME: Make this more sane and safe.
3966 		 */
3967 		dev_info(dev, "nonexclusive access to GPIO for %s\n", con_id ?: devname);
3968 		return desc;
3969 	}
3970 
3971 	ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
3972 	if (ret < 0) {
3973 		dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
3974 		gpiod_put(desc);
3975 		return ERR_PTR(ret);
3976 	}
3977 
3978 	blocking_notifier_call_chain(&desc->gdev->notifier,
3979 				     GPIOLINE_CHANGED_REQUESTED, desc);
3980 
3981 	return desc;
3982 }
3983 EXPORT_SYMBOL_GPL(gpiod_get_index);
3984 
3985 /**
3986  * fwnode_get_named_gpiod - obtain a GPIO from firmware node
3987  * @fwnode:	handle of the firmware node
3988  * @propname:	name of the firmware property representing the GPIO
3989  * @index:	index of the GPIO to obtain for the consumer
3990  * @dflags:	GPIO initialization flags
3991  * @label:	label to attach to the requested GPIO
3992  *
3993  * This function can be used for drivers that get their configuration
3994  * from opaque firmware.
3995  *
3996  * The function properly finds the corresponding GPIO using whatever is the
3997  * underlying firmware interface and then makes sure that the GPIO
3998  * descriptor is requested before it is returned to the caller.
3999  *
4000  * Returns:
4001  * On successful request the GPIO pin is configured in accordance with
4002  * provided @dflags.
4003  *
4004  * In case of error an ERR_PTR() is returned.
4005  */
4006 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4007 					 const char *propname, int index,
4008 					 enum gpiod_flags dflags,
4009 					 const char *label)
4010 {
4011 	unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4012 	struct gpio_desc *desc = ERR_PTR(-ENODEV);
4013 	int ret;
4014 
4015 	if (is_of_node(fwnode)) {
4016 		desc = gpiod_get_from_of_node(to_of_node(fwnode),
4017 					      propname, index,
4018 					      dflags,
4019 					      label);
4020 		return desc;
4021 	} else if (is_acpi_node(fwnode)) {
4022 		struct acpi_gpio_info info;
4023 
4024 		desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4025 		if (IS_ERR(desc))
4026 			return desc;
4027 
4028 		acpi_gpio_update_gpiod_flags(&dflags, &info);
4029 		acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4030 	} else
4031 		return ERR_PTR(-EINVAL);
4032 
4033 	/* Currently only ACPI takes this path */
4034 	ret = gpiod_request(desc, label);
4035 	if (ret)
4036 		return ERR_PTR(ret);
4037 
4038 	ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4039 	if (ret < 0) {
4040 		gpiod_put(desc);
4041 		return ERR_PTR(ret);
4042 	}
4043 
4044 	blocking_notifier_call_chain(&desc->gdev->notifier,
4045 				     GPIOLINE_CHANGED_REQUESTED, desc);
4046 
4047 	return desc;
4048 }
4049 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4050 
4051 /**
4052  * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4053  *                            function
4054  * @dev: GPIO consumer, can be NULL for system-global GPIOs
4055  * @con_id: function within the GPIO consumer
4056  * @index: index of the GPIO to obtain in the consumer
4057  * @flags: optional GPIO initialization flags
4058  *
4059  * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4060  * specified index was assigned to the requested function it will return NULL.
4061  * This is convenient for drivers that need to handle optional GPIOs.
4062  */
4063 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4064 							const char *con_id,
4065 							unsigned int index,
4066 							enum gpiod_flags flags)
4067 {
4068 	struct gpio_desc *desc;
4069 
4070 	desc = gpiod_get_index(dev, con_id, index, flags);
4071 	if (gpiod_not_found(desc))
4072 		return NULL;
4073 
4074 	return desc;
4075 }
4076 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4077 
4078 /**
4079  * gpiod_hog - Hog the specified GPIO desc given the provided flags
4080  * @desc:	gpio whose value will be assigned
4081  * @name:	gpio line name
4082  * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
4083  *		of_find_gpio() or of_get_gpio_hog()
4084  * @dflags:	gpiod_flags - optional GPIO initialization flags
4085  */
4086 int gpiod_hog(struct gpio_desc *desc, const char *name,
4087 	      unsigned long lflags, enum gpiod_flags dflags)
4088 {
4089 	struct gpio_chip *gc;
4090 	struct gpio_desc *local_desc;
4091 	int hwnum;
4092 	int ret;
4093 
4094 	gc = gpiod_to_chip(desc);
4095 	hwnum = gpio_chip_hwgpio(desc);
4096 
4097 	local_desc = gpiochip_request_own_desc(gc, hwnum, name,
4098 					       lflags, dflags);
4099 	if (IS_ERR(local_desc)) {
4100 		ret = PTR_ERR(local_desc);
4101 		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4102 		       name, gc->label, hwnum, ret);
4103 		return ret;
4104 	}
4105 
4106 	/* Mark GPIO as hogged so it can be identified and removed later */
4107 	set_bit(FLAG_IS_HOGGED, &desc->flags);
4108 
4109 	gpiod_info(desc, "hogged as %s%s\n",
4110 		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4111 		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
4112 		  (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
4113 
4114 	return 0;
4115 }
4116 
4117 /**
4118  * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4119  * @gc:	gpio chip to act on
4120  */
4121 static void gpiochip_free_hogs(struct gpio_chip *gc)
4122 {
4123 	struct gpio_desc *desc;
4124 	int id;
4125 
4126 	for_each_gpio_desc_with_flag(id, gc, desc, FLAG_IS_HOGGED)
4127 		gpiochip_free_own_desc(desc);
4128 }
4129 
4130 /**
4131  * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4132  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
4133  * @con_id:	function within the GPIO consumer
4134  * @flags:	optional GPIO initialization flags
4135  *
4136  * This function acquires all the GPIOs defined under a given function.
4137  *
4138  * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4139  * no GPIO has been assigned to the requested function, or another IS_ERR()
4140  * code if an error occurred while trying to acquire the GPIOs.
4141  */
4142 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4143 						const char *con_id,
4144 						enum gpiod_flags flags)
4145 {
4146 	struct gpio_desc *desc;
4147 	struct gpio_descs *descs;
4148 	struct gpio_array *array_info = NULL;
4149 	struct gpio_chip *gc;
4150 	int count, bitmap_size;
4151 
4152 	count = gpiod_count(dev, con_id);
4153 	if (count < 0)
4154 		return ERR_PTR(count);
4155 
4156 	descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4157 	if (!descs)
4158 		return ERR_PTR(-ENOMEM);
4159 
4160 	for (descs->ndescs = 0; descs->ndescs < count; ) {
4161 		desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4162 		if (IS_ERR(desc)) {
4163 			gpiod_put_array(descs);
4164 			return ERR_CAST(desc);
4165 		}
4166 
4167 		descs->desc[descs->ndescs] = desc;
4168 
4169 		gc = gpiod_to_chip(desc);
4170 		/*
4171 		 * If pin hardware number of array member 0 is also 0, select
4172 		 * its chip as a candidate for fast bitmap processing path.
4173 		 */
4174 		if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4175 			struct gpio_descs *array;
4176 
4177 			bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
4178 						    gc->ngpio : count);
4179 
4180 			array = kzalloc(struct_size(descs, desc, count) +
4181 					struct_size(array_info, invert_mask,
4182 					3 * bitmap_size), GFP_KERNEL);
4183 			if (!array) {
4184 				gpiod_put_array(descs);
4185 				return ERR_PTR(-ENOMEM);
4186 			}
4187 
4188 			memcpy(array, descs,
4189 			       struct_size(descs, desc, descs->ndescs + 1));
4190 			kfree(descs);
4191 
4192 			descs = array;
4193 			array_info = (void *)(descs->desc + count);
4194 			array_info->get_mask = array_info->invert_mask +
4195 						  bitmap_size;
4196 			array_info->set_mask = array_info->get_mask +
4197 						  bitmap_size;
4198 
4199 			array_info->desc = descs->desc;
4200 			array_info->size = count;
4201 			array_info->chip = gc;
4202 			bitmap_set(array_info->get_mask, descs->ndescs,
4203 				   count - descs->ndescs);
4204 			bitmap_set(array_info->set_mask, descs->ndescs,
4205 				   count - descs->ndescs);
4206 			descs->info = array_info;
4207 		}
4208 		/* Unmark array members which don't belong to the 'fast' chip */
4209 		if (array_info && array_info->chip != gc) {
4210 			__clear_bit(descs->ndescs, array_info->get_mask);
4211 			__clear_bit(descs->ndescs, array_info->set_mask);
4212 		}
4213 		/*
4214 		 * Detect array members which belong to the 'fast' chip
4215 		 * but their pins are not in hardware order.
4216 		 */
4217 		else if (array_info &&
4218 			   gpio_chip_hwgpio(desc) != descs->ndescs) {
4219 			/*
4220 			 * Don't use fast path if all array members processed so
4221 			 * far belong to the same chip as this one but its pin
4222 			 * hardware number is different from its array index.
4223 			 */
4224 			if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4225 				array_info = NULL;
4226 			} else {
4227 				__clear_bit(descs->ndescs,
4228 					    array_info->get_mask);
4229 				__clear_bit(descs->ndescs,
4230 					    array_info->set_mask);
4231 			}
4232 		} else if (array_info) {
4233 			/* Exclude open drain or open source from fast output */
4234 			if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
4235 			    gpiochip_line_is_open_source(gc, descs->ndescs))
4236 				__clear_bit(descs->ndescs,
4237 					    array_info->set_mask);
4238 			/* Identify 'fast' pins which require invertion */
4239 			if (gpiod_is_active_low(desc))
4240 				__set_bit(descs->ndescs,
4241 					  array_info->invert_mask);
4242 		}
4243 
4244 		descs->ndescs++;
4245 	}
4246 	if (array_info)
4247 		dev_dbg(dev,
4248 			"GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4249 			array_info->chip->label, array_info->size,
4250 			*array_info->get_mask, *array_info->set_mask,
4251 			*array_info->invert_mask);
4252 	return descs;
4253 }
4254 EXPORT_SYMBOL_GPL(gpiod_get_array);
4255 
4256 /**
4257  * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4258  *                            function
4259  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
4260  * @con_id:	function within the GPIO consumer
4261  * @flags:	optional GPIO initialization flags
4262  *
4263  * This is equivalent to gpiod_get_array(), except that when no GPIO was
4264  * assigned to the requested function it will return NULL.
4265  */
4266 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4267 							const char *con_id,
4268 							enum gpiod_flags flags)
4269 {
4270 	struct gpio_descs *descs;
4271 
4272 	descs = gpiod_get_array(dev, con_id, flags);
4273 	if (gpiod_not_found(descs))
4274 		return NULL;
4275 
4276 	return descs;
4277 }
4278 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4279 
4280 /**
4281  * gpiod_put - dispose of a GPIO descriptor
4282  * @desc:	GPIO descriptor to dispose of
4283  *
4284  * No descriptor can be used after gpiod_put() has been called on it.
4285  */
4286 void gpiod_put(struct gpio_desc *desc)
4287 {
4288 	if (desc)
4289 		gpiod_free(desc);
4290 }
4291 EXPORT_SYMBOL_GPL(gpiod_put);
4292 
4293 /**
4294  * gpiod_put_array - dispose of multiple GPIO descriptors
4295  * @descs:	struct gpio_descs containing an array of descriptors
4296  */
4297 void gpiod_put_array(struct gpio_descs *descs)
4298 {
4299 	unsigned int i;
4300 
4301 	for (i = 0; i < descs->ndescs; i++)
4302 		gpiod_put(descs->desc[i]);
4303 
4304 	kfree(descs);
4305 }
4306 EXPORT_SYMBOL_GPL(gpiod_put_array);
4307 
4308 
4309 static int gpio_bus_match(struct device *dev, struct device_driver *drv)
4310 {
4311 	struct fwnode_handle *fwnode = dev_fwnode(dev);
4312 
4313 	/*
4314 	 * Only match if the fwnode doesn't already have a proper struct device
4315 	 * created for it.
4316 	 */
4317 	if (fwnode && fwnode->dev != dev)
4318 		return 0;
4319 	return 1;
4320 }
4321 
4322 static int gpio_stub_drv_probe(struct device *dev)
4323 {
4324 	/*
4325 	 * The DT node of some GPIO chips have a "compatible" property, but
4326 	 * never have a struct device added and probed by a driver to register
4327 	 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
4328 	 * the consumers of the GPIO chip to get probe deferred forever because
4329 	 * they will be waiting for a device associated with the GPIO chip
4330 	 * firmware node to get added and bound to a driver.
4331 	 *
4332 	 * To allow these consumers to probe, we associate the struct
4333 	 * gpio_device of the GPIO chip with the firmware node and then simply
4334 	 * bind it to this stub driver.
4335 	 */
4336 	return 0;
4337 }
4338 
4339 static struct device_driver gpio_stub_drv = {
4340 	.name = "gpio_stub_drv",
4341 	.bus = &gpio_bus_type,
4342 	.probe = gpio_stub_drv_probe,
4343 };
4344 
4345 static int __init gpiolib_dev_init(void)
4346 {
4347 	int ret;
4348 
4349 	/* Register GPIO sysfs bus */
4350 	ret = bus_register(&gpio_bus_type);
4351 	if (ret < 0) {
4352 		pr_err("gpiolib: could not register GPIO bus type\n");
4353 		return ret;
4354 	}
4355 
4356 	ret = driver_register(&gpio_stub_drv);
4357 	if (ret < 0) {
4358 		pr_err("gpiolib: could not register GPIO stub driver\n");
4359 		bus_unregister(&gpio_bus_type);
4360 		return ret;
4361 	}
4362 
4363 	ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
4364 	if (ret < 0) {
4365 		pr_err("gpiolib: failed to allocate char dev region\n");
4366 		driver_unregister(&gpio_stub_drv);
4367 		bus_unregister(&gpio_bus_type);
4368 		return ret;
4369 	}
4370 
4371 	gpiolib_initialized = true;
4372 	gpiochip_setup_devs();
4373 
4374 #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
4375 	WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
4376 #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
4377 
4378 	return ret;
4379 }
4380 core_initcall(gpiolib_dev_init);
4381 
4382 #ifdef CONFIG_DEBUG_FS
4383 
4384 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4385 {
4386 	unsigned		i;
4387 	struct gpio_chip	*gc = gdev->chip;
4388 	unsigned		gpio = gdev->base;
4389 	struct gpio_desc	*gdesc = &gdev->descs[0];
4390 	bool			is_out;
4391 	bool			is_irq;
4392 	bool			active_low;
4393 
4394 	for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4395 		if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4396 			if (gdesc->name) {
4397 				seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4398 					   gpio, gdesc->name);
4399 			}
4400 			continue;
4401 		}
4402 
4403 		gpiod_get_direction(gdesc);
4404 		is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4405 		is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4406 		active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4407 		seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4408 			gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4409 			is_out ? "out" : "in ",
4410 			gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "?  ",
4411 			is_irq ? "IRQ " : "",
4412 			active_low ? "ACTIVE LOW" : "");
4413 		seq_printf(s, "\n");
4414 	}
4415 }
4416 
4417 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4418 {
4419 	unsigned long flags;
4420 	struct gpio_device *gdev = NULL;
4421 	loff_t index = *pos;
4422 
4423 	s->private = "";
4424 
4425 	spin_lock_irqsave(&gpio_lock, flags);
4426 	list_for_each_entry(gdev, &gpio_devices, list)
4427 		if (index-- == 0) {
4428 			spin_unlock_irqrestore(&gpio_lock, flags);
4429 			return gdev;
4430 		}
4431 	spin_unlock_irqrestore(&gpio_lock, flags);
4432 
4433 	return NULL;
4434 }
4435 
4436 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
4437 {
4438 	unsigned long flags;
4439 	struct gpio_device *gdev = v;
4440 	void *ret = NULL;
4441 
4442 	spin_lock_irqsave(&gpio_lock, flags);
4443 	if (list_is_last(&gdev->list, &gpio_devices))
4444 		ret = NULL;
4445 	else
4446 		ret = list_first_entry(&gdev->list, struct gpio_device, list);
4447 	spin_unlock_irqrestore(&gpio_lock, flags);
4448 
4449 	s->private = "\n";
4450 	++*pos;
4451 
4452 	return ret;
4453 }
4454 
4455 static void gpiolib_seq_stop(struct seq_file *s, void *v)
4456 {
4457 }
4458 
4459 static int gpiolib_seq_show(struct seq_file *s, void *v)
4460 {
4461 	struct gpio_device *gdev = v;
4462 	struct gpio_chip *gc = gdev->chip;
4463 	struct device *parent;
4464 
4465 	if (!gc) {
4466 		seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
4467 			   dev_name(&gdev->dev));
4468 		return 0;
4469 	}
4470 
4471 	seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
4472 		   dev_name(&gdev->dev),
4473 		   gdev->base, gdev->base + gdev->ngpio - 1);
4474 	parent = gc->parent;
4475 	if (parent)
4476 		seq_printf(s, ", parent: %s/%s",
4477 			   parent->bus ? parent->bus->name : "no-bus",
4478 			   dev_name(parent));
4479 	if (gc->label)
4480 		seq_printf(s, ", %s", gc->label);
4481 	if (gc->can_sleep)
4482 		seq_printf(s, ", can sleep");
4483 	seq_printf(s, ":\n");
4484 
4485 	if (gc->dbg_show)
4486 		gc->dbg_show(s, gc);
4487 	else
4488 		gpiolib_dbg_show(s, gdev);
4489 
4490 	return 0;
4491 }
4492 
4493 static const struct seq_operations gpiolib_sops = {
4494 	.start = gpiolib_seq_start,
4495 	.next = gpiolib_seq_next,
4496 	.stop = gpiolib_seq_stop,
4497 	.show = gpiolib_seq_show,
4498 };
4499 DEFINE_SEQ_ATTRIBUTE(gpiolib);
4500 
4501 static int __init gpiolib_debugfs_init(void)
4502 {
4503 	/* /sys/kernel/debug/gpio */
4504 	debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
4505 	return 0;
4506 }
4507 subsys_initcall(gpiolib_debugfs_init);
4508 
4509 #endif	/* DEBUG_FS */
4510