xref: /openbmc/linux/drivers/gpio/gpiolib.c (revision 4f205687)
1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/interrupt.h>
4 #include <linux/irq.h>
5 #include <linux/spinlock.h>
6 #include <linux/list.h>
7 #include <linux/device.h>
8 #include <linux/err.h>
9 #include <linux/debugfs.h>
10 #include <linux/seq_file.h>
11 #include <linux/gpio.h>
12 #include <linux/of_gpio.h>
13 #include <linux/idr.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/gpio/machine.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/idr.h>
20 #include <linux/cdev.h>
21 #include <linux/fs.h>
22 #include <linux/uaccess.h>
23 #include <linux/compat.h>
24 #include <uapi/linux/gpio.h>
25 
26 #include "gpiolib.h"
27 
28 #define CREATE_TRACE_POINTS
29 #include <trace/events/gpio.h>
30 
31 /* Implementation infrastructure for GPIO interfaces.
32  *
33  * The GPIO programming interface allows for inlining speed-critical
34  * get/set operations for common cases, so that access to SOC-integrated
35  * GPIOs can sometimes cost only an instruction or two per bit.
36  */
37 
38 
39 /* When debugging, extend minimal trust to callers and platform code.
40  * Also emit diagnostic messages that may help initial bringup, when
41  * board setup or driver bugs are most common.
42  *
43  * Otherwise, minimize overhead in what may be bitbanging codepaths.
44  */
45 #ifdef	DEBUG
46 #define	extra_checks	1
47 #else
48 #define	extra_checks	0
49 #endif
50 
51 /* Device and char device-related information */
52 static DEFINE_IDA(gpio_ida);
53 static dev_t gpio_devt;
54 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
55 static struct bus_type gpio_bus_type = {
56 	.name = "gpio",
57 };
58 
59 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
60  * While any GPIO is requested, its gpio_chip is not removable;
61  * each GPIO's "requested" flag serves as a lock and refcount.
62  */
63 DEFINE_SPINLOCK(gpio_lock);
64 
65 static DEFINE_MUTEX(gpio_lookup_lock);
66 static LIST_HEAD(gpio_lookup_list);
67 LIST_HEAD(gpio_devices);
68 
69 static void gpiochip_free_hogs(struct gpio_chip *chip);
70 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
71 
72 static bool gpiolib_initialized;
73 
74 static inline void desc_set_label(struct gpio_desc *d, const char *label)
75 {
76 	d->label = label;
77 }
78 
79 /**
80  * Convert a GPIO number to its descriptor
81  */
82 struct gpio_desc *gpio_to_desc(unsigned gpio)
83 {
84 	struct gpio_device *gdev;
85 	unsigned long flags;
86 
87 	spin_lock_irqsave(&gpio_lock, flags);
88 
89 	list_for_each_entry(gdev, &gpio_devices, list) {
90 		if (gdev->base <= gpio &&
91 		    gdev->base + gdev->ngpio > gpio) {
92 			spin_unlock_irqrestore(&gpio_lock, flags);
93 			return &gdev->descs[gpio - gdev->base];
94 		}
95 	}
96 
97 	spin_unlock_irqrestore(&gpio_lock, flags);
98 
99 	if (!gpio_is_valid(gpio))
100 		WARN(1, "invalid GPIO %d\n", gpio);
101 
102 	return NULL;
103 }
104 EXPORT_SYMBOL_GPL(gpio_to_desc);
105 
106 /**
107  * Get the GPIO descriptor corresponding to the given hw number for this chip.
108  */
109 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
110 				    u16 hwnum)
111 {
112 	struct gpio_device *gdev = chip->gpiodev;
113 
114 	if (hwnum >= gdev->ngpio)
115 		return ERR_PTR(-EINVAL);
116 
117 	return &gdev->descs[hwnum];
118 }
119 
120 /**
121  * Convert a GPIO descriptor to the integer namespace.
122  * This should disappear in the future but is needed since we still
123  * use GPIO numbers for error messages and sysfs nodes
124  */
125 int desc_to_gpio(const struct gpio_desc *desc)
126 {
127 	return desc->gdev->base + (desc - &desc->gdev->descs[0]);
128 }
129 EXPORT_SYMBOL_GPL(desc_to_gpio);
130 
131 
132 /**
133  * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
134  * @desc:	descriptor to return the chip of
135  */
136 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
137 {
138 	if (!desc || !desc->gdev || !desc->gdev->chip)
139 		return NULL;
140 	return desc->gdev->chip;
141 }
142 EXPORT_SYMBOL_GPL(gpiod_to_chip);
143 
144 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
145 static int gpiochip_find_base(int ngpio)
146 {
147 	struct gpio_device *gdev;
148 	int base = ARCH_NR_GPIOS - ngpio;
149 
150 	list_for_each_entry_reverse(gdev, &gpio_devices, list) {
151 		/* found a free space? */
152 		if (gdev->base + gdev->ngpio <= base)
153 			break;
154 		else
155 			/* nope, check the space right before the chip */
156 			base = gdev->base - ngpio;
157 	}
158 
159 	if (gpio_is_valid(base)) {
160 		pr_debug("%s: found new base at %d\n", __func__, base);
161 		return base;
162 	} else {
163 		pr_err("%s: cannot find free range\n", __func__);
164 		return -ENOSPC;
165 	}
166 }
167 
168 /**
169  * gpiod_get_direction - return the current direction of a GPIO
170  * @desc:	GPIO to get the direction of
171  *
172  * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
173  *
174  * This function may sleep if gpiod_cansleep() is true.
175  */
176 int gpiod_get_direction(struct gpio_desc *desc)
177 {
178 	struct gpio_chip	*chip;
179 	unsigned		offset;
180 	int			status = -EINVAL;
181 
182 	chip = gpiod_to_chip(desc);
183 	offset = gpio_chip_hwgpio(desc);
184 
185 	if (!chip->get_direction)
186 		return status;
187 
188 	status = chip->get_direction(chip, offset);
189 	if (status > 0) {
190 		/* GPIOF_DIR_IN, or other positive */
191 		status = 1;
192 		clear_bit(FLAG_IS_OUT, &desc->flags);
193 	}
194 	if (status == 0) {
195 		/* GPIOF_DIR_OUT */
196 		set_bit(FLAG_IS_OUT, &desc->flags);
197 	}
198 	return status;
199 }
200 EXPORT_SYMBOL_GPL(gpiod_get_direction);
201 
202 /*
203  * Add a new chip to the global chips list, keeping the list of chips sorted
204  * by range(means [base, base + ngpio - 1]) order.
205  *
206  * Return -EBUSY if the new chip overlaps with some other chip's integer
207  * space.
208  */
209 static int gpiodev_add_to_list(struct gpio_device *gdev)
210 {
211 	struct gpio_device *prev, *next;
212 
213 	if (list_empty(&gpio_devices)) {
214 		/* initial entry in list */
215 		list_add_tail(&gdev->list, &gpio_devices);
216 		return 0;
217 	}
218 
219 	next = list_entry(gpio_devices.next, struct gpio_device, list);
220 	if (gdev->base + gdev->ngpio <= next->base) {
221 		/* add before first entry */
222 		list_add(&gdev->list, &gpio_devices);
223 		return 0;
224 	}
225 
226 	prev = list_entry(gpio_devices.prev, struct gpio_device, list);
227 	if (prev->base + prev->ngpio <= gdev->base) {
228 		/* add behind last entry */
229 		list_add_tail(&gdev->list, &gpio_devices);
230 		return 0;
231 	}
232 
233 	list_for_each_entry_safe(prev, next, &gpio_devices, list) {
234 		/* at the end of the list */
235 		if (&next->list == &gpio_devices)
236 			break;
237 
238 		/* add between prev and next */
239 		if (prev->base + prev->ngpio <= gdev->base
240 				&& gdev->base + gdev->ngpio <= next->base) {
241 			list_add(&gdev->list, &prev->list);
242 			return 0;
243 		}
244 	}
245 
246 	dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
247 	return -EBUSY;
248 }
249 
250 /**
251  * Convert a GPIO name to its descriptor
252  */
253 static struct gpio_desc *gpio_name_to_desc(const char * const name)
254 {
255 	struct gpio_device *gdev;
256 	unsigned long flags;
257 
258 	spin_lock_irqsave(&gpio_lock, flags);
259 
260 	list_for_each_entry(gdev, &gpio_devices, list) {
261 		int i;
262 
263 		for (i = 0; i != gdev->ngpio; ++i) {
264 			struct gpio_desc *desc = &gdev->descs[i];
265 
266 			if (!desc->name || !name)
267 				continue;
268 
269 			if (!strcmp(desc->name, name)) {
270 				spin_unlock_irqrestore(&gpio_lock, flags);
271 				return desc;
272 			}
273 		}
274 	}
275 
276 	spin_unlock_irqrestore(&gpio_lock, flags);
277 
278 	return NULL;
279 }
280 
281 /*
282  * Takes the names from gc->names and checks if they are all unique. If they
283  * are, they are assigned to their gpio descriptors.
284  *
285  * Warning if one of the names is already used for a different GPIO.
286  */
287 static int gpiochip_set_desc_names(struct gpio_chip *gc)
288 {
289 	struct gpio_device *gdev = gc->gpiodev;
290 	int i;
291 
292 	if (!gc->names)
293 		return 0;
294 
295 	/* First check all names if they are unique */
296 	for (i = 0; i != gc->ngpio; ++i) {
297 		struct gpio_desc *gpio;
298 
299 		gpio = gpio_name_to_desc(gc->names[i]);
300 		if (gpio)
301 			dev_warn(&gdev->dev,
302 				 "Detected name collision for GPIO name '%s'\n",
303 				 gc->names[i]);
304 	}
305 
306 	/* Then add all names to the GPIO descriptors */
307 	for (i = 0; i != gc->ngpio; ++i)
308 		gdev->descs[i].name = gc->names[i];
309 
310 	return 0;
311 }
312 
313 /**
314  * gpio_ioctl() - ioctl handler for the GPIO chardev
315  */
316 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
317 {
318 	struct gpio_device *gdev = filp->private_data;
319 	struct gpio_chip *chip = gdev->chip;
320 	void __user *ip = (void __user *)arg;
321 
322 	/* We fail any subsequent ioctl():s when the chip is gone */
323 	if (!chip)
324 		return -ENODEV;
325 
326 	/* Fill in the struct and pass to userspace */
327 	if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
328 		struct gpiochip_info chipinfo;
329 
330 		strncpy(chipinfo.name, dev_name(&gdev->dev),
331 			sizeof(chipinfo.name));
332 		chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
333 		strncpy(chipinfo.label, gdev->label,
334 			sizeof(chipinfo.label));
335 		chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
336 		chipinfo.lines = gdev->ngpio;
337 		if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
338 			return -EFAULT;
339 		return 0;
340 	} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
341 		struct gpioline_info lineinfo;
342 		struct gpio_desc *desc;
343 
344 		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
345 			return -EFAULT;
346 		if (lineinfo.line_offset > gdev->ngpio)
347 			return -EINVAL;
348 
349 		desc = &gdev->descs[lineinfo.line_offset];
350 		if (desc->name) {
351 			strncpy(lineinfo.name, desc->name,
352 				sizeof(lineinfo.name));
353 			lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
354 		} else {
355 			lineinfo.name[0] = '\0';
356 		}
357 		if (desc->label) {
358 			strncpy(lineinfo.consumer, desc->label,
359 				sizeof(lineinfo.consumer));
360 			lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
361 		} else {
362 			lineinfo.consumer[0] = '\0';
363 		}
364 
365 		/*
366 		 * Userspace only need to know that the kernel is using
367 		 * this GPIO so it can't use it.
368 		 */
369 		lineinfo.flags = 0;
370 		if (test_bit(FLAG_REQUESTED, &desc->flags) ||
371 		    test_bit(FLAG_IS_HOGGED, &desc->flags) ||
372 		    test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
373 		    test_bit(FLAG_EXPORT, &desc->flags) ||
374 		    test_bit(FLAG_SYSFS, &desc->flags))
375 			lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
376 		if (test_bit(FLAG_IS_OUT, &desc->flags))
377 			lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
378 		if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
379 			lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
380 		if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
381 			lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
382 		if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
383 			lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
384 
385 		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
386 			return -EFAULT;
387 		return 0;
388 	}
389 	return -EINVAL;
390 }
391 
392 #ifdef CONFIG_COMPAT
393 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
394 			      unsigned long arg)
395 {
396 	return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
397 }
398 #endif
399 
400 /**
401  * gpio_chrdev_open() - open the chardev for ioctl operations
402  * @inode: inode for this chardev
403  * @filp: file struct for storing private data
404  * Returns 0 on success
405  */
406 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
407 {
408 	struct gpio_device *gdev = container_of(inode->i_cdev,
409 					      struct gpio_device, chrdev);
410 
411 	/* Fail on open if the backing gpiochip is gone */
412 	if (!gdev || !gdev->chip)
413 		return -ENODEV;
414 	get_device(&gdev->dev);
415 	filp->private_data = gdev;
416 	return 0;
417 }
418 
419 /**
420  * gpio_chrdev_release() - close chardev after ioctl operations
421  * @inode: inode for this chardev
422  * @filp: file struct for storing private data
423  * Returns 0 on success
424  */
425 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
426 {
427 	struct gpio_device *gdev = container_of(inode->i_cdev,
428 					      struct gpio_device, chrdev);
429 
430 	if (!gdev)
431 		return -ENODEV;
432 	put_device(&gdev->dev);
433 	return 0;
434 }
435 
436 
437 static const struct file_operations gpio_fileops = {
438 	.release = gpio_chrdev_release,
439 	.open = gpio_chrdev_open,
440 	.owner = THIS_MODULE,
441 	.llseek = noop_llseek,
442 	.unlocked_ioctl = gpio_ioctl,
443 #ifdef CONFIG_COMPAT
444 	.compat_ioctl = gpio_ioctl_compat,
445 #endif
446 };
447 
448 static void gpiodevice_release(struct device *dev)
449 {
450 	struct gpio_device *gdev = dev_get_drvdata(dev);
451 
452 	list_del(&gdev->list);
453 	ida_simple_remove(&gpio_ida, gdev->id);
454 	kfree(gdev->label);
455 	kfree(gdev->descs);
456 	kfree(gdev);
457 }
458 
459 static int gpiochip_setup_dev(struct gpio_device *gdev)
460 {
461 	int status;
462 
463 	cdev_init(&gdev->chrdev, &gpio_fileops);
464 	gdev->chrdev.owner = THIS_MODULE;
465 	gdev->chrdev.kobj.parent = &gdev->dev.kobj;
466 	gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
467 	status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
468 	if (status < 0)
469 		chip_warn(gdev->chip, "failed to add char device %d:%d\n",
470 			  MAJOR(gpio_devt), gdev->id);
471 	else
472 		chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
473 			 MAJOR(gpio_devt), gdev->id);
474 	status = device_add(&gdev->dev);
475 	if (status)
476 		goto err_remove_chardev;
477 
478 	status = gpiochip_sysfs_register(gdev);
479 	if (status)
480 		goto err_remove_device;
481 
482 	/* From this point, the .release() function cleans up gpio_device */
483 	gdev->dev.release = gpiodevice_release;
484 	pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
485 		 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
486 		 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
487 
488 	return 0;
489 
490 err_remove_device:
491 	device_del(&gdev->dev);
492 err_remove_chardev:
493 	cdev_del(&gdev->chrdev);
494 	return status;
495 }
496 
497 static void gpiochip_setup_devs(void)
498 {
499 	struct gpio_device *gdev;
500 	int err;
501 
502 	list_for_each_entry(gdev, &gpio_devices, list) {
503 		err = gpiochip_setup_dev(gdev);
504 		if (err)
505 			pr_err("%s: Failed to initialize gpio device (%d)\n",
506 			       dev_name(&gdev->dev), err);
507 	}
508 }
509 
510 /**
511  * gpiochip_add_data() - register a gpio_chip
512  * @chip: the chip to register, with chip->base initialized
513  * Context: potentially before irqs will work
514  *
515  * Returns a negative errno if the chip can't be registered, such as
516  * because the chip->base is invalid or already associated with a
517  * different chip.  Otherwise it returns zero as a success code.
518  *
519  * When gpiochip_add_data() is called very early during boot, so that GPIOs
520  * can be freely used, the chip->parent device must be registered before
521  * the gpio framework's arch_initcall().  Otherwise sysfs initialization
522  * for GPIOs will fail rudely.
523  *
524  * gpiochip_add_data() must only be called after gpiolib initialization,
525  * ie after core_initcall().
526  *
527  * If chip->base is negative, this requests dynamic assignment of
528  * a range of valid GPIOs.
529  */
530 int gpiochip_add_data(struct gpio_chip *chip, void *data)
531 {
532 	unsigned long	flags;
533 	int		status = 0;
534 	unsigned	i;
535 	int		base = chip->base;
536 	struct gpio_device *gdev;
537 
538 	/*
539 	 * First: allocate and populate the internal stat container, and
540 	 * set up the struct device.
541 	 */
542 	gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
543 	if (!gdev)
544 		return -ENOMEM;
545 	gdev->dev.bus = &gpio_bus_type;
546 	gdev->chip = chip;
547 	chip->gpiodev = gdev;
548 	if (chip->parent) {
549 		gdev->dev.parent = chip->parent;
550 		gdev->dev.of_node = chip->parent->of_node;
551 	} else {
552 #ifdef CONFIG_OF_GPIO
553 	/* If the gpiochip has an assigned OF node this takes precedence */
554 		if (chip->of_node)
555 			gdev->dev.of_node = chip->of_node;
556 #endif
557 	}
558 	gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
559 	if (gdev->id < 0) {
560 		status = gdev->id;
561 		goto err_free_gdev;
562 	}
563 	dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
564 	device_initialize(&gdev->dev);
565 	dev_set_drvdata(&gdev->dev, gdev);
566 	if (chip->parent && chip->parent->driver)
567 		gdev->owner = chip->parent->driver->owner;
568 	else if (chip->owner)
569 		/* TODO: remove chip->owner */
570 		gdev->owner = chip->owner;
571 	else
572 		gdev->owner = THIS_MODULE;
573 
574 	gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
575 	if (!gdev->descs) {
576 		status = -ENOMEM;
577 		goto err_free_gdev;
578 	}
579 
580 	if (chip->ngpio == 0) {
581 		chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
582 		status = -EINVAL;
583 		goto err_free_descs;
584 	}
585 
586 	if (chip->label)
587 		gdev->label = kstrdup(chip->label, GFP_KERNEL);
588 	else
589 		gdev->label = kstrdup("unknown", GFP_KERNEL);
590 	if (!gdev->label) {
591 		status = -ENOMEM;
592 		goto err_free_descs;
593 	}
594 
595 	gdev->ngpio = chip->ngpio;
596 	gdev->data = data;
597 
598 	spin_lock_irqsave(&gpio_lock, flags);
599 
600 	/*
601 	 * TODO: this allocates a Linux GPIO number base in the global
602 	 * GPIO numberspace for this chip. In the long run we want to
603 	 * get *rid* of this numberspace and use only descriptors, but
604 	 * it may be a pipe dream. It will not happen before we get rid
605 	 * of the sysfs interface anyways.
606 	 */
607 	if (base < 0) {
608 		base = gpiochip_find_base(chip->ngpio);
609 		if (base < 0) {
610 			status = base;
611 			spin_unlock_irqrestore(&gpio_lock, flags);
612 			goto err_free_label;
613 		}
614 		/*
615 		 * TODO: it should not be necessary to reflect the assigned
616 		 * base outside of the GPIO subsystem. Go over drivers and
617 		 * see if anyone makes use of this, else drop this and assign
618 		 * a poison instead.
619 		 */
620 		chip->base = base;
621 	}
622 	gdev->base = base;
623 
624 	status = gpiodev_add_to_list(gdev);
625 	if (status) {
626 		spin_unlock_irqrestore(&gpio_lock, flags);
627 		goto err_free_label;
628 	}
629 
630 	spin_unlock_irqrestore(&gpio_lock, flags);
631 
632 	for (i = 0; i < chip->ngpio; i++) {
633 		struct gpio_desc *desc = &gdev->descs[i];
634 
635 		desc->gdev = gdev;
636 		/*
637 		 * REVISIT: most hardware initializes GPIOs as inputs
638 		 * (often with pullups enabled) so power usage is
639 		 * minimized. Linux code should set the gpio direction
640 		 * first thing; but until it does, and in case
641 		 * chip->get_direction is not set, we may expose the
642 		 * wrong direction in sysfs.
643 		 */
644 
645 		if (chip->get_direction) {
646 			/*
647 			 * If we have .get_direction, set up the initial
648 			 * direction flag from the hardware.
649 			 */
650 			int dir = chip->get_direction(chip, i);
651 
652 			if (!dir)
653 				set_bit(FLAG_IS_OUT, &desc->flags);
654 		} else if (!chip->direction_input) {
655 			/*
656 			 * If the chip lacks the .direction_input callback
657 			 * we logically assume all lines are outputs.
658 			 */
659 			set_bit(FLAG_IS_OUT, &desc->flags);
660 		}
661 	}
662 
663 #ifdef CONFIG_PINCTRL
664 	INIT_LIST_HEAD(&gdev->pin_ranges);
665 #endif
666 
667 	status = gpiochip_set_desc_names(chip);
668 	if (status)
669 		goto err_remove_from_list;
670 
671 	status = of_gpiochip_add(chip);
672 	if (status)
673 		goto err_remove_chip;
674 
675 	acpi_gpiochip_add(chip);
676 
677 	/*
678 	 * By first adding the chardev, and then adding the device,
679 	 * we get a device node entry in sysfs under
680 	 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
681 	 * coldplug of device nodes and other udev business.
682 	 * We can do this only if gpiolib has been initialized.
683 	 * Otherwise, defer until later.
684 	 */
685 	if (gpiolib_initialized) {
686 		status = gpiochip_setup_dev(gdev);
687 		if (status)
688 			goto err_remove_chip;
689 	}
690 	return 0;
691 
692 err_remove_chip:
693 	acpi_gpiochip_remove(chip);
694 	gpiochip_free_hogs(chip);
695 	of_gpiochip_remove(chip);
696 err_remove_from_list:
697 	spin_lock_irqsave(&gpio_lock, flags);
698 	list_del(&gdev->list);
699 	spin_unlock_irqrestore(&gpio_lock, flags);
700 err_free_label:
701 	kfree(gdev->label);
702 err_free_descs:
703 	kfree(gdev->descs);
704 err_free_gdev:
705 	ida_simple_remove(&gpio_ida, gdev->id);
706 	/* failures here can mean systems won't boot... */
707 	pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
708 	       gdev->base, gdev->base + gdev->ngpio - 1,
709 	       chip->label ? : "generic");
710 	kfree(gdev);
711 	return status;
712 }
713 EXPORT_SYMBOL_GPL(gpiochip_add_data);
714 
715 /**
716  * gpiochip_get_data() - get per-subdriver data for the chip
717  */
718 void *gpiochip_get_data(struct gpio_chip *chip)
719 {
720 	return chip->gpiodev->data;
721 }
722 EXPORT_SYMBOL_GPL(gpiochip_get_data);
723 
724 /**
725  * gpiochip_remove() - unregister a gpio_chip
726  * @chip: the chip to unregister
727  *
728  * A gpio_chip with any GPIOs still requested may not be removed.
729  */
730 void gpiochip_remove(struct gpio_chip *chip)
731 {
732 	struct gpio_device *gdev = chip->gpiodev;
733 	struct gpio_desc *desc;
734 	unsigned long	flags;
735 	unsigned	i;
736 	bool		requested = false;
737 
738 	/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
739 	gpiochip_sysfs_unregister(gdev);
740 	/* Numb the device, cancelling all outstanding operations */
741 	gdev->chip = NULL;
742 	gpiochip_irqchip_remove(chip);
743 	acpi_gpiochip_remove(chip);
744 	gpiochip_remove_pin_ranges(chip);
745 	gpiochip_free_hogs(chip);
746 	of_gpiochip_remove(chip);
747 	/*
748 	 * We accept no more calls into the driver from this point, so
749 	 * NULL the driver data pointer
750 	 */
751 	gdev->data = NULL;
752 
753 	spin_lock_irqsave(&gpio_lock, flags);
754 	for (i = 0; i < gdev->ngpio; i++) {
755 		desc = &gdev->descs[i];
756 		if (test_bit(FLAG_REQUESTED, &desc->flags))
757 			requested = true;
758 	}
759 	spin_unlock_irqrestore(&gpio_lock, flags);
760 
761 	if (requested)
762 		dev_crit(&gdev->dev,
763 			 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
764 
765 	/*
766 	 * The gpiochip side puts its use of the device to rest here:
767 	 * if there are no userspace clients, the chardev and device will
768 	 * be removed, else it will be dangling until the last user is
769 	 * gone.
770 	 */
771 	cdev_del(&gdev->chrdev);
772 	device_del(&gdev->dev);
773 	put_device(&gdev->dev);
774 }
775 EXPORT_SYMBOL_GPL(gpiochip_remove);
776 
777 static void devm_gpio_chip_release(struct device *dev, void *res)
778 {
779 	struct gpio_chip *chip = *(struct gpio_chip **)res;
780 
781 	gpiochip_remove(chip);
782 }
783 
784 static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
785 
786 {
787 	struct gpio_chip **r = res;
788 
789 	if (!r || !*r) {
790 		WARN_ON(!r || !*r);
791 		return 0;
792 	}
793 
794 	return *r == data;
795 }
796 
797 /**
798  * devm_gpiochip_add_data() - Resource manager piochip_add_data()
799  * @dev: the device pointer on which irq_chip belongs to.
800  * @chip: the chip to register, with chip->base initialized
801  * Context: potentially before irqs will work
802  *
803  * Returns a negative errno if the chip can't be registered, such as
804  * because the chip->base is invalid or already associated with a
805  * different chip.  Otherwise it returns zero as a success code.
806  *
807  * The gpio chip automatically be released when the device is unbound.
808  */
809 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
810 			   void *data)
811 {
812 	struct gpio_chip **ptr;
813 	int ret;
814 
815 	ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
816 			     GFP_KERNEL);
817 	if (!ptr)
818 		return -ENOMEM;
819 
820 	ret = gpiochip_add_data(chip, data);
821 	if (ret < 0) {
822 		devres_free(ptr);
823 		return ret;
824 	}
825 
826 	*ptr = chip;
827 	devres_add(dev, ptr);
828 
829 	return 0;
830 }
831 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
832 
833 /**
834  * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
835  * @dev: device for which which resource was allocated
836  * @chip: the chip to remove
837  *
838  * A gpio_chip with any GPIOs still requested may not be removed.
839  */
840 void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
841 {
842 	int ret;
843 
844 	ret = devres_release(dev, devm_gpio_chip_release,
845 			     devm_gpio_chip_match, chip);
846 	if (!ret)
847 		WARN_ON(ret);
848 }
849 EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
850 
851 /**
852  * gpiochip_find() - iterator for locating a specific gpio_chip
853  * @data: data to pass to match function
854  * @callback: Callback function to check gpio_chip
855  *
856  * Similar to bus_find_device.  It returns a reference to a gpio_chip as
857  * determined by a user supplied @match callback.  The callback should return
858  * 0 if the device doesn't match and non-zero if it does.  If the callback is
859  * non-zero, this function will return to the caller and not iterate over any
860  * more gpio_chips.
861  */
862 struct gpio_chip *gpiochip_find(void *data,
863 				int (*match)(struct gpio_chip *chip,
864 					     void *data))
865 {
866 	struct gpio_device *gdev;
867 	struct gpio_chip *chip;
868 	unsigned long flags;
869 
870 	spin_lock_irqsave(&gpio_lock, flags);
871 	list_for_each_entry(gdev, &gpio_devices, list)
872 		if (gdev->chip && match(gdev->chip, data))
873 			break;
874 
875 	/* No match? */
876 	if (&gdev->list == &gpio_devices)
877 		chip = NULL;
878 	else
879 		chip = gdev->chip;
880 
881 	spin_unlock_irqrestore(&gpio_lock, flags);
882 
883 	return chip;
884 }
885 EXPORT_SYMBOL_GPL(gpiochip_find);
886 
887 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
888 {
889 	const char *name = data;
890 
891 	return !strcmp(chip->label, name);
892 }
893 
894 static struct gpio_chip *find_chip_by_name(const char *name)
895 {
896 	return gpiochip_find((void *)name, gpiochip_match_name);
897 }
898 
899 #ifdef CONFIG_GPIOLIB_IRQCHIP
900 
901 /*
902  * The following is irqchip helper code for gpiochips.
903  */
904 
905 /**
906  * gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
907  * @gpiochip: the gpiochip to set the irqchip chain to
908  * @irqchip: the irqchip to chain to the gpiochip
909  * @parent_irq: the irq number corresponding to the parent IRQ for this
910  * chained irqchip
911  * @parent_handler: the parent interrupt handler for the accumulated IRQ
912  * coming out of the gpiochip. If the interrupt is nested rather than
913  * cascaded, pass NULL in this handler argument
914  */
915 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
916 				  struct irq_chip *irqchip,
917 				  int parent_irq,
918 				  irq_flow_handler_t parent_handler)
919 {
920 	unsigned int offset;
921 
922 	if (!gpiochip->irqdomain) {
923 		chip_err(gpiochip, "called %s before setting up irqchip\n",
924 			 __func__);
925 		return;
926 	}
927 
928 	if (parent_handler) {
929 		if (gpiochip->can_sleep) {
930 			chip_err(gpiochip,
931 				 "you cannot have chained interrupts on a "
932 				 "chip that may sleep\n");
933 			return;
934 		}
935 		/*
936 		 * The parent irqchip is already using the chip_data for this
937 		 * irqchip, so our callbacks simply use the handler_data.
938 		 */
939 		irq_set_chained_handler_and_data(parent_irq, parent_handler,
940 						 gpiochip);
941 
942 		gpiochip->irq_parent = parent_irq;
943 	}
944 
945 	/* Set the parent IRQ for all affected IRQs */
946 	for (offset = 0; offset < gpiochip->ngpio; offset++)
947 		irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
948 			       parent_irq);
949 }
950 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
951 
952 /**
953  * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
954  * @d: the irqdomain used by this irqchip
955  * @irq: the global irq number used by this GPIO irqchip irq
956  * @hwirq: the local IRQ/GPIO line offset on this gpiochip
957  *
958  * This function will set up the mapping for a certain IRQ line on a
959  * gpiochip by assigning the gpiochip as chip data, and using the irqchip
960  * stored inside the gpiochip.
961  */
962 static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
963 			    irq_hw_number_t hwirq)
964 {
965 	struct gpio_chip *chip = d->host_data;
966 
967 	irq_set_chip_data(irq, chip);
968 	/*
969 	 * This lock class tells lockdep that GPIO irqs are in a different
970 	 * category than their parents, so it won't report false recursion.
971 	 */
972 	irq_set_lockdep_class(irq, chip->lock_key);
973 	irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
974 	/* Chips that can sleep need nested thread handlers */
975 	if (chip->can_sleep && !chip->irq_not_threaded)
976 		irq_set_nested_thread(irq, 1);
977 	irq_set_noprobe(irq);
978 
979 	/*
980 	 * No set-up of the hardware will happen if IRQ_TYPE_NONE
981 	 * is passed as default type.
982 	 */
983 	if (chip->irq_default_type != IRQ_TYPE_NONE)
984 		irq_set_irq_type(irq, chip->irq_default_type);
985 
986 	return 0;
987 }
988 
989 static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
990 {
991 	struct gpio_chip *chip = d->host_data;
992 
993 	if (chip->can_sleep)
994 		irq_set_nested_thread(irq, 0);
995 	irq_set_chip_and_handler(irq, NULL, NULL);
996 	irq_set_chip_data(irq, NULL);
997 }
998 
999 static const struct irq_domain_ops gpiochip_domain_ops = {
1000 	.map	= gpiochip_irq_map,
1001 	.unmap	= gpiochip_irq_unmap,
1002 	/* Virtually all GPIO irqchips are twocell:ed */
1003 	.xlate	= irq_domain_xlate_twocell,
1004 };
1005 
1006 static int gpiochip_irq_reqres(struct irq_data *d)
1007 {
1008 	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1009 
1010 	if (!try_module_get(chip->gpiodev->owner))
1011 		return -ENODEV;
1012 
1013 	if (gpiochip_lock_as_irq(chip, d->hwirq)) {
1014 		chip_err(chip,
1015 			"unable to lock HW IRQ %lu for IRQ\n",
1016 			d->hwirq);
1017 		module_put(chip->gpiodev->owner);
1018 		return -EINVAL;
1019 	}
1020 	return 0;
1021 }
1022 
1023 static void gpiochip_irq_relres(struct irq_data *d)
1024 {
1025 	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1026 
1027 	gpiochip_unlock_as_irq(chip, d->hwirq);
1028 	module_put(chip->gpiodev->owner);
1029 }
1030 
1031 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1032 {
1033 	return irq_find_mapping(chip->irqdomain, offset);
1034 }
1035 
1036 /**
1037  * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1038  * @gpiochip: the gpiochip to remove the irqchip from
1039  *
1040  * This is called only from gpiochip_remove()
1041  */
1042 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1043 {
1044 	unsigned int offset;
1045 
1046 	acpi_gpiochip_free_interrupts(gpiochip);
1047 
1048 	if (gpiochip->irq_parent) {
1049 		irq_set_chained_handler(gpiochip->irq_parent, NULL);
1050 		irq_set_handler_data(gpiochip->irq_parent, NULL);
1051 	}
1052 
1053 	/* Remove all IRQ mappings and delete the domain */
1054 	if (gpiochip->irqdomain) {
1055 		for (offset = 0; offset < gpiochip->ngpio; offset++)
1056 			irq_dispose_mapping(
1057 				irq_find_mapping(gpiochip->irqdomain, offset));
1058 		irq_domain_remove(gpiochip->irqdomain);
1059 	}
1060 
1061 	if (gpiochip->irqchip) {
1062 		gpiochip->irqchip->irq_request_resources = NULL;
1063 		gpiochip->irqchip->irq_release_resources = NULL;
1064 		gpiochip->irqchip = NULL;
1065 	}
1066 }
1067 
1068 /**
1069  * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1070  * @gpiochip: the gpiochip to add the irqchip to
1071  * @irqchip: the irqchip to add to the gpiochip
1072  * @first_irq: if not dynamically assigned, the base (first) IRQ to
1073  * allocate gpiochip irqs from
1074  * @handler: the irq handler to use (often a predefined irq core function)
1075  * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
1076  * to have the core avoid setting up any default type in the hardware.
1077  * @lock_key: lockdep class
1078  *
1079  * This function closely associates a certain irqchip with a certain
1080  * gpiochip, providing an irq domain to translate the local IRQs to
1081  * global irqs in the gpiolib core, and making sure that the gpiochip
1082  * is passed as chip data to all related functions. Driver callbacks
1083  * need to use gpiochip_get_data() to get their local state containers back
1084  * from the gpiochip passed as chip data. An irqdomain will be stored
1085  * in the gpiochip that shall be used by the driver to handle IRQ number
1086  * translation. The gpiochip will need to be initialized and registered
1087  * before calling this function.
1088  *
1089  * This function will handle two cell:ed simple IRQs and assumes all
1090  * the pins on the gpiochip can generate a unique IRQ. Everything else
1091  * need to be open coded.
1092  */
1093 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1094 			  struct irq_chip *irqchip,
1095 			  unsigned int first_irq,
1096 			  irq_flow_handler_t handler,
1097 			  unsigned int type,
1098 			  struct lock_class_key *lock_key)
1099 {
1100 	struct device_node *of_node;
1101 	unsigned int offset;
1102 	unsigned irq_base = 0;
1103 
1104 	if (!gpiochip || !irqchip)
1105 		return -EINVAL;
1106 
1107 	if (!gpiochip->parent) {
1108 		pr_err("missing gpiochip .dev parent pointer\n");
1109 		return -EINVAL;
1110 	}
1111 	of_node = gpiochip->parent->of_node;
1112 #ifdef CONFIG_OF_GPIO
1113 	/*
1114 	 * If the gpiochip has an assigned OF node this takes precedence
1115 	 * FIXME: get rid of this and use gpiochip->parent->of_node
1116 	 * everywhere
1117 	 */
1118 	if (gpiochip->of_node)
1119 		of_node = gpiochip->of_node;
1120 #endif
1121 	gpiochip->irqchip = irqchip;
1122 	gpiochip->irq_handler = handler;
1123 	gpiochip->irq_default_type = type;
1124 	gpiochip->to_irq = gpiochip_to_irq;
1125 	gpiochip->lock_key = lock_key;
1126 	gpiochip->irqdomain = irq_domain_add_simple(of_node,
1127 					gpiochip->ngpio, first_irq,
1128 					&gpiochip_domain_ops, gpiochip);
1129 	if (!gpiochip->irqdomain) {
1130 		gpiochip->irqchip = NULL;
1131 		return -EINVAL;
1132 	}
1133 
1134 	/*
1135 	 * It is possible for a driver to override this, but only if the
1136 	 * alternative functions are both implemented.
1137 	 */
1138 	if (!irqchip->irq_request_resources &&
1139 	    !irqchip->irq_release_resources) {
1140 		irqchip->irq_request_resources = gpiochip_irq_reqres;
1141 		irqchip->irq_release_resources = gpiochip_irq_relres;
1142 	}
1143 
1144 	/*
1145 	 * Prepare the mapping since the irqchip shall be orthogonal to
1146 	 * any gpiochip calls. If the first_irq was zero, this is
1147 	 * necessary to allocate descriptors for all IRQs.
1148 	 */
1149 	for (offset = 0; offset < gpiochip->ngpio; offset++) {
1150 		irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1151 		if (offset == 0)
1152 			/*
1153 			 * Store the base into the gpiochip to be used when
1154 			 * unmapping the irqs.
1155 			 */
1156 			gpiochip->irq_base = irq_base;
1157 	}
1158 
1159 	acpi_gpiochip_request_interrupts(gpiochip);
1160 
1161 	return 0;
1162 }
1163 EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
1164 
1165 #else /* CONFIG_GPIOLIB_IRQCHIP */
1166 
1167 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1168 
1169 #endif /* CONFIG_GPIOLIB_IRQCHIP */
1170 
1171 /**
1172  * gpiochip_generic_request() - request the gpio function for a pin
1173  * @chip: the gpiochip owning the GPIO
1174  * @offset: the offset of the GPIO to request for GPIO function
1175  */
1176 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
1177 {
1178 	return pinctrl_request_gpio(chip->gpiodev->base + offset);
1179 }
1180 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
1181 
1182 /**
1183  * gpiochip_generic_free() - free the gpio function from a pin
1184  * @chip: the gpiochip to request the gpio function for
1185  * @offset: the offset of the GPIO to free from GPIO function
1186  */
1187 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
1188 {
1189 	pinctrl_free_gpio(chip->gpiodev->base + offset);
1190 }
1191 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
1192 
1193 #ifdef CONFIG_PINCTRL
1194 
1195 /**
1196  * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1197  * @chip: the gpiochip to add the range for
1198  * @pctldev: the pin controller to map to
1199  * @gpio_offset: the start offset in the current gpio_chip number space
1200  * @pin_group: name of the pin group inside the pin controller
1201  */
1202 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1203 			struct pinctrl_dev *pctldev,
1204 			unsigned int gpio_offset, const char *pin_group)
1205 {
1206 	struct gpio_pin_range *pin_range;
1207 	struct gpio_device *gdev = chip->gpiodev;
1208 	int ret;
1209 
1210 	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1211 	if (!pin_range) {
1212 		chip_err(chip, "failed to allocate pin ranges\n");
1213 		return -ENOMEM;
1214 	}
1215 
1216 	/* Use local offset as range ID */
1217 	pin_range->range.id = gpio_offset;
1218 	pin_range->range.gc = chip;
1219 	pin_range->range.name = chip->label;
1220 	pin_range->range.base = gdev->base + gpio_offset;
1221 	pin_range->pctldev = pctldev;
1222 
1223 	ret = pinctrl_get_group_pins(pctldev, pin_group,
1224 					&pin_range->range.pins,
1225 					&pin_range->range.npins);
1226 	if (ret < 0) {
1227 		kfree(pin_range);
1228 		return ret;
1229 	}
1230 
1231 	pinctrl_add_gpio_range(pctldev, &pin_range->range);
1232 
1233 	chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1234 		 gpio_offset, gpio_offset + pin_range->range.npins - 1,
1235 		 pinctrl_dev_get_devname(pctldev), pin_group);
1236 
1237 	list_add_tail(&pin_range->node, &gdev->pin_ranges);
1238 
1239 	return 0;
1240 }
1241 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1242 
1243 /**
1244  * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1245  * @chip: the gpiochip to add the range for
1246  * @pinctrl_name: the dev_name() of the pin controller to map to
1247  * @gpio_offset: the start offset in the current gpio_chip number space
1248  * @pin_offset: the start offset in the pin controller number space
1249  * @npins: the number of pins from the offset of each pin space (GPIO and
1250  *	pin controller) to accumulate in this range
1251  */
1252 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
1253 			   unsigned int gpio_offset, unsigned int pin_offset,
1254 			   unsigned int npins)
1255 {
1256 	struct gpio_pin_range *pin_range;
1257 	struct gpio_device *gdev = chip->gpiodev;
1258 	int ret;
1259 
1260 	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1261 	if (!pin_range) {
1262 		chip_err(chip, "failed to allocate pin ranges\n");
1263 		return -ENOMEM;
1264 	}
1265 
1266 	/* Use local offset as range ID */
1267 	pin_range->range.id = gpio_offset;
1268 	pin_range->range.gc = chip;
1269 	pin_range->range.name = chip->label;
1270 	pin_range->range.base = gdev->base + gpio_offset;
1271 	pin_range->range.pin_base = pin_offset;
1272 	pin_range->range.npins = npins;
1273 	pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
1274 			&pin_range->range);
1275 	if (IS_ERR(pin_range->pctldev)) {
1276 		ret = PTR_ERR(pin_range->pctldev);
1277 		chip_err(chip, "could not create pin range\n");
1278 		kfree(pin_range);
1279 		return ret;
1280 	}
1281 	chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1282 		 gpio_offset, gpio_offset + npins - 1,
1283 		 pinctl_name,
1284 		 pin_offset, pin_offset + npins - 1);
1285 
1286 	list_add_tail(&pin_range->node, &gdev->pin_ranges);
1287 
1288 	return 0;
1289 }
1290 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
1291 
1292 /**
1293  * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1294  * @chip: the chip to remove all the mappings for
1295  */
1296 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1297 {
1298 	struct gpio_pin_range *pin_range, *tmp;
1299 	struct gpio_device *gdev = chip->gpiodev;
1300 
1301 	list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
1302 		list_del(&pin_range->node);
1303 		pinctrl_remove_gpio_range(pin_range->pctldev,
1304 				&pin_range->range);
1305 		kfree(pin_range);
1306 	}
1307 }
1308 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1309 
1310 #endif /* CONFIG_PINCTRL */
1311 
1312 /* These "optional" allocation calls help prevent drivers from stomping
1313  * on each other, and help provide better diagnostics in debugfs.
1314  * They're called even less than the "set direction" calls.
1315  */
1316 static int __gpiod_request(struct gpio_desc *desc, const char *label)
1317 {
1318 	struct gpio_chip	*chip = desc->gdev->chip;
1319 	int			status;
1320 	unsigned long		flags;
1321 
1322 	spin_lock_irqsave(&gpio_lock, flags);
1323 
1324 	/* NOTE:  gpio_request() can be called in early boot,
1325 	 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
1326 	 */
1327 
1328 	if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1329 		desc_set_label(desc, label ? : "?");
1330 		status = 0;
1331 	} else {
1332 		status = -EBUSY;
1333 		goto done;
1334 	}
1335 
1336 	if (chip->request) {
1337 		/* chip->request may sleep */
1338 		spin_unlock_irqrestore(&gpio_lock, flags);
1339 		status = chip->request(chip, gpio_chip_hwgpio(desc));
1340 		spin_lock_irqsave(&gpio_lock, flags);
1341 
1342 		if (status < 0) {
1343 			desc_set_label(desc, NULL);
1344 			clear_bit(FLAG_REQUESTED, &desc->flags);
1345 			goto done;
1346 		}
1347 	}
1348 	if (chip->get_direction) {
1349 		/* chip->get_direction may sleep */
1350 		spin_unlock_irqrestore(&gpio_lock, flags);
1351 		gpiod_get_direction(desc);
1352 		spin_lock_irqsave(&gpio_lock, flags);
1353 	}
1354 done:
1355 	spin_unlock_irqrestore(&gpio_lock, flags);
1356 	return status;
1357 }
1358 
1359 /*
1360  * This descriptor validation needs to be inserted verbatim into each
1361  * function taking a descriptor, so we need to use a preprocessor
1362  * macro to avoid endless duplication. If the desc is NULL it is an
1363  * optional GPIO and calls should just bail out.
1364  */
1365 #define VALIDATE_DESC(desc) do { \
1366 	if (!desc) \
1367 		return 0; \
1368 	if (IS_ERR(desc)) {						\
1369 		pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1370 		return PTR_ERR(desc); \
1371 	} \
1372 	if (!desc->gdev) { \
1373 		pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1374 		return -EINVAL; \
1375 	} \
1376 	if ( !desc->gdev->chip ) { \
1377 		dev_warn(&desc->gdev->dev, \
1378 			 "%s: backing chip is gone\n", __func__); \
1379 		return 0; \
1380 	} } while (0)
1381 
1382 #define VALIDATE_DESC_VOID(desc) do { \
1383 	if (!desc) \
1384 		return; \
1385 	if (IS_ERR(desc)) {						\
1386 		pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
1387 		return; \
1388 	} \
1389 	if (!desc->gdev) { \
1390 		pr_warn("%s: invalid GPIO (no device)\n", __func__); \
1391 		return; \
1392 	} \
1393 	if (!desc->gdev->chip) { \
1394 		dev_warn(&desc->gdev->dev, \
1395 			 "%s: backing chip is gone\n", __func__); \
1396 		return; \
1397 	} } while (0)
1398 
1399 
1400 int gpiod_request(struct gpio_desc *desc, const char *label)
1401 {
1402 	int status = -EPROBE_DEFER;
1403 	struct gpio_device *gdev;
1404 
1405 	VALIDATE_DESC(desc);
1406 	gdev = desc->gdev;
1407 
1408 	if (try_module_get(gdev->owner)) {
1409 		status = __gpiod_request(desc, label);
1410 		if (status < 0)
1411 			module_put(gdev->owner);
1412 		else
1413 			get_device(&gdev->dev);
1414 	}
1415 
1416 	if (status)
1417 		gpiod_dbg(desc, "%s: status %d\n", __func__, status);
1418 
1419 	return status;
1420 }
1421 
1422 static bool __gpiod_free(struct gpio_desc *desc)
1423 {
1424 	bool			ret = false;
1425 	unsigned long		flags;
1426 	struct gpio_chip	*chip;
1427 
1428 	might_sleep();
1429 
1430 	gpiod_unexport(desc);
1431 
1432 	spin_lock_irqsave(&gpio_lock, flags);
1433 
1434 	chip = desc->gdev->chip;
1435 	if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1436 		if (chip->free) {
1437 			spin_unlock_irqrestore(&gpio_lock, flags);
1438 			might_sleep_if(chip->can_sleep);
1439 			chip->free(chip, gpio_chip_hwgpio(desc));
1440 			spin_lock_irqsave(&gpio_lock, flags);
1441 		}
1442 		desc_set_label(desc, NULL);
1443 		clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
1444 		clear_bit(FLAG_REQUESTED, &desc->flags);
1445 		clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
1446 		clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
1447 		clear_bit(FLAG_IS_HOGGED, &desc->flags);
1448 		ret = true;
1449 	}
1450 
1451 	spin_unlock_irqrestore(&gpio_lock, flags);
1452 	return ret;
1453 }
1454 
1455 void gpiod_free(struct gpio_desc *desc)
1456 {
1457 	if (desc && desc->gdev && __gpiod_free(desc)) {
1458 		module_put(desc->gdev->owner);
1459 		put_device(&desc->gdev->dev);
1460 	} else {
1461 		WARN_ON(extra_checks);
1462 	}
1463 }
1464 
1465 /**
1466  * gpiochip_is_requested - return string iff signal was requested
1467  * @chip: controller managing the signal
1468  * @offset: of signal within controller's 0..(ngpio - 1) range
1469  *
1470  * Returns NULL if the GPIO is not currently requested, else a string.
1471  * The string returned is the label passed to gpio_request(); if none has been
1472  * passed it is a meaningless, non-NULL constant.
1473  *
1474  * This function is for use by GPIO controller drivers.  The label can
1475  * help with diagnostics, and knowing that the signal is used as a GPIO
1476  * can help avoid accidentally multiplexing it to another controller.
1477  */
1478 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1479 {
1480 	struct gpio_desc *desc;
1481 
1482 	if (offset >= chip->ngpio)
1483 		return NULL;
1484 
1485 	desc = &chip->gpiodev->descs[offset];
1486 
1487 	if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
1488 		return NULL;
1489 	return desc->label;
1490 }
1491 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1492 
1493 /**
1494  * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1495  * @desc: GPIO descriptor to request
1496  * @label: label for the GPIO
1497  *
1498  * Function allows GPIO chip drivers to request and use their own GPIO
1499  * descriptors via gpiolib API. Difference to gpiod_request() is that this
1500  * function will not increase reference count of the GPIO chip module. This
1501  * allows the GPIO chip module to be unloaded as needed (we assume that the
1502  * GPIO chip driver handles freeing the GPIOs it has requested).
1503  */
1504 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
1505 					    const char *label)
1506 {
1507 	struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
1508 	int err;
1509 
1510 	if (IS_ERR(desc)) {
1511 		chip_err(chip, "failed to get GPIO descriptor\n");
1512 		return desc;
1513 	}
1514 
1515 	err = __gpiod_request(desc, label);
1516 	if (err < 0)
1517 		return ERR_PTR(err);
1518 
1519 	return desc;
1520 }
1521 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
1522 
1523 /**
1524  * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1525  * @desc: GPIO descriptor to free
1526  *
1527  * Function frees the given GPIO requested previously with
1528  * gpiochip_request_own_desc().
1529  */
1530 void gpiochip_free_own_desc(struct gpio_desc *desc)
1531 {
1532 	if (desc)
1533 		__gpiod_free(desc);
1534 }
1535 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
1536 
1537 /*
1538  * Drivers MUST set GPIO direction before making get/set calls.  In
1539  * some cases this is done in early boot, before IRQs are enabled.
1540  *
1541  * As a rule these aren't called more than once (except for drivers
1542  * using the open-drain emulation idiom) so these are natural places
1543  * to accumulate extra debugging checks.  Note that we can't (yet)
1544  * rely on gpio_request() having been called beforehand.
1545  */
1546 
1547 /**
1548  * gpiod_direction_input - set the GPIO direction to input
1549  * @desc:	GPIO to set to input
1550  *
1551  * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1552  * be called safely on it.
1553  *
1554  * Return 0 in case of success, else an error code.
1555  */
1556 int gpiod_direction_input(struct gpio_desc *desc)
1557 {
1558 	struct gpio_chip	*chip;
1559 	int			status = -EINVAL;
1560 
1561 	VALIDATE_DESC(desc);
1562 	chip = desc->gdev->chip;
1563 
1564 	if (!chip->get || !chip->direction_input) {
1565 		gpiod_warn(desc,
1566 			"%s: missing get() or direction_input() operations\n",
1567 			__func__);
1568 		return -EIO;
1569 	}
1570 
1571 	status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
1572 	if (status == 0)
1573 		clear_bit(FLAG_IS_OUT, &desc->flags);
1574 
1575 	trace_gpio_direction(desc_to_gpio(desc), 1, status);
1576 
1577 	return status;
1578 }
1579 EXPORT_SYMBOL_GPL(gpiod_direction_input);
1580 
1581 static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1582 {
1583 	struct gpio_chip *gc = desc->gdev->chip;
1584 	int ret;
1585 
1586 	/* GPIOs used for IRQs shall not be set as output */
1587 	if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
1588 		gpiod_err(desc,
1589 			  "%s: tried to set a GPIO tied to an IRQ as output\n",
1590 			  __func__);
1591 		return -EIO;
1592 	}
1593 
1594 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1595 		/* First see if we can enable open drain in hardware */
1596 		if (gc->set_single_ended) {
1597 			ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
1598 						   LINE_MODE_OPEN_DRAIN);
1599 			if (!ret)
1600 				goto set_output_value;
1601 		}
1602 		/* Emulate open drain by not actively driving the line high */
1603 		if (value)
1604 			return gpiod_direction_input(desc);
1605 	}
1606 	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1607 		if (gc->set_single_ended) {
1608 			ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
1609 						   LINE_MODE_OPEN_SOURCE);
1610 			if (!ret)
1611 				goto set_output_value;
1612 		}
1613 		/* Emulate open source by not actively driving the line low */
1614 		if (!value)
1615 			return gpiod_direction_input(desc);
1616 	} else {
1617 		/* Make sure to disable open drain/source hardware, if any */
1618 		if (gc->set_single_ended)
1619 			gc->set_single_ended(gc,
1620 					     gpio_chip_hwgpio(desc),
1621 					     LINE_MODE_PUSH_PULL);
1622 	}
1623 
1624 set_output_value:
1625 	if (!gc->set || !gc->direction_output) {
1626 		gpiod_warn(desc,
1627 		       "%s: missing set() or direction_output() operations\n",
1628 		       __func__);
1629 		return -EIO;
1630 	}
1631 
1632 	ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
1633 	if (!ret)
1634 		set_bit(FLAG_IS_OUT, &desc->flags);
1635 	trace_gpio_value(desc_to_gpio(desc), 0, value);
1636 	trace_gpio_direction(desc_to_gpio(desc), 0, ret);
1637 	return ret;
1638 }
1639 
1640 /**
1641  * gpiod_direction_output_raw - set the GPIO direction to output
1642  * @desc:	GPIO to set to output
1643  * @value:	initial output value of the GPIO
1644  *
1645  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1646  * be called safely on it. The initial value of the output must be specified
1647  * as raw value on the physical line without regard for the ACTIVE_LOW status.
1648  *
1649  * Return 0 in case of success, else an error code.
1650  */
1651 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
1652 {
1653 	VALIDATE_DESC(desc);
1654 	return _gpiod_direction_output_raw(desc, value);
1655 }
1656 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
1657 
1658 /**
1659  * gpiod_direction_output - set the GPIO direction to output
1660  * @desc:	GPIO to set to output
1661  * @value:	initial output value of the GPIO
1662  *
1663  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
1664  * be called safely on it. The initial value of the output must be specified
1665  * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1666  * account.
1667  *
1668  * Return 0 in case of success, else an error code.
1669  */
1670 int gpiod_direction_output(struct gpio_desc *desc, int value)
1671 {
1672 	VALIDATE_DESC(desc);
1673 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1674 		value = !value;
1675 	return _gpiod_direction_output_raw(desc, value);
1676 }
1677 EXPORT_SYMBOL_GPL(gpiod_direction_output);
1678 
1679 /**
1680  * gpiod_set_debounce - sets @debounce time for a @gpio
1681  * @gpio: the gpio to set debounce time
1682  * @debounce: debounce time is microseconds
1683  *
1684  * returns -ENOTSUPP if the controller does not support setting
1685  * debounce.
1686  */
1687 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
1688 {
1689 	struct gpio_chip	*chip;
1690 
1691 	VALIDATE_DESC(desc);
1692 	chip = desc->gdev->chip;
1693 	if (!chip->set || !chip->set_debounce) {
1694 		gpiod_dbg(desc,
1695 			  "%s: missing set() or set_debounce() operations\n",
1696 			  __func__);
1697 		return -ENOTSUPP;
1698 	}
1699 
1700 	return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
1701 }
1702 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
1703 
1704 /**
1705  * gpiod_is_active_low - test whether a GPIO is active-low or not
1706  * @desc: the gpio descriptor to test
1707  *
1708  * Returns 1 if the GPIO is active-low, 0 otherwise.
1709  */
1710 int gpiod_is_active_low(const struct gpio_desc *desc)
1711 {
1712 	VALIDATE_DESC(desc);
1713 	return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
1714 }
1715 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
1716 
1717 /* I/O calls are only valid after configuration completed; the relevant
1718  * "is this a valid GPIO" error checks should already have been done.
1719  *
1720  * "Get" operations are often inlinable as reading a pin value register,
1721  * and masking the relevant bit in that register.
1722  *
1723  * When "set" operations are inlinable, they involve writing that mask to
1724  * one register to set a low value, or a different register to set it high.
1725  * Otherwise locking is needed, so there may be little value to inlining.
1726  *
1727  *------------------------------------------------------------------------
1728  *
1729  * IMPORTANT!!!  The hot paths -- get/set value -- assume that callers
1730  * have requested the GPIO.  That can include implicit requesting by
1731  * a direction setting call.  Marking a gpio as requested locks its chip
1732  * in memory, guaranteeing that these table lookups need no more locking
1733  * and that gpiochip_remove() will fail.
1734  *
1735  * REVISIT when debugging, consider adding some instrumentation to ensure
1736  * that the GPIO was actually requested.
1737  */
1738 
1739 static int _gpiod_get_raw_value(const struct gpio_desc *desc)
1740 {
1741 	struct gpio_chip	*chip;
1742 	int offset;
1743 	int value;
1744 
1745 	chip = desc->gdev->chip;
1746 	offset = gpio_chip_hwgpio(desc);
1747 	value = chip->get ? chip->get(chip, offset) : -EIO;
1748 	value = value < 0 ? value : !!value;
1749 	trace_gpio_value(desc_to_gpio(desc), 1, value);
1750 	return value;
1751 }
1752 
1753 /**
1754  * gpiod_get_raw_value() - return a gpio's raw value
1755  * @desc: gpio whose value will be returned
1756  *
1757  * Return the GPIO's raw value, i.e. the value of the physical line disregarding
1758  * its ACTIVE_LOW status, or negative errno on failure.
1759  *
1760  * This function should be called from contexts where we cannot sleep, and will
1761  * complain if the GPIO chip functions potentially sleep.
1762  */
1763 int gpiod_get_raw_value(const struct gpio_desc *desc)
1764 {
1765 	VALIDATE_DESC(desc);
1766 	/* Should be using gpio_get_value_cansleep() */
1767 	WARN_ON(desc->gdev->chip->can_sleep);
1768 	return _gpiod_get_raw_value(desc);
1769 }
1770 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
1771 
1772 /**
1773  * gpiod_get_value() - return a gpio's value
1774  * @desc: gpio whose value will be returned
1775  *
1776  * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
1777  * account, or negative errno on failure.
1778  *
1779  * This function should be called from contexts where we cannot sleep, and will
1780  * complain if the GPIO chip functions potentially sleep.
1781  */
1782 int gpiod_get_value(const struct gpio_desc *desc)
1783 {
1784 	int value;
1785 
1786 	VALIDATE_DESC(desc);
1787 	/* Should be using gpio_get_value_cansleep() */
1788 	WARN_ON(desc->gdev->chip->can_sleep);
1789 
1790 	value = _gpiod_get_raw_value(desc);
1791 	if (value < 0)
1792 		return value;
1793 
1794 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1795 		value = !value;
1796 
1797 	return value;
1798 }
1799 EXPORT_SYMBOL_GPL(gpiod_get_value);
1800 
1801 /*
1802  *  _gpio_set_open_drain_value() - Set the open drain gpio's value.
1803  * @desc: gpio descriptor whose state need to be set.
1804  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1805  */
1806 static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
1807 {
1808 	int err = 0;
1809 	struct gpio_chip *chip = desc->gdev->chip;
1810 	int offset = gpio_chip_hwgpio(desc);
1811 
1812 	if (value) {
1813 		err = chip->direction_input(chip, offset);
1814 		if (!err)
1815 			clear_bit(FLAG_IS_OUT, &desc->flags);
1816 	} else {
1817 		err = chip->direction_output(chip, offset, 0);
1818 		if (!err)
1819 			set_bit(FLAG_IS_OUT, &desc->flags);
1820 	}
1821 	trace_gpio_direction(desc_to_gpio(desc), value, err);
1822 	if (err < 0)
1823 		gpiod_err(desc,
1824 			  "%s: Error in set_value for open drain err %d\n",
1825 			  __func__, err);
1826 }
1827 
1828 /*
1829  *  _gpio_set_open_source_value() - Set the open source gpio's value.
1830  * @desc: gpio descriptor whose state need to be set.
1831  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
1832  */
1833 static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
1834 {
1835 	int err = 0;
1836 	struct gpio_chip *chip = desc->gdev->chip;
1837 	int offset = gpio_chip_hwgpio(desc);
1838 
1839 	if (value) {
1840 		err = chip->direction_output(chip, offset, 1);
1841 		if (!err)
1842 			set_bit(FLAG_IS_OUT, &desc->flags);
1843 	} else {
1844 		err = chip->direction_input(chip, offset);
1845 		if (!err)
1846 			clear_bit(FLAG_IS_OUT, &desc->flags);
1847 	}
1848 	trace_gpio_direction(desc_to_gpio(desc), !value, err);
1849 	if (err < 0)
1850 		gpiod_err(desc,
1851 			  "%s: Error in set_value for open source err %d\n",
1852 			  __func__, err);
1853 }
1854 
1855 static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
1856 {
1857 	struct gpio_chip	*chip;
1858 
1859 	chip = desc->gdev->chip;
1860 	trace_gpio_value(desc_to_gpio(desc), 0, value);
1861 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1862 		_gpio_set_open_drain_value(desc, value);
1863 	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1864 		_gpio_set_open_source_value(desc, value);
1865 	else
1866 		chip->set(chip, gpio_chip_hwgpio(desc), value);
1867 }
1868 
1869 /*
1870  * set multiple outputs on the same chip;
1871  * use the chip's set_multiple function if available;
1872  * otherwise set the outputs sequentially;
1873  * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
1874  *        defines which outputs are to be changed
1875  * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
1876  *        defines the values the outputs specified by mask are to be set to
1877  */
1878 static void gpio_chip_set_multiple(struct gpio_chip *chip,
1879 				   unsigned long *mask, unsigned long *bits)
1880 {
1881 	if (chip->set_multiple) {
1882 		chip->set_multiple(chip, mask, bits);
1883 	} else {
1884 		int i;
1885 		for (i = 0; i < chip->ngpio; i++) {
1886 			if (mask[BIT_WORD(i)] == 0) {
1887 				/* no more set bits in this mask word;
1888 				 * skip ahead to the next word */
1889 				i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
1890 				continue;
1891 			}
1892 			/* set outputs if the corresponding mask bit is set */
1893 			if (__test_and_clear_bit(i, mask))
1894 				chip->set(chip, i, test_bit(i, bits));
1895 		}
1896 	}
1897 }
1898 
1899 void gpiod_set_array_value_complex(bool raw, bool can_sleep,
1900 				   unsigned int array_size,
1901 				   struct gpio_desc **desc_array,
1902 				   int *value_array)
1903 {
1904 	int i = 0;
1905 
1906 	while (i < array_size) {
1907 		struct gpio_chip *chip = desc_array[i]->gdev->chip;
1908 		unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
1909 		unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
1910 		int count = 0;
1911 
1912 		if (!can_sleep)
1913 			WARN_ON(chip->can_sleep);
1914 
1915 		memset(mask, 0, sizeof(mask));
1916 		do {
1917 			struct gpio_desc *desc = desc_array[i];
1918 			int hwgpio = gpio_chip_hwgpio(desc);
1919 			int value = value_array[i];
1920 
1921 			if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1922 				value = !value;
1923 			trace_gpio_value(desc_to_gpio(desc), 0, value);
1924 			/*
1925 			 * collect all normal outputs belonging to the same chip
1926 			 * open drain and open source outputs are set individually
1927 			 */
1928 			if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
1929 				_gpio_set_open_drain_value(desc, value);
1930 			} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
1931 				_gpio_set_open_source_value(desc, value);
1932 			} else {
1933 				__set_bit(hwgpio, mask);
1934 				if (value)
1935 					__set_bit(hwgpio, bits);
1936 				else
1937 					__clear_bit(hwgpio, bits);
1938 				count++;
1939 			}
1940 			i++;
1941 		} while ((i < array_size) &&
1942 			 (desc_array[i]->gdev->chip == chip));
1943 		/* push collected bits to outputs */
1944 		if (count != 0)
1945 			gpio_chip_set_multiple(chip, mask, bits);
1946 	}
1947 }
1948 
1949 /**
1950  * gpiod_set_raw_value() - assign a gpio's raw value
1951  * @desc: gpio whose value will be assigned
1952  * @value: value to assign
1953  *
1954  * Set the raw value of the GPIO, i.e. the value of its physical line without
1955  * regard for its ACTIVE_LOW status.
1956  *
1957  * This function should be called from contexts where we cannot sleep, and will
1958  * complain if the GPIO chip functions potentially sleep.
1959  */
1960 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
1961 {
1962 	VALIDATE_DESC_VOID(desc);
1963 	/* Should be using gpiod_set_value_cansleep() */
1964 	WARN_ON(desc->gdev->chip->can_sleep);
1965 	_gpiod_set_raw_value(desc, value);
1966 }
1967 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
1968 
1969 /**
1970  * gpiod_set_value() - assign a gpio's value
1971  * @desc: gpio whose value will be assigned
1972  * @value: value to assign
1973  *
1974  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
1975  * account
1976  *
1977  * This function should be called from contexts where we cannot sleep, and will
1978  * complain if the GPIO chip functions potentially sleep.
1979  */
1980 void gpiod_set_value(struct gpio_desc *desc, int value)
1981 {
1982 	VALIDATE_DESC_VOID(desc);
1983 	/* Should be using gpiod_set_value_cansleep() */
1984 	WARN_ON(desc->gdev->chip->can_sleep);
1985 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1986 		value = !value;
1987 	_gpiod_set_raw_value(desc, value);
1988 }
1989 EXPORT_SYMBOL_GPL(gpiod_set_value);
1990 
1991 /**
1992  * gpiod_set_raw_array_value() - assign values to an array of GPIOs
1993  * @array_size: number of elements in the descriptor / value arrays
1994  * @desc_array: array of GPIO descriptors whose values will be assigned
1995  * @value_array: array of values to assign
1996  *
1997  * Set the raw values of the GPIOs, i.e. the values of the physical lines
1998  * without regard for their ACTIVE_LOW status.
1999  *
2000  * This function should be called from contexts where we cannot sleep, and will
2001  * complain if the GPIO chip functions potentially sleep.
2002  */
2003 void gpiod_set_raw_array_value(unsigned int array_size,
2004 			 struct gpio_desc **desc_array, int *value_array)
2005 {
2006 	if (!desc_array)
2007 		return;
2008 	gpiod_set_array_value_complex(true, false, array_size, desc_array,
2009 				      value_array);
2010 }
2011 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
2012 
2013 /**
2014  * gpiod_set_array_value() - assign values to an array of GPIOs
2015  * @array_size: number of elements in the descriptor / value arrays
2016  * @desc_array: array of GPIO descriptors whose values will be assigned
2017  * @value_array: array of values to assign
2018  *
2019  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2020  * into account.
2021  *
2022  * This function should be called from contexts where we cannot sleep, and will
2023  * complain if the GPIO chip functions potentially sleep.
2024  */
2025 void gpiod_set_array_value(unsigned int array_size,
2026 			   struct gpio_desc **desc_array, int *value_array)
2027 {
2028 	if (!desc_array)
2029 		return;
2030 	gpiod_set_array_value_complex(false, false, array_size, desc_array,
2031 				      value_array);
2032 }
2033 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
2034 
2035 /**
2036  * gpiod_cansleep() - report whether gpio value access may sleep
2037  * @desc: gpio to check
2038  *
2039  */
2040 int gpiod_cansleep(const struct gpio_desc *desc)
2041 {
2042 	VALIDATE_DESC(desc);
2043 	return desc->gdev->chip->can_sleep;
2044 }
2045 EXPORT_SYMBOL_GPL(gpiod_cansleep);
2046 
2047 /**
2048  * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2049  * @desc: gpio whose IRQ will be returned (already requested)
2050  *
2051  * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2052  * error.
2053  */
2054 int gpiod_to_irq(const struct gpio_desc *desc)
2055 {
2056 	struct gpio_chip *chip;
2057 	int offset;
2058 
2059 	/*
2060 	 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
2061 	 * requires this function to not return zero on an invalid descriptor
2062 	 * but rather a negative error number.
2063 	 */
2064 	if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
2065 		return -EINVAL;
2066 
2067 	chip = desc->gdev->chip;
2068 	offset = gpio_chip_hwgpio(desc);
2069 	if (chip->to_irq) {
2070 		int retirq = chip->to_irq(chip, offset);
2071 
2072 		/* Zero means NO_IRQ */
2073 		if (!retirq)
2074 			return -ENXIO;
2075 
2076 		return retirq;
2077 	}
2078 	return -ENXIO;
2079 }
2080 EXPORT_SYMBOL_GPL(gpiod_to_irq);
2081 
2082 /**
2083  * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
2084  * @chip: the chip the GPIO to lock belongs to
2085  * @offset: the offset of the GPIO to lock as IRQ
2086  *
2087  * This is used directly by GPIO drivers that want to lock down
2088  * a certain GPIO line to be used for IRQs.
2089  */
2090 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2091 {
2092 	struct gpio_desc *desc;
2093 
2094 	desc = gpiochip_get_desc(chip, offset);
2095 	if (IS_ERR(desc))
2096 		return PTR_ERR(desc);
2097 
2098 	/* Flush direction if something changed behind our back */
2099 	if (chip->get_direction) {
2100 		int dir = chip->get_direction(chip, offset);
2101 
2102 		if (dir)
2103 			clear_bit(FLAG_IS_OUT, &desc->flags);
2104 		else
2105 			set_bit(FLAG_IS_OUT, &desc->flags);
2106 	}
2107 
2108 	if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2109 		chip_err(chip,
2110 			  "%s: tried to flag a GPIO set as output for IRQ\n",
2111 			  __func__);
2112 		return -EIO;
2113 	}
2114 
2115 	set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2116 	return 0;
2117 }
2118 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
2119 
2120 /**
2121  * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
2122  * @chip: the chip the GPIO to lock belongs to
2123  * @offset: the offset of the GPIO to lock as IRQ
2124  *
2125  * This is used directly by GPIO drivers that want to indicate
2126  * that a certain GPIO is no longer used exclusively for IRQ.
2127  */
2128 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2129 {
2130 	if (offset >= chip->ngpio)
2131 		return;
2132 
2133 	clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2134 }
2135 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
2136 
2137 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
2138 {
2139 	if (offset >= chip->ngpio)
2140 		return false;
2141 
2142 	return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
2143 }
2144 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
2145 
2146 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
2147 {
2148 	if (offset >= chip->ngpio)
2149 		return false;
2150 
2151 	return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
2152 }
2153 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
2154 
2155 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
2156 {
2157 	if (offset >= chip->ngpio)
2158 		return false;
2159 
2160 	return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
2161 }
2162 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
2163 
2164 /**
2165  * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2166  * @desc: gpio whose value will be returned
2167  *
2168  * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2169  * its ACTIVE_LOW status, or negative errno on failure.
2170  *
2171  * This function is to be called from contexts that can sleep.
2172  */
2173 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
2174 {
2175 	might_sleep_if(extra_checks);
2176 	VALIDATE_DESC(desc);
2177 	return _gpiod_get_raw_value(desc);
2178 }
2179 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
2180 
2181 /**
2182  * gpiod_get_value_cansleep() - return a gpio's value
2183  * @desc: gpio whose value will be returned
2184  *
2185  * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2186  * account, or negative errno on failure.
2187  *
2188  * This function is to be called from contexts that can sleep.
2189  */
2190 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
2191 {
2192 	int value;
2193 
2194 	might_sleep_if(extra_checks);
2195 	VALIDATE_DESC(desc);
2196 	value = _gpiod_get_raw_value(desc);
2197 	if (value < 0)
2198 		return value;
2199 
2200 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2201 		value = !value;
2202 
2203 	return value;
2204 }
2205 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
2206 
2207 /**
2208  * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2209  * @desc: gpio whose value will be assigned
2210  * @value: value to assign
2211  *
2212  * Set the raw value of the GPIO, i.e. the value of its physical line without
2213  * regard for its ACTIVE_LOW status.
2214  *
2215  * This function is to be called from contexts that can sleep.
2216  */
2217 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
2218 {
2219 	might_sleep_if(extra_checks);
2220 	VALIDATE_DESC_VOID(desc);
2221 	_gpiod_set_raw_value(desc, value);
2222 }
2223 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
2224 
2225 /**
2226  * gpiod_set_value_cansleep() - assign a gpio's value
2227  * @desc: gpio whose value will be assigned
2228  * @value: value to assign
2229  *
2230  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2231  * account
2232  *
2233  * This function is to be called from contexts that can sleep.
2234  */
2235 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
2236 {
2237 	might_sleep_if(extra_checks);
2238 	VALIDATE_DESC_VOID(desc);
2239 	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2240 		value = !value;
2241 	_gpiod_set_raw_value(desc, value);
2242 }
2243 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
2244 
2245 /**
2246  * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
2247  * @array_size: number of elements in the descriptor / value arrays
2248  * @desc_array: array of GPIO descriptors whose values will be assigned
2249  * @value_array: array of values to assign
2250  *
2251  * Set the raw values of the GPIOs, i.e. the values of the physical lines
2252  * without regard for their ACTIVE_LOW status.
2253  *
2254  * This function is to be called from contexts that can sleep.
2255  */
2256 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
2257 					struct gpio_desc **desc_array,
2258 					int *value_array)
2259 {
2260 	might_sleep_if(extra_checks);
2261 	if (!desc_array)
2262 		return;
2263 	gpiod_set_array_value_complex(true, true, array_size, desc_array,
2264 				      value_array);
2265 }
2266 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
2267 
2268 /**
2269  * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
2270  * @array_size: number of elements in the descriptor / value arrays
2271  * @desc_array: array of GPIO descriptors whose values will be assigned
2272  * @value_array: array of values to assign
2273  *
2274  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
2275  * into account.
2276  *
2277  * This function is to be called from contexts that can sleep.
2278  */
2279 void gpiod_set_array_value_cansleep(unsigned int array_size,
2280 				    struct gpio_desc **desc_array,
2281 				    int *value_array)
2282 {
2283 	might_sleep_if(extra_checks);
2284 	if (!desc_array)
2285 		return;
2286 	gpiod_set_array_value_complex(false, true, array_size, desc_array,
2287 				      value_array);
2288 }
2289 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
2290 
2291 /**
2292  * gpiod_add_lookup_table() - register GPIO device consumers
2293  * @table: table of consumers to register
2294  */
2295 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
2296 {
2297 	mutex_lock(&gpio_lookup_lock);
2298 
2299 	list_add_tail(&table->list, &gpio_lookup_list);
2300 
2301 	mutex_unlock(&gpio_lookup_lock);
2302 }
2303 
2304 /**
2305  * gpiod_remove_lookup_table() - unregister GPIO device consumers
2306  * @table: table of consumers to unregister
2307  */
2308 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
2309 {
2310 	mutex_lock(&gpio_lookup_lock);
2311 
2312 	list_del(&table->list);
2313 
2314 	mutex_unlock(&gpio_lookup_lock);
2315 }
2316 
2317 static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
2318 				      unsigned int idx,
2319 				      enum gpio_lookup_flags *flags)
2320 {
2321 	char prop_name[32]; /* 32 is max size of property name */
2322 	enum of_gpio_flags of_flags;
2323 	struct gpio_desc *desc;
2324 	unsigned int i;
2325 
2326 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2327 		if (con_id)
2328 			snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
2329 				 gpio_suffixes[i]);
2330 		else
2331 			snprintf(prop_name, sizeof(prop_name), "%s",
2332 				 gpio_suffixes[i]);
2333 
2334 		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
2335 						&of_flags);
2336 		if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
2337 			break;
2338 	}
2339 
2340 	if (IS_ERR(desc))
2341 		return desc;
2342 
2343 	if (of_flags & OF_GPIO_ACTIVE_LOW)
2344 		*flags |= GPIO_ACTIVE_LOW;
2345 
2346 	if (of_flags & OF_GPIO_SINGLE_ENDED) {
2347 		if (of_flags & OF_GPIO_ACTIVE_LOW)
2348 			*flags |= GPIO_OPEN_DRAIN;
2349 		else
2350 			*flags |= GPIO_OPEN_SOURCE;
2351 	}
2352 
2353 	return desc;
2354 }
2355 
2356 static struct gpio_desc *acpi_find_gpio(struct device *dev,
2357 					const char *con_id,
2358 					unsigned int idx,
2359 					enum gpiod_flags flags,
2360 					enum gpio_lookup_flags *lookupflags)
2361 {
2362 	struct acpi_device *adev = ACPI_COMPANION(dev);
2363 	struct acpi_gpio_info info;
2364 	struct gpio_desc *desc;
2365 	char propname[32];
2366 	int i;
2367 
2368 	/* Try first from _DSD */
2369 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2370 		if (con_id && strcmp(con_id, "gpios")) {
2371 			snprintf(propname, sizeof(propname), "%s-%s",
2372 				 con_id, gpio_suffixes[i]);
2373 		} else {
2374 			snprintf(propname, sizeof(propname), "%s",
2375 				 gpio_suffixes[i]);
2376 		}
2377 
2378 		desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
2379 		if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
2380 			break;
2381 	}
2382 
2383 	/* Then from plain _CRS GPIOs */
2384 	if (IS_ERR(desc)) {
2385 		if (!acpi_can_fallback_to_crs(adev, con_id))
2386 			return ERR_PTR(-ENOENT);
2387 
2388 		desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
2389 		if (IS_ERR(desc))
2390 			return desc;
2391 
2392 		if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
2393 		    info.gpioint) {
2394 			dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
2395 			return ERR_PTR(-ENOENT);
2396 		}
2397 	}
2398 
2399 	if (info.polarity == GPIO_ACTIVE_LOW)
2400 		*lookupflags |= GPIO_ACTIVE_LOW;
2401 
2402 	return desc;
2403 }
2404 
2405 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2406 {
2407 	const char *dev_id = dev ? dev_name(dev) : NULL;
2408 	struct gpiod_lookup_table *table;
2409 
2410 	mutex_lock(&gpio_lookup_lock);
2411 
2412 	list_for_each_entry(table, &gpio_lookup_list, list) {
2413 		if (table->dev_id && dev_id) {
2414 			/*
2415 			 * Valid strings on both ends, must be identical to have
2416 			 * a match
2417 			 */
2418 			if (!strcmp(table->dev_id, dev_id))
2419 				goto found;
2420 		} else {
2421 			/*
2422 			 * One of the pointers is NULL, so both must be to have
2423 			 * a match
2424 			 */
2425 			if (dev_id == table->dev_id)
2426 				goto found;
2427 		}
2428 	}
2429 	table = NULL;
2430 
2431 found:
2432 	mutex_unlock(&gpio_lookup_lock);
2433 	return table;
2434 }
2435 
2436 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
2437 				    unsigned int idx,
2438 				    enum gpio_lookup_flags *flags)
2439 {
2440 	struct gpio_desc *desc = ERR_PTR(-ENOENT);
2441 	struct gpiod_lookup_table *table;
2442 	struct gpiod_lookup *p;
2443 
2444 	table = gpiod_find_lookup_table(dev);
2445 	if (!table)
2446 		return desc;
2447 
2448 	for (p = &table->table[0]; p->chip_label; p++) {
2449 		struct gpio_chip *chip;
2450 
2451 		/* idx must always match exactly */
2452 		if (p->idx != idx)
2453 			continue;
2454 
2455 		/* If the lookup entry has a con_id, require exact match */
2456 		if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2457 			continue;
2458 
2459 		chip = find_chip_by_name(p->chip_label);
2460 
2461 		if (!chip) {
2462 			dev_err(dev, "cannot find GPIO chip %s\n",
2463 				p->chip_label);
2464 			return ERR_PTR(-ENODEV);
2465 		}
2466 
2467 		if (chip->ngpio <= p->chip_hwnum) {
2468 			dev_err(dev,
2469 				"requested GPIO %d is out of range [0..%d] for chip %s\n",
2470 				idx, chip->ngpio, chip->label);
2471 			return ERR_PTR(-EINVAL);
2472 		}
2473 
2474 		desc = gpiochip_get_desc(chip, p->chip_hwnum);
2475 		*flags = p->flags;
2476 
2477 		return desc;
2478 	}
2479 
2480 	return desc;
2481 }
2482 
2483 static int dt_gpio_count(struct device *dev, const char *con_id)
2484 {
2485 	int ret;
2486 	char propname[32];
2487 	unsigned int i;
2488 
2489 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
2490 		if (con_id)
2491 			snprintf(propname, sizeof(propname), "%s-%s",
2492 				 con_id, gpio_suffixes[i]);
2493 		else
2494 			snprintf(propname, sizeof(propname), "%s",
2495 				 gpio_suffixes[i]);
2496 
2497 		ret = of_gpio_named_count(dev->of_node, propname);
2498 		if (ret >= 0)
2499 			break;
2500 	}
2501 	return ret;
2502 }
2503 
2504 static int platform_gpio_count(struct device *dev, const char *con_id)
2505 {
2506 	struct gpiod_lookup_table *table;
2507 	struct gpiod_lookup *p;
2508 	unsigned int count = 0;
2509 
2510 	table = gpiod_find_lookup_table(dev);
2511 	if (!table)
2512 		return -ENOENT;
2513 
2514 	for (p = &table->table[0]; p->chip_label; p++) {
2515 		if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
2516 		    (!con_id && !p->con_id))
2517 			count++;
2518 	}
2519 	if (!count)
2520 		return -ENOENT;
2521 
2522 	return count;
2523 }
2524 
2525 /**
2526  * gpiod_count - return the number of GPIOs associated with a device / function
2527  *		or -ENOENT if no GPIO has been assigned to the requested function
2528  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
2529  * @con_id:	function within the GPIO consumer
2530  */
2531 int gpiod_count(struct device *dev, const char *con_id)
2532 {
2533 	int count = -ENOENT;
2534 
2535 	if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
2536 		count = dt_gpio_count(dev, con_id);
2537 	else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
2538 		count = acpi_gpio_count(dev, con_id);
2539 
2540 	if (count < 0)
2541 		count = platform_gpio_count(dev, con_id);
2542 
2543 	return count;
2544 }
2545 EXPORT_SYMBOL_GPL(gpiod_count);
2546 
2547 /**
2548  * gpiod_get - obtain a GPIO for a given GPIO function
2549  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
2550  * @con_id:	function within the GPIO consumer
2551  * @flags:	optional GPIO initialization flags
2552  *
2553  * Return the GPIO descriptor corresponding to the function con_id of device
2554  * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2555  * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
2556  */
2557 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
2558 					 enum gpiod_flags flags)
2559 {
2560 	return gpiod_get_index(dev, con_id, 0, flags);
2561 }
2562 EXPORT_SYMBOL_GPL(gpiod_get);
2563 
2564 /**
2565  * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
2566  * @dev: GPIO consumer, can be NULL for system-global GPIOs
2567  * @con_id: function within the GPIO consumer
2568  * @flags: optional GPIO initialization flags
2569  *
2570  * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
2571  * the requested function it will return NULL. This is convenient for drivers
2572  * that need to handle optional GPIOs.
2573  */
2574 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
2575 						  const char *con_id,
2576 						  enum gpiod_flags flags)
2577 {
2578 	return gpiod_get_index_optional(dev, con_id, 0, flags);
2579 }
2580 EXPORT_SYMBOL_GPL(gpiod_get_optional);
2581 
2582 
2583 /**
2584  * gpiod_configure_flags - helper function to configure a given GPIO
2585  * @desc:	gpio whose value will be assigned
2586  * @con_id:	function within the GPIO consumer
2587  * @lflags:	gpio_lookup_flags - returned from of_find_gpio() or
2588  *		of_get_gpio_hog()
2589  * @dflags:	gpiod_flags - optional GPIO initialization flags
2590  *
2591  * Return 0 on success, -ENOENT if no GPIO has been assigned to the
2592  * requested function and/or index, or another IS_ERR() code if an error
2593  * occurred while trying to acquire the GPIO.
2594  */
2595 static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
2596 		unsigned long lflags, enum gpiod_flags dflags)
2597 {
2598 	int status;
2599 
2600 	if (lflags & GPIO_ACTIVE_LOW)
2601 		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2602 	if (lflags & GPIO_OPEN_DRAIN)
2603 		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2604 	if (lflags & GPIO_OPEN_SOURCE)
2605 		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2606 
2607 	/* No particular flag request, return here... */
2608 	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
2609 		pr_debug("no flags found for %s\n", con_id);
2610 		return 0;
2611 	}
2612 
2613 	/* Process flags */
2614 	if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
2615 		status = gpiod_direction_output(desc,
2616 					      dflags & GPIOD_FLAGS_BIT_DIR_VAL);
2617 	else
2618 		status = gpiod_direction_input(desc);
2619 
2620 	return status;
2621 }
2622 
2623 /**
2624  * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
2625  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
2626  * @con_id:	function within the GPIO consumer
2627  * @idx:	index of the GPIO to obtain in the consumer
2628  * @flags:	optional GPIO initialization flags
2629  *
2630  * This variant of gpiod_get() allows to access GPIOs other than the first
2631  * defined one for functions that define several GPIOs.
2632  *
2633  * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2634  * requested function and/or index, or another IS_ERR() code if an error
2635  * occurred while trying to acquire the GPIO.
2636  */
2637 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2638 					       const char *con_id,
2639 					       unsigned int idx,
2640 					       enum gpiod_flags flags)
2641 {
2642 	struct gpio_desc *desc = NULL;
2643 	int status;
2644 	enum gpio_lookup_flags lookupflags = 0;
2645 
2646 	dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2647 
2648 	if (dev) {
2649 		/* Using device tree? */
2650 		if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
2651 			dev_dbg(dev, "using device tree for GPIO lookup\n");
2652 			desc = of_find_gpio(dev, con_id, idx, &lookupflags);
2653 		} else if (ACPI_COMPANION(dev)) {
2654 			dev_dbg(dev, "using ACPI for GPIO lookup\n");
2655 			desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
2656 		}
2657 	}
2658 
2659 	/*
2660 	 * Either we are not using DT or ACPI, or their lookup did not return
2661 	 * a result. In that case, use platform lookup as a fallback.
2662 	 */
2663 	if (!desc || desc == ERR_PTR(-ENOENT)) {
2664 		dev_dbg(dev, "using lookup tables for GPIO lookup\n");
2665 		desc = gpiod_find(dev, con_id, idx, &lookupflags);
2666 	}
2667 
2668 	if (IS_ERR(desc)) {
2669 		dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
2670 		return desc;
2671 	}
2672 
2673 	status = gpiod_request(desc, con_id);
2674 	if (status < 0)
2675 		return ERR_PTR(status);
2676 
2677 	status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
2678 	if (status < 0) {
2679 		dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
2680 		gpiod_put(desc);
2681 		return ERR_PTR(status);
2682 	}
2683 
2684 	return desc;
2685 }
2686 EXPORT_SYMBOL_GPL(gpiod_get_index);
2687 
2688 /**
2689  * fwnode_get_named_gpiod - obtain a GPIO from firmware node
2690  * @fwnode:	handle of the firmware node
2691  * @propname:	name of the firmware property representing the GPIO
2692  *
2693  * This function can be used for drivers that get their configuration
2694  * from firmware.
2695  *
2696  * Function properly finds the corresponding GPIO using whatever is the
2697  * underlying firmware interface and then makes sure that the GPIO
2698  * descriptor is requested before it is returned to the caller.
2699  *
2700  * In case of error an ERR_PTR() is returned.
2701  */
2702 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
2703 					 const char *propname)
2704 {
2705 	struct gpio_desc *desc = ERR_PTR(-ENODEV);
2706 	bool active_low = false;
2707 	bool single_ended = false;
2708 	int ret;
2709 
2710 	if (!fwnode)
2711 		return ERR_PTR(-EINVAL);
2712 
2713 	if (is_of_node(fwnode)) {
2714 		enum of_gpio_flags flags;
2715 
2716 		desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
2717 						&flags);
2718 		if (!IS_ERR(desc)) {
2719 			active_low = flags & OF_GPIO_ACTIVE_LOW;
2720 			single_ended = flags & OF_GPIO_SINGLE_ENDED;
2721 		}
2722 	} else if (is_acpi_node(fwnode)) {
2723 		struct acpi_gpio_info info;
2724 
2725 		desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
2726 		if (!IS_ERR(desc))
2727 			active_low = info.polarity == GPIO_ACTIVE_LOW;
2728 	}
2729 
2730 	if (IS_ERR(desc))
2731 		return desc;
2732 
2733 	ret = gpiod_request(desc, NULL);
2734 	if (ret)
2735 		return ERR_PTR(ret);
2736 
2737 	if (active_low)
2738 		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
2739 
2740 	if (single_ended) {
2741 		if (active_low)
2742 			set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2743 		else
2744 			set_bit(FLAG_OPEN_SOURCE, &desc->flags);
2745 	}
2746 
2747 	return desc;
2748 }
2749 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
2750 
2751 /**
2752  * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
2753  *                            function
2754  * @dev: GPIO consumer, can be NULL for system-global GPIOs
2755  * @con_id: function within the GPIO consumer
2756  * @index: index of the GPIO to obtain in the consumer
2757  * @flags: optional GPIO initialization flags
2758  *
2759  * This is equivalent to gpiod_get_index(), except that when no GPIO with the
2760  * specified index was assigned to the requested function it will return NULL.
2761  * This is convenient for drivers that need to handle optional GPIOs.
2762  */
2763 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
2764 							const char *con_id,
2765 							unsigned int index,
2766 							enum gpiod_flags flags)
2767 {
2768 	struct gpio_desc *desc;
2769 
2770 	desc = gpiod_get_index(dev, con_id, index, flags);
2771 	if (IS_ERR(desc)) {
2772 		if (PTR_ERR(desc) == -ENOENT)
2773 			return NULL;
2774 	}
2775 
2776 	return desc;
2777 }
2778 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
2779 
2780 /**
2781  * gpiod_hog - Hog the specified GPIO desc given the provided flags
2782  * @desc:	gpio whose value will be assigned
2783  * @name:	gpio line name
2784  * @lflags:	gpio_lookup_flags - returned from of_find_gpio() or
2785  *		of_get_gpio_hog()
2786  * @dflags:	gpiod_flags - optional GPIO initialization flags
2787  */
2788 int gpiod_hog(struct gpio_desc *desc, const char *name,
2789 	      unsigned long lflags, enum gpiod_flags dflags)
2790 {
2791 	struct gpio_chip *chip;
2792 	struct gpio_desc *local_desc;
2793 	int hwnum;
2794 	int status;
2795 
2796 	chip = gpiod_to_chip(desc);
2797 	hwnum = gpio_chip_hwgpio(desc);
2798 
2799 	local_desc = gpiochip_request_own_desc(chip, hwnum, name);
2800 	if (IS_ERR(local_desc)) {
2801 		status = PTR_ERR(local_desc);
2802 		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
2803 		       name, chip->label, hwnum, status);
2804 		return status;
2805 	}
2806 
2807 	status = gpiod_configure_flags(desc, name, lflags, dflags);
2808 	if (status < 0) {
2809 		pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
2810 		       name, chip->label, hwnum, status);
2811 		gpiochip_free_own_desc(desc);
2812 		return status;
2813 	}
2814 
2815 	/* Mark GPIO as hogged so it can be identified and removed later */
2816 	set_bit(FLAG_IS_HOGGED, &desc->flags);
2817 
2818 	pr_info("GPIO line %d (%s) hogged as %s%s\n",
2819 		desc_to_gpio(desc), name,
2820 		(dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
2821 		(dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
2822 		  (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
2823 
2824 	return 0;
2825 }
2826 
2827 /**
2828  * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
2829  * @chip:	gpio chip to act on
2830  *
2831  * This is only used by of_gpiochip_remove to free hogged gpios
2832  */
2833 static void gpiochip_free_hogs(struct gpio_chip *chip)
2834 {
2835 	int id;
2836 
2837 	for (id = 0; id < chip->ngpio; id++) {
2838 		if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
2839 			gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
2840 	}
2841 }
2842 
2843 /**
2844  * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
2845  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
2846  * @con_id:	function within the GPIO consumer
2847  * @flags:	optional GPIO initialization flags
2848  *
2849  * This function acquires all the GPIOs defined under a given function.
2850  *
2851  * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
2852  * no GPIO has been assigned to the requested function, or another IS_ERR()
2853  * code if an error occurred while trying to acquire the GPIOs.
2854  */
2855 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
2856 						const char *con_id,
2857 						enum gpiod_flags flags)
2858 {
2859 	struct gpio_desc *desc;
2860 	struct gpio_descs *descs;
2861 	int count;
2862 
2863 	count = gpiod_count(dev, con_id);
2864 	if (count < 0)
2865 		return ERR_PTR(count);
2866 
2867 	descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
2868 			GFP_KERNEL);
2869 	if (!descs)
2870 		return ERR_PTR(-ENOMEM);
2871 
2872 	for (descs->ndescs = 0; descs->ndescs < count; ) {
2873 		desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
2874 		if (IS_ERR(desc)) {
2875 			gpiod_put_array(descs);
2876 			return ERR_CAST(desc);
2877 		}
2878 		descs->desc[descs->ndescs] = desc;
2879 		descs->ndescs++;
2880 	}
2881 	return descs;
2882 }
2883 EXPORT_SYMBOL_GPL(gpiod_get_array);
2884 
2885 /**
2886  * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
2887  *                            function
2888  * @dev:	GPIO consumer, can be NULL for system-global GPIOs
2889  * @con_id:	function within the GPIO consumer
2890  * @flags:	optional GPIO initialization flags
2891  *
2892  * This is equivalent to gpiod_get_array(), except that when no GPIO was
2893  * assigned to the requested function it will return NULL.
2894  */
2895 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
2896 							const char *con_id,
2897 							enum gpiod_flags flags)
2898 {
2899 	struct gpio_descs *descs;
2900 
2901 	descs = gpiod_get_array(dev, con_id, flags);
2902 	if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
2903 		return NULL;
2904 
2905 	return descs;
2906 }
2907 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
2908 
2909 /**
2910  * gpiod_put - dispose of a GPIO descriptor
2911  * @desc:	GPIO descriptor to dispose of
2912  *
2913  * No descriptor can be used after gpiod_put() has been called on it.
2914  */
2915 void gpiod_put(struct gpio_desc *desc)
2916 {
2917 	gpiod_free(desc);
2918 }
2919 EXPORT_SYMBOL_GPL(gpiod_put);
2920 
2921 /**
2922  * gpiod_put_array - dispose of multiple GPIO descriptors
2923  * @descs:	struct gpio_descs containing an array of descriptors
2924  */
2925 void gpiod_put_array(struct gpio_descs *descs)
2926 {
2927 	unsigned int i;
2928 
2929 	for (i = 0; i < descs->ndescs; i++)
2930 		gpiod_put(descs->desc[i]);
2931 
2932 	kfree(descs);
2933 }
2934 EXPORT_SYMBOL_GPL(gpiod_put_array);
2935 
2936 static int __init gpiolib_dev_init(void)
2937 {
2938 	int ret;
2939 
2940 	/* Register GPIO sysfs bus */
2941 	ret  = bus_register(&gpio_bus_type);
2942 	if (ret < 0) {
2943 		pr_err("gpiolib: could not register GPIO bus type\n");
2944 		return ret;
2945 	}
2946 
2947 	ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
2948 	if (ret < 0) {
2949 		pr_err("gpiolib: failed to allocate char dev region\n");
2950 		bus_unregister(&gpio_bus_type);
2951 	} else {
2952 		gpiolib_initialized = true;
2953 		gpiochip_setup_devs();
2954 	}
2955 	return ret;
2956 }
2957 core_initcall(gpiolib_dev_init);
2958 
2959 #ifdef CONFIG_DEBUG_FS
2960 
2961 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
2962 {
2963 	unsigned		i;
2964 	struct gpio_chip	*chip = gdev->chip;
2965 	unsigned		gpio = gdev->base;
2966 	struct gpio_desc	*gdesc = &gdev->descs[0];
2967 	int			is_out;
2968 	int			is_irq;
2969 
2970 	for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
2971 		if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
2972 			if (gdesc->name) {
2973 				seq_printf(s, " gpio-%-3d (%-20.20s)\n",
2974 					   gpio, gdesc->name);
2975 			}
2976 			continue;
2977 		}
2978 
2979 		gpiod_get_direction(gdesc);
2980 		is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
2981 		is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2982 		seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
2983 			gpio, gdesc->name ? gdesc->name : "", gdesc->label,
2984 			is_out ? "out" : "in ",
2985 			chip->get
2986 				? (chip->get(chip, i) ? "hi" : "lo")
2987 				: "?  ",
2988 			is_irq ? "IRQ" : "   ");
2989 		seq_printf(s, "\n");
2990 	}
2991 }
2992 
2993 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
2994 {
2995 	unsigned long flags;
2996 	struct gpio_device *gdev = NULL;
2997 	loff_t index = *pos;
2998 
2999 	s->private = "";
3000 
3001 	spin_lock_irqsave(&gpio_lock, flags);
3002 	list_for_each_entry(gdev, &gpio_devices, list)
3003 		if (index-- == 0) {
3004 			spin_unlock_irqrestore(&gpio_lock, flags);
3005 			return gdev;
3006 		}
3007 	spin_unlock_irqrestore(&gpio_lock, flags);
3008 
3009 	return NULL;
3010 }
3011 
3012 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
3013 {
3014 	unsigned long flags;
3015 	struct gpio_device *gdev = v;
3016 	void *ret = NULL;
3017 
3018 	spin_lock_irqsave(&gpio_lock, flags);
3019 	if (list_is_last(&gdev->list, &gpio_devices))
3020 		ret = NULL;
3021 	else
3022 		ret = list_entry(gdev->list.next, struct gpio_device, list);
3023 	spin_unlock_irqrestore(&gpio_lock, flags);
3024 
3025 	s->private = "\n";
3026 	++*pos;
3027 
3028 	return ret;
3029 }
3030 
3031 static void gpiolib_seq_stop(struct seq_file *s, void *v)
3032 {
3033 }
3034 
3035 static int gpiolib_seq_show(struct seq_file *s, void *v)
3036 {
3037 	struct gpio_device *gdev = v;
3038 	struct gpio_chip *chip = gdev->chip;
3039 	struct device *parent;
3040 
3041 	if (!chip) {
3042 		seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
3043 			   dev_name(&gdev->dev));
3044 		return 0;
3045 	}
3046 
3047 	seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
3048 		   dev_name(&gdev->dev),
3049 		   gdev->base, gdev->base + gdev->ngpio - 1);
3050 	parent = chip->parent;
3051 	if (parent)
3052 		seq_printf(s, ", parent: %s/%s",
3053 			   parent->bus ? parent->bus->name : "no-bus",
3054 			   dev_name(parent));
3055 	if (chip->label)
3056 		seq_printf(s, ", %s", chip->label);
3057 	if (chip->can_sleep)
3058 		seq_printf(s, ", can sleep");
3059 	seq_printf(s, ":\n");
3060 
3061 	if (chip->dbg_show)
3062 		chip->dbg_show(s, chip);
3063 	else
3064 		gpiolib_dbg_show(s, gdev);
3065 
3066 	return 0;
3067 }
3068 
3069 static const struct seq_operations gpiolib_seq_ops = {
3070 	.start = gpiolib_seq_start,
3071 	.next = gpiolib_seq_next,
3072 	.stop = gpiolib_seq_stop,
3073 	.show = gpiolib_seq_show,
3074 };
3075 
3076 static int gpiolib_open(struct inode *inode, struct file *file)
3077 {
3078 	return seq_open(file, &gpiolib_seq_ops);
3079 }
3080 
3081 static const struct file_operations gpiolib_operations = {
3082 	.owner		= THIS_MODULE,
3083 	.open		= gpiolib_open,
3084 	.read		= seq_read,
3085 	.llseek		= seq_lseek,
3086 	.release	= seq_release,
3087 };
3088 
3089 static int __init gpiolib_debugfs_init(void)
3090 {
3091 	/* /sys/kernel/debug/gpio */
3092 	(void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
3093 				NULL, NULL, &gpiolib_operations);
3094 	return 0;
3095 }
3096 subsys_initcall(gpiolib_debugfs_init);
3097 
3098 #endif	/* DEBUG_FS */
3099