brintos / linux-shallow public Read only

1// SPDX-License-Identifier: GPL-2.02 3#include <linux/acpi.h>4#include <linux/array_size.h>5#include <linux/bitmap.h>6#include <linux/cleanup.h>7#include <linux/compat.h>8#include <linux/debugfs.h>9#include <linux/device.h>10#include <linux/err.h>11#include <linux/errno.h>12#include <linux/file.h>13#include <linux/fs.h>14#include <linux/idr.h>15#include <linux/interrupt.h>16#include <linux/irq.h>17#include <linux/kernel.h>18#include <linux/list.h>19#include <linux/lockdep.h>20#include <linux/module.h>21#include <linux/nospec.h>22#include <linux/of.h>23#include <linux/pinctrl/consumer.h>24#include <linux/seq_file.h>25#include <linux/slab.h>26#include <linux/spinlock.h>27#include <linux/srcu.h>28#include <linux/string.h>29 30#include <linux/gpio.h>31#include <linux/gpio/driver.h>32#include <linux/gpio/machine.h>33 34#include <uapi/linux/gpio.h>35 36#include "gpiolib-acpi.h"37#include "gpiolib-cdev.h"38#include "gpiolib-of.h"39#include "gpiolib-swnode.h"40#include "gpiolib-sysfs.h"41#include "gpiolib.h"42 43#define CREATE_TRACE_POINTS44#include <trace/events/gpio.h>45 46/* Implementation infrastructure for GPIO interfaces.47 *48 * The GPIO programming interface allows for inlining speed-critical49 * get/set operations for common cases, so that access to SOC-integrated50 * GPIOs can sometimes cost only an instruction or two per bit.51 */52 53/* Device and char device-related information */54static DEFINE_IDA(gpio_ida);55static dev_t gpio_devt;56#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */57 58static int gpio_bus_match(struct device *dev, const struct device_driver *drv)59{60	struct fwnode_handle *fwnode = dev_fwnode(dev);61 62	/*63	 * Only match if the fwnode doesn't already have a proper struct device64	 * created for it.65	 */66	if (fwnode && fwnode->dev != dev)67		return 0;68	return 1;69}70 71static const struct bus_type gpio_bus_type = {72	.name = "gpio",73	.match = gpio_bus_match,74};75 76/*77 * Number of GPIOs to use for the fast path in set array78 */79#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT80 81static DEFINE_MUTEX(gpio_lookup_lock);82static LIST_HEAD(gpio_lookup_list);83 84static LIST_HEAD(gpio_devices);85/* Protects the GPIO device list against concurrent modifications. */86static DEFINE_MUTEX(gpio_devices_lock);87/* Ensures coherence during read-only accesses to the list of GPIO devices. */88DEFINE_STATIC_SRCU(gpio_devices_srcu);89 90static DEFINE_MUTEX(gpio_machine_hogs_mutex);91static LIST_HEAD(gpio_machine_hogs);92 93const char *const gpio_suffixes[] = { "gpios", "gpio", NULL };94 95static void gpiochip_free_hogs(struct gpio_chip *gc);96static int gpiochip_add_irqchip(struct gpio_chip *gc,97				struct lock_class_key *lock_key,98				struct lock_class_key *request_key);99static void gpiochip_irqchip_remove(struct gpio_chip *gc);100static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);101static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);102static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);103 104static bool gpiolib_initialized;105 106const char *gpiod_get_label(struct gpio_desc *desc)107{108	struct gpio_desc_label *label;109	unsigned long flags;110 111	flags = READ_ONCE(desc->flags);112 113	label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu,114				srcu_read_lock_held(&desc->gdev->desc_srcu));115 116	if (test_bit(FLAG_USED_AS_IRQ, &flags))117		return label ? label->str : "interrupt";118 119	if (!test_bit(FLAG_REQUESTED, &flags))120		return NULL;121 122	return label ? label->str : NULL;123}124 125static void desc_free_label(struct rcu_head *rh)126{127	kfree(container_of(rh, struct gpio_desc_label, rh));128}129 130static int desc_set_label(struct gpio_desc *desc, const char *label)131{132	struct gpio_desc_label *new = NULL, *old;133 134	if (label) {135		new = kzalloc(struct_size(new, str, strlen(label) + 1),136			      GFP_KERNEL);137		if (!new)138			return -ENOMEM;139 140		strcpy(new->str, label);141	}142 143	old = rcu_replace_pointer(desc->label, new, 1);144	if (old)145		call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label);146 147	return 0;148}149 150/**151 * gpio_to_desc - Convert a GPIO number to its descriptor152 * @gpio: global GPIO number153 *154 * Returns:155 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO156 * with the given number exists in the system.157 */158struct gpio_desc *gpio_to_desc(unsigned gpio)159{160	struct gpio_device *gdev;161 162	scoped_guard(srcu, &gpio_devices_srcu) {163		list_for_each_entry_srcu(gdev, &gpio_devices, list,164				srcu_read_lock_held(&gpio_devices_srcu)) {165			if (gdev->base <= gpio &&166			    gdev->base + gdev->ngpio > gpio)167				return &gdev->descs[gpio - gdev->base];168		}169	}170 171	return NULL;172}173EXPORT_SYMBOL_GPL(gpio_to_desc);174 175/* This function is deprecated and will be removed soon, don't use. */176struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,177				    unsigned int hwnum)178{179	return gpio_device_get_desc(gc->gpiodev, hwnum);180}181 182/**183 * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given184 *                          hardware number for this GPIO device185 * @gdev: GPIO device to get the descriptor from186 * @hwnum: hardware number of the GPIO for this chip187 *188 * Returns:189 * A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given190 * chip for the specified hardware number or %ENODEV if the underlying chip191 * already vanished.192 *193 * The reference count of struct gpio_device is *NOT* increased like when the194 * GPIO is being requested for exclusive usage. It's up to the caller to make195 * sure the GPIO device will stay alive together with the descriptor returned196 * by this function.197 */198struct gpio_desc *199gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum)200{201	if (hwnum >= gdev->ngpio)202		return ERR_PTR(-EINVAL);203 204	return &gdev->descs[array_index_nospec(hwnum, gdev->ngpio)];205}206EXPORT_SYMBOL_GPL(gpio_device_get_desc);207 208/**209 * desc_to_gpio - convert a GPIO descriptor to the integer namespace210 * @desc: GPIO descriptor211 *212 * This should disappear in the future but is needed since we still213 * use GPIO numbers for error messages and sysfs nodes.214 *215 * Returns:216 * The global GPIO number for the GPIO specified by its descriptor.217 */218int desc_to_gpio(const struct gpio_desc *desc)219{220	return desc->gdev->base + (desc - &desc->gdev->descs[0]);221}222EXPORT_SYMBOL_GPL(desc_to_gpio);223 224 225/**226 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs227 * @desc:	descriptor to return the chip of228 *229 * *DEPRECATED*230 * This function is unsafe and should not be used. Using the chip address231 * without taking the SRCU read lock may result in dereferencing a dangling232 * pointer.233 *234 * Returns:235 * Address of the GPIO chip backing this device.236 */237struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)238{239	if (!desc)240		return NULL;241 242	return gpio_device_get_chip(desc->gdev);243}244EXPORT_SYMBOL_GPL(gpiod_to_chip);245 246/**247 * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor248 *                          belongs.249 * @desc: Descriptor for which to return the GPIO device.250 *251 * This *DOES NOT* increase the reference count of the GPIO device as it's252 * expected that the descriptor is requested and the users already holds a253 * reference to the device.254 *255 * Returns:256 * Address of the GPIO device owning this descriptor.257 */258struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc)259{260	if (!desc)261		return NULL;262 263	return desc->gdev;264}265EXPORT_SYMBOL_GPL(gpiod_to_gpio_device);266 267/**268 * gpio_device_get_base() - Get the base GPIO number allocated by this device269 * @gdev: GPIO device270 *271 * Returns:272 * First GPIO number in the global GPIO numberspace for this device.273 */274int gpio_device_get_base(struct gpio_device *gdev)275{276	return gdev->base;277}278EXPORT_SYMBOL_GPL(gpio_device_get_base);279 280/**281 * gpio_device_get_label() - Get the label of this GPIO device282 * @gdev: GPIO device283 *284 * Returns:285 * Pointer to the string containing the GPIO device label. The string's286 * lifetime is tied to that of the underlying GPIO device.287 */288const char *gpio_device_get_label(struct gpio_device *gdev)289{290	return gdev->label;291}292EXPORT_SYMBOL(gpio_device_get_label);293 294/**295 * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device296 * @gdev: GPIO device297 *298 * Returns:299 * Address of the GPIO chip backing this device.300 *301 * *DEPRECATED*302 * Until we can get rid of all non-driver users of struct gpio_chip, we must303 * provide a way of retrieving the pointer to it from struct gpio_device. This304 * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the305 * chip can dissapear at any moment (unlike reference-counted struct306 * gpio_device).307 *308 * Use at your own risk.309 */310struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)311{312	return rcu_dereference_check(gdev->chip, 1);313}314EXPORT_SYMBOL_GPL(gpio_device_get_chip);315 316/* dynamic allocation of GPIOs, e.g. on a hotplugged device */317static int gpiochip_find_base_unlocked(u16 ngpio)318{319	unsigned int base = GPIO_DYNAMIC_BASE;320	struct gpio_device *gdev;321 322	list_for_each_entry_srcu(gdev, &gpio_devices, list,323				 lockdep_is_held(&gpio_devices_lock)) {324		/* found a free space? */325		if (gdev->base >= base + ngpio)326			break;327		/* nope, check the space right after the chip */328		base = gdev->base + gdev->ngpio;329		if (base < GPIO_DYNAMIC_BASE)330			base = GPIO_DYNAMIC_BASE;331		if (base > GPIO_DYNAMIC_MAX - ngpio)332			break;333	}334 335	if (base <= GPIO_DYNAMIC_MAX - ngpio) {336		pr_debug("%s: found new base at %d\n", __func__, base);337		return base;338	} else {339		pr_err("%s: cannot find free range\n", __func__);340		return -ENOSPC;341	}342}343 344/**345 * gpiod_get_direction - return the current direction of a GPIO346 * @desc:	GPIO to get the direction of347 *348 * Returns:349 * 0 for output, 1 for input, or an error code in case of error.350 *351 * This function may sleep if gpiod_cansleep() is true.352 */353int gpiod_get_direction(struct gpio_desc *desc)354{355	unsigned long flags;356	unsigned int offset;357	int ret;358 359	/*360	 * We cannot use VALIDATE_DESC() as we must not return 0 for a NULL361	 * descriptor like we usually do.362	 */363	if (IS_ERR_OR_NULL(desc))364		return -EINVAL;365 366	CLASS(gpio_chip_guard, guard)(desc);367	if (!guard.gc)368		return -ENODEV;369 370	offset = gpio_chip_hwgpio(desc);371	flags = READ_ONCE(desc->flags);372 373	/*374	 * Open drain emulation using input mode may incorrectly report375	 * input here, fix that up.376	 */377	if (test_bit(FLAG_OPEN_DRAIN, &flags) &&378	    test_bit(FLAG_IS_OUT, &flags))379		return 0;380 381	if (!guard.gc->get_direction)382		return -ENOTSUPP;383 384	ret = guard.gc->get_direction(guard.gc, offset);385	if (ret < 0)386		return ret;387 388	/*389	 * GPIO_LINE_DIRECTION_IN or other positive,390	 * otherwise GPIO_LINE_DIRECTION_OUT.391	 */392	if (ret > 0)393		ret = 1;394 395	assign_bit(FLAG_IS_OUT, &flags, !ret);396	WRITE_ONCE(desc->flags, flags);397 398	return ret;399}400EXPORT_SYMBOL_GPL(gpiod_get_direction);401 402/*403 * Add a new chip to the global chips list, keeping the list of chips sorted404 * by range(means [base, base + ngpio - 1]) order.405 *406 * Returns:407 * -EBUSY if the new chip overlaps with some other chip's integer space.408 */409static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)410{411	struct gpio_device *prev, *next;412 413	lockdep_assert_held(&gpio_devices_lock);414 415	if (list_empty(&gpio_devices)) {416		/* initial entry in list */417		list_add_tail_rcu(&gdev->list, &gpio_devices);418		return 0;419	}420 421	next = list_first_entry(&gpio_devices, struct gpio_device, list);422	if (gdev->base + gdev->ngpio <= next->base) {423		/* add before first entry */424		list_add_rcu(&gdev->list, &gpio_devices);425		return 0;426	}427 428	prev = list_last_entry(&gpio_devices, struct gpio_device, list);429	if (prev->base + prev->ngpio <= gdev->base) {430		/* add behind last entry */431		list_add_tail_rcu(&gdev->list, &gpio_devices);432		return 0;433	}434 435	list_for_each_entry_safe(prev, next, &gpio_devices, list) {436		/* at the end of the list */437		if (&next->list == &gpio_devices)438			break;439 440		/* add between prev and next */441		if (prev->base + prev->ngpio <= gdev->base442				&& gdev->base + gdev->ngpio <= next->base) {443			list_add_rcu(&gdev->list, &prev->list);444			return 0;445		}446	}447 448	synchronize_srcu(&gpio_devices_srcu);449 450	return -EBUSY;451}452 453/*454 * Convert a GPIO name to its descriptor455 * Note that there is no guarantee that GPIO names are globally unique!456 * Hence this function will return, if it exists, a reference to the first GPIO457 * line found that matches the given name.458 */459static struct gpio_desc *gpio_name_to_desc(const char * const name)460{461	struct gpio_device *gdev;462	struct gpio_desc *desc;463	struct gpio_chip *gc;464 465	if (!name)466		return NULL;467 468	guard(srcu)(&gpio_devices_srcu);469 470	list_for_each_entry_srcu(gdev, &gpio_devices, list,471				 srcu_read_lock_held(&gpio_devices_srcu)) {472		guard(srcu)(&gdev->srcu);473 474		gc = srcu_dereference(gdev->chip, &gdev->srcu);475		if (!gc)476			continue;477 478		for_each_gpio_desc(gc, desc) {479			if (desc->name && !strcmp(desc->name, name))480				return desc;481		}482	}483 484	return NULL;485}486 487/*488 * Take the names from gc->names and assign them to their GPIO descriptors.489 * Warn if a name is already used for a GPIO line on a different GPIO chip.490 *491 * Note that:492 *   1. Non-unique names are still accepted,493 *   2. Name collisions within the same GPIO chip are not reported.494 */495static void gpiochip_set_desc_names(struct gpio_chip *gc)496{497	struct gpio_device *gdev = gc->gpiodev;498	int i;499 500	/* First check all names if they are unique */501	for (i = 0; i != gc->ngpio; ++i) {502		struct gpio_desc *gpio;503 504		gpio = gpio_name_to_desc(gc->names[i]);505		if (gpio)506			dev_warn(&gdev->dev,507				 "Detected name collision for GPIO name '%s'\n",508				 gc->names[i]);509	}510 511	/* Then add all names to the GPIO descriptors */512	for (i = 0; i != gc->ngpio; ++i)513		gdev->descs[i].name = gc->names[i];514}515 516/*517 * gpiochip_set_names - Set GPIO line names using device properties518 * @chip: GPIO chip whose lines should be named, if possible519 *520 * Looks for device property "gpio-line-names" and if it exists assigns521 * GPIO line names for the chip. The memory allocated for the assigned522 * names belong to the underlying firmware node and should not be released523 * by the caller.524 */525static int gpiochip_set_names(struct gpio_chip *chip)526{527	struct gpio_device *gdev = chip->gpiodev;528	struct device *dev = &gdev->dev;529	const char **names;530	int ret, i;531	int count;532 533	count = device_property_string_array_count(dev, "gpio-line-names");534	if (count < 0)535		return 0;536 537	/*538	 * When offset is set in the driver side we assume the driver internally539	 * is using more than one gpiochip per the same device. We have to stop540	 * setting friendly names if the specified ones with 'gpio-line-names'541	 * are less than the offset in the device itself. This means all the542	 * lines are not present for every single pin within all the internal543	 * gpiochips.544	 */545	if (count <= chip->offset) {546		dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",547			 count, chip->offset);548		return 0;549	}550 551	names = kcalloc(count, sizeof(*names), GFP_KERNEL);552	if (!names)553		return -ENOMEM;554 555	ret = device_property_read_string_array(dev, "gpio-line-names",556						names, count);557	if (ret < 0) {558		dev_warn(dev, "failed to read GPIO line names\n");559		kfree(names);560		return ret;561	}562 563	/*564	 * When more that one gpiochip per device is used, 'count' can565	 * contain at most number gpiochips x chip->ngpio. We have to566	 * correctly distribute all defined lines taking into account567	 * chip->offset as starting point from where we will assign568	 * the names to pins from the 'names' array. Since property569	 * 'gpio-line-names' cannot contains gaps, we have to be sure570	 * we only assign those pins that really exists since chip->ngpio571	 * can be different of the chip->offset.572	 */573	count = (count > chip->offset) ? count - chip->offset : count;574	if (count > chip->ngpio)575		count = chip->ngpio;576 577	for (i = 0; i < count; i++) {578		/*579		 * Allow overriding "fixed" names provided by the GPIO580		 * provider. The "fixed" names are more often than not581		 * generic and less informative than the names given in582		 * device properties.583		 */584		if (names[chip->offset + i] && names[chip->offset + i][0])585			gdev->descs[i].name = names[chip->offset + i];586	}587 588	kfree(names);589 590	return 0;591}592 593static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)594{595	unsigned long *p;596 597	p = bitmap_alloc(gc->ngpio, GFP_KERNEL);598	if (!p)599		return NULL;600 601	/* Assume by default all GPIOs are valid */602	bitmap_fill(p, gc->ngpio);603 604	return p;605}606 607static void gpiochip_free_mask(unsigned long **p)608{609	bitmap_free(*p);610	*p = NULL;611}612 613static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc)614{615	struct device *dev = &gc->gpiodev->dev;616	int size;617 618	/* Format is "start, count, ..." */619	size = device_property_count_u32(dev, "gpio-reserved-ranges");620	if (size > 0 && size % 2 == 0)621		return size;622 623	return 0;624}625 626static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc)627{628	struct device *dev = &gc->gpiodev->dev;629	unsigned int size;630	u32 *ranges;631	int ret;632 633	size = gpiochip_count_reserved_ranges(gc);634	if (size == 0)635		return 0;636 637	ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL);638	if (!ranges)639		return -ENOMEM;640 641	ret = device_property_read_u32_array(dev, "gpio-reserved-ranges",642					     ranges, size);643	if (ret) {644		kfree(ranges);645		return ret;646	}647 648	while (size) {649		u32 count = ranges[--size];650		u32 start = ranges[--size];651 652		if (start >= gc->ngpio || start + count > gc->ngpio)653			continue;654 655		bitmap_clear(gc->valid_mask, start, count);656	}657 658	kfree(ranges);659	return 0;660}661 662static int gpiochip_init_valid_mask(struct gpio_chip *gc)663{664	int ret;665 666	if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask))667		return 0;668 669	gc->valid_mask = gpiochip_allocate_mask(gc);670	if (!gc->valid_mask)671		return -ENOMEM;672 673	ret = gpiochip_apply_reserved_ranges(gc);674	if (ret)675		return ret;676 677	if (gc->init_valid_mask)678		return gc->init_valid_mask(gc,679					   gc->valid_mask,680					   gc->ngpio);681 682	return 0;683}684 685static void gpiochip_free_valid_mask(struct gpio_chip *gc)686{687	gpiochip_free_mask(&gc->valid_mask);688}689 690static int gpiochip_add_pin_ranges(struct gpio_chip *gc)691{692	/*693	 * Device Tree platforms are supposed to use "gpio-ranges"694	 * property. This check ensures that the ->add_pin_ranges()695	 * won't be called for them.696	 */697	if (device_property_present(&gc->gpiodev->dev, "gpio-ranges"))698		return 0;699 700	if (gc->add_pin_ranges)701		return gc->add_pin_ranges(gc);702 703	return 0;704}705 706bool gpiochip_line_is_valid(const struct gpio_chip *gc,707				unsigned int offset)708{709	/* No mask means all valid */710	if (likely(!gc->valid_mask))711		return true;712	return test_bit(offset, gc->valid_mask);713}714EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);715 716static void gpiodev_release(struct device *dev)717{718	struct gpio_device *gdev = to_gpio_device(dev);719 720	/* Call pending kfree()s for descriptor labels. */721	synchronize_srcu(&gdev->desc_srcu);722	cleanup_srcu_struct(&gdev->desc_srcu);723 724	ida_free(&gpio_ida, gdev->id);725	kfree_const(gdev->label);726	kfree(gdev->descs);727	cleanup_srcu_struct(&gdev->srcu);728	kfree(gdev);729}730 731static const struct device_type gpio_dev_type = {732	.name = "gpio_chip",733	.release = gpiodev_release,734};735 736#ifdef CONFIG_GPIO_CDEV737#define gcdev_register(gdev, devt)	gpiolib_cdev_register((gdev), (devt))738#define gcdev_unregister(gdev)		gpiolib_cdev_unregister((gdev))739#else740/*741 * gpiolib_cdev_register() indirectly calls device_add(), which is still742 * required even when cdev is not selected.743 */744#define gcdev_register(gdev, devt)	device_add(&(gdev)->dev)745#define gcdev_unregister(gdev)		device_del(&(gdev)->dev)746#endif747 748static int gpiochip_setup_dev(struct gpio_device *gdev)749{750	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);751	int ret;752 753	device_initialize(&gdev->dev);754 755	/*756	 * If fwnode doesn't belong to another device, it's safe to clear its757	 * initialized flag.758	 */759	if (fwnode && !fwnode->dev)760		fwnode_dev_initialized(fwnode, false);761 762	ret = gcdev_register(gdev, gpio_devt);763	if (ret)764		return ret;765 766	ret = gpiochip_sysfs_register(gdev);767	if (ret)768		goto err_remove_device;769 770	dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base,771		gdev->base + gdev->ngpio - 1, gdev->label);772 773	return 0;774 775err_remove_device:776	gcdev_unregister(gdev);777	return ret;778}779 780static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)781{782	struct gpio_desc *desc;783	int rv;784 785	desc = gpiochip_get_desc(gc, hog->chip_hwnum);786	if (IS_ERR(desc)) {787		chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,788			 PTR_ERR(desc));789		return;790	}791 792	rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);793	if (rv)794		gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",795			  __func__, gc->label, hog->chip_hwnum, rv);796}797 798static void machine_gpiochip_add(struct gpio_chip *gc)799{800	struct gpiod_hog *hog;801 802	mutex_lock(&gpio_machine_hogs_mutex);803 804	list_for_each_entry(hog, &gpio_machine_hogs, list) {805		if (!strcmp(gc->label, hog->chip_label))806			gpiochip_machine_hog(gc, hog);807	}808 809	mutex_unlock(&gpio_machine_hogs_mutex);810}811 812static void gpiochip_setup_devs(void)813{814	struct gpio_device *gdev;815	int ret;816 817	guard(srcu)(&gpio_devices_srcu);818 819	list_for_each_entry_srcu(gdev, &gpio_devices, list,820				 srcu_read_lock_held(&gpio_devices_srcu)) {821		ret = gpiochip_setup_dev(gdev);822		if (ret)823			dev_err(&gdev->dev,824				"Failed to initialize gpio device (%d)\n", ret);825	}826}827 828static void gpiochip_set_data(struct gpio_chip *gc, void *data)829{830	gc->gpiodev->data = data;831}832 833/**834 * gpiochip_get_data() - get per-subdriver data for the chip835 * @gc: GPIO chip836 *837 * Returns:838 * The per-subdriver data for the chip.839 */840void *gpiochip_get_data(struct gpio_chip *gc)841{842	return gc->gpiodev->data;843}844EXPORT_SYMBOL_GPL(gpiochip_get_data);845 846int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)847{848	u32 ngpios = gc->ngpio;849	int ret;850 851	if (ngpios == 0) {852		ret = device_property_read_u32(dev, "ngpios", &ngpios);853		if (ret == -ENODATA)854			/*855			 * -ENODATA means that there is no property found and856			 * we want to issue the error message to the user.857			 * Besides that, we want to return different error code858			 * to state that supplied value is not valid.859			 */860			ngpios = 0;861		else if (ret)862			return ret;863 864		gc->ngpio = ngpios;865	}866 867	if (gc->ngpio == 0) {868		chip_err(gc, "tried to insert a GPIO chip with zero lines\n");869		return -EINVAL;870	}871 872	if (gc->ngpio > FASTPATH_NGPIO)873		chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",874			gc->ngpio, FASTPATH_NGPIO);875 876	return 0;877}878EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);879 880int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,881			       struct lock_class_key *lock_key,882			       struct lock_class_key *request_key)883{884	struct gpio_device *gdev;885	unsigned int desc_index;886	int base = 0;887	int ret = 0;888 889	/*890	 * First: allocate and populate the internal stat container, and891	 * set up the struct device.892	 */893	gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);894	if (!gdev)895		return -ENOMEM;896 897	gdev->dev.type = &gpio_dev_type;898	gdev->dev.bus = &gpio_bus_type;899	gdev->dev.parent = gc->parent;900	rcu_assign_pointer(gdev->chip, gc);901 902	gc->gpiodev = gdev;903	gpiochip_set_data(gc, data);904 905	/*906	 * If the calling driver did not initialize firmware node,907	 * do it here using the parent device, if any.908	 */909	if (gc->fwnode)910		device_set_node(&gdev->dev, gc->fwnode);911	else if (gc->parent)912		device_set_node(&gdev->dev, dev_fwnode(gc->parent));913 914	gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);915	if (gdev->id < 0) {916		ret = gdev->id;917		goto err_free_gdev;918	}919 920	ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);921	if (ret)922		goto err_free_ida;923 924	if (gc->parent && gc->parent->driver)925		gdev->owner = gc->parent->driver->owner;926	else if (gc->owner)927		/* TODO: remove chip->owner */928		gdev->owner = gc->owner;929	else930		gdev->owner = THIS_MODULE;931 932	ret = gpiochip_get_ngpios(gc, &gdev->dev);933	if (ret)934		goto err_free_dev_name;935 936	gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);937	if (!gdev->descs) {938		ret = -ENOMEM;939		goto err_free_dev_name;940	}941 942	gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);943	if (!gdev->label) {944		ret = -ENOMEM;945		goto err_free_descs;946	}947 948	gdev->ngpio = gc->ngpio;949	gdev->can_sleep = gc->can_sleep;950 951	scoped_guard(mutex, &gpio_devices_lock) {952		/*953		 * TODO: this allocates a Linux GPIO number base in the global954		 * GPIO numberspace for this chip. In the long run we want to955		 * get *rid* of this numberspace and use only descriptors, but956		 * it may be a pipe dream. It will not happen before we get rid957		 * of the sysfs interface anyways.958		 */959		base = gc->base;960		if (base < 0) {961			base = gpiochip_find_base_unlocked(gc->ngpio);962			if (base < 0) {963				ret = base;964				base = 0;965				goto err_free_label;966			}967 968			/*969			 * TODO: it should not be necessary to reflect the970			 * assigned base outside of the GPIO subsystem. Go over971			 * drivers and see if anyone makes use of this, else972			 * drop this and assign a poison instead.973			 */974			gc->base = base;975		} else {976			dev_warn(&gdev->dev,977				 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");978		}979 980		gdev->base = base;981 982		ret = gpiodev_add_to_list_unlocked(gdev);983		if (ret) {984			chip_err(gc, "GPIO integer space overlap, cannot add chip\n");985			goto err_free_label;986		}987	}988 989	for (desc_index = 0; desc_index < gc->ngpio; desc_index++)990		gdev->descs[desc_index].gdev = gdev;991 992	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);993	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);994 995	ret = init_srcu_struct(&gdev->srcu);996	if (ret)997		goto err_remove_from_list;998 999	ret = init_srcu_struct(&gdev->desc_srcu);1000	if (ret)1001		goto err_cleanup_gdev_srcu;1002 1003#ifdef CONFIG_PINCTRL1004	INIT_LIST_HEAD(&gdev->pin_ranges);1005#endif1006 1007	if (gc->names)1008		gpiochip_set_desc_names(gc);1009 1010	ret = gpiochip_set_names(gc);1011	if (ret)1012		goto err_cleanup_desc_srcu;1013 1014	ret = gpiochip_init_valid_mask(gc);1015	if (ret)1016		goto err_cleanup_desc_srcu;1017 1018	for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {1019		struct gpio_desc *desc = &gdev->descs[desc_index];1020 1021		if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {1022			assign_bit(FLAG_IS_OUT,1023				   &desc->flags, !gc->get_direction(gc, desc_index));1024		} else {1025			assign_bit(FLAG_IS_OUT,1026				   &desc->flags, !gc->direction_input);1027		}1028	}1029 1030	ret = of_gpiochip_add(gc);1031	if (ret)1032		goto err_free_valid_mask;1033 1034	ret = gpiochip_add_pin_ranges(gc);1035	if (ret)1036		goto err_remove_of_chip;1037 1038	acpi_gpiochip_add(gc);1039 1040	machine_gpiochip_add(gc);1041 1042	ret = gpiochip_irqchip_init_valid_mask(gc);1043	if (ret)1044		goto err_free_hogs;1045 1046	ret = gpiochip_irqchip_init_hw(gc);1047	if (ret)1048		goto err_remove_irqchip_mask;1049 1050	ret = gpiochip_add_irqchip(gc, lock_key, request_key);1051	if (ret)1052		goto err_remove_irqchip_mask;1053 1054	/*1055	 * By first adding the chardev, and then adding the device,1056	 * we get a device node entry in sysfs under1057	 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for1058	 * coldplug of device nodes and other udev business.1059	 * We can do this only if gpiolib has been initialized.1060	 * Otherwise, defer until later.1061	 */1062	if (gpiolib_initialized) {1063		ret = gpiochip_setup_dev(gdev);1064		if (ret)1065			goto err_remove_irqchip;1066	}1067	return 0;1068 1069err_remove_irqchip:1070	gpiochip_irqchip_remove(gc);1071err_remove_irqchip_mask:1072	gpiochip_irqchip_free_valid_mask(gc);1073err_free_hogs:1074	gpiochip_free_hogs(gc);1075	acpi_gpiochip_remove(gc);1076	gpiochip_remove_pin_ranges(gc);1077err_remove_of_chip:1078	of_gpiochip_remove(gc);1079err_free_valid_mask:1080	gpiochip_free_valid_mask(gc);1081err_cleanup_desc_srcu:1082	cleanup_srcu_struct(&gdev->desc_srcu);1083err_cleanup_gdev_srcu:1084	cleanup_srcu_struct(&gdev->srcu);1085err_remove_from_list:1086	scoped_guard(mutex, &gpio_devices_lock)1087		list_del_rcu(&gdev->list);1088	synchronize_srcu(&gpio_devices_srcu);1089	if (gdev->dev.release) {1090		/* release() has been registered by gpiochip_setup_dev() */1091		gpio_device_put(gdev);1092		goto err_print_message;1093	}1094err_free_label:1095	kfree_const(gdev->label);1096err_free_descs:1097	kfree(gdev->descs);1098err_free_dev_name:1099	kfree(dev_name(&gdev->dev));1100err_free_ida:1101	ida_free(&gpio_ida, gdev->id);1102err_free_gdev:1103	kfree(gdev);1104err_print_message:1105	/* failures here can mean systems won't boot... */1106	if (ret != -EPROBE_DEFER) {1107		pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,1108		       base, base + (int)gc->ngpio - 1,1109		       gc->label ? : "generic", ret);1110	}1111	return ret;1112}1113EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);1114 1115/**1116 * gpiochip_remove() - unregister a gpio_chip1117 * @gc: the chip to unregister1118 *1119 * A gpio_chip with any GPIOs still requested may not be removed.1120 */1121void gpiochip_remove(struct gpio_chip *gc)1122{1123	struct gpio_device *gdev = gc->gpiodev;1124 1125	/* FIXME: should the legacy sysfs handling be moved to gpio_device? */1126	gpiochip_sysfs_unregister(gdev);1127	gpiochip_free_hogs(gc);1128 1129	scoped_guard(mutex, &gpio_devices_lock)1130		list_del_rcu(&gdev->list);1131	synchronize_srcu(&gpio_devices_srcu);1132 1133	/* Numb the device, cancelling all outstanding operations */1134	rcu_assign_pointer(gdev->chip, NULL);1135	synchronize_srcu(&gdev->srcu);1136	gpiochip_irqchip_remove(gc);1137	acpi_gpiochip_remove(gc);1138	of_gpiochip_remove(gc);1139	gpiochip_remove_pin_ranges(gc);1140	gpiochip_free_valid_mask(gc);1141	/*1142	 * We accept no more calls into the driver from this point, so1143	 * NULL the driver data pointer.1144	 */1145	gpiochip_set_data(gc, NULL);1146 1147	/*1148	 * The gpiochip side puts its use of the device to rest here:1149	 * if there are no userspace clients, the chardev and device will1150	 * be removed, else it will be dangling until the last user is1151	 * gone.1152	 */1153	gcdev_unregister(gdev);1154	gpio_device_put(gdev);1155}1156EXPORT_SYMBOL_GPL(gpiochip_remove);1157 1158/**1159 * gpio_device_find() - find a specific GPIO device1160 * @data: data to pass to match function1161 * @match: Callback function to check gpio_chip1162 *1163 * Returns:1164 * New reference to struct gpio_device.1165 *1166 * Similar to bus_find_device(). It returns a reference to a gpio_device as1167 * determined by a user supplied @match callback. The callback should return1168 * 0 if the device doesn't match and non-zero if it does. If the callback1169 * returns non-zero, this function will return to the caller and not iterate1170 * over any more gpio_devices.1171 *1172 * The callback takes the GPIO chip structure as argument. During the execution1173 * of the callback function the chip is protected from being freed. TODO: This1174 * actually has yet to be implemented.1175 *1176 * If the function returns non-NULL, the returned reference must be freed by1177 * the caller using gpio_device_put().1178 */1179struct gpio_device *gpio_device_find(const void *data,1180				     int (*match)(struct gpio_chip *gc,1181						  const void *data))1182{1183	struct gpio_device *gdev;1184	struct gpio_chip *gc;1185 1186	/*1187	 * Not yet but in the future the spinlock below will become a mutex.1188	 * Annotate this function before anyone tries to use it in interrupt1189	 * context like it happened with gpiochip_find().1190	 */1191	might_sleep();1192 1193	guard(srcu)(&gpio_devices_srcu);1194 1195	list_for_each_entry_srcu(gdev, &gpio_devices, list,1196				 srcu_read_lock_held(&gpio_devices_srcu)) {1197		if (!device_is_registered(&gdev->dev))1198			continue;1199 1200		guard(srcu)(&gdev->srcu);1201 1202		gc = srcu_dereference(gdev->chip, &gdev->srcu);1203 1204		if (gc && match(gc, data))1205			return gpio_device_get(gdev);1206	}1207 1208	return NULL;1209}1210EXPORT_SYMBOL_GPL(gpio_device_find);1211 1212static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)1213{1214	return gc->label && !strcmp(gc->label, label);1215}1216 1217/**1218 * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the1219 *                               GPIO device by its backing chip's label1220 * @label: Label to lookup1221 *1222 * Returns:1223 * Reference to the GPIO device or NULL. Reference must be released with1224 * gpio_device_put().1225 */1226struct gpio_device *gpio_device_find_by_label(const char *label)1227{1228	return gpio_device_find((void *)label, gpio_chip_match_by_label);1229}1230EXPORT_SYMBOL_GPL(gpio_device_find_by_label);1231 1232static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)1233{1234	return device_match_fwnode(&gc->gpiodev->dev, fwnode);1235}1236 1237/**1238 * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding1239 *                                the GPIO device by its fwnode1240 * @fwnode: Firmware node to lookup1241 *1242 * Returns:1243 * Reference to the GPIO device or NULL. Reference must be released with1244 * gpio_device_put().1245 */1246struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)1247{1248	return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);1249}1250EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);1251 1252/**1253 * gpio_device_get() - Increase the reference count of this GPIO device1254 * @gdev: GPIO device to increase the refcount for1255 *1256 * Returns:1257 * Pointer to @gdev.1258 */1259struct gpio_device *gpio_device_get(struct gpio_device *gdev)1260{1261	return to_gpio_device(get_device(&gdev->dev));1262}1263EXPORT_SYMBOL_GPL(gpio_device_get);1264 1265/**1266 * gpio_device_put() - Decrease the reference count of this GPIO device and1267 *                     possibly free all resources associated with it.1268 * @gdev: GPIO device to decrease the reference count for1269 */1270void gpio_device_put(struct gpio_device *gdev)1271{1272	put_device(&gdev->dev);1273}1274EXPORT_SYMBOL_GPL(gpio_device_put);1275 1276/**1277 * gpio_device_to_device() - Retrieve the address of the underlying struct1278 *                           device.1279 * @gdev: GPIO device for which to return the address.1280 *1281 * This does not increase the reference count of the GPIO device nor the1282 * underlying struct device.1283 *1284 * Returns:1285 * Address of struct device backing this GPIO device.1286 */1287struct device *gpio_device_to_device(struct gpio_device *gdev)1288{1289	return &gdev->dev;1290}1291EXPORT_SYMBOL_GPL(gpio_device_to_device);1292 1293#ifdef CONFIG_GPIOLIB_IRQCHIP1294 1295/*1296 * The following is irqchip helper code for gpiochips.1297 */1298 1299static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)1300{1301	struct gpio_irq_chip *girq = &gc->irq;1302 1303	if (!girq->init_hw)1304		return 0;1305 1306	return girq->init_hw(gc);1307}1308 1309static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)1310{1311	struct gpio_irq_chip *girq = &gc->irq;1312 1313	if (!girq->init_valid_mask)1314		return 0;1315 1316	girq->valid_mask = gpiochip_allocate_mask(gc);1317	if (!girq->valid_mask)1318		return -ENOMEM;1319 1320	girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);1321 1322	return 0;1323}1324 1325static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)1326{1327	gpiochip_free_mask(&gc->irq.valid_mask);1328}1329 1330static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,1331				       unsigned int offset)1332{1333	if (!gpiochip_line_is_valid(gc, offset))1334		return false;1335	/* No mask means all valid */1336	if (likely(!gc->irq.valid_mask))1337		return true;1338	return test_bit(offset, gc->irq.valid_mask);1339}1340 1341#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY1342 1343/**1344 * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip1345 * to a gpiochip1346 * @gc: the gpiochip to set the irqchip hierarchical handler to1347 * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt1348 * will then percolate up to the parent1349 */1350static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,1351					      struct irq_chip *irqchip)1352{1353	/* DT will deal with mapping each IRQ as we go along */1354	if (is_of_node(gc->irq.fwnode))1355		return;1356 1357	/*1358	 * This is for legacy and boardfile "irqchip" fwnodes: allocate1359	 * irqs upfront instead of dynamically since we don't have the1360	 * dynamic type of allocation that hardware description languages1361	 * provide. Once all GPIO drivers using board files are gone from1362	 * the kernel we can delete this code, but for a transitional period1363	 * it is necessary to keep this around.1364	 */1365	if (is_fwnode_irqchip(gc->irq.fwnode)) {1366		int i;1367		int ret;1368 1369		for (i = 0; i < gc->ngpio; i++) {1370			struct irq_fwspec fwspec;1371			unsigned int parent_hwirq;1372			unsigned int parent_type;1373			struct gpio_irq_chip *girq = &gc->irq;1374 1375			/*1376			 * We call the child to parent translation function1377			 * only to check if the child IRQ is valid or not.1378			 * Just pick the rising edge type here as that is what1379			 * we likely need to support.1380			 */1381			ret = girq->child_to_parent_hwirq(gc, i,1382							  IRQ_TYPE_EDGE_RISING,1383							  &parent_hwirq,1384							  &parent_type);1385			if (ret) {1386				chip_err(gc, "skip set-up on hwirq %d\n",1387					 i);1388				continue;1389			}1390 1391			fwspec.fwnode = gc->irq.fwnode;1392			/* This is the hwirq for the GPIO line side of things */1393			fwspec.param[0] = girq->child_offset_to_irq(gc, i);1394			/* Just pick something */1395			fwspec.param[1] = IRQ_TYPE_EDGE_RISING;1396			fwspec.param_count = 2;1397			ret = irq_domain_alloc_irqs(gc->irq.domain, 1,1398						    NUMA_NO_NODE, &fwspec);1399			if (ret < 0) {1400				chip_err(gc,1401					 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",1402					 i, parent_hwirq,1403					 ret);1404			}1405		}1406	}1407 1408	chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);1409 1410	return;1411}1412 1413static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,1414						   struct irq_fwspec *fwspec,1415						   unsigned long *hwirq,1416						   unsigned int *type)1417{1418	/* We support standard DT translation */1419	if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {1420		return irq_domain_translate_twocell(d, fwspec, hwirq, type);1421	}1422 1423	/* This is for board files and others not using DT */1424	if (is_fwnode_irqchip(fwspec->fwnode)) {1425		int ret;1426 1427		ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);1428		if (ret)1429			return ret;1430		WARN_ON(*type == IRQ_TYPE_NONE);1431		return 0;1432	}1433	return -EINVAL;1434}1435 1436static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,1437					       unsigned int irq,1438					       unsigned int nr_irqs,1439					       void *data)1440{1441	struct gpio_chip *gc = d->host_data;1442	irq_hw_number_t hwirq;1443	unsigned int type = IRQ_TYPE_NONE;1444	struct irq_fwspec *fwspec = data;1445	union gpio_irq_fwspec gpio_parent_fwspec = {};1446	unsigned int parent_hwirq;1447	unsigned int parent_type;1448	struct gpio_irq_chip *girq = &gc->irq;1449	int ret;1450 1451	/*1452	 * The nr_irqs parameter is always one except for PCI multi-MSI1453	 * so this should not happen.1454	 */1455	WARN_ON(nr_irqs != 1);1456 1457	ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);1458	if (ret)1459		return ret;1460 1461	chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);1462 1463	ret = girq->child_to_parent_hwirq(gc, hwirq, type,1464					  &parent_hwirq, &parent_type);1465	if (ret) {1466		chip_err(gc, "can't look up hwirq %lu\n", hwirq);1467		return ret;1468	}1469	chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);1470 1471	/*1472	 * We set handle_bad_irq because the .set_type() should1473	 * always be invoked and set the right type of handler.1474	 */1475	irq_domain_set_info(d,1476			    irq,1477			    hwirq,1478			    gc->irq.chip,1479			    gc,1480			    girq->handler,1481			    NULL, NULL);1482	irq_set_probe(irq);1483 1484	/* This parent only handles asserted level IRQs */1485	ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,1486					      parent_hwirq, parent_type);1487	if (ret)1488		return ret;1489 1490	chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",1491		  irq, parent_hwirq);1492	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);1493	ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);1494	/*1495	 * If the parent irqdomain is msi, the interrupts have already1496	 * been allocated, so the EEXIST is good.1497	 */1498	if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))1499		ret = 0;1500	if (ret)1501		chip_err(gc,1502			 "failed to allocate parent hwirq %d for hwirq %lu\n",1503			 parent_hwirq, hwirq);1504 1505	return ret;1506}1507 1508static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,1509						      unsigned int offset)1510{1511	return offset;1512}1513 1514/**1515 * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ1516 * @domain: The IRQ domain used by this IRQ chip1517 * @data: Outermost irq_data associated with the IRQ1518 * @reserve: If set, only reserve an interrupt vector instead of assigning one1519 *1520 * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be1521 * used as the activate function for the &struct irq_domain_ops. The host_data1522 * for the IRQ domain must be the &struct gpio_chip.1523 *1524 * Returns:1525 * 0 on success, or negative errno on failure.1526 */1527static int gpiochip_irq_domain_activate(struct irq_domain *domain,1528					struct irq_data *data, bool reserve)1529{1530	struct gpio_chip *gc = domain->host_data;1531	unsigned int hwirq = irqd_to_hwirq(data);1532 1533	return gpiochip_lock_as_irq(gc, hwirq);1534}1535 1536/**1537 * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ1538 * @domain: The IRQ domain used by this IRQ chip1539 * @data: Outermost irq_data associated with the IRQ1540 *1541 * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to1542 * be used as the deactivate function for the &struct irq_domain_ops. The1543 * host_data for the IRQ domain must be the &struct gpio_chip.1544 */1545static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,1546					   struct irq_data *data)1547{1548	struct gpio_chip *gc = domain->host_data;1549	unsigned int hwirq = irqd_to_hwirq(data);1550 1551	return gpiochip_unlock_as_irq(gc, hwirq);1552}1553 1554static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)1555{1556	ops->activate = gpiochip_irq_domain_activate;1557	ops->deactivate = gpiochip_irq_domain_deactivate;1558	ops->alloc = gpiochip_hierarchy_irq_domain_alloc;1559 1560	/*1561	 * We only allow overriding the translate() and free() functions for1562	 * hierarchical chips, and this should only be done if the user1563	 * really need something other than 1:1 translation for translate()1564	 * callback and free if user wants to free up any resources which1565	 * were allocated during callbacks, for example populate_parent_alloc_arg.1566	 */1567	if (!ops->translate)1568		ops->translate = gpiochip_hierarchy_irq_domain_translate;1569	if (!ops->free)1570		ops->free = irq_domain_free_irqs_common;1571}1572 1573static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)1574{1575	struct irq_domain *domain;1576 1577	if (!gc->irq.child_to_parent_hwirq ||1578	    !gc->irq.fwnode) {1579		chip_err(gc, "missing irqdomain vital data\n");1580		return ERR_PTR(-EINVAL);1581	}1582 1583	if (!gc->irq.child_offset_to_irq)1584		gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;1585 1586	if (!gc->irq.populate_parent_alloc_arg)1587		gc->irq.populate_parent_alloc_arg =1588			gpiochip_populate_parent_fwspec_twocell;1589 1590	gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);1591 1592	domain = irq_domain_create_hierarchy(1593		gc->irq.parent_domain,1594		0,1595		gc->ngpio,1596		gc->irq.fwnode,1597		&gc->irq.child_irq_domain_ops,1598		gc);1599 1600	if (!domain)1601		return ERR_PTR(-ENOMEM);1602 1603	gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);1604 1605	return domain;1606}1607 1608static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)1609{1610	return !!gc->irq.parent_domain;1611}1612 1613int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,1614					    union gpio_irq_fwspec *gfwspec,1615					    unsigned int parent_hwirq,1616					    unsigned int parent_type)1617{1618	struct irq_fwspec *fwspec = &gfwspec->fwspec;1619 1620	fwspec->fwnode = gc->irq.parent_domain->fwnode;1621	fwspec->param_count = 2;1622	fwspec->param[0] = parent_hwirq;1623	fwspec->param[1] = parent_type;1624 1625	return 0;1626}1627EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);1628 1629int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,1630					     union gpio_irq_fwspec *gfwspec,1631					     unsigned int parent_hwirq,1632					     unsigned int parent_type)1633{1634	struct irq_fwspec *fwspec = &gfwspec->fwspec;1635 1636	fwspec->fwnode = gc->irq.parent_domain->fwnode;1637	fwspec->param_count = 4;1638	fwspec->param[0] = 0;1639	fwspec->param[1] = parent_hwirq;1640	fwspec->param[2] = 0;1641	fwspec->param[3] = parent_type;1642 1643	return 0;1644}1645EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);1646 1647#else1648 1649static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)1650{1651	return ERR_PTR(-EINVAL);1652}1653 1654static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)1655{1656	return false;1657}1658 1659#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */1660 1661/**1662 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip1663 * @d: the irqdomain used by this irqchip1664 * @irq: the global irq number used by this GPIO irqchip irq1665 * @hwirq: the local IRQ/GPIO line offset on this gpiochip1666 *1667 * This function will set up the mapping for a certain IRQ line on a1668 * gpiochip by assigning the gpiochip as chip data, and using the irqchip1669 * stored inside the gpiochip.1670 *1671 * Returns:1672 * 0 on success, or negative errno on failure.1673 */1674static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,1675			    irq_hw_number_t hwirq)1676{1677	struct gpio_chip *gc = d->host_data;1678	int ret = 0;1679 1680	if (!gpiochip_irqchip_irq_valid(gc, hwirq))1681		return -ENXIO;1682 1683	irq_set_chip_data(irq, gc);1684	/*1685	 * This lock class tells lockdep that GPIO irqs are in a different1686	 * category than their parents, so it won't report false recursion.1687	 */1688	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);1689	irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);1690	/* Chips that use nested thread handlers have them marked */1691	if (gc->irq.threaded)1692		irq_set_nested_thread(irq, 1);1693	irq_set_noprobe(irq);1694 1695	if (gc->irq.num_parents == 1)1696		ret = irq_set_parent(irq, gc->irq.parents[0]);1697	else if (gc->irq.map)1698		ret = irq_set_parent(irq, gc->irq.map[hwirq]);1699 1700	if (ret < 0)1701		return ret;1702 1703	/*1704	 * No set-up of the hardware will happen if IRQ_TYPE_NONE1705	 * is passed as default type.1706	 */1707	if (gc->irq.default_type != IRQ_TYPE_NONE)1708		irq_set_irq_type(irq, gc->irq.default_type);1709 1710	return 0;1711}1712 1713static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)1714{1715	struct gpio_chip *gc = d->host_data;1716 1717	if (gc->irq.threaded)1718		irq_set_nested_thread(irq, 0);1719	irq_set_chip_and_handler(irq, NULL, NULL);1720	irq_set_chip_data(irq, NULL);1721}1722 1723static const struct irq_domain_ops gpiochip_domain_ops = {1724	.map	= gpiochip_irq_map,1725	.unmap	= gpiochip_irq_unmap,1726	/* Virtually all GPIO irqchips are twocell:ed */1727	.xlate	= irq_domain_xlate_twocell,1728};1729 1730static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)1731{1732	struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);1733	struct irq_domain *domain;1734 1735	domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,1736					  &gpiochip_domain_ops, gc);1737	if (!domain)1738		return ERR_PTR(-EINVAL);1739 1740	return domain;1741}1742 1743static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)1744{1745	struct irq_domain *domain = gc->irq.domain;1746 1747#ifdef CONFIG_GPIOLIB_IRQCHIP1748	/*1749	 * Avoid race condition with other code, which tries to lookup1750	 * an IRQ before the irqchip has been properly registered,1751	 * i.e. while gpiochip is still being brought up.1752	 */1753	if (!gc->irq.initialized)1754		return -EPROBE_DEFER;1755#endif1756 1757	if (!gpiochip_irqchip_irq_valid(gc, offset))1758		return -ENXIO;1759 1760#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY1761	if (irq_domain_is_hierarchy(domain)) {1762		struct irq_fwspec spec;1763 1764		spec.fwnode = domain->fwnode;1765		spec.param_count = 2;1766		spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);1767		spec.param[1] = IRQ_TYPE_NONE;1768 1769		return irq_create_fwspec_mapping(&spec);1770	}1771#endif1772 1773	return irq_create_mapping(domain, offset);1774}1775 1776int gpiochip_irq_reqres(struct irq_data *d)1777{1778	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1779	unsigned int hwirq = irqd_to_hwirq(d);1780 1781	return gpiochip_reqres_irq(gc, hwirq);1782}1783EXPORT_SYMBOL(gpiochip_irq_reqres);1784 1785void gpiochip_irq_relres(struct irq_data *d)1786{1787	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1788	unsigned int hwirq = irqd_to_hwirq(d);1789 1790	gpiochip_relres_irq(gc, hwirq);1791}1792EXPORT_SYMBOL(gpiochip_irq_relres);1793 1794static void gpiochip_irq_mask(struct irq_data *d)1795{1796	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1797	unsigned int hwirq = irqd_to_hwirq(d);1798 1799	if (gc->irq.irq_mask)1800		gc->irq.irq_mask(d);1801	gpiochip_disable_irq(gc, hwirq);1802}1803 1804static void gpiochip_irq_unmask(struct irq_data *d)1805{1806	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1807	unsigned int hwirq = irqd_to_hwirq(d);1808 1809	gpiochip_enable_irq(gc, hwirq);1810	if (gc->irq.irq_unmask)1811		gc->irq.irq_unmask(d);1812}1813 1814static void gpiochip_irq_enable(struct irq_data *d)1815{1816	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1817	unsigned int hwirq = irqd_to_hwirq(d);1818 1819	gpiochip_enable_irq(gc, hwirq);1820	gc->irq.irq_enable(d);1821}1822 1823static void gpiochip_irq_disable(struct irq_data *d)1824{1825	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1826	unsigned int hwirq = irqd_to_hwirq(d);1827 1828	gc->irq.irq_disable(d);1829	gpiochip_disable_irq(gc, hwirq);1830}1831 1832static void gpiochip_set_irq_hooks(struct gpio_chip *gc)1833{1834	struct irq_chip *irqchip = gc->irq.chip;1835 1836	if (irqchip->flags & IRQCHIP_IMMUTABLE)1837		return;1838 1839	chip_warn(gc, "not an immutable chip, please consider fixing it!\n");1840 1841	if (!irqchip->irq_request_resources &&1842	    !irqchip->irq_release_resources) {1843		irqchip->irq_request_resources = gpiochip_irq_reqres;1844		irqchip->irq_release_resources = gpiochip_irq_relres;1845	}1846	if (WARN_ON(gc->irq.irq_enable))1847		return;1848	/* Check if the irqchip already has this hook... */1849	if (irqchip->irq_enable == gpiochip_irq_enable ||1850		irqchip->irq_mask == gpiochip_irq_mask) {1851		/*1852		 * ...and if so, give a gentle warning that this is bad1853		 * practice.1854		 */1855		chip_info(gc,1856			  "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");1857		return;1858	}1859 1860	if (irqchip->irq_disable) {1861		gc->irq.irq_disable = irqchip->irq_disable;1862		irqchip->irq_disable = gpiochip_irq_disable;1863	} else {1864		gc->irq.irq_mask = irqchip->irq_mask;1865		irqchip->irq_mask = gpiochip_irq_mask;1866	}1867 1868	if (irqchip->irq_enable) {1869		gc->irq.irq_enable = irqchip->irq_enable;1870		irqchip->irq_enable = gpiochip_irq_enable;1871	} else {1872		gc->irq.irq_unmask = irqchip->irq_unmask;1873		irqchip->irq_unmask = gpiochip_irq_unmask;1874	}1875}1876 1877static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,1878						 struct irq_domain *domain,1879						 bool allocated_externally)1880{1881	if (!domain)1882		return -EINVAL;1883 1884	if (gc->to_irq)1885		chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);1886 1887	gc->to_irq = gpiochip_to_irq;1888	gc->irq.domain = domain;1889	gc->irq.domain_is_allocated_externally = allocated_externally;1890 1891	/*1892	 * Using barrier() here to prevent compiler from reordering1893	 * gc->irq.initialized before adding irqdomain.1894	 */1895	barrier();1896 1897	gc->irq.initialized = true;1898 1899	return 0;1900}1901 1902/**1903 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip1904 * @gc: the GPIO chip to add the IRQ chip to1905 * @lock_key: lockdep class for IRQ lock1906 * @request_key: lockdep class for IRQ request1907 *1908 * Returns:1909 * 0 on success, or a negative errno on failure.1910 */1911static int gpiochip_add_irqchip(struct gpio_chip *gc,1912				struct lock_class_key *lock_key,1913				struct lock_class_key *request_key)1914{1915	struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);1916	struct irq_chip *irqchip = gc->irq.chip;1917	struct irq_domain *domain;1918	unsigned int type;1919	unsigned int i;1920	int ret;1921 1922	if (!irqchip)1923		return 0;1924 1925	if (gc->irq.parent_handler && gc->can_sleep) {1926		chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");1927		return -EINVAL;1928	}1929 1930	type = gc->irq.default_type;1931 1932	/*1933	 * Specifying a default trigger is a terrible idea if DT or ACPI is1934	 * used to configure the interrupts, as you may end up with1935	 * conflicting triggers. Tell the user, and reset to NONE.1936	 */1937	if (WARN(fwnode && type != IRQ_TYPE_NONE,1938		 "%pfw: Ignoring %u default trigger\n", fwnode, type))1939		type = IRQ_TYPE_NONE;1940 1941	gc->irq.default_type = type;1942	gc->irq.lock_key = lock_key;1943	gc->irq.request_key = request_key;1944 1945	/* If a parent irqdomain is provided, let's build a hierarchy */1946	if (gpiochip_hierarchy_is_hierarchical(gc)) {1947		domain = gpiochip_hierarchy_create_domain(gc);1948	} else {1949		domain = gpiochip_simple_create_domain(gc);1950	}1951	if (IS_ERR(domain))1952		return PTR_ERR(domain);1953 1954	if (gc->irq.parent_handler) {1955		for (i = 0; i < gc->irq.num_parents; i++) {1956			void *data;1957 1958			if (gc->irq.per_parent_data)1959				data = gc->irq.parent_handler_data_array[i];1960			else1961				data = gc->irq.parent_handler_data ?: gc;1962 1963			/*1964			 * The parent IRQ chip is already using the chip_data1965			 * for this IRQ chip, so our callbacks simply use the1966			 * handler_data.1967			 */1968			irq_set_chained_handler_and_data(gc->irq.parents[i],1969							 gc->irq.parent_handler,1970							 data);1971		}1972	}1973 1974	gpiochip_set_irq_hooks(gc);1975 1976	ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);1977	if (ret)1978		return ret;1979 1980	acpi_gpiochip_request_interrupts(gc);1981 1982	return 0;1983}1984 1985/**1986 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip1987 * @gc: the gpiochip to remove the irqchip from1988 *1989 * This is called only from gpiochip_remove()1990 */1991static void gpiochip_irqchip_remove(struct gpio_chip *gc)1992{1993	struct irq_chip *irqchip = gc->irq.chip;1994	unsigned int offset;1995 1996	acpi_gpiochip_free_interrupts(gc);1997 1998	if (irqchip && gc->irq.parent_handler) {1999		struct gpio_irq_chip *irq = &gc->irq;2000		unsigned int i;2001 2002		for (i = 0; i < irq->num_parents; i++)2003			irq_set_chained_handler_and_data(irq->parents[i],2004							 NULL, NULL);2005	}2006 2007	/* Remove all IRQ mappings and delete the domain */2008	if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {2009		unsigned int irq;2010 2011		for (offset = 0; offset < gc->ngpio; offset++) {2012			if (!gpiochip_irqchip_irq_valid(gc, offset))2013				continue;2014 2015			irq = irq_find_mapping(gc->irq.domain, offset);2016			irq_dispose_mapping(irq);2017		}2018 2019		irq_domain_remove(gc->irq.domain);2020	}2021 2022	if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {2023		if (irqchip->irq_request_resources == gpiochip_irq_reqres) {2024			irqchip->irq_request_resources = NULL;2025			irqchip->irq_release_resources = NULL;2026		}2027		if (irqchip->irq_enable == gpiochip_irq_enable) {2028			irqchip->irq_enable = gc->irq.irq_enable;2029			irqchip->irq_disable = gc->irq.irq_disable;2030		}2031	}2032	gc->irq.irq_enable = NULL;2033	gc->irq.irq_disable = NULL;2034	gc->irq.chip = NULL;2035 2036	gpiochip_irqchip_free_valid_mask(gc);2037}2038 2039/**2040 * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip2041 * @gc: the gpiochip to add the irqchip to2042 * @domain: the irqdomain to add to the gpiochip2043 *2044 * This function adds an IRQ domain to the gpiochip.2045 *2046 * Returns:2047 * 0 on success, or negative errno on failure.2048 */2049int gpiochip_irqchip_add_domain(struct gpio_chip *gc,2050				struct irq_domain *domain)2051{2052	return gpiochip_irqchip_add_allocated_domain(gc, domain, true);2053}2054EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);2055 2056#else /* CONFIG_GPIOLIB_IRQCHIP */2057 2058static inline int gpiochip_add_irqchip(struct gpio_chip *gc,2059				       struct lock_class_key *lock_key,2060				       struct lock_class_key *request_key)2061{2062	return 0;2063}2064static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}2065 2066static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)2067{2068	return 0;2069}2070 2071static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)2072{2073	return 0;2074}2075static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)2076{ }2077 2078#endif /* CONFIG_GPIOLIB_IRQCHIP */2079 2080/**2081 * gpiochip_generic_request() - request the gpio function for a pin2082 * @gc: the gpiochip owning the GPIO2083 * @offset: the offset of the GPIO to request for GPIO function2084 *2085 * Returns:2086 * 0 on success, or negative errno on failure.2087 */2088int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)2089{2090#ifdef CONFIG_PINCTRL2091	if (list_empty(&gc->gpiodev->pin_ranges))2092		return 0;2093#endif2094 2095	return pinctrl_gpio_request(gc, offset);2096}2097EXPORT_SYMBOL_GPL(gpiochip_generic_request);2098 2099/**2100 * gpiochip_generic_free() - free the gpio function from a pin2101 * @gc: the gpiochip to request the gpio function for2102 * @offset: the offset of the GPIO to free from GPIO function2103 */2104void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)2105{2106#ifdef CONFIG_PINCTRL2107	if (list_empty(&gc->gpiodev->pin_ranges))2108		return;2109#endif2110 2111	pinctrl_gpio_free(gc, offset);2112}2113EXPORT_SYMBOL_GPL(gpiochip_generic_free);2114 2115/**2116 * gpiochip_generic_config() - apply configuration for a pin2117 * @gc: the gpiochip owning the GPIO2118 * @offset: the offset of the GPIO to apply the configuration2119 * @config: the configuration to be applied2120 *2121 * Returns:2122 * 0 on success, or negative errno on failure.2123 */2124int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,2125			    unsigned long config)2126{2127#ifdef CONFIG_PINCTRL2128	if (list_empty(&gc->gpiodev->pin_ranges))2129		return -ENOTSUPP;2130#endif2131 2132	return pinctrl_gpio_set_config(gc, offset, config);2133}2134EXPORT_SYMBOL_GPL(gpiochip_generic_config);2135 2136#ifdef CONFIG_PINCTRL2137 2138/**2139 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping2140 * @gc: the gpiochip to add the range for2141 * @pctldev: the pin controller to map to2142 * @gpio_offset: the start offset in the current gpio_chip number space2143 * @pin_group: name of the pin group inside the pin controller2144 *2145 * Calling this function directly from a DeviceTree-supported2146 * pinctrl driver is DEPRECATED. Please see Section 2.1 of2147 * Documentation/devicetree/bindings/gpio/gpio.txt on how to2148 * bind pinctrl and gpio drivers via the "gpio-ranges" property.2149 *2150 * Returns:2151 * 0 on success, or negative errno on failure.2152 */2153int gpiochip_add_pingroup_range(struct gpio_chip *gc,2154			struct pinctrl_dev *pctldev,2155			unsigned int gpio_offset, const char *pin_group)2156{2157	struct gpio_pin_range *pin_range;2158	struct gpio_device *gdev = gc->gpiodev;2159	int ret;2160 2161	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);2162	if (!pin_range) {2163		chip_err(gc, "failed to allocate pin ranges\n");2164		return -ENOMEM;2165	}2166 2167	/* Use local offset as range ID */2168	pin_range->range.id = gpio_offset;2169	pin_range->range.gc = gc;2170	pin_range->range.name = gc->label;2171	pin_range->range.base = gdev->base + gpio_offset;2172	pin_range->pctldev = pctldev;2173 2174	ret = pinctrl_get_group_pins(pctldev, pin_group,2175					&pin_range->range.pins,2176					&pin_range->range.npins);2177	if (ret < 0) {2178		kfree(pin_range);2179		return ret;2180	}2181 2182	pinctrl_add_gpio_range(pctldev, &pin_range->range);2183 2184	chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",2185		 gpio_offset, gpio_offset + pin_range->range.npins - 1,2186		 pinctrl_dev_get_devname(pctldev), pin_group);2187 2188	list_add_tail(&pin_range->node, &gdev->pin_ranges);2189 2190	return 0;2191}2192EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);2193 2194/**2195 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping2196 * @gc: the gpiochip to add the range for2197 * @pinctl_name: the dev_name() of the pin controller to map to2198 * @gpio_offset: the start offset in the current gpio_chip number space2199 * @pin_offset: the start offset in the pin controller number space2200 * @npins: the number of pins from the offset of each pin space (GPIO and2201 *	pin controller) to accumulate in this range2202 *2203 * Calling this function directly from a DeviceTree-supported2204 * pinctrl driver is DEPRECATED. Please see Section 2.1 of2205 * Documentation/devicetree/bindings/gpio/gpio.txt on how to2206 * bind pinctrl and gpio drivers via the "gpio-ranges" property.2207 *2208 * Returns:2209 * 0 on success, or a negative errno on failure.2210 */2211int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,2212			   unsigned int gpio_offset, unsigned int pin_offset,2213			   unsigned int npins)2214{2215	struct gpio_pin_range *pin_range;2216	struct gpio_device *gdev = gc->gpiodev;2217	int ret;2218 2219	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);2220	if (!pin_range) {2221		chip_err(gc, "failed to allocate pin ranges\n");2222		return -ENOMEM;2223	}2224 2225	/* Use local offset as range ID */2226	pin_range->range.id = gpio_offset;2227	pin_range->range.gc = gc;2228	pin_range->range.name = gc->label;2229	pin_range->range.base = gdev->base + gpio_offset;2230	pin_range->range.pin_base = pin_offset;2231	pin_range->range.npins = npins;2232	pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,2233			&pin_range->range);2234	if (IS_ERR(pin_range->pctldev)) {2235		ret = PTR_ERR(pin_range->pctldev);2236		chip_err(gc, "could not create pin range\n");2237		kfree(pin_range);2238		return ret;2239	}2240	chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",2241		 gpio_offset, gpio_offset + npins - 1,2242		 pinctl_name,2243		 pin_offset, pin_offset + npins - 1);2244 2245	list_add_tail(&pin_range->node, &gdev->pin_ranges);2246 2247	return 0;2248}2249EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);2250 2251/**2252 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings2253 * @gc: the chip to remove all the mappings for2254 */2255void gpiochip_remove_pin_ranges(struct gpio_chip *gc)2256{2257	struct gpio_pin_range *pin_range, *tmp;2258	struct gpio_device *gdev = gc->gpiodev;2259 2260	list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {2261		list_del(&pin_range->node);2262		pinctrl_remove_gpio_range(pin_range->pctldev,2263				&pin_range->range);2264		kfree(pin_range);2265	}2266}2267EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);2268 2269#endif /* CONFIG_PINCTRL */2270 2271/* These "optional" allocation calls help prevent drivers from stomping2272 * on each other, and help provide better diagnostics in debugfs.2273 * They're called even less than the "set direction" calls.2274 */2275static int gpiod_request_commit(struct gpio_desc *desc, const char *label)2276{2277	unsigned int offset;2278	int ret;2279 2280	CLASS(gpio_chip_guard, guard)(desc);2281	if (!guard.gc)2282		return -ENODEV;2283 2284	if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))2285		return -EBUSY;2286 2287	/* NOTE:  gpio_request() can be called in early boot,2288	 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.2289	 */2290 2291	if (guard.gc->request) {2292		offset = gpio_chip_hwgpio(desc);2293		if (gpiochip_line_is_valid(guard.gc, offset))2294			ret = guard.gc->request(guard.gc, offset);2295		else2296			ret = -EINVAL;2297		if (ret)2298			goto out_clear_bit;2299	}2300 2301	if (guard.gc->get_direction)2302		gpiod_get_direction(desc);2303 2304	ret = desc_set_label(desc, label ? : "?");2305	if (ret)2306		goto out_clear_bit;2307 2308	return 0;2309 2310out_clear_bit:2311	clear_bit(FLAG_REQUESTED, &desc->flags);2312	return ret;2313}2314 2315/*2316 * This descriptor validation needs to be inserted verbatim into each2317 * function taking a descriptor, so we need to use a preprocessor2318 * macro to avoid endless duplication. If the desc is NULL it is an2319 * optional GPIO and calls should just bail out.2320 */2321static int validate_desc(const struct gpio_desc *desc, const char *func)2322{2323	if (!desc)2324		return 0;2325 2326	if (IS_ERR(desc)) {2327		pr_warn("%s: invalid GPIO (errorpointer)\n", func);2328		return PTR_ERR(desc);2329	}2330 2331	return 1;2332}2333 2334#define VALIDATE_DESC(desc) do { \2335	int __valid = validate_desc(desc, __func__); \2336	if (__valid <= 0) \2337		return __valid; \2338	} while (0)2339 2340#define VALIDATE_DESC_VOID(desc) do { \2341	int __valid = validate_desc(desc, __func__); \2342	if (__valid <= 0) \2343		return; \2344	} while (0)2345 2346int gpiod_request(struct gpio_desc *desc, const char *label)2347{2348	int ret = -EPROBE_DEFER;2349 2350	VALIDATE_DESC(desc);2351 2352	if (try_module_get(desc->gdev->owner)) {2353		ret = gpiod_request_commit(desc, label);2354		if (ret)2355			module_put(desc->gdev->owner);2356		else2357			gpio_device_get(desc->gdev);2358	}2359 2360	if (ret)2361		gpiod_dbg(desc, "%s: status %d\n", __func__, ret);2362 2363	return ret;2364}2365 2366static void gpiod_free_commit(struct gpio_desc *desc)2367{2368	unsigned long flags;2369 2370	might_sleep();2371 2372	CLASS(gpio_chip_guard, guard)(desc);2373 2374	flags = READ_ONCE(desc->flags);2375 2376	if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {2377		if (guard.gc->free)2378			guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));2379 2380		clear_bit(FLAG_ACTIVE_LOW, &flags);2381		clear_bit(FLAG_REQUESTED, &flags);2382		clear_bit(FLAG_OPEN_DRAIN, &flags);2383		clear_bit(FLAG_OPEN_SOURCE, &flags);2384		clear_bit(FLAG_PULL_UP, &flags);2385		clear_bit(FLAG_PULL_DOWN, &flags);2386		clear_bit(FLAG_BIAS_DISABLE, &flags);2387		clear_bit(FLAG_EDGE_RISING, &flags);2388		clear_bit(FLAG_EDGE_FALLING, &flags);2389		clear_bit(FLAG_IS_HOGGED, &flags);2390#ifdef CONFIG_OF_DYNAMIC2391		WRITE_ONCE(desc->hog, NULL);2392#endif2393		desc_set_label(desc, NULL);2394		WRITE_ONCE(desc->flags, flags);2395 2396		gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED);2397	}2398}2399 2400void gpiod_free(struct gpio_desc *desc)2401{2402	VALIDATE_DESC_VOID(desc);2403 2404	gpiod_free_commit(desc);2405	module_put(desc->gdev->owner);2406	gpio_device_put(desc->gdev);2407}2408 2409/**2410 * gpiochip_dup_line_label - Get a copy of the consumer label.2411 * @gc: GPIO chip controlling this line.2412 * @offset: Hardware offset of the line.2413 *2414 * Returns:2415 * Pointer to a copy of the consumer label if the line is requested or NULL2416 * if it's not. If a valid pointer was returned, it must be freed using2417 * kfree(). In case of a memory allocation error, the function returns %ENOMEM.2418 *2419 * Must not be called from atomic context.2420 */2421char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)2422{2423	struct gpio_desc *desc;2424	char *label;2425 2426	desc = gpiochip_get_desc(gc, offset);2427	if (IS_ERR(desc))2428		return NULL;2429 2430	if (!test_bit(FLAG_REQUESTED, &desc->flags))2431		return NULL;2432 2433	guard(srcu)(&desc->gdev->desc_srcu);2434 2435	label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);2436	if (!label)2437		return ERR_PTR(-ENOMEM);2438 2439	return label;2440}2441EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);2442 2443static inline const char *function_name_or_default(const char *con_id)2444{2445	return con_id ?: "(default)";2446}2447 2448/**2449 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor2450 * @gc: GPIO chip2451 * @hwnum: hardware number of the GPIO for which to request the descriptor2452 * @label: label for the GPIO2453 * @lflags: lookup flags for this GPIO or 0 if default, this can be used to2454 * specify things like line inversion semantics with the machine flags2455 * such as GPIO_OUT_LOW2456 * @dflags: descriptor request flags for this GPIO or 0 if default, this2457 * can be used to specify consumer semantics such as open drain2458 *2459 * Function allows GPIO chip drivers to request and use their own GPIO2460 * descriptors via gpiolib API. Difference to gpiod_request() is that this2461 * function will not increase reference count of the GPIO chip module. This2462 * allows the GPIO chip module to be unloaded as needed (we assume that the2463 * GPIO chip driver handles freeing the GPIOs it has requested).2464 *2465 * Returns:2466 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error2467 * code on failure.2468 */2469struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,2470					    unsigned int hwnum,2471					    const char *label,2472					    enum gpio_lookup_flags lflags,2473					    enum gpiod_flags dflags)2474{2475	struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);2476	const char *name = function_name_or_default(label);2477	int ret;2478 2479	if (IS_ERR(desc)) {2480		chip_err(gc, "failed to get GPIO %s descriptor\n", name);2481		return desc;2482	}2483 2484	ret = gpiod_request_commit(desc, label);2485	if (ret < 0)2486		return ERR_PTR(ret);2487 2488	ret = gpiod_configure_flags(desc, label, lflags, dflags);2489	if (ret) {2490		gpiod_free_commit(desc);2491		chip_err(gc, "setup of own GPIO %s failed\n", name);2492		return ERR_PTR(ret);2493	}2494 2495	return desc;2496}2497EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);2498 2499/**2500 * gpiochip_free_own_desc - Free GPIO requested by the chip driver2501 * @desc: GPIO descriptor to free2502 *2503 * Function frees the given GPIO requested previously with2504 * gpiochip_request_own_desc().2505 */2506void gpiochip_free_own_desc(struct gpio_desc *desc)2507{2508	if (desc)2509		gpiod_free_commit(desc);2510}2511EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);2512 2513/*2514 * Drivers MUST set GPIO direction before making get/set calls.  In2515 * some cases this is done in early boot, before IRQs are enabled.2516 *2517 * As a rule these aren't called more than once (except for drivers2518 * using the open-drain emulation idiom) so these are natural places2519 * to accumulate extra debugging checks.  Note that we can't (yet)2520 * rely on gpio_request() having been called beforehand.2521 */2522 2523static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,2524			      unsigned long config)2525{2526	if (!gc->set_config)2527		return -ENOTSUPP;2528 2529	return gc->set_config(gc, offset, config);2530}2531 2532static int gpio_set_config_with_argument(struct gpio_desc *desc,2533					 enum pin_config_param mode,2534					 u32 argument)2535{2536	unsigned long config;2537 2538	CLASS(gpio_chip_guard, guard)(desc);2539	if (!guard.gc)2540		return -ENODEV;2541 2542	config = pinconf_to_config_packed(mode, argument);2543	return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);2544}2545 2546static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,2547						  enum pin_config_param mode,2548						  u32 argument)2549{2550	struct device *dev = &desc->gdev->dev;2551	int gpio = gpio_chip_hwgpio(desc);2552	int ret;2553 2554	ret = gpio_set_config_with_argument(desc, mode, argument);2555	if (ret != -ENOTSUPP)2556		return ret;2557 2558	switch (mode) {2559	case PIN_CONFIG_PERSIST_STATE:2560		dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);2561		break;2562	default:2563		break;2564	}2565 2566	return 0;2567}2568 2569static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)2570{2571	return gpio_set_config_with_argument(desc, mode, 0);2572}2573 2574static int gpio_set_bias(struct gpio_desc *desc)2575{2576	enum pin_config_param bias;2577	unsigned long flags;2578	unsigned int arg;2579 2580	flags = READ_ONCE(desc->flags);2581 2582	if (test_bit(FLAG_BIAS_DISABLE, &flags))2583		bias = PIN_CONFIG_BIAS_DISABLE;2584	else if (test_bit(FLAG_PULL_UP, &flags))2585		bias = PIN_CONFIG_BIAS_PULL_UP;2586	else if (test_bit(FLAG_PULL_DOWN, &flags))2587		bias = PIN_CONFIG_BIAS_PULL_DOWN;2588	else2589		return 0;2590 2591	switch (bias) {2592	case PIN_CONFIG_BIAS_PULL_DOWN:2593	case PIN_CONFIG_BIAS_PULL_UP:2594		arg = 1;2595		break;2596 2597	default:2598		arg = 0;2599		break;2600	}2601 2602	return gpio_set_config_with_argument_optional(desc, bias, arg);2603}2604 2605/**2606 * gpio_set_debounce_timeout() - Set debounce timeout2607 * @desc:	GPIO descriptor to set the debounce timeout2608 * @debounce:	Debounce timeout in microseconds2609 *2610 * The function calls the certain GPIO driver to set debounce timeout2611 * in the hardware.2612 *2613 * Returns:2614 * 0 on success, or negative errno on failure.2615 */2616int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)2617{2618	return gpio_set_config_with_argument_optional(desc,2619						      PIN_CONFIG_INPUT_DEBOUNCE,2620						      debounce);2621}2622 2623/**2624 * gpiod_direction_input - set the GPIO direction to input2625 * @desc:	GPIO to set to input2626 *2627 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can2628 * be called safely on it.2629 *2630 * Returns:2631 * 0 on success, or negative errno on failure.2632 */2633int gpiod_direction_input(struct gpio_desc *desc)2634{2635	int ret = 0;2636 2637	VALIDATE_DESC(desc);2638 2639	CLASS(gpio_chip_guard, guard)(desc);2640	if (!guard.gc)2641		return -ENODEV;2642 2643	/*2644	 * It is legal to have no .get() and .direction_input() specified if2645	 * the chip is output-only, but you can't specify .direction_input()2646	 * and not support the .get() operation, that doesn't make sense.2647	 */2648	if (!guard.gc->get && guard.gc->direction_input) {2649		gpiod_warn(desc,2650			   "%s: missing get() but have direction_input()\n",2651			   __func__);2652		return -EIO;2653	}2654 2655	/*2656	 * If we have a .direction_input() callback, things are simple,2657	 * just call it. Else we are some input-only chip so try to check the2658	 * direction (if .get_direction() is supported) else we silently2659	 * assume we are in input mode after this.2660	 */2661	if (guard.gc->direction_input) {2662		ret = guard.gc->direction_input(guard.gc,2663						gpio_chip_hwgpio(desc));2664	} else if (guard.gc->get_direction &&2665		  (guard.gc->get_direction(guard.gc,2666					   gpio_chip_hwgpio(desc)) != 1)) {2667		gpiod_warn(desc,2668			   "%s: missing direction_input() operation and line is output\n",2669			   __func__);2670		return -EIO;2671	}2672	if (ret == 0) {2673		clear_bit(FLAG_IS_OUT, &desc->flags);2674		ret = gpio_set_bias(desc);2675	}2676 2677	trace_gpio_direction(desc_to_gpio(desc), 1, ret);2678 2679	return ret;2680}2681EXPORT_SYMBOL_GPL(gpiod_direction_input);2682 2683static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)2684{2685	int val = !!value, ret = 0;2686 2687	CLASS(gpio_chip_guard, guard)(desc);2688	if (!guard.gc)2689		return -ENODEV;2690 2691	/*2692	 * It's OK not to specify .direction_output() if the gpiochip is2693	 * output-only, but if there is then not even a .set() operation it2694	 * is pretty tricky to drive the output line.2695	 */2696	if (!guard.gc->set && !guard.gc->direction_output) {2697		gpiod_warn(desc,2698			   "%s: missing set() and direction_output() operations\n",2699			   __func__);2700		return -EIO;2701	}2702 2703	if (guard.gc->direction_output) {2704		ret = guard.gc->direction_output(guard.gc,2705						 gpio_chip_hwgpio(desc), val);2706	} else {2707		/* Check that we are in output mode if we can */2708		if (guard.gc->get_direction &&2709		    guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) {2710			gpiod_warn(desc,2711				"%s: missing direction_output() operation\n",2712				__func__);2713			return -EIO;2714		}2715		/*2716		 * If we can't actively set the direction, we are some2717		 * output-only chip, so just drive the output as desired.2718		 */2719		guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), val);2720	}2721 2722	if (!ret)2723		set_bit(FLAG_IS_OUT, &desc->flags);2724	trace_gpio_value(desc_to_gpio(desc), 0, val);2725	trace_gpio_direction(desc_to_gpio(desc), 0, ret);2726	return ret;2727}2728 2729/**2730 * gpiod_direction_output_raw - set the GPIO direction to output2731 * @desc:	GPIO to set to output2732 * @value:	initial output value of the GPIO2733 *2734 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can2735 * be called safely on it. The initial value of the output must be specified2736 * as raw value on the physical line without regard for the ACTIVE_LOW status.2737 *2738 * Returns:2739 * 0 on success, or negative errno on failure.2740 */2741int gpiod_direction_output_raw(struct gpio_desc *desc, int value)2742{2743	VALIDATE_DESC(desc);2744	return gpiod_direction_output_raw_commit(desc, value);2745}2746EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);2747 2748/**2749 * gpiod_direction_output - set the GPIO direction to output2750 * @desc:	GPIO to set to output2751 * @value:	initial output value of the GPIO2752 *2753 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can2754 * be called safely on it. The initial value of the output must be specified2755 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into2756 * account.2757 *2758 * Returns:2759 * 0 on success, or negative errno on failure.2760 */2761int gpiod_direction_output(struct gpio_desc *desc, int value)2762{2763	unsigned long flags;2764	int ret;2765 2766	VALIDATE_DESC(desc);2767 2768	flags = READ_ONCE(desc->flags);2769 2770	if (test_bit(FLAG_ACTIVE_LOW, &flags))2771		value = !value;2772	else2773		value = !!value;2774 2775	/* GPIOs used for enabled IRQs shall not be set as output */2776	if (test_bit(FLAG_USED_AS_IRQ, &flags) &&2777	    test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {2778		gpiod_err(desc,2779			  "%s: tried to set a GPIO tied to an IRQ as output\n",2780			  __func__);2781		return -EIO;2782	}2783 2784	if (test_bit(FLAG_OPEN_DRAIN, &flags)) {2785		/* First see if we can enable open drain in hardware */2786		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);2787		if (!ret)2788			goto set_output_value;2789		/* Emulate open drain by not actively driving the line high */2790		if (value) {2791			ret = gpiod_direction_input(desc);2792			goto set_output_flag;2793		}2794	} else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {2795		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);2796		if (!ret)2797			goto set_output_value;2798		/* Emulate open source by not actively driving the line low */2799		if (!value) {2800			ret = gpiod_direction_input(desc);2801			goto set_output_flag;2802		}2803	} else {2804		gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);2805	}2806 2807set_output_value:2808	ret = gpio_set_bias(desc);2809	if (ret)2810		return ret;2811	return gpiod_direction_output_raw_commit(desc, value);2812 2813set_output_flag:2814	/*2815	 * When emulating open-source or open-drain functionalities by not2816	 * actively driving the line (setting mode to input) we still need to2817	 * set the IS_OUT flag or otherwise we won't be able to set the line2818	 * value anymore.2819	 */2820	if (ret == 0)2821		set_bit(FLAG_IS_OUT, &desc->flags);2822	return ret;2823}2824EXPORT_SYMBOL_GPL(gpiod_direction_output);2825 2826/**2827 * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.2828 *2829 * @desc: GPIO to enable.2830 * @flags: Flags related to GPIO edge.2831 *2832 * Returns:2833 * 0 on success, or negative errno on failure.2834 */2835int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)2836{2837	int ret = 0;2838 2839	VALIDATE_DESC(desc);2840 2841	CLASS(gpio_chip_guard, guard)(desc);2842	if (!guard.gc)2843		return -ENODEV;2844 2845	if (!guard.gc->en_hw_timestamp) {2846		gpiod_warn(desc, "%s: hw ts not supported\n", __func__);2847		return -ENOTSUPP;2848	}2849 2850	ret = guard.gc->en_hw_timestamp(guard.gc,2851					gpio_chip_hwgpio(desc), flags);2852	if (ret)2853		gpiod_warn(desc, "%s: hw ts request failed\n", __func__);2854 2855	return ret;2856}2857EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);2858 2859/**2860 * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.2861 *2862 * @desc: GPIO to disable.2863 * @flags: Flags related to GPIO edge, same value as used during enable call.2864 *2865 * Returns:2866 * 0 on success, or negative errno on failure.2867 */2868int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)2869{2870	int ret = 0;2871 2872	VALIDATE_DESC(desc);2873 2874	CLASS(gpio_chip_guard, guard)(desc);2875	if (!guard.gc)2876		return -ENODEV;2877 2878	if (!guard.gc->dis_hw_timestamp) {2879		gpiod_warn(desc, "%s: hw ts not supported\n", __func__);2880		return -ENOTSUPP;2881	}2882 2883	ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),2884					 flags);2885	if (ret)2886		gpiod_warn(desc, "%s: hw ts release failed\n", __func__);2887 2888	return ret;2889}2890EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);2891 2892/**2893 * gpiod_set_config - sets @config for a GPIO2894 * @desc: descriptor of the GPIO for which to set the configuration2895 * @config: Same packed config format as generic pinconf2896 *2897 * Returns:2898 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the2899 * configuration.2900 */2901int gpiod_set_config(struct gpio_desc *desc, unsigned long config)2902{2903	VALIDATE_DESC(desc);2904 2905	CLASS(gpio_chip_guard, guard)(desc);2906	if (!guard.gc)2907		return -ENODEV;2908 2909	return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);2910}2911EXPORT_SYMBOL_GPL(gpiod_set_config);2912 2913/**2914 * gpiod_set_debounce - sets @debounce time for a GPIO2915 * @desc: descriptor of the GPIO for which to set debounce time2916 * @debounce: debounce time in microseconds2917 *2918 * Returns:2919 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the2920 * debounce time.2921 */2922int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)2923{2924	unsigned long config;2925 2926	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);2927	return gpiod_set_config(desc, config);2928}2929EXPORT_SYMBOL_GPL(gpiod_set_debounce);2930 2931/**2932 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset2933 * @desc: descriptor of the GPIO for which to configure persistence2934 * @transitory: True to lose state on suspend or reset, false for persistence2935 *2936 * Returns:2937 * 0 on success, otherwise a negative error code.2938 */2939int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)2940{2941	VALIDATE_DESC(desc);2942	/*2943	 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for2944	 * persistence state.2945	 */2946	assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);2947 2948	/* If the driver supports it, set the persistence state now */2949	return gpio_set_config_with_argument_optional(desc,2950						      PIN_CONFIG_PERSIST_STATE,2951						      !transitory);2952}2953 2954/**2955 * gpiod_is_active_low - test whether a GPIO is active-low or not2956 * @desc: the gpio descriptor to test2957 *2958 * Returns:2959 * 1 if the GPIO is active-low, 0 otherwise.2960 */2961int gpiod_is_active_low(const struct gpio_desc *desc)2962{2963	VALIDATE_DESC(desc);2964	return test_bit(FLAG_ACTIVE_LOW, &desc->flags);2965}2966EXPORT_SYMBOL_GPL(gpiod_is_active_low);2967 2968/**2969 * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not2970 * @desc: the gpio descriptor to change2971 */2972void gpiod_toggle_active_low(struct gpio_desc *desc)2973{2974	VALIDATE_DESC_VOID(desc);2975	change_bit(FLAG_ACTIVE_LOW, &desc->flags);2976}2977EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);2978 2979static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)2980{2981	return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO;2982}2983 2984/* I/O calls are only valid after configuration completed; the relevant2985 * "is this a valid GPIO" error checks should already have been done.2986 *2987 * "Get" operations are often inlinable as reading a pin value register,2988 * and masking the relevant bit in that register.2989 *2990 * When "set" operations are inlinable, they involve writing that mask to2991 * one register to set a low value, or a different register to set it high.2992 * Otherwise locking is needed, so there may be little value to inlining.2993 *2994 *------------------------------------------------------------------------2995 *2996 * IMPORTANT!!!  The hot paths -- get/set value -- assume that callers2997 * have requested the GPIO.  That can include implicit requesting by2998 * a direction setting call.  Marking a gpio as requested locks its chip2999 * in memory, guaranteeing that these table lookups need no more locking3000 * and that gpiochip_remove() will fail.3001 *3002 * REVISIT when debugging, consider adding some instrumentation to ensure3003 * that the GPIO was actually requested.3004 */3005 3006static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)3007{3008	struct gpio_device *gdev;3009	struct gpio_chip *gc;3010	int value;3011 3012	/* FIXME Unable to use gpio_chip_guard due to const desc. */3013	gdev = desc->gdev;3014 3015	guard(srcu)(&gdev->srcu);3016 3017	gc = srcu_dereference(gdev->chip, &gdev->srcu);3018	if (!gc)3019		return -ENODEV;3020 3021	value = gpio_chip_get_value(gc, desc);3022	value = value < 0 ? value : !!value;3023	trace_gpio_value(desc_to_gpio(desc), 1, value);3024	return value;3025}3026 3027static int gpio_chip_get_multiple(struct gpio_chip *gc,3028				  unsigned long *mask, unsigned long *bits)3029{3030	if (gc->get_multiple)3031		return gc->get_multiple(gc, mask, bits);3032	if (gc->get) {3033		int i, value;3034 3035		for_each_set_bit(i, mask, gc->ngpio) {3036			value = gc->get(gc, i);3037			if (value < 0)3038				return value;3039			__assign_bit(i, bits, value);3040		}3041		return 0;3042	}3043	return -EIO;3044}3045 3046/* The 'other' chip must be protected with its GPIO device's SRCU. */3047static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)3048{3049	guard(srcu)(&gdev->srcu);3050 3051	return gc == srcu_dereference(gdev->chip, &gdev->srcu);3052}3053 3054int gpiod_get_array_value_complex(bool raw, bool can_sleep,3055				  unsigned int array_size,3056				  struct gpio_desc **desc_array,3057				  struct gpio_array *array_info,3058				  unsigned long *value_bitmap)3059{3060	int ret, i = 0;3061 3062	/*3063	 * Validate array_info against desc_array and its size.3064	 * It should immediately follow desc_array if both3065	 * have been obtained from the same gpiod_get_array() call.3066	 */3067	if (array_info && array_info->desc == desc_array &&3068	    array_size <= array_info->size &&3069	    (void *)array_info == desc_array + array_info->size) {3070		if (!can_sleep)3071			WARN_ON(array_info->chip->can_sleep);3072 3073		ret = gpio_chip_get_multiple(array_info->chip,3074					     array_info->get_mask,3075					     value_bitmap);3076		if (ret)3077			return ret;3078 3079		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))3080			bitmap_xor(value_bitmap, value_bitmap,3081				   array_info->invert_mask, array_size);3082 3083		i = find_first_zero_bit(array_info->get_mask, array_size);3084		if (i == array_size)3085			return 0;3086	} else {3087		array_info = NULL;3088	}3089 3090	while (i < array_size) {3091		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);3092		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);3093		unsigned long *mask, *bits;3094		int first, j;3095 3096		CLASS(gpio_chip_guard, guard)(desc_array[i]);3097		if (!guard.gc)3098			return -ENODEV;3099 3100		if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {3101			mask = fastpath_mask;3102			bits = fastpath_bits;3103		} else {3104			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;3105 3106			mask = bitmap_alloc(guard.gc->ngpio, flags);3107			if (!mask)3108				return -ENOMEM;3109 3110			bits = bitmap_alloc(guard.gc->ngpio, flags);3111			if (!bits) {3112				bitmap_free(mask);3113				return -ENOMEM;3114			}3115		}3116 3117		bitmap_zero(mask, guard.gc->ngpio);3118 3119		if (!can_sleep)3120			WARN_ON(guard.gc->can_sleep);3121 3122		/* collect all inputs belonging to the same chip */3123		first = i;3124		do {3125			const struct gpio_desc *desc = desc_array[i];3126			int hwgpio = gpio_chip_hwgpio(desc);3127 3128			__set_bit(hwgpio, mask);3129			i++;3130 3131			if (array_info)3132				i = find_next_zero_bit(array_info->get_mask,3133						       array_size, i);3134		} while ((i < array_size) &&3135			 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));3136 3137		ret = gpio_chip_get_multiple(guard.gc, mask, bits);3138		if (ret) {3139			if (mask != fastpath_mask)3140				bitmap_free(mask);3141			if (bits != fastpath_bits)3142				bitmap_free(bits);3143			return ret;3144		}3145 3146		for (j = first; j < i; ) {3147			const struct gpio_desc *desc = desc_array[j];3148			int hwgpio = gpio_chip_hwgpio(desc);3149			int value = test_bit(hwgpio, bits);3150 3151			if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))3152				value = !value;3153			__assign_bit(j, value_bitmap, value);3154			trace_gpio_value(desc_to_gpio(desc), 1, value);3155			j++;3156 3157			if (array_info)3158				j = find_next_zero_bit(array_info->get_mask, i,3159						       j);3160		}3161 3162		if (mask != fastpath_mask)3163			bitmap_free(mask);3164		if (bits != fastpath_bits)3165			bitmap_free(bits);3166	}3167	return 0;3168}3169 3170/**3171 * gpiod_get_raw_value() - return a gpio's raw value3172 * @desc: gpio whose value will be returned3173 *3174 * Returns:3175 * The GPIO's raw value, i.e. the value of the physical line disregarding3176 * its ACTIVE_LOW status, or negative errno on failure.3177 *3178 * This function can be called from contexts where we cannot sleep, and will3179 * complain if the GPIO chip functions potentially sleep.3180 */3181int gpiod_get_raw_value(const struct gpio_desc *desc)3182{3183	VALIDATE_DESC(desc);3184	/* Should be using gpiod_get_raw_value_cansleep() */3185	WARN_ON(desc->gdev->can_sleep);3186	return gpiod_get_raw_value_commit(desc);3187}3188EXPORT_SYMBOL_GPL(gpiod_get_raw_value);3189 3190/**3191 * gpiod_get_value() - return a gpio's value3192 * @desc: gpio whose value will be returned3193 *3194 * Returns:3195 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into3196 * account, or negative errno on failure.3197 *3198 * This function can be called from contexts where we cannot sleep, and will3199 * complain if the GPIO chip functions potentially sleep.3200 */3201int gpiod_get_value(const struct gpio_desc *desc)3202{3203	int value;3204 3205	VALIDATE_DESC(desc);3206	/* Should be using gpiod_get_value_cansleep() */3207	WARN_ON(desc->gdev->can_sleep);3208 3209	value = gpiod_get_raw_value_commit(desc);3210	if (value < 0)3211		return value;3212 3213	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))3214		value = !value;3215 3216	return value;3217}3218EXPORT_SYMBOL_GPL(gpiod_get_value);3219 3220/**3221 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs3222 * @array_size: number of elements in the descriptor array / value bitmap3223 * @desc_array: array of GPIO descriptors whose values will be read3224 * @array_info: information on applicability of fast bitmap processing path3225 * @value_bitmap: bitmap to store the read values3226 *3227 * Read the raw values of the GPIOs, i.e. the values of the physical lines3228 * without regard for their ACTIVE_LOW status.3229 *3230 * This function can be called from contexts where we cannot sleep,3231 * and it will complain if the GPIO chip functions potentially sleep.3232 *3233 * Returns:3234 * 0 on success, or negative errno on failure.3235 */3236int gpiod_get_raw_array_value(unsigned int array_size,3237			      struct gpio_desc **desc_array,3238			      struct gpio_array *array_info,3239			      unsigned long *value_bitmap)3240{3241	if (!desc_array)3242		return -EINVAL;3243	return gpiod_get_array_value_complex(true, false, array_size,3244					     desc_array, array_info,3245					     value_bitmap);3246}3247EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);3248 3249/**3250 * gpiod_get_array_value() - read values from an array of GPIOs3251 * @array_size: number of elements in the descriptor array / value bitmap3252 * @desc_array: array of GPIO descriptors whose values will be read3253 * @array_info: information on applicability of fast bitmap processing path3254 * @value_bitmap: bitmap to store the read values3255 *3256 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status3257 * into account.3258 *3259 * This function can be called from contexts where we cannot sleep,3260 * and it will complain if the GPIO chip functions potentially sleep.3261 *3262 * Returns:3263 * 0 on success, or negative errno on failure.3264 */3265int gpiod_get_array_value(unsigned int array_size,3266			  struct gpio_desc **desc_array,3267			  struct gpio_array *array_info,3268			  unsigned long *value_bitmap)3269{3270	if (!desc_array)3271		return -EINVAL;3272	return gpiod_get_array_value_complex(false, false, array_size,3273					     desc_array, array_info,3274					     value_bitmap);3275}3276EXPORT_SYMBOL_GPL(gpiod_get_array_value);3277 3278/*3279 *  gpio_set_open_drain_value_commit() - Set the open drain gpio's value.3280 * @desc: gpio descriptor whose state need to be set.3281 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.3282 */3283static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)3284{3285	int ret = 0, offset = gpio_chip_hwgpio(desc);3286 3287	CLASS(gpio_chip_guard, guard)(desc);3288	if (!guard.gc)3289		return;3290 3291	if (value) {3292		ret = guard.gc->direction_input(guard.gc, offset);3293	} else {3294		ret = guard.gc->direction_output(guard.gc, offset, 0);3295		if (!ret)3296			set_bit(FLAG_IS_OUT, &desc->flags);3297	}3298	trace_gpio_direction(desc_to_gpio(desc), value, ret);3299	if (ret < 0)3300		gpiod_err(desc,3301			  "%s: Error in set_value for open drain err %d\n",3302			  __func__, ret);3303}3304 3305/*3306 *  _gpio_set_open_source_value() - Set the open source gpio's value.3307 * @desc: gpio descriptor whose state need to be set.3308 * @value: Non-zero for setting it HIGH otherwise it will set to LOW.3309 */3310static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)3311{3312	int ret = 0, offset = gpio_chip_hwgpio(desc);3313 3314	CLASS(gpio_chip_guard, guard)(desc);3315	if (!guard.gc)3316		return;3317 3318	if (value) {3319		ret = guard.gc->direction_output(guard.gc, offset, 1);3320		if (!ret)3321			set_bit(FLAG_IS_OUT, &desc->flags);3322	} else {3323		ret = guard.gc->direction_input(guard.gc, offset);3324	}3325	trace_gpio_direction(desc_to_gpio(desc), !value, ret);3326	if (ret < 0)3327		gpiod_err(desc,3328			  "%s: Error in set_value for open source err %d\n",3329			  __func__, ret);3330}3331 3332static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)3333{3334	CLASS(gpio_chip_guard, guard)(desc);3335	if (!guard.gc)3336		return;3337 3338	trace_gpio_value(desc_to_gpio(desc), 0, value);3339	guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), value);3340}3341 3342/*3343 * set multiple outputs on the same chip;3344 * use the chip's set_multiple function if available;3345 * otherwise set the outputs sequentially;3346 * @chip: the GPIO chip we operate on3347 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word3348 *        defines which outputs are to be changed3349 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word3350 *        defines the values the outputs specified by mask are to be set to3351 */3352static void gpio_chip_set_multiple(struct gpio_chip *gc,3353				   unsigned long *mask, unsigned long *bits)3354{3355	if (gc->set_multiple) {3356		gc->set_multiple(gc, mask, bits);3357	} else {3358		unsigned int i;3359 3360		/* set outputs if the corresponding mask bit is set */3361		for_each_set_bit(i, mask, gc->ngpio)3362			gc->set(gc, i, test_bit(i, bits));3363	}3364}3365 3366int gpiod_set_array_value_complex(bool raw, bool can_sleep,3367				  unsigned int array_size,3368				  struct gpio_desc **desc_array,3369				  struct gpio_array *array_info,3370				  unsigned long *value_bitmap)3371{3372	int i = 0;3373 3374	/*3375	 * Validate array_info against desc_array and its size.3376	 * It should immediately follow desc_array if both3377	 * have been obtained from the same gpiod_get_array() call.3378	 */3379	if (array_info && array_info->desc == desc_array &&3380	    array_size <= array_info->size &&3381	    (void *)array_info == desc_array + array_info->size) {3382		if (!can_sleep)3383			WARN_ON(array_info->chip->can_sleep);3384 3385		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))3386			bitmap_xor(value_bitmap, value_bitmap,3387				   array_info->invert_mask, array_size);3388 3389		gpio_chip_set_multiple(array_info->chip, array_info->set_mask,3390				       value_bitmap);3391 3392		i = find_first_zero_bit(array_info->set_mask, array_size);3393		if (i == array_size)3394			return 0;3395	} else {3396		array_info = NULL;3397	}3398 3399	while (i < array_size) {3400		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);3401		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);3402		unsigned long *mask, *bits;3403		int count = 0;3404 3405		CLASS(gpio_chip_guard, guard)(desc_array[i]);3406		if (!guard.gc)3407			return -ENODEV;3408 3409		if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {3410			mask = fastpath_mask;3411			bits = fastpath_bits;3412		} else {3413			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;3414 3415			mask = bitmap_alloc(guard.gc->ngpio, flags);3416			if (!mask)3417				return -ENOMEM;3418 3419			bits = bitmap_alloc(guard.gc->ngpio, flags);3420			if (!bits) {3421				bitmap_free(mask);3422				return -ENOMEM;3423			}3424		}3425 3426		bitmap_zero(mask, guard.gc->ngpio);3427 3428		if (!can_sleep)3429			WARN_ON(guard.gc->can_sleep);3430 3431		do {3432			struct gpio_desc *desc = desc_array[i];3433			int hwgpio = gpio_chip_hwgpio(desc);3434			int value = test_bit(i, value_bitmap);3435 3436			/*3437			 * Pins applicable for fast input but not for3438			 * fast output processing may have been already3439			 * inverted inside the fast path, skip them.3440			 */3441			if (!raw && !(array_info &&3442			    test_bit(i, array_info->invert_mask)) &&3443			    test_bit(FLAG_ACTIVE_LOW, &desc->flags))3444				value = !value;3445			trace_gpio_value(desc_to_gpio(desc), 0, value);3446			/*3447			 * collect all normal outputs belonging to the same chip3448			 * open drain and open source outputs are set individually3449			 */3450			if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {3451				gpio_set_open_drain_value_commit(desc, value);3452			} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {3453				gpio_set_open_source_value_commit(desc, value);3454			} else {3455				__set_bit(hwgpio, mask);3456				__assign_bit(hwgpio, bits, value);3457				count++;3458			}3459			i++;3460 3461			if (array_info)3462				i = find_next_zero_bit(array_info->set_mask,3463						       array_size, i);3464		} while ((i < array_size) &&3465			 gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));3466		/* push collected bits to outputs */3467		if (count != 0)3468			gpio_chip_set_multiple(guard.gc, mask, bits);3469 3470		if (mask != fastpath_mask)3471			bitmap_free(mask);3472		if (bits != fastpath_bits)3473			bitmap_free(bits);3474	}3475	return 0;3476}3477 3478/**3479 * gpiod_set_raw_value() - assign a gpio's raw value3480 * @desc: gpio whose value will be assigned3481 * @value: value to assign3482 *3483 * Set the raw value of the GPIO, i.e. the value of its physical line without3484 * regard for its ACTIVE_LOW status.3485 *3486 * This function can be called from contexts where we cannot sleep, and will3487 * complain if the GPIO chip functions potentially sleep.3488 */3489void gpiod_set_raw_value(struct gpio_desc *desc, int value)3490{3491	VALIDATE_DESC_VOID(desc);3492	/* Should be using gpiod_set_raw_value_cansleep() */3493	WARN_ON(desc->gdev->can_sleep);3494	gpiod_set_raw_value_commit(desc, value);3495}3496EXPORT_SYMBOL_GPL(gpiod_set_raw_value);3497 3498/**3499 * gpiod_set_value_nocheck() - set a GPIO line value without checking3500 * @desc: the descriptor to set the value on3501 * @value: value to set3502 *3503 * This sets the value of a GPIO line backing a descriptor, applying3504 * different semantic quirks like active low and open drain/source3505 * handling.3506 */3507static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)3508{3509	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))3510		value = !value;3511	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))3512		gpio_set_open_drain_value_commit(desc, value);3513	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))3514		gpio_set_open_source_value_commit(desc, value);3515	else3516		gpiod_set_raw_value_commit(desc, value);3517}3518 3519/**3520 * gpiod_set_value() - assign a gpio's value3521 * @desc: gpio whose value will be assigned3522 * @value: value to assign3523 *3524 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,3525 * OPEN_DRAIN and OPEN_SOURCE flags into account.3526 *3527 * This function can be called from contexts where we cannot sleep, and will3528 * complain if the GPIO chip functions potentially sleep.3529 */3530void gpiod_set_value(struct gpio_desc *desc, int value)3531{3532	VALIDATE_DESC_VOID(desc);3533	/* Should be using gpiod_set_value_cansleep() */3534	WARN_ON(desc->gdev->can_sleep);3535	gpiod_set_value_nocheck(desc, value);3536}3537EXPORT_SYMBOL_GPL(gpiod_set_value);3538 3539/**3540 * gpiod_set_raw_array_value() - assign values to an array of GPIOs3541 * @array_size: number of elements in the descriptor array / value bitmap3542 * @desc_array: array of GPIO descriptors whose values will be assigned3543 * @array_info: information on applicability of fast bitmap processing path3544 * @value_bitmap: bitmap of values to assign3545 *3546 * Set the raw values of the GPIOs, i.e. the values of the physical lines3547 * without regard for their ACTIVE_LOW status.3548 *3549 * This function can be called from contexts where we cannot sleep, and will3550 * complain if the GPIO chip functions potentially sleep.3551 *3552 * Returns:3553 * 0 on success, or negative errno on failure.3554 */3555int gpiod_set_raw_array_value(unsigned int array_size,3556			      struct gpio_desc **desc_array,3557			      struct gpio_array *array_info,3558			      unsigned long *value_bitmap)3559{3560	if (!desc_array)3561		return -EINVAL;3562	return gpiod_set_array_value_complex(true, false, array_size,3563					desc_array, array_info, value_bitmap);3564}3565EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);3566 3567/**3568 * gpiod_set_array_value() - assign values to an array of GPIOs3569 * @array_size: number of elements in the descriptor array / value bitmap3570 * @desc_array: array of GPIO descriptors whose values will be assigned3571 * @array_info: information on applicability of fast bitmap processing path3572 * @value_bitmap: bitmap of values to assign3573 *3574 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status3575 * into account.3576 *3577 * This function can be called from contexts where we cannot sleep, and will3578 * complain if the GPIO chip functions potentially sleep.3579 *3580 * Returns:3581 * 0 on success, or negative errno on failure.3582 */3583int gpiod_set_array_value(unsigned int array_size,3584			  struct gpio_desc **desc_array,3585			  struct gpio_array *array_info,3586			  unsigned long *value_bitmap)3587{3588	if (!desc_array)3589		return -EINVAL;3590	return gpiod_set_array_value_complex(false, false, array_size,3591					     desc_array, array_info,3592					     value_bitmap);3593}3594EXPORT_SYMBOL_GPL(gpiod_set_array_value);3595 3596/**3597 * gpiod_cansleep() - report whether gpio value access may sleep3598 * @desc: gpio to check3599 *3600 * Returns:3601 * 0 for non-sleepable, 1 for sleepable, or an error code in case of error.3602 */3603int gpiod_cansleep(const struct gpio_desc *desc)3604{3605	VALIDATE_DESC(desc);3606	return desc->gdev->can_sleep;3607}3608EXPORT_SYMBOL_GPL(gpiod_cansleep);3609 3610/**3611 * gpiod_set_consumer_name() - set the consumer name for the descriptor3612 * @desc: gpio to set the consumer name on3613 * @name: the new consumer name3614 *3615 * Returns:3616 * 0 on success, or negative errno on failure.3617 */3618int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)3619{3620	VALIDATE_DESC(desc);3621 3622	return desc_set_label(desc, name);3623}3624EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);3625 3626/**3627 * gpiod_to_irq() - return the IRQ corresponding to a GPIO3628 * @desc: gpio whose IRQ will be returned (already requested)3629 *3630 * Returns:3631 * The IRQ corresponding to the passed GPIO, or an error code in case of error.3632 */3633int gpiod_to_irq(const struct gpio_desc *desc)3634{3635	struct gpio_device *gdev;3636	struct gpio_chip *gc;3637	int offset;3638 3639	/*3640	 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics3641	 * requires this function to not return zero on an invalid descriptor3642	 * but rather a negative error number.3643	 */3644	if (IS_ERR_OR_NULL(desc))3645		return -EINVAL;3646 3647	gdev = desc->gdev;3648	/* FIXME Cannot use gpio_chip_guard due to const desc. */3649	guard(srcu)(&gdev->srcu);3650	gc = srcu_dereference(gdev->chip, &gdev->srcu);3651	if (!gc)3652		return -ENODEV;3653 3654	offset = gpio_chip_hwgpio(desc);3655	if (gc->to_irq) {3656		int retirq = gc->to_irq(gc, offset);3657 3658		/* Zero means NO_IRQ */3659		if (!retirq)3660			return -ENXIO;3661 3662		return retirq;3663	}3664#ifdef CONFIG_GPIOLIB_IRQCHIP3665	if (gc->irq.chip) {3666		/*3667		 * Avoid race condition with other code, which tries to lookup3668		 * an IRQ before the irqchip has been properly registered,3669		 * i.e. while gpiochip is still being brought up.3670		 */3671		return -EPROBE_DEFER;3672	}3673#endif3674	return -ENXIO;3675}3676EXPORT_SYMBOL_GPL(gpiod_to_irq);3677 3678/**3679 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ3680 * @gc: the chip the GPIO to lock belongs to3681 * @offset: the offset of the GPIO to lock as IRQ3682 *3683 * This is used directly by GPIO drivers that want to lock down3684 * a certain GPIO line to be used for IRQs.3685 *3686 * Returns:3687 * 0 on success, or negative errno on failure.3688 */3689int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)3690{3691	struct gpio_desc *desc;3692 3693	desc = gpiochip_get_desc(gc, offset);3694	if (IS_ERR(desc))3695		return PTR_ERR(desc);3696 3697	/*3698	 * If it's fast: flush the direction setting if something changed3699	 * behind our back3700	 */3701	if (!gc->can_sleep && gc->get_direction) {3702		int dir = gpiod_get_direction(desc);3703 3704		if (dir < 0) {3705			chip_err(gc, "%s: cannot get GPIO direction\n",3706				 __func__);3707			return dir;3708		}3709	}3710 3711	/* To be valid for IRQ the line needs to be input or open drain */3712	if (test_bit(FLAG_IS_OUT, &desc->flags) &&3713	    !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {3714		chip_err(gc,3715			 "%s: tried to flag a GPIO set as output for IRQ\n",3716			 __func__);3717		return -EIO;3718	}3719 3720	set_bit(FLAG_USED_AS_IRQ, &desc->flags);3721	set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);3722 3723	return 0;3724}3725EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);3726 3727/**3728 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ3729 * @gc: the chip the GPIO to lock belongs to3730 * @offset: the offset of the GPIO to lock as IRQ3731 *3732 * This is used directly by GPIO drivers that want to indicate3733 * that a certain GPIO is no longer used exclusively for IRQ.3734 */3735void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)3736{3737	struct gpio_desc *desc;3738 3739	desc = gpiochip_get_desc(gc, offset);3740	if (IS_ERR(desc))3741		return;3742 3743	clear_bit(FLAG_USED_AS_IRQ, &desc->flags);3744	clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);3745}3746EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);3747 3748void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)3749{3750	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);3751 3752	if (!IS_ERR(desc) &&3753	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))3754		clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);3755}3756EXPORT_SYMBOL_GPL(gpiochip_disable_irq);3757 3758void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)3759{3760	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);3761 3762	if (!IS_ERR(desc) &&3763	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {3764		/*3765		 * We must not be output when using IRQ UNLESS we are3766		 * open drain.3767		 */3768		WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&3769			!test_bit(FLAG_OPEN_DRAIN, &desc->flags));3770		set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);3771	}3772}3773EXPORT_SYMBOL_GPL(gpiochip_enable_irq);3774 3775bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)3776{3777	if (offset >= gc->ngpio)3778		return false;3779 3780	return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);3781}3782EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);3783 3784int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)3785{3786	int ret;3787 3788	if (!try_module_get(gc->gpiodev->owner))3789		return -ENODEV;3790 3791	ret = gpiochip_lock_as_irq(gc, offset);3792	if (ret) {3793		chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);3794		module_put(gc->gpiodev->owner);3795		return ret;3796	}3797	return 0;3798}3799EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);3800 3801void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)3802{3803	gpiochip_unlock_as_irq(gc, offset);3804	module_put(gc->gpiodev->owner);3805}3806EXPORT_SYMBOL_GPL(gpiochip_relres_irq);3807 3808bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)3809{3810	if (offset >= gc->ngpio)3811		return false;3812 3813	return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);3814}3815EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);3816 3817bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)3818{3819	if (offset >= gc->ngpio)3820		return false;3821 3822	return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);3823}3824EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);3825 3826bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)3827{3828	if (offset >= gc->ngpio)3829		return false;3830 3831	return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);3832}3833EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);3834 3835/**3836 * gpiod_get_raw_value_cansleep() - return a gpio's raw value3837 * @desc: gpio whose value will be returned3838 *3839 * Returns:3840 * The GPIO's raw value, i.e. the value of the physical line disregarding3841 * its ACTIVE_LOW status, or negative errno on failure.3842 *3843 * This function is to be called from contexts that can sleep.3844 */3845int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)3846{3847	might_sleep();3848	VALIDATE_DESC(desc);3849	return gpiod_get_raw_value_commit(desc);3850}3851EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);3852 3853/**3854 * gpiod_get_value_cansleep() - return a gpio's value3855 * @desc: gpio whose value will be returned3856 *3857 * Returns:3858 * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into3859 * account, or negative errno on failure.3860 *3861 * This function is to be called from contexts that can sleep.3862 */3863int gpiod_get_value_cansleep(const struct gpio_desc *desc)3864{3865	int value;3866 3867	might_sleep();3868	VALIDATE_DESC(desc);3869	value = gpiod_get_raw_value_commit(desc);3870	if (value < 0)3871		return value;3872 3873	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))3874		value = !value;3875 3876	return value;3877}3878EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);3879 3880/**3881 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs3882 * @array_size: number of elements in the descriptor array / value bitmap3883 * @desc_array: array of GPIO descriptors whose values will be read3884 * @array_info: information on applicability of fast bitmap processing path3885 * @value_bitmap: bitmap to store the read values3886 *3887 * Read the raw values of the GPIOs, i.e. the values of the physical lines3888 * without regard for their ACTIVE_LOW status.3889 *3890 * This function is to be called from contexts that can sleep.3891 *3892 * Returns:3893 * 0 on success, or negative errno on failure.3894 */3895int gpiod_get_raw_array_value_cansleep(unsigned int array_size,3896				       struct gpio_desc **desc_array,3897				       struct gpio_array *array_info,3898				       unsigned long *value_bitmap)3899{3900	might_sleep();3901	if (!desc_array)3902		return -EINVAL;3903	return gpiod_get_array_value_complex(true, true, array_size,3904					     desc_array, array_info,3905					     value_bitmap);3906}3907EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);3908 3909/**3910 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs3911 * @array_size: number of elements in the descriptor array / value bitmap3912 * @desc_array: array of GPIO descriptors whose values will be read3913 * @array_info: information on applicability of fast bitmap processing path3914 * @value_bitmap: bitmap to store the read values3915 *3916 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status3917 * into account.3918 *3919 * This function is to be called from contexts that can sleep.3920 *3921 * Returns:3922 * 0 on success, or negative errno on failure.3923 */3924int gpiod_get_array_value_cansleep(unsigned int array_size,3925				   struct gpio_desc **desc_array,3926				   struct gpio_array *array_info,3927				   unsigned long *value_bitmap)3928{3929	might_sleep();3930	if (!desc_array)3931		return -EINVAL;3932	return gpiod_get_array_value_complex(false, true, array_size,3933					     desc_array, array_info,3934					     value_bitmap);3935}3936EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);3937 3938/**3939 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value3940 * @desc: gpio whose value will be assigned3941 * @value: value to assign3942 *3943 * Set the raw value of the GPIO, i.e. the value of its physical line without3944 * regard for its ACTIVE_LOW status.3945 *3946 * This function is to be called from contexts that can sleep.3947 */3948void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)3949{3950	might_sleep();3951	VALIDATE_DESC_VOID(desc);3952	gpiod_set_raw_value_commit(desc, value);3953}3954EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);3955 3956/**3957 * gpiod_set_value_cansleep() - assign a gpio's value3958 * @desc: gpio whose value will be assigned3959 * @value: value to assign3960 *3961 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into3962 * account3963 *3964 * This function is to be called from contexts that can sleep.3965 */3966void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)3967{3968	might_sleep();3969	VALIDATE_DESC_VOID(desc);3970	gpiod_set_value_nocheck(desc, value);3971}3972EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);3973 3974/**3975 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs3976 * @array_size: number of elements in the descriptor array / value bitmap3977 * @desc_array: array of GPIO descriptors whose values will be assigned3978 * @array_info: information on applicability of fast bitmap processing path3979 * @value_bitmap: bitmap of values to assign3980 *3981 * Set the raw values of the GPIOs, i.e. the values of the physical lines3982 * without regard for their ACTIVE_LOW status.3983 *3984 * This function is to be called from contexts that can sleep.3985 *3986 * Returns:3987 * 0 on success, or negative errno on failure.3988 */3989int gpiod_set_raw_array_value_cansleep(unsigned int array_size,3990				       struct gpio_desc **desc_array,3991				       struct gpio_array *array_info,3992				       unsigned long *value_bitmap)3993{3994	might_sleep();3995	if (!desc_array)3996		return -EINVAL;3997	return gpiod_set_array_value_complex(true, true, array_size, desc_array,3998				      array_info, value_bitmap);3999}4000EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);4001 4002/**4003 * gpiod_add_lookup_tables() - register GPIO device consumers4004 * @tables: list of tables of consumers to register4005 * @n: number of tables in the list4006 */4007void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)4008{4009	unsigned int i;4010 4011	mutex_lock(&gpio_lookup_lock);4012 4013	for (i = 0; i < n; i++)4014		list_add_tail(&tables[i]->list, &gpio_lookup_list);4015 4016	mutex_unlock(&gpio_lookup_lock);4017}4018 4019/**4020 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs4021 * @array_size: number of elements in the descriptor array / value bitmap4022 * @desc_array: array of GPIO descriptors whose values will be assigned4023 * @array_info: information on applicability of fast bitmap processing path4024 * @value_bitmap: bitmap of values to assign4025 *4026 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status4027 * into account.4028 *4029 * This function is to be called from contexts that can sleep.4030 *4031 * Returns:4032 * 0 on success, or negative errno on failure.4033 */4034int gpiod_set_array_value_cansleep(unsigned int array_size,4035				   struct gpio_desc **desc_array,4036				   struct gpio_array *array_info,4037				   unsigned long *value_bitmap)4038{4039	might_sleep();4040	if (!desc_array)4041		return -EINVAL;4042	return gpiod_set_array_value_complex(false, true, array_size,4043					     desc_array, array_info,4044					     value_bitmap);4045}4046EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);4047 4048void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)4049{4050	blocking_notifier_call_chain(&desc->gdev->line_state_notifier,4051				     action, desc);4052}4053 4054/**4055 * gpiod_add_lookup_table() - register GPIO device consumers4056 * @table: table of consumers to register4057 */4058void gpiod_add_lookup_table(struct gpiod_lookup_table *table)4059{4060	gpiod_add_lookup_tables(&table, 1);4061}4062EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);4063 4064/**4065 * gpiod_remove_lookup_table() - unregister GPIO device consumers4066 * @table: table of consumers to unregister4067 */4068void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)4069{4070	/* Nothing to remove */4071	if (!table)4072		return;4073 4074	mutex_lock(&gpio_lookup_lock);4075 4076	list_del(&table->list);4077 4078	mutex_unlock(&gpio_lookup_lock);4079}4080EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);4081 4082/**4083 * gpiod_add_hogs() - register a set of GPIO hogs from machine code4084 * @hogs: table of gpio hog entries with a zeroed sentinel at the end4085 */4086void gpiod_add_hogs(struct gpiod_hog *hogs)4087{4088	struct gpiod_hog *hog;4089 4090	mutex_lock(&gpio_machine_hogs_mutex);4091 4092	for (hog = &hogs[0]; hog->chip_label; hog++) {4093		list_add_tail(&hog->list, &gpio_machine_hogs);4094 4095		/*4096		 * The chip may have been registered earlier, so check if it4097		 * exists and, if so, try to hog the line now.4098		 */4099		struct gpio_device *gdev __free(gpio_device_put) =4100				gpio_device_find_by_label(hog->chip_label);4101		if (gdev)4102			gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);4103	}4104 4105	mutex_unlock(&gpio_machine_hogs_mutex);4106}4107EXPORT_SYMBOL_GPL(gpiod_add_hogs);4108 4109void gpiod_remove_hogs(struct gpiod_hog *hogs)4110{4111	struct gpiod_hog *hog;4112 4113	mutex_lock(&gpio_machine_hogs_mutex);4114	for (hog = &hogs[0]; hog->chip_label; hog++)4115		list_del(&hog->list);4116	mutex_unlock(&gpio_machine_hogs_mutex);4117}4118EXPORT_SYMBOL_GPL(gpiod_remove_hogs);4119 4120static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)4121{4122	const char *dev_id = dev ? dev_name(dev) : NULL;4123	struct gpiod_lookup_table *table;4124 4125	list_for_each_entry(table, &gpio_lookup_list, list) {4126		if (table->dev_id && dev_id) {4127			/*4128			 * Valid strings on both ends, must be identical to have4129			 * a match4130			 */4131			if (!strcmp(table->dev_id, dev_id))4132				return table;4133		} else {4134			/*4135			 * One of the pointers is NULL, so both must be to have4136			 * a match4137			 */4138			if (dev_id == table->dev_id)4139				return table;4140		}4141	}4142 4143	return NULL;4144}4145 4146static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,4147				    unsigned int idx, unsigned long *flags)4148{4149	struct gpio_desc *desc = ERR_PTR(-ENOENT);4150	struct gpiod_lookup_table *table;4151	struct gpiod_lookup *p;4152	struct gpio_chip *gc;4153 4154	guard(mutex)(&gpio_lookup_lock);4155 4156	table = gpiod_find_lookup_table(dev);4157	if (!table)4158		return desc;4159 4160	for (p = &table->table[0]; p->key; p++) {4161		/* idx must always match exactly */4162		if (p->idx != idx)4163			continue;4164 4165		/* If the lookup entry has a con_id, require exact match */4166		if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))4167			continue;4168 4169		if (p->chip_hwnum == U16_MAX) {4170			desc = gpio_name_to_desc(p->key);4171			if (desc) {4172				*flags = p->flags;4173				return desc;4174			}4175 4176			dev_warn(dev, "cannot find GPIO line %s, deferring\n",4177				 p->key);4178			return ERR_PTR(-EPROBE_DEFER);4179		}4180 4181		struct gpio_device *gdev __free(gpio_device_put) =4182					gpio_device_find_by_label(p->key);4183		if (!gdev) {4184			/*4185			 * As the lookup table indicates a chip with4186			 * p->key should exist, assume it may4187			 * still appear later and let the interested4188			 * consumer be probed again or let the Deferred4189			 * Probe infrastructure handle the error.4190			 */4191			dev_warn(dev, "cannot find GPIO chip %s, deferring\n",4192				 p->key);4193			return ERR_PTR(-EPROBE_DEFER);4194		}4195 4196		gc = gpio_device_get_chip(gdev);4197 4198		if (gc->ngpio <= p->chip_hwnum) {4199			dev_err(dev,4200				"requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",4201				idx, p->chip_hwnum, gc->ngpio - 1,4202				gc->label);4203			return ERR_PTR(-EINVAL);4204		}4205 4206		desc = gpio_device_get_desc(gdev, p->chip_hwnum);4207		*flags = p->flags;4208 4209		return desc;4210	}4211 4212	return desc;4213}4214 4215static int platform_gpio_count(struct device *dev, const char *con_id)4216{4217	struct gpiod_lookup_table *table;4218	struct gpiod_lookup *p;4219	unsigned int count = 0;4220 4221	scoped_guard(mutex, &gpio_lookup_lock) {4222		table = gpiod_find_lookup_table(dev);4223		if (!table)4224			return -ENOENT;4225 4226		for (p = &table->table[0]; p->key; p++) {4227			if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||4228			    (!con_id && !p->con_id))4229				count++;4230		}4231	}4232 4233	if (!count)4234		return -ENOENT;4235 4236	return count;4237}4238 4239static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,4240					      struct device *consumer,4241					      const char *con_id,4242					      unsigned int idx,4243					      enum gpiod_flags *flags,4244					      unsigned long *lookupflags)4245{4246	const char *name = function_name_or_default(con_id);4247	struct gpio_desc *desc = ERR_PTR(-ENOENT);4248 4249	if (is_of_node(fwnode)) {4250		dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);4251		desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);4252	} else if (is_acpi_node(fwnode)) {4253		dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);4254		desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);4255	} else if (is_software_node(fwnode)) {4256		dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);4257		desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);4258	}4259 4260	return desc;4261}4262 4263struct gpio_desc *gpiod_find_and_request(struct device *consumer,4264					 struct fwnode_handle *fwnode,4265					 const char *con_id,4266					 unsigned int idx,4267					 enum gpiod_flags flags,4268					 const char *label,4269					 bool platform_lookup_allowed)4270{4271	unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;4272	const char *name = function_name_or_default(con_id);4273	/*4274	 * scoped_guard() is implemented as a for loop, meaning static4275	 * analyzers will complain about these two not being initialized.4276	 */4277	struct gpio_desc *desc = NULL;4278	int ret = 0;4279 4280	scoped_guard(srcu, &gpio_devices_srcu) {4281		desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,4282					    &flags, &lookupflags);4283		if (gpiod_not_found(desc) && platform_lookup_allowed) {4284			/*4285			 * Either we are not using DT or ACPI, or their lookup4286			 * did not return a result. In that case, use platform4287			 * lookup as a fallback.4288			 */4289			dev_dbg(consumer,4290				"using lookup tables for GPIO lookup\n");4291			desc = gpiod_find(consumer, con_id, idx, &lookupflags);4292		}4293 4294		if (IS_ERR(desc)) {4295			dev_dbg(consumer, "No GPIO consumer %s found\n", name);4296			return desc;4297		}4298 4299		/*4300		 * If a connection label was passed use that, else attempt to use4301		 * the device name as label4302		 */4303		ret = gpiod_request(desc, label);4304	}4305	if (ret) {4306		if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))4307			return ERR_PTR(ret);4308 4309		/*4310		 * This happens when there are several consumers for4311		 * the same GPIO line: we just return here without4312		 * further initialization. It is a bit of a hack.4313		 * This is necessary to support fixed regulators.4314		 *4315		 * FIXME: Make this more sane and safe.4316		 */4317		dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);4318		return desc;4319	}4320 4321	ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);4322	if (ret < 0) {4323		gpiod_put(desc);4324		dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret);4325		return ERR_PTR(ret);4326	}4327 4328	gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED);4329 4330	return desc;4331}4332 4333/**4334 * fwnode_gpiod_get_index - obtain a GPIO from firmware node4335 * @fwnode:	handle of the firmware node4336 * @con_id:	function within the GPIO consumer4337 * @index:	index of the GPIO to obtain for the consumer4338 * @flags:	GPIO initialization flags4339 * @label:	label to attach to the requested GPIO4340 *4341 * This function can be used for drivers that get their configuration4342 * from opaque firmware.4343 *4344 * The function properly finds the corresponding GPIO using whatever is the4345 * underlying firmware interface and then makes sure that the GPIO4346 * descriptor is requested before it is returned to the caller.4347 *4348 * Returns:4349 * On successful request the GPIO pin is configured in accordance with4350 * provided @flags.4351 *4352 * In case of error an ERR_PTR() is returned.4353 */4354struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,4355					 const char *con_id,4356					 int index,4357					 enum gpiod_flags flags,4358					 const char *label)4359{4360	return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);4361}4362EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);4363 4364/**4365 * gpiod_count - return the number of GPIOs associated with a device / function4366 * @dev:	GPIO consumer, can be NULL for system-global GPIOs4367 * @con_id:	function within the GPIO consumer4368 *4369 * Returns:4370 * The number of GPIOs associated with a device / function or -ENOENT if no4371 * GPIO has been assigned to the requested function.4372 */4373int gpiod_count(struct device *dev, const char *con_id)4374{4375	const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;4376	int count = -ENOENT;4377 4378	if (is_of_node(fwnode))4379		count = of_gpio_count(fwnode, con_id);4380	else if (is_acpi_node(fwnode))4381		count = acpi_gpio_count(fwnode, con_id);4382	else if (is_software_node(fwnode))4383		count = swnode_gpio_count(fwnode, con_id);4384 4385	if (count < 0)4386		count = platform_gpio_count(dev, con_id);4387 4388	return count;4389}4390EXPORT_SYMBOL_GPL(gpiod_count);4391 4392/**4393 * gpiod_get - obtain a GPIO for a given GPIO function4394 * @dev:	GPIO consumer, can be NULL for system-global GPIOs4395 * @con_id:	function within the GPIO consumer4396 * @flags:	optional GPIO initialization flags4397 *4398 * Returns:4399 * The GPIO descriptor corresponding to the function @con_id of device4400 * dev, -ENOENT if no GPIO has been assigned to the requested function, or4401 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.4402 */4403struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,4404					 enum gpiod_flags flags)4405{4406	return gpiod_get_index(dev, con_id, 0, flags);4407}4408EXPORT_SYMBOL_GPL(gpiod_get);4409 4410/**4411 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function4412 * @dev: GPIO consumer, can be NULL for system-global GPIOs4413 * @con_id: function within the GPIO consumer4414 * @flags: optional GPIO initialization flags4415 *4416 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to4417 * the requested function it will return NULL. This is convenient for drivers4418 * that need to handle optional GPIOs.4419 *4420 * Returns:4421 * The GPIO descriptor corresponding to the function @con_id of device4422 * dev, NULL if no GPIO has been assigned to the requested function, or4423 * another IS_ERR() code if an error occurred while trying to acquire the GPIO.4424 */4425struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,4426						  const char *con_id,4427						  enum gpiod_flags flags)4428{4429	return gpiod_get_index_optional(dev, con_id, 0, flags);4430}4431EXPORT_SYMBOL_GPL(gpiod_get_optional);4432 4433 4434/**4435 * gpiod_configure_flags - helper function to configure a given GPIO4436 * @desc:	gpio whose value will be assigned4437 * @con_id:	function within the GPIO consumer4438 * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from4439 *		of_find_gpio() or of_get_gpio_hog()4440 * @dflags:	gpiod_flags - optional GPIO initialization flags4441 *4442 * Returns:4443 * 0 on success, -ENOENT if no GPIO has been assigned to the4444 * requested function and/or index, or another IS_ERR() code if an error4445 * occurred while trying to acquire the GPIO.4446 */4447int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,4448		unsigned long lflags, enum gpiod_flags dflags)4449{4450	const char *name = function_name_or_default(con_id);4451	int ret;4452 4453	if (lflags & GPIO_ACTIVE_LOW)4454		set_bit(FLAG_ACTIVE_LOW, &desc->flags);4455 4456	if (lflags & GPIO_OPEN_DRAIN)4457		set_bit(FLAG_OPEN_DRAIN, &desc->flags);4458	else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {4459		/*4460		 * This enforces open drain mode from the consumer side.4461		 * This is necessary for some busses like I2C, but the lookup4462		 * should *REALLY* have specified them as open drain in the4463		 * first place, so print a little warning here.4464		 */4465		set_bit(FLAG_OPEN_DRAIN, &desc->flags);4466		gpiod_warn(desc,4467			   "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");4468	}4469 4470	if (lflags & GPIO_OPEN_SOURCE)4471		set_bit(FLAG_OPEN_SOURCE, &desc->flags);4472 4473	if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||4474	    ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||4475	    ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {4476		gpiod_err(desc,4477			  "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");4478		return -EINVAL;4479	}4480 4481	if (lflags & GPIO_PULL_UP)4482		set_bit(FLAG_PULL_UP, &desc->flags);4483	else if (lflags & GPIO_PULL_DOWN)4484		set_bit(FLAG_PULL_DOWN, &desc->flags);4485	else if (lflags & GPIO_PULL_DISABLE)4486		set_bit(FLAG_BIAS_DISABLE, &desc->flags);4487 4488	ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));4489	if (ret < 0)4490		return ret;4491 4492	/* No particular flag request, return here... */4493	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {4494		gpiod_dbg(desc, "no flags found for GPIO %s\n", name);4495		return 0;4496	}4497 4498	/* Process flags */4499	if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)4500		ret = gpiod_direction_output(desc,4501				!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));4502	else4503		ret = gpiod_direction_input(desc);4504 4505	return ret;4506}4507 4508/**4509 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function4510 * @dev:	GPIO consumer, can be NULL for system-global GPIOs4511 * @con_id:	function within the GPIO consumer4512 * @idx:	index of the GPIO to obtain in the consumer4513 * @flags:	optional GPIO initialization flags4514 *4515 * This variant of gpiod_get() allows to access GPIOs other than the first4516 * defined one for functions that define several GPIOs.4517 *4518 * Returns:4519 * A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the4520 * requested function and/or index, or another IS_ERR() code if an error4521 * occurred while trying to acquire the GPIO.4522 */4523struct gpio_desc *__must_check gpiod_get_index(struct device *dev,4524					       const char *con_id,4525					       unsigned int idx,4526					       enum gpiod_flags flags)4527{4528	struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;4529	const char *devname = dev ? dev_name(dev) : "?";4530	const char *label = con_id ?: devname;4531 4532	return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);4533}4534EXPORT_SYMBOL_GPL(gpiod_get_index);4535 4536/**4537 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO4538 *                            function4539 * @dev: GPIO consumer, can be NULL for system-global GPIOs4540 * @con_id: function within the GPIO consumer4541 * @index: index of the GPIO to obtain in the consumer4542 * @flags: optional GPIO initialization flags4543 *4544 * This is equivalent to gpiod_get_index(), except that when no GPIO with the4545 * specified index was assigned to the requested function it will return NULL.4546 * This is convenient for drivers that need to handle optional GPIOs.4547 *4548 * Returns:4549 * A valid GPIO descriptor, NULL if no GPIO has been assigned to the4550 * requested function and/or index, or another IS_ERR() code if an error4551 * occurred while trying to acquire the GPIO.4552 */4553struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,4554							const char *con_id,4555							unsigned int index,4556							enum gpiod_flags flags)4557{4558	struct gpio_desc *desc;4559 4560	desc = gpiod_get_index(dev, con_id, index, flags);4561	if (gpiod_not_found(desc))4562		return NULL;4563 4564	return desc;4565}4566EXPORT_SYMBOL_GPL(gpiod_get_index_optional);4567 4568/**4569 * gpiod_hog - Hog the specified GPIO desc given the provided flags4570 * @desc:	gpio whose value will be assigned4571 * @name:	gpio line name4572 * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from4573 *		of_find_gpio() or of_get_gpio_hog()4574 * @dflags:	gpiod_flags - optional GPIO initialization flags4575 *4576 * Returns:4577 * 0 on success, or negative errno on failure.4578 */4579int gpiod_hog(struct gpio_desc *desc, const char *name,4580	      unsigned long lflags, enum gpiod_flags dflags)4581{4582	struct gpio_device *gdev = desc->gdev;4583	struct gpio_desc *local_desc;4584	int hwnum;4585	int ret;4586 4587	CLASS(gpio_chip_guard, guard)(desc);4588	if (!guard.gc)4589		return -ENODEV;4590 4591	if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))4592		return 0;4593 4594	hwnum = gpio_chip_hwgpio(desc);4595 4596	local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,4597					       lflags, dflags);4598	if (IS_ERR(local_desc)) {4599		clear_bit(FLAG_IS_HOGGED, &desc->flags);4600		ret = PTR_ERR(local_desc);4601		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",4602		       name, gdev->label, hwnum, ret);4603		return ret;4604	}4605 4606	gpiod_dbg(desc, "hogged as %s%s\n",4607		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",4608		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?4609		  (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");4610 4611	return 0;4612}4613 4614/**4615 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog4616 * @gc:	gpio chip to act on4617 */4618static void gpiochip_free_hogs(struct gpio_chip *gc)4619{4620	struct gpio_desc *desc;4621 4622	for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)4623		gpiochip_free_own_desc(desc);4624}4625 4626/**4627 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function4628 * @dev:	GPIO consumer, can be NULL for system-global GPIOs4629 * @con_id:	function within the GPIO consumer4630 * @flags:	optional GPIO initialization flags4631 *4632 * This function acquires all the GPIOs defined under a given function.4633 *4634 * Returns:4635 * The GPIO descriptors corresponding to the function @con_id of device4636 * dev, -ENOENT if no GPIO has been assigned to the requested function,4637 * or another IS_ERR() code if an error occurred while trying to acquire4638 * the GPIOs.4639 */4640struct gpio_descs *__must_check gpiod_get_array(struct device *dev,4641						const char *con_id,4642						enum gpiod_flags flags)4643{4644	struct gpio_desc *desc;4645	struct gpio_descs *descs;4646	struct gpio_array *array_info = NULL;4647	struct gpio_chip *gc;4648	int count, bitmap_size;4649	size_t descs_size;4650 4651	count = gpiod_count(dev, con_id);4652	if (count < 0)4653		return ERR_PTR(count);4654 4655	descs_size = struct_size(descs, desc, count);4656	descs = kzalloc(descs_size, GFP_KERNEL);4657	if (!descs)4658		return ERR_PTR(-ENOMEM);4659 4660	for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {4661		desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);4662		if (IS_ERR(desc)) {4663			gpiod_put_array(descs);4664			return ERR_CAST(desc);4665		}4666 4667		descs->desc[descs->ndescs] = desc;4668 4669		gc = gpiod_to_chip(desc);4670		/*4671		 * If pin hardware number of array member 0 is also 0, select4672		 * its chip as a candidate for fast bitmap processing path.4673		 */4674		if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {4675			struct gpio_descs *array;4676 4677			bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?4678						    gc->ngpio : count);4679 4680			array = krealloc(descs, descs_size +4681					 struct_size(array_info, invert_mask, 3 * bitmap_size),4682					 GFP_KERNEL | __GFP_ZERO);4683			if (!array) {4684				gpiod_put_array(descs);4685				return ERR_PTR(-ENOMEM);4686			}4687 4688			descs = array;4689 4690			array_info = (void *)descs + descs_size;4691			array_info->get_mask = array_info->invert_mask +4692						  bitmap_size;4693			array_info->set_mask = array_info->get_mask +4694						  bitmap_size;4695 4696			array_info->desc = descs->desc;4697			array_info->size = count;4698			array_info->chip = gc;4699			bitmap_set(array_info->get_mask, descs->ndescs,4700				   count - descs->ndescs);4701			bitmap_set(array_info->set_mask, descs->ndescs,4702				   count - descs->ndescs);4703			descs->info = array_info;4704		}4705 4706		/* If there is no cache for fast bitmap processing path, continue */4707		if (!array_info)4708			continue;4709 4710		/* Unmark array members which don't belong to the 'fast' chip */4711		if (array_info->chip != gc) {4712			__clear_bit(descs->ndescs, array_info->get_mask);4713			__clear_bit(descs->ndescs, array_info->set_mask);4714		}4715		/*4716		 * Detect array members which belong to the 'fast' chip4717		 * but their pins are not in hardware order.4718		 */4719		else if (gpio_chip_hwgpio(desc) != descs->ndescs) {4720			/*4721			 * Don't use fast path if all array members processed so4722			 * far belong to the same chip as this one but its pin4723			 * hardware number is different from its array index.4724			 */4725			if (bitmap_full(array_info->get_mask, descs->ndescs)) {4726				array_info = NULL;4727			} else {4728				__clear_bit(descs->ndescs,4729					    array_info->get_mask);4730				__clear_bit(descs->ndescs,4731					    array_info->set_mask);4732			}4733		} else {4734			/* Exclude open drain or open source from fast output */4735			if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||4736			    gpiochip_line_is_open_source(gc, descs->ndescs))4737				__clear_bit(descs->ndescs,4738					    array_info->set_mask);4739			/* Identify 'fast' pins which require invertion */4740			if (gpiod_is_active_low(desc))4741				__set_bit(descs->ndescs,4742					  array_info->invert_mask);4743		}4744	}4745	if (array_info)4746		dev_dbg(dev,4747			"GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",4748			array_info->chip->label, array_info->size,4749			*array_info->get_mask, *array_info->set_mask,4750			*array_info->invert_mask);4751	return descs;4752}4753EXPORT_SYMBOL_GPL(gpiod_get_array);4754 4755/**4756 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO4757 *                            function4758 * @dev:	GPIO consumer, can be NULL for system-global GPIOs4759 * @con_id:	function within the GPIO consumer4760 * @flags:	optional GPIO initialization flags4761 *4762 * This is equivalent to gpiod_get_array(), except that when no GPIO was4763 * assigned to the requested function it will return NULL.4764 *4765 * Returns:4766 * The GPIO descriptors corresponding to the function @con_id of device4767 * dev, NULL if no GPIO has been assigned to the requested function,4768 * or another IS_ERR() code if an error occurred while trying to acquire4769 * the GPIOs.4770 */4771struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,4772							const char *con_id,4773							enum gpiod_flags flags)4774{4775	struct gpio_descs *descs;4776 4777	descs = gpiod_get_array(dev, con_id, flags);4778	if (gpiod_not_found(descs))4779		return NULL;4780 4781	return descs;4782}4783EXPORT_SYMBOL_GPL(gpiod_get_array_optional);4784 4785/**4786 * gpiod_put - dispose of a GPIO descriptor4787 * @desc:	GPIO descriptor to dispose of4788 *4789 * No descriptor can be used after gpiod_put() has been called on it.4790 */4791void gpiod_put(struct gpio_desc *desc)4792{4793	if (desc)4794		gpiod_free(desc);4795}4796EXPORT_SYMBOL_GPL(gpiod_put);4797 4798/**4799 * gpiod_put_array - dispose of multiple GPIO descriptors4800 * @descs:	struct gpio_descs containing an array of descriptors4801 */4802void gpiod_put_array(struct gpio_descs *descs)4803{4804	unsigned int i;4805 4806	for (i = 0; i < descs->ndescs; i++)4807		gpiod_put(descs->desc[i]);4808 4809	kfree(descs);4810}4811EXPORT_SYMBOL_GPL(gpiod_put_array);4812 4813static int gpio_stub_drv_probe(struct device *dev)4814{4815	/*4816	 * The DT node of some GPIO chips have a "compatible" property, but4817	 * never have a struct device added and probed by a driver to register4818	 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause4819	 * the consumers of the GPIO chip to get probe deferred forever because4820	 * they will be waiting for a device associated with the GPIO chip4821	 * firmware node to get added and bound to a driver.4822	 *4823	 * To allow these consumers to probe, we associate the struct4824	 * gpio_device of the GPIO chip with the firmware node and then simply4825	 * bind it to this stub driver.4826	 */4827	return 0;4828}4829 4830static struct device_driver gpio_stub_drv = {4831	.name = "gpio_stub_drv",4832	.bus = &gpio_bus_type,4833	.probe = gpio_stub_drv_probe,4834};4835 4836static int __init gpiolib_dev_init(void)4837{4838	int ret;4839 4840	/* Register GPIO sysfs bus */4841	ret = bus_register(&gpio_bus_type);4842	if (ret < 0) {4843		pr_err("gpiolib: could not register GPIO bus type\n");4844		return ret;4845	}4846 4847	ret = driver_register(&gpio_stub_drv);4848	if (ret < 0) {4849		pr_err("gpiolib: could not register GPIO stub driver\n");4850		bus_unregister(&gpio_bus_type);4851		return ret;4852	}4853 4854	ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);4855	if (ret < 0) {4856		pr_err("gpiolib: failed to allocate char dev region\n");4857		driver_unregister(&gpio_stub_drv);4858		bus_unregister(&gpio_bus_type);4859		return ret;4860	}4861 4862	gpiolib_initialized = true;4863	gpiochip_setup_devs();4864 4865#if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)4866	WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));4867#endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */4868 4869	return ret;4870}4871core_initcall(gpiolib_dev_init);4872 4873#ifdef CONFIG_DEBUG_FS4874 4875static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)4876{4877	bool active_low, is_irq, is_out;4878	unsigned int gpio = gdev->base;4879	struct gpio_desc *desc;4880	struct gpio_chip *gc;4881	int value;4882 4883	guard(srcu)(&gdev->srcu);4884 4885	gc = srcu_dereference(gdev->chip, &gdev->srcu);4886	if (!gc) {4887		seq_puts(s, "Underlying GPIO chip is gone\n");4888		return;4889	}4890 4891	for_each_gpio_desc(gc, desc) {4892		guard(srcu)(&desc->gdev->desc_srcu);4893		is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);4894		if (is_irq || test_bit(FLAG_REQUESTED, &desc->flags)) {4895			gpiod_get_direction(desc);4896			is_out = test_bit(FLAG_IS_OUT, &desc->flags);4897			value = gpio_chip_get_value(gc, desc);4898			active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags);4899			seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",4900				   gpio, desc->name ?: "", gpiod_get_label(desc),4901				   is_out ? "out" : "in ",4902				   value >= 0 ? (value ? "hi" : "lo") : "?  ",4903				   is_irq ? "IRQ " : "",4904				   active_low ? "ACTIVE LOW" : "");4905		} else if (desc->name) {4906			seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name);4907		}4908 4909		gpio++;4910	}4911}4912 4913struct gpiolib_seq_priv {4914	bool newline;4915	int idx;4916};4917 4918static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)4919{4920	struct gpiolib_seq_priv *priv;4921	struct gpio_device *gdev;4922	loff_t index = *pos;4923 4924	priv = kzalloc(sizeof(*priv), GFP_KERNEL);4925	if (!priv)4926		return NULL;4927 4928	s->private = priv;4929	if (*pos > 0)4930		priv->newline = true;4931	priv->idx = srcu_read_lock(&gpio_devices_srcu);4932 4933	list_for_each_entry_srcu(gdev, &gpio_devices, list,4934				 srcu_read_lock_held(&gpio_devices_srcu)) {4935		if (index-- == 0)4936			return gdev;4937	}4938 4939	return NULL;4940}4941 4942static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)4943{4944	struct gpiolib_seq_priv *priv = s->private;4945	struct gpio_device *gdev = v, *next;4946 4947	next = list_entry_rcu(gdev->list.next, struct gpio_device, list);4948	gdev = &next->list == &gpio_devices ? NULL : next;4949	priv->newline = true;4950	++*pos;4951 4952	return gdev;4953}4954 4955static void gpiolib_seq_stop(struct seq_file *s, void *v)4956{4957	struct gpiolib_seq_priv *priv = s->private;4958 4959	srcu_read_unlock(&gpio_devices_srcu, priv->idx);4960	kfree(priv);4961}4962 4963static int gpiolib_seq_show(struct seq_file *s, void *v)4964{4965	struct gpiolib_seq_priv *priv = s->private;4966	struct gpio_device *gdev = v;4967	struct gpio_chip *gc;4968	struct device *parent;4969 4970	guard(srcu)(&gdev->srcu);4971 4972	gc = srcu_dereference(gdev->chip, &gdev->srcu);4973	if (!gc) {4974		seq_printf(s, "%s%s: (dangling chip)\n",4975			   priv->newline ? "\n" : "",4976			   dev_name(&gdev->dev));4977		return 0;4978	}4979 4980	seq_printf(s, "%s%s: GPIOs %u-%u", priv->newline ? "\n" : "",4981		   dev_name(&gdev->dev),4982		   gdev->base, gdev->base + gdev->ngpio - 1);4983	parent = gc->parent;4984	if (parent)4985		seq_printf(s, ", parent: %s/%s",4986			   parent->bus ? parent->bus->name : "no-bus",4987			   dev_name(parent));4988	if (gc->label)4989		seq_printf(s, ", %s", gc->label);4990	if (gc->can_sleep)4991		seq_printf(s, ", can sleep");4992	seq_printf(s, ":\n");4993 4994	if (gc->dbg_show)4995		gc->dbg_show(s, gc);4996	else4997		gpiolib_dbg_show(s, gdev);4998 4999	return 0;5000}5001 5002static const struct seq_operations gpiolib_sops = {5003	.start = gpiolib_seq_start,5004	.next = gpiolib_seq_next,5005	.stop = gpiolib_seq_stop,5006	.show = gpiolib_seq_show,5007};5008DEFINE_SEQ_ATTRIBUTE(gpiolib);5009 5010static int __init gpiolib_debugfs_init(void)5011{5012	/* /sys/kernel/debug/gpio */5013	debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);5014	return 0;5015}5016subsys_initcall(gpiolib_debugfs_init);5017 5018#endif	/* DEBUG_FS */5019