text: // SPDX-License-Identifier: GPL-2.0
  
  #include <linux/bitmap.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/spinlock.h>
  #include <linux/list.h>
  #include <linux/device.h>
  #include <linux/err.h>
  #include <linux/debugfs.h>
  #include <linux/seq_file.h>
  #include <linux/gpio.h>
  #include <linux/idr.h>
  #include <linux/slab.h>
  #include <linux/acpi.h>
  #include <linux/gpio/driver.h>
  #include <linux/gpio/machine.h>
  #include <linux/pinctrl/consumer.h>
  #include <linux/fs.h>
  #include <linux/compat.h>
  #include <linux/file.h>
  #include <uapi/linux/gpio.h>
  
  #include "gpiolib.h"
  #include "gpiolib-of.h"
  #include "gpiolib-acpi.h"
  #include "gpiolib-cdev.h"
  #include "gpiolib-sysfs.h"
  
  #define CREATE_TRACE_POINTS
  #include <trace/events/gpio.h>
  
  /* Implementation infrastructure for GPIO interfaces.
   *
   * The GPIO programming interface allows for inlining speed-critical
   * get/set operations for common cases, so that access to SOC-integrated
   * GPIOs can sometimes cost only an instruction or two per bit.
   */
  
  
  /* When debugging, extend minimal trust to callers and platform code.
   * Also emit diagnostic messages that may help initial bringup, when
   * board setup or driver bugs are most common.
   *
   * Otherwise, minimize overhead in what may be bitbanging codepaths.
   */
  #ifdef	DEBUG
  #define	extra_checks	1
  #else
  #define	extra_checks	0
  #endif
  
  /* Device and char device-related information */
  static DEFINE_IDA(gpio_ida);
  static dev_t gpio_devt;
  #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
  static int gpio_bus_match(struct device *dev, struct device_driver *drv);
  static struct bus_type gpio_bus_type = {
  	.name = "gpio",
  	.match = gpio_bus_match,
  };
  
  /*
   * Number of GPIOs to use for the fast path in set array
   */
  #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
  
  /* gpio_lock prevents conflicts during gpio_desc[] table updates.
   * While any GPIO is requested, its gpio_chip is not removable;
   * each GPIO's "requested" flag serves as a lock and refcount.
   */
  DEFINE_SPINLOCK(gpio_lock);
  
  static DEFINE_MUTEX(gpio_lookup_lock);
  static LIST_HEAD(gpio_lookup_list);
  LIST_HEAD(gpio_devices);
  
  static DEFINE_MUTEX(gpio_machine_hogs_mutex);
  static LIST_HEAD(gpio_machine_hogs);
  
  static void gpiochip_free_hogs(struct gpio_chip *gc);
  static int gpiochip_add_irqchip(struct gpio_chip *gc,
  				struct lock_class_key *lock_key,
  				struct lock_class_key *request_key);
  static void gpiochip_irqchip_remove(struct gpio_chip *gc);
  static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
  static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
  static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
  
  static bool gpiolib_initialized;
  
  static inline void desc_set_label(struct gpio_desc *d, const char *label)
  {
  	d->label = label;
  }
  
  /**
   * gpio_to_desc - Convert a GPIO number to its descriptor
   * @gpio: global GPIO number
   *
   * Returns:
   * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
   * with the given number exists in the system.
   */
  struct gpio_desc *gpio_to_desc(unsigned gpio)
  {
  	struct gpio_device *gdev;
  	unsigned long flags;
  
  	spin_lock_irqsave(&gpio_lock, flags);
  
  	list_for_each_entry(gdev, &gpio_devices, list) {
  		if (gdev->base <= gpio &&
  		    gdev->base + gdev->ngpio > gpio) {
  			spin_unlock_irqrestore(&gpio_lock, flags);
  			return &gdev->descs[gpio - gdev->base];
  		}
  	}
  
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	if (!gpio_is_valid(gpio))
  		pr_warn("invalid GPIO %d\n", gpio);
  
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(gpio_to_desc);
  
  /**
   * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
   *                     hardware number for this chip
   * @gc: GPIO chip
   * @hwnum: hardware number of the GPIO for this chip
   *
   * Returns:
   * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
   * in the given chip for the specified hardware number.
   */
  struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
  				    unsigned int hwnum)
  {
  	struct gpio_device *gdev = gc->gpiodev;
  
  	if (hwnum >= gdev->ngpio)
  		return ERR_PTR(-EINVAL);
  
  	return &gdev->descs[hwnum];
  }
  EXPORT_SYMBOL_GPL(gpiochip_get_desc);
  
  /**
   * desc_to_gpio - convert a GPIO descriptor to the integer namespace
   * @desc: GPIO descriptor
   *
   * This should disappear in the future but is needed since we still
   * use GPIO numbers for error messages and sysfs nodes.
   *
   * Returns:
   * The global GPIO number for the GPIO specified by its descriptor.
   */
  int desc_to_gpio(const struct gpio_desc *desc)
  {
  	return desc->gdev->base + (desc - &desc->gdev->descs[0]);
  }
  EXPORT_SYMBOL_GPL(desc_to_gpio);
  
  
  /**
   * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
   * @desc:	descriptor to return the chip of
   */
  struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
  {
  	if (!desc || !desc->gdev)
  		return NULL;
  	return desc->gdev->chip;
  }
  EXPORT_SYMBOL_GPL(gpiod_to_chip);
  
  /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
  static int gpiochip_find_base(int ngpio)
  {
  	struct gpio_device *gdev;
  	int base = ARCH_NR_GPIOS - ngpio;
  
  	list_for_each_entry_reverse(gdev, &gpio_devices, list) {
  		/* found a free space? */
  		if (gdev->base + gdev->ngpio <= base)
  			break;
  		else
  			/* nope, check the space right before the chip */
  			base = gdev->base - ngpio;
  	}
  
  	if (gpio_is_valid(base)) {
  		pr_debug("%s: found new base at %d\n", __func__, base);
  		return base;
  	} else {
  		pr_err("%s: cannot find free range\n", __func__);
  		return -ENOSPC;
  	}
  }
  
  /**
   * gpiod_get_direction - return the current direction of a GPIO
   * @desc:	GPIO to get the direction of
   *
   * Returns 0 for output, 1 for input, or an error code in case of error.
   *
   * This function may sleep if gpiod_cansleep() is true.
   */
  int gpiod_get_direction(struct gpio_desc *desc)
  {
  	struct gpio_chip *gc;
  	unsigned int offset;
  	int ret;
  
  	gc = gpiod_to_chip(desc);
  	offset = gpio_chip_hwgpio(desc);
  
  	/*
  	 * Open drain emulation using input mode may incorrectly report
  	 * input here, fix that up.
  	 */
  	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
  	    test_bit(FLAG_IS_OUT, &desc->flags))
  		return 0;
  
  	if (!gc->get_direction)
  		return -ENOTSUPP;
  
  	ret = gc->get_direction(gc, offset);
  	if (ret < 0)
  		return ret;
  
  	/* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
  	if (ret > 0)
  		ret = 1;
  
  	assign_bit(FLAG_IS_OUT, &desc->flags, !ret);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(gpiod_get_direction);
  
  /*
   * Add a new chip to the global chips list, keeping the list of chips sorted
   * by range(means [base, base + ngpio - 1]) order.
   *
   * Return -EBUSY if the new chip overlaps with some other chip's integer
   * space.
   */
  static int gpiodev_add_to_list(struct gpio_device *gdev)
  {
  	struct gpio_device *prev, *next;
  
  	if (list_empty(&gpio_devices)) {
  		/* initial entry in list */
  		list_add_tail(&gdev->list, &gpio_devices);
  		return 0;
  	}
  
  	next = list_first_entry(&gpio_devices, struct gpio_device, list);
  	if (gdev->base + gdev->ngpio <= next->base) {
  		/* add before first entry */
  		list_add(&gdev->list, &gpio_devices);
  		return 0;
  	}
  
  	prev = list_last_entry(&gpio_devices, struct gpio_device, list);
  	if (prev->base + prev->ngpio <= gdev->base) {
  		/* add behind last entry */
  		list_add_tail(&gdev->list, &gpio_devices);
  		return 0;
  	}
  
  	list_for_each_entry_safe(prev, next, &gpio_devices, list) {
  		/* at the end of the list */
  		if (&next->list == &gpio_devices)
  			break;
  
  		/* add between prev and next */
  		if (prev->base + prev->ngpio <= gdev->base
  				&& gdev->base + gdev->ngpio <= next->base) {
  			list_add(&gdev->list, &prev->list);
  			return 0;
  		}
  	}
  
  	dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
  	return -EBUSY;
  }
  
  /*
   * Convert a GPIO name to its descriptor
   * Note that there is no guarantee that GPIO names are globally unique!
   * Hence this function will return, if it exists, a reference to the first GPIO
   * line found that matches the given name.
   */
  static struct gpio_desc *gpio_name_to_desc(const char * const name)
  {
  	struct gpio_device *gdev;
  	unsigned long flags;
  
  	if (!name)
  		return NULL;
  
  	spin_lock_irqsave(&gpio_lock, flags);
  
  	list_for_each_entry(gdev, &gpio_devices, list) {
  		int i;
  
  		for (i = 0; i != gdev->ngpio; ++i) {
  			struct gpio_desc *desc = &gdev->descs[i];
  
  			if (!desc->name)
  				continue;
  
  			if (!strcmp(desc->name, name)) {
  				spin_unlock_irqrestore(&gpio_lock, flags);
  				return desc;
  			}
  		}
  	}
  
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	return NULL;
  }
  
  /*
   * Take the names from gc->names and assign them to their GPIO descriptors.
   * Warn if a name is already used for a GPIO line on a different GPIO chip.
   *
   * Note that:
   *   1. Non-unique names are still accepted,
   *   2. Name collisions within the same GPIO chip are not reported.
   */
  static int gpiochip_set_desc_names(struct gpio_chip *gc)
  {
  	struct gpio_device *gdev = gc->gpiodev;
  	int i;
  
  	/* First check all names if they are unique */
  	for (i = 0; i != gc->ngpio; ++i) {
  		struct gpio_desc *gpio;
  
  		gpio = gpio_name_to_desc(gc->names[i]);
  		if (gpio)
  			dev_warn(&gdev->dev,
  				 "Detected name collision for GPIO name '%s'\n",
  				 gc->names[i]);
  	}
  
  	/* Then add all names to the GPIO descriptors */
  	for (i = 0; i != gc->ngpio; ++i)
  		gdev->descs[i].name = gc->names[i];
  
  	return 0;
  }
  
  /*
   * devprop_gpiochip_set_names - Set GPIO line names using device properties
   * @chip: GPIO chip whose lines should be named, if possible
   *
   * Looks for device property "gpio-line-names" and if it exists assigns
   * GPIO line names for the chip. The memory allocated for the assigned
   * names belong to the underlying firmware node and should not be released
   * by the caller.
   */
  static int devprop_gpiochip_set_names(struct gpio_chip *chip)
  {
  	struct gpio_device *gdev = chip->gpiodev;
  	struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
  	const char **names;
  	int ret, i;
  	int count;
  
  	count = fwnode_property_string_array_count(fwnode, "gpio-line-names");
  	if (count < 0)
  		return 0;
  
  	/*
  	 * When offset is set in the driver side we assume the driver internally
  	 * is using more than one gpiochip per the same device. We have to stop
  	 * setting friendly names if the specified ones with 'gpio-line-names'
  	 * are less than the offset in the device itself. This means all the
  	 * lines are not present for every single pin within all the internal
  	 * gpiochips.
  	 */
  	if (count <= chip->offset) {
  		dev_warn(&gdev->dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
  			 count, chip->offset);
  		return 0;
  	}
  
  	names = kcalloc(count, sizeof(*names), GFP_KERNEL);
  	if (!names)
  		return -ENOMEM;
  
  	ret = fwnode_property_read_string_array(fwnode, "gpio-line-names",
  						names, count);
  	if (ret < 0) {
  		dev_warn(&gdev->dev, "failed to read GPIO line names\n");
  		kfree(names);
  		return ret;
  	}
  
  	/*
  	 * When more that one gpiochip per device is used, 'count' can
  	 * contain at most number gpiochips x chip->ngpio. We have to
  	 * correctly distribute all defined lines taking into account
  	 * chip->offset as starting point from where we will assign
  	 * the names to pins from the 'names' array. Since property
  	 * 'gpio-line-names' cannot contains gaps, we have to be sure
  	 * we only assign those pins that really exists since chip->ngpio
  	 * can be different of the chip->offset.
  	 */
  	count = (count > chip->offset) ? count - chip->offset : count;
  	if (count > chip->ngpio)
  		count = chip->ngpio;
  
  	for (i = 0; i < count; i++) {
  		/*
  		 * Allow overriding "fixed" names provided by the GPIO
  		 * provider. The "fixed" names are more often than not
  		 * generic and less informative than the names given in
  		 * device properties.
  		 */
  		if (names[chip->offset + i] && names[chip->offset + i][0])
  			gdev->descs[i].name = names[chip->offset + i];
  	}
  
  	kfree(names);
  
  	return 0;
  }
  
  static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
  {
  	unsigned long *p;
  
  	p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
  	if (!p)
  		return NULL;
  
  	/* Assume by default all GPIOs are valid */
  	bitmap_fill(p, gc->ngpio);
  
  	return p;
  }
  
  static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
  {
  	if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
  		return 0;
  
  	gc->valid_mask = gpiochip_allocate_mask(gc);
  	if (!gc->valid_mask)
  		return -ENOMEM;
  
  	return 0;
  }
  
  static int gpiochip_init_valid_mask(struct gpio_chip *gc)
  {
  	if (gc->init_valid_mask)
  		return gc->init_valid_mask(gc,
  					   gc->valid_mask,
  					   gc->ngpio);
  
  	return 0;
  }
  
  static void gpiochip_free_valid_mask(struct gpio_chip *gc)
  {
  	bitmap_free(gc->valid_mask);
  	gc->valid_mask = NULL;
  }
  
  static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
  {
  	if (gc->add_pin_ranges)
  		return gc->add_pin_ranges(gc);
  
  	return 0;
  }
  
  bool gpiochip_line_is_valid(const struct gpio_chip *gc,
  				unsigned int offset)
  {
  	/* No mask means all valid */
  	if (likely(!gc->valid_mask))
  		return true;
  	return test_bit(offset, gc->valid_mask);
  }
  EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
  
  static void gpiodevice_release(struct device *dev)
  {
  	struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
  	unsigned long flags;
  
  	spin_lock_irqsave(&gpio_lock, flags);
  	list_del(&gdev->list);
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	ida_free(&gpio_ida, gdev->id);
  	kfree_const(gdev->label);
  	kfree(gdev->descs);
  	kfree(gdev);
  }
  
  #ifdef CONFIG_GPIO_CDEV
  #define gcdev_register(gdev, devt)	gpiolib_cdev_register((gdev), (devt))
  #define gcdev_unregister(gdev)		gpiolib_cdev_unregister((gdev))
  #else
  /*
   * gpiolib_cdev_register() indirectly calls device_add(), which is still
   * required even when cdev is not selected.
   */
  #define gcdev_register(gdev, devt)	device_add(&(gdev)->dev)
  #define gcdev_unregister(gdev)		device_del(&(gdev)->dev)
  #endif
  
  static int gpiochip_setup_dev(struct gpio_device *gdev)
  {
  	int ret;
  
  	ret = gcdev_register(gdev, gpio_devt);
  	if (ret)
  		return ret;
  
  	ret = gpiochip_sysfs_register(gdev);
  	if (ret)
  		goto err_remove_device;
  
  	/* From this point, the .release() function cleans up gpio_device */
  	gdev->dev.release = gpiodevice_release;
  	dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base,
  		gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic");
  
  	return 0;
  
  err_remove_device:
  	gcdev_unregister(gdev);
  	return ret;
  }
  
  static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
  {
  	struct gpio_desc *desc;
  	int rv;
  
  	desc = gpiochip_get_desc(gc, hog->chip_hwnum);
  	if (IS_ERR(desc)) {
  		chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
  			 PTR_ERR(desc));
  		return;
  	}
  
  	if (test_bit(FLAG_IS_HOGGED, &desc->flags))
  		return;
  
  	rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
  	if (rv)
  		gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
  			  __func__, gc->label, hog->chip_hwnum, rv);
  }
  
  static void machine_gpiochip_add(struct gpio_chip *gc)
  {
  	struct gpiod_hog *hog;
  
  	mutex_lock(&gpio_machine_hogs_mutex);
  
  	list_for_each_entry(hog, &gpio_machine_hogs, list) {
  		if (!strcmp(gc->label, hog->chip_label))
  			gpiochip_machine_hog(gc, hog);
  	}
  
  	mutex_unlock(&gpio_machine_hogs_mutex);
  }
  
  static void gpiochip_setup_devs(void)
  {
  	struct gpio_device *gdev;
  	int ret;
  
  	list_for_each_entry(gdev, &gpio_devices, list) {
  		ret = gpiochip_setup_dev(gdev);
  		if (ret)
  			dev_err(&gdev->dev,
  				"Failed to initialize gpio device (%d)\n", ret);
  	}
  }
  
  int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
  			       struct lock_class_key *lock_key,
  			       struct lock_class_key *request_key)
  {
  	struct fwnode_handle *fwnode = NULL;
  	struct gpio_device *gdev;
  	unsigned long flags;
  	int base = gc->base;
  	unsigned int i;
  	int ret = 0;
  	u32 ngpios;
  
  	if (gc->fwnode)
  		fwnode = gc->fwnode;
  	else if (gc->parent)
  		fwnode = dev_fwnode(gc->parent);
  
  	/*
  	 * First: allocate and populate the internal stat container, and
  	 * set up the struct device.
  	 */
  	gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
  	if (!gdev)
  		return -ENOMEM;
  	gdev->dev.bus = &gpio_bus_type;
  	gdev->dev.parent = gc->parent;
  	gdev->chip = gc;
  	gc->gpiodev = gdev;
  
  	of_gpio_dev_init(gc, gdev);
  	acpi_gpio_dev_init(gc, gdev);
  
  	/*
  	 * Assign fwnode depending on the result of the previous calls,
  	 * if none of them succeed, assign it to the parent's one.
  	 */
  	gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode;
  
  	gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
  	if (gdev->id < 0) {
  		ret = gdev->id;
  		goto err_free_gdev;
  	}
  
  	ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
  	if (ret)
  		goto err_free_ida;
  
  	device_initialize(&gdev->dev);
  	if (gc->parent && gc->parent->driver)
  		gdev->owner = gc->parent->driver->owner;
  	else if (gc->owner)
  		/* TODO: remove chip->owner */
  		gdev->owner = gc->owner;
  	else
  		gdev->owner = THIS_MODULE;
  
  	gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
  	if (!gdev->descs) {
  		ret = -ENOMEM;
  		goto err_free_dev_name;
  	}
  
  	/*
  	 * Try the device properties if the driver didn't supply the number
  	 * of GPIO lines.
  	 */
  	if (gc->ngpio == 0) {
  		ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios);
  		if (ret == -ENODATA)
  			/*
  			 * -ENODATA means that there is no property found and
  			 * we want to issue the error message to the user.
  			 * Besides that, we want to return different error code
  			 * to state that supplied value is not valid.
  			 */
  			ngpios = 0;
  		else if (ret)
  			goto err_free_descs;
  
  		gc->ngpio = ngpios;
  	}
  
  	if (gc->ngpio == 0) {
  		chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
  		ret = -EINVAL;
  		goto err_free_descs;
  	}
  
  	if (gc->ngpio > FASTPATH_NGPIO)
  		chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
  			  gc->ngpio, FASTPATH_NGPIO);
  
  	gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
  	if (!gdev->label) {
  		ret = -ENOMEM;
  		goto err_free_descs;
  	}
  
  	gdev->ngpio = gc->ngpio;
  	gdev->data = data;
  
  	spin_lock_irqsave(&gpio_lock, flags);
  
  	/*
  	 * TODO: this allocates a Linux GPIO number base in the global
  	 * GPIO numberspace for this chip. In the long run we want to
  	 * get *rid* of this numberspace and use only descriptors, but
  	 * it may be a pipe dream. It will not happen before we get rid
  	 * of the sysfs interface anyways.
  	 */
  	if (base < 0) {
  		base = gpiochip_find_base(gc->ngpio);
  		if (base < 0) {
  			ret = base;
  			spin_unlock_irqrestore(&gpio_lock, flags);
  			goto err_free_label;
  		}
  		/*
  		 * TODO: it should not be necessary to reflect the assigned
  		 * base outside of the GPIO subsystem. Go over drivers and
  		 * see if anyone makes use of this, else drop this and assign
  		 * a poison instead.
  		 */
  		gc->base = base;
  	}
  	gdev->base = base;
  
  	ret = gpiodev_add_to_list(gdev);
  	if (ret) {
  		spin_unlock_irqrestore(&gpio_lock, flags);
  		goto err_free_label;
  	}
  
  	for (i = 0; i < gc->ngpio; i++)
  		gdev->descs[i].gdev = gdev;
  
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
  
  #ifdef CONFIG_PINCTRL
  	INIT_LIST_HEAD(&gdev->pin_ranges);
  #endif
  
  	if (gc->names) {
  		ret = gpiochip_set_desc_names(gc);
  		if (ret)
  			goto err_remove_from_list;
  	}
  	ret = devprop_gpiochip_set_names(gc);
  	if (ret)
  		goto err_remove_from_list;
  
  	ret = gpiochip_alloc_valid_mask(gc);
  	if (ret)
  		goto err_remove_from_list;
  
  	ret = of_gpiochip_add(gc);
  	if (ret)
  		goto err_free_gpiochip_mask;
  
  	ret = gpiochip_init_valid_mask(gc);
  	if (ret)
  		goto err_remove_of_chip;
  
  	for (i = 0; i < gc->ngpio; i++) {
  		struct gpio_desc *desc = &gdev->descs[i];
  
  		if (gc->get_direction && gpiochip_line_is_valid(gc, i)) {
  			assign_bit(FLAG_IS_OUT,
  				   &desc->flags, !gc->get_direction(gc, i));
  		} else {
  			assign_bit(FLAG_IS_OUT,
  				   &desc->flags, !gc->direction_input);
  		}
  	}
  
  	ret = gpiochip_add_pin_ranges(gc);
  	if (ret)
  		goto err_remove_of_chip;
  
  	acpi_gpiochip_add(gc);
  
  	machine_gpiochip_add(gc);
  
  	ret = gpiochip_irqchip_init_valid_mask(gc);
  	if (ret)
  		goto err_remove_acpi_chip;
  
  	ret = gpiochip_irqchip_init_hw(gc);
  	if (ret)
  		goto err_remove_acpi_chip;
  
  	ret = gpiochip_add_irqchip(gc, lock_key, request_key);
  	if (ret)
  		goto err_remove_irqchip_mask;
  
  	/*
  	 * By first adding the chardev, and then adding the device,
  	 * we get a device node entry in sysfs under
  	 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
  	 * coldplug of device nodes and other udev business.
  	 * We can do this only if gpiolib has been initialized.
  	 * Otherwise, defer until later.
  	 */
  	if (gpiolib_initialized) {
  		ret = gpiochip_setup_dev(gdev);
  		if (ret)
  			goto err_remove_irqchip;
  	}
  	return 0;
  
  err_remove_irqchip:
  	gpiochip_irqchip_remove(gc);
  err_remove_irqchip_mask:
  	gpiochip_irqchip_free_valid_mask(gc);
  err_remove_acpi_chip:
  	acpi_gpiochip_remove(gc);
  err_remove_of_chip:
  	gpiochip_free_hogs(gc);
  	of_gpiochip_remove(gc);
  err_free_gpiochip_mask:
  	gpiochip_remove_pin_ranges(gc);
  	gpiochip_free_valid_mask(gc);
  err_remove_from_list:
  	spin_lock_irqsave(&gpio_lock, flags);
  	list_del(&gdev->list);
  	spin_unlock_irqrestore(&gpio_lock, flags);
  err_free_label:
  	kfree_const(gdev->label);
  err_free_descs:
  	kfree(gdev->descs);
  err_free_dev_name:
  	kfree(dev_name(&gdev->dev));
  err_free_ida:
  	ida_free(&gpio_ida, gdev->id);
  err_free_gdev:
  	/* failures here can mean systems won't boot... */
  	if (ret != -EPROBE_DEFER) {
  		pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
  		       gdev->base, gdev->base + gdev->ngpio - 1,
  		       gc->label ? : "generic", ret);
  	}
  	kfree(gdev);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
  
  /**
   * gpiochip_get_data() - get per-subdriver data for the chip
   * @gc: GPIO chip
   *
   * Returns:
   * The per-subdriver data for the chip.
   */
  void *gpiochip_get_data(struct gpio_chip *gc)
  {
  	return gc->gpiodev->data;
  }
  EXPORT_SYMBOL_GPL(gpiochip_get_data);
  
  /**
   * gpiochip_remove() - unregister a gpio_chip
   * @gc: the chip to unregister
   *
   * A gpio_chip with any GPIOs still requested may not be removed.
   */
  void gpiochip_remove(struct gpio_chip *gc)
  {
  	struct gpio_device *gdev = gc->gpiodev;
  	unsigned long	flags;
  	unsigned int	i;
  
  	/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
  	gpiochip_sysfs_unregister(gdev);
  	gpiochip_free_hogs(gc);
  	/* Numb the device, cancelling all outstanding operations */
  	gdev->chip = NULL;
  	gpiochip_irqchip_remove(gc);
  	acpi_gpiochip_remove(gc);
  	of_gpiochip_remove(gc);
  	gpiochip_remove_pin_ranges(gc);
  	gpiochip_free_valid_mask(gc);
  	/*
  	 * We accept no more calls into the driver from this point, so
  	 * NULL the driver data pointer
  	 */
  	gdev->data = NULL;
  
  	spin_lock_irqsave(&gpio_lock, flags);
  	for (i = 0; i < gdev->ngpio; i++) {
  		if (gpiochip_is_requested(gc, i))
  			break;
  	}
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	if (i != gdev->ngpio)
  		dev_crit(&gdev->dev,
  			 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
  
  	/*
  	 * The gpiochip side puts its use of the device to rest here:
  	 * if there are no userspace clients, the chardev and device will
  	 * be removed, else it will be dangling until the last user is
  	 * gone.
  	 */
  	gcdev_unregister(gdev);
  	put_device(&gdev->dev);
  }
  EXPORT_SYMBOL_GPL(gpiochip_remove);
  
  /**
   * gpiochip_find() - iterator for locating a specific gpio_chip
   * @data: data to pass to match function
   * @match: Callback function to check gpio_chip
   *
   * Similar to bus_find_device.  It returns a reference to a gpio_chip as
   * determined by a user supplied @match callback.  The callback should return
   * 0 if the device doesn't match and non-zero if it does.  If the callback is
   * non-zero, this function will return to the caller and not iterate over any
   * more gpio_chips.
   */
  struct gpio_chip *gpiochip_find(void *data,
  				int (*match)(struct gpio_chip *gc,
  					     void *data))
  {
  	struct gpio_device *gdev;
  	struct gpio_chip *gc = NULL;
  	unsigned long flags;
  
  	spin_lock_irqsave(&gpio_lock, flags);
  	list_for_each_entry(gdev, &gpio_devices, list)
  		if (gdev->chip && match(gdev->chip, data)) {
  			gc = gdev->chip;
  			break;
  		}
  
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	return gc;
  }
  EXPORT_SYMBOL_GPL(gpiochip_find);
  
  static int gpiochip_match_name(struct gpio_chip *gc, void *data)
  {
  	const char *name = data;
  
  	return !strcmp(gc->label, name);
  }
  
  static struct gpio_chip *find_chip_by_name(const char *name)
  {
  	return gpiochip_find((void *)name, gpiochip_match_name);
  }
  
  #ifdef CONFIG_GPIOLIB_IRQCHIP
  
  /*
   * The following is irqchip helper code for gpiochips.
   */
  
  static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
  {
  	struct gpio_irq_chip *girq = &gc->irq;
  
  	if (!girq->init_hw)
  		return 0;
  
  	return girq->init_hw(gc);
  }
  
  static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
  {
  	struct gpio_irq_chip *girq = &gc->irq;
  
  	if (!girq->init_valid_mask)
  		return 0;
  
  	girq->valid_mask = gpiochip_allocate_mask(gc);
  	if (!girq->valid_mask)
  		return -ENOMEM;
  
  	girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
  
  	return 0;
  }
  
  static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
  {
  	bitmap_free(gc->irq.valid_mask);
  	gc->irq.valid_mask = NULL;
  }
  
  bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
  				unsigned int offset)
  {
  	if (!gpiochip_line_is_valid(gc, offset))
  		return false;
  	/* No mask means all valid */
  	if (likely(!gc->irq.valid_mask))
  		return true;
  	return test_bit(offset, gc->irq.valid_mask);
  }
  EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
  
  #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
  
  /**
   * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
   * to a gpiochip
   * @gc: the gpiochip to set the irqchip hierarchical handler to
   * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
   * will then percolate up to the parent
   */
  static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
  					      struct irq_chip *irqchip)
  {
  	/* DT will deal with mapping each IRQ as we go along */
  	if (is_of_node(gc->irq.fwnode))
  		return;
  
  	/*
  	 * This is for legacy and boardfile "irqchip" fwnodes: allocate
  	 * irqs upfront instead of dynamically since we don't have the
  	 * dynamic type of allocation that hardware description languages
  	 * provide. Once all GPIO drivers using board files are gone from
  	 * the kernel we can delete this code, but for a transitional period
  	 * it is necessary to keep this around.
  	 */
  	if (is_fwnode_irqchip(gc->irq.fwnode)) {
  		int i;
  		int ret;
  
  		for (i = 0; i < gc->ngpio; i++) {
  			struct irq_fwspec fwspec;
  			unsigned int parent_hwirq;
  			unsigned int parent_type;
  			struct gpio_irq_chip *girq = &gc->irq;
  
  			/*
  			 * We call the child to parent translation function
  			 * only to check if the child IRQ is valid or not.
  			 * Just pick the rising edge type here as that is what
  			 * we likely need to support.
  			 */
  			ret = girq->child_to_parent_hwirq(gc, i,
  							  IRQ_TYPE_EDGE_RISING,
  							  &parent_hwirq,
  							  &parent_type);
  			if (ret) {
  				chip_err(gc, "skip set-up on hwirq %d\n",
  					 i);
  				continue;
  			}
  
  			fwspec.fwnode = gc->irq.fwnode;
  			/* This is the hwirq for the GPIO line side of things */
  			fwspec.param[0] = girq->child_offset_to_irq(gc, i);
  			/* Just pick something */
  			fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
  			fwspec.param_count = 2;
  			ret = __irq_domain_alloc_irqs(gc->irq.domain,
  						      /* just pick something */
  						      -1,
  						      1,
  						      NUMA_NO_NODE,
  						      &fwspec,
  						      false,
  						      NULL);
  			if (ret < 0) {
  				chip_err(gc,
  					 "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
  					 i, parent_hwirq,
  					 ret);
  			}
  		}
  	}
  
  	chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
  
  	return;
  }
  
  static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
  						   struct irq_fwspec *fwspec,
  						   unsigned long *hwirq,
  						   unsigned int *type)
  {
  	/* We support standard DT translation */
  	if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
  		return irq_domain_translate_twocell(d, fwspec, hwirq, type);
  	}
  
  	/* This is for board files and others not using DT */
  	if (is_fwnode_irqchip(fwspec->fwnode)) {
  		int ret;
  
  		ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
  		if (ret)
  			return ret;
  		WARN_ON(*type == IRQ_TYPE_NONE);
  		return 0;
  	}
  	return -EINVAL;
  }
  
  static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
  					       unsigned int irq,
  					       unsigned int nr_irqs,
  					       void *data)
  {
  	struct gpio_chip *gc = d->host_data;
  	irq_hw_number_t hwirq;
  	unsigned int type = IRQ_TYPE_NONE;
  	struct irq_fwspec *fwspec = data;
  	void *parent_arg;
  	unsigned int parent_hwirq;
  	unsigned int parent_type;
  	struct gpio_irq_chip *girq = &gc->irq;
  	int ret;
  
  	/*
  	 * The nr_irqs parameter is always one except for PCI multi-MSI
  	 * so this should not happen.
  	 */
  	WARN_ON(nr_irqs != 1);
  
  	ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
  	if (ret)
  		return ret;
  
  	chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq,  hwirq);
  
  	ret = girq->child_to_parent_hwirq(gc, hwirq, type,
  					  &parent_hwirq, &parent_type);
  	if (ret) {
  		chip_err(gc, "can't look up hwirq %lu\n", hwirq);
  		return ret;
  	}
  	chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
  
  	/*
  	 * We set handle_bad_irq because the .set_type() should
  	 * always be invoked and set the right type of handler.
  	 */
  	irq_domain_set_info(d,
  			    irq,
  			    hwirq,
  			    gc->irq.chip,
  			    gc,
  			    girq->handler,
  			    NULL, NULL);
  	irq_set_probe(irq);
  
  	/* This parent only handles asserted level IRQs */
  	parent_arg = girq->populate_parent_alloc_arg(gc, parent_hwirq, parent_type);
  	if (!parent_arg)
  		return -ENOMEM;
  
  	chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
  		  irq, parent_hwirq);
  	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
  	ret = irq_domain_alloc_irqs_parent(d, irq, 1, parent_arg);
  	/*
  	 * If the parent irqdomain is msi, the interrupts have already
  	 * been allocated, so the EEXIST is good.
  	 */
  	if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
  		ret = 0;
  	if (ret)
  		chip_err(gc,
  			 "failed to allocate parent hwirq %d for hwirq %lu\n",
  			 parent_hwirq, hwirq);
  
  	kfree(parent_arg);
  	return ret;
  }
  
  static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
  						      unsigned int offset)
  {
  	return offset;
  }
  
  static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
  {
  	ops->activate = gpiochip_irq_domain_activate;
  	ops->deactivate = gpiochip_irq_domain_deactivate;
  	ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
  	ops->free = irq_domain_free_irqs_common;
  
  	/*
  	 * We only allow overriding the translate() function for
  	 * hierarchical chips, and this should only be done if the user
  	 * really need something other than 1:1 translation.
  	 */
  	if (!ops->translate)
  		ops->translate = gpiochip_hierarchy_irq_domain_translate;
  }
  
  static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
  {
  	if (!gc->irq.child_to_parent_hwirq ||
  	    !gc->irq.fwnode) {
  		chip_err(gc, "missing irqdomain vital data\n");
  		return -EINVAL;
  	}
  
  	if (!gc->irq.child_offset_to_irq)
  		gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
  
  	if (!gc->irq.populate_parent_alloc_arg)
  		gc->irq.populate_parent_alloc_arg =
  			gpiochip_populate_parent_fwspec_twocell;
  
  	gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
  
  	gc->irq.domain = irq_domain_create_hierarchy(
  		gc->irq.parent_domain,
  		0,
  		gc->ngpio,
  		gc->irq.fwnode,
  		&gc->irq.child_irq_domain_ops,
  		gc);
  
  	if (!gc->irq.domain)
  		return -ENOMEM;
  
  	gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
  
  	return 0;
  }
  
  static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
  {
  	return !!gc->irq.parent_domain;
  }
  
  void *gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
  					     unsigned int parent_hwirq,
  					     unsigned int parent_type)
  {
  	struct irq_fwspec *fwspec;
  
  	fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
  	if (!fwspec)
  		return NULL;
  
  	fwspec->fwnode = gc->irq.parent_domain->fwnode;
  	fwspec->param_count = 2;
  	fwspec->param[0] = parent_hwirq;
  	fwspec->param[1] = parent_type;
  
  	return fwspec;
  }
  EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
  
  void *gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
  					      unsigned int parent_hwirq,
  					      unsigned int parent_type)
  {
  	struct irq_fwspec *fwspec;
  
  	fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
  	if (!fwspec)
  		return NULL;
  
  	fwspec->fwnode = gc->irq.parent_domain->fwnode;
  	fwspec->param_count = 4;
  	fwspec->param[0] = 0;
  	fwspec->param[1] = parent_hwirq;
  	fwspec->param[2] = 0;
  	fwspec->param[3] = parent_type;
  
  	return fwspec;
  }
  EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
  
  #else
  
  static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
  {
  	return -EINVAL;
  }
  
  static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
  {
  	return false;
  }
  
  #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
  
  /**
   * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
   * @d: the irqdomain used by this irqchip
   * @irq: the global irq number used by this GPIO irqchip irq
   * @hwirq: the local IRQ/GPIO line offset on this gpiochip
   *
   * This function will set up the mapping for a certain IRQ line on a
   * gpiochip by assigning the gpiochip as chip data, and using the irqchip
   * stored inside the gpiochip.
   */
  int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
  		     irq_hw_number_t hwirq)
  {
  	struct gpio_chip *gc = d->host_data;
  	int ret = 0;
  
  	if (!gpiochip_irqchip_irq_valid(gc, hwirq))
  		return -ENXIO;
  
  	irq_set_chip_data(irq, gc);
  	/*
  	 * This lock class tells lockdep that GPIO irqs are in a different
  	 * category than their parents, so it won't report false recursion.
  	 */
  	irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
  	irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
  	/* Chips that use nested thread handlers have them marked */
  	if (gc->irq.threaded)
  		irq_set_nested_thread(irq, 1);
  	irq_set_noprobe(irq);
  
  	if (gc->irq.num_parents == 1)
  		ret = irq_set_parent(irq, gc->irq.parents[0]);
  	else if (gc->irq.map)
  		ret = irq_set_parent(irq, gc->irq.map[hwirq]);
  
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * No set-up of the hardware will happen if IRQ_TYPE_NONE
  	 * is passed as default type.
  	 */
  	if (gc->irq.default_type != IRQ_TYPE_NONE)
  		irq_set_irq_type(irq, gc->irq.default_type);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(gpiochip_irq_map);
  
  void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
  {
  	struct gpio_chip *gc = d->host_data;
  
  	if (gc->irq.threaded)
  		irq_set_nested_thread(irq, 0);
  	irq_set_chip_and_handler(irq, NULL, NULL);
  	irq_set_chip_data(irq, NULL);
  }
  EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
  
  static const struct irq_domain_ops gpiochip_domain_ops = {
  	.map	= gpiochip_irq_map,
  	.unmap	= gpiochip_irq_unmap,
  	/* Virtually all GPIO irqchips are twocell:ed */
  	.xlate	= irq_domain_xlate_twocell,
  };
  
  /*
   * TODO: move these activate/deactivate in under the hierarchicial
   * irqchip implementation as static once SPMI and SSBI (all external
   * users) are phased over.
   */
  /**
   * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
   * @domain: The IRQ domain used by this IRQ chip
   * @data: Outermost irq_data associated with the IRQ
   * @reserve: If set, only reserve an interrupt vector instead of assigning one
   *
   * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
   * used as the activate function for the &struct irq_domain_ops. The host_data
   * for the IRQ domain must be the &struct gpio_chip.
   */
  int gpiochip_irq_domain_activate(struct irq_domain *domain,
  				 struct irq_data *data, bool reserve)
  {
  	struct gpio_chip *gc = domain->host_data;
  
  	return gpiochip_lock_as_irq(gc, data->hwirq);
  }
  EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
  
  /**
   * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
   * @domain: The IRQ domain used by this IRQ chip
   * @data: Outermost irq_data associated with the IRQ
   *
   * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
   * be used as the deactivate function for the &struct irq_domain_ops. The
   * host_data for the IRQ domain must be the &struct gpio_chip.
   */
  void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
  				    struct irq_data *data)
  {
  	struct gpio_chip *gc = domain->host_data;
  
  	return gpiochip_unlock_as_irq(gc, data->hwirq);
  }
  EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
  
  static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	struct irq_domain *domain = gc->irq.domain;
  
  #ifdef CONFIG_GPIOLIB_IRQCHIP
  	/*
  	 * Avoid race condition with other code, which tries to lookup
  	 * an IRQ before the irqchip has been properly registered,
  	 * i.e. while gpiochip is still being brought up.
  	 */
  	if (!gc->irq.initialized)
  		return -EPROBE_DEFER;
  #endif
  
  	if (!gpiochip_irqchip_irq_valid(gc, offset))
  		return -ENXIO;
  
  #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
  	if (irq_domain_is_hierarchy(domain)) {
  		struct irq_fwspec spec;
  
  		spec.fwnode = domain->fwnode;
  		spec.param_count = 2;
  		spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
  		spec.param[1] = IRQ_TYPE_NONE;
  
  		return irq_create_fwspec_mapping(&spec);
  	}
  #endif
  
  	return irq_create_mapping(domain, offset);
  }
  
  static int gpiochip_irq_reqres(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  
  	return gpiochip_reqres_irq(gc, d->hwirq);
  }
  
  static void gpiochip_irq_relres(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  
  	gpiochip_relres_irq(gc, d->hwirq);
  }
  
  static void gpiochip_irq_mask(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  
  	if (gc->irq.irq_mask)
  		gc->irq.irq_mask(d);
  	gpiochip_disable_irq(gc, d->hwirq);
  }
  
  static void gpiochip_irq_unmask(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  
  	gpiochip_enable_irq(gc, d->hwirq);
  	if (gc->irq.irq_unmask)
  		gc->irq.irq_unmask(d);
  }
  
  static void gpiochip_irq_enable(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  
  	gpiochip_enable_irq(gc, d->hwirq);
  	gc->irq.irq_enable(d);
  }
  
  static void gpiochip_irq_disable(struct irq_data *d)
  {
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  
  	gc->irq.irq_disable(d);
  	gpiochip_disable_irq(gc, d->hwirq);
  }
  
  static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
  {
  	struct irq_chip *irqchip = gc->irq.chip;
  
  	if (!irqchip->irq_request_resources &&
  	    !irqchip->irq_release_resources) {
  		irqchip->irq_request_resources = gpiochip_irq_reqres;
  		irqchip->irq_release_resources = gpiochip_irq_relres;
  	}
  	if (WARN_ON(gc->irq.irq_enable))
  		return;
  	/* Check if the irqchip already has this hook... */
  	if (irqchip->irq_enable == gpiochip_irq_enable ||
  		irqchip->irq_mask == gpiochip_irq_mask) {
  		/*
  		 * ...and if so, give a gentle warning that this is bad
  		 * practice.
  		 */
  		chip_info(gc,
  			  "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
  		return;
  	}
  
  	if (irqchip->irq_disable) {
  		gc->irq.irq_disable = irqchip->irq_disable;
  		irqchip->irq_disable = gpiochip_irq_disable;
  	} else {
  		gc->irq.irq_mask = irqchip->irq_mask;
  		irqchip->irq_mask = gpiochip_irq_mask;
  	}
  
  	if (irqchip->irq_enable) {
  		gc->irq.irq_enable = irqchip->irq_enable;
  		irqchip->irq_enable = gpiochip_irq_enable;
  	} else {
  		gc->irq.irq_unmask = irqchip->irq_unmask;
  		irqchip->irq_unmask = gpiochip_irq_unmask;
  	}
  }
  
  /**
   * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
   * @gc: the GPIO chip to add the IRQ chip to
   * @lock_key: lockdep class for IRQ lock
   * @request_key: lockdep class for IRQ request
   */
  static int gpiochip_add_irqchip(struct gpio_chip *gc,
  				struct lock_class_key *lock_key,
  				struct lock_class_key *request_key)
  {
  	struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
  	struct irq_chip *irqchip = gc->irq.chip;
  	unsigned int type;
  	unsigned int i;
  
  	if (!irqchip)
  		return 0;
  
  	if (gc->irq.parent_handler && gc->can_sleep) {
  		chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
  		return -EINVAL;
  	}
  
  	type = gc->irq.default_type;
  
  	/*
  	 * Specifying a default trigger is a terrible idea if DT or ACPI is
  	 * used to configure the interrupts, as you may end up with
  	 * conflicting triggers. Tell the user, and reset to NONE.
  	 */
  	if (WARN(fwnode && type != IRQ_TYPE_NONE,
  		 "%pfw: Ignoring %u default trigger\n", fwnode, type))
  		type = IRQ_TYPE_NONE;
  
  	if (gc->to_irq)
  		chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
  
  	gc->to_irq = gpiochip_to_irq;
  	gc->irq.default_type = type;
  	gc->irq.lock_key = lock_key;
  	gc->irq.request_key = request_key;
  
  	/* If a parent irqdomain is provided, let's build a hierarchy */
  	if (gpiochip_hierarchy_is_hierarchical(gc)) {
  		int ret = gpiochip_hierarchy_add_domain(gc);
  		if (ret)
  			return ret;
  	} else {
  		/* Some drivers provide custom irqdomain ops */
  		gc->irq.domain = irq_domain_create_simple(fwnode,
  			gc->ngpio,
  			gc->irq.first,
  			gc->irq.domain_ops ?: &gpiochip_domain_ops,
  			gc);
  		if (!gc->irq.domain)
  			return -EINVAL;
  	}
  
  	if (gc->irq.parent_handler) {
  		for (i = 0; i < gc->irq.num_parents; i++) {
  			void *data;
  
  			if (gc->irq.per_parent_data)
  				data = gc->irq.parent_handler_data_array[i];
  			else
  				data = gc->irq.parent_handler_data ?: gc;
  
  			/*
  			 * The parent IRQ chip is already using the chip_data
  			 * for this IRQ chip, so our callbacks simply use the
  			 * handler_data.
  			 */
  			irq_set_chained_handler_and_data(gc->irq.parents[i],
  							 gc->irq.parent_handler,
  							 data);
  		}
  	}
  
  	gpiochip_set_irq_hooks(gc);
  
  	/*
  	 * Using barrier() here to prevent compiler from reordering
  	 * gc->irq.initialized before initialization of above
  	 * GPIO chip irq members.
  	 */
  	barrier();
  
  	gc->irq.initialized = true;
  
  	acpi_gpiochip_request_interrupts(gc);
  
  	return 0;
  }
  
  /**
   * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
   * @gc: the gpiochip to remove the irqchip from
   *
   * This is called only from gpiochip_remove()
   */
  static void gpiochip_irqchip_remove(struct gpio_chip *gc)
  {
  	struct irq_chip *irqchip = gc->irq.chip;
  	unsigned int offset;
  
  	acpi_gpiochip_free_interrupts(gc);
  
  	if (irqchip && gc->irq.parent_handler) {
  		struct gpio_irq_chip *irq = &gc->irq;
  		unsigned int i;
  
  		for (i = 0; i < irq->num_parents; i++)
  			irq_set_chained_handler_and_data(irq->parents[i],
  							 NULL, NULL);
  	}
  
  	/* Remove all IRQ mappings and delete the domain */
  	if (gc->irq.domain) {
  		unsigned int irq;
  
  		for (offset = 0; offset < gc->ngpio; offset++) {
  			if (!gpiochip_irqchip_irq_valid(gc, offset))
  				continue;
  
  			irq = irq_find_mapping(gc->irq.domain, offset);
  			irq_dispose_mapping(irq);
  		}
  
  		irq_domain_remove(gc->irq.domain);
  	}
  
  	if (irqchip) {
  		if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
  			irqchip->irq_request_resources = NULL;
  			irqchip->irq_release_resources = NULL;
  		}
  		if (irqchip->irq_enable == gpiochip_irq_enable) {
  			irqchip->irq_enable = gc->irq.irq_enable;
  			irqchip->irq_disable = gc->irq.irq_disable;
  		}
  	}
  	gc->irq.irq_enable = NULL;
  	gc->irq.irq_disable = NULL;
  	gc->irq.chip = NULL;
  
  	gpiochip_irqchip_free_valid_mask(gc);
  }
  
  /**
   * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
   * @gc: the gpiochip to add the irqchip to
   * @domain: the irqdomain to add to the gpiochip
   *
   * This function adds an IRQ domain to the gpiochip.
   */
  int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
  				struct irq_domain *domain)
  {
  	if (!domain)
  		return -EINVAL;
  
  	gc->to_irq = gpiochip_to_irq;
  	gc->irq.domain = domain;
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
  
  #else /* CONFIG_GPIOLIB_IRQCHIP */
  
  static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
  				       struct lock_class_key *lock_key,
  				       struct lock_class_key *request_key)
  {
  	return 0;
  }
  static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
  
  static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
  {
  	return 0;
  }
  
  static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
  {
  	return 0;
  }
  static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
  { }
  
  #endif /* CONFIG_GPIOLIB_IRQCHIP */
  
  /**
   * gpiochip_generic_request() - request the gpio function for a pin
   * @gc: the gpiochip owning the GPIO
   * @offset: the offset of the GPIO to request for GPIO function
   */
  int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
  {
  #ifdef CONFIG_PINCTRL
  	if (list_empty(&gc->gpiodev->pin_ranges))
  		return 0;
  #endif
  
  	return pinctrl_gpio_request(gc->gpiodev->base + offset);
  }
  EXPORT_SYMBOL_GPL(gpiochip_generic_request);
  
  /**
   * gpiochip_generic_free() - free the gpio function from a pin
   * @gc: the gpiochip to request the gpio function for
   * @offset: the offset of the GPIO to free from GPIO function
   */
  void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
  {
  #ifdef CONFIG_PINCTRL
  	if (list_empty(&gc->gpiodev->pin_ranges))
  		return;
  #endif
  
  	pinctrl_gpio_free(gc->gpiodev->base + offset);
  }
  EXPORT_SYMBOL_GPL(gpiochip_generic_free);
  
  /**
   * gpiochip_generic_config() - apply configuration for a pin
   * @gc: the gpiochip owning the GPIO
   * @offset: the offset of the GPIO to apply the configuration
   * @config: the configuration to be applied
   */
  int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
  			    unsigned long config)
  {
  	return pinctrl_gpio_set_config(gc->gpiodev->base + offset, config);
  }
  EXPORT_SYMBOL_GPL(gpiochip_generic_config);
  
  #ifdef CONFIG_PINCTRL
  
  /**
   * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
   * @gc: the gpiochip to add the range for
   * @pctldev: the pin controller to map to
   * @gpio_offset: the start offset in the current gpio_chip number space
   * @pin_group: name of the pin group inside the pin controller
   *
   * Calling this function directly from a DeviceTree-supported
   * pinctrl driver is DEPRECATED. Please see Section 2.1 of
   * Documentation/devicetree/bindings/gpio/gpio.txt on how to
   * bind pinctrl and gpio drivers via the "gpio-ranges" property.
   */
  int gpiochip_add_pingroup_range(struct gpio_chip *gc,
  			struct pinctrl_dev *pctldev,
  			unsigned int gpio_offset, const char *pin_group)
  {
  	struct gpio_pin_range *pin_range;
  	struct gpio_device *gdev = gc->gpiodev;
  	int ret;
  
  	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
  	if (!pin_range) {
  		chip_err(gc, "failed to allocate pin ranges\n");
  		return -ENOMEM;
  	}
  
  	/* Use local offset as range ID */
  	pin_range->range.id = gpio_offset;
  	pin_range->range.gc = gc;
  	pin_range->range.name = gc->label;
  	pin_range->range.base = gdev->base + gpio_offset;
  	pin_range->pctldev = pctldev;
  
  	ret = pinctrl_get_group_pins(pctldev, pin_group,
  					&pin_range->range.pins,
  					&pin_range->range.npins);
  	if (ret < 0) {
  		kfree(pin_range);
  		return ret;
  	}
  
  	pinctrl_add_gpio_range(pctldev, &pin_range->range);
  
  	chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
  		 gpio_offset, gpio_offset + pin_range->range.npins - 1,
  		 pinctrl_dev_get_devname(pctldev), pin_group);
  
  	list_add_tail(&pin_range->node, &gdev->pin_ranges);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
  
  /**
   * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
   * @gc: the gpiochip to add the range for
   * @pinctl_name: the dev_name() of the pin controller to map to
   * @gpio_offset: the start offset in the current gpio_chip number space
   * @pin_offset: the start offset in the pin controller number space
   * @npins: the number of pins from the offset of each pin space (GPIO and
   *	pin controller) to accumulate in this range
   *
   * Returns:
   * 0 on success, or a negative error-code on failure.
   *
   * Calling this function directly from a DeviceTree-supported
   * pinctrl driver is DEPRECATED. Please see Section 2.1 of
   * Documentation/devicetree/bindings/gpio/gpio.txt on how to
   * bind pinctrl and gpio drivers via the "gpio-ranges" property.
   */
  int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
  			   unsigned int gpio_offset, unsigned int pin_offset,
  			   unsigned int npins)
  {
  	struct gpio_pin_range *pin_range;
  	struct gpio_device *gdev = gc->gpiodev;
  	int ret;
  
  	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
  	if (!pin_range) {
  		chip_err(gc, "failed to allocate pin ranges\n");
  		return -ENOMEM;
  	}
  
  	/* Use local offset as range ID */
  	pin_range->range.id = gpio_offset;
  	pin_range->range.gc = gc;
  	pin_range->range.name = gc->label;
  	pin_range->range.base = gdev->base + gpio_offset;
  	pin_range->range.pin_base = pin_offset;
  	pin_range->range.npins = npins;
  	pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
  			&pin_range->range);
  	if (IS_ERR(pin_range->pctldev)) {
  		ret = PTR_ERR(pin_range->pctldev);
  		chip_err(gc, "could not create pin range\n");
  		kfree(pin_range);
  		return ret;
  	}
  	chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
  		 gpio_offset, gpio_offset + npins - 1,
  		 pinctl_name,
  		 pin_offset, pin_offset + npins - 1);
  
  	list_add_tail(&pin_range->node, &gdev->pin_ranges);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
  
  /**
   * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
   * @gc: the chip to remove all the mappings for
   */
  void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
  {
  	struct gpio_pin_range *pin_range, *tmp;
  	struct gpio_device *gdev = gc->gpiodev;
  
  	list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
  		list_del(&pin_range->node);
  		pinctrl_remove_gpio_range(pin_range->pctldev,
  				&pin_range->range);
  		kfree(pin_range);
  	}
  }
  EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
  
  #endif /* CONFIG_PINCTRL */
  
  /* These "optional" allocation calls help prevent drivers from stomping
   * on each other, and help provide better diagnostics in debugfs.
   * They're called even less than the "set direction" calls.
   */
  static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
  {
  	struct gpio_chip	*gc = desc->gdev->chip;
  	int			ret;
  	unsigned long		flags;
  	unsigned		offset;
  
  	if (label) {
  		label = kstrdup_const(label, GFP_KERNEL);
  		if (!label)
  			return -ENOMEM;
  	}
  
  	spin_lock_irqsave(&gpio_lock, flags);
  
  	/* NOTE:  gpio_request() can be called in early boot,
  	 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
  	 */
  
  	if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
  		desc_set_label(desc, label ? : "?");
  	} else {
  		ret = -EBUSY;
  		goto out_free_unlock;
  	}
  
  	if (gc->request) {
  		/* gc->request may sleep */
  		spin_unlock_irqrestore(&gpio_lock, flags);
  		offset = gpio_chip_hwgpio(desc);
  		if (gpiochip_line_is_valid(gc, offset))
  			ret = gc->request(gc, offset);
  		else
  			ret = -EINVAL;
  		spin_lock_irqsave(&gpio_lock, flags);
  
  		if (ret) {
  			desc_set_label(desc, NULL);
  			clear_bit(FLAG_REQUESTED, &desc->flags);
  			goto out_free_unlock;
  		}
  	}
  	if (gc->get_direction) {
  		/* gc->get_direction may sleep */
  		spin_unlock_irqrestore(&gpio_lock, flags);
  		gpiod_get_direction(desc);
  		spin_lock_irqsave(&gpio_lock, flags);
  	}
  	spin_unlock_irqrestore(&gpio_lock, flags);
  	return 0;
  
  out_free_unlock:
  	spin_unlock_irqrestore(&gpio_lock, flags);
  	kfree_const(label);
  	return ret;
  }
  
  /*
   * This descriptor validation needs to be inserted verbatim into each
   * function taking a descriptor, so we need to use a preprocessor
   * macro to avoid endless duplication. If the desc is NULL it is an
   * optional GPIO and calls should just bail out.
   */
  static int validate_desc(const struct gpio_desc *desc, const char *func)
  {
  	if (!desc)
  		return 0;
  	if (IS_ERR(desc)) {
  		pr_warn("%s: invalid GPIO (errorpointer)\n", func);
  		return PTR_ERR(desc);
  	}
  	if (!desc->gdev) {
  		pr_warn("%s: invalid GPIO (no device)\n", func);
  		return -EINVAL;
  	}
  	if (!desc->gdev->chip) {
  		dev_warn(&desc->gdev->dev,
  			 "%s: backing chip is gone\n", func);
  		return 0;
  	}
  	return 1;
  }
  
  #define VALIDATE_DESC(desc) do { \
  	int __valid = validate_desc(desc, __func__); \
  	if (__valid <= 0) \
  		return __valid; \
  	} while (0)
  
  #define VALIDATE_DESC_VOID(desc) do { \
  	int __valid = validate_desc(desc, __func__); \
  	if (__valid <= 0) \
  		return; \
  	} while (0)
  
  int gpiod_request(struct gpio_desc *desc, const char *label)
  {
  	int ret = -EPROBE_DEFER;
  	struct gpio_device *gdev;
  
  	VALIDATE_DESC(desc);
  	gdev = desc->gdev;
  
  	if (try_module_get(gdev->owner)) {
  		ret = gpiod_request_commit(desc, label);
  		if (ret)
  			module_put(gdev->owner);
  		else
  			get_device(&gdev->dev);
  	}
  
  	if (ret)
  		gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
  
  	return ret;
  }
  
  static bool gpiod_free_commit(struct gpio_desc *desc)
  {
  	bool			ret = false;
  	unsigned long		flags;
  	struct gpio_chip	*gc;
  
  	might_sleep();
  
  	gpiod_unexport(desc);
  
  	spin_lock_irqsave(&gpio_lock, flags);
  
  	gc = desc->gdev->chip;
  	if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) {
  		if (gc->free) {
  			spin_unlock_irqrestore(&gpio_lock, flags);
  			might_sleep_if(gc->can_sleep);
  			gc->free(gc, gpio_chip_hwgpio(desc));
  			spin_lock_irqsave(&gpio_lock, flags);
  		}
  		kfree_const(desc->label);
  		desc_set_label(desc, NULL);
  		clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
  		clear_bit(FLAG_REQUESTED, &desc->flags);
  		clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
  		clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
  		clear_bit(FLAG_PULL_UP, &desc->flags);
  		clear_bit(FLAG_PULL_DOWN, &desc->flags);
  		clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
  		clear_bit(FLAG_EDGE_RISING, &desc->flags);
  		clear_bit(FLAG_EDGE_FALLING, &desc->flags);
  		clear_bit(FLAG_IS_HOGGED, &desc->flags);
  #ifdef CONFIG_OF_DYNAMIC
  		desc->hog = NULL;
  #endif
  #ifdef CONFIG_GPIO_CDEV
  		WRITE_ONCE(desc->debounce_period_us, 0);
  #endif
  		ret = true;
  	}
  
  	spin_unlock_irqrestore(&gpio_lock, flags);
  	blocking_notifier_call_chain(&desc->gdev->notifier,
  				     GPIOLINE_CHANGED_RELEASED, desc);
  
  	return ret;
  }
  
  void gpiod_free(struct gpio_desc *desc)
  {
  	if (desc && desc->gdev && gpiod_free_commit(desc)) {
  		module_put(desc->gdev->owner);
  		put_device(&desc->gdev->dev);
  	} else {
  		WARN_ON(extra_checks);
  	}
  }
  
  /**
   * gpiochip_is_requested - return string iff signal was requested
   * @gc: controller managing the signal
   * @offset: of signal within controller's 0..(ngpio - 1) range
   *
   * Returns NULL if the GPIO is not currently requested, else a string.
   * The string returned is the label passed to gpio_request(); if none has been
   * passed it is a meaningless, non-NULL constant.
   *
   * This function is for use by GPIO controller drivers.  The label can
   * help with diagnostics, and knowing that the signal is used as a GPIO
   * can help avoid accidentally multiplexing it to another controller.
   */
  const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
  {
  	struct gpio_desc *desc;
  
  	desc = gpiochip_get_desc(gc, offset);
  	if (IS_ERR(desc))
  		return NULL;
  
  	if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
  		return NULL;
  	return desc->label;
  }
  EXPORT_SYMBOL_GPL(gpiochip_is_requested);
  
  /**
   * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
   * @gc: GPIO chip
   * @hwnum: hardware number of the GPIO for which to request the descriptor
   * @label: label for the GPIO
   * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
   * specify things like line inversion semantics with the machine flags
   * such as GPIO_OUT_LOW
   * @dflags: descriptor request flags for this GPIO or 0 if default, this
   * can be used to specify consumer semantics such as open drain
   *
   * Function allows GPIO chip drivers to request and use their own GPIO
   * descriptors via gpiolib API. Difference to gpiod_request() is that this
   * function will not increase reference count of the GPIO chip module. This
   * allows the GPIO chip module to be unloaded as needed (we assume that the
   * GPIO chip driver handles freeing the GPIOs it has requested).
   *
   * Returns:
   * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
   * code on failure.
   */
  struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
  					    unsigned int hwnum,
  					    const char *label,
  					    enum gpio_lookup_flags lflags,
  					    enum gpiod_flags dflags)
  {
  	struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
  	int ret;
  
  	if (IS_ERR(desc)) {
  		chip_err(gc, "failed to get GPIO descriptor\n");
  		return desc;
  	}
  
  	ret = gpiod_request_commit(desc, label);
  	if (ret < 0)
  		return ERR_PTR(ret);
  
  	ret = gpiod_configure_flags(desc, label, lflags, dflags);
  	if (ret) {
  		chip_err(gc, "setup of own GPIO %s failed\n", label);
  		gpiod_free_commit(desc);
  		return ERR_PTR(ret);
  	}
  
  	return desc;
  }
  EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
  
  /**
   * gpiochip_free_own_desc - Free GPIO requested by the chip driver
   * @desc: GPIO descriptor to free
   *
   * Function frees the given GPIO requested previously with
   * gpiochip_request_own_desc().
   */
  void gpiochip_free_own_desc(struct gpio_desc *desc)
  {
  	if (desc)
  		gpiod_free_commit(desc);
  }
  EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
  
  /*
   * Drivers MUST set GPIO direction before making get/set calls.  In
   * some cases this is done in early boot, before IRQs are enabled.
   *
   * As a rule these aren't called more than once (except for drivers
   * using the open-drain emulation idiom) so these are natural places
   * to accumulate extra debugging checks.  Note that we can't (yet)
   * rely on gpio_request() having been called beforehand.
   */
  
  static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
  			      unsigned long config)
  {
  	if (!gc->set_config)
  		return -ENOTSUPP;
  
  	return gc->set_config(gc, offset, config);
  }
  
  static int gpio_set_config_with_argument(struct gpio_desc *desc,
  					 enum pin_config_param mode,
  					 u32 argument)
  {
  	struct gpio_chip *gc = desc->gdev->chip;
  	unsigned long config;
  
  	config = pinconf_to_config_packed(mode, argument);
  	return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
  }
  
  static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
  						  enum pin_config_param mode,
  						  u32 argument)
  {
  	struct device *dev = &desc->gdev->dev;
  	int gpio = gpio_chip_hwgpio(desc);
  	int ret;
  
  	ret = gpio_set_config_with_argument(desc, mode, argument);
  	if (ret != -ENOTSUPP)
  		return ret;
  
  	switch (mode) {
  	case PIN_CONFIG_PERSIST_STATE:
  		dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
  		break;
  	default:
  		break;
  	}
  
  	return 0;
  }
  
  static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
  {
  	return gpio_set_config_with_argument(desc, mode, 0);
  }
  
  static int gpio_set_bias(struct gpio_desc *desc)
  {
  	enum pin_config_param bias;
  	unsigned int arg;
  
  	if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
  		bias = PIN_CONFIG_BIAS_DISABLE;
  	else if (test_bit(FLAG_PULL_UP, &desc->flags))
  		bias = PIN_CONFIG_BIAS_PULL_UP;
  	else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
  		bias = PIN_CONFIG_BIAS_PULL_DOWN;
  	else
  		return 0;
  
  	switch (bias) {
  	case PIN_CONFIG_BIAS_PULL_DOWN:
  	case PIN_CONFIG_BIAS_PULL_UP:
  		arg = 1;
  		break;
  
  	default:
  		arg = 0;
  		break;
  	}
  
  	return gpio_set_config_with_argument_optional(desc, bias, arg);
  }
  
  /**
   * gpio_set_debounce_timeout() - Set debounce timeout
   * @desc:	GPIO descriptor to set the debounce timeout
   * @debounce:	Debounce timeout in microseconds
   *
   * The function calls the certain GPIO driver to set debounce timeout
   * in the hardware.
   *
   * Returns 0 on success, or negative error code otherwise.
   */
  int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
  {
  	return gpio_set_config_with_argument_optional(desc,
  						      PIN_CONFIG_INPUT_DEBOUNCE,
  						      debounce);
  }
  
  /**
   * gpiod_direction_input - set the GPIO direction to input
   * @desc:	GPIO to set to input
   *
   * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
   * be called safely on it.
   *
   * Return 0 in case of success, else an error code.
   */
  int gpiod_direction_input(struct gpio_desc *desc)
  {
  	struct gpio_chip	*gc;
  	int			ret = 0;
  
  	VALIDATE_DESC(desc);
  	gc = desc->gdev->chip;
  
  	/*
  	 * It is legal to have no .get() and .direction_input() specified if
  	 * the chip is output-only, but you can't specify .direction_input()
  	 * and not support the .get() operation, that doesn't make sense.
  	 */
  	if (!gc->get && gc->direction_input) {
  		gpiod_warn(desc,
  			   "%s: missing get() but have direction_input()\n",
  			   __func__);
  		return -EIO;
  	}
  
  	/*
  	 * If we have a .direction_input() callback, things are simple,
  	 * just call it. Else we are some input-only chip so try to check the
  	 * direction (if .get_direction() is supported) else we silently
  	 * assume we are in input mode after this.
  	 */
  	if (gc->direction_input) {
  		ret = gc->direction_input(gc, gpio_chip_hwgpio(desc));
  	} else if (gc->get_direction &&
  		  (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) {
  		gpiod_warn(desc,
  			   "%s: missing direction_input() operation and line is output\n",
  			   __func__);
  		return -EIO;
  	}
  	if (ret == 0) {
  		clear_bit(FLAG_IS_OUT, &desc->flags);
  		ret = gpio_set_bias(desc);
  	}
  
  	trace_gpio_direction(desc_to_gpio(desc), 1, ret);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(gpiod_direction_input);
  
  static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
  {
  	struct gpio_chip *gc = desc->gdev->chip;
  	int val = !!value;
  	int ret = 0;
  
  	/*
  	 * It's OK not to specify .direction_output() if the gpiochip is
  	 * output-only, but if there is then not even a .set() operation it
  	 * is pretty tricky to drive the output line.
  	 */
  	if (!gc->set && !gc->direction_output) {
  		gpiod_warn(desc,
  			   "%s: missing set() and direction_output() operations\n",
  			   __func__);
  		return -EIO;
  	}
  
  	if (gc->direction_output) {
  		ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
  	} else {
  		/* Check that we are in output mode if we can */
  		if (gc->get_direction &&
  		    gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
  			gpiod_warn(desc,
  				"%s: missing direction_output() operation\n",
  				__func__);
  			return -EIO;
  		}
  		/*
  		 * If we can't actively set the direction, we are some
  		 * output-only chip, so just drive the output as desired.
  		 */
  		gc->set(gc, gpio_chip_hwgpio(desc), val);
  	}
  
  	if (!ret)
  		set_bit(FLAG_IS_OUT, &desc->flags);
  	trace_gpio_value(desc_to_gpio(desc), 0, val);
  	trace_gpio_direction(desc_to_gpio(desc), 0, ret);
  	return ret;
  }
  
  /**
   * gpiod_direction_output_raw - set the GPIO direction to output
   * @desc:	GPIO to set to output
   * @value:	initial output value of the GPIO
   *
   * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
   * be called safely on it. The initial value of the output must be specified
   * as raw value on the physical line without regard for the ACTIVE_LOW status.
   *
   * Return 0 in case of success, else an error code.
   */
  int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
  {
  	VALIDATE_DESC(desc);
  	return gpiod_direction_output_raw_commit(desc, value);
  }
  EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
  
  /**
   * gpiod_direction_output - set the GPIO direction to output
   * @desc:	GPIO to set to output
   * @value:	initial output value of the GPIO
   *
   * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
   * be called safely on it. The initial value of the output must be specified
   * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
   * account.
   *
   * Return 0 in case of success, else an error code.
   */
  int gpiod_direction_output(struct gpio_desc *desc, int value)
  {
  	int ret;
  
  	VALIDATE_DESC(desc);
  	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
  		value = !value;
  	else
  		value = !!value;
  
  	/* GPIOs used for enabled IRQs shall not be set as output */
  	if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
  	    test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
  		gpiod_err(desc,
  			  "%s: tried to set a GPIO tied to an IRQ as output\n",
  			  __func__);
  		return -EIO;
  	}
  
  	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
  		/* First see if we can enable open drain in hardware */
  		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
  		if (!ret)
  			goto set_output_value;
  		/* Emulate open drain by not actively driving the line high */
  		if (value) {
  			ret = gpiod_direction_input(desc);
  			goto set_output_flag;
  		}
  	}
  	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
  		ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
  		if (!ret)
  			goto set_output_value;
  		/* Emulate open source by not actively driving the line low */
  		if (!value) {
  			ret = gpiod_direction_input(desc);
  			goto set_output_flag;
  		}
  	} else {
  		gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
  	}
  
  set_output_value:
  	ret = gpio_set_bias(desc);
  	if (ret)
  		return ret;
  	return gpiod_direction_output_raw_commit(desc, value);
  
  set_output_flag:
  	/*
  	 * When emulating open-source or open-drain functionalities by not
  	 * actively driving the line (setting mode to input) we still need to
  	 * set the IS_OUT flag or otherwise we won't be able to set the line
  	 * value anymore.
  	 */
  	if (ret == 0)
  		set_bit(FLAG_IS_OUT, &desc->flags);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(gpiod_direction_output);
  
  /**
   * gpiod_set_config - sets @config for a GPIO
   * @desc: descriptor of the GPIO for which to set the configuration
   * @config: Same packed config format as generic pinconf
   *
   * Returns:
   * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
   * configuration.
   */
  int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
  {
  	struct gpio_chip *gc;
  
  	VALIDATE_DESC(desc);
  	gc = desc->gdev->chip;
  
  	return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_config);
  
  /**
   * gpiod_set_debounce - sets @debounce time for a GPIO
   * @desc: descriptor of the GPIO for which to set debounce time
   * @debounce: debounce time in microseconds
   *
   * Returns:
   * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
   * debounce time.
   */
  int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
  {
  	unsigned long config;
  
  	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
  	return gpiod_set_config(desc, config);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_debounce);
  
  /**
   * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
   * @desc: descriptor of the GPIO for which to configure persistence
   * @transitory: True to lose state on suspend or reset, false for persistence
   *
   * Returns:
   * 0 on success, otherwise a negative error code.
   */
  int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
  {
  	VALIDATE_DESC(desc);
  	/*
  	 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
  	 * persistence state.
  	 */
  	assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
  
  	/* If the driver supports it, set the persistence state now */
  	return gpio_set_config_with_argument_optional(desc,
  						      PIN_CONFIG_PERSIST_STATE,
  						      !transitory);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_transitory);
  
  /**
   * gpiod_is_active_low - test whether a GPIO is active-low or not
   * @desc: the gpio descriptor to test
   *
   * Returns 1 if the GPIO is active-low, 0 otherwise.
   */
  int gpiod_is_active_low(const struct gpio_desc *desc)
  {
  	VALIDATE_DESC(desc);
  	return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
  }
  EXPORT_SYMBOL_GPL(gpiod_is_active_low);
  
  /**
   * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
   * @desc: the gpio descriptor to change
   */
  void gpiod_toggle_active_low(struct gpio_desc *desc)
  {
  	VALIDATE_DESC_VOID(desc);
  	change_bit(FLAG_ACTIVE_LOW, &desc->flags);
  }
  EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
  
  /* I/O calls are only valid after configuration completed; the relevant
   * "is this a valid GPIO" error checks should already have been done.
   *
   * "Get" operations are often inlinable as reading a pin value register,
   * and masking the relevant bit in that register.
   *
   * When "set" operations are inlinable, they involve writing that mask to
   * one register to set a low value, or a different register to set it high.
   * Otherwise locking is needed, so there may be little value to inlining.
   *
   *------------------------------------------------------------------------
   *
   * IMPORTANT!!!  The hot paths -- get/set value -- assume that callers
   * have requested the GPIO.  That can include implicit requesting by
   * a direction setting call.  Marking a gpio as requested locks its chip
   * in memory, guaranteeing that these table lookups need no more locking
   * and that gpiochip_remove() will fail.
   *
   * REVISIT when debugging, consider adding some instrumentation to ensure
   * that the GPIO was actually requested.
   */
  
  static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
  {
  	struct gpio_chip	*gc;
  	int offset;
  	int value;
  
  	gc = desc->gdev->chip;
  	offset = gpio_chip_hwgpio(desc);
  	value = gc->get ? gc->get(gc, offset) : -EIO;
  	value = value < 0 ? value : !!value;
  	trace_gpio_value(desc_to_gpio(desc), 1, value);
  	return value;
  }
  
  static int gpio_chip_get_multiple(struct gpio_chip *gc,
  				  unsigned long *mask, unsigned long *bits)
  {
  	if (gc->get_multiple) {
  		return gc->get_multiple(gc, mask, bits);
  	} else if (gc->get) {
  		int i, value;
  
  		for_each_set_bit(i, mask, gc->ngpio) {
  			value = gc->get(gc, i);
  			if (value < 0)
  				return value;
  			__assign_bit(i, bits, value);
  		}
  		return 0;
  	}
  	return -EIO;
  }
  
  int gpiod_get_array_value_complex(bool raw, bool can_sleep,
  				  unsigned int array_size,
  				  struct gpio_desc **desc_array,
  				  struct gpio_array *array_info,
  				  unsigned long *value_bitmap)
  {
  	int ret, i = 0;
  
  	/*
  	 * Validate array_info against desc_array and its size.
  	 * It should immediately follow desc_array if both
  	 * have been obtained from the same gpiod_get_array() call.
  	 */
  	if (array_info && array_info->desc == desc_array &&
  	    array_size <= array_info->size &&
  	    (void *)array_info == desc_array + array_info->size) {
  		if (!can_sleep)
  			WARN_ON(array_info->chip->can_sleep);
  
  		ret = gpio_chip_get_multiple(array_info->chip,
  					     array_info->get_mask,
  					     value_bitmap);
  		if (ret)
  			return ret;
  
  		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
  			bitmap_xor(value_bitmap, value_bitmap,
  				   array_info->invert_mask, array_size);
  
  		i = find_first_zero_bit(array_info->get_mask, array_size);
  		if (i == array_size)
  			return 0;
  	} else {
  		array_info = NULL;
  	}
  
  	while (i < array_size) {
  		struct gpio_chip *gc = desc_array[i]->gdev->chip;
  		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
  		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
  		unsigned long *mask, *bits;
  		int first, j;
  
  		if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
  			mask = fastpath_mask;
  			bits = fastpath_bits;
  		} else {
  			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
  
  			mask = bitmap_alloc(gc->ngpio, flags);
  			if (!mask)
  				return -ENOMEM;
  
  			bits = bitmap_alloc(gc->ngpio, flags);
  			if (!bits) {
  				bitmap_free(mask);
  				return -ENOMEM;
  			}
  		}
  
  		bitmap_zero(mask, gc->ngpio);
  
  		if (!can_sleep)
  			WARN_ON(gc->can_sleep);
  
  		/* collect all inputs belonging to the same chip */
  		first = i;
  		do {
  			const struct gpio_desc *desc = desc_array[i];
  			int hwgpio = gpio_chip_hwgpio(desc);
  
  			__set_bit(hwgpio, mask);
  			i++;
  
  			if (array_info)
  				i = find_next_zero_bit(array_info->get_mask,
  						       array_size, i);
  		} while ((i < array_size) &&
  			 (desc_array[i]->gdev->chip == gc));
  
  		ret = gpio_chip_get_multiple(gc, mask, bits);
  		if (ret) {
  			if (mask != fastpath_mask)
  				bitmap_free(mask);
  			if (bits != fastpath_bits)
  				bitmap_free(bits);
  			return ret;
  		}
  
  		for (j = first; j < i; ) {
  			const struct gpio_desc *desc = desc_array[j];
  			int hwgpio = gpio_chip_hwgpio(desc);
  			int value = test_bit(hwgpio, bits);
  
  			if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
  				value = !value;
  			__assign_bit(j, value_bitmap, value);
  			trace_gpio_value(desc_to_gpio(desc), 1, value);
  			j++;
  
  			if (array_info)
  				j = find_next_zero_bit(array_info->get_mask, i,
  						       j);
  		}
  
  		if (mask != fastpath_mask)
  			bitmap_free(mask);
  		if (bits != fastpath_bits)
  			bitmap_free(bits);
  	}
  	return 0;
  }
  
  /**
   * gpiod_get_raw_value() - return a gpio's raw value
   * @desc: gpio whose value will be returned
   *
   * Return the GPIO's raw value, i.e. the value of the physical line disregarding
   * its ACTIVE_LOW status, or negative errno on failure.
   *
   * This function can be called from contexts where we cannot sleep, and will
   * complain if the GPIO chip functions potentially sleep.
   */
  int gpiod_get_raw_value(const struct gpio_desc *desc)
  {
  	VALIDATE_DESC(desc);
  	/* Should be using gpiod_get_raw_value_cansleep() */
  	WARN_ON(desc->gdev->chip->can_sleep);
  	return gpiod_get_raw_value_commit(desc);
  }
  EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
  
  /**
   * gpiod_get_value() - return a gpio's value
   * @desc: gpio whose value will be returned
   *
   * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
   * account, or negative errno on failure.
   *
   * This function can be called from contexts where we cannot sleep, and will
   * complain if the GPIO chip functions potentially sleep.
   */
  int gpiod_get_value(const struct gpio_desc *desc)
  {
  	int value;
  
  	VALIDATE_DESC(desc);
  	/* Should be using gpiod_get_value_cansleep() */
  	WARN_ON(desc->gdev->chip->can_sleep);
  
  	value = gpiod_get_raw_value_commit(desc);
  	if (value < 0)
  		return value;
  
  	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
  		value = !value;
  
  	return value;
  }
  EXPORT_SYMBOL_GPL(gpiod_get_value);
  
  /**
   * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be read
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap to store the read values
   *
   * Read the raw values of the GPIOs, i.e. the values of the physical lines
   * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
   * else an error code.
   *
   * This function can be called from contexts where we cannot sleep,
   * and it will complain if the GPIO chip functions potentially sleep.
   */
  int gpiod_get_raw_array_value(unsigned int array_size,
  			      struct gpio_desc **desc_array,
  			      struct gpio_array *array_info,
  			      unsigned long *value_bitmap)
  {
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_get_array_value_complex(true, false, array_size,
  					     desc_array, array_info,
  					     value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
  
  /**
   * gpiod_get_array_value() - read values from an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be read
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap to store the read values
   *
   * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
   * into account.  Return 0 in case of success, else an error code.
   *
   * This function can be called from contexts where we cannot sleep,
   * and it will complain if the GPIO chip functions potentially sleep.
   */
  int gpiod_get_array_value(unsigned int array_size,
  			  struct gpio_desc **desc_array,
  			  struct gpio_array *array_info,
  			  unsigned long *value_bitmap)
  {
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_get_array_value_complex(false, false, array_size,
  					     desc_array, array_info,
  					     value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_get_array_value);
  
  /*
   *  gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
   * @desc: gpio descriptor whose state need to be set.
   * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
   */
  static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
  {
  	int ret = 0;
  	struct gpio_chip *gc = desc->gdev->chip;
  	int offset = gpio_chip_hwgpio(desc);
  
  	if (value) {
  		ret = gc->direction_input(gc, offset);
  	} else {
  		ret = gc->direction_output(gc, offset, 0);
  		if (!ret)
  			set_bit(FLAG_IS_OUT, &desc->flags);
  	}
  	trace_gpio_direction(desc_to_gpio(desc), value, ret);
  	if (ret < 0)
  		gpiod_err(desc,
  			  "%s: Error in set_value for open drain err %d\n",
  			  __func__, ret);
  }
  
  /*
   *  _gpio_set_open_source_value() - Set the open source gpio's value.
   * @desc: gpio descriptor whose state need to be set.
   * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
   */
  static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
  {
  	int ret = 0;
  	struct gpio_chip *gc = desc->gdev->chip;
  	int offset = gpio_chip_hwgpio(desc);
  
  	if (value) {
  		ret = gc->direction_output(gc, offset, 1);
  		if (!ret)
  			set_bit(FLAG_IS_OUT, &desc->flags);
  	} else {
  		ret = gc->direction_input(gc, offset);
  	}
  	trace_gpio_direction(desc_to_gpio(desc), !value, ret);
  	if (ret < 0)
  		gpiod_err(desc,
  			  "%s: Error in set_value for open source err %d\n",
  			  __func__, ret);
  }
  
  static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
  {
  	struct gpio_chip	*gc;
  
  	gc = desc->gdev->chip;
  	trace_gpio_value(desc_to_gpio(desc), 0, value);
  	gc->set(gc, gpio_chip_hwgpio(desc), value);
  }
  
  /*
   * set multiple outputs on the same chip;
   * use the chip's set_multiple function if available;
   * otherwise set the outputs sequentially;
   * @chip: the GPIO chip we operate on
   * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
   *        defines which outputs are to be changed
   * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
   *        defines the values the outputs specified by mask are to be set to
   */
  static void gpio_chip_set_multiple(struct gpio_chip *gc,
  				   unsigned long *mask, unsigned long *bits)
  {
  	if (gc->set_multiple) {
  		gc->set_multiple(gc, mask, bits);
  	} else {
  		unsigned int i;
  
  		/* set outputs if the corresponding mask bit is set */
  		for_each_set_bit(i, mask, gc->ngpio)
  			gc->set(gc, i, test_bit(i, bits));
  	}
  }
  
  int gpiod_set_array_value_complex(bool raw, bool can_sleep,
  				  unsigned int array_size,
  				  struct gpio_desc **desc_array,
  				  struct gpio_array *array_info,
  				  unsigned long *value_bitmap)
  {
  	int i = 0;
  
  	/*
  	 * Validate array_info against desc_array and its size.
  	 * It should immediately follow desc_array if both
  	 * have been obtained from the same gpiod_get_array() call.
  	 */
  	if (array_info && array_info->desc == desc_array &&
  	    array_size <= array_info->size &&
  	    (void *)array_info == desc_array + array_info->size) {
  		if (!can_sleep)
  			WARN_ON(array_info->chip->can_sleep);
  
  		if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
  			bitmap_xor(value_bitmap, value_bitmap,
  				   array_info->invert_mask, array_size);
  
  		gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
  				       value_bitmap);
  
  		i = find_first_zero_bit(array_info->set_mask, array_size);
  		if (i == array_size)
  			return 0;
  	} else {
  		array_info = NULL;
  	}
  
  	while (i < array_size) {
  		struct gpio_chip *gc = desc_array[i]->gdev->chip;
  		DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
  		DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
  		unsigned long *mask, *bits;
  		int count = 0;
  
  		if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
  			mask = fastpath_mask;
  			bits = fastpath_bits;
  		} else {
  			gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
  
  			mask = bitmap_alloc(gc->ngpio, flags);
  			if (!mask)
  				return -ENOMEM;
  
  			bits = bitmap_alloc(gc->ngpio, flags);
  			if (!bits) {
  				bitmap_free(mask);
  				return -ENOMEM;
  			}
  		}
  
  		bitmap_zero(mask, gc->ngpio);
  
  		if (!can_sleep)
  			WARN_ON(gc->can_sleep);
  
  		do {
  			struct gpio_desc *desc = desc_array[i];
  			int hwgpio = gpio_chip_hwgpio(desc);
  			int value = test_bit(i, value_bitmap);
  
  			/*
  			 * Pins applicable for fast input but not for
  			 * fast output processing may have been already
  			 * inverted inside the fast path, skip them.
  			 */
  			if (!raw && !(array_info &&
  			    test_bit(i, array_info->invert_mask)) &&
  			    test_bit(FLAG_ACTIVE_LOW, &desc->flags))
  				value = !value;
  			trace_gpio_value(desc_to_gpio(desc), 0, value);
  			/*
  			 * collect all normal outputs belonging to the same chip
  			 * open drain and open source outputs are set individually
  			 */
  			if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
  				gpio_set_open_drain_value_commit(desc, value);
  			} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
  				gpio_set_open_source_value_commit(desc, value);
  			} else {
  				__set_bit(hwgpio, mask);
  				__assign_bit(hwgpio, bits, value);
  				count++;
  			}
  			i++;
  
  			if (array_info)
  				i = find_next_zero_bit(array_info->set_mask,
  						       array_size, i);
  		} while ((i < array_size) &&
  			 (desc_array[i]->gdev->chip == gc));
  		/* push collected bits to outputs */
  		if (count != 0)
  			gpio_chip_set_multiple(gc, mask, bits);
  
  		if (mask != fastpath_mask)
  			bitmap_free(mask);
  		if (bits != fastpath_bits)
  			bitmap_free(bits);
  	}
  	return 0;
  }
  
  /**
   * gpiod_set_raw_value() - assign a gpio's raw value
   * @desc: gpio whose value will be assigned
   * @value: value to assign
   *
   * Set the raw value of the GPIO, i.e. the value of its physical line without
   * regard for its ACTIVE_LOW status.
   *
   * This function can be called from contexts where we cannot sleep, and will
   * complain if the GPIO chip functions potentially sleep.
   */
  void gpiod_set_raw_value(struct gpio_desc *desc, int value)
  {
  	VALIDATE_DESC_VOID(desc);
  	/* Should be using gpiod_set_raw_value_cansleep() */
  	WARN_ON(desc->gdev->chip->can_sleep);
  	gpiod_set_raw_value_commit(desc, value);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
  
  /**
   * gpiod_set_value_nocheck() - set a GPIO line value without checking
   * @desc: the descriptor to set the value on
   * @value: value to set
   *
   * This sets the value of a GPIO line backing a descriptor, applying
   * different semantic quirks like active low and open drain/source
   * handling.
   */
  static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
  {
  	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
  		value = !value;
  	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
  		gpio_set_open_drain_value_commit(desc, value);
  	else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
  		gpio_set_open_source_value_commit(desc, value);
  	else
  		gpiod_set_raw_value_commit(desc, value);
  }
  
  /**
   * gpiod_set_value() - assign a gpio's value
   * @desc: gpio whose value will be assigned
   * @value: value to assign
   *
   * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
   * OPEN_DRAIN and OPEN_SOURCE flags into account.
   *
   * This function can be called from contexts where we cannot sleep, and will
   * complain if the GPIO chip functions potentially sleep.
   */
  void gpiod_set_value(struct gpio_desc *desc, int value)
  {
  	VALIDATE_DESC_VOID(desc);
  	/* Should be using gpiod_set_value_cansleep() */
  	WARN_ON(desc->gdev->chip->can_sleep);
  	gpiod_set_value_nocheck(desc, value);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_value);
  
  /**
   * gpiod_set_raw_array_value() - assign values to an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be assigned
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap of values to assign
   *
   * Set the raw values of the GPIOs, i.e. the values of the physical lines
   * without regard for their ACTIVE_LOW status.
   *
   * This function can be called from contexts where we cannot sleep, and will
   * complain if the GPIO chip functions potentially sleep.
   */
  int gpiod_set_raw_array_value(unsigned int array_size,
  			      struct gpio_desc **desc_array,
  			      struct gpio_array *array_info,
  			      unsigned long *value_bitmap)
  {
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_set_array_value_complex(true, false, array_size,
  					desc_array, array_info, value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
  
  /**
   * gpiod_set_array_value() - assign values to an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be assigned
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap of values to assign
   *
   * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
   * into account.
   *
   * This function can be called from contexts where we cannot sleep, and will
   * complain if the GPIO chip functions potentially sleep.
   */
  int gpiod_set_array_value(unsigned int array_size,
  			  struct gpio_desc **desc_array,
  			  struct gpio_array *array_info,
  			  unsigned long *value_bitmap)
  {
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_set_array_value_complex(false, false, array_size,
  					     desc_array, array_info,
  					     value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_array_value);
  
  /**
   * gpiod_cansleep() - report whether gpio value access may sleep
   * @desc: gpio to check
   *
   */
  int gpiod_cansleep(const struct gpio_desc *desc)
  {
  	VALIDATE_DESC(desc);
  	return desc->gdev->chip->can_sleep;
  }
  EXPORT_SYMBOL_GPL(gpiod_cansleep);
  
  /**
   * gpiod_set_consumer_name() - set the consumer name for the descriptor
   * @desc: gpio to set the consumer name on
   * @name: the new consumer name
   */
  int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
  {
  	VALIDATE_DESC(desc);
  	if (name) {
  		name = kstrdup_const(name, GFP_KERNEL);
  		if (!name)
  			return -ENOMEM;
  	}
  
  	kfree_const(desc->label);
  	desc_set_label(desc, name);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
  
  /**
   * gpiod_to_irq() - return the IRQ corresponding to a GPIO
   * @desc: gpio whose IRQ will be returned (already requested)
   *
   * Return the IRQ corresponding to the passed GPIO, or an error code in case of
   * error.
   */
  int gpiod_to_irq(const struct gpio_desc *desc)
  {
  	struct gpio_chip *gc;
  	int offset;
  
  	/*
  	 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
  	 * requires this function to not return zero on an invalid descriptor
  	 * but rather a negative error number.
  	 */
  	if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
  		return -EINVAL;
  
  	gc = desc->gdev->chip;
  	offset = gpio_chip_hwgpio(desc);
  	if (gc->to_irq) {
  		int retirq = gc->to_irq(gc, offset);
  
  		/* Zero means NO_IRQ */
  		if (!retirq)
  			return -ENXIO;
  
  		return retirq;
  	}
  #ifdef CONFIG_GPIOLIB_IRQCHIP
  	if (gc->irq.chip) {
  		/*
  		 * Avoid race condition with other code, which tries to lookup
  		 * an IRQ before the irqchip has been properly registered,
  		 * i.e. while gpiochip is still being brought up.
  		 */
  		return -EPROBE_DEFER;
  	}
  #endif
  	return -ENXIO;
  }
  EXPORT_SYMBOL_GPL(gpiod_to_irq);
  
  /**
   * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
   * @gc: the chip the GPIO to lock belongs to
   * @offset: the offset of the GPIO to lock as IRQ
   *
   * This is used directly by GPIO drivers that want to lock down
   * a certain GPIO line to be used for IRQs.
   */
  int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	struct gpio_desc *desc;
  
  	desc = gpiochip_get_desc(gc, offset);
  	if (IS_ERR(desc))
  		return PTR_ERR(desc);
  
  	/*
  	 * If it's fast: flush the direction setting if something changed
  	 * behind our back
  	 */
  	if (!gc->can_sleep && gc->get_direction) {
  		int dir = gpiod_get_direction(desc);
  
  		if (dir < 0) {
  			chip_err(gc, "%s: cannot get GPIO direction\n",
  				 __func__);
  			return dir;
  		}
  	}
  
  	/* To be valid for IRQ the line needs to be input or open drain */
  	if (test_bit(FLAG_IS_OUT, &desc->flags) &&
  	    !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
  		chip_err(gc,
  			 "%s: tried to flag a GPIO set as output for IRQ\n",
  			 __func__);
  		return -EIO;
  	}
  
  	set_bit(FLAG_USED_AS_IRQ, &desc->flags);
  	set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
  
  	/*
  	 * If the consumer has not set up a label (such as when the
  	 * IRQ is referenced from .to_irq()) we set up a label here
  	 * so it is clear this is used as an interrupt.
  	 */
  	if (!desc->label)
  		desc_set_label(desc, "interrupt");
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
  
  /**
   * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
   * @gc: the chip the GPIO to lock belongs to
   * @offset: the offset of the GPIO to lock as IRQ
   *
   * This is used directly by GPIO drivers that want to indicate
   * that a certain GPIO is no longer used exclusively for IRQ.
   */
  void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	struct gpio_desc *desc;
  
  	desc = gpiochip_get_desc(gc, offset);
  	if (IS_ERR(desc))
  		return;
  
  	clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
  	clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
  
  	/* If we only had this marking, erase it */
  	if (desc->label && !strcmp(desc->label, "interrupt"))
  		desc_set_label(desc, NULL);
  }
  EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
  
  void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
  
  	if (!IS_ERR(desc) &&
  	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
  		clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
  }
  EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
  
  void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
  
  	if (!IS_ERR(desc) &&
  	    !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
  		/*
  		 * We must not be output when using IRQ UNLESS we are
  		 * open drain.
  		 */
  		WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
  			!test_bit(FLAG_OPEN_DRAIN, &desc->flags));
  		set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
  	}
  }
  EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
  
  bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	if (offset >= gc->ngpio)
  		return false;
  
  	return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
  }
  EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
  
  int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	int ret;
  
  	if (!try_module_get(gc->gpiodev->owner))
  		return -ENODEV;
  
  	ret = gpiochip_lock_as_irq(gc, offset);
  	if (ret) {
  		chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
  		module_put(gc->gpiodev->owner);
  		return ret;
  	}
  	return 0;
  }
  EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
  
  void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
  {
  	gpiochip_unlock_as_irq(gc, offset);
  	module_put(gc->gpiodev->owner);
  }
  EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
  
  bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
  {
  	if (offset >= gc->ngpio)
  		return false;
  
  	return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
  }
  EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
  
  bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
  {
  	if (offset >= gc->ngpio)
  		return false;
  
  	return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
  }
  EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
  
  bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
  {
  	if (offset >= gc->ngpio)
  		return false;
  
  	return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
  }
  EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
  
  /**
   * gpiod_get_raw_value_cansleep() - return a gpio's raw value
   * @desc: gpio whose value will be returned
   *
   * Return the GPIO's raw value, i.e. the value of the physical line disregarding
   * its ACTIVE_LOW status, or negative errno on failure.
   *
   * This function is to be called from contexts that can sleep.
   */
  int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
  {
  	might_sleep_if(extra_checks);
  	VALIDATE_DESC(desc);
  	return gpiod_get_raw_value_commit(desc);
  }
  EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
  
  /**
   * gpiod_get_value_cansleep() - return a gpio's value
   * @desc: gpio whose value will be returned
   *
   * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
   * account, or negative errno on failure.
   *
   * This function is to be called from contexts that can sleep.
   */
  int gpiod_get_value_cansleep(const struct gpio_desc *desc)
  {
  	int value;
  
  	might_sleep_if(extra_checks);
  	VALIDATE_DESC(desc);
  	value = gpiod_get_raw_value_commit(desc);
  	if (value < 0)
  		return value;
  
  	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
  		value = !value;
  
  	return value;
  }
  EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
  
  /**
   * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be read
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap to store the read values
   *
   * Read the raw values of the GPIOs, i.e. the values of the physical lines
   * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
   * else an error code.
   *
   * This function is to be called from contexts that can sleep.
   */
  int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
  				       struct gpio_desc **desc_array,
  				       struct gpio_array *array_info,
  				       unsigned long *value_bitmap)
  {
  	might_sleep_if(extra_checks);
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_get_array_value_complex(true, true, array_size,
  					     desc_array, array_info,
  					     value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
  
  /**
   * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be read
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap to store the read values
   *
   * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
   * into account.  Return 0 in case of success, else an error code.
   *
   * This function is to be called from contexts that can sleep.
   */
  int gpiod_get_array_value_cansleep(unsigned int array_size,
  				   struct gpio_desc **desc_array,
  				   struct gpio_array *array_info,
  				   unsigned long *value_bitmap)
  {
  	might_sleep_if(extra_checks);
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_get_array_value_complex(false, true, array_size,
  					     desc_array, array_info,
  					     value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
  
  /**
   * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
   * @desc: gpio whose value will be assigned
   * @value: value to assign
   *
   * Set the raw value of the GPIO, i.e. the value of its physical line without
   * regard for its ACTIVE_LOW status.
   *
   * This function is to be called from contexts that can sleep.
   */
  void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
  {
  	might_sleep_if(extra_checks);
  	VALIDATE_DESC_VOID(desc);
  	gpiod_set_raw_value_commit(desc, value);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
  
  /**
   * gpiod_set_value_cansleep() - assign a gpio's value
   * @desc: gpio whose value will be assigned
   * @value: value to assign
   *
   * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
   * account
   *
   * This function is to be called from contexts that can sleep.
   */
  void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
  {
  	might_sleep_if(extra_checks);
  	VALIDATE_DESC_VOID(desc);
  	gpiod_set_value_nocheck(desc, value);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
  
  /**
   * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be assigned
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap of values to assign
   *
   * Set the raw values of the GPIOs, i.e. the values of the physical lines
   * without regard for their ACTIVE_LOW status.
   *
   * This function is to be called from contexts that can sleep.
   */
  int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
  				       struct gpio_desc **desc_array,
  				       struct gpio_array *array_info,
  				       unsigned long *value_bitmap)
  {
  	might_sleep_if(extra_checks);
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_set_array_value_complex(true, true, array_size, desc_array,
  				      array_info, value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
  
  /**
   * gpiod_add_lookup_tables() - register GPIO device consumers
   * @tables: list of tables of consumers to register
   * @n: number of tables in the list
   */
  void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
  {
  	unsigned int i;
  
  	mutex_lock(&gpio_lookup_lock);
  
  	for (i = 0; i < n; i++)
  		list_add_tail(&tables[i]->list, &gpio_lookup_list);
  
  	mutex_unlock(&gpio_lookup_lock);
  }
  
  /**
   * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
   * @array_size: number of elements in the descriptor array / value bitmap
   * @desc_array: array of GPIO descriptors whose values will be assigned
   * @array_info: information on applicability of fast bitmap processing path
   * @value_bitmap: bitmap of values to assign
   *
   * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
   * into account.
   *
   * This function is to be called from contexts that can sleep.
   */
  int gpiod_set_array_value_cansleep(unsigned int array_size,
  				   struct gpio_desc **desc_array,
  				   struct gpio_array *array_info,
  				   unsigned long *value_bitmap)
  {
  	might_sleep_if(extra_checks);
  	if (!desc_array)
  		return -EINVAL;
  	return gpiod_set_array_value_complex(false, true, array_size,
  					     desc_array, array_info,
  					     value_bitmap);
  }
  EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
  
  /**
   * gpiod_add_lookup_table() - register GPIO device consumers
   * @table: table of consumers to register
   */
  void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
  {
  	gpiod_add_lookup_tables(&table, 1);
  }
  EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
  
  /**
   * gpiod_remove_lookup_table() - unregister GPIO device consumers
   * @table: table of consumers to unregister
   */
  void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
  {
  	/* Nothing to remove */
  	if (!table)
  		return;
  
  	mutex_lock(&gpio_lookup_lock);
  
  	list_del(&table->list);
  
  	mutex_unlock(&gpio_lookup_lock);
  }
  EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
  
  /**
   * gpiod_add_hogs() - register a set of GPIO hogs from machine code
   * @hogs: table of gpio hog entries with a zeroed sentinel at the end
   */
  void gpiod_add_hogs(struct gpiod_hog *hogs)
  {
  	struct gpio_chip *gc;
  	struct gpiod_hog *hog;
  
  	mutex_lock(&gpio_machine_hogs_mutex);
  
  	for (hog = &hogs[0]; hog->chip_label; hog++) {
  		list_add_tail(&hog->list, &gpio_machine_hogs);
  
  		/*
  		 * The chip may have been registered earlier, so check if it
  		 * exists and, if so, try to hog the line now.
  		 */
  		gc = find_chip_by_name(hog->chip_label);
  		if (gc)
  			gpiochip_machine_hog(gc, hog);
  	}
  
  	mutex_unlock(&gpio_machine_hogs_mutex);
  }
  EXPORT_SYMBOL_GPL(gpiod_add_hogs);
  
  void gpiod_remove_hogs(struct gpiod_hog *hogs)
  {
  	struct gpiod_hog *hog;
  
  	mutex_lock(&gpio_machine_hogs_mutex);
  	for (hog = &hogs[0]; hog->chip_label; hog++)
  		list_del(&hog->list);
  	mutex_unlock(&gpio_machine_hogs_mutex);
  }
  EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
  
  static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
  {
  	const char *dev_id = dev ? dev_name(dev) : NULL;
  	struct gpiod_lookup_table *table;
  
  	mutex_lock(&gpio_lookup_lock);
  
  	list_for_each_entry(table, &gpio_lookup_list, list) {
  		if (table->dev_id && dev_id) {
  			/*
  			 * Valid strings on both ends, must be identical to have
  			 * a match
  			 */
  			if (!strcmp(table->dev_id, dev_id))
  				goto found;
  		} else {
  			/*
  			 * One of the pointers is NULL, so both must be to have
  			 * a match
  			 */
  			if (dev_id == table->dev_id)
  				goto found;
  		}
  	}
  	table = NULL;
  
  found:
  	mutex_unlock(&gpio_lookup_lock);
  	return table;
  }
  
  static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
  				    unsigned int idx, unsigned long *flags)
  {
  	struct gpio_desc *desc = ERR_PTR(-ENOENT);
  	struct gpiod_lookup_table *table;
  	struct gpiod_lookup *p;
  
  	table = gpiod_find_lookup_table(dev);
  	if (!table)
  		return desc;
  
  	for (p = &table->table[0]; p->key; p++) {
  		struct gpio_chip *gc;
  
  		/* idx must always match exactly */
  		if (p->idx != idx)
  			continue;
  
  		/* If the lookup entry has a con_id, require exact match */
  		if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
  			continue;
  
  		if (p->chip_hwnum == U16_MAX) {
  			desc = gpio_name_to_desc(p->key);
  			if (desc) {
  				*flags = p->flags;
  				return desc;
  			}
  
  			dev_warn(dev, "cannot find GPIO line %s, deferring\n",
  				 p->key);
  			return ERR_PTR(-EPROBE_DEFER);
  		}
  
  		gc = find_chip_by_name(p->key);
  
  		if (!gc) {
  			/*
  			 * As the lookup table indicates a chip with
  			 * p->key should exist, assume it may
  			 * still appear later and let the interested
  			 * consumer be probed again or let the Deferred
  			 * Probe infrastructure handle the error.
  			 */
  			dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
  				 p->key);
  			return ERR_PTR(-EPROBE_DEFER);
  		}
  
  		if (gc->ngpio <= p->chip_hwnum) {
  			dev_err(dev,
  				"requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
  				idx, p->chip_hwnum, gc->ngpio - 1,
  				gc->label);
  			return ERR_PTR(-EINVAL);
  		}
  
  		desc = gpiochip_get_desc(gc, p->chip_hwnum);
  		*flags = p->flags;
  
  		return desc;
  	}
  
  	return desc;
  }
  
  static int platform_gpio_count(struct device *dev, const char *con_id)
  {
  	struct gpiod_lookup_table *table;
  	struct gpiod_lookup *p;
  	unsigned int count = 0;
  
  	table = gpiod_find_lookup_table(dev);
  	if (!table)
  		return -ENOENT;
  
  	for (p = &table->table[0]; p->key; p++) {
  		if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
  		    (!con_id && !p->con_id))
  			count++;
  	}
  	if (!count)
  		return -ENOENT;
  
  	return count;
  }
  
  /**
   * fwnode_gpiod_get_index - obtain a GPIO from firmware node
   * @fwnode:	handle of the firmware node
   * @con_id:	function within the GPIO consumer
   * @index:	index of the GPIO to obtain for the consumer
   * @flags:	GPIO initialization flags
   * @label:	label to attach to the requested GPIO
   *
   * This function can be used for drivers that get their configuration
   * from opaque firmware.
   *
   * The function properly finds the corresponding GPIO using whatever is the
   * underlying firmware interface and then makes sure that the GPIO
   * descriptor is requested before it is returned to the caller.
   *
   * Returns:
   * On successful request the GPIO pin is configured in accordance with
   * provided @flags.
   *
   * In case of error an ERR_PTR() is returned.
   */
  struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
  					 const char *con_id, int index,
  					 enum gpiod_flags flags,
  					 const char *label)
  {
  	struct gpio_desc *desc;
  	char prop_name[32]; /* 32 is max size of property name */
  	unsigned int i;
  
  	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
  		if (con_id)
  			snprintf(prop_name, sizeof(prop_name), "%s-%s",
  					    con_id, gpio_suffixes[i]);
  		else
  			snprintf(prop_name, sizeof(prop_name), "%s",
  					    gpio_suffixes[i]);
  
  		desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
  					      label);
  		if (!gpiod_not_found(desc))
  			break;
  	}
  
  	return desc;
  }
  EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
  
  /**
   * gpiod_count - return the number of GPIOs associated with a device / function
   *		or -ENOENT if no GPIO has been assigned to the requested function
   * @dev:	GPIO consumer, can be NULL for system-global GPIOs
   * @con_id:	function within the GPIO consumer
   */
  int gpiod_count(struct device *dev, const char *con_id)
  {
  	const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
  	int count = -ENOENT;
  
  	if (is_of_node(fwnode))
  		count = of_gpio_get_count(dev, con_id);
  	else if (is_acpi_node(fwnode))
  		count = acpi_gpio_count(dev, con_id);
  
  	if (count < 0)
  		count = platform_gpio_count(dev, con_id);
  
  	return count;
  }
  EXPORT_SYMBOL_GPL(gpiod_count);
  
  /**
   * gpiod_get - obtain a GPIO for a given GPIO function
   * @dev:	GPIO consumer, can be NULL for system-global GPIOs
   * @con_id:	function within the GPIO consumer
   * @flags:	optional GPIO initialization flags
   *
   * Return the GPIO descriptor corresponding to the function con_id of device
   * dev, -ENOENT if no GPIO has been assigned to the requested function, or
   * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
   */
  struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
  					 enum gpiod_flags flags)
  {
  	return gpiod_get_index(dev, con_id, 0, flags);
  }
  EXPORT_SYMBOL_GPL(gpiod_get);
  
  /**
   * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
   * @dev: GPIO consumer, can be NULL for system-global GPIOs
   * @con_id: function within the GPIO consumer
   * @flags: optional GPIO initialization flags
   *
   * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
   * the requested function it will return NULL. This is convenient for drivers
   * that need to handle optional GPIOs.
   */
  struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
  						  const char *con_id,
  						  enum gpiod_flags flags)
  {
  	return gpiod_get_index_optional(dev, con_id, 0, flags);
  }
  EXPORT_SYMBOL_GPL(gpiod_get_optional);
  
  
  /**
   * gpiod_configure_flags - helper function to configure a given GPIO
   * @desc:	gpio whose value will be assigned
   * @con_id:	function within the GPIO consumer
   * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
   *		of_find_gpio() or of_get_gpio_hog()
   * @dflags:	gpiod_flags - optional GPIO initialization flags
   *
   * Return 0 on success, -ENOENT if no GPIO has been assigned to the
   * requested function and/or index, or another IS_ERR() code if an error
   * occurred while trying to acquire the GPIO.
   */
  int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
  		unsigned long lflags, enum gpiod_flags dflags)
  {
  	int ret;
  
  	if (lflags & GPIO_ACTIVE_LOW)
  		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
  
  	if (lflags & GPIO_OPEN_DRAIN)
  		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
  	else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
  		/*
  		 * This enforces open drain mode from the consumer side.
  		 * This is necessary for some busses like I2C, but the lookup
  		 * should *REALLY* have specified them as open drain in the
  		 * first place, so print a little warning here.
  		 */
  		set_bit(FLAG_OPEN_DRAIN, &desc->flags);
  		gpiod_warn(desc,
  			   "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
  	}
  
  	if (lflags & GPIO_OPEN_SOURCE)
  		set_bit(FLAG_OPEN_SOURCE, &desc->flags);
  
  	if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
  		gpiod_err(desc,
  			  "both pull-up and pull-down enabled, invalid configuration\n");
  		return -EINVAL;
  	}
  
  	if (lflags & GPIO_PULL_UP)
  		set_bit(FLAG_PULL_UP, &desc->flags);
  	else if (lflags & GPIO_PULL_DOWN)
  		set_bit(FLAG_PULL_DOWN, &desc->flags);
  
  	ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
  	if (ret < 0)
  		return ret;
  
  	/* No particular flag request, return here... */
  	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
  		gpiod_dbg(desc, "no flags found for %s\n", con_id);
  		return 0;
  	}
  
  	/* Process flags */
  	if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
  		ret = gpiod_direction_output(desc,
  				!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
  	else
  		ret = gpiod_direction_input(desc);
  
  	return ret;
  }
  
  /**
   * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
   * @dev:	GPIO consumer, can be NULL for system-global GPIOs
   * @con_id:	function within the GPIO consumer
   * @idx:	index of the GPIO to obtain in the consumer
   * @flags:	optional GPIO initialization flags
   *
   * This variant of gpiod_get() allows to access GPIOs other than the first
   * defined one for functions that define several GPIOs.
   *
   * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
   * requested function and/or index, or another IS_ERR() code if an error
   * occurred while trying to acquire the GPIO.
   */
  struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
  					       const char *con_id,
  					       unsigned int idx,
  					       enum gpiod_flags flags)
  {
  	unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
  	struct gpio_desc *desc = NULL;
  	int ret;
  	/* Maybe we have a device name, maybe not */
  	const char *devname = dev ? dev_name(dev) : "?";
  	const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
  
  	dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
  
  	/* Using device tree? */
  	if (is_of_node(fwnode)) {
  		dev_dbg(dev, "using device tree for GPIO lookup\n");
  		desc = of_find_gpio(dev, con_id, idx, &lookupflags);
  	} else if (is_acpi_node(fwnode)) {
  		dev_dbg(dev, "using ACPI for GPIO lookup\n");
  		desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
  	}
  
  	/*
  	 * Either we are not using DT or ACPI, or their lookup did not return
  	 * a result. In that case, use platform lookup as a fallback.
  	 */
  	if (!desc || gpiod_not_found(desc)) {
  		dev_dbg(dev, "using lookup tables for GPIO lookup\n");
  		desc = gpiod_find(dev, con_id, idx, &lookupflags);
  	}
  
  	if (IS_ERR(desc)) {
  		dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
  		return desc;
  	}
  
  	/*
  	 * If a connection label was passed use that, else attempt to use
  	 * the device name as label
  	 */
  	ret = gpiod_request(desc, con_id ?: devname);
  	if (ret) {
  		if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
  			return ERR_PTR(ret);
  
  		/*
  		 * This happens when there are several consumers for
  		 * the same GPIO line: we just return here without
  		 * further initialization. It is a bit of a hack.
  		 * This is necessary to support fixed regulators.
  		 *
  		 * FIXME: Make this more sane and safe.
  		 */
  		dev_info(dev, "nonexclusive access to GPIO for %s\n", con_id ?: devname);
  		return desc;
  	}
  
  	ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
  	if (ret < 0) {
  		dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
  		gpiod_put(desc);
  		return ERR_PTR(ret);
  	}
  
  	blocking_notifier_call_chain(&desc->gdev->notifier,
  				     GPIOLINE_CHANGED_REQUESTED, desc);
  
  	return desc;
  }
  EXPORT_SYMBOL_GPL(gpiod_get_index);
  
  /**
   * fwnode_get_named_gpiod - obtain a GPIO from firmware node
   * @fwnode:	handle of the firmware node
   * @propname:	name of the firmware property representing the GPIO
   * @index:	index of the GPIO to obtain for the consumer
   * @dflags:	GPIO initialization flags
   * @label:	label to attach to the requested GPIO
   *
   * This function can be used for drivers that get their configuration
   * from opaque firmware.
   *
   * The function properly finds the corresponding GPIO using whatever is the
   * underlying firmware interface and then makes sure that the GPIO
   * descriptor is requested before it is returned to the caller.
   *
   * Returns:
   * On successful request the GPIO pin is configured in accordance with
   * provided @dflags.
   *
   * In case of error an ERR_PTR() is returned.
   */
  struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
  					 const char *propname, int index,
  					 enum gpiod_flags dflags,
  					 const char *label)
  {
  	unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
  	struct gpio_desc *desc = ERR_PTR(-ENODEV);
  	int ret;
  
  	if (is_of_node(fwnode)) {
  		desc = gpiod_get_from_of_node(to_of_node(fwnode),
  					      propname, index,
  					      dflags,
  					      label);
  		return desc;
  	} else if (is_acpi_node(fwnode)) {
  		struct acpi_gpio_info info;
  
  		desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
  		if (IS_ERR(desc))
  			return desc;
  
  		acpi_gpio_update_gpiod_flags(&dflags, &info);
  		acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
  	} else
  		return ERR_PTR(-EINVAL);
  
  	/* Currently only ACPI takes this path */
  	ret = gpiod_request(desc, label);
  	if (ret)
  		return ERR_PTR(ret);
  
  	ret = gpiod_configure_flags(desc, propname, lflags, dflags);
  	if (ret < 0) {
  		gpiod_put(desc);
  		return ERR_PTR(ret);
  	}
  
  	blocking_notifier_call_chain(&desc->gdev->notifier,
  				     GPIOLINE_CHANGED_REQUESTED, desc);
  
  	return desc;
  }
  EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
  
  /**
   * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
   *                            function
   * @dev: GPIO consumer, can be NULL for system-global GPIOs
   * @con_id: function within the GPIO consumer
   * @index: index of the GPIO to obtain in the consumer
   * @flags: optional GPIO initialization flags
   *
   * This is equivalent to gpiod_get_index(), except that when no GPIO with the
   * specified index was assigned to the requested function it will return NULL.
   * This is convenient for drivers that need to handle optional GPIOs.
   */
  struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
  							const char *con_id,
  							unsigned int index,
  							enum gpiod_flags flags)
  {
  	struct gpio_desc *desc;
  
  	desc = gpiod_get_index(dev, con_id, index, flags);
  	if (gpiod_not_found(desc))
  		return NULL;
  
  	return desc;
  }
  EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
  
  /**
   * gpiod_hog - Hog the specified GPIO desc given the provided flags
   * @desc:	gpio whose value will be assigned
   * @name:	gpio line name
   * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
   *		of_find_gpio() or of_get_gpio_hog()
   * @dflags:	gpiod_flags - optional GPIO initialization flags
   */
  int gpiod_hog(struct gpio_desc *desc, const char *name,
  	      unsigned long lflags, enum gpiod_flags dflags)
  {
  	struct gpio_chip *gc;
  	struct gpio_desc *local_desc;
  	int hwnum;
  	int ret;
  
  	gc = gpiod_to_chip(desc);
  	hwnum = gpio_chip_hwgpio(desc);
  
  	local_desc = gpiochip_request_own_desc(gc, hwnum, name,
  					       lflags, dflags);
  	if (IS_ERR(local_desc)) {
  		ret = PTR_ERR(local_desc);
  		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
  		       name, gc->label, hwnum, ret);
  		return ret;
  	}
  
  	/* Mark GPIO as hogged so it can be identified and removed later */
  	set_bit(FLAG_IS_HOGGED, &desc->flags);
  
  	gpiod_info(desc, "hogged as %s%s\n",
  		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
  		(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
  		  (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
  
  	return 0;
  }
  
  /**
   * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
   * @gc:	gpio chip to act on
   */
  static void gpiochip_free_hogs(struct gpio_chip *gc)
  {
  	struct gpio_desc *desc;
  	int id;
  
  	for_each_gpio_desc_with_flag(id, gc, desc, FLAG_IS_HOGGED)
  		gpiochip_free_own_desc(desc);
  }
  
  /**
   * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
   * @dev:	GPIO consumer, can be NULL for system-global GPIOs
   * @con_id:	function within the GPIO consumer
   * @flags:	optional GPIO initialization flags
   *
   * This function acquires all the GPIOs defined under a given function.
   *
   * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
   * no GPIO has been assigned to the requested function, or another IS_ERR()
   * code if an error occurred while trying to acquire the GPIOs.
   */
  struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
  						const char *con_id,
  						enum gpiod_flags flags)
  {
  	struct gpio_desc *desc;
  	struct gpio_descs *descs;
  	struct gpio_array *array_info = NULL;
  	struct gpio_chip *gc;
  	int count, bitmap_size;
  
  	count = gpiod_count(dev, con_id);
  	if (count < 0)
  		return ERR_PTR(count);
  
  	descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
  	if (!descs)
  		return ERR_PTR(-ENOMEM);
  
  	for (descs->ndescs = 0; descs->ndescs < count; ) {
  		desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
  		if (IS_ERR(desc)) {
  			gpiod_put_array(descs);
  			return ERR_CAST(desc);
  		}
  
  		descs->desc[descs->ndescs] = desc;
  
  		gc = gpiod_to_chip(desc);
  		/*
  		 * If pin hardware number of array member 0 is also 0, select
  		 * its chip as a candidate for fast bitmap processing path.
  		 */
  		if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
  			struct gpio_descs *array;
  
  			bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
  						    gc->ngpio : count);
  
  			array = kzalloc(struct_size(descs, desc, count) +
  					struct_size(array_info, invert_mask,
  					3 * bitmap_size), GFP_KERNEL);
  			if (!array) {
  				gpiod_put_array(descs);
  				return ERR_PTR(-ENOMEM);
  			}
  
  			memcpy(array, descs,
  			       struct_size(descs, desc, descs->ndescs + 1));
  			kfree(descs);
  
  			descs = array;
  			array_info = (void *)(descs->desc + count);
  			array_info->get_mask = array_info->invert_mask +
  						  bitmap_size;
  			array_info->set_mask = array_info->get_mask +
  						  bitmap_size;
  
  			array_info->desc = descs->desc;
  			array_info->size = count;
  			array_info->chip = gc;
  			bitmap_set(array_info->get_mask, descs->ndescs,
  				   count - descs->ndescs);
  			bitmap_set(array_info->set_mask, descs->ndescs,
  				   count - descs->ndescs);
  			descs->info = array_info;
  		}
  		/* Unmark array members which don't belong to the 'fast' chip */
  		if (array_info && array_info->chip != gc) {
  			__clear_bit(descs->ndescs, array_info->get_mask);
  			__clear_bit(descs->ndescs, array_info->set_mask);
  		}
  		/*
  		 * Detect array members which belong to the 'fast' chip
  		 * but their pins are not in hardware order.
  		 */
  		else if (array_info &&
  			   gpio_chip_hwgpio(desc) != descs->ndescs) {
  			/*
  			 * Don't use fast path if all array members processed so
  			 * far belong to the same chip as this one but its pin
  			 * hardware number is different from its array index.
  			 */
  			if (bitmap_full(array_info->get_mask, descs->ndescs)) {
  				array_info = NULL;
  			} else {
  				__clear_bit(descs->ndescs,
  					    array_info->get_mask);
  				__clear_bit(descs->ndescs,
  					    array_info->set_mask);
  			}
  		} else if (array_info) {
  			/* Exclude open drain or open source from fast output */
  			if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
  			    gpiochip_line_is_open_source(gc, descs->ndescs))
  				__clear_bit(descs->ndescs,
  					    array_info->set_mask);
  			/* Identify 'fast' pins which require invertion */
  			if (gpiod_is_active_low(desc))
  				__set_bit(descs->ndescs,
  					  array_info->invert_mask);
  		}
  
  		descs->ndescs++;
  	}
  	if (array_info)
  		dev_dbg(dev,
  			"GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
  			array_info->chip->label, array_info->size,
  			*array_info->get_mask, *array_info->set_mask,
  			*array_info->invert_mask);
  	return descs;
  }
  EXPORT_SYMBOL_GPL(gpiod_get_array);
  
  /**
   * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
   *                            function
   * @dev:	GPIO consumer, can be NULL for system-global GPIOs
   * @con_id:	function within the GPIO consumer
   * @flags:	optional GPIO initialization flags
   *
   * This is equivalent to gpiod_get_array(), except that when no GPIO was
   * assigned to the requested function it will return NULL.
   */
  struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
  							const char *con_id,
  							enum gpiod_flags flags)
  {
  	struct gpio_descs *descs;
  
  	descs = gpiod_get_array(dev, con_id, flags);
  	if (gpiod_not_found(descs))
  		return NULL;
  
  	return descs;
  }
  EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
  
  /**
   * gpiod_put - dispose of a GPIO descriptor
   * @desc:	GPIO descriptor to dispose of
   *
   * No descriptor can be used after gpiod_put() has been called on it.
   */
  void gpiod_put(struct gpio_desc *desc)
  {
  	if (desc)
  		gpiod_free(desc);
  }
  EXPORT_SYMBOL_GPL(gpiod_put);
  
  /**
   * gpiod_put_array - dispose of multiple GPIO descriptors
   * @descs:	struct gpio_descs containing an array of descriptors
   */
  void gpiod_put_array(struct gpio_descs *descs)
  {
  	unsigned int i;
  
  	for (i = 0; i < descs->ndescs; i++)
  		gpiod_put(descs->desc[i]);
  
  	kfree(descs);
  }
  EXPORT_SYMBOL_GPL(gpiod_put_array);
  
  
  static int gpio_bus_match(struct device *dev, struct device_driver *drv)
  {
  	struct fwnode_handle *fwnode = dev_fwnode(dev);
  
  	/*
  	 * Only match if the fwnode doesn't already have a proper struct device
  	 * created for it.
  	 */
  	if (fwnode && fwnode->dev != dev)
  		return 0;
  	return 1;
  }
  
  static int gpio_stub_drv_probe(struct device *dev)
  {
  	/*
  	 * The DT node of some GPIO chips have a "compatible" property, but
  	 * never have a struct device added and probed by a driver to register
  	 * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
  	 * the consumers of the GPIO chip to get probe deferred forever because
  	 * they will be waiting for a device associated with the GPIO chip
  	 * firmware node to get added and bound to a driver.
  	 *
  	 * To allow these consumers to probe, we associate the struct
  	 * gpio_device of the GPIO chip with the firmware node and then simply
  	 * bind it to this stub driver.
  	 */
  	return 0;
  }
  
  static struct device_driver gpio_stub_drv = {
  	.name = "gpio_stub_drv",
  	.bus = &gpio_bus_type,
  	.probe = gpio_stub_drv_probe,
  };
  
  static int __init gpiolib_dev_init(void)
  {
  	int ret;
  
  	/* Register GPIO sysfs bus */
  	ret = bus_register(&gpio_bus_type);
  	if (ret < 0) {
  		pr_err("gpiolib: could not register GPIO bus type\n");
  		return ret;
  	}
  
  	ret = driver_register(&gpio_stub_drv);
  	if (ret < 0) {
  		pr_err("gpiolib: could not register GPIO stub driver\n");
  		bus_unregister(&gpio_bus_type);
  		return ret;
  	}
  
  	ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
  	if (ret < 0) {
  		pr_err("gpiolib: failed to allocate char dev region\n");
  		driver_unregister(&gpio_stub_drv);
  		bus_unregister(&gpio_bus_type);
  		return ret;
  	}
  
  	gpiolib_initialized = true;
  	gpiochip_setup_devs();
  
  #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
  	WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
  #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
  
  	return ret;
  }
  core_initcall(gpiolib_dev_init);
  
  #ifdef CONFIG_DEBUG_FS
  
  static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
  {
  	unsigned		i;
  	struct gpio_chip	*gc = gdev->chip;
  	unsigned		gpio = gdev->base;
  	struct gpio_desc	*gdesc = &gdev->descs[0];
  	bool			is_out;
  	bool			is_irq;
  	bool			active_low;
  
  	for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
  		if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
  			if (gdesc->name) {
  				seq_printf(s, " gpio-%-3d (%-20.20s)\n",
  					   gpio, gdesc->name);
  			}
  			continue;
  		}
  
  		gpiod_get_direction(gdesc);
  		is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
  		is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
  		active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
  		seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
  			gpio, gdesc->name ? gdesc->name : "", gdesc->label,
  			is_out ? "out" : "in ",
  			gc->get ? (gc->get(gc, i) ? "hi" : "lo") : "?  ",
  			is_irq ? "IRQ " : "",
  			active_low ? "ACTIVE LOW" : "");
  		seq_printf(s, "\n");
  	}
  }
  
  static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
  {
  	unsigned long flags;
  	struct gpio_device *gdev = NULL;
  	loff_t index = *pos;
  
  	s->private = "";
  
  	spin_lock_irqsave(&gpio_lock, flags);
  	list_for_each_entry(gdev, &gpio_devices, list)
  		if (index-- == 0) {
  			spin_unlock_irqrestore(&gpio_lock, flags);
  			return gdev;
  		}
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	return NULL;
  }
  
  static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
  {
  	unsigned long flags;
  	struct gpio_device *gdev = v;
  	void *ret = NULL;
  
  	spin_lock_irqsave(&gpio_lock, flags);
  	if (list_is_last(&gdev->list, &gpio_devices))
  		ret = NULL;
  	else
  		ret = list_first_entry(&gdev->list, struct gpio_device, list);
  	spin_unlock_irqrestore(&gpio_lock, flags);
  
  	s->private = "\n";
  	++*pos;
  
  	return ret;
  }
  
  static void gpiolib_seq_stop(struct seq_file *s, void *v)
  {
  }
  
  static int gpiolib_seq_show(struct seq_file *s, void *v)
  {
  	struct gpio_device *gdev = v;
  	struct gpio_chip *gc = gdev->chip;
  	struct device *parent;
  
  	if (!gc) {
  		seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
  			   dev_name(&gdev->dev));
  		return 0;
  	}
  
  	seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
  		   dev_name(&gdev->dev),
  		   gdev->base, gdev->base + gdev->ngpio - 1);
  	parent = gc->parent;
  	if (parent)
  		seq_printf(s, ", parent: %s/%s",
  			   parent->bus ? parent->bus->name : "no-bus",
  			   dev_name(parent));
  	if (gc->label)
  		seq_printf(s, ", %s", gc->label);
  	if (gc->can_sleep)
  		seq_printf(s, ", can sleep");
  	seq_printf(s, ":\n");
  
  	if (gc->dbg_show)
  		gc->dbg_show(s, gc);
  	else
  		gpiolib_dbg_show(s, gdev);
  
  	return 0;
  }
  
  static const struct seq_operations gpiolib_sops = {
  	.start = gpiolib_seq_start,
  	.next = gpiolib_seq_next,
  	.stop = gpiolib_seq_stop,
  	.show = gpiolib_seq_show,
  };
  DEFINE_SEQ_ATTRIBUTE(gpiolib);
  
  static int __init gpiolib_debugfs_init(void)
  {
  	/* /sys/kernel/debug/gpio */
  	debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
  	return 0;
  }
  subsys_initcall(gpiolib_debugfs_init);
  
  #endif	/* DEBUG_FS */
  