Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4485 insertions, 0 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
new file mode 100644
index 000000000..12472b84a
--- /dev/null
+++ b/drivers/gpio/gpiolib.c
@@ -0,0 +1,4485 @@
+#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/of_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/cdev.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/compat.h>
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+#include <linux/kfifo.h>
+#include <linux/poll.h>
+#include <linux/timekeeping.h>
+#include <uapi/linux/gpio.h>
+
+#include "gpiolib.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 struct bus_type gpio_bus_type = {
+	.name = "gpio",
+};
+
+/*
+ * 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 *chip);
+static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
+				struct lock_class_key *lock_key,
+				struct lock_class_key *request_key);
+static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
+static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
+static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
+
+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))
+		WARN(1, "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
+ * @chip: 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 *chip,
+				    u16 hwnum)
+{
+	struct gpio_device *gdev = chip->gpiodev;
+
+	if (hwnum >= gdev->ngpio)
+		return ERR_PTR(-EINVAL);
+
+	return &gdev->descs[hwnum];
+}
+
+/**
+ * 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	*chip;
+	unsigned		offset;
+	int			status = -EINVAL;
+
+	chip = 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 (!chip->get_direction)
+		return status;
+
+	status = chip->get_direction(chip, offset);
+	if (status > 0) {
+		/* GPIOF_DIR_IN, or other positive */
+		status = 1;
+		clear_bit(FLAG_IS_OUT, &desc->flags);
+	}
+	if (status == 0) {
+		/* GPIOF_DIR_OUT */
+		set_bit(FLAG_IS_OUT, &desc->flags);
+	}
+	return status;
+}
+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_entry(gpio_devices.next, 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_entry(gpio_devices.prev, 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
+ */
+static struct gpio_desc *gpio_name_to_desc(const char * const name)
+{
+	struct gpio_device *gdev;
+	unsigned long flags;
+
+	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 || !name)
+				continue;
+
+			if (!strcmp(desc->name, name)) {
+				spin_unlock_irqrestore(&gpio_lock, flags);
+				return desc;
+			}
+		}
+	}
+
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
+	return NULL;
+}
+
+/*
+ * Takes the names from gc->names and checks if they are all unique. If they
+ * are, they are assigned to their gpio descriptors.
+ *
+ * Warning if one of the names is already used for a different GPIO.
+ */
+static int gpiochip_set_desc_names(struct gpio_chip *gc)
+{
+	struct gpio_device *gdev = gc->gpiodev;
+	int i;
+
+	if (!gc->names)
+		return 0;
+
+	/* 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;
+}
+
+static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
+{
+	unsigned long *p;
+
+	p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return NULL;
+
+	/* Assume by default all GPIOs are valid */
+	bitmap_fill(p, chip->ngpio);
+
+	return p;
+}
+
+static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
+{
+#ifdef CONFIG_OF_GPIO
+	int size;
+	struct device_node *np = gpiochip->of_node;
+
+	size = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
+	if (size > 0 && size % 2 == 0)
+		gpiochip->need_valid_mask = true;
+#endif
+
+	if (!gpiochip->need_valid_mask)
+		return 0;
+
+	gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
+	if (!gpiochip->valid_mask)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
+{
+	kfree(gpiochip->valid_mask);
+	gpiochip->valid_mask = NULL;
+}
+
+bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
+				unsigned int offset)
+{
+	/* No mask means all valid */
+	if (likely(!gpiochip->valid_mask))
+		return true;
+	return test_bit(offset, gpiochip->valid_mask);
+}
+EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
+
+/*
+ * GPIO line handle management
+ */
+
+/**
+ * struct linehandle_state - contains the state of a userspace handle
+ * @gdev: the GPIO device the handle pertains to
+ * @label: consumer label used to tag descriptors
+ * @descs: the GPIO descriptors held by this handle
+ * @numdescs: the number of descriptors held in the descs array
+ */
+struct linehandle_state {
+	struct gpio_device *gdev;
+	const char *label;
+	struct gpio_desc *descs[GPIOHANDLES_MAX];
+	u32 numdescs;
+};
+
+#define GPIOHANDLE_REQUEST_VALID_FLAGS \
+	(GPIOHANDLE_REQUEST_INPUT | \
+	GPIOHANDLE_REQUEST_OUTPUT | \
+	GPIOHANDLE_REQUEST_ACTIVE_LOW | \
+	GPIOHANDLE_REQUEST_OPEN_DRAIN | \
+	GPIOHANDLE_REQUEST_OPEN_SOURCE)
+
+static long linehandle_ioctl(struct file *filep, unsigned int cmd,
+			     unsigned long arg)
+{
+	struct linehandle_state *lh = filep->private_data;
+	void __user *ip = (void __user *)arg;
+	struct gpiohandle_data ghd;
+	int vals[GPIOHANDLES_MAX];
+	int i;
+
+	if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
+		/* NOTE: It's ok to read values of output lines. */
+		int ret = gpiod_get_array_value_complex(false,
+							true,
+							lh->numdescs,
+							lh->descs,
+							vals);
+		if (ret)
+			return ret;
+
+		memset(&ghd, 0, sizeof(ghd));
+		for (i = 0; i < lh->numdescs; i++)
+			ghd.values[i] = vals[i];
+
+		if (copy_to_user(ip, &ghd, sizeof(ghd)))
+			return -EFAULT;
+
+		return 0;
+	} else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
+		/*
+		 * All line descriptors were created at once with the same
+		 * flags so just check if the first one is really output.
+		 */
+		if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
+			return -EPERM;
+
+		if (copy_from_user(&ghd, ip, sizeof(ghd)))
+			return -EFAULT;
+
+		/* Clamp all values to [0,1] */
+		for (i = 0; i < lh->numdescs; i++)
+			vals[i] = !!ghd.values[i];
+
+		/* Reuse the array setting function */
+		return gpiod_set_array_value_complex(false,
+					      true,
+					      lh->numdescs,
+					      lh->descs,
+					      vals);
+	}
+	return -EINVAL;
+}
+
+#ifdef CONFIG_COMPAT
+static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
+			     unsigned long arg)
+{
+	return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static int linehandle_release(struct inode *inode, struct file *filep)
+{
+	struct linehandle_state *lh = filep->private_data;
+	struct gpio_device *gdev = lh->gdev;
+	int i;
+
+	for (i = 0; i < lh->numdescs; i++)
+		gpiod_free(lh->descs[i]);
+	kfree(lh->label);
+	kfree(lh);
+	put_device(&gdev->dev);
+	return 0;
+}
+
+static const struct file_operations linehandle_fileops = {
+	.release = linehandle_release,
+	.owner = THIS_MODULE,
+	.llseek = noop_llseek,
+	.unlocked_ioctl = linehandle_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = linehandle_ioctl_compat,
+#endif
+};
+
+static int linehandle_create(struct gpio_device *gdev, void __user *ip)
+{
+	struct gpiohandle_request handlereq;
+	struct linehandle_state *lh;
+	struct file *file;
+	int fd, i, count = 0, ret;
+	u32 lflags;
+
+	if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
+		return -EFAULT;
+	if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
+		return -EINVAL;
+
+	lflags = handlereq.flags;
+
+	/* Return an error if an unknown flag is set */
+	if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
+		return -EINVAL;
+
+	/*
+	 * Do not allow both INPUT & OUTPUT flags to be set as they are
+	 * contradictory.
+	 */
+	if ((lflags & GPIOHANDLE_REQUEST_INPUT) &&
+	    (lflags & GPIOHANDLE_REQUEST_OUTPUT))
+		return -EINVAL;
+
+	/*
+	 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
+	 * the hardware actually supports enabling both at the same time the
+	 * electrical result would be disastrous.
+	 */
+	if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
+	    (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
+		return -EINVAL;
+
+	/* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
+	if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
+	    ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
+	     (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
+		return -EINVAL;
+
+	lh = kzalloc(sizeof(*lh), GFP_KERNEL);
+	if (!lh)
+		return -ENOMEM;
+	lh->gdev = gdev;
+	get_device(&gdev->dev);
+
+	/* Make sure this is terminated */
+	handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
+	if (strlen(handlereq.consumer_label)) {
+		lh->label = kstrdup(handlereq.consumer_label,
+				    GFP_KERNEL);
+		if (!lh->label) {
+			ret = -ENOMEM;
+			goto out_free_lh;
+		}
+	}
+
+	/* Request each GPIO */
+	for (i = 0; i < handlereq.lines; i++) {
+		u32 offset = handlereq.lineoffsets[i];
+		struct gpio_desc *desc;
+
+		if (offset >= gdev->ngpio) {
+			ret = -EINVAL;
+			goto out_free_descs;
+		}
+
+		desc = &gdev->descs[offset];
+		ret = gpiod_request(desc, lh->label);
+		if (ret)
+			goto out_free_descs;
+		lh->descs[i] = desc;
+		count = i + 1;
+
+		if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
+			set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+		if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
+			set_bit(FLAG_OPEN_DRAIN, &desc->flags);
+		if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
+			set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+
+		ret = gpiod_set_transitory(desc, false);
+		if (ret < 0)
+			goto out_free_descs;
+
+		/*
+		 * Lines have to be requested explicitly for input
+		 * or output, else the line will be treated "as is".
+		 */
+		if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
+			int val = !!handlereq.default_values[i];
+
+			ret = gpiod_direction_output(desc, val);
+			if (ret)
+				goto out_free_descs;
+		} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
+			ret = gpiod_direction_input(desc);
+			if (ret)
+				goto out_free_descs;
+		}
+		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
+			offset);
+	}
+	/* Let i point at the last handle */
+	i--;
+	lh->numdescs = handlereq.lines;
+
+	fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
+	if (fd < 0) {
+		ret = fd;
+		goto out_free_descs;
+	}
+
+	file = anon_inode_getfile("gpio-linehandle",
+				  &linehandle_fileops,
+				  lh,
+				  O_RDONLY | O_CLOEXEC);
+	if (IS_ERR(file)) {
+		ret = PTR_ERR(file);
+		goto out_put_unused_fd;
+	}
+
+	handlereq.fd = fd;
+	if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
+		/*
+		 * fput() will trigger the release() callback, so do not go onto
+		 * the regular error cleanup path here.
+		 */
+		fput(file);
+		put_unused_fd(fd);
+		return -EFAULT;
+	}
+
+	fd_install(fd, file);
+
+	dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
+		lh->numdescs);
+
+	return 0;
+
+out_put_unused_fd:
+	put_unused_fd(fd);
+out_free_descs:
+	for (i = 0; i < count; i++)
+		gpiod_free(lh->descs[i]);
+	kfree(lh->label);
+out_free_lh:
+	kfree(lh);
+	put_device(&gdev->dev);
+	return ret;
+}
+
+/*
+ * GPIO line event management
+ */
+
+/**
+ * struct lineevent_state - contains the state of a userspace event
+ * @gdev: the GPIO device the event pertains to
+ * @label: consumer label used to tag descriptors
+ * @desc: the GPIO descriptor held by this event
+ * @eflags: the event flags this line was requested with
+ * @irq: the interrupt that trigger in response to events on this GPIO
+ * @wait: wait queue that handles blocking reads of events
+ * @events: KFIFO for the GPIO events
+ * @read_lock: mutex lock to protect reads from colliding with adding
+ * new events to the FIFO
+ * @timestamp: cache for the timestamp storing it between hardirq
+ * and IRQ thread, used to bring the timestamp close to the actual
+ * event
+ */
+struct lineevent_state {
+	struct gpio_device *gdev;
+	const char *label;
+	struct gpio_desc *desc;
+	u32 eflags;
+	int irq;
+	wait_queue_head_t wait;
+	DECLARE_KFIFO(events, struct gpioevent_data, 16);
+	struct mutex read_lock;
+	u64 timestamp;
+};
+
+#define GPIOEVENT_REQUEST_VALID_FLAGS \
+	(GPIOEVENT_REQUEST_RISING_EDGE | \
+	GPIOEVENT_REQUEST_FALLING_EDGE)
+
+static __poll_t lineevent_poll(struct file *filep,
+				   struct poll_table_struct *wait)
+{
+	struct lineevent_state *le = filep->private_data;
+	__poll_t events = 0;
+
+	poll_wait(filep, &le->wait, wait);
+
+	if (!kfifo_is_empty(&le->events))
+		events = EPOLLIN | EPOLLRDNORM;
+
+	return events;
+}
+
+
+static ssize_t lineevent_read(struct file *filep,
+			      char __user *buf,
+			      size_t count,
+			      loff_t *f_ps)
+{
+	struct lineevent_state *le = filep->private_data;
+	unsigned int copied;
+	int ret;
+
+	if (count < sizeof(struct gpioevent_data))
+		return -EINVAL;
+
+	do {
+		if (kfifo_is_empty(&le->events)) {
+			if (filep->f_flags & O_NONBLOCK)
+				return -EAGAIN;
+
+			ret = wait_event_interruptible(le->wait,
+					!kfifo_is_empty(&le->events));
+			if (ret)
+				return ret;
+		}
+
+		if (mutex_lock_interruptible(&le->read_lock))
+			return -ERESTARTSYS;
+		ret = kfifo_to_user(&le->events, buf, count, &copied);
+		mutex_unlock(&le->read_lock);
+
+		if (ret)
+			return ret;
+
+		/*
+		 * If we couldn't read anything from the fifo (a different
+		 * thread might have been faster) we either return -EAGAIN if
+		 * the file descriptor is non-blocking, otherwise we go back to
+		 * sleep and wait for more data to arrive.
+		 */
+		if (copied == 0 && (filep->f_flags & O_NONBLOCK))
+			return -EAGAIN;
+
+	} while (copied == 0);
+
+	return copied;
+}
+
+static int lineevent_release(struct inode *inode, struct file *filep)
+{
+	struct lineevent_state *le = filep->private_data;
+	struct gpio_device *gdev = le->gdev;
+
+	free_irq(le->irq, le);
+	gpiod_free(le->desc);
+	kfree(le->label);
+	kfree(le);
+	put_device(&gdev->dev);
+	return 0;
+}
+
+static long lineevent_ioctl(struct file *filep, unsigned int cmd,
+			    unsigned long arg)
+{
+	struct lineevent_state *le = filep->private_data;
+	void __user *ip = (void __user *)arg;
+	struct gpiohandle_data ghd;
+
+	/*
+	 * We can get the value for an event line but not set it,
+	 * because it is input by definition.
+	 */
+	if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
+		int val;
+
+		memset(&ghd, 0, sizeof(ghd));
+
+		val = gpiod_get_value_cansleep(le->desc);
+		if (val < 0)
+			return val;
+		ghd.values[0] = val;
+
+		if (copy_to_user(ip, &ghd, sizeof(ghd)))
+			return -EFAULT;
+
+		return 0;
+	}
+	return -EINVAL;
+}
+
+#ifdef CONFIG_COMPAT
+static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
+				   unsigned long arg)
+{
+	return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static const struct file_operations lineevent_fileops = {
+	.release = lineevent_release,
+	.read = lineevent_read,
+	.poll = lineevent_poll,
+	.owner = THIS_MODULE,
+	.llseek = noop_llseek,
+	.unlocked_ioctl = lineevent_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = lineevent_ioctl_compat,
+#endif
+};
+
+static irqreturn_t lineevent_irq_thread(int irq, void *p)
+{
+	struct lineevent_state *le = p;
+	struct gpioevent_data ge;
+	int ret, level;
+
+	/* Do not leak kernel stack to userspace */
+	memset(&ge, 0, sizeof(ge));
+
+	/*
+	 * We may be running from a nested threaded interrupt in which case
+	 * we didn't get the timestamp from lineevent_irq_handler().
+	 */
+	if (!le->timestamp)
+		ge.timestamp = ktime_get_real_ns();
+	else
+		ge.timestamp = le->timestamp;
+
+	level = gpiod_get_value_cansleep(le->desc);
+
+	if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
+	    && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
+		if (level)
+			/* Emit low-to-high event */
+			ge.id = GPIOEVENT_EVENT_RISING_EDGE;
+		else
+			/* Emit high-to-low event */
+			ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
+	} else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
+		/* Emit low-to-high event */
+		ge.id = GPIOEVENT_EVENT_RISING_EDGE;
+	} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
+		/* Emit high-to-low event */
+		ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
+	} else {
+		return IRQ_NONE;
+	}
+
+	ret = kfifo_put(&le->events, ge);
+	if (ret != 0)
+		wake_up_poll(&le->wait, EPOLLIN);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t lineevent_irq_handler(int irq, void *p)
+{
+	struct lineevent_state *le = p;
+
+	/*
+	 * Just store the timestamp in hardirq context so we get it as
+	 * close in time as possible to the actual event.
+	 */
+	le->timestamp = ktime_get_real_ns();
+
+	return IRQ_WAKE_THREAD;
+}
+
+static int lineevent_create(struct gpio_device *gdev, void __user *ip)
+{
+	struct gpioevent_request eventreq;
+	struct lineevent_state *le;
+	struct gpio_desc *desc;
+	struct file *file;
+	u32 offset;
+	u32 lflags;
+	u32 eflags;
+	int fd;
+	int ret;
+	int irqflags = 0;
+
+	if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
+		return -EFAULT;
+
+	le = kzalloc(sizeof(*le), GFP_KERNEL);
+	if (!le)
+		return -ENOMEM;
+	le->gdev = gdev;
+	get_device(&gdev->dev);
+
+	/* Make sure this is terminated */
+	eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
+	if (strlen(eventreq.consumer_label)) {
+		le->label = kstrdup(eventreq.consumer_label,
+				    GFP_KERNEL);
+		if (!le->label) {
+			ret = -ENOMEM;
+			goto out_free_le;
+		}
+	}
+
+	offset = eventreq.lineoffset;
+	lflags = eventreq.handleflags;
+	eflags = eventreq.eventflags;
+
+	if (offset >= gdev->ngpio) {
+		ret = -EINVAL;
+		goto out_free_label;
+	}
+
+	/* Return an error if a unknown flag is set */
+	if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
+	    (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
+		ret = -EINVAL;
+		goto out_free_label;
+	}
+
+	/* This is just wrong: we don't look for events on output lines */
+	if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
+	    (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
+	    (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
+		ret = -EINVAL;
+		goto out_free_label;
+	}
+
+	desc = &gdev->descs[offset];
+	ret = gpiod_request(desc, le->label);
+	if (ret)
+		goto out_free_label;
+	le->desc = desc;
+	le->eflags = eflags;
+
+	if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
+		set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+
+	ret = gpiod_direction_input(desc);
+	if (ret)
+		goto out_free_desc;
+
+	le->irq = gpiod_to_irq(desc);
+	if (le->irq <= 0) {
+		ret = -ENODEV;
+		goto out_free_desc;
+	}
+
+	if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
+		irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
+			IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
+	if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
+		irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
+			IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
+	irqflags |= IRQF_ONESHOT;
+	irqflags |= IRQF_SHARED;
+
+	INIT_KFIFO(le->events);
+	init_waitqueue_head(&le->wait);
+	mutex_init(&le->read_lock);
+
+	/* Request a thread to read the events */
+	ret = request_threaded_irq(le->irq,
+			lineevent_irq_handler,
+			lineevent_irq_thread,
+			irqflags,
+			le->label,
+			le);
+	if (ret)
+		goto out_free_desc;
+
+	fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
+	if (fd < 0) {
+		ret = fd;
+		goto out_free_irq;
+	}
+
+	file = anon_inode_getfile("gpio-event",
+				  &lineevent_fileops,
+				  le,
+				  O_RDONLY | O_CLOEXEC);
+	if (IS_ERR(file)) {
+		ret = PTR_ERR(file);
+		goto out_put_unused_fd;
+	}
+
+	eventreq.fd = fd;
+	if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
+		/*
+		 * fput() will trigger the release() callback, so do not go onto
+		 * the regular error cleanup path here.
+		 */
+		fput(file);
+		put_unused_fd(fd);
+		return -EFAULT;
+	}
+
+	fd_install(fd, file);
+
+	return 0;
+
+out_put_unused_fd:
+	put_unused_fd(fd);
+out_free_irq:
+	free_irq(le->irq, le);
+out_free_desc:
+	gpiod_free(le->desc);
+out_free_label:
+	kfree(le->label);
+out_free_le:
+	kfree(le);
+	put_device(&gdev->dev);
+	return ret;
+}
+
+/*
+ * gpio_ioctl() - ioctl handler for the GPIO chardev
+ */
+static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct gpio_device *gdev = filp->private_data;
+	struct gpio_chip *chip = gdev->chip;
+	void __user *ip = (void __user *)arg;
+
+	/* We fail any subsequent ioctl():s when the chip is gone */
+	if (!chip)
+		return -ENODEV;
+
+	/* Fill in the struct and pass to userspace */
+	if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
+		struct gpiochip_info chipinfo;
+
+		memset(&chipinfo, 0, sizeof(chipinfo));
+
+		strncpy(chipinfo.name, dev_name(&gdev->dev),
+			sizeof(chipinfo.name));
+		chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
+		strncpy(chipinfo.label, gdev->label,
+			sizeof(chipinfo.label));
+		chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
+		chipinfo.lines = gdev->ngpio;
+		if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
+			return -EFAULT;
+		return 0;
+	} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
+		struct gpioline_info lineinfo;
+		struct gpio_desc *desc;
+
+		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
+			return -EFAULT;
+		if (lineinfo.line_offset >= gdev->ngpio)
+			return -EINVAL;
+
+		desc = &gdev->descs[lineinfo.line_offset];
+		if (desc->name) {
+			strncpy(lineinfo.name, desc->name,
+				sizeof(lineinfo.name));
+			lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
+		} else {
+			lineinfo.name[0] = '\0';
+		}
+		if (desc->label) {
+			strncpy(lineinfo.consumer, desc->label,
+				sizeof(lineinfo.consumer));
+			lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
+		} else {
+			lineinfo.consumer[0] = '\0';
+		}
+
+		/*
+		 * Userspace only need to know that the kernel is using
+		 * this GPIO so it can't use it.
+		 */
+		lineinfo.flags = 0;
+		if (test_bit(FLAG_REQUESTED, &desc->flags) ||
+		    test_bit(FLAG_IS_HOGGED, &desc->flags) ||
+		    test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
+		    test_bit(FLAG_EXPORT, &desc->flags) ||
+		    test_bit(FLAG_SYSFS, &desc->flags))
+			lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
+		if (test_bit(FLAG_IS_OUT, &desc->flags))
+			lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
+		if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+			lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
+		if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+			lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
+					   GPIOLINE_FLAG_IS_OUT);
+		if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+			lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
+					   GPIOLINE_FLAG_IS_OUT);
+
+		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
+			return -EFAULT;
+		return 0;
+	} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
+		return linehandle_create(gdev, ip);
+	} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
+		return lineevent_create(gdev, ip);
+	}
+	return -EINVAL;
+}
+
+#ifdef CONFIG_COMPAT
+static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
+			      unsigned long arg)
+{
+	return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+/**
+ * gpio_chrdev_open() - open the chardev for ioctl operations
+ * @inode: inode for this chardev
+ * @filp: file struct for storing private data
+ * Returns 0 on success
+ */
+static int gpio_chrdev_open(struct inode *inode, struct file *filp)
+{
+	struct gpio_device *gdev = container_of(inode->i_cdev,
+					      struct gpio_device, chrdev);
+
+	/* Fail on open if the backing gpiochip is gone */
+	if (!gdev->chip)
+		return -ENODEV;
+	get_device(&gdev->dev);
+	filp->private_data = gdev;
+
+	return nonseekable_open(inode, filp);
+}
+
+/**
+ * gpio_chrdev_release() - close chardev after ioctl operations
+ * @inode: inode for this chardev
+ * @filp: file struct for storing private data
+ * Returns 0 on success
+ */
+static int gpio_chrdev_release(struct inode *inode, struct file *filp)
+{
+	struct gpio_device *gdev = container_of(inode->i_cdev,
+					      struct gpio_device, chrdev);
+
+	put_device(&gdev->dev);
+	return 0;
+}
+
+
+static const struct file_operations gpio_fileops = {
+	.release = gpio_chrdev_release,
+	.open = gpio_chrdev_open,
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+	.unlocked_ioctl = gpio_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = gpio_ioctl_compat,
+#endif
+};
+
+static void gpiodevice_release(struct device *dev)
+{
+	struct gpio_device *gdev = dev_get_drvdata(dev);
+
+	list_del(&gdev->list);
+	ida_simple_remove(&gpio_ida, gdev->id);
+	kfree_const(gdev->label);
+	kfree(gdev->descs);
+	kfree(gdev);
+}
+
+static int gpiochip_setup_dev(struct gpio_device *gdev)
+{
+	int status;
+
+	cdev_init(&gdev->chrdev, &gpio_fileops);
+	gdev->chrdev.owner = THIS_MODULE;
+	gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
+
+	status = cdev_device_add(&gdev->chrdev, &gdev->dev);
+	if (status)
+		return status;
+
+	chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
+		 MAJOR(gpio_devt), gdev->id);
+
+	status = gpiochip_sysfs_register(gdev);
+	if (status)
+		goto err_remove_device;
+
+	/* From this point, the .release() function cleans up gpio_device */
+	gdev->dev.release = gpiodevice_release;
+	pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
+		 __func__, gdev->base, gdev->base + gdev->ngpio - 1,
+		 dev_name(&gdev->dev), gdev->chip->label ? : "generic");
+
+	return 0;
+
+err_remove_device:
+	cdev_device_del(&gdev->chrdev, &gdev->dev);
+	return status;
+}
+
+static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
+{
+	struct gpio_desc *desc;
+	int rv;
+
+	desc = gpiochip_get_desc(chip, hog->chip_hwnum);
+	if (IS_ERR(desc)) {
+		pr_err("%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)
+		pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
+		       __func__, chip->label, hog->chip_hwnum, rv);
+}
+
+static void machine_gpiochip_add(struct gpio_chip *chip)
+{
+	struct gpiod_hog *hog;
+
+	mutex_lock(&gpio_machine_hogs_mutex);
+
+	list_for_each_entry(hog, &gpio_machine_hogs, list) {
+		if (!strcmp(chip->label, hog->chip_label))
+			gpiochip_machine_hog(chip, hog);
+	}
+
+	mutex_unlock(&gpio_machine_hogs_mutex);
+}
+
+static void gpiochip_setup_devs(void)
+{
+	struct gpio_device *gdev;
+	int err;
+
+	list_for_each_entry(gdev, &gpio_devices, list) {
+		err = gpiochip_setup_dev(gdev);
+		if (err)
+			pr_err("%s: Failed to initialize gpio device (%d)\n",
+			       dev_name(&gdev->dev), err);
+	}
+}
+
+int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
+			       struct lock_class_key *lock_key,
+			       struct lock_class_key *request_key)
+{
+	unsigned long	flags;
+	int		status = 0;
+	unsigned	i;
+	int		base = chip->base;
+	struct gpio_device *gdev;
+
+	/*
+	 * 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->chip = chip;
+	chip->gpiodev = gdev;
+	if (chip->parent) {
+		gdev->dev.parent = chip->parent;
+		gdev->dev.of_node = chip->parent->of_node;
+	}
+
+#ifdef CONFIG_OF_GPIO
+	/* If the gpiochip has an assigned OF node this takes precedence */
+	if (chip->of_node)
+		gdev->dev.of_node = chip->of_node;
+	else
+		chip->of_node = gdev->dev.of_node;
+#endif
+
+	gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
+	if (gdev->id < 0) {
+		status = gdev->id;
+		goto err_free_gdev;
+	}
+	dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
+	device_initialize(&gdev->dev);
+	dev_set_drvdata(&gdev->dev, gdev);
+	if (chip->parent && chip->parent->driver)
+		gdev->owner = chip->parent->driver->owner;
+	else if (chip->owner)
+		/* TODO: remove chip->owner */
+		gdev->owner = chip->owner;
+	else
+		gdev->owner = THIS_MODULE;
+
+	gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
+	if (!gdev->descs) {
+		status = -ENOMEM;
+		goto err_free_ida;
+	}
+
+	if (chip->ngpio == 0) {
+		chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
+		status = -EINVAL;
+		goto err_free_descs;
+	}
+
+	if (chip->ngpio > FASTPATH_NGPIO)
+		chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
+		chip->ngpio, FASTPATH_NGPIO);
+
+	gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
+	if (!gdev->label) {
+		status = -ENOMEM;
+		goto err_free_descs;
+	}
+
+	gdev->ngpio = chip->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(chip->ngpio);
+		if (base < 0) {
+			status = 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.
+		 */
+		chip->base = base;
+	}
+	gdev->base = base;
+
+	status = gpiodev_add_to_list(gdev);
+	if (status) {
+		spin_unlock_irqrestore(&gpio_lock, flags);
+		goto err_free_label;
+	}
+
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
+	for (i = 0; i < chip->ngpio; i++) {
+		struct gpio_desc *desc = &gdev->descs[i];
+
+		desc->gdev = gdev;
+
+		/* REVISIT: most hardware initializes GPIOs as inputs (often
+		 * with pullups enabled) so power usage is minimized. Linux
+		 * code should set the gpio direction first thing; but until
+		 * it does, and in case chip->get_direction is not set, we may
+		 * expose the wrong direction in sysfs.
+		 */
+		desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
+	}
+
+#ifdef CONFIG_PINCTRL
+	INIT_LIST_HEAD(&gdev->pin_ranges);
+#endif
+
+	status = gpiochip_set_desc_names(chip);
+	if (status)
+		goto err_remove_from_list;
+
+	status = gpiochip_irqchip_init_valid_mask(chip);
+	if (status)
+		goto err_remove_from_list;
+
+	status = gpiochip_init_valid_mask(chip);
+	if (status)
+		goto err_remove_irqchip_mask;
+
+	status = gpiochip_add_irqchip(chip, lock_key, request_key);
+	if (status)
+		goto err_remove_chip;
+
+	status = of_gpiochip_add(chip);
+	if (status)
+		goto err_remove_chip;
+
+	acpi_gpiochip_add(chip);
+
+	machine_gpiochip_add(chip);
+
+	/*
+	 * 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) {
+		status = gpiochip_setup_dev(gdev);
+		if (status)
+			goto err_remove_chip;
+	}
+	return 0;
+
+err_remove_chip:
+	acpi_gpiochip_remove(chip);
+	gpiochip_free_hogs(chip);
+	of_gpiochip_remove(chip);
+	gpiochip_free_valid_mask(chip);
+err_remove_irqchip_mask:
+	gpiochip_irqchip_free_valid_mask(chip);
+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_ida:
+	ida_simple_remove(&gpio_ida, gdev->id);
+err_free_gdev:
+	/* failures here can mean systems won't boot... */
+	pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
+	       gdev->base, gdev->base + gdev->ngpio - 1,
+	       chip->label ? : "generic", status);
+	kfree(gdev);
+	return status;
+}
+EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
+
+/**
+ * gpiochip_get_data() - get per-subdriver data for the chip
+ * @chip: GPIO chip
+ *
+ * Returns:
+ * The per-subdriver data for the chip.
+ */
+void *gpiochip_get_data(struct gpio_chip *chip)
+{
+	return chip->gpiodev->data;
+}
+EXPORT_SYMBOL_GPL(gpiochip_get_data);
+
+/**
+ * gpiochip_remove() - unregister a gpio_chip
+ * @chip: the chip to unregister
+ *
+ * A gpio_chip with any GPIOs still requested may not be removed.
+ */
+void gpiochip_remove(struct gpio_chip *chip)
+{
+	struct gpio_device *gdev = chip->gpiodev;
+	struct gpio_desc *desc;
+	unsigned long	flags;
+	unsigned	i;
+	bool		requested = false;
+
+	/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
+	gpiochip_sysfs_unregister(gdev);
+	gpiochip_free_hogs(chip);
+	/* Numb the device, cancelling all outstanding operations */
+	gdev->chip = NULL;
+	gpiochip_irqchip_remove(chip);
+	acpi_gpiochip_remove(chip);
+	gpiochip_remove_pin_ranges(chip);
+	of_gpiochip_remove(chip);
+	gpiochip_free_valid_mask(chip);
+	/*
+	 * 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++) {
+		desc = &gdev->descs[i];
+		if (test_bit(FLAG_REQUESTED, &desc->flags))
+			requested = true;
+	}
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
+	if (requested)
+		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.
+	 */
+	cdev_device_del(&gdev->chrdev, &gdev->dev);
+	put_device(&gdev->dev);
+}
+EXPORT_SYMBOL_GPL(gpiochip_remove);
+
+static void devm_gpio_chip_release(struct device *dev, void *res)
+{
+	struct gpio_chip *chip = *(struct gpio_chip **)res;
+
+	gpiochip_remove(chip);
+}
+
+static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
+
+{
+	struct gpio_chip **r = res;
+
+	if (!r || !*r) {
+		WARN_ON(!r || !*r);
+		return 0;
+	}
+
+	return *r == data;
+}
+
+/**
+ * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
+ * @dev: the device pointer on which irq_chip belongs to.
+ * @chip: the chip to register, with chip->base initialized
+ * @data: driver-private data associated with this chip
+ *
+ * Context: potentially before irqs will work
+ *
+ * The gpio chip automatically be released when the device is unbound.
+ *
+ * Returns:
+ * A negative errno if the chip can't be registered, such as because the
+ * chip->base is invalid or already associated with a different chip.
+ * Otherwise it returns zero as a success code.
+ */
+int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
+			   void *data)
+{
+	struct gpio_chip **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
+			     GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = gpiochip_add_data(chip, data);
+	if (ret < 0) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	*ptr = chip;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
+
+/**
+ * devm_gpiochip_remove() - Resource manager of gpiochip_remove()
+ * @dev: device for which which resource was allocated
+ * @chip: the chip to remove
+ *
+ * A gpio_chip with any GPIOs still requested may not be removed.
+ */
+void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
+{
+	int ret;
+
+	ret = devres_release(dev, devm_gpio_chip_release,
+			     devm_gpio_chip_match, chip);
+	WARN_ON(ret);
+}
+EXPORT_SYMBOL_GPL(devm_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 *chip,
+					     void *data))
+{
+	struct gpio_device *gdev;
+	struct gpio_chip *chip = 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)) {
+			chip = gdev->chip;
+			break;
+		}
+
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
+	return chip;
+}
+EXPORT_SYMBOL_GPL(gpiochip_find);
+
+static int gpiochip_match_name(struct gpio_chip *chip, void *data)
+{
+	const char *name = data;
+
+	return !strcmp(chip->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_valid_mask(struct gpio_chip *gpiochip)
+{
+	if (!gpiochip->irq.need_valid_mask)
+		return 0;
+
+	gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
+	if (!gpiochip->irq.valid_mask)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
+{
+	kfree(gpiochip->irq.valid_mask);
+	gpiochip->irq.valid_mask = NULL;
+}
+
+bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
+				unsigned int offset)
+{
+	if (!gpiochip_line_is_valid(gpiochip, offset))
+		return false;
+	/* No mask means all valid */
+	if (likely(!gpiochip->irq.valid_mask))
+		return true;
+	return test_bit(offset, gpiochip->irq.valid_mask);
+}
+EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
+
+/**
+ * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
+ * @gpiochip: the gpiochip to set the irqchip chain to
+ * @irqchip: the irqchip to chain to the gpiochip
+ * @parent_irq: the irq number corresponding to the parent IRQ for this
+ * chained irqchip
+ * @parent_handler: the parent interrupt handler for the accumulated IRQ
+ * coming out of the gpiochip. If the interrupt is nested rather than
+ * cascaded, pass NULL in this handler argument
+ */
+static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
+					  struct irq_chip *irqchip,
+					  unsigned int parent_irq,
+					  irq_flow_handler_t parent_handler)
+{
+	unsigned int offset;
+
+	if (!gpiochip->irq.domain) {
+		chip_err(gpiochip, "called %s before setting up irqchip\n",
+			 __func__);
+		return;
+	}
+
+	if (parent_handler) {
+		if (gpiochip->can_sleep) {
+			chip_err(gpiochip,
+				 "you cannot have chained interrupts on a chip that may sleep\n");
+			return;
+		}
+		/*
+		 * The parent irqchip is already using the chip_data for this
+		 * irqchip, so our callbacks simply use the handler_data.
+		 */
+		irq_set_chained_handler_and_data(parent_irq, parent_handler,
+						 gpiochip);
+
+		gpiochip->irq.parent_irq = parent_irq;
+		gpiochip->irq.parents = &gpiochip->irq.parent_irq;
+		gpiochip->irq.num_parents = 1;
+	}
+
+	/* Set the parent IRQ for all affected IRQs */
+	for (offset = 0; offset < gpiochip->ngpio; offset++) {
+		if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
+			continue;
+		irq_set_parent(irq_find_mapping(gpiochip->irq.domain, offset),
+			       parent_irq);
+	}
+}
+
+/**
+ * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
+ * @gpiochip: the gpiochip to set the irqchip chain to
+ * @irqchip: the irqchip to chain to the gpiochip
+ * @parent_irq: the irq number corresponding to the parent IRQ for this
+ * chained irqchip
+ * @parent_handler: the parent interrupt handler for the accumulated IRQ
+ * coming out of the gpiochip. If the interrupt is nested rather than
+ * cascaded, pass NULL in this handler argument
+ */
+void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
+				  struct irq_chip *irqchip,
+				  unsigned int parent_irq,
+				  irq_flow_handler_t parent_handler)
+{
+	if (gpiochip->irq.threaded) {
+		chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
+		return;
+	}
+
+	gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
+				      parent_handler);
+}
+EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
+
+/**
+ * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
+ * @gpiochip: the gpiochip to set the irqchip nested handler to
+ * @irqchip: the irqchip to nest to the gpiochip
+ * @parent_irq: the irq number corresponding to the parent IRQ for this
+ * nested irqchip
+ */
+void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
+				 struct irq_chip *irqchip,
+				 unsigned int parent_irq)
+{
+	gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
+				      NULL);
+}
+EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
+
+/**
+ * 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 *chip = d->host_data;
+	int err = 0;
+
+	if (!gpiochip_irqchip_irq_valid(chip, hwirq))
+		return -ENXIO;
+
+	irq_set_chip_data(irq, chip);
+	/*
+	 * 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, chip->irq.lock_key, chip->irq.request_key);
+	irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
+	/* Chips that use nested thread handlers have them marked */
+	if (chip->irq.threaded)
+		irq_set_nested_thread(irq, 1);
+	irq_set_noprobe(irq);
+
+	if (chip->irq.num_parents == 1)
+		err = irq_set_parent(irq, chip->irq.parents[0]);
+	else if (chip->irq.map)
+		err = irq_set_parent(irq, chip->irq.map[hwirq]);
+
+	if (err < 0)
+		return err;
+
+	/*
+	 * No set-up of the hardware will happen if IRQ_TYPE_NONE
+	 * is passed as default type.
+	 */
+	if (chip->irq.default_type != IRQ_TYPE_NONE)
+		irq_set_irq_type(irq, chip->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 *chip = d->host_data;
+
+	if (chip->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,
+};
+
+static int gpiochip_irq_reqres(struct irq_data *d)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+	int ret;
+
+	if (!try_module_get(chip->gpiodev->owner))
+		return -ENODEV;
+
+	ret = gpiochip_lock_as_irq(chip, d->hwirq);
+	if (ret) {
+		chip_err(chip,
+			"unable to lock HW IRQ %lu for IRQ\n",
+			d->hwirq);
+		module_put(chip->gpiodev->owner);
+		return ret;
+	}
+	return 0;
+}
+
+static void gpiochip_irq_relres(struct irq_data *d)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+
+	gpiochip_unlock_as_irq(chip, d->hwirq);
+	module_put(chip->gpiodev->owner);
+}
+
+static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	if (!gpiochip_irqchip_irq_valid(chip, offset))
+		return -ENXIO;
+
+	return irq_create_mapping(chip->irq.domain, offset);
+}
+
+/**
+ * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
+ * @gpiochip: 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 *gpiochip,
+				struct lock_class_key *lock_key,
+				struct lock_class_key *request_key)
+{
+	struct irq_chip *irqchip = gpiochip->irq.chip;
+	const struct irq_domain_ops *ops;
+	struct device_node *np;
+	unsigned int type;
+	unsigned int i;
+
+	if (!irqchip)
+		return 0;
+
+	if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
+		chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
+		return -EINVAL;
+	}
+
+	np = gpiochip->gpiodev->dev.of_node;
+	type = gpiochip->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(np && type != IRQ_TYPE_NONE,
+		 "%s: Ignoring %u default trigger\n", np->full_name, type))
+		type = IRQ_TYPE_NONE;
+
+	if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
+		acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
+				 "Ignoring %u default trigger\n", type);
+		type = IRQ_TYPE_NONE;
+	}
+
+	gpiochip->to_irq = gpiochip_to_irq;
+	gpiochip->irq.default_type = type;
+	gpiochip->irq.lock_key = lock_key;
+	gpiochip->irq.request_key = request_key;
+
+	if (gpiochip->irq.domain_ops)
+		ops = gpiochip->irq.domain_ops;
+	else
+		ops = &gpiochip_domain_ops;
+
+	gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
+						     gpiochip->irq.first,
+						     ops, gpiochip);
+	if (!gpiochip->irq.domain)
+		return -EINVAL;
+
+	/*
+	 * It is possible for a driver to override this, but only if the
+	 * alternative functions are both implemented.
+	 */
+	if (!irqchip->irq_request_resources &&
+	    !irqchip->irq_release_resources) {
+		irqchip->irq_request_resources = gpiochip_irq_reqres;
+		irqchip->irq_release_resources = gpiochip_irq_relres;
+	}
+
+	if (gpiochip->irq.parent_handler) {
+		void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
+
+		for (i = 0; i < gpiochip->irq.num_parents; i++) {
+			/*
+			 * 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(gpiochip->irq.parents[i],
+							 gpiochip->irq.parent_handler,
+							 data);
+		}
+	}
+
+	acpi_gpiochip_request_interrupts(gpiochip);
+
+	return 0;
+}
+
+/**
+ * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
+ * @gpiochip: the gpiochip to remove the irqchip from
+ *
+ * This is called only from gpiochip_remove()
+ */
+static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
+{
+	unsigned int offset;
+
+	acpi_gpiochip_free_interrupts(gpiochip);
+
+	if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {
+		struct gpio_irq_chip *irq = &gpiochip->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 (gpiochip->irq.domain) {
+		unsigned int irq;
+
+		for (offset = 0; offset < gpiochip->ngpio; offset++) {
+			if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
+				continue;
+
+			irq = irq_find_mapping(gpiochip->irq.domain, offset);
+			irq_dispose_mapping(irq);
+		}
+
+		irq_domain_remove(gpiochip->irq.domain);
+	}
+
+	if (gpiochip->irq.chip) {
+		gpiochip->irq.chip->irq_request_resources = NULL;
+		gpiochip->irq.chip->irq_release_resources = NULL;
+		gpiochip->irq.chip = NULL;
+	}
+
+	gpiochip_irqchip_free_valid_mask(gpiochip);
+}
+
+/**
+ * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
+ * @gpiochip: the gpiochip to add the irqchip to
+ * @irqchip: the irqchip to add to the gpiochip
+ * @first_irq: if not dynamically assigned, the base (first) IRQ to
+ * allocate gpiochip irqs from
+ * @handler: the irq handler to use (often a predefined irq core function)
+ * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
+ * to have the core avoid setting up any default type in the hardware.
+ * @threaded: whether this irqchip uses a nested thread handler
+ * @lock_key: lockdep class for IRQ lock
+ * @request_key: lockdep class for IRQ request
+ *
+ * This function closely associates a certain irqchip with a certain
+ * gpiochip, providing an irq domain to translate the local IRQs to
+ * global irqs in the gpiolib core, and making sure that the gpiochip
+ * is passed as chip data to all related functions. Driver callbacks
+ * need to use gpiochip_get_data() to get their local state containers back
+ * from the gpiochip passed as chip data. An irqdomain will be stored
+ * in the gpiochip that shall be used by the driver to handle IRQ number
+ * translation. The gpiochip will need to be initialized and registered
+ * before calling this function.
+ *
+ * This function will handle two cell:ed simple IRQs and assumes all
+ * the pins on the gpiochip can generate a unique IRQ. Everything else
+ * need to be open coded.
+ */
+int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
+			     struct irq_chip *irqchip,
+			     unsigned int first_irq,
+			     irq_flow_handler_t handler,
+			     unsigned int type,
+			     bool threaded,
+			     struct lock_class_key *lock_key,
+			     struct lock_class_key *request_key)
+{
+	struct device_node *of_node;
+
+	if (!gpiochip || !irqchip)
+		return -EINVAL;
+
+	if (!gpiochip->parent) {
+		pr_err("missing gpiochip .dev parent pointer\n");
+		return -EINVAL;
+	}
+	gpiochip->irq.threaded = threaded;
+	of_node = gpiochip->parent->of_node;
+#ifdef CONFIG_OF_GPIO
+	/*
+	 * If the gpiochip has an assigned OF node this takes precedence
+	 * FIXME: get rid of this and use gpiochip->parent->of_node
+	 * everywhere
+	 */
+	if (gpiochip->of_node)
+		of_node = gpiochip->of_node;
+#endif
+	/*
+	 * 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(of_node && type != IRQ_TYPE_NONE,
+		 "%pOF: Ignoring %d default trigger\n", of_node, type))
+		type = IRQ_TYPE_NONE;
+	if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
+		acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
+				 "Ignoring %d default trigger\n", type);
+		type = IRQ_TYPE_NONE;
+	}
+
+	gpiochip->irq.chip = irqchip;
+	gpiochip->irq.handler = handler;
+	gpiochip->irq.default_type = type;
+	gpiochip->to_irq = gpiochip_to_irq;
+	gpiochip->irq.lock_key = lock_key;
+	gpiochip->irq.request_key = request_key;
+	gpiochip->irq.domain = irq_domain_add_simple(of_node,
+					gpiochip->ngpio, first_irq,
+					&gpiochip_domain_ops, gpiochip);
+	if (!gpiochip->irq.domain) {
+		gpiochip->irq.chip = NULL;
+		return -EINVAL;
+	}
+
+	/*
+	 * It is possible for a driver to override this, but only if the
+	 * alternative functions are both implemented.
+	 */
+	if (!irqchip->irq_request_resources &&
+	    !irqchip->irq_release_resources) {
+		irqchip->irq_request_resources = gpiochip_irq_reqres;
+		irqchip->irq_release_resources = gpiochip_irq_relres;
+	}
+
+	acpi_gpiochip_request_interrupts(gpiochip);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
+
+#else /* CONFIG_GPIOLIB_IRQCHIP */
+
+static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
+				       struct lock_class_key *lock_key,
+				       struct lock_class_key *request_key)
+{
+	return 0;
+}
+
+static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
+static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
+{
+	return 0;
+}
+static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
+{ }
+
+#endif /* CONFIG_GPIOLIB_IRQCHIP */
+
+/**
+ * gpiochip_generic_request() - request the gpio function for a pin
+ * @chip: the gpiochip owning the GPIO
+ * @offset: the offset of the GPIO to request for GPIO function
+ */
+int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
+{
+	return pinctrl_gpio_request(chip->gpiodev->base + offset);
+}
+EXPORT_SYMBOL_GPL(gpiochip_generic_request);
+
+/**
+ * gpiochip_generic_free() - free the gpio function from a pin
+ * @chip: 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 *chip, unsigned offset)
+{
+	pinctrl_gpio_free(chip->gpiodev->base + offset);
+}
+EXPORT_SYMBOL_GPL(gpiochip_generic_free);
+
+/**
+ * gpiochip_generic_config() - apply configuration for a pin
+ * @chip: 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 *chip, unsigned offset,
+			    unsigned long config)
+{
+	return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
+}
+EXPORT_SYMBOL_GPL(gpiochip_generic_config);
+
+#ifdef CONFIG_PINCTRL
+
+/**
+ * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
+ * @chip: 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 *chip,
+			struct pinctrl_dev *pctldev,
+			unsigned int gpio_offset, const char *pin_group)
+{
+	struct gpio_pin_range *pin_range;
+	struct gpio_device *gdev = chip->gpiodev;
+	int ret;
+
+	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
+	if (!pin_range) {
+		chip_err(chip, "failed to allocate pin ranges\n");
+		return -ENOMEM;
+	}
+
+	/* Use local offset as range ID */
+	pin_range->range.id = gpio_offset;
+	pin_range->range.gc = chip;
+	pin_range->range.name = chip->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(chip, "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
+ * @chip: 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 *chip, 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 = chip->gpiodev;
+	int ret;
+
+	pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
+	if (!pin_range) {
+		chip_err(chip, "failed to allocate pin ranges\n");
+		return -ENOMEM;
+	}
+
+	/* Use local offset as range ID */
+	pin_range->range.id = gpio_offset;
+	pin_range->range.gc = chip;
+	pin_range->range.name = chip->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(chip, "could not create pin range\n");
+		kfree(pin_range);
+		return ret;
+	}
+	chip_dbg(chip, "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
+ * @chip: the chip to remove all the mappings for
+ */
+void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
+{
+	struct gpio_pin_range *pin_range, *tmp;
+	struct gpio_device *gdev = chip->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	*chip = desc->gdev->chip;
+	int			status;
+	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 ? : "?");
+		status = 0;
+	} else {
+		kfree_const(label);
+		status = -EBUSY;
+		goto done;
+	}
+
+	if (chip->request) {
+		/* chip->request may sleep */
+		spin_unlock_irqrestore(&gpio_lock, flags);
+		offset = gpio_chip_hwgpio(desc);
+		if (gpiochip_line_is_valid(chip, offset))
+			status = chip->request(chip, offset);
+		else
+			status = -EINVAL;
+		spin_lock_irqsave(&gpio_lock, flags);
+
+		if (status < 0) {
+			desc_set_label(desc, NULL);
+			kfree_const(label);
+			clear_bit(FLAG_REQUESTED, &desc->flags);
+			goto done;
+		}
+	}
+	if (chip->get_direction) {
+		/* chip->get_direction may sleep */
+		spin_unlock_irqrestore(&gpio_lock, flags);
+		gpiod_get_direction(desc);
+		spin_lock_irqsave(&gpio_lock, flags);
+	}
+done:
+	spin_unlock_irqrestore(&gpio_lock, flags);
+	return status;
+}
+
+/*
+ * 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 status = -EPROBE_DEFER;
+	struct gpio_device *gdev;
+
+	VALIDATE_DESC(desc);
+	gdev = desc->gdev;
+
+	if (try_module_get(gdev->owner)) {
+		status = gpiod_request_commit(desc, label);
+		if (status < 0)
+			module_put(gdev->owner);
+		else
+			get_device(&gdev->dev);
+	}
+
+	if (status)
+		gpiod_dbg(desc, "%s: status %d\n", __func__, status);
+
+	return status;
+}
+
+static bool gpiod_free_commit(struct gpio_desc *desc)
+{
+	bool			ret = false;
+	unsigned long		flags;
+	struct gpio_chip	*chip;
+
+	might_sleep();
+
+	gpiod_unexport(desc);
+
+	spin_lock_irqsave(&gpio_lock, flags);
+
+	chip = desc->gdev->chip;
+	if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
+		if (chip->free) {
+			spin_unlock_irqrestore(&gpio_lock, flags);
+			might_sleep_if(chip->can_sleep);
+			chip->free(chip, 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_IS_HOGGED, &desc->flags);
+		ret = true;
+	}
+
+	spin_unlock_irqrestore(&gpio_lock, flags);
+	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
+ * @chip: 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 *chip, unsigned offset)
+{
+	struct gpio_desc *desc;
+
+	if (offset >= chip->ngpio)
+		return NULL;
+
+	desc = &chip->gpiodev->descs[offset];
+
+	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
+ * @chip: GPIO chip
+ * @hwnum: hardware number of the GPIO for which to request the descriptor
+ * @label: label for the GPIO
+ *
+ * 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 *chip, u16 hwnum,
+					    const char *label)
+{
+	struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
+	int err;
+
+	if (IS_ERR(desc)) {
+		chip_err(chip, "failed to get GPIO descriptor\n");
+		return desc;
+	}
+
+	err = gpiod_request_commit(desc, label);
+	if (err < 0)
+		return ERR_PTR(err);
+
+	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.
+ */
+
+/**
+ * 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	*chip;
+	int			status = 0;
+
+	VALIDATE_DESC(desc);
+	chip = desc->gdev->chip;
+
+	if (!chip->get && chip->direction_input) {
+		gpiod_warn(desc,
+			"%s: missing get() and direction_input() operations\n",
+			__func__);
+		return -EIO;
+	}
+
+	if (chip->direction_input) {
+		status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
+	} else if (chip->get_direction &&
+		  (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
+		gpiod_warn(desc,
+			"%s: missing direction_input() operation\n",
+			__func__);
+		return -EIO;
+	}
+	if (status == 0)
+		clear_bit(FLAG_IS_OUT, &desc->flags);
+
+	trace_gpio_direction(desc_to_gpio(desc), 1, status);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(gpiod_direction_input);
+
+static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
+				       enum pin_config_param mode)
+{
+	unsigned long config = { PIN_CONF_PACKED(mode, 0) };
+
+	return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
+}
+
+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;
+
+	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 {
+		if (gc->get_direction &&
+		    gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
+			gpiod_warn(desc,
+				"%s: missing direction_output() operation\n",
+				__func__);
+			return -EIO;
+		}
+		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)
+{
+	struct gpio_chip *gc;
+	int ret;
+
+	VALIDATE_DESC(desc);
+	if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+		value = !value;
+	else
+		value = !!value;
+
+	/* GPIOs used for IRQs shall not be set as output */
+	if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
+		gpiod_err(desc,
+			  "%s: tried to set a GPIO tied to an IRQ as output\n",
+			  __func__);
+		return -EIO;
+	}
+
+	gc = desc->gdev->chip;
+	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
+		/* First see if we can enable open drain in hardware */
+		ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(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_drive_single_ended(gc, gpio_chip_hwgpio(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_drive_single_ended(gc, gpio_chip_hwgpio(desc),
+					    PIN_CONFIG_DRIVE_PUSH_PULL);
+	}
+
+set_output_value:
+	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_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 debounce)
+{
+	struct gpio_chip	*chip;
+	unsigned long		config;
+
+	VALIDATE_DESC(desc);
+	chip = desc->gdev->chip;
+	if (!chip->set || !chip->set_config) {
+		gpiod_dbg(desc,
+			  "%s: missing set() or set_config() operations\n",
+			  __func__);
+		return -ENOTSUPP;
+	}
+
+	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
+	return chip->set_config(chip, gpio_chip_hwgpio(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)
+{
+	struct gpio_chip *chip;
+	unsigned long packed;
+	int gpio;
+	int rc;
+
+	VALIDATE_DESC(desc);
+	/*
+	 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
+	 * persistence state.
+	 */
+	if (transitory)
+		set_bit(FLAG_TRANSITORY, &desc->flags);
+	else
+		clear_bit(FLAG_TRANSITORY, &desc->flags);
+
+	/* If the driver supports it, set the persistence state now */
+	chip = desc->gdev->chip;
+	if (!chip->set_config)
+		return 0;
+
+	packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
+					  !transitory);
+	gpio = gpio_chip_hwgpio(desc);
+	rc = chip->set_config(chip, gpio, packed);
+	if (rc == -ENOTSUPP) {
+		dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
+				gpio);
+		return 0;
+	}
+
+	return rc;
+}
+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);
+
+/* 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	*chip;
+	int offset;
+	int value;
+
+	chip = desc->gdev->chip;
+	offset = gpio_chip_hwgpio(desc);
+	value = chip->get ? chip->get(chip, 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 *chip,
+				  unsigned long *mask, unsigned long *bits)
+{
+	if (chip->get_multiple) {
+		return chip->get_multiple(chip, mask, bits);
+	} else if (chip->get) {
+		int i, value;
+
+		for_each_set_bit(i, mask, chip->ngpio) {
+			value = chip->get(chip, 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,
+				  int *value_array)
+{
+	int i = 0;
+
+	while (i < array_size) {
+		struct gpio_chip *chip = desc_array[i]->gdev->chip;
+		unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
+		unsigned long *mask, *bits;
+		int first, j, ret;
+
+		if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
+			mask = fastpath;
+		} else {
+			mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
+					   sizeof(*mask),
+					   can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+			if (!mask)
+				return -ENOMEM;
+		}
+
+		bits = mask + BITS_TO_LONGS(chip->ngpio);
+		bitmap_zero(mask, chip->ngpio);
+
+		if (!can_sleep)
+			WARN_ON(chip->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++;
+		} while ((i < array_size) &&
+			 (desc_array[i]->gdev->chip == chip));
+
+		ret = gpio_chip_get_multiple(chip, mask, bits);
+		if (ret) {
+			if (mask != fastpath)
+				kfree(mask);
+			return ret;
+		}
+
+		for (j = first; j < i; j++) {
+			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;
+			value_array[j] = value;
+			trace_gpio_value(desc_to_gpio(desc), 1, value);
+		}
+
+		if (mask != fastpath)
+			kfree(mask);
+	}
+	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 should 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 should 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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be read
+ * @value_array: array 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 should 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, int *value_array)
+{
+	if (!desc_array)
+		return -EINVAL;
+	return gpiod_get_array_value_complex(true, false, array_size,
+					     desc_array, value_array);
+}
+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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be read
+ * @value_array: array 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 should 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, int *value_array)
+{
+	if (!desc_array)
+		return -EINVAL;
+	return gpiod_get_array_value_complex(false, false, array_size,
+					     desc_array, value_array);
+}
+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 err = 0;
+	struct gpio_chip *chip = desc->gdev->chip;
+	int offset = gpio_chip_hwgpio(desc);
+
+	if (value) {
+		err = chip->direction_input(chip, offset);
+	} else {
+		err = chip->direction_output(chip, offset, 0);
+		if (!err)
+			set_bit(FLAG_IS_OUT, &desc->flags);
+	}
+	trace_gpio_direction(desc_to_gpio(desc), value, err);
+	if (err < 0)
+		gpiod_err(desc,
+			  "%s: Error in set_value for open drain err %d\n",
+			  __func__, err);
+}
+
+/*
+ *  _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 err = 0;
+	struct gpio_chip *chip = desc->gdev->chip;
+	int offset = gpio_chip_hwgpio(desc);
+
+	if (value) {
+		err = chip->direction_output(chip, offset, 1);
+		if (!err)
+			set_bit(FLAG_IS_OUT, &desc->flags);
+	} else {
+		err = chip->direction_input(chip, offset);
+	}
+	trace_gpio_direction(desc_to_gpio(desc), !value, err);
+	if (err < 0)
+		gpiod_err(desc,
+			  "%s: Error in set_value for open source err %d\n",
+			  __func__, err);
+}
+
+static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
+{
+	struct gpio_chip	*chip;
+
+	chip = desc->gdev->chip;
+	trace_gpio_value(desc_to_gpio(desc), 0, value);
+	chip->set(chip, 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;
+ * @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 *chip,
+				   unsigned long *mask, unsigned long *bits)
+{
+	if (chip->set_multiple) {
+		chip->set_multiple(chip, mask, bits);
+	} else {
+		unsigned int i;
+
+		/* set outputs if the corresponding mask bit is set */
+		for_each_set_bit(i, mask, chip->ngpio)
+			chip->set(chip, 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,
+				   int *value_array)
+{
+	int i = 0;
+
+	while (i < array_size) {
+		struct gpio_chip *chip = desc_array[i]->gdev->chip;
+		unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
+		unsigned long *mask, *bits;
+		int count = 0;
+
+		if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
+			mask = fastpath;
+		} else {
+			mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
+					   sizeof(*mask),
+					   can_sleep ? GFP_KERNEL : GFP_ATOMIC);
+			if (!mask)
+				return -ENOMEM;
+		}
+
+		bits = mask + BITS_TO_LONGS(chip->ngpio);
+		bitmap_zero(mask, chip->ngpio);
+
+		if (!can_sleep)
+			WARN_ON(chip->can_sleep);
+
+		do {
+			struct gpio_desc *desc = desc_array[i];
+			int hwgpio = gpio_chip_hwgpio(desc);
+			int value = value_array[i];
+
+			if (!raw && 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);
+				if (value)
+					__set_bit(hwgpio, bits);
+				else
+					__clear_bit(hwgpio, bits);
+				count++;
+			}
+			i++;
+		} while ((i < array_size) &&
+			 (desc_array[i]->gdev->chip == chip));
+		/* push collected bits to outputs */
+		if (count != 0)
+			gpio_chip_set_multiple(chip, mask, bits);
+
+		if (mask != fastpath)
+			kfree(mask);
+	}
+	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 should 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 should 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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be assigned
+ * @value_array: array 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 should 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, int *value_array)
+{
+	if (!desc_array)
+		return -EINVAL;
+	return gpiod_set_array_value_complex(true, false, array_size,
+					desc_array, value_array);
+}
+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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be assigned
+ * @value_array: array of values to assign
+ *
+ * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
+ * into account.
+ *
+ * This function should be called from contexts where we cannot sleep, and will
+ * complain if the GPIO chip functions potentially sleep.
+ */
+void gpiod_set_array_value(unsigned int array_size,
+			   struct gpio_desc **desc_array, int *value_array)
+{
+	if (!desc_array)
+		return;
+	gpiod_set_array_value_complex(false, false, array_size, desc_array,
+				      value_array);
+}
+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 *chip;
+	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;
+
+	chip = desc->gdev->chip;
+	offset = gpio_chip_hwgpio(desc);
+	if (chip->to_irq) {
+		int retirq = chip->to_irq(chip, offset);
+
+		/* Zero means NO_IRQ */
+		if (!retirq)
+			return -ENXIO;
+
+		return retirq;
+	}
+	return -ENXIO;
+}
+EXPORT_SYMBOL_GPL(gpiod_to_irq);
+
+/**
+ * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
+ * @chip: 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 *chip, unsigned int offset)
+{
+	struct gpio_desc *desc;
+
+	desc = gpiochip_get_desc(chip, offset);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	/*
+	 * If it's fast: flush the direction setting if something changed
+	 * behind our back
+	 */
+	if (!chip->can_sleep && chip->get_direction) {
+		int dir = gpiod_get_direction(desc);
+
+		if (dir < 0) {
+			chip_err(chip, "%s: cannot get GPIO direction\n",
+				 __func__);
+			return dir;
+		}
+	}
+
+	if (test_bit(FLAG_IS_OUT, &desc->flags)) {
+		chip_err(chip,
+			 "%s: tried to flag a GPIO set as output for IRQ\n",
+			 __func__);
+		return -EIO;
+	}
+
+	set_bit(FLAG_USED_AS_IRQ, &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
+ * @chip: 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 *chip, unsigned int offset)
+{
+	struct gpio_desc *desc;
+
+	desc = gpiochip_get_desc(chip, offset);
+	if (IS_ERR(desc))
+		return;
+
+	clear_bit(FLAG_USED_AS_IRQ, &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);
+
+bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	if (offset >= chip->ngpio)
+		return false;
+
+	return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
+}
+EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
+
+bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
+{
+	if (offset >= chip->ngpio)
+		return false;
+
+	return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
+}
+EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
+
+bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
+{
+	if (offset >= chip->ngpio)
+		return false;
+
+	return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
+}
+EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
+
+bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
+{
+	if (offset >= chip->ngpio)
+		return false;
+
+	return !test_bit(FLAG_TRANSITORY, &chip->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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be read
+ * @value_array: array 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,
+				       int *value_array)
+{
+	might_sleep_if(extra_checks);
+	if (!desc_array)
+		return -EINVAL;
+	return gpiod_get_array_value_complex(true, true, array_size,
+					     desc_array, value_array);
+}
+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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be read
+ * @value_array: array 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,
+				   int *value_array)
+{
+	might_sleep_if(extra_checks);
+	if (!desc_array)
+		return -EINVAL;
+	return gpiod_get_array_value_complex(false, true, array_size,
+					     desc_array, value_array);
+}
+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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be assigned
+ * @value_array: array 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,
+					int *value_array)
+{
+	might_sleep_if(extra_checks);
+	if (!desc_array)
+		return -EINVAL;
+	return gpiod_set_array_value_complex(true, true, array_size, desc_array,
+				      value_array);
+}
+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 / value arrays
+ * @desc_array: array of GPIO descriptors whose values will be assigned
+ * @value_array: array 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.
+ */
+void gpiod_set_array_value_cansleep(unsigned int array_size,
+				    struct gpio_desc **desc_array,
+				    int *value_array)
+{
+	might_sleep_if(extra_checks);
+	if (!desc_array)
+		return;
+	gpiod_set_array_value_complex(false, true, array_size, desc_array,
+				      value_array);
+}
+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)
+{
+	mutex_lock(&gpio_lookup_lock);
+
+	list_add_tail(&table->list, &gpio_lookup_list);
+
+	mutex_unlock(&gpio_lookup_lock);
+}
+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)
+{
+	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 *chip;
+	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.
+		 */
+		chip = find_chip_by_name(hog->chip_label);
+		if (chip)
+			gpiochip_machine_hog(chip, hog);
+	}
+
+	mutex_unlock(&gpio_machine_hogs_mutex);
+}
+EXPORT_SYMBOL_GPL(gpiod_add_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,
+				    enum gpio_lookup_flags *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->chip_label; p++) {
+		struct gpio_chip *chip;
+
+		/* 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;
+
+		chip = find_chip_by_name(p->chip_label);
+
+		if (!chip) {
+			/*
+			 * As the lookup table indicates a chip with
+			 * p->chip_label 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->chip_label);
+			return ERR_PTR(-EPROBE_DEFER);
+		}
+
+		if (chip->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, chip->ngpio - 1,
+				chip->label);
+			return ERR_PTR(-EINVAL);
+		}
+
+		desc = gpiochip_get_desc(chip, p->chip_hwnum);
+		*flags = p->flags;
+
+		return desc;
+	}
+
+	return desc;
+}
+
+static int dt_gpio_count(struct device *dev, const char *con_id)
+{
+	int ret;
+	char propname[32];
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+		if (con_id)
+			snprintf(propname, sizeof(propname), "%s-%s",
+				 con_id, gpio_suffixes[i]);
+		else
+			snprintf(propname, sizeof(propname), "%s",
+				 gpio_suffixes[i]);
+
+		ret = of_gpio_named_count(dev->of_node, propname);
+		if (ret > 0)
+			break;
+	}
+	return ret ? ret : -ENOENT;
+}
+
+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->chip_label; 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;
+}
+
+/**
+ * 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)
+{
+	int count = -ENOENT;
+
+	if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
+		count = dt_gpio_count(dev, con_id);
+	else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
+		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:	gpio_lookup_flags - 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 status;
+
+	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);
+
+	status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
+	if (status < 0)
+		return status;
+
+	/* No particular flag request, return here... */
+	if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
+		pr_debug("no flags found for %s\n", con_id);
+		return 0;
+	}
+
+	/* Process flags */
+	if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
+		status = gpiod_direction_output(desc,
+				!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
+	else
+		status = gpiod_direction_input(desc);
+
+	return status;
+}
+
+/**
+ * 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)
+{
+	struct gpio_desc *desc = NULL;
+	int status;
+	enum gpio_lookup_flags lookupflags = 0;
+	/* Maybe we have a device name, maybe not */
+	const char *devname = dev ? dev_name(dev) : "?";
+
+	dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
+
+	if (dev) {
+		/* Using device tree? */
+		if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
+			dev_dbg(dev, "using device tree for GPIO lookup\n");
+			desc = of_find_gpio(dev, con_id, idx, &lookupflags);
+		} else if (ACPI_COMPANION(dev)) {
+			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 || desc == ERR_PTR(-ENOENT)) {
+		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
+	 */
+	status = gpiod_request(desc, con_id ? con_id : devname);
+	if (status < 0)
+		return ERR_PTR(status);
+
+	status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
+	if (status < 0) {
+		dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
+		gpiod_put(desc);
+		return ERR_PTR(status);
+	}
+
+	return desc;
+}
+EXPORT_SYMBOL_GPL(gpiod_get_index);
+
+/**
+ * gpiod_get_from_of_node() - obtain a GPIO from an OF node
+ * @node:	handle of the OF node
+ * @propname:	name of the DT 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
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @dflags. If the node does not have the requested GPIO
+ * property, NULL is returned.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
+					 const char *propname, int index,
+					 enum gpiod_flags dflags,
+					 const char *label)
+{
+	struct gpio_desc *desc;
+	unsigned long lflags = 0;
+	enum of_gpio_flags flags;
+	bool active_low = false;
+	bool single_ended = false;
+	bool open_drain = false;
+	bool transitory = false;
+	int ret;
+
+	desc = of_get_named_gpiod_flags(node, propname,
+					index, &flags);
+
+	if (!desc || IS_ERR(desc)) {
+		/* If it is not there, just return NULL */
+		if (PTR_ERR(desc) == -ENOENT)
+			return NULL;
+		return desc;
+	}
+
+	active_low = flags & OF_GPIO_ACTIVE_LOW;
+	single_ended = flags & OF_GPIO_SINGLE_ENDED;
+	open_drain = flags & OF_GPIO_OPEN_DRAIN;
+	transitory = flags & OF_GPIO_TRANSITORY;
+
+	ret = gpiod_request(desc, label);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (active_low)
+		lflags |= GPIO_ACTIVE_LOW;
+
+	if (single_ended) {
+		if (open_drain)
+			lflags |= GPIO_OPEN_DRAIN;
+		else
+			lflags |= GPIO_OPEN_SOURCE;
+	}
+
+	if (transitory)
+		lflags |= GPIO_TRANSITORY;
+
+	ret = gpiod_configure_flags(desc, propname, lflags, dflags);
+	if (ret < 0) {
+		gpiod_put(desc);
+		return ERR_PTR(ret);
+	}
+
+	return desc;
+}
+EXPORT_SYMBOL(gpiod_get_from_of_node);
+
+/**
+ * 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)
+{
+	struct gpio_desc *desc = ERR_PTR(-ENODEV);
+	unsigned long lflags = 0;
+	int ret;
+
+	if (!fwnode)
+		return ERR_PTR(-EINVAL);
+
+	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);
+
+		if (info.polarity == GPIO_ACTIVE_LOW)
+			lflags |= GPIO_ACTIVE_LOW;
+	}
+
+	/* 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);
+	}
+
+	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 (IS_ERR(desc)) {
+		if (PTR_ERR(desc) == -ENOENT)
+			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:	gpio_lookup_flags - 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 *chip;
+	struct gpio_desc *local_desc;
+	int hwnum;
+	int status;
+
+	chip = gpiod_to_chip(desc);
+	hwnum = gpio_chip_hwgpio(desc);
+
+	local_desc = gpiochip_request_own_desc(chip, hwnum, name);
+	if (IS_ERR(local_desc)) {
+		status = PTR_ERR(local_desc);
+		pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
+		       name, chip->label, hwnum, status);
+		return status;
+	}
+
+	status = gpiod_configure_flags(desc, name, lflags, dflags);
+	if (status < 0) {
+		pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
+		       name, chip->label, hwnum, status);
+		gpiochip_free_own_desc(desc);
+		return status;
+	}
+
+	/* Mark GPIO as hogged so it can be identified and removed later */
+	set_bit(FLAG_IS_HOGGED, &desc->flags);
+
+	pr_info("GPIO line %d (%s) hogged as %s%s\n",
+		desc_to_gpio(desc), name,
+		(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
+ * @chip:	gpio chip to act on
+ *
+ * This is only used by of_gpiochip_remove to free hogged gpios
+ */
+static void gpiochip_free_hogs(struct gpio_chip *chip)
+{
+	int id;
+
+	for (id = 0; id < chip->ngpio; id++) {
+		if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
+			gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
+	}
+}
+
+/**
+ * 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;
+	int count;
+
+	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;
+		descs->ndescs++;
+	}
+	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 (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
+		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)
+{
+	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 __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 = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
+	if (ret < 0) {
+		pr_err("gpiolib: failed to allocate char dev region\n");
+		bus_unregister(&gpio_bus_type);
+	} else {
+		gpiolib_initialized = true;
+		gpiochip_setup_devs();
+	}
+	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	*chip = gdev->chip;
+	unsigned		gpio = gdev->base;
+	struct gpio_desc	*gdesc = &gdev->descs[0];
+	int			is_out;
+	int			is_irq;
+
+	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);
+		seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
+			gpio, gdesc->name ? gdesc->name : "", gdesc->label,
+			is_out ? "out" : "in ",
+			chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "?  ",
+			is_irq ? "IRQ" : "   ");
+		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_entry(gdev->list.next, 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 *chip = gdev->chip;
+	struct device *parent;
+
+	if (!chip) {
+		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 = chip->parent;
+	if (parent)
+		seq_printf(s, ", parent: %s/%s",
+			   parent->bus ? parent->bus->name : "no-bus",
+			   dev_name(parent));
+	if (chip->label)
+		seq_printf(s, ", %s", chip->label);
+	if (chip->can_sleep)
+		seq_printf(s, ", can sleep");
+	seq_printf(s, ":\n");
+
+	if (chip->dbg_show)
+		chip->dbg_show(s, chip);
+	else
+		gpiolib_dbg_show(s, gdev);
+
+	return 0;
+}
+
+static const struct seq_operations gpiolib_seq_ops = {
+	.start = gpiolib_seq_start,
+	.next = gpiolib_seq_next,
+	.stop = gpiolib_seq_stop,
+	.show = gpiolib_seq_show,
+};
+
+static int gpiolib_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &gpiolib_seq_ops);
+}
+
+static const struct file_operations gpiolib_operations = {
+	.owner		= THIS_MODULE,
+	.open		= gpiolib_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int __init gpiolib_debugfs_init(void)
+{
+	/* /sys/kernel/debug/gpio */
+	(void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
+				NULL, NULL, &gpiolib_operations);
+	return 0;
+}
+subsys_initcall(gpiolib_debugfs_init);
+
+#endif	/* DEBUG_FS */