--- /dev/null
+#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 "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
+
+/* 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);
+
+#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
+
+static DEFINE_MUTEX(gpio_lookup_lock);
+static LIST_HEAD(gpio_lookup_list);
+LIST_HEAD(gpio_chips);
+
+
+static void gpiochip_free_hogs(struct gpio_chip *chip);
+static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
+
+
+static inline void desc_set_label(struct gpio_desc *d, const char *label)
+{
+ d->label = label;
+}
+
+/**
+ * Convert a GPIO number to its descriptor
+ */
+struct gpio_desc *gpio_to_desc(unsigned gpio)
+{
+ struct gpio_chip *chip;
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ list_for_each_entry(chip, &gpio_chips, list) {
+ if (chip->base <= gpio && chip->base + chip->ngpio > gpio) {
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ return &chip->desc[gpio - chip->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);
+
+/**
+ * Get the GPIO descriptor corresponding to the given hw number for this chip.
+ */
+struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
+ u16 hwnum)
+{
+ if (hwnum >= chip->ngpio)
+ return ERR_PTR(-EINVAL);
+
+ return &chip->desc[hwnum];
+}
+
+/**
+ * Convert a GPIO descriptor to the integer namespace.
+ * This should disappear in the future but is needed since we still
+ * use GPIO numbers for error messages and sysfs nodes
+ */
+int desc_to_gpio(const struct gpio_desc *desc)
+{
+ return desc->chip->base + (desc - &desc->chip->desc[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)
+{
+ return desc ? desc->chip : NULL;
+}
+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_chip *chip;
+ int base = ARCH_NR_GPIOS - ngpio;
+
+ list_for_each_entry_reverse(chip, &gpio_chips, list) {
+ /* found a free space? */
+ if (chip->base + chip->ngpio <= base)
+ break;
+ else
+ /* nope, check the space right before the chip */
+ base = chip->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
+ *
+ * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, 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);
+
+ 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 base order.
+ *
+ * Return -EBUSY if the new chip overlaps with some other chip's integer
+ * space.
+ */
+static int gpiochip_add_to_list(struct gpio_chip *chip)
+{
+ struct list_head *pos = &gpio_chips;
+ struct gpio_chip *_chip;
+ int err = 0;
+
+ /* find where to insert our chip */
+ list_for_each(pos, &gpio_chips) {
+ _chip = list_entry(pos, struct gpio_chip, list);
+ /* shall we insert before _chip? */
+ if (_chip->base >= chip->base + chip->ngpio)
+ break;
+ }
+
+ /* are we stepping on the chip right before? */
+ if (pos != &gpio_chips && pos->prev != &gpio_chips) {
+ _chip = list_entry(pos->prev, struct gpio_chip, list);
+ if (_chip->base + _chip->ngpio > chip->base) {
+ dev_err(chip->dev,
+ "GPIO integer space overlap, cannot add chip\n");
+ err = -EBUSY;
+ }
+ }
+
+ if (!err)
+ list_add_tail(&chip->list, pos);
+
+ return err;
+}
+
+/**
+ * gpiochip_add() - register a gpio_chip
+ * @chip: the chip to register, with chip->base initialized
+ * Context: potentially before irqs will work
+ *
+ * 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.
+ *
+ * When gpiochip_add() is called very early during boot, so that GPIOs
+ * can be freely used, the chip->dev device must be registered before
+ * the gpio framework's arch_initcall(). Otherwise sysfs initialization
+ * for GPIOs will fail rudely.
+ *
+ * If chip->base is negative, this requests dynamic assignment of
+ * a range of valid GPIOs.
+ */
+int gpiochip_add(struct gpio_chip *chip)
+{
+ unsigned long flags;
+ int status = 0;
+ unsigned id;
+ int base = chip->base;
+ struct gpio_desc *descs;
+
+ descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL);
+ if (!descs)
+ return -ENOMEM;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ if (base < 0) {
+ base = gpiochip_find_base(chip->ngpio);
+ if (base < 0) {
+ status = base;
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ goto err_free_descs;
+ }
+ chip->base = base;
+ }
+
+ status = gpiochip_add_to_list(chip);
+ if (status) {
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ goto err_free_descs;
+ }
+
+ for (id = 0; id < chip->ngpio; id++) {
+ struct gpio_desc *desc = &descs[id];
+
+ desc->chip = chip;
+
+ /* 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;
+ }
+
+ chip->desc = descs;
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+#ifdef CONFIG_PINCTRL
+ INIT_LIST_HEAD(&chip->pin_ranges);
+#endif
+
+ of_gpiochip_add(chip);
+ acpi_gpiochip_add(chip);
+
+ status = gpiochip_export(chip);
+ if (status)
+ goto err_remove_chip;
+
+ pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
+ chip->base, chip->base + chip->ngpio - 1,
+ chip->label ? : "generic");
+
+ return 0;
+
+err_remove_chip:
+ acpi_gpiochip_remove(chip);
+ gpiochip_free_hogs(chip);
+ of_gpiochip_remove(chip);
+ spin_lock_irqsave(&gpio_lock, flags);
+ list_del(&chip->list);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ chip->desc = NULL;
+err_free_descs:
+ kfree(descs);
+
+ /* failures here can mean systems won't boot... */
+ pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
+ chip->base, chip->base + chip->ngpio - 1,
+ chip->label ? : "generic");
+ return status;
+}
+EXPORT_SYMBOL_GPL(gpiochip_add);
+
+/**
+ * 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)
+{
+ unsigned long flags;
+ unsigned id;
+
+ gpiochip_unexport(chip);
+
+ gpiochip_irqchip_remove(chip);
+
+ acpi_gpiochip_remove(chip);
+ gpiochip_remove_pin_ranges(chip);
+ gpiochip_free_hogs(chip);
+ of_gpiochip_remove(chip);
+
+ spin_lock_irqsave(&gpio_lock, flags);
+ for (id = 0; id < chip->ngpio; id++) {
+ if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags))
+ dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
+ }
+ for (id = 0; id < chip->ngpio; id++)
+ chip->desc[id].chip = NULL;
+
+ list_del(&chip->list);
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ kfree(chip->desc);
+ chip->desc = NULL;
+}
+EXPORT_SYMBOL_GPL(gpiochip_remove);
+
+/**
+ * gpiochip_find() - iterator for locating a specific gpio_chip
+ * @data: data to pass to match function
+ * @callback: 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_chip *chip;
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+ list_for_each_entry(chip, &gpio_chips, list)
+ if (match(chip, data))
+ break;
+
+ /* No match? */
+ if (&chip->list == &gpio_chips)
+ chip = NULL;
+ 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.
+ */
+
+/**
+ * gpiochip_set_chained_irqchip() - sets 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,
+ int parent_irq,
+ irq_flow_handler_t parent_handler)
+{
+ unsigned int offset;
+
+ if (!gpiochip->irqdomain) {
+ 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_handler_data(parent_irq, gpiochip);
+ irq_set_chained_handler(parent_irq, parent_handler);
+ }
+
+ /* Set the parent IRQ for all affected IRQs */
+ for (offset = 0; offset < gpiochip->ngpio; offset++)
+ irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
+ parent_irq);
+}
+EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
+
+/*
+ * This lock class tells lockdep that GPIO irqs are in a different
+ * category than their parents, so it won't report false recursion.
+ */
+static struct lock_class_key gpiochip_irq_lock_class;
+
+/**
+ * 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.
+ */
+static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ struct gpio_chip *chip = d->host_data;
+
+ irq_set_chip_data(irq, chip);
+ irq_set_lockdep_class(irq, &gpiochip_irq_lock_class);
+ irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
+ /* Chips that can sleep need nested thread handlers */
+ if (chip->can_sleep && !chip->irq_not_threaded)
+ irq_set_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, IRQF_VALID);
+#else
+ irq_set_noprobe(irq);
+#endif
+ /*
+ * 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;
+}
+
+static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
+{
+ struct gpio_chip *chip = d->host_data;
+
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, 0);
+#endif
+ if (chip->can_sleep)
+ irq_set_nested_thread(irq, 0);
+ irq_set_chip_and_handler(irq, NULL, NULL);
+ irq_set_chip_data(irq, NULL);
+}
+
+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);
+
+ if (gpiochip_lock_as_irq(chip, d->hwirq)) {
+ chip_err(chip,
+ "unable to lock HW IRQ %lu for IRQ\n",
+ d->hwirq);
+ return -EINVAL;
+ }
+ 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);
+}
+
+static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ return irq_find_mapping(chip->irqdomain, offset);
+}
+
+/**
+ * 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);
+
+ /* Remove all IRQ mappings and delete the domain */
+ if (gpiochip->irqdomain) {
+ for (offset = 0; offset < gpiochip->ngpio; offset++)
+ irq_dispose_mapping(
+ irq_find_mapping(gpiochip->irqdomain, offset));
+ irq_domain_remove(gpiochip->irqdomain);
+ }
+
+ if (gpiochip->irqchip) {
+ gpiochip->irqchip->irq_request_resources = NULL;
+ gpiochip->irqchip->irq_release_resources = NULL;
+ gpiochip->irqchip = NULL;
+ }
+}
+
+/**
+ * gpiochip_irqchip_add() - 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.
+ *
+ * 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 container_of() 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(struct gpio_chip *gpiochip,
+ struct irq_chip *irqchip,
+ unsigned int first_irq,
+ irq_flow_handler_t handler,
+ unsigned int type)
+{
+ struct device_node *of_node;
+ unsigned int offset;
+ unsigned irq_base = 0;
+
+ if (!gpiochip || !irqchip)
+ return -EINVAL;
+
+ if (!gpiochip->dev) {
+ pr_err("missing gpiochip .dev parent pointer\n");
+ return -EINVAL;
+ }
+ of_node = gpiochip->dev->of_node;
+#ifdef CONFIG_OF_GPIO
+ /*
+ * If the gpiochip has an assigned OF node this takes precendence
+ * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
+ */
+ if (gpiochip->of_node)
+ of_node = gpiochip->of_node;
+#endif
+ gpiochip->irqchip = irqchip;
+ gpiochip->irq_handler = handler;
+ gpiochip->irq_default_type = type;
+ gpiochip->to_irq = gpiochip_to_irq;
+ gpiochip->irqdomain = irq_domain_add_simple(of_node,
+ gpiochip->ngpio, first_irq,
+ &gpiochip_domain_ops, gpiochip);
+ if (!gpiochip->irqdomain) {
+ gpiochip->irqchip = NULL;
+ return -EINVAL;
+ }
+ irqchip->irq_request_resources = gpiochip_irq_reqres;
+ irqchip->irq_release_resources = gpiochip_irq_relres;
+
+ /*
+ * Prepare the mapping since the irqchip shall be orthogonal to
+ * any gpiochip calls. If the first_irq was zero, this is
+ * necessary to allocate descriptors for all IRQs.
+ */
+ for (offset = 0; offset < gpiochip->ngpio; offset++) {
+ irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
+ if (offset == 0)
+ /*
+ * Store the base into the gpiochip to be used when
+ * unmapping the irqs.
+ */
+ gpiochip->irq_base = irq_base;
+ }
+
+ acpi_gpiochip_request_interrupts(gpiochip);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
+
+#else /* CONFIG_GPIOLIB_IRQCHIP */
+
+static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
+
+#endif /* CONFIG_GPIOLIB_IRQCHIP */
+
+#ifdef CONFIG_PINCTRL
+
+/**
+ * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
+ * @chip: the gpiochip to add the range for
+ * @pinctrl: the dev_name() of 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
+ */
+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;
+ 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 = chip->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, &chip->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
+ * @pinctrl_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
+ */
+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;
+ 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 = chip->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, &chip->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;
+
+ list_for_each_entry_safe(pin_range, tmp, &chip->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(struct gpio_desc *desc, const char *label)
+{
+ struct gpio_chip *chip = desc->chip;
+ int status;
+ unsigned long flags;
+
+ 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 {
+ status = -EBUSY;
+ goto done;
+ }
+
+ if (chip->request) {
+ /* chip->request may sleep */
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ status = chip->request(chip, gpio_chip_hwgpio(desc));
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ if (status < 0) {
+ desc_set_label(desc, NULL);
+ 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;
+}
+
+int gpiod_request(struct gpio_desc *desc, const char *label)
+{
+ int status = -EPROBE_DEFER;
+ struct gpio_chip *chip;
+
+ if (!desc) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+
+ chip = desc->chip;
+ if (!chip)
+ goto done;
+
+ if (try_module_get(chip->owner)) {
+ status = __gpiod_request(desc, label);
+ if (status < 0)
+ module_put(chip->owner);
+ }
+
+done:
+ if (status)
+ gpiod_dbg(desc, "%s: status %d\n", __func__, status);
+
+ return status;
+}
+
+static bool __gpiod_free(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->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);
+ }
+ 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 && __gpiod_free(desc))
+ module_put(desc->chip->owner);
+ 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 (!GPIO_OFFSET_VALID(chip, offset))
+ return NULL;
+
+ desc = &chip->desc[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
+ * @desc: GPIO descriptor to request
+ * @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).
+ */
+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(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(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 = -EINVAL;
+
+ if (!desc || !desc->chip) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+
+ chip = desc->chip;
+ if (!chip->get || !chip->direction_input) {
+ gpiod_warn(desc,
+ "%s: missing get() or direction_input() operations\n",
+ __func__);
+ return -EIO;
+ }
+
+ status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
+ 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 _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
+{
+ struct gpio_chip *chip;
+ int status = -EINVAL;
+
+ /* 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;
+ }
+
+ /* Open drain pin should not be driven to 1 */
+ if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+ return gpiod_direction_input(desc);
+
+ /* Open source pin should not be driven to 0 */
+ if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+ return gpiod_direction_input(desc);
+
+ chip = desc->chip;
+ if (!chip->set || !chip->direction_output) {
+ gpiod_warn(desc,
+ "%s: missing set() or direction_output() operations\n",
+ __func__);
+ return -EIO;
+ }
+
+ status = chip->direction_output(chip, gpio_chip_hwgpio(desc), value);
+ if (status == 0)
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ trace_gpio_value(desc_to_gpio(desc), 0, value);
+ trace_gpio_direction(desc_to_gpio(desc), 0, status);
+ return status;
+}
+
+/**
+ * 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)
+{
+ if (!desc || !desc->chip) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+ return _gpiod_direction_output_raw(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)
+{
+ if (!desc || !desc->chip) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+ return _gpiod_direction_output_raw(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_direction_output);
+
+/**
+ * gpiod_set_debounce - sets @debounce time for a @gpio
+ * @gpio: the gpio to set debounce time
+ * @debounce: debounce time is microseconds
+ *
+ * returns -ENOTSUPP if the controller does not support setting
+ * debounce.
+ */
+int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
+{
+ struct gpio_chip *chip;
+
+ if (!desc || !desc->chip) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+
+ chip = desc->chip;
+ if (!chip->set || !chip->set_debounce) {
+ gpiod_dbg(desc,
+ "%s: missing set() or set_debounce() operations\n",
+ __func__);
+ return -ENOTSUPP;
+ }
+
+ return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_debounce);
+
+/**
+ * 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)
+{
+ 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 bool _gpiod_get_raw_value(const struct gpio_desc *desc)
+{
+ struct gpio_chip *chip;
+ bool value;
+ int offset;
+
+ chip = desc->chip;
+ offset = gpio_chip_hwgpio(desc);
+ value = chip->get ? chip->get(chip, offset) : false;
+ trace_gpio_value(desc_to_gpio(desc), 1, value);
+ return value;
+}
+
+/**
+ * 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.
+ *
+ * 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)
+{
+ if (!desc)
+ return 0;
+ /* Should be using gpio_get_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+ return _gpiod_get_raw_value(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.
+ *
+ * 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;
+ if (!desc)
+ return 0;
+ /* Should be using gpio_get_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+
+ value = _gpiod_get_raw_value(desc);
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+
+ return value;
+}
+EXPORT_SYMBOL_GPL(gpiod_get_value);
+
+/*
+ * _gpio_set_open_drain_value() - Set the open drain gpio's value.
+ * @desc: gpio descriptor whose state need to be set.
+ * @value: Non-zero for setting it HIGH otherise it will set to LOW.
+ */
+static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
+{
+ int err = 0;
+ struct gpio_chip *chip = desc->chip;
+ int offset = gpio_chip_hwgpio(desc);
+
+ if (value) {
+ err = chip->direction_input(chip, offset);
+ if (!err)
+ clear_bit(FLAG_IS_OUT, &desc->flags);
+ } 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 otherise it will set to LOW.
+ */
+static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
+{
+ int err = 0;
+ struct gpio_chip *chip = desc->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);
+ if (!err)
+ clear_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 source err %d\n",
+ __func__, err);
+}
+
+static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
+{
+ struct gpio_chip *chip;
+
+ chip = desc->chip;
+ trace_gpio_value(desc_to_gpio(desc), 0, value);
+ if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+ _gpio_set_open_drain_value(desc, value);
+ else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+ _gpio_set_open_source_value(desc, value);
+ else
+ 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 {
+ int i;
+ for (i = 0; i < chip->ngpio; i++) {
+ if (mask[BIT_WORD(i)] == 0) {
+ /* no more set bits in this mask word;
+ * skip ahead to the next word */
+ i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
+ continue;
+ }
+ /* set outputs if the corresponding mask bit is set */
+ if (__test_and_clear_bit(i, mask)) {
+ chip->set(chip, i, test_bit(i, bits));
+ }
+ }
+ }
+}
+
+static void gpiod_set_array_priv(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]->chip;
+ unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
+ unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
+ int count = 0;
+
+ if (!can_sleep) {
+ WARN_ON(chip->can_sleep);
+ }
+ memset(mask, 0, sizeof(mask));
+ 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)) {
+ _gpio_set_open_drain_value(desc,value);
+ } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
+ _gpio_set_open_source_value(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]->chip == chip));
+ /* push collected bits to outputs */
+ if (count != 0) {
+ gpio_chip_set_multiple(chip, mask, bits);
+ }
+ }
+}
+
+/**
+ * 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)
+{
+ if (!desc)
+ return;
+ /* Should be using gpio_set_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+ _gpiod_set_raw_value(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_raw_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 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_value(struct gpio_desc *desc, int value)
+{
+ if (!desc)
+ return;
+ /* Should be using gpio_set_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+ _gpiod_set_raw_value(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_value);
+
+/**
+ * gpiod_set_raw_array() - 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.
+ */
+void gpiod_set_raw_array(unsigned int array_size,
+ struct gpio_desc **desc_array, int *value_array)
+{
+ if (!desc_array)
+ return;
+ gpiod_set_array_priv(true, false, array_size, desc_array, value_array);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_raw_array);
+
+/**
+ * gpiod_set_array() - 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(unsigned int array_size,
+ struct gpio_desc **desc_array, int *value_array)
+{
+ if (!desc_array)
+ return;
+ gpiod_set_array_priv(false, false, array_size, desc_array, value_array);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_array);
+
+/**
+ * gpiod_cansleep() - report whether gpio value access may sleep
+ * @desc: gpio to check
+ *
+ */
+int gpiod_cansleep(const struct gpio_desc *desc)
+{
+ if (!desc)
+ return 0;
+ return desc->chip->can_sleep;
+}
+EXPORT_SYMBOL_GPL(gpiod_cansleep);
+
+/**
+ * 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;
+
+ if (!desc)
+ return -EINVAL;
+ chip = desc->chip;
+ offset = gpio_chip_hwgpio(desc);
+ return chip->to_irq ? chip->to_irq(chip, offset) : -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)
+{
+ if (offset >= chip->ngpio)
+ return -EINVAL;
+
+ if (test_bit(FLAG_IS_OUT, &chip->desc[offset].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, &chip->desc[offset].flags);
+ 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)
+{
+ if (offset >= chip->ngpio)
+ return;
+
+ clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
+}
+EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
+
+/**
+ * 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.
+ *
+ * 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);
+ if (!desc)
+ return 0;
+ return _gpiod_get_raw_value(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.
+ *
+ * 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);
+ if (!desc)
+ return 0;
+
+ value = _gpiod_get_raw_value(desc);
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+
+ return value;
+}
+EXPORT_SYMBOL_GPL(gpiod_get_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);
+ if (!desc)
+ return;
+ _gpiod_set_raw_value(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);
+ if (!desc)
+ return;
+
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+ _gpiod_set_raw_value(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
+
+/**
+ * gpiod_set_raw_array_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.
+ */
+void gpiod_set_raw_array_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_priv(true, true, array_size, desc_array, value_array);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_raw_array_cansleep);
+
+/**
+ * gpiod_set_array_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_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_priv(false, true, array_size, desc_array, value_array);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_array_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);
+}
+
+static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
+ unsigned int idx,
+ enum gpio_lookup_flags *flags)
+{
+ char prop_name[32]; /* 32 is max size of property name */
+ enum of_gpio_flags of_flags;
+ struct gpio_desc *desc;
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+ if (con_id)
+ snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
+ gpio_suffixes[i]);
+ else
+ snprintf(prop_name, sizeof(prop_name), "%s",
+ gpio_suffixes[i]);
+
+ desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
+ &of_flags);
+ if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
+ break;
+ }
+
+ if (IS_ERR(desc))
+ return desc;
+
+ if (of_flags & OF_GPIO_ACTIVE_LOW)
+ *flags |= GPIO_ACTIVE_LOW;
+
+ return desc;
+}
+
+static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
+ unsigned int idx,
+ enum gpio_lookup_flags *flags)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+ struct acpi_gpio_info info;
+ struct gpio_desc *desc;
+ char propname[32];
+ int i;
+
+ /* Try first from _DSD */
+ for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+ if (con_id && strcmp(con_id, "gpios")) {
+ snprintf(propname, sizeof(propname), "%s-%s",
+ con_id, gpio_suffixes[i]);
+ } else {
+ snprintf(propname, sizeof(propname), "%s",
+ gpio_suffixes[i]);
+ }
+
+ desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
+ if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
+ break;
+ }
+
+ /* Then from plain _CRS GPIOs */
+ if (IS_ERR(desc)) {
+ desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
+ if (IS_ERR(desc))
+ return desc;
+ }
+
+ if (info.active_low)
+ *flags |= GPIO_ACTIVE_LOW;
+
+ return desc;
+}
+
+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) {
+ dev_err(dev, "cannot find GPIO chip %s\n",
+ p->chip_label);
+ return ERR_PTR(-ENODEV);
+ }
+
+ if (chip->ngpio <= p->chip_hwnum) {
+ dev_err(dev,
+ "requested GPIO %d is out of range [0..%d] for chip %s\n",
+ idx, chip->ngpio, 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;
+}
+
+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 occured 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.
+ */
+static 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);
+ if (lflags & GPIO_OPEN_SOURCE)
+ set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+
+ /* 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
+ * occured 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;
+
+ 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, &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, "lookup for GPIO %s failed\n", con_id);
+ return desc;
+ }
+
+ status = gpiod_request(desc, con_id);
+ 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);
+
+/**
+ * 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
+ *
+ * This function can be used for drivers that get their configuration
+ * from firmware.
+ *
+ * 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.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
+ const char *propname)
+{
+ struct gpio_desc *desc = ERR_PTR(-ENODEV);
+ bool active_low = false;
+ int ret;
+
+ if (!fwnode)
+ return ERR_PTR(-EINVAL);
+
+ if (is_of_node(fwnode)) {
+ enum of_gpio_flags flags;
+
+ desc = of_get_named_gpiod_flags(of_node(fwnode), propname, 0,
+ &flags);
+ if (!IS_ERR(desc))
+ active_low = flags & OF_GPIO_ACTIVE_LOW;
+ } else if (is_acpi_node(fwnode)) {
+ struct acpi_gpio_info info;
+
+ desc = acpi_get_gpiod_by_index(acpi_node(fwnode), propname, 0,
+ &info);
+ if (!IS_ERR(desc))
+ active_low = info.active_low;
+ }
+
+ if (IS_ERR(desc))
+ return desc;
+
+ ret = gpiod_request(desc, NULL);
+ if (ret)
+ return ERR_PTR(ret);
+
+ /* Only value flag can be set from both DT and ACPI is active_low */
+ if (active_low)
+ set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+
+ 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)) {
+ pr_debug("requesting own GPIO %s failed\n", name);
+ return PTR_ERR(local_desc);
+ }
+
+ status = gpiod_configure_flags(desc, name, lflags, dflags);
+ if (status < 0) {
+ pr_debug("setup of GPIO %s failed\n", name);
+ 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->desc[id].flags))
+ gpiochip_free_own_desc(&chip->desc[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(sizeof(*descs) + sizeof(descs->desc[0]) * 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);
+
+#ifdef CONFIG_DEBUG_FS
+
+static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+ unsigned i;
+ unsigned gpio = chip->base;
+ struct gpio_desc *gdesc = &chip->desc[0];
+ int is_out;
+ int is_irq;
+
+ for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
+ if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
+ 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) %s %s %s",
+ gpio, 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_chip *chip = NULL;
+ loff_t index = *pos;
+
+ s->private = "";
+
+ spin_lock_irqsave(&gpio_lock, flags);
+ list_for_each_entry(chip, &gpio_chips, list)
+ if (index-- == 0) {
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ return chip;
+ }
+ 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_chip *chip = v;
+ void *ret = NULL;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+ if (list_is_last(&chip->list, &gpio_chips))
+ ret = NULL;
+ else
+ ret = list_entry(chip->list.next, struct gpio_chip, 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_chip *chip = v;
+ struct device *dev;
+
+ seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
+ chip->base, chip->base + chip->ngpio - 1);
+ dev = chip->dev;
+ if (dev)
+ seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
+ dev_name(dev));
+ 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, chip);
+
+ 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 */
Code Review / kvmfornfv.git / blobdiff