// SPDX-License-Identifier: GPL-2.0 #include <linux/acpi.h> #include <linux/array_size.h> #include <linux/bitmap.h> #include <linux/cleanup.h> #include <linux/compat.h> #include <linux/debugfs.h> #include <linux/device.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/idr.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/lockdep.h> #include <linux/module.h> #include <linux/nospec.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/srcu.h> #include <linux/string.h> #include <linux/gpio.h> #include <linux/gpio/driver.h> #include <linux/gpio/machine.h> #include <uapi/linux/gpio.h> #include "gpiolib-acpi.h" #include "gpiolib-cdev.h" #include "gpiolib-of.h" #include "gpiolib-swnode.h" #include "gpiolib-sysfs.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. */ /* Device and char device-related information */ static DEFINE_IDA(gpio_ida); static dev_t gpio_devt; #define GPIO_DEV_MAX … static int gpio_bus_match(struct device *dev, const struct device_driver *drv) { … } static const struct bus_type gpio_bus_type = …; /* * Number of GPIOs to use for the fast path in set array */ #define FASTPATH_NGPIO … static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); static LIST_HEAD(gpio_devices); /* Protects the GPIO device list against concurrent modifications. */ static DEFINE_MUTEX(gpio_devices_lock); /* Ensures coherence during read-only accesses to the list of GPIO devices. */ DEFINE_STATIC_SRCU(…); static DEFINE_MUTEX(gpio_machine_hogs_mutex); static LIST_HEAD(gpio_machine_hogs); const char *const gpio_suffixes[] = …; const size_t gpio_suffix_count = …; static void gpiochip_free_hogs(struct gpio_chip *gc); static int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, struct lock_class_key *request_key); static void gpiochip_irqchip_remove(struct gpio_chip *gc); static int gpiochip_irqchip_init_hw(struct gpio_chip *gc); static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc); static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc); static bool gpiolib_initialized; const char *gpiod_get_label(struct gpio_desc *desc) { … } static void desc_free_label(struct rcu_head *rh) { … } static int desc_set_label(struct gpio_desc *desc, const char *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) { … } EXPORT_SYMBOL_GPL(…); /* This function is deprecated and will be removed soon, don't use. */ struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum) { … } /** * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given * hardware number for this GPIO device * @gdev: GPIO device to get the descriptor from * @hwnum: hardware number of the GPIO for this chip * * Returns: * A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given * chip for the specified hardware number or %ENODEV if the underlying chip * already vanished. * * The reference count of struct gpio_device is *NOT* increased like when the * GPIO is being requested for exclusive usage. It's up to the caller to make * sure the GPIO device will stay alive together with the descriptor returned * by this function. */ struct gpio_desc * gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs * @desc: descriptor to return the chip of * * *DEPRECATED* * This function is unsafe and should not be used. Using the chip address * without taking the SRCU read lock may result in dereferencing a dangling * pointer. */ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor * belongs. * @desc: Descriptor for which to return the GPIO device. * * This *DOES NOT* increase the reference count of the GPIO device as it's * expected that the descriptor is requested and the users already holds a * reference to the device. * * Returns: * Address of the GPIO device owning this descriptor. */ struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc) { … } EXPORT_SYMBOL_GPL(…); /** * gpio_device_get_base() - Get the base GPIO number allocated by this device * @gdev: GPIO device * * Returns: * First GPIO number in the global GPIO numberspace for this device. */ int gpio_device_get_base(struct gpio_device *gdev) { … } EXPORT_SYMBOL_GPL(…); /** * gpio_device_get_label() - Get the label of this GPIO device * @gdev: GPIO device * * Returns: * Pointer to the string containing the GPIO device label. The string's * lifetime is tied to that of the underlying GPIO device. */ const char *gpio_device_get_label(struct gpio_device *gdev) { … } EXPORT_SYMBOL(…); /** * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device * @gdev: GPIO device * * Returns: * Address of the GPIO chip backing this device. * * *DEPRECATED* * Until we can get rid of all non-driver users of struct gpio_chip, we must * provide a way of retrieving the pointer to it from struct gpio_device. This * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the * chip can dissapear at any moment (unlike reference-counted struct * gpio_device). * * Use at your own risk. */ struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev) { … } EXPORT_SYMBOL_GPL(…); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base_unlocked(u16 ngpio) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /* * 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_unlocked(struct gpio_device *gdev) { … } /* * Convert a GPIO name to its descriptor * Note that there is no guarantee that GPIO names are globally unique! * Hence this function will return, if it exists, a reference to the first GPIO * line found that matches the given name. */ static struct gpio_desc *gpio_name_to_desc(const char * const name) { … } /* * Take the names from gc->names and assign them to their GPIO descriptors. * Warn if a name is already used for a GPIO line on a different GPIO chip. * * Note that: * 1. Non-unique names are still accepted, * 2. Name collisions within the same GPIO chip are not reported. */ static void gpiochip_set_desc_names(struct gpio_chip *gc) { … } /* * gpiochip_set_names - Set GPIO line names using device properties * @chip: GPIO chip whose lines should be named, if possible * * Looks for device property "gpio-line-names" and if it exists assigns * GPIO line names for the chip. The memory allocated for the assigned * names belong to the underlying firmware node and should not be released * by the caller. */ static int gpiochip_set_names(struct gpio_chip *chip) { … } static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc) { … } static void gpiochip_free_mask(unsigned long **p) { … } static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc) { … } static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc) { … } static int gpiochip_init_valid_mask(struct gpio_chip *gc) { … } static void gpiochip_free_valid_mask(struct gpio_chip *gc) { … } static int gpiochip_add_pin_ranges(struct gpio_chip *gc) { … } bool gpiochip_line_is_valid(const struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); static void gpiodev_release(struct device *dev) { … } static const struct device_type gpio_dev_type = …; #ifdef CONFIG_GPIO_CDEV #define gcdev_register(gdev, devt) … #define gcdev_unregister(gdev) … #else /* * gpiolib_cdev_register() indirectly calls device_add(), which is still * required even when cdev is not selected. */ #define gcdev_register … #define gcdev_unregister … #endif static int gpiochip_setup_dev(struct gpio_device *gdev) { … } static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog) { … } static void machine_gpiochip_add(struct gpio_chip *gc) { … } static void gpiochip_setup_devs(void) { … } static void gpiochip_set_data(struct gpio_chip *gc, void *data) { … } /** * gpiochip_get_data() - get per-subdriver data for the chip * @gc: GPIO chip * * Returns: * The per-subdriver data for the chip. */ void *gpiochip_get_data(struct gpio_chip *gc) { … } EXPORT_SYMBOL_GPL(…); int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev) { … } EXPORT_SYMBOL_GPL(…); int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct lock_class_key *lock_key, struct lock_class_key *request_key) { … } EXPORT_SYMBOL_GPL(…); /** * gpiochip_remove() - unregister a gpio_chip * @gc: the chip to unregister * * A gpio_chip with any GPIOs still requested may not be removed. */ void gpiochip_remove(struct gpio_chip *gc) { … } EXPORT_SYMBOL_GPL(…); /** * gpio_device_find() - find a specific GPIO device * @data: data to pass to match function * @match: Callback function to check gpio_chip * * Returns: * New reference to struct gpio_device. * * Similar to bus_find_device(). It returns a reference to a gpio_device 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 * returns non-zero, this function will return to the caller and not iterate * over any more gpio_devices. * * The callback takes the GPIO chip structure as argument. During the execution * of the callback function the chip is protected from being freed. TODO: This * actually has yet to be implemented. * * If the function returns non-NULL, the returned reference must be freed by * the caller using gpio_device_put(). */ struct gpio_device *gpio_device_find(const void *data, int (*match)(struct gpio_chip *gc, const void *data)) { … } EXPORT_SYMBOL_GPL(…); static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label) { … } /** * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the * GPIO device by its backing chip's label * @label: Label to lookup * * Returns: * Reference to the GPIO device or NULL. Reference must be released with * gpio_device_put(). */ struct gpio_device *gpio_device_find_by_label(const char *label) { … } EXPORT_SYMBOL_GPL(…); static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode) { … } /** * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding * the GPIO device by its fwnode * @fwnode: Firmware node to lookup * * Returns: * Reference to the GPIO device or NULL. Reference must be released with * gpio_device_put(). */ struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode) { … } EXPORT_SYMBOL_GPL(…); /** * gpio_device_get() - Increase the reference count of this GPIO device * @gdev: GPIO device to increase the refcount for * * Returns: * Pointer to @gdev. */ struct gpio_device *gpio_device_get(struct gpio_device *gdev) { … } EXPORT_SYMBOL_GPL(…); /** * gpio_device_put() - Decrease the reference count of this GPIO device and * possibly free all resources associated with it. * @gdev: GPIO device to decrease the reference count for */ void gpio_device_put(struct gpio_device *gdev) { … } EXPORT_SYMBOL_GPL(…); /** * gpio_device_to_device() - Retrieve the address of the underlying struct * device. * @gdev: GPIO device for which to return the address. * * This does not increase the reference count of the GPIO device nor the * underlying struct device. * * Returns: * Address of struct device backing this GPIO device. */ struct device *gpio_device_to_device(struct gpio_device *gdev) { … } EXPORT_SYMBOL_GPL(…); #ifdef CONFIG_GPIOLIB_IRQCHIP /* * The following is irqchip helper code for gpiochips. */ static int gpiochip_irqchip_init_hw(struct gpio_chip *gc) { … } static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc) { … } static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) { … } static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc, unsigned int offset) { … } #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY /** * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip * to a gpiochip * @gc: the gpiochip to set the irqchip hierarchical handler to * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt * will then percolate up to the parent */ static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc, struct irq_chip *irqchip) { … } static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec, unsigned long *hwirq, unsigned int *type) { … } static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d, unsigned int irq, unsigned int nr_irqs, void *data) { … } static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc, unsigned int offset) { … } /** * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ * @domain: The IRQ domain used by this IRQ chip * @data: Outermost irq_data associated with the IRQ * @reserve: If set, only reserve an interrupt vector instead of assigning one * * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be * used as the activate function for the &struct irq_domain_ops. The host_data * for the IRQ domain must be the &struct gpio_chip. */ static int gpiochip_irq_domain_activate(struct irq_domain *domain, struct irq_data *data, bool reserve) { … } /** * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ * @domain: The IRQ domain used by this IRQ chip * @data: Outermost irq_data associated with the IRQ * * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to * be used as the deactivate function for the &struct irq_domain_ops. The * host_data for the IRQ domain must be the &struct gpio_chip. */ static void gpiochip_irq_domain_deactivate(struct irq_domain *domain, struct irq_data *data) { … } static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops) { … } static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc) { … } static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc) { … } int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc, union gpio_irq_fwspec *gfwspec, unsigned int parent_hwirq, unsigned int parent_type) { … } EXPORT_SYMBOL_GPL(…); int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc, union gpio_irq_fwspec *gfwspec, unsigned int parent_hwirq, unsigned int parent_type) { … } EXPORT_SYMBOL_GPL(…); #else static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc) { return ERR_PTR(-EINVAL); } static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc) { return false; } #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */ /** * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip * @d: the irqdomain used by this irqchip * @irq: the global irq number used by this GPIO irqchip irq * @hwirq: the local IRQ/GPIO line offset on this gpiochip * * This function will set up the mapping for a certain IRQ line on a * gpiochip by assigning the gpiochip as chip data, and using the irqchip * stored inside the gpiochip. */ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq) { … } static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) { … } static const struct irq_domain_ops gpiochip_domain_ops = …; static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc) { … } static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset) { … } int gpiochip_irq_reqres(struct irq_data *d) { … } EXPORT_SYMBOL(…); void gpiochip_irq_relres(struct irq_data *d) { … } EXPORT_SYMBOL(…); static void gpiochip_irq_mask(struct irq_data *d) { … } static void gpiochip_irq_unmask(struct irq_data *d) { … } static void gpiochip_irq_enable(struct irq_data *d) { … } static void gpiochip_irq_disable(struct irq_data *d) { … } static void gpiochip_set_irq_hooks(struct gpio_chip *gc) { … } static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc, struct irq_domain *domain, bool allocated_externally) { … } /** * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip * @gc: the GPIO chip to add the IRQ chip to * @lock_key: lockdep class for IRQ lock * @request_key: lockdep class for IRQ request */ static int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, struct lock_class_key *request_key) { … } /** * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip * @gc: the gpiochip to remove the irqchip from * * This is called only from gpiochip_remove() */ static void gpiochip_irqchip_remove(struct gpio_chip *gc) { … } /** * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip * @gc: the gpiochip to add the irqchip to * @domain: the irqdomain to add to the gpiochip * * This function adds an IRQ domain to the gpiochip. */ int gpiochip_irqchip_add_domain(struct gpio_chip *gc, struct irq_domain *domain) { … } EXPORT_SYMBOL_GPL(…); #else /* CONFIG_GPIOLIB_IRQCHIP */ static inline int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, struct lock_class_key *request_key) { return 0; } static void gpiochip_irqchip_remove(struct gpio_chip *gc) {} static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc) { return 0; } static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc) { return 0; } static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) { } #endif /* CONFIG_GPIOLIB_IRQCHIP */ /** * gpiochip_generic_request() - request the gpio function for a pin * @gc: the gpiochip owning the GPIO * @offset: the offset of the GPIO to request for GPIO function */ int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); /** * gpiochip_generic_free() - free the gpio function from a pin * @gc: the gpiochip to request the gpio function for * @offset: the offset of the GPIO to free from GPIO function */ void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); /** * gpiochip_generic_config() - apply configuration for a pin * @gc: the gpiochip owning the GPIO * @offset: the offset of the GPIO to apply the configuration * @config: the configuration to be applied */ int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset, unsigned long config) { … } EXPORT_SYMBOL_GPL(…); #ifdef CONFIG_PINCTRL /** * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping * @gc: the gpiochip to add the range for * @pctldev: the pin controller to map to * @gpio_offset: the start offset in the current gpio_chip number space * @pin_group: name of the pin group inside the pin controller * * Calling this function directly from a DeviceTree-supported * pinctrl driver is DEPRECATED. Please see Section 2.1 of * Documentation/devicetree/bindings/gpio/gpio.txt on how to * bind pinctrl and gpio drivers via the "gpio-ranges" property. */ int gpiochip_add_pingroup_range(struct gpio_chip *gc, struct pinctrl_dev *pctldev, unsigned int gpio_offset, const char *pin_group) { … } EXPORT_SYMBOL_GPL(…); /** * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping * @gc: the gpiochip to add the range for * @pinctl_name: the dev_name() of the pin controller to map to * @gpio_offset: the start offset in the current gpio_chip number space * @pin_offset: the start offset in the pin controller number space * @npins: the number of pins from the offset of each pin space (GPIO and * pin controller) to accumulate in this range * * Returns: * 0 on success, or a negative error-code on failure. * * Calling this function directly from a DeviceTree-supported * pinctrl driver is DEPRECATED. Please see Section 2.1 of * Documentation/devicetree/bindings/gpio/gpio.txt on how to * bind pinctrl and gpio drivers via the "gpio-ranges" property. */ int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name, unsigned int gpio_offset, unsigned int pin_offset, unsigned int npins) { … } EXPORT_SYMBOL_GPL(…); /** * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings * @gc: the chip to remove all the mappings for */ void gpiochip_remove_pin_ranges(struct gpio_chip *gc) { … } EXPORT_SYMBOL_GPL(…); #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) { … } /* * 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) { … } #define VALIDATE_DESC(desc) … #define VALIDATE_DESC_VOID(desc) … int gpiod_request(struct gpio_desc *desc, const char *label) { … } static void gpiod_free_commit(struct gpio_desc *desc) { … } void gpiod_free(struct gpio_desc *desc) { … } /** * gpiochip_dup_line_label - Get a copy of the consumer label. * @gc: GPIO chip controlling this line. * @offset: Hardware offset of the line. * * Returns: * Pointer to a copy of the consumer label if the line is requested or NULL * if it's not. If a valid pointer was returned, it must be freed using * kfree(). In case of a memory allocation error, the function returns %ENOMEM. * * Must not be called from atomic context. */ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); static inline const char *function_name_or_default(const char *con_id) { … } /** * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor * @gc: GPIO chip * @hwnum: hardware number of the GPIO for which to request the descriptor * @label: label for the GPIO * @lflags: lookup flags for this GPIO or 0 if default, this can be used to * specify things like line inversion semantics with the machine flags * such as GPIO_OUT_LOW * @dflags: descriptor request flags for this GPIO or 0 if default, this * can be used to specify consumer semantics such as open drain * * Function allows GPIO chip drivers to request and use their own GPIO * descriptors via gpiolib API. Difference to gpiod_request() is that this * function will not increase reference count of the GPIO chip module. This * allows the GPIO chip module to be unloaded as needed (we assume that the * GPIO chip driver handles freeing the GPIOs it has requested). * * Returns: * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error * code on failure. */ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc, unsigned int hwnum, const char *label, enum gpio_lookup_flags lflags, enum gpiod_flags dflags) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /* * Drivers MUST set GPIO direction before making get/set calls. In * some cases this is done in early boot, before IRQs are enabled. * * As a rule these aren't called more than once (except for drivers * using the open-drain emulation idiom) so these are natural places * to accumulate extra debugging checks. Note that we can't (yet) * rely on gpio_request() having been called beforehand. */ static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset, unsigned long config) { … } static int gpio_set_config_with_argument(struct gpio_desc *desc, enum pin_config_param mode, u32 argument) { … } static int gpio_set_config_with_argument_optional(struct gpio_desc *desc, enum pin_config_param mode, u32 argument) { … } static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode) { … } static int gpio_set_bias(struct gpio_desc *desc) { … } /** * gpio_set_debounce_timeout() - Set debounce timeout * @desc: GPIO descriptor to set the debounce timeout * @debounce: Debounce timeout in microseconds * * The function calls the certain GPIO driver to set debounce timeout * in the hardware. * * Returns 0 on success, or negative error code otherwise. */ int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds. * * @desc: GPIO to enable. * @flags: Flags related to GPIO edge. * * Return 0 in case of success, else negative error code. */ int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp. * * @desc: GPIO to disable. * @flags: Flags related to GPIO edge, same value as used during enable call. * * Return 0 in case of success, else negative error code. */ int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_set_config - sets @config for a GPIO * @desc: descriptor of the GPIO for which to set the configuration * @config: Same packed config format as generic pinconf * * Returns: * 0 on success, %-ENOTSUPP if the controller doesn't support setting the * configuration. */ int gpiod_set_config(struct gpio_desc *desc, unsigned long config) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_set_debounce - sets @debounce time for a GPIO * @desc: descriptor of the GPIO for which to set debounce time * @debounce: debounce time in microseconds * * Returns: * 0 on success, %-ENOTSUPP if the controller doesn't support setting the * debounce time. */ int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not * @desc: the gpio descriptor to change */ void gpiod_toggle_active_low(struct gpio_desc *desc) { … } EXPORT_SYMBOL_GPL(…); static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc) { … } /* 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) { … } static int gpio_chip_get_multiple(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits) { … } /* The 'other' chip must be protected with its GPIO device's SRCU. */ static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc) { … } int gpiod_get_array_value_complex(bool raw, bool can_sleep, unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } /** * gpiod_get_raw_value() - return a gpio's raw value * @desc: gpio whose value will be returned * * Return the GPIO's raw value, i.e. the value of the physical line disregarding * its ACTIVE_LOW status, or negative errno on failure. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_get_raw_value(const struct gpio_desc *desc) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_get_value() - return a gpio's value * @desc: gpio whose value will be returned * * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into * account, or negative errno on failure. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_get_value(const struct gpio_desc *desc) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_get_raw_array_value() - read raw values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. Return 0 in case of success, * else an error code. * * This function can be called from contexts where we cannot sleep, * and it will complain if the GPIO chip functions potentially sleep. */ int gpiod_get_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_get_array_value() - read values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. Return 0 in case of success, else an error code. * * This function can be called from contexts where we cannot sleep, * and it will complain if the GPIO chip functions potentially sleep. */ int gpiod_get_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); /* * 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) { … } /* * _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) { … } static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value) { … } /* * set multiple outputs on the same chip; * use the chip's set_multiple function if available; * otherwise set the outputs sequentially; * @chip: the GPIO chip we operate on * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word * defines which outputs are to be changed * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word * defines the values the outputs specified by mask are to be set to */ static void gpio_chip_set_multiple(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits) { … } int gpiod_set_array_value_complex(bool raw, bool can_sleep, unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } /** * gpiod_set_raw_value() - assign a gpio's raw value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the raw value of the GPIO, i.e. the value of its physical line without * regard for its ACTIVE_LOW status. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_raw_value(struct gpio_desc *desc, int value) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } /** * gpiod_set_value() - assign a gpio's value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW, * OPEN_DRAIN and OPEN_SOURCE flags into account. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_value(struct gpio_desc *desc, int value) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_set_raw_array_value() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_set_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_set_array_value() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_set_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_cansleep() - report whether gpio value access may sleep * @desc: gpio to check * */ int gpiod_cansleep(const struct gpio_desc *desc) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ * @gc: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to lock down * a certain GPIO line to be used for IRQs. */ int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); /** * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ * @gc: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to indicate * that a certain GPIO is no longer used exclusively for IRQ. */ void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. Return 0 in case of success, * else an error code. * * This function is to be called from contexts that can sleep. */ int gpiod_get_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_get_array_value_cansleep() - read values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. Return 0 in case of success, else an error code. * * This function is to be called from contexts that can sleep. */ int gpiod_get_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. */ int gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } /** * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. * * This function is to be called from contexts that can sleep. */ int gpiod_set_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { … } EXPORT_SYMBOL_GPL(…); void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action) { … } /** * gpiod_add_lookup_table() - register GPIO device consumers * @table: table of consumers to register */ void gpiod_add_lookup_table(struct gpiod_lookup_table *table) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_remove_lookup_table() - unregister GPIO device consumers * @table: table of consumers to unregister */ void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); void gpiod_remove_hogs(struct gpiod_hog *hogs) { … } EXPORT_SYMBOL_GPL(…); static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev) { … } static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, unsigned int idx, unsigned long *flags) { … } static int platform_gpio_count(struct device *dev, const char *con_id) { … } static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode, struct device *consumer, const char *con_id, unsigned int idx, enum gpiod_flags *flags, unsigned long *lookupflags) { … } struct gpio_desc *gpiod_find_and_request(struct device *consumer, struct fwnode_handle *fwnode, const char *con_id, unsigned int idx, enum gpiod_flags flags, const char *label, bool platform_lookup_allowed) { … } /** * fwnode_gpiod_get_index - obtain a GPIO from firmware node * @fwnode: handle of the firmware node * @con_id: function within the GPIO consumer * @index: index of the GPIO to obtain for the consumer * @flags: GPIO initialization flags * @label: label to attach to the requested GPIO * * This function can be used for drivers that get their configuration * from opaque firmware. * * The function properly finds the corresponding GPIO using whatever is the * underlying firmware interface and then makes sure that the GPIO * descriptor is requested before it is returned to the caller. * * Returns: * On successful request the GPIO pin is configured in accordance with * provided @flags. * * In case of error an ERR_PTR() is returned. */ struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode, const char *con_id, int index, enum gpiod_flags flags, const char *label) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_configure_flags - helper function to configure a given GPIO * @desc: gpio whose value will be assigned * @con_id: function within the GPIO consumer * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from * of_find_gpio() or of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags * * Return 0 on success, -ENOENT if no GPIO has been assigned to the * requested function and/or index, or another IS_ERR() code if an error * occurred while trying to acquire the GPIO. */ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, unsigned long lflags, enum gpiod_flags dflags) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * gpiod_hog - Hog the specified GPIO desc given the provided flags * @desc: gpio whose value will be assigned * @name: gpio line name * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from * of_find_gpio() or of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags */ int gpiod_hog(struct gpio_desc *desc, const char *name, unsigned long lflags, enum gpiod_flags dflags) { … } /** * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog * @gc: gpio chip to act on */ static void gpiochip_free_hogs(struct gpio_chip *gc) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); static int gpio_stub_drv_probe(struct device *dev) { … } static struct device_driver gpio_stub_drv = …; static int __init gpiolib_dev_init(void) { … } core_initcall(gpiolib_dev_init); #ifdef CONFIG_DEBUG_FS static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) { … } struct gpiolib_seq_priv { … }; static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { … } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { … } static void gpiolib_seq_stop(struct seq_file *s, void *v) { … } static int gpiolib_seq_show(struct seq_file *s, void *v) { … } static const struct seq_operations gpiolib_sops = …; DEFINE_SEQ_ATTRIBUTE(…); static int __init gpiolib_debugfs_init(void) { … } subsys_initcall(gpiolib_debugfs_init); #endif /* DEBUG_FS */
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