#ifndef __LINUX_GPIO_DRIVER_H #define __LINUX_GPIO_DRIVER_H #include #include struct device; struct gpio_desc; struct of_phandle_args; struct device_node; struct seq_file; /** * struct gpio_chip - abstract a GPIO controller * @label: for diagnostics * @dev: optional device providing the GPIOs * @owner: helps prevent removal of modules exporting active GPIOs * @list: links gpio_chips together for traversal * @request: optional hook for chip-specific activation, such as * enabling module power and clock; may sleep * @free: optional hook for chip-specific deactivation, such as * disabling module power and clock; may sleep * @get_direction: returns direction for signal "offset", 0=out, 1=in, * (same as GPIOF_DIR_XXX), or negative error * @direction_input: configures signal "offset" as input, or returns error * @direction_output: configures signal "offset" as output, or returns error * @get: returns value for signal "offset"; for output signals this * returns either the value actually sensed, or zero * @set: assigns output value for signal "offset" * @set_debounce: optional hook for setting debounce time for specified gpio in * interrupt triggered gpio chips * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; * implementation may not sleep * @dbg_show: optional routine to show contents in debugfs; default code * will be used when this is omitted, but custom code can show extra * state (such as pullup/pulldown configuration). * @base: identifies the first GPIO number handled by this chip; or, if * negative during registration, requests dynamic ID allocation. * @ngpio: the number of GPIOs handled by this controller; the last GPIO * handled is (base + ngpio - 1). * @desc: array of ngpio descriptors. Private. * @names: if set, must be an array of strings to use as alternative * names for the GPIOs in this chip. Any entry in the array * may be NULL if there is no alias for the GPIO, however the * array must be @ngpio entries long. A name can include a single printk * format specifier for an unsigned int. It is substituted by the actual * number of the gpio. * @can_sleep: flag must be set iff get()/set() methods sleep, as they * must while accessing GPIO expander chips over I2C or SPI * @exported: flags if the gpiochip is exported for use from sysfs. Private. * * A gpio_chip can help platforms abstract various sources of GPIOs so * they can all be accessed through a common programing interface. * Example sources would be SOC controllers, FPGAs, multifunction * chips, dedicated GPIO expanders, and so on. * * Each chip controls a number of signals, identified in method calls * by "offset" values in the range 0..(@ngpio - 1). When those signals * are referenced through calls like gpio_get_value(gpio), the offset * is calculated by subtracting @base from the gpio number. */ struct gpio_chip { const char *label; struct device *dev; struct module *owner; struct list_head list; int (*request)(struct gpio_chip *chip, unsigned offset); void (*free)(struct gpio_chip *chip, unsigned offset); int (*get_direction)(struct gpio_chip *chip, unsigned offset); int (*direction_input)(struct gpio_chip *chip, unsigned offset); int (*direction_output)(struct gpio_chip *chip, unsigned offset, int value); int (*get)(struct gpio_chip *chip, unsigned offset); void (*set)(struct gpio_chip *chip, unsigned offset, int value); int (*set_debounce)(struct gpio_chip *chip, unsigned offset, unsigned debounce); int (*to_irq)(struct gpio_chip *chip, unsigned offset); void (*dbg_show)(struct seq_file *s, struct gpio_chip *chip); int base; u16 ngpio; struct gpio_desc *desc; const char *const *names; bool can_sleep; bool exported; #if defined(CONFIG_OF_GPIO) /* * If CONFIG_OF is enabled, then all GPIO controllers described in the * device tree automatically may have an OF translation */ struct device_node *of_node; int of_gpio_n_cells; int (*of_xlate)(struct gpio_chip *gc, const struct of_phandle_args *gpiospec, u32 *flags); #endif #ifdef CONFIG_PINCTRL /* * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally * describe the actual pin range which they serve in an SoC. This * information would be used by pinctrl subsystem to configure * corresponding pins for gpio usage. */ struct list_head pin_ranges; #endif }; extern const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset); /* add/remove chips */ extern int gpiochip_add(struct gpio_chip *chip); extern int __must_check gpiochip_remove(struct gpio_chip *chip); extern struct gpio_chip *gpiochip_find(void *data, int (*match)(struct gpio_chip *chip, void *data)); /* lock/unlock as IRQ */ int gpiod_lock_as_irq(struct gpio_desc *desc); void gpiod_unlock_as_irq(struct gpio_desc *desc); enum gpio_lookup_flags { GPIO_ACTIVE_HIGH = (0 << 0), GPIO_ACTIVE_LOW = (1 << 0), GPIO_OPEN_DRAIN = (1 << 1), GPIO_OPEN_SOURCE = (1 << 2), }; /** * struct gpiod_lookup - lookup table * @chip_label: name of the chip the GPIO belongs to * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO * @con_id: name of the GPIO from the device's point of view * @idx: index of the GPIO in case several GPIOs share the same name * @flags: mask of GPIO_* values * * gpiod_lookup is a lookup table for associating GPIOs to specific devices and * functions using platform data. */ struct gpiod_lookup { const char *chip_label; u16 chip_hwnum; const char *con_id; unsigned int idx; enum gpio_lookup_flags flags; }; struct gpiod_lookup_table { struct list_head list; const char *dev_id; struct gpiod_lookup table[]; }; /* * Simple definition of a single GPIO under a con_id */ #define GPIO_LOOKUP(_chip_label, _chip_hwnum, _con_id, _flags) \ GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, 0, _flags) /* * Use this macro if you need to have several GPIOs under the same con_id. * Each GPIO needs to use a different index and can be accessed using * gpiod_get_index() */ #define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, _idx, _flags) \ { \ .chip_label = _chip_label, \ .chip_hwnum = _chip_hwnum, \ .con_id = _con_id, \ .idx = _idx, \ .flags = _flags, \ } void gpiod_add_lookup_table(struct gpiod_lookup_table *table); #endif