diff options
Diffstat (limited to 'include/asm-generic/gpio.h')
| -rw-r--r-- | include/asm-generic/gpio.h | 88 |
1 files changed, 83 insertions, 5 deletions
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index d6c379dc64fa..ff5c66080c8c 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -1,6 +1,7 @@ #ifndef _ASM_GENERIC_GPIO_H #define _ASM_GENERIC_GPIO_H +#include <linux/kernel.h> #include <linux/types.h> #include <linux/errno.h> @@ -15,20 +16,34 @@ * While the GPIO programming interface defines valid GPIO numbers * to be in the range 0..MAX_INT, this library restricts them to the * smaller range 0..ARCH_NR_GPIOS-1. + * + * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of + * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is + * actually an estimate of a board-specific value. */ #ifndef ARCH_NR_GPIOS #define ARCH_NR_GPIOS 256 #endif +/* + * "valid" GPIO numbers are nonnegative and may be passed to + * setup routines like gpio_request(). only some valid numbers + * can successfully be requested and used. + * + * Invalid GPIO numbers are useful for indicating no-such-GPIO in + * platform data and other tables. + */ + static inline int gpio_is_valid(int number) { - /* only some non-negative numbers are valid */ return ((unsigned)number) < ARCH_NR_GPIOS; } +struct device; struct seq_file; struct module; +struct device_node; /** * struct gpio_chip - abstract a GPIO controller @@ -58,7 +73,9 @@ struct module; * @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. + * 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. * * A gpio_chip can help platforms abstract various sources of GPIOs so * they can all be accessed through a common programing interface. @@ -86,6 +103,9 @@ struct gpio_chip { unsigned offset); int (*direction_output)(struct gpio_chip *chip, unsigned offset, int value); + int (*set_debounce)(struct gpio_chip *chip, + unsigned offset, unsigned debounce); + void (*set)(struct gpio_chip *chip, unsigned offset, int value); @@ -96,9 +116,20 @@ struct gpio_chip { struct gpio_chip *chip); int base; u16 ngpio; - char **names; + const char *const *names; unsigned can_sleep:1; unsigned exported:1; + +#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, struct device_node *np, + const void *gpio_spec, u32 *flags); +#endif }; extern const char *gpiochip_is_requested(struct gpio_chip *chip, @@ -108,6 +139,9 @@ extern int __must_check gpiochip_reserve(int start, int ngpio); /* 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)); /* Always use the library code for GPIO management calls, @@ -119,6 +153,8 @@ extern void gpio_free(unsigned gpio); extern int gpio_direction_input(unsigned gpio); extern int gpio_direction_output(unsigned gpio, int value); +extern int gpio_set_debounce(unsigned gpio, unsigned debounce); + extern int gpio_get_value_cansleep(unsigned gpio); extern void gpio_set_value_cansleep(unsigned gpio, int value); @@ -134,6 +170,32 @@ extern int __gpio_cansleep(unsigned gpio); extern int __gpio_to_irq(unsigned gpio); +#define GPIOF_DIR_OUT (0 << 0) +#define GPIOF_DIR_IN (1 << 0) + +#define GPIOF_INIT_LOW (0 << 1) +#define GPIOF_INIT_HIGH (1 << 1) + +#define GPIOF_IN (GPIOF_DIR_IN) +#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) +#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) + +/** + * struct gpio - a structure describing a GPIO with configuration + * @gpio: the GPIO number + * @flags: GPIO configuration as specified by GPIOF_* + * @label: a literal description string of this GPIO + */ +struct gpio { + unsigned gpio; + unsigned long flags; + const char *label; +}; + +extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); +extern int gpio_request_array(struct gpio *array, size_t num); +extern void gpio_free_array(struct gpio *array, size_t num); + #ifdef CONFIG_GPIO_SYSFS /* @@ -141,11 +203,14 @@ extern int __gpio_to_irq(unsigned gpio); * but more typically is configured entirely from userspace. */ extern int gpio_export(unsigned gpio, bool direction_may_change); +extern int gpio_export_link(struct device *dev, const char *name, + unsigned gpio); +extern int gpio_sysfs_set_active_low(unsigned gpio, int value); extern void gpio_unexport(unsigned gpio); #endif /* CONFIG_GPIO_SYSFS */ -#else /* !CONFIG_HAVE_GPIO_LIB */ +#else /* !CONFIG_GPIOLIB */ static inline int gpio_is_valid(int number) { @@ -174,10 +239,12 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value) gpio_set_value(gpio, value); } -#endif /* !CONFIG_HAVE_GPIO_LIB */ +#endif /* !CONFIG_GPIOLIB */ #ifndef CONFIG_GPIO_SYSFS +struct device; + /* sysfs support is only available with gpiolib, where it's optional */ static inline int gpio_export(unsigned gpio, bool direction_may_change) @@ -185,6 +252,17 @@ static inline int gpio_export(unsigned gpio, bool direction_may_change) return -ENOSYS; } +static inline int gpio_export_link(struct device *dev, const char *name, + unsigned gpio) +{ + return -ENOSYS; +} + +static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) +{ + return -ENOSYS; +} + static inline void gpio_unexport(unsigned gpio) { } |