diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 03fc19654..cafef907e 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -85,6 +85,72 @@ void gpio_free(unsigned gpio) free(gi->label); } +/** + * gpio_request_one - request a single GPIO with initial configuration + * @gpio: the GPIO number + * @flags: GPIO configuration as specified by GPIOF_* + * @label: a literal description string of this GPIO + */ +int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) +{ + int err; + + err = gpio_request(gpio, label); + if (err) + return err; + + if (flags & GPIOF_DIR_IN) + err = gpio_direction_input(gpio); + else + err = gpio_direction_output(gpio, + (flags & GPIOF_INIT_HIGH) ? 1 : 0); + + if (err) + goto free_gpio; + + return 0; + + free_gpio: + gpio_free(gpio); + return err; +} +EXPORT_SYMBOL_GPL(gpio_request_one); + +/** + * gpio_request_array - request multiple GPIOs in a single call + * @array: array of the 'struct gpio' + * @num: how many GPIOs in the array + */ +int gpio_request_array(const struct gpio *array, size_t num) +{ + int i, err; + + for (i = 0; i < num; i++, array++) { + err = gpio_request_one(array->gpio, array->flags, array->label); + if (err) + goto err_free; + } + return 0; + +err_free: + while (i--) + gpio_free((--array)->gpio); + return err; +} +EXPORT_SYMBOL_GPL(gpio_request_array); + +/** + * gpio_free_array - release multiple GPIOs in a single call + * @array: array of the 'struct gpio' + * @num: how many GPIOs in the array + */ +void gpio_free_array(const struct gpio *array, size_t num) +{ + while (num--) + gpio_free((array++)->gpio); +} +EXPORT_SYMBOL_GPL(gpio_free_array); + void gpio_set_value(unsigned gpio, int value) { struct gpio_info *gi = gpio_to_desc(gpio); diff --git a/include/gpio.h b/include/gpio.h index f33b43550..4a97521ae 100644 --- a/include/gpio.h +++ b/include/gpio.h @@ -6,6 +6,25 @@ #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; +}; + #ifndef CONFIG_GPIOLIB static inline int gpio_request(unsigned gpio, const char *label) { @@ -15,9 +34,29 @@ static inline int gpio_request(unsigned gpio, const char *label) static inline void gpio_free(unsigned gpio) { } + +static inline int gpio_request_one(unsigned gpio, + unsigned long flags, const char *label) +{ + return -ENOSYS; +} + +static inline int gpio_request_array(const struct gpio *array, size_t num) +{ + return -ENOSYS; +} + +static inline void gpio_free_array(const struct gpio *array, size_t num) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} #else int gpio_request(unsigned gpio, const char *label); void gpio_free(unsigned gpio); +int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); +int gpio_request_array(const struct gpio *array, size_t num); +void gpio_free_array(const struct gpio *array, size_t num); #endif struct gpio_chip;