From 79a9becda8940deb2274b5aa4577c86d52ee7ecb Mon Sep 17 00:00:00 2001 From: Alexandre Courbot Date: Thu, 17 Oct 2013 10:21:36 -0700 Subject: gpiolib: export descriptor-based GPIO interface This patch exports the gpiod_* family of API functions, a safer alternative to the legacy GPIO interface. Differences between the gpiod and legacy gpio APIs are: - gpio works with integers, whereas gpiod operates on opaque handlers which cannot be forged or used before proper acquisition - gpiod get/set functions are aware of the active low state of a GPIO - gpio consumers should now include to access the new interface, whereas chips drivers will use The legacy gpio API is now built as inline functions on top of gpiod. Signed-off-by: Alexandre Courbot Signed-off-by: Linus Walleij --- include/linux/gpio/consumer.h | 238 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 238 insertions(+) create mode 100644 include/linux/gpio/consumer.h (limited to 'include/linux/gpio/consumer.h') diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h new file mode 100644 index 000000000000..2088eb50421c --- /dev/null +++ b/include/linux/gpio/consumer.h @@ -0,0 +1,238 @@ +#ifndef __LINUX_GPIO_CONSUMER_H +#define __LINUX_GPIO_CONSUMER_H + +#include +#include + +#ifdef CONFIG_GPIOLIB + +struct device; +struct gpio_chip; + +/** + * Opaque descriptor for a GPIO. These are obtained using gpiod_get() and are + * preferable to the old integer-based handles. + * + * Contrary to integers, a pointer to a gpio_desc is guaranteed to be valid + * until the GPIO is released. + */ +struct gpio_desc; + +int gpiod_get_direction(const struct gpio_desc *desc); +int gpiod_direction_input(struct gpio_desc *desc); +int gpiod_direction_output(struct gpio_desc *desc, int value); + +/* Value get/set from non-sleeping context */ +int gpiod_get_value(const struct gpio_desc *desc); +void gpiod_set_value(struct gpio_desc *desc, int value); +int gpiod_get_raw_value(const struct gpio_desc *desc); +void gpiod_set_raw_value(struct gpio_desc *desc, int value); + +/* Value get/set from sleeping context */ +int gpiod_get_value_cansleep(const struct gpio_desc *desc); +void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); +int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc); +void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value); + +int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); + +int gpiod_is_active_low(const struct gpio_desc *desc); +int gpiod_cansleep(const struct gpio_desc *desc); + +int gpiod_to_irq(const struct gpio_desc *desc); + +/* Convert between the old gpio_ and new gpiod_ interfaces */ +struct gpio_desc *gpio_to_desc(unsigned gpio); +int desc_to_gpio(const struct gpio_desc *desc); +struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc); + +#else /* CONFIG_GPIOLIB */ + +static inline struct gpio_desc *__must_check gpiod_get(struct device *dev, + const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} +static inline struct gpio_desc *__must_check gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + return ERR_PTR(-ENOSYS); +} +static inline void gpiod_put(struct gpio_desc *desc) +{ + might_sleep(); + + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, + const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} +static inline +struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + return ERR_PTR(-ENOSYS); +} +static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) +{ + might_sleep(); + + /* GPIO can never have been requested */ + WARN_ON(1); +} + + +static inline int gpiod_get_direction(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} +static inline int gpiod_direction_input(struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} +static inline int gpiod_direction_output(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} + + +static inline int gpiod_get_value(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_value(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} +static inline int gpiod_get_raw_value(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_raw_value(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline int gpiod_get_value_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} +static inline int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, + int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} + +static inline int gpiod_is_active_low(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline int gpiod_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} + +static inline int gpiod_to_irq(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -EINVAL; +} + +static inline struct gpio_desc *gpio_to_desc(unsigned gpio) +{ + return ERR_PTR(-EINVAL); +} +static inline int desc_to_gpio(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -EINVAL; +} +static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return ERR_PTR(-ENODEV); +} + + +#endif /* CONFIG_GPIOLIB */ + +#if IS_ENABLED(CONFIG_GPIOLIB) && IS_ENABLED(CONFIG_GPIO_SYSFS) + +int gpiod_export(struct gpio_desc *desc, bool direction_may_change); +int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc); +int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); +void gpiod_unexport(struct gpio_desc *desc); + +#else /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */ + +static inline int gpiod_export(struct gpio_desc *desc, + bool direction_may_change) +{ + return -ENOSYS; +} + +static inline int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) +{ + return -ENOSYS; +} + +static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) +{ + return -ENOSYS; +} + +static inline void gpiod_unexport(struct gpio_desc *desc) +{ +} + +#endif /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */ + +#endif -- cgit v1.2.3