Introduce new functions for conveniently obtaining and disposing of an entire array of GPIOs with one function call.
Suggested-by: Alexandre Courbot <[email protected]> Signed-off-by: Rojhalat Ibrahim <[email protected]> --- Documentation/gpio/consumer.txt | 28 ++++++++++++- drivers/gpio/gpiolib.c | 84 ++++++++++++++++++++++++++++++++++++++++ include/linux/gpio/consumer.h | 42 ++++++++++++++++++++ 3 files changed, 153 insertions(+), 1 deletion(-) diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index c67f806..d02f341 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -58,7 +58,6 @@ pattern where a GPIO is optional, the gpiod_get_optional() and gpiod_get_index_optional() functions can be used. These functions return NULL instead of -ENOENT if no GPIO has been assigned to the requested function: - struct gpio_desc *gpiod_get_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) @@ -68,6 +67,29 @@ instead of -ENOENT if no GPIO has been assigned to the requested function: unsigned int index, enum gpiod_flags flags) +For a function using multiple GPIOs all of those can be obtained with one call: + + int gpiod_get_array(struct device *dev, + const char *con_id, + struct gpio_desc **desc_array, + unsigned int count, + enum gpiod_flags flags) + +In this case an array for storing the GPIO descriptors and the number of GPIOs +are required as additional arguments. This function either returns the +requested number of GPIOs or an error code. It will not return a positive +number if some but not all of the requested GPIOs could be obtained. +The following function behaves differently: + + int gpiod_get_array_optional(struct device *dev, + const char *con_id, + struct gpio_desc **desc_array, + unsigned int could, + enum gpiod_flags flags) + +This one returns the number of GPIOs actually available which can be smaller +than the requested number or even 0. + Device-managed variants of these functions are also defined: struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id, @@ -91,6 +113,10 @@ A GPIO descriptor can be disposed of using the gpiod_put() function: void gpiod_put(struct gpio_desc *desc) +For an array of GPIOs this function can be used: + + void gpiod_put_array(struct gpio_desc **desc_array, unsigned int count) + It is strictly forbidden to use a descriptor after calling this function. The device-managed variant is, unsurprisingly: diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 56b7c5d..d45fa9c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1925,6 +1925,76 @@ struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev, EXPORT_SYMBOL_GPL(__gpiod_get_index_optional); /** + * 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 + * @desc_array: descriptor array for the acquired GPIOs + * @count: number of GPIOs to obtain in the consumer + * @flags: optional GPIO initialization flags + * + * This function obtains the specified number of GPIOs starting with index 0 + * for functions that define several GPIOs. + * + * Return the actual number of acquired GPIOs, -ENOENT if the actual number of + * GPIOs assigned to the requested function is smaller than @count, + * or another IS_ERR() code if an error occurred while trying to acquire the + * GPIOs. + */ +int __must_check __gpiod_get_array(struct device *dev, const char *con_id, + struct gpio_desc **desc_array, + unsigned int count, + enum gpiod_flags flags) +{ + int r; + + r = gpiod_get_array_optional(dev, con_id, desc_array, count, flags); + if ((r >= 0) && (r != count)) { + gpiod_put_array(desc_array, r); + return -ENOENT; + } + return r; +} +EXPORT_SYMBOL_GPL(__gpiod_get_array); + +/** + * 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 + * @desc_array: descriptor array for the acquired GPIOs + * @count: number of GPIOs to obtain in the consumer + * @flags: optional GPIO initialization flags + * + * This is equivalent to gpiod_get_array(), except that when the actual number + * of GPIOs assigned to the requested function is smaller than @count it will + * not return an error but the number of GPIOs actually available. + */ +int __must_check __gpiod_get_array_optional(struct device *dev, + const char *con_id, + struct gpio_desc **desc_array, + unsigned int count, + enum gpiod_flags flags) +{ + struct gpio_desc *desc; + unsigned int n; + + for (n = 0; n < count; ) { + desc = gpiod_get_index(dev, con_id, n, flags); + if (IS_ERR(desc)) { + if (PTR_ERR(desc) != -ENOENT) { + gpiod_put_array(desc_array, n); + return PTR_ERR(desc); + } + break; + } + desc_array[n] = desc; + n++; + } + return n; +} +EXPORT_SYMBOL_GPL(__gpiod_get_array_optional); + +/** * gpiod_put - dispose of a GPIO descriptor * @desc: GPIO descriptor to dispose of * @@ -1936,6 +2006,20 @@ void gpiod_put(struct gpio_desc *desc) } EXPORT_SYMBOL_GPL(gpiod_put); +/** + * gpiod_put_array - dispose of multiple GPIO descriptors + * @desc_array: GPIO descriptor array + * @count: number of GPIOs in the array + */ +void gpiod_put_array(struct gpio_desc **desc_array, unsigned int count) +{ + unsigned int n; + + for (n = 0; n < count; n++) + gpiod_put(desc_array[n]); +} +EXPORT_SYMBOL_GPL(gpiod_put_array); + #ifdef CONFIG_DEBUG_FS static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index d54d158..f225d25 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -49,7 +49,17 @@ struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev, const char *con_id, unsigned int index, enum gpiod_flags flags); +int __must_check __gpiod_get_array(struct device *dev, const char *con_id, + struct gpio_desc **desc_array, + unsigned int count, + enum gpiod_flags flags); +int __must_check __gpiod_get_array_optional(struct device *dev, + const char *con_id, + struct gpio_desc **desc_array, + unsigned int count, + enum gpiod_flags flags); void gpiod_put(struct gpio_desc *desc); +void gpiod_put_array(struct gpio_desc **desc_array, unsigned int count); struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev, const char *con_id, @@ -135,6 +145,22 @@ __gpiod_get_index_optional(struct device *dev, const char *con_id, return ERR_PTR(-ENOSYS); } +static inline int __must_check +__gpiod_get_array(struct device *dev, const char *con_id, + struct gpio_desc **desc_array, unsigned int count, + enum gpiod_flags flags) +{ + return ERR_PTR(-ENOSYS); +} + +static inline int __must_check +__gpiod_get_array_optional(struct device *dev, const char *con_id, + struct gpio_desc **desc_array, unsigned int count, + enum gpiod_flags flags) +{ + return ERR_PTR(-ENOSYS); +} + static inline void gpiod_put(struct gpio_desc *desc) { might_sleep(); @@ -143,6 +169,15 @@ static inline void gpiod_put(struct gpio_desc *desc) WARN_ON(1); } +static inline void gpiod_put_array(struct gpio_desc **desc_array, + unsigned int count) +{ + 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, @@ -344,6 +379,13 @@ static inline int desc_to_gpio(const struct gpio_desc *desc) __gpiod_get_index_optional(dev, con_id, index, flags) #define gpiod_get_index_optional(varargs...) \ __gpiod_get_index_optional(varargs, 0) +#define __gpiod_get_array(dev, con_id, desc_array, count, flags, ...) \ + __gpiod_get_array(dev, con_id, desc_array, count, flags) +#define gpiod_get_array(varargs...) __gpiod_get_array(varargs, 0) +#define __gpiod_get_array_optional(dev, con_id, desc_array, count, flags, ...) \ + __gpiod_get_array_optional(dev, con_id, desc_array, count, flags) +#define gpiod_get_array_optional(varargs...) \ + __gpiod_get_array_optional(varargs, 0) #define __devm_gpiod_get(dev, con_id, flags, ...) \ __devm_gpiod_get(dev, con_id, flags) #define devm_gpiod_get(varargs...) __devm_gpiod_get(varargs, 0) -- 2.0.5 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
