diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index d8abfc31abbebf136bccee55174a8321f7c92ba3..76546324e968cf70394144beb86817c16586ceb3 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -29,13 +29,24 @@ gpiod_get() functions. Like many other kernel subsystems, gpiod_get() takes the device that will use the GPIO and the function the requested GPIO is supposed to fulfill: - struct gpio_desc *gpiod_get(struct device *dev, const char *con_id) + struct gpio_desc *gpiod_get(struct device *dev, const char *con_id, + enum gpiod_flags flags) If a function is implemented by using several GPIOs together (e.g. a simple LED device that displays digits), an additional index argument can be specified: struct gpio_desc *gpiod_get_index(struct device *dev, - const char *con_id, unsigned int idx) + const char *con_id, unsigned int idx, + enum gpiod_flags flags) + +The flags parameter is used to optionally specify a direction and initial value +for the GPIO. Values can be: + +* GPIOD_ASIS or 0 to not initialize the GPIO at all. The direction must be set + later with one of the dedicated functions. +* GPIOD_IN to initialize the GPIO as input. +* GPIOD_OUT_LOW to initialize the GPIO as output with a value of 0. +* GPIOD_OUT_HIGH to initialize the GPIO as output with a value of 1. Both functions return either a valid GPIO descriptor, or an error code checkable with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned @@ -46,11 +57,13 @@ errors and an absence of GPIO for optional GPIO parameters. Device-managed variants of these functions are also defined: - struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id) + struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id, + enum gpiod_flags flags) struct gpio_desc *devm_gpiod_get_index(struct device *dev, const char *con_id, - unsigned int idx) + unsigned int idx, + enum gpiod_flags flags) A GPIO descriptor can be disposed of using the gpiod_put() function: @@ -67,8 +80,9 @@ Using GPIOs Setting Direction ----------------- -The first thing a driver must do with a GPIO is setting its direction. This is -done by invoking one of the gpiod_direction_*() functions: +The first thing a driver must do with a GPIO is setting its direction. If no +direction-setting flags have been given to gpiod_get*(), this is done by +invoking one of the gpiod_direction_*() functions: int gpiod_direction_input(struct gpio_desc *desc) int gpiod_direction_output(struct gpio_desc *desc, int value) diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c index 65978cf85f791cefbf494b9f2cfc694d9a3929ba..41b2f40578d5e78e88ab1afdb1d5f066a3913658 100644 --- a/drivers/gpio/devres.c +++ b/drivers/gpio/devres.c @@ -39,47 +39,53 @@ static int devm_gpiod_match(struct device *dev, void *res, void *data) * devm_gpiod_get - Resource-managed gpiod_get() * @dev: GPIO consumer * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags * * Managed gpiod_get(). GPIO descriptors returned from this function are * automatically disposed on driver detach. See gpiod_get() for detailed * information about behavior and return values. */ -struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, - const char *con_id) +struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev, + const char *con_id, + enum gpiod_flags flags) { - return devm_gpiod_get_index(dev, con_id, 0); + return devm_gpiod_get_index(dev, con_id, 0, flags); } -EXPORT_SYMBOL(devm_gpiod_get); +EXPORT_SYMBOL(__devm_gpiod_get); /** * devm_gpiod_get_optional - Resource-managed gpiod_get_optional() * @dev: GPIO consumer * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags * * Managed gpiod_get_optional(). GPIO descriptors returned from this function * are automatically disposed on driver detach. See gpiod_get_optional() for * detailed information about behavior and return values. */ -struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev, - const char *con_id) +struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) { - return devm_gpiod_get_index_optional(dev, con_id, 0); + return devm_gpiod_get_index_optional(dev, con_id, 0, flags); } -EXPORT_SYMBOL(devm_gpiod_get_optional); +EXPORT_SYMBOL(__devm_gpiod_get_optional); /** * devm_gpiod_get_index - Resource-managed gpiod_get_index() * @dev: GPIO consumer * @con_id: function within the GPIO consumer * @idx: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags * * Managed gpiod_get_index(). GPIO descriptors returned from this function are * automatically disposed on driver detach. See gpiod_get_index() for detailed * information about behavior and return values. */ -struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, +struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev, const char *con_id, - unsigned int idx) + unsigned int idx, + enum gpiod_flags flags) { struct gpio_desc **dr; struct gpio_desc *desc; @@ -89,7 +95,7 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, if (!dr) return ERR_PTR(-ENOMEM); - desc = gpiod_get_index(dev, con_id, idx); + desc = gpiod_get_index(dev, con_id, idx, flags); if (IS_ERR(desc)) { devres_free(dr); return desc; @@ -100,26 +106,28 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, return desc; } -EXPORT_SYMBOL(devm_gpiod_get_index); +EXPORT_SYMBOL(__devm_gpiod_get_index); /** * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional() * @dev: GPIO consumer * @con_id: function within the GPIO consumer * @index: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags * * Managed gpiod_get_index_optional(). GPIO descriptors returned from this * function are automatically disposed on driver detach. See * gpiod_get_index_optional() for detailed information about behavior and * return values. */ -struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev, +struct gpio_desc *__must_check __devm_gpiod_get_index_optional(struct device *dev, const char *con_id, - unsigned int index) + unsigned int index, + enum gpiod_flags flags) { struct gpio_desc *desc; - desc = devm_gpiod_get_index(dev, con_id, index); + desc = devm_gpiod_get_index(dev, con_id, index, flags); if (IS_ERR(desc)) { if (PTR_ERR(desc) == -ENOENT) return NULL; @@ -127,7 +135,7 @@ struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev, return desc; } -EXPORT_SYMBOL(devm_gpiod_get_index_optional); +EXPORT_SYMBOL(__devm_gpiod_get_index_optional); /** * devm_gpiod_put - Resource-managed gpiod_put() diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 330227581a25c46903f217676eedaa3de641f17d..15cc0bb65dda84f8e5b8151722434f6073e61e5b 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1582,38 +1582,43 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, * gpiod_get - obtain a GPIO for a given GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags * * Return the GPIO descriptor corresponding to the function con_id of device * dev, -ENOENT if no GPIO has been assigned to the requested function, or * another IS_ERR() code if an error occured while trying to acquire the GPIO. */ -struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id) +struct gpio_desc *__must_check __gpiod_get(struct device *dev, const char *con_id, + enum gpiod_flags flags) { - return gpiod_get_index(dev, con_id, 0); + return gpiod_get_index(dev, con_id, 0, flags); } -EXPORT_SYMBOL_GPL(gpiod_get); +EXPORT_SYMBOL_GPL(__gpiod_get); /** * gpiod_get_optional - obtain an optional GPIO for a given GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer + * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get(), except that when no GPIO was assigned to * the requested function it will return NULL. This is convenient for drivers * that need to handle optional GPIOs. */ -struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, - const char *con_id) +struct gpio_desc *__must_check __gpiod_get_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) { - return gpiod_get_index_optional(dev, con_id, 0); + return gpiod_get_index_optional(dev, con_id, 0, flags); } -EXPORT_SYMBOL_GPL(gpiod_get_optional); +EXPORT_SYMBOL_GPL(__gpiod_get_optional); /** * gpiod_get_index - obtain a GPIO from a multi-index GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @idx: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags * * This variant of gpiod_get() allows to access GPIOs other than the first * defined one for functions that define several GPIOs. @@ -1622,23 +1627,24 @@ EXPORT_SYMBOL_GPL(gpiod_get_optional); * requested function and/or index, or another IS_ERR() code if an error * occured while trying to acquire the GPIO. */ -struct gpio_desc *__must_check gpiod_get_index(struct device *dev, +struct gpio_desc *__must_check __gpiod_get_index(struct device *dev, const char *con_id, - unsigned int idx) + unsigned int idx, + enum gpiod_flags flags) { struct gpio_desc *desc = NULL; int status; - enum gpio_lookup_flags flags = 0; + enum gpio_lookup_flags lookupflags = 0; dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); /* Using device tree? */ if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) { dev_dbg(dev, "using device tree for GPIO lookup\n"); - desc = of_find_gpio(dev, con_id, idx, &flags); + desc = of_find_gpio(dev, con_id, idx, &lookupflags); } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) { dev_dbg(dev, "using ACPI for GPIO lookup\n"); - desc = acpi_find_gpio(dev, con_id, idx, &flags); + desc = acpi_find_gpio(dev, con_id, idx, &lookupflags); } /* @@ -1647,7 +1653,7 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, */ if (!desc || desc == ERR_PTR(-ENOENT)) { dev_dbg(dev, "using lookup tables for GPIO lookup"); - desc = gpiod_find(dev, con_id, idx, &flags); + desc = gpiod_find(dev, con_id, idx, &lookupflags); } if (IS_ERR(desc)) { @@ -1660,16 +1666,33 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, if (status < 0) return ERR_PTR(status); - if (flags & GPIO_ACTIVE_LOW) + if (lookupflags & GPIO_ACTIVE_LOW) set_bit(FLAG_ACTIVE_LOW, &desc->flags); - if (flags & GPIO_OPEN_DRAIN) + if (lookupflags & GPIO_OPEN_DRAIN) set_bit(FLAG_OPEN_DRAIN, &desc->flags); - if (flags & GPIO_OPEN_SOURCE) + if (lookupflags & GPIO_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); + /* No particular flag request, return here... */ + if (flags & GPIOD_FLAGS_BIT_DIR_SET) + return desc; + + /* Process flags */ + if (flags & GPIOD_FLAGS_BIT_DIR_OUT) + status = gpiod_direction_output(desc, + flags & GPIOD_FLAGS_BIT_DIR_VAL); + else + status = gpiod_direction_input(desc); + + if (status < 0) { + dev_dbg(dev, "setup of GPIO %s failed\n", con_id); + gpiod_put(desc); + return ERR_PTR(status); + } + return desc; } -EXPORT_SYMBOL_GPL(gpiod_get_index); +EXPORT_SYMBOL_GPL(__gpiod_get_index); /** * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO @@ -1677,18 +1700,20 @@ EXPORT_SYMBOL_GPL(gpiod_get_index); * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @index: index of the GPIO to obtain in the consumer + * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get_index(), except that when no GPIO with the * specified index was assigned to the requested function it will return NULL. * This is convenient for drivers that need to handle optional GPIOs. */ -struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, +struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev, const char *con_id, - unsigned int index) + unsigned int index, + enum gpiod_flags flags) { struct gpio_desc *desc; - desc = gpiod_get_index(dev, con_id, index); + desc = gpiod_get_index(dev, con_id, index, flags); if (IS_ERR(desc)) { if (PTR_ERR(desc) == -ENOENT) return NULL; @@ -1696,7 +1721,7 @@ struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, return desc; } -EXPORT_SYMBOL_GPL(gpiod_get_index_optional); +EXPORT_SYMBOL_GPL(__gpiod_get_index_optional); /** * gpiod_put - dispose of a GPIO descriptor diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 05e53ccb708b390b7a1f7afb01682fd65046eb3c..b7ce0c64c6f3186e4acf37857db3ed3a8390b1e7 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -18,30 +18,79 @@ struct gpio_desc; #ifdef CONFIG_GPIOLIB +#define GPIOD_FLAGS_BIT_DIR_SET BIT(0) +#define GPIOD_FLAGS_BIT_DIR_OUT BIT(1) +#define GPIOD_FLAGS_BIT_DIR_VAL BIT(2) + +/** + * Optional flags that can be passed to one of gpiod_* to configure direction + * and output value. These values cannot be OR'd. + */ +enum gpiod_flags { + GPIOD_ASIS = 0, + GPIOD_IN = GPIOD_FLAGS_BIT_DIR_SET, + GPIOD_OUT_LOW = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT, + GPIOD_OUT_HIGH = GPIOD_FLAGS_BIT_DIR_SET | GPIOD_FLAGS_BIT_DIR_OUT | + GPIOD_FLAGS_BIT_DIR_VAL, +}; + /* Acquire and dispose GPIOs */ -struct gpio_desc *__must_check gpiod_get(struct device *dev, - const char *con_id); -struct gpio_desc *__must_check gpiod_get_index(struct device *dev, +struct gpio_desc *__must_check __gpiod_get(struct device *dev, + const char *con_id, + enum gpiod_flags flags); +#define __gpiod_get(dev, con_id, flags, ...) __gpiod_get(dev, con_id, flags) +#define gpiod_get(varargs...) __gpiod_get(varargs, 0) +struct gpio_desc *__must_check __gpiod_get_index(struct device *dev, const char *con_id, - unsigned int idx); -struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, - const char *con_id); -struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, + unsigned int idx, + enum gpiod_flags flags); +#define __gpiod_get_index(dev, con_id, index, flags, ...) \ + __gpiod_get_index(dev, con_id, index, flags) +#define gpiod_get_index(varargs...) __gpiod_get_index(varargs, 0) +struct gpio_desc *__must_check __gpiod_get_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags); +#define __gpiod_get_optional(dev, con_id, flags, ...) \ + __gpiod_get_optional(dev, con_id, flags) +#define gpiod_get_optional(varargs...) __gpiod_get_optional(varargs, 0) +struct gpio_desc *__must_check __gpiod_get_index_optional(struct device *dev, const char *con_id, - unsigned int index); + unsigned int index, + enum gpiod_flags flags); +#define __gpiod_get_index_optional(dev, con_id, index, flags, ...) \ + __gpiod_get_index_optional(dev, con_id, index, flags) +#define gpiod_get_index_optional(varargs...) \ + __gpiod_get_index_optional(varargs, 0) void gpiod_put(struct gpio_desc *desc); -struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, - const char *con_id); -struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, +struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev, + const char *con_id, + enum gpiod_flags flags); +#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) +struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev, const char *con_id, - unsigned int idx); -struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev, - const char *con_id); + unsigned int idx, + enum gpiod_flags flags); +#define __devm_gpiod_get_index(dev, con_id, index, flags, ...) \ + __devm_gpiod_get_index(dev, con_id, index, flags) +#define devm_gpiod_get_index(varargs...) __devm_gpiod_get_index(varargs, 0) +struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags); +#define __devm_gpiod_get_optional(dev, con_id, flags, ...) \ + __devm_gpiod_get_optional(dev, con_id, flags) +#define devm_gpiod_get_optional(varargs...) \ + __devm_gpiod_get_optional(varargs, 0) struct gpio_desc *__must_check -devm_gpiod_get_index_optional(struct device *dev, const char *con_id, - unsigned int index); +__devm_gpiod_get_index_optional(struct device *dev, const char *con_id, + unsigned int index, enum gpiod_flags flags); +#define __devm_gpiod_get_index_optional(dev, con_id, index, flags, ...) \ + __devm_gpiod_get_index_optional(dev, con_id, index, flags) +#define devm_gpiod_get_index_optional(varargs...) \ + __devm_gpiod_get_index_optional(varargs, 0) void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);