From ef70bbe1aaa612f75360e5df5952fddec50b7ca9 Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Tue, 7 Jan 2014 12:34:11 +0100 Subject: [PATCH] gpio: make gpiod_direction_output take a logical value The documentation was not clear about whether gpio_direction_output should take a logical value or the physical level on the output line, i.e. whether the ACTIVE_LOW status would be taken into account. This converts gpiod_direction_output to use the logical level and adds a new gpiod_direction_output_raw for the raw value. Signed-off-by: Philipp Zabel Reviewed-by: Alexandre Courbot Signed-off-by: Linus Walleij --- Documentation/gpio/consumer.txt | 1 + drivers/gpio/gpiolib.c | 67 +++++++++++++++++++++++---------- include/asm-generic/gpio.h | 2 +- include/linux/gpio/consumer.h | 7 ++++ 4 files changed, 57 insertions(+), 20 deletions(-) diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index e42f77d8d4ca..09854fe59307 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -154,6 +154,7 @@ raw line value: void gpiod_set_raw_value(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_direction_output_raw(struct gpio_desc *desc, int value) The active-low state of a GPIO can also be queried using the following call: diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 50c4922fe53a..80da9f1940c9 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -350,9 +350,9 @@ static ssize_t gpio_direction_store(struct device *dev, if (!test_bit(FLAG_EXPORT, &desc->flags)) status = -EIO; else if (sysfs_streq(buf, "high")) - status = gpiod_direction_output(desc, 1); + status = gpiod_direction_output_raw(desc, 1); else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) - status = gpiod_direction_output(desc, 0); + status = gpiod_direction_output_raw(desc, 0); else if (sysfs_streq(buf, "in")) status = gpiod_direction_input(desc); else @@ -1590,7 +1590,7 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) if (flags & GPIOF_DIR_IN) err = gpiod_direction_input(desc); else - err = gpiod_direction_output(desc, + err = gpiod_direction_output_raw(desc, (flags & GPIOF_INIT_HIGH) ? 1 : 0); if (err) @@ -1756,28 +1756,13 @@ fail: } EXPORT_SYMBOL_GPL(gpiod_direction_input); -/** - * gpiod_direction_output - set the GPIO direction to input - * @desc: GPIO to set to output - * @value: initial output value of the GPIO - * - * Set the direction of the passed GPIO to output, such as gpiod_set_value() can - * be called safely on it. The initial value of the output must be specified. - * - * Return 0 in case of success, else an error code. - */ -int gpiod_direction_output(struct gpio_desc *desc, int value) +static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value) { unsigned long flags; struct gpio_chip *chip; int status = -EINVAL; int offset; - if (!desc || !desc->chip) { - pr_warn("%s: invalid GPIO\n", __func__); - return -EINVAL; - } - /* GPIOs used for IRQs shall not be set as output */ if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { gpiod_err(desc, @@ -1840,6 +1825,50 @@ fail: gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); return status; } + +/** + * gpiod_direction_output_raw - set the GPIO direction to output + * @desc: GPIO to set to output + * @value: initial output value of the GPIO + * + * Set the direction of the passed GPIO to output, such as gpiod_set_value() can + * be called safely on it. The initial value of the output must be specified + * as raw value on the physical line without regard for the ACTIVE_LOW status. + * + * Return 0 in case of success, else an error code. + */ +int gpiod_direction_output_raw(struct gpio_desc *desc, int value) +{ + if (!desc || !desc->chip) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + return _gpiod_direction_output_raw(desc, value); +} +EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); + +/** + * gpiod_direction_output - set the GPIO direction to input + * @desc: GPIO to set to output + * @value: initial output value of the GPIO + * + * Set the direction of the passed GPIO to output, such as gpiod_set_value() can + * be called safely on it. The initial value of the output must be specified + * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into + * account. + * + * Return 0 in case of success, else an error code. + */ +int gpiod_direction_output(struct gpio_desc *desc, int value) +{ + if (!desc || !desc->chip) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + return _gpiod_direction_output_raw(desc, value); +} EXPORT_SYMBOL_GPL(gpiod_direction_output); /** diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index a5f56a0213a7..23e364538ab5 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -69,7 +69,7 @@ static inline int gpio_direction_input(unsigned gpio) } static inline int gpio_direction_output(unsigned gpio, int value) { - return gpiod_direction_output(gpio_to_desc(gpio), value); + return gpiod_direction_output_raw(gpio_to_desc(gpio), value); } static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 4d34dbbbad4d..387994325122 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -36,6 +36,7 @@ void devm_gpiod_put(struct device *dev, struct gpio_desc *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); +int gpiod_direction_output_raw(struct gpio_desc *desc, int value); /* Value get/set from non-sleeping context */ int gpiod_get_value(const struct gpio_desc *desc); @@ -121,6 +122,12 @@ static inline int gpiod_direction_output(struct gpio_desc *desc, int value) WARN_ON(1); return -ENOSYS; } +static inline int gpiod_direction_output_raw(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) -- 2.39.2