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gpio: make gpiod_direction_output take a logical value

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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 <p.zabel@pengutronix.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Philipp Zabel 2014-01-07 12:34:11 +01:00 committed by Linus Walleij
parent 25b35da7f4
commit ef70bbe1aa
4 changed files with 57 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Documentation/gpio/consumer.txt
View File

@ -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:

67
drivers/gpio/gpiolib.c
View File

@ -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 @@ int gpiod_direction_input(struct gpio_desc *desc)
}
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 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
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);
/**

2
include/asm-generic/gpio.h
View File

@ -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)

7
include/linux/gpio/consumer.h
View File

@ -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)