gpiolib: add gpio get direction callback support

Add .get_direction callback to gpio_chip. This allows gpiolib
to check the current direction of a gpio.
Used to show the correct gpio direction in sysfs and debug entries.

If callback is not set then gpiolib will work as previously;
e.g. guessing everything is input until a direction is set.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Mathias Nyman
2012-10-24 17:25:27 +03:00
committed by Linus Walleij
parent d6a2fa0424
commit 80b0a60292
2 changed files with 41 additions and 2 deletions

View File

@@ -56,6 +56,8 @@ struct device_node;
* enabling module power and clock; may sleep
* @free: optional hook for chip-specific deactivation, such as
* disabling module power and clock; may sleep
* @get_direction: returns direction for signal "offset", 0=out, 1=in,
* (same as GPIOF_DIR_XXX), or negative error
* @direction_input: configures signal "offset" as input, or returns error
* @get: returns value for signal "offset"; for output signals this
* returns either the value actually sensed, or zero
@@ -100,7 +102,8 @@ struct gpio_chip {
unsigned offset);
void (*free)(struct gpio_chip *chip,
unsigned offset);
int (*get_direction)(struct gpio_chip *chip,
unsigned offset);
int (*direction_input)(struct gpio_chip *chip,
unsigned offset);
int (*get)(struct gpio_chip *chip,