gpio: gpiolib: Support for open source/emitter gpios

Adding support for the open source gpio on which client
can specify the open source property through GPIO flag
GPIOF_OPEN_SOURCE at the time of gpio request.
The open source pins are normally pulled low and it
cannot be driven to output with value of 0 and so
when client request for setting the pin to LOW, the
gpio will be set to input direction to make pin in tristate
and hence PULL-DOWN on pins will make the state to LOW.
The open source pin can be driven to HIGH by setting output
with value of 1.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Laxman Dewangan 2012-02-17 20:26:22 +05:30 committed by Grant Likely
parent aca5ce14eb
commit 25553ff075
2 changed files with 42 additions and 0 deletions

View file

@ -17,6 +17,9 @@
/* Gpio pin is open drain */
#define GPIOF_OPEN_DRAIN (1 << 2)
/* Gpio pin is open source */
#define GPIOF_OPEN_SOURCE (1 << 3)
/**
* struct gpio - a structure describing a GPIO with configuration
* @gpio: the GPIO number