diff options
| author | Laxman Dewangan <ldewangan@nvidia.com> | 2012-02-17 20:26:21 +0530 |
|---|---|---|
| committer | Simone Willett <swillett@nvidia.com> | 2012-03-07 22:24:14 -0800 |
| commit | 38ca86e591ad3e80e21d40ff647622a85e110f95 (patch) | |
| tree | 233444b56e4292d4629bbf6814154166cbc0aeeb /include | |
| parent | 0d441392be71b23aa5adaa2533318bf2d38c643e (diff) | |
gpio: gpiolib: Support for open drain/collector gpios
Adding support for the open drain gpio on which client
can specify the open drain property through GPIO flag
GPIOF_OPEN_DRAIN at the time of gpio request.
The open drain pins are normally pulled high and it
cannot be driven to output with value of 1 and so
when client request for setting the pin to HIGH, the
gpio will be set to input direction to make pin in tristate
and hence PULL-UP on pins will make the state to HIGH.
The open drain pin can be driven to LOW by setting output
with value of 0.
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>
Cherry-picked from mainline
aca5ce14eb773a75e5d935968b2e390dc5bd29c3
Change-Id: I097caebcc7cf6fb1497bb0395320dfc061bb6277
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/88264
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/gpio.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 17b5a0d80e42..8d3a8011f312 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -14,6 +14,9 @@ #define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) #define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) +/* Gpio pin is open drain */ +#define GPIOF_OPEN_DRAIN (1 << 2) + #ifdef CONFIG_GENERIC_GPIO #include <asm/gpio.h> |