aleph/lkl_linux
1
0
Fork 0
mirror of https://github.com/lkl/linux.git synced 2025-12-19 16:13:19 +09:00
Code Issues Packages Projects Releases Wiki Activity

gpio: gpiolib: Support for open drain/collector gpios

Browse Source 
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>
This commit is contained in:
Laxman Dewangan
2012-02-17 20:26:21 +05:30
committed by Grant Likely
parent 3d2ddfdcf0
commit aca5ce14eb
2 changed files with 45 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
include/linux/gpio.h
View File

@@ -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)
/**
* struct gpio - a structure describing a GPIO with configuration
* @gpio: the GPIO number