diff options
| author | Laxman Dewangan <ldewangan@nvidia.com> | 2017-04-06 16:35:52 +0300 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2017-04-07 13:23:29 +0300 |
| commit | 4c0facddb7d88c78c8bd977c16faa647f079ccda (patch) | |
| tree | d7bbe718888ae2348a7b315c69bf6c4eebb33d9c /include/dt-bindings | |
| parent | 11598d1740500e3c1848122f3e77ab017aa38b77 (diff) | |
| download | linux-4c0facddb7d88c78c8bd977c16faa647f079ccda.tar.xz | |
gpio: core: Decouple open drain/source flag with active low/high
Currently, the GPIO interface is said to Open Drain if it is Single
Ended and active LOW. Similarly, it is said as Open Source if it is
Single Ended and active HIGH.
The active HIGH/LOW is used in the interface for setting the pin
state to HIGH or LOW when enabling/disabling the interface.
In Open Drain interface, pin is set to HIGH by putting pin in
high impedance and LOW by driving to the LOW.
In Open Source interface, pin is set to HIGH by driving pin to
HIGH and set to LOW by putting pin in high impedance.
With above, the Open Drain/Source is unrelated to the active LOW/HIGH
in interface. There is interface where the enable/disable of interface
is ether active LOW or HIGH but it is Open Drain type.
Hence decouple the Open Drain with Single Ended + Active LOW and
Open Source with Single Ended + Active HIGH.
Adding different flag for the Open Drain/Open Source which is valid
only when Single ended flag is enabled.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'include/dt-bindings')
| -rw-r--r-- | include/dt-bindings/gpio/gpio.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h index c673d2c87c60..b4f54da694eb 100644 --- a/include/dt-bindings/gpio/gpio.h +++ b/include/dt-bindings/gpio/gpio.h @@ -17,11 +17,15 @@ #define GPIO_PUSH_PULL 0 #define GPIO_SINGLE_ENDED 2 +/* Bit 2 express Open drain or open source */ +#define GPIO_LINE_OPEN_SOURCE 0 +#define GPIO_LINE_OPEN_DRAIN 4 + /* - * Open Drain/Collector is the combination of single-ended active low, - * Open Source/Emitter is the combination of single-ended active high. + * Open Drain/Collector is the combination of single-ended open drain interface. + * Open Source/Emitter is the combination of single-ended open source interface. */ -#define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_ACTIVE_LOW) -#define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_ACTIVE_HIGH) +#define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_DRAIN) +#define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_SOURCE) #endif |