linux/Documentation/devicetree/bindings/gpio/gpio-omap.txt
Jon Hunter a2797beadf gpio/omap: force restore if context loss is not detectable
When booting with device-tree the function pointer for detecting context
loss is not populated. Ideally, the pm_runtime framework should be
enhanced to allow a means for reporting context/state loss and we could
avoid populating such function pointers altogether. In the interim until
a generic non-device specific solution is in place, force a restore of
the gpio bank when enabling the gpio controller.

Adds a new device-tree property for the OMAP GPIO controller to indicate
if the GPIO controller is located in a power-domain that never loses
power and hence will always maintain its logic state.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-04-10 23:41:16 +02:00

40 lines
1.2 KiB
Plaintext

OMAP GPIO controller bindings
Required properties:
- compatible:
- "ti,omap2-gpio" for OMAP2 controllers
- "ti,omap3-gpio" for OMAP3 controllers
- "ti,omap4-gpio" for OMAP4 controllers
- #gpio-cells : Should be two.
- first cell is the pin number
- second cell is used to specify optional parameters (unused)
- gpio-controller : Marks the device node as a GPIO controller.
- #interrupt-cells : Should be 2.
- interrupt-controller: Mark the device node as an interrupt controller
The first cell is the GPIO number.
The second cell is used to specify flags:
bits[3:0] trigger type and level flags:
1 = low-to-high edge triggered.
2 = high-to-low edge triggered.
4 = active high level-sensitive.
8 = active low level-sensitive.
OMAP specific properties:
- ti,hwmods: Name of the hwmod associated to the GPIO:
"gpio<X>", <X> being the 1-based instance number
from the HW spec.
- ti,gpio-always-on: Indicates if a GPIO bank is always powered and
so will never lose its logic state.
Example:
gpio4: gpio4 {
compatible = "ti,omap4-gpio";
ti,hwmods = "gpio4";
#gpio-cells = <2>;
gpio-controller;
#interrupt-cells = <2>;
interrupt-controller;
};