[PATCH 1/3] dt-bindings: Add a binding for the RPi firmware GPIO driver.
stefan.wahren at i2se.com
Fri Sep 23 11:39:01 PDT 2016
> Eric Anholt <eric at anholt.net> hat am 19. September 2016 um 18:13 geschrieben:
> The RPi firmware exposes all of the board's GPIO lines through
> property calls. Linux chooses to control most lines directly through
> the pinctrl driver, but for the FXL6408 GPIO expander on the Pi3, we
> need to access them through the firmware.
> Signed-off-by: Eric Anholt <eric at anholt.net>
> .../bindings/gpio/gpio-raspberrypi-firmware.txt | 22
> 1 file changed, 22 insertions(+)
> create mode 100644
> diff --git
> new file mode 100644
> index 000000000000..2b635c23a6f8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-raspberrypi-firmware.txt
> @@ -0,0 +1,22 @@
> +Raspberry Pi power domain driver
> +Required properties:
> +- compatible: Should be "raspberrypi,firmware-gpio"
i think the compatible should be more specific like
and all information which aren't requestable from the firmware should be stored
in a info structure. This makes the driver easier to extend in the future by
adding new compatibles and their info structures.
> +- gpio-controller: Marks the device node as a gpio controller
> +- #gpio-cells: Should be <2> for GPIO number and flags
> +- ngpios: Number of GPIO lines to control. See gpio.txt
> +- firmware: Reference to the RPi firmware device node
> +- raspberrypi,firmware-gpio-offset:
> + Number the firmware uses for the first GPIO line
> + controlled by this driver
We should avoid such properties because they don't really describe the hardware.
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