On Mon, Sep 19, 2016 at 6:13 PM, Eric Anholt <[email protected]> wrote:
> 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 <[email protected]> Aha > +++ b/Documentation/devicetree/bindings/gpio/gpio-raspberrypi-firmware.txt > @@ -0,0 +1,22 @@ > +Raspberry Pi power domain driver Really? :) > +Required properties: > + > +- compatible: Should be "raspberrypi,firmware-gpio" Usually this is vendor,compat, is the vendors name "raspberrypi"? > +- 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 Is this ever anything else than 8? Else omit it and hardcode 8 in the driver instead. > +- firmware: Reference to the RPi firmware device node Reference the DT binding for this. > +- raspberrypi,firmware-gpio-offset: > + Number the firmware uses for the first GPIO line > + controlled by this driver Does this differ between different instances of this hardware or can it just be open coded in the driver instead? Yours, Linus Walleij
