Hi Rob,
Thanks again for reviewing.
On Tue, Feb 13, 2018 at 05:20:07PM -0600, Rob Herring wrote:
> On Wed, Feb 07, 2018 at 08:35:23PM +0200, Baruch Siach wrote:
> > +Raspberry Pi GPIO expander
> > +
> > +The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware. The
> > +firmware exposes a mailbox interface that allows the ARM core to control the
> > +GPIO lines on the expander.
> > +
> > +Required properties:
> > +
> > +- compatible : Should be "raspberrypi,firmware-gpio"
> > +- gpio-controller : Marks the device node as a gpio controller
> > +- #gpio-cells : Should be two. The first cell is the pin number, and
> > + the second cell is used to specify the gpio polarity:
> > + 0 = active high
> > + 1 = active low
> > +- firmware : Reference to the RPi firmware device node
>
> This is the parent node. You don't need it.
OK. I guess of_get_parent() will do the trick.
> > +Example:
> > +
> > +firmware: firmware {
> > + compatible = "raspberrypi,bcm2835-firmware";
> > + mboxes = <&mailbox>;
>
> No, sorry. /firmware is the container of firmware nodes. So
> something like this:
>
> firmware {
> rpi-firmware {
> compatible = "raspberrypi,bcm2835-firmware";
> mboxes = <&mailbox>;
> gpio {
> compatible = "raspberrypi,firmware-gpio";
>
> };
> };
> };
This is the hierarchy we currently have at arch/arm/boot/dts/bcm2835-rpi.dtsi:
/ {
soc {
firmware: firmware {
compatible = "raspberrypi,bcm2835-firmware";
mboxes = <&mailbox>;
};
};
};
Are you suggesting to add another container between 'soc' and 'firmware'? Or
is it the 'firmware' node name that we need to change to 'rpi-firmware'?
> > +
> > + expgpio: gpio {
> > + compatible = "raspberrypi,firmware-gpio";
> > + gpio-controller;
> > + #gpio-cells = <2>;
> > + firmware = <&firmware>;
> > + };
> > +};
baruch
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