Re: [RFC v2 5/5] dt-bindings: gpio: Add bindings for pinctrl based generic gpio driver
From: Cristian Marussi
Date: Mon Oct 09 2023 - 11:08:20 EST
On Mon, Oct 09, 2023 at 03:13:24PM +0200, Linus Walleij wrote:
> On Mon, Oct 9, 2023 at 11:08 AM Cristian Marussi
> <cristian.marussi@xxxxxxx> wrote:
>
> > > > + gpio0: gpio@0 {
> > > > + compatible = "pin-control-gpio";
> > > > + gpio-controller;
> > > > + #gpio-cells = <2>;
> > > > + gpio-ranges = <&scmi_pinctrl 0 10 5>,
> > > > + <&scmi_pinctrl 5 0 0>;
> > > > + gpio-ranges-group-names = "",
> > > > + "pinmux_gpio";
> > > > + };
> > >
> >
> > Assuming the above &scmi_pinctrl refers to the protocol node as we
> > usually do,
>
> No it does not, it is a three-layer cake.
>
> scmi <-> scmi_pinctrl <-> scmi_gpio
>
> it refers to the scmi_pinctrl node.
>
Thanks, this explains a lot.
Cristian
> There is no SCMI GPIO protocol, instead SCMI is using the
> operations already available in the pin controller to exercise
> GPIO. Generic pin control has operations to drive lines for
> example, and Takahiro is adding the ability for a generic pin
> controller to also read a line.
>
> Yours,
> Linus Walleij