[RFC v2 5/5] dt-bindings: gpio: Add bindings for pinctrl based generic gpio driver

[Linus Walleij]

On Mon, Oct 9, 2023 at 11:08 AM Cristian Marussi
<cristian.marussi at arm.com> wrote:

> > > +    gpio0: gpio at 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.

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