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

Cristian Marussi cristian.marussi at arm.com
Mon Oct 9 08:08:13 PDT 2023


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 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.
> 

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



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