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From:   Stephen Boyd <swboyd@chromium.org>
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Date:   Sat, 30 Apr 2022 04:34:57 +0900
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Subject: Re: [PATCH 1/2] dt-bindings: google,cros-ec-keyb: Introduce switches
 only compatible
To:     Doug Anderson <dianders@chromium.org>,
        Krzysztof Kozlowski <krzk@kernel.org>
Cc:     Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>, patches@lists.linux.dev,
        Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org,
        Benson Leung <bleung@chromium.org>,
        Guenter Roeck <groeck@chromium.org>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        "Joseph S. Barrera III" <joebar@chromium.org>
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Quoting Krzysztof Kozlowski (2022-04-29 09:35:58)
> On 29/04/2022 18:31, Doug Anderson wrote:
> >>    - $ref: "/schemas/input/matrix-keymap.yaml#"
> >>
> >>  properties:
> >>    compatible:
> >> -    const: google,cros-ec-keyb
> >> +    oneOf:
> >> +      - items:
> >> +          - const: google,cros-ec-keyb-switches
> >> +          - const: google,cros-ec-keyb
> >> +      - items:
> >> +          - const: google,cros-ec-keyb
> >
> > nit: if I come back and read this binding later I'm not sure it would
> > be obvious which compatible I should pick. Can we give any description
> > here that indicates that the first choice is for devices that _only_
> > have buttons and switches (the google,cros-ec-keyb is just for
> > backward compatibility) and the second choice is for devices that have
> > a physical keyboard and _also_ possibly some buttons/switches?

Sounds fair. I have to figure out how to add a description to the
choices. I guess a comment is the approach?

> >
> > I could also imagine people in the future being confused about whether
> > it's allowed to specify matrix properties even for devices that don't
> > have a matrix keyboard. It might be worth noting that it's allowed (to
> > support old drivers that might still be matching against the
> > google,cros-ec-keyb compatible) but not required.
>
> +1

Sure. I'll work that into the description for the first one with two
compatibles.

>
> >
> >
> >>    google,needs-ghost-filter:
> >>      description:
> >> @@ -50,7 +56,7 @@ examples:
> >>    - |
> >>      #include <dt-bindings/input/input.h>
> >>      cros-ec-keyb {
> >> -        compatible = "google,cros-ec-keyb";
> >> +        compatible = "google,cros-ec-keyb-switches", "google,cros-ec-keyb";
> >
> > Feels like we should create a second example?
>
> +1 as well, because it really would confuse what's the difference
> between them.

Ok.