Hi,
On Wed, Apr 27, 2022 at 1:30 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
>
> If the device is a detachable, this device won't have a matrix keyboard
> but it may have some button switches, e.g. volume buttons and power
> buttons. Let's add a more specific compatible for this type of device
> that indicates to the OS that there are only switches and no matrix
> keyboard present.
>
> Cc: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: <devicetree@xxxxxxxxxxxxxxx>
> Cc: Benson Leung <bleung@xxxxxxxxxxxx>
> Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>
> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> Cc: "Joseph S. Barrera III" <joebar@xxxxxxxxxxxx>
> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> ---
> .../bindings/input/google,cros-ec-keyb.yaml | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml b/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml
> index e8f137abb03c..edc1194d558d 100644
> --- a/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml
> +++ b/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml
> @@ -15,14 +15,20 @@ description: |
> Google's ChromeOS EC Keyboard is a simple matrix keyboard
> implemented on a separate EC (Embedded Controller) device. It provides
> a message for reading key scans from the EC. These are then converted
> - into keycodes for processing by the kernel.
> + into keycodes for processing by the kernel. This device also supports
> + switches/buttons like power and volume buttons.
>
> allOf:
> - $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?
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.
> 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?
