Re: [PATCH v2 2/2] dt-bindings: google,cros-ec-keyb: add use-fn-overlay prop

[Krzysztof Kozlowski]

On Wed, Dec 24, 2025 at 03:22:38PM +0000, Fabio Baltieri wrote:
> Add binding documentation for the use-fn-overlay property.
> 
> Signed-off-by: Fabio Baltieri <fabiobaltieri@xxxxxxxxxxxx>
> ---
>  .../bindings/input/google,cros-ec-keyb.yaml   | 25 +++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml b/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml
> index fefaaf46a240..437575cdf352 100644
> --- a/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml
> +++ b/Documentation/devicetree/bindings/input/google,cros-ec-keyb.yaml
> @@ -44,6 +44,14 @@ properties:
>        where the lower 16 bits are reserved. This property is specified only
>        when the keyboard has a custom design for the top row keys.
>  
> +  google,use-fn-overlay:
> +    description: |
> +      Use a function key overlay. This allows defining an extra set of codes

What is a function key overlay? Overlays are DT term and therefore are
not suitable for bindings.

> +      that are sent if a key is pressed while the KEY_FN is held pressed as
> +      well. The function codes have to be defined in the linux,keymap property
> +      with an offset of keypad,num-rows from the normal ones.
> +    type: boolean
> +
>  dependencies:
>    function-row-physmap: [ 'linux,keymap' ]
>    google,needs-ghost-filter: [ 'linux,keymap' ]
> @@ -132,6 +140,23 @@ examples:
>              /* UP      LEFT    */
>              0x070b0067 0x070c0069>;
>      };
> +  - |
> +    /* With function keys */
> +    #include <dt-bindings/input/input.h>
> +    keyboard-controller {
> +        compatible = "google,cros-ec-keyb";
> +        keypad,num-rows = <8>;
> +        keypad,num-columns = <18>;
> +        google,use-fn-overlay;

Difference in one property does not justify new example.

Best regards,
Krzysztof