Re: [PATCH v2 1/2] dt-bindings: input: add GPIO charlieplex keypad

[Rob Herring <robh@kernel.org>]

On Fri, Feb 13, 2026 at 12:14:25PM -0500, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> 
> Add DT bindings for GPIO charlieplex keypad.
> 
> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> ---
>  .../input/gpio-charlieplex-keypad.yaml        | 82 +++++++++++++++++++
>  1 file changed, 82 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/gpio-charlieplex-keypad.yaml
> 
> diff --git a/Documentation/devicetree/bindings/input/gpio-charlieplex-keypad.yaml b/Documentation/devicetree/bindings/input/gpio-charlieplex-keypad.yaml
> new file mode 100644
> index 0000000000000..1672491a75a85
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/gpio-charlieplex-keypad.yaml
> @@ -0,0 +1,82 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +
> +$id: http://devicetree.org/schemas/input/gpio-charlieplex-keypad.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: GPIO charlieplex keypad
> +
> +maintainers:
> +  - Hugo Villeneuve <hvilleneuve@dimonoff.com>
> +
> +description:
> +  The charlieplex keypad supports N^2)-N different key combinations (where N is
> +  the number of lines). Key presses and releases are detected by configuring
> +  only one line as output at a time, and reading other line states. This process
> +  is repeated for each line.
> +  This mechanism doesn't allow to detect simultaneous key presses.
> +
> +allOf:
> +  - $ref: input.yaml#
> +  - $ref: /schemas/input/matrix-keymap.yaml#
> +
> +properties:
> +  compatible:
> +    const: gpio-charlieplex-keypad
> +
> +  autorepeat: true
> +
> +  line-scan-delay-us:
> +    description:
> +      Delay, measured in microseconds, that is needed
> +      before we can scan keypad after activating one line.
> +    default: 0

Isn't this the same as "col-scan-delay-us" in gpio-matrix-keypad.yaml? 
If so, move it to matrix-keymap.yaml to re-use it here.

If not, there's a bunch of other scan delay properties just from 
grepping "delay" in the input bindings. Surely we can define something 
common.

Rob