The MediaTek keypad has 2 modes of detecting key events:
* single key: each (row, column) can detect one key
* double key: each (row, column) is a group of 2 keys

With double key, two keys are physically wired to one (row, column) pin.
These keys are in the same "group".

Multiple keys in the same group reduces the number of pins which
minimizes cost.

Add a keys-per-group property to describe this.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

diff --git a/Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml b/Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml
index ca8ae40a73f7..387d0448ff77 100644
--- a/Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml
+++ b/Documentation/devicetree/bindings/input/mediatek,mt6779-keypad.yaml
@@ -49,6 +49,12 @@ properties:
     maximum: 256
     default: 16
 
+  mediatek,keys-per-group:
+    description: each (row, column) group has multiple keys
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 1
+    maximum: 2
+
 required:
   - compatible
   - reg

-- 
b4 0.10.0-dev-78725

On 26/07/2022 14:56, Mattijs Korpershoek wrote:
> The MediaTek keypad has 2 modes of detecting key events:
> * single key: each (row, column) can detect one key
> * double key: each (row, column) is a group of 2 keys
> 
> With double key, two keys are physically wired to one (row, column) pin.
> These keys are in the same "group".
> 
> Multiple keys in the same group reduces the number of pins which
> minimizes cost.
> 
> Add a keys-per-group property to describe this.
> 
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>


Best regards,
Krzysztof