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Message-ID: <98ec7967-d007-46d7-ef54-aa41426b5f9f@linaro.org>
Date:   Wed, 20 Jul 2022 19:26:17 +0200
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Subject: Re: [PATCH v1 3/6] dt-bindings: mediatek,mt6779-keypad: add
 mediatek,double-keys
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To:     Mattijs Korpershoek <mkorpershoek@baylibre.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Matthias Brugger <matthias.bgg@gmail.com>
Cc:     linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
        Fabien Parent <parent.f@gmail.com>, devicetree@vger.kernel.org,
        linux-mediatek@lists.infradead.org,
        Fabien Parent <fparent@baylibre.com>,
        linux-arm-kernel@lists.infradead.org
References: <20220720-mt8183-keypad-v1-0-ef9fc29dbff4@baylibre.com>
 <20220720-mt8183-keypad-v1-3-ef9fc29dbff4@baylibre.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20220720-mt8183-keypad-v1-3-ef9fc29dbff4@baylibre.com>
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Precedence: bulk

On 20/07/2022 16:48, Mattijs Korpershoek wrote:
> 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
> 
> Currently, only single key detection is supported (by default)
> Add an optional property, mediatek,double-keys to support double
> key detection.

You focus here on driver implementation and behavior, but should rather
focus on hardware, like - in such setup two keys are physically wired to
one (row,column) pin.

> 
> Double key support exists to minimize cost, since it reduces the number
> of pins required for physical keys.
> 
> 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..03c9555849e5 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,double-keys:

Do you think there could be another MT keypad version with triple-keys?

> +    description: |
> +      use double key matrix instead of single key
> +      when set, each (row,column) is a group that can detect 2 keys
> +    type: boolean
> +
>  required:
>    - compatible
>    - reg
> 


Best regards,
Krzysztof