Re: [PATCH v3 1/5] dt-bindings: input: Add Atmel PTC subsystem bindings

[Dmitry Torokhov]

Hi Ludovic,

On Fri, Oct 20, 2017 at 03:31:17PM +0200, Ludovic Desroches wrote:
> Add description of the Atmel PTC subsystem bindings.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroc...@microchip.com>
> Acked-by: Rob Herring <r...@kernel.org>
> ---
>  .../devicetree/bindings/input/atmel,ptc.txt        | 67 
> ++++++++++++++++++++++
>  1 file changed, 67 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/atmel,ptc.txt
> 
> diff --git a/Documentation/devicetree/bindings/input/atmel,ptc.txt 
> b/Documentation/devicetree/bindings/input/atmel,ptc.txt
> new file mode 100644
> index 000000000000..a183fd511e04
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/atmel,ptc.txt
> @@ -0,0 +1,67 @@
> +Atmel PTC Subsystem
> +
> +The Atmel Peripheral Touch Controller subsystem offers built-in hardware
> +for capacitive touch measurement on sensors that function as buttons, sliders
> +and wheels.
> +
> +1) PTC Subsystem node
> +
> +Required properties:
> +- compatible:                Must be "atmel,sama5d2-ptc"
> +- reg:                       Address, length of the shared memory and ppp 
> registers location
> +                     and length.
> +- clocks:            Phandlers to the clocks.
> +- clock-names:               Must be "ptc_clk", "ptc_int_osc", "slow_clk".
> +- #address-cells:    Must be one. The cell is the button or scroller id.
> +- #size-cells:               Must be zero.
> +
> +Example:
> +     ptc@fc060000 {
> +             compatible = "atmel,sama5d2-ptc";
> +             reg = <0x00800000 0x10000
> +                    0xfc060000 0xcf>;
> +             interrupts = <58 IRQ_TYPE_LEVEL_HIGH 7>;
> +             clocks = <&ptc_clk>, <&main>, <&clk32k>;
> +             clock-names = "ptc_clk", "ptc_int_osc", "slow_clk";
> +             #address-cells = <1>;
> +             #size-cells = <0>;
> +
> +             [ child node definitions... ]
> +     };
> +
> +2) Scroller / buttons subnodes
> +
> +Subnodes describe the kind of sensors the customer want to use. They have to 
> be
> +named according to their function: button, slider or wheel.

I wonder do we really need this? Or we can have a generic:

        slider@0 {
                reg = <0>;
                linux,type = <EV_ABS>;
                linux,code = <ABS_X>;
        },
        vertical-slider@1 {
                reg = <1>;
                linux,type = <EV_ABS>;
                linux,code = <ABS_Y>;
        },
        wheel@2 {
                reg = <2>;
                linux,type = <EV_ABS>;
                linux,code = <ABS_WHEEL>;
        },
        button@3 {
                reg = <3>;
                linux,type = <EV_KEY>;
                linux,code = <KEY_A>;
        },
        ...

I.e. you specify type/code in a generic way.

Thanks.

-- 
Dmitry