Subject: [PATCH v7 3/8] ARM: dt: Binding documentation for imx25 touchscreen controller

From: [email-masked] (Jonathan Cameron)
Date: Sat, 07 Mar 2015 17:37:04 +0000

On 03/03/15 07:58, Markus Pargmann wrote:
> This is the touchscreen conversion queue binding documentation. It uses
> the shared imx25 ADC.
> 
> Signed-off-by: Markus Pargmann <[email-masked]>
Looks fine, one more general binding approach comment though.
A lot of the vendor specific elements in here are awfully generic.
Does it not make sense to have them as standard attributes for
touch screen drivers?
> ---
> 
> Notes:
>     Changes in v5:
>      - Fix signed/unsigned comparison
>      - Fix unused variable settling_time by putting it in the correct argument list
>      - Use continous conversion queue with the repeat feature and a proper
>        repeat-wait. Previously the touchscreen caused massive number of interrupts.
> 
>  .../bindings/input/touchscreen/fsl-mx25-tcq.txt    | 29 ++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt b/Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
> new file mode 100644
> index 000000000000..4214a99d197a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
> @@ -0,0 +1,29 @@
> +Freescale mx25 TS conversion queue module
> +
> +mx25 touchscreen conversion queue module which controls the ADC unit of the
> +mx25 for attached touchscreens.
> +
> +Required properties:
> + - compatible: Should be "fsl,imx25-tcq".
> + - reg: Memory range of the device.
> + - interrupts: Should be the interrupt number associated with this module within
> +   the tscadc unit (<0>).
> + - interrupt-parent: Should be a phandle to the tscadc unit.
> + - fsl,wires: Should be '<4>' or '<5>'
> +
> +Optional properties:
> + - fsl,pen-debounce: Pen debounce time.
> + - fsl,pen-threshold: Pen-down threshold for the touchscreen.
> + - fsl,settling-time: Settling time in nanoseconds.
Obviously it's up to Dmitry etc, but are these not standard enough attributes to
not be vendor specific?  I'd expect say touch-pen-debouce and touch-pen-threshold
etc to be standard binding elements for touch screens.

> +
> +This device includes two conversion queues which can be added as subnodes.
> +The first queue is for the touchscreen, the second for general purpose ADC.
> +
> +Example:
> +	tsc: tcq at 50030400 {
> +		compatible = "fsl,imx25-tcq";
> +		reg = <0x50030400 0x60>;
> +		interrupt-parent = <&tscadc>;
> +		interrupts = <0>;
> +		fsl,wires = <4>;
> +	};
>