Re: [PATCH v2 03/10] dt-bindings: input: touchscreen: touch_adc: create bindings

From: Rob Herring
Date: Mon Apr 09 2018 - 14:46:57 EST


On Tue, Mar 27, 2018 at 03:32:36PM +0300, Eugen Hristev wrote:
> Added bindings for generic resistive touchscreen ADC.
>
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> ---
> Changes in v2:
> - modified bindings to have a generic resistive touchscreen adc driver
> instead of specific architecture one.
>
> .../bindings/input/touchscreen/touch_adc.txt | 33 ++++++++++++++++++++++
> 1 file changed, 33 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/input/touchscreen/touch_adc.txt
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/touch_adc.txt b/Documentation/devicetree/bindings/input/touchscreen/touch_adc.txt
> new file mode 100644
> index 0000000..27abcdc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/touch_adc.txt
> @@ -0,0 +1,33 @@
> +Generic resistive touchscreen ADC
> +
> +Required properties:
> +
> + - compatible: must be "generic-resistive-adc-touch"

Drop "generic-" and rename the file after the compatible string.

> +The device must be connected to an IIO device that provides channels for

s/IIO/ADC/

> +position measurement and optional pressure.
> +Refer to ../iio/iio-bindings.txt for details
> + - iio-channels: must have at least two channels connected to an IIO device.
> +These should correspond to the channels exposed by the IIO device and should
> +have the right index as the IIO device registers them. These channels
> +represent the relative position on the "x" and "y" axes.
> + - iio-channel-names: must have all the channels' names. Mandatory channels
> +are "x" and "y".
> +
> +Optional properties:
> + - iio-channels: The third channel named "pressure" is optional and can be
> +used if the IIO device also measures pressure besides position.
> +If this channel is missing, pressure will be ignored and the touchscreen
> +will only report position.
> + - iio-channel-names: optional channel named "pressure".
> + - generic-resistive-adc-touch,pressure-threshold: a pressure threshold for
> +the touchscreen, if we are using the "pressure" channel as well.
> +Represented by an integer value.

Define a common touchscreen property for this. We already have several
definitions.

It seems to me that "contact-threshold" would have been the same thing,
but it is deprecated in favor of "touchscreen-fuzz-pressure" which
doesn't really sound like the same thing.

Rob