[PATCH v4 4/8] MFD: ti_am335x_tscadc: add device tree binding information

Peter Korsgaard jacmet at sunsite.dk
Sun Jan 27 09:11:14 EST 2013

>>>>> "P" == Patil, Rachna <rachna at ti.com> writes:


 P> From: "Patil, Rachna" <rachna at ti.com>
 P> Signed-off-by: Patil, Rachna <rachna at ti.com>
 P> ---
 P> Changes in v4:
 P> 	Subnodes and their properties documentation added.
 P> 	Non-standard properties prefixed with vendor name.

 P>  .../devicetree/bindings/mfd/ti_am335x_tscadc.txt   |   52 ++++++++++++++++++++
 P>  1 file changed, 52 insertions(+)
 P>  create mode 100644 Documentation/devicetree/bindings/mfd/ti_am335x_tscadc.txt

 P> diff --git a/Documentation/devicetree/bindings/mfd/ti_am335x_tscadc.txt b/Documentation/devicetree/bindings/mfd/ti_am335x_tscadc.txt
 P> new file mode 100644
 P> index 0000000..0100771
 P> --- /dev/null
 P> +++ b/Documentation/devicetree/bindings/mfd/ti_am335x_tscadc.txt
 P> @@ -0,0 +1,52 @@
 P> +Texas Instruments - TSC / ADC multi-functional device
 P> +
 P> +ti_tscadc is a multi-function device with touchscreen and ADC on chip.
 P> +This document describes the binding for mfd device.
 P> +
 P> +Required properties:
 P> +- compatible: "ti,ti-tscadc"

That's a very generic name (and double ti). How about ti,am3352-tsadc

No pinmux?

 P> +Sub-node device required properties:
 P> +tsc:
 P> +- ti,wires:  4/5/8 wire touchscreen support on the platform.
 P> +- ti,x-plate-resistance: X plate resistance.

In what kind of units?

 P> +- ti,steps-to-configure: A step is configured to read a single co-ordinate value,
 P> +			can be applied more number of times for better results.

So it is some kind of averaging? Doesn't tslib do that for you already?
Is there any limit to how many steps you can/will handle?

 P> +- ti,wire-config: Order for connecting wires on touchscreen.

ti,wires seems redundant given ti,wire-config (E.G. number of elements
in array). It is not clear to me what the magic values in wire-config

 P> +
 P> +adc:
 P> +- ti,adc-channels: Number of ADC channels used.

Is there ever any use case for this being something else than 8 -

Bye, Peter Korsgaard

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