On Friday 11 November 2016 09:00 AM, John Syne wrote:
>
>> On Nov 9, 2016, at 9:07 PM, Vignesh R <vigneshr@xxxxxx> wrote:
>>
>> Hi,
>>
>> On Thursday 10 November 2016 05:23 AM, John Syne wrote:
>>> OK, then back to my original question. Given that these DT properties are supported in the driver
>>>
>>
>> Below properties are supported by only by ti_am3335x_adc driver and not
>> ti_am335x_tsc driver. As author of this patch pointed out in another
>> reply, there is no need to change step-opendelay for tsc. AFAIK, I don't
>> see a use case where these values needs to be tweaked for tsc channels,
>> therefore it does not make sense to be DT properties.
> Yeah, the confusion was mine because the author of this patch series was proposing to hard code these settings while DT properties already existed in the ti_am335x_adc driver. I use the ADC for sensor measurement and do not use the touchscreen features. I already pointed out where these DT parameters should be added by referencing how this was done in one of the BBB DT overlay files [1]. I am just proposing the same is done as a default in the AM33xx.dtsi and AM4372.dtsi files. Here is what I was proposing.
> Granted, the adc-channels should be restricted to the subset of channels not used by tsc, but you get the idea.
There are 4 wire, 5 wire and 8 wire touchscreens. Therefore there is no
way to know in advance, how many channels are available for adc. IMO,
this is not a SoC specific configuration but board dependent. Hence, all
channel related configurations need to be in board specific dts files
and not in top level dtsi files.
>
> tscadc: tscadc@44e0d000 {
> compatible = "ti,am3359-tscadc";
> reg = <0x44e0d000 0x1000>;
> interrupt-parent = <&intc>;
> interrupts = <16>;
> ti,hwmods = "adc_tsc";
> status = "disabled";
> dmas = <&edma 53 0>, <&edma 57 0>;
> dma-names = "fifo0", "fifo1”;
>
> tsc {
> compatible = "ti,am3359-tsc";
> };
> am335x_adc: adc {
> #io-channel-cells = <1>;
> ti,adc-channels = <0 1 2 3 4 5 6>;
> ti,chan-step-avg = <0x16 0x16 0x16 0x16 0x16 0x16 0x16>;
> ti,chan-step-opendelay = <0x98 0x98 0x98 0x98 0x98 0x98 0x98>;
> ti,chan-step-sampledelay = <0x0 0x0 0x0 0x0 0x0 0x0 0x0>;
> compatible = "ti,am3359-adc";
> };
> };
>
> [1]https://github.com/RobertCNelson/bb.org-overlays/blob/master/src/arm/BB-ADC-00A0.dts
>
--
Regards
Vignesh
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