Re: [PATCH 3/6] dt-bindings: display: add data-enable polarity property

Stefan Agner
2018-09-05T18:10:10Z

On 05.09.2018 00:07, Laurent Pinchart wrote:
> Hi Stefan,
>
> Thank you for the patch.
>
> On Wednesday, 5 September 2018 08:21:10 EEST Stefan Agner wrote:
>> Allow to specify the data-enable polarity required by a dumb VGA
>> DAC converting parallel RGB to VGA.
>>
>> Signed-off-by: Stefan Agner <stefan@agner.ch>
>> ---
>> .../devicetree/bindings/display/bridge/dumb-vga-dac.txt | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git
>> a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>> b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt index
>> 164cbb15f04c..adbd2ca0af2f 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga-dac.txt
>> @@ -18,6 +18,7 @@ graph bindings specified in
>> Documentation/devicetree/bindings/graph.txt.
>>
>> Optional properties:
>> - vdd-supply: Power supply for DAC
>> +- de-active: data-enable pulse is active low/high/ignored
>
> Which value corresponds to low, high and ignored ?
>

The wording is taken from
Documentation/devicetree/bindings/display/panel/display-timing.txt. But
I agree, not very useful.

0 is low active, 1 is high active, and none is using driver defaults.

How about:
- de-active: data-enable pulse is 0=active low/1=active high

--
Stefan

>> Example
>> -------