Re: [PATCH v2 1/4] dt-bindings: drm/bridge: adv7511: Add regulator bindings

[Archit Taneja <architt-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

Hi Laurent,

On 9/25/2016 10:58 PM, Laurent Pinchart wrote:
> Hi Archit,
>
> Thank you for the patch.
>
> On Friday 23 Sep 2016 14:50:27 Archit Taneja wrote:
>> Add the regulator supply properties needed by ADV7511 and ADV7533. The
>> regulator names are named after the pin names, except for DVDD_3V on
>> ADV7511, which is left v3p3 to have the same name as it's on ADV7533.
>>
>> ADV7511 has a BGVDD pin for which the voltage to be configured isn't
>> clear. This needs to be updated in the document later.
>>
>> The regulators are specified as optional properties since there can
>> be boards which have a fixed supply directly routed to the pins, and
>> these may not be modelled as regulator supplies.
>>
>> Cc: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
>> Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> Signed-off-by: Archit Taneja <architt-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>> ---
>> v2:
>> - Specify regulator supplies for ADV7511 too.
>> - Have separate supply entries for AVDD, DVDD, PVDD, A2VDD pins.
>> - Add additional BGVDD supply for ADV7511.
>>
>>   .../devicetree/bindings/display/bridge/adi,adv7511.txt     | 14 +++++++++++
>>   1 file changed, 14 insertions(+)
>>
>> diff --git
>> a/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt
>> b/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt index
>> 6532a59..66e6bae 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt
>> +++ b/Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt
>> @@ -56,6 +56,20 @@ Optional properties:
>>   - adi,disable-timing-generator: Only for ADV7533. Disables the internal
>> timing generator. The chip will rely on the sync signals in the DSI data
>> lanes, rather than generate its own timings for HDMI output.
>> +- avdd-supply: A 1.8V supply that powers up the AVDD pin on the chip.
>> +- dvdd-supply: A 1.8V supply that powers up the DVDD pin on the chip.
>> +- pvdd-supply: A 1.8V supply that powers up the PVDD pin on the chip.
>> +- v3p3-supply: A 3.3V supply that powers up the pin called DVDD_3V on
>> +  ADV7511 and V3P3 on ADV7533.
>> +
>> +ADV7511 specific supplies:
>> +- bgvdd-supply: Powers the BGVDD pin. The voltage isn't clear from
>> +  available datasheets.
>
> It's a 1.8V supply. The ADV7511 hardware user's guide recommends tying it to
> the PVDD supply, so I'm not sure we need a separate supply in DT.

Thanks for providing the info. I'll update it in the doc.

>
> Similarly, the user's guide recommends supplying the AVDD, DVDD and PVDD pins
> with a single 1.8V LDO and three independent filters. We could thus possibly
> combine them into a single 1.8V supply.
>

I'd originally specified only one AVDD supply for all the 1.8 V
supplies, but Rob had recommended using separate supplies for each pin.

I guess it doesn't do much harm specifying separate supplies, a
board can just provide avdd-supply, and the rest would be assumed dummy.
It could also help describe boards which may not have followed the
user guide's recommendation, but I agree that's probably a rare
scenario.

Is it okay if we stick with multiple supplies as it is in this version?

Thanks for the review.

Archit

>> +ADV7533 specific supplies:
>> +- a2vdd-supply: 1.8V supply that powers up the A2VDD pin on the chip.
>> +- v1p2-supply: A supply that powers up the V1P2 pin on the chip. It can be
>> +  either 1.2V or 1.8V.
>>
>>   Required nodes:
>

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