Re: [PATCH v2 1/3] devicetree/bindings: add reset-gpios and vcc-supply for panel-dpi

[Rob Herring <robh@kernel.org>]

On Wed, Dec 30, 2015 at 4:29 AM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> On Tue, Dec 29, 2015 at 9:54 PM, Rob Herring <robh@kernel.org> wrote:
>> On Sun, Dec 20, 2015 at 12:13:20PM +0100, Uwe Kleine-König wrote:
>>> Some displays have a reset input and/or need a regulator to function
>>> properly. Allow to specify them for panel-dpi devices.
>>>
>>> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
>>> ---
>>>  Documentation/devicetree/bindings/display/panel/panel-dpi.txt | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/display/panel/panel-dpi.txt b/Documentation/devicetree/bindings/display/panel/panel-dpi.txt
>>> index 216c894d4f99..b52ac52757df 100644
>>> --- a/Documentation/devicetree/bindings/display/panel/panel-dpi.txt
>>> +++ b/Documentation/devicetree/bindings/display/panel/panel-dpi.txt
>>> @@ -7,6 +7,8 @@ Required properties:
>>>  Optional properties:
>>>  - label: a symbolic name for the panel
>>>  - enable-gpios: panel enable gpio
>>> +- reset-gpios: GPIO to control the RESET pin
>>
>> The problem with this in a generic binding is what if the panel has
>> ordering requirements like enable gpio has to be inactive when reset
>> is deasserted?
>>
>>> +- vcc-supply: phandle of regulator that will be used to enable power to the display
>>
>> What if there are 2 supplies?
>
> So it should be "vcc-supplies". Most properties containing phandles use plural
> naming, even if Linux supports a single phandle only (e.g. "power-domains").
> You also may want to add an optional "vcc-supply-names" property to
> differentiate.

True, but the regulator binding is an exception and we don't do that
with it. The prefix is the name and other supplies are not going to be
called Vcc.

Rob