On 2018-12-19 12:38, Laurent Pinchart wrote: > Hello, > > On Wednesday, 19 December 2018 11:57:32 EET Peter Rosin wrote: >> On 2018-12-19 10:12, Andrzej Hajda wrote: >>> On 19.12.2018 00:19, Peter Rosin wrote: >>>> Add optional property to specify a power-down GPIO. >>>> The pwdn-gpios name is already in use by the thine,thc63lvdm83d >>>> binding, so go with that. >>>> >>>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx> >>>> --- >>>> >>>> Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt | >>>> 3 +++ >>>> 1 file changed, 3 insertions(+) >>>> >>>> diff --git >>>> a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt >>>> b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt >>>> index f9e7dd666f58..47941d39f92f 100644 >>>> --- >>>> a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt >>>> +++ >>>> b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt >>>> @@ -31,6 +31,9 @@ Required properties: >>>> device-specific version corresponding to the device first >>>> followed by the generic version. >>>> >>>> +Optional properties: >>>> +- pwdn-gpios: Power-down control GPIO >>>> + >>> >>> Since naming is not enforced by any datasheet I would propose something >>> more popular with less twisted logic. Maybe: >>> >>> - enable-gpios: ... (active high). >> >> That was my original thought too, but the driver implementing the >> lvds-encoder bindings also handles the mentioned thine,thc63lvdm83d >> lvds encoder, and that binding has the "pwdn" naming. So, for driver >> implementation simplicity I went with what was already there, thus >> allowing adding support for both bindings with one implementation >> (in patch 3/3). >> >> Adding code just to handle multiple names for the same thing does >> not sounds too appealing. > > I'm afraid I think we shouldn't add pwdn-gpios support to the lvds encoder DT > bindings. The reason is that control GPIOs (and regulators) come with device- > specific semantics. If we add pwdn-gpios now, we'll then add reset-gpios, and > power supplies, and all of a sudden we'll end up having to encode sequencing > of GPIOs and power supplies in DT. That path has been tried in the past, with > no good results. > > I would instead create device-specific bindings, like done for > thine,thc63lvdm83d. It's fine to then add support for the pwdn-gpios property > in the lvds-encoder driver, as long as the meaning of the property comes from > specific DT bindings, not from the generic ones. Right, I'll fork out the bindings for the texas chips. v2 coming up. Cheers, Peter
