Re: [RFC PATCH 1/3] dt-bindings: display: simple: Add the panel on sc7180-trogdor-pompom

From: Rob Herring
Date: Thu Mar 25 2021 - 20:09:53 EST


On Tue, Mar 16, 2021 at 02:08:19PM -0700, Douglas Anderson wrote:
> The sc7180-trogdor-pompom board might be attached to any number of a
> pile of eDP panels. At the moment I'm told that the list might include:
> - KD KD116N21-30NV-A010
> - KD KD116N09-30NH-A016
> - Starry 2081116HHD028001-51D
> - Sharp LQ116M1JW10
>
> It should be noted that while the EDID programmed in the first 3
> panels indicates that they should run with exactly the same timing (to
> keep things simple), the 4th panel not only needs different timing but
> has a different resolution.
>
> As is true in general with eDP panels, we can figure out which panel
> we have and all the info needed to drive its pixel clock by reading
> the EDID. However, we can do this only after we've powered the panel
> on. Powering on the panels requires following the timing diagram in
> each panel's datasheet which specifies delays between certain
> actions. This means that, while we can be quite dynamic about handling
> things we can't just totally skip out on describing the panel like we
> could do if it was connected to an external-facing DP port.

Is this a 'standard' eDP connector? AFAICT, there does seem to be
such a thing. I've said in the past I'd be okay with a edp-connector
node. If that needs just the "HPD absent delay" property, I think that
would be okay. It's just a never ending stream of new properties with
each new panel that I don't want to see.

Rob