On 23/09/2020 23:00, Rob Herring wrote: > On Wed, Sep 23, 2020 at 11:15 AM Tomi Valkeinen <tomi.valkeinen@xxxxxx> wrote: >> >> Hi Rob, >> >> On 23/09/2020 19:17, Rob Herring wrote: >> >>>> * No eDP. There's really no "eDP connector", as it's always a custom >>>> made connection between the DP and the DP panel. So possibly there is >>>> no need for edp-connector binding, but even if there is, I don't want >>>> to guess what it could look like, and could it be part of the >>>> dp-connector binding. >>> >>> I don't think that's true. Do an image search for 'edp pinout'. AFAICT, >>> there's 2 lane 30 pin and 4 lane 40 pin. One image says 'Table 5-3 in >>> eDP v1.2'. Of course, I'm sure there's custom ones too. From a binding >>> perspective, we probably don't care about the differences, but just need >>> to be able to describe HPD, backlight power, enable, and pwm, and LCD >>> power. >> >> That's true. The eDP spec lists 4 different standard pinouts (how >> strictly those are followed, I have no idea). But it does not define a >> connector or a cable. And afaik eDP is defined to be not user-detachable. > > Yes, but HPD is still used (or sometimes broken). We could just put > that all in panel nodes, but IIRC the last time this came up the issue > was handling devices with different panels stuffed by the > manufacturer. An eDP connector binding would be one way to handle that > as it is somewhat standardized while panel connections aren't at all. HPD in DisplayPort, and especially in eDP, is not strictly speaking "cable inserted or removed", but rather signaling that the monitor/panel is ready (e.g. after powering it up), or there has been a link issue, or there has been a major change in settings, or signaling DP interrupt, etc. And HPD (and EDID and some other things) are optional with eDP. I don't think those rule out an edp-connector, but just things to consider. Tomi -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
