Hi! On Fri, Jun 28, 2019 at 12:39:32PM +0200, Andrzej Hajda wrote: > On 12.06.2019 17:20, Maxime Ripard wrote: > >> I am not sure if I understand whole discussion here, but I also do not > >> understand whole edp-connector thing. > > The context is this one: > > https://patchwork.freedesktop.org/patch/257352/?series=51182&rev=1 > > https://patchwork.freedesktop.org/patch/283012/?series=56163&rev=1 > > https://patchwork.freedesktop.org/patch/286468/?series=56776&rev=2 > > > > TL;DR: This bridge is being used on ARM laptops that can come with > > different eDP panels. Some of these panels require a regulator to be > > enabled for the panel to work, and this is obviously something that > > should be in the DT. > > > > However, we can't really describe the panel itself, since the vendor > > uses several of them and just relies on the eDP bus to do its job at > > retrieving the EDIDs. A generic panel isn't really working either > > since that would mean having a generic behaviour for all the panels > > connected to that bus, which isn't there either. > > > > The connector allows to expose this nicely. > > As VESA presentation says[1] eDP is based on DP but is much more > flexible, it is up to integrator (!!!) how the connection, power > up/down, initialization sequence should be performed. Trying to cover > every such case in edp-connector seems to me similar to panel-simple > attempt failure. Moreover there is no such thing as physical standard > eDP connector. Till now I though DT connector should describe physical > connector on the device, now I am lost, are there some DT bindings > guidelines about definition of a connector? This might be semantics but I guess we're in some kind of grey area? Like, for eDP, if it's soldered I guess we could say that there's no connector. But what happens if for some other board, that signal is routed through a ribbon? You could argue that there's no physical connector in both cases, or that there's one in both, or one for the ribbon and no connector for the one soldered in. > Maybe instead of edp-connector one would introduce integrator's specific > connector, for example with compatible "olimex,teres-edp-connector" > which should follow edp abstract connector rules? This will be at least > consistent with below presentation[1] - eDP requirements depends on > integrator. Then if olimex has standard way of dealing with panels > present in olimex/teres platforms the driver would then create > drm_panel/drm_connector/drm_bridge(?) according to these rules, I guess. > Anyway it still looks fishy for me :), maybe because I am not > familiarized with details of these platforms. That makes sense yes Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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