From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v2 7/7] arm64: dts: allwinner: a64: enable ANX6345 bridge on Teres-I Date: Mon, 1 Jul 2019 11:58:42 +0200 Message-ID: <20190701095842.fvganvycce2cy7jn@flea> References: <20190605101317.GA9345@lst.de> <20190605120237.ekmytfxcwbjaqy3x@flea> <20190607062802.m5wslx3imiqooq5a@flea> <20190607094030.GA12373@lst.de> <66707fcc-b48e-02d3-5ed7-6b7e77d53266@samsung.com> <20190612152022.c3cfhp4cauhzhfyr@flea> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="rwl7bnhaabkczsql" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Andrzej Hajda Cc: Torsten Duwe , Harald Geyer , Vasily Khoruzhick , Chen-Yu Tsai , Rob Herring , Mark Rutland , Thierry Reding , David Airlie , Daniel Vetter , Laurent Pinchart , Icenowy Zheng , Sean Paul , Greg Kroah-Hartman , Thomas Gleixner , dri-devel , devicetree , arm-linux , linux-kernel List-Id: devicetree@vger.kernel.org --rwl7bnhaabkczsql Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 --rwl7bnhaabkczsql Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXRnZUgAKCRDj7w1vZxhR xQ/8AQCtFPO8zhV4+U5EfDXkE+JHOXvpVHx/qJISWs88VLbjXAD+PhSV9xHUBgZC Wga4ICpNkMVIAA056iwnPqJ5wScM6Qc= =ijEm -----END PGP SIGNATURE----- --rwl7bnhaabkczsql--