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: Tue, 9 Jul 2019 10:55:32 +0200 Message-ID: <20190709085532.cdqv7whuesrjs64c@flea> References: <20190605120237.ekmytfxcwbjaqy3x@flea> <20190607062802.m5wslx3imiqooq5a@flea> <20190607094030.GA12373@lst.de> <66707fcc-b48e-02d3-5ed7-6b7e77d53266@samsung.com> <20190612152022.c3cfhp4cauhzhfyr@flea> <20190701095842.fvganvycce2cy7jn@flea> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0671666576==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Vasily Khoruzhick Cc: Mark Rutland , devicetree , Sean Paul , David Airlie , Greg Kroah-Hartman , linux-kernel , dri-devel , Chen-Yu Tsai , Rob Herring , Torsten Duwe , Laurent Pinchart , Harald Geyer , Thierry Reding , Thomas Gleixner , arm-linux , Icenowy Zheng List-Id: devicetree@vger.kernel.org --===============0671666576== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ejhhd7l2mldty4ew" Content-Disposition: inline --ejhhd7l2mldty4ew Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Jul 08, 2019 at 05:49:21PM -0700, Vasily Khoruzhick wrote: > > > 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 > > Actually, it makes no sense at all. Current implementation for anx6345 > driver works fine as is with any panel specified assuming panel delays > are long enough for connected panel. It just doesn't use panel timings > from the driver. Creating a platform driver for connector itself looks > redundant since it can't be reused, it doesn't describe actual > hardware and it's just defeats purpose of DT by introducing > board-specific code. I'm not sure where you got the idea that the purpose of DT is to not have any board-specific code. It's perfectly fine to have some, that's even why there's a compatible assigned to each and every board. What the DT is about is allowing us to have a generic behaviour that we can detect: we can have a given behaviour for a given board, and a separate one for another one, and this will be evaluated at runtime. This is *exactly* what this is about: we can have a compatible that sets a given, more specific, behaviour (olimex,teres-edp-connector) while saying that this is compatible with the generic behaviour (edp-connector). That way, any OS will know what quirk to apply if needed, and if not that it can use the generic behaviour. And we could create a generic driver, for the generic behaviour if needed. > There's another issue: if we introduce edp-connector we'll have to > specify power up delays somewhere (in dts? or in platform driver?), so > edp-connector doesn't really solve the issue of multiple panels with > same motherboard. And that's what that compatible is about :) > I'd say DT overlays should be preferred solution here, not another > connector binding. Overlays are a way to apply a device tree dynamically. It's orthogonal to the binding. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --ejhhd7l2mldty4ew Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXSRWhAAKCRDj7w1vZxhR xX17AP9m55K0q2PlhGjTg96EP4qSaUJ3PeJP4YHnC9hGYGMuWwD9HbDHJHhrb3wn zWBH9y7+q3si+oAQDJcL8eGh17MSBgc= =IVjC -----END PGP SIGNATURE----- --ejhhd7l2mldty4ew-- --===============0671666576== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVs --===============0671666576==--