From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752194AbdLFV70 (ORCPT ); Wed, 6 Dec 2017 16:59:26 -0500 Received: from mail-ot0-f196.google.com ([74.125.82.196]:36487 "EHLO mail-ot0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751604AbdLFV7Y (ORCPT ); Wed, 6 Dec 2017 16:59:24 -0500 X-Google-Smtp-Source: AGs4zMb3cXGJM/vzG0Im0xFsNAz6dQdHAJBhmaFm4GLZPCV5whNjTScE0N1zYMKDVHpLAfHXGsDdqw== Date: Wed, 6 Dec 2017 15:59:22 -0600 From: Rob Herring To: Maxime Ripard Cc: Daniel Vetter , David Airlie , Chen-Yu Tsai , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Mark Rutland , linux-arm-kernel@lists.infradead.org, plaes@plaes.org, icenowy@aosc.io, Thomas Petazzoni , jernej.skrabec@siol.net, devicetree@vger.kernel.org Subject: Re: [PATCH v3 04/15] dt-bindings: display: sun4i-drm: Add A83T pipeline Message-ID: <20171206215922.vtsa4xqa2e5xz7cp@rob-hp-laptop> References: <3762a8428aaf207e80ae86d4db2e50473576bb6d.1512486553.git-series.maxime.ripard@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3762a8428aaf207e80ae86d4db2e50473576bb6d.1512486553.git-series.maxime.ripard@free-electrons.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 05, 2017 at 04:10:16PM +0100, Maxime Ripard wrote: > The A83T has two video pipelines in parallel that looks quite similar to > the other SoCs. > > The video planes are handled through a controller called the mixer, and the > video signal is then passed to the timing controller (TCON). > > And while there is two instances of the mixers and TCONs, they have a > significant number of differences. The TCONs are quite easy to deal with, > one is supposed to generate TV (in the broader term, so including things > like HDMI) signals, the other one LCD (so RGB, LVDS, DSI) signals. And > while they are called TCON0 and TCON1 in the A83t datasheet, newer SoCs > call them TCON-TV and TCON-LCD, which seems more appropriate. > > However, the mixers differ mostly by their capabilities, with some features > being available only in the first one, or the number of planes they expose, > but also through their register layout. And while the capabilities could be > represented as properties, the register layout differences would need to > express all the registers offsets as properties, which is usually quite > bad. Especially since documentation on that hardware block is close to > non-existant and we don't even have the list of all those registers in the > first place. > > So let's call them mixer 0 and 1 in our compatibles, even though the name > is pretty bad... > > At the moment, we only have tested the code on a board that has a single > display output, so we're leaving the tcon-tv and mixer1 out. > > Signed-off-by: Maxime Ripard > --- > Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt | 3 +++ > 1 file changed, 3 insertions(+) Reviewed-by: Rob Herring