From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753469AbeDRI3R (ORCPT ); Wed, 18 Apr 2018 04:29:17 -0400 Received: from mail.bootlin.com ([62.4.15.54]:55340 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753114AbeDRI3P (ORCPT ); Wed, 18 Apr 2018 04:29:15 -0400 Date: Wed, 18 Apr 2018 10:29:00 +0200 From: Boris Brezillon To: Peter Rosin Cc: linux-kernel@vger.kernel.org, David Airlie , Rob Herring , Mark Rutland , Nicolas Ferre , Alexandre Belloni , Boris Brezillon , Daniel Vetter , Gustavo Padovan , Sean Paul , Laurent Pinchart , Russell King - ARM Linux , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 2/6] dt-bindings: display: atmel: optional video-interface of endpoints Message-ID: <20180418102900.3d36e424@bbrezillon> In-Reply-To: References: <20180417131052.16336-1-peda@axentia.se> <20180417131052.16336-3-peda@axentia.se> <20180418091658.690e3d5e@bbrezillon> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 Apr 2018 09:31:53 +0200 Peter Rosin wrote: > On 2018-04-18 09:16, Boris Brezillon wrote: > > Hi Peter, > > > > On Tue, 17 Apr 2018 15:10:48 +0200 > > Peter Rosin wrote: > > > >> With bus-type/bus-width properties in the endpoint nodes, the video- > >> interface of the connection can be specified for cases where the > >> heuristic fails to select the correct output mode. This can happen > >> e.g. if not all RGB pins are routed on the PCB; the driver has no > >> way of knowing this, and needs to be told explicitly. > >> > >> This is critical for the devices that have the "conflicting output > >> formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant > >> RGB bits move around depending on the selected output mode. For > >> devices that do not have the "conflicting output formats" issue > >> (SAMA5D2, SAMA5D4), this is completely irrelevant. > >> > >> Signed-off-by: Peter Rosin > >> --- > >> Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt | 8 ++++++++ > >> 1 file changed, 8 insertions(+) > >> > >> diff --git a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt > >> index 82f2acb3d374..244b48869eb4 100644 > >> --- a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt > >> +++ b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt > >> @@ -15,6 +15,14 @@ Required children nodes: > >> to external devices using the OF graph reprensentation (see ../graph.txt). > >> At least one port node is required. > >> > >> +Optional properties in grandchild nodes: > >> + Any endpoint grandchild node may specify a desired video interface > >> + according to ../../media/video-interfaces.txt, specifically > >> + - bus-type: must be <0>. > >> + - bus-width: recognized values are <12>, <16>, <18> and <24>, and > >> + override any output mode selection hueristic, forcing "rgb444", > > heuristic, I'll fix that for v3, so please review as if it wasn't there... > > >> + "rgb565", "rgb666" and "rgb888" respectively. > >> + > > > > Can you add an example or update the existing one to show how this > > should be defined? > > For v3, I'll extend the binding with this after the preexisting example: > > ------------------8<----------------- > Example 2: With a video interface override to force rgb565, as above > but with these changes/additions: > > &hlcdc { > hlcdc-display-controller { > pinctrl-names = "default"; > pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>; > > port@0 { > hlcdc_panel_output: endpoint@0 { > bus-type = <0>; > bus-width = <16>; > }; > }; > }; > }; > ------------------8<----------------- > > Is that a good plan, or should I perhaps duplicate the whole example? Looks good to me, no need to add a new example. Thanks, Boris