From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08D90C43381 for ; Fri, 1 Mar 2019 20:16:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C759D2084D for ; Fri, 1 Mar 2019 20:16:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725982AbfCAUQb (ORCPT ); Fri, 1 Mar 2019 15:16:31 -0500 Received: from asavdk4.altibox.net ([109.247.116.15]:60881 "EHLO asavdk4.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725862AbfCAUQb (ORCPT ); Fri, 1 Mar 2019 15:16:31 -0500 Received: from ravnborg.org (unknown [158.248.194.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by asavdk4.altibox.net (Postfix) with ESMTPS id F3D30803E0; Fri, 1 Mar 2019 21:16:25 +0100 (CET) Date: Fri, 1 Mar 2019 21:16:24 +0100 From: Sam Ravnborg To: Paul Cercueil Cc: David Airlie , Daniel Vetter , Rob Herring , Mark Rutland , Maarten Lankhorst , Maxime Ripard , Sean Paul , devicetree@vger.kernel.org, linux-mips@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] dt-bindings: Add doc for the ingenic-drm driver Message-ID: <20190301201624.GA22317@ravnborg.org> References: <20190228220756.20262-1-paul@crapouillou.net> <20190228220756.20262-2-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190228220756.20262-2-paul@crapouillou.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=UpRNyd4B c=1 sm=1 tr=0 a=UWs3HLbX/2nnQ3s7vZ42gw==:117 a=UWs3HLbX/2nnQ3s7vZ42gw==:17 a=kj9zAlcOel0A:10 a=ER_8r6IbAAAA:8 a=p6pI0oa4AAAA:8 a=NUxJ9A_SPYP8DFnNYRMA:9 a=CjuIK1q_8ugA:10 a=9LHmKk7ezEChjTCyhBa9:22 a=9cw2y2bKwytFd151gpuR:22 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Hi Paul. Good to see work migrating fbdev => drm. Following comments is based on experience while working on migrating another driver from fbdev => drm. On Thu, Feb 28, 2019 at 07:07:54PM -0300, Paul Cercueil wrote: > Add documentation for the devicetree bindings of the DRM driver for the > JZ47xx family of SoCs from Ingenic. > > Signed-off-by: Paul Cercueil > Tested-by: Artur Rojek > --- > .../devicetree/bindings/display/ingenic,drm.txt | 30 ++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > create mode 100644 Documentation/devicetree/bindings/display/ingenic,drm.txt > > diff --git a/Documentation/devicetree/bindings/display/ingenic,drm.txt b/Documentation/devicetree/bindings/display/ingenic,drm.txt > new file mode 100644 > index 000000000000..52a368ec35cd > --- /dev/null > +++ b/Documentation/devicetree/bindings/display/ingenic,drm.txt > @@ -0,0 +1,30 @@ > +Ingenic JZ47xx DRM driver > + > +Required properties: > +- compatible: one of: > + * ingenic,jz4740-drm > + * ingenic,jz4725b-drm > +- reg: LCD registers location and length The fbdev way of doing this was to hardcode register setttings. In the drm world we read the configuration of the panel and let this decide the actual configuration. Note that no drm drivers supports stn displays and that there is really no use for this these days. So you can skip the STN parts. Also the modern way to specify a panel in the DT is using OF graph bindings. You can find many examples how to do this. I was there with the atmel LCDC driver (not in the kernel yet), and had some challenges with this. Sam