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=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED 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 E0F8EC43381 for ; Fri, 1 Mar 2019 22:41:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ABBE620848 for ; Fri, 1 Mar 2019 22:41:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=crapouillou.net header.i=@crapouillou.net header.b="gLCodwqD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727735AbfCAWlB (ORCPT ); Fri, 1 Mar 2019 17:41:01 -0500 Received: from outils.crapouillou.net ([89.234.176.41]:60514 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726337AbfCAWlB (ORCPT ); Fri, 1 Mar 2019 17:41:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1551480058; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aZOCv1w4NpvFoFLPRHBg18/Ij6Qbf5c21dh3PnLMa+k=; b=gLCodwqDPk5pDeaYvFBR5R2YeU6bA/m5Yk9SWLmMfqA2CaVBlosdjGd4pI2whfPYG6bjN3 fpucZ57Ss73jieXJ0G+zIkqxBq7/nHecn8/uPLzE+mwS8OLtpwcFZ263InzXM4P0ue4HTr 6lUzRdS2liQ4aOMyi849smqwYzFZmKw= Date: Fri, 01 Mar 2019 19:40:42 -0300 From: Paul Cercueil Subject: Re: [PATCH 1/3] dt-bindings: Add doc for the ingenic-drm driver To: Sam Ravnborg 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 Message-Id: <1551480042.1526.0@crapouillou.net> In-Reply-To: <20190301201624.GA22317@ravnborg.org> References: <20190228220756.20262-1-paul@crapouillou.net> <20190228220756.20262-2-paul@crapouillou.net> <20190301201624.GA22317@ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sam, thanks for the feedback. Le ven. 1 mars 2019 =E0 17:16, Sam Ravnborg a =E9crit : > Hi Paul. >=20 > Good to see work migrating fbdev =3D> drm. >=20 > Following comments is based on experience while working on migrating > another driver from fbdev =3D> drm. >=20 > On Thu, Feb 28, 2019 at 07:07:54PM -0300, Paul Cercueil wrote: >> Add documentation for the devicetree bindings of the DRM driver for=20 >> the >> JZ47xx family of SoCs from Ingenic. >>=20 >> Signed-off-by: Paul Cercueil >> Tested-by: Artur Rojek >> --- >> .../devicetree/bindings/display/ingenic,drm.txt | 30=20 >> ++++++++++++++++++++++ >> 1 file changed, 30 insertions(+) >> create mode 100644=20 >> Documentation/devicetree/bindings/display/ingenic,drm.txt >>=20 >> diff --git=20 >> a/Documentation/devicetree/bindings/display/ingenic,drm.txt=20 >> 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. >=20 > 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. STN panels aren't really my problem; but I have a board with a Sharp LS020B1DD01D panel, which requires the LCD IP to be configured for a "special 2" panel. I also have a board with a "smart" panel (ili9331) that needs a special configuration in the IP. There is nothing in the drm_panel interface that tells me what mode I should use for what panel... > Also the modern way to specify a panel in the DT is using OF graph=20 > bindings. > You can find many examples how to do this. Ok, I was looking at the Tegra driver, which uses a "nvidia,panel" DT property. I will change it to use the graph thing. > I was there with the atmel LCDC driver (not in the kernel yet), > and had some challenges with this. >=20 > Sam Thanks, -Paul =