From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from galahad.ideasonboard.com ([185.26.127.97]:39161 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753566AbcKVJgj (ORCPT ); Tue, 22 Nov 2016 04:36:39 -0500 From: Laurent Pinchart To: Rob Herring Cc: Laurent Pinchart , dri-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, Tomi Valkeinen , devicetree@vger.kernel.org Subject: Re: [PATCH v2 01/13] devicetree/bindings: display: Document common panel properties Date: Tue, 22 Nov 2016 11:36:55 +0200 Message-ID: <2307840.2mk6E40XHl@avalon> In-Reply-To: <20161121164815.bxca4rfvifloizdh@rob-hp-laptop> References: <1479526093-7014-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <1479526093-7014-2-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <20161121164815.bxca4rfvifloizdh@rob-hp-laptop> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: Hi Rob, On Monday 21 Nov 2016 10:48:15 Rob Herring wrote: > On Sat, Nov 19, 2016 at 05:28:01AM +0200, Laurent Pinchart wrote: > > Document properties common to several display panels in a central > > location that can be referenced by the panel device tree bindings. > > Looks good. Just one comment... > > [...] > > > +Connectivity > > +------------ > > + > > +- ports: Panels receive video data through one or multiple connections. > > While > > + the nature of those connections is specific to the panel type, the > > + connectivity is expressed in a standard fashion using ports as > > specified in > > + the device graph bindings defined in > > + Documentation/devicetree/bindings/graph.txt. > > We allow panels to either use graph binding or be a child of the display > controller. I knew that some display controllers use a phandle to the panel (see the fsl,panel and nvidia,panel properties), but I didn't know we had panels as children of display controller nodes. I don't think we should allow that for anything but DSI panels, as the DT hierarchy is based on control buses. Are you sure we have other panels instantiated through that mechanism ? > Using the graph is preferred, but in the simple cases just a child node is > sufficient. This should be described here or somewhere in this doc. -- Regards, Laurent Pinchart