From patchwork Thu Nov 13 08:50:07 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 5294321 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 92D5A9FD71 for ; Thu, 13 Nov 2014 08:51:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ABE87201F4 for ; Thu, 13 Nov 2014 08:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD62D201E4 for ; Thu, 13 Nov 2014 08:51:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932170AbaKMIvJ (ORCPT ); Thu, 13 Nov 2014 03:51:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37090 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932319AbaKMIvE (ORCPT ); Thu, 13 Nov 2014 03:51:04 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sAD8oFWf027696 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 13 Nov 2014 03:50:15 -0500 Received: from shalem.localdomain.com (vpn1-7-31.ams2.redhat.com [10.36.7.31]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id sAD8oBfj027437; Thu, 13 Nov 2014 03:50:12 -0500 From: Hans de Goede To: Tomi Valkeinen Cc: Stephen Warren , Jean-Christophe Plagniol-Villard , Grant Likely , Rob Herring , Luc Verhaegen , Maxime Ripard , David Herrmann , Geert Uytterhoeven , linux-fbdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree , linux-sunxi@googlegroups.com, Hans de Goede Subject: [PATCH v2 1/4] dt-bindings: simplefb: Specify node location and handoff related properties Date: Thu, 13 Nov 2014 09:50:07 +0100 Message-Id: <1415868610-13297-1-git-send-email-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Since simplefb nodes do not relate directly to hw typically they have been placed in the root of the devicetree. As the represent runtime information having them as sub-nodes of /chosen is more logical, specify this. Also specify when to set the chosen stdout-path property to a simplefb node. For reliable handover to a hardware specific driver, that driver needs to know which simplefb to unregister when taking over, specify how the hw driver can find the matching simplefb node. Last add some advice on how to fill and use simplefb nodes from a firmware pov. Signed-off-by: Hans de Goede Acked-by: Geert Uytterhoeven Acked-by: Maxime Ripard --- Changes in v2: -Add stdout-path to the example code --- .../bindings/video/simple-framebuffer.txt | 38 +++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/video/simple-framebuffer.txt b/Documentation/devicetree/bindings/video/simple-framebuffer.txt index 8f35718..8b7ecf6 100644 --- a/Documentation/devicetree/bindings/video/simple-framebuffer.txt +++ b/Documentation/devicetree/bindings/video/simple-framebuffer.txt @@ -4,6 +4,26 @@ A simple frame-buffer describes a frame-buffer setup by firmware or the bootloader, with the assumption that the display hardware has already been set up to scan out from the memory pointed to by the reg property. +Since simplefb nodes represent runtime information they must be sub-nodes of +the chosen node (*). The primary display node must be named framebuffer0, +additional nodes must be called framebuffer1, etc. + +If a simplefb node represents the preferred console for user interaction, +then the chosen node's stdout-path property must point to it. + +If the devicetree contains nodes for the display hardware used by a simplefb, +then one of the hw nodes must have a property called "framebuffer" pointing to +the framebuffer# node in chosen, so that the operating system knows which +simplefb to disable when handing over control to a driver for the real +hardware. The bindings for the hw nodes must specify which node contains the +framebuffer property. + +It is advised that devicetree files contain pre-filled, disabled framebuffer# +nodes, so that the firmware only needs to update the mode information and +enable them. This way if e.g. later on support for more display clocks get +added, the simplefb nodes will already contain this info and the firmware +does not need to be updated. + Required properties: - compatible: "simple-framebuffer" - reg: Should contain the location and size of the framebuffer memory. @@ -22,11 +42,27 @@ Optional properties: Example: - framebuffer { +chosen { + framebuffer0 { compatible = "simple-framebuffer"; reg = <0x1d385000 (1600 * 1200 * 2)>; width = <1600>; height = <1200>; stride = <(1600 * 2)>; format = "r5g6b5"; + clocks = <&ahb_gates 36>, <&ahb_gates 43>, <&ahb_gates 44>; }; + stdout-path = &framebuffer0; +}; + +soc@01c00000 { + lcdc0: lcdc@1c0c000 { + compatible = "allwinner,sun4i-a10-lcdc"; + framebuffer = <&framebuffer0>; + }; +}; + + +*) Older devicetree files may have a compatible = "simple-framebuffer" node +in a different place, operating systems must first enumerate any framebuffer# +nodes found under chosen and then check for other compatible nodes.