From patchwork Wed Nov 12 22:08:41 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: 410135 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id BE2A61400AB for ; Thu, 13 Nov 2014 09:09:51 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752597AbaKLWJc (ORCPT ); Wed, 12 Nov 2014 17:09:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44180 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752373AbaKLWJ3 (ORCPT ); Wed, 12 Nov 2014 17:09:29 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sACM8oJB007211 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 12 Nov 2014 17:08:50 -0500 Received: from shalem.localdomain.com (vpn1-6-163.ams2.redhat.com [10.36.6.163]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id sACM8jeV002193; Wed, 12 Nov 2014 17:08:46 -0500 From: Hans de Goede To: Tomi Valkeinen Cc: Stephen Warren , Jean-Christophe Plagniol-Villard , Grant Likely , Rob Herring , Luc Verhaegen , Maxime Ripard , Mike Turquette , 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 1/4] dt-bindings: simplefb: Specify node location and handoff related properties Date: Wed, 12 Nov 2014 23:08:41 +0100 Message-Id: <1415830124-28787-1-git-send-email-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 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: Grant Likely --- .../bindings/video/simple-framebuffer.txt | 37 +++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/video/simple-framebuffer.txt b/Documentation/devicetree/bindings/video/simple-framebuffer.txt index 8f35718..95fe284 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 +42,26 @@ 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>; }; +}; + +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.