From patchwork Sat Nov 19 03:28:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 9437827 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E6D6160755 for ; Sat, 19 Nov 2016 03:28:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DA51020453 for ; Sat, 19 Nov 2016 03:28:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CEF3A28526; Sat, 19 Nov 2016 03:28:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A3C3D205B0 for ; Sat, 19 Nov 2016 03:28:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D65046E2D5; Sat, 19 Nov 2016 03:28:10 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from galahad.ideasonboard.com (galahad.ideasonboard.com [185.26.127.97]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6AAC46E2CA for ; Sat, 19 Nov 2016 03:28:05 +0000 (UTC) Received: from avalon.bb.dnainternet.fi (dfj612ybrt5fhg77mgycy-3.rev.dnainternet.fi [IPv6:2001:14ba:21f5:5b00:2e86:4862:ef6a:2804]) by galahad.ideasonboard.com (Postfix) with ESMTPSA id 438C22112E; Sat, 19 Nov 2016 04:28:03 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1479526083; bh=a3t5lFhGs6659mGRCYiYIwcl1qcx2EFDzwN1fMKtOMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oUkD9KhhjalFxOB2cPqbQdXfwHC3kFY3G8C8Z1ZnRAIs031vqR/9lNk4vnoSH2jjm bt7nZl0k9c1EoNFqEr72nvfL5Z7JXixUvSwAPZHK957acpffQFB9Xr8NGCfr/swz3K sFSqSMRRPqy1npZ3zCeJj91V6Pla9Dt8QCclnzFU= From: Laurent Pinchart To: dri-devel@lists.freedesktop.org Subject: [PATCH v2 01/13] devicetree/bindings: display: Document common panel properties Date: Sat, 19 Nov 2016 05:28:01 +0200 Message-Id: <1479526093-7014-2-git-send-email-laurent.pinchart+renesas@ideasonboard.com> X-Mailer: git-send-email 2.7.3 In-Reply-To: <1479526093-7014-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> References: <1479526093-7014-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> Cc: linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, Tomi Valkeinen X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Document properties common to several display panels in a central location that can be referenced by the panel device tree bindings. Signed-off-by: Laurent Pinchart Acked-by: Rob Herring --- .../bindings/display/panel/panel-common.txt | 91 ++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 Documentation/devicetree/bindings/display/panel/panel-common.txt diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.txt b/Documentation/devicetree/bindings/display/panel/panel-common.txt new file mode 100644 index 000000000000..ec52c472c845 --- /dev/null +++ b/Documentation/devicetree/bindings/display/panel/panel-common.txt @@ -0,0 +1,91 @@ +Common Properties for Display Panel +=================================== + +This document defines device tree properties common to several classes of +display panels. It doesn't constitue a device tree binding specification by +itself but is meant to be referenced by device tree bindings. + +When referenced from panel device tree bindings the properties defined in this +document are defined as follows. The panel device tree bindings are +responsible for defining whether each property is required or optional. + + +Descriptive Properties +---------------------- + +- width-mm, +- height-mm: The width-mm and height-mm specify the width and height of the + physical area where images are displayed. These properties are expressed in + millimeters and rounded to the closest unit. + +- label: The label property specifies a symbolic name for the panel as a + string suitable for use by humans. It typically contains a name inscribed on + the system (e.g. as an affixed label) or specified in the system's + documentation (e.g. in the user's manual). + + If no such name exists, and unless the property is mandatory according to + device tree bindings, it shall rather be omitted than constructed of + non-descriptive information. For instance an LCD panel in a system that + contains a single panel shall not be labelled "LCD" if that name is not + inscribed on the system or used in a descriptive fashion in system + documentation. + + +Display Timings +--------------- + +- panel-timing: Most display panels are restricted to a single resolution and + require specific display timings. The panel-timing subnode expresses those + timings as specified in the timing subnode section of the display timing + bindings defined in + Documentation/devicetree/bindings/display/display-timing.txt. + + +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. + +- ddc-i2c-bus: Some panels expose EDID information through an I2C-compatible + bus such as DDC2 or E-DDC. For such panels the ddc-i2c-bus contains a + phandle to the system I2C controller connected to that bus. + + +Control I/Os +------------ + +Many display panels can be controlled through pins driven by GPIOs. The nature +and timing of those control signals are device-specific and left for panel +device tree bindings to specify. The following GPIO specifiers can however be +used for panels that implement compatible control signals. + +- enable-gpios: Specifier for a GPIO connected to the panel enable control + signal. The enable signal is active high and enables operation of the panel. + This property can also be used for panels implementing an active low power + down signal, which is a negated version of the enable signal. Active low + enable signals (or active high power down signals) can be supported by + inverting the GPIO specifier polarity flag. + + Note that the enable signal control panel operation only and must not be + confused with a backlight enable signal. + +- reset-gpios: Specifier for a GPIO coonnected to the panel reset control + signal. The reset signal is active low and resets the panel internal logic + while active. Active high reset signals can be supported by inverting the + GPIO specifier polarity flag. + + +Backlight +--------- + +Most display panels include a backlight. Some of them also include a backlight +controller exposed through a control bus such as I2C or DSI. Others expose +backlight control through GPIO, PWM or other signals connected to an external +backlight controller. + +- backlight: For panels whose backlight is controlled by an external backlight + controller, this property contains a phandle that references the controller.