From patchwork Fri Jun 11 17:17:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 1491096 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=ggi+grjz; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4G1nc06rW1z9sX5 for ; Sat, 12 Jun 2021 03:18:08 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230468AbhFKRUE (ORCPT ); Fri, 11 Jun 2021 13:20:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230434AbhFKRUE (ORCPT ); Fri, 11 Jun 2021 13:20:04 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48AD5C0617AF for ; Fri, 11 Jun 2021 10:18:06 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id y11so2978961pgp.11 for ; Fri, 11 Jun 2021 10:18:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=RSdDmWvM+qzpAmf31JtYtbWsLIaOjDvF/qkbEZxua7o=; b=ggi+grjzzCRdXuViwFNZ33p2WAyiVmcb/ctIQAx0vKFlNqqkWDAcOCQlJ2tD+tWH3f vHh3ZHEGEdsBHoQkEvf2aK5IrHI0b9Rp9HuEMrMx3Zg3QrgJ6HCD5ZHwoQ9iDYKKEGOL n4zZlGgTSOPC2tHPAi73dnkyRDdmTgC9zev+8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=RSdDmWvM+qzpAmf31JtYtbWsLIaOjDvF/qkbEZxua7o=; b=aoFlRfkhyQEyV4gJQSYLpNOp9k5YuQPr5DX11wllITBPe30A6jxpGqYS4yq2YsaW5h klX6r8to52LU1C0UEfX2ayR3PtNbSW6QbH4VHUhclBfWabZg/NmKfumkqtGcdTMxT1Uc /IAl1jM7u5ySXal/OVLV3Oo/xSiM0/vqqktv5ZDPhNavcEt/AacTnSHD7Hd3ljd4o8aQ DIAxkgg8PWQimB29g810hOPdgPgsd7N7U6QayhRkc3AASoXL7W9nGDQK5nZ1Vw2BmetP UlMf1tpNLQTzw9G/RyMiOMN/O57Rh1gVdT12f98htQHOcIDYyhg7KXQHuFXLJW4C9r8m +3oQ== X-Gm-Message-State: AOAM531c1b5Gi+7gMZN7S/ZOaBrRSiidwTRak82h2bNMl4PeJWFaiKxf SuUCiMFHXM6a+P7Ac8RbfqHn2Q== X-Google-Smtp-Source: ABdhPJx78EglKulG9xe66rpTctZdSqRdhziUHbpBUTfaQeV6/K8y/AfhL7r9eoLmbB9vsD98/A0eBw== X-Received: by 2002:a63:a50a:: with SMTP id n10mr4663164pgf.13.1623431885813; Fri, 11 Jun 2021 10:18:05 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:201:4128:5428:5cd0:cfa5]) by smtp.gmail.com with ESMTPSA id f17sm5837850pgm.37.2021.06.11.10.18.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Jun 2021 10:18:05 -0700 (PDT) From: Douglas Anderson To: Andrzej Hajda , Neil Armstrong , Laurent Pinchart , Jonas Karlman , Sam Ravnborg Cc: Maarten Lankhorst , linux-arm-msm@vger.kernel.org, Bjorn Andersson , Thierry Reding , Stanislav Lisovskiy , Lyude Paul , Stephen Boyd , Steev Klimaszewski , Linus W , robdclark@chromium.org, dri-devel@lists.freedesktop.org, Douglas Anderson , Rob Herring , Daniel Vetter , David Airlie , Rob Herring , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v10 02/11] dt-bindings: drm: Introduce the DP AUX bus Date: Fri, 11 Jun 2021 10:17:38 -0700 Message-Id: <20210611101711.v10.2.Id3c048d22e72a9f90084a543b5b4e3f43bc9ab62@changeid> X-Mailer: git-send-email 2.32.0.272.g935e593368-goog In-Reply-To: <20210611171747.1263039-1-dianders@chromium.org> References: <20210611171747.1263039-1-dianders@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org We want to be able to list an eDP panel as a child of an eDP controller node to represent the fact that the panel is connected to the controller's DP AUX bus. Though the panel and the controller are connected in several ways, the DP AUX bus is the primary control interface between the two and thus makes the most sense to model in device tree hierarchy. Listing a panel in this way makes it possible for the panel driver to easily get access to the DP AUX bus that it resides on, which can be useful to help in auto-detecting the panel and for turning on various bits. NOTE: historically eDP panels were _not_ listed under their controller but were listed at the top level of the device tree. This will still be supported for backward compatibility (and while DP controller drivers are adapted to support the new DT syntax) but should be considered deprecated since there is no downside to listing the panel under the controller. For now, the DP AUX bus bindings will only support an eDP panel underneath. It's possible it could be extended to allow having a DP connector under it in the future. NOTE: there is no "Example" in this bindings file. Yikes! This avoids duplicating the same example lots of places. See users of the aux bus (like ti-sn65dsi86) for examples. The idea for this bus's design was hashed out over IRC [1]. [1] https://people.freedesktop.org/~cbrill/dri-log/?channel=dri-devel&date=2021-05-11 Signed-off-by: Douglas Anderson Reviewed-by: Rob Herring Reviewed-by: Linus Walleij --- (no changes since v9) Changes in v9: - Commit message now notes aux-bus yaml won't have an "Example". Changes in v8: - Separate DP AUX bus binding is new for v8. .../bindings/display/dp-aux-bus.yaml | 37 +++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 Documentation/devicetree/bindings/display/dp-aux-bus.yaml diff --git a/Documentation/devicetree/bindings/display/dp-aux-bus.yaml b/Documentation/devicetree/bindings/display/dp-aux-bus.yaml new file mode 100644 index 000000000000..5e4afe9f98fb --- /dev/null +++ b/Documentation/devicetree/bindings/display/dp-aux-bus.yaml @@ -0,0 +1,37 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/dp-aux-bus.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: DisplayPort AUX bus + +maintainers: + - Douglas Anderson + +description: + DisplayPort controllers provide a control channel to the sinks that + are hooked up to them. This is the DP AUX bus. Over the DP AUX bus + we can query properties about a sink and also configure it. In + particular, DP sinks support DDC over DP AUX which allows tunneling + a standard I2C DDC connection over the AUX channel. + + To model this relationship, DP sinks should be placed as children + of the DP controller under the "aux-bus" node. + + At the moment, this binding only handles the eDP case. It is + possible it will be extended in the future to handle the DP case. + For DP, presumably a connector would be listed under the DP AUX + bus instead of a panel. + +properties: + $nodename: + const: "aux-bus" + + panel: + $ref: panel/panel-common.yaml# + +additionalProperties: false + +required: + - panel