From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83B3BC48BCD for ; Wed, 9 Jun 2021 11:05:23 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 50BF761364 for ; Wed, 9 Jun 2021 11:05:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 50BF761364 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B1AA46E4A6; Wed, 9 Jun 2021 11:05:22 +0000 (UTC) Received: from mail-lj1-x22f.google.com (mail-lj1-x22f.google.com [IPv6:2a00:1450:4864:20::22f]) by gabe.freedesktop.org (Postfix) with ESMTPS id 53A546E4A6 for ; Wed, 9 Jun 2021 11:05:21 +0000 (UTC) Received: by mail-lj1-x22f.google.com with SMTP id e11so31087959ljn.13 for ; Wed, 09 Jun 2021 04:05:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VePCktjSiUwy7zF0X3i1kiD5uKEWitdsZcvT2ZeLJmk=; b=lCebyaKzT4o+/UcvZ1XICOmUN7/NHBX1soF6VpaCp/TCvgmk56jULiWBAvNk3i6Loj z5wJnqwqEEUANW+u3ygdh5BEaWLy9N8xhJu5CTPM9oqJnYdl30CwZZWEux+H+KOeGDDI ZwxIVZKMULaK7VsCRoihYTZ7UtCWnM65PGo6NHphuP4WS/bf4zw9cd5uz3z8exwr9+E+ E0IPZfYfPD1onxv89/78rZD4LBFvbPBKfdvrtQUSz1tXKO9FIUkI8KHkdhFzDrpC0hZk 00RJQFVtqyf2oOP2/m8/mM9pqWN6bbJzWLMo5fac27BiLh4WA2TgtZvcRfZEggy9XQoF IdAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VePCktjSiUwy7zF0X3i1kiD5uKEWitdsZcvT2ZeLJmk=; b=shZ39Am2xuLmM3pUbnWf/R81/OGXaCBCy6MSROukf/8z88ucMjrWjsJ8zWBHvkJg0l qEYAxno8YIY44xBpmdOLfk5XjnJxx+dqGiws335eh8gt7ptSfXcooWudwA5Bu87zcMUU 791PiE+KcXpVROTJzoi/3RQDwWuNm6mDo2RdDaI7JM3ITtHEl3kJA5K2fNR+vDF/Cq7i d7Q1RvOuJL3ipj2S2VnKwk9z1nrVPNKqVX17+fKDbliB2mJobPmciGnLFhLUnytd8uwD ohk9W5+XX5kUtpmMY754W3LMoPCR+dcYXrLTnQ9xlMK3kHkCaOhhUZe/ImnhGhHmrEsr G8Qw== X-Gm-Message-State: AOAM531SMEAkBudNluBO54c3uvnFoxXd6WP2kwCqr9m+56cgYrG7DeSF mxKks5GuzgRclJ/A5RmmCxolLQgE0KO8LcpRCv6hMQ== X-Google-Smtp-Source: ABdhPJybvThxOzTqKAq2tM0a2YQzhSX2mOBRONdPJcNN5UbQix2w4ogjAjPGxmyqXPR5egn25taCVXJw2O2j5xJPZ+4= X-Received: by 2002:a05:651c:4c6:: with SMTP id e6mr21901557lji.326.1623236719658; Wed, 09 Jun 2021 04:05:19 -0700 (PDT) MIME-Version: 1.0 References: <20210607170555.4006050-1-dianders@chromium.org> <20210607100234.v9.2.Id3c048d22e72a9f90084a543b5b4e3f43bc9ab62@changeid> In-Reply-To: <20210607100234.v9.2.Id3c048d22e72a9f90084a543b5b4e3f43bc9ab62@changeid> From: Linus Walleij Date: Wed, 9 Jun 2021 13:05:08 +0200 Message-ID: Subject: Re: [PATCH v9 02/11] dt-bindings: drm: Introduce the DP AUX bus To: Douglas Anderson Content-Type: text/plain; charset="UTF-8" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rob Clark , Jonas Karlman , David Airlie , MSM , "open list:DRM PANEL DRIVERS" , Neil Armstrong , linux-kernel , Steev Klimaszewski , Bjorn Andersson , Stanislav Lisovskiy , Andrzej Hajda , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Rob Herring , Laurent Pinchart , Stephen Boyd , Thierry Reding , Sam Ravnborg Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, Jun 7, 2021 at 7:06 PM Douglas Anderson wrote: > 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 I overall like this approach a lot: Reviewed-by: Linus Walleij Yours, Linus Walleij