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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6920DC433E0 for ; Thu, 18 Mar 2021 01:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F5A764F24 for ; Thu, 18 Mar 2021 01:54:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230227AbhCRBxw (ORCPT ); Wed, 17 Mar 2021 21:53:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229934AbhCRBxR (ORCPT ); Wed, 17 Mar 2021 21:53:17 -0400 Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6BB58C06174A; Wed, 17 Mar 2021 18:53:17 -0700 (PDT) Received: by mail-wr1-x42f.google.com with SMTP id 61so3766508wrm.12; Wed, 17 Mar 2021 18:53:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=v1i0KsQ3h/jMhWbwFpzMC40inc+yYjGhis5/F6IuRMg=; b=ghXDIHNTetOEFrxwksmP6rkHT/cT6FkMc6GeMKOmmng1mTpWSNSM8idAOizGUMojRL loy+GhV/jAIPCFByU00CR1sg1Dj2go35NWVxYJRpc1kBxdxlgn7BI/t1WJ3YlOr06ORu DJenjLuf0NTv9UheLiyK9ii/nOOFRBEcBJqZq/r5WcKnQymCdx5aetPOv2KLOOQSyoxV R324HpbD472f5qAI74A/frwF84q6MIxjkP6wi/9xcjVU9SQe+YTn/IElPcb3qqdmBZcB lWEqBjukB/q7C7hYH65ryR2D413L9VEj4PIH1Jn3xtRkzJqbleF1GU+Mtc0g/H+LtB+F o1Ew== 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=v1i0KsQ3h/jMhWbwFpzMC40inc+yYjGhis5/F6IuRMg=; b=qYZv9eHhTmHwWzHhePAtwcscE8UDRNDVw++8SJriRU+5rztCG0hfefgQlZlxJ40EwS E71B7Q0YZgJfC8dWcJmLfc16k5qfnX+S72MUfMdGzGJbbTgBHQmdoiJC90Cx5y371eIv /FZJDh6qJg3T2/p9qNb8iyhYx3tJ57B9rZtgu1ZKmIcE53k1zOg/X3Kw2jwHrJ4p1697 mqSZJ2phnoPzUvxjBUvOX/PLTfAjfuSsoJikj4KZ5DQhSMLLU0/ndyCpnXsbK+ZISmT/ uJWIfO8lBOH8S8obY3xzj98ORapwjz+cuDtRN0L47qfrnigyhjcHUGsFFlXvNzNchxhJ a8Mg== X-Gm-Message-State: AOAM530EuE14IxM01Gr2apvbDlcrYqIyX6QjDd7YlGgHRF+wkmflX63S QYmN2ymVin9tdljWJfWORGU2ktuEvfQplsUY8nI= X-Google-Smtp-Source: ABdhPJzp1l2ljBrXjRJyXLSIUcbc7uR3HCZrC/smDRvMByEEPcM6+4fdLIhY0qI8M8J0QaQ7PYdClv8p8v+qQDtKNK0= X-Received: by 2002:adf:f587:: with SMTP id f7mr7047833wro.147.1616032396097; Wed, 17 Mar 2021 18:53:16 -0700 (PDT) MIME-Version: 1.0 References: <20210316140707.RFC.1.I3a21995726282f1e9fcb70da5eb96f19ed96634f@changeid> In-Reply-To: From: Rob Clark Date: Wed, 17 Mar 2021 18:53:04 -0700 Message-ID: Subject: Re: [RFC PATCH 1/3] dt-bindings: display: simple: Add the panel on sc7180-trogdor-pompom To: Matthias Kaehlcke Cc: Douglas Anderson , Rob Clark , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Nicolas Boichat , David Airlie , linux-arm-msm , Andy Gross , dri-devel , Bjorn Andersson , Rob Herring , Thierry Reding , Steev Klimaszewski , Stephen Boyd , Sam Ravnborg , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Wed, Mar 17, 2021 at 4:27 PM Matthias Kaehlcke wrote: > > On Tue, Mar 16, 2021 at 02:08:19PM -0700, Douglas Anderson wrote: > > The sc7180-trogdor-pompom board might be attached to any number of a > > pile of eDP panels. At the moment I'm told that the list might include: > > - KD KD116N21-30NV-A010 > > - KD KD116N09-30NH-A016 > > - Starry 2081116HHD028001-51D > > - Sharp LQ116M1JW10 > > > > It should be noted that while the EDID programmed in the first 3 > > panels indicates that they should run with exactly the same timing (to > > keep things simple), the 4th panel not only needs different timing but > > has a different resolution. > > > > As is true in general with eDP panels, we can figure out which panel > > we have and all the info needed to drive its pixel clock by reading > > the EDID. However, we can do this only after we've powered the panel > > on. Powering on the panels requires following the timing diagram in > > each panel's datasheet which specifies delays between certain > > actions. This means that, while we can be quite dynamic about handling > > things we can't just totally skip out on describing the panel like we > > could do if it was connected to an external-facing DP port. > > > > While the different panels have slightly different delays, it's > > possible to come up with a set of unified delays that will work on all > > the panels. From reading the datasheets: > > * KD KD116N21-30NV-A010 and KD KD116N09-30NH-A016 > > - HPD absent delay: 200 ms > > - Unprepare delay: 150 ms (datasheet is confusing, might be 500 ms) > > * Starry 2081116HHD028001-51D > > - HPD absent delay: 100 ms > > - Enable delay: (link training done till enable BL): 200 ms > > - Unprepare delay: 500 ms > > * Sharp LQ116M1JW10 > > - HPD absent delay: 200 ms > > - Unprepare delay: 500 ms > > - Prepare to enable delay (power on till backlight): 100 ms > > > > Unified: > > - HPD absent delay: 200 ms > > - Unprepare delay: 500 ms > > - Enable delay: 200 ms > > > > NOTE: in theory the only thing that we _really_ need unity on is the > > "HPD absent delay" since once the panel asserts HPD we can read the > > EDID and could make per-panel decisions if we wanted. > > > > Let's create a definition of "a panel that can be attached to pompom" > > as a panel that provides a valid EDID and can work with the standard > > pompom power sequencing. If more panels are later attached to pompom > > then it's fine as long as they work in a compatible way. > > > > One might ask why we can't just use a generic string here and provide > > the timings directly in the device tree file. As I understand it, > > trying to describe generic power sequencing in the device tree is > > frowned upon and the one instance (SD/MMC) is regarded as a mistake > > that shouldn't be repeated. Specifying a power sequence per board (or > > per board class) feels like a reasonable compromise. We're not trying > > to define fully generic power sequence bindings but we can also take > > advantage of the semi-probable properties of the attached device. > > > > NOTE: I believe that past instances of supporting this type of thing > > have used the "white lie" approach. One representative panel was > > listed in the device tree. The power sequencings of this > > representative panel were OK to use across all panels that might be > > attached and other differences were handled by EDID. This patch > > attempts to set a new precedent and avoid the need for the white lie. > > > > Signed-off-by: Douglas Anderson > > --- > > Sounds reasonable to me if DT maintainers can live with this abstract > hardware definition. It's clearer than the 'white lie' approach. Yeah, it is a weird grey area between "discoverable" and "not discoverable".. but I favor DT reflecting reality as much as possible/feasible, so I think this is definity cleaner than "white lies" Reviewed-by: Rob Clark > It's then up to the vendor/manufacturer to ensure to only ship devices > with panels that have compatible timings. > > > .../devicetree/bindings/display/panel/panel-simple.yaml | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml > > index 62b0d54d87b7..9807dbc1cceb 100644 > > --- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml > > +++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml > > @@ -140,6 +140,10 @@ properties: > > - giantplus,gpg48273qs5 > > # GiantPlus GPM940B0 3.0" QVGA TFT LCD panel > > - giantplus,gpm940b0 > > + # A panel connected to a google,pompom board. Panel is guaranteed to > > + # confirm to google,pompom-panel power sequencing requirements and then > > s/confirm/conform/ ? > > > + # the specific panel will be probed via EDID. > > + - google,pompom-panel > > # HannStar Display Corp. HSD070PWW1 7.0" WXGA TFT LCD panel > > - hannstar,hsd070pww1 > > # HannStar Display Corp. HSD100PXN1 10.1" XGA LVDS panel > > FWIW: > > Reviewed-by: Matthias Kaehlcke > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel 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=-10.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 63057C433E0 for ; Thu, 18 Mar 2021 01:53:20 +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 E6DF064F3B for ; Thu, 18 Mar 2021 01:53:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6DF064F3B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com 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 308526E86C; Thu, 18 Mar 2021 01:53:19 +0000 (UTC) Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8B9026E86C for ; Thu, 18 Mar 2021 01:53:17 +0000 (UTC) Received: by mail-wr1-x435.google.com with SMTP id b9so3775949wrt.8 for ; Wed, 17 Mar 2021 18:53:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=v1i0KsQ3h/jMhWbwFpzMC40inc+yYjGhis5/F6IuRMg=; b=ghXDIHNTetOEFrxwksmP6rkHT/cT6FkMc6GeMKOmmng1mTpWSNSM8idAOizGUMojRL loy+GhV/jAIPCFByU00CR1sg1Dj2go35NWVxYJRpc1kBxdxlgn7BI/t1WJ3YlOr06ORu DJenjLuf0NTv9UheLiyK9ii/nOOFRBEcBJqZq/r5WcKnQymCdx5aetPOv2KLOOQSyoxV R324HpbD472f5qAI74A/frwF84q6MIxjkP6wi/9xcjVU9SQe+YTn/IElPcb3qqdmBZcB lWEqBjukB/q7C7hYH65ryR2D413L9VEj4PIH1Jn3xtRkzJqbleF1GU+Mtc0g/H+LtB+F o1Ew== 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=v1i0KsQ3h/jMhWbwFpzMC40inc+yYjGhis5/F6IuRMg=; b=s5FzQ2w229xHUjNQM8Ag3XZOK9J/f2JfWOdspqgfcq9teNBjWzecOTDyuHOYsq51S4 lbmE3KwrNQexjwdgZRoS99faMyqM/ZtAFsPsU5mL1RH4GJsKkSfIhsg6Ey75iurunzkB 0sWbYsdT+Unnrrdlt63FdPuvMTUA7bPSItiJQl04y1Oq31ufYItgCQCyc/bRSo0YGi+k eiEgkNyUpBPhceW++loI3VqyQF+fpcl5y41iqAw/ALoFFq57+bAl3W2he0msAJj7eXB3 1P8D0xrSVypwXhrsnl54vvv1G9oLwRJQr8xPWygtKLR1IhxO6QEIguKZkp3XyDq7dF57 wwpw== X-Gm-Message-State: AOAM531tI7NNBfus+GutZvPv1n09Jq4AHHns5UPmFeTCeU1FD4QLbco+ BPNX86Q8XDLFkTGpsXDIWqqqM1vyblxpvTKlE7c= X-Google-Smtp-Source: ABdhPJzp1l2ljBrXjRJyXLSIUcbc7uR3HCZrC/smDRvMByEEPcM6+4fdLIhY0qI8M8J0QaQ7PYdClv8p8v+qQDtKNK0= X-Received: by 2002:adf:f587:: with SMTP id f7mr7047833wro.147.1616032396097; Wed, 17 Mar 2021 18:53:16 -0700 (PDT) MIME-Version: 1.0 References: <20210316140707.RFC.1.I3a21995726282f1e9fcb70da5eb96f19ed96634f@changeid> In-Reply-To: From: Rob Clark Date: Wed, 17 Mar 2021 18:53:04 -0700 Message-ID: Subject: Re: [RFC PATCH 1/3] dt-bindings: display: simple: Add the panel on sc7180-trogdor-pompom To: Matthias Kaehlcke 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 , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Nicolas Boichat , David Airlie , linux-arm-msm , Douglas Anderson , dri-devel , Bjorn Andersson , Rob Herring , Andy Gross , Thierry Reding , Steev Klimaszewski , Stephen Boyd , Sam Ravnborg , Linux Kernel Mailing List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Mar 17, 2021 at 4:27 PM Matthias Kaehlcke wrote: > > On Tue, Mar 16, 2021 at 02:08:19PM -0700, Douglas Anderson wrote: > > The sc7180-trogdor-pompom board might be attached to any number of a > > pile of eDP panels. At the moment I'm told that the list might include: > > - KD KD116N21-30NV-A010 > > - KD KD116N09-30NH-A016 > > - Starry 2081116HHD028001-51D > > - Sharp LQ116M1JW10 > > > > It should be noted that while the EDID programmed in the first 3 > > panels indicates that they should run with exactly the same timing (to > > keep things simple), the 4th panel not only needs different timing but > > has a different resolution. > > > > As is true in general with eDP panels, we can figure out which panel > > we have and all the info needed to drive its pixel clock by reading > > the EDID. However, we can do this only after we've powered the panel > > on. Powering on the panels requires following the timing diagram in > > each panel's datasheet which specifies delays between certain > > actions. This means that, while we can be quite dynamic about handling > > things we can't just totally skip out on describing the panel like we > > could do if it was connected to an external-facing DP port. > > > > While the different panels have slightly different delays, it's > > possible to come up with a set of unified delays that will work on all > > the panels. From reading the datasheets: > > * KD KD116N21-30NV-A010 and KD KD116N09-30NH-A016 > > - HPD absent delay: 200 ms > > - Unprepare delay: 150 ms (datasheet is confusing, might be 500 ms) > > * Starry 2081116HHD028001-51D > > - HPD absent delay: 100 ms > > - Enable delay: (link training done till enable BL): 200 ms > > - Unprepare delay: 500 ms > > * Sharp LQ116M1JW10 > > - HPD absent delay: 200 ms > > - Unprepare delay: 500 ms > > - Prepare to enable delay (power on till backlight): 100 ms > > > > Unified: > > - HPD absent delay: 200 ms > > - Unprepare delay: 500 ms > > - Enable delay: 200 ms > > > > NOTE: in theory the only thing that we _really_ need unity on is the > > "HPD absent delay" since once the panel asserts HPD we can read the > > EDID and could make per-panel decisions if we wanted. > > > > Let's create a definition of "a panel that can be attached to pompom" > > as a panel that provides a valid EDID and can work with the standard > > pompom power sequencing. If more panels are later attached to pompom > > then it's fine as long as they work in a compatible way. > > > > One might ask why we can't just use a generic string here and provide > > the timings directly in the device tree file. As I understand it, > > trying to describe generic power sequencing in the device tree is > > frowned upon and the one instance (SD/MMC) is regarded as a mistake > > that shouldn't be repeated. Specifying a power sequence per board (or > > per board class) feels like a reasonable compromise. We're not trying > > to define fully generic power sequence bindings but we can also take > > advantage of the semi-probable properties of the attached device. > > > > NOTE: I believe that past instances of supporting this type of thing > > have used the "white lie" approach. One representative panel was > > listed in the device tree. The power sequencings of this > > representative panel were OK to use across all panels that might be > > attached and other differences were handled by EDID. This patch > > attempts to set a new precedent and avoid the need for the white lie. > > > > Signed-off-by: Douglas Anderson > > --- > > Sounds reasonable to me if DT maintainers can live with this abstract > hardware definition. It's clearer than the 'white lie' approach. Yeah, it is a weird grey area between "discoverable" and "not discoverable".. but I favor DT reflecting reality as much as possible/feasible, so I think this is definity cleaner than "white lies" Reviewed-by: Rob Clark > It's then up to the vendor/manufacturer to ensure to only ship devices > with panels that have compatible timings. > > > .../devicetree/bindings/display/panel/panel-simple.yaml | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml > > index 62b0d54d87b7..9807dbc1cceb 100644 > > --- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml > > +++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml > > @@ -140,6 +140,10 @@ properties: > > - giantplus,gpg48273qs5 > > # GiantPlus GPM940B0 3.0" QVGA TFT LCD panel > > - giantplus,gpm940b0 > > + # A panel connected to a google,pompom board. Panel is guaranteed to > > + # confirm to google,pompom-panel power sequencing requirements and then > > s/confirm/conform/ ? > > > + # the specific panel will be probed via EDID. > > + - google,pompom-panel > > # HannStar Display Corp. HSD070PWW1 7.0" WXGA TFT LCD panel > > - hannstar,hsd070pww1 > > # HannStar Display Corp. HSD100PXN1 10.1" XGA LVDS panel > > FWIW: > > Reviewed-by: Matthias Kaehlcke > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel