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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 5DEC5C2BD09 for ; Mon, 9 Dec 2019 15:31:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D7142068E for ; Mon, 9 Dec 2019 15:31:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575905519; bh=ofqIYIemd1D0b3yzkB6LCuueWfFwja6Mfc7dfyMtTLw=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=Y9pPVriQEXssin8DFNovnnW3106mLN1IwRrU2QnRyEe+gapMW/R9nnBTNKtRoYy4F W6pBQSJb3RJOla5ioXROW4SgpaenqOGFwNUhsSL4oS0u4UeANSW1dXS4ChHWB4W2+o owC1RJCT+gNfrl89FD3tW2QBkTrEEsd2KI1qIPzo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726831AbfLIPby (ORCPT ); Mon, 9 Dec 2019 10:31:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:38856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726408AbfLIPby (ORCPT ); Mon, 9 Dec 2019 10:31:54 -0500 Received: from mail-qk1-f174.google.com (mail-qk1-f174.google.com [209.85.222.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2145324653; Mon, 9 Dec 2019 15:31:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575905513; bh=ofqIYIemd1D0b3yzkB6LCuueWfFwja6Mfc7dfyMtTLw=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=HeHu/WczDuuQ+b3lqLaESpVihmzfEFNIaCPnKUJzWPJy4JSBtt6+xlLUv3pT2PnR3 Lcl0iKZ/xjEKW+lSPCuwP4tlRUQLyowK8UNJZ/+0n54qy+zwA5T3j5HNhZ8923XWFs Fv1mWFCSvAhOX0Hd77vT+5U3V0NXNNAg8ktrn9hQ= Received: by mail-qk1-f174.google.com with SMTP id a203so3247493qkc.3; Mon, 09 Dec 2019 07:31:53 -0800 (PST) X-Gm-Message-State: APjAAAUCPUNx9m6AQNQUegP7VIM9QUOC/qYVal6CW3prGSocBN7av7Xi 2Qfxg9h0gMP+AbGOJwBkOMm36i2tEINLNg2zBg== X-Google-Smtp-Source: APXvYqyfkfzQ/i4Lsc3E69M49ZOIyASsab3VnWlhaCawfK85eSyUl3IfhJlvAVUYIQ0qxm+a4uEWnbu24j4V/Gz9iWU= X-Received: by 2002:a37:85c4:: with SMTP id h187mr27896771qkd.223.1575905512012; Mon, 09 Dec 2019 07:31:52 -0800 (PST) MIME-Version: 1.0 References: <20191207203553.286017-1-robdclark@gmail.com> <20191207203553.286017-2-robdclark@gmail.com> <20191208144533.GA14311@pendragon.ideasonboard.com> <20191208182757.GE14311@pendragon.ideasonboard.com> In-Reply-To: From: Rob Herring Date: Mon, 9 Dec 2019 09:31:40 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/4] dt-bindings: display: panel: document panel-id To: Rob Clark Cc: Laurent Pinchart , dri-devel , linux-arm-msm , aarch64-laptops@lists.linaro.org, Vasily Khoruzhick , Bjorn Andersson , Jeffrey Hugo , Rob Clark , Thierry Reding , Sam Ravnborg , David Airlie , Daniel Vetter , Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list Content-Type: text/plain; charset="UTF-8" Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Sun, Dec 8, 2019 at 3:24 PM Rob Clark wrote: > > On Sun, Dec 8, 2019 at 10:28 AM Laurent Pinchart > wrote: > > > > Hi Rob, > > > > On Sun, Dec 08, 2019 at 08:50:32AM -0800, Rob Clark wrote: > > > On Sun, Dec 8, 2019 at 6:45 AM Laurent Pinchart wrote: > > > > On Sat, Dec 07, 2019 at 12:35:50PM -0800, Rob Clark wrote: > > > > > From: Rob Clark > > > > > > > > > > For devices that have one of several possible panels installed, the > > > > > panel-id property gives firmware a generic way to locate and enable the > > > > > panel node corresponding to the installed panel. Example of how to use > > > > > this property: > > > > > > > > > > ivo_panel { > > > > > compatible = "ivo,m133nwf4-r0"; > > > > > panel-id = <0xc5>; > > > > > status = "disabled"; > > > > > > > > > > ports { > > > > > port { > > > > > ivo_panel_in_edp: endpoint { > > > > > remote-endpoint = <&sn65dsi86_out_ivo>; > > > > > }; > > > > > }; > > > > > }; > > > > > }; > > > > > > > > > > boe_panel { > > > > > compatible = "boe,nv133fhm-n61"; > > > > > panel-id = <0xc4>; > > > > > status = "disabled"; > > > > > > > > > > ports { > > > > > port { > > > > > boe_panel_in_edp: endpoint { > > > > > remote-endpoint = <&sn65dsi86_out_boe>; > > > > > }; > > > > > }; > > > > > }; > > > > > }; > > > > > > > > > > sn65dsi86: bridge@2c { > > > > > compatible = "ti,sn65dsi86"; > > > > > > > > > > ports { > > > > > #address-cells = <1>; > > > > > #size-cells = <0>; > > > > > > > > > > port@0 { > > > > > reg = <0>; > > > > > sn65dsi86_in_a: endpoint { > > > > > remote-endpoint = <&dsi0_out>; > > > > > }; > > > > > }; > > > > > > > > > > port@1 { > > > > > reg = <1>; > > > > > > > > > > sn65dsi86_out_boe: endpoint@c4 { > > > > > remote-endpoint = <&boe_panel_in_edp>; > > > > > }; > > > > > > > > > > sn65dsi86_out_ivo: endpoint@c5 { > > > > > remote-endpoint = <&ivo_panel_in_edp>; > > > > > }; > > > > > }; > > > > > }; > > > > > }; > > > > > > > > > > Signed-off-by: Rob Clark > > > > > --- > > > > > .../bindings/display/panel/panel-common.yaml | 26 +++++++++++++++++++ > > > > > 1 file changed, 26 insertions(+) > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-common.yaml > > > > > index ef8d8cdfcede..6113319b91dd 100644 > > > > > --- a/Documentation/devicetree/bindings/display/panel/panel-common.yaml > > > > > +++ b/Documentation/devicetree/bindings/display/panel/panel-common.yaml > > > > > @@ -75,6 +75,32 @@ properties: > > > > > in the device graph bindings defined in > > > > > Documentation/devicetree/bindings/graph.txt. > > > > > > > > > > + panel-id: > > > > > + description: > > > > > + To support the case where one of several different panels can be installed > > > > > + on a device, the panel-id property can be used by the firmware to identify > > > > > + which panel should have it's status changed to "ok". This property is not > > > > > + used by the HLOS itself. > > > > > > > > If your firmware can modify the status property of a panel, it can also > > > > add DT nodes. As discussed before, I don't think this belongs to DT. > > > > Even if panel-id isn't used by the operating system, you have Linux > > > > kernel patches in this series that show that this isn't transparent. > > > > > > I've already explained several times why this is not feasible. It > > > would require DtbLoader to be familiar with each individual device, > > > and be rev'd every time a new device appears. That is not practical > > > at all. > > > > > > (And fwiw, the ACPI tables describe each panel.. with an ACPI method > > > that is passed the the panel-id and returns the appropriate table.. > > > since DT doesn't have methods, this is the solution.) > > > > > > I stand by this patch, we can't keep running away from this problem > > > and wave the magic firmware wand. > > > > I believe in firmware solutions more than firmware magic wands :-) > > > > and with that in mind, I think I've come up with a firmware solution, > in the form of dtb overlays :-) > > I've managed to get DtbLoader to find and load a panel overlay based > on the panel-id it reads, which drops all patches in the patchset > except the last one, which now has this delta: This looks good to me. The only slight concern I have with it is making the overlay filename an ABI. I don't have a better suggestion though. How would this work for other vendors or the same panel ID (for different panels) used on different platforms? For different vendors at least, I guess dtbloader gets the base dtb path somehow and the overlay's are relative to that? > --------- > diff --git a/arch/arm64/boot/dts/qcom/Makefile > b/arch/arm64/boot/dts/qcom/Makefile > index 6498a1ec893f..1a61e8da2521 100644 > --- a/arch/arm64/boot/dts/qcom/Makefile > +++ b/arch/arm64/boot/dts/qcom/Makefile > @@ -1,4 +1,5 @@ > # SPDX-License-Identifier: GPL-2.0 > +subdir-y += panels > dtb-$(CONFIG_ARCH_QCOM) += apq8016-sbc.dtb > dtb-$(CONFIG_ARCH_QCOM) += apq8096-db820c.dtb > dtb-$(CONFIG_ARCH_QCOM) += ipq8074-hk01.dtb > diff --git a/arch/arm64/boot/dts/qcom/panels/Makefile > b/arch/arm64/boot/dts/qcom/panels/Makefile > new file mode 100644 > index 000000000000..dbf55f423555 > --- /dev/null > +++ b/arch/arm64/boot/dts/qcom/panels/Makefile > @@ -0,0 +1,3 @@ > +# SPDX-License-Identifier: GPL-2.0 > +dtb-$(CONFIG_ARCH_QCOM) += panel-c4.dtb > +dtb-$(CONFIG_ARCH_QCOM) += panel-c5.dtb > diff --git a/arch/arm64/boot/dts/qcom/panels/panel-c4.dts > b/arch/arm64/boot/dts/qcom/panels/panel-c4.dts > new file mode 100644 > index 000000000000..ebcf65419dad > --- /dev/null > +++ b/arch/arm64/boot/dts/qcom/panels/panel-c4.dts > @@ -0,0 +1,17 @@ > +// SPDX-License-Identifier: BSD-3-Clause > +/* > + * Panel overlay for panel-id 0xc4 > + * > + * Copyright (c) 2019, Linaro Ltd. > + */ > + > +/dts-v1/; > +/plugin/; > +/ { > + fragment@0 { > + target-path = "/panel"; > + __overlay__ { > + compatible = "boe,nv133fhm-n61"; > + }; > + }; > +}; > diff --git a/arch/arm64/boot/dts/qcom/panels/panel-c5.dts > b/arch/arm64/boot/dts/qcom/panels/panel-c5.dts > new file mode 100644 > index 000000000000..0ad5bb6003e3 > --- /dev/null > +++ b/arch/arm64/boot/dts/qcom/panels/panel-c5.dts > @@ -0,0 +1,17 @@ > +// SPDX-License-Identifier: BSD-3-Clause > +/* > + * Panel overlay for panel-id 0xc5 > + * > + * Copyright (c) 2019, Linaro Ltd. > + */ > + > +/dts-v1/; > +/plugin/; > +/ { > + fragment@0 { > + target-path = "/panel"; > + __overlay__ { > + compatible = "ivo,m133nwf4-r0"; > + }; > + }; > +}; > diff --git a/arch/arm64/boot/dts/qcom/sdm850-lenovo-yoga-c630.dts > b/arch/arm64/boot/dts/qcom/sdm850-lenovo-yoga-c630.dts > index c35d8099d8eb..92c76afb721c 100644 > --- a/arch/arm64/boot/dts/qcom/sdm850-lenovo-yoga-c630.dts > +++ b/arch/arm64/boot/dts/qcom/sdm850-lenovo-yoga-c630.dts > @@ -22,11 +22,13 @@ > hsuart0 = &uart6; > }; > > + /* > + * stub node which defines how panel is connected to bridge, which > + * will be updated by panel specific overlay > + */ > panel { > - compatible = "ivo,m133nwf4-r0"; > power-supply = <&vlcm_3v3>; > no-hpd; > - > ports { > port { > panel_in_edp: endpoint { > --------- > > Side note, try as I might, I couldn't get the 'target = <&phandle>' > approach to work in the overlays, so I ended up going with target-path > instead. From digging thru the fdt_overlay code, I *think* it is > because I end up w/ an overlay dtb without symbols. In the end, I > guess target-path works just as well. It's the base dtb that needs the symbols I think. BTW, to answer the question on #dri-devel, if you wanted to put the full panel into an overlay, the way to solve the problem of having bridge specific knowledge is defining a connector node. That should provide enough abstraction. Presumably the connector is actually the same across panels in this situation, so that should match up with the actual h/w. It could be possible to have a different physical connector populated for each possible panel, but hopefully that's not the common case. Rob