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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 85201C04E30 for ; Mon, 9 Dec 2019 11:05:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4093520726 for ; Mon, 9 Dec 2019 11:05:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="jMjYClSK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727591AbfLILF4 (ORCPT ); Mon, 9 Dec 2019 06:05:56 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:56600 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726377AbfLILF4 (ORCPT ); Mon, 9 Dec 2019 06:05:56 -0500 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 8D02999A; Mon, 9 Dec 2019 12:05:52 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1575889552; bh=N4w4AXaS16p/lwcdBi2cR5SP3Xey0/2llcHIAVZmHOI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jMjYClSKlGqv65k+anEjhCc845ZQnnelSeRjHrx1ZoPJ/516MitNKZzs8KN3k9IDT 8PXnJUk5Tp/klOC19o/ECHdPvwxzEWZagboLI2SxFWEZkrIJMP9fDbxhuWl3+L7uLp drm9DmTcuKdECLzM+ZSkGi5H+lUkEIIqgxKfVnUY= Date: Mon, 9 Dec 2019 13:05:45 +0200 From: Laurent Pinchart To: Rob Clark Cc: 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 , Rob Herring , Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list Subject: Re: [PATCH 1/4] dt-bindings: display: panel: document panel-id Message-ID: <20191209110545.GB4853@pendragon.ideasonboard.com> References: <20191207203553.286017-1-robdclark@gmail.com> <20191207203553.286017-2-robdclark@gmail.com> <20191208144533.GA14311@pendragon.ideasonboard.com> <20191208182757.GE14311@pendragon.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rob, On Sun, Dec 08, 2019 at 01:23:59PM -0800, Rob Clark wrote: > On Sun, Dec 8, 2019 at 10:28 AM Laurent Pinchart wrote: > > 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: Thank you for looking into this, I really like the outcome :-) > --------- > 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. -- Regards, Laurent Pinchart