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=-8.2 required=3.0 tests=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 E5930C43603 for ; Sat, 7 Dec 2019 21:13:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9F0424670 for ; Sat, 7 Dec 2019 21:13:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726661AbfLGVN4 (ORCPT ); Sat, 7 Dec 2019 16:13:56 -0500 Received: from asavdk3.altibox.net ([109.247.116.14]:59594 "EHLO asavdk3.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726555AbfLGVN4 (ORCPT ); Sat, 7 Dec 2019 16:13:56 -0500 Received: from ravnborg.org (unknown [158.248.194.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk3.altibox.net (Postfix) with ESMTPS id 208A520041; Sat, 7 Dec 2019 22:13:47 +0100 (CET) Date: Sat, 7 Dec 2019 22:13:45 +0100 From: Sam Ravnborg To: Rob Clark Cc: dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, aarch64-laptops@lists.linaro.org, Rob Clark , Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Jeffrey Hugo , open list , Rob Herring , Bjorn Andersson , Vasily Khoruzhick , David Airlie , Thierry Reding , Laurent Pinchart Subject: Re: [PATCH 1/4] dt-bindings: display: panel: document panel-id Message-ID: <20191207211345.GA32369@ravnborg.org> References: <20191207203553.286017-1-robdclark@gmail.com> <20191207203553.286017-2-robdclark@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191207203553.286017-2-robdclark@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=eMA9ckh1 c=1 sm=1 tr=0 a=UWs3HLbX/2nnQ3s7vZ42gw==:117 a=UWs3HLbX/2nnQ3s7vZ42gw==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=cm27Pg_UAAAA:8 a=e5mUnYsNAAAA:8 a=2slYeMzxh5QCkdzES2IA:9 a=CjuIK1q_8ugA:10 a=xmb-EsYY8bH0VWELuYED:22 a=Vxmtnl_E_bksehYqCbjh:22 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 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. For display timings there is something similar. Here the property is named native-mode and is a phandle to the preferred timing. And it is documented that if no native-mode is specified the first timing in the tree is chosen. So a different concept than this. I could not from your otherwise well-documented changelog see why you wanted to go for an opauge integer and status rather than a phandle to the active display. The panel-id, if I get it right, is optional and the important part is that the first panel with staus = "okay" is selected. This would cover my usecase fine. I have a target with four different displays and the bootloader knows what display is used (based on gpio etc). The bootloader (barebox in my case) uses a simple variant of the DT, but reads in the DT used by the kernel and can modify the DT before it is passed to the kernel. Sam > 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. > + > + For a device with multiple potential panels, a node for each potential > + should be defined with status = "disabled", and an appropriate panel-id > + property. The video data producer should be setup with endpoints going to > + each possible panel. The firmware will find the dt node with a panel-id > + matching the actual panel installed, and change it's status to "ok". > + > + The exact method the firmware uses to determine the panel-id of the installed > + panel is outside the scope of this binding, but a few examples are > + > + 1) u-boot module reading a value from a u-boot env var > + 2) EFI driver module reading a value from an EFI variable > + 3) device specific firmware reading some device specific GPIOs or > + e-fuse > + > + The panel-id values are an opaque integer. They can be sparse. The only > + important thing is that each possible panel in the system has a unique > + panel-id, and that the values configured in the device's DTB match the > + values that the firmware is looking for. > + > ddc-i2c-bus: > $ref: /schemas/types.yaml#/definitions/phandle > description: > -- > 2.23.0 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel