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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2D636C04A68 for ; Thu, 28 Jul 2022 11:17:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EC5A8112649; Thu, 28 Jul 2022 11:16:59 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3B6D812BB59 for ; Thu, 28 Jul 2022 11:16:55 +0000 (UTC) Received: from [192.168.1.111] (91-158-154-79.elisa-laajakaista.fi [91.158.154.79]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 9F2E456D; Thu, 28 Jul 2022 13:16:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1659007013; bh=ZXDDTP7gbp5CtebP+uzx922dTPzjkRRWm+m1wpG6948=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=wXqMzzh/jxJP3crL8z8bZF3/7Mt1a2VsDJSyJRaNncQKV25vb0+TR+47op7CjPi3r 8He1mhylIfOxSYNuliSsjziSX0OjvipzoiXlRZOBuhTwUfkJNZRwME3cXVyykMfJbS 52ZU75GgIi56Iqd6M9u/g6HWOogvFxtDAevK52EU= Message-ID: Date: Thu, 28 Jul 2022 14:16:50 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH 1/8] dt-bindings: display: ti,am65x-dss: Add port properties for DSS Content-Language: en-US To: Aradhya Bhatia , Jyri Sarha , Rob Herring , David Airlie , Daniel Vetter , Krzysztof Kozlowski References: <20220719080845.22122-1-a-bhatia1@ti.com> <20220719080845.22122-2-a-bhatia1@ti.com> From: Tomi Valkeinen In-Reply-To: <20220719080845.22122-2-a-bhatia1@ti.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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: Nishanth Menon , Devicetree List , Vignesh Raghavendra , Devarsh Thakkar , Linux Kernel List , DRI Development List , Darren Etheridge , Rahul T R , Krunal Bhargav Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 19/07/2022 11:08, Aradhya Bhatia wrote: > Add "ti,oldi-mode" property to indicate the tidss driver the OLDI output > mode. The 2 OLDI TXes on am625-dss allow a 3 different types of panel > connections with the board. > > 1. Single Link / Single Mode on OLDI TX 0 OR 1. > 2. Single Link / Duplicate Mode on OLDI TX 0 and 1. > 3. Dual Link / Single Mode on OLDI TX 0 and 1. > > Add "ti,rgb565-to-888" property to override 16bit output from a videoport > for a bridge that only accepts 24bit RGB888 DPI input. > > On some boards the HDMI bridge takes a 24bit DPI input, but only 16 data > pins are actually enabled from the SoC. This new property forces the > output to be RGB565 on a specific video port if the bridge requests a > 24bit RGB color space. > > This assumes that the video port is connected like so: > > SoC : Bridge > R0 -> R3 > R1 -> R4 > R2 -> R5 > R3 -> R6 > R4 -> R7 > G0 -> G2 > G1 -> G3 > G2 -> G4 > G3 -> G5 > G4 -> G6 > G5 -> G7 > B0 -> B3 > B1 -> B4 > B2 -> B5 > B3 -> B6 > B4 -> B7 > > On the bridge side R0->R2, G0->G1, B0->B2 would be tied to ground. > The bridge sees 24bits of data, but the lsb's are always zero. > > Signed-off-by: Aradhya Bhatia > --- > .../bindings/display/ti/ti,am65x-dss.yaml | 25 +++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) > > diff --git a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml > index 6bbce921479d..11d9b3821409 100644 > --- a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml > +++ b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml > @@ -80,15 +80,35 @@ properties: > > properties: > port@0: > - $ref: /schemas/graph.yaml#/properties/port > + $ref: /schemas/graph.yaml#/$defs/port-base > + unevaluatedProperties: false > description: > The DSS OLDI output port node form video port 1 > > + properties: > + ti,oldi-mode: > + description: TI specific property to indicate the mode the OLDI TXes > + and the display panel are connected in. > + 0 -> OLDI TXes OFF (driver default for am625-dss) > + 1 -> Single link, Single Mode (OLDI0) (driver default for am65x-dss) > + 2 -> Single link, Single Mode (OLDI1) > + 3 -> Single link, Duplicate Mode > + 4 -> Dual link (Only Single Mode) > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [0, 1, 2, 3, 4] > + > port@1: > - $ref: /schemas/graph.yaml#/properties/port > + $ref: /schemas/graph.yaml#/$defs/port-base > + unevaluatedProperties: false > description: > The DSS DPI output port node from video port 2 > > + properties: > + ti,rgb565-to-888: > + description: > + property to override DPI output to 16bit for 24bit bridge > + type: boolean So you have a board with 16 DSS pins connected, going to a bridge/panel that only supports 24 bit input. I don't think there's anything TI specific here, sounds like a common situation. "rgb565-to-888" sounds like there's some kind of conversion happening, but all this does is set the videoport width to 16 bits. I'm not sure if there's a better solution but in the OMAP DSS we have "data-lines" property for an endpoint, which tells the driver the width of the bus. Tomi