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 4434AC19F32 for ; Wed, 5 Mar 2025 09:35:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9F0F610E246; Wed, 5 Mar 2025 09:35:49 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=tq-group.com header.i=@tq-group.com header.b="qZeJLqd+"; dkim=fail reason="key not found in DNS" (0-bit key; unprotected) header.d=ew.tq-group.com header.i=@ew.tq-group.com header.b="rN9bkF/6"; dkim-atps=neutral Received: from mx1.tq-group.com (mx1.tq-group.com [93.104.207.81]) by gabe.freedesktop.org (Postfix) with ESMTPS id 87AB310E246 for ; Wed, 5 Mar 2025 09:35:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1741167345; x=1772703345; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Jyc0o/VMOXI30xo+J36YcCxvEuBKWlv1PliS5DKyB2A=; b=qZeJLqd+9JafMLdvUcZBXBAHyfVhHjsj/t3xEk45uy/Vxs53subxAXYg 6E0G2qz91PGWRS+VehDbFNtTJEM5uA4OXpMPIxCeQ9sUlubhmWRvhHg2I hl8LHqgSu7hw5iKtqZqxJ0WuTTS/u4QbeyTotOabUOgaS884F7wzb1GHR 0n9VaIIMNGD9zraf90bfML+exCcLDl6M/EfYRe5W6QWXW3j5hvUwrwm8I 8vGuiwtumnmt8y5xlU/lLZ2UzGAU2Bk6gMUljs3yESQnd/m263y+Gem2X qEQfWgmboDBBVygb390cNKhUziHIZCM6ytVSPaxDAlOxmCYV0b8l/MZ7P Q==; X-CSE-ConnectionGUID: Eay/tyQ3TEGpHgghp7C/4A== X-CSE-MsgGUID: vxq+5lkuQv2w7HG+jB/54A== X-IronPort-AV: E=Sophos;i="6.14,222,1736809200"; d="scan'208";a="42303871" Received: from vmailcow01.tq-net.de ([10.150.86.48]) by mx1.tq-group.com with ESMTP; 05 Mar 2025 10:35:39 +0100 X-CheckPoint: {67C81AEB-E-B1D34AC3-DEA5B19F} X-MAIL-CPID: E9EC19DC2DEB38BC23034233209DF469_4 X-Control-Analysis: str=0001.0A00636A.67C81AEB.0146, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0 Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 67C14170FF5; Wed, 5 Mar 2025 10:35:27 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ew.tq-group.com; s=dkim; t=1741167334; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Jyc0o/VMOXI30xo+J36YcCxvEuBKWlv1PliS5DKyB2A=; b=rN9bkF/64KDDTPYAyySZk0Mm0QNhup6z5oj0FdVBAJZjJE3bsTsZc4IrHgusmWoLXEdRfI 3moeKx8BUzdxufYlLxK9uTJJSD/f9UHhUodtpxkAiiS7fVcDdR8uVIXxMP4nsm7g+/F6iG tzLt7nOzX/+NGGSUBHDVSeIEdT8qNofcL/iM+VJL58YtoyYKDQo53dXBR1O/aQ6cUwWXRB mxzHyJ3JzEcS1mHeZDs5kHKI529jrZoYjponLS7KZRBlJr55rx2GM+q8uGrt61SVqmRcyk E+2Ppd1dlHzFasqxvSSGWtwtXEzDSVxlS8pRk6nQeDzSFOz5UQRx2lMwF3mmkg== From: Alexander Stein To: Liu Ying , dri-devel@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se, jernej.skrabec@gmail.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, Rob Herring Subject: Re: [PATCH 3/5] dt-bindings: display: simple-bridge: Document DPI color encoder Date: Wed, 05 Mar 2025 10:35:26 +0100 Message-ID: <1891036.atdPhlSkOF@steina-w> Organization: TQ-Systems GmbH In-Reply-To: <20250304152320.GA2630063-robh@kernel.org> References: <20250304101530.969920-1-victor.liu@nxp.com> <20250304101530.969920-4-victor.liu@nxp.com> <20250304152320.GA2630063-robh@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" X-Last-TLS-Session-Version: TLSv1.3 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi, Am Dienstag, 4. M=E4rz 2025, 16:23:20 CET schrieb Rob Herring: > On Tue, Mar 04, 2025 at 06:15:28PM +0800, Liu Ying wrote: > > A DPI color encoder, as a simple display bridge, converts input DPI col= or > > coding to output DPI color coding, like Adafruit Kippah DPI hat[1] which > > converts input 18-bit pixel data to 24-bit pixel data(with 2 low padding > > bits in every color component though). Document the DPI color encoder. >=20 > Why do we need a node for this? Isn't this just wired how it is wired=20 > and there's nothing for s/w to see or do? I suppose if you are trying to= =20 > resolve the mode with 24-bit on one end and 18-bit on the other end, you= =20 > need to allow that and not require an exact match. You still might need=20 > to figure out which pins the 18-bit data comes out on, but you have that= =20 > problem with an 18-bit panel too. IOW, how is this any different if you=20 > have an 18-bit panel versus 24-bit panel? Especially panel-simple.c has a fixed configuration for each display, such = as: > .bus_format =3D MEDIA_BUS_FMT_RGB666_1X18 How would you allow or even know it should be addressed as MEDIA_BUS_FMT_RGB888_1X24 instead? I see different ways: 1. Create a new display setting/compatible 2. Add an overwrite property to the displays 3. Use a (transparent) bridge (this series) Number 1 is IMHO out of question. I personally don't like number 2 as this feels like adding quirks to displays, which they don't have. Number 3 actually describe the hardware connection. The only impact for software is to know which bus format it should use. Best regards Alexander =2D-=20 TQ-Systems GmbH | M=FChlstra=DFe 2, Gut Delling | 82229 Seefeld, Germany Amtsgericht M=FCnchen, HRB 105018 Gesch=E4ftsf=FChrer: Detlef Schneider, R=FCdiger Stahl, Stefan Schneider http://www.tq-group.com/