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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A7F18C433E7 for ; Tue, 13 Oct 2020 02:08:48 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 41D932078E for ; Tue, 13 Oct 2020 02:08:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KAWRKZFu"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="FWzWrgms" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 41D932078E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=BJRnBkRKDdM9AmVUFJFoPq5AOihmBA+D0uVEfO8fdpI=; b=KAWRKZFu+zoTDp+Psd7/L2332 gE5ZLm+/nHkoOZ2NT9Ka0gMh7yQNw9TCP8yS77/Ulv5YxLu/Q8CkNHLBp8Z6BohvNALivRUul/zHI dhX3WoysbltMiT3j8aL64Z7NhROLetVQ9DYQIpkSuVMPQwVE+bZcw4orAjagtNqFvAzbLQGYbRPp+ O52iLRFRHr+yyeFT7dDB3X4eorxEaoP/dvGC2WA9Uli3pz2CpjXz7LFXWM6XCOgk8l3g2LE1DtRFU ygNjWhtEsQgs03VcKJ5dHbQctn+/UpQdftI4Qtq8M22Ct01700EH0+UzAir262+hHotcnRmeen4Cp cX7VcDsxQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kS9ic-0000S1-1R; Tue, 13 Oct 2020 02:07:14 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kS9iY-0000RF-KH for linux-arm-kernel@lists.infradead.org; Tue, 13 Oct 2020 02:07:11 +0000 Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 3BEEDA42; Tue, 13 Oct 2020 04:07:05 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1602554825; bh=faWxdeUdzwGgd/jdihkSsVgvmpiWFPdtpRaopaRFFgU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FWzWrgms5AnQ5j0dxgRvZj1ljA30FYKM26WFUb4UG3G0QrOafcvS05e2JR4MMoSMZ mLD650iS6w2fq+3BI293vsXLWZBMw/Jh2ChVyV2N7lmh+ISjiwIriQ1R+kcBC9RqFq hoc688eHC3if1k1U7nA8ANv7QAUZqsTRYG4A+RYU= Date: Tue, 13 Oct 2020 05:06:19 +0300 From: Laurent Pinchart To: Marek Vasut Subject: Re: [PATCH v2 3/7] dt-bindings: display: mxsfb: Add a bus-width endpoint property Message-ID: <20201013020619.GG3942@pendragon.ideasonboard.com> References: <20201007012438.27970-1-laurent.pinchart@ideasonboard.com> <20201007012438.27970-4-laurent.pinchart@ideasonboard.com> <7b8df7af-5ca8-708b-4975-2fdf4280116f@denx.de> <20201009235843.GR25040@pendragon.ideasonboard.com> <9c7615d6-0f69-5f67-0795-b86ecea2eea8@denx.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9c7615d6-0f69-5f67-0795-b86ecea2eea8@denx.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201012_220710_788717_599F374E X-CRM114-Status: GOOD ( 21.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Guido =?utf-8?Q?G=C3=BCnther?= , Stefan Agner , Rob Herring , dri-devel@lists.freedesktop.org, Pengutronix Kernel Team , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Marek, On Sat, Oct 10, 2020 at 10:47:05AM +0200, Marek Vasut wrote: > On 10/10/20 1:58 AM, Laurent Pinchart wrote: > > Hi Marek, > > Hi, > > > On Wed, Oct 07, 2020 at 10:40:26AM +0200, Marek Vasut wrote: > >> On 10/7/20 3:24 AM, Laurent Pinchart wrote: > >> > >> [...] > >> > >>> + bus-width: > >>> + enum: [16, 18, 24] > >>> + description: | > >>> + The output bus width. This value overrides the configuration > >>> + derived from the connected device (encoder or panel). It should > >>> + only be specified when PCB routing of the data signals require a > >>> + different bus width on the LCDIF and the connected device. For > >>> + instance, when a 18-bit RGB panel has its R[5:0], G[5:0] and > >>> + B[5:0] signals connected to LCD_DATA[7:2], LCD_DATA[15:10] and > >>> + LCD_DATA[23:18] instead of LCD_DATA[5:0], LCD_DATA[11:6] and > >>> + LCD_DATA[17:12], bus-width should be set to 24. > >> > >> The iMX6 IPUv3 uses interface-pix-fmt which is a bit more flexible, but > >> I'm not sure whether it's the right way to go about this, see: > >> Documentation/devicetree/bindings/display/imx/fsl-imx-drm.txt > > > > I think specifying the bus with is better. It's a standard property, but > > more than that, a given bus width can carry different formats. For > > instance, a 24-bus could carry RGB666 data (with dithering for the > > LSBs). > > I think that's exactly what the interface-pix-fmt was trying to solve > for the IPUv3, there you could have e.g. both RGB666 and LVDS666 , which > were different. My point is that the driver should support multiple formats that can be carried over a given bus width, with the actual format to be used queried from the sink (usually a panel) instead of being hardcoded in DT. -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel