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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 C73ABECAAA1 for ; Mon, 5 Sep 2022 22:05:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=1oIJcD4oH0wRP033dWrA51UBR1aEQDBoIejBBqNyfcU=; b=YGAB4vTeml1bhs tepyFXhS6cD5qri5MENYADM6poS1Cj1wwqJtXDwhWFXYG6Kb4SUcsN8auzXS7Z6SATAl1hqzZgwc+ 5zUw62x/lyDkbqLVA4pTfhdGO7AHLTof2GatqjJkvZZuNT9QWc1ULfDJalo73zIs+q1xi7GD2pqEQ NAWIXBJijNKytubojGVpzuoZwBVSXFgwIq/CtzuNtB6/g+iNiqEn61P5OQiHsoSuZp1SUSSuv6qH0 Oh22SSV7bT7dPrwRXo85X2def/dT9MLf+Mj9ELKxvGje1uI59cA6kqcZxiwFuy7hQ8uHQc7efHl3h y5T9POOFLfqKwowle3bw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVKCG-00H0Ar-2D; Mon, 05 Sep 2022 22:04:00 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVKCA-00H045-BD for linux-arm-kernel@lists.infradead.org; Mon, 05 Sep 2022 22:03:59 +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 54FCC6BC; Tue, 6 Sep 2022 00:03:50 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1662415430; bh=m4TKbAl1A87gPnt2CNIsocJYJ+XEr3vdGXNPIz1nCWg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jhOgkEZCkRWKa7EjpoLTZajFnDHNU8Z6k1YlaSOANVZNSwK9C6k6Y7GUm4SSzmVAX mknI5mNl6Uw0iHRPmm7HixBcZ16nAQJWNuNLCEFNVUBVnHy/OuBcXRUJaGfwL2a7hQ /sVG3XdD0QWx+1/+8Gmyayl0nQ5zf9V7QGrVL3G4= Date: Tue, 6 Sep 2022 01:03:35 +0300 From: Laurent Pinchart To: Francesco Dolcini Cc: Francesco Dolcini , Max Krummenacher , Max Krummenacher , Fabio Estevam , Krzysztof Kozlowski , Marcel Ziswiler , NXP Linux Team , Pengutronix Kernel Team , Philippe Schenker , Rob Herring , Sascha Hauer , Shawn Guo , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] arm64: dts: imx8mp-verdin: add dsi to hdmi functionality Message-ID: References: <20220901154051.1885509-1-max.oss.09@gmail.com> <20220902155720.GB5699@francesco-nb.int.toradex.com> <20220905211703.GA6180@francesco-nb.int.toradex.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220905211703.GA6180@francesco-nb.int.toradex.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220905_150357_808942_69EB4DC9 X-CRM114-Status: GOOD ( 37.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Francesco, On Mon, Sep 05, 2022 at 11:17:03PM +0200, Francesco Dolcini wrote: > On Mon, Sep 05, 2022 at 10:26:14PM +0300, Laurent Pinchart wrote: > > On Sat, Sep 03, 2022 at 02:47:43PM +0200, Francesco Dolcini wrote: > > > On Sat, Sep 03, 2022 at 03:24:51AM +0300, Laurent Pinchart wrote: > > > > On Fri, Sep 02, 2022 at 05:57:20PM +0200, Francesco Dolcini wrote: > > > > > On Thu, Sep 01, 2022 at 09:07:49PM +0300, Laurent Pinchart wrote: > > > > Someone can integrate a Verdin SoM with a carrier board that has no DSI > > > > to HDMI (or LVDS) bridge, there should thus be no such device in the > > > > device tree. The SoM has DSI signals present on its connector, that's > > > > what the SoM .dtsi should expose. > > > > > > Just for the record Verdin i.MX8M Plus do have both HDMI and LVDS on the > > > connector (in addition to DSI) [1], of course we do have also the option to > > > have LVDS or HDMI using an external add-on DSI bridge as this patches are > > > about. > > > > > > Said that it's true that sometime we describe peripherals that are part of the > > > SOM family into the SOM dtsi, this avoid quite a lot of duplications given the > > > amount of carrier board that are available on the market that use just the same > > > building blocks (and this was one of the 2 points I mentioned as a reasoning > > > for our current DTS files structure). > > > > If those "SoM family" peripherals are on the carrier board, what's the > > issue with describing them in the carrier board .dtsi ? And if they're > > on an add-on board (such as, if I understand correctly, the DSI to HDMI > > encoder for the Dahlia carrier board), what's the issue with describing > > them in an overlay ? > > These SOM family peripherals are in multiples(!) carrier boards AND on > accessories. The drawback of being strict as you are asking is that we > would end-up with a massive duplication of this small DTS building > blocks, therefore the decision in the past to put those in the base SOM > dtsi file. OK, I got it now. > Maybe adding something like imx8mp-verdin-dsi-hdmi.dtsi and > imx8mp-verdin-dsi-lvds.dtsi that can be included by both overlay and > carrier dts files as needed would solve both the need of being strict on > the board definition in the dts file and avoid duplications? > Not sure if that would work smoothly, it looks like adding some > complexity and maintenance overhead, but maybe is the correct solution. That sounds good to me. Would you be able to give it a try to see if it works well ? > Anyway, while I fully understand your reasoning, I'm still not happy to > change this for the current toradex products, since users of > our dts file currently rely on the expectations I tried to explain in > this email thread and Max patches are implementing (and this is > currently uniform over the whole toradex product range). This sounds like a broader question, not specific to Toradex, opinions from Rob and Krzysztof would be useful. > > Maybe I'm missing something ? > > I tried to give more insights. Thank you, that's very appreciated. -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel