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 E2814CC6B08 for ; Tue, 13 Oct 2026 09:07:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Orl7eWHVdHFy+WR+gD9uQiA0hr6q43qRIWv8DdjKbbM=; b=cLFVEoD6w+YTLBtc6i/ysZcCZ8 QqEIylY1Ge8smtx5Rd+SjkV3Do8BxYs8rACr9LXqboqquI2bDL68etYHIzhbnplcok2odgJ8eALbr yyeBX/DTL16+eh5VxMTELKJ785q4sFukBW3dDxtSi+giAuFYWQoWnmcN1Ek/Kp3kTP/6se3BbLlGH nYe75mqmrqukwgUdxJnSBfxgroDq78dXo2TqykTDVfojUfOB1xUoUR8WjZHnKjM0rQtxD5aMg36s0 ZzOKua5KorSH4qeEp1u4VTmCNa6MW6+AXA7SYtq8eIpWe6g19LyUcxvayGu+TZe0uNNKW95Te2HFL 0qop29Uw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xGYTC-0000000CP0w-4BQm; Tue, 13 Oct 2026 09:06:51 +0000 Received: from mail11.truemail.it ([2001:4b7e:0:8::81]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xGYT6-0000000COzf-0v2I for linux-arm-kernel@lists.infradead.org; Tue, 13 Oct 2026 09:06:49 +0000 Received: from francesco-nb (248.201.173.83.static.wline.lns.sme.cust.swisscom.ch [83.173.201.248]) by mail11.truemail.it (Postfix) with ESMTPA id 955931F8BD; Tue, 13 Oct 2026 11:06:35 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dolcini.it; s=default; t=1791882396; bh=Orl7eWHVdHFy+WR+gD9uQiA0hr6q43qRIWv8DdjKbbM=; h=From:To:Subject; b=ntUHKu9mg7FGUcRTRomXe/QAChsiHB5hBkj3e0+P3of2MKQqsGccxGbo+PIHOVk7L 2SsEGB/kFXdXxGqL2WvX/jBdjhuDUew7i6ZTxEkvbDzG/+gyU1WiiEmkC5YwtC7aO/ OLxmM/be3SJ0fgnd0iMiV0V9dVPWXaem0HMi7OfAzthlZC8WfxhxHwpjRsA5kRaDTn PV5VcPWmvCZ9U+9EIZUBt41GpfGXdf3LWjpml8XslO9PBiR56gyl07HqXjkleIF9SJ atAU7Ncjo7FZeRswdyxCxHIJQtXG3khsubegJpd8A+ORztvDoTMpOUbgzorP65YYlX QPUHZGjn1vyxw== Date: Tue, 13 Oct 2026 11:06:31 +0200 From: Francesco Dolcini To: Laurent Pinchart Cc: Leonardo Costa , Andrzej Hajda , Neil Armstrong , Robert Foss , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Frank Li , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Leonardo Costa Subject: Re: [PATCH 0/3] Add VGA support for Apalis iMX6 Message-ID: <20261013090631.GA33628@francesco-nb> References: <20261012-v1-apalis-imx6-enable-vga-v1-0-8905d8746504@toradex.com> <20261012164054.GA56180@killaraus.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261012164054.GA56180@killaraus.ideasonboard.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261013_020645_278788_1187DB3C X-CRM114-Status: GOOD ( 17.09 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello Laurent, On Mon, Oct 12, 2026 at 06:40:54PM +0200, Laurent Pinchart wrote: > On Mon, Oct 12, 2026 at 04:25:22AM -0300, Leonardo Costa wrote: > > This series adds a device tree overlay that enables the VGA output on Apalis > > iMX6, which is driven from a parallel RGB interface passing through a > > non-programmable video DAC. > > > > The video DAC is a simple resistor network gated by an active-low > > data-enable signal. For the bridge to work properly, this series also > > changes the following in the dt-bindings and simple-bridge driver: > > > > - dt-bindings: Add a new compatible for the bridge in the simple-bridge > > binding. This is necessary because the existing dumb-vga-dac compatible > > doesn't describe a data-enable signal polarity. > > > > - simple-bridge: Add the VGA bridge match-table entry and timings > > struct, setting the DRM_BUS_FLAG_DE_LOW flag for the bridge. > > Is there schematics available anywhere ? That would help reviewing the > series ? This circuit is on the SoM, and the SoM schematics are confidential and not generally available. I tried to extract as ascii art the relevant circuit, hope it helps BLUE (5 bits) ============= DISP0_DATA[4] ---[R30 348R]---+ DISP0_DATA[3] ---[R33 715R]---+ DISP0_DATA[2] ---[R36 1.47K]---+-------- VGA1_B DISP0_DATA[1] ---[R39 2.94K]---+ | DISP0_DATA[0] ---[R42 5.90K]---+ D | DI0_PIN15 ------------------------------ G | T4 MMBF2201N S | GND RED (5 bits) ============ DISP0_DATA[15] --[R31 348R]---+ DISP0_DATA[14] --[R34 715R]---+ DISP0_DATA[13] --[R37 1.47K]---+-------- VGA1_R DISP0_DATA[12] --[R40 2.94K]---+ | DISP0_DATA[11] --[R43 5.90K]---+ D | DI0_PIN15 ------------------------------ G | T5 MMBF2201N S | GND GREEN (6 bits) ============== DISP0_DATA[10] --[R32 348R]---+ DISP0_DATA[9] --[R35 715R]---+ DISP0_DATA[8] --[R38 1.47K]---+ DISP0_DATA[7] --[R41 2.94K]---+-------- VGA1_G DISP0_DATA[6] --[R44 5.90K]---+ | DISP0_DATA[5] --[R45 11.8K]---+ D | DI0_PIN15 ------------------------------ G | T6 MMBF2201N S | GND Francesco