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 5D7B3CD8CA8 for ; Fri, 12 Jun 2026 10:06:24 +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:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=hLoQHEYgMDts8PaREYdyuIclaSf1yNKukBVuA2wOHpQ=; b=mmI+2hpitNDu4N1162KrxaTIMy 8n0Ses5QZI8BOCtb8KBnkGrqGoVQbXCbI/qb0RX4fhXXLl+4TAJnsvxDK7iK1nweSpbOFjCH7qpxH /wq9mI5HQm3Wua+JK/BqN2EEfBWC8ZnFyZcdR5fey5DbKSsdNeR38puMyWtpCt4+i/QX23z+MsVEH ARe9EFbbvwziqQiVr8d+fWxbE+CydIpOUq016PGI84QIkSwMFJbv4kYNOITHltlZtr5ADVyMVCHR2 WZ9KRcoLUHONCn8gps2JDbPpLbTQaNwFLqYXrP4CMXWZ8jUzRUHzQuct5CSi5erRzth8yroMLANI5 kepCg12g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wXymI-0000000AjFj-02Oh; Fri, 12 Jun 2026 10:06:18 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wXymD-0000000AjD2-447c for linux-arm-kernel@lists.infradead.org; Fri, 12 Jun 2026 10:06:16 +0000 Received: from [192.168.88.20] (91-158-153-178.elisa-laajakaista.fi [91.158.153.178]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id A346F8D4; Fri, 12 Jun 2026 12:05:36 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1781258737; bh=nVO1wcbg8Vyx+jEaPD7eQL4wlG4suC+xgJm3XjJHzpg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=jhmgg5IwvBUCs/OSuHJNsZIzZlsohD32QTJgQASAhzb9brW3FYhPMeYd3GRJOQpcK 0oZ63Hs4/bd3Xrf8drPKsYfOU/fch0EOrnnqa44sgCHh9R7RvCVbcC/LESDnUQJxbF yIAVIgFaGOzp6hkm/qJJ68/VgAGTO/UqwDEF8ygw= Message-ID: <059f2866-b39d-4c26-8889-b5acff5372ad@ideasonboard.com> Date: Fri, 12 Jun 2026 13:06:03 +0300 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/6] arm64: ti: Use syscon for the Control Module To: Andrew Davis Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Nishanth Menon , Vignesh Raghavendra , Tero Kristo , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Abraham I , Roger Quadros , Devarsh Thakkar , Swamil Jain References: <20260528-ti-main-conf-v1-0-a54ac5c8d081@ideasonboard.com> <29c9bd27-df32-4c56-8df2-987722d02b9a@ti.com> From: Tomi Valkeinen Content-Language: en-US In-Reply-To: <29c9bd27-df32-4c56-8df2-987722d02b9a@ti.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260612_030614_456302_AB6E99DF X-CRM114-Status: GOOD ( 12.52 ) 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 Hi Andrew, On 29/05/2026 01:59, Andrew Davis wrote: > On 5/28/26 7:53 AM, Tomi Valkeinen wrote: >> I have been trying to get BeagleY-AI display support to upstream: >> >> 20260513-beagley-ai-display-v2-0-9e9bcefde6bc@ideasonboard.com >> >> One difficulty has been the handling of the Control Module region, as >> we need access to a single in that region, surrounded by registers for >> other subsystems. In my series I made the related node a syscon, thus >> allowing versatile access to the registers: >> >> https://lore.kernel.org/all/20260513-beagley-ai-display- >> v2-14-9e9bcefde6bc@ideasonboard.com/ >> >> However, that's not a correct way to handle it. I realized we already >> have ti,j721e-system-controller.yaml binding for older SoCs, which has >> syscon but it's not used for the newer TI SoCs. This series takes the >> same binding into use for the newer SoCs. >> > > We moved away from this system-controller thing because it was always > a hack to allow us to poke into random control registers from nodes > throughout the DT. This was a mess and also caused issues with multiple > mappings to the same registers (some sub nodes inside the control space > also make their own mappings). If you need access to registers then make > a node with those registers in the `reg` property. Like in this patch (dss_dpi0_clk_ctrl)? https://lore.kernel.org/all/20260420-beagley-ai-display-v1-14-f628543dfd14%40ideasonboard.com/ My understanding is that that's NACKed, as we end up adding new syscon compats and syscon nodes for (possibly many) single register blocks. Tomi