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 36D6CCD98DC for ; Fri, 12 Jun 2026 16:22:20 +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=X7p2Kiie/VwPTVeZsZUYTTjk6TXHw3XumFkCp16/1eI=; b=uvQsfPSgVTaEUrI9XB7/Je81h9 eMHLdjGZnTPhV7YXVbwwYwHmykToMsGDrvGbxJg4iaE6tA/3RyA4MDDVGOFk3j/+R4eVvee3qhi5Q R7ZyxMRBEApOIocB35/LfjLZ9UydBoSOHTxmHvN2bQzQCcOTakrZUrf4XYxBZvFQCdSvyrmBbQxwo fzg8dabrDL5yhwhRf0JHSIZWBjxXDCbl1X0/4S19ggDd+ofQnVRZsjklEHeIAT7oBcVbfIaBMxLR9 nnDGR4ZJggkja6/ILPoklDlyrDdOp8MYqBFeMUFsjGh9z0aZm9j+3SLfBFMyjEWhXGkKigQ9kiyHE +3/XYBCg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wY4e4-0000000BEW8-2Wov; Fri, 12 Jun 2026 16:22:12 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wY4dw-0000000BE9r-1E95; Fri, 12 Jun 2026 16:22:04 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 8753360008; Fri, 12 Jun 2026 16:22:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18B1E1F00A3A; Fri, 12 Jun 2026 16:22:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781281323; bh=X7p2Kiie/VwPTVeZsZUYTTjk6TXHw3XumFkCp16/1eI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Z22YVM6WMIASp6bj1/Lj5CY65UT+3UNWrBON6qYWNpw0F0ROXkocPb7+mxyQK9JXv XPhj7R63As+LKNe48ExXO+TlZCvteRV2aCuTZJYYDOLZynJgw42IRVmzFln5mPS+B9 W0aeKwkDtkcyMvTAMJ3T7pbJNaE6vqwB67v7GFkRfQ/p0PPxLYu0BNrTtrGo8LG3X6 D1uFff4UvovL0WBLq7iZRvv12GLKLps4GmetJoUDJI0z9UwdMukaGnsxzZ7BLxz5ZP pmf8rKWC/hKZSQb/2iYXEwLi/86TiQqEpUcRqfSfI7L336oBRhWagti2L1hzgefXZy f667hOdnhLW7A== Date: Fri, 12 Jun 2026 11:22:02 -0500 From: "Rob Herring (Arm)" To: Krzysztof Kozlowski Cc: Roger Quadros , linux-omap@vger.kernel.org, Andreas Kemnade , Kevin Hilman , Jacky Huang , Tony Lindgren , linux-rockchip@lists.infradead.org, Conor Dooley , Lee Jones , Heiko Stuebner , AngeloGioacchino Del Regno , Matthias Brugger , Krzysztof Kozlowski , devicetree@vger.kernel.org, Shan-Chun Hung , linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Magnus Damm , Geert Uytterhoeven , Aaro Koskinen , linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH v3 1/3] dt-bindings: mfd: syscon: Disallow simple-bus with syscon Message-ID: <178128132175.1153833.2573734544472661843.robh@kernel.org> References: <20260608-n-dt-bindings-simple-bus-syscon-v3-0-4eba9ec1212a@oss.qualcomm.com> <20260608-n-dt-bindings-simple-bus-syscon-v3-1-4eba9ec1212a@oss.qualcomm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260608-n-dt-bindings-simple-bus-syscon-v3-1-4eba9ec1212a@oss.qualcomm.com> 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 On Mon, 08 Jun 2026 22:44:24 +0200, Krzysztof Kozlowski wrote: > "syscon" is a system controller with registers having their own > functions, thus not really a trivial MMIO simple bus. "simple-bus" on > the other hand is just a bus on which multiple devices sit and the > "simple" means no functions are allowed here. > > Combination of both "syscon" and "simple-bus" is abuse of DT for easier > instantiating of Linux device drivers so add a schema to disallow that. > > Unfortunately there are a few old cases of that patterns, so add > exceptions: > > 1. "cznic,turris1x-cpld" and "img,pistachio-cr-periph" are already used > in upstream DTS. > > 2. TI has several DTSI with a child of SCM device (e.g. "ti,am3-scm") > using "syscon" and "simple-bus" but without a dedicated compatible > documented anywhere. Add new compatibles for such cases. > > Additionally, add comments around code enforcing two or three > compatibles: it is similar safeguard detecting incorrect bindings. > > Signed-off-by: Krzysztof Kozlowski > > --- > > Changes in v3: > 1. s/ti,omap5-scm-conf/ti,omap5-sysc-padconf-global/ because it is more > appropriate (specific) > 2. Add comments, why simple-mfd+syscon has dedicated if:then: > > Changes in v2: > 1. Complete patch. I accidentally sent only part of it, built on top of > internal WIP which I forgot to squash. > I received Ack from Rob, but change is significant, so please kindly > re-review. > --- > .../devicetree/bindings/mfd/syscon-common.yaml | 34 ++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > Acked-by: Rob Herring (Arm)