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 3FBE3C433FE for ; Mon, 17 Jan 2022 17:08:07 +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=cJNYd6h3DQg+dBnMAdoMKmi7eKGSlL6Xrrb7ce7zqIs=; b=Dtgntws7WD7noJ szHDghcRFCh2c8s5QTLPF7ELeKGDxd7ZYwp0Csbjg9iyH1ANZ0+mJjXcfClFJIJF6gfGrwJFm81vw 4ndBvbBv7GmCSkG9j3RWuqwXJ3ZXzWvgNoQOio7vBn14+89pVZF7TEBIEw/vYAlMeX3N6WV2rvcwX TW6e1SE1OU0wdDxlZ1ZBlCuYanFjVl0Dt72Br42FtO1Fx1wZ5fBlxo1gqhxXj8IgPXxmnkJEF19yG 7LIZoS036U2DZhHJ8VUjZM9mo4U7fU+KntxR97stLw29Pzy6AUtp+dt3IN9ctuR/ekDPjm125LjYt 8mWs2NQrEc0skTF/oEcQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9VSY-00FjMd-V6; Mon, 17 Jan 2022 17:06:24 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9VOp-00Fh4l-6Z for linux-arm-kernel@lists.infradead.org; Mon, 17 Jan 2022 17:02:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 01A756D; Mon, 17 Jan 2022 09:02:30 -0800 (PST) Received: from C02TD0UTHF1T.local (unknown [10.57.38.30]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B57253F766; Mon, 17 Jan 2022 09:02:28 -0800 (PST) Date: Mon, 17 Jan 2022 17:02:25 +0000 From: Mark Rutland To: Guenter Roeck Cc: Boris Lysov , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: Missing ARM TWD Watchdog driver? Message-ID: <20220117170225.GB94025@C02TD0UTHF1T.local> References: <20220117190112.2b2c2f53@pc> <60dceae6-5c7c-9f2d-9fcb-5e849f1d8ce5@roeck-us.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <60dceae6-5c7c-9f2d-9fcb-5e849f1d8ce5@roeck-us.net> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220117_090231_344494_FB384071 X-CRM114-Status: GOOD ( 17.01 ) 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 On Mon, Jan 17, 2022 at 08:34:57AM -0800, Guenter Roeck wrote: > On 1/17/22 8:01 AM, Boris Lysov wrote: > > Hello everyone, > > > > I stumbled upon the ARM TWD Watchdog driver which seems to be missing (or I'm > > just blind). > > > > As per commit a33f5c380c4bd3fa5278d690421b72052456d9fe ("Merge tag > > 'xfs-5.17-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux"), multiple > > device trees declare usage of arm-twd: > > > > arch/arm/boot/dts/arm-realview-eb-mp.dtsi > > arch/arm/boot/dts/arm-realview-pb11mp.dts > > arch/arm/boot/dts/arm-realview-pbx-a9.dts > > arch/arm/boot/dts/bcm5301x.dtsi > > arch/arm/boot/dts/bcm63138.dtsi > > arch/arm/boot/dts/bcm-hr2.dtsi > > arch/arm/boot/dts/bcm-nsp.dtsi > > arch/arm/boot/dts/berlin2cd.dtsi > > arch/arm/boot/dts/highbank.dts > > arch/arm/boot/dts/mmp3.dtsi > > arch/arm/boot/dts/owl-s500.dtsi > > arch/arm/boot/dts/spear13xx.dtsi > > arch/arm/boot/dts/ste-dbx5x0.dtsi > > arch/arm/boot/dts/vexpress-v2p-ca5s.dts > > arch/arm/boot/dts/vexpress-v2p-ca9.dts > > > > and it is documented in > > Documentation/devicetree/bindings/watchdog/arm,twd-wdt.yaml > > > > However I could not find the driver itself. I tried running case-insensitive > > grep and ripgrep to no avail. Does this driver actually exist? Is it gone? > > > > I may be missing it, but I do not see any evidence that it ever existed. Likewise, AFAICT we added the binding but never the driver. Looking at the git history, that schema was introduced in commit: 50e02e9a030a9ae3 ("dt-bindings: timer: arm,twd: Convert to json-schema") ... and replaced Documentation/devicetree/bindings/timer/arm,twd.txt Per: $ git log --follow Documentation/devicetree/bindings/timer/arm,twd.txt That was introduced alongside a driver in commit: d8e0364364d333fe ("ARM: smp_twd: add device tree support") ... which only introduced a driver for the timer, and not the watchdog, as the commit message notes. Thanks. Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel