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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A266EC4332F for ; Fri, 29 Oct 2021 13:04:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B3F3611C1 for ; Fri, 29 Oct 2021 13:04:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231639AbhJ2NG0 (ORCPT ); Fri, 29 Oct 2021 09:06:26 -0400 Received: from mail-ot1-f47.google.com ([209.85.210.47]:34406 "EHLO mail-ot1-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231669AbhJ2NGP (ORCPT ); Fri, 29 Oct 2021 09:06:15 -0400 Received: by mail-ot1-f47.google.com with SMTP id t17-20020a056830083100b00553ced10177so13289081ots.1; Fri, 29 Oct 2021 06:03:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=GUgwMXhwSQTFzdsPOpVylcxzTUCtR44EYeKlhGLEh1U=; b=e9IQStTn6RDzTvcK39e2aIpAVGaa7JP5UQAhQZT/ka2ptkASM/583BpLK5ia/WH5oj kBp/uJVNYreA+BviTU43HYxBsfsUuix74j6wMdLoFF8qkec4h9tzOamZA4o7r07zKCOv ghA4QGhfRevYt1YLfMnXeQ3CnysV+6hMShPjGH8RsVTR7Sfl01wmo5VyFkSWoQ81BUBU iVC6yp5kLysJq0zChqGNqosvu1Y+B78cUEwsm5hNZyw26UgBxI5IO6CKhKtzNxDwiVqG H7M/BtrCQo88qqWvBALEgpUa6ufljJEPYbFvQreJ8fNra0RKTw+t73nTMQzmQSIlRUg/ U1AQ== X-Gm-Message-State: AOAM532Id+7TukJxfzFebjMkTz0sj9PTaV6BKDonq1dRUysBpXQYyw4z eK5RWK2BstNNTay7vVuchPSRLkilLw== X-Google-Smtp-Source: ABdhPJyIltRRP6sAabUPC3/q0WHhW9vBTKyllyRe/hBhVRmRd1KUvkdgCMdJyiyJnXk9pBKD+Sz75Q== X-Received: by 2002:a9d:4a8d:: with SMTP id i13mr8485328otf.180.1635512626347; Fri, 29 Oct 2021 06:03:46 -0700 (PDT) Received: from robh.at.kernel.org (66-90-148-213.dyn.grandenetworks.net. [66.90.148.213]) by smtp.gmail.com with ESMTPSA id 46sm1925284otf.49.2021.10.29.06.03.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Oct 2021 06:03:45 -0700 (PDT) Received: (nullmailer pid 2062293 invoked by uid 1000); Fri, 29 Oct 2021 13:03:44 -0000 Date: Fri, 29 Oct 2021 08:03:44 -0500 From: Rob Herring To: =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Florian Fainelli , Wim Van Sebroeck , Guenter Roeck , bcm-kernel-feedback-list@broadcom.com, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-mips@vger.kernel.org, =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= Subject: Re: [PATCH 3/3] watchdog: bcm7038_wdt: support BCM4908 SoC Message-ID: References: <20211028093059.32535-1-zajec5@gmail.com> <20211028093059.32535-3-zajec5@gmail.com> <9d57d026-19f3-e92d-4c02-d7e8e2c2bc25@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9d57d026-19f3-e92d-4c02-d7e8e2c2bc25@gmail.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, Oct 29, 2021 at 01:39:02PM +0200, Rafał Miłecki wrote: > [Rob: please kindly comment on this] > > On 28.10.2021 18:29, Florian Fainelli wrote: > > On 10/28/21 2:30 AM, Rafał Miłecki wrote: > > > From: Rafał Miłecki > > > > > > Hardware supported by this driver goes back to the old bcm63xx days. It > > > was then reused in BCM7038 and later also in BCM4908. > > > > > > Depending on SoC model registers layout differs a bit. This commit > > > introduces support for per-chipset registers offsets & adds BCM4908 > > > layout. > > > > > > Later on BCM63xx SoCs support should be added too (probably as platform > > > devices due to missing DT). Eventually this driver should replace > > > bcm63xx_wdt.c. > > > > > > Signed-off-by: Rafał Miłecki > > > --- > > > > [snip] > > > > > + > > > +static const u16 bcm7038_wdt_regs_bcm4908[] = { > > > + [BCM63XX_WDT_REG_DEFVAL] = 0x28, > > > + [BCM63XX_WDT_REG_CTL] = 0x2c, > > > + [BCM63XX_WDT_REG_SOFTRESET] = 0x34, > > > > I don't understand what you are doing here and why you are not > > offsetting the "reg" property appropriately when you create your > > bcm4908-wdt Device Tree node such that the base starts at 0, and the > > existing driver becomes usable as-is. This does not make any sense to me > > when it is obviously the simplest way to make the driver "accept" the > > resource being passed. > > I believe that DT binding should cover the whole hardware block and > describe it (here: use proper compatible to allow recognizing block > variant). > > That's because (as far as I understand) DT should be used to describe > hardware as closely as possible. I think it shouldn't be adjusted to > make mapping match Linux's driver implementation. > > > So if: > 1. Hardware block is mapped at 0xff800400 > 2. It has interesting registers at 0xff800428 and 0xff80042c > > I think mapping should use: > reg = <0xff800400 0x3c>; > even if we don't use the first N registers. > > That way, at some point, you can extend Linux (or whatever) driver to > use extra registers without reworking the whole binding. That's why I > think we need to map whole hardware block & handle different registers > layouts in a driver. Yes, that's the correct thing to do. The question is whether you'd need sub nodes for the other functions. Folks tend to want to have sub nodes for convenience which isn't really needed and then requires a DT update ('cause they add nodes as adding drivers). Based on the registers, you really don't need sub nodes here. Rob 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C717DC433F5 for ; Fri, 29 Oct 2021 13:05:33 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 971C160FC4 for ; Fri, 29 Oct 2021 13:05:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 971C160FC4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org 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=Wta/pNCABdi4z/xhS0vb2XP9RzFePabL7QRHTsKvq18=; b=fKp9cEsvEKgMjt T2XifBqws57d6op3joJqm02nAgkx2f2U7TNAJz2GWo4yI98TTaiz7U8+sj2b9n6/MXZmJKdlXoscj Ee4znrAYuCXZXyfNzlsaJTfaAXpOUuVQnyWP0yvgW6wqsVkrpLzby/pJyHsX+pVtQrZbySv1vJAvS 1IFLP+Dy3dSaf4YOXAmwOsQva1+W7bsavlXvHZhejHEpMGwu2Juh3zz9iMoehIe7MTsrDFwt/dS/L 0HxJqrS7OqKsy36vRrOF1R9SoZu4VMs/e8N0M6E/NPF3+hv6ORP+HgrfXNKH5ooPQPzW+iEpE1PqV DzCIbwWJ2ZLUAmqn6nhg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgRY0-00B0Qv-KC; Fri, 29 Oct 2021 13:03:52 +0000 Received: from mail-ot1-f44.google.com ([209.85.210.44]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgRXx-00B0Pn-90 for linux-arm-kernel@lists.infradead.org; Fri, 29 Oct 2021 13:03:50 +0000 Received: by mail-ot1-f44.google.com with SMTP id c8-20020a056830348800b00555b0c12d95so277336otu.5 for ; Fri, 29 Oct 2021 06:03:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=GUgwMXhwSQTFzdsPOpVylcxzTUCtR44EYeKlhGLEh1U=; b=23heDzTRImKbUJpt5aKFNDwuZEV5WVo5yOIqsVpcG1SZ+J+QkAt0Qs4UAc0oHBCiCq xEVsC2vtua0rUwVwofNEzCGOvow9qkf88uB79ybcZxdCcUMMNS7v/4nzLf7WHzPiwrko 9tPUPRZWO1Qn+JKPYVD10AIiZw/aH7ohu03yH/F4p430LyaxWd2lP5VMUyp1Dl94Qh0O R0hEUQfMoRoFOgwMRDwmWwCUS/rkF+Mq1ghHfb29PFPtNuUJCCGOMQNwkYmEdOJZqYJj E9MPvQOumxZyfNtJpGqzUUACgkMvYKd15xdWvGNkE8t12mFwk4Joq7R1Evcz81+DqaOa KS5Q== X-Gm-Message-State: AOAM532VozS7Te/ZC4jZtmbEvLa3ukpwLGC/zgZSzJokggBBBjbpDCRB xaQUmT58QXBXpxT/T3XqWA== X-Google-Smtp-Source: ABdhPJyIltRRP6sAabUPC3/q0WHhW9vBTKyllyRe/hBhVRmRd1KUvkdgCMdJyiyJnXk9pBKD+Sz75Q== X-Received: by 2002:a9d:4a8d:: with SMTP id i13mr8485328otf.180.1635512626347; Fri, 29 Oct 2021 06:03:46 -0700 (PDT) Received: from robh.at.kernel.org (66-90-148-213.dyn.grandenetworks.net. [66.90.148.213]) by smtp.gmail.com with ESMTPSA id 46sm1925284otf.49.2021.10.29.06.03.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Oct 2021 06:03:45 -0700 (PDT) Received: (nullmailer pid 2062293 invoked by uid 1000); Fri, 29 Oct 2021 13:03:44 -0000 Date: Fri, 29 Oct 2021 08:03:44 -0500 From: Rob Herring To: =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Florian Fainelli , Wim Van Sebroeck , Guenter Roeck , bcm-kernel-feedback-list@broadcom.com, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-mips@vger.kernel.org, =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= Subject: Re: [PATCH 3/3] watchdog: bcm7038_wdt: support BCM4908 SoC Message-ID: References: <20211028093059.32535-1-zajec5@gmail.com> <20211028093059.32535-3-zajec5@gmail.com> <9d57d026-19f3-e92d-4c02-d7e8e2c2bc25@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9d57d026-19f3-e92d-4c02-d7e8e2c2bc25@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211029_060349_343463_F6515398 X-CRM114-Status: GOOD ( 31.54 ) 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; 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