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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3760C4332B for ; Mon, 1 Mar 2021 09:46:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AF4C64E40 for ; Mon, 1 Mar 2021 09:46:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234129AbhCAJqP (ORCPT ); Mon, 1 Mar 2021 04:46:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:49874 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234104AbhCAJpq (ORCPT ); Mon, 1 Mar 2021 04:45:46 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7292E601FE; Mon, 1 Mar 2021 09:45:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614591905; bh=+kVuRMmJFA3NeZk2H02s5z77HTpE92uBU8CQsiK21zs=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=LgMxrB4SnOanZzGeiI5celQIQV1vl6N9orOE5JGd/h5qiYvPQpkj/nr3ASZKtGnBj cHO72uDzTQ0VVPkY6iUDCCPGDK1bEKT7rSXxZQ78tbrROe/sk1Tpxu3Jks8k2kHUBK DWxtB6VmJWbtNoGI/q6E86+bd5PoUb8fLTuiPR6HFVVR6i7W7Yxw7iQC4FnSPmR5Eq ggL8W6JNfRZT1rSlwtSXZnx5K6mVJx0gR5GFJwQ8JN+1Q/ADEyIBqVxA9StpE5o32Q BZKximWs7IaSZjwOMFW5MEdd5sc9Pd7ZycWru39dYcFCby/rhegy1Y6j+FL7t0NaSf 2ksqojn0V+gnw== Received: by mail-ot1-f53.google.com with SMTP id h22so15858265otr.6; Mon, 01 Mar 2021 01:45:05 -0800 (PST) X-Gm-Message-State: AOAM532E0dezNLa9zQCM9HAACx11SdCp86sH+6zjVXxmlTjL4cKrGQgJ mQbO4kNc6BdcDxj7mRTplq1SHP//g8FweEbYzig= X-Google-Smtp-Source: ABdhPJxqvjLn6W5eFEMQcS7P3mahZ0tKYSfy6AiKZY4imuyX6VCPZwA1wKdoKFwqWARtFs6NqMB/I+f4BREMDuCxYOU= X-Received: by 2002:a9d:6b8b:: with SMTP id b11mr12801036otq.210.1614591904691; Mon, 01 Mar 2021 01:45:04 -0800 (PST) MIME-Version: 1.0 References: <20210226141411.2517368-1-linux@rasmusvillemoes.dk> <2208f466-e509-6bbe-0358-34effb965610@roeck-us.net> <285d739a-b343-c411-5461-0fe1f44177a5@rasmusvillemoes.dk> In-Reply-To: <285d739a-b343-c411-5461-0fe1f44177a5@rasmusvillemoes.dk> From: Arnd Bergmann Date: Mon, 1 Mar 2021 10:44:48 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 0/2] add ripple counter dt binding and driver To: Rasmus Villemoes Cc: Guenter Roeck , Greg Kroah-Hartman , Rob Herring , DTML , "linux-kernel@vger.kernel.org" , Arnd Bergmann , linux-clk , Wim Van Sebroeck , "linux-watchdog@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org On Mon, Mar 1, 2021 at 9:34 AM Rasmus Villemoes wrote: > On 26/02/2021 20.53, Guenter Roeck wrote: > > > > Sorry, I am missing something. If the watchdog is controlled by the clock, > > it is a consumer of that clock. > > But that's just it, the watchdog chip is _not_ a consumer of the clock - > I don't think I've ever seen a gpio_wdt that is not internally clocked, > but even if they exist, that's not the case for this board. > > What else does "consumer" mean ? And why > > not just add optional clock support to the gpio_wdt driver ? > > Because, the consumer is a piece of electronics sitting _between_ the > watchdog chip's reset output and the SOCs reset pin, namely the ripple > counter that implements a 64 ms delay from the watchdog fires till the > actual reset. (The watchdog's reset is also routed directly to an > interrupt; so software gets a 64 ms warning that a hard reset is imminent). I think it's a question of how you look at what the gpio_wdt device is. While physical gpio chip is not a consumer of the clock, I agree with Guenter that the conceptual device is: The functionality of the watchdog in this case is provided by the combination of the external chip with the ripple counter. I think it is therefore appropriate to have the gpio_wdt and the driver refer to the clock as part of the watchdog. Arnd