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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 AD856C4727D for ; Thu, 24 Sep 2020 16:59:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 326DE2311A for ; Thu, 24 Sep 2020 16:59:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="opeaTU8h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728461AbgIXQ7v (ORCPT ); Thu, 24 Sep 2020 12:59:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727010AbgIXQ7u (ORCPT ); Thu, 24 Sep 2020 12:59:50 -0400 Received: from mail-ej1-x642.google.com (mail-ej1-x642.google.com [IPv6:2a00:1450:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4470C0613CE; Thu, 24 Sep 2020 09:59:50 -0700 (PDT) Received: by mail-ej1-x642.google.com with SMTP id e23so5514813eja.3; Thu, 24 Sep 2020 09:59:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+1TNRMBksp0ZgyPa79AqDX/KsIzG5AY4VLIzrVQYq/s=; b=opeaTU8hCe8259r7Jy3Bwmk8TeN10WvSFkY4pGk0h2k+pVLxnmrcR7anMAVBEGfW3l zAIVq3cj1CvSDhR2B7YEYynA9wE+GFw6xsjZiQ9jQJtyGPfPOUr+PWnu0AscIM89h7gb K8gYXq6GWR9Sxjp7fd7wmlnIMPYkZo4gqskb+D+WKGQA9u3MbiZ0excKw+IczPRks99X e+VMH86xPl1LV+DzCOIva90my3DNxiyFvdqhieuO7igLDCsQr4qQWFISXBhJAUThcP/a Bfbc5EdrmmuP6PwTArek6/4nJzq5g9OIoqIBtq9x0BGXGRgc3kdTY1ce5q3pp5Tsp7aI agPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+1TNRMBksp0ZgyPa79AqDX/KsIzG5AY4VLIzrVQYq/s=; b=MkN/lZb707HRnlfL2dYgtNq4pn7b0FldPI8Ki2VWSABYotiRV8OmQ0XoMr1vBCxWLo MB4BGKPK22u//LB353P4Q+hWUl5xtH3QM3yYzcnDeu3JVFtDXDExR/fLmDTLjdQdzC+k p5TzJVbgGI11Z2SluQFdNws8GUSlnH5XFy3gob7LaJyboPaWb1H001LEsQ35AprxKn2y SsGjFSqT53EElem1VQY/zjoj0jzmPmyoG8Yhl34UUJuQVdg1tF6CJrjfMi+qPwANjXJl 4GUkGWAOfZK29s1FDmJ5T37vuxG4hA+eX6fODr8uhTyBfFrQsJASWrDpTte1+BLnJwUc TurQ== X-Gm-Message-State: AOAM532rJ7MM/oOl0YBm2ppHbk4n7GoqSFXoYuG3nMmUvEWXUFrtwFOh R0Tp4VGYhVVaQr6i7tmW7+C6KezvSto066rprpk= X-Google-Smtp-Source: ABdhPJyvmZQkFTapW8MqkbWB0p7BH9gIdf2jN0mm+srARTEERotirnhHqtVSSegNQTH+02fWXv/y2S9UoAa79UKY82E= X-Received: by 2002:a17:907:9ed:: with SMTP id ce13mr859425ejc.180.1600966789263; Thu, 24 Sep 2020 09:59:49 -0700 (PDT) MIME-Version: 1.0 References: <20200921054821.26071-1-qiang.zhao@nxp.com> <20200923094449.GP9675@piout.net> <20200924070456.rovgp6n5q25s53vc@pengutronix.de> <20200924074715.GT9675@piout.net> In-Reply-To: <20200924074715.GT9675@piout.net> From: Bruno Thomsen Date: Thu, 24 Sep 2020 18:59:33 +0200 Message-ID: Subject: Re: [Patch v2 1/3] dt-bindings: rtc: pcf2127: Add bindings for nxp,pcf2127 To: Alexandre Belloni Cc: Qiang Zhao , =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= , Wim Van Sebroeck , Guenter Roeck , "linux-watchdog@vger.kernel.org" , "a.zummo@towertech.it" , "robh+dt@kernel.org" , "linux-rtc@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kernel@pengutronix.de" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Den tor. 24. sep. 2020 kl. 09.47 skrev Alexandre Belloni : > > Hi, > > On 24/09/2020 07:23:18+0000, Qiang Zhao wrote: > > > > Yes, you are right, There is not a fundamental solution. > > > > However it somewhat avoid this situation at least. > > > > > > > > And if without this issue, > > > > is it correct to register a rtc device as watchdog no matter it is used as > > > watchdog on the board? > > > > Every time Linux are booted up, watchdog device should be configured to the > > > right one manually. > > > > So the patch are useful, even though it is not for the issue. > > > > > > > > What should we do to really resolve this issue? > > > > > > I still think we need a kernel solution here. I would expect that most assembled > > > pcf2127 chips are unable to act as a watchdog (i.e. don't have the RST output > > > connected to something that resets the machine). > > > > > > So my favoured solution would be a positive property like: > > > > > > has-watchdog; > > > > > > or something similar. In my eyes this is definitely something we want to specify > > > in the device tree because it is a relevant hardware property. > > > I consider it a bug to give a watchdog device to userspace that isn't functional. > > > > > > Best regards > > > Uwe > > > > I strongly agree with you! It should be positive property. > > However, we couldn't identify which board are using pcf2127 as watchdog, > > So we are unable to modify the boards' dts to correct (watchdog or not) in this patchset. > > > > I noticed that only LS series platforms and imx6 have pcf2127 node, as far as I know, the LS platforms don't use it as watchdog, > > But I am not sure about imx6 > > > > I don't think there is any user upstream and it is recent engouh that we > can probably make that a positive property. > > Bruno, is it ok for you? you are the only know user of the feature. Hi This seems like an okay solution to me. I have a patch series on the way with a new product dts[1] that is using the watchdog feature in the pcf2127 chip. I know that the watchdog feature is used by other products with out-of-tree dts, but I will make sure to give them a heads up. /Bruno [1] https://lore.kernel.org/linux-arm-kernel/20200923154024.11417-2-bruno.thomsen@gmail.com/