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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CB31C433EF for ; Sun, 30 Jan 2022 01:42:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346058AbiA3Bma (ORCPT ); Sat, 29 Jan 2022 20:42:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234657AbiA3Bma (ORCPT ); Sat, 29 Jan 2022 20:42:30 -0500 Received: from mail-oi1-x230.google.com (mail-oi1-x230.google.com [IPv6:2607:f8b0:4864:20::230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66B21C061714; Sat, 29 Jan 2022 17:42:30 -0800 (PST) Received: by mail-oi1-x230.google.com with SMTP id b186so13708604oif.1; Sat, 29 Jan 2022 17:42:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Zr0+itf3l3WQkRTR+PpQ8hwMMp3+UJoNxwrHlZB+5AM=; b=MVhytGO/Z/+1GV3CN8v7GzGwjOcJy0EHTFkRMoPBc9rdwJHVde2xpJCFjKq6xCIpxF 3a4sRklP5Ej7D6DFcun0uh8eahS8KMAiCjVnYTugbliyXLbxhL7AzP1TAFFudjH342Og HaVVkHq0kdwg2dTjQ3O7cwQwLn22lKlvL33JA3hSs3EUfd3vxH5eYUSEPPIO4snJG373 2amhXg4WT17LtbQusIYEvxzGZbbwgo81jIR474ro3mxWRIAPiI0kK0y/O/F2AfPLYXvv n2UMi8cPuSUualnfu8n+ISow+QdBlXoaMC6FAVHQ1ipjOhp38pf6Fz4zR8VyvqEoJqNR Cl4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=Zr0+itf3l3WQkRTR+PpQ8hwMMp3+UJoNxwrHlZB+5AM=; b=uxmmun7ZEvKqoGBuPMxiuvL6B/w8FwpERiRJU6PfUu4YpH5x6UkeaAvvsRqLj5NuuB b34YvDwjRgsgLZ1SymmNCZKLkivXOH4F1uE0B2i8Ear9qXHKtKUhxMFFbciV6jv470WV JBzG/CnAVY8nR9yldFFdPWO+NE5MkvOtK7YJRL0TPbjiSsX4npJWZ/QkHOyVNrxLE6RH +oCNIN2ETH2XE86xtlo8WCoVkE60kentxI7ASh3Zzn2i3lrTdDKtPFVwVWR+d9xYiyFP eWpGNzxFF1MuYUMuVE+ZdKjlY4zz4f6t80ppOnrwPKHPk83n+JnHzS6O6pkwRG86ijfI K4yg== X-Gm-Message-State: AOAM530SdLBO06PkNybJdP9qWUtX5eoUbnKaVEzjhBOqavAxh63DXIHx tX+I8cPtkKwKrK4Q58QxFJY= X-Google-Smtp-Source: ABdhPJyqCaxHevYNt962g3u/kf4yguim55rtn7KFHSVEx3B8AmpEw4NN8zuWTreigrAFMlpRdauYAA== X-Received: by 2002:aca:34c4:: with SMTP id b187mr5223999oia.137.1643506949278; Sat, 29 Jan 2022 17:42:29 -0800 (PST) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id u25sm14151371oth.56.2022.01.29.17.42.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Jan 2022 17:42:28 -0800 (PST) Sender: Guenter Roeck Date: Sat, 29 Jan 2022 17:42:26 -0800 From: Guenter Roeck To: Alistair Francis Cc: linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, shawnguo@kernel.org, wim@linux-watchdog.org, s.hauer@pengutronix.de, robh+dt@kernel.org, linux-imx@nxp.com, devicetree@vger.kernel.org, kernel@pengutronix.de, festevam@gmail.com Subject: Re: [PATCH v3] watchdog: imx2_wdg: Alow ping on suspend Message-ID: <20220130014226.GA1805103@roeck-us.net> References: <20220127104739.312592-1-alistair@alistair23.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220127104739.312592-1-alistair@alistair23.me> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, Jan 27, 2022 at 08:47:39PM +1000, Alistair Francis wrote: > The i.MX watchdog cannot be disabled by software once it has been > enabled. This means that it can't be stopped before suspend. > > For systems that enter low power mode this is fine, as the watchdog will > be automatically stopped by hardware in low power mode. Not all i.MX > platforms support low power mode in the mainline kernel. For example the > i.MX7D does not enter low power mode and so will be rebooted 2 minutes > after entering sleep states. > > This patch introduces a device tree property "fsl,ping-during-suspend" > that can be used to enable ping on suspend support for these systems. > > Signed-off-by: Alistair Francis Reviewed-by: Guenter Roeck > --- > v3: > - Fixup typos in commit message > v2: > - Remove custom property > > drivers/watchdog/imx2_wdt.c | 27 ++++++++++++++++++++------- > 1 file changed, 20 insertions(+), 7 deletions(-) > > diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c > index 51bfb796898b..d0c5d47ddede 100644 > --- a/drivers/watchdog/imx2_wdt.c > +++ b/drivers/watchdog/imx2_wdt.c > @@ -66,6 +66,7 @@ struct imx2_wdt_device { > struct watchdog_device wdog; > bool ext_reset; > bool clk_is_on; > + bool no_ping; > }; > > static bool nowayout = WATCHDOG_NOWAYOUT; > @@ -312,12 +313,18 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) > > wdev->ext_reset = of_property_read_bool(dev->of_node, > "fsl,ext-reset-output"); > + /* > + * The i.MX7D doesn't support low power mode, so we need to ping the watchdog > + * during suspend. > + */ > + wdev->no_ping = !of_device_is_compatible(dev->of_node, "fsl,imx7d-wdt"); > platform_set_drvdata(pdev, wdog); > watchdog_set_drvdata(wdog, wdev); > watchdog_set_nowayout(wdog, nowayout); > watchdog_set_restart_priority(wdog, 128); > watchdog_init_timeout(wdog, timeout, dev); > - watchdog_stop_ping_on_suspend(wdog); > + if (wdev->no_ping) > + watchdog_stop_ping_on_suspend(wdog); > > if (imx2_wdt_is_running(wdev)) { > imx2_wdt_set_timeout(wdog, wdog->timeout); > @@ -366,9 +373,11 @@ static int __maybe_unused imx2_wdt_suspend(struct device *dev) > imx2_wdt_ping(wdog); > } > > - clk_disable_unprepare(wdev->clk); > + if (wdev->no_ping) { > + clk_disable_unprepare(wdev->clk); > > - wdev->clk_is_on = false; > + wdev->clk_is_on = false; > + } > > return 0; > } > @@ -380,11 +389,14 @@ static int __maybe_unused imx2_wdt_resume(struct device *dev) > struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); > int ret; > > - ret = clk_prepare_enable(wdev->clk); > - if (ret) > - return ret; > + if (wdev->no_ping) { > + ret = clk_prepare_enable(wdev->clk); > > - wdev->clk_is_on = true; > + if (ret) > + return ret; > + > + wdev->clk_is_on = true; > + } > > if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) { > /* > @@ -407,6 +419,7 @@ static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend, > > static const struct of_device_id imx2_wdt_dt_ids[] = { > { .compatible = "fsl,imx21-wdt", }, > + { .compatible = "fsl,imx7d-wdt", }, > { /* sentinel */ } > }; > MODULE_DEVICE_TABLE(of, imx2_wdt_dt_ids);