From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756771AbaKTNQc (ORCPT ); Thu, 20 Nov 2014 08:16:32 -0500 Received: from atl4mhob11.myregisteredsite.com ([209.17.115.49]:54519 "EHLO atl4mhob11.myregisteredsite.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756319AbaKTNQb (ORCPT ); Thu, 20 Nov 2014 08:16:31 -0500 X-TCPREMOTEIP: 88.159.208.100 X-Authenticated-UID: mike@milosoftware.com From: Mike Looijmans To: wim@iguana.be Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Looijmans Subject: [PATCH] gpio_wdt: Add "always_running" feature to GPIO watchdog Date: Thu, 20 Nov 2014 14:16:17 +0100 Message-Id: <1416489377-13633-1-git-send-email-mike.looijmans@topic.nl> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On some chips, like the TPS386000, the trigger cannot be disabled and the CPU must keep toggling the line at all times. Add a switch "always_running" to keep toggling the GPIO line regardless of the state of the soft part of the watchdog. The "armed" member keeps track of whether a timeout must also cause a reset. Signed-off-by: Mike Looijmans --- drivers/watchdog/gpio_wdt.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c index 220a9e0..921ee67 100644 --- a/drivers/watchdog/gpio_wdt.c +++ b/drivers/watchdog/gpio_wdt.c @@ -31,6 +31,8 @@ struct gpio_wdt_priv { int gpio; bool active_low; bool state; + bool always_running; + bool armed; unsigned int hw_algo; unsigned int hw_margin; unsigned long last_jiffies; @@ -56,6 +58,7 @@ static int gpio_wdt_start(struct watchdog_device *wdd) gpio_direction_output(priv->gpio, priv->state); priv->last_jiffies = jiffies; mod_timer(&priv->timer, priv->last_jiffies + priv->hw_margin); + priv->armed = true; return 0; } @@ -64,8 +67,11 @@ static int gpio_wdt_stop(struct watchdog_device *wdd) { struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); - mod_timer(&priv->timer, 0); - gpio_wdt_disable(priv); + priv->armed = false; + if (!priv->always_running) { + mod_timer(&priv->timer, 0); + gpio_wdt_disable(priv); + } return 0; } @@ -91,7 +97,7 @@ static void gpio_wdt_hwping(unsigned long data) struct watchdog_device *wdd = (struct watchdog_device *)data; struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); - if (time_after(jiffies, priv->last_jiffies + + if (priv->armed && time_after(jiffies, priv->last_jiffies + msecs_to_jiffies(wdd->timeout * 1000))) { dev_crit(wdd->dev, "Timer expired. System will reboot soon!\n"); return; @@ -197,6 +203,9 @@ static int gpio_wdt_probe(struct platform_device *pdev) /* Use safe value (1/2 of real timeout) */ priv->hw_margin = msecs_to_jiffies(hw_margin / 2); + priv->always_running = of_property_read_bool(pdev->dev.of_node, + "always_running"); + watchdog_set_drvdata(&priv->wdd, priv); priv->wdd.info = &gpio_wdt_ident; @@ -218,6 +227,11 @@ static int gpio_wdt_probe(struct platform_device *pdev) if (ret) watchdog_unregister_device(&priv->wdd); + if (priv->always_running) { + gpio_wdt_start(&priv->wdd); + priv->armed = false; + } + return ret; } -- 1.7.9.5