diff options
| -rw-r--r-- | Documentation/devicetree/bindings/watchdog/gpio-wdt.txt | 5 | ||||
| -rw-r--r-- | drivers/watchdog/gpio_wdt.c | 37 |
2 files changed, 34 insertions, 8 deletions
diff --git a/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt index 37afec194949..198794963786 100644 --- a/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt +++ b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt @@ -13,6 +13,11 @@ Required Properties: by the GPIO flags. - hw_margin_ms: Maximum time to reset watchdog circuit (milliseconds). +Optional Properties: +- always-running: If the watchdog timer cannot be disabled, add this flag to + have the driver keep toggling the signal without a client. It will only cease + to toggle the signal when the device is open and the timeout elapsed. + Example: watchdog: watchdog { /* ADM706 */ diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c index bbdb19b45332..cbc313d37c59 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; @@ -48,14 +50,20 @@ static void gpio_wdt_disable(struct gpio_wdt_priv *priv) gpio_direction_input(priv->gpio); } -static int gpio_wdt_start(struct watchdog_device *wdd) +static void gpio_wdt_start_impl(struct gpio_wdt_priv *priv) { - struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); - priv->state = priv->active_low; gpio_direction_output(priv->gpio, priv->state); priv->last_jiffies = jiffies; mod_timer(&priv->timer, priv->last_jiffies + priv->hw_margin); +} + +static int gpio_wdt_start(struct watchdog_device *wdd) +{ + struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); + + gpio_wdt_start_impl(priv); + priv->armed = true; return 0; } @@ -64,8 +72,11 @@ 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; } @@ -91,8 +102,8 @@ 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 + - msecs_to_jiffies(wdd->timeout * 1000))) { + 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 +208,9 @@ 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; @@ -216,8 +230,15 @@ static int gpio_wdt_probe(struct platform_device *pdev) priv->notifier.notifier_call = gpio_wdt_notify_sys; ret = register_reboot_notifier(&priv->notifier); if (ret) - watchdog_unregister_device(&priv->wdd); + goto error_unregister; + if (priv->always_running) + gpio_wdt_start_impl(priv); + + return 0; + +error_unregister: + watchdog_unregister_device(&priv->wdd); return ret; } |