diff options
| author | Mike Looijmans <mike.looijmans@topic.nl> | 2015-01-14 07:28:29 +0100 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2015-02-17 21:33:22 +0100 |
| commit | ba804a9510df555c42c2be6c340960879afe39d2 (patch) | |
| tree | 39ddf8b02b9004c5f9124c5ebd2eae23e149344c /drivers | |
| parent | 396f163ceba3ac2829e3076764efcfb10797293c (diff) | |
| download | linux-rpi3-ba804a9510df555c42c2be6c340960879afe39d2.tar.gz linux-rpi3-ba804a9510df555c42c2be6c340960879afe39d2.tar.bz2 linux-rpi3-ba804a9510df555c42c2be6c340960879afe39d2.zip | |
watchdog: gpio_wdt: Add "always_running" feature to GPIO watchdog
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 <mike.looijmans@topic.nl>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/watchdog/gpio_wdt.c | 37 |
1 files changed, 29 insertions, 8 deletions
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; } |