watchdog: softdog: implement pretimeout support

Give devices which do not have hardware support for pretimeout at least a
software version of it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c
index 1ae469e94045a827cc0b054d07325c576b566d05..c7bdc986dca1c249c2b61ad902504cdd1df4fb2d 100644 (file)
--- a/drivers/watchdog/softdog.c
+++ b/drivers/watchdog/softdog.c
@@ -72,10 +72,27 @@ static void softdog_fire(unsigned long data)
 static struct timer_list softdog_ticktock =
                TIMER_INITIALIZER(softdog_fire, 0, 0);
 
+static struct watchdog_device softdog_dev;
+
+static void softdog_pretimeout(unsigned long data)
+{
+       watchdog_notify_pretimeout(&softdog_dev);
+}
+
+static struct timer_list softdog_preticktock =
+               TIMER_INITIALIZER(softdog_pretimeout, 0, 0);
+
 static int softdog_ping(struct watchdog_device *w)
 {
        if (!mod_timer(&softdog_ticktock, jiffies + (w->timeout * HZ)))
                __module_get(THIS_MODULE);
+
+       if (w->pretimeout)
+               mod_timer(&softdog_preticktock, jiffies +
+                         (w->timeout - w->pretimeout) * HZ);
+       else
+               del_timer(&softdog_preticktock);
+
        return 0;
 }
 
@@ -84,12 +101,15 @@ static int softdog_stop(struct watchdog_device *w)
        if (del_timer(&softdog_ticktock))
                module_put(THIS_MODULE);
 
+       del_timer(&softdog_preticktock);
+
        return 0;
 }
 
 static struct watchdog_info softdog_info = {
        .identity = "Software Watchdog",
-       .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+       .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
+                  WDIOF_PRETIMEOUT,
 };
 
 static const struct watchdog_ops softdog_ops = {