watchdog: bcm47xx_wdt.c: add restart handler support

Just like in case of other watchdog drivers, use the new kernel core
API to provide restart support.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/bcm47xx_wdt.c b/drivers/watchdog/bcm47xx_wdt.c
index 9816485..b28a072 100644
--- a/drivers/watchdog/bcm47xx_wdt.c
+++ b/drivers/watchdog/bcm47xx_wdt.c
@@ -169,6 +169,17 @@
 	return NOTIFY_DONE;
 }
 
+static int bcm47xx_wdt_restart(struct notifier_block *this, unsigned long mode,
+			       void *cmd)
+{
+	struct bcm47xx_wdt *wdt;
+
+	wdt = container_of(this, struct bcm47xx_wdt, restart_handler);
+	wdt->timer_set(wdt, 1);
+
+	return NOTIFY_DONE;
+}
+
 static struct watchdog_ops bcm47xx_wdt_soft_ops = {
 	.owner		= THIS_MODULE,
 	.start		= bcm47xx_wdt_soft_start,
@@ -209,15 +220,23 @@
 	if (ret)
 		goto err_timer;
 
-	ret = watchdog_register_device(&wdt->wdd);
+	wdt->restart_handler.notifier_call = &bcm47xx_wdt_restart;
+	wdt->restart_handler.priority = 64;
+	ret = register_restart_handler(&wdt->restart_handler);
 	if (ret)
 		goto err_notifier;
 
+	ret = watchdog_register_device(&wdt->wdd);
+	if (ret)
+		goto err_handler;
+
 	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
 		timeout, nowayout ? ", nowayout" : "",
 		soft ? ", Software Timer" : "");
 	return 0;
 
+err_handler:
+	unregister_restart_handler(&wdt->restart_handler);
 err_notifier:
 	unregister_reboot_notifier(&wdt->notifier);
 err_timer:
diff --git a/include/linux/bcm47xx_wdt.h b/include/linux/bcm47xx_wdt.h
index b708786..5582c21 100644
--- a/include/linux/bcm47xx_wdt.h
+++ b/include/linux/bcm47xx_wdt.h
@@ -16,6 +16,7 @@
 
 	struct watchdog_device wdd;
 	struct notifier_block notifier;
+	struct notifier_block restart_handler;
 
 	struct timer_list soft_timer;
 	atomic_t soft_ticks;