diff -ur linux-3.7.7/drivers/watchdog/mpc8xxx_wdt.c linux/drivers/watchdog/mpc8xxx_wdt.c
--- linux-3.7.7/drivers/watchdog/mpc8xxx_wdt.c	2013-02-11 18:05:09.000000000 +0100
+++ linux/drivers/watchdog/mpc8xxx_wdt.c	2013-02-13 15:55:22.000000000 +0100
@@ -52,10 +52,17 @@
 static struct mpc8xxx_wdt __iomem *wd_base;
 static int mpc8xxx_wdt_init_late(void);
 
+#define WD_TIMO 10			/* Default heartbeat = 10 seconds */
+
+static int heartbeat = WD_TIMO;
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat,
+	"Watchdog SW heartbeat in seconds. (0 < heartbeat < 65536s, default="
+				__MODULE_STRING(WD_TIMO) "s)");
 static u16 timeout = 0xffff;
 module_param(timeout, ushort, 0);
 MODULE_PARM_DESC(timeout,
-	"Watchdog timeout in ticks. (0<timeout<65536, default=65535)");
+	"Watchdog HW timeout in ticks. (0<timeout<65536, default=65535)");
 
 static bool reset = 1;
 module_param(reset, bool, 0);
@@ -74,8 +81,10 @@
 static int prescale = 1;
 static unsigned int timeout_sec;
 
+static int wdt_auto = 1;
 static unsigned long wdt_is_open;
 static DEFINE_SPINLOCK(wdt_spinlock);
+static unsigned long wdt_last_ping;
 
 static void mpc8xxx_wdt_keepalive(void)
 {
@@ -91,9 +100,20 @@
 
 static void mpc8xxx_wdt_timer_ping(unsigned long arg)
 {
-	mpc8xxx_wdt_keepalive();
-	/* We're pinging it twice faster than needed, just to be sure. */
-	mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2);
+	if (wdt_auto)
+		wdt_last_ping = jiffies;
+
+	if (jiffies - wdt_last_ping <= heartbeat * HZ) {
+		mpc8xxx_wdt_keepalive();
+		/* We're pinging it twice faster than needed, to be sure. */
+		mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2);
+	}
+}
+
+static void mpc8xxx_wdt_sw_keepalive(void)
+{
+	wdt_last_ping = jiffies;
+	mpc8xxx_wdt_timer_ping(0);
 }
 
 static void mpc8xxx_wdt_pr_warn(const char *msg)
@@ -106,7 +126,7 @@
 				 size_t count, loff_t *ppos)
 {
 	if (count)
-		mpc8xxx_wdt_keepalive();
+		mpc8xxx_wdt_sw_keepalive();
 	return count;
 }
 
@@ -130,7 +150,7 @@
 
 	out_be32(&wd_base->swcrr, tmp);
 
-	del_timer_sync(&wdt_timer);
+	wdt_auto = 0;
 
 	return nonseekable_open(inode, file);
 }
@@ -138,7 +158,8 @@
 static int mpc8xxx_wdt_release(struct inode *inode, struct file *file)
 {
 	if (!nowayout)
-		mpc8xxx_wdt_timer_ping(0);
+		wdt_auto = 1;
+
 	else
 		mpc8xxx_wdt_pr_warn("watchdog closed");
 	clear_bit(0, &wdt_is_open);
@@ -163,10 +184,12 @@
 	case WDIOC_GETBOOTSTATUS:
 		return put_user(0, p);
 	case WDIOC_KEEPALIVE:
-		mpc8xxx_wdt_keepalive();
+		mpc8xxx_wdt_sw_keepalive();
 		return 0;
 	case WDIOC_GETTIMEOUT:
-		return put_user(timeout_sec, p);
+		return put_user(heartbeat, p);
+	case WDIOC_SETTIMEOUT:
+		return get_user(heartbeat, p);
 	default:
 		return -ENOTTY;
 	}
@@ -215,6 +238,8 @@
 		ret = -ENOSYS;
 		goto err_unmap;
 	}
+	if (enabled)
+		timeout = in_be32(&wd_base->swcrr) >> 16;
 
 	/* Calculate the timeout in seconds */
 	if (prescale)
@@ -273,6 +298,7 @@
 		.compatible = "fsl,mpc823-wdt",
 		.data = &(struct mpc8xxx_wdt_type) {
 			.prescaler = 0x800,
+			.hw_enabled = true,
 		},
 	},
 	{},