--- linux-2.6.26.5/drivers/watchdog/mpc83xx_wdt.c	2008-09-08 13:40:20.000000000 -0400
+++ linux-2.6.26.5-rb600/drivers/watchdog/mpc83xx_wdt.c	2008-09-20 23:51:05.040468827 -0400
@@ -24,6 +24,13 @@
 #include <linux/watchdog.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>
+#include <asm/of_device.h>
+
+#define RESET_CAUSE_IOCTL _IO('R', 1)
+
+#define RESET_COLD	0
+#define RESET_WARM	1
+#define RESET_WATCHDOG	2
 
 struct mpc83xx_wdt {
 	__be32 res0;
@@ -39,6 +46,8 @@ struct mpc83xx_wdt {
 };
 
 static struct mpc83xx_wdt __iomem *wd_base;
+static unsigned __iomem *rsr = NULL;
+#define RSR_WDT_RESET 0x8
 
 static u16 timeout = 0xffff;
 module_param(timeout, ushort, 0);
@@ -48,6 +57,9 @@ static int reset = 1;
 module_param(reset, bool, 0);
 MODULE_PARM_DESC(reset, "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
 
+static void mpc83xx_timer(unsigned long data);
+static DEFINE_TIMER(autotimer, mpc83xx_timer, 0, 0);
+
 /*
  * We always prescale, but if someone really doesn't want to they can set this
  * to 0
@@ -57,6 +69,7 @@ static unsigned int timeout_sec;
 
 static unsigned long wdt_is_open;
 static DEFINE_SPINLOCK(wdt_spinlock);
+static int expect_close;
 
 static void mpc83xx_wdt_keepalive(void)
 {
@@ -67,11 +80,29 @@ static void mpc83xx_wdt_keepalive(void)
 	spin_unlock(&wdt_spinlock);
 }
 
+static void mpc83xx_timer(unsigned long data)
+{
+	mpc83xx_wdt_keepalive();
+	mod_timer(&autotimer, jiffies + HZ);
+}
+
 static ssize_t mpc83xx_wdt_write(struct file *file, const char __user *buf,
 				 size_t count, loff_t *ppos)
 {
-	if (count)
+	/* check for a magic close character */
+	if (count) {
+		size_t i;
+
+		expect_close = 0;
+		for (i = 0; i < count; ++i) {
+			char c;
+			if (get_user(c, buf + i))
+				return -EFAULT;
+			if (c == 'V')
+				expect_close = 1;
+		}
 		mpc83xx_wdt_keepalive();
+	}
 	return count;
 }
 
@@ -81,6 +112,8 @@ static int mpc83xx_wdt_open(struct inode
 	if (test_and_set_bit(0, &wdt_is_open))
 		return -EBUSY;
 
+	del_timer(&autotimer);
+
 	/* Once we start the watchdog we can't stop it */
 	__module_get(THIS_MODULE);
 
@@ -99,9 +132,13 @@ static int mpc83xx_wdt_open(struct inode
 
 static int mpc83xx_wdt_release(struct inode *inode, struct file *file)
 {
+	if (expect_close)
+		mod_timer(&autotimer, jiffies + HZ);
+	else
 	printk(KERN_CRIT "Unexpected close, not stopping watchdog!\n");
 	mpc83xx_wdt_keepalive();
 	clear_bit(0, &wdt_is_open);
+	expect_close = 0;
 	return 0;
 }
 
@@ -117,6 +154,13 @@ static int mpc83xx_wdt_ioctl(struct inod
 	};
 
 	switch (cmd) {
+	case RESET_CAUSE_IOCTL:
+		if (rsr && (in_be32(rsr) & RSR_WDT_RESET)) {
+			out_be32(rsr, in_be32(rsr) | RSR_WDT_RESET);
+			return RESET_WATCHDOG;
+		}
+		else
+			return RESET_WARM;
 	case WDIOC_GETSUPPORT:
 		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 	case WDIOC_GETSTATUS:
@@ -147,12 +191,31 @@ static struct miscdevice mpc83xx_wdt_mis
 	.fops	= &mpc83xx_wdt_fops,
 };
 
+static void clean_rsr(void) {
+	if (rsr) {
+		iounmap(rsr);
+		rsr = NULL;
+	}
+}
+
 static int __devinit mpc83xx_wdt_probe(struct platform_device *dev)
 {
 	struct resource *r;
+	struct device_node *soc;
 	int ret;
 	unsigned int *freq = dev->dev.platform_data;
 
+	/* get reset status register */
+	soc = of_find_node_by_type(NULL, "soc");
+	if (soc) {
+		unsigned int size;
+		static phys_addr_t immrbase = -1;
+		const void *prop = of_get_property(soc, "reg", &size);
+		immrbase = of_translate_address(soc, prop);
+		rsr = (unsigned *) ioremap_nocache(immrbase + 0x910, 0x4);
+		of_node_put(soc);
+	}
+
 	/* get a pointer to the register memory */
 	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
 
@@ -189,6 +252,7 @@ static int __devinit mpc83xx_wdt_probe(s
 
 err_unmap:
 	iounmap(wd_base);
+	clean_rsr();
 err_out:
 	return ret;
 }
@@ -197,6 +261,7 @@ static int __devexit mpc83xx_wdt_remove(
 {
 	misc_deregister(&mpc83xx_wdt_miscdev);
 	iounmap(wd_base);
+	clean_rsr();
 
 	return 0;
 }