iTCO_wdt: fix TCO V1 timeout values and limits

For TCO V1 devices the programmed timeout was twice too long
because the fact that the TCO V1 timer needs to count down
twice before triggering the watchdog, wasn't accounted for.
Also the timeout values in the module description and error
message were clarified. And the _STS registers are 16 bit
instead of 8 bit.

Signed-off-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Simon Kagstrom <simon.kagstrom@netinsight.se>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 20 insertions, 9 deletions

diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index 8da8860..69de871 100644
--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -40,7 +40,7 @@
 
 /* Module and version information */
 #define DRV_NAME	"iTCO_wdt"
-#define DRV_VERSION	"1.05"
+#define DRV_VERSION	"1.06"
 #define PFX		DRV_NAME ": "
 
 /* Includes */
@@ -391,8 +391,8 @@ static struct platform_device *iTCO_wdt_platform_device;
 #define WATCHDOG_HEARTBEAT 30	/* 30 sec default heartbeat */
 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
 module_param(heartbeat, int, 0);
-MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
-	"(2<heartbeat<39 (TCO v1) or 613 (TCO v2), default="
+MODULE_PARM_DESC(heartbeat, "Watchdog timeout in seconds. "
+	"5..76 (TCO v1) or 3..614 (TCO v2), default="
 				__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 
 static int nowayout = WATCHDOG_NOWAYOUT;
@@ -523,8 +523,13 @@ static int iTCO_wdt_keepalive(void)
 	/* Reload the timer by writing to the TCO Timer Counter register */
 	if (iTCO_wdt_private.iTCO_version == 2)
 		outw(0x01, TCO_RLD);
-	else if (iTCO_wdt_private.iTCO_version == 1)
+	else if (iTCO_wdt_private.iTCO_version == 1) {
+		/* Reset the timeout status bit so that the timer
+		 * needs to count down twice again before rebooting */
+		outw(0x0008, TCO1_STS);	/* write 1 to clear bit */
+
 		outb(0x01, TCO_RLD);
+	}
 
 	spin_unlock(&iTCO_wdt_private.io_lock);
 	return 0;
@@ -537,6 +542,11 @@ static int iTCO_wdt_set_heartbeat(int t)
 	unsigned int tmrval;
 
 	tmrval = seconds_to_ticks(t);
+
+	/* For TCO v1 the timer counts down twice before rebooting */
+	if (iTCO_wdt_private.iTCO_version == 1)
+		tmrval /= 2;
+
 	/* from the specs: */
 	/* "Values of 0h-3h are ignored and should not be attempted" */
 	if (tmrval < 0x04)
@@ -593,6 +603,8 @@ static int iTCO_wdt_get_timeleft(int *time_left)
 		spin_lock(&iTCO_wdt_private.io_lock);
 		val8 = inb(TCO_RLD);
 		val8 &= 0x3f;
+		if (!(inw(TCO1_STS) & 0x0008))
+			val8 += (inb(TCOv1_TMR) & 0x3f);
 		spin_unlock(&iTCO_wdt_private.io_lock);
 
 		*time_left = (val8 * 6) / 10;
@@ -832,9 +844,9 @@ static int __devinit iTCO_wdt_init(struct pci_dev *pdev,
 			TCOBASE);
 
 	/* Clear out the (probably old) status */
-	outb(8, TCO1_STS);	/* Clear the Time Out Status bit */
-	outb(2, TCO2_STS);	/* Clear SECOND_TO_STS bit */
-	outb(4, TCO2_STS);	/* Clear BOOT_STS bit */
+	outw(0x0008, TCO1_STS);	/* Clear the Time Out Status bit */
+	outw(0x0002, TCO2_STS);	/* Clear SECOND_TO_STS bit */
+	outw(0x0004, TCO2_STS);	/* Clear BOOT_STS bit */
 
 	/* Make sure the watchdog is not running */
 	iTCO_wdt_stop();
@@ -844,8 +856,7 @@ static int __devinit iTCO_wdt_init(struct pci_dev *pdev,
 	if (iTCO_wdt_set_heartbeat(heartbeat)) {
 		iTCO_wdt_set_heartbeat(WATCHDOG_HEARTBEAT);
 		printk(KERN_INFO PFX
-			"heartbeat value must be 2 < heartbeat < 39 (TCO v1) "
-				"or 613 (TCO v2), using %d\n", heartbeat);
+			"timeout value out of range, using %d\n", heartbeat);
 	}
 
 	ret = misc_register(&iTCO_wdt_miscdev);