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path: root/drivers/watchdog/imx2_wdt.c
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Diffstat (limited to 'drivers/watchdog/imx2_wdt.c')
-rw-r--r--drivers/watchdog/imx2_wdt.c40
1 files changed, 31 insertions, 9 deletions
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index d6add516a7a7..5142bbabe027 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -52,6 +52,8 @@
 #define IMX2_WDT_WRSR		0x04		/* Reset Status Register */
 #define IMX2_WDT_WRSR_TOUT	(1 << 1)	/* -> Reset due to Timeout */
 
+#define IMX2_WDT_WMCR		0x08		/* Misc Register */
+
 #define IMX2_WDT_MAX_TIME	128
 #define IMX2_WDT_DEFAULT_TIME	60		/* in seconds */
 
@@ -274,6 +276,13 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 
 	imx2_wdt_ping_if_active(wdog);
 
+	/*
+	 * Disable the watchdog power down counter at boot. Otherwise the power
+	 * down counter will pull down the #WDOG interrupt line for one clock
+	 * cycle.
+	 */
+	regmap_write(wdev->regmap, IMX2_WDT_WMCR, 0);
+
 	ret = watchdog_register_device(wdog);
 	if (ret) {
 		dev_err(&pdev->dev, "cannot register watchdog device\n");
@@ -327,18 +336,21 @@ static void imx2_wdt_shutdown(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM_SLEEP
-/* Disable watchdog if it is active during suspend */
+/* Disable watchdog if it is active or non-active but still running */
 static int imx2_wdt_suspend(struct device *dev)
 {
 	struct watchdog_device *wdog = dev_get_drvdata(dev);
 	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
 
-	imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
-	imx2_wdt_ping(wdog);
+	/* The watchdog IP block is running */
+	if (imx2_wdt_is_running(wdev)) {
+		imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
+		imx2_wdt_ping(wdog);
 
-	/* Watchdog has been stopped but IP block is still running */
-	if (!watchdog_active(wdog) && imx2_wdt_is_running(wdev))
-		del_timer_sync(&wdev->timer);
+		/* The watchdog is not active */
+		if (!watchdog_active(wdog))
+			del_timer_sync(&wdev->timer);
+	}
 
 	clk_disable_unprepare(wdev->clk);
 
@@ -354,15 +366,25 @@ static int imx2_wdt_resume(struct device *dev)
 	clk_prepare_enable(wdev->clk);
 
 	if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) {
-		/* Resumes from deep sleep we need restart
-		 * the watchdog again.
+		/*
+		 * If the watchdog is still active and resumes
+		 * from deep sleep state, need to restart the
+		 * watchdog again.
 		 */
 		imx2_wdt_setup(wdog);
 		imx2_wdt_set_timeout(wdog, wdog->timeout);
 		imx2_wdt_ping(wdog);
 	} else if (imx2_wdt_is_running(wdev)) {
+		/* Resuming from non-deep sleep state. */
+		imx2_wdt_set_timeout(wdog, wdog->timeout);
 		imx2_wdt_ping(wdog);
-		mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2);
+		/*
+		 * But the watchdog is not active, then start
+		 * the timer again.
+		 */
+		if (!watchdog_active(wdog))
+			mod_timer(&wdev->timer,
+				  jiffies + wdog->timeout * HZ / 2);
 	}
 
 	return 0;