1 files changed, 69 insertions, 1 deletions

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 7e12f88bb4a6..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");
@@ -326,6 +335,65 @@ static void imx2_wdt_shutdown(struct platform_device *pdev)
 	}
 }
 
+#ifdef CONFIG_PM_SLEEP
+/* 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);
+
+	/* 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);
+
+		/* The watchdog is not active */
+		if (!watchdog_active(wdog))
+			del_timer_sync(&wdev->timer);
+	}
+
+	clk_disable_unprepare(wdev->clk);
+
+	return 0;
+}
+
+/* Enable watchdog and configure it if necessary */
+static int imx2_wdt_resume(struct device *dev)
+{
+	struct watchdog_device *wdog = dev_get_drvdata(dev);
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+	clk_prepare_enable(wdev->clk);
+
+	if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) {
+		/*
+		 * 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);
+		/*
+		 * 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;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend,
+			 imx2_wdt_resume);
+
 static const struct of_device_id imx2_wdt_dt_ids[] = {
 	{ .compatible = "fsl,imx21-wdt", },
 	{ /* sentinel */ }
@@ -337,7 +405,7 @@ static struct platform_driver imx2_wdt_driver = {
 	.shutdown	= imx2_wdt_shutdown,
 	.driver		= {
 		.name	= DRIVER_NAME,
-		.owner	= THIS_MODULE,
+		.pm     = &imx2_wdt_pm_ops,
 		.of_match_table = imx2_wdt_dt_ids,
 	},
 };