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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;