MLK-16988: watchdog: imx8_wdt: stop watchdog while suspend

Since watchdog on i.mx8 is a software watchdog in scfw side, it should be
stopped while kernel enter system suspend if watchdog fired. Otherwise,
unexpected watchdog reset will happen. Restore back if watchdog fired too.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reviewed-by: Anson Huang <Anson.Huang@nxp.com>

diff --git a/drivers/watchdog/imx8_wdt.c b/drivers/watchdog/imx8_wdt.c
index c78eb00..6564532 100644 (file)
--- a/drivers/watchdog/imx8_wdt.c
+++ b/drivers/watchdog/imx8_wdt.c
@@ -119,6 +119,36 @@ static struct notifier_block imx8_wdt_notifier = {
        .notifier_call = imx8_wdt_notify,
 };
 
+#ifdef CONFIG_PM_SLEEP
+static int imx8_wdt_suspend(struct device *dev)
+{
+       if (test_bit(WDOG_ACTIVE, &imx8_wdd.status))
+               imx8_wdt_stop(&imx8_wdd);
+
+       return 0;
+}
+
+static int imx8_wdt_resume(struct device *dev)
+{
+       if (test_bit(WDOG_ACTIVE, &imx8_wdd.status))
+               imx8_wdt_start(&imx8_wdd);
+
+       return 0;
+}
+
+static const struct dev_pm_ops imx8_wdt_pm_ops = {
+       .suspend = imx8_wdt_suspend,
+       .resume = imx8_wdt_resume,
+};
+
+#define IMX8_WDT_PM_OPS        (&imx8_wdt_pm_ops)
+
+#else
+
+#define IMX8_WDT_PM_OPS        NULL
+
+#endif
+
 static int imx8_wdt_probe(struct platform_device *pdev)
 {
        struct watchdog_device *wdt = &imx8_wdd;
@@ -181,6 +211,7 @@ static struct platform_driver imx8_wdt_driver = {
        .driver         = {
                .name   = "imx8-wdt",
                .of_match_table = imx8_wdt_dt_ids,
+               .pm     = IMX8_WDT_PM_OPS,
        },
 };