[PATCH v5, 1/2] driver: watchdog: reset watchdog in designware_wdt_stop() function

[Meng.Li at windriver.com]

From: MengLi <meng.li at windriver.com>

In uboot command line environment, watchdog is not able to be
stopped with below commands:
SOCFPGA_STRATIX10 # wdt dev watchdog at ffd00200
SOCFPGA_STRATIX10 # wdt stop
Refer to watchdog driver in linux kernel, it is also need to reset
watchdog after disable it so that the disable action takes effect.

Signed-off-by: Meng Li <Meng.Li at windriver.com>
Reviewed-by: Stefan Roese <sr at denx.de>

---
v5:
fix build issue, and verify this patch with latest upstream u-boot.
v4:
Remove the unauthorized signature.
v3:
Add the resets to designware_wdt_priv and initialize it in probe().
v2:
Change "#if CONFIG_IS_ENABLED(DM_RESET)" into
"if (CONFIG_IS_ENABLED(DM_RESET)) {", and define the variable
into if condition sentence.
---
 drivers/watchdog/designware_wdt.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/designware_wdt.c b/drivers/watchdog/designware_wdt.c
index 9e5487168c..afed81e6c6 100644
--- a/drivers/watchdog/designware_wdt.c
+++ b/drivers/watchdog/designware_wdt.c
@@ -22,6 +22,7 @@
 struct designware_wdt_priv {
 	void __iomem	*base;
 	unsigned int	clk_khz;
+	struct reset_ctl_bulk *resets;
 };
 
 /*
@@ -95,6 +96,18 @@ static int designware_wdt_stop(struct udevice *dev)
 	designware_wdt_reset(dev);
 	writel(0, priv->base + DW_WDT_CR);
 
+        if (CONFIG_IS_ENABLED(DM_RESET)) {
+		int ret;
+
+		ret = reset_assert_bulk(priv->resets);
+		if (ret)
+			return ret;
+
+		ret = reset_deassert_bulk(priv->resets);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -143,13 +156,11 @@ static int designware_wdt_probe(struct udevice *dev)
 #endif
 
 	if (CONFIG_IS_ENABLED(DM_RESET)) {
-		struct reset_ctl_bulk resets;
-
-		ret = reset_get_bulk(dev, &resets);
+		ret = reset_get_bulk(dev, priv->resets);
 		if (ret)
 			goto err;
 
-		ret = reset_deassert_bulk(&resets);
+		ret = reset_deassert_bulk(priv->resets);
 		if (ret)
 			goto err;
 	}
-- 
2.17.1