[PATCH v2 2/4] watchdog: rzg2l_wdt: Add error check for reset_control_{deassert/reset}

[Biju Das <biju.das.jz@xxxxxxxxxxxxxx>]

If reset_control_deassert() fails, then we won't be able to
access the device registers. Therefore check the return code of
reset_control_deassert() and bail out in case of error.

While at it remove the unnecessary pm_runtime_resume_and_get()
from probe(), as it turns on the clocks.

Replace reset_control_assert()->reset_control_reset() in rzg2l_wdt
_stop() and remove the unnecessary reset_control_deassert() from
rzg2l_wdt_start(). Also add error check for reset_control_reset()

Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v1->v2:
 * Updated commit description and removed Rb tag from Guenter,
   since there is code change
 * Replaced reset_control_assert with reset_control_reset in stop
   and removed reset_control_deassert() from start.
 * 
---
 drivers/watchdog/rzg2l_wdt.c | 34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 96f2a018ab62..0e62d7be153c 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -86,7 +86,6 @@ static int rzg2l_wdt_start(struct watchdog_device *wdev)
 {
 	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
 
-	reset_control_deassert(priv->rstc);
 	pm_runtime_get_sync(wdev->parent);
 
 	/* Initialize time out */
@@ -106,18 +105,24 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
 	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
 
 	pm_runtime_put(wdev->parent);
-	reset_control_assert(priv->rstc);
 
-	return 0;
+	/* Reset the module for stopping watchdog */
+	return reset_control_reset(priv->rstc);
 }
 
 static int rzg2l_wdt_restart(struct watchdog_device *wdev,
 			     unsigned long action, void *data)
 {
 	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	int ret;
 
 	/* Reset the module before we modify any register */
-	reset_control_reset(priv->rstc);
+	ret = reset_control_reset(priv->rstc);
+	if (ret) {
+		dev_err(wdev->parent, "failed to reset");
+		return ret;
+	}
+
 	pm_runtime_get_sync(wdev->parent);
 
 	/* smallest counter value to reboot soon */
@@ -151,12 +156,11 @@ static const struct watchdog_ops rzg2l_wdt_ops = {
 	.restart = rzg2l_wdt_restart,
 };
 
-static void rzg2l_wdt_reset_assert_pm_disable_put(void *data)
+static void rzg2l_wdt_reset_assert_pm_disable(void *data)
 {
 	struct watchdog_device *wdev = data;
 	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
 
-	pm_runtime_put(wdev->parent);
 	pm_runtime_disable(wdev->parent);
 	reset_control_assert(priv->rstc);
 }
@@ -204,13 +208,11 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc),
 				     "failed to get cpg reset");
 
-	reset_control_deassert(priv->rstc);
+	ret = reset_control_deassert(priv->rstc);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to deassert");
+
 	pm_runtime_enable(&pdev->dev);
-	ret = pm_runtime_resume_and_get(&pdev->dev);
-	if (ret < 0) {
-		dev_err(dev, "pm_runtime_resume_and_get failed ret=%pe", ERR_PTR(ret));
-		goto out_pm_get;
-	}
 
 	priv->wdev.info = &rzg2l_wdt_ident;
 	priv->wdev.ops = &rzg2l_wdt_ops;
@@ -222,7 +224,7 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
 
 	watchdog_set_drvdata(&priv->wdev, priv);
 	ret = devm_add_action_or_reset(&pdev->dev,
-				       rzg2l_wdt_reset_assert_pm_disable_put,
+				       rzg2l_wdt_reset_assert_pm_disable,
 				       &priv->wdev);
 	if (ret < 0)
 		return ret;
@@ -235,12 +237,6 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
 		dev_warn(dev, "Specified timeout invalid, using default");
 
 	return devm_watchdog_register_device(&pdev->dev, &priv->wdev);
-
-out_pm_get:
-	pm_runtime_disable(dev);
-	reset_control_assert(priv->rstc);
-
-	return ret;
 }
 
 static const struct of_device_id rzg2l_wdt_ids[] = {
-- 
2.17.1