Add check for the return value of clk_enable() in order to catch the
potential exception.

Fixes: 3192ade7b6f6 ("iio: trigger: stm32-timer: enable clock when in master mode")
Fixes: 90938ca432e6 ("iio: trigger: stm32-timer: add enable attribute")
Fixes: 93fbe91b5521 ("iio: Add STM32 timer trigger driver")
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
---
 drivers/iio/trigger/stm32-timer-trigger.c | 40 +++++++++++++++++++----
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
index 0684329956d9..0d5bb808c61d 100644
--- a/drivers/iio/trigger/stm32-timer-trigger.c
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -119,7 +119,7 @@ static int stm32_timer_start(struct stm32_timer_trigger *priv,
 			     unsigned int frequency)
 {
 	unsigned long long prd, div;
-	int prescaler = 0;
+	int prescaler = 0, ret;
 	u32 ccer;
 
 	/* Period and prescaler values depends of clock rate */
@@ -153,7 +153,13 @@ static int stm32_timer_start(struct stm32_timer_trigger *priv,
 	mutex_lock(&priv->lock);
 	if (!priv->enabled) {
 		priv->enabled = true;
-		clk_enable(priv->clk);
+		ret = clk_enable(priv->clk);
+		if (ret) {
+			mutex_unlock(&priv->lock);
+			return dev_err_probe(priv->dev, ret,
+					     "failed to enable clock: %d\n",
+					     ret);
+		}
 	}
 
 	regmap_write(priv->regmap, TIM_PSC, prescaler);
@@ -307,7 +313,7 @@ static ssize_t stm32_tt_store_master_mode(struct device *dev,
 	struct stm32_timer_trigger *priv = dev_get_drvdata(dev);
 	struct iio_trigger *trig = to_iio_trigger(dev);
 	u32 mask, shift, master_mode_max;
-	int i;
+	int i, ret;
 
 	if (stm32_timer_is_trgo2_name(trig->name)) {
 		mask = TIM_CR2_MMS2;
@@ -326,7 +332,13 @@ static ssize_t stm32_tt_store_master_mode(struct device *dev,
 			if (!priv->enabled) {
 				/* Clock should be enabled first */
 				priv->enabled = true;
-				clk_enable(priv->clk);
+				ret = clk_enable(priv->clk);
+				if (ret) {
+					mutex_unlock(&priv->lock);
+					return dev_err_probe(priv->dev, ret,
+							     "failed to enable clock: %d\n",
+							     ret);
+				}
 			}
 			regmap_update_bits(priv->regmap, TIM_CR2, mask,
 					   i << shift);
@@ -482,6 +494,7 @@ static int stm32_counter_write_raw(struct iio_dev *indio_dev,
 				   int val, int val2, long mask)
 {
 	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
+	int ret;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
@@ -496,7 +509,13 @@ static int stm32_counter_write_raw(struct iio_dev *indio_dev,
 		if (val) {
 			if (!priv->enabled) {
 				priv->enabled = true;
-				clk_enable(priv->clk);
+				ret = clk_enable(priv->clk);
+				if (ret) {
+					mutex_unlock(&priv->lock);
+					return dev_err_probe(priv->dev, ret,
+							     "failed to enable clock: %d\n",
+							     ret);
+				}
 			}
 			regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
 		} else {
@@ -601,7 +620,7 @@ static int stm32_set_enable_mode(struct iio_dev *indio_dev,
 				 unsigned int mode)
 {
 	struct stm32_timer_trigger *priv = iio_priv(indio_dev);
-	int sms = stm32_enable_mode2sms(mode);
+	int sms = stm32_enable_mode2sms(mode), ret;
 
 	if (sms < 0)
 		return sms;
@@ -611,7 +630,14 @@ static int stm32_set_enable_mode(struct iio_dev *indio_dev,
 	 */
 	mutex_lock(&priv->lock);
 	if (sms == 6 && !priv->enabled) {
-		clk_enable(priv->clk);
+		ret = clk_enable(priv->clk);
+		if (ret) {
+			mutex_unlock(&priv->lock);
+			return dev_err_probe(priv->dev, ret,
+					     "failed to enable clock: %d\n",
+					     ret);
+		}
+
 		priv->enabled = true;
 	}
 	mutex_unlock(&priv->lock);
-- 
2.25.1