[PATCH v3] iio: light: vcnl4000: use lock guard()

[Raffael Raiel Trindade]

From: Raffael Raiel Trindade <raffaelraiel em usp.br>

Use guard() for handling mutex lock instead of manually locking and
unlocking. Remove gotos in error handling logic. This prevents forgotten
locks on early exits.

Signed-off-by: Raffael Raiel Trindade <raffaelraiel em usp.br>
Co-developed-by: Kim Carvalho <kim.ca em usp.br>
Signed-off-by: Kim Carvalho <kim.ca em usp.br>
---
v3:
 - fix indentation problems on line breaks

v2:
 - remove unnecessary ret attributions on non-error logic.
 - remove breaks on switch-case after return

 drivers/iio/light/vcnl4000.c | 55 +++++++++++-------------------------
 1 file changed, 16 insertions(+), 39 deletions(-)

diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
index c08927e34b4e..023176ff14c7 100644
--- a/drivers/iio/light/vcnl4000.c
+++ b/drivers/iio/light/vcnl4000.c
@@ -18,6 +18,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
@@ -268,46 +269,36 @@ static ssize_t vcnl4000_write_als_enable(struct vcnl4000_data *data, bool en)
 {
 	int ret;
 
-	mutex_lock(&data->vcnl4000_lock);
+	guard(mutex)(&data->vcnl4000_lock);
 
 	ret = i2c_smbus_read_word_data(data->client, VCNL4200_AL_CONF);
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	if (en)
 		ret &= ~VCNL4040_ALS_CONF_ALS_SHUTDOWN;
 	else
 		ret |= VCNL4040_ALS_CONF_ALS_SHUTDOWN;
 
-	ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, ret);
-
-out:
-	mutex_unlock(&data->vcnl4000_lock);
-
-	return ret;
+	return i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, ret);
 }
 
 static ssize_t vcnl4000_write_ps_enable(struct vcnl4000_data *data, bool en)
 {
 	int ret;
 
-	mutex_lock(&data->vcnl4000_lock);
+	guard(mutex)(&data->vcnl4000_lock);
 
 	ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF1);
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	if (en)
 		ret &= ~VCNL4040_PS_CONF1_PS_SHUTDOWN;
 	else
 		ret |= VCNL4040_PS_CONF1_PS_SHUTDOWN;
 
-	ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, ret);
-
-out:
-	mutex_unlock(&data->vcnl4000_lock);
-
-	return ret;
+	return i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, ret);
 }
 
 static int vcnl4200_set_power_state(struct vcnl4000_data *data, bool on)
@@ -660,20 +651,15 @@ static ssize_t vcnl4040_write_ps_it(struct vcnl4000_data *data, int val)
 
 	data->vcnl4200_ps.sampling_rate = ktime_set(0, val * 60 * NSEC_PER_USEC);
 
-	mutex_lock(&data->vcnl4000_lock);
+	guard(mutex)(&data->vcnl4000_lock);
 
 	ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF1);
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	regval = (ret & ~VCNL4040_PS_CONF2_PS_IT) |
 	    FIELD_PREP(VCNL4040_PS_CONF2_PS_IT, index);
-	ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1,
-					regval);
-
-out:
-	mutex_unlock(&data->vcnl4000_lock);
-	return ret;
+	return i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, regval);
 }
 
 static ssize_t vcnl4040_read_als_period(struct vcnl4000_data *data, int *val, int *val2)
@@ -1480,13 +1466,13 @@ static int vcnl4040_write_event_config(struct iio_dev *indio_dev,
 	u16 val, mask;
 	struct vcnl4000_data *data = iio_priv(indio_dev);
 
-	mutex_lock(&data->vcnl4000_lock);
+	guard(mutex)(&data->vcnl4000_lock);
 
 	switch (chan->type) {
 	case IIO_LIGHT:
 		ret = i2c_smbus_read_word_data(data->client, VCNL4200_AL_CONF);
 		if (ret < 0)
-			goto out;
+			return ret;
 
 		mask = VCNL4040_ALS_CONF_INT_EN;
 		if (state)
@@ -1495,13 +1481,11 @@ static int vcnl4040_write_event_config(struct iio_dev *indio_dev,
 			val = (ret & ~mask);
 
 		data->als_int = FIELD_GET(VCNL4040_ALS_CONF_INT_EN, val);
-		ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF,
-						val);
-		break;
+		return i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, val);
 	case IIO_PROXIMITY:
 		ret = i2c_smbus_read_word_data(data->client, VCNL4200_PS_CONF1);
 		if (ret < 0)
-			goto out;
+			return ret;
 
 		if (dir == IIO_EV_DIR_RISING)
 			mask = VCNL4040_PS_IF_AWAY;
@@ -1511,17 +1495,10 @@ static int vcnl4040_write_event_config(struct iio_dev *indio_dev,
 		val = state ? (ret | mask) : (ret & ~mask);
 
 		data->ps_int = FIELD_GET(VCNL4040_PS_CONF2_PS_INT, val);
-		ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1,
-						val);
-		break;
+		return i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, val);
 	default:
-		break;
+		return ret;
 	}
-
-out:
-	mutex_unlock(&data->vcnl4000_lock);
-
-	return ret;
 }
 
 static irqreturn_t vcnl4040_irq_thread(int irq, void *p)
-- 
2.51.0