iio: light: iqs621-als: use lock guards

Use guard(mutex)() for handling mutex lock instead of
manually locking and unlocking the mutex. This prevents forgotten
locks due to early exits and removes the need of gotos.

Signed-off-by: Pedro Barletta Gennari <pedro.pbg@usp.br>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Author: pedrobgennari

drivers/iio/light/iqs621-als.c

@@ -5,6 +5,7 @@
  * Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
  */
 
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/iio/events.h>
 #include <linux/iio/iio.h>
@@ -107,26 +108,20 @@ static int iqs621_als_notifier(struct notifier_block *notifier,
 	indio_dev = iqs621_als->indio_dev;
 	timestamp = iio_get_time_ns(indio_dev);
 
-	mutex_lock(&iqs621_als->lock);
+	guard(mutex)(&iqs621_als->lock);
 
 	if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
 		ret = iqs621_als_init(iqs621_als);
 		if (ret) {
 			dev_err(indio_dev->dev.parent,
 				"Failed to re-initialize device: %d\n", ret);
-			ret = NOTIFY_BAD;
-		} else {
-			ret = NOTIFY_OK;
+			return NOTIFY_BAD;
 		}
-
-		goto err_mutex;
+		return NOTIFY_OK;
 	}
 
-	if (!iqs621_als->light_en && !iqs621_als->range_en &&
-	    !iqs621_als->prox_en) {
-		ret = NOTIFY_DONE;
-		goto err_mutex;
-	}
+	if (!iqs621_als->light_en && !iqs621_als->range_en && !iqs621_als->prox_en)
+		return NOTIFY_DONE;
 
 	/* IQS621 only */
 	light_new = event_data->als_flags & IQS621_ALS_FLAGS_LIGHT;
@@ -181,12 +176,7 @@ static int iqs621_als_notifier(struct notifier_block *notifier,
 
 	iqs621_als->als_flags = event_data->als_flags;
 	iqs621_als->ir_flags = event_data->ir_flags;
-	ret = NOTIFY_OK;
-
-err_mutex:
-	mutex_unlock(&iqs621_als->lock);
-
-	return ret;
+	return NOTIFY_OK;
 }
 
 static void iqs621_als_notifier_unregister(void *context)
@@ -241,30 +231,22 @@ static int iqs621_als_read_event_config(struct iio_dev *indio_dev,
 					enum iio_event_direction dir)
 {
 	struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
-	int ret;
 
-	mutex_lock(&iqs621_als->lock);
+	guard(mutex)(&iqs621_als->lock);
 
 	switch (chan->type) {
 	case IIO_LIGHT:
-		ret = iqs621_als->light_en;
-		break;
+		return iqs621_als->light_en;
 
 	case IIO_INTENSITY:
-		ret = iqs621_als->range_en;
-		break;
+		return iqs621_als->range_en;
 
 	case IIO_PROXIMITY:
-		ret = iqs621_als->prox_en;
-		break;
+		return iqs621_als->prox_en;
 
 	default:
-		ret = -EINVAL;
+		return -EINVAL;
 	}
-
-	mutex_unlock(&iqs621_als->lock);
-
-	return ret;
 }
 
 static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
@@ -278,11 +260,11 @@ static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
 	unsigned int val;
 	int ret;
 
-	mutex_lock(&iqs621_als->lock);
+	guard(mutex)(&iqs621_als->lock);
 
 	ret = regmap_read(iqs62x->regmap, iqs62x->dev_desc->als_flags, &val);
 	if (ret)
-		goto err_mutex;
+		return ret;
 	iqs621_als->als_flags = val;
 
 	switch (chan->type) {
@@ -293,7 +275,7 @@ static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
 									 0xFF);
 		if (!ret)
 			iqs621_als->light_en = state;
-		break;
+		return ret;
 
 	case IIO_INTENSITY:
 		ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
@@ -302,29 +284,24 @@ static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
 									 0xFF);
 		if (!ret)
 			iqs621_als->range_en = state;
-		break;
+		return ret;
 
 	case IIO_PROXIMITY:
 		ret = regmap_read(iqs62x->regmap, IQS622_IR_FLAGS, &val);
 		if (ret)
-			goto err_mutex;
+			return ret;
 		iqs621_als->ir_flags = val;
 
 		ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
 					 iqs62x->dev_desc->ir_mask,
 					 state ? 0 : 0xFF);
 		if (!ret)
 			iqs621_als->prox_en = state;
-		break;
+		return ret;
 
 	default:
-		ret = -EINVAL;
+		return -EINVAL;
 	}
-
-err_mutex:
-	mutex_unlock(&iqs621_als->lock);
-
-	return ret;
 }
 
 static int iqs621_als_read_event_value(struct iio_dev *indio_dev,
@@ -335,33 +312,28 @@ static int iqs621_als_read_event_value(struct iio_dev *indio_dev,
 				       int *val, int *val2)
 {
 	struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
-	int ret = IIO_VAL_INT;
 
-	mutex_lock(&iqs621_als->lock);
+	guard(mutex)(&iqs621_als->lock);
 
 	switch (dir) {
 	case IIO_EV_DIR_RISING:
 		*val = iqs621_als->thresh_light * 16;
-		break;
+		return IIO_VAL_INT;
 
 	case IIO_EV_DIR_FALLING:
 		*val = iqs621_als->thresh_dark * 4;
-		break;
+		return IIO_VAL_INT;
 
 	case IIO_EV_DIR_EITHER:
 		if (iqs621_als->ir_flags_mask == IQS622_IR_FLAGS_TOUCH)
 			*val = iqs621_als->thresh_prox * 4;
 		else
 			*val = iqs621_als->thresh_prox;
-		break;
+		return IIO_VAL_INT;
 
 	default:
-		ret = -EINVAL;
+		return -EINVAL;
 	}
-
-	mutex_unlock(&iqs621_als->lock);
-
-	return ret;
 }
 
 static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
@@ -375,9 +347,9 @@ static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
 	struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
 	unsigned int thresh_reg, thresh_val;
 	u8 ir_flags_mask, *thresh_cache;
-	int ret = -EINVAL;
+	int ret;
 
-	mutex_lock(&iqs621_als->lock);
+	guard(mutex)(&iqs621_als->lock);
 
 	switch (dir) {
 	case IIO_EV_DIR_RISING:
@@ -426,30 +398,27 @@ static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
 			break;
 
 		default:
-			goto err_mutex;
+			return -EINVAL;
 		}
 
 		thresh_cache = &iqs621_als->thresh_prox;
 		break;
 
 	default:
-		goto err_mutex;
+		return -EINVAL;
 	}
 
 	if (thresh_val > 0xFF)
-		goto err_mutex;
+		return -EINVAL;
 
 	ret = regmap_write(iqs62x->regmap, thresh_reg, thresh_val);
 	if (ret)
-		goto err_mutex;
+		return ret;
 
 	*thresh_cache = thresh_val;
 	iqs621_als->ir_flags_mask = ir_flags_mask;
 
-err_mutex:
-	mutex_unlock(&iqs621_als->lock);
-
-	return ret;
+	return 0;
 }
 
 static const struct iio_info iqs621_als_info = {