[PATCH 1/5] gpio: sysfs: use cleanup guards for gpiod_data::mutex

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Shrink the code and drop some goto labels by using lock guards around
gpiod_data::mutex.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
---
 drivers/gpio/gpiolib-sysfs.c | 57 +++++++++++++-------------------------------
 1 file changed, 17 insertions(+), 40 deletions(-)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 0c713baa7784..3ccb41a93ea7 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -77,12 +77,10 @@ static ssize_t direction_show(struct device *dev,
 	struct gpio_desc *desc = data->desc;
 	int value;
 
-	mutex_lock(&data->mutex);
-
-	gpiod_get_direction(desc);
-	value = !!test_bit(FLAG_IS_OUT, &desc->flags);
-
-	mutex_unlock(&data->mutex);
+	scoped_guard(mutex, &data->mutex) {
+		gpiod_get_direction(desc);
+		value = !!test_bit(FLAG_IS_OUT, &desc->flags);
+	}
 
 	return sysfs_emit(buf, "%s\n", value ? "out" : "in");
 }
@@ -94,7 +92,7 @@ static ssize_t direction_store(struct device *dev,
 	struct gpio_desc *desc = data->desc;
 	ssize_t			status;
 
-	mutex_lock(&data->mutex);
+	guard(mutex)(&data->mutex);
 
 	if (sysfs_streq(buf, "high"))
 		status = gpiod_direction_output_raw(desc, 1);
@@ -105,8 +103,6 @@ static ssize_t direction_store(struct device *dev,
 	else
 		status = -EINVAL;
 
-	mutex_unlock(&data->mutex);
-
 	return status ? : size;
 }
 static DEVICE_ATTR_RW(direction);
@@ -118,11 +114,8 @@ static ssize_t value_show(struct device *dev,
 	struct gpio_desc *desc = data->desc;
 	ssize_t			status;
 
-	mutex_lock(&data->mutex);
-
-	status = gpiod_get_value_cansleep(desc);
-
-	mutex_unlock(&data->mutex);
+	scoped_guard(mutex, &data->mutex)
+		status = gpiod_get_value_cansleep(desc);
 
 	if (status < 0)
 		return status;
@@ -140,7 +133,7 @@ static ssize_t value_store(struct device *dev,
 
 	status = kstrtol(buf, 0, &value);
 
-	mutex_lock(&data->mutex);
+	guard(mutex)(&data->mutex);
 
 	if (!test_bit(FLAG_IS_OUT, &desc->flags)) {
 		status = -EPERM;
@@ -149,8 +142,6 @@ static ssize_t value_store(struct device *dev,
 		status = size;
 	}
 
-	mutex_unlock(&data->mutex);
-
 	return status;
 }
 static DEVICE_ATTR_PREALLOC(value, S_IWUSR | S_IRUGO, value_show, value_store);
@@ -253,11 +244,8 @@ static ssize_t edge_show(struct device *dev,
 	struct gpiod_data *data = dev_get_drvdata(dev);
 	int flags;
 
-	mutex_lock(&data->mutex);
-
-	flags = data->irq_flags;
-
-	mutex_unlock(&data->mutex);
+	scoped_guard(mutex, &data->mutex)
+		flags = data->irq_flags;
 
 	if (flags >= ARRAY_SIZE(trigger_names))
 		return 0;
@@ -276,12 +264,10 @@ static ssize_t edge_store(struct device *dev,
 	if (flags < 0)
 		return flags;
 
-	mutex_lock(&data->mutex);
+	guard(mutex)(&data->mutex);
 
-	if (flags == data->irq_flags) {
-		status = size;
-		goto out_unlock;
-	}
+	if (flags == data->irq_flags)
+		return size;
 
 	if (data->irq_flags)
 		gpio_sysfs_free_irq(dev);
@@ -292,9 +278,6 @@ static ssize_t edge_store(struct device *dev,
 			status = size;
 	}
 
-out_unlock:
-	mutex_unlock(&data->mutex);
-
 	return status;
 }
 static DEVICE_ATTR_RW(edge);
@@ -330,11 +313,8 @@ static ssize_t active_low_show(struct device *dev,
 	struct gpio_desc *desc = data->desc;
 	int value;
 
-	mutex_lock(&data->mutex);
-
-	value = !!test_bit(FLAG_ACTIVE_LOW, &desc->flags);
-
-	mutex_unlock(&data->mutex);
+	scoped_guard(mutex, &data->mutex)
+		value = !!test_bit(FLAG_ACTIVE_LOW, &desc->flags);
 
 	return sysfs_emit(buf, "%d\n", value);
 }
@@ -350,11 +330,8 @@ static ssize_t active_low_store(struct device *dev,
 	if (status)
 		return status;
 
-	mutex_lock(&data->mutex);
-
-	status = gpio_sysfs_set_active_low(dev, value);
-
-	mutex_unlock(&data->mutex);
+	scoped_guard(mutex, &data->mutex)
+		status = gpio_sysfs_set_active_low(dev, value);
 
 	return status ? : size;
 }

-- 
2.45.2