gpio: sysfs: use cleanup guards for gpiod_data::mutex

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

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241031-gpio-notify-sysfs-v4-1-142021c2195c@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 203fc33..8a40238 100644 (file)
--- 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;
@@ -140,18 +133,17 @@ 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;
-       } else if (status == 0) {
-               gpiod_set_value_cansleep(desc, value);
-               status = size;
-       }
+       if (!test_bit(FLAG_IS_OUT, &desc->flags))
+               return -EPERM;
+
+       if (status)
+               return status;
 
-       mutex_unlock(&data->mutex);
+       gpiod_set_value_cansleep(desc, value);
 
-       return status;
+       return size;
 }
 static DEVICE_ATTR_PREALLOC(value, S_IWUSR | S_IRUGO, value_show, value_store);
 
@@ -253,11 +245,8 @@ 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;
@@ -276,26 +265,22 @@ 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);
 
-       if (flags) {
-               status = gpio_sysfs_request_irq(dev, flags);
-               if (!status)
-                       status = size;
-       }
+       if (!flags)
+               return size;
 
-out_unlock:
-       mutex_unlock(&data->mutex);
+       status = gpio_sysfs_request_irq(dev, flags);
+       if (status)
+               return status;
 
-       return status;
+       return size;
 }
 static DEVICE_ATTR_RW(edge);
 
@@ -330,11 +315,8 @@ 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);
 }
@@ -350,13 +332,9 @@ static ssize_t active_low_store(struct device *dev,
        if (status)
                return status;
 
-       mutex_lock(&data->mutex);
+       guard(mutex)(&data->mutex);
 
-       status = gpio_sysfs_set_active_low(dev, value);
-
-       mutex_unlock(&data->mutex);
-
-       return status ? : size;
+       return gpio_sysfs_set_active_low(dev, value) ?: size;
 }
 static DEVICE_ATTR_RW(active_low);