iio: tcs3472: convert remaining locking to guard(mutex)

Convert several functions to use guard(mutex)()

This avoids manual unlock calls on each return path, drops the goto
in tcs3472_write_event(), and removes 'ret' variables only needed to
return after the unlock.

While the conversion is in progress, take the opportunity to make a
few small cleanups that guard() enables:

  - In tcs3472_read_event_config(), replace '!!(...)' with
    '(...) ? 1 : 0' for readability.

  - In tcs3472_write_event_config(), tcs3472_powerdown() and
    tcs3472_resume() use an early return on the I2C
    write failure path.

No functional change.

Signed-off-by: Aldo Conte <aldocontelk@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/light/tcs3472.c b/drivers/iio/light/tcs3472.c
index 68d9032973dc0cc0abb7fd5daedcc9e3fce0c5e2..8956ed058a2043856fbcc82e401a51567da51fcf 100644 (file)
--- a/drivers/iio/light/tcs3472.c
+++ b/drivers/iio/light/tcs3472.c
@@ -13,6 +13,7 @@
  * TODO: wait time
  */
 
+#include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
@@ -220,32 +221,24 @@ static int tcs3472_read_event(struct iio_dev *indio_dev,
        int *val2)
 {
        struct tcs3472_data *data = iio_priv(indio_dev);
-       int ret;
        unsigned int period;
 
-       mutex_lock(&data->lock);
+       guard(mutex)(&data->lock);
 
        switch (info) {
        case IIO_EV_INFO_VALUE:
                *val = (dir == IIO_EV_DIR_RISING) ?
                        data->high_thresh : data->low_thresh;
-               ret = IIO_VAL_INT;
-               break;
+               return IIO_VAL_INT;
        case IIO_EV_INFO_PERIOD:
                period = (256 - data->atime) * 2400 *
                        tcs3472_intr_pers[data->apers];
                *val = period / USEC_PER_SEC;
                *val2 = period % USEC_PER_SEC;
-               ret = IIO_VAL_INT_PLUS_MICRO;
-               break;
+               return IIO_VAL_INT_PLUS_MICRO;
        default:
-               ret = -EINVAL;
-               break;
+               return -EINVAL;
        }
-
-       mutex_unlock(&data->lock);
-
-       return ret;
 }
 
 static int tcs3472_write_event(struct iio_dev *indio_dev,
@@ -259,7 +252,8 @@ static int tcs3472_write_event(struct iio_dev *indio_dev,
        int period;
        int i;
 
-       mutex_lock(&data->lock);
+       guard(mutex)(&data->lock);
+
        switch (info) {
        case IIO_EV_INFO_VALUE:
                switch (dir) {
@@ -270,18 +264,18 @@ static int tcs3472_write_event(struct iio_dev *indio_dev,
                        command = TCS3472_AILT;
                        break;
                default:
-                       ret = -EINVAL;
-                       goto error;
+                       return -EINVAL;
                }
                ret = i2c_smbus_write_word_data(data->client, command, val);
                if (ret)
-                       goto error;
+                       return ret;
 
                if (dir == IIO_EV_DIR_RISING)
                        data->high_thresh = val;
                else
                        data->low_thresh = val;
-               break;
+
+               return 0;
        case IIO_EV_INFO_PERIOD:
                period = val * USEC_PER_SEC + val2;
                for (i = 1; i < ARRAY_SIZE(tcs3472_intr_pers) - 1; i++) {
@@ -291,18 +285,14 @@ static int tcs3472_write_event(struct iio_dev *indio_dev,
                }
                ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS, i);
                if (ret)
-                       goto error;
+                       return ret;
 
                data->apers = i;
-               break;
+
+               return 0;
        default:
-               ret = -EINVAL;
-               break;
+               return -EINVAL;
        }
-error:
-       mutex_unlock(&data->lock);
-
-       return ret;
 }
 
 static int tcs3472_read_event_config(struct iio_dev *indio_dev,
@@ -310,13 +300,10 @@ static int tcs3472_read_event_config(struct iio_dev *indio_dev,
        enum iio_event_direction dir)
 {
        struct tcs3472_data *data = iio_priv(indio_dev);
-       int ret;
 
-       mutex_lock(&data->lock);
-       ret = !!(data->enable & TCS3472_ENABLE_AIEN);
-       mutex_unlock(&data->lock);
+       guard(mutex)(&data->lock);
 
-       return ret;
+       return (data->enable & TCS3472_ENABLE_AIEN) ? 1 : 0;
 }
 
 static int tcs3472_write_event_config(struct iio_dev *indio_dev,
@@ -327,7 +314,7 @@ static int tcs3472_write_event_config(struct iio_dev *indio_dev,
        int ret = 0;
        u8 enable_old;
 
-       mutex_lock(&data->lock);
+       guard(mutex)(&data->lock);
 
        enable_old = data->enable;
 
@@ -339,12 +326,13 @@ static int tcs3472_write_event_config(struct iio_dev *indio_dev,
        if (enable_old != data->enable) {
                ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
                                                data->enable);
-               if (ret)
+               if (ret) {
                        data->enable = enable_old;
+                       return ret;
+               }
        }
-       mutex_unlock(&data->lock);
 
-       return ret;
+       return 0;
 }
 
 static irqreturn_t tcs3472_event_handler(int irq, void *priv)
@@ -445,16 +433,16 @@ static int tcs3472_powerdown(struct tcs3472_data *data)
        int ret;
        u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
 
-       mutex_lock(&data->lock);
+       guard(mutex)(&data->lock);
 
        ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
                                        data->enable & ~enable_mask);
-       if (!ret)
-               data->enable &= ~enable_mask;
+       if (ret)
+               return ret;
 
-       mutex_unlock(&data->lock);
+       data->enable &= ~enable_mask;
 
-       return ret;
+       return 0;
 }
 
 static int tcs3472_probe(struct i2c_client *client)
@@ -583,16 +571,16 @@ static int tcs3472_resume(struct device *dev)
        int ret;
        u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
 
-       mutex_lock(&data->lock);
+       guard(mutex)(&data->lock);
 
        ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
                data->enable | enable_mask);
-       if (!ret)
-               data->enable |= enable_mask;
+       if (ret)
+               return ret;
 
-       mutex_unlock(&data->lock);
+       data->enable |= enable_mask;
 
-       return ret;
+       return 0;
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend,