iio: adc: max1027: Move claim of direct mode up one level and use guard()

Move iio_device_claim_direct_mode() into the read_raw() callback
and use guard() to release a mutex. This enables simpler error
handling via direct returns.

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://patch.msgid.link/20250217141630.897334-24-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index f5ba4a1b5a7de253361effcbb84f76524a6513da..3cab89464fb5233d8a518d46c030915acff7cef0 100644 (file)
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -336,10 +336,6 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
        int ret;
        struct max1027_state *st = iio_priv(indio_dev);
 
-       ret = iio_device_claim_direct_mode(indio_dev);
-       if (ret)
-               return ret;
-
        /* Configure conversion register with the requested chan */
        st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
                  MAX1027_NOSCAN;
@@ -349,7 +345,7 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
        if (ret < 0) {
                dev_err(&indio_dev->dev,
                        "Failed to configure conversion register\n");
-               goto release;
+               return ret;
        }
 
        /*
@@ -359,14 +355,10 @@ static int max1027_read_single_value(struct iio_dev *indio_dev,
         */
        ret = max1027_wait_eoc(indio_dev);
        if (ret)
-               goto release;
+               return ret;
 
        /* Read result */
        ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
-
-release:
-       iio_device_release_direct_mode(indio_dev);
-
        if (ret < 0)
                return ret;
 
@@ -382,37 +374,33 @@ static int max1027_read_raw(struct iio_dev *indio_dev,
        int ret = 0;
        struct max1027_state *st = iio_priv(indio_dev);
 
-       mutex_lock(&st->lock);
+       guard(mutex)(&st->lock);
 
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
+               ret = iio_device_claim_direct_mode(indio_dev);
+               if (ret)
+                       return ret;
+
                ret = max1027_read_single_value(indio_dev, chan, val);
-               break;
+               iio_device_release_direct_mode(indio_dev);
+               return ret;
        case IIO_CHAN_INFO_SCALE:
                switch (chan->type) {
                case IIO_TEMP:
                        *val = 1;
                        *val2 = 8;
-                       ret = IIO_VAL_FRACTIONAL;
-                       break;
+                       return IIO_VAL_FRACTIONAL;
                case IIO_VOLTAGE:
                        *val = 2500;
                        *val2 = chan->scan_type.realbits;
-                       ret = IIO_VAL_FRACTIONAL_LOG2;
-                       break;
+                       return IIO_VAL_FRACTIONAL_LOG2;
                default:
-                       ret = -EINVAL;
-                       break;
+                       return -EINVAL;
                }
-               break;
        default:
-               ret = -EINVAL;
-               break;
+               return -EINVAL;
        }
-
-       mutex_unlock(&st->lock);
-
-       return ret;
 }
 
 static int max1027_debugfs_reg_access(struct iio_dev *indio_dev,