iio: addac: ad74413r: simplify with cleanup.h

Make use of mutex guard() and IIO iio_device_claim_direct_scoped() to
simplify code and error handling.

While at it, use devm_mutex_init() to initialize the mutex.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20241016-dev-ad74413r-minor-improv-v1-3-13c9c769237d@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
index cfe26a39446597cc5d863cb2f7f5bf9c54d310ce..daea2bde7acf95211d705bfc6a86f754c82642e0 100644 (file)
--- a/drivers/iio/addac/ad74413r.c
+++ b/drivers/iio/addac/ad74413r.c
@@ -6,6 +6,7 @@
 
 #include <linux/unaligned.h>
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/crc8.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -864,19 +865,12 @@ static int ad74413r_get_single_adc_result(struct iio_dev *indio_dev,
                                          unsigned int channel, int *val)
 {
        struct ad74413r_state *st = iio_priv(indio_dev);
-       int ret;
-
-       ret = iio_device_claim_direct_mode(indio_dev);
-       if (ret)
-               return ret;
-
-       mutex_lock(&st->lock);
-       ret = _ad74413r_get_single_adc_result(st, channel, val);
-       mutex_unlock(&st->lock);
 
-       iio_device_release_direct_mode(indio_dev);
-
-       return ret;
+       iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
+               guard(mutex)(&st->lock);
+               return _ad74413r_get_single_adc_result(st, channel, val);
+       }
+       unreachable();
 }
 
 static void ad74413r_adc_to_resistance_result(int adc_result, int *val)
@@ -898,7 +892,7 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
        unsigned int channel;
        int ret = -EINVAL;
 
-       mutex_lock(&st->lock);
+       guard(mutex)(&st->lock);
 
        spi_message_init(&st->adc_samples_msg);
        st->adc_active_channels = 0;
@@ -906,11 +900,11 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
        for_each_clear_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
                ret = ad74413r_set_adc_channel_enable(st, channel, false);
                if (ret)
-                       goto out;
+                       return ret;
        }
 
        if (*active_scan_mask == 0)
-               goto out;
+               return ret;
 
        /*
         * The read select register is used to select which register's value
@@ -928,7 +922,7 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
        for_each_set_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
                ret = ad74413r_set_adc_channel_enable(st, channel, true);
                if (ret)
-                       goto out;
+                       return ret;
 
                st->adc_active_channels++;
 
@@ -959,11 +953,7 @@ static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
        xfer->cs_change = 0;
 
        spi_message_add_tail(xfer, &st->adc_samples_msg);
-
-out:
-       mutex_unlock(&st->lock);
-
-       return ret;
+       return 0;
 }
 
 static int ad74413r_buffer_postenable(struct iio_dev *indio_dev)
@@ -1368,7 +1358,10 @@ static int ad74413r_probe(struct spi_device *spi)
        if (!st->chip_info)
                return -EINVAL;
 
-       mutex_init(&st->lock);
+       ret = devm_mutex_init(st->dev, &st->lock);
+       if (ret)
+               return ret;
+
        init_completion(&st->adc_data_completion);
 
        st->regmap = devm_regmap_init(st->dev, NULL, st,