iio: light: gp2ap020a00f: use iio helper function to lock direct mode

Replace the code that guarantees the device stays in direct mode
with iio_device_claim_direct_mode() which does same.  Includes a
tiny bit of refactoring (single case -> if) and simplified return
flow.

Also prevents a theoretical race condition by effectively taking the lock
a little earlier than before.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/light/gp2ap020a00f.c b/drivers/iio/light/gp2ap020a00f.c
index 6d41086..af73af3 100644 (file)
--- a/drivers/iio/light/gp2ap020a00f.c
+++ b/drivers/iio/light/gp2ap020a00f.c
@@ -1287,22 +1287,14 @@ static int gp2ap020a00f_read_raw(struct iio_dev *indio_dev,
        struct gp2ap020a00f_data *data = iio_priv(indio_dev);
        int err = -EINVAL;
 
-       mutex_lock(&data->lock);
-
-       switch (mask) {
-       case IIO_CHAN_INFO_RAW:
-               if (iio_buffer_enabled(indio_dev)) {
-                       err = -EBUSY;
-                       goto error_unlock;
-               }
+       if (mask == IIO_CHAN_INFO_RAW) {
+               err = iio_device_claim_direct_mode(indio_dev);
+               if (err)
+                       return err;
 
                err = gp2ap020a00f_read_channel(data, chan, val);
-               break;
+               iio_device_release_direct_mode(indio_dev);
        }
-
-error_unlock:
-       mutex_unlock(&data->lock);
-
        return err < 0 ? err : IIO_VAL_INT;
 }