staging:iio:meter:ad7758 use iio_sw_buffer_preenable to avoid code repition

Using this generic function adds a little overhead to a slow path but
reduces the amount of code repitition in exchange.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/iio/meter/ade7758_ring.c b/drivers/staging/iio/meter/ade7758_ring.c
index c45b23bb122964f69c0b46dbe8ee5bcc44648fc3..3dfd788c10a16915e5ffc07504c0fa320f00fcc6 100644 (file)
--- a/drivers/staging/iio/meter/ade7758_ring.c
+++ b/drivers/staging/iio/meter/ade7758_ring.c
@@ -92,29 +92,19 @@ static irqreturn_t ade7758_trigger_handler(int irq, void *p)
 static int ade7758_ring_preenable(struct iio_dev *indio_dev)
 {
        struct ade7758_state *st = iio_priv(indio_dev);
-       struct iio_buffer *ring = indio_dev->buffer;
-       size_t d_size;
        unsigned channel;
+       int ret;
 
        if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
                return -EINVAL;
 
+       ret = iio_sw_buffer_preenable(indio_dev);
+       if (ret < 0)
+               return ret;
+
        channel = find_first_bit(indio_dev->active_scan_mask,
                                 indio_dev->masklength);
 
-       d_size = st->ade7758_ring_channels[channel].scan_type.storagebits / 8;
-
-       if (ring->scan_timestamp) {
-               d_size += sizeof(s64);
-
-               if (d_size % sizeof(s64))
-                       d_size += sizeof(s64) - (d_size % sizeof(s64));
-       }
-
-       if (indio_dev->buffer->access->set_bytes_per_datum)
-               indio_dev->buffer->access->
-                       set_bytes_per_datum(indio_dev->buffer, d_size);
-
        ade7758_write_waveform_type(&indio_dev->dev,
                st->ade7758_ring_channels[channel].address);