staging:iio:adc:ad7793 use iio_sw_buffer_preenable to avoid repitition.

Now the generic function caches the scan size a lot of what was here
was redundant and is removed.

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/adc/ad7793.c b/drivers/staging/iio/adc/ad7793.c
index 9d21e394012fd4b9e01fb72059124b866e8cc4de..2aeeaa2a339772201d1abeeb77165df1b78bebb6 100644 (file)
--- a/drivers/staging/iio/adc/ad7793.c
+++ b/drivers/staging/iio/adc/ad7793.c
@@ -319,31 +319,18 @@ out:
 static int ad7793_ring_preenable(struct iio_dev *indio_dev)
 {
        struct ad7793_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 = bitmap_weight(indio_dev->active_scan_mask,
-                              indio_dev->masklength) *
-               indio_dev->channels[0].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);
-
        st->mode  = (st->mode & ~AD7793_MODE_SEL(-1)) |
                    AD7793_MODE_SEL(AD7793_MODE_CONT);
        st->conf  = (st->conf & ~AD7793_CONF_CHAN(-1)) |