staging:iio:buffer: pull computation of scan length into a utility function.

Principal reason is to make later patches more coherent and easier to review
but this set in itself separates a logical entity out nicely wihin the code.

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/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c
index 59b0caf..389fe16 100644 (file)
--- a/drivers/staging/iio/industrialio-buffer.c
+++ b/drivers/staging/iio/industrialio-buffer.c
@@ -508,29 +508,41 @@ static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
        return NULL;
 }
 
-int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
+static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask,
+                                 bool timestamp)
 {
-       struct iio_buffer *buffer = indio_dev->buffer;
        const struct iio_chan_spec *ch;
        unsigned bytes = 0;
        int length, i;
-       dev_dbg(&indio_dev->dev, "%s\n", __func__);
 
        /* How much space will the demuxed element take? */
-       for_each_set_bit(i, buffer->scan_mask,
+       for_each_set_bit(i, mask,
                         indio_dev->masklength) {
                ch = iio_find_channel_from_si(indio_dev, i);
-               length = ch->scan_type.storagebits/8;
+               length = ch->scan_type.storagebits / 8;
                bytes = ALIGN(bytes, length);
                bytes += length;
        }
-       if (buffer->scan_timestamp) {
+       if (timestamp) {
                ch = iio_find_channel_from_si(indio_dev,
-                                             buffer->scan_index_timestamp);
-               length = ch->scan_type.storagebits/8;
+                                             indio_dev
+                                             ->buffer->scan_index_timestamp);
+               length = ch->scan_type.storagebits / 8;
                bytes = ALIGN(bytes, length);
                bytes += length;
        }
+       return bytes;
+}
+
+int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
+{
+       struct iio_buffer *buffer = indio_dev->buffer;
+       unsigned bytes;
+       dev_dbg(&indio_dev->dev, "%s\n", __func__);
+
+       /* How much space will the demuxed element take? */
+       bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
+                                      buffer->scan_timestamp);
        buffer->access->set_bytes_per_datum(buffer, bytes);
 
        /* What scan mask do we actually have ?*/