staging: iio: Add a bits per element element to ring_generic allowing a general ring_sw_preenable_function.
Signed-off-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/iio/ring_sw.c b/drivers/staging/iio/ring_sw.c
index 294272d..ca0e79e4 100644
--- a/drivers/staging/iio/ring_sw.c
+++ b/drivers/staging/iio/ring_sw.c
@@ -431,5 +431,30 @@
iio_put_ring_buffer(r);
}
EXPORT_SYMBOL(iio_sw_rb_free);
+
+int iio_sw_ring_preenable(struct iio_dev *indio_dev)
+{
+ size_t size;
+ dev_dbg(&indio_dev->dev, "%s\n", __func__);
+ /* Check if there are any scan elements enabled, if not fail*/
+ if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
+ return -EINVAL;
+ if (indio_dev->scan_timestamp)
+ if (indio_dev->scan_count)
+ /* Timestamp (aligned to s64) and data */
+ size = (((indio_dev->scan_count * indio_dev->ring->bpe)
+ + sizeof(s64) - 1)
+ & ~(sizeof(s64) - 1))
+ + sizeof(s64);
+ else /* Timestamp only */
+ size = sizeof(s64);
+ else /* Data only */
+ size = indio_dev->scan_count * indio_dev->ring->bpe;
+ indio_dev->ring->access.set_bpd(indio_dev->ring, size);
+
+ return 0;
+}
+EXPORT_SYMBOL(iio_sw_ring_preenable);
+
MODULE_DESCRIPTION("Industrialio I/O software ring buffer");
MODULE_LICENSE("GPL");