staging: iio: Add a bits per element element to ring_generic allowing a general ring_...

[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / staging / iio / ring_sw.c

diff --git a/drivers/staging/iio/ring_sw.c b/drivers/staging/iio/ring_sw.c
index 294272d..ca0e79e 100644 (file)
--- a/drivers/staging/iio/ring_sw.c
+++ b/drivers/staging/iio/ring_sw.c
@@ -431,5 +431,30 @@ void iio_sw_rb_free(struct iio_ring_buffer *r)
                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");