[media] v4l: vb2-dma-contig: add prepare/finish to dma-contig allocator

Add prepare/finish callbacks to vb2-dma-contig allocator.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/v4l2-core/videobuf2-dma-contig.c

@@ -103,6 +103,28 @@ static unsigned int vb2_dc_num_users(void *buf_priv)
 	return atomic_read(&buf->refcount);
 }
 
+static void vb2_dc_prepare(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (!sgt)
+		return;
+
+	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
+static void vb2_dc_finish(void *buf_priv)
+{
+	struct vb2_dc_buf *buf = buf_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (!sgt)
+		return;
+
+	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
 /*********************************************/
 /*        callbacks for MMAP buffers         */
 /*********************************************/
@@ -366,6 +388,8 @@ const struct vb2_mem_ops vb2_dma_contig_memops = {
 	.mmap		= vb2_dc_mmap,
 	.get_userptr	= vb2_dc_get_userptr,
 	.put_userptr	= vb2_dc_put_userptr,
+	.prepare	= vb2_dc_prepare,
+	.finish		= vb2_dc_finish,
 	.num_users	= vb2_dc_num_users,
 };
 EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);