[PATCH 2/6] V4L2: OMAP: VOUT: dma map and unmap v4l2 buffers in qbuf and dqbuf

[Amber Jain]

Add support to map the buffer using dma_map_single during qbuf which inturn
calls cache flush and unmap the same during dqbuf. This is done to prevent
the artifacts seen because of cache-coherency issues on OMAP4

Signed-off-by: Amber Jain <am...@ti.com>
---
 drivers/media/video/omap/omap_vout.c |   29 +++++++++++++++++++++++++++--
 1 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/drivers/media/video/omap/omap_vout.c 
b/drivers/media/video/omap/omap_vout.c
index 6fe7efa..435fe65 100644
--- a/drivers/media/video/omap/omap_vout.c
+++ b/drivers/media/video/omap/omap_vout.c
@@ -37,6 +37,7 @@
 #include <linux/platform_device.h>
 #include <linux/irq.h>
 #include <linux/videodev2.h>
+#include <linux/dma-mapping.h>
 
 #include <media/videobuf-dma-contig.h>
 #include <media/v4l2-device.h>
@@ -768,6 +769,17 @@ static int omap_vout_buffer_prepare(struct videobuf_queue 
*q,
                vout->queued_buf_addr[vb->i] = (u8 *)
                        omap_vout_uservirt_to_phys(vb->baddr);
        } else {
+               int addr, dma_addr;
+               unsigned long size;
+
+               addr = (unsigned long) vout->buf_virt_addr[vb->i];
+               size = (unsigned long) vb->size;
+
+               dma_addr = dma_map_single(vout->vid_dev->v4l2_dev.dev, (void *) 
addr,
+                               (unsigned) size, DMA_TO_DEVICE);
+               if (dma_mapping_error(vout->vid_dev->v4l2_dev.dev, dma_addr))
+                       printk(KERN_ERR "dma_map_single failed\n");
+
                vout->queued_buf_addr[vb->i] = (u8 *)vout->buf_phy_addr[vb->i];
        }
 
@@ -1549,15 +1561,28 @@ static int vidioc_dqbuf(struct file *file, void *fh, 
struct v4l2_buffer *b)
        struct omap_vout_device *vout = fh;
        struct videobuf_queue *q = &vout->vbq;
 
+       unsigned long size;
+       u32 addr;
+       struct videobuf_buffer *vb;
+       int ret;
+
+       vb = q->bufs[b->index];
+
        if (!vout->streaming)
                return -EINVAL;
 
        if (file->f_flags & O_NONBLOCK)
                /* Call videobuf_dqbuf for non blocking mode */
-               return videobuf_dqbuf(q, (struct v4l2_buffer *)b, 1);
+               ret = videobuf_dqbuf(q, (struct v4l2_buffer *)b, 1);
        else
                /* Call videobuf_dqbuf for  blocking mode */
-               return videobuf_dqbuf(q, (struct v4l2_buffer *)b, 0);
+               ret = videobuf_dqbuf(q, (struct v4l2_buffer *)b, 0);
+
+       addr = (unsigned long) vout->buf_phy_addr[vb->i];
+       size = (unsigned long) vb->size;
+       dma_unmap_single(vout->vid_dev->v4l2_dev.dev,  addr,
+                               (unsigned) size, DMA_TO_DEVICE);
+       return ret;
 }
 
 static int vidioc_streamon(struct file *file, void *fh, enum v4l2_buf_type i)
-- 
1.7.1

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