v4l: ti-vps: vpdma: Use write desciptor bit in dtd

VPDMA can create a descriptor after an outbound descriptor is processed.
The output descriptor contains useful information like the width height
of the DMA transfer, Also it contains field id of the data.

update_dma_addr function changes the descriptor so that, every time the
write descriptor bit is set allowing the driver to read these properties.

Change-Id: I69db45fe86b79f00dbd6d0ab4ed42bd86a166782
Signed-off-by: Nikhil Devshatwar <nikhil.nd@ti.com>

5 files changed, 29 insertions, 18 deletions

diff --git a/drivers/media/platform/ti-vps/vip.c b/drivers/media/platform/ti-vps/vip.c
index 5ed03269818..0c07cc21157 100644
--- a/drivers/media/platform/ti-vps/vip.c
+++ b/drivers/media/platform/ti-vps/vip.c
@@ -52,7 +52,7 @@ MODULE_VERSION("0.1");
 
 /*
  * Need a descriptor entry for each of up to 15 outputs,
- * and up to 2 control transfers.
+ * and up to 2 write descriptor.
  */
 #define VIP_DESC_LIST_SIZE      (17 * sizeof(struct vpdma_dtd))
 
@@ -891,6 +891,7 @@ static void populate_desc_list(struct vip_stream *stream)
 static void start_dma(struct vip_dev *dev, struct vip_buffer *buf)
 {
         struct vpdma_data *vpdma = dev->shared->vpdma;
+        struct vpdma_dtd *write_dtd;
         dma_addr_t dma_addr;
         int drop_data;
 
@@ -912,8 +913,12 @@ static void start_dma(struct vip_dev *dev, struct vip_buffer *buf)
 
         enable_irqs(dev, dev->slice_id);
 
+        vpdma_buf_unmap(dev->shared->vpdma, &dev->desc_list.buf);
+
         vpdma_update_dma_addr(dev->shared->vpdma, &dev->desc_list,
-                                dma_addr, drop_data);
+                dma_addr, dev->write_desc, drop_data);
+        vpdma_buf_map(dev->shared->vpdma, &dev->desc_list.buf);
+
         vpdma_submit_descs(dev->shared->vpdma, &dev->desc_list, dev->slice_id);
 }
 
@@ -1607,6 +1612,8 @@ static int vip_init_dev(struct vip_dev *dev)
         if (ret != 0)
                 return ret;
 
+        dev->write_desc = (struct vpdma_dtd *)dev->desc_list.buf.addr
+                                + 15;
         vip_set_clock_enable(dev, 1);
 done:
         dev->num_ports++;
diff --git a/drivers/media/platform/ti-vps/vip.h b/drivers/media/platform/ti-vps/vip.h
index 801b2279c1a..8cf04ef770d 100644
--- a/drivers/media/platform/ti-vps/vip.h
+++ b/drivers/media/platform/ti-vps/vip.h
@@ -92,6 +92,7 @@ struct vip_dev {
         void __iomem            *base;
 
         struct vpdma_desc_list  desc_list;      /* DMA descriptor list */
+        struct vpdma_dtd        *write_desc;
         void                    *desc_next;     /* next unused desc_list addr */
         struct list_head        vip_bufs;       /* vip_bufs to be DMAed */
         struct vb2_alloc_ctx    *alloc_ctx;
diff --git a/drivers/media/platform/ti-vps/vpdma.c b/drivers/media/platform/ti-vps/vpdma.c
index 8e2340f616f..deb3193ffcc 100644
--- a/drivers/media/platform/ti-vps/vpdma.c
+++ b/drivers/media/platform/ti-vps/vpdma.c
@@ -313,7 +313,7 @@ void vpdma_buf_map(struct vpdma_data *vpdma, struct vpdma_buf *buf)
 
         WARN_ON(buf->mapped != 0);
         buf->dma_addr = dma_map_single(dev, buf->addr, buf->size,
-                                DMA_TO_DEVICE);
+                                DMA_BIDIRECTIONAL);
         buf->mapped = 1;
         WARN_ON(dma_mapping_error(dev, buf->dma_addr));
 }
@@ -333,7 +333,8 @@ void vpdma_buf_unmap(struct vpdma_data *vpdma, struct vpdma_buf *buf)
         }
 
         if (buf->mapped)
-                dma_unmap_single(dev, buf->dma_addr, buf->size, DMA_TO_DEVICE);
+                dma_unmap_single(dev, buf->dma_addr, buf->size,
+                        DMA_BIDIRECTIONAL);
 
         buf->mapped = 0;
 }
@@ -420,24 +421,25 @@ int vpdma_submit_descs(struct vpdma_data *vpdma,
 EXPORT_SYMBOL(vpdma_submit_descs);
 
 void vpdma_update_dma_addr(struct vpdma_data *vpdma,
-                struct vpdma_desc_list *list, dma_addr_t dma_addr, int drop)
+        struct vpdma_desc_list *list, dma_addr_t dma_addr,
+        struct vpdma_dtd *write_dtd, int drop)
 {
         struct vpdma_dtd *dtd = list->buf.addr;
-        unsigned int write_desc_addr;
-
-        vpdma_buf_unmap(vpdma, &list->buf);
+        dma_addr_t write_desc_addr;
+        int offset;
 
         dtd_set_start_addr(dtd, dma_addr);
 
-        if (drop) {
-                write_desc_addr = virt_to_phys(
-                        (struct vpdma_dtd *)list->buf.dma_addr + 2);
+        /* Calculate write address from the offset of write_dtd from start
+         * of the list->buf
+         */
+        offset = (void *)write_dtd - list->buf.addr;
+        write_desc_addr = list->buf.dma_addr + offset;
 
+        if (drop)
                 dtd_set_desc_write_addr(dtd, write_desc_addr, 1, 1, 0);
-        } else
-                dtd_set_desc_write_addr(dtd, 0, 0, 0, 0);
-
-        vpdma_buf_map(vpdma, &list->buf);
+        else
+                dtd_set_desc_write_addr(dtd, write_desc_addr, 1, 0, 0);
 }
 EXPORT_SYMBOL(vpdma_update_dma_addr);
 
diff --git a/drivers/media/platform/ti-vps/vpdma.h b/drivers/media/platform/ti-vps/vpdma.h
index 30c1fc41a42..016f30a248e 100644
--- a/drivers/media/platform/ti-vps/vpdma.h
+++ b/drivers/media/platform/ti-vps/vpdma.h
@@ -28,7 +28,7 @@ struct vpdma_buf {
 
 struct vpdma_desc_list {
         struct vpdma_buf buf;
-        void *next;
+        void *next, *current_desc;
         int type;
 };
 
@@ -203,7 +203,8 @@ void vpdma_free_desc_list(struct vpdma_desc_list *list);
 int vpdma_submit_descs(struct vpdma_data *vpdma,
         struct vpdma_desc_list *list, int list_num);
 void vpdma_update_dma_addr(struct vpdma_data *vpdma,
-                struct vpdma_desc_list *list, dma_addr_t dma_addr, int drop);
+        struct vpdma_desc_list *list, dma_addr_t dma_addr,
+        struct vpdma_dtd *write_dtd, int drop);
 
 void vpdma_enable_channel_3_irq(struct vpdma_data *vpdma, bool enable);
 void vpdma_set_max_size(struct vpdma_data *vpdma, int reg_addr,
diff --git a/drivers/media/platform/ti-vps/vpdma_priv.h b/drivers/media/platform/ti-vps/vpdma_priv.h
index a576463e2d0..3b949aec0b3 100644
--- a/drivers/media/platform/ti-vps/vpdma_priv.h
+++ b/drivers/media/platform/ti-vps/vpdma_priv.h
@@ -219,7 +219,7 @@ struct vpdma_dtd {
 #define DTD_V_START_MASK        0xffff
 #define DTD_V_START_SHFT        0
 
-#define DTD_DESC_START_MASK     0xffe0
+#define DTD_DESC_START_MASK     0xffffffe0
 #define DTD_DESC_START_SHIFT    5
 #define DTD_WRITE_DESC_MASK     0x01
 #define DTD_WRITE_DESC_SHIFT    2