media: rzg2l-cru: Manually track active slot number

The CRU cycles over the hardware slots where the destination address for
the next frame has to be programmed.

The RZ/G2L version of the IP has a register that tells which is the
last used slot by the hardware but, unfortunately, such register is not
available on RZ/G3E and RZ/V2H(P).

The driver currently compares the value of the AMnMADRSL/H register
which report "the memory address which the current video data was
written to" and compares it with the address programmed in the slots.

This heuristic requires a bit of book keeping and proper locking. As the
driver handles the FrameEnd interrupt, it's way easier to keep track
of the slot that has been used by ourselves with a driver variable.

Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com>
Tested-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
index 12d574182eb85900c2d8ec95d0ee11ce6a0bff4d..25f17069585c35139eb20a7a7fc431f41f1bf15d 100644 (file)
--- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-cru.h
@@ -119,9 +119,10 @@ struct rzg2l_cru_info {
  * @mdev_lock:         protects the count, notifier and csi members
  * @pad:               media pad for the video device entity
  *
- * @hw_lock:           protects the slot counter, hardware programming of
- *                     slot addresses and the @buf_addr[] list
+ * @hw_lock:           protects the @active_slot counter, hardware programming
+ *                     of slot addresses and the @buf_addr[] list
  * @buf_addr:          Memory addresses where current video data is written
+ * @active_slot:       The slot in use
  *
  * @lock:              protects @queue
  * @queue:             vb2 buffers queue
@@ -162,6 +163,7 @@ struct rzg2l_cru_dev {
 
        spinlock_t hw_lock;
        dma_addr_t buf_addr[RZG2L_CRU_HW_BUFFER_DEFAULT];
+       unsigned int active_slot;
 
        struct mutex lock;
        struct vb2_queue queue;

diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
index 5769dbcbd0843287265fb1e85975a8189c63beff..b02940369a18bf67dcc775ca2a9e081860c53588 100644 (file)
--- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
+++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
@@ -634,31 +634,6 @@ irqreturn_t rzg2l_cru_irq(int irq, void *data)
        return IRQ_RETVAL(handled);
 }
 
-static int rzg3e_cru_get_current_slot(struct rzg2l_cru_dev *cru)
-{
-       u64 amnmadrs;
-       int slot;
-
-       /*
-        * When AMnMADRSL is read, AMnMADRSH of the higher-order
-        * address also latches the address.
-        *
-        * AMnMADRSH must be read after AMnMADRSL has been read.
-        */
-       amnmadrs = rzg2l_cru_read(cru, AMnMADRSL);
-       amnmadrs |= (u64)rzg2l_cru_read(cru, AMnMADRSH) << 32;
-
-       /* Ensure amnmadrs is within this buffer range */
-       for (slot = 0; slot < cru->num_buf; slot++) {
-               if (amnmadrs >= cru->buf_addr[slot] &&
-                   amnmadrs < cru->buf_addr[slot] + cru->format.sizeimage)
-                       return slot;
-       }
-
-       dev_err(cru->dev, "Invalid MB address 0x%llx (out of range)\n", amnmadrs);
-       return -EINVAL;
-}
-
 irqreturn_t rzg3e_cru_irq(int irq, void *data)
 {
        struct rzg2l_cru_dev *cru = data;
@@ -690,9 +665,8 @@ irqreturn_t rzg3e_cru_irq(int irq, void *data)
                return IRQ_HANDLED;
        }
 
-       slot = rzg3e_cru_get_current_slot(cru);
-       if (slot < 0)
-               return IRQ_HANDLED;
+       slot = cru->active_slot;
+       cru->active_slot = (cru->active_slot + 1) % cru->num_buf;
 
        dev_dbg(cru->dev, "Current written slot: %d\n", slot);
        cru->buf_addr[slot] = 0;
@@ -769,6 +743,7 @@ static int rzg2l_cru_start_streaming_vq(struct vb2_queue *vq, unsigned int count
                goto assert_presetn;
        }
 
+       cru->active_slot = 0;
        cru->sequence = 0;
 
        ret = rzg2l_cru_set_stream(cru, 1);