I2S simplifed audio buffer queuing

4 files changed, 116 insertions, 163 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index fca89d458..bcb6668f3 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -6027,4 +6027,6 @@
 	  NuttX Kernel build (2013-11-10).
 	* arch/arm/src/sama5/sam_ssc.c and Kconfig:  Add configurable support
 	  for SSC loopback mode (2013-11-10).
-
+	* include/nuttx/audio/i2s.h, arch/arm/src/sama5/sam_ssc.c, and
+	  drivers/audio/i2schar.c:  Improvied I2S interface design:  Simplified
+	  audio buffer queuing (2013-11-10).
diff --git a/nuttx/arch/arm/src/sama5/sam_ssc.c b/nuttx/arch/arm/src/sama5/sam_ssc.c
index d244a75f9..9490e7c15 100644
--- a/nuttx/arch/arm/src/sama5/sam_ssc.c
+++ b/nuttx/arch/arm/src/sama5/sam_ssc.c
@@ -242,11 +242,10 @@
 struct sam_buffer_s
 {
   struct sam_buffer_s *flink;  /* Supports a singly linked list */
-  void *callback;              /* Function to call when the transfer completes */
+  i2s_callback_t callback;     /* Function to call when the transfer completes */
   uint32_t timeout;            /* The timeout value to use with DMA transfers */
   void *arg;                   /* The argument to be returned with the callback */
-  void *buffer;                /* I/O buffer */
-  size_t nbytes;               /* Number of valid bytes in the buffer */
+  struct ap_buffer_s *apb;     /* The audio buffer */
   int result;                  /* The result of the transfer */
 };
 
@@ -399,13 +398,12 @@ static void     ssc_txdma_callback(DMA_HANDLE handle, void *arg, int result);
 
 static uint32_t ssc_rxsamplerate(struct i2s_dev_s *dev, uint32_t rate);
 static uint32_t ssc_rxdatawidth(struct i2s_dev_s *dev, int bits);
-static int      ssc_receive(struct i2s_dev_s *dev, void *buffer,
-                  size_t nbytes, i2s_rxcallback_t callback, void *arg,
-                  uint32_t timeout);
+static int      ssc_receive(struct i2s_dev_s *dev, struct ap_buffer_s *apb,
+                  i2s_callback_t callback, void *arg, uint32_t timeout);
 static uint32_t ssc_txsamplerate(struct i2s_dev_s *dev, uint32_t rate);
 static uint32_t ssc_txdatawidth(struct i2s_dev_s *dev, int bits);
-static int      ssc_send(struct i2s_dev_s *dev, const void *buffer,
-                  size_t nbytes, i2s_txcallback_t callback, void *arg,
+static int      ssc_send(struct i2s_dev_s *dev, struct ap_buffer_s *apb,
+                  i2s_callback_t callback, void *arg,
                   uint32_t timeout);
 
 /* Initialization */
@@ -1013,6 +1011,7 @@ static void ssc_rxdma_timeout(int argc, uint32_t arg)
 static int ssc_rxdma_setup(struct sam_ssc_s *priv)
 {
   struct sam_buffer_s *bfcontainer;
+  struct ap_buffer_s *apb;
   uintptr_t paddr;
   uintptr_t maddr;
   uint32_t timeout;
@@ -1049,17 +1048,21 @@ static int ssc_rxdma_setup(struct sam_ssc_s *priv)
       /* Remove the pending RX transfer at the head of the RX pending queue. */
 
       bfcontainer = (struct sam_buffer_s *)sq_remfirst(&priv->rxpend);
+      DEBUGASSERT(bfcontainer && bfcontainer->apb);
+
+      apb = bfcontainer->apb;
+      DEBUGASSERT(((uintptr_t)apb->samp & 3) == 0);
 
       /* Physical address of the SSC RHR register and of the buffer location
        * in RAM.
        */
 
       paddr = ssc_physregaddr(priv, SAM_SSC_RHR_OFFSET);
-      maddr = sam_physramaddr((uintptr_t)bfcontainer->buffer);
+      maddr = sam_physramaddr((uintptr_t)apb->samp);
 
       /* Configure the RX DMA */
 
-      sam_dmarxsetup(priv->rxdma, paddr, maddr, bfcontainer->nbytes);
+      sam_dmarxsetup(priv->rxdma, paddr, maddr, apb->nmaxbytes);
 
       /* Increment the DMA timeout */
 
@@ -1075,6 +1078,14 @@ static int ssc_rxdma_setup(struct sam_ssc_s *priv)
       /* Add the container to the list of active DMAs */
 
       sq_addlast((sq_entry_t *)bfcontainer, &priv->rxact);
+
+      /* Invalidate the data cache so that nothing gets flush into the
+       * DMA buffer after starting the DMA transfer.
+       */
+
+      cp15_invalidate_dcache((uintptr_t)apb->samp,
+                             (uintptr_t)apb->samp + apb->nmaxbytes);
+
     }
   while (!sq_empty(&priv->rxpend));
 
@@ -1082,13 +1093,6 @@ static int ssc_rxdma_setup(struct sam_ssc_s *priv)
 
   ssc_rxdma_sample(priv, DMA_AFTER_SETUP);
 
-  /* Invalidate the data cache so that nothing gets flush into the
-   * DMA buffer after starting the DMA transfer.
-   */
-
-  cp15_invalidate_dcache((uintptr_t)bfcontainer->buffer,
-                         (uintptr_t)bfcontainer->buffer + bfcontainer->nbytes);
-
   /* Start the DMA, saving the container as the current active transfer */
 
   sam_dmastart(priv->rxdma, ssc_rxdma_callback, priv);
@@ -1140,7 +1144,6 @@ static void ssc_rx_worker(void *arg)
 {
   struct sam_ssc_s *priv = (struct sam_ssc_s *)arg;
   struct sam_buffer_s *bfcontainer;
-  i2s_rxcallback_t callback;
   irqstate_t flags;
 
   DEBUGASSERT(priv);
@@ -1203,10 +1206,12 @@ static void ssc_rx_worker(void *arg)
       /* Perform the TX transfer done callback */
 
       DEBUGASSERT(bfcontainer && bfcontainer->callback);
+      bfcontainer->callback(&priv->dev, bfcontainer->apb,
+                            bfcontainer->arg, bfcontainer->result);
+
+      /* Release our reference on the audio buffer */
 
-      callback = (i2s_rxcallback_t)bfcontainer->callback;
-      callback(&priv->dev, bfcontainer->buffer, bfcontainer->nbytes,
-               bfcontainer->arg, bfcontainer->result);
+      apb_free(bfcontainer->apb);
 
       /* And release the buffer container */
 
@@ -1381,6 +1386,7 @@ static void ssc_txdma_timeout(int argc, uint32_t arg)
 static int ssc_txdma_setup(struct sam_ssc_s *priv)
 {
   struct sam_buffer_s *bfcontainer;
+  struct ap_buffer_s *apb;
   uintptr_t paddr;
   uintptr_t maddr;
   uint32_t timeout;
@@ -1417,6 +1423,10 @@ static int ssc_txdma_setup(struct sam_ssc_s *priv)
       /* Remove the pending TX transfer at the head of the TX pending queue. */
 
       bfcontainer = (struct sam_buffer_s *)sq_remfirst(&priv->txpend);
+      DEBUGASSERT(bfcontainer && bfcontainer->apb);
+
+      apb = bfcontainer->apb;
+      DEBUGASSERT(((uintptr_t)apb->samp & 3) == 0);
 
       /* Physical address of the SSC THR register and of the buffer location
        * in
@@ -1424,11 +1434,11 @@ static int ssc_txdma_setup(struct sam_ssc_s *priv)
        */
 
       paddr = ssc_physregaddr(priv, SAM_SSC_THR_OFFSET);
-      maddr = sam_physramaddr((uintptr_t)bfcontainer->buffer);
+      maddr = sam_physramaddr((uintptr_t)apb->samp);
 
       /* Configure the TX DMA */
 
-      sam_dmatxsetup(priv->txdma, paddr, maddr, bfcontainer->nbytes);
+      sam_dmatxsetup(priv->txdma, paddr, maddr, apb->nbytes);
 
       /* Increment the DMA timeout */
 
@@ -1444,6 +1454,14 @@ static int ssc_txdma_setup(struct sam_ssc_s *priv)
       /* Add the container to the list of active DMAs */
 
       sq_addlast((sq_entry_t *)bfcontainer, &priv->txact);
+
+      /* Flush the data cache so that everything is in the physical memory
+       * before starting the DMA.
+       */
+
+      cp15_clean_dcache((uintptr_t)apb->samp,
+                        (uintptr_t)apb->samp + apb->nbytes);
+
     }
   while (!sq_empty(&priv->txpend));
 
@@ -1451,13 +1469,6 @@ static int ssc_txdma_setup(struct sam_ssc_s *priv)
   
   ssc_txdma_sample(priv, DMA_AFTER_SETUP);
 
-  /* Flush the data cache so that everything is in the physical memory
-   * before starting the DMA.
-   */
-
-  cp15_clean_dcache((uintptr_t)bfcontainer->buffer,
-                    (uintptr_t)bfcontainer->buffer + bfcontainer->nbytes);
-
   /* Start the DMA, saving the container as the current active transfer */
 
   sam_dmastart(priv->txdma, ssc_txdma_callback, priv);
@@ -1509,7 +1520,6 @@ static void ssc_tx_worker(void *arg)
 {
   struct sam_ssc_s *priv = (struct sam_ssc_s *)arg;
   struct sam_buffer_s *bfcontainer;
-  i2s_txcallback_t callback;
   irqstate_t flags;
 
   DEBUGASSERT(priv);
@@ -1572,10 +1582,12 @@ static void ssc_tx_worker(void *arg)
       /* Perform the TX transfer done callback */
 
       DEBUGASSERT(bfcontainer && bfcontainer->callback);
+      bfcontainer->callback(&priv->dev, bfcontainer->apb,
+                            bfcontainer->arg, bfcontainer->result);
+
+      /* Release our reference on the audio buffer */
 
-      callback = (i2s_txcallback_t)bfcontainer->callback;
-      callback(&priv->dev, bfcontainer->buffer, bfcontainer->nbytes,
-               bfcontainer->arg, bfcontainer->result);
+      apb_free(bfcontainer->apb);
 
       /* And release the buffer container */
 
@@ -1780,9 +1792,7 @@ static uint32_t ssc_rxdatawidth(struct i2s_dev_s *dev, int bits)
  *
  * Input Parameters:
  *   dev      - Device-specific state data
- *   buffer   - A pointer to the buffer in which to recieve data
- *   nbytes   - The length of data that can be received in the buffer in number
- *              of bytes.
+ *   apb      - A pointer to the audio buffer in which to recieve data
  *   callback - A user provided callback function that will be called at
  *              the completion of the transfer.  The callback will be
  *              performed in the context of the worker thread.
@@ -1804,18 +1814,17 @@ static uint32_t ssc_rxdatawidth(struct i2s_dev_s *dev, int bits)
  *
  ****************************************************************************/
 
-static int ssc_receive(struct i2s_dev_s *dev, void *buffer,
-                       size_t nbytes, i2s_rxcallback_t callback,
-                       void *arg, uint32_t timeout)
+static int ssc_receive(struct i2s_dev_s *dev, struct ap_buffer_s *apb,
+                       i2s_callback_t callback, void *arg, uint32_t timeout)
 {
   struct sam_ssc_s *priv = (struct sam_ssc_s *)dev;
   struct sam_buffer_s *bfcontainer;
   irqstate_t flags;
   int ret;
 
-  i2svdbg("buffer=%p nbytes=%d\n", buffer, (int)nbytes);
-  DEBUGASSERT(priv && buffer && ((uintptr_t)buffer & 3) == 0);
-
+  DEBUGASSERT(priv && apb && ((uintptr_t)apb->samp & 3) == 0);
+  i2svdbg("apb=%p nmaxbytes=%d\n", apb, apb->nmaxbytes);
+ 
 #ifdef SSC_HAVE_RX
   /* Allocate a buffer container in advance */
 
@@ -1835,13 +1844,16 @@ static int ssc_receive(struct i2s_dev_s *dev, void *buffer,
       goto errout_with_exclsem;
     }
 
+  /* Add a reference to the audio buffer */
+
+  apb_reference(apb);
+
   /* Initialize the buffer container structure */
 
   bfcontainer->callback = (void *)callback;
   bfcontainer->timeout  = timeout;
   bfcontainer->arg      = arg;
-  bfcontainer->buffer   = buffer;
-  bfcontainer->nbytes   = nbytes;
+  bfcontainer->apb      = apb;
   bfcontainer->result   = -EBUSY;
 
   /* Add the buffer container to the end of the RX pending queue */
@@ -1957,9 +1969,8 @@ static uint32_t ssc_txdatawidth(struct i2s_dev_s *dev, int bits)
  *   Send a block of data on I2S.
  *
  * Input Parameters:
- *   dev    - Device-specific state data
- *   buffer - A pointer to the buffer of data to be sent
- *   nbytes - the length of data to send from the buffer in number of bytes.
+ *   dev      - Device-specific state data
+ *   apb      - A pointer to the audio buffer from which to send data
  *   callback - A user provided callback function that will be called at
  *              the completion of the transfer.  The callback will be
  *              performed in the context of the worker thread.
@@ -1981,17 +1992,16 @@ static uint32_t ssc_txdatawidth(struct i2s_dev_s *dev, int bits)
  *
  ****************************************************************************/
 
-static int ssc_send(struct i2s_dev_s *dev, const void *buffer,
-                    size_t nbytes, i2s_txcallback_t callback,
-                    void *arg, uint32_t timeout)
+static int ssc_send(struct i2s_dev_s *dev, struct ap_buffer_s *apb,
+                    i2s_callback_t callback, void *arg, uint32_t timeout)
 {
   struct sam_ssc_s *priv = (struct sam_ssc_s *)dev;
   struct sam_buffer_s *bfcontainer;
   irqstate_t flags;
   int ret;
 
-  i2svdbg("buffer=%p nbytes=%d\n", buffer, (int)nbytes);
-  DEBUGASSERT(priv && buffer && ((uintptr_t)buffer & 3) == 0);
+  DEBUGASSERT(priv && apb && ((uintptr_t)apb->samp & 3) == 0);
+  i2svdbg("apb=%p nbytes=%d\n", apb, apb->nbytes);
 
 #ifdef SSC_HAVE_TX
   /* Allocate a buffer container in advance */
@@ -2012,13 +2022,16 @@ static int ssc_send(struct i2s_dev_s *dev, const void *buffer,
       goto errout_with_exclsem;
     }
 
+  /* Add a reference to the audio buffer */
+
+  apb_reference(apb);
+
   /* Initialize the buffer container structure */
 
   bfcontainer->callback = (void *)callback;
   bfcontainer->timeout  = timeout;
   bfcontainer->arg      = arg;
-  bfcontainer->buffer   = (void *)buffer;
-  bfcontainer->nbytes   = nbytes;
+  bfcontainer->apb      = apb;
   bfcontainer->result   = -EBUSY;
 
   /* Add the buffer container to the end of the TX pending queue */
diff --git a/nuttx/drivers/audio/i2schar.c b/nuttx/drivers/audio/i2schar.c
index 52e945d5b..f7f251d7f 100644
--- a/nuttx/drivers/audio/i2schar.c
+++ b/nuttx/drivers/audio/i2schar.c
@@ -52,7 +52,6 @@
 #include <string.h>
 #include <debug.h>
 #include <errno.h>
-#include <queue.h>
 
 #include <nuttx/kmalloc.h>
 #include <nuttx/fs/fs.h>
@@ -100,8 +99,6 @@ struct i2schar_dev_s
 {
   FAR struct i2s_dev_s *i2s;  /* The lower half i2s driver */
   sem_t exclsem;              /* Assures mutually exclusive access */
-  dq_queue_t rxq;             /* RX audio buffers awaiting transfer */
-  dq_queue_t txq;             /* TX audio buffers awaiting transfer */
 };
 
 /****************************************************************************
@@ -110,9 +107,9 @@ struct i2schar_dev_s
 /* I2S callback function */
 
 static void    i2schar_rxcallback(FAR struct i2s_dev_s *dev,
-                 FAR void *buffer, size_t nbytes, FAR void *arg, int result);
+                 FAR struct ap_buffer_s *apb, FAR void *arg, int result);
 static void    i2schar_txcallback(FAR struct i2s_dev_s *dev,
-                 FAR const void *buffer, size_t nbytes, FAR void *arg,
+                 FAR struct ap_buffer_s *apb, FAR void *arg,
                  int result);
 
 /* Character driver methods */
@@ -161,47 +158,25 @@ static const struct file_operations i2schar_fops =
  ****************************************************************************/
 
 static void i2schar_rxcallback(FAR struct i2s_dev_s *dev,
-                               FAR void *buffer, size_t nbytes,
+                               FAR struct ap_buffer_s *apb,
                                FAR void *arg, int result)
 {
   FAR struct i2schar_dev_s *priv = (FAR struct i2schar_dev_s *)arg;
-  FAR struct ap_buffer_s *apb;
 
-  i2svdbg("buffer=%p nbytes=%d result=%d\n", buffer, (int)nbytes, result);
-  DEBUGASSERT(dev && buffer && priv);
+  DEBUGASSERT(priv && apb);
+  i2svdbg("apb=%p nbytes=%d result=%d\n", apb, apb->nbytes, result);
 
-  /* The returned buffer should match the buffer at the head of the RX audio
-   * buffer queue.
+  /* REVISIT: If you want this to actually do something other than
+   * test I2S data transfer, then this is the point where you would
+   * want to pass the received I2S to some application.
    */
 
-  apb = (FAR struct ap_buffer_s *)dq_peek(&priv->rxq);
-  if ((FAR const void *)apb->samp != buffer)
-    {
-      i2sdbg("ERROR: apb=%p apb->samp=%p buffer=%p\n",
-             apb, apb->samp, buffer);
-    }
-  else
-    {
-      if (apb->nmaxbytes != nbytes)
-        {
-          i2sdbg("ERROR: apb->nmaxbytes=%d nbytes=%d\n",
-                 (int)apb->nmaxbytes, (int)nbytes);
-        }
-
-      /* REVISIT: If you want this to actually do something other than
-       * test I2S data transfer, then this is the point where you would
-       * want to pass the received I2S to some application.
-       */
-
-      /* Remove the buffer from the beginning of the RX queue and release
-       * our reference to it.  Hopefully it will be freed now.
-       */
-
-      (void)dq_remfirst(&priv->rxq);
+  /* Release our reference to the audio buffer. Hopefully it will be freed
+   * now.
+   */
 
-      i2svdbg("Freeing apb=%p crefs=%d\n", apb, apb->crefs);
-      apb_free(apb);
-    }
+  i2svdbg("Freeing apb=%p crefs=%d\n", apb, apb->crefs);
+  apb_free(apb);
 }
 
 /****************************************************************************
@@ -218,47 +193,25 @@ static void i2schar_rxcallback(FAR struct i2s_dev_s *dev,
  ****************************************************************************/
 
 static void i2schar_txcallback(FAR struct i2s_dev_s *dev,
-                               FAR const void *buffer, size_t nbytes,
+                               FAR struct ap_buffer_s *apb,
                                FAR void *arg, int result)
 {
   FAR struct i2schar_dev_s *priv = (FAR struct i2schar_dev_s *)arg;
-  FAR struct ap_buffer_s *apb;
 
-  i2svdbg("buffer=%p nbytes=%d result=%d\n", buffer, (int)nbytes, result);
-  DEBUGASSERT(dev && buffer && priv);
+  DEBUGASSERT(priv && apb);
+  i2svdbg("apb=%p nbytes=%d result=%d\n", apb, apb->nbytes, result);
 
-  /* The returned buffer should match the buffer at the head of the RX audio
-   * buffer queue.
+  /* REVISIT: If you want this to actually do something other than
+   * test I2S data transfer, then this is the point where you would
+   * want to let some application know that the transfer has complete.
    */
 
-  apb = (FAR struct ap_buffer_s *)dq_peek(&priv->txq);
-  if ((FAR const void *)apb->samp != buffer)
-    {
-      i2sdbg("ERROR: apb=%p apb->samp=%p buffer=%p\n",
-             apb, apb->samp, buffer);
-    }
-  else
-    {
-      if (apb->nmaxbytes != nbytes)
-        {
-          i2sdbg("ERROR: apb->nmaxbytes=%d nbytes=%d\n",
-                 (int)apb->nmaxbytes, (int)nbytes);
-        }
-
-      /* REVISIT: If you want this to actually do something other than
-       * test I2S data transfer, then this is the point where you would
-       * want to pass the received I2S to some application.
-       */
-
-      /* Remove the buffer from the beginning of the RX queue and release
-       * our reference to it.  Hopefully it will be freed now.
-       */
-
-      (void)dq_remfirst(&priv->txq);
+  /* Release our reference to the audio buffer.  Hopefully it will be freed
+   * now.
+   */
 
-      i2svdbg("Freeing apb=%p crefs=%d\n", apb, apb->crefs);
-      apb_free(apb);
-    }
+  i2svdbg("Freeing apb=%p crefs=%d\n", apb, apb->crefs);
+  apb_free(apb);
 }
 
 /****************************************************************************
@@ -298,7 +251,7 @@ static ssize_t i2schar_read(FAR struct file *filep, FAR char *buffer,
   nbytes = apb->nmaxbytes;
   DEBUGASSERT(buflen >= (sizeof(struct ap_buffer_s) + nbytes));
 
-  /* Add our buffer reference */
+  /* Add a reference to the audio buffer */
 
   apb_reference(apb);
 
@@ -313,13 +266,9 @@ static ssize_t i2schar_read(FAR struct file *filep, FAR char *buffer,
       goto errout_with_reference;
     }
 
-  /* Add the audio buffer to the I2S receiver queue */
- 
-  dq_addlast(&apb->dq_entry, &priv->rxq);
-
-  /* And give the buffer to the I2S driver */
+  /* Give the buffer to the I2S driver */
 
-  ret = I2S_RECEIVE(priv->i2s, apb->samp, nbytes, i2schar_rxcallback, priv, 0);
+  ret = I2S_RECEIVE(priv->i2s, apb, i2schar_rxcallback, priv, 0);
   if (ret < 0)
     {
       i2sdbg("ERROR: I2S_RECEIVE returned: %d\n", ret);
@@ -376,7 +325,7 @@ static ssize_t i2schar_write(FAR struct file *filep, FAR const char *buffer,
   nbytes = apb->nmaxbytes;
   DEBUGASSERT(buflen >= (sizeof(struct ap_buffer_s) + nbytes));
 
-  /* Add our buffer reference */
+  /* Add a reference to the audio buffer */
 
   apb_reference(apb);
 
@@ -391,13 +340,9 @@ static ssize_t i2schar_write(FAR struct file *filep, FAR const char *buffer,
       goto errout_with_reference;
     }
 
-  /* Add the audio buffer to the I2S transmitter queue */
- 
-  dq_addlast(&apb->dq_entry, &priv->txq);
-
-  /* And give the buffer to the I2S driver */
+  /* Give the audio buffer to the I2S driver */
 
-  ret = I2S_SEND(priv->i2s, apb->samp, nbytes, i2schar_txcallback, priv, 0);
+  ret = I2S_SEND(priv->i2s, apb, i2schar_txcallback, priv, 0);
   if (ret < 0)
     {
       i2sdbg("ERROR: I2S_SEND returned: %d\n", ret);
@@ -457,8 +402,6 @@ int i2schar_register(FAR struct i2s_dev_s *i2s, int minor)
 
       priv->i2s = i2s;
       sem_init(&priv->exclsem, 0, 1);
-      dq_init(&priv->rxq);
-      dq_init(&priv->txq);
 
       /* Create the character device name */
 
diff --git a/nuttx/include/nuttx/audio/i2s.h b/nuttx/include/nuttx/audio/i2s.h
index 6318be005..e9addf784 100644
--- a/nuttx/include/nuttx/audio/i2s.h
+++ b/nuttx/include/nuttx/audio/i2s.h
@@ -46,6 +46,8 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#include <nuttx/audio/audio.h>
+
 #ifdef CONFIG_I2S
 
 /****************************************************************************
@@ -99,9 +101,7 @@
  *
  * Input Parameters:
  *   dev      - Device-specific state data
- *   buffer   - A pointer to the buffer in which to recieve data
- *   nbytes   - The length of data that can be received in the buffer in number
- *              of bytes.
+ *   apb      - A pointer to the audio buffer in which to recieve data
  *   callback - A user provided callback function that will be called at
  *              the completion of the transfer.  The callback will be
  *              performed in the context of the worker thread.
@@ -123,7 +123,7 @@
  *
  ****************************************************************************/
 
-#define I2S_RECEIVE(d,b,n,c,a,t) ((d)->ops->i2s_receive(d,b,n,c,a,t))
+#define I2S_RECEIVE(d,b,c,a,t) ((d)->ops->i2s_receive(d,b,c,a,t))
 
 /****************************************************************************
  * Name: I2S_TXSAMPLERATE
@@ -170,9 +170,8 @@
  *   Send a block of data on I2S.
  *
  * Input Parameters:
- *   dev    - Device-specific state data
- *   buffer - A pointer to the buffer of data to be sent
- *   nbytes - the length of data to send from the buffer in number of bytes.
+ *   dev      - Device-specific state data
+ *   apb      - A pointer to the audio buffer from which to send data
  *   callback - A user provided callback function that will be called at
  *              the completion of the transfer.  The callback will be
  *              performed in the context of the worker thread.
@@ -194,7 +193,7 @@
  *
  ****************************************************************************/
 
-#define I2S_SEND(d,b,n,c,a,t) ((d)->ops->i2s_send(d,b,n,c,a,t))
+#define I2S_SEND(d,b,c,a,t) ((d)->ops->i2s_send(d,b,c,a,t))
 
 /****************************************************************************
  * Public Types
@@ -202,12 +201,8 @@
 /* Transfer complete callbacks */
 
 struct i2s_dev_s;
-typedef CODE void (*i2s_rxcallback_t)(FAR struct i2s_dev_s *dev,
-                  FAR void *buffer, size_t nbytes, FAR void *arg,
-                  int result);
-typedef CODE void (*i2s_txcallback_t)(FAR struct i2s_dev_s *dev,
-                  FAR const void *buffer, size_t nbytes, FAR void *arg,
-                  int result);
+typedef CODE void (*i2s_callback_t)(FAR struct i2s_dev_s *dev,
+                  FAR struct ap_buffer_s *apb, FAR void *arg, int result);
 
 /* The I2S vtable */
 
@@ -217,17 +212,17 @@ struct i2s_ops_s
 
   CODE uint32_t (*i2s_rxsamplerate)(FAR struct i2s_dev_s *dev, uint32_t rate);
   CODE uint32_t (*i2s_rxdatawidth)(FAR struct i2s_dev_s *dev, int bits);
-  CODE int      (*i2s_receive)(FAR struct i2s_dev_s *dev, FAR void *buffer,
-                  size_t nbytes, i2s_rxcallback_t callback, FAR void *arg,
-                  uint32_t timeout);
+  CODE int      (*i2s_receive)(FAR struct i2s_dev_s *dev,
+                  FAR struct ap_buffer_s *apb, i2s_callback_t callback,
+                  FAR void *arg, uint32_t timeout);
 
   /* Transmitter methods */
 
   CODE uint32_t (*i2s_txsamplerate)(FAR struct i2s_dev_s *dev, uint32_t rate);
   CODE uint32_t (*i2s_txdatawidth)(FAR struct i2s_dev_s *dev, int bits);
-  CODE int      (*i2s_send)(FAR struct i2s_dev_s *dev, FAR const void *buffer,
-                  size_t nbytes, i2s_txcallback_t callback, FAR void *arg,
-                  uint32_t timeout);
+  CODE int      (*i2s_send)(FAR struct i2s_dev_s *dev,
+                  FAR struct ap_buffer_s *apb, i2s_callback_t callback,
+                  FAR void *arg, uint32_t timeout);
 };
 
 /* I2S private data.  This structure only defines the initial fields of the