Revise the PCM callback system after adding multichannel audio.

Additional status callback is added to pcm_play/rec_data instead of
using a special function to set it. Status includes DMA error
reporting to the status callback. Playback and recording callback
become more alike except playback uses "const void **addr" (because
the data should not be altered) and recording  uses "void **addr".
"const" is put in place throughout where appropriate.

Most changes are fairly trivial. One that should be checked in
particular because it isn't so much is telechips, if anyone cares to
bother. PP5002 is not so trivial either but that tested as working.

Change-Id: I4928d69b3b3be7fb93e259f81635232df9bd1df2
Reviewed-on: http://gerrit.rockbox.org/166
Reviewed-by: Michael Sevakis <jethead71@rockbox.org>
Tested-by: Michael Sevakis <jethead71@rockbox.org>

1 files changed, 56 insertions, 63 deletions

diff --git a/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c
index e106cf78e3..c26349b72e 100644
--- a/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c
@@ -78,12 +78,20 @@ static struct dma_data dma_play_data =
     .state = 0
 };
 
-static void play_dma_callback(void)
+static void play_start_dma(const void *addr, size_t size)
 {
-    void *start;
-    size_t size;
-    bool rror;
+    commit_dcache_range(addr, size);
+
+    dma_play_bd.buf_addr = (void *)addr_virt_to_phys((unsigned long)addr);
+    dma_play_bd.mode.count = size;
+    dma_play_bd.mode.command = TRANSFER_16BIT;
+    dma_play_bd.mode.status = BD_DONE | BD_WRAP | BD_INTR;
+
+    sdma_channel_run(DMA_PLAY_CH_NUM);
+}
 
+static void play_dma_callback(void)
+{
     if (dma_play_data.locked != 0)
     {
         /* Callback is locked out */
@@ -91,22 +99,17 @@ static void play_dma_callback(void)
         return;
     }
 
-    rror = dma_play_bd.mode.status & BD_RROR;
-
-    pcm_play_get_more_callback(rror ? NULL : &start, &size);
-
-    if (size == 0)
-        return;
-
-     /* Flush any pending cache writes */
-    commit_dcache_range(start, size);
-    dma_play_bd.buf_addr = (void *)addr_virt_to_phys((unsigned long)start);
-    dma_play_bd.mode.count = size;
-    dma_play_bd.mode.command = TRANSFER_16BIT;
-    dma_play_bd.mode.status = BD_DONE | BD_WRAP | BD_INTR;
-    sdma_channel_run(DMA_PLAY_CH_NUM);
-
-    pcm_play_dma_started_callback();
+    /* Inform of status and get new buffer */
+    enum pcm_dma_status status = (dma_play_bd.mode.status & BD_RROR) ?
+                  PCM_DMAST_ERR_DMA : PCM_DMAST_OK;
+    const void *addr;
+    size_t size;
+    
+    if (pcm_play_dma_complete_callback(status, &addr, &size))
+    {
+        play_start_dma(addr, size);
+        pcm_play_dma_status_callback(PCM_DMAST_STARTED);
+    }
 }
 
 void pcm_play_lock(void)
@@ -221,15 +224,11 @@ void pcm_play_dma_start(const void *addr, size_t size)
     if (!sdma_channel_reset(DMA_PLAY_CH_NUM))
         return;
 
-    commit_dcache_range(addr, size);
-    dma_play_bd.buf_addr =
-        (void *)addr_virt_to_phys((unsigned long)(void *)addr);
-    dma_play_bd.mode.count = size;
-    dma_play_bd.mode.command = TRANSFER_16BIT;
-    dma_play_bd.mode.status = BD_DONE | BD_WRAP | BD_INTR;
-
+    /* Begin I2S transmission */
     play_start_pcm();
-    sdma_channel_run(DMA_PLAY_CH_NUM);
+
+    /* Begin DMA transfer */
+    play_start_dma(addr, size);
 }
 
 void pcm_play_dma_stop(void)
@@ -332,37 +331,39 @@ static struct dma_data dma_rec_data =
     .state = 0
 };
 
-static void rec_dma_callback(void)
+static void rec_start_dma(void *addr, size_t size)
 {
-    int status = 0;
-    void *start;
-    size_t size;
+    discard_dcache_range(addr, size);
+
+    addr = (void *)addr_virt_to_phys((unsigned long)addr);
 
+    dma_rec_bd.buf_addr = addr;
+    dma_rec_bd.mode.count = size;
+    dma_rec_bd.mode.command = TRANSFER_16BIT;
+    dma_rec_bd.mode.status = BD_DONE | BD_WRAP | BD_INTR;
+
+    sdma_channel_run(DMA_REC_CH_NUM);
+}
+
+static void rec_dma_callback(void)
+{
     if (dma_rec_data.locked != 0)
     {
         dma_rec_data.callback_pending = dma_rec_data.state;
         return; /* Callback is locked out */
     }
 
-    if (dma_rec_bd.mode.status & BD_RROR)
-        status = DMA_REC_ERROR_DMA;
-
-    pcm_rec_more_ready_callback(status, &start, &size);
-
-    if (size == 0)
-        return;
-
-    /* Invalidate - buffer must be coherent */
-    discard_dcache_range(start, size);
-
-    start = (void *)addr_virt_to_phys((unsigned long)start);
-
-    dma_rec_bd.buf_addr = start;
-    dma_rec_bd.mode.count = size;
-    dma_rec_bd.mode.command = TRANSFER_16BIT;
-    dma_rec_bd.mode.status = BD_DONE | BD_WRAP | BD_INTR;
+    /* Inform middle layer */
+    enum pcm_dma_status status = (dma_rec_bd.mode.status & BD_RROR) ?
+                                  PCM_DMAST_ERR_DMA : PCM_DMAST_OK;
+    void *addr;
+    size_t size;
 
-    sdma_channel_run(DMA_REC_CH_NUM);
+    if (pcm_rec_dma_complete_callback(status, &addr, &size))
+    {
+        rec_start_dma(addr, size);
+        pcm_rec_dma_status_callback(PCM_DMAST_STARTED);
+    }
 }
 
 void pcm_rec_lock(void)
@@ -426,29 +427,21 @@ void pcm_rec_dma_start(void *addr, size_t size)
 
     if (!sdma_channel_reset(DMA_REC_CH_NUM))
         return;
-    
-    /* Invalidate - buffer must be coherent */
-    discard_dcache_range(addr, size);
 
-    addr = (void *)addr_virt_to_phys((unsigned long)addr);
-    dma_rec_bd.buf_addr = addr;
-    dma_rec_bd.mode.count = size;
-    dma_rec_bd.mode.command = TRANSFER_16BIT;
-    dma_rec_bd.mode.status = BD_DONE | BD_WRAP | BD_INTR;
+    /* Ensure clear FIFO */
+    while (SSI_SFCSR1 & SSI_SFCSR_RFCNT0)
+        SSI_SRX0_1;
 
     dma_rec_data.state = 1; /* Check callback on unlock */
 
     SSI_SRCR1 |= SSI_SRCR_RFEN0; /* Enable RX FIFO */
 
-    /* Ensure clear FIFO */
-    while (SSI_SFCSR1 & SSI_SFCSR_RFCNT0)
-        SSI_SRX0_1;
-
     /* Enable receive */
     SSI_SCR1 |= SSI_SCR_RE;
     SSI_SIER1 |= SSI_SIER_RDMAE; /* Enable DMA req. */
 
-    sdma_channel_run(DMA_REC_CH_NUM);
+    /* Begin DMA transfer */
+    rec_start_dma(addr, size);
 }
 
 void pcm_rec_dma_close(void)