iRiver: Major PCM DMA code cleanup, added pcm_init() and pcm_play_pause()

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6234 a1c6a512-1295-4272-9138-f99709370657

firmware/export/pcm_playback.h

@@ -19,10 +19,12 @@
 #ifndef PCM_PLAYBACK_H
 #define PCM_PLAYBACK_H
 
+void pcm_init(void);
 void pcm_set_frequency(unsigned int frequency);
 void pcm_play_data(const unsigned char* start, int size,
                    void (*get_more)(unsigned char** start, long* size));
 void pcm_play_stop(void);
+void pcm_play_pause(bool play);
 bool pcm_is_playing(void);
 void pcm_set_volume(int volume);
 

firmware/pcm_playback.c

@@ -42,57 +42,37 @@
 #include <string.h>
 
 static bool pcm_playing;
-static int pcm_freq = 0x6; // 44.1 in default
+static bool pcm_paused;
+static int pcm_freq = 0x6; /* 44.1 is default */
 
 /* Set up the DMA transfer that kicks in when the audio FIFO gets empty */
-static void dma_start(const void *addr_r, long size)
+static void dma_start(const void *addr, long size)
 {
-    pcm_playing = 1;
-    int i;
+    pcm_playing = true;
 
-    int align;
-    align = 4;
+    addr = (void *)((unsigned long)addr & ~3); /* Align data */
+    size &= ~3; /* Size must be multiple of 4 */
 
-    void* addr = (void*)((((unsigned int)addr_r) >> 2) << 2); // always align data, never pass unaligned data
-    size = (size >> 2) << 2; // size shoudl also be always multiple of 4
-
-    BUSMASTER_CTRL = 0x81; /* PARK[1,0]=10 + BCR24BIT */
+    /* Reset the audio FIFO */
+    IIS2CONFIG = 0x800;
     
     /* Set up DMA transfer  */
-    DIVR0 = 54;          /* DMA0 is mapped into vector 54 in system.c */
-    SAR0 = ((unsigned long)addr) + align*4;         /* Source address */
+    SAR0 = ((unsigned long)addr); /* Source address */
     DAR0 = (unsigned long)&PDOR3; /* Destination address */
-    BCR0 = size-(align*4);                        /* Bytes to transfer */
-    DMAROUTE = (DMAROUTE & 0xffffff00) | DMA0_REQ_AUDIO_1;
-    DMACONFIG = 1;   /* Enable DMA0Req => set DMAROUTE |= DMA0_REQ_AUDIO_1 */
+    BCR0 = size;                  /* Bytes to transfer */
 
-    /* Start transfer when requested */
-    DCR0 = DMA_INT | DMA_EEXT | DMA_CS | DMA_SINC;
-
-    /* Enable interrupt at level 7, priority 0 */
-    ICR4 = (ICR4 & 0xffff00ff) | 0x00001c00;
-    IMR &= ~(1<<14);      /* bit 14 is DMA0 */
-
-    IIS2CONFIG = (pcm_freq << 12) | 0x300;   /* CLOCKSEL for right frequency +  data source = PDOR3 */
-
-    for(i = 0; i < align; i++)
-        PDOR3 = ((unsigned int*)(addr))[i]; /* These are needed to generate FIFO empty request to DMA.. */
+    /* Enable the FIFO and force one write to it */
+    IIS2CONFIG = (pcm_freq << 12) | 0x300;
+    DCR0 = DMA_INT | DMA_EEXT | DMA_CS | DMA_SINC | DMA_START;
 }
 
 /* Stops the DMA transfer and interrupt */
 static void dma_stop(void)
 {
-    pcm_playing = 0;
-    DCR0 = 0;
-                       
-/*    DMAROUTE &= 0xffffff00;
-    DMACONFIG = 0;*/
+    pcm_playing = false;
 
+    /* Reset the FIFO */
     IIS2CONFIG = 0x800;
-    
-    /* Disable DMA0 interrupt */
-    IMR |= (1<<14);
-    ICR4 &= 0xffff00ff;
 }
 
 
@@ -126,6 +106,7 @@ void pcm_set_frequency(unsigned int frequency)
         break;
     default:
         pcm_freq = 0x6;
+        break;
     }
 }
 
@@ -145,6 +126,23 @@ void pcm_play_stop(void)
     dma_stop();
 }
 
+void pcm_play_pause(bool play)
+{
+    if(pcm_paused && play)
+    {
+        /* Enable the FIFO and force one write to it */
+        IIS2CONFIG = (pcm_freq << 12) | 0x300;
+        DCR0 |= DMA_START;
+        
+        pcm_paused = false;
+    }
+    else if(!pcm_paused && !play)
+    {
+        IIS2CONFIG = 0x800;
+        pcm_paused = true;
+    }
+}
+
 bool pcm_is_playing(void)
 {
     return pcm_playing;
@@ -161,11 +159,13 @@ void DMA0(void)
 
     DSR0 = 1;    /* Clear interrupt */
 
-    if(res == 0x41)
+    /* Stop on error */
+    if(res & 0x70)
     {
        dma_stop();
     }
-
+    else
+    {
         if (callback_for_more)
         {
             callback_for_more(&start, &size);
@@ -181,6 +181,29 @@ void DMA0(void)
             /* Finished playing */
             dma_stop();
         }
+    }
     
     IPR |= (1<<14); /* Clear pending interrupt request */
 }
+
+void pcm_init(void)
+{
+    pcm_playing = false;
+    pcm_paused = false;
+    
+    uda1380_init();
+
+    BUSMASTER_CTRL = 0x81; /* PARK[1,0]=10 + BCR24BIT */
+    DIVR0 = 54;            /* DMA0 is mapped into vector 54 in system.c */
+    DMAROUTE = (DMAROUTE & 0xffffff00) | DMA0_REQ_AUDIO_1;
+    DMACONFIG = 1;   /* DMA0Req = PDOR3 */
+
+    /* Reset the audio FIFO */
+    IIS2CONFIG = 0x800;
+    
+    /* Enable interrupt at level 7, priority 0 */
+    ICR4 = (ICR4 & 0xffff00ff) | 0x00001c00;
+    IMR &= ~(1<<14);      /* bit 14 is DMA0 */
+
+    pcm_set_frequency(44100);
+}