iPod - Initial skeleton of an audio driver

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8248 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 101 insertions, 10 deletions

diff --git a/firmware/pcm_playback.c b/firmware/pcm_playback.c
index 6703c6a622..8a6de9a8b9 100644
--- a/firmware/pcm_playback.c
+++ b/firmware/pcm_playback.c
@@ -26,6 +26,8 @@
 #include "i2c.h"
 #if defined(HAVE_UDA1380)
 #include "uda1380.h"
+#elif defined(HAVE_WM8975)
+#include "wm8975.h"
 #elif defined(HAVE_TLV320)
 #include "tlv320.h"
 #endif
@@ -343,50 +345,139 @@ void pcm_init(void)
 
 #elif defined(HAVE_WM8975)
 
-/* TODO: Implement for iPod - we should probably move the UDA1380 and
-   WM8975 specific code into separate files. 
-
-   For now, just implement some dummy functions.
+/* We need to unify this code with the uda1380 code as much as possible, but
+   we will keep it separate during early development.
 */
 
+static bool pcm_playing;
+static bool pcm_paused;
+static int pcm_freq = 0x6; /* 44.1 is default */
+
+static unsigned char *next_start;
+static long next_size;
+
+/* Set up the DMA transfer that kicks in when the audio FIFO gets empty */
+static void dma_start(const void *addr, long size)
+{
+    pcm_playing = true;
+
+    addr = (void *)((unsigned long)addr & ~3); /* Align data */
+    size &= ~3; /* Size must be multiple of 4 */
+
+    return;
+
+/* This is the uda1380 code */
+#if 0
+    /* Reset the audio FIFO */
+
+    /* Set up DMA transfer  */
+    SAR0 = ((unsigned long)addr); /* Source address */
+    DAR0 = (unsigned long)&PDOR3; /* Destination address */
+    BCR0 = size;                  /* Bytes to transfer */
+
+    /* Enable the FIFO and force one write to it */
+    IIS2CONFIG = IIS_DEFPARM(pcm_freq);
+
+    DCR0 = DMA_INT | DMA_EEXT | DMA_CS | DMA_SINC | DMA_START;
+#endif
+}
+
+/* Stops the DMA transfer and interrupt */
+static void dma_stop(void)
+{
+    pcm_playing = false;
+
+#if 0
+/* This is the uda1380 code */
+    DCR0 = 0;
+    DSR0 = 1;
+    /* Reset the FIFO */
+    IIS2CONFIG = IIS_RESET | IIS_DEFPARM(pcm_freq);
+#endif
+    next_start = NULL;
+    next_size = 0;
+    pcm_paused = false;
+}
+
+
 void pcm_init(void)
 {
+    pcm_playing = false;
+    pcm_paused = false;
+
+    /* Initialize default register values. */
+    wm8975_init();
+    
+    /* The uda1380 needs a sleep(HZ) here - do we need one? */
 
+    /* Power on */
+    wm8975_enable_output(true);
+
+    /* Unmute the master channel (DAC should be at zero point now). */
+    wm8975_mute(false);
+    
+    /* Call dma_stop to initialize everything. */
+    dma_stop();
 }
 
 void pcm_set_frequency(unsigned int frequency)
 {
     (void)frequency;
+    pcm_freq=frequency;
 }
 
+/* the registered callback function to ask for more mp3 data */
+static void (*callback_for_more)(unsigned char**, long*) = NULL;
+
 void pcm_play_data(void (*get_more)(unsigned char** start, long* size))
 {
-    (void)get_more;
+    unsigned char *start;
+    long size;
+
+    callback_for_more = get_more;
+
+    get_more((unsigned char **)&start, (long *)&size);
+    get_more(&next_start, &next_size);
+
+    dma_start(start, size);
 }
 
 void pcm_play_stop(void)
 {
+    if (pcm_playing) {
+        dma_stop();
+    }
 }
 
 void pcm_play_pause(bool play)
 {
-    (void)play;
+    if(pcm_paused && play && next_size)
+    {
+        logf("unpause");
+        /* We need to enable DMA here */
+    }
+    else if(!pcm_paused && !play)
+    {
+        logf("pause");
+        /* We need to disable DMA here */
+    }
+    pcm_paused = !play;
 }
 
 bool pcm_is_paused(void)
 {
-    return false;
+    return pcm_paused;
 }
 
 bool pcm_is_playing(void)
 {
-    return false;
+    return pcm_playing;
 }
 
 void pcm_calculate_peaks(int *left, int *right)
 {
-    (void)left;
-    (void)right;
+    *left=0;
+    *right=0;
 }
 
 long pcm_get_bytes_waiting(void)