Commit FS#12150 - Fully-functional audio mixer - and finally whip old limitations about playback of voice and other sounds when paused. Channels are independent in state and amplitude. Fade on stop/pause is handled by the channel's volume control rather than global volume which means it now works from anywhere. Opens up the possibility of plugin sounds during music playback by merely adding an additional channel enum. If any PCM drivers were not properly modified, see one of the last comments in the task for a description of the simple change that is expected. Some params are tunable in firmware/export/pcm-mixer.h as well.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30097 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 18 insertions, 8 deletions

diff --git a/firmware/target/arm/pcm-telechips.c b/firmware/target/arm/pcm-telechips.c
index 851ebee7de..aff43171f6 100644
--- a/firmware/target/arm/pcm-telechips.c
+++ b/firmware/target/arm/pcm-telechips.c
@@ -27,6 +27,7 @@
 #include "sound.h"
 #include "i2s.h"
 #include "pcm.h"
+#include "pcm-internal.h"
 
 struct dma_data
 {
@@ -247,6 +248,8 @@ void fiq_handler(void)
      * r0-r3 and r12 is a working register.
      */
     asm volatile (
+        "stmfd   sp!, { r0-r4, lr }  \n" /* stack scratch regs and lr */
+        "mov     r4, #0              \n" /* Was the callback called? */
 #if defined(CPU_TCC780X)
         "mov     r8, #0xc000         \n" /* DAI_TX_IRQ_MASK | DAI_RX_IRQ_MASK */
         "ldr     r9, =0xf3001004     \n" /* CREQ */
@@ -279,33 +282,41 @@ void fiq_handler(void)
         "sub     r9, r9, #0x10       \n" /* 4 words written */
         "stmia   r11, { r8-r9 }      \n" /* save p and size */
 
+        "cmp     r4, #0              \n" /* Callback called? */
+        "beq     .exit               \n"
+        /* "mov     r4, #0              \n" If get_more could be called multiple times! */
+        "ldr     r2, =pcm_play_dma_started\n"
+        "ldr     r2, [r2]            \n"
+        "cmp     r2, #0              \n"
+        "blxne   r2                  \n"
+
     ".exit:                          \n"
+        "ldmfd   sp!, { r0-r4, lr }  \n"
         "subs    pc, lr, #4          \n" /* FIQ specific return sequence */
 
     ".more_data:                     \n"
-        "stmfd   sp!, { r0-r3, lr }  \n" /* stack scratch regs and lr */
+        "mov     r4, #1              \n" /* Remember we got more data in this FIQ */
         "ldr     r2, =pcm_play_get_more_callback \n"
         "mov     r0, r11             \n" /* r0 = &p */
         "add     r1, r11, #4         \n" /* r1 = &size */
         "blx     r2                  \n" /* call pcm_play_get_more_callback */
         "ldmia   r11, { r8-r9 }      \n" /* load new p and size */
         "cmp     r9, #0x10           \n" /* did we actually get enough data? */
-        "ldmfd   sp!, { r0-r3, lr }  \n"
         "bpl     .fill_fifo          \n" /* not stop and enough? refill */
         "b       .exit               \n"
         ".ltorg                      \n"
     );
 }
 #else /* C version for reference */
-void fiq_handler(void) ICODE_ATTR __attribute__((naked));
+void fiq_handler(void) ICODE_ATTR;
 void fiq_handler(void)
 {
-    asm volatile(   "stmfd sp!, {r0-r7, ip, lr} \n"   /* Store context */
-                    "sub   sp, sp, #8           \n"); /* Reserve stack */
+    register bool new_buffer = false;
 
     if (dma_play_data.size < 16)
     {
         /* p is empty, get some more data */
+        new_buffer = true;
         pcm_play_get_more_callback((void**)&dma_play_data.p,
                                    &dma_play_data.size);
     }
@@ -327,9 +338,8 @@ void fiq_handler(void)
     /* Clear FIQ status */
     CREQ = DAI_TX_IRQ_MASK | DAI_RX_IRQ_MASK;
 
-    asm volatile(   "add   sp, sp, #8           \n"   /* Cleanup stack   */
-                    "ldmfd sp!, {r0-r7, ip, lr} \n"   /* Restore context */
-                    "subs  pc, lr, #4           \n"); /* Return from FIQ */
+    if (new_buffer)
+        pcm_play_dma_started_callback();
 }
 #endif