From a834f8b1f69bc62fb8f56dc529860ed8c7f5bd54 Mon Sep 17 00:00:00 2001
From: Jeffrey Pfau <jeffrey@endrift.com>
Date: Wed, 2 Oct 2013 00:46:51 -0700
Subject: [PATCH] Sample FIFOs with sound DMA timer

---
 src/gba/gba-audio.h | 20 ++++++++++----------
 src/gba/gba-io.c    |  4 +---
 src/gba/gba.c       | 20 ++++++++++++++++++++
 3 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/src/gba/gba-audio.h b/src/gba/gba-audio.h
index 210f57aed..bf56a4643 100644
--- a/src/gba/gba-audio.h
+++ b/src/gba/gba-audio.h
@@ -138,17 +138,17 @@ struct GBAAudio {
 	union {
 		struct {
 			unsigned volume : 2;
-			unsigned volumeDmaA : 1;
-			unsigned volumeDmaB : 1;
+			unsigned volumeChA : 1;
+			unsigned volumeChB : 1;
 			unsigned : 4;
-			unsigned dmaARight : 1;
-			unsigned dmaALeft : 1;
-			unsigned dmaATimer : 1;
-			unsigned dmaAReset : 1;
-			unsigned dmaBRight : 1;
-			unsigned dmaBLeft : 1;
-			unsigned dmaBTimer : 1;
-			unsigned dmaBReset : 1;
+			unsigned chARight : 1;
+			unsigned chALeft : 1;
+			unsigned chATimer : 1;
+			unsigned chAReset : 1;
+			unsigned chBRight : 1;
+			unsigned chBLeft : 1;
+			unsigned chBTimer : 1;
+			unsigned chBReset : 1;
 		};
 		uint16_t soundcntHi;
 	};
diff --git a/src/gba/gba-io.c b/src/gba/gba-io.c
index 524814745..22fa4fb77 100644
--- a/src/gba/gba-io.c
+++ b/src/gba/gba-io.c
@@ -209,10 +209,8 @@ void GBAIOWrite32(struct GBA* gba, uint32_t address, uint32_t value) {
 		GBAAudioWriteWaveRAM(&gba->audio, 3, value);
 		break;
 	case REG_FIFO_A_LO:
-		GBAAudioWriteFIFO(&gba->audio, 0, value);
-		break;
 	case REG_FIFO_B_LO:
-		GBAAudioWriteFIFO(&gba->audio, 1, value);
+		GBAAudioWriteFIFO(&gba->audio, address, value);
 		break;
 	case REG_DMA0SAD_LO:
 		GBAMemoryWriteDMASAD(&gba->memory, 0, value);
diff --git a/src/gba/gba.c b/src/gba/gba.c
index 79b9d5e4f..88e8159b8 100644
--- a/src/gba/gba.c
+++ b/src/gba/gba.c
@@ -136,6 +136,16 @@ static int32_t GBATimersProcessEvents(struct GBA* gba, int32_t cycles) {
 					GBARaiseIRQ(gba, IRQ_TIMER0);
 				}
 
+				if (gba->audio.enable) {
+					if ((gba->audio.chALeft || gba->audio.chARight) && gba->audio.chATimer == 0) {
+						GBAAudioSampleFIFO(&gba->audio, 0);
+					}
+
+					if ((gba->audio.chBLeft || gba->audio.chBRight) && gba->audio.chBTimer == 0) {
+						GBAAudioSampleFIFO(&gba->audio, 1);
+					}
+				}
+
 				nextTimer = &gba->timers[1];
 				if (nextTimer->countUp) {
 					++gba->memory.io[REG_TM1CNT_LO >> 1];
@@ -161,6 +171,16 @@ static int32_t GBATimersProcessEvents(struct GBA* gba, int32_t cycles) {
 					GBARaiseIRQ(gba, IRQ_TIMER1);
 				}
 
+				if (gba->audio.enable) {
+					if ((gba->audio.chALeft || gba->audio.chARight) && gba->audio.chATimer == 1) {
+						GBAAudioSampleFIFO(&gba->audio, 0);
+					}
+
+					if ((gba->audio.chBLeft || gba->audio.chBRight) && gba->audio.chBTimer == 1) {
+						GBAAudioSampleFIFO(&gba->audio, 1);
+					}
+				}
+
 				if (timer->countUp) {
 					timer->nextEvent = INT_MAX;
 				}