From 203af4c4716a47ba8bd711c2680e5003c180e05c Mon Sep 17 00:00:00 2001
From: Rekai Musuka <rekai@musuka.dev>
Date: Fri, 21 Oct 2022 05:12:50 -0300
Subject: [PATCH] chore: 32-bit reads for PSG audio

---
 src/apu.zig    | 33 +++++++++++++++++++++++++++++----
 src/bus/io.zig |  2 +-
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/src/apu.zig b/src/apu.zig
index 640eda3..dfca370 100644
--- a/src/apu.zig
+++ b/src/apu.zig
@@ -64,10 +64,16 @@ pub fn write(comptime T: type, apu: *Apu, addr: u32, value: T) void {
 
     switch (T) {
         u32 => switch (byte) {
-            0x80 => {
-                apu.psg_cnt.raw = @truncate(u16, value); // SOUNDCNT_L
-                apu.dma_cnt.raw = @truncate(u16, value >> 16); // SOUNDCNT_H
-            },
+            0x60 => apu.ch1.setSoundCnt(value),
+            0x64 => apu.ch1.setSoundCntX(&apu.fs, @truncate(u16, value)),
+            0x68 => apu.ch2.setSoundCntL(@truncate(u16, value)),
+            0x6C => apu.ch2.setSoundCntH(&apu.fs, @truncate(u16, value)),
+            0x70 => apu.ch3.setSoundCnt(value),
+            0x74 => apu.ch3.setSoundCntX(&apu.fs, @truncate(u16, value)),
+            0x78 => apu.ch4.setSoundCntL(@truncate(u16, value)),
+            0x7C => apu.ch4.setSoundCntH(&apu.fs, @truncate(u16, value)),
+
+            0x80 => apu.setSoundCnt(value),
             // WAVE_RAM
             0x90...0x9F => apu.ch3.wave_dev.write(T, apu.ch3.select, addr, value),
             0xA0 => apu.chA.push(value), // FIFO_A
@@ -196,6 +202,12 @@ pub const Apu = struct {
         self.ch4.reset();
     }
 
+    /// SOUNDCNT
+    fn setSoundCnt(self: *Self, value: u32) void {
+        self.psg_cnt.raw = @truncate(u16, value);
+        self.setSoundCntH(@truncate(u16, value >> 16));
+    }
+
     /// SOUNDCNT_H_L
     fn setSoundCntHL(self: *Self, value: u8) void {
         const merged = (self.dma_cnt.raw & 0xFF00) | value;
@@ -208,6 +220,7 @@ pub const Apu = struct {
         self.setSoundCntH(merged);
     }
 
+    /// SOUNDCNT_H
     pub fn setSoundCntH(self: *Self, value: u16) void {
         const new: io.DmaSoundControl = .{ .raw = value };
 
@@ -521,6 +534,12 @@ const ToneSweep = struct {
         return @as(i16, self.sample);
     }
 
+    /// NR10, NR11, NR12
+    fn setSoundCnt(self: *Self, value: u32) void {
+        self.sweep.raw = @truncate(u8, value);
+        self.setSoundCntH(@truncate(u16, value >> 16));
+    }
+
     /// NR10
     pub fn getSoundCntL(self: *const Self) u8 {
         return self.sweep.raw & 0x7F;
@@ -789,6 +808,12 @@ const Wave = struct {
         self.len_dev.tick(self.freq.length_enable.read(), &self.enabled);
     }
 
+    /// NR30, NR31, NR32
+    fn setSoundCnt(self: *Self, value: u32) void {
+        self.setSoundCntL(@truncate(u8, value));
+        self.setSoundCntH(@truncate(u16, value >> 16));
+    }
+
     /// NR30
     pub fn setSoundCntL(self: *Self, value: u8) void {
         self.select.raw = value;
diff --git a/src/bus/io.zig b/src/bus/io.zig
index 49fce0d..68ed62d 100644
--- a/src/bus/io.zig
+++ b/src/bus/io.zig
@@ -171,7 +171,7 @@ pub fn write(bus: *Bus, comptime T: type, address: u32, value: T) void {
             0x0400_0058...0x0400_005C => {}, // Unused
 
             // Sound
-            0x0400_0080...0x0400_00A4 => apu.write(T, &bus.apu, address, value),
+            0x0400_0060...0x0400_00A4 => apu.write(T, &bus.apu, address, value),
             0x0400_00A8, 0x0400_00AC => {}, // Unused
 
             // DMA Transfers