Merge pull request #44 from YushiOMOTE/refactor-apu

Refactor apu

Author: YushiOMOTE

Cargo.lock

@@ -16,6 +16,7 @@ lazy_static = { version = "1.2", features = ["spin_no_std"] }
 log = "0.4"
 hashbrown = "0.14"
 spin = "0.9"
+bitfield-struct = "0.8.0"
 
 [dev-dependencies]
 env_logger = "0.11"

core/Cargo.toml

@@ -6,35 +6,52 @@ use super::{
 };
 use crate::hardware::Stream;
 use alloc::sync::Arc;
+use bitfield_struct::bitfield;
 use core::sync::atomic::{AtomicBool, AtomicUsize};
 use spin::Mutex;
 
 pub struct Mixer {
     power: bool,
-    ctrl: u8,
-    so1_volume: usize,
-    so2_volume: usize,
-    so_mask: usize,
-    enable: bool,
+    nr50: Nr50,
+    nr51: Nr51,
     stream: MixerStream,
 }
 
+#[bitfield(u8)]
+struct Nr50 {
+    #[bits(3)]
+    right_volume: usize,
+    vin_right_enable: bool,
+    #[bits(3)]
+    left_volume: usize,
+    vin_left_enable: bool,
+}
+
+#[bitfield(u8)]
+struct Nr51 {
+    ch1_right: bool,
+    ch2_right: bool,
+    ch3_right: bool,
+    ch4_right: bool,
+    ch1_left: bool,
+    ch2_left: bool,
+    ch3_left: bool,
+    ch4_left: bool,
+}
+
 impl Mixer {
     pub fn new() -> Self {
         Self {
             power: false,
-            ctrl: 0,
-            so1_volume: 0,
-            so2_volume: 0,
-            so_mask: 0,
-            enable: false,
+            nr50: Nr50::default(),
+            nr51: Nr51::default(),
             stream: MixerStream::new(),
         }
     }
 
     /// Read NR50 register (0xff24)
     pub fn read_ctrl(&self) -> u8 {
-        self.ctrl
+        self.nr50.into_bits()
     }
 
     /// Write NR50 register (0xff24)
@@ -43,15 +60,14 @@ impl Mixer {
             return;
         }
 
-        self.ctrl = value;
-        self.so1_volume = (value as usize & 0x70) >> 4;
-        self.so2_volume = value as usize & 0x07;
+        self.nr50 = Nr50::from_bits(value);
+
         self.update_stream();
     }
 
     /// Read NR51 register (0xff25)
     pub fn read_so_mask(&self) -> u8 {
-        self.so_mask as u8
+        self.nr51.into_bits()
     }
 
     /// Write NR51 register (0xff25)
@@ -60,7 +76,8 @@ impl Mixer {
             return;
         }
 
-        self.so_mask = value as usize;
+        self.nr51 = Nr51::from_bits(value);
+
         self.update_stream();
     }
 
@@ -82,54 +99,68 @@ impl Mixer {
         self.stream.clone()
     }
 
-    pub fn enable(&mut self, enable: bool) {
-        self.enable = enable;
-        self.update_stream();
-    }
-
     // Update streams based on register settings
     fn update_stream(&mut self) {
-        self.stream.enable.set(self.enable);
+        self.stream.enable.set(self.power);
 
-        if self.enable {
+        if self.power {
             for (i, tone) in self.stream.tones.iter().enumerate() {
-                tone.volume.set(self.get_volume(i as u8))
+                tone.volume.set(self.get_tone_volume(i))
             }
-            self.stream.wave.volume.set(self.get_volume(2));
-            self.stream.noise.volume.set(self.get_volume(3));
+            self.stream.wave.volume.set(self.get_wave_volume());
+            self.stream.noise.volume.set(self.get_noise_volume());
         }
     }
 
-    fn get_volume(&self, id: u8) -> usize {
-        let mask = 1 << id;
-        let v1 = if self.so_mask & mask != 0 {
-            self.so1_volume
+    fn get_tone_volume(&self, tone: usize) -> usize {
+        if tone == 0 {
+            self.get_volume(self.nr51.ch1_right(), self.nr51.ch1_left())
+        } else {
+            self.get_volume(self.nr51.ch2_right(), self.nr51.ch2_left())
+        }
+    }
+
+    fn get_wave_volume(&self) -> usize {
+        self.get_volume(self.nr51.ch3_right(), self.nr51.ch3_left())
+    }
+
+    fn get_noise_volume(&self) -> usize {
+        self.get_volume(self.nr51.ch4_right(), self.nr51.ch4_left())
+    }
+
+    fn get_volume(&self, right_enable: bool, left_enable: bool) -> usize {
+        let right = if right_enable {
+            self.nr50.right_volume()
         } else {
             0
         };
-        let v2 = if self.so_mask & (mask << 4) != 0 {
-            self.so2_volume
+
+        let left = if left_enable {
+            self.nr50.left_volume()
         } else {
             0
         };
-        v1 + v2
+
+        right + left
     }
 
     pub fn power_on(&mut self) {
         self.power = true;
+        self.update_stream();
     }
 
     pub fn power_off(&mut self) {
         self.power = false;
-        self.ctrl = 0;
-        self.so1_volume = 0;
-        self.so2_volume = 0;
-        self.so_mask = 0;
+
+        self.nr50 = Nr50::default();
+        self.nr51 = Nr51::default();
+
         for tone in &mut self.stream.tones {
             tone.clear();
         }
         self.stream.wave.clear();
         self.stream.noise.clear();
+        self.update_stream();
     }
 }
 

core/src/apu/mixer.rs

@@ -6,6 +6,8 @@ use crate::hardware::HardwareHandle;
 
 use self::{mixer::Mixer, noise::Noise, tone::Tone, wave::Wave};
 
+use bitfield_struct::bitfield;
+
 mod clock_divider;
 mod frame_sequencer;
 mod length_counter;
@@ -23,7 +25,18 @@ pub struct Apu {
     wave: Wave,
     noise: Noise,
     mixer: Mixer,
-    enable: bool,
+    nr52: Nr52,
+}
+
+#[bitfield(u8)]
+struct Nr52 {
+    ch1_on: bool,
+    ch2_on: bool,
+    ch3_on: bool,
+    ch4_on: bool,
+    #[bits(3)]
+    _unused: u8,
+    power_on: bool,
 }
 
 impl Apu {
@@ -39,7 +52,7 @@ impl Apu {
             wave: Wave::new(),
             noise: Noise::new(),
             mixer,
-            enable: false,
+            nr52: Nr52::default(),
         }
     }
 
@@ -226,40 +239,33 @@ impl Apu {
 
     /// Read NR52 register (0xff26)
     pub fn read_enable(&self) -> u8 {
-        let mut v = 0x70;
-        v |= if self.enable { 0x80 } else { 0x00 };
-        v |= if self.tones[0].is_active() {
-            0x01
-        } else {
-            0x00
-        };
-        v |= if self.tones[1].is_active() {
-            0x02
-        } else {
-            0x00
-        };
-        v |= if self.wave.is_active() { 0x04 } else { 0x00 };
-        v |= if self.noise.is_active() { 0x08 } else { 0x00 };
-        v
+        self.nr52
+            .with_ch1_on(self.tones[0].is_active())
+            .with_ch2_on(self.tones[1].is_active())
+            .with_ch3_on(self.wave.is_active())
+            .with_ch4_on(self.noise.is_active())
+            .into_bits()
+            | 0x70
     }
 
     /// Write NR52 register (0xff26)
     pub fn write_enable(&mut self, value: u8) {
-        debug!("Write NR52: {:02x}", value);
+        let before = self.nr52.power_on();
 
-        let enable = value & 0x80 != 0;
+        self.nr52 = Nr52::from_bits(value);
 
-        self.mixer.enable(enable);
+        let after = self.nr52.power_on();
 
-        if !self.enable && enable {
+        if !before && after {
             info!("Sound master enabled");
             for tone in &mut self.tones {
                 tone.power_on();
             }
+
             self.wave.power_on();
             self.noise.power_on();
             self.mixer.power_on();
-        } else if self.enable && !enable {
+        } else if before && !after {
             info!("Sound master disabled");
 
             for tone in &mut self.tones {
@@ -269,8 +275,6 @@ impl Apu {
             self.noise.power_off();
             self.mixer.power_off();
         }
-
-        self.enable = enable;
     }
 
     pub fn step(&mut self, cycles: usize) {