Start working on DMA sound

Former-commit-id: 066210a86a7836b6ae1dfd5ce229d050cbe00ca4

src/core/dma.rs

@@ -2,7 +2,7 @@ use std::collections::VecDeque;
 
 use super::arm7tdmi::{Addr, Bus};
 use super::sysbus::SysBus;
-use super::{Interrupt, IrqBitmask, SyncedIoDevice};
+use super::{Interrupt, IrqBitmask};
 
 use num::FromPrimitive;
 
@@ -27,6 +27,7 @@ pub struct DmaChannel {
     running: bool,
     cycles: usize,
     start_cycles: usize,
+    fifo_mode: bool,
     irq: Interrupt,
 }
 
@@ -52,6 +53,7 @@ impl DmaChannel {
             ctrl: DmaChannelCtrl(0),
             cycles: 0,
             start_cycles: 0,
+            fifo_mode: false,
             internal: Default::default(),
         }
     }
@@ -88,19 +90,37 @@ impl DmaChannel {
 
     pub fn write_dma_ctrl(&mut self, value: u16) -> bool {
         let ctrl = DmaChannelCtrl(value);
+        let timing = ctrl.timing();
         let mut start_immediately = false;
         if ctrl.is_enabled() && !self.ctrl.is_enabled() {
             self.start_cycles = self.cycles;
             self.running = true;
-            start_immediately = ctrl.timing() == 0;
+            start_immediately = timing == 0;
             self.internal.src_addr = self.src;
             self.internal.dst_addr = self.dst;
             self.internal.count = self.wc;
+            self.fifo_mode = timing == 3 && (self.id == 0 || self.id == 1);
         }
         self.ctrl = ctrl;
         return start_immediately;
     }
 
+    #[inline]
+    fn xfer_adj_addrs(&mut self, word_size: u32) {
+        match self.ctrl.src_adj() {
+            /* Increment */ 0 => self.internal.src_addr += word_size,
+            /* Decrement */ 1 => self.internal.src_addr -= word_size,
+            /* Fixed */ 2 => {}
+            _ => panic!("forbidden DMA source address adjustment"),
+        }
+        match self.ctrl.dst_adj() {
+            /* Increment[+Reload] */ 0 | 3 => self.internal.dst_addr += word_size,
+            /* Decrement */ 1 => self.internal.dst_addr -= word_size,
+            /* Fixed */ 2 => {}
+            _ => panic!("forbidden DMA dest address adjustment"),
+        }
+    }
+
     fn xfer(&mut self, sb: &mut SysBus, irqs: &mut IrqBitmask) {
         let word_size = if self.ctrl.is_32bit() { 4 } else { 2 };
         let count = match self.internal.count {
@@ -110,25 +130,26 @@ impl DmaChannel {
             },
             _ => self.internal.count,
         };
-        for _ in 0..count {
-            if word_size == 4 {
+        let fifo_mode = self.fifo_mode;
+
+        if fifo_mode {
+            println!("FIFO Tranfer");
+            for _ in 0..count {
+                let v = sb.read_16(self.internal.src_addr);
+                sb.write_16(self.internal.dst_addr, v);
+                self.internal.src_addr += 2;
+            }
+        } else if word_size == 4 {
+            for _ in 0..count {
                 let w = sb.read_32(self.internal.src_addr);
-                sb.write_32(self.internal.dst_addr, w)
-            } else {
+                sb.write_32(self.internal.dst_addr, w);
+                self.xfer_adj_addrs(word_size);
+            }
+        } else {
+            for _ in 0..count {
                 let hw = sb.read_16(self.internal.src_addr);
-                sb.write_16(self.internal.dst_addr, hw)
-            }
-            match self.ctrl.src_adj() {
-                /* Increment */ 0 => self.internal.src_addr += word_size,
-                /* Decrement */ 1 => self.internal.src_addr -= word_size,
-                /* Fixed */ 2 => {}
-                _ => panic!("forbidden DMA source address adjustment"),
-            }
-            match self.ctrl.dst_adj() {
-                /* Increment[+Reload] */ 0 | 3 => self.internal.dst_addr += word_size,
-                /* Decrement */ 1 => self.internal.dst_addr -= word_size,
-                /* Fixed */ 2 => {}
-                _ => panic!("forbidden DMA dest address adjustment"),
+                sb.write_16(self.internal.dst_addr, hw);
+                self.xfer_adj_addrs(word_size)
             }
         }
         if self.ctrl.is_triggering_irq() {
@@ -210,6 +231,17 @@ impl DmaController {
             }
         }
     }
+
+    pub fn notify_sound_fifo(&mut self, fifo_addr: u32) {
+        for i in 1..=2 {
+            if self.channels[i].ctrl.is_enabled()
+                && self.channels[i].ctrl.timing() == 3
+                && self.channels[i].dst == fifo_addr
+            {
+                self.xfers_queue.push_back(i);
+            }
+        }
+    }
 }
 
 bitfield! {

src/core/gba.rs

@@ -8,6 +8,7 @@ use super::gpu::*;
 use super::interrupt::*;
 use super::iodev::*;
 use super::sysbus::SysBus;
+use super::timer::TimerEvent;
 
 use super::SyncedIoDevice;
 
@@ -113,7 +114,8 @@ where
             0
         };
 
-        io.timers.step(cycles, &mut self.sysbus, &mut irqs);
+        io.timers.tick(cycles, &mut self.sysbus, &mut irqs);
+
         if let Some(new_gpu_state) = io.gpu.step(cycles, &mut self.sysbus, &mut irqs) {
             match new_gpu_state {
                 GpuState::VBlank => {

src/core/sound/fifo.rs

@@ -0,0 +1,51 @@
+// TODO write tests or replace with a crate
+
+const SOUND_FIFO_CAPACITY: usize = 32;
+
+#[derive(Debug)]
+pub struct SoundFifo {
+    wr_pos: usize,
+    rd_pos: usize,
+    count: usize,
+    data: [i8; SOUND_FIFO_CAPACITY],
+}
+
+impl SoundFifo {
+    pub fn new() -> SoundFifo {
+        SoundFifo {
+            wr_pos: 0,
+            rd_pos: 0,
+            count: 0,
+            data: [0; SOUND_FIFO_CAPACITY],
+        }
+    }
+
+    pub fn write(&mut self, value: i8) {
+        if self.count >= SOUND_FIFO_CAPACITY {
+            return;
+        }
+        self.data[self.wr_pos] = value;
+        self.wr_pos = (self.wr_pos + 1) % SOUND_FIFO_CAPACITY;
+        self.count += 1;
+    }
+
+    pub fn read(&mut self) -> i8 {
+        if self.count == 0 {
+            return 0;
+        };
+        let value = self.data[self.rd_pos];
+        self.rd_pos = (self.rd_pos + 1) % SOUND_FIFO_CAPACITY;
+        self.count -= 1;
+        value
+    }
+
+    pub fn count(&self) -> usize {
+        self.count
+    }
+
+    pub fn reset(&mut self) {
+        self.wr_pos = 0;
+        self.rd_pos = 0;
+        self.count = 0;
+    }
+}

src/core/sound/mod.rs

@@ -1,15 +1,45 @@
 use bit::BitIndex;
 
+use super::dma::DmaController;
 use super::iodev::consts::*;
 use super::iodev::io_reg_string;
 
+mod fifo;
+use fifo::SoundFifo;
+
 const DMG_RATIOS: [f32; 4] = [0.25, 0.5, 1.0, 0.0];
+const DMA_RATIOS: [f32; 2] = [0.5, 1.0];
+const DMA_TIMERS: [usize; 2] = [0, 1];
 const DUTY_RATIOS: [f32; 4] = [0.125, 0.25, 0.5, 0.75];
 
+#[derive(Debug)]
+struct NoiseChannel {}
+
+#[derive(Debug)]
+struct DmaSound {
+    volume: f32,
+    enable_right: bool,
+    enable_left: bool,
+    timer_select: usize,
+    fifo: SoundFifo<i8>,
+}
+
+impl Default for DmaSound {
+    fn default() -> DmaSound {
+        DmaSound {
+            volume: DMA_RATIOS[0],
+            enable_right: false,
+            enable_left: false,
+            timer_select: 0,
+            fifo: SoundFifo::new(),
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct SoundController {
     sample_rate_to_cpu_freq: usize, // how many "cycles" are a sample?
-    last_sample_cycles: usize, // cycles count when we last provided a new sample.
+    last_sample_cycles: usize,      // cycles count when we last provided a new sample.
 
     mse: bool,
 
@@ -35,6 +65,9 @@ pub struct SoundController {
     sqr1_step_increase: bool,
     sqr1_initial_vol: usize,
     sqr1_cur_vol: usize,
+
+    sound_a: DmaSound,
+    sound_b: DmaSound,
 }
 
 impl SoundController {
@@ -62,6 +95,8 @@ impl SoundController {
             sqr1_step_increase: false,
             sqr1_initial_vol: 0,
             sqr1_cur_vol: 0,
+            sound_a: Default::default(),
+            sound_b: Default::default(),
         }
     }
 
@@ -81,10 +116,26 @@ impl SoundController {
                     | cbit(15, self.right_noise)
             }
 
-            REG_SOUNDCNT_H => DMG_RATIOS
-                .iter()
-                .position(|&f| f == self.dmg_volume_ratio)
-                .expect("bad dmg_volume_ratio!") as u16,
+            REG_SOUNDCNT_H => {
+                DMG_RATIOS
+                    .iter()
+                    .position(|&f| f == self.dmg_volume_ratio)
+                    .expect("bad dmg_volume_ratio!") as u16
+                    | DMA_RATIOS
+                        .iter()
+                        .position(|&f| f == self.sound_a.volume)
+                        .unwrap() as u16
+                    | DMA_RATIOS
+                        .iter()
+                        .position(|&f| f == self.sound_b.volume)
+                        .unwrap() as u16
+                    | cbit(8, self.sound_a.enable_right)
+                    | cbit(9, self.sound_a.enable_left)
+                    | cbit(10, self.sound_a.timer_select != 0)
+                    | cbit(12, self.sound_b.enable_right)
+                    | cbit(13, self.sound_b.enable_left)
+                    | cbit(14, self.sound_b.timer_select != 0)
+            }
 
             _ => {
                 println!(
@@ -105,12 +156,6 @@ impl SoundController {
     }
 
     pub fn handle_write(&mut self, io_addr: u32, value: u16) {
-        println!(
-            "Write {} ({:08x}) = {:04x}",
-            io_reg_string(io_addr),
-            io_addr,
-            value
-        );
         if io_addr == REG_SOUNDCNT_X {
             if value & bit(7) != 0 {
                 if !self.mse {
@@ -149,11 +194,20 @@ impl SoundController {
 
             REG_SOUNDCNT_H => {
                 self.dmg_volume_ratio = DMG_RATIOS[value.bit_range(0..1) as usize];
-                if value.bit_range(2..15) != 0 {
-                    println!(
-                        "unsupported bits in REG_SOUNDCNT_H, {:04x}",
-                        value.bit_range(2..15)
-                    );
+                self.sound_a.volume = DMA_RATIOS[value.bit(2) as usize];
+                self.sound_b.volume = DMA_RATIOS[value.bit(3) as usize];
+                self.sound_a.enable_right = value.bit(8);
+                self.sound_a.enable_left = value.bit(9);
+                self.sound_a.timer_select = DMA_TIMERS[value.bit(10) as usize];
+                self.sound_b.enable_right = value.bit(12);
+                self.sound_b.enable_left = value.bit(13);
+                self.sound_b.timer_select = DMA_TIMERS[value.bit(14) as usize];
+
+                if value.bit(11) {
+                    self.sound_a.fifo.reset();
+                }
+                if value.bit(15) {
+                    self.sound_b.fifo.reset();
                 }
             }
 
@@ -173,6 +227,16 @@ impl SoundController {
                 }
             }
 
+            REG_FIFO_A => {
+                self.sound_a.fifo.write((value & 0xff00 >> 8) as i8);
+                self.sound_a.fifo.write((value & 0xff) as i8);
+            }
+
+            REG_FIFO_B => {
+                self.sound_b.fifo.write((value & 0xff00 >> 8) as i8);
+                self.sound_b.fifo.write((value & 0xff) as i8);
+            }
+
             _ => {
                 println!(
                     "Unimplemented write to {:x} {}",
@@ -183,10 +247,23 @@ impl SoundController {
         }
     }
 
+    pub fn handle_timer_overflow(&mut self, dmac: &mut DmaController, timer_id: usize) {
+        if !self.mse {
+            return;
+        }
+        // TODO - play sound ?
+
+        if timer_id == self.sound_a.timer_select {
+            dmac.notify_sound_fifo(REG_FIFO_A);
+        }
+        if timer_id == self.sound_b.timer_select {
+            dmac.notify_sound_fifo(REG_FIFO_B);
+        }
+    }
+
     pub fn update(&mut self, cycles: usize) {
-        if cycles - self.last_sample_cycles >= self.sample_rate_to_cpu_freq {
+        while cycles - self.last_sample_cycles >= self.sample_rate_to_cpu_freq {
             self.last_sample_cycles += self.sample_rate_to_cpu_freq;
-            println!("{:?}", cycles);
         }
     }
 }

src/core/timer.rs

@@ -19,9 +19,9 @@ pub struct Timer {
     pub cycles: usize,
 }
 
-pub enum TimerAction {
-    Overflow(usize),
-    Increment,
+pub enum TimerEvent {
+    Overflow(usize, usize),
+    Increment(usize),
 }
 
 impl Timer {
@@ -49,7 +49,7 @@ impl Timer {
         }
     }
 
-    pub fn add_cycles(&mut self, cycles: usize, irqs: &mut IrqBitmask) -> TimerAction {
+    pub fn add_cycles(&mut self, cycles: usize, irqs: &mut IrqBitmask) -> TimerEvent {
         let mut num_overflows = 0;
         self.cycles += cycles;
 
@@ -66,9 +66,9 @@ impl Timer {
             }
         }
         if num_overflows > 0 {
-            return TimerAction::Overflow(num_overflows);
+            return TimerEvent::Overflow(self.timer_id, num_overflows);
         } else {
-            return TimerAction::Increment;
+            return TimerEvent::Increment(self.timer_id);
         }
     }
 }
@@ -112,31 +112,37 @@ impl Timers {
             );
         }
     }
-}
 
-impl SyncedIoDevice for Timers {
-    fn step(&mut self, cycles: usize, _sb: &mut SysBus, irqs: &mut IrqBitmask) {
+    pub fn tick(
+        &mut self,
+        cycles: usize,
+        sb: &mut SysBus,
+        irqs: &mut IrqBitmask,
+    ) -> Option<TimerEvent> {
         for i in 0..4 {
             if self[i].timer_ctl.enabled() && !self[i].timer_ctl.cascade() {
-                match self[i].add_cycles(cycles, irqs) {
-                    TimerAction::Overflow(num_overflows) => {
+                let event = self[i].add_cycles(cycles, irqs);
+                match event {
+                    TimerEvent::Overflow(_, num_overflows) => {
                         if self.trace {
                             println!("TMR{} overflown!", i);
                         }
-                        match i {
-                            3 => {}
-                            _ => {
-                                let next_i = i + 1;
-                                if self[next_i].timer_ctl.cascade() {
-                                    self[next_i].add_cycles(num_overflows, irqs);
-                                }
+                        if i != 3 {
+                            let next_i = i + 1;
+                            if self[next_i].timer_ctl.cascade() {
+                                self[next_i].add_cycles(num_overflows, irqs);
                             }
                         }
+                        if i == 0 || i == 1 {
+                            sb.io.sound.handle_timer_overflow(&mut sb.io.dmac, i);
+                        }
                     }
-                    TimerAction::Increment => {}
+                    _ => {}
                 }
+                return Some(event);
             }
         }
+        None
     }
 }