X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=pico%2F32x%2Fpwm.c;h=50735642070dade44b90ef555c33ad51b642124e;hb=refs%2Fremotes%2Fgithub%2Fmaster;hp=6f9cd07eedd99eac7b4cef51d9d1a5c42cf61d8d;hpb=8ce9c3a782e47ed355a12789859e5359c4a81e77;p=picodrive.git

diff --git a/pico/32x/pwm.c b/pico/32x/pwm.c
index 6f9cd07e..6c66146e 100644
--- a/pico/32x/pwm.c
+++ b/pico/32x/pwm.c
@@ -1,46 +1,57 @@
 /*
  * PicoDrive
  * (C) notaz, 2009,2010,2013
+ * (C) irixxxx, 2019-2023
  *
  * This work is licensed under the terms of MAME license.
  * See COPYING file in the top-level directory.
  */
 #include "../pico_int.h"
 
-static int pwm_cycles;
-static int pwm_mult;
-static int pwm_ptr;
-static int pwm_irq_reload;
-static int pwm_doing_fifo;
-static int pwm_silent;
+static struct {
+  int cycles;
+  unsigned mult;
+  int ptr;
+  int irq_reload;
+  int doing_fifo;
+  int silent;
+  int irq_timer;
+  int irq_state;
+  short current[2];
+} pwm;
+
+enum { PWM_IRQ_LOCKED, PWM_IRQ_STOPPED, PWM_IRQ_LOW, PWM_IRQ_HIGH };
 
 void p32x_pwm_ctl_changed(void)
 {
   int control = Pico32x.regs[0x30 / 2];
   int cycles = Pico32x.regs[0x32 / 2];
+  int pwm_irq_opt = PicoIn.opt & POPT_PWM_IRQ_OPT;
 
   cycles = (cycles - 1) & 0x0fff;
-  pwm_cycles = cycles;
+  pwm.cycles = cycles;
 
   // supposedly we should stop FIFO when xMd is 0,
   // but mars test disagrees
-  pwm_mult = 0;
+  pwm.mult = 0;
   if ((control & 0x0f) != 0)
-    pwm_mult = 0x10000 / cycles;
+    pwm.mult = (0x10000<<8) / (cycles+1);
 
-  pwm_irq_reload = (control & 0x0f00) >> 8;
-  pwm_irq_reload = ((pwm_irq_reload - 1) & 0x0f) + 1;
+  pwm.irq_timer = (control & 0x0f00) >> 8;
+  pwm.irq_timer = ((pwm.irq_timer - 1) & 0x0f) + 1;
+  pwm.irq_reload = pwm.irq_timer;
+  pwm.irq_state = pwm_irq_opt ? PWM_IRQ_STOPPED: PWM_IRQ_LOCKED;
 
-  if (Pico32x.pwm_irq_cnt == 0)
-    Pico32x.pwm_irq_cnt = pwm_irq_reload;
+  if (Pico32x.pwm_irq_cnt <= 0)
+    Pico32x.pwm_irq_cnt = pwm.irq_reload;
 }
 
 static void do_pwm_irq(SH2 *sh2, unsigned int m68k_cycles)
 {
-  p32x_trigger_irq(sh2, m68k_cycles, P32XI_PWM);
+  p32x_trigger_irq(NULL, m68k_cycles, P32XI_PWM);
 
   if (Pico32x.regs[0x30 / 2] & P32XP_RTP) {
-    p32x_event_schedule(m68k_cycles, P32X_EVENT_PWM, pwm_cycles / 3 + 1);
+    p32x_event_schedule(m68k_cycles, P32X_EVENT_PWM, pwm.cycles / 3 + 1);
     // note: might recurse
     p32x_dreq1_trigger();
   }
@@ -48,16 +59,14 @@ static void do_pwm_irq(SH2 *sh2, unsigned int m68k_cycles)
 
 static int convert_sample(unsigned int v)
 {
-  if (v == 0)
-    return 0;
-  if (v > pwm_cycles)
-    v = pwm_cycles;
-  return ((int)v - pwm_cycles / 2) * pwm_mult;
+  if (v > pwm.cycles)
+    v = pwm.cycles;
+  return (v * pwm.mult >> 8) - 0x10000/2;
 }
 
 #define consume_fifo(sh2, m68k_cycles) { \
   int cycles_diff = ((m68k_cycles) * 3) - Pico32x.pwm_cycle_p; \
-  if (cycles_diff >= pwm_cycles) \
+  if (cycles_diff >= pwm.cycles) \
     consume_fifo_do(sh2, m68k_cycles, cycles_diff); \
 }
 
@@ -69,67 +78,70 @@ static void consume_fifo_do(SH2 *sh2, unsigned int m68k_cycles,
   unsigned short *fifo_r = mem->pwm_fifo[1];
   int sum = 0;
 
-  if (pwm_cycles == 0 || pwm_doing_fifo)
+  if (pwm.cycles == 0 || pwm.doing_fifo)
     return;
 
   elprintf(EL_PWM, "pwm: %u: consume %d/%d, %d,%d ptr %d",
-    m68k_cycles, sh2_cycles_diff, sh2_cycles_diff / pwm_cycles,
-    Pico32x.pwm_p[0], Pico32x.pwm_p[1], pwm_ptr);
+    m68k_cycles, sh2_cycles_diff, sh2_cycles_diff / pwm.cycles,
+    Pico32x.pwm_p[0], Pico32x.pwm_p[1], pwm.ptr);
 
   // this is for recursion from dreq1 writes
-  pwm_doing_fifo = 1;
+  pwm.doing_fifo = 1;
 
-  for (; sh2_cycles_diff >= pwm_cycles; sh2_cycles_diff -= pwm_cycles)
+  while (sh2_cycles_diff >= pwm.cycles)
   {
+    sh2_cycles_diff -= pwm.cycles;
+
     if (Pico32x.pwm_p[0] > 0) {
-      fifo_l[0] = fifo_l[1];
-      fifo_l[1] = fifo_l[2];
-      fifo_l[2] = fifo_l[3];
+      mem->pwm_index[0] = (mem->pwm_index[0]+1) % 4;
       Pico32x.pwm_p[0]--;
-      mem->pwm_current[0] = convert_sample(fifo_l[0]);
-      sum += mem->pwm_current[0];
+      pwm.current[0] = convert_sample(fifo_l[mem->pwm_index[0]]);
+      sum |= (u16)pwm.current[0];
     }
     if (Pico32x.pwm_p[1] > 0) {
-      fifo_r[0] = fifo_r[1];
-      fifo_r[1] = fifo_r[2];
-      fifo_r[2] = fifo_r[3];
+      mem->pwm_index[1] = (mem->pwm_index[1]+1) % 4;
       Pico32x.pwm_p[1]--;
-      mem->pwm_current[1] = convert_sample(fifo_r[0]);
-      sum += mem->pwm_current[1];
+      pwm.current[1] = convert_sample(fifo_r[mem->pwm_index[1]]);
+      sum |= (u16)pwm.current[1];
     }
 
-    mem->pwm[pwm_ptr * 2    ] = mem->pwm_current[0];
-    mem->pwm[pwm_ptr * 2 + 1] = mem->pwm_current[1];
-    pwm_ptr = (pwm_ptr + 1) & (PWM_BUFF_LEN - 1);
+    mem->pwm[pwm.ptr * 2    ] = pwm.current[0];
+    mem->pwm[pwm.ptr * 2 + 1] = pwm.current[1];
+    pwm.ptr = (pwm.ptr + 1) & (PWM_BUFF_LEN - 1);
 
-    if (--Pico32x.pwm_irq_cnt == 0) {
-      Pico32x.pwm_irq_cnt = pwm_irq_reload;
+    if (--Pico32x.pwm_irq_cnt <= 0) {
+      Pico32x.pwm_irq_cnt = pwm.irq_reload;
       do_pwm_irq(sh2, m68k_cycles);
+    } else if (Pico32x.pwm_p[1] == 0 && pwm.irq_state >= PWM_IRQ_LOW) {
+      // buffer underrun. Reduce reload rate if above programmed setting.
+      if (pwm.irq_reload > pwm.irq_timer)
+        pwm.irq_reload--;
+      pwm.irq_state = PWM_IRQ_LOW;
     }
   }
   Pico32x.pwm_cycle_p = m68k_cycles * 3 - sh2_cycles_diff;
-  pwm_doing_fifo = 0;
+  pwm.doing_fifo = 0;
   if (sum != 0)
-    pwm_silent = 0;
+    pwm.silent = 0;
 }
 
 static int p32x_pwm_schedule_(SH2 *sh2, unsigned int m68k_now)
 {
-  unsigned int sh2_now = m68k_now * 3;
+  unsigned int pwm_now = m68k_now * 3;
   int cycles_diff_sh2;
 
-  if (pwm_cycles == 0)
+  if (pwm.cycles == 0)
     return 0;
 
-  cycles_diff_sh2 = sh2_now - Pico32x.pwm_cycle_p;
-  if (cycles_diff_sh2 >= pwm_cycles)
+  cycles_diff_sh2 = pwm_now - Pico32x.pwm_cycle_p;
+  if (cycles_diff_sh2 >= pwm.cycles)
     consume_fifo_do(sh2, m68k_now, cycles_diff_sh2);
 
   if (!((Pico32x.sh2irq_mask[0] | Pico32x.sh2irq_mask[1]) & 1))
     return 0; // masked by everyone
 
-  cycles_diff_sh2 = sh2_now - Pico32x.pwm_cycle_p;
-  return (Pico32x.pwm_irq_cnt * pwm_cycles
+  cycles_diff_sh2 = pwm_now - Pico32x.pwm_cycle_p;
+  return (Pico32x.pwm_irq_cnt * pwm.cycles
            - cycles_diff_sh2) / 3 + 1;
 }
 
@@ -158,29 +170,28 @@ void p32x_pwm_irq_event(unsigned int m68k_now)
   p32x_pwm_schedule(m68k_now);
 }
 
-unsigned int p32x_pwm_read16(unsigned int a, SH2 *sh2,
-  unsigned int m68k_cycles)
+unsigned int p32x_pwm_read16(u32 a, SH2 *sh2, unsigned int m68k_cycles)
 {
   unsigned int d = 0;
 
   consume_fifo(sh2, m68k_cycles);
 
   a &= 0x0e;
-  switch (a) {
-    case 0: // control
-    case 2: // cycle
+  switch (a/2) {
+    case 0/2: // control
+    case 2/2: // cycle
       d = Pico32x.regs[(0x30 + a) / 2];
       break;
 
-    case 4: // L ch
+    case 4/2: // L ch
       if (Pico32x.pwm_p[0] == 3)
         d |= P32XP_FULL;
       else if (Pico32x.pwm_p[0] == 0)
         d |= P32XP_EMPTY;
       break;
 
-    case 6: // R ch
-    case 8: // MONO
+    case 6/2: // R ch
+    case 8/2: // MONO
       if (Pico32x.pwm_p[1] == 3)
         d |= P32XP_FULL;
       else if (Pico32x.pwm_p[1] == 0)
@@ -193,69 +204,83 @@ unsigned int p32x_pwm_read16(unsigned int a, SH2 *sh2,
   return d;
 }
 
-void p32x_pwm_write16(unsigned int a, unsigned int d,
-  SH2 *sh2, unsigned int m68k_cycles)
+void p32x_pwm_write16(u32 a, unsigned int d, SH2 *sh2, unsigned int m68k_cycles)
 {
+  unsigned short *fifo;
+  int idx;
+
   elprintf(EL_PWM, "pwm: %u: w16 %02x %04x (p %d %d)",
     m68k_cycles, a & 0x0e, d, Pico32x.pwm_p[0], Pico32x.pwm_p[1]);
 
   consume_fifo(sh2, m68k_cycles);
 
   a &= 0x0e;
-  if (a == 0) { // control
-    // avoiding pops..
-    if ((Pico32x.regs[0x30 / 2] & 0x0f) == 0)
-      Pico32xMem->pwm_fifo[0][0] = Pico32xMem->pwm_fifo[1][0] = 0;
-    Pico32x.regs[0x30 / 2] = d;
-    p32x_pwm_ctl_changed();
-    Pico32x.pwm_irq_cnt = pwm_irq_reload; // ?
-  }
-  else if (a == 2) { // cycle
-    Pico32x.regs[0x32 / 2] = d & 0x0fff;
-    p32x_pwm_ctl_changed();
-  }
-  else if (a <= 8) {
-    d = (d - 1) & 0x0fff;
-
-    if (a == 4 || a == 8) { // L ch or MONO
-      unsigned short *fifo = Pico32xMem->pwm_fifo[0];
+  switch (a/2) {
+    case 0/2: // control
+      // avoiding pops..
+      if ((Pico32x.regs[0x30 / 2] & 0x0f) == 0)
+        Pico32xMem->pwm_fifo[0][0] = Pico32xMem->pwm_fifo[1][0] = 0;
+      Pico32x.regs[0x30 / 2] = d;
+      p32x_pwm_ctl_changed();
+      Pico32x.pwm_irq_cnt = pwm.irq_reload; // ?
+      break;
+    case 2/2: // cycle
+      Pico32x.regs[0x32 / 2] = d & 0x0fff;
+      p32x_pwm_ctl_changed();
+      break;
+    case 8/2: // MONO
+    case 6/2: // R ch
+      fifo = Pico32xMem->pwm_fifo[1];
+      idx = Pico32xMem->pwm_index[1];
+      if (Pico32x.pwm_p[1] < 3) {
+        if (Pico32x.pwm_p[1] == 2 && pwm.irq_state >= PWM_IRQ_STOPPED) {
+          // buffer full. If there was no buffer underrun after last fill,
+          // try increasing reload rate to reduce IRQs
+          if (pwm.irq_reload < 3 && pwm.irq_state == PWM_IRQ_HIGH)
+            pwm.irq_reload ++;
+          pwm.irq_state = PWM_IRQ_HIGH;
+        }
+        Pico32x.pwm_p[1]++;
+      } else {
+        // buffer overflow. Some roms always fill the complete buffer even if
+        // reload rate is set below max. Lock reload rate to programmed setting.
+        pwm.irq_reload = pwm.irq_timer;
+        pwm.irq_state = PWM_IRQ_LOCKED;
+        idx = (idx+1) % 4;
+        Pico32xMem->pwm_index[1] = idx;
+      }
+      fifo[(idx+Pico32x.pwm_p[1]) % 4] = (d - 1) & 0x0fff;
+      if (a != 8) break; // fallthrough if MONO
+    case 4/2: // L ch
+      fifo = Pico32xMem->pwm_fifo[0];
+      idx = Pico32xMem->pwm_index[0];
       if (Pico32x.pwm_p[0] < 3)
         Pico32x.pwm_p[0]++;
       else {
-        fifo[1] = fifo[2];
-        fifo[2] = fifo[3];
-      }
-      fifo[Pico32x.pwm_p[0]] = d;
-    }
-    if (a == 6 || a == 8) { // R ch or MONO
-      unsigned short *fifo = Pico32xMem->pwm_fifo[1];
-      if (Pico32x.pwm_p[1] < 3)
-        Pico32x.pwm_p[1]++;
-      else {
-        fifo[1] = fifo[2];
-        fifo[2] = fifo[3];
+        idx = (idx+1) % 4;
+        Pico32xMem->pwm_index[0] = idx;
       }
-      fifo[Pico32x.pwm_p[1]] = d;
-    }
+      fifo[(idx+Pico32x.pwm_p[0]) % 4] = (d - 1) & 0x0fff;
+      break;
   }
 }
 
-void p32x_pwm_update(int *buf32, int length, int stereo)
+void p32x_pwm_update(s32 *buf32, int length, int stereo)
 {
   short *pwmb;
   int step;
   int p = 0;
   int xmd;
 
-  consume_fifo(NULL, SekCyclesDoneT2());
+  consume_fifo(NULL, SekCyclesDone());
 
   xmd = Pico32x.regs[0x30 / 2] & 0x0f;
   if (xmd == 0 || xmd == 0x06 || xmd == 0x09 || xmd == 0x0f)
     goto out; // invalid?
-  if (pwm_silent)
+  if (pwm.silent)
     return;
 
-  step = (pwm_ptr << 16) / length;
+  step = (pwm.ptr << 16) / length;
   pwmb = Pico32xMem->pwm;
 
   if (stereo)
@@ -310,13 +335,12 @@ void p32x_pwm_update(int *buf32, int length, int stereo)
     }
   }
 
-  elprintf(EL_PWM, "pwm_update: pwm_ptr %d, len %d, step %04x, done %d",
-    pwm_ptr, length, step, (pwmb - Pico32xMem->pwm) / 2);
+  elprintf(EL_PWM, "pwm_update: pwm.ptr %d, len %d, step %04x, done %d",
+    pwm.ptr, length, step, (pwmb - Pico32xMem->pwm) / 2);
 
 out:
-  pwm_ptr = 0;
-  pwm_silent = Pico32xMem->pwm_current[0] == 0
-    && Pico32xMem->pwm_current[1] == 0;
+  pwm.ptr = 0;
+  pwm.silent = pwm.current[0] == 0 && pwm.current[1] == 0;
 }
 
 void p32x_pwm_state_loaded(void)
@@ -326,11 +350,11 @@ void p32x_pwm_state_loaded(void)
   p32x_pwm_ctl_changed();
 
   // for old savestates
-  cycles_diff_sh2 = SekCycleCntT * 3 - Pico32x.pwm_cycle_p;
-  if (cycles_diff_sh2 >= pwm_cycles || cycles_diff_sh2 < 0) {
-    Pico32x.pwm_irq_cnt = pwm_irq_reload;
-    Pico32x.pwm_cycle_p = SekCycleCntT * 3;
-    p32x_pwm_schedule(SekCycleCntT);
+  cycles_diff_sh2 = Pico.t.m68c_cnt * 3 - Pico32x.pwm_cycle_p;
+  if (cycles_diff_sh2 >= pwm.cycles || cycles_diff_sh2 < 0) {
+    Pico32x.pwm_irq_cnt = pwm.irq_reload;
+    Pico32x.pwm_cycle_p = Pico.t.m68c_cnt * 3;
+    p32x_pwm_schedule(Pico.t.m68c_cnt);
   }
 }