+/*
+ * 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_line_samples;
-static int pwm_cycles;
-static int pwm_mult;
-static int pwm_ptr;
-int pwm_frame_smp_cnt;
+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_refresh(void)
+void p32x_pwm_ctl_changed(void)
{
+ int control = Pico32x.regs[0x30 / 2];
int cycles = Pico32x.regs[0x32 / 2];
- int frame_samples;
+ int pwm_irq_opt = PicoIn.opt & POPT_PWM_IRQ_OPT;
cycles = (cycles - 1) & 0x0fff;
- if (cycles < 500) {
- elprintf(EL_32X|EL_ANOMALY, "pwm: low cycle value: %d", cycles + 1);
- cycles = 500;
+ pwm.cycles = cycles;
+
+ // supposedly we should stop FIFO when xMd is 0,
+ // but mars test disagrees
+ pwm.mult = 0;
+ if ((control & 0x0f) != 0)
+ pwm.mult = (0x10000<<8) / (cycles+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;
+}
+
+static void do_pwm_irq(SH2 *sh2, unsigned int m68k_cycles)
+{
+ 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);
+ // note: might recurse
+ p32x_dreq1_trigger();
}
- pwm_cycles = cycles;
- pwm_mult = 0x10000 / cycles;
- if (Pico.m.pal)
- frame_samples = OSC_PAL / 7 * 3 / 50 / cycles;
- else
- frame_samples = OSC_NTSC / 7 * 3 / 60 / cycles;
+}
- pwm_line_samples = (frame_samples << 16) / scanlines_total;
+static int convert_sample(unsigned int v)
+{
+ if (v > pwm.cycles)
+ v = pwm.cycles;
+ return (v * pwm.mult >> 8) - 0x10000/2;
}
-// irq for every sample??
-// FIXME: we need to hit more than once per line :(
-void p32x_pwm_irq_check(int new_line)
+#define consume_fifo(sh2, m68k_cycles) { \
+ int cycles_diff = ((m68k_cycles) * 3) - Pico32x.pwm_cycle_p; \
+ if (cycles_diff >= pwm.cycles) \
+ consume_fifo_do(sh2, m68k_cycles, cycles_diff); \
+}
+
+static void consume_fifo_do(SH2 *sh2, unsigned int m68k_cycles,
+ int sh2_cycles_diff)
{
- int tm = (Pico32x.regs[0x30 / 2] & 0x0f00) >> 8;
- if (tm == 0)
- return; // TODO: verify
-
- if (new_line)
- Pico32x.pwm_irq_sample_cnt += pwm_line_samples;
- if (Pico32x.pwm_irq_sample_cnt >= (tm << 16)) {
- Pico32x.pwm_irq_sample_cnt -= tm << 16;
- Pico32x.sh2irqs |= P32XI_PWM;
- p32x_update_irls();
+ struct Pico32xMem *mem = Pico32xMem;
+ unsigned short *fifo_l = mem->pwm_fifo[0];
+ unsigned short *fifo_r = mem->pwm_fifo[1];
+ int sum = 0;
+
+ 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);
+
+ // this is for recursion from dreq1 writes
+ pwm.doing_fifo = 1;
+
+ while (sh2_cycles_diff >= pwm.cycles)
+ {
+ sh2_cycles_diff -= pwm.cycles;
+
+ if (Pico32x.pwm_p[0] > 0) {
+ mem->pwm_index[0] = (mem->pwm_index[0]+1) % 4;
+ Pico32x.pwm_p[0]--;
+ pwm.current[0] = convert_sample(fifo_l[mem->pwm_index[0]]);
+ sum |= (u16)pwm.current[0];
+ }
+ if (Pico32x.pwm_p[1] > 0) {
+ mem->pwm_index[1] = (mem->pwm_index[1]+1) % 4;
+ Pico32x.pwm_p[1]--;
+ pwm.current[1] = convert_sample(fifo_r[mem->pwm_index[1]]);
+ sum |= (u16)pwm.current[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;
+ 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;
+ if (sum != 0)
+ pwm.silent = 0;
+}
+
+static int p32x_pwm_schedule_(SH2 *sh2, unsigned int m68k_now)
+{
+ unsigned int pwm_now = m68k_now * 3;
+ int cycles_diff_sh2;
+
+ if (pwm.cycles == 0)
+ return 0;
+
+ 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 = pwm_now - Pico32x.pwm_cycle_p;
+ return (Pico32x.pwm_irq_cnt * pwm.cycles
+ - cycles_diff_sh2) / 3 + 1;
+}
+
+void p32x_pwm_schedule(unsigned int m68k_now)
+{
+ int after = p32x_pwm_schedule_(NULL, m68k_now);
+ if (after != 0)
+ p32x_event_schedule(m68k_now, P32X_EVENT_PWM, after);
+}
+
+void p32x_pwm_schedule_sh2(SH2 *sh2)
+{
+ int after = p32x_pwm_schedule_(sh2, sh2_cycles_done_m68k(sh2));
+ if (after != 0)
+ p32x_event_schedule_sh2(sh2, P32X_EVENT_PWM, after);
}
-unsigned int p32x_pwm_read16(unsigned int a)
+void p32x_pwm_sync_to_sh2(SH2 *sh2)
+{
+ int m68k_cycles = sh2_cycles_done_m68k(sh2);
+ consume_fifo(sh2, m68k_cycles);
+}
+
+void p32x_pwm_irq_event(unsigned int m68k_now)
+{
+ p32x_pwm_schedule(m68k_now);
+}
+
+unsigned int p32x_pwm_read16(u32 a, SH2 *sh2, unsigned int m68k_cycles)
{
unsigned int d = 0;
- int predict;
+
+ consume_fifo(sh2, m68k_cycles);
a &= 0x0e;
- switch (a) {
- case 0: // control
- case 2: // cycle
- return Pico32x.regs[(0x30 + a) / 2];
-
- case 4: // L ch
- case 6: // R ch
- case 8: // MONO
- predict = (pwm_line_samples * Pico.m.scanline) >> 16;
- elprintf(EL_32X, "pwm: read status: ptr %d/%d, predict %d",
- pwm_frame_smp_cnt, (pwm_line_samples * scanlines_total) >> 16, predict);
- if (pwm_frame_smp_cnt > predict + 3)
+ switch (a/2) {
+ case 0/2: // control
+ case 2/2: // cycle
+ d = Pico32x.regs[(0x30 + a) / 2];
+ break;
+
+ case 4/2: // L ch
+ if (Pico32x.pwm_p[0] == 3)
d |= P32XP_FULL;
- else if (pwm_frame_smp_cnt == 0 || pwm_frame_smp_cnt < predict - 1)
+ else if (Pico32x.pwm_p[0] == 0)
+ d |= P32XP_EMPTY;
+ break;
+
+ 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)
d |= P32XP_EMPTY;
break;
}
+ elprintf(EL_PWM, "pwm: %u: r16 %02x %04x (p %d %d)",
+ m68k_cycles, a, d, Pico32x.pwm_p[0], Pico32x.pwm_p[1]);
return d;
}
-void p32x_pwm_write16(unsigned int a, unsigned int d)
+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
- Pico32x.regs[0x30 / 2] = d;
- else if (a == 2) { // cycle
- Pico32x.regs[0x32 / 2] = d & 0x0fff;
- p32x_pwm_refresh();
- Pico32x.pwm_irq_sample_cnt = 0; // resets?
- }
- else if (a <= 8) {
- d &= 0x0fff;
- if (d > pwm_cycles)
- d = pwm_cycles;
- d = (d - pwm_cycles / 2) * pwm_mult;
-
- if (a < 6) // L ch
- Pico32xMem->pwm[pwm_ptr * 2] = d;
- else if (a == 6) // R ch
- Pico32xMem->pwm[pwm_ptr * 2 + 1] = d;
- else // MONO
- Pico32xMem->pwm[pwm_ptr * 2] = Pico32xMem->pwm[pwm_ptr * 2 + 1] = d;
-
- if (a >= 6) { // R or MONO
- pwm_frame_smp_cnt++;
- pwm_ptr = (pwm_ptr + 1) & (PWM_BUFF_LEN - 1);
- elprintf(EL_32X, "pwm: smp_cnt %d, ptr %d, smp %x", pwm_frame_smp_cnt, pwm_ptr, d);
- }
+ 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 {
+ idx = (idx+1) % 4;
+ Pico32xMem->pwm_index[0] = idx;
+ }
+ 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)
{
- extern int pwm_ptr;
short *pwmb;
int step;
int p = 0;
+ int xmd;
+
+ consume_fifo(NULL, SekCyclesDone());
- if (pwm_ptr <= 16) // at least some samples..
+ xmd = Pico32x.regs[0x30 / 2] & 0x0f;
+ if (xmd == 0 || xmd == 0x06 || xmd == 0x09 || xmd == 0x0f)
+ goto out; // invalid?
+ if (pwm.silent)
return;
- step = (pwm_ptr << 16) / length; // FIXME: division..
+ step = (pwm.ptr << 16) / length;
pwmb = Pico32xMem->pwm;
if (stereo)
{
- while (length-- > 0) {
- *buf32++ += pwmb[0];
- *buf32++ += pwmb[1];
+ if (xmd == 0x05) {
+ // normal
+ while (length-- > 0) {
+ *buf32++ += pwmb[0];
+ *buf32++ += pwmb[1];
- p += step;
- pwmb += (p >> 16) * 2;
- p &= 0xffff;
+ p += step;
+ pwmb += (p >> 16) * 2;
+ p &= 0xffff;
+ }
+ }
+ else if (xmd == 0x0a) {
+ // channel swap
+ while (length-- > 0) {
+ *buf32++ += pwmb[1];
+ *buf32++ += pwmb[0];
+
+ p += step;
+ pwmb += (p >> 16) * 2;
+ p &= 0xffff;
+ }
+ }
+ else {
+ // mono - LMD, RMD specify dst
+ if (xmd & 0x06) // src is R
+ pwmb++;
+ if (xmd & 0x0c) // dst is R
+ buf32++;
+ while (length-- > 0) {
+ *buf32 += *pwmb;
+
+ p += step;
+ pwmb += (p >> 16) * 2;
+ p &= 0xffff;
+ buf32 += 2;
+ }
}
}
else
{
+ // mostly unused
while (length-- > 0) {
*buf32++ += pwmb[0];
}
}
- elprintf(EL_32X, "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 = pwm.current[0] == 0 && pwm.current[1] == 0;
+}
- pwm_ptr = 0;
+void p32x_pwm_state_loaded(void)
+{
+ int cycles_diff_sh2;
+
+ p32x_pwm_ctl_changed();
+
+ // for old savestates
+ 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);
+ }
}
+// vim:shiftwidth=2:ts=2:expandtab
notaz.gp2x.de / picodrive.git / blobdiff