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- /*
- * PicoDrive
- * (C) notaz, 2009,2010,2013
- *
- * This work is licensed under the terms of MAME license.
- * See COPYING file in the top-level directory.
- */
- #include "../pico_int.h"
- 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;
- // supposedly we should stop FIFO when xMd is 0,
- // but mars test disagrees
- pwm.mult = 0;
- if ((control & 0x0f) != 0)
- pwm.mult = 0x10000 / cycles;
- 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(sh2, 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();
- }
- }
- static int convert_sample(unsigned int v)
- {
- if (v > pwm.cycles)
- v = pwm.cycles;
- if (v == 0)
- return 0;
- return v * pwm.mult - 0x10000/2;
- }
- #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)
- {
- 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);
- }
- 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;
- consume_fifo(sh2, m68k_cycles);
- a &= 0x0e;
- 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 (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(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;
- 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)
- {
- short *pwmb;
- int step;
- int p = 0;
- int xmd;
- 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)
- return;
- step = (pwm.ptr << 16) / length;
- pwmb = Pico32xMem->pwm;
- if (stereo)
- {
- if (xmd == 0x05) {
- // normal
- while (length-- > 0) {
- *buf32++ += pwmb[0];
- *buf32++ += pwmb[1];
- 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];
- p += step;
- pwmb += (p >> 16) * 2;
- p &= 0xffff;
- }
- }
- 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;
- }
- 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
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