+#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;
+
+
+void p32x_pwm_refresh(void)
+{
+ int cycles = Pico32x.regs[0x32 / 2];
+ int frame_samples;
+
+ cycles = (cycles - 1) & 0x0fff;
+ if (cycles < 500) {
+ elprintf(EL_32X|EL_ANOMALY, "pwm: low cycle value: %d", cycles + 1);
+ cycles = 500;
+ }
+ 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;
+}
+
+// irq for every sample??
+// FIXME: we need to hit more than once per line :(
+void p32x_pwm_irq_check(void)
+{
+ int tm = (Pico32x.regs[0x30 / 2] & 0x0f00) >> 8;
+ if (tm == 0)
+ return; // TODO: verify
+
+ 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();
+ }
+}
+
+unsigned int p32x_pwm_read16(unsigned int a)
+{
+ unsigned int d = 0;
+ int predict;
+
+ 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)
+ d |= P32XP_FULL;
+ else if (pwm_frame_smp_cnt == 0 || pwm_frame_smp_cnt < predict - 1)
+ d |= P32XP_EMPTY;
+ break;
+ }
+
+ return d;
+}
+
+void p32x_pwm_write16(unsigned int a, unsigned int d)
+{
+ 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);
+ }
+ }
+}
+
+void p32x_pwm_update(int *buf32, int length, int stereo)
+{
+ extern int pwm_ptr;
+ short *pwmb;
+ int step;
+ int p = 0;
+
+ if (pwm_ptr <= 16) // at least some samples..
+ return;
+
+ step = (pwm_ptr << 16) / length; // FIXME: division..
+ pwmb = Pico32xMem->pwm;
+
+ if (stereo)
+ {
+ while (length-- > 0) {
+ *buf32++ += pwmb[0];
+ *buf32++ += pwmb[1];
+
+ p += step;
+ pwmb += (p >> 16) * 2;
+ p &= 0xffff;
+ }
+ }
+ else
+ {
+ while (length-- > 0) {
+ *buf32++ += pwmb[0];
+
+ p += step;
+ pwmb += (p >> 16) * 2;
+ p &= 0xffff;
+ }
+ }
+
+ elprintf(EL_STATUS, "pwm_update: pwm_ptr %d, len %d, step %04x, done %d",
+ pwm_ptr, length, step, (pwmb - Pico32xMem->pwm) / 2);
+
+ pwm_ptr = 0;
+}
+