/*IBM AT -
  Write B0
  Write aa55
  Expects aa55 back*/

#include <string.h>
#include "ibm.h"

#include "cpu.h"
#include "device.h"
#include "dma.h"
#include "io.h"
#include "pic.h"
#include "pit.h"
#include "sound_speaker.h"
#include "timer.h"
#include "video.h"
#include "model.h"
/*B0 to 40, two writes to 43, then two reads - value does not change!*/
/*B4 to 40, two writes to 43, then two reads - value _does_ change!*/
//Tyrian writes 4300 or 17512
int displine;

uint64_t PITCONST;
uint64_t CGACONST;
uint64_t MDACONST;
uint64_t VGACONST1, VGACONST2;
uint64_t RTCCONST;

float cpuclock;
float isa_timing, bus_timing;

int firsttime = 1;
void setpitclock(float clock) {
//        printf("PIT clock %f\n",clock);
	cpuclock = clock;
	PITCONST = (uint64_t)(clock / 1193182.0 * (float)(1ull << 32));
	CGACONST = (uint64_t)((clock / (19687503.0 / 11.0)) * (float)(1ull << 32));
	MDACONST = (uint64_t)((clock / 2032125.0) * (float)(1ull << 32));
	VGACONST1 = (uint64_t)((clock / 25175000.0) * (float)(1ull << 32));
	VGACONST2 = (uint64_t)((clock / 28322000.0) * (float)(1ull << 32));
	isa_timing = clock / 8000000.0;
	bus_timing = clock / (double)cpu_busspeed;
	video_updatetiming();
//        pclog("PITCONST=%f CGACONST=%f\n", PITCONST, CGACONST);
//        pclog("CPUMULTI=%g\n", ((14318184.0*(double)(1 << TIMER_SHIFT)) / (double)models[model]->cpu[cpu_manufacturer].cpus[cpu].rspeed));

	xt_cpu_multi = (uint64_t)((14318184.0 * (double)(1ull << 32)) / (double)cpu_get_speed());
//        pclog("egacycles %i egacycles2 %i temp %f clock %f\n",egacycles,egacycles2,temp,clock);
/*        if (video_recalctimings)
                video_recalctimings();*/
	RTCCONST = (uint64_t)((clock / 32768.0) * (float)(1ull << 32));
	TIMER_USEC = (uint64_t)((clock / 1000000.0) * (float)(1ull << 32));
	device_speed_changed();
}

//#define PITCONST (8000000.0/1193000.0)
//#define PITCONST (cpuclock/1193000.0)
void pit_reset(PIT *pit) {
	memset(pit, 0, sizeof(PIT));
	pit->l[0] = 0xFFFF;
	pit->l[1] = 0xFFFF;
	pit->l[2] = 0xFFFF;
	pit->m[0] = pit->m[1] = pit->m[2] = 0;
	pit->ctrls[0] = pit->ctrls[1] = pit->ctrls[2] = 0;
	pit->thit[0] = 1;
	pit->gate[0] = pit->gate[1] = 1;
	pit->gate[2] = 0;
	pit->using_timer[0] = pit->using_timer[1] = pit->using_timer[2] = 1;
}

float pit_timer0_freq() {
	if (pit.l[0])
		return 1193182.0f / (float)pit.l[0];
	else
		return 1193182.0f / (float)0x10000;
}

static void pit_set_out(PIT *pit, int t, int out) {
	pit->set_out_funcs[t](out, pit->out[t]);
	pit->out[t] = out;
}

static int pit_read_timer(PIT *pit, int t) {
//        pclog("pit_read_timer: t=%i using_timer=%i m=%i enabled=%i\n", t, pit->using_timer[t], pit->m[t], timer_is_enabled(&pit->timer[t]));
	if (pit->using_timer[t] && !(pit->m[t] == 3 && !pit->gate[t]) && timer_is_enabled(&pit->timer[t])) {
		int read = (int)((timer_get_remaining_u64(&pit->timer[t])) / PITCONST);
//		pclog(" read %i %08x %016llx\n", t, read, timer_get_remaining_u64(&pit->timer[t]));
		if (pit->m[t] == 2)
			read++;
		if (read < 0)
			read = 0;
		if (read > 0x10000)
			read = 0x10000;
		if (pit->m[t] == 3)
			read <<= 1;
		return read;
	}
	if (pit->m[t] == 2)
		return pit->count[t] + 1;
	return pit->count[t];
}

/*Dump timer count back to pit->count[], and disable timer. This should be used
  when stopping a PIT timer, to ensure the correct value can be read back.*/
static void pit_dump_and_disable_timer(PIT *pit, int t) {
	if (pit->using_timer[t] && timer_is_enabled(&pit->timer[t])) {
		pit->count[t] = pit_read_timer(pit, t);
		timer_disable(&pit->timer[t]);
	}
}

static void pit_load(PIT *pit, int t) {
	int l = pit->l[t] ? pit->l[t] : 0x10000;

	pit->newcount[t] = 0;
	pit->disabled[t] = 0;
//        pclog("pit_load: t=%i l=%x m=%i %016llx\n", t, l, pit->m[t], PITCONST);
	switch (pit->m[t]) {
	case 0: /*Interrupt on terminal count*/
		pit->count[t] = l;
		if (pit->using_timer[t])
			timer_set_delay_u64(&pit->timer[t], (uint64_t)(l * PITCONST));
		pit_set_out(pit, t, 0);
		pit->thit[t] = 0;
		pit->enabled[t] = pit->gate[t];
		break;
	case 1: /*Hardware retriggerable one-shot*/
		pit->enabled[t] = 1;
		break;
	case 2: /*Rate generator*/
		if (pit->initial[t]) {
			pit->count[t] = l - 1;
			if (pit->using_timer[t])
				timer_set_delay_u64(&pit->timer[t], (uint64_t)((l - 1) * PITCONST));
			pit_set_out(pit, t, 1);
			pit->thit[t] = 0;
		}
		pit->enabled[t] = pit->gate[t];
		break;
	case 3: /*Square wave mode*/
		if (pit->initial[t]) {
			pit->count[t] = l;
			if (pit->using_timer[t])
				timer_set_delay_u64(&pit->timer[t], (uint64_t)(((l + 1) >> 1) * PITCONST));
			pit_set_out(pit, t, 1);
			pit->thit[t] = 0;
		}
		pit->enabled[t] = pit->gate[t];
//                pclog("pit_load: square wave mode c=%x\n", );
		break;
	case 4: /*Software triggered stobe*/
		if (!pit->thit[t] && !pit->initial[t])
			pit->newcount[t] = 1;
		else {
			pit->count[t] = l;
			if (pit->using_timer[t])
				timer_set_delay_u64(&pit->timer[t], (uint64_t)(l * PITCONST));
			pit_set_out(pit, t, 0);
			pit->thit[t] = 0;
		}
		pit->enabled[t] = pit->gate[t];
		break;
	case 5: /*Hardware triggered stobe*/
		pit->enabled[t] = 1;
		break;
	}
	pit->initial[t] = 0;
	pit->running[t] = pit->enabled[t] && pit->using_timer[t] && !pit->disabled[t];
	if (pit->using_timer[t] && !pit->running[t])
		pit_dump_and_disable_timer(pit, t);

//        pclog("pit_load: t=%i running=%i thit=%i enabled=%i m=%i l=%x c=%g gate=%i\n", t, pit.running[t], pit.thit[t], pit.enabled[t], pit.m[t], pit.l[t], pit.c[t], pit.gate[t]);
}

void pit_set_gate_no_timer(PIT *pit, int t, int gate) {
	int l = pit->l[t] ? pit->l[t] : 0x10000;

	if (pit->disabled[t]) {
		pit->gate[t] = gate;
		return;
	}

	switch (pit->m[t]) {
	case 0: /*Interrupt on terminal count*/
	case 4: /*Software triggered stobe*/
		if (pit->using_timer[t] && !pit->running[t])
			timer_set_delay_u64(&pit->timer[t], (uint64_t)(l * PITCONST));
		pit->enabled[t] = gate;
		break;
	case 1: /*Hardware retriggerable one-shot*/
	case 5: /*Hardware triggered stobe*/
		if (gate && !pit->gate[t]) {
			pit->count[t] = l;
			if (pit->using_timer[t])
				timer_set_delay_u64(&pit->timer[t], (uint64_t)(l * PITCONST));
			pit_set_out(pit, t, 0);
			pit->thit[t] = 0;
			pit->enabled[t] = 1;
		}
		break;
	case 2: /*Rate generator*/
		if (gate && !pit->gate[t]) {
			pit->count[t] = l - 1;
			if (pit->using_timer[t])
				timer_set_delay_u64(&pit->timer[t], (uint64_t)(l * PITCONST));
			pit_set_out(pit, t, 1);
			pit->thit[t] = 0;
		}
		pit->enabled[t] = gate;
		break;
	case 3: /*Square wave mode*/
		if (gate && !pit->gate[t]) {
			pit->count[t] = l;
			if (pit->using_timer[t])
				timer_set_delay_u64(&pit->timer[t], (uint64_t)(((l + 1) >> 1) * PITCONST));
			pit_set_out(pit, t, 1);
			pit->thit[t] = 0;
		}
		pit->enabled[t] = gate;
		break;
	}
	pit->gate[t] = gate;
	pit->running[t] = pit->enabled[t] && pit->using_timer[t] && !pit->disabled[t];
	if (pit->using_timer[t] && !pit->running[t])
		pit_dump_and_disable_timer(pit, t);
//        pclog("pit_set_gate: t=%i gate=%i\n", t, gate);
}

void pit_set_gate(PIT *pit, int t, int gate) {
//        pclog("pit_set_gate: t=%i gate=%i\n", t, gate);
	if (pit->disabled[t]) {
		pit->gate[t] = gate;
		return;
	}

	pit_set_gate_no_timer(pit, t, gate);
}

static void pit_over(PIT *pit, int t) {
	int l = pit->l[t] ? pit->l[t] : 0x10000;
	if (pit->disabled[t]) {
		pit->count[t] += 0xffff;
		if (pit->using_timer[t])
			timer_advance_u64(&pit->timer[t], (uint64_t)(0xffff * PITCONST));
		return;
	}

//        if (t == 2) pclog("pit_over: t=%i l=%x c=%llx hit=%i %016llx\n", t, pit->l[t], timer_get_remaining_u64(&pit->timer[t]), pit->thit[t], tsc);
	switch (pit->m[t]) {
	case 0: /*Interrupt on terminal count*/
	case 1: /*Hardware retriggerable one-shot*/
		if (!pit->thit[t])
			pit_set_out(pit, t, 1);
		pit->thit[t] = 1;
		pit->count[t] += 0xffff;
		if (pit->using_timer[t])
			timer_advance_u64(&pit->timer[t], (uint64_t)(0xffff * PITCONST));
		break;
	case 2: /*Rate generator*/
		pit->count[t] += l;
		if (pit->using_timer[t])
			timer_advance_u64(&pit->timer[t], (uint64_t)(l * PITCONST));
		pit_set_out(pit, t, 0);
		pit_set_out(pit, t, 1);
		break;
	case 3: /*Square wave mode*/
		if (pit->out[t]) {
			pit_set_out(pit, t, 0);
			pit->count[t] += (l >> 1);
			if (pit->using_timer[t])
				timer_advance_u64(&pit->timer[t], (uint64_t)((l >> 1) * PITCONST));
		} else {
			pit_set_out(pit, t, 1);
			pit->count[t] += ((l + 1) >> 1);
			if (pit->using_timer[t])
				timer_advance_u64(&pit->timer[t], (uint64_t)(((l + 1) >> 1) * PITCONST));
		}
//                if (!t) pclog("pit_over: square wave mode c=%x  %lli  %f\n", pit.c[t], tsc, PITCONST);
		break;
	case 4: /*Software triggered strove*/
		if (!pit->thit[t]) {
			pit_set_out(pit, t, 0);
			pit_set_out(pit, t, 1);
		}
		if (pit->newcount[t]) {
			pit->newcount[t] = 0;
			pit->count[t] += l;
			if (pit->using_timer[t])
				timer_advance_u64(&pit->timer[t], (uint64_t)(l * PITCONST));
		} else {
			pit->thit[t] = 1;
			pit->count[t] += 0xffff;
			if (pit->using_timer[t])
				timer_advance_u64(&pit->timer[t], (uint64_t)(0xffff * PITCONST));
		}
		break;
	case 5: /*Hardware triggered strove*/
		if (!pit->thit[t]) {
			pit_set_out(pit, t, 0);
			pit_set_out(pit, t, 1);
		}
		pit->thit[t] = 1;
		pit->count[t] += 0xffff;
		if (pit->using_timer[t])
			timer_advance_u64(&pit->timer[t], (uint64_t)(0xffff * PITCONST));
		break;
	}
	pit->running[t] = pit->enabled[t] && pit->using_timer[t] && !pit->disabled[t];
	if (pit->using_timer[t] && !pit->running[t])
		pit_dump_and_disable_timer(pit, t);
}

void pit_write(uint16_t addr, uint8_t val, void *p) {
	PIT *pit = (PIT *)p;
	int t;
//        /*if (val != 0x40) */pclog("Write PIT %04X %02X %04X:%08X %i %i\n",addr,val,CS,cpu_state.pc,ins, pit->gate[0]);

	switch (addr & 3) {
	case 3: /*CTRL*/
		if ((val & 0xC0) == 0xC0) {
			if (!(val & 0x20)) {
				if (val & 2)
					pit->rl[0] = pit_read_timer(pit, 0);
				if (val & 4)
					pit->rl[1] = pit_read_timer(pit, 1);
				if (val & 8)
					pit->rl[2] = pit_read_timer(pit, 2);
			}
			if (!(val & 0x10)) {
				if (val & 2) {
					pit->read_status[0] = (pit->ctrls[0] & 0x3f) | (pit->out[0] ? 0x80 : 0);
					pit->do_read_status[0] = 1;
				}
				if (val & 4) {
					pit->read_status[1] = (pit->ctrls[1] & 0x3f) | (pit->out[1] ? 0x80 : 0);
					pit->do_read_status[1] = 1;
				}
				if (val & 8) {
					pit->read_status[2] = (pit->ctrls[2] & 0x3f) | (pit->out[2] ? 0x80 : 0);
					pit->do_read_status[2] = 1;
				}
			}
			return;
		}
		t = val >> 6;
		pit->ctrl = val;
		if ((val >> 7) == 3) {
			printf("Bad PIT reg select\n");
			return;
//                        dumpregs();
//                        exit(-1);
		}
//                printf("CTRL write %02X\n",val);
		if (!(pit->ctrl & 0x30)) {
			pit->rl[t] = pit_read_timer(pit, t);
//                        pclog("Timer latch %f %04X %04X\n",pit->c[0],pit->rl[0],pit->l[0]);
			pit->ctrl |= 0x30;
			pit->rereadlatch[t] = 0;
			pit->rm[t] = 3;
			pit->latched[t] = 1;
		} else {
			pit->ctrls[t] = val;
			pit->rm[t] = pit->wm[t] = (pit->ctrl >> 4) & 3;
			pit->m[t] = (val >> 1) & 7;
			if (pit->m[t] > 5)
				pit->m[t] &= 3;
			if (!(pit->rm[t])) {
				pit->rm[t] = 3;
				pit->rl[t] = pit_read_timer(pit, t);
			}
			pit->rereadlatch[t] = 1;
			pit->initial[t] = 1;
			if (!pit->m[t])
				pit_set_out(pit, t, 0);
			else
				pit_set_out(pit, t, 1);
			pit->disabled[t] = 1;
//                                pclog("ppispeakon %i\n",ppispeakon);
		}
		pit->wp = 0;
		pit->thit[t] = 0;
		break;
	case 0:
	case 1:
	case 2: /*Timers*/
		t = addr & 3;
//                if (t==2) ppispeakon=speakon=0;
//                pclog("Write timer %02X %i\n",pit.ctrls[t],pit.wm[t]);
		switch (pit->wm[t]) {
		case 1:pit->l[t] = val;
			pit_load(pit, t);
			break;
		case 2:pit->l[t] = (val << 8);
			pit_load(pit, t);
			break;
		case 0:pit->l[t] &= 0xFF;
			pit->l[t] |= (val << 8);
			pit_load(pit, t);
			pit->wm[t] = 3;
			break;
		case 3:pit->l[t] &= 0xFF00;
			pit->l[t] |= val;
			pit->wm[t] = 0;
			break;
		}
		speakval = (((float)pit->l[2] / (float)pit->l[0]) * 0x4000) - 0x2000;
//                printf("Speakval now %i\n",speakval);
//                if (speakval>0x2000)
//                   printf("Speaker overflow - %i %i %04X %04X\n",pit.l[0],pit.l[2],pit.l[0],pit.l[2]);
		if (speakval > 0x2000)
			speakval = 0x2000;
/*                if (!pit.l[t])
                {
                        pit.l[t]|=0x10000;
                        pit.c[t]=pit.l[t]*PITCONST;
                }*/
		break;
	}
}

uint8_t pit_read(uint16_t addr, void *p) {
	PIT *pit = (PIT *)p;
	int t;
	uint8_t temp = 0xff;
//        printf("Read PIT %04X\n",addr);
	switch (addr & 3) {
	case 0:
	case 1:
	case 2: /*Timers*/
		t = addr & 3;
		if (pit->do_read_status[t]) {
			pit->do_read_status[t] = 0;
			temp = pit->read_status[t];
			break;
		}
		if (pit->rereadlatch[addr & 3] && !pit->latched[addr & 3]) {
			pit->rereadlatch[addr & 3] = 0;
			pit->rl[t] = pit_read_timer(pit, t);
		}
		switch (pit->rm[addr & 3]) {
		case 0:temp = pit->rl[addr & 3] >> 8;
			pit->rm[addr & 3] = 3;
			pit->latched[addr & 3] = 0;
			pit->rereadlatch[addr & 3] = 1;
			break;
		case 1:temp = (pit->rl[addr & 3]) & 0xFF;
			pit->latched[addr & 3] = 0;
			pit->rereadlatch[addr & 3] = 1;
			break;
		case 2:temp = (pit->rl[addr & 3]) >> 8;
			pit->latched[addr & 3] = 0;
			pit->rereadlatch[addr & 3] = 1;
			break;
		case 3:temp = (pit->rl[addr & 3]) & 0xFF;
			if (pit->m[addr & 3] & 0x80)
				pit->m[addr & 3] &= 7;
			else
				pit->rm[addr & 3] = 0;
			break;
		}
		break;
	case 3: /*Control*/
		temp = pit->ctrl;
		break;
	}
//        pclog("%02X\n", temp);
//        printf("%02X %i %i %04X:%04X %i\n",temp,pit.rm[addr&3],pit.wp,cs>>4,pc, ins);
	return temp;
}

void pit_timer_over(void *p) {
	PIT_nr *pit_nr = (PIT_nr *)p;
	PIT *pit = pit_nr->pit;
	int timer = pit_nr->nr;
//        pclog("pit_timer_over %i\n", timer);

	pit_over(pit, timer);
}

void pit_clock(PIT *pit, int t) {
	if (pit->thit[t] || !pit->enabled[t])
		return;

	if (pit->using_timer[t])
		return;

	pit->count[t] -= (pit->m[t] == 3) ? 2 : 1;
	if (!pit->count[t])
		pit_over(pit, t);
}

void pit_set_using_timer(PIT *pit, int t, int using_timer) {
//        pclog("pit_set_using_timer: t=%i using_timer=%i\n", t, using_timer);        
	timer_process();
	if (pit->using_timer[t] && !using_timer)
		pit->count[t] = pit_read_timer(pit, t);
	pit->running[t] = pit->enabled[t] && using_timer && !pit->disabled[t];
	if (!pit->using_timer[t] && using_timer && pit->running[t])
		timer_set_delay_u64(&pit->timer[t], (uint64_t)(pit->count[t] * PITCONST));
	else if (!pit->running[t])
		timer_disable(&pit->timer[t]);
	pit->using_timer[t] = using_timer;
}

void pit_set_out_func(PIT *pit, int t, void (*func)(int new_out, int old_out)) {
	pit->set_out_funcs[t] = func;
}

void pit_null_timer(int new_out, int old_out) {
}

void pit_irq0_timer(int new_out, int old_out) {
	if (new_out && !old_out)
		picint(1);
	if (!new_out)
		picintc(1);
}

void pit_irq0_timer_pcjr(int new_out, int old_out) {
	if (new_out && !old_out) {
		picint(1);
		pit_clock(&pit, 1);
	}
	if (!new_out)
		picintc(1);
}

void pit_irq0_ps2(int new_out, int old_out) {
	//pclog("pit_irq0_ps2 %i %i\n", new_out, old_out);
	if (new_out && !old_out) {
		picint(1);
		pit_set_gate_no_timer(&pit2, 0, 1);
	}
	if (!new_out)
		picintc(1);
	if (!new_out && old_out)
		pit_clock(&pit2, 0);
}

void pit_refresh_timer_xt(int new_out, int old_out) {
	if (new_out && !old_out)
		dma_channel_read(0);
}

void pit_refresh_timer_at(int new_out, int old_out) {
	if (new_out && !old_out)
		ppi.pb ^= 0x10;
}

void pit_speaker_timer(int new_out, int old_out) {
	int l;

	speaker_update();

	l = pit.l[2] ? pit.l[2] : 0x10000;
	if (l < 25)
		speakon = 0;
	else
		speakon = new_out;
	ppispeakon = new_out;
}

void pit_nmi_ps2(int new_out, int old_out) {
	nmi = new_out;
	if (nmi)
		nmi_auto_clear = 1;
}

void pit_init() {
	pit_reset(&pit);

	io_sethandler(0x0040, 0x0004, pit_read, NULL, NULL, pit_write, NULL, NULL, &pit);
	pit.gate[0] = pit.gate[1] = 1;
	pit.gate[2] = 0;
	pit.using_timer[0] = pit.using_timer[1] = pit.using_timer[2] = 1;

	pit.pit_nr[0].nr = 0;
	pit.pit_nr[1].nr = 1;
	pit.pit_nr[2].nr = 2;
	pit.pit_nr[0].pit = pit.pit_nr[1].pit = pit.pit_nr[2].pit = &pit;

	timer_add(&pit.timer[0], pit_timer_over, (void *)&pit.pit_nr[0], 0);
	timer_add(&pit.timer[1], pit_timer_over, (void *)&pit.pit_nr[1], 0);
	timer_add(&pit.timer[2], pit_timer_over, (void *)&pit.pit_nr[2], 0);

	pit_set_out_func(&pit, 0, pit_irq0_timer);
	pit_set_out_func(&pit, 1, pit_null_timer);
	pit_set_out_func(&pit, 2, pit_speaker_timer);
}

void pit_ps2_init() {
	pit_reset(&pit2);

	io_sethandler(0x0044, 0x0001, pit_read, NULL, NULL, pit_write, NULL, NULL, &pit2);
	io_sethandler(0x0047, 0x0001, pit_read, NULL, NULL, pit_write, NULL, NULL, &pit2);

	pit2.gate[0] = 0;
	pit2.using_timer[0] = 0;
	pit2.disabled[0] = 1;

	pit2.pit_nr[0].nr = 0;
	pit2.pit_nr[0].pit = &pit2;

	timer_add(&pit2.timer[0], pit_timer_over, (void *)&pit2.pit_nr[0], 0);

	pit_set_out_func(&pit, 0, pit_irq0_ps2);
	pit_set_out_func(&pit2, 0, pit_nmi_ps2);
}

