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06ad98bea9860e66c06d1b23b84a7e492d2c16db
VARCem/src/pit.c
waltje 0252e76226 More warnings fixed. Only 180 to go!
2018-03-28 02:25:23 -04:00

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/*
* VARCem Virtual ARchaeological Computer EMulator.
* An emulator of (mostly) x86-based PC systems and devices,
* using the ISA,EISA,VLB,MCA and PCI system buses, roughly
* spanning the era between 1981 and 1995.
*
* This file is part of the VARCem Project.
*
* Implement the PIT (Programmable Interval Timer.)
*
* Version: @(#)pit.c 1.0.4 2018/03/27
*
* Authors: Fred N. van Kempen, <decwiz@yahoo.com>
* Miran Grca, <mgrca8@gmail.com>
* Sarah Walker, <tommowalker@tommowalker.co.uk>
*
* Copyright 2017,2018 Fred N. van Kempen.
* Copyright 2016-2018 Miran Grca.
* Copyright 2008-2018 Sarah Walker.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the:
*
* Free Software Foundation, Inc.
* 59 Temple Place - Suite 330
* Boston, MA 02111-1307
* USA.
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <wchar.h>
#include "emu.h"
#include "cpu/cpu.h"
#include "dma.h"
#include "io.h"
#include "nmi.h"
#include "pic.h"
#include "pit.h"
#include "ppi.h"
#include "device.h"
#include "timer.h"
#include "machine/machine.h"
#include "sound/sound.h"
#include "sound/snd_speaker.h"
#include "video/video.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!*/
int displine;
int firsttime = 1;
PIT pit,
pit2;
float cpuclock;
float isa_timing, bus_timing;
double PITCONST;
float CGACONST;
float MDACONST;
float VGACONST1,
VGACONST2;
float RTCCONST;
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 void
pit_load(PIT *pit, int t)
{
int l = pit->l[t] ? pit->l[t] : 0x10000;
timer_clock();
pit->newcount[t] = 0;
pit->disabled[t] = 0;
switch (pit->m[t]) {
case 0: /*Interrupt on terminal count*/
pit->count[t] = l;
pit->c[t] = (int64_t)((((int64_t) l) << TIMER_SHIFT) * 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;
pit->c[t] = (int64_t)(((((int64_t) l) - 1LL) << TIMER_SHIFT) * 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;
pit->c[t] = (int64_t)((((((int64_t) l) + 1LL) >> 1) << TIMER_SHIFT) * PITCONST);
pit_set_out(pit, t, 1);
pit->thit[t] = 0;
}
pit->enabled[t] = pit->gate[t];
break;
case 4: /*Software triggered stobe*/
if (!pit->thit[t] && !pit->initial[t]) {
pit->newcount[t] = 1;
} else {
pit->count[t] = l;
pit->c[t] = (int64_t)((l << TIMER_SHIFT) * 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];
timer_update_outstanding();
}
static void
pit_over(PIT *pit, int t)
{
int64_t l = pit->l[t] ? pit->l[t] : 0x10000LL;
if (pit->disabled[t]) {
pit->count[t] += 0xffff;
pit->c[t] += (int64_t)(((int64_t)0xffff << TIMER_SHIFT) * PITCONST);
return;
}
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;
pit->c[t] += (int64_t)(((int64_t)0xffff << TIMER_SHIFT) * PITCONST);
break;
case 2: /*Rate generator*/
pit->count[t] += (int)l;
pit->c[t] += (int64_t)((l << TIMER_SHIFT) * 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] += (int)(l >> 1);
pit->c[t] += (int64_t)(((l >> 1) << TIMER_SHIFT) * PITCONST);
} else {
pit_set_out(pit, t, 1);
pit->count[t] += (int)((l + 1) >> 1);
pit->c[t] = (int64_t)((((l + 1) >> 1) << TIMER_SHIFT) * 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] += (int)l;
pit->c[t] += (int64_t)((l << TIMER_SHIFT) * PITCONST);
} else {
pit->thit[t] = 1;
pit->count[t] += 0xffff;
pit->c[t] += (int64_t)(((int64_t)0xffff << TIMER_SHIFT) * 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;
pit->c[t] += (int64_t)(((int64_t)0xffff << TIMER_SHIFT) * PITCONST);
break;
}
pit->running[t] = pit->enabled[t] &&
pit->using_timer[t] && !pit->disabled[t];
}
static void
pit_set_gate_no_timer(PIT *pit, int t, int gate)
{
int64_t l = pit->l[t] ? pit->l[t] : 0x10000LL;
if (pit->disabled[t]) {
pit->gate[t] = gate;
return;
}
switch (pit->m[t]) {
case 0: /*Interrupt on terminal count*/
case 4: /*Software triggered stobe*/
pit->enabled[t] = gate;
break;
case 1: /*Hardware retriggerable one-shot*/
case 5: /*Hardware triggered stobe*/
if (gate && !pit->gate[t]) {
pit->count[t] = (int)l;
pit->c[t] = (int64_t)((l << TIMER_SHIFT) * 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] = (int)(l - 1);
pit->c[t] = (int64_t)((l << TIMER_SHIFT) * 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] = (int)l;
pit->c[t] = (int64_t)((((l+1)>>1)<<TIMER_SHIFT)*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];
}
static 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);
}
static void
pit_timer_over(void *priv)
{
PIT_nr *pit_nr = (PIT_nr *)priv;
PIT *pit = pit_nr->pit;
int timer = pit_nr->nr;
pit_over(pit, timer);
}
static int
pit_read_timer(PIT *pit, int t)
{
int r;
timer_clock();
if (pit->using_timer[t] && !(pit->m[t] == 3 && !pit->gate[t])) {
r = (int)((int64_t)((pit->c[t] + ((1LL << TIMER_SHIFT) - 1)) / PITCONST) >> TIMER_SHIFT);
if (pit->m[t] == 2)
r++;
if (r < 0)
r = 0;
if (r > 0x10000)
r = 0x10000;
if (pit->m[t] == 3)
r <<= 1;
return r;
}
if (pit->m[t] == 2)
return (pit->count[t] + 1);
return pit->count[t];
}
static void
pit_write(uint16_t addr, uint8_t val, void *priv)
{
PIT *pit = (PIT *)priv;
int t;
cycles -= (int)PITCONST;
switch (addr & 3) {
case 3: /*CTRL*/
if ((val & 0xc0) == 0xc0) {
if (! (val & 0x20)) {
if (val & 2)
pit->rl[0] = (uint32_t)pit_read_timer(pit, 0);
if (val & 4)
pit->rl[1] = (uint32_t)pit_read_timer(pit, 1);
if (val & 8)
pit->rl[2] = (uint32_t)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)
return;
if (! (pit->ctrl & 0x30)) {
pit->rl[t] = (uint32_t)pit_read_timer(pit, t);
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] = (uint32_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;
}
pit->wp = 0;
pit->thit[t] = 0;
break;
case 0: /*Timers*/
case 1:
case 2:
t = addr & 3;
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 = (int)(((float)pit->l[2]/(float)pit->l[0])*0x4000)-0x2000;
if (speakval > 0x2000)
speakval = 0x2000;
break;
}
}
static uint8_t
pit_read(uint16_t addr, void *priv)
{
PIT *pit = (PIT *)priv;
uint8_t temp = 0xff;
int t;
cycles -= (int)PITCONST;
switch (addr&3) {
case 0: /*Timers*/
case 1:
case 2:
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;
}
return temp;
}
static void
pit_null_timer(int new_out, int old_out)
{
}
static void
pit_irq0_timer(int new_out, int old_out)
{
if (new_out && !old_out)
picint(1);
if (! new_out)
picintc(1);
}
static void
pit_speaker_timer(int new_out, int old_out)
{
int64_t l;
speaker_update();
l = pit.l[2] ? pit.l[2] : 0x10000LL;
if (l < 25LL)
speakon = 0;
else
speakon = new_out;
ppispeakon = new_out;
}
void
pit_init(void)
{
pit_reset(&pit);
io_sethandler(0x0040, 4,
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_over,
&pit.c[0], &pit.running[0], (void *)&pit.pit_nr[0]);
timer_add(pit_timer_over,
&pit.c[1], &pit.running[1], (void *)&pit.pit_nr[1]);
timer_add(pit_timer_over,
&pit.c[2], &pit.running[2], (void *)&pit.pit_nr[2]);
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);
}
static void
pit_ps2_irq0(int new_out, int 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);
}
static void
pit_ps2_nmi(int new_out, int old_out)
{
nmi = new_out;
if (nmi)
nmi_auto_clear = 1;
}
void
pit_ps2_init(void)
{
pit_reset(&pit2);
io_sethandler(0x0044, 1,
pit_read,NULL,NULL, pit_write,NULL,NULL, &pit2);
io_sethandler(0x0047, 1,
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(pit_timer_over,
&pit2.c[0], &pit2.running[0], (void *)&pit2.pit_nr[0]);
pit_set_out_func(&pit, 0, pit_ps2_irq0);
pit_set_out_func(&pit2, 0, pit_ps2_nmi);
}
void
pit_reset(PIT *pit)
{
void (*old_set_out_funcs[3])(int new_out, int old_out);
PIT_nr old_pit_nr[3];
memcpy(old_set_out_funcs, pit->set_out_funcs, 3 * sizeof(void *));
memcpy(old_pit_nr, pit->pit_nr, 3 * sizeof(PIT_nr));
memset(pit, 0, sizeof(PIT));
memcpy(pit->set_out_funcs, old_set_out_funcs, 3 * sizeof(void *));
memcpy(pit->pit_nr, old_pit_nr, 3 * sizeof(PIT_nr));
pit->l[0] = 0xffff; pit->c[0] = (int64_t)(0xffffLL*PITCONST);
pit->l[1] = 0xffff; pit->c[1] = (int64_t)(0xffffLL*PITCONST);
pit->l[2] = 0xffff; pit->c[2] = (int64_t)(0xffffLL*PITCONST);
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;
}
void
setpitclock(float clock)
{
cpuclock = clock;
TIMER_USEC = (int64_t)((clock / 1000000.0f) * (float)(1 << TIMER_SHIFT));
PITCONST = clock/(1193181.0f + (2.0f / 3.0f));
RTCCONST = clock/32768.0f;
CGACONST = (clock/(19687503.0f/11.0f));
MDACONST = (clock/2032125.0f);
VGACONST1 = (clock/25175000.0f);
VGACONST2 = (clock/28322000.0f);
isa_timing = clock/8000000.0f;
bus_timing = clock/(float)cpu_busspeed;
video_update_timing();
xt_cpu_multi = (int)((14318184.0*(double)(1 << TIMER_SHIFT)) / (double)machines[machine].cpu[cpu_manufacturer].cpus[cpu_effective].rspeed);
device_speed_changed();
}
void
clearpit(void)
{
pit.c[0] = (pit.l[0]<<2);
}
int
pit_get_timer_0(void)
{
int r = (int)((int64_t)((pit.c[0] + ((1LL << TIMER_SHIFT) - 1)) / PITCONST) >> TIMER_SHIFT);
if (pit.m[0] == 2)
r++;
if (r < 0)
r = 0;
if (r > 0x10000)
r = 0x10000;
if (pit.m[0] == 3)
r <<= 1;
return r;
}
float
pit_timer0_freq(void)
{
if (pit.l[0])
return (1193181.0f + (2.0f / 3.0f))/(float)pit.l[0];
else
return (1193181.0f + (2.0f / 3.0f))/(float)0x10000;
}
void
pit_set_gate(PIT *pit, int t, int gate)
{
if (pit->disabled[t]) {
pit->gate[t] = gate;
return;
}
timer_process();
pit_set_gate_no_timer(pit, t, gate);
timer_update_outstanding();
}
void
pit_set_using_timer(PIT *pit, int t, int using_timer)
{
timer_process();
if (pit->using_timer[t] && !using_timer)
pit->count[t] = pit_read_timer(pit, t);
if (!pit->using_timer[t] && using_timer)
pit->c[t] = (int64_t)((((int64_t) pit->count[t]) << TIMER_SHIFT) * PITCONST);
pit->using_timer[t] = using_timer;
pit->running[t] = pit->enabled[t] &&
pit->using_timer[t] && !pit->disabled[t];
timer_update_outstanding();
}
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_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_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;
}
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