Files
86Box-fork/src/pit_fast.c
2024-04-04 03:09:35 +02:00

828 lines
23 KiB
C

/*
* 86Box A hypervisor and IBM PC system emulator that specializes in
* running old operating systems and software designed for IBM
* PC systems and compatibles from 1981 through fairly recent
* system designs based on the PCI bus.
*
* This file is part of the 86Box distribution.
*
* Implementation of the Intel 8253/8254 Programmable Interval
* Timer.
*
*
*
* Authors: Miran Grca, <mgrca8@gmail.com>
*
* Copyright 2019 Miran Grca.
*/
#include <inttypes.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#define HAVE_STDARG_H
#include <86box/86box.h>
#include "cpu.h"
#include <86box/device.h>
#include <86box/timer.h>
#include <86box/cassette.h>
#include <86box/dma.h>
#include <86box/io.h>
#include <86box/nmi.h>
#include <86box/pic.h>
#include <86box/timer.h>
#include <86box/pit.h>
#include <86box/pit_fast.h>
#include <86box/ppi.h>
#include <86box/machine.h>
#include <86box/sound.h>
#include <86box/snd_speaker.h>
#include <86box/video.h>
#define PIT_PS2 16 /* The PIT is the PS/2's second PIT. */
#define PIT_EXT_IO 32 /* The PIT has externally specified port I/O. */
#define PIT_CUSTOM_CLOCK 64 /* The PIT uses custom clock inputs provided by another provider. */
#define PIT_SECONDARY 128 /* The PIT is secondary (ports 0048-004B). */
#ifdef ENABLE_PIT_LOG
int pit_do_log = ENABLE_PIT_LOG;
static void
pit_log(const char *fmt, ...)
{
va_list ap;
if (pit_do_log) {
va_start(ap, fmt);
pclog_ex(fmt, ap);
va_end(ap);
}
}
#else
# define pit_log(fmt, ...)
#endif
static void
pitf_ctr_set_out(ctrf_t *ctr, int out, void *priv)
{
pitf_t *pit = (pitf_t *)priv;
if (ctr == NULL)
return;
if (ctr->out_func != NULL)
ctr->out_func(out, ctr->out, pit);
ctr->out = out;
}
static void
pitf_ctr_set_load_func(void *data, int counter_id, void (*func)(uint8_t new_m, int new_count))
{
if (data == NULL)
return;
pitf_t *pit = (pitf_t *) data;
ctrf_t *ctr = &pit->counters[counter_id];
ctr->load_func = func;
}
static uint16_t
pitf_ctr_get_count(void *data, int counter_id)
{
const pitf_t *pit = (pitf_t *) data;
const ctrf_t *ctr = &pit->counters[counter_id];
return (uint16_t) ctr->l;
}
void
pitf_ctr_set_out_func(void *data, int counter_id, void (*func)(int new_out, int old_out, void *priv))
{
if (data == NULL)
return;
pitf_t *pit = (pitf_t *) data;
ctrf_t *ctr = &pit->counters[counter_id];
ctr->out_func = func;
}
void
pitf_ctr_set_using_timer(void *data, int counter_id, int using_timer)
{
if (tsc > 0)
timer_process();
pitf_t *pit = (pitf_t *) data;
ctrf_t *ctr = &pit->counters[counter_id];
ctr->using_timer = using_timer;
}
static int
pitf_read_timer(ctrf_t *ctr)
{
if (ctr->using_timer && !(ctr->m == 3 && !ctr->gate) && timer_is_enabled(&ctr->timer)) {
int read = (int) ((timer_get_remaining_u64(&ctr->timer)) / ctr->pit_const);
if (ctr->m == 2)
read++;
if (read < 0)
read = 0;
if (read > 0x10000)
read = 0x10000;
if ((ctr->m == 3) && ctr->using_timer)
read <<= 1;
return read;
}
if (ctr->m == 2)
return ctr->count + 1;
return ctr->count;
}
/*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
pitf_dump_and_disable_timer(ctrf_t *ctr)
{
if (ctr->using_timer && timer_is_enabled(&ctr->timer)) {
ctr->count = pitf_read_timer(ctr);
if (ctr->m == 2)
ctr->count--; /* Don't store the offset from pitf_read_timer */
timer_disable(&ctr->timer);
}
}
static void
pitf_ctr_load(ctrf_t *ctr, void *priv)
{
pitf_t *pit = (pitf_t *)priv;
int l = ctr->l ? ctr->l : 0x10000;
ctr->newcount = 0;
ctr->disabled = 0;
switch (ctr->m) {
case 0: /*Interrupt on terminal count*/
ctr->count = l;
if (ctr->using_timer)
timer_set_delay_u64(&ctr->timer, (uint64_t) (l * ctr->pit_const));
pitf_ctr_set_out(ctr, 0, pit);
ctr->thit = 0;
ctr->enabled = ctr->gate;
break;
case 1: /*Hardware retriggerable one-shot*/
ctr->enabled = 1;
break;
case 2: /*Rate generator*/
if (ctr->initial) {
ctr->count = l - 1;
if (ctr->using_timer)
timer_set_delay_u64(&ctr->timer, (uint64_t) ((l - 1) * ctr->pit_const));
pitf_ctr_set_out(ctr, 1, pit);
ctr->thit = 0;
}
ctr->enabled = ctr->gate;
break;
case 3: /*Square wave mode*/
if (ctr->initial) {
ctr->count = l;
if (ctr->using_timer)
timer_set_delay_u64(&ctr->timer, (uint64_t) (((l + 1) >> 1) * ctr->pit_const));
else
ctr->newcount = (l & 1);
pitf_ctr_set_out(ctr, 1, pit);
ctr->thit = 0;
}
ctr->enabled = ctr->gate;
break;
case 4: /*Software triggered stobe*/
if (!ctr->thit && !ctr->initial)
ctr->newcount = 1;
else {
ctr->count = l;
if (ctr->using_timer)
timer_set_delay_u64(&ctr->timer, (uint64_t) (l * ctr->pit_const));
pitf_ctr_set_out(ctr, 0, pit);
ctr->thit = 0;
}
ctr->enabled = ctr->gate;
break;
case 5: /*Hardware triggered stobe*/
ctr->enabled = 1;
break;
default:
break;
}
if (ctr->load_func != NULL)
ctr->load_func(ctr->m, l);
ctr->initial = 0;
ctr->running = ctr->enabled && ctr->using_timer && !ctr->disabled;
if (ctr->using_timer && !ctr->running)
pitf_dump_and_disable_timer(ctr);
}
static void
pitf_set_gate_no_timer(ctrf_t *ctr, int gate, void *priv)
{
pitf_t *pit = (pitf_t *)priv;
int l = ctr->l ? ctr->l : 0x10000;
if (ctr->disabled) {
ctr->gate = gate;
return;
}
switch (ctr->m) {
case 0: /*Interrupt on terminal count*/
case 4: /*Software triggered stobe*/
if (ctr->using_timer && !ctr->running)
timer_set_delay_u64(&ctr->timer, (uint64_t) (l * ctr->pit_const));
ctr->enabled = gate;
break;
case 1: /*Hardware retriggerable one-shot*/
case 5: /*Hardware triggered stobe*/
if (gate && !ctr->gate) {
ctr->count = l;
if (ctr->using_timer)
timer_set_delay_u64(&ctr->timer, (uint64_t) (l * ctr->pit_const));
pitf_ctr_set_out(ctr, 0, pit);
ctr->thit = 0;
ctr->enabled = 1;
}
break;
case 2: /*Rate generator*/
if (gate && !ctr->gate) {
ctr->count = l - 1;
if (ctr->using_timer)
timer_set_delay_u64(&ctr->timer, (uint64_t) (l * ctr->pit_const));
pitf_ctr_set_out(ctr, 1, pit);
ctr->thit = 0;
}
ctr->enabled = gate;
break;
case 3: /*Square wave mode*/
if (gate && !ctr->gate) {
ctr->count = l;
if (ctr->using_timer)
timer_set_delay_u64(&ctr->timer, (uint64_t) (((l + 1) >> 1) * ctr->pit_const));
else
ctr->newcount = (l & 1);
pitf_ctr_set_out(ctr, 1, pit);
ctr->thit = 0;
}
ctr->enabled = gate;
break;
default:
break;
}
ctr->gate = gate;
ctr->running = ctr->enabled && ctr->using_timer && !ctr->disabled;
if (ctr->using_timer && !ctr->running)
pitf_dump_and_disable_timer(ctr);
}
void
pitf_ctr_set_gate(void *data, int counter_id, int gate)
{
pitf_t *pit = (pitf_t *) data;
ctrf_t *ctr = &pit->counters[counter_id];
if (ctr->disabled) {
ctr->gate = gate;
return;
}
pitf_set_gate_no_timer(ctr, gate, pit);
}
static void
pitf_over(ctrf_t *ctr, void *priv)
{
pitf_t *pit = (pitf_t *)priv;
int l = ctr->l ? ctr->l : 0x10000;
if (ctr->disabled) {
ctr->count += 0xffff;
if (ctr->using_timer)
timer_advance_u64(&ctr->timer, (uint64_t) (0xffff * ctr->pit_const));
return;
}
switch (ctr->m) {
case 0: /*Interrupt on terminal count*/
case 1: /*Hardware retriggerable one-shot*/
if (!ctr->thit)
pitf_ctr_set_out(ctr, 1, pit);
ctr->thit = 1;
ctr->count += 0xffff;
if (ctr->using_timer)
timer_advance_u64(&ctr->timer, (uint64_t) (0xffff * ctr->pit_const));
break;
case 2: /*Rate generator*/
ctr->count += l;
if (ctr->using_timer)
timer_advance_u64(&ctr->timer, (uint64_t) (l * ctr->pit_const));
pitf_ctr_set_out(ctr, 0, pit);
pitf_ctr_set_out(ctr, 1, pit);
break;
case 3: /*Square wave mode*/
if (ctr->out) {
pitf_ctr_set_out(ctr, 0, pit);
if (ctr->using_timer) {
ctr->count += (l >> 1);
timer_advance_u64(&ctr->timer, (uint64_t) ((l >> 1) * ctr->pit_const));
} else {
ctr->count += l;
ctr->newcount = (l & 1);
}
} else {
pitf_ctr_set_out(ctr, 1, pit);
ctr->count += ((l + 1) >> 1);
if (ctr->using_timer) {
ctr->count += (l >> 1);
timer_advance_u64(&ctr->timer, (uint64_t) (((l + 1) >> 1) * ctr->pit_const));
} else {
ctr->count += l;
ctr->newcount = (l & 1);
}
}
#if 0
if (!t)
pclog("pit_over: square wave mode c=%x %lli %f\n", pit.c[t], tsc, ctr->pit_const);
#endif
break;
case 4: /*Software triggered strove*/
if (!ctr->thit) {
pitf_ctr_set_out(ctr, 0, pit);
pitf_ctr_set_out(ctr, 1, pit);
}
if (ctr->newcount) {
ctr->newcount = 0;
ctr->count += l;
if (ctr->using_timer)
timer_advance_u64(&ctr->timer, (uint64_t) (l * ctr->pit_const));
} else {
ctr->thit = 1;
ctr->count += 0xffff;
if (ctr->using_timer)
timer_advance_u64(&ctr->timer, (uint64_t) (0xffff * ctr->pit_const));
}
break;
case 5: /*Hardware triggered strove*/
if (!ctr->thit) {
pitf_ctr_set_out(ctr, 0, pit);
pitf_ctr_set_out(ctr, 1, pit);
}
ctr->thit = 1;
ctr->count += 0xffff;
if (ctr->using_timer)
timer_advance_u64(&ctr->timer, (uint64_t) (0xffff * ctr->pit_const));
break;
default:
break;
}
ctr->running = ctr->enabled && ctr->using_timer && !ctr->disabled;
if (ctr->using_timer && !ctr->running)
pitf_dump_and_disable_timer(ctr);
}
static __inline void
pitf_ctr_latch_count(ctrf_t *ctr)
{
ctr->rl = pitf_read_timer(ctr);
#if 0
pclog("Timer latch %f %04X %04X\n",pit->c[0],pit->rl[0],pit->l[0]);
pit->ctrl |= 0x30;
#endif
ctr->rereadlatch = 0;
ctr->rm = 3;
ctr->latched = 1;
}
static __inline void
pitf_ctr_latch_status(ctrf_t *ctr)
{
ctr->read_status = (ctr->ctrl & 0x3f) | (ctr->out ? 0x80 : 0);
ctr->do_read_status = 1;
}
static void
pitf_write(uint16_t addr, uint8_t val, void *priv)
{
pitf_t *dev = (pitf_t *) priv;
int t = (addr & 3);
ctrf_t *ctr;
pit_log("[%04X:%08X] pit_write(%04X, %02X, %08X)\n", CS, cpu_state.pc, addr, val, priv);
cycles -= ISA_CYCLES(8);
switch (addr & 3) {
case 3: /* control */
t = val >> 6;
if (t == 3) {
if (dev->flags & PIT_8254) {
/* This is 8254-only. */
if (!(val & 0x20)) {
if (val & 2)
pitf_ctr_latch_count(&dev->counters[0]);
if (val & 4)
pitf_ctr_latch_count(&dev->counters[1]);
if (val & 8)
pitf_ctr_latch_count(&dev->counters[2]);
pit_log("PIT %i: Initiated readback command\n", t);
}
if (!(val & 0x10)) {
if (val & 2)
pitf_ctr_latch_status(&dev->counters[0]);
if (val & 4)
pitf_ctr_latch_status(&dev->counters[1]);
if (val & 8)
pitf_ctr_latch_status(&dev->counters[2]);
}
}
} else {
dev->ctrl = val;
ctr = &dev->counters[t];
if (!(dev->ctrl & 0x30)) {
pitf_ctr_latch_count(ctr);
dev->ctrl |= 0x30;
pit_log("PIT %i: Initiated latched read, %i bytes latched\n",
t, ctr->latched);
} else {
ctr->ctrl = val;
ctr->rm = ctr->wm = (ctr->ctrl >> 4) & 3;
ctr->m = (val >> 1) & 7;
if (ctr->m > 5)
ctr->m &= 3;
if (!(ctr->rm)) {
ctr->rm = 3;
ctr->rl = pitf_read_timer(ctr);
}
ctr->rereadlatch = 1;
ctr->initial = 1;
if (!ctr->m)
pitf_ctr_set_out(ctr, 0, dev);
else
pitf_ctr_set_out(ctr, 1, dev);
ctr->disabled = 1;
pit_log("PIT %i: M = %i, RM/WM = %i, State = %i, Out = %i\n", t, ctr->m, ctr->rm, ctr->state, ctr->out);
}
ctr->thit = 0;
}
break;
case 0:
case 1:
case 2: /* the actual timers */
ctr = &dev->counters[t];
switch (ctr->wm) {
case 1:
ctr->l = val;
pitf_ctr_load(ctr, dev);
break;
case 2:
ctr->l = (val << 8);
pitf_ctr_load(ctr, dev);
break;
case 0:
ctr->l &= 0xFF;
ctr->l |= (val << 8);
pitf_ctr_load(ctr, dev);
ctr->wm = 3;
break;
case 3:
ctr->l &= 0xFF00;
ctr->l |= val;
ctr->wm = 0;
break;
default:
break;
}
break;
default:
break;
}
}
uint8_t
pitf_read_reg(void *priv, uint8_t reg)
{
pitf_t *dev = (pitf_t *) priv;
uint8_t ret = 0xff;
switch (reg) {
case 0x00:
case 0x02:
case 0x04:
ret = dev->counters[reg >> 1].l & 0xff;
break;
case 0x01:
case 0x03:
case 0x05:
ret = (dev->counters[reg >> 1].l >> 8) & 0xff;
break;
case 0x06:
ret = dev->ctrl;
break;
case 0x07:
/* The SiS 551x datasheet is unclear about how exactly
this register is structured.
Update: But the SiS 5571 datasheet is clear. */
ret = (dev->counters[0].rm & 0x80) ? 0x01 : 0x00;
ret |= (dev->counters[1].rm & 0x80) ? 0x02 : 0x00;
ret |= (dev->counters[2].rm & 0x80) ? 0x04 : 0x00;
ret |= (dev->counters[0].wm & 0x80) ? 0x08 : 0x00;
ret |= (dev->counters[1].wm & 0x80) ? 0x10 : 0x00;
ret |= (dev->counters[2].wm & 0x80) ? 0x20 : 0x00;
break;
}
return ret;
}
static uint8_t
pitf_read(uint16_t addr, void *priv)
{
pitf_t *dev = (pitf_t *) priv;
uint8_t ret = 0xff;
int t = (addr & 3);
ctrf_t *ctr;
cycles -= ISA_CYCLES(8);
switch (addr & 3) {
case 3: /* Control. */
/* This is 8254-only, 8253 returns 0x00. */
ret = (dev->flags & PIT_8254) ? dev->ctrl : 0x00;
break;
case 0:
case 1:
case 2: /* The actual timers. */
ctr = &dev->counters[t];
if (ctr->do_read_status) {
ctr->do_read_status = 0;
ret = ctr->read_status;
break;
}
if (ctr->rereadlatch && !ctr->latched) {
ctr->rereadlatch = 0;
ctr->rl = pitf_read_timer(ctr);
}
switch (ctr->rm) {
case 0:
ret = ctr->rl >> 8;
ctr->rm = 3;
ctr->latched = 0;
ctr->rereadlatch = 1;
break;
case 1:
ret = (ctr->rl) & 0xFF;
ctr->latched = 0;
ctr->rereadlatch = 1;
break;
case 2:
ret = (ctr->rl) >> 8;
ctr->latched = 0;
ctr->rereadlatch = 1;
break;
case 3:
ret = (ctr->rl) & 0xFF;
if (ctr->m & 0x80)
ctr->m &= 7;
else
ctr->rm = 0;
break;
default:
break;
}
break;
default:
break;
}
pit_log("[%04X:%08X] pit_read(%04X, %08X) = %02X\n", CS, cpu_state.pc, addr, priv, ret);
return ret;
}
static void
pitf_timer_over(void *priv)
{
ctrf_t *ctr = (ctrf_t *) priv;
pit_t *pit = (pit_t *)ctr->priv;
pitf_over(ctr, pit);
}
void
pitf_ctr_clock(void *data, int counter_id)
{
pitf_t *pit = (pitf_t *) data;
ctrf_t *ctr = &pit->counters[counter_id];
if (ctr->thit || !ctr->enabled)
return;
if (ctr->using_timer)
return;
if ((ctr->m == 3) && ctr->newcount) {
ctr->count -= ctr->out ? 1 : 3;
ctr->newcount = 0;
} else
ctr->count -= (ctr->m == 3) ? 2 : 1;
if (!ctr->count)
pitf_over(ctr, pit);
}
static void
ctr_reset(ctrf_t *ctr)
{
ctr->ctrl = 0;
ctr->m = 0;
ctr->gate = 0;
ctr->l = 0xffff;
ctr->thit = 1;
ctr->using_timer = 1;
}
static void
pitf_reset(pitf_t *dev)
{
memset(dev, 0, sizeof(pitf_t));
for (uint8_t i = 0; i < 3; i++)
ctr_reset(&dev->counters[i]);
/* Disable speaker gate. */
dev->counters[2].gate = 0;
}
void
pitf_set_pit_const(void *data, uint64_t pit_const)
{
pitf_t *pit = (pitf_t *) data;
ctrf_t *ctr;
for (uint8_t i = 0; i < 3; i++) {
ctr = &pit->counters[i];
ctr->pit_const = pit_const;
}
}
static void
pitf_speed_changed(void *priv)
{
pitf_set_pit_const(priv, PITCONST);
}
static void
pitf_close(void *priv)
{
pitf_t *dev = (pitf_t *) priv;
if (dev == pit_devs[0].data)
pit_devs[0].data = NULL;
if (dev == pit_devs[1].data)
pit_devs[1].data = NULL;
if (dev != NULL)
free(dev);
}
void
pitf_handler(int set, uint16_t base, int size, void *priv)
{
io_handler(set, base, size, pitf_read, NULL, NULL, pitf_write, NULL, NULL, priv);
}
static void *
pitf_init(const device_t *info)
{
pitf_t *dev = (pitf_t *) malloc(sizeof(pitf_t));
pitf_reset(dev);
pitf_set_pit_const(dev, PITCONST);
dev->flags = info->local;
if (!(dev->flags & PIT_PS2) && !(dev->flags & PIT_CUSTOM_CLOCK)) {
for (int i = 0; i < 3; i++) {
ctrf_t *ctr = &dev->counters[i];
ctr->priv = dev;
timer_add(&ctr->timer, pitf_timer_over, (void *) ctr, 0);
}
}
if (!(dev->flags & PIT_EXT_IO)) {
io_sethandler((dev->flags & PIT_SECONDARY) ? 0x0048 : 0x0040, 0x0004,
pitf_read, NULL, NULL, pitf_write, NULL, NULL, dev);
}
return dev;
}
const device_t i8253_fast_device = {
.name = "Intel 8253/8253-5 Programmable Interval Timer",
.internal_name = "i8253_fast",
.flags = DEVICE_ISA | DEVICE_PIT,
.local = PIT_8253,
.init = pitf_init,
.close = pitf_close,
.reset = NULL,
{ .available = NULL },
.speed_changed = pitf_speed_changed,
.force_redraw = NULL,
.config = NULL
};
const device_t i8254_fast_device = {
.name = "Intel 8254 Programmable Interval Timer",
.internal_name = "i8254_fast",
.flags = DEVICE_ISA | DEVICE_PIT,
.local = PIT_8254,
.init = pitf_init,
.close = pitf_close,
.reset = NULL,
{ .available = NULL },
.speed_changed = pitf_speed_changed,
.force_redraw = NULL,
.config = NULL
};
const device_t i8254_sec_fast_device = {
.name = "Intel 8254 Programmable Interval Timer (Secondary)",
.internal_name = "i8254_sec_fast",
.flags = DEVICE_ISA,
.local = PIT_8254 | PIT_SECONDARY,
.init = pitf_init,
.close = pitf_close,
.reset = NULL,
{ .available = NULL },
.speed_changed = pitf_speed_changed,
.force_redraw = NULL,
.config = NULL
};
const device_t i8254_ext_io_fast_device = {
.name = "Intel 8254 Programmable Interval Timer (External I/O)",
.internal_name = "i8254_ext_io_fast",
.flags = DEVICE_ISA,
.local = PIT_8254 | PIT_EXT_IO,
.init = pitf_init,
.close = pitf_close,
.reset = NULL,
{ .available = NULL },
.speed_changed = NULL,
.force_redraw = NULL,
.config = NULL
};
const device_t i8254_ps2_fast_device = {
.name = "Intel 8254 Programmable Interval Timer (PS/2)",
.internal_name = "i8254_ps2_fast",
.flags = DEVICE_ISA,
.local = PIT_8254 | PIT_PS2 | PIT_EXT_IO,
.init = pitf_init,
.close = pitf_close,
.reset = NULL,
{ .available = NULL },
.speed_changed = pitf_speed_changed,
.force_redraw = NULL,
.config = NULL
};
const pit_intf_t pit_fast_intf = {
&pitf_read,
&pitf_write,
&pitf_ctr_get_count,
&pitf_ctr_set_gate,
&pitf_ctr_set_using_timer,
&pitf_ctr_set_out_func,
&pitf_ctr_set_load_func,
&pitf_ctr_clock,
&pitf_set_pit_const,
NULL,
};