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xemu/hw/misc/mos6522.c
Mark Cave-Ayland b6c7e42f74 mos6522: expose mos6522_update_irq() through MOS6522DeviceClass 
In the case where we have an interrupt generated externally from inputs to
bits 1 and 2 of port A and/or port B, it is necessary to expose
mos6522_update_irq() so it can be called by the interrupt source.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-06-16 16:32:33 +10:00

489 lines
14 KiB
C
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/*
* QEMU MOS6522 VIA emulation
*
* Copyright (c) 2004-2007 Fabrice Bellard
* Copyright (c) 2007 Jocelyn Mayer
* Copyright (c) 2018 Mark Cave-Ayland
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/input/adb.h"
#include "hw/misc/mos6522.h"
#include "qemu/timer.h"
#include "sysemu/sysemu.h"
#include "qemu/cutils.h"
#include "qemu/log.h"
#include "trace.h"
/* XXX: implement all timer modes */
static void mos6522_timer_update(MOS6522State *s, MOS6522Timer *ti,
int64_t current_time);
static void mos6522_update_irq(MOS6522State *s)
{
if (s->ifr & s->ier) {
qemu_irq_raise(s->irq);
} else {
qemu_irq_lower(s->irq);
}
}
static uint64_t get_counter_value(MOS6522State *s, MOS6522Timer *ti)
{
MOS6522DeviceClass *mdc = MOS6522_DEVICE_GET_CLASS(s);
if (ti->index == 0) {
return mdc->get_timer1_counter_value(s, ti);
} else {
return mdc->get_timer2_counter_value(s, ti);
}
}
static uint64_t get_load_time(MOS6522State *s, MOS6522Timer *ti)
{
MOS6522DeviceClass *mdc = MOS6522_DEVICE_GET_CLASS(s);
if (ti->index == 0) {
return mdc->get_timer1_load_time(s, ti);
} else {
return mdc->get_timer2_load_time(s, ti);
}
}
static unsigned int get_counter(MOS6522State *s, MOS6522Timer *ti)
{
int64_t d;
unsigned int counter;
d = get_counter_value(s, ti);
if (ti->index == 0) {
/* the timer goes down from latch to -1 (period of latch + 2) */
if (d <= (ti->counter_value + 1)) {
counter = (ti->counter_value - d) & 0xffff;
} else {
counter = (d - (ti->counter_value + 1)) % (ti->latch + 2);
counter = (ti->latch - counter) & 0xffff;
}
} else {
counter = (ti->counter_value - d) & 0xffff;
}
return counter;
}
static void set_counter(MOS6522State *s, MOS6522Timer *ti, unsigned int val)
{
trace_mos6522_set_counter(1 + ti->index, val);
ti->load_time = get_load_time(s, ti);
ti->counter_value = val;
mos6522_timer_update(s, ti, ti->load_time);
}
static int64_t get_next_irq_time(MOS6522State *s, MOS6522Timer *ti,
int64_t current_time)
{
int64_t d, next_time;
unsigned int counter;
/* current counter value */
d = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - ti->load_time,
ti->frequency, NANOSECONDS_PER_SECOND);
/* the timer goes down from latch to -1 (period of latch + 2) */
if (d <= (ti->counter_value + 1)) {
counter = (ti->counter_value - d) & 0xffff;
} else {
counter = (d - (ti->counter_value + 1)) % (ti->latch + 2);
counter = (ti->latch - counter) & 0xffff;
}
/* Note: we consider the irq is raised on 0 */
if (counter == 0xffff) {
next_time = d + ti->latch + 1;
} else if (counter == 0) {
next_time = d + ti->latch + 2;
} else {
next_time = d + counter;
}
trace_mos6522_get_next_irq_time(ti->latch, d, next_time - d);
next_time = muldiv64(next_time, NANOSECONDS_PER_SECOND, ti->frequency) +
ti->load_time;
if (next_time <= current_time) {
next_time = current_time + 1;
}
return next_time;
}
static void mos6522_timer_update(MOS6522State *s, MOS6522Timer *ti,
int64_t current_time)
{
if (!ti->timer) {
return;
}
if (ti->index == 0 && (s->acr & T1MODE) != T1MODE_CONT) {
timer_del(ti->timer);
} else {
ti->next_irq_time = get_next_irq_time(s, ti, current_time);
timer_mod(ti->timer, ti->next_irq_time);
}
}
static void mos6522_timer1(void *opaque)
{
MOS6522State *s = opaque;
MOS6522Timer *ti = &s->timers[0];
mos6522_timer_update(s, ti, ti->next_irq_time);
s->ifr |= T1_INT;
mos6522_update_irq(s);
}
static void mos6522_timer2(void *opaque)
{
MOS6522State *s = opaque;
MOS6522Timer *ti = &s->timers[1];
mos6522_timer_update(s, ti, ti->next_irq_time);
s->ifr |= T2_INT;
mos6522_update_irq(s);
}
static void mos6522_set_sr_int(MOS6522State *s)
{
trace_mos6522_set_sr_int();
s->ifr |= SR_INT;
mos6522_update_irq(s);
}
static uint64_t mos6522_get_counter_value(MOS6522State *s, MOS6522Timer *ti)
{
return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - ti->load_time,
ti->frequency, NANOSECONDS_PER_SECOND);
}
static uint64_t mos6522_get_load_time(MOS6522State *s, MOS6522Timer *ti)
{
uint64_t load_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
return load_time;
}
static void mos6522_portA_write(MOS6522State *s)
{
qemu_log_mask(LOG_UNIMP, "portA_write unimplemented\n");
}
static void mos6522_portB_write(MOS6522State *s)
{
qemu_log_mask(LOG_UNIMP, "portB_write unimplemented\n");
}
uint64_t mos6522_read(void *opaque, hwaddr addr, unsigned size)
{
MOS6522State *s = opaque;
uint32_t val;
switch (addr) {
case VIA_REG_B:
val = s->b;
break;
case VIA_REG_A:
val = s->a;
break;
case VIA_REG_DIRB:
val = s->dirb;
break;
case VIA_REG_DIRA:
val = s->dira;
break;
case VIA_REG_T1CL:
val = get_counter(s, &s->timers[0]) & 0xff;
s->ifr &= ~T1_INT;
mos6522_update_irq(s);
break;
case VIA_REG_T1CH:
val = get_counter(s, &s->timers[0]) >> 8;
mos6522_update_irq(s);
break;
case VIA_REG_T1LL:
val = s->timers[0].latch & 0xff;
break;
case VIA_REG_T1LH:
/* XXX: check this */
val = (s->timers[0].latch >> 8) & 0xff;
break;
case VIA_REG_T2CL:
val = get_counter(s, &s->timers[1]) & 0xff;
s->ifr &= ~T2_INT;
mos6522_update_irq(s);
break;
case VIA_REG_T2CH:
val = get_counter(s, &s->timers[1]) >> 8;
break;
case VIA_REG_SR:
val = s->sr;
s->ifr &= ~SR_INT;
mos6522_update_irq(s);
break;
case VIA_REG_ACR:
val = s->acr;
break;
case VIA_REG_PCR:
val = s->pcr;
break;
case VIA_REG_IFR:
val = s->ifr;
if (s->ifr & s->ier) {
val |= 0x80;
}
break;
case VIA_REG_IER:
val = s->ier | 0x80;
break;
default:
case VIA_REG_ANH:
val = s->anh;
break;
}
if (addr != VIA_REG_IFR || val != 0) {
trace_mos6522_read(addr, val);
}
return val;
}
void mos6522_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
{
MOS6522State *s = opaque;
MOS6522DeviceClass *mdc = MOS6522_DEVICE_GET_CLASS(s);
trace_mos6522_write(addr, val);
switch (addr) {
case VIA_REG_B:
s->b = (s->b & ~s->dirb) | (val & s->dirb);
mdc->portB_write(s);
break;
case VIA_REG_A:
s->a = (s->a & ~s->dira) | (val & s->dira);
mdc->portA_write(s);
break;
case VIA_REG_DIRB:
s->dirb = val;
break;
case VIA_REG_DIRA:
s->dira = val;
break;
case VIA_REG_T1CL:
s->timers[0].latch = (s->timers[0].latch & 0xff00) | val;
mos6522_timer_update(s, &s->timers[0],
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
break;
case VIA_REG_T1CH:
s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8);
s->ifr &= ~T1_INT;
set_counter(s, &s->timers[0], s->timers[0].latch);
break;
case VIA_REG_T1LL:
s->timers[0].latch = (s->timers[0].latch & 0xff00) | val;
mos6522_timer_update(s, &s->timers[0],
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
break;
case VIA_REG_T1LH:
s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8);
s->ifr &= ~T1_INT;
mos6522_timer_update(s, &s->timers[0],
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
break;
case VIA_REG_T2CL:
s->timers[1].latch = (s->timers[1].latch & 0xff00) | val;
break;
case VIA_REG_T2CH:
/* To ensure T2 generates an interrupt on zero crossing with the
common timer code, write the value directly from the latch to
the counter */
s->timers[1].latch = (s->timers[1].latch & 0xff) | (val << 8);
s->ifr &= ~T2_INT;
set_counter(s, &s->timers[1], s->timers[1].latch);
break;
case VIA_REG_SR:
s->sr = val;
break;
case VIA_REG_ACR:
s->acr = val;
mos6522_timer_update(s, &s->timers[0],
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
break;
case VIA_REG_PCR:
s->pcr = val;
break;
case VIA_REG_IFR:
/* reset bits */
s->ifr &= ~val;
mos6522_update_irq(s);
break;
case VIA_REG_IER:
if (val & IER_SET) {
/* set bits */
s->ier |= val & 0x7f;
} else {
/* reset bits */
s->ier &= ~val;
}
mos6522_update_irq(s);
break;
default:
case VIA_REG_ANH:
s->anh = val;
break;
}
}
static const MemoryRegionOps mos6522_ops = {
.read = mos6522_read,
.write = mos6522_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 1,
},
};
static const VMStateDescription vmstate_mos6522_timer = {
.name = "mos6522_timer",
.version_id = 0,
.minimum_version_id = 0,
.fields = (VMStateField[]) {
VMSTATE_UINT16(latch, MOS6522Timer),
VMSTATE_UINT16(counter_value, MOS6522Timer),
VMSTATE_INT64(load_time, MOS6522Timer),
VMSTATE_INT64(next_irq_time, MOS6522Timer),
VMSTATE_TIMER_PTR(timer, MOS6522Timer),
VMSTATE_END_OF_LIST()
}
};
const VMStateDescription vmstate_mos6522 = {
.name = "mos6522",
.version_id = 0,
.minimum_version_id = 0,
.fields = (VMStateField[]) {
VMSTATE_UINT8(a, MOS6522State),
VMSTATE_UINT8(b, MOS6522State),
VMSTATE_UINT8(dira, MOS6522State),
VMSTATE_UINT8(dirb, MOS6522State),
VMSTATE_UINT8(sr, MOS6522State),
VMSTATE_UINT8(acr, MOS6522State),
VMSTATE_UINT8(pcr, MOS6522State),
VMSTATE_UINT8(ifr, MOS6522State),
VMSTATE_UINT8(ier, MOS6522State),
VMSTATE_UINT8(anh, MOS6522State),
VMSTATE_STRUCT_ARRAY(timers, MOS6522State, 2, 0,
vmstate_mos6522_timer, MOS6522Timer),
VMSTATE_END_OF_LIST()
}
};
static void mos6522_reset(DeviceState *dev)
{
MOS6522State *s = MOS6522(dev);
s->b = 0;
s->a = 0;
s->dirb = 0xff;
s->dira = 0;
s->sr = 0;
s->acr = 0;
s->pcr = 0;
s->ifr = 0;
s->ier = 0;
/* s->ier = T1_INT | SR_INT; */
s->anh = 0;
s->timers[0].frequency = s->frequency;
s->timers[0].latch = 0xffff;
set_counter(s, &s->timers[0], 0xffff);
s->timers[1].frequency = s->frequency;
s->timers[1].latch = 0xffff;
}
static void mos6522_init(Object *obj)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
MOS6522State *s = MOS6522(obj);
int i;
memory_region_init_io(&s->mem, obj, &mos6522_ops, s, "mos6522", 0x10);
sysbus_init_mmio(sbd, &s->mem);
sysbus_init_irq(sbd, &s->irq);
for (i = 0; i < ARRAY_SIZE(s->timers); i++) {
s->timers[i].index = i;
}
s->timers[0].timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, mos6522_timer1, s);
s->timers[1].timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, mos6522_timer2, s);
}
static Property mos6522_properties[] = {
DEFINE_PROP_UINT64("frequency", MOS6522State, frequency, 0),
DEFINE_PROP_END_OF_LIST()
};
static void mos6522_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
MOS6522DeviceClass *mdc = MOS6522_DEVICE_CLASS(oc);
dc->reset = mos6522_reset;
dc->vmsd = &vmstate_mos6522;
dc->props = mos6522_properties;
mdc->parent_reset = dc->reset;
mdc->set_sr_int = mos6522_set_sr_int;
mdc->portB_write = mos6522_portB_write;
mdc->portA_write = mos6522_portA_write;
mdc->update_irq = mos6522_update_irq;
mdc->get_timer1_counter_value = mos6522_get_counter_value;
mdc->get_timer2_counter_value = mos6522_get_counter_value;
mdc->get_timer1_load_time = mos6522_get_load_time;
mdc->get_timer2_load_time = mos6522_get_load_time;
}
static const TypeInfo mos6522_type_info = {
.name = TYPE_MOS6522,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(MOS6522State),
.instance_init = mos6522_init,
.abstract = true,
.class_size = sizeof(MOS6522DeviceClass),
.class_init = mos6522_class_init,
};
static void mos6522_register_types(void)
{
type_register_static(&mos6522_type_info);
}
type_init(mos6522_register_types)
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