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/*
* Xilinx Zynq cadence TTC model
*
* Copyright (c) 2011 Xilinx Inc.
* Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
* Copyright (c) 2012 PetaLogix Pty Ltd.
* Written By Haibing Ma
* M. Habib
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "hw/irq.h"
#include "hw/sysbus.h"
#include "migration/vmstate.h"
#include "qemu/module.h"
#include "qemu/timer.h"
#include "qom/object.h"
#include "hw/timer/cadence_ttc.h"
#ifdef CADENCE_TTC_ERR_DEBUG
#define DB_PRINT(...) do { \
fprintf(stderr, ": %s: ", __func__); \
fprintf(stderr, ## __VA_ARGS__); \
} while (0)
#else
#define DB_PRINT(...)
#endif
#define COUNTER_INTR_IV 0x00000001
#define COUNTER_INTR_M1 0x00000002
#define COUNTER_INTR_M2 0x00000004
#define COUNTER_INTR_M3 0x00000008
#define COUNTER_INTR_OV 0x00000010
#define COUNTER_INTR_EV 0x00000020
#define COUNTER_CTRL_DIS 0x00000001
#define COUNTER_CTRL_INT 0x00000002
#define COUNTER_CTRL_DEC 0x00000004
#define COUNTER_CTRL_MATCH 0x00000008
#define COUNTER_CTRL_RST 0x00000010
#define CLOCK_CTRL_PS_EN 0x00000001
#define CLOCK_CTRL_PS_V 0x0000001e
static void cadence_timer_update(CadenceTimerState *s)
{
qemu_set_irq(s->irq, !!(s->reg_intr & s->reg_intr_en));
}
static CadenceTimerState *cadence_timer_from_addr(void *opaque,
hwaddr offset)
{
unsigned int index;
CadenceTTCState *s = (CadenceTTCState *)opaque;
index = (offset >> 2) % 3;
return &s->timer[index];
}
static uint64_t cadence_timer_get_ns(CadenceTimerState *s, uint64_t timer_steps)
{
/* timer_steps has max value of 0x100000000. double check it
* (or overflow can happen below) */
assert(timer_steps <= 1ULL << 32);
uint64_t r = timer_steps * 1000000000ULL;
if (s->reg_clock & CLOCK_CTRL_PS_EN) {
r >>= 16 - (((s->reg_clock & CLOCK_CTRL_PS_V) >> 1) + 1);
} else {
r >>= 16;
}
r /= (uint64_t)s->freq;
return r;
}
static uint64_t cadence_timer_get_steps(CadenceTimerState *s, uint64_t ns)
{
uint64_t to_divide = 1000000000ULL;
uint64_t r = ns;
/* for very large intervals (> 8s) do some division first to stop
* overflow (costs some prescision) */
while (r >= 8ULL << 30 && to_divide > 1) {
r /= 1000;
to_divide /= 1000;
}
r <<= 16;
/* keep early-dividing as needed */
while (r >= 8ULL << 30 && to_divide > 1) {
r /= 1000;
to_divide /= 1000;
}
r *= (uint64_t)s->freq;
if (s->reg_clock & CLOCK_CTRL_PS_EN) {
r /= 1 << (((s->reg_clock & CLOCK_CTRL_PS_V) >> 1) + 1);
}
r /= to_divide;
return r;
}
/* determine if x is in between a and b, exclusive of a, inclusive of b */
static inline int64_t is_between(int64_t x, int64_t a, int64_t b)
{
if (a < b) {
return x > a && x <= b;
}
return x < a && x >= b;
}
static void cadence_timer_run(CadenceTimerState *s)
{
int i;
int64_t event_interval, next_value;
assert(s->cpu_time_valid); /* cadence_timer_sync must be called first */
if (s->reg_count & COUNTER_CTRL_DIS) {
s->cpu_time_valid = 0;
return;
}
{ /* figure out what's going to happen next (rollover or match) */
int64_t interval = (uint64_t)((s->reg_count & COUNTER_CTRL_INT) ?
(int64_t)s->reg_interval + 1 : 0x10000ULL) << 16;
next_value = (s->reg_count & COUNTER_CTRL_DEC) ? -1ULL : interval;
for (i = 0; i < 3; ++i) {
int64_t cand = (uint64_t)s->reg_match[i] << 16;
if (is_between(cand, (uint64_t)s->reg_value, next_value)) {
next_value = cand;
}
}
}
DB_PRINT("next timer event value: %09llx\n",
(unsigned long long)next_value);
event_interval = next_value - (int64_t)s->reg_value;
event_interval = (event_interval < 0) ? -event_interval : event_interval;
timer_mod(s->timer, s->cpu_time +
cadence_timer_get_ns(s, event_interval));
}
static void cadence_timer_sync(CadenceTimerState *s)
{
int i;
int64_t r, x;
int64_t interval = ((s->reg_count & COUNTER_CTRL_INT) ?
(int64_t)s->reg_interval + 1 : 0x10000ULL) << 16;
uint64_t old_time = s->cpu_time;
s->cpu_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
DB_PRINT("cpu time: %lld ns\n", (long long)old_time);
if (!s->cpu_time_valid || old_time == s->cpu_time) {
s->cpu_time_valid = 1;
return;
}
r = (int64_t)cadence_timer_get_steps(s, s->cpu_time - old_time);
x = (int64_t)s->reg_value + ((s->reg_count & COUNTER_CTRL_DEC) ? -r : r);
for (i = 0; i < 3; ++i) {
int64_t m = (int64_t)s->reg_match[i] << 16;
if (m > interval) {
continue;
}
/* check to see if match event has occurred. check m +/- interval
* to account for match events in wrap around cases */
if (is_between(m, s->reg_value, x) ||
is_between(m + interval, s->reg_value, x) ||
is_between(m - interval, s->reg_value, x)) {
s->reg_intr |= (2 << i);
}
}
if ((x < 0) || (x >= interval)) {
s->reg_intr |= (s->reg_count & COUNTER_CTRL_INT) ?
COUNTER_INTR_IV : COUNTER_INTR_OV;
}
while (x < 0) {
x += interval;
}
s->reg_value = (uint32_t)(x % interval);
cadence_timer_update(s);
}
static void cadence_timer_tick(void *opaque)
{
CadenceTimerState *s = opaque;
DB_PRINT("\n");
cadence_timer_sync(s);
cadence_timer_run(s);
}
static uint32_t cadence_ttc_read_imp(void *opaque, hwaddr offset)
{
CadenceTimerState *s = cadence_timer_from_addr(opaque, offset);
uint32_t value;
cadence_timer_sync(s);
cadence_timer_run(s);
switch (offset) {
case 0x00: /* clock control */
case 0x04:
case 0x08:
return s->reg_clock;
case 0x0c: /* counter control */
case 0x10:
case 0x14:
return s->reg_count;
case 0x18: /* counter value */
case 0x1c:
case 0x20:
return (uint16_t)(s->reg_value >> 16);
case 0x24: /* reg_interval counter */
case 0x28:
case 0x2c:
return s->reg_interval;
case 0x30: /* match 1 counter */
case 0x34:
case 0x38:
return s->reg_match[0];
case 0x3c: /* match 2 counter */
case 0x40:
case 0x44:
return s->reg_match[1];
case 0x48: /* match 3 counter */
case 0x4c:
case 0x50:
return s->reg_match[2];
case 0x54: /* interrupt register */
case 0x58:
case 0x5c:
/* cleared after read */
value = s->reg_intr;
s->reg_intr = 0;
cadence_timer_update(s);
return value;
case 0x60: /* interrupt enable */
case 0x64:
case 0x68:
return s->reg_intr_en;
case 0x6c:
case 0x70:
case 0x74:
return s->reg_event_ctrl;
case 0x78:
case 0x7c:
case 0x80:
return s->reg_event;
default:
return 0;
}
}
static uint64_t cadence_ttc_read(void *opaque, hwaddr offset,
unsigned size)
{
uint32_t ret = cadence_ttc_read_imp(opaque, offset);
DB_PRINT("addr: %08x data: %08x\n", (unsigned)offset, (unsigned)ret);
return ret;
}
static void cadence_ttc_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
CadenceTimerState *s = cadence_timer_from_addr(opaque, offset);
DB_PRINT("addr: %08x data %08x\n", (unsigned)offset, (unsigned)value);
cadence_timer_sync(s);
switch (offset) {
case 0x00: /* clock control */
case 0x04:
case 0x08:
s->reg_clock = value & 0x3F;
break;
case 0x0c: /* counter control */
case 0x10:
case 0x14:
if (value & COUNTER_CTRL_RST) {
s->reg_value = 0;
}
s->reg_count = value & 0x3f & ~COUNTER_CTRL_RST;
break;
case 0x24: /* interval register */
case 0x28:
case 0x2c:
s->reg_interval = value & 0xffff;
break;
case 0x30: /* match register */
case 0x34:
case 0x38:
s->reg_match[0] = value & 0xffff;
break;
case 0x3c: /* match register */
case 0x40:
case 0x44:
s->reg_match[1] = value & 0xffff;
break;
case 0x48: /* match register */
case 0x4c:
case 0x50:
s->reg_match[2] = value & 0xffff;
break;
case 0x54: /* interrupt register */
case 0x58:
case 0x5c:
break;
case 0x60: /* interrupt enable */
case 0x64:
case 0x68:
s->reg_intr_en = value & 0x3f;
break;
case 0x6c: /* event control */
case 0x70:
case 0x74:
s->reg_event_ctrl = value & 0x07;
break;
default:
return;
}
cadence_timer_run(s);
cadence_timer_update(s);
}
static const MemoryRegionOps cadence_ttc_ops = {
.read = cadence_ttc_read,
.write = cadence_ttc_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void cadence_timer_reset(CadenceTimerState *s)
{
s->reg_count = 0x21;
}
static void cadence_timer_init(uint32_t freq, CadenceTimerState *s)
{
memset(s, 0, sizeof(CadenceTimerState));
s->freq = freq;
cadence_timer_reset(s);
s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, cadence_timer_tick, s);
}
static void cadence_ttc_init(Object *obj)
{
CadenceTTCState *s = CADENCE_TTC(obj);
memory_region_init_io(&s->iomem, obj, &cadence_ttc_ops, s,
"timer", 0x1000);
sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
}
static void cadence_ttc_realize(DeviceState *dev, Error **errp)
{
CadenceTTCState *s = CADENCE_TTC(dev);
int i;
for (i = 0; i < 3; ++i) {
cadence_timer_init(133000000, &s->timer[i]);
sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->timer[i].irq);
}
}
static int cadence_timer_pre_save(void *opaque)
{
cadence_timer_sync((CadenceTimerState *)opaque);
return 0;
}
static int cadence_timer_post_load(void *opaque, int version_id)
{
CadenceTimerState *s = opaque;
s->cpu_time_valid = 0;
cadence_timer_sync(s);
cadence_timer_run(s);
cadence_timer_update(s);
return 0;
}
static const VMStateDescription vmstate_cadence_timer = {
.name = "cadence_timer",
.version_id = 1,
.minimum_version_id = 1,
.pre_save = cadence_timer_pre_save,
.post_load = cadence_timer_post_load,
.fields = (const VMStateField[]) {
VMSTATE_UINT32(reg_clock, CadenceTimerState),
VMSTATE_UINT32(reg_count, CadenceTimerState),
VMSTATE_UINT32(reg_value, CadenceTimerState),
VMSTATE_UINT16(reg_interval, CadenceTimerState),
VMSTATE_UINT16_ARRAY(reg_match, CadenceTimerState, 3),
VMSTATE_UINT32(reg_intr, CadenceTimerState),
VMSTATE_UINT32(reg_intr_en, CadenceTimerState),
VMSTATE_UINT32(reg_event_ctrl, CadenceTimerState),
VMSTATE_UINT32(reg_event, CadenceTimerState),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_cadence_ttc = {
.name = "cadence_TTC",
.version_id = 1,
.minimum_version_id = 1,
.fields = (const VMStateField[]) {
VMSTATE_STRUCT_ARRAY(timer, CadenceTTCState, 3, 0,
vmstate_cadence_timer,
CadenceTimerState),
VMSTATE_END_OF_LIST()
}
};
static void cadence_ttc_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &vmstate_cadence_ttc;
dc->realize = cadence_ttc_realize;
}
static const TypeInfo cadence_ttc_info = {
.name = TYPE_CADENCE_TTC,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(CadenceTTCState),
.instance_init = cadence_ttc_init,
.class_init = cadence_ttc_class_init,
};
static void cadence_ttc_register_types(void)
{
type_register_static(&cadence_ttc_info);
}
type_init(cadence_ttc_register_types)