qemu/hw/timer/allwinner-a10-pit.c
Peter Maydell 9598c1bb39 ptimer: Rename PTIMER_POLICY_DEFAULT to PTIMER_POLICY_LEGACY
The traditional ptimer behaviour includes a collection of weird edge
case behaviours.  In 2016 we improved the ptimer implementation to
fix these and generally make the behaviour more flexible, with
ptimers opting in to the new behaviour by passing an appropriate set
of policy flags to ptimer_init().  For backwards-compatibility, we
defined PTIMER_POLICY_DEFAULT (which sets no flags) to give the old
weird behaviour.

This turns out to be a poor choice of name, because people writing
new devices which use ptimers are misled into thinking that the
default is probably a sensible choice of flags, when in fact it is
almost always not what you want.  Rename PTIMER_POLICY_DEFAULT to
PTIMER_POLICY_LEGACY and beef up the comment to more clearly say that
new devices should not be using it.

The code-change part of this commit was produced by
  sed -i -e 's/PTIMER_POLICY_DEFAULT/PTIMER_POLICY_LEGACY/g' $(git grep -l PTIMER_POLICY_DEFAULT)
with the exception of a test name string change in
tests/unit/ptimer-test.c which was added manually.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220516103058.162280-1-peter.maydell@linaro.org
2022-05-19 16:19:03 +01:00

317 lines
9.4 KiB
C

/*
* Allwinner A10 timer device emulation
*
* Copyright (C) 2013 Li Guang
* Written by Li Guang <lig.fnst@cn.fujitsu.com>
*
* 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.
*/
#include "qemu/osdep.h"
#include "hw/irq.h"
#include "hw/qdev-properties.h"
#include "hw/sysbus.h"
#include "hw/timer/allwinner-a10-pit.h"
#include "migration/vmstate.h"
#include "qemu/log.h"
#include "qemu/module.h"
static void a10_pit_update_irq(AwA10PITState *s)
{
int i;
for (i = 0; i < AW_A10_PIT_TIMER_NR; i++) {
qemu_set_irq(s->irq[i], !!(s->irq_status & s->irq_enable & (1 << i)));
}
}
static uint64_t a10_pit_read(void *opaque, hwaddr offset, unsigned size)
{
AwA10PITState *s = AW_A10_PIT(opaque);
uint8_t index;
switch (offset) {
case AW_A10_PIT_TIMER_IRQ_EN:
return s->irq_enable;
case AW_A10_PIT_TIMER_IRQ_ST:
return s->irq_status;
case AW_A10_PIT_TIMER_BASE ... AW_A10_PIT_TIMER_BASE_END:
index = offset & 0xf0;
index >>= 4;
index -= 1;
switch (offset & 0x0f) {
case AW_A10_PIT_TIMER_CONTROL:
return s->control[index];
case AW_A10_PIT_TIMER_INTERVAL:
return s->interval[index];
case AW_A10_PIT_TIMER_COUNT:
s->count[index] = ptimer_get_count(s->timer[index]);
return s->count[index];
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%x\n", __func__, (int)offset);
break;
}
case AW_A10_PIT_WDOG_CONTROL:
break;
case AW_A10_PIT_WDOG_MODE:
break;
case AW_A10_PIT_COUNT_LO:
return s->count_lo;
case AW_A10_PIT_COUNT_HI:
return s->count_hi;
case AW_A10_PIT_COUNT_CTL:
return s->count_ctl;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%x\n", __func__, (int)offset);
break;
}
return 0;
}
/* Must be called inside a ptimer transaction block for s->timer[index] */
static void a10_pit_set_freq(AwA10PITState *s, int index)
{
uint32_t prescaler, source, source_freq;
prescaler = 1 << extract32(s->control[index], 4, 3);
source = extract32(s->control[index], 2, 2);
source_freq = s->clk_freq[source];
if (source_freq) {
ptimer_set_freq(s->timer[index], source_freq / prescaler);
} else {
qemu_log_mask(LOG_GUEST_ERROR, "%s: Invalid clock source %u\n",
__func__, source);
}
}
static void a10_pit_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
AwA10PITState *s = AW_A10_PIT(opaque);
uint8_t index;
switch (offset) {
case AW_A10_PIT_TIMER_IRQ_EN:
s->irq_enable = value;
a10_pit_update_irq(s);
break;
case AW_A10_PIT_TIMER_IRQ_ST:
s->irq_status &= ~value;
a10_pit_update_irq(s);
break;
case AW_A10_PIT_TIMER_BASE ... AW_A10_PIT_TIMER_BASE_END:
index = offset & 0xf0;
index >>= 4;
index -= 1;
switch (offset & 0x0f) {
case AW_A10_PIT_TIMER_CONTROL:
s->control[index] = value;
ptimer_transaction_begin(s->timer[index]);
a10_pit_set_freq(s, index);
if (s->control[index] & AW_A10_PIT_TIMER_RELOAD) {
ptimer_set_count(s->timer[index], s->interval[index]);
}
if (s->control[index] & AW_A10_PIT_TIMER_EN) {
int oneshot = 0;
if (s->control[index] & AW_A10_PIT_TIMER_MODE) {
oneshot = 1;
}
ptimer_run(s->timer[index], oneshot);
} else {
ptimer_stop(s->timer[index]);
}
ptimer_transaction_commit(s->timer[index]);
break;
case AW_A10_PIT_TIMER_INTERVAL:
s->interval[index] = value;
ptimer_transaction_begin(s->timer[index]);
ptimer_set_limit(s->timer[index], s->interval[index], 1);
ptimer_transaction_commit(s->timer[index]);
break;
case AW_A10_PIT_TIMER_COUNT:
s->count[index] = value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%x\n", __func__, (int)offset);
}
break;
case AW_A10_PIT_WDOG_CONTROL:
s->watch_dog_control = value;
break;
case AW_A10_PIT_WDOG_MODE:
s->watch_dog_mode = value;
break;
case AW_A10_PIT_COUNT_LO:
s->count_lo = value;
break;
case AW_A10_PIT_COUNT_HI:
s->count_hi = value;
break;
case AW_A10_PIT_COUNT_CTL:
s->count_ctl = value;
if (s->count_ctl & AW_A10_PIT_COUNT_RL_EN) {
uint64_t tmp_count = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
s->count_lo = tmp_count;
s->count_hi = tmp_count >> 32;
s->count_ctl &= ~AW_A10_PIT_COUNT_RL_EN;
}
if (s->count_ctl & AW_A10_PIT_COUNT_CLR_EN) {
s->count_lo = 0;
s->count_hi = 0;
s->count_ctl &= ~AW_A10_PIT_COUNT_CLR_EN;
}
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Bad offset 0x%x\n", __func__, (int)offset);
break;
}
}
static const MemoryRegionOps a10_pit_ops = {
.read = a10_pit_read,
.write = a10_pit_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static Property a10_pit_properties[] = {
DEFINE_PROP_UINT32("clk0-freq", AwA10PITState, clk_freq[0], 0),
DEFINE_PROP_UINT32("clk1-freq", AwA10PITState, clk_freq[1], 0),
DEFINE_PROP_UINT32("clk2-freq", AwA10PITState, clk_freq[2], 0),
DEFINE_PROP_UINT32("clk3-freq", AwA10PITState, clk_freq[3], 0),
DEFINE_PROP_END_OF_LIST(),
};
static const VMStateDescription vmstate_a10_pit = {
.name = "a10.pit",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(irq_enable, AwA10PITState),
VMSTATE_UINT32(irq_status, AwA10PITState),
VMSTATE_UINT32_ARRAY(control, AwA10PITState, AW_A10_PIT_TIMER_NR),
VMSTATE_UINT32_ARRAY(interval, AwA10PITState, AW_A10_PIT_TIMER_NR),
VMSTATE_UINT32_ARRAY(count, AwA10PITState, AW_A10_PIT_TIMER_NR),
VMSTATE_UINT32(watch_dog_mode, AwA10PITState),
VMSTATE_UINT32(watch_dog_control, AwA10PITState),
VMSTATE_UINT32(count_lo, AwA10PITState),
VMSTATE_UINT32(count_hi, AwA10PITState),
VMSTATE_UINT32(count_ctl, AwA10PITState),
VMSTATE_PTIMER_ARRAY(timer, AwA10PITState, AW_A10_PIT_TIMER_NR),
VMSTATE_END_OF_LIST()
}
};
static void a10_pit_reset(DeviceState *dev)
{
AwA10PITState *s = AW_A10_PIT(dev);
uint8_t i;
s->irq_enable = 0;
s->irq_status = 0;
a10_pit_update_irq(s);
for (i = 0; i < 6; i++) {
s->control[i] = AW_A10_PIT_DEFAULT_CLOCK;
s->interval[i] = 0;
s->count[i] = 0;
ptimer_transaction_begin(s->timer[i]);
ptimer_stop(s->timer[i]);
a10_pit_set_freq(s, i);
ptimer_transaction_commit(s->timer[i]);
}
s->watch_dog_mode = 0;
s->watch_dog_control = 0;
s->count_lo = 0;
s->count_hi = 0;
s->count_ctl = 0;
}
static void a10_pit_timer_cb(void *opaque)
{
AwA10TimerContext *tc = opaque;
AwA10PITState *s = tc->container;
uint8_t i = tc->index;
if (s->control[i] & AW_A10_PIT_TIMER_EN) {
s->irq_status |= 1 << i;
if (s->control[i] & AW_A10_PIT_TIMER_MODE) {
ptimer_stop(s->timer[i]);
s->control[i] &= ~AW_A10_PIT_TIMER_EN;
}
a10_pit_update_irq(s);
}
}
static void a10_pit_init(Object *obj)
{
AwA10PITState *s = AW_A10_PIT(obj);
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
uint8_t i;
for (i = 0; i < AW_A10_PIT_TIMER_NR; i++) {
sysbus_init_irq(sbd, &s->irq[i]);
}
memory_region_init_io(&s->iomem, OBJECT(s), &a10_pit_ops, s,
TYPE_AW_A10_PIT, 0x400);
sysbus_init_mmio(sbd, &s->iomem);
for (i = 0; i < AW_A10_PIT_TIMER_NR; i++) {
AwA10TimerContext *tc = &s->timer_context[i];
tc->container = s;
tc->index = i;
s->timer[i] = ptimer_init(a10_pit_timer_cb, tc, PTIMER_POLICY_LEGACY);
}
}
static void a10_pit_finalize(Object *obj)
{
AwA10PITState *s = AW_A10_PIT(obj);
int i;
for (i = 0; i < AW_A10_PIT_TIMER_NR; i++) {
ptimer_free(s->timer[i]);
}
}
static void a10_pit_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->reset = a10_pit_reset;
device_class_set_props(dc, a10_pit_properties);
dc->desc = "allwinner a10 timer";
dc->vmsd = &vmstate_a10_pit;
}
static const TypeInfo a10_pit_info = {
.name = TYPE_AW_A10_PIT,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(AwA10PITState),
.instance_init = a10_pit_init,
.instance_finalize = a10_pit_finalize,
.class_init = a10_pit_class_init,
};
static void a10_register_types(void)
{
type_register_static(&a10_pit_info);
}
type_init(a10_register_types);