qemu-e2k/hw/timer/puv3_ost.c

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/*
* OSTimer device simulation in PKUnity SoC
*
* Copyright (C) 2010-2012 Guan Xuetao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation, or any later version.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "hw/sysbus.h"
#include "hw/ptimer.h"
#include "qemu/main-loop.h"
#undef DEBUG_PUV3
#include "hw/unicore32/puv3.h"
#define TYPE_PUV3_OST "puv3_ost"
#define PUV3_OST(obj) OBJECT_CHECK(PUV3OSTState, (obj), TYPE_PUV3_OST)
/* puv3 ostimer implementation. */
typedef struct PUV3OSTState {
SysBusDevice parent_obj;
MemoryRegion iomem;
QEMUBH *bh;
qemu_irq irq;
ptimer_state *ptimer;
uint32_t reg_OSMR0;
uint32_t reg_OSCR;
uint32_t reg_OSSR;
uint32_t reg_OIER;
} PUV3OSTState;
static uint64_t puv3_ost_read(void *opaque, hwaddr offset,
unsigned size)
{
PUV3OSTState *s = opaque;
uint32_t ret = 0;
switch (offset) {
case 0x10: /* Counter Register */
ret = s->reg_OSMR0 - (uint32_t)ptimer_get_count(s->ptimer);
break;
case 0x14: /* Status Register */
ret = s->reg_OSSR;
break;
case 0x1c: /* Interrupt Enable Register */
ret = s->reg_OIER;
break;
default:
DPRINTF("Bad offset %x\n", (int)offset);
}
DPRINTF("offset 0x%x, value 0x%x\n", offset, ret);
return ret;
}
static void puv3_ost_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
PUV3OSTState *s = opaque;
DPRINTF("offset 0x%x, value 0x%x\n", offset, value);
switch (offset) {
case 0x00: /* Match Register 0 */
s->reg_OSMR0 = value;
if (s->reg_OSMR0 > s->reg_OSCR) {
ptimer_set_count(s->ptimer, s->reg_OSMR0 - s->reg_OSCR);
} else {
ptimer_set_count(s->ptimer, s->reg_OSMR0 +
(0xffffffff - s->reg_OSCR));
}
ptimer_run(s->ptimer, 2);
break;
case 0x14: /* Status Register */
assert(value == 0);
if (s->reg_OSSR) {
s->reg_OSSR = value;
qemu_irq_lower(s->irq);
}
break;
case 0x1c: /* Interrupt Enable Register */
s->reg_OIER = value;
break;
default:
DPRINTF("Bad offset %x\n", (int)offset);
}
}
static const MemoryRegionOps puv3_ost_ops = {
.read = puv3_ost_read,
.write = puv3_ost_write,
.impl = {
.min_access_size = 4,
.max_access_size = 4,
},
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void puv3_ost_tick(void *opaque)
{
PUV3OSTState *s = opaque;
DPRINTF("ost hit when ptimer counter from 0x%x to 0x%x!\n",
s->reg_OSCR, s->reg_OSMR0);
s->reg_OSCR = s->reg_OSMR0;
if (s->reg_OIER) {
s->reg_OSSR = 1;
qemu_irq_raise(s->irq);
}
}
static int puv3_ost_init(SysBusDevice *dev)
{
PUV3OSTState *s = PUV3_OST(dev);
s->reg_OIER = 0;
s->reg_OSSR = 0;
s->reg_OSMR0 = 0;
s->reg_OSCR = 0;
sysbus_init_irq(dev, &s->irq);
s->bh = qemu_bh_new(puv3_ost_tick, s);
s->ptimer = ptimer_init(s->bh, PTIMER_POLICY_DEFAULT);
ptimer_set_freq(s->ptimer, 50 * 1000 * 1000);
memory_region_init_io(&s->iomem, OBJECT(s), &puv3_ost_ops, s, "puv3_ost",
PUV3_REGS_OFFSET);
sysbus_init_mmio(dev, &s->iomem);
return 0;
}
static void puv3_ost_class_init(ObjectClass *klass, void *data)
{
SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
sdc->init = puv3_ost_init;
}
static const TypeInfo puv3_ost_info = {
.name = TYPE_PUV3_OST,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(PUV3OSTState),
.class_init = puv3_ost_class_init,
};
static void puv3_ost_register_type(void)
{
type_register_static(&puv3_ost_info);
}
type_init(puv3_ost_register_type)