qemu/hw/syborg_rtc.c

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/*
* Syborg RTC
*
* Copyright (c) 2008 CodeSourcery
*
* 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 "sysbus.h"
#include "qemu-timer.h"
#include "syborg.h"
enum {
RTC_ID = 0,
RTC_LATCH = 1,
RTC_DATA_LOW = 2,
RTC_DATA_HIGH = 3
};
typedef struct {
SysBusDevice busdev;
int64_t offset;
int64_t data;
qemu_irq irq;
} SyborgRTCState;
static uint32_t syborg_rtc_read(void *opaque, target_phys_addr_t offset)
{
SyborgRTCState *s = (SyborgRTCState *)opaque;
offset &= 0xfff;
switch (offset >> 2) {
case RTC_ID:
return SYBORG_ID_RTC;
case RTC_DATA_LOW:
return (uint32_t)s->data;
case RTC_DATA_HIGH:
return (uint32_t)(s->data >> 32);
default:
cpu_abort(cpu_single_env, "syborg_rtc_read: Bad offset %x\n",
(int)offset);
return 0;
}
}
static void syborg_rtc_write(void *opaque, target_phys_addr_t offset, uint32_t value)
{
SyborgRTCState *s = (SyborgRTCState *)opaque;
uint64_t now;
offset &= 0xfff;
switch (offset >> 2) {
case RTC_LATCH:
now = qemu_get_clock(vm_clock);
if (value >= 4) {
s->offset = s->data - now;
} else {
s->data = now + s->offset;
while (value) {
s->data /= 1000;
value--;
}
}
break;
case RTC_DATA_LOW:
s->data = (s->data & ~(uint64_t)0xffffffffu) | value;
break;
case RTC_DATA_HIGH:
s->data = (s->data & 0xffffffffu) | ((uint64_t)value << 32);
break;
default:
cpu_abort(cpu_single_env, "syborg_rtc_write: Bad offset %x\n",
(int)offset);
break;
}
}
static CPUReadMemoryFunc *syborg_rtc_readfn[] = {
syborg_rtc_read,
syborg_rtc_read,
syborg_rtc_read
};
static CPUWriteMemoryFunc *syborg_rtc_writefn[] = {
syborg_rtc_write,
syborg_rtc_write,
syborg_rtc_write
};
static void syborg_rtc_save(QEMUFile *f, void *opaque)
{
SyborgRTCState *s = opaque;
qemu_put_be64(f, s->offset);
qemu_put_be64(f, s->data);
}
static int syborg_rtc_load(QEMUFile *f, void *opaque, int version_id)
{
SyborgRTCState *s = opaque;
if (version_id != 1)
return -EINVAL;
s->offset = qemu_get_be64(f);
s->data = qemu_get_be64(f);
return 0;
}
static void syborg_rtc_init(SysBusDevice *dev)
{
SyborgRTCState *s = FROM_SYSBUS(SyborgRTCState, dev);
struct tm tm;
int iomemtype;
iomemtype = cpu_register_io_memory(0, syborg_rtc_readfn,
syborg_rtc_writefn, s);
sysbus_init_mmio(dev, 0x1000, iomemtype);
qemu_get_timedate(&tm, 0);
s->offset = (uint64_t)mktime(&tm) * 1000000000;
register_savevm("syborg_rtc", -1, 1, syborg_rtc_save, syborg_rtc_load, s);
}
static void syborg_rtc_register_devices(void)
{
sysbus_register_dev("syborg,rtc", sizeof(SyborgRTCState), syborg_rtc_init);
}
device_init(syborg_rtc_register_devices)