qemu-e2k/hw/rtc/m41t80.c

120 lines
2.5 KiB
C

/*
* M41T80 serial rtc emulation
*
* Copyright (c) 2018 BALATON Zoltan
*
* This work is licensed under the GNU GPL license version 2 or later.
*
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "qemu/timer.h"
#include "qemu/bcd.h"
#include "hw/i2c/i2c.h"
#define TYPE_M41T80 "m41t80"
#define M41T80(obj) OBJECT_CHECK(M41t80State, (obj), TYPE_M41T80)
typedef struct M41t80State {
I2CSlave parent_obj;
int8_t addr;
} M41t80State;
static void m41t80_realize(DeviceState *dev, Error **errp)
{
M41t80State *s = M41T80(dev);
s->addr = -1;
}
static int m41t80_send(I2CSlave *i2c, uint8_t data)
{
M41t80State *s = M41T80(i2c);
if (s->addr < 0) {
s->addr = data;
} else {
s->addr++;
}
return 0;
}
static uint8_t m41t80_recv(I2CSlave *i2c)
{
M41t80State *s = M41T80(i2c);
struct tm now;
qemu_timeval tv;
if (s->addr < 0) {
s->addr = 0;
}
if (s->addr >= 1 && s->addr <= 7) {
qemu_get_timedate(&now, -1);
}
switch (s->addr++) {
case 0:
qemu_gettimeofday(&tv);
return to_bcd(tv.tv_usec / 10000);
case 1:
return to_bcd(now.tm_sec);
case 2:
return to_bcd(now.tm_min);
case 3:
return to_bcd(now.tm_hour);
case 4:
return to_bcd(now.tm_wday);
case 5:
return to_bcd(now.tm_mday);
case 6:
return to_bcd(now.tm_mon + 1);
case 7:
return to_bcd(now.tm_year % 100);
case 8 ... 19:
qemu_log_mask(LOG_UNIMP, "%s: unimplemented register: %d\n",
__func__, s->addr - 1);
return 0;
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid register: %d\n",
__func__, s->addr - 1);
return 0;
}
}
static int m41t80_event(I2CSlave *i2c, enum i2c_event event)
{
M41t80State *s = M41T80(i2c);
if (event == I2C_START_SEND) {
s->addr = -1;
}
return 0;
}
static void m41t80_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
dc->realize = m41t80_realize;
sc->send = m41t80_send;
sc->recv = m41t80_recv;
sc->event = m41t80_event;
}
static const TypeInfo m41t80_info = {
.name = TYPE_M41T80,
.parent = TYPE_I2C_SLAVE,
.instance_size = sizeof(M41t80State),
.class_init = m41t80_class_init,
};
static void m41t80_register_types(void)
{
type_register_static(&m41t80_info);
}
type_init(m41t80_register_types)