qemu/hw/wdt_ib700.c

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/*
* Virtual hardware watchdog.
*
* Copyright (C) 2009 Red Hat Inc.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*
* By Richard W.M. Jones (rjones@redhat.com).
*/
#include "qemu-common.h"
#include "qemu-timer.h"
#include "watchdog.h"
#include "hw.h"
#include "isa.h"
#include "pc.h"
/*#define IB700_DEBUG 1*/
#ifdef IB700_DEBUG
#define ib700_debug(fs,...) \
fprintf(stderr,"ib700: %s: "fs,__func__,##__VA_ARGS__)
#else
#define ib700_debug(fs,...)
#endif
typedef struct IB700state {
ISADevice dev;
QEMUTimer *timer;
} IB700State;
/* This is the timer. We use a global here because the watchdog
* code ensures there is only one watchdog (it is located at a fixed,
* unchangable IO port, so there could only ever be one anyway).
*/
/* A write to this register enables the timer. */
static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
{
IB700State *s = vp;
static int time_map[] = {
30, 28, 26, 24, 22, 20, 18, 16,
14, 12, 10, 8, 6, 4, 2, 0
};
int64_t timeout;
ib700_debug("addr = %x, data = %x\n", addr, data);
timeout = (int64_t) time_map[data & 0xF] * get_ticks_per_sec();
qemu_mod_timer(s->timer, qemu_get_clock (vm_clock) + timeout);
}
/* A write (of any value) to this register disables the timer. */
static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
{
IB700State *s = vp;
ib700_debug("addr = %x, data = %x\n", addr, data);
qemu_del_timer(s->timer);
}
/* This is called when the watchdog expires. */
static void ib700_timer_expired(void *vp)
{
IB700State *s = vp;
ib700_debug("watchdog expired\n");
watchdog_perform_action();
qemu_del_timer(s->timer);
}
static const VMStateDescription vmstate_ib700 = {
.name = "ib700_wdt",
.version_id = 0,
.minimum_version_id = 0,
.minimum_version_id_old = 0,
.fields = (VMStateField []) {
VMSTATE_TIMER(timer, IB700State),
VMSTATE_END_OF_LIST()
}
};
static int wdt_ib700_init(ISADevice *dev)
{
IB700State *s = DO_UPCAST(IB700State, dev, dev);
ib700_debug("watchdog init\n");
s->timer = qemu_new_timer(vm_clock, ib700_timer_expired, s);
register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, s);
register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, s);
return 0;
}
static void wdt_ib700_reset(DeviceState *dev)
{
IB700State *s = DO_UPCAST(IB700State, dev.qdev, dev);
ib700_debug("watchdog reset\n");
qemu_del_timer(s->timer);
}
static WatchdogTimerModel model = {
.wdt_name = "ib700",
.wdt_description = "iBASE 700",
};
static ISADeviceInfo wdt_ib700_info = {
.qdev.name = "ib700",
.qdev.size = sizeof(IB700State),
.qdev.vmsd = &vmstate_ib700,
.qdev.reset = wdt_ib700_reset,
.init = wdt_ib700_init,
};
static void wdt_ib700_register_devices(void)
{
watchdog_add_model(&model);
isa_qdev_register(&wdt_ib700_info);
}
device_init(wdt_ib700_register_devices);