qemu/hw/wdt_ib700.c

111 lines
2.9 KiB
C

/*
* 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
/* 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).
*/
static QEMUTimer *timer = NULL;
/* A write to this register enables the timer. */
static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
{
static int time_map[] = {
30, 28, 26, 24, 22, 20, 18, 16,
14, 12, 10, 8, 6, 4, 2, 0
};
int64 timeout;
ib700_debug("addr = %x, data = %x\n", addr, data);
timeout = (int64_t) time_map[data & 0xF] * ticks_per_sec;
qemu_mod_timer(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)
{
ib700_debug("addr = %x, data = %x\n", addr, data);
qemu_del_timer(timer);
}
/* This is called when the watchdog expires. */
static void ib700_timer_expired(void *vp)
{
ib700_debug("watchdog expired\n");
watchdog_perform_action();
qemu_del_timer(timer);
}
static void ib700_save(QEMUFile *f, void *vp)
{
qemu_put_timer(f, timer);
}
static int ib700_load(QEMUFile *f, void *vp, int version)
{
if (version != 0)
return -EINVAL;
qemu_get_timer(f, timer);
return 0;
}
/* Create and initialize a virtual IB700 during PC creation. */
static void ib700_pc_init(PCIBus *unused)
{
register_savevm("ib700_wdt", -1, 0, ib700_save, ib700_load, NULL);
register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, NULL);
register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, NULL);
}
static WatchdogTimerModel model = {
.wdt_name = "ib700",
.wdt_description = "iBASE 700",
.wdt_pc_init = ib700_pc_init,
};
void wdt_ib700_init(void)
{
watchdog_add_model(&model);
timer = qemu_new_timer(vm_clock, ib700_timer_expired, NULL);
}