Archipelago » qemu

/*

 * 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_ns (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_ns(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);