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/*
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 * Virtual hardware watchdog.
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 *
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 * Copyright (C) 2009 Red Hat Inc.
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License
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 * as published by the Free Software Foundation; either version 2
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 * of the License, or (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, see <http://www.gnu.org/licenses/>.
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 *
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 * By Richard W.M. Jones (rjones@redhat.com).
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 */
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#include "qemu-common.h"
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#include "qemu-timer.h"
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#include "watchdog.h"
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#include "hw.h"
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#include "isa.h"
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#include "pc.h"
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/*#define IB700_DEBUG 1*/
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#ifdef IB700_DEBUG
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#define ib700_debug(fs,...)                                        \
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    fprintf(stderr,"ib700: %s: "fs,__func__,##__VA_ARGS__)
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#else
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#define ib700_debug(fs,...)
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#endif
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typedef struct IB700state {
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    ISADevice dev;
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    QEMUTimer *timer;
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} IB700State;
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/* This is the timer.  We use a global here because the watchdog
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 * code ensures there is only one watchdog (it is located at a fixed,
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 * unchangable IO port, so there could only ever be one anyway).
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 */
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/* A write to this register enables the timer. */
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static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
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{
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    IB700State *s = vp;
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    static int time_map[] = {
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        30, 28, 26, 24, 22, 20, 18, 16,
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        14, 12, 10,  8,  6,  4,  2,  0
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    };
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    int64 timeout;
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    ib700_debug("addr = %x, data = %x\n", addr, data);
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    timeout = (int64_t) time_map[data & 0xF] * get_ticks_per_sec();
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    qemu_mod_timer(s->timer, qemu_get_clock (vm_clock) + timeout);
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}
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/* A write (of any value) to this register disables the timer. */
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static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
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{
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    IB700State *s = vp;
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    ib700_debug("addr = %x, data = %x\n", addr, data);
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    qemu_del_timer(s->timer);
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}
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/* This is called when the watchdog expires. */
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static void ib700_timer_expired(void *vp)
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{
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    IB700State *s = vp;
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    ib700_debug("watchdog expired\n");
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    watchdog_perform_action();
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    qemu_del_timer(s->timer);
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}
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static const VMStateDescription vmstate_ib700 = {
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    .name = "ib700_wdt",
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    .version_id = 0,
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    .minimum_version_id = 0,
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    .minimum_version_id_old = 0,
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    .fields      = (VMStateField []) {
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        VMSTATE_TIMER(timer, IB700State),
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        VMSTATE_END_OF_LIST()
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    }
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};
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static int wdt_ib700_init(ISADevice *dev)
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{
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    IB700State *s = DO_UPCAST(IB700State, dev, dev);
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    s->timer = qemu_new_timer(vm_clock, ib700_timer_expired, s);
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    vmstate_register(-1, &vmstate_ib700, s);
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    register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, s);
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    register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, s);
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    return 0;
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}
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static WatchdogTimerModel model = {
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    .wdt_name = "ib700",
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    .wdt_description = "iBASE 700",
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};
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static ISADeviceInfo wdt_ib700_info = {
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    .qdev.name = "ib700",
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    .qdev.size = sizeof(IB700State),
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    .init      = wdt_ib700_init,
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};
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static void wdt_ib700_register_devices(void)
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{
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    watchdog_add_model(&model);
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    isa_qdev_register(&wdt_ib700_info);
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}
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device_init(wdt_ib700_register_devices);