LXR qemu/hw/wdt

   1/*
   2 * Virtual hardware watchdog.
   3 *
   4 * Copyright (C) 2009 Red Hat Inc.
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version 2
   9 * of the License, or (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 *
  19 * By Richard W.M. Jones (rjones@redhat.com).
  20 */
  21
  22#include "qemu-common.h"
  23#include "qemu/timer.h"
  24#include "watchdog.h"
  25#include "hw.h"
  26#include "isa.h"
  27#include "pc.h"
  28
  29/*#define IB700_DEBUG 1*/
  30
  31#ifdef IB700_DEBUG
  32#define ib700_debug(fs,...)                                     \
  33    fprintf(stderr,"ib700: %s: "fs,__func__,##__VA_ARGS__)
  34#else
  35#define ib700_debug(fs,...)
  36#endif
  37
  38typedef struct IB700state {
  39    ISADevice dev;
  40    QEMUTimer *timer;
  41} IB700State;
  42
  43/* This is the timer.  We use a global here because the watchdog
  44 * code ensures there is only one watchdog (it is located at a fixed,
  45 * unchangeable IO port, so there could only ever be one anyway).
  46 */
  47
  48/* A write to this register enables the timer. */
  49static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
  50{
  51    IB700State *s = vp;
  52    static int time_map[] = {
  53        30, 28, 26, 24, 22, 20, 18, 16,
  54        14, 12, 10,  8,  6,  4,  2,  0
  55    };
  56    int64_t timeout;
  57
  58    ib700_debug("addr = %x, data = %x\n", addr, data);
  59
  60    timeout = (int64_t) time_map[data & 0xF] * get_ticks_per_sec();
  61    qemu_mod_timer(s->timer, qemu_get_clock_ns (vm_clock) + timeout);
  62}
  63
  64/* A write (of any value) to this register disables the timer. */
  65static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
  66{
  67    IB700State *s = vp;
  68
  69    ib700_debug("addr = %x, data = %x\n", addr, data);
  70
  71    qemu_del_timer(s->timer);
  72}
  73
  74/* This is called when the watchdog expires. */
  75static void ib700_timer_expired(void *vp)
  76{
  77    IB700State *s = vp;
  78
  79    ib700_debug("watchdog expired\n");
  80
  81    watchdog_perform_action();
  82    qemu_del_timer(s->timer);
  83}
  84
  85static const VMStateDescription vmstate_ib700 = {
  86    .name = "ib700_wdt",
  87    .version_id = 0,
  88    .minimum_version_id = 0,
  89    .minimum_version_id_old = 0,
  90    .fields      = (VMStateField []) {
  91        VMSTATE_TIMER(timer, IB700State),
  92        VMSTATE_END_OF_LIST()
  93    }
  94};
  95
  96static int wdt_ib700_init(ISADevice *dev)
  97{
  98    IB700State *s = DO_UPCAST(IB700State, dev, dev);
  99
 100    ib700_debug("watchdog init\n");
 101
 102    s->timer = qemu_new_timer_ns(vm_clock, ib700_timer_expired, s);
 103    register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, s);
 104    register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, s);
 105
 106    return 0;
 107}
 108
 109static void wdt_ib700_reset(DeviceState *dev)
 110{
 111    IB700State *s = DO_UPCAST(IB700State, dev.qdev, dev);
 112
 113    ib700_debug("watchdog reset\n");
 114
 115    qemu_del_timer(s->timer);
 116}
 117
 118static WatchdogTimerModel model = {
 119    .wdt_name = "ib700",
 120    .wdt_description = "iBASE 700",
 121};
 122
 123static void wdt_ib700_class_init(ObjectClass *klass, void *data)
 124{
 125    DeviceClass *dc = DEVICE_CLASS(klass);
 126    ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
 127    ic->init = wdt_ib700_init;
 128    dc->reset = wdt_ib700_reset;
 129    dc->vmsd = &vmstate_ib700;
 130}
 131
 132static const TypeInfo wdt_ib700_info = {
 133    .name          = "ib700",
 134    .parent        = TYPE_ISA_DEVICE,
 135    .instance_size = sizeof(IB700State),
 136    .class_init    = wdt_ib700_class_init,
 137};
 138
 139static void wdt_ib700_register_types(void)
 140{
 141    watchdog_add_model(&model);
 142    type_register_static(&wdt_ib700_info);
 143}
 144
 145type_init(wdt_ib700_register_types)
 146