LXR qemu/hw/watchdog/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/osdep.h"
  23#include "qemu/module.h"
  24#include "qemu/timer.h"
  25#include "sysemu/watchdog.h"
  26#include "hw/hw.h"
  27#include "hw/isa/isa.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
  38#define TYPE_IB700 "ib700"
  39#define IB700(obj) OBJECT_CHECK(IB700State, (obj), TYPE_IB700)
  40
  41typedef struct IB700state {
  42    ISADevice parent_obj;
  43
  44    QEMUTimer *timer;
  45
  46    PortioList port_list;
  47} IB700State;
  48
  49/* This is the timer.  We use a global here because the watchdog
  50 * code ensures there is only one watchdog (it is located at a fixed,
  51 * unchangeable IO port, so there could only ever be one anyway).
  52 */
  53
  54/* A write to this register enables the timer. */
  55static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
  56{
  57    IB700State *s = vp;
  58    static int time_map[] = {
  59        30, 28, 26, 24, 22, 20, 18, 16,
  60        14, 12, 10,  8,  6,  4,  2,  0
  61    };
  62    int64_t timeout;
  63
  64    ib700_debug("addr = %x, data = %x\n", addr, data);
  65
  66    timeout = (int64_t) time_map[data & 0xF] * NANOSECONDS_PER_SECOND;
  67    timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + timeout);
  68}
  69
  70/* A write (of any value) to this register disables the timer. */
  71static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
  72{
  73    IB700State *s = vp;
  74
  75    ib700_debug("addr = %x, data = %x\n", addr, data);
  76
  77    timer_del(s->timer);
  78}
  79
  80/* This is called when the watchdog expires. */
  81static void ib700_timer_expired(void *vp)
  82{
  83    IB700State *s = vp;
  84
  85    ib700_debug("watchdog expired\n");
  86
  87    watchdog_perform_action();
  88    timer_del(s->timer);
  89}
  90
  91static const VMStateDescription vmstate_ib700 = {
  92    .name = "ib700_wdt",
  93    .version_id = 0,
  94    .minimum_version_id = 0,
  95    .fields = (VMStateField[]) {
  96        VMSTATE_TIMER_PTR(timer, IB700State),
  97        VMSTATE_END_OF_LIST()
  98    }
  99};
 100
 101static const MemoryRegionPortio wdt_portio_list[] = {
 102    { 0x441, 2, 1, .write = ib700_write_disable_reg, },
 103    { 0x443, 2, 1, .write = ib700_write_enable_reg, },
 104    PORTIO_END_OF_LIST(),
 105};
 106
 107static void wdt_ib700_realize(DeviceState *dev, Error **errp)
 108{
 109    IB700State *s = IB700(dev);
 110
 111    ib700_debug("watchdog init\n");
 112
 113    s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ib700_timer_expired, s);
 114
 115    portio_list_init(&s->port_list, OBJECT(s), wdt_portio_list, s, "ib700");
 116    portio_list_add(&s->port_list, isa_address_space_io(&s->parent_obj), 0);
 117}
 118
 119static void wdt_ib700_reset(DeviceState *dev)
 120{
 121    IB700State *s = IB700(dev);
 122
 123    ib700_debug("watchdog reset\n");
 124
 125    timer_del(s->timer);
 126}
 127
 128static WatchdogTimerModel model = {
 129    .wdt_name = "ib700",
 130    .wdt_description = "iBASE 700",
 131};
 132
 133static void wdt_ib700_class_init(ObjectClass *klass, void *data)
 134{
 135    DeviceClass *dc = DEVICE_CLASS(klass);
 136
 137    dc->realize = wdt_ib700_realize;
 138    dc->reset = wdt_ib700_reset;
 139    dc->vmsd = &vmstate_ib700;
 140    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 141}
 142
 143static const TypeInfo wdt_ib700_info = {
 144    .name          = TYPE_IB700,
 145    .parent        = TYPE_ISA_DEVICE,
 146    .instance_size = sizeof(IB700State),
 147    .class_init    = wdt_ib700_class_init,
 148};
 149
 150static void wdt_ib700_register_types(void)
 151{
 152    watchdog_add_model(&model);
 153    type_register_static(&wdt_ib700_info);
 154}
 155
 156type_init(wdt_ib700_register_types)
 157