hw/watchdog/wdt_ib700.c

   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 "sysemu/watchdog.h"
  25 #include "hw/hw.h"
  26 #include "hw/isa/isa.h"
  27 #include "hw/i386/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
  38 #define TYPE_IB700 "ib700"
  39 #define IB700(obj) OBJECT_CHECK(IB700State, (obj), TYPE_IB700)
  40
  41 typedef struct IB700state {
  42     ISADevice parent_obj;
  43
  44     QEMUTimer *timer;
  45 } IB700State;
  46
  47 /* This is the timer.  We use a global here because the watchdog
  48  * code ensures there is only one watchdog (it is located at a fixed,
  49  * unchangeable IO port, so there could only ever be one anyway).
  50  */
  51
  52 /* A write to this register enables the timer. */
  53 static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
  54 {
  55     IB700State *s = vp;
  56     static int time_map[] = {
  57         30, 28, 26, 24, 22, 20, 18, 16,
  58         14, 12, 10,  8,  6,  4,  2,  0
  59     };
  60     int64_t timeout;
  61
  62     ib700_debug("addr = %x, data = %x\n", addr, data);
  63
  64     timeout = (int64_t) time_map[data & 0xF] * get_ticks_per_sec();
  65     qemu_mod_timer(s->timer, qemu_get_clock_ns (vm_clock) + timeout);
  66 }
  67
  68 /* A write (of any value) to this register disables the timer. */
  69 static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
  70 {
  71     IB700State *s = vp;
  72
  73     ib700_debug("addr = %x, data = %x\n", addr, data);
  74
  75     qemu_del_timer(s->timer);
  76 }
  77
  78 /* This is called when the watchdog expires. */
  79 static void ib700_timer_expired(void *vp)
  80 {
  81     IB700State *s = vp;
  82
  83     ib700_debug("watchdog expired\n");
  84
  85     watchdog_perform_action();
  86     qemu_del_timer(s->timer);
  87 }
  88
  89 static const VMStateDescription vmstate_ib700 = {
  90     .name = "ib700_wdt",
  91     .version_id = 0,
  92     .minimum_version_id = 0,
  93     .minimum_version_id_old = 0,
  94     .fields      = (VMStateField []) {
  95         VMSTATE_TIMER(timer, IB700State),
  96         VMSTATE_END_OF_LIST()
  97     }
  98 };
  99
 100 static void wdt_ib700_realize(DeviceState *dev, Error **errp)
 101 {
 102     IB700State *s = IB700(dev);
 103
 104     ib700_debug("watchdog init\n");
 105
 106     s->timer = qemu_new_timer_ns(vm_clock, ib700_timer_expired, s);
 107     register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, s);
 108     register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, s);
 109 }
 110
 111 static void wdt_ib700_reset(DeviceState *dev)
 112 {
 113     IB700State *s = IB700(dev);
 114
 115     ib700_debug("watchdog reset\n");
 116
 117     qemu_del_timer(s->timer);
 118 }
 119
 120 static WatchdogTimerModel model = {
 121     .wdt_name = "ib700",
 122     .wdt_description = "iBASE 700",
 123 };
 124
 125 static void wdt_ib700_class_init(ObjectClass *klass, void *data)
 126 {
 127     DeviceClass *dc = DEVICE_CLASS(klass);
 128
 129     dc->realize = wdt_ib700_realize;
 130     dc->reset = wdt_ib700_reset;
 131     dc->vmsd = &vmstate_ib700;
 132 }
 133
 134 static const TypeInfo wdt_ib700_info = {
 135     .name          = TYPE_IB700,
 136     .parent        = TYPE_ISA_DEVICE,
 137     .instance_size = sizeof(IB700State),
 138     .class_init    = wdt_ib700_class_init,
 139 };
 140
 141 static void wdt_ib700_register_types(void)
 142 {
 143     watchdog_add_model(&model);
 144     type_register_static(&wdt_ib700_info);
 145 }
 146
 147 type_init(wdt_ib700_register_types)