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/osdep.h"
  23 #include "qemu/module.h"
  24 #include "qemu/timer.h"
  25 #include "sysemu/watchdog.h"
  26 #include "hw/isa/isa.h"
  27 #include "migration/vmstate.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
  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. */
  55 static 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. */
  71 static 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. */
  81 static 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
  91 static 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
 101 static 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
 107 static 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
 119 static 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
 128 static WatchdogTimerModel model = {
 129     .wdt_name = "ib700",
 130     .wdt_description = "iBASE 700",
 131 };
 132
 133 static 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
 143 static 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
 150 static void wdt_ib700_register_types(void)
 151 {
 152     watchdog_add_model(&model);
 153     type_register_static(&wdt_ib700_info);
 154 }
 155
 156 type_init(wdt_ib700_register_types)