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 #include "qom/object.h"
  29
  30 /*#define IB700_DEBUG 1*/
  31
  32 #ifdef IB700_DEBUG
  33 #define ib700_debug(fs,...)                                     \
  34     fprintf(stderr,"ib700: %s: "fs,__func__,##__VA_ARGS__)
  35 #else
  36 #define ib700_debug(fs,...)
  37 #endif
  38
  39 #define TYPE_IB700 "ib700"
  40 typedef struct IB700state IB700State;
  41 DECLARE_INSTANCE_CHECKER(IB700State, IB700,
  42                          TYPE_IB700)
  43
  44 struct IB700state {
  45     ISADevice parent_obj;
  46
  47     QEMUTimer *timer;
  48
  49     PortioList port_list;
  50 };
  51
  52 /* This is the timer.  We use a global here because the watchdog
  53  * code ensures there is only one watchdog (it is located at a fixed,
  54  * unchangeable IO port, so there could only ever be one anyway).
  55  */
  56
  57 /* A write to this register enables the timer. */
  58 static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
  59 {
  60     IB700State *s = vp;
  61     static int time_map[] = {
  62         30, 28, 26, 24, 22, 20, 18, 16,
  63         14, 12, 10,  8,  6,  4,  2,  0
  64     };
  65     int64_t timeout;
  66
  67     ib700_debug("addr = %x, data = %x\n", addr, data);
  68
  69     timeout = (int64_t) time_map[data & 0xF] * NANOSECONDS_PER_SECOND;
  70     timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + timeout);
  71 }
  72
  73 /* A write (of any value) to this register disables the timer. */
  74 static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
  75 {
  76     IB700State *s = vp;
  77
  78     ib700_debug("addr = %x, data = %x\n", addr, data);
  79
  80     timer_del(s->timer);
  81 }
  82
  83 /* This is called when the watchdog expires. */
  84 static void ib700_timer_expired(void *vp)
  85 {
  86     IB700State *s = vp;
  87
  88     ib700_debug("watchdog expired\n");
  89
  90     watchdog_perform_action();
  91     timer_del(s->timer);
  92 }
  93
  94 static const VMStateDescription vmstate_ib700 = {
  95     .name = "ib700_wdt",
  96     .version_id = 0,
  97     .minimum_version_id = 0,
  98     .fields = (VMStateField[]) {
  99         VMSTATE_TIMER_PTR(timer, IB700State),
 100         VMSTATE_END_OF_LIST()
 101     }
 102 };
 103
 104 static const MemoryRegionPortio wdt_portio_list[] = {
 105     { 0x441, 2, 1, .write = ib700_write_disable_reg, },
 106     { 0x443, 2, 1, .write = ib700_write_enable_reg, },
 107     PORTIO_END_OF_LIST(),
 108 };
 109
 110 static void wdt_ib700_realize(DeviceState *dev, Error **errp)
 111 {
 112     IB700State *s = IB700(dev);
 113
 114     ib700_debug("watchdog init\n");
 115
 116     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ib700_timer_expired, s);
 117
 118     portio_list_init(&s->port_list, OBJECT(s), wdt_portio_list, s, "ib700");
 119     portio_list_add(&s->port_list, isa_address_space_io(&s->parent_obj), 0);
 120 }
 121
 122 static void wdt_ib700_reset(DeviceState *dev)
 123 {
 124     IB700State *s = IB700(dev);
 125
 126     ib700_debug("watchdog reset\n");
 127
 128     timer_del(s->timer);
 129 }
 130
 131 static WatchdogTimerModel model = {
 132     .wdt_name = "ib700",
 133     .wdt_description = "iBASE 700",
 134 };
 135
 136 static void wdt_ib700_class_init(ObjectClass *klass, void *data)
 137 {
 138     DeviceClass *dc = DEVICE_CLASS(klass);
 139
 140     dc->realize = wdt_ib700_realize;
 141     dc->reset = wdt_ib700_reset;
 142     dc->vmsd = &vmstate_ib700;
 143     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 144 }
 145
 146 static const TypeInfo wdt_ib700_info = {
 147     .name          = TYPE_IB700,
 148     .parent        = TYPE_ISA_DEVICE,
 149     .instance_size = sizeof(IB700State),
 150     .class_init    = wdt_ib700_class_init,
 151 };
 152
 153 static void wdt_ib700_register_types(void)
 154 {
 155     watchdog_add_model(&model);
 156     type_register_static(&wdt_ib700_info);
 157 }
 158
 159 type_init(wdt_ib700_register_types)