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-common.h"
  24 #include "qemu/timer.h"
  25 #include "sysemu/watchdog.h"
  26 #include "hw/hw.h"
  27 #include "hw/isa/isa.h"
  28 #include "hw/i386/pc.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 #define IB700(obj) OBJECT_CHECK(IB700State, (obj), TYPE_IB700)
  41
  42 typedef struct IB700state {
  43     ISADevice parent_obj;
  44
  45     QEMUTimer *timer;
  46
  47     PortioList port_list;
  48 } IB700State;
  49
  50 /* This is the timer.  We use a global here because the watchdog
  51  * code ensures there is only one watchdog (it is located at a fixed,
  52  * unchangeable IO port, so there could only ever be one anyway).
  53  */
  54
  55 /* A write to this register enables the timer. */
  56 static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
  57 {
  58     IB700State *s = vp;
  59     static int time_map[] = {
  60         30, 28, 26, 24, 22, 20, 18, 16,
  61         14, 12, 10,  8,  6,  4,  2,  0
  62     };
  63     int64_t timeout;
  64
  65     ib700_debug("addr = %x, data = %x\n", addr, data);
  66
  67     timeout = (int64_t) time_map[data & 0xF] * NANOSECONDS_PER_SECOND;
  68     timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + timeout);
  69 }
  70
  71 /* A write (of any value) to this register disables the timer. */
  72 static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
  73 {
  74     IB700State *s = vp;
  75
  76     ib700_debug("addr = %x, data = %x\n", addr, data);
  77
  78     timer_del(s->timer);
  79 }
  80
  81 /* This is called when the watchdog expires. */
  82 static void ib700_timer_expired(void *vp)
  83 {
  84     IB700State *s = vp;
  85
  86     ib700_debug("watchdog expired\n");
  87
  88     watchdog_perform_action();
  89     timer_del(s->timer);
  90 }
  91
  92 static const VMStateDescription vmstate_ib700 = {
  93     .name = "ib700_wdt",
  94     .version_id = 0,
  95     .minimum_version_id = 0,
  96     .fields = (VMStateField[]) {
  97         VMSTATE_TIMER_PTR(timer, IB700State),
  98         VMSTATE_END_OF_LIST()
  99     }
 100 };
 101
 102 static const MemoryRegionPortio wdt_portio_list[] = {
 103     { 0x441, 2, 1, .write = ib700_write_disable_reg, },
 104     { 0x443, 2, 1, .write = ib700_write_enable_reg, },
 105     PORTIO_END_OF_LIST(),
 106 };
 107
 108 static void wdt_ib700_realize(DeviceState *dev, Error **errp)
 109 {
 110     IB700State *s = IB700(dev);
 111
 112     ib700_debug("watchdog init\n");
 113
 114     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ib700_timer_expired, s);
 115
 116     portio_list_init(&s->port_list, OBJECT(s), wdt_portio_list, s, "ib700");
 117     portio_list_add(&s->port_list, isa_address_space_io(&s->parent_obj), 0);
 118 }
 119
 120 static void wdt_ib700_reset(DeviceState *dev)
 121 {
 122     IB700State *s = IB700(dev);
 123
 124     ib700_debug("watchdog reset\n");
 125
 126     timer_del(s->timer);
 127 }
 128
 129 static WatchdogTimerModel model = {
 130     .wdt_name = "ib700",
 131     .wdt_description = "iBASE 700",
 132 };
 133
 134 static void wdt_ib700_class_init(ObjectClass *klass, void *data)
 135 {
 136     DeviceClass *dc = DEVICE_CLASS(klass);
 137
 138     dc->realize = wdt_ib700_realize;
 139     dc->reset = wdt_ib700_reset;
 140     dc->vmsd = &vmstate_ib700;
 141     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 142 }
 143
 144 static const TypeInfo wdt_ib700_info = {
 145     .name          = TYPE_IB700,
 146     .parent        = TYPE_ISA_DEVICE,
 147     .instance_size = sizeof(IB700State),
 148     .class_init    = wdt_ib700_class_init,
 149 };
 150
 151 static void wdt_ib700_register_types(void)
 152 {
 153     watchdog_add_model(&model);
 154     type_register_static(&wdt_ib700_info);
 155 }
 156
 157 type_init(wdt_ib700_register_types)