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. */
ib700_write_enable_reg(void * vp,uint32_t addr,uint32_t data)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. */
ib700_write_disable_reg(void * vp,uint32_t addr,uint32_t data)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. */
ib700_timer_expired(void * vp)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 = (const 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
wdt_ib700_realize(DeviceState * dev,Error ** errp)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
wdt_ib700_reset(DeviceState * dev)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
wdt_ib700_class_init(ObjectClass * klass,void * data)131 static void wdt_ib700_class_init(ObjectClass *klass, void *data)
132 {
133 DeviceClass *dc = DEVICE_CLASS(klass);
134
135 dc->realize = wdt_ib700_realize;
136 device_class_set_legacy_reset(dc, wdt_ib700_reset);
137 dc->vmsd = &vmstate_ib700;
138 set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories);
139 dc->desc = "iBASE 700";
140 }
141
142 static const TypeInfo wdt_ib700_info = {
143 .name = TYPE_IB700,
144 .parent = TYPE_ISA_DEVICE,
145 .instance_size = sizeof(IB700State),
146 .class_init = wdt_ib700_class_init,
147 };
148
wdt_ib700_register_types(void)149 static void wdt_ib700_register_types(void)
150 {
151 type_register_static(&wdt_ib700_info);
152 }
153
154 type_init(wdt_ib700_register_types)
155