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) |
157 | |