| 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 "system/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 = (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 | |
| 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 void wdt_ib700_class_init(ObjectClass *klass, const 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 | |
| 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) |