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 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