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. */ 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 = (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, void *data) 132 { 133 DeviceClass *dc = DEVICE_CLASS(klass); 134 135 dc->realize = wdt_ib700_realize; 136 dc->reset = 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) 155