/* * Virtual hardware watchdog. * * Copyright (C) 2009 Red Hat Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. * * By Richard W.M. Jones (rjones@redhat.com). */ #include "qemu-common.h" #include "qemu-timer.h" #include "watchdog.h" #include "hw.h" #include "isa.h" #include "pc.h" /*#define IB700_DEBUG 1*/ #ifdef IB700_DEBUG #define ib700_debug(fs,...) \ fprintf(stderr,"ib700: %s: "fs,__func__,##__VA_ARGS__) #else #define ib700_debug(fs,...) #endif typedef struct IB700state { ISADevice dev; QEMUTimer *timer; } IB700State; /* This is the timer. We use a global here because the watchdog * code ensures there is only one watchdog (it is located at a fixed, * unchangable IO port, so there could only ever be one anyway). */ /* A write to this register enables the timer. */ static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data) { IB700State *s = vp; static int time_map[] = { 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0 }; int64_t timeout; ib700_debug("addr = %x, data = %x\n", addr, data); timeout = (int64_t) time_map[data & 0xF] * get_ticks_per_sec(); qemu_mod_timer(s->timer, qemu_get_clock_ns (vm_clock) + timeout); } /* A write (of any value) to this register disables the timer. */ static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data) { IB700State *s = vp; ib700_debug("addr = %x, data = %x\n", addr, data); qemu_del_timer(s->timer); } /* This is called when the watchdog expires. */ static void ib700_timer_expired(void *vp) { IB700State *s = vp; ib700_debug("watchdog expired\n"); watchdog_perform_action(); qemu_del_timer(s->timer); } static const VMStateDescription vmstate_ib700 = { .name = "ib700_wdt", .version_id = 0, .minimum_version_id = 0, .minimum_version_id_old = 0, .fields = (VMStateField []) { VMSTATE_TIMER(timer, IB700State), VMSTATE_END_OF_LIST() } }; static int wdt_ib700_init(ISADevice *dev) { IB700State *s = DO_UPCAST(IB700State, dev, dev); ib700_debug("watchdog init\n"); s->timer = qemu_new_timer_ns(vm_clock, ib700_timer_expired, s); register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, s); register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, s); return 0; } static void wdt_ib700_reset(DeviceState *dev) { IB700State *s = DO_UPCAST(IB700State, dev.qdev, dev); ib700_debug("watchdog reset\n"); qemu_del_timer(s->timer); } static WatchdogTimerModel model = { .wdt_name = "ib700", .wdt_description = "iBASE 700", }; static ISADeviceInfo wdt_ib700_info = { .qdev.name = "ib700", .qdev.size = sizeof(IB700State), .qdev.vmsd = &vmstate_ib700, .qdev.reset = wdt_ib700_reset, .init = wdt_ib700_init, }; static void wdt_ib700_register_devices(void) { watchdog_add_model(&model); isa_qdev_register(&wdt_ib700_info); } device_init(wdt_ib700_register_devices);