viawd.c revision 331722
1/*- 2 * Copyright (c) 2011 Fabien Thomas <fabient@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: stable/11/sys/dev/viawd/viawd.c 331722 2018-03-29 02:50:57Z eadler $"); 29 30#include <sys/param.h> 31#include <sys/kernel.h> 32#include <sys/module.h> 33#include <sys/systm.h> 34#include <sys/bus.h> 35#include <machine/bus.h> 36#include <sys/rman.h> 37#include <machine/resource.h> 38#include <sys/watchdog.h> 39 40#include <isa/isavar.h> 41#include <dev/pci/pcivar.h> 42 43#include "viawd.h" 44 45#define viawd_read_4(sc, off) bus_read_4((sc)->wd_res, (off)) 46#define viawd_write_4(sc, off, val) \ 47 bus_write_4((sc)->wd_res, (off), (val)) 48 49static struct viawd_device viawd_devices[] = { 50 { DEVICEID_VT8251, "VIA VT8251 watchdog timer" }, 51 { DEVICEID_CX700, "VIA CX700 watchdog timer" }, 52 { DEVICEID_VX800, "VIA VX800 watchdog timer" }, 53 { DEVICEID_VX855, "VIA VX855 watchdog timer" }, 54 { DEVICEID_VX900, "VIA VX900 watchdog timer" }, 55 { 0, NULL }, 56}; 57 58static devclass_t viawd_devclass; 59 60static void 61viawd_tmr_state(struct viawd_softc *sc, int enable) 62{ 63 uint32_t reg; 64 65 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 66 if (enable) 67 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE; 68 else 69 reg &= ~VIAWD_MEM_CTRL_ENABLE; 70 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 71} 72 73static void 74viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout) 75{ 76 77 /* Keep value in range. */ 78 if (timeout < VIAWD_MEM_COUNT_MIN) 79 timeout = VIAWD_MEM_COUNT_MIN; 80 else if (timeout > VIAWD_MEM_COUNT_MAX) 81 timeout = VIAWD_MEM_COUNT_MAX; 82 83 viawd_write_4(sc, VIAWD_MEM_COUNT, timeout); 84 sc->timeout = timeout; 85} 86 87/* 88 * Watchdog event handler - called by the framework to enable or disable 89 * the watchdog or change the initial timeout value. 90 */ 91static void 92viawd_event(void *arg, unsigned int cmd, int *error) 93{ 94 struct viawd_softc *sc = arg; 95 unsigned int timeout; 96 97 /* Convert from power-of-two-ns to second. */ 98 cmd &= WD_INTERVAL; 99 timeout = ((uint64_t)1 << cmd) / 1000000000; 100 if (cmd) { 101 if (timeout != sc->timeout) 102 viawd_tmr_set(sc, timeout); 103 viawd_tmr_state(sc, 1); 104 *error = 0; 105 } else 106 viawd_tmr_state(sc, 0); 107} 108 109/* Look for a supported VIA south bridge. */ 110static struct viawd_device * 111viawd_find(device_t dev) 112{ 113 struct viawd_device *id; 114 115 if (pci_get_vendor(dev) != VENDORID_VIA) 116 return (NULL); 117 for (id = viawd_devices; id->desc != NULL; id++) 118 if (pci_get_device(dev) == id->device) 119 return (id); 120 return (NULL); 121} 122 123static void 124viawd_identify(driver_t *driver, device_t parent) 125{ 126 127 if (viawd_find(parent) == NULL) 128 return; 129 130 if (device_find_child(parent, driver->name, -1) == NULL) 131 BUS_ADD_CHILD(parent, 0, driver->name, 0); 132} 133 134static int 135viawd_probe(device_t dev) 136{ 137 struct viawd_device *id; 138 139 id = viawd_find(device_get_parent(dev)); 140 KASSERT(id != NULL, ("parent should be a valid VIA SB")); 141 device_set_desc(dev, id->desc); 142 return (BUS_PROBE_GENERIC); 143} 144 145static int 146viawd_attach(device_t dev) 147{ 148 device_t sb_dev; 149 struct viawd_softc *sc; 150 uint32_t pmbase, reg; 151 152 sc = device_get_softc(dev); 153 sc->dev = dev; 154 155 sb_dev = device_get_parent(dev); 156 if (sb_dev == NULL) { 157 device_printf(dev, "Can not find watchdog device.\n"); 158 goto fail; 159 } 160 sc->sb_dev = sb_dev; 161 162 /* Get watchdog memory base. */ 163 pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4); 164 if (pmbase == 0) { 165 device_printf(dev, 166 "Watchdog disabled in BIOS or hardware\n"); 167 goto fail; 168 } 169 170 /* Allocate I/O register space. */ 171 sc->wd_rid = VIAWD_CONFIG_BASE; 172 sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid, 173 RF_ACTIVE | RF_SHAREABLE); 174 if (sc->wd_res == NULL) { 175 device_printf(dev, "Unable to map watchdog memory\n"); 176 goto fail; 177 } 178 if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) { 179 device_printf(dev, "Bad size for watchdog memory: %#x\n", 180 (unsigned)rman_get_size(sc->wd_res)); 181 goto fail; 182 } 183 184 /* Check if watchdog fired last boot. */ 185 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 186 if (reg & VIAWD_MEM_CTRL_FIRED) { 187 device_printf(dev, 188 "ERROR: watchdog rebooted the system\n"); 189 /* Reset bit state. */ 190 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 191 } 192 193 /* Register the watchdog event handler. */ 194 sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0); 195 196 return (0); 197fail: 198 if (sc->wd_res != NULL) 199 bus_release_resource(sb_dev, SYS_RES_MEMORY, 200 sc->wd_rid, sc->wd_res); 201 return (ENXIO); 202} 203 204static int 205viawd_detach(device_t dev) 206{ 207 struct viawd_softc *sc; 208 uint32_t reg; 209 210 sc = device_get_softc(dev); 211 212 /* Deregister event handler. */ 213 if (sc->ev_tag != NULL) 214 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag); 215 sc->ev_tag = NULL; 216 217 /* 218 * Do not stop the watchdog on shutdown if active but bump the 219 * timer to avoid spurious reset. 220 */ 221 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 222 if (reg & VIAWD_MEM_CTRL_ENABLE) { 223 viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN); 224 viawd_tmr_state(sc, 1); 225 device_printf(dev, 226 "Keeping watchog alive during shutdown for %d seconds\n", 227 VIAWD_TIMEOUT_SHUTDOWN); 228 } 229 230 if (sc->wd_res != NULL) 231 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY, 232 sc->wd_rid, sc->wd_res); 233 234 return (0); 235} 236 237static device_method_t viawd_methods[] = { 238 DEVMETHOD(device_identify, viawd_identify), 239 DEVMETHOD(device_probe, viawd_probe), 240 DEVMETHOD(device_attach, viawd_attach), 241 DEVMETHOD(device_detach, viawd_detach), 242 DEVMETHOD(device_shutdown, viawd_detach), 243 {0,0} 244}; 245 246static driver_t viawd_driver = { 247 "viawd", 248 viawd_methods, 249 sizeof(struct viawd_softc), 250}; 251 252DRIVER_MODULE(viawd, isab, viawd_driver, viawd_devclass, NULL, NULL); 253