1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2011 Fabien Thomas <fabient@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/module.h> 35 #include <sys/systm.h> 36 #include <sys/bus.h> 37 #include <machine/bus.h> 38 #include <sys/rman.h> 39 #include <machine/resource.h> 40 #include <sys/watchdog.h> 41 42 #include <isa/isavar.h> 43 #include <dev/pci/pcivar.h> 44 45 #include "viawd.h" 46 47 #define viawd_read_4(sc, off) bus_read_4((sc)->wd_res, (off)) 48 #define viawd_write_4(sc, off, val) \ 49 bus_write_4((sc)->wd_res, (off), (val)) 50 51 static struct viawd_device viawd_devices[] = { 52 { DEVICEID_VT8251, "VIA VT8251 watchdog timer" }, 53 { DEVICEID_CX700, "VIA CX700 watchdog timer" }, 54 { DEVICEID_VX800, "VIA VX800 watchdog timer" }, 55 { DEVICEID_VX855, "VIA VX855 watchdog timer" }, 56 { DEVICEID_VX900, "VIA VX900 watchdog timer" }, 57 { 0, NULL }, 58 }; 59 60 static devclass_t viawd_devclass; 61 62 static void 63 viawd_tmr_state(struct viawd_softc *sc, int enable) 64 { 65 uint32_t reg; 66 67 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 68 if (enable) 69 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE; 70 else 71 reg &= ~VIAWD_MEM_CTRL_ENABLE; 72 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 73 } 74 75 static void 76 viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout) 77 { 78 79 /* Keep value in range. */ 80 if (timeout < VIAWD_MEM_COUNT_MIN) 81 timeout = VIAWD_MEM_COUNT_MIN; 82 else if (timeout > VIAWD_MEM_COUNT_MAX) 83 timeout = VIAWD_MEM_COUNT_MAX; 84 85 viawd_write_4(sc, VIAWD_MEM_COUNT, timeout); 86 sc->timeout = timeout; 87 } 88 89 /* 90 * Watchdog event handler - called by the framework to enable or disable 91 * the watchdog or change the initial timeout value. 92 */ 93 static void 94 viawd_event(void *arg, unsigned int cmd, int *error) 95 { 96 struct viawd_softc *sc = arg; 97 unsigned int timeout; 98 99 /* Convert from power-of-two-ns to second. */ 100 cmd &= WD_INTERVAL; 101 timeout = ((uint64_t)1 << cmd) / 1000000000; 102 if (cmd) { 103 if (timeout != sc->timeout) 104 viawd_tmr_set(sc, timeout); 105 viawd_tmr_state(sc, 1); 106 *error = 0; 107 } else 108 viawd_tmr_state(sc, 0); 109 } 110 111 /* Look for a supported VIA south bridge. */ 112 static struct viawd_device * 113 viawd_find(device_t dev) 114 { 115 struct viawd_device *id; 116 117 if (pci_get_vendor(dev) != VENDORID_VIA) 118 return (NULL); 119 for (id = viawd_devices; id->desc != NULL; id++) 120 if (pci_get_device(dev) == id->device) 121 return (id); 122 return (NULL); 123 } 124 125 static void 126 viawd_identify(driver_t *driver, device_t parent) 127 { 128 129 if (viawd_find(parent) == NULL) 130 return; 131 132 if (device_find_child(parent, driver->name, -1) == NULL) 133 BUS_ADD_CHILD(parent, 0, driver->name, 0); 134 } 135 136 static int 137 viawd_probe(device_t dev) 138 { 139 struct viawd_device *id; 140 141 id = viawd_find(device_get_parent(dev)); 142 KASSERT(id != NULL, ("parent should be a valid VIA SB")); 143 device_set_desc(dev, id->desc); 144 return (BUS_PROBE_GENERIC); 145 } 146 147 static int 148 viawd_attach(device_t dev) 149 { 150 device_t sb_dev; 151 struct viawd_softc *sc; 152 uint32_t pmbase, reg; 153 154 sc = device_get_softc(dev); 155 sc->dev = dev; 156 157 sb_dev = device_get_parent(dev); 158 if (sb_dev == NULL) { 159 device_printf(dev, "Can not find watchdog device.\n"); 160 goto fail; 161 } 162 sc->sb_dev = sb_dev; 163 164 /* Get watchdog memory base. */ 165 pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4); 166 if (pmbase == 0) { 167 device_printf(dev, 168 "Watchdog disabled in BIOS or hardware\n"); 169 goto fail; 170 } 171 172 /* Allocate I/O register space. */ 173 sc->wd_rid = VIAWD_CONFIG_BASE; 174 sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid, 175 RF_ACTIVE | RF_SHAREABLE); 176 if (sc->wd_res == NULL) { 177 device_printf(dev, "Unable to map watchdog memory\n"); 178 goto fail; 179 } 180 if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) { 181 device_printf(dev, "Bad size for watchdog memory: %#x\n", 182 (unsigned)rman_get_size(sc->wd_res)); 183 goto fail; 184 } 185 186 /* Check if watchdog fired last boot. */ 187 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 188 if (reg & VIAWD_MEM_CTRL_FIRED) { 189 device_printf(dev, 190 "ERROR: watchdog rebooted the system\n"); 191 /* Reset bit state. */ 192 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 193 } 194 195 /* Register the watchdog event handler. */ 196 sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0); 197 198 return (0); 199 fail: 200 if (sc->wd_res != NULL) 201 bus_release_resource(sb_dev, SYS_RES_MEMORY, 202 sc->wd_rid, sc->wd_res); 203 return (ENXIO); 204 } 205 206 static int 207 viawd_detach(device_t dev) 208 { 209 struct viawd_softc *sc; 210 uint32_t reg; 211 212 sc = device_get_softc(dev); 213 214 /* Deregister event handler. */ 215 if (sc->ev_tag != NULL) 216 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag); 217 sc->ev_tag = NULL; 218 219 /* 220 * Do not stop the watchdog on shutdown if active but bump the 221 * timer to avoid spurious reset. 222 */ 223 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 224 if (reg & VIAWD_MEM_CTRL_ENABLE) { 225 viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN); 226 viawd_tmr_state(sc, 1); 227 device_printf(dev, 228 "Keeping watchog alive during shutdown for %d seconds\n", 229 VIAWD_TIMEOUT_SHUTDOWN); 230 } 231 232 if (sc->wd_res != NULL) 233 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY, 234 sc->wd_rid, sc->wd_res); 235 236 return (0); 237 } 238 239 static device_method_t viawd_methods[] = { 240 DEVMETHOD(device_identify, viawd_identify), 241 DEVMETHOD(device_probe, viawd_probe), 242 DEVMETHOD(device_attach, viawd_attach), 243 DEVMETHOD(device_detach, viawd_detach), 244 DEVMETHOD(device_shutdown, viawd_detach), 245 {0,0} 246 }; 247 248 static driver_t viawd_driver = { 249 "viawd", 250 viawd_methods, 251 sizeof(struct viawd_softc), 252 }; 253 254 DRIVER_MODULE(viawd, isab, viawd_driver, viawd_devclass, NULL, NULL); 255