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/eventhandler.h> 34 #include <sys/kernel.h> 35 #include <sys/module.h> 36 #include <sys/systm.h> 37 #include <sys/bus.h> 38 #include <machine/bus.h> 39 #include <sys/rman.h> 40 #include <machine/resource.h> 41 #include <sys/watchdog.h> 42 43 #include <isa/isavar.h> 44 #include <dev/pci/pcivar.h> 45 46 #include "viawd.h" 47 48 #define viawd_read_4(sc, off) bus_read_4((sc)->wd_res, (off)) 49 #define viawd_write_4(sc, off, val) \ 50 bus_write_4((sc)->wd_res, (off), (val)) 51 52 static struct viawd_device viawd_devices[] = { 53 { DEVICEID_VT8251, "VIA VT8251 watchdog timer" }, 54 { DEVICEID_CX700, "VIA CX700 watchdog timer" }, 55 { DEVICEID_VX800, "VIA VX800 watchdog timer" }, 56 { DEVICEID_VX855, "VIA VX855 watchdog timer" }, 57 { DEVICEID_VX900, "VIA VX900 watchdog timer" }, 58 { 0, NULL }, 59 }; 60 61 static void 62 viawd_tmr_state(struct viawd_softc *sc, int enable) 63 { 64 uint32_t reg; 65 66 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 67 if (enable) 68 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE; 69 else 70 reg &= ~VIAWD_MEM_CTRL_ENABLE; 71 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 72 } 73 74 static void 75 viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout) 76 { 77 78 /* Keep value in range. */ 79 if (timeout < VIAWD_MEM_COUNT_MIN) 80 timeout = VIAWD_MEM_COUNT_MIN; 81 else if (timeout > VIAWD_MEM_COUNT_MAX) 82 timeout = VIAWD_MEM_COUNT_MAX; 83 84 viawd_write_4(sc, VIAWD_MEM_COUNT, timeout); 85 sc->timeout = timeout; 86 } 87 88 /* 89 * Watchdog event handler - called by the framework to enable or disable 90 * the watchdog or change the initial timeout value. 91 */ 92 static void 93 viawd_event(void *arg, unsigned int cmd, int *error) 94 { 95 struct viawd_softc *sc = arg; 96 unsigned int timeout; 97 98 /* Convert from power-of-two-ns to second. */ 99 cmd &= WD_INTERVAL; 100 timeout = ((uint64_t)1 << cmd) / 1000000000; 101 if (cmd) { 102 if (timeout != sc->timeout) 103 viawd_tmr_set(sc, timeout); 104 viawd_tmr_state(sc, 1); 105 *error = 0; 106 } else 107 viawd_tmr_state(sc, 0); 108 } 109 110 /* Look for a supported VIA south bridge. */ 111 static struct viawd_device * 112 viawd_find(device_t dev) 113 { 114 struct viawd_device *id; 115 116 if (pci_get_vendor(dev) != VENDORID_VIA) 117 return (NULL); 118 for (id = viawd_devices; id->desc != NULL; id++) 119 if (pci_get_device(dev) == id->device) 120 return (id); 121 return (NULL); 122 } 123 124 static void 125 viawd_identify(driver_t *driver, device_t parent) 126 { 127 128 if (viawd_find(parent) == NULL) 129 return; 130 131 if (device_find_child(parent, driver->name, -1) == NULL) 132 BUS_ADD_CHILD(parent, 0, driver->name, 0); 133 } 134 135 static int 136 viawd_probe(device_t dev) 137 { 138 struct viawd_device *id; 139 140 id = viawd_find(device_get_parent(dev)); 141 KASSERT(id != NULL, ("parent should be a valid VIA SB")); 142 device_set_desc(dev, id->desc); 143 return (BUS_PROBE_GENERIC); 144 } 145 146 static int 147 viawd_attach(device_t dev) 148 { 149 device_t sb_dev; 150 struct viawd_softc *sc; 151 uint32_t pmbase, reg; 152 153 sc = device_get_softc(dev); 154 sc->dev = dev; 155 156 sb_dev = device_get_parent(dev); 157 if (sb_dev == NULL) { 158 device_printf(dev, "Can not find watchdog device.\n"); 159 goto fail; 160 } 161 sc->sb_dev = sb_dev; 162 163 /* Get watchdog memory base. */ 164 pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4); 165 if (pmbase == 0) { 166 device_printf(dev, 167 "Watchdog disabled in BIOS or hardware\n"); 168 goto fail; 169 } 170 171 /* Allocate I/O register space. */ 172 sc->wd_rid = VIAWD_CONFIG_BASE; 173 sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid, 174 RF_ACTIVE | RF_SHAREABLE); 175 if (sc->wd_res == NULL) { 176 device_printf(dev, "Unable to map watchdog memory\n"); 177 goto fail; 178 } 179 if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) { 180 device_printf(dev, "Bad size for watchdog memory: %#x\n", 181 (unsigned)rman_get_size(sc->wd_res)); 182 goto fail; 183 } 184 185 /* Check if watchdog fired last boot. */ 186 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 187 if (reg & VIAWD_MEM_CTRL_FIRED) { 188 device_printf(dev, 189 "ERROR: watchdog rebooted the system\n"); 190 /* Reset bit state. */ 191 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 192 } 193 194 /* Register the watchdog event handler. */ 195 sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0); 196 197 return (0); 198 fail: 199 if (sc->wd_res != NULL) 200 bus_release_resource(sb_dev, SYS_RES_MEMORY, 201 sc->wd_rid, sc->wd_res); 202 return (ENXIO); 203 } 204 205 static int 206 viawd_detach(device_t dev) 207 { 208 struct viawd_softc *sc; 209 uint32_t reg; 210 211 sc = device_get_softc(dev); 212 213 /* Deregister event handler. */ 214 if (sc->ev_tag != NULL) 215 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag); 216 sc->ev_tag = NULL; 217 218 /* 219 * Do not stop the watchdog on shutdown if active but bump the 220 * timer to avoid spurious reset. 221 */ 222 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 223 if (reg & VIAWD_MEM_CTRL_ENABLE) { 224 viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN); 225 viawd_tmr_state(sc, 1); 226 device_printf(dev, 227 "Keeping watchdog alive during shutdown for %d seconds\n", 228 VIAWD_TIMEOUT_SHUTDOWN); 229 } 230 231 if (sc->wd_res != NULL) 232 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY, 233 sc->wd_rid, sc->wd_res); 234 235 return (0); 236 } 237 238 static device_method_t viawd_methods[] = { 239 DEVMETHOD(device_identify, viawd_identify), 240 DEVMETHOD(device_probe, viawd_probe), 241 DEVMETHOD(device_attach, viawd_attach), 242 DEVMETHOD(device_detach, viawd_detach), 243 DEVMETHOD(device_shutdown, viawd_detach), 244 {0,0} 245 }; 246 247 static driver_t viawd_driver = { 248 "viawd", 249 viawd_methods, 250 sizeof(struct viawd_softc), 251 }; 252 253 DRIVER_MODULE(viawd, isab, viawd_driver, NULL, NULL); 254