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 devclass_t viawd_devclass; 62 63 static void 64 viawd_tmr_state(struct viawd_softc *sc, int enable) 65 { 66 uint32_t reg; 67 68 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 69 if (enable) 70 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE; 71 else 72 reg &= ~VIAWD_MEM_CTRL_ENABLE; 73 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 74 } 75 76 static void 77 viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout) 78 { 79 80 /* Keep value in range. */ 81 if (timeout < VIAWD_MEM_COUNT_MIN) 82 timeout = VIAWD_MEM_COUNT_MIN; 83 else if (timeout > VIAWD_MEM_COUNT_MAX) 84 timeout = VIAWD_MEM_COUNT_MAX; 85 86 viawd_write_4(sc, VIAWD_MEM_COUNT, timeout); 87 sc->timeout = timeout; 88 } 89 90 /* 91 * Watchdog event handler - called by the framework to enable or disable 92 * the watchdog or change the initial timeout value. 93 */ 94 static void 95 viawd_event(void *arg, unsigned int cmd, int *error) 96 { 97 struct viawd_softc *sc = arg; 98 unsigned int timeout; 99 100 /* Convert from power-of-two-ns to second. */ 101 cmd &= WD_INTERVAL; 102 timeout = ((uint64_t)1 << cmd) / 1000000000; 103 if (cmd) { 104 if (timeout != sc->timeout) 105 viawd_tmr_set(sc, timeout); 106 viawd_tmr_state(sc, 1); 107 *error = 0; 108 } else 109 viawd_tmr_state(sc, 0); 110 } 111 112 /* Look for a supported VIA south bridge. */ 113 static struct viawd_device * 114 viawd_find(device_t dev) 115 { 116 struct viawd_device *id; 117 118 if (pci_get_vendor(dev) != VENDORID_VIA) 119 return (NULL); 120 for (id = viawd_devices; id->desc != NULL; id++) 121 if (pci_get_device(dev) == id->device) 122 return (id); 123 return (NULL); 124 } 125 126 static void 127 viawd_identify(driver_t *driver, device_t parent) 128 { 129 130 if (viawd_find(parent) == NULL) 131 return; 132 133 if (device_find_child(parent, driver->name, -1) == NULL) 134 BUS_ADD_CHILD(parent, 0, driver->name, 0); 135 } 136 137 static int 138 viawd_probe(device_t dev) 139 { 140 struct viawd_device *id; 141 142 id = viawd_find(device_get_parent(dev)); 143 KASSERT(id != NULL, ("parent should be a valid VIA SB")); 144 device_set_desc(dev, id->desc); 145 return (BUS_PROBE_GENERIC); 146 } 147 148 static int 149 viawd_attach(device_t dev) 150 { 151 device_t sb_dev; 152 struct viawd_softc *sc; 153 uint32_t pmbase, reg; 154 155 sc = device_get_softc(dev); 156 sc->dev = dev; 157 158 sb_dev = device_get_parent(dev); 159 if (sb_dev == NULL) { 160 device_printf(dev, "Can not find watchdog device.\n"); 161 goto fail; 162 } 163 sc->sb_dev = sb_dev; 164 165 /* Get watchdog memory base. */ 166 pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4); 167 if (pmbase == 0) { 168 device_printf(dev, 169 "Watchdog disabled in BIOS or hardware\n"); 170 goto fail; 171 } 172 173 /* Allocate I/O register space. */ 174 sc->wd_rid = VIAWD_CONFIG_BASE; 175 sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid, 176 RF_ACTIVE | RF_SHAREABLE); 177 if (sc->wd_res == NULL) { 178 device_printf(dev, "Unable to map watchdog memory\n"); 179 goto fail; 180 } 181 if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) { 182 device_printf(dev, "Bad size for watchdog memory: %#x\n", 183 (unsigned)rman_get_size(sc->wd_res)); 184 goto fail; 185 } 186 187 /* Check if watchdog fired last boot. */ 188 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 189 if (reg & VIAWD_MEM_CTRL_FIRED) { 190 device_printf(dev, 191 "ERROR: watchdog rebooted the system\n"); 192 /* Reset bit state. */ 193 viawd_write_4(sc, VIAWD_MEM_CTRL, reg); 194 } 195 196 /* Register the watchdog event handler. */ 197 sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0); 198 199 return (0); 200 fail: 201 if (sc->wd_res != NULL) 202 bus_release_resource(sb_dev, SYS_RES_MEMORY, 203 sc->wd_rid, sc->wd_res); 204 return (ENXIO); 205 } 206 207 static int 208 viawd_detach(device_t dev) 209 { 210 struct viawd_softc *sc; 211 uint32_t reg; 212 213 sc = device_get_softc(dev); 214 215 /* Deregister event handler. */ 216 if (sc->ev_tag != NULL) 217 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag); 218 sc->ev_tag = NULL; 219 220 /* 221 * Do not stop the watchdog on shutdown if active but bump the 222 * timer to avoid spurious reset. 223 */ 224 reg = viawd_read_4(sc, VIAWD_MEM_CTRL); 225 if (reg & VIAWD_MEM_CTRL_ENABLE) { 226 viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN); 227 viawd_tmr_state(sc, 1); 228 device_printf(dev, 229 "Keeping watchdog alive during shutdown for %d seconds\n", 230 VIAWD_TIMEOUT_SHUTDOWN); 231 } 232 233 if (sc->wd_res != NULL) 234 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY, 235 sc->wd_rid, sc->wd_res); 236 237 return (0); 238 } 239 240 static device_method_t viawd_methods[] = { 241 DEVMETHOD(device_identify, viawd_identify), 242 DEVMETHOD(device_probe, viawd_probe), 243 DEVMETHOD(device_attach, viawd_attach), 244 DEVMETHOD(device_detach, viawd_detach), 245 DEVMETHOD(device_shutdown, viawd_detach), 246 {0,0} 247 }; 248 249 static driver_t viawd_driver = { 250 "viawd", 251 viawd_methods, 252 sizeof(struct viawd_softc), 253 }; 254 255 DRIVER_MODULE(viawd, isab, viawd_driver, viawd_devclass, NULL, NULL); 256