2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2011 Fabien Thomas <fabient@FreeBSD.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/systm.h>
37 #include <machine/bus.h>
39 #include <machine/resource.h>
40 #include <sys/watchdog.h>
42 #include <isa/isavar.h>
43 #include <dev/pci/pcivar.h>
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))
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" },
60 static devclass_t viawd_devclass;
63 viawd_tmr_state(struct viawd_softc *sc, int enable)
67 reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
69 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE;
71 reg &= ~VIAWD_MEM_CTRL_ENABLE;
72 viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
76 viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout)
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;
85 viawd_write_4(sc, VIAWD_MEM_COUNT, timeout);
86 sc->timeout = timeout;
90 * Watchdog event handler - called by the framework to enable or disable
91 * the watchdog or change the initial timeout value.
94 viawd_event(void *arg, unsigned int cmd, int *error)
96 struct viawd_softc *sc = arg;
99 /* Convert from power-of-two-ns to second. */
101 timeout = ((uint64_t)1 << cmd) / 1000000000;
103 if (timeout != sc->timeout)
104 viawd_tmr_set(sc, timeout);
105 viawd_tmr_state(sc, 1);
108 viawd_tmr_state(sc, 0);
111 /* Look for a supported VIA south bridge. */
112 static struct viawd_device *
113 viawd_find(device_t dev)
115 struct viawd_device *id;
117 if (pci_get_vendor(dev) != VENDORID_VIA)
119 for (id = viawd_devices; id->desc != NULL; id++)
120 if (pci_get_device(dev) == id->device)
126 viawd_identify(driver_t *driver, device_t parent)
129 if (viawd_find(parent) == NULL)
132 if (device_find_child(parent, driver->name, -1) == NULL)
133 BUS_ADD_CHILD(parent, 0, driver->name, 0);
137 viawd_probe(device_t dev)
139 struct viawd_device *id;
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);
148 viawd_attach(device_t dev)
151 struct viawd_softc *sc;
152 uint32_t pmbase, reg;
154 sc = device_get_softc(dev);
157 sb_dev = device_get_parent(dev);
158 if (sb_dev == NULL) {
159 device_printf(dev, "Can not find watchdog device.\n");
164 /* Get watchdog memory base. */
165 pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4);
168 "Watchdog disabled in BIOS or hardware\n");
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");
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));
186 /* Check if watchdog fired last boot. */
187 reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
188 if (reg & VIAWD_MEM_CTRL_FIRED) {
190 "ERROR: watchdog rebooted the system\n");
191 /* Reset bit state. */
192 viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
195 /* Register the watchdog event handler. */
196 sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0);
200 if (sc->wd_res != NULL)
201 bus_release_resource(sb_dev, SYS_RES_MEMORY,
202 sc->wd_rid, sc->wd_res);
207 viawd_detach(device_t dev)
209 struct viawd_softc *sc;
212 sc = device_get_softc(dev);
214 /* Deregister event handler. */
215 if (sc->ev_tag != NULL)
216 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
220 * Do not stop the watchdog on shutdown if active but bump the
221 * timer to avoid spurious reset.
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);
228 "Keeping watchog alive during shutdown for %d seconds\n",
229 VIAWD_TIMEOUT_SHUTDOWN);
232 if (sc->wd_res != NULL)
233 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY,
234 sc->wd_rid, sc->wd_res);
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),
248 static driver_t viawd_driver = {
251 sizeof(struct viawd_softc),
254 DRIVER_MODULE(viawd, isab, viawd_driver, viawd_devclass, NULL, NULL);