1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
30 #include <sys/eventhandler.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
49 static 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
58 static void
viawd_tmr_state(struct viawd_softc * sc,int enable)59 viawd_tmr_state(struct viawd_softc *sc, int enable)
60 {
61 uint32_t reg;
62
63 reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
64 if (enable)
65 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE;
66 else
67 reg &= ~VIAWD_MEM_CTRL_ENABLE;
68 viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
69 }
70
71 static void
viawd_tmr_set(struct viawd_softc * sc,unsigned int timeout)72 viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout)
73 {
74
75 /* Keep value in range. */
76 if (timeout < VIAWD_MEM_COUNT_MIN)
77 timeout = VIAWD_MEM_COUNT_MIN;
78 else if (timeout > VIAWD_MEM_COUNT_MAX)
79 timeout = VIAWD_MEM_COUNT_MAX;
80
81 viawd_write_4(sc, VIAWD_MEM_COUNT, timeout);
82 sc->timeout = timeout;
83 }
84
85 /*
86 * Watchdog event handler - called by the framework to enable or disable
87 * the watchdog or change the initial timeout value.
88 */
89 static void
viawd_event(void * arg,unsigned int cmd,int * error)90 viawd_event(void *arg, unsigned int cmd, int *error)
91 {
92 struct viawd_softc *sc = arg;
93 unsigned int timeout;
94
95 /* Convert from power-of-two-ns to second. */
96 cmd &= WD_INTERVAL;
97 timeout = ((uint64_t)1 << cmd) / 1000000000;
98 if (cmd) {
99 if (timeout != sc->timeout)
100 viawd_tmr_set(sc, timeout);
101 viawd_tmr_state(sc, 1);
102 *error = 0;
103 } else
104 viawd_tmr_state(sc, 0);
105 }
106
107 /* Look for a supported VIA south bridge. */
108 static struct viawd_device *
viawd_find(device_t dev)109 viawd_find(device_t dev)
110 {
111 struct viawd_device *id;
112
113 if (pci_get_vendor(dev) != VENDORID_VIA)
114 return (NULL);
115 for (id = viawd_devices; id->desc != NULL; id++)
116 if (pci_get_device(dev) == id->device)
117 return (id);
118 return (NULL);
119 }
120
121 static void
viawd_identify(driver_t * driver,device_t parent)122 viawd_identify(driver_t *driver, device_t parent)
123 {
124
125 if (viawd_find(parent) == NULL)
126 return;
127
128 if (device_find_child(parent, driver->name, -1) == NULL)
129 BUS_ADD_CHILD(parent, 0, driver->name, 0);
130 }
131
132 static int
viawd_probe(device_t dev)133 viawd_probe(device_t dev)
134 {
135 struct viawd_device *id;
136
137 id = viawd_find(device_get_parent(dev));
138 KASSERT(id != NULL, ("parent should be a valid VIA SB"));
139 device_set_desc(dev, id->desc);
140 return (BUS_PROBE_GENERIC);
141 }
142
143 static int
viawd_attach(device_t dev)144 viawd_attach(device_t dev)
145 {
146 device_t sb_dev;
147 struct viawd_softc *sc;
148 uint32_t pmbase, reg;
149
150 sc = device_get_softc(dev);
151 sc->dev = dev;
152
153 sb_dev = device_get_parent(dev);
154 if (sb_dev == NULL) {
155 device_printf(dev, "Can not find watchdog device.\n");
156 goto fail;
157 }
158 sc->sb_dev = sb_dev;
159
160 /* Get watchdog memory base. */
161 pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4);
162 if (pmbase == 0) {
163 device_printf(dev,
164 "Watchdog disabled in BIOS or hardware\n");
165 goto fail;
166 }
167
168 /* Allocate I/O register space. */
169 sc->wd_rid = VIAWD_CONFIG_BASE;
170 sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid,
171 RF_ACTIVE | RF_SHAREABLE);
172 if (sc->wd_res == NULL) {
173 device_printf(dev, "Unable to map watchdog memory\n");
174 goto fail;
175 }
176 if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) {
177 device_printf(dev, "Bad size for watchdog memory: %#x\n",
178 (unsigned)rman_get_size(sc->wd_res));
179 goto fail;
180 }
181
182 /* Check if watchdog fired last boot. */
183 reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
184 if (reg & VIAWD_MEM_CTRL_FIRED) {
185 device_printf(dev,
186 "ERROR: watchdog rebooted the system\n");
187 /* Reset bit state. */
188 viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
189 }
190
191 /* Register the watchdog event handler. */
192 sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0);
193
194 return (0);
195 fail:
196 if (sc->wd_res != NULL)
197 bus_release_resource(sb_dev, SYS_RES_MEMORY,
198 sc->wd_rid, sc->wd_res);
199 return (ENXIO);
200 }
201
202 static int
viawd_detach(device_t dev)203 viawd_detach(device_t dev)
204 {
205 struct viawd_softc *sc;
206 uint32_t reg;
207
208 sc = device_get_softc(dev);
209
210 /* Deregister event handler. */
211 if (sc->ev_tag != NULL)
212 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
213 sc->ev_tag = NULL;
214
215 /*
216 * Do not stop the watchdog on shutdown if active but bump the
217 * timer to avoid spurious reset.
218 */
219 reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
220 if (reg & VIAWD_MEM_CTRL_ENABLE) {
221 viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN);
222 viawd_tmr_state(sc, 1);
223 device_printf(dev,
224 "Keeping watchdog alive during shutdown for %d seconds\n",
225 VIAWD_TIMEOUT_SHUTDOWN);
226 }
227
228 if (sc->wd_res != NULL)
229 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY,
230 sc->wd_rid, sc->wd_res);
231
232 return (0);
233 }
234
235 static device_method_t viawd_methods[] = {
236 DEVMETHOD(device_identify, viawd_identify),
237 DEVMETHOD(device_probe, viawd_probe),
238 DEVMETHOD(device_attach, viawd_attach),
239 DEVMETHOD(device_detach, viawd_detach),
240 DEVMETHOD(device_shutdown, viawd_detach),
241 {0,0}
242 };
243
244 static driver_t viawd_driver = {
245 "viawd",
246 viawd_methods,
247 sizeof(struct viawd_softc),
248 };
249
250 DRIVER_MODULE(viawd, isab, viawd_driver, NULL, NULL);
251