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