FreeBSD/Linux Kernel Cross Reference
sys/dev/viawd/viawd.c
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);
Cache object: 26e8ef71940df0c434c312cb2ed99552
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