xref: /freebsd/sys/dev/ichwd/ichwd.c (revision 5861f9665471e98e544f6fa3ce73c4912229ff82)
1 /*-
2  * Copyright (c) 2004 Texas A&M University
3  * All rights reserved.
4  *
5  * Developer: Wm. Daryl Hawkins
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 /*
30  * Intel ICH Watchdog Timer (WDT) driver
31  *
32  * Originally developed by Wm. Daryl Hawkins of Texas A&M
33  * Heavily modified by <des@FreeBSD.org>
34  *
35  * This is a tricky one.  The ICH WDT can't be treated as a regular PCI
36  * device as it's actually an integrated function of the ICH LPC interface
37  * bridge.  Detection is also awkward, because we can only infer the
38  * presence of the watchdog timer from the fact that the machine has an
39  * ICH chipset, or, on ACPI 2.x systems, by the presence of the 'WDDT'
40  * ACPI table (although this driver does not support the ACPI detection
41  * method).
42  *
43  * There is one slight problem on non-ACPI or ACPI 1.x systems: we have no
44  * way of knowing if the WDT is permanently disabled (either by the BIOS
45  * or in hardware).
46  *
47  * The WDT is programmed through I/O registers in the ACPI I/O space.
48  * Intel swears it's always at offset 0x60, so we use that.
49  *
50  * For details about the ICH WDT, see Intel Application Note AP-725
51  * (document no. 292273-001).  The WDT is also described in the individual
52  * chipset datasheets, e.g. Intel82801EB ICH5 / 82801ER ICH5R Datasheet
53  * (document no. 252516-001) sections 9.10 and 9.11.
54  *
55  * ICH6/7/8 support by Takeharu KATO <takeharu1219@ybb.ne.jp>
56  */
57 
58 #include <sys/cdefs.h>
59 __FBSDID("$FreeBSD$");
60 
61 #include <sys/param.h>
62 #include <sys/kernel.h>
63 #include <sys/module.h>
64 #include <sys/systm.h>
65 #include <sys/bus.h>
66 #include <machine/bus.h>
67 #include <sys/rman.h>
68 #include <machine/resource.h>
69 #include <sys/watchdog.h>
70 
71 #include <dev/pci/pcivar.h>
72 
73 #include <dev/ichwd/ichwd.h>
74 
75 static struct ichwd_device ichwd_devices[] = {
76 	{ DEVICEID_82801AA,  "Intel 82801AA watchdog timer",	1 },
77 	{ DEVICEID_82801AB,  "Intel 82801AB watchdog timer",	1 },
78 	{ DEVICEID_82801BA,  "Intel 82801BA watchdog timer",	2 },
79 	{ DEVICEID_82801BAM, "Intel 82801BAM watchdog timer",	2 },
80 	{ DEVICEID_82801CA,  "Intel 82801CA watchdog timer",	3 },
81 	{ DEVICEID_82801CAM, "Intel 82801CAM watchdog timer",	3 },
82 	{ DEVICEID_82801DB,  "Intel 82801DB watchdog timer",	4 },
83 	{ DEVICEID_82801DBM, "Intel 82801DBM watchdog timer",	4 },
84 	{ DEVICEID_82801E,   "Intel 82801E watchdog timer",	5 },
85 	{ DEVICEID_82801EB,  "Intel 82801EB watchdog timer",	5 },
86 	{ DEVICEID_82801EBR, "Intel 82801EB/ER watchdog timer",	5 },
87 	{ DEVICEID_6300ESB,  "Intel 6300ESB watchdog timer",	5 },
88 	{ DEVICEID_82801FBR, "Intel 82801FB/FR watchdog timer",	6 },
89 	{ DEVICEID_ICH6M,    "Intel ICH6M watchdog timer",	6 },
90 	{ DEVICEID_ICH6W,    "Intel ICH6W watchdog timer",	6 },
91 	{ DEVICEID_ICH7,     "Intel ICH7 watchdog timer",	7 },
92 	{ DEVICEID_ICH7DH,   "Intel ICH7DH watchdog timer",	7 },
93 	{ DEVICEID_ICH7M,    "Intel ICH7M watchdog timer",	7 },
94 	{ DEVICEID_ICH7MDH,  "Intel ICH7MDH watchdog timer",	7 },
95 	{ DEVICEID_ICH8,     "Intel ICH8 watchdog timer",	8 },
96 	{ DEVICEID_ICH8DH,   "Intel ICH8DH watchdog timer",	8 },
97 	{ DEVICEID_ICH8DO,   "Intel ICH8DO watchdog timer",	8 },
98 	{ DEVICEID_ICH8M,    "Intel ICH8M watchdog timer",	8 },
99 	{ DEVICEID_ICH8ME,   "Intel ICH8M-E watchdog timer",	8 },
100 	{ DEVICEID_63XXESB,  "Intel 63XXESB watchdog timer",	8 },
101 	{ DEVICEID_ICH9,     "Intel ICH9 watchdog timer",	9 },
102 	{ DEVICEID_ICH9DH,   "Intel ICH9DH watchdog timer",	9 },
103 	{ DEVICEID_ICH9DO,   "Intel ICH9DO watchdog timer",	9 },
104 	{ DEVICEID_ICH9M,    "Intel ICH9M watchdog timer",	9 },
105 	{ DEVICEID_ICH9ME,   "Intel ICH9M-E watchdog timer",	9 },
106 	{ DEVICEID_ICH9R,    "Intel ICH9R watchdog timer",	9 },
107 	{ DEVICEID_ICH10,    "Intel ICH10 watchdog timer",	10 },
108 	{ DEVICEID_ICH10D,   "Intel ICH10D watchdog timer",	10 },
109 	{ DEVICEID_ICH10DO,  "Intel ICH10DO watchdog timer",	10 },
110 	{ DEVICEID_ICH10R,   "Intel ICH10R watchdog timer",	10 },
111 	{ 0, NULL, 0 },
112 };
113 
114 static devclass_t ichwd_devclass;
115 
116 #define ichwd_read_tco_1(sc, off) \
117 	bus_space_read_1((sc)->tco_bst, (sc)->tco_bsh, (off))
118 #define ichwd_read_tco_2(sc, off) \
119 	bus_space_read_2((sc)->tco_bst, (sc)->tco_bsh, (off))
120 #define ichwd_read_tco_4(sc, off) \
121 	bus_space_read_4((sc)->tco_bst, (sc)->tco_bsh, (off))
122 #define ichwd_read_smi_4(sc, off) \
123 	bus_space_read_4((sc)->smi_bst, (sc)->smi_bsh, (off))
124 #define ichwd_read_gcs_4(sc, off) \
125 	bus_space_read_4((sc)->gcs_bst, (sc)->gcs_bsh, (off))
126 
127 #define ichwd_write_tco_1(sc, off, val) \
128 	bus_space_write_1((sc)->tco_bst, (sc)->tco_bsh, (off), (val))
129 #define ichwd_write_tco_2(sc, off, val) \
130 	bus_space_write_2((sc)->tco_bst, (sc)->tco_bsh, (off), (val))
131 #define ichwd_write_tco_4(sc, off, val) \
132 	bus_space_write_4((sc)->tco_bst, (sc)->tco_bsh, (off), (val))
133 #define ichwd_write_smi_4(sc, off, val) \
134 	bus_space_write_4((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
135 #define ichwd_write_gcs_4(sc, off, val) \
136 	bus_space_write_4((sc)->gcs_bst, (sc)->gcs_bsh, (off), (val))
137 
138 #define ichwd_verbose_printf(dev, ...) \
139 	do {						\
140 		if (bootverbose)			\
141 			device_printf(dev, __VA_ARGS__);\
142 	} while (0)
143 
144 /*
145  * Disable the watchdog timeout SMI handler.
146  *
147  * Apparently, some BIOSes install handlers that reset or disable the
148  * watchdog timer instead of resetting the system, so we disable the SMI
149  * (by clearing the SMI_TCO_EN bit of the SMI_EN register) to prevent this
150  * from happening.
151  */
152 static __inline void
153 ichwd_smi_disable(struct ichwd_softc *sc)
154 {
155 	ichwd_write_smi_4(sc, SMI_EN, ichwd_read_smi_4(sc, SMI_EN) & ~SMI_TCO_EN);
156 }
157 
158 /*
159  * Enable the watchdog timeout SMI handler.  See above for details.
160  */
161 static __inline void
162 ichwd_smi_enable(struct ichwd_softc *sc)
163 {
164 	ichwd_write_smi_4(sc, SMI_EN, ichwd_read_smi_4(sc, SMI_EN) | SMI_TCO_EN);
165 }
166 
167 /*
168  * Reset the watchdog status bits.
169  */
170 static __inline void
171 ichwd_sts_reset(struct ichwd_softc *sc)
172 {
173 	/*
174 	 * The watchdog status bits are set to 1 by the hardware to
175 	 * indicate various conditions.  They can be cleared by software
176 	 * by writing a 1, not a 0.
177 	 */
178 	ichwd_write_tco_2(sc, TCO1_STS, TCO_TIMEOUT);
179 	/*
180 	 * XXX The datasheet says that TCO_SECOND_TO_STS must be cleared
181 	 * before TCO_BOOT_STS, not the other way around.
182 	 */
183 	ichwd_write_tco_2(sc, TCO2_STS, TCO_BOOT_STS);
184 	ichwd_write_tco_2(sc, TCO2_STS, TCO_SECOND_TO_STS);
185 }
186 
187 /*
188  * Enable the watchdog timer by clearing the TCO_TMR_HALT bit in the
189  * TCO1_CNT register.  This is complicated by the need to preserve bit 9
190  * of that same register, and the requirement that all other bits must be
191  * written back as zero.
192  */
193 static __inline void
194 ichwd_tmr_enable(struct ichwd_softc *sc)
195 {
196 	uint16_t cnt;
197 
198 	cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
199 	ichwd_write_tco_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
200 	sc->active = 1;
201 	ichwd_verbose_printf(sc->device, "timer enabled\n");
202 }
203 
204 /*
205  * Disable the watchdog timer.  See above for details.
206  */
207 static __inline void
208 ichwd_tmr_disable(struct ichwd_softc *sc)
209 {
210 	uint16_t cnt;
211 
212 	cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
213 	ichwd_write_tco_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);
214 	sc->active = 0;
215 	ichwd_verbose_printf(sc->device, "timer disabled\n");
216 }
217 
218 /*
219  * Reload the watchdog timer: writing anything to any of the lower five
220  * bits of the TCO_RLD register reloads the timer from the last value
221  * written to TCO_TMR.
222  */
223 static __inline void
224 ichwd_tmr_reload(struct ichwd_softc *sc)
225 {
226 	if (sc->ich_version <= 5)
227 		ichwd_write_tco_1(sc, TCO_RLD, 1);
228 	else
229 		ichwd_write_tco_2(sc, TCO_RLD, 1);
230 
231 	ichwd_verbose_printf(sc->device, "timer reloaded\n");
232 }
233 
234 /*
235  * Set the initial timeout value.  Note that this must always be followed
236  * by a reload.
237  */
238 static __inline void
239 ichwd_tmr_set(struct ichwd_softc *sc, unsigned int timeout)
240 {
241 
242 	/*
243 	 * If the datasheets are to be believed, the minimum value
244 	 * actually varies from chipset to chipset - 4 for ICH5 and 2 for
245 	 * all other chipsets.  I suspect this is a bug in the ICH5
246 	 * datasheet and that the minimum is uniformly 2, but I'd rather
247 	 * err on the side of caution.
248 	 */
249 	if (timeout < 4)
250 		timeout = 4;
251 
252 	if (sc->ich_version <= 5) {
253 		uint8_t tmr_val8 = ichwd_read_tco_1(sc, TCO_TMR1);
254 
255 		tmr_val8 &= 0xc0;
256 		if (timeout > 0xbf)
257 			timeout = 0xbf;
258 		tmr_val8 |= timeout;
259 		ichwd_write_tco_1(sc, TCO_TMR1, tmr_val8);
260 	} else {
261 		uint16_t tmr_val16 = ichwd_read_tco_2(sc, TCO_TMR2);
262 
263 		tmr_val16 &= 0xfc00;
264 		if (timeout > 0x03ff)
265 			timeout = 0x03ff;
266 		tmr_val16 |= timeout;
267 		ichwd_write_tco_2(sc, TCO_TMR2, tmr_val16);
268 	}
269 
270 	sc->timeout = timeout;
271 
272 	ichwd_verbose_printf(sc->device, "timeout set to %u ticks\n", timeout);
273 }
274 
275 static __inline int
276 ichwd_clear_noreboot(struct ichwd_softc *sc)
277 {
278 	uint32_t status;
279 	int rc = 0;
280 
281 	/* try to clear the NO_REBOOT bit */
282 	if (sc->ich_version <= 5) {
283 		status = pci_read_config(sc->ich, ICH_GEN_STA, 1);
284 		status &= ~ICH_GEN_STA_NO_REBOOT;
285 		pci_write_config(sc->ich, ICH_GEN_STA, status, 1);
286 		status = pci_read_config(sc->ich, ICH_GEN_STA, 1);
287 		if (status & ICH_GEN_STA_NO_REBOOT)
288 			rc = EIO;
289 	} else {
290 		status = ichwd_read_gcs_4(sc, 0);
291 		status &= ~ICH_GCS_NO_REBOOT;
292 		ichwd_write_gcs_4(sc, 0, status);
293 		status = ichwd_read_gcs_4(sc, 0);
294 		if (status & ICH_GCS_NO_REBOOT)
295 			rc = EIO;
296 	}
297 
298 	if (rc)
299 		device_printf(sc->device,
300 		    "ICH WDT present but disabled in BIOS or hardware\n");
301 
302 	return (rc);
303 }
304 
305 /*
306  * Watchdog event handler - called by the framework to enable or disable
307  * the watchdog or change the initial timeout value.
308  */
309 static void
310 ichwd_event(void *arg, unsigned int cmd, int *error)
311 {
312 	struct ichwd_softc *sc = arg;
313 	unsigned int timeout;
314 
315 	/* convert from power-of-two-ns to WDT ticks */
316 	cmd &= WD_INTERVAL;
317 	timeout = ((uint64_t)1 << cmd) / ICHWD_TICK;
318 	if (cmd) {
319 		if (timeout != sc->timeout) {
320 			if (!sc->active)
321 				ichwd_tmr_enable(sc);
322 			ichwd_tmr_set(sc, timeout);
323 		}
324 		ichwd_tmr_reload(sc);
325 		*error = 0;
326 	} else {
327 		if (sc->active)
328 			ichwd_tmr_disable(sc);
329 	}
330 }
331 
332 static device_t
333 ichwd_find_ich_lpc_bridge(struct ichwd_device **id_p)
334 {
335 	struct ichwd_device *id;
336 	device_t ich = NULL;
337 
338 	/* look for an ICH LPC interface bridge */
339 	for (id = ichwd_devices; id->desc != NULL; ++id)
340 		if ((ich = pci_find_device(VENDORID_INTEL, id->device)) != NULL)
341 			break;
342 
343 	if (ich == NULL)
344 		return (NULL);
345 
346 	ichwd_verbose_printf(ich, "found ICH%d or equivalent chipset: %s\n",
347 	    id->version, id->desc);
348 
349 	if (id_p)
350 		*id_p = id;
351 
352 	return (ich);
353 }
354 
355 /*
356  * Look for an ICH LPC interface bridge.  If one is found, register an
357  * ichwd device.  There can be only one.
358  */
359 static void
360 ichwd_identify(driver_t *driver, device_t parent)
361 {
362 	struct ichwd_device *id_p;
363 	device_t ich = NULL;
364 	device_t dev;
365 	uint32_t rcba;
366 	int rc;
367 
368 	ich = ichwd_find_ich_lpc_bridge(&id_p);
369 	if (ich == NULL)
370 		return;
371 
372 	/* good, add child to bus */
373 	if ((dev = device_find_child(parent, driver->name, 0)) == NULL)
374 		dev = BUS_ADD_CHILD(parent, 0, driver->name, 0);
375 
376 	if (dev == NULL)
377 		return;
378 
379 	device_set_desc_copy(dev, id_p->desc);
380 
381 	if (id_p->version >= 6) {
382 		/* get RCBA (root complex base address) */
383 		rcba = pci_read_config(ich, ICH_RCBA, 4);
384 		rc = bus_set_resource(ich, SYS_RES_MEMORY, 0,
385 		    (rcba & 0xffffc000) + ICH_GCS_OFFSET, ICH_GCS_SIZE);
386 		if (rc)
387 			ichwd_verbose_printf(dev,
388 			    "Can not set memory resource for RCBA\n");
389 	}
390 }
391 
392 static int
393 ichwd_probe(device_t dev)
394 {
395 
396 	(void)dev;
397 	return (0);
398 }
399 
400 static int
401 ichwd_attach(device_t dev)
402 {
403 	struct ichwd_softc *sc;
404 	struct ichwd_device *id_p;
405 	device_t ich;
406 	unsigned int pmbase = 0;
407 
408 	sc = device_get_softc(dev);
409 	sc->device = dev;
410 
411 	ich = ichwd_find_ich_lpc_bridge(&id_p);
412 	if (ich == NULL) {
413 		device_printf(sc->device, "Can not find ICH device.\n");
414 		goto fail;
415 	}
416 	sc->ich = ich;
417 	sc->ich_version = id_p->version;
418 
419 	/* get ACPI base address */
420 	pmbase = pci_read_config(ich, ICH_PMBASE, 2) & ICH_PMBASE_MASK;
421 	if (pmbase == 0) {
422 		device_printf(dev, "ICH PMBASE register is empty\n");
423 		goto fail;
424 	}
425 
426 	/* allocate I/O register space */
427 	sc->smi_rid = 0;
428 	sc->smi_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->smi_rid,
429 	    pmbase + SMI_BASE, pmbase + SMI_BASE + SMI_LEN - 1, SMI_LEN,
430 	    RF_ACTIVE | RF_SHAREABLE);
431 	if (sc->smi_res == NULL) {
432 		device_printf(dev, "unable to reserve SMI registers\n");
433 		goto fail;
434 	}
435 	sc->smi_bst = rman_get_bustag(sc->smi_res);
436 	sc->smi_bsh = rman_get_bushandle(sc->smi_res);
437 
438 	sc->tco_rid = 1;
439 	sc->tco_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->tco_rid,
440 	    pmbase + TCO_BASE, pmbase + TCO_BASE + TCO_LEN - 1, TCO_LEN,
441 	    RF_ACTIVE | RF_SHAREABLE);
442 	if (sc->tco_res == NULL) {
443 		device_printf(dev, "unable to reserve TCO registers\n");
444 		goto fail;
445 	}
446 	sc->tco_bst = rman_get_bustag(sc->tco_res);
447 	sc->tco_bsh = rman_get_bushandle(sc->tco_res);
448 
449 	sc->gcs_rid = 0;
450 	if (sc->ich_version >= 6) {
451 		sc->gcs_res = bus_alloc_resource_any(ich, SYS_RES_MEMORY,
452 		    &sc->gcs_rid, RF_ACTIVE|RF_SHAREABLE);
453 		if (sc->gcs_res == NULL) {
454 			device_printf(dev, "unable to reserve GCS registers\n");
455 			goto fail;
456 		}
457 		sc->gcs_bst = rman_get_bustag(sc->gcs_res);
458 		sc->gcs_bsh = rman_get_bushandle(sc->gcs_res);
459 	} else {
460 		sc->gcs_res = 0;
461 		sc->gcs_bst = 0;
462 		sc->gcs_bsh = 0;
463 	}
464 
465 	if (ichwd_clear_noreboot(sc) != 0)
466 		goto fail;
467 
468 	device_printf(dev, "%s (ICH%d or equivalent)\n",
469 	    device_get_desc(dev), sc->ich_version);
470 
471 	/*
472 	 * XXX we should check the status registers (specifically, the
473 	 * TCO_SECOND_TO_STS bit in the TCO2_STS register) to see if we
474 	 * just came back from a watchdog-induced reset, and let the user
475 	 * know.
476 	 */
477 
478 	/* reset the watchdog status registers */
479 	ichwd_sts_reset(sc);
480 
481 	/* make sure the WDT starts out inactive */
482 	ichwd_tmr_disable(sc);
483 
484 	/* register the watchdog event handler */
485 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, ichwd_event, sc, 0);
486 
487 	/* disable the SMI handler */
488 	ichwd_smi_disable(sc);
489 
490 	return (0);
491  fail:
492 	sc = device_get_softc(dev);
493 	if (sc->tco_res != NULL)
494 		bus_release_resource(dev, SYS_RES_IOPORT,
495 		    sc->tco_rid, sc->tco_res);
496 	if (sc->smi_res != NULL)
497 		bus_release_resource(dev, SYS_RES_IOPORT,
498 		    sc->smi_rid, sc->smi_res);
499 	if (sc->gcs_res != NULL)
500 		bus_release_resource(ich, SYS_RES_MEMORY,
501 		    sc->gcs_rid, sc->gcs_res);
502 
503 	return (ENXIO);
504 }
505 
506 static int
507 ichwd_detach(device_t dev)
508 {
509 	struct ichwd_softc *sc;
510 	device_t ich = NULL;
511 
512 	sc = device_get_softc(dev);
513 
514 	/* halt the watchdog timer */
515 	if (sc->active)
516 		ichwd_tmr_disable(sc);
517 
518 	/* enable the SMI handler */
519 	ichwd_smi_enable(sc);
520 
521 	/* deregister event handler */
522 	if (sc->ev_tag != NULL)
523 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
524 	sc->ev_tag = NULL;
525 
526 	/* reset the watchdog status registers */
527 	ichwd_sts_reset(sc);
528 
529 	/* deallocate I/O register space */
530 	bus_release_resource(dev, SYS_RES_IOPORT, sc->tco_rid, sc->tco_res);
531 	bus_release_resource(dev, SYS_RES_IOPORT, sc->smi_rid, sc->smi_res);
532 
533 	/* deallocate memory resource */
534 	ich = ichwd_find_ich_lpc_bridge(NULL);
535 	if (sc->gcs_res && ich)
536 		bus_release_resource(ich, SYS_RES_MEMORY, sc->gcs_rid, sc->gcs_res);
537 
538 	return (0);
539 }
540 
541 static device_method_t ichwd_methods[] = {
542 	DEVMETHOD(device_identify, ichwd_identify),
543 	DEVMETHOD(device_probe,	ichwd_probe),
544 	DEVMETHOD(device_attach, ichwd_attach),
545 	DEVMETHOD(device_detach, ichwd_detach),
546 	DEVMETHOD(device_shutdown, ichwd_detach),
547 	{0,0}
548 };
549 
550 static driver_t ichwd_driver = {
551 	"ichwd",
552 	ichwd_methods,
553 	sizeof(struct ichwd_softc),
554 };
555 
556 static int
557 ichwd_modevent(module_t mode, int type, void *data)
558 {
559 	int error = 0;
560 
561 	switch (type) {
562 	case MOD_LOAD:
563 		printf("ichwd module loaded\n");
564 		break;
565 	case MOD_UNLOAD:
566 		printf("ichwd module unloaded\n");
567 		break;
568 	case MOD_SHUTDOWN:
569 		printf("ichwd module shutting down\n");
570 		break;
571 	}
572 	return (error);
573 }
574 
575 DRIVER_MODULE(ichwd, isa, ichwd_driver, ichwd_devclass, ichwd_modevent, NULL);
576