xref: /freebsd/sys/dev/ichwd/ichwd.c (revision 955c8cbb4960e6cf3602de144b1b9154a5092968)
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 <isa/isavar.h>
72 #include <dev/pci/pcivar.h>
73 
74 #include <dev/ichwd/ichwd.h>
75 
76 static struct ichwd_device ichwd_devices[] = {
77 	{ DEVICEID_82801AA,  "Intel 82801AA watchdog timer",	1 },
78 	{ DEVICEID_82801AB,  "Intel 82801AB watchdog timer",	1 },
79 	{ DEVICEID_82801BA,  "Intel 82801BA watchdog timer",	2 },
80 	{ DEVICEID_82801BAM, "Intel 82801BAM watchdog timer",	2 },
81 	{ DEVICEID_82801CA,  "Intel 82801CA watchdog timer",	3 },
82 	{ DEVICEID_82801CAM, "Intel 82801CAM watchdog timer",	3 },
83 	{ DEVICEID_82801DB,  "Intel 82801DB watchdog timer",	4 },
84 	{ DEVICEID_82801DBM, "Intel 82801DBM watchdog timer",	4 },
85 	{ DEVICEID_82801E,   "Intel 82801E watchdog timer",	5 },
86 	{ DEVICEID_82801EB,  "Intel 82801EB watchdog timer",	5 },
87 	{ DEVICEID_82801EBR, "Intel 82801EB/ER watchdog timer",	5 },
88 	{ DEVICEID_6300ESB,  "Intel 6300ESB watchdog timer",	5 },
89 	{ DEVICEID_82801FBR, "Intel 82801FB/FR watchdog timer",	6 },
90 	{ DEVICEID_ICH6M,    "Intel ICH6M watchdog timer",	6 },
91 	{ DEVICEID_ICH6W,    "Intel ICH6W watchdog timer",	6 },
92 	{ DEVICEID_ICH7,     "Intel ICH7 watchdog timer",	7 },
93 	{ DEVICEID_ICH7DH,   "Intel ICH7DH watchdog timer",	7 },
94 	{ DEVICEID_ICH7M,    "Intel ICH7M watchdog timer",	7 },
95 	{ DEVICEID_ICH7MDH,  "Intel ICH7MDH watchdog timer",	7 },
96 	{ DEVICEID_NM10,     "Intel NM10 watchdog timer",	7 },
97 	{ DEVICEID_ICH8,     "Intel ICH8 watchdog timer",	8 },
98 	{ DEVICEID_ICH8DH,   "Intel ICH8DH watchdog timer",	8 },
99 	{ DEVICEID_ICH8DO,   "Intel ICH8DO watchdog timer",	8 },
100 	{ DEVICEID_ICH8M,    "Intel ICH8M watchdog timer",	8 },
101 	{ DEVICEID_ICH8ME,   "Intel ICH8M-E watchdog timer",	8 },
102 	{ DEVICEID_63XXESB,  "Intel 63XXESB watchdog timer",	8 },
103 	{ DEVICEID_ICH9,     "Intel ICH9 watchdog timer",	9 },
104 	{ DEVICEID_ICH9DH,   "Intel ICH9DH watchdog timer",	9 },
105 	{ DEVICEID_ICH9DO,   "Intel ICH9DO watchdog timer",	9 },
106 	{ DEVICEID_ICH9M,    "Intel ICH9M watchdog timer",	9 },
107 	{ DEVICEID_ICH9ME,   "Intel ICH9M-E watchdog timer",	9 },
108 	{ DEVICEID_ICH9R,    "Intel ICH9R watchdog timer",	9 },
109 	{ DEVICEID_ICH10,    "Intel ICH10 watchdog timer",	10 },
110 	{ DEVICEID_ICH10D,   "Intel ICH10D watchdog timer",	10 },
111 	{ DEVICEID_ICH10DO,  "Intel ICH10DO watchdog timer",	10 },
112 	{ DEVICEID_ICH10R,   "Intel ICH10R watchdog timer",	10 },
113 	{ DEVICEID_PCH,      "Intel PCH watchdog timer",	10 },
114 	{ DEVICEID_PCHM,     "Intel PCH watchdog timer",	10 },
115 	{ DEVICEID_P55,      "Intel P55 watchdog timer",	10 },
116 	{ DEVICEID_PM55,     "Intel PM55 watchdog timer",	10 },
117 	{ DEVICEID_H55,      "Intel H55 watchdog timer",	10 },
118 	{ DEVICEID_QM57,     "Intel QM57 watchdog timer",       10 },
119 	{ DEVICEID_H57,      "Intel H57 watchdog timer",        10 },
120 	{ DEVICEID_HM55,     "Intel HM55 watchdog timer",       10 },
121 	{ DEVICEID_Q57,      "Intel Q57 watchdog timer",        10 },
122 	{ DEVICEID_HM57,     "Intel HM57 watchdog timer",       10 },
123 	{ DEVICEID_PCHMSFF,  "Intel PCHMSFF watchdog timer",    10 },
124 	{ DEVICEID_QS57,     "Intel QS57 watchdog timer",       10 },
125 	{ DEVICEID_3400,     "Intel 3400 watchdog timer",       10 },
126 	{ DEVICEID_3420,     "Intel 3420 watchdog timer",       10 },
127 	{ DEVICEID_3450,     "Intel 3450 watchdog timer",       10 },
128 	{ DEVICEID_CPT0,     "Intel Cougar Point watchdog timer",	10 },
129 	{ DEVICEID_CPT1,     "Intel Cougar Point watchdog timer",	10 },
130 	{ DEVICEID_CPT2,     "Intel Cougar Point watchdog timer",	10 },
131 	{ DEVICEID_CPT3,     "Intel Cougar Point watchdog timer",	10 },
132 	{ DEVICEID_CPT4,     "Intel Cougar Point watchdog timer",	10 },
133 	{ DEVICEID_CPT5,     "Intel Cougar Point watchdog timer",	10 },
134 	{ DEVICEID_CPT6,     "Intel Cougar Point watchdog timer",	10 },
135 	{ DEVICEID_CPT7,     "Intel Cougar Point watchdog timer",	10 },
136 	{ DEVICEID_CPT8,     "Intel Cougar Point watchdog timer",	10 },
137 	{ DEVICEID_CPT9,     "Intel Cougar Point watchdog timer",	10 },
138 	{ DEVICEID_CPT10,    "Intel Cougar Point watchdog timer",	10 },
139 	{ DEVICEID_CPT11,    "Intel Cougar Point watchdog timer",	10 },
140 	{ DEVICEID_CPT12,    "Intel Cougar Point watchdog timer",	10 },
141 	{ DEVICEID_CPT13,    "Intel Cougar Point watchdog timer",	10 },
142 	{ DEVICEID_CPT14,    "Intel Cougar Point watchdog timer",	10 },
143 	{ DEVICEID_CPT15,    "Intel Cougar Point watchdog timer",	10 },
144 	{ DEVICEID_CPT16,    "Intel Cougar Point watchdog timer",	10 },
145 	{ DEVICEID_CPT17,    "Intel Cougar Point watchdog timer",	10 },
146 	{ DEVICEID_CPT18,    "Intel Cougar Point watchdog timer",	10 },
147 	{ DEVICEID_CPT19,    "Intel Cougar Point watchdog timer",	10 },
148 	{ DEVICEID_CPT20,    "Intel Cougar Point watchdog timer",	10 },
149 	{ DEVICEID_CPT21,    "Intel Cougar Point watchdog timer",	10 },
150 	{ DEVICEID_CPT22,    "Intel Cougar Point watchdog timer",	10 },
151 	{ DEVICEID_CPT23,    "Intel Cougar Point watchdog timer",	10 },
152 	{ DEVICEID_CPT23,    "Intel Cougar Point watchdog timer",	10 },
153 	{ DEVICEID_CPT25,    "Intel Cougar Point watchdog timer",	10 },
154 	{ DEVICEID_CPT26,    "Intel Cougar Point watchdog timer",	10 },
155 	{ DEVICEID_CPT27,    "Intel Cougar Point watchdog timer",	10 },
156 	{ DEVICEID_CPT28,    "Intel Cougar Point watchdog timer",	10 },
157 	{ DEVICEID_CPT29,    "Intel Cougar Point watchdog timer",	10 },
158 	{ DEVICEID_CPT30,    "Intel Cougar Point watchdog timer",	10 },
159 	{ DEVICEID_CPT31,    "Intel Cougar Point watchdog timer",	10 },
160 	{ DEVICEID_PATSBURG_LPC1, "Intel Patsburg watchdog timer",	10 },
161 	{ DEVICEID_PATSBURG_LPC2, "Intel Patsburg watchdog timer",	10 },
162 	{ DEVICEID_PPT0,     "Intel Panther Point watchdog timer",	10 },
163 	{ DEVICEID_PPT1,     "Intel Panther Point watchdog timer",	10 },
164 	{ DEVICEID_PPT2,     "Intel Panther Point watchdog timer",	10 },
165 	{ DEVICEID_PPT3,     "Intel Panther Point watchdog timer",	10 },
166 	{ DEVICEID_PPT4,     "Intel Panther Point watchdog timer",	10 },
167 	{ DEVICEID_PPT5,     "Intel Panther Point watchdog timer",	10 },
168 	{ DEVICEID_PPT6,     "Intel Panther Point watchdog timer",	10 },
169 	{ DEVICEID_PPT7,     "Intel Panther Point watchdog timer",	10 },
170 	{ DEVICEID_PPT8,     "Intel Panther Point watchdog timer",	10 },
171 	{ DEVICEID_PPT9,     "Intel Panther Point watchdog timer",	10 },
172 	{ DEVICEID_PPT10,    "Intel Panther Point watchdog timer",	10 },
173 	{ DEVICEID_PPT11,    "Intel Panther Point watchdog timer",	10 },
174 	{ DEVICEID_PPT12,    "Intel Panther Point watchdog timer",	10 },
175 	{ DEVICEID_PPT13,    "Intel Panther Point watchdog timer",	10 },
176 	{ DEVICEID_PPT14,    "Intel Panther Point watchdog timer",	10 },
177 	{ DEVICEID_PPT15,    "Intel Panther Point watchdog timer",	10 },
178 	{ DEVICEID_PPT16,    "Intel Panther Point watchdog timer",	10 },
179 	{ DEVICEID_PPT17,    "Intel Panther Point watchdog timer",	10 },
180 	{ DEVICEID_PPT18,    "Intel Panther Point watchdog timer",	10 },
181 	{ DEVICEID_PPT19,    "Intel Panther Point watchdog timer",	10 },
182 	{ DEVICEID_PPT20,    "Intel Panther Point watchdog timer",	10 },
183 	{ DEVICEID_PPT21,    "Intel Panther Point watchdog timer",	10 },
184 	{ DEVICEID_PPT22,    "Intel Panther Point watchdog timer",	10 },
185 	{ DEVICEID_PPT23,    "Intel Panther Point watchdog timer",	10 },
186 	{ DEVICEID_PPT24,    "Intel Panther Point watchdog timer",	10 },
187 	{ DEVICEID_PPT25,    "Intel Panther Point watchdog timer",	10 },
188 	{ DEVICEID_PPT26,    "Intel Panther Point watchdog timer",	10 },
189 	{ DEVICEID_PPT27,    "Intel Panther Point watchdog timer",	10 },
190 	{ DEVICEID_PPT28,    "Intel Panther Point watchdog timer",	10 },
191 	{ DEVICEID_PPT29,    "Intel Panther Point watchdog timer",	10 },
192 	{ DEVICEID_PPT30,    "Intel Panther Point watchdog timer",	10 },
193 	{ DEVICEID_PPT31,    "Intel Panther Point watchdog timer",	10 },
194 	{ DEVICEID_LPT0,     "Intel Lynx Point watchdog timer",		10 },
195 	{ DEVICEID_LPT1,     "Intel Lynx Point watchdog timer",		10 },
196 	{ DEVICEID_LPT2,     "Intel Lynx Point watchdog timer",		10 },
197 	{ DEVICEID_DH89XXCC_LPC,  "Intel DH89xxCC watchdog timer",	10 },
198 	{ 0, NULL, 0 },
199 };
200 
201 static devclass_t ichwd_devclass;
202 
203 #define ichwd_read_tco_1(sc, off) \
204 	bus_read_1((sc)->tco_res, (off))
205 #define ichwd_read_tco_2(sc, off) \
206 	bus_read_2((sc)->tco_res, (off))
207 #define ichwd_read_tco_4(sc, off) \
208 	bus_read_4((sc)->tco_res, (off))
209 #define ichwd_read_smi_4(sc, off) \
210 	bus_read_4((sc)->smi_res, (off))
211 #define ichwd_read_gcs_4(sc, off) \
212 	bus_read_4((sc)->gcs_res, (off))
213 
214 #define ichwd_write_tco_1(sc, off, val) \
215 	bus_write_1((sc)->tco_res, (off), (val))
216 #define ichwd_write_tco_2(sc, off, val) \
217 	bus_write_2((sc)->tco_res, (off), (val))
218 #define ichwd_write_tco_4(sc, off, val) \
219 	bus_write_4((sc)->tco_res, (off), (val))
220 #define ichwd_write_smi_4(sc, off, val) \
221 	bus_write_4((sc)->smi_res, (off), (val))
222 #define ichwd_write_gcs_4(sc, off, val) \
223 	bus_write_4((sc)->gcs_res, (off), (val))
224 
225 #define ichwd_verbose_printf(dev, ...) \
226 	do {						\
227 		if (bootverbose)			\
228 			device_printf(dev, __VA_ARGS__);\
229 	} while (0)
230 
231 /*
232  * Disable the watchdog timeout SMI handler.
233  *
234  * Apparently, some BIOSes install handlers that reset or disable the
235  * watchdog timer instead of resetting the system, so we disable the SMI
236  * (by clearing the SMI_TCO_EN bit of the SMI_EN register) to prevent this
237  * from happening.
238  */
239 static __inline void
240 ichwd_smi_disable(struct ichwd_softc *sc)
241 {
242 	ichwd_write_smi_4(sc, SMI_EN, ichwd_read_smi_4(sc, SMI_EN) & ~SMI_TCO_EN);
243 }
244 
245 /*
246  * Enable the watchdog timeout SMI handler.  See above for details.
247  */
248 static __inline void
249 ichwd_smi_enable(struct ichwd_softc *sc)
250 {
251 	ichwd_write_smi_4(sc, SMI_EN, ichwd_read_smi_4(sc, SMI_EN) | SMI_TCO_EN);
252 }
253 
254 /*
255  * Check if the watchdog SMI triggering is enabled.
256  */
257 static __inline int
258 ichwd_smi_is_enabled(struct ichwd_softc *sc)
259 {
260 	return ((ichwd_read_smi_4(sc, SMI_EN) & SMI_TCO_EN) != 0);
261 }
262 
263 /*
264  * Reset the watchdog status bits.
265  */
266 static __inline void
267 ichwd_sts_reset(struct ichwd_softc *sc)
268 {
269 	/*
270 	 * The watchdog status bits are set to 1 by the hardware to
271 	 * indicate various conditions.  They can be cleared by software
272 	 * by writing a 1, not a 0.
273 	 */
274 	ichwd_write_tco_2(sc, TCO1_STS, TCO_TIMEOUT);
275 	/*
276 	 * According to Intel's docs, clearing SECOND_TO_STS and BOOT_STS must
277 	 * be done in two separate operations.
278 	 */
279 	ichwd_write_tco_2(sc, TCO2_STS, TCO_SECOND_TO_STS);
280 	ichwd_write_tco_2(sc, TCO2_STS, TCO_BOOT_STS);
281 }
282 
283 /*
284  * Enable the watchdog timer by clearing the TCO_TMR_HALT bit in the
285  * TCO1_CNT register.  This is complicated by the need to preserve bit 9
286  * of that same register, and the requirement that all other bits must be
287  * written back as zero.
288  */
289 static __inline void
290 ichwd_tmr_enable(struct ichwd_softc *sc)
291 {
292 	uint16_t cnt;
293 
294 	cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
295 	ichwd_write_tco_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
296 	sc->active = 1;
297 	ichwd_verbose_printf(sc->device, "timer enabled\n");
298 }
299 
300 /*
301  * Disable the watchdog timer.  See above for details.
302  */
303 static __inline void
304 ichwd_tmr_disable(struct ichwd_softc *sc)
305 {
306 	uint16_t cnt;
307 
308 	cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
309 	ichwd_write_tco_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);
310 	sc->active = 0;
311 	ichwd_verbose_printf(sc->device, "timer disabled\n");
312 }
313 
314 /*
315  * Reload the watchdog timer: writing anything to any of the lower five
316  * bits of the TCO_RLD register reloads the timer from the last value
317  * written to TCO_TMR.
318  */
319 static __inline void
320 ichwd_tmr_reload(struct ichwd_softc *sc)
321 {
322 	if (sc->ich_version <= 5)
323 		ichwd_write_tco_1(sc, TCO_RLD, 1);
324 	else
325 		ichwd_write_tco_2(sc, TCO_RLD, 1);
326 
327 	ichwd_verbose_printf(sc->device, "timer reloaded\n");
328 }
329 
330 /*
331  * Set the initial timeout value.  Note that this must always be followed
332  * by a reload.
333  */
334 static __inline void
335 ichwd_tmr_set(struct ichwd_softc *sc, unsigned int timeout)
336 {
337 
338 	if (timeout < TCO_RLD_TMR_MIN)
339 		timeout = TCO_RLD_TMR_MIN;
340 
341 	if (sc->ich_version <= 5) {
342 		uint8_t tmr_val8 = ichwd_read_tco_1(sc, TCO_TMR1);
343 
344 		tmr_val8 &= (~TCO_RLD1_TMR_MAX & 0xff);
345 		if (timeout > TCO_RLD1_TMR_MAX)
346 			timeout = TCO_RLD1_TMR_MAX;
347 		tmr_val8 |= timeout;
348 		ichwd_write_tco_1(sc, TCO_TMR1, tmr_val8);
349 	} else {
350 		uint16_t tmr_val16 = ichwd_read_tco_2(sc, TCO_TMR2);
351 
352 		tmr_val16 &= (~TCO_RLD2_TMR_MAX & 0xffff);
353 		if (timeout > TCO_RLD2_TMR_MAX)
354 			timeout = TCO_RLD2_TMR_MAX;
355 		tmr_val16 |= timeout;
356 		ichwd_write_tco_2(sc, TCO_TMR2, tmr_val16);
357 	}
358 
359 	sc->timeout = timeout;
360 
361 	ichwd_verbose_printf(sc->device, "timeout set to %u ticks\n", timeout);
362 }
363 
364 static __inline int
365 ichwd_clear_noreboot(struct ichwd_softc *sc)
366 {
367 	uint32_t status;
368 	int rc = 0;
369 
370 	/* try to clear the NO_REBOOT bit */
371 	if (sc->ich_version <= 5) {
372 		status = pci_read_config(sc->ich, ICH_GEN_STA, 1);
373 		status &= ~ICH_GEN_STA_NO_REBOOT;
374 		pci_write_config(sc->ich, ICH_GEN_STA, status, 1);
375 		status = pci_read_config(sc->ich, ICH_GEN_STA, 1);
376 		if (status & ICH_GEN_STA_NO_REBOOT)
377 			rc = EIO;
378 	} else {
379 		status = ichwd_read_gcs_4(sc, 0);
380 		status &= ~ICH_GCS_NO_REBOOT;
381 		ichwd_write_gcs_4(sc, 0, status);
382 		status = ichwd_read_gcs_4(sc, 0);
383 		if (status & ICH_GCS_NO_REBOOT)
384 			rc = EIO;
385 	}
386 
387 	if (rc)
388 		device_printf(sc->device,
389 		    "ICH WDT present but disabled in BIOS or hardware\n");
390 
391 	return (rc);
392 }
393 
394 /*
395  * Watchdog event handler - called by the framework to enable or disable
396  * the watchdog or change the initial timeout value.
397  */
398 static void
399 ichwd_event(void *arg, unsigned int cmd, int *error)
400 {
401 	struct ichwd_softc *sc = arg;
402 	unsigned int timeout;
403 
404 	/* convert from power-of-two-ns to WDT ticks */
405 	cmd &= WD_INTERVAL;
406 	timeout = ((uint64_t)1 << cmd) / ICHWD_TICK;
407 	if (cmd) {
408 		if (!sc->active)
409 			ichwd_tmr_enable(sc);
410 		if (timeout != sc->timeout)
411 			ichwd_tmr_set(sc, timeout);
412 		ichwd_tmr_reload(sc);
413 		*error = 0;
414 	} else {
415 		if (sc->active)
416 			ichwd_tmr_disable(sc);
417 	}
418 }
419 
420 static device_t
421 ichwd_find_ich_lpc_bridge(struct ichwd_device **id_p)
422 {
423 	struct ichwd_device *id;
424 	device_t ich = NULL;
425 
426 	/* look for an ICH LPC interface bridge */
427 	for (id = ichwd_devices; id->desc != NULL; ++id)
428 		if ((ich = pci_find_device(VENDORID_INTEL, id->device)) != NULL)
429 			break;
430 
431 	if (ich == NULL)
432 		return (NULL);
433 
434 	ichwd_verbose_printf(ich, "found ICH%d or equivalent chipset: %s\n",
435 	    id->version, id->desc);
436 
437 	if (id_p)
438 		*id_p = id;
439 
440 	return (ich);
441 }
442 
443 /*
444  * Look for an ICH LPC interface bridge.  If one is found, register an
445  * ichwd device.  There can be only one.
446  */
447 static void
448 ichwd_identify(driver_t *driver, device_t parent)
449 {
450 	struct ichwd_device *id_p;
451 	device_t ich = NULL;
452 	device_t dev;
453 	uint32_t rcba;
454 	int rc;
455 
456 	ich = ichwd_find_ich_lpc_bridge(&id_p);
457 	if (ich == NULL)
458 		return;
459 
460 	/* good, add child to bus */
461 	if ((dev = device_find_child(parent, driver->name, 0)) == NULL)
462 		dev = BUS_ADD_CHILD(parent, 0, driver->name, 0);
463 
464 	if (dev == NULL)
465 		return;
466 
467 	device_set_desc_copy(dev, id_p->desc);
468 
469 	if (id_p->version >= 6) {
470 		/* get RCBA (root complex base address) */
471 		rcba = pci_read_config(ich, ICH_RCBA, 4);
472 		rc = bus_set_resource(ich, SYS_RES_MEMORY, 0,
473 		    (rcba & 0xffffc000) + ICH_GCS_OFFSET, ICH_GCS_SIZE);
474 		if (rc)
475 			ichwd_verbose_printf(dev,
476 			    "Can not set memory resource for RCBA\n");
477 	}
478 }
479 
480 static int
481 ichwd_probe(device_t dev)
482 {
483 
484 	/* Do not claim some ISA PnP device by accident. */
485 	if (isa_get_logicalid(dev) != 0)
486 		return (ENXIO);
487 	return (0);
488 }
489 
490 static int
491 ichwd_attach(device_t dev)
492 {
493 	struct ichwd_softc *sc;
494 	struct ichwd_device *id_p;
495 	device_t ich;
496 	unsigned int pmbase = 0;
497 
498 	sc = device_get_softc(dev);
499 	sc->device = dev;
500 
501 	ich = ichwd_find_ich_lpc_bridge(&id_p);
502 	if (ich == NULL) {
503 		device_printf(sc->device, "Can not find ICH device.\n");
504 		goto fail;
505 	}
506 	sc->ich = ich;
507 	sc->ich_version = id_p->version;
508 
509 	/* get ACPI base address */
510 	pmbase = pci_read_config(ich, ICH_PMBASE, 2) & ICH_PMBASE_MASK;
511 	if (pmbase == 0) {
512 		device_printf(dev, "ICH PMBASE register is empty\n");
513 		goto fail;
514 	}
515 
516 	/* allocate I/O register space */
517 	sc->smi_rid = 0;
518 	sc->smi_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->smi_rid,
519 	    pmbase + SMI_BASE, pmbase + SMI_BASE + SMI_LEN - 1, SMI_LEN,
520 	    RF_ACTIVE | RF_SHAREABLE);
521 	if (sc->smi_res == NULL) {
522 		device_printf(dev, "unable to reserve SMI registers\n");
523 		goto fail;
524 	}
525 
526 	sc->tco_rid = 1;
527 	sc->tco_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->tco_rid,
528 	    pmbase + TCO_BASE, pmbase + TCO_BASE + TCO_LEN - 1, TCO_LEN,
529 	    RF_ACTIVE | RF_SHAREABLE);
530 	if (sc->tco_res == NULL) {
531 		device_printf(dev, "unable to reserve TCO registers\n");
532 		goto fail;
533 	}
534 
535 	sc->gcs_rid = 0;
536 	if (sc->ich_version >= 6) {
537 		sc->gcs_res = bus_alloc_resource_any(ich, SYS_RES_MEMORY,
538 		    &sc->gcs_rid, RF_ACTIVE|RF_SHAREABLE);
539 		if (sc->gcs_res == NULL) {
540 			device_printf(dev, "unable to reserve GCS registers\n");
541 			goto fail;
542 		}
543 	}
544 
545 	if (ichwd_clear_noreboot(sc) != 0)
546 		goto fail;
547 
548 	ichwd_verbose_printf(dev, "%s (ICH%d or equivalent)\n",
549 	    device_get_desc(dev), sc->ich_version);
550 
551 	/*
552 	 * Determine if we are coming up after a watchdog-induced reset.  Some
553 	 * BIOSes may clear this bit at bootup, preventing us from reporting
554 	 * this case on such systems.  We clear this bit in ichwd_sts_reset().
555 	 */
556 	if ((ichwd_read_tco_2(sc, TCO2_STS) & TCO_SECOND_TO_STS) != 0)
557 		device_printf(dev,
558 		    "resuming after hardware watchdog timeout\n");
559 
560 	/* reset the watchdog status registers */
561 	ichwd_sts_reset(sc);
562 
563 	/* make sure the WDT starts out inactive */
564 	ichwd_tmr_disable(sc);
565 
566 	/* register the watchdog event handler */
567 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, ichwd_event, sc, 0);
568 
569 	/* disable the SMI handler */
570 	sc->smi_enabled = ichwd_smi_is_enabled(sc);
571 	ichwd_smi_disable(sc);
572 
573 	return (0);
574  fail:
575 	sc = device_get_softc(dev);
576 	if (sc->tco_res != NULL)
577 		bus_release_resource(dev, SYS_RES_IOPORT,
578 		    sc->tco_rid, sc->tco_res);
579 	if (sc->smi_res != NULL)
580 		bus_release_resource(dev, SYS_RES_IOPORT,
581 		    sc->smi_rid, sc->smi_res);
582 	if (sc->gcs_res != NULL)
583 		bus_release_resource(ich, SYS_RES_MEMORY,
584 		    sc->gcs_rid, sc->gcs_res);
585 
586 	return (ENXIO);
587 }
588 
589 static int
590 ichwd_detach(device_t dev)
591 {
592 	struct ichwd_softc *sc;
593 	device_t ich = NULL;
594 
595 	sc = device_get_softc(dev);
596 
597 	/* halt the watchdog timer */
598 	if (sc->active)
599 		ichwd_tmr_disable(sc);
600 
601 	/* enable the SMI handler */
602 	if (sc->smi_enabled != 0)
603 		ichwd_smi_enable(sc);
604 
605 	/* deregister event handler */
606 	if (sc->ev_tag != NULL)
607 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
608 	sc->ev_tag = NULL;
609 
610 	/* reset the watchdog status registers */
611 	ichwd_sts_reset(sc);
612 
613 	/* deallocate I/O register space */
614 	bus_release_resource(dev, SYS_RES_IOPORT, sc->tco_rid, sc->tco_res);
615 	bus_release_resource(dev, SYS_RES_IOPORT, sc->smi_rid, sc->smi_res);
616 
617 	/* deallocate memory resource */
618 	ich = ichwd_find_ich_lpc_bridge(NULL);
619 	if (sc->gcs_res && ich)
620 		bus_release_resource(ich, SYS_RES_MEMORY, sc->gcs_rid, sc->gcs_res);
621 
622 	return (0);
623 }
624 
625 static device_method_t ichwd_methods[] = {
626 	DEVMETHOD(device_identify, ichwd_identify),
627 	DEVMETHOD(device_probe,	ichwd_probe),
628 	DEVMETHOD(device_attach, ichwd_attach),
629 	DEVMETHOD(device_detach, ichwd_detach),
630 	DEVMETHOD(device_shutdown, ichwd_detach),
631 	{0,0}
632 };
633 
634 static driver_t ichwd_driver = {
635 	"ichwd",
636 	ichwd_methods,
637 	sizeof(struct ichwd_softc),
638 };
639 
640 DRIVER_MODULE(ichwd, isa, ichwd_driver, ichwd_devclass, NULL, NULL);
641