xref: /freebsd/sys/dev/wbwd/wbwd.c (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 Sandvine Incorporated ULC.
5  * Copyright (c) 2012 iXsystems, Inc.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 /*
30  * Support for Winbond watchdog.
31  *
32  * With minor abstractions it might be possible to add support for other
33  * different Winbond Super I/O chips as well.  Winbond seems to have four
34  * different types of chips, four different ways to get into extended config
35  * mode.
36  *
37  * Note: there is no serialization between the debugging sysctl handlers and
38  * the watchdog functions and possibly others poking the registers at the same
39  * time.  For that at least possibly interfering sysctls are hidden by default.
40  */
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/kernel.h>
47 #include <sys/systm.h>
48 #include <sys/bus.h>
49 #include <sys/eventhandler.h>
50 #include <sys/lock.h>
51 #include <sys/module.h>
52 #include <sys/rman.h>
53 #include <sys/sbuf.h>
54 #include <sys/sysctl.h>
55 #include <sys/watchdog.h>
56 
57 #include <isa/isavar.h>
58 
59 #include <machine/bus.h>
60 #include <machine/resource.h>
61 
62 /*
63  * Global registers.
64  */
65 #define	WB_DEVICE_ID_REG	0x20	/* Device ID */
66 #define	WB_DEVICE_REV_REG	0x21	/* Device revision */
67 #define	WB_CR26			0x26	/* Bit6: HEFRAS (base port selector) */
68 
69 /* LDN selection. */
70 #define	WB_LDN_REG		0x07
71 #define	WB_LDN_REG_LDN8		0x08	/* GPIO 2, Watchdog */
72 
73 /*
74  * LDN8 (GPIO 2, Watchdog) specific registers and options.
75  */
76 /* CR30: LDN8 activation control. */
77 #define	WB_LDN8_CR30		0x30
78 #define	WB_LDN8_CR30_ACTIVE	0x01	/* 1: LD active */
79 
80 /* CRF5: Watchdog scale, P20. Mapped to reg_1. */
81 #define	WB_LDN8_CRF5		0xF5
82 #define	WB_LDN8_CRF5_SCALE	0x08	/* 0: 1s, 1: 60s */
83 #define	WB_LDN8_CRF5_KEYB_P20	0x04	/* 1: keyb P20 forces timeout */
84 #define	WB_LDN8_CRF5_KBRST	0x02	/* 1: timeout causes pin60 kbd reset */
85 
86 /* CRF6: Watchdog Timeout (0 == off). Mapped to reg_timeout. */
87 #define	WB_LDN8_CRF6		0xF6
88 
89 /* CRF7: Watchdog mouse, keyb, force, .. Mapped to reg_2. */
90 #define	WB_LDN8_CRF7		0xF7
91 #define	WB_LDN8_CRF7_MOUSE	0x80	/* 1: mouse irq resets wd timer */
92 #define	WB_LDN8_CRF7_KEYB	0x40	/* 1: keyb irq resets wd timer */
93 #define	WB_LDN8_CRF7_FORCE	0x20	/* 1: force timeout (self-clear) */
94 #define	WB_LDN8_CRF7_TS		0x10	/* 0: counting, 1: fired */
95 #define	WB_LDN8_CRF7_IRQS	0x0f	/* irq source for watchdog, 2 == SMI */
96 
97 enum chips { w83627hf, w83627s, w83697hf, w83697ug, w83637hf, w83627thf,
98 	     w83687thf, w83627ehf, w83627dhg, w83627uhg, w83667hg,
99 	     w83627dhg_p, w83667hg_b, nct6775, nct6776, nct6779, nct6791,
100 	     nct6792, nct6793, nct6795, nct6102 };
101 
102 struct wb_softc {
103 	device_t		dev;
104 	struct resource		*portres;
105 	bus_space_tag_t		bst;
106 	bus_space_handle_t	bsh;
107 	int			rid;
108 	eventhandler_tag	ev_tag;
109 	int			(*ext_cfg_enter_f)(struct wb_softc *, u_short);
110 	void			(*ext_cfg_exit_f)(struct wb_softc *, u_short);
111 	enum chips		chip;
112 	uint8_t			ctl_reg;
113 	uint8_t			time_reg;
114 	uint8_t			csr_reg;
115 	int			debug_verbose;
116 
117 	/*
118 	 * Special feature to let the watchdog fire at a different
119 	 * timeout as set by watchdog(4) but still use that API to
120 	 * re-load it periodically.
121 	 */
122 	unsigned int		timeout_override;
123 
124 	/*
125 	 * Space to save current state temporary and for sysctls.
126 	 * We want to know the timeout value and usually need two
127 	 * additional registers for options. Do not name them by
128 	 * register as these might be different by chip.
129 	 */
130 	uint8_t			reg_timeout;
131 	uint8_t			reg_1;
132 	uint8_t			reg_2;
133 };
134 
135 static int	ext_cfg_enter_0x87_0x87(struct wb_softc *, u_short);
136 static void	ext_cfg_exit_0xaa(struct wb_softc *, u_short);
137 
138 struct winbond_superio_cfg {
139 	uint8_t			efer;	/* and efir */
140 	int			(*ext_cfg_enter_f)(struct wb_softc *, u_short);
141 	void			(*ext_cfg_exit_f)(struct wb_softc *, u_short);
142 } probe_addrs[] = {
143 	{
144 		.efer			= 0x2e,
145 		.ext_cfg_enter_f	= ext_cfg_enter_0x87_0x87,
146 		.ext_cfg_exit_f		= ext_cfg_exit_0xaa,
147 	},
148 	{
149 		.efer			= 0x4e,
150 		.ext_cfg_enter_f	= ext_cfg_enter_0x87_0x87,
151 		.ext_cfg_exit_f		= ext_cfg_exit_0xaa,
152 	},
153 };
154 
155 struct winbond_vendor_device_id {
156 	uint8_t			device_id;
157 	enum chips		chip;
158 	const char *		descr;
159 } wb_devs[] = {
160 	{
161 		.device_id	= 0x52,
162 		.chip		= w83627hf,
163 		.descr		= "Winbond 83627HF/F/HG/G",
164 	},
165 	{
166 		.device_id	= 0x59,
167 		.chip		= w83627s,
168 		.descr		= "Winbond 83627S",
169 	},
170 	{
171 		.device_id	= 0x60,
172 		.chip		= w83697hf,
173 		.descr		= "Winbond 83697HF",
174 	},
175 	{
176 		.device_id	= 0x68,
177 		.chip		= w83697ug,
178 		.descr		= "Winbond 83697UG",
179 	},
180 	{
181 		.device_id	= 0x70,
182 		.chip		= w83637hf,
183 		.descr		= "Winbond 83637HF",
184 	},
185 	{
186 		.device_id	= 0x82,
187 		.chip		= w83627thf,
188 		.descr		= "Winbond 83627THF",
189 	},
190 	{
191 		.device_id	= 0x85,
192 		.chip		= w83687thf,
193 		.descr		= "Winbond 83687THF",
194 	},
195 	{
196 		.device_id	= 0x88,
197 		.chip		= w83627ehf,
198 		.descr		= "Winbond 83627EHF",
199 	},
200 	{
201 		.device_id	= 0xa0,
202 		.chip		= w83627dhg,
203 		.descr		= "Winbond 83627DHG",
204 	},
205 	{
206 		.device_id	= 0xa2,
207 		.chip		= w83627uhg,
208 		.descr		= "Winbond 83627UHG",
209 	},
210 	{
211 		.device_id	= 0xa5,
212 		.chip		= w83667hg,
213 		.descr		= "Winbond 83667HG",
214 	},
215 	{
216 		.device_id	= 0xb0,
217 		.chip		= w83627dhg_p,
218 		.descr		= "Winbond 83627DHG-P",
219 	},
220 	{
221 		.device_id	= 0xb3,
222 		.chip		= w83667hg_b,
223 		.descr		= "Winbond 83667HG-B",
224 	},
225 	{
226 		.device_id	= 0xb4,
227 		.chip		= nct6775,
228 		.descr		= "Nuvoton NCT6775",
229 	},
230 	{
231 		.device_id	= 0xc3,
232 		.chip		= nct6776,
233 		.descr		= "Nuvoton NCT6776",
234 	},
235 	{
236 		.device_id	= 0xc4,
237 		.chip		= nct6102,
238 		.descr		= "Nuvoton NCT6102",
239 	},
240 	{
241 		.device_id	= 0xc5,
242 		.chip		= nct6779,
243 		.descr		= "Nuvoton NCT6779",
244 	},
245 	{
246 		.device_id	= 0xc8,
247 		.chip		= nct6791,
248 		.descr		= "Nuvoton NCT6791",
249 	},
250 	{
251 		.device_id	= 0xc9,
252 		.chip		= nct6792,
253 		.descr		= "Nuvoton NCT6792",
254 	},
255 	{
256 		.device_id	= 0xd1,
257 		.chip		= nct6793,
258 		.descr		= "Nuvoton NCT6793",
259 	},
260 	{
261 		.device_id	= 0xd3,
262 		.chip		= nct6795,
263 		.descr		= "Nuvoton NCT6795",
264 	},
265 };
266 
267 static void
268 write_efir_1(struct wb_softc *sc, u_short baseport, uint8_t value)
269 {
270 
271 	MPASS(sc != NULL || baseport != 0);
272 	if (sc != NULL)
273 		bus_space_write_1((sc)->bst, (sc)->bsh, 0, (value));
274 	else
275 		outb(baseport, value);
276 }
277 
278 static uint8_t __unused
279 read_efir_1(struct wb_softc *sc, u_short baseport)
280 {
281 
282 	MPASS(sc != NULL || baseport != 0);
283 	if (sc != NULL)
284 		return (bus_space_read_1((sc)->bst, (sc)->bsh, 0));
285 	else
286 		return (inb(baseport));
287 }
288 
289 static void
290 write_efdr_1(struct wb_softc *sc, u_short baseport, uint8_t value)
291 {
292 
293 	MPASS(sc != NULL || baseport != 0);
294 	if (sc != NULL)
295 		bus_space_write_1((sc)->bst, (sc)->bsh, 1, (value));
296 	else
297 		outb(baseport + 1, value);
298 }
299 
300 static uint8_t
301 read_efdr_1(struct wb_softc *sc, u_short baseport)
302 {
303 
304 	MPASS(sc != NULL || baseport != 0);
305 	if (sc != NULL)
306 		return (bus_space_read_1((sc)->bst, (sc)->bsh, 1));
307 	else
308 		return (inb(baseport + 1));
309 }
310 
311 static void
312 write_reg(struct wb_softc *sc, uint8_t reg, uint8_t value)
313 {
314 
315 	write_efir_1(sc, 0, reg);
316 	write_efdr_1(sc, 0, value);
317 }
318 
319 static uint8_t
320 read_reg(struct wb_softc *sc, uint8_t reg)
321 {
322 
323 	write_efir_1(sc, 0, reg);
324 	return (read_efdr_1(sc, 0));
325 }
326 
327 /*
328  * Return the watchdog related registers as we last read them.  This will
329  * usually not give the current timeout or state on whether the watchdog
330  * fired.
331  */
332 static int
333 sysctl_wb_debug(SYSCTL_HANDLER_ARGS)
334 {
335 	struct wb_softc *sc;
336 	struct sbuf sb;
337 	int error;
338 
339 	sc = arg1;
340 
341 	sbuf_new_for_sysctl(&sb, NULL, 64, req);
342 
343 	sbuf_printf(&sb, "LDN8 (GPIO2, Watchdog): ");
344 	sbuf_printf(&sb, "CR%02X 0x%02x ", sc->ctl_reg, sc->reg_1);
345 	sbuf_printf(&sb, "CR%02X 0x%02x ", sc->time_reg, sc->reg_timeout);
346 	sbuf_printf(&sb, "CR%02X 0x%02x", sc->csr_reg, sc->reg_2);
347 
348 	error = sbuf_finish(&sb);
349 	sbuf_delete(&sb);
350 	return (error);
351 }
352 
353 /*
354  * Read the current values before returning them.  Given this might poke
355  * the registers the same time as the watchdog, this sysctl handler should
356  * be marked CTLFLAG_SKIP to not show up by default.
357  */
358 static int
359 sysctl_wb_debug_current(SYSCTL_HANDLER_ARGS)
360 {
361 	struct wb_softc *sc;
362 
363 	sc = arg1;
364 
365 	if ((*sc->ext_cfg_enter_f)(sc, 0) != 0)
366 		return (ENXIO);
367 
368 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog). */
369 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
370 
371 	sc->reg_1 = read_reg(sc, sc->ctl_reg);
372 	sc->reg_timeout = read_reg(sc, sc->time_reg);
373 	sc->reg_2 = read_reg(sc, sc->csr_reg);
374 
375 	(*sc->ext_cfg_exit_f)(sc, 0);
376 
377 	return (sysctl_wb_debug(oidp, arg1, arg2, req));
378 }
379 
380 /*
381  * Sysctl handlers to force a watchdog timeout or to test the NMI functionality
382  * works as expetced.
383  * For testing we could set a test_nmi flag in the softc that, in case of NMI, a
384  * callback function from trap.c could check whether we fired and not report the
385  * timeout but clear the flag for the sysctl again.  This is interesting given a
386  * lot of boards have jumpers to change the action on watchdog timeout or
387  * disable the watchdog completely.
388  * XXX-BZ notyet: currently no general infrastructure exists to do this.
389  */
390 static int
391 sysctl_wb_force_test_nmi(SYSCTL_HANDLER_ARGS)
392 {
393 	struct wb_softc *sc;
394 	int error, test, val;
395 
396 	sc = arg1;
397 	test = arg2;
398 
399 #ifdef notyet
400 	val = sc->test_nmi;
401 #else
402 	val = 0;
403 #endif
404 	error = sysctl_handle_int(oidp, &val, 0, req);
405         if (error || !req->newptr)
406                 return (error);
407 
408 #ifdef notyet
409 	/* Manually clear the test for a value of 0 and do nothing else. */
410 	if (test && val == 0) {
411 		sc->test_nmi = 0;
412 		return (0);
413 	}
414 #endif
415 
416 	if ((*sc->ext_cfg_enter_f)(sc, 0) != 0)
417 		return (ENXIO);
418 
419 #ifdef notyet
420 	/*
421 	 * If we are testing the NMI functionality, set the flag before
422 	 * forcing the timeout.
423 	 */
424 	if (test)
425 		sc->test_nmi = 1;
426 #endif
427 
428 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog). */
429 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
430 
431 	/* Force watchdog to fire. */
432 	sc->reg_2 = read_reg(sc, sc->csr_reg);
433 	sc->reg_2 |= WB_LDN8_CRF7_FORCE;
434 	write_reg(sc, sc->csr_reg, sc->reg_2);
435 
436 	(*sc->ext_cfg_exit_f)(sc, 0);
437 
438 	return (0);
439 }
440 
441 /*
442  * Print current watchdog state.
443  *
444  * Note: it is the responsibility of the caller to update the registers
445  * upfront.
446  */
447 static void
448 wb_print_state(struct wb_softc *sc, const char *msg)
449 {
450 
451 	device_printf(sc->dev, "%s%sWatchdog %sabled. %s"
452 	    "Scaling by %ds, timer at %d (%s=%ds%s). "
453 	    "CRF5 0x%02x CRF7 0x%02x\n",
454 	    (msg != NULL) ? msg : "", (msg != NULL) ? ": " : "",
455 	    (sc->reg_timeout > 0x00) ? "en" : "dis",
456 	    (sc->reg_2 & WB_LDN8_CRF7_TS) ? "Watchdog fired. " : "",
457 	    (sc->reg_1 & WB_LDN8_CRF5_SCALE) ? 60 : 1,
458 	    sc->reg_timeout,
459 	    (sc->reg_timeout > 0x00) ? "<" : "",
460 	    sc->reg_timeout * ((sc->reg_1 & WB_LDN8_CRF5_SCALE) ? 60 : 1),
461 	    (sc->reg_timeout > 0x00) ? " left" : "",
462 	    sc->reg_1, sc->reg_2);
463 }
464 
465 /*
466  * Functions to enter and exit extended function mode.  Possibly shared
467  * between different chips.
468  */
469 static int
470 ext_cfg_enter_0x87_0x87(struct wb_softc *sc, u_short baseport)
471 {
472 
473 	/*
474 	 * Enable extended function mode.
475 	 * Winbond does not allow us to validate so always return success.
476 	 */
477 	write_efir_1(sc, baseport, 0x87);
478 	write_efir_1(sc, baseport, 0x87);
479 
480 	return (0);
481 }
482 
483 static void
484 ext_cfg_exit_0xaa(struct wb_softc *sc, u_short baseport)
485 {
486 
487 	write_efir_1(sc, baseport, 0xaa);
488 }
489 
490 /*
491  * (Re)load the watchdog counter depending on timeout.  A timeout of 0 will
492  * disable the watchdog.
493  */
494 static int
495 wb_set_watchdog(struct wb_softc *sc, unsigned int timeout)
496 {
497 
498 	if (timeout != 0) {
499 		/*
500 		 * In case an override is set, let it override.  It may lead
501 		 * to strange results as we do not check the input of the sysctl.
502 		 */
503 		if (sc->timeout_override > 0)
504 			timeout = sc->timeout_override;
505 
506 		/* Make sure we support the requested timeout. */
507 		if (timeout > 255 * 60)
508 			return (EINVAL);
509 	}
510 
511 	if (sc->debug_verbose)
512 		wb_print_state(sc, "Before watchdog counter (re)load");
513 
514 	if ((*sc->ext_cfg_enter_f)(sc, 0) != 0)
515 		return (ENXIO);
516 
517 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog) */
518 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
519 
520 	if (timeout == 0) {
521 		/* Disable watchdog. */
522 		sc->reg_timeout = 0;
523 		write_reg(sc, sc->time_reg, sc->reg_timeout);
524 
525 	} else {
526 		/* Read current scaling factor. */
527 		sc->reg_1 = read_reg(sc, sc->ctl_reg);
528 
529 		if (timeout > 255) {
530 			/* Set scaling factor to 60s. */
531 			sc->reg_1 |= WB_LDN8_CRF5_SCALE;
532 			sc->reg_timeout = (timeout / 60);
533 			if (timeout % 60)
534 				sc->reg_timeout++;
535 		} else {
536 			/* Set scaling factor to 1s. */
537 			sc->reg_1 &= ~WB_LDN8_CRF5_SCALE;
538 			sc->reg_timeout = timeout;
539 		}
540 
541 		/* In case we fired before we need to clear to fire again. */
542 		sc->reg_2 = read_reg(sc, sc->csr_reg);
543 		if (sc->reg_2 & WB_LDN8_CRF7_TS) {
544 			sc->reg_2 &= ~WB_LDN8_CRF7_TS;
545 			write_reg(sc, sc->csr_reg, sc->reg_2);
546 		}
547 
548 		/* Write back scaling factor. */
549 		write_reg(sc, sc->ctl_reg, sc->reg_1);
550 
551 		/* Set timer and arm/reset the watchdog. */
552 		write_reg(sc, sc->time_reg, sc->reg_timeout);
553 	}
554 
555 	(*sc->ext_cfg_exit_f)(sc, 0);
556 
557 	if (sc->debug_verbose)
558 		wb_print_state(sc, "After watchdog counter (re)load");
559 	return (0);
560 }
561 
562 /*
563  * watchdog(9) EVENTHANDLER function implementation to (re)load the counter
564  * with the given timeout or disable the watchdog.
565  */
566 static void
567 wb_watchdog_fn(void *private, u_int cmd, int *error)
568 {
569 	struct wb_softc *sc;
570 	unsigned int timeout;
571 	int e;
572 
573 	sc = private;
574 	KASSERT(sc != NULL, ("%s: watchdog handler function called without "
575 	    "softc.", __func__));
576 
577 	cmd &= WD_INTERVAL;
578 	if (cmd > 0 && cmd <= 63) {
579 		/* Reset (and arm) watchdog. */
580 		timeout = ((uint64_t)1 << cmd) / 1000000000;
581 		if (timeout == 0)
582 			timeout = 1;
583 		e = wb_set_watchdog(sc, timeout);
584 		if (e == 0) {
585 			if (error != NULL)
586 				*error = 0;
587 		} else {
588 			/* On error, try to make sure the WD is disabled. */
589 			wb_set_watchdog(sc, 0);
590 		}
591 
592 	} else {
593 		/* Disable watchdog. */
594 		e = wb_set_watchdog(sc, 0);
595 		if (e != 0 && cmd == 0 && error != NULL) {
596 			/* Failed to disable watchdog. */
597 			*error = EOPNOTSUPP;
598 		}
599 	}
600 }
601 
602 /*
603  * Probe/attach the Winbond Super I/O chip.
604  *
605  * Initial abstraction to possibly support more chips:
606  * - Iterate over the well known base ports, try to enable extended function
607  *   mode and read and match the device ID and device revision.  Unfortunately
608  *   the Vendor ID is in the hardware monitoring section accessible by different
609  *   base ports only.
610  * - Also HEFRAS, which would tell use the base port, is only accessible after
611  *   entering extended function mode, for which the base port is needed.
612  *   At least check HEFRAS to match the current base port we are probing.
613  * - On match set the description, remember functions to enter/exit extended
614  *   function mode as well as the base port.
615  */
616 static int
617 wb_probe_enable(device_t dev, int probe)
618 {
619 	struct wb_softc *sc;
620 	int error, found, i, j;
621 	uint8_t dev_id, dev_rev, cr26;
622 	char buf[128];
623 
624 	if (dev == NULL)
625 		sc = NULL;
626 	else {
627 		sc = device_get_softc(dev);
628 		bzero(sc, sizeof(*sc));
629 		sc->dev = dev;
630 	}
631 
632 	error = ENXIO;
633 	found = 0;
634 	for (i = 0; i < nitems(probe_addrs); i++) {
635 
636 		if (sc != NULL) {
637 			/* Allocate bus resources for IO index/data register access. */
638 			sc->portres = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->rid,
639 			    probe_addrs[i].efer, probe_addrs[i].efer + 1, 2, RF_ACTIVE);
640 			if (sc->portres == NULL)
641 				continue;
642 			sc->bst = rman_get_bustag(sc->portres);
643 			sc->bsh = rman_get_bushandle(sc->portres);
644 		}
645 
646 		error = (*probe_addrs[i].ext_cfg_enter_f)(sc, probe_addrs[i].efer);
647 		if (error != 0)
648 			goto cleanup;
649 
650 		/* Identify the SuperIO chip. */
651 		write_efir_1(sc, probe_addrs[i].efer, WB_DEVICE_ID_REG);
652 		dev_id = read_efdr_1(sc, probe_addrs[i].efer);
653 		write_efir_1(sc, probe_addrs[i].efer, WB_DEVICE_REV_REG);
654 		dev_rev = read_efdr_1(sc, probe_addrs[i].efer);
655 		write_efir_1(sc, probe_addrs[i].efer, WB_CR26);
656 		cr26 = read_efdr_1(sc, probe_addrs[i].efer);
657 
658 		if (dev_id == 0xff && dev_rev == 0xff)
659 			goto cleanup;
660 
661 		/* HEFRAS of 0 means EFER at 0x2e, 1 means EFER at 0x4e. */
662 		if (((cr26 & 0x40) == 0x00 && probe_addrs[i].efer != 0x2e) ||
663 		    ((cr26 & 0x40) == 0x40 && probe_addrs[i].efer != 0x4e)) {
664 			if (dev != NULL)
665 				device_printf(dev, "HEFRAS and EFER do not "
666 				    "align: EFER 0x%02x DevID 0x%02x DevRev "
667 				    "0x%02x CR26 0x%02x\n",
668 				    probe_addrs[i].efer, dev_id, dev_rev, cr26);
669 			goto cleanup;
670 		}
671 
672 		for (j = 0; j < nitems(wb_devs); j++) {
673 			if (wb_devs[j].device_id == dev_id) {
674 				found = 1;
675 				break;
676 			}
677 		}
678 
679 		if (probe && dev != NULL) {
680 			snprintf(buf, sizeof(buf),
681 			    "%s (0x%02x/0x%02x) Watchdog Timer",
682 			    found ? wb_devs[j].descr :
683 			     "Unknown Winbond/Nuvoton", dev_id, dev_rev);
684 			device_set_desc_copy(dev, buf);
685 		}
686 
687 		/* If this is hinted attach, try to guess the model. */
688 		if (dev != NULL && !found) {
689 			found = 1;
690 			j = 0;
691 		}
692 
693 cleanup:
694 		if (probe || !found) {
695 			(*probe_addrs[i].ext_cfg_exit_f)(sc, probe_addrs[i].efer);
696 			if (sc != NULL)
697 				(void) bus_release_resource(dev, SYS_RES_IOPORT,
698 				    sc->rid, sc->portres);
699 		}
700 
701 		/*
702 		 * Stop probing if have successfully identified the SuperIO.
703 		 * Remember the extended function mode enter/exit functions
704 		 * for operations.
705 		 */
706 		if (found) {
707 			if (sc != NULL) {
708 				sc->ext_cfg_enter_f = probe_addrs[i].ext_cfg_enter_f;
709 				sc->ext_cfg_exit_f = probe_addrs[i].ext_cfg_exit_f;
710 				sc->chip = wb_devs[j].chip;
711 				sc->ctl_reg = 0xf5;
712 				sc->time_reg = 0xf6;
713 				sc->csr_reg = 0xf7;
714 				if (sc->chip == w83697hf ||
715 				    sc->chip == w83697ug) {
716 					sc->ctl_reg = 0xf3;
717 					sc->time_reg = 0xf4;
718 				} else if (sc->chip == nct6102) {
719 					sc->ctl_reg = 0xf0;
720 					sc->time_reg = 0xf1;
721 					sc->csr_reg = 0xf2;
722 				}
723 			}
724 			return (BUS_PROBE_SPECIFIC);
725 		} else
726 			error = ENXIO;
727 	}
728 
729 	return (error);
730 }
731 
732 static void
733 wb_identify(driver_t *driver, device_t parent)
734 {
735 
736 	if (device_find_child(parent, driver->name, 0) == NULL) {
737 		if (wb_probe_enable(NULL, 1) <= 0)
738 			BUS_ADD_CHILD(parent, 0, driver->name, 0);
739 	}
740 }
741 
742 static int
743 wb_probe(device_t dev)
744 {
745 
746 	/* Make sure we do not claim some ISA PNP device. */
747 	if (isa_get_logicalid(dev) != 0)
748 		return (ENXIO);
749 
750 	return (wb_probe_enable(dev, 1));
751 }
752 
753 static int
754 wb_attach(device_t dev)
755 {
756 	struct wb_softc *sc;
757 	struct sysctl_ctx_list *sctx;
758 	struct sysctl_oid *soid;
759 	unsigned long timeout;
760 	int error;
761 	uint8_t t;
762 
763 	error = wb_probe_enable(dev, 0);
764 	if (error > 0)
765 		return (ENXIO);
766 
767 	sc = device_get_softc(dev);
768 	KASSERT(sc->ext_cfg_enter_f != NULL && sc->ext_cfg_exit_f != NULL,
769 	    ("%s: successful probe result but not setup correctly", __func__));
770 
771 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog). */
772 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
773 
774 	/* Make sure WDT is enabled. */
775 	write_reg(sc, WB_LDN8_CR30,
776 	    read_reg(sc, WB_LDN8_CR30) | WB_LDN8_CR30_ACTIVE);
777 
778 	switch (sc->chip) {
779 	case w83627hf:
780 	case w83627s:
781 		t = read_reg(sc, 0x2B) & ~0x10;
782 		write_reg(sc, 0x2B, t); /* set GPIO24 to WDT0 */
783 		break;
784 	case w83697hf:
785 		/* Set pin 119 to WDTO# mode (= CR29, WDT0) */
786 		t = read_reg(sc, 0x29) & ~0x60;
787 		t |= 0x20;
788 		write_reg(sc, 0x29, t);
789 		break;
790 	case w83697ug:
791 		/* Set pin 118 to WDTO# mode */
792 		t = read_reg(sc, 0x2b) & ~0x04;
793 		write_reg(sc, 0x2b, t);
794 		break;
795 	case w83627thf:
796 		t = (read_reg(sc, 0x2B) & ~0x08) | 0x04;
797 		write_reg(sc, 0x2B, t); /* set GPIO3 to WDT0 */
798 		break;
799 	case w83627dhg:
800 	case w83627dhg_p:
801 		t = read_reg(sc, 0x2D) & ~0x01; /* PIN77 -> WDT0# */
802 		write_reg(sc, 0x2D, t); /* set GPIO5 to WDT0 */
803 		t = read_reg(sc, sc->ctl_reg);
804 		t |= 0x02;	/* enable the WDTO# output low pulse
805 				 * to the KBRST# pin */
806 		write_reg(sc, sc->ctl_reg, t);
807 		break;
808 	case w83637hf:
809 		break;
810 	case w83687thf:
811 		t = read_reg(sc, 0x2C) & ~0x80; /* PIN47 -> WDT0# */
812 		write_reg(sc, 0x2C, t);
813 		break;
814 	case w83627ehf:
815 	case w83627uhg:
816 	case w83667hg:
817 	case w83667hg_b:
818 	case nct6775:
819 	case nct6776:
820 	case nct6779:
821 	case nct6791:
822 	case nct6792:
823 	case nct6793:
824 	case nct6795:
825 	case nct6102:
826 		/*
827 		 * These chips have a fixed WDTO# output pin (W83627UHG),
828 		 * or support more than one WDTO# output pin.
829 		 * Don't touch its configuration, and hope the BIOS
830 		 * does the right thing.
831 		 */
832 		t = read_reg(sc, sc->ctl_reg);
833 		t |= 0x02;	/* enable the WDTO# output low pulse
834 				 * to the KBRST# pin */
835 		write_reg(sc, sc->ctl_reg, t);
836 		break;
837 	default:
838 		break;
839 	}
840 
841 	/* Read the current watchdog configuration. */
842 	sc->reg_1 = read_reg(sc, sc->ctl_reg);
843 	sc->reg_timeout = read_reg(sc, sc->time_reg);
844 	sc->reg_2 = read_reg(sc, sc->csr_reg);
845 
846 	/* Print current state if bootverbose or watchdog already enabled. */
847 	if (bootverbose || (sc->reg_timeout > 0x00))
848 		wb_print_state(sc, "Before watchdog attach");
849 
850 	sc->reg_1 &= ~WB_LDN8_CRF5_KEYB_P20;
851 	sc->reg_1 |= WB_LDN8_CRF5_KBRST;
852 	write_reg(sc, sc->ctl_reg, sc->reg_1);
853 
854 	/*
855 	 * Clear a previous watchdog timeout event (if still set).
856 	 * Disable timer reset on mouse interrupts.  Leave reset on keyboard,
857 	 * since one of my boards is getting stuck in reboot without it.
858 	 */
859 	sc->reg_2 &= ~(WB_LDN8_CRF7_MOUSE|WB_LDN8_CRF7_TS);
860 	write_reg(sc, sc->csr_reg, sc->reg_2);
861 
862 	(*sc->ext_cfg_exit_f)(sc, 0);
863 
864 	/* Read global timeout override tunable, Add per device sysctls. */
865 	if (TUNABLE_ULONG_FETCH("hw.wbwd.timeout_override", &timeout)) {
866 		if (timeout > 0)
867 			sc->timeout_override = timeout;
868 	}
869 	sctx = device_get_sysctl_ctx(dev);
870 	soid = device_get_sysctl_tree(dev);
871         SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO,
872 	    "timeout_override", CTLFLAG_RW, &sc->timeout_override, 0,
873             "Timeout in seconds overriding default watchdog timeout");
874         SYSCTL_ADD_INT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO,
875 	    "debug_verbose", CTLFLAG_RW, &sc->debug_verbose, 0,
876             "Enables extra debugging information");
877         SYSCTL_ADD_PROC(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "debug",
878 	    CTLTYPE_STRING|CTLFLAG_RD, sc, 0, sysctl_wb_debug, "A",
879             "Selected register information from last change by driver");
880         SYSCTL_ADD_PROC(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "debug_current",
881 	    CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_SKIP, sc, 0,
882 	     sysctl_wb_debug_current, "A",
883 	     "Selected register information (may interfere)");
884 	SYSCTL_ADD_PROC(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "force_timeout",
885 	    CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_SKIP, sc, 0,
886 	    sysctl_wb_force_test_nmi, "I", "Enable to force watchdog to fire.");
887 
888 	/* Register watchdog. */
889 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, wb_watchdog_fn, sc,
890 	    0);
891 
892 	if (bootverbose)
893 		wb_print_state(sc, "After watchdog attach");
894 
895 	return (0);
896 }
897 
898 static int
899 wb_detach(device_t dev)
900 {
901 	struct wb_softc *sc;
902 
903 	sc = device_get_softc(dev);
904 
905 	/* Unregister and stop the watchdog if running. */
906 	if (sc->ev_tag)
907 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
908 	wb_set_watchdog(sc, 0);
909 
910 	/* Disable extended function mode. */
911 	(*sc->ext_cfg_exit_f)(sc, 0);
912 
913 	/* Cleanup resources. */
914 	(void) bus_release_resource(dev, SYS_RES_IOPORT, sc->rid, sc->portres);
915 
916 	/* Bus subroutines take care of sysctls already. */
917 
918 	return (0);
919 }
920 
921 static device_method_t wb_methods[] = {
922 	/* Device interface */
923 	DEVMETHOD(device_identify,	wb_identify),
924 	DEVMETHOD(device_probe,		wb_probe),
925 	DEVMETHOD(device_attach,	wb_attach),
926 	DEVMETHOD(device_detach,	wb_detach),
927 
928 	DEVMETHOD_END
929 };
930 
931 static driver_t wb_isa_driver = {
932 	"wbwd",
933 	wb_methods,
934 	sizeof(struct wb_softc)
935 };
936 
937 static devclass_t wb_devclass;
938 
939 DRIVER_MODULE(wb, isa, wb_isa_driver, wb_devclass, NULL, NULL);
940