xref: /freebsd/sys/dev/wbwd/wbwd.c (revision 7447ca0eb235974642312b9555caec00b57d8fc1)
1 /*-
2  * Copyright (c) 2011 Sandvine Incorporated ULC.
3  * Copyright (c) 2012 iXsystems, Inc.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 /*
28  * Support for Winbond watchdog.
29  *
30  * With minor abstractions it might be possible to add support for other
31  * different Winbond Super I/O chips as well.  Winbond seems to have four
32  * different types of chips, four different ways to get into extended config
33  * mode.
34  *
35  * Note: there is no serialization between the debugging sysctl handlers and
36  * the watchdog functions and possibly others poking the registers at the same
37  * time.  For that at least possibly interfering sysctls are hidden by default.
38  */
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <sys/param.h>
44 #include <sys/kernel.h>
45 #include <sys/systm.h>
46 #include <sys/bus.h>
47 #include <sys/eventhandler.h>
48 #include <sys/lock.h>
49 #include <sys/module.h>
50 #include <sys/rman.h>
51 #include <sys/sbuf.h>
52 #include <sys/sysctl.h>
53 #include <sys/watchdog.h>
54 
55 #include <isa/isavar.h>
56 
57 #include <machine/bus.h>
58 #include <machine/resource.h>
59 
60 /*
61  * Global registers.
62  */
63 #define	WB_DEVICE_ID_REG	0x20	/* Device ID */
64 #define	WB_DEVICE_REV_REG	0x21	/* Device revision */
65 #define	WB_CR26			0x26	/* Bit6: HEFRAS (base port selector) */
66 
67 /* LDN selection. */
68 #define	WB_LDN_REG		0x07
69 #define	WB_LDN_REG_LDN8		0x08	/* GPIO 2, Watchdog */
70 
71 /*
72  * LDN8 (GPIO 2, Watchdog) specific registers and options.
73  */
74 /* CR30: LDN8 activation control. */
75 #define	WB_LDN8_CR30		0x30
76 #define	WB_LDN8_CR30_ACTIVE	0x01	/* 1: LD active */
77 
78 /* CRF5: Watchdog scale, P20. Mapped to reg_1. */
79 #define	WB_LDN8_CRF5		0xF5
80 #define	WB_LDN8_CRF5_SCALE	0x08	/* 0: 1s, 1: 60s */
81 #define	WB_LDN8_CRF5_KEYB_P20	0x04	/* 1: keyb P20 forces timeout */
82 #define	WB_LDN8_CRF5_KBRST	0x02	/* 1: timeout causes pin60 kbd reset */
83 
84 /* CRF6: Watchdog Timeout (0 == off). Mapped to reg_timeout. */
85 #define	WB_LDN8_CRF6		0xF6
86 
87 /* CRF7: Watchdog mouse, keyb, force, .. Mapped to reg_2. */
88 #define	WB_LDN8_CRF7		0xF7
89 #define	WB_LDN8_CRF7_MOUSE	0x80	/* 1: mouse irq resets wd timer */
90 #define	WB_LDN8_CRF7_KEYB	0x40	/* 1: keyb irq resets wd timer */
91 #define	WB_LDN8_CRF7_FORCE	0x20	/* 1: force timeout (self-clear) */
92 #define	WB_LDN8_CRF7_TS		0x10	/* 0: counting, 1: fired */
93 #define	WB_LDN8_CRF7_IRQS	0x0f	/* irq source for watchdog, 2 == SMI */
94 
95 enum chips { w83627hf, w83627s, w83697hf, w83697ug, w83637hf, w83627thf,
96 	     w83687thf, w83627ehf, w83627dhg, w83627uhg, w83667hg,
97 	     w83627dhg_p, w83667hg_b, nct6775, nct6776, nct6779, nct6791,
98 	     nct6792, nct6102 };
99 
100 struct wb_softc {
101 	device_t		dev;
102 	struct resource		*portres;
103 	bus_space_tag_t		bst;
104 	bus_space_handle_t	bsh;
105 	int			rid;
106 	eventhandler_tag	ev_tag;
107 	int			(*ext_cfg_enter_f)(struct wb_softc *, u_short);
108 	void			(*ext_cfg_exit_f)(struct wb_softc *, u_short);
109 	enum chips		chip;
110 	uint8_t			ctl_reg;
111 	uint8_t			time_reg;
112 	uint8_t			csr_reg;
113 	int			debug_verbose;
114 
115 	/*
116 	 * Special feature to let the watchdog fire at a different
117 	 * timeout as set by watchdog(4) but still use that API to
118 	 * re-load it periodically.
119 	 */
120 	unsigned int		timeout_override;
121 
122 	/*
123 	 * Space to save current state temporary and for sysctls.
124 	 * We want to know the timeout value and usually need two
125 	 * additional registers for options. Do not name them by
126 	 * register as these might be different by chip.
127 	 */
128 	uint8_t			reg_timeout;
129 	uint8_t			reg_1;
130 	uint8_t			reg_2;
131 };
132 
133 static int	ext_cfg_enter_0x87_0x87(struct wb_softc *, u_short);
134 static void	ext_cfg_exit_0xaa(struct wb_softc *, u_short);
135 
136 struct winbond_superio_cfg {
137 	uint8_t			efer;	/* and efir */
138 	int			(*ext_cfg_enter_f)(struct wb_softc *, u_short);
139 	void			(*ext_cfg_exit_f)(struct wb_softc *, u_short);
140 } probe_addrs[] = {
141 	{
142 		.efer			= 0x2e,
143 		.ext_cfg_enter_f	= ext_cfg_enter_0x87_0x87,
144 		.ext_cfg_exit_f		= ext_cfg_exit_0xaa,
145 	},
146 	{
147 		.efer			= 0x4e,
148 		.ext_cfg_enter_f	= ext_cfg_enter_0x87_0x87,
149 		.ext_cfg_exit_f		= ext_cfg_exit_0xaa,
150 	},
151 };
152 
153 struct winbond_vendor_device_id {
154 	uint8_t			device_id;
155 	enum chips		chip;
156 	const char *		descr;
157 } wb_devs[] = {
158 	{
159 		.device_id	= 0x52,
160 		.chip		= w83627hf,
161 		.descr		= "Winbond 83627HF/F/HG/G",
162 	},
163 	{
164 		.device_id	= 0x59,
165 		.chip		= w83627s,
166 		.descr		= "Winbond 83627S",
167 	},
168 	{
169 		.device_id	= 0x60,
170 		.chip		= w83697hf,
171 		.descr		= "Winbond 83697HF",
172 	},
173 	{
174 		.device_id	= 0x68,
175 		.chip		= w83697ug,
176 		.descr		= "Winbond 83697UG",
177 	},
178 	{
179 		.device_id	= 0x70,
180 		.chip		= w83637hf,
181 		.descr		= "Winbond 83637HF",
182 	},
183 	{
184 		.device_id	= 0x82,
185 		.chip		= w83627thf,
186 		.descr		= "Winbond 83627THF",
187 	},
188 	{
189 		.device_id	= 0x85,
190 		.chip		= w83687thf,
191 		.descr		= "Winbond 83687THF",
192 	},
193 	{
194 		.device_id	= 0x88,
195 		.chip		= w83627ehf,
196 		.descr		= "Winbond 83627EHF",
197 	},
198 	{
199 		.device_id	= 0xa0,
200 		.chip		= w83627dhg,
201 		.descr		= "Winbond 83627DHG",
202 	},
203 	{
204 		.device_id	= 0xa2,
205 		.chip		= w83627uhg,
206 		.descr		= "Winbond 83627UHG",
207 	},
208 	{
209 		.device_id	= 0xa5,
210 		.chip		= w83667hg,
211 		.descr		= "Winbond 83667HG",
212 	},
213 	{
214 		.device_id	= 0xb0,
215 		.chip		= w83627dhg_p,
216 		.descr		= "Winbond 83627DHG-P",
217 	},
218 	{
219 		.device_id	= 0xb3,
220 		.chip		= w83667hg_b,
221 		.descr		= "Winbond 83667HG-B",
222 	},
223 	{
224 		.device_id	= 0xb4,
225 		.chip		= nct6775,
226 		.descr		= "Nuvoton NCT6775",
227 	},
228 	{
229 		.device_id	= 0xc3,
230 		.chip		= nct6776,
231 		.descr		= "Nuvoton NCT6776",
232 	},
233 	{
234 		.device_id	= 0xc4,
235 		.chip		= nct6102,
236 		.descr		= "Nuvoton NCT6102",
237 	},
238 	{
239 		.device_id	= 0xc5,
240 		.chip		= nct6779,
241 		.descr		= "Nuvoton NCT6779",
242 	},
243 	{
244 		.device_id	= 0xc8,
245 		.chip		= nct6791,
246 		.descr		= "Nuvoton NCT6791",
247 	},
248 	{
249 		.device_id	= 0xc9,
250 		.chip		= nct6792,
251 		.descr		= "Nuvoton NCT6792",
252 	},
253 };
254 
255 static void
256 write_efir_1(struct wb_softc *sc, u_short baseport, uint8_t value)
257 {
258 
259 	MPASS(sc != NULL || baseport != 0);
260 	if (sc != NULL)
261 		bus_space_write_1((sc)->bst, (sc)->bsh, 0, (value));
262 	else
263 		outb(baseport, value);
264 }
265 
266 static uint8_t __unused
267 read_efir_1(struct wb_softc *sc, u_short baseport)
268 {
269 
270 	MPASS(sc != NULL || baseport != 0);
271 	if (sc != NULL)
272 		return (bus_space_read_1((sc)->bst, (sc)->bsh, 0));
273 	else
274 		return (inb(baseport));
275 }
276 
277 static void
278 write_efdr_1(struct wb_softc *sc, u_short baseport, uint8_t value)
279 {
280 
281 	MPASS(sc != NULL || baseport != 0);
282 	if (sc != NULL)
283 		bus_space_write_1((sc)->bst, (sc)->bsh, 1, (value));
284 	else
285 		outb(baseport + 1, value);
286 }
287 
288 static uint8_t
289 read_efdr_1(struct wb_softc *sc, u_short baseport)
290 {
291 
292 	MPASS(sc != NULL || baseport != 0);
293 	if (sc != NULL)
294 		return (bus_space_read_1((sc)->bst, (sc)->bsh, 1));
295 	else
296 		return (inb(baseport + 1));
297 }
298 
299 static void
300 write_reg(struct wb_softc *sc, uint8_t reg, uint8_t value)
301 {
302 
303 	write_efir_1(sc, 0, reg);
304 	write_efdr_1(sc, 0, value);
305 }
306 
307 static uint8_t
308 read_reg(struct wb_softc *sc, uint8_t reg)
309 {
310 
311 	write_efir_1(sc, 0, reg);
312 	return (read_efdr_1(sc, 0));
313 }
314 
315 /*
316  * Return the watchdog related registers as we last read them.  This will
317  * usually not give the current timeout or state on whether the watchdog
318  * fired.
319  */
320 static int
321 sysctl_wb_debug(SYSCTL_HANDLER_ARGS)
322 {
323 	struct wb_softc *sc;
324 	struct sbuf sb;
325 	int error;
326 
327 	sc = arg1;
328 
329 	sbuf_new_for_sysctl(&sb, NULL, 64, req);
330 
331 	sbuf_printf(&sb, "LDN8 (GPIO2, Watchdog): ");
332 	sbuf_printf(&sb, "CR%02X 0x%02x ", sc->ctl_reg, sc->reg_1);
333 	sbuf_printf(&sb, "CR%02X 0x%02x ", sc->time_reg, sc->reg_timeout);
334 	sbuf_printf(&sb, "CR%02X 0x%02x", sc->csr_reg, sc->reg_2);
335 
336 	error = sbuf_finish(&sb);
337 	sbuf_delete(&sb);
338 	return (error);
339 }
340 
341 /*
342  * Read the current values before returning them.  Given this might poke
343  * the registers the same time as the watchdog, this sysctl handler should
344  * be marked CTLFLAG_SKIP to not show up by default.
345  */
346 static int
347 sysctl_wb_debug_current(SYSCTL_HANDLER_ARGS)
348 {
349 	struct wb_softc *sc;
350 
351 	sc = arg1;
352 
353 	if ((*sc->ext_cfg_enter_f)(sc, 0) != 0)
354 		return (ENXIO);
355 
356 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog). */
357 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
358 
359 	sc->reg_1 = read_reg(sc, sc->ctl_reg);
360 	sc->reg_timeout = read_reg(sc, sc->time_reg);
361 	sc->reg_2 = read_reg(sc, sc->csr_reg);
362 
363 	(*sc->ext_cfg_exit_f)(sc, 0);
364 
365 	return (sysctl_wb_debug(oidp, arg1, arg2, req));
366 }
367 
368 /*
369  * Sysctl handlers to force a watchdog timeout or to test the NMI functionality
370  * works as expetced.
371  * For testing we could set a test_nmi flag in the softc that, in case of NMI, a
372  * callback function from trap.c could check whether we fired and not report the
373  * timeout but clear the flag for the sysctl again.  This is interesting given a
374  * lot of boards have jumpers to change the action on watchdog timeout or
375  * disable the watchdog completely.
376  * XXX-BZ notyet: currently no general infrastructure exists to do this.
377  */
378 static int
379 sysctl_wb_force_test_nmi(SYSCTL_HANDLER_ARGS)
380 {
381 	struct wb_softc *sc;
382 	int error, test, val;
383 
384 	sc = arg1;
385 	test = arg2;
386 
387 #ifdef notyet
388 	val = sc->test_nmi;
389 #else
390 	val = 0;
391 #endif
392 	error = sysctl_handle_int(oidp, &val, 0, req);
393         if (error || !req->newptr)
394                 return (error);
395 
396 #ifdef notyet
397 	/* Manually clear the test for a value of 0 and do nothing else. */
398 	if (test && val == 0) {
399 		sc->test_nmi = 0;
400 		return (0);
401 	}
402 #endif
403 
404 	if ((*sc->ext_cfg_enter_f)(sc, 0) != 0)
405 		return (ENXIO);
406 
407 #ifdef notyet
408 	/*
409 	 * If we are testing the NMI functionality, set the flag before
410 	 * forcing the timeout.
411 	 */
412 	if (test)
413 		sc->test_nmi = 1;
414 #endif
415 
416 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog). */
417 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
418 
419 	/* Force watchdog to fire. */
420 	sc->reg_2 = read_reg(sc, sc->csr_reg);
421 	sc->reg_2 |= WB_LDN8_CRF7_FORCE;
422 	write_reg(sc, sc->csr_reg, sc->reg_2);
423 
424 	(*sc->ext_cfg_exit_f)(sc, 0);
425 
426 	return (0);
427 }
428 
429 /*
430  * Print current watchdog state.
431  *
432  * Note: it is the responsibility of the caller to update the registers
433  * upfront.
434  */
435 static void
436 wb_print_state(struct wb_softc *sc, const char *msg)
437 {
438 
439 	device_printf(sc->dev, "%s%sWatchdog %sabled. %s"
440 	    "Scaling by %ds, timer at %d (%s=%ds%s). "
441 	    "CRF5 0x%02x CRF7 0x%02x\n",
442 	    (msg != NULL) ? msg : "", (msg != NULL) ? ": " : "",
443 	    (sc->reg_timeout > 0x00) ? "en" : "dis",
444 	    (sc->reg_2 & WB_LDN8_CRF7_TS) ? "Watchdog fired. " : "",
445 	    (sc->reg_1 & WB_LDN8_CRF5_SCALE) ? 60 : 1,
446 	    sc->reg_timeout,
447 	    (sc->reg_timeout > 0x00) ? "<" : "",
448 	    sc->reg_timeout * ((sc->reg_1 & WB_LDN8_CRF5_SCALE) ? 60 : 1),
449 	    (sc->reg_timeout > 0x00) ? " left" : "",
450 	    sc->reg_1, sc->reg_2);
451 }
452 
453 /*
454  * Functions to enter and exit extended function mode.  Possibly shared
455  * between different chips.
456  */
457 static int
458 ext_cfg_enter_0x87_0x87(struct wb_softc *sc, u_short baseport)
459 {
460 
461 	/*
462 	 * Enable extended function mode.
463 	 * Winbond does not allow us to validate so always return success.
464 	 */
465 	write_efir_1(sc, baseport, 0x87);
466 	write_efir_1(sc, baseport, 0x87);
467 
468 	return (0);
469 }
470 
471 static void
472 ext_cfg_exit_0xaa(struct wb_softc *sc, u_short baseport)
473 {
474 
475 	write_efir_1(sc, baseport, 0xaa);
476 }
477 
478 /*
479  * (Re)load the watchdog counter depending on timeout.  A timeout of 0 will
480  * disable the watchdog.
481  */
482 static int
483 wb_set_watchdog(struct wb_softc *sc, unsigned int timeout)
484 {
485 
486 	if (timeout != 0) {
487 		/*
488 		 * In case an override is set, let it override.  It may lead
489 		 * to strange results as we do not check the input of the sysctl.
490 		 */
491 		if (sc->timeout_override > 0)
492 			timeout = sc->timeout_override;
493 
494 		/* Make sure we support the requested timeout. */
495 		if (timeout > 255 * 60)
496 			return (EINVAL);
497 	}
498 
499 	if (sc->debug_verbose)
500 		wb_print_state(sc, "Before watchdog counter (re)load");
501 
502 	if ((*sc->ext_cfg_enter_f)(sc, 0) != 0)
503 		return (ENXIO);
504 
505 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog) */
506 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
507 
508 	if (timeout == 0) {
509 		/* Disable watchdog. */
510 		sc->reg_timeout = 0;
511 		write_reg(sc, sc->time_reg, sc->reg_timeout);
512 
513 	} else {
514 		/* Read current scaling factor. */
515 		sc->reg_1 = read_reg(sc, sc->ctl_reg);
516 
517 		if (timeout > 255) {
518 			/* Set scaling factor to 60s. */
519 			sc->reg_1 |= WB_LDN8_CRF5_SCALE;
520 			sc->reg_timeout = (timeout / 60);
521 			if (timeout % 60)
522 				sc->reg_timeout++;
523 		} else {
524 			/* Set scaling factor to 1s. */
525 			sc->reg_1 &= ~WB_LDN8_CRF5_SCALE;
526 			sc->reg_timeout = timeout;
527 		}
528 
529 		/* In case we fired before we need to clear to fire again. */
530 		sc->reg_2 = read_reg(sc, sc->csr_reg);
531 		if (sc->reg_2 & WB_LDN8_CRF7_TS) {
532 			sc->reg_2 &= ~WB_LDN8_CRF7_TS;
533 			write_reg(sc, sc->csr_reg, sc->reg_2);
534 		}
535 
536 		/* Write back scaling factor. */
537 		write_reg(sc, sc->ctl_reg, sc->reg_1);
538 
539 		/* Set timer and arm/reset the watchdog. */
540 		write_reg(sc, sc->time_reg, sc->reg_timeout);
541 	}
542 
543 	(*sc->ext_cfg_exit_f)(sc, 0);
544 
545 	if (sc->debug_verbose)
546 		wb_print_state(sc, "After watchdog counter (re)load");
547 	return (0);
548 }
549 
550 /*
551  * watchdog(9) EVENTHANDLER function implementation to (re)load the counter
552  * with the given timeout or disable the watchdog.
553  */
554 static void
555 wb_watchdog_fn(void *private, u_int cmd, int *error)
556 {
557 	struct wb_softc *sc;
558 	unsigned int timeout;
559 	int e;
560 
561 	sc = private;
562 	KASSERT(sc != NULL, ("%s: watchdog handler function called without "
563 	    "softc.", __func__));
564 
565 	cmd &= WD_INTERVAL;
566 	if (cmd > 0 && cmd <= 63) {
567 		/* Reset (and arm) watchdog. */
568 		timeout = ((uint64_t)1 << cmd) / 1000000000;
569 		if (timeout == 0)
570 			timeout = 1;
571 		e = wb_set_watchdog(sc, timeout);
572 		if (e == 0) {
573 			if (error != NULL)
574 				*error = 0;
575 		} else {
576 			/* On error, try to make sure the WD is disabled. */
577 			wb_set_watchdog(sc, 0);
578 		}
579 
580 	} else {
581 		/* Disable watchdog. */
582 		e = wb_set_watchdog(sc, 0);
583 		if (e != 0 && cmd == 0 && error != NULL) {
584 			/* Failed to disable watchdog. */
585 			*error = EOPNOTSUPP;
586 		}
587 	}
588 }
589 
590 /*
591  * Probe/attach the Winbond Super I/O chip.
592  *
593  * Initial abstraction to possibly support more chips:
594  * - Iterate over the well known base ports, try to enable extended function
595  *   mode and read and match the device ID and device revision.  Unfortunately
596  *   the Vendor ID is in the hardware monitoring section accessible by different
597  *   base ports only.
598  * - Also HEFRAS, which would tell use the base port, is only accessible after
599  *   entering extended function mode, for which the base port is needed.
600  *   At least check HEFRAS to match the current base port we are probing.
601  * - On match set the description, remember functions to enter/exit extended
602  *   function mode as well as the base port.
603  */
604 static int
605 wb_probe_enable(device_t dev, int probe)
606 {
607 	struct wb_softc *sc;
608 	int error, found, i, j;
609 	uint8_t dev_id, dev_rev, cr26;
610 	char buf[128];
611 
612 	if (dev == NULL)
613 		sc = NULL;
614 	else {
615 		sc = device_get_softc(dev);
616 		bzero(sc, sizeof(*sc));
617 		sc->dev = dev;
618 	}
619 
620 	error = ENXIO;
621 	found = 0;
622 	for (i = 0; i < nitems(probe_addrs); i++) {
623 
624 		if (sc != NULL) {
625 			/* Allocate bus resources for IO index/data register access. */
626 			sc->portres = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->rid,
627 			    probe_addrs[i].efer, probe_addrs[i].efer + 1, 2, RF_ACTIVE);
628 			if (sc->portres == NULL)
629 				continue;
630 			sc->bst = rman_get_bustag(sc->portres);
631 			sc->bsh = rman_get_bushandle(sc->portres);
632 		}
633 
634 		error = (*probe_addrs[i].ext_cfg_enter_f)(sc, probe_addrs[i].efer);
635 		if (error != 0)
636 			goto cleanup;
637 
638 		/* Identify the SuperIO chip. */
639 		write_efir_1(sc, probe_addrs[i].efer, WB_DEVICE_ID_REG);
640 		dev_id = read_efdr_1(sc, probe_addrs[i].efer);
641 		write_efir_1(sc, probe_addrs[i].efer, WB_DEVICE_REV_REG);
642 		dev_rev = read_efdr_1(sc, probe_addrs[i].efer);
643 		write_efir_1(sc, probe_addrs[i].efer, WB_CR26);
644 		cr26 = read_efdr_1(sc, probe_addrs[i].efer);
645 
646 		if (dev_id == 0xff && dev_rev == 0xff)
647 			goto cleanup;
648 
649 		/* HEFRAS of 0 means EFER at 0x2e, 1 means EFER at 0x4e. */
650 		if (((cr26 & 0x40) == 0x00 && probe_addrs[i].efer != 0x2e) ||
651 		    ((cr26 & 0x40) == 0x40 && probe_addrs[i].efer != 0x4e)) {
652 			if (dev != NULL)
653 				device_printf(dev, "HEFRAS and EFER do not "
654 				    "align: EFER 0x%02x DevID 0x%02x DevRev "
655 				    "0x%02x CR26 0x%02x\n",
656 				    probe_addrs[i].efer, dev_id, dev_rev, cr26);
657 			goto cleanup;
658 		}
659 
660 		for (j = 0; j < nitems(wb_devs); j++) {
661 			if (wb_devs[j].device_id == dev_id) {
662 				found = 1;
663 				break;
664 			}
665 		}
666 
667 		if (probe && dev != NULL) {
668 			snprintf(buf, sizeof(buf),
669 			    "%s (0x%02x/0x%02x) Watchdog Timer",
670 			    found ? wb_devs[j].descr :
671 			     "Unknown Winbond/Nuvoton", dev_id, dev_rev);
672 			device_set_desc_copy(dev, buf);
673 		}
674 
675 		/* If this is hinted attach, try to guess the model. */
676 		if (dev != NULL && !found) {
677 			found = 1;
678 			j = 0;
679 		}
680 
681 cleanup:
682 		if (probe || !found) {
683 			(*probe_addrs[i].ext_cfg_exit_f)(sc, probe_addrs[i].efer);
684 			if (sc != NULL)
685 				(void) bus_release_resource(dev, SYS_RES_IOPORT,
686 				    sc->rid, sc->portres);
687 		}
688 
689 		/*
690 		 * Stop probing if have successfully identified the SuperIO.
691 		 * Remember the extended function mode enter/exit functions
692 		 * for operations.
693 		 */
694 		if (found) {
695 			if (sc != NULL) {
696 				sc->ext_cfg_enter_f = probe_addrs[i].ext_cfg_enter_f;
697 				sc->ext_cfg_exit_f = probe_addrs[i].ext_cfg_exit_f;
698 				sc->chip = wb_devs[j].chip;
699 				sc->ctl_reg = 0xf5;
700 				sc->time_reg = 0xf6;
701 				sc->csr_reg = 0xf7;
702 				if (sc->chip == w83697hf ||
703 				    sc->chip == w83697ug) {
704 					sc->ctl_reg = 0xf3;
705 					sc->time_reg = 0xf4;
706 				} else if (sc->chip == nct6102) {
707 					sc->ctl_reg = 0xf0;
708 					sc->time_reg = 0xf1;
709 					sc->csr_reg = 0xf2;
710 				}
711 			}
712 			return (BUS_PROBE_SPECIFIC);
713 		} else
714 			error = ENXIO;
715 	}
716 
717 	return (error);
718 }
719 
720 static void
721 wb_identify(driver_t *driver, device_t parent)
722 {
723 
724 	if (device_find_child(parent, driver->name, 0) == NULL) {
725 		if (wb_probe_enable(NULL, 1) <= 0)
726 			BUS_ADD_CHILD(parent, 0, driver->name, 0);
727 	}
728 }
729 
730 static int
731 wb_probe(device_t dev)
732 {
733 
734 	/* Make sure we do not claim some ISA PNP device. */
735 	if (isa_get_logicalid(dev) != 0)
736 		return (ENXIO);
737 
738 	return (wb_probe_enable(dev, 1));
739 }
740 
741 static int
742 wb_attach(device_t dev)
743 {
744 	struct wb_softc *sc;
745 	struct sysctl_ctx_list *sctx;
746 	struct sysctl_oid *soid;
747 	unsigned long timeout;
748 	int error;
749 	uint8_t t;
750 
751 	error = wb_probe_enable(dev, 0);
752 	if (error > 0)
753 		return (ENXIO);
754 
755 	sc = device_get_softc(dev);
756 	KASSERT(sc->ext_cfg_enter_f != NULL && sc->ext_cfg_exit_f != NULL,
757 	    ("%s: successful probe result but not setup correctly", __func__));
758 
759 	/* Watchdog is configured as part of LDN 8 (GPIO Port2, Watchdog). */
760 	write_reg(sc, WB_LDN_REG, WB_LDN_REG_LDN8);
761 
762 	/* Make sure WDT is enabled. */
763 	write_reg(sc, WB_LDN8_CR30,
764 	    read_reg(sc, WB_LDN8_CR30) | WB_LDN8_CR30_ACTIVE);
765 
766 	switch (sc->chip) {
767 	case w83627hf:
768 	case w83627s:
769 		t = read_reg(sc, 0x2B) & ~0x10;
770 		write_reg(sc, 0x2B, t); /* set GPIO24 to WDT0 */
771 		break;
772 	case w83697hf:
773 		/* Set pin 119 to WDTO# mode (= CR29, WDT0) */
774 		t = read_reg(sc, 0x29) & ~0x60;
775 		t |= 0x20;
776 		write_reg(sc, 0x29, t);
777 		break;
778 	case w83697ug:
779 		/* Set pin 118 to WDTO# mode */
780 		t = read_reg(sc, 0x2b) & ~0x04;
781 		write_reg(sc, 0x2b, t);
782 		break;
783 	case w83627thf:
784 		t = (read_reg(sc, 0x2B) & ~0x08) | 0x04;
785 		write_reg(sc, 0x2B, t); /* set GPIO3 to WDT0 */
786 		break;
787 	case w83627dhg:
788 	case w83627dhg_p:
789 		t = read_reg(sc, 0x2D) & ~0x01; /* PIN77 -> WDT0# */
790 		write_reg(sc, 0x2D, t); /* set GPIO5 to WDT0 */
791 		t = read_reg(sc, sc->ctl_reg);
792 		t |= 0x02;	/* enable the WDTO# output low pulse
793 				 * to the KBRST# pin */
794 		write_reg(sc, sc->ctl_reg, t);
795 		break;
796 	case w83637hf:
797 		break;
798 	case w83687thf:
799 		t = read_reg(sc, 0x2C) & ~0x80; /* PIN47 -> WDT0# */
800 		write_reg(sc, 0x2C, t);
801 		break;
802 	case w83627ehf:
803 	case w83627uhg:
804 	case w83667hg:
805 	case w83667hg_b:
806 	case nct6775:
807 	case nct6776:
808 	case nct6779:
809 	case nct6791:
810 	case nct6792:
811 	case nct6102:
812 		/*
813 		 * These chips have a fixed WDTO# output pin (W83627UHG),
814 		 * or support more than one WDTO# output pin.
815 		 * Don't touch its configuration, and hope the BIOS
816 		 * does the right thing.
817 		 */
818 		t = read_reg(sc, sc->ctl_reg);
819 		t |= 0x02;	/* enable the WDTO# output low pulse
820 				 * to the KBRST# pin */
821 		write_reg(sc, sc->ctl_reg, t);
822 		break;
823 	default:
824 		break;
825 	}
826 
827 	/* Read the current watchdog configuration. */
828 	sc->reg_1 = read_reg(sc, sc->ctl_reg);
829 	sc->reg_timeout = read_reg(sc, sc->time_reg);
830 	sc->reg_2 = read_reg(sc, sc->csr_reg);
831 
832 	/* Print current state if bootverbose or watchdog already enabled. */
833 	if (bootverbose || (sc->reg_timeout > 0x00))
834 		wb_print_state(sc, "Before watchdog attach");
835 
836 	sc->reg_1 &= ~WB_LDN8_CRF5_KEYB_P20;
837 	sc->reg_1 |= WB_LDN8_CRF5_KBRST;
838 	write_reg(sc, sc->ctl_reg, sc->reg_1);
839 
840 	/*
841 	 * Clear a previous watchdog timeout event (if still set).
842 	 * Disable timer reset on mouse interrupts.  Leave reset on keyboard,
843 	 * since one of my boards is getting stuck in reboot without it.
844 	 */
845 	sc->reg_2 &= ~(WB_LDN8_CRF7_MOUSE|WB_LDN8_CRF7_TS);
846 	write_reg(sc, sc->csr_reg, sc->reg_2);
847 
848 	(*sc->ext_cfg_exit_f)(sc, 0);
849 
850 	/* Read global timeout override tunable, Add per device sysctls. */
851 	if (TUNABLE_ULONG_FETCH("hw.wbwd.timeout_override", &timeout)) {
852 		if (timeout > 0)
853 			sc->timeout_override = timeout;
854 	}
855 	sctx = device_get_sysctl_ctx(dev);
856 	soid = device_get_sysctl_tree(dev);
857         SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO,
858 	    "timeout_override", CTLFLAG_RW, &sc->timeout_override, 0,
859             "Timeout in seconds overriding default watchdog timeout");
860         SYSCTL_ADD_INT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO,
861 	    "debug_verbose", CTLFLAG_RW, &sc->debug_verbose, 0,
862             "Enables extra debugging information");
863         SYSCTL_ADD_PROC(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "debug",
864 	    CTLTYPE_STRING|CTLFLAG_RD, sc, 0, sysctl_wb_debug, "A",
865             "Selected register information from last change by driver");
866         SYSCTL_ADD_PROC(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "debug_current",
867 	    CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_SKIP, sc, 0,
868 	     sysctl_wb_debug_current, "A",
869 	     "Selected register information (may interfere)");
870 	SYSCTL_ADD_PROC(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "force_timeout",
871 	    CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_SKIP, sc, 0,
872 	    sysctl_wb_force_test_nmi, "I", "Enable to force watchdog to fire.");
873 
874 	/* Register watchdog. */
875 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, wb_watchdog_fn, sc,
876 	    0);
877 
878 	if (bootverbose)
879 		wb_print_state(sc, "After watchdog attach");
880 
881 	return (0);
882 }
883 
884 static int
885 wb_detach(device_t dev)
886 {
887 	struct wb_softc *sc;
888 
889 	sc = device_get_softc(dev);
890 
891 	/* Unregister and stop the watchdog if running. */
892 	if (sc->ev_tag)
893 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
894 	wb_set_watchdog(sc, 0);
895 
896 	/* Disable extended function mode. */
897 	(*sc->ext_cfg_exit_f)(sc, 0);
898 
899 	/* Cleanup resources. */
900 	(void) bus_release_resource(dev, SYS_RES_IOPORT, sc->rid, sc->portres);
901 
902 	/* Bus subroutines take care of sysctls already. */
903 
904 	return (0);
905 }
906 
907 static device_method_t wb_methods[] = {
908 	/* Device interface */
909 	DEVMETHOD(device_identify,	wb_identify),
910 	DEVMETHOD(device_probe,		wb_probe),
911 	DEVMETHOD(device_attach,	wb_attach),
912 	DEVMETHOD(device_detach,	wb_detach),
913 
914 	DEVMETHOD_END
915 };
916 
917 static driver_t wb_isa_driver = {
918 	"wbwd",
919 	wb_methods,
920 	sizeof(struct wb_softc)
921 };
922 
923 static devclass_t wb_devclass;
924 
925 DRIVER_MODULE(wb, isa, wb_isa_driver, wb_devclass, NULL, NULL);
926