xref: /freebsd/sys/dev/amdsbwd/amdsbwd.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2009 Andriy Gapon <avg@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * This is a driver for watchdog timer present in AMD SB600/SB7xx/SB8xx
31  * southbridges.
32  * Please see the following specifications for the descriptions of the
33  * registers and flags:
34  * - AMD SB600 Register Reference Guide, Public Version,  Rev. 3.03 (SB600 RRG)
35  *   http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/46155_sb600_rrg_pub_3.03.pdf
36  * - AMD SB700/710/750 Register Reference Guide (RRG)
37  *   http://developer.amd.com/assets/43009_sb7xx_rrg_pub_1.00.pdf
38  * - AMD SB700/710/750 Register Programming Requirements (RPR)
39  *   http://developer.amd.com/assets/42413_sb7xx_rpr_pub_1.00.pdf
40  * - AMD SB800-Series Southbridges Register Reference Guide (RRG)
41  *   http://support.amd.com/us/Embedded_TechDocs/45482.pdf
42  * Please see the following for Watchdog Resource Table specification:
43  * - Watchdog Timer Hardware Requirements for Windows Server 2003 (WDRT)
44  *   http://www.microsoft.com/whdc/system/sysinternals/watchdog.mspx
45  * AMD SB600/SB7xx/SB8xx watchdog hardware seems to conform to the above
46  * specifications, but the table hasn't been spotted in the wild yet.
47  */
48 
49 #include <sys/cdefs.h>
50 __FBSDID("$FreeBSD$");
51 
52 #include "opt_amdsbwd.h"
53 
54 #include <sys/param.h>
55 #include <sys/kernel.h>
56 #include <sys/module.h>
57 #include <sys/systm.h>
58 #include <sys/sysctl.h>
59 #include <sys/bus.h>
60 #include <machine/bus.h>
61 #include <sys/rman.h>
62 #include <machine/resource.h>
63 #include <sys/watchdog.h>
64 
65 #include <dev/pci/pcivar.h>
66 #include <dev/amdsbwd/amd_chipset.h>
67 #include <isa/isavar.h>
68 
69 /*
70  * Registers in the Watchdog IO space.
71  * See SB7xx RRG 2.3.4, WDRT.
72  */
73 #define	AMDSB_WD_CTRL			0x00
74 #define		AMDSB_WD_RUN		0x01
75 #define		AMDSB_WD_FIRED		0x02
76 #define		AMDSB_WD_SHUTDOWN	0x04
77 #define		AMDSB_WD_DISABLE	0x08
78 #define		AMDSB_WD_RESERVED	0x70
79 #define		AMDSB_WD_RELOAD		0x80
80 #define	AMDSB_WD_COUNT			0x04
81 #define		AMDSB_WD_COUNT_MASK	0xffff
82 #define	AMDSB_WDIO_REG_WIDTH		4
83 
84 #define	amdsbwd_verbose_printf(dev, ...)	\
85 	do {						\
86 		if (bootverbose)			\
87 			device_printf(dev, __VA_ARGS__);\
88 	} while (0)
89 
90 struct amdsbwd_softc {
91 	device_t		dev;
92 	eventhandler_tag	ev_tag;
93 	struct resource		*res_ctrl;
94 	struct resource		*res_count;
95 	int			rid_ctrl;
96 	int			rid_count;
97 	int			ms_per_tick;
98 	int			max_ticks;
99 	int			active;
100 	unsigned int		timeout;
101 };
102 
103 static void	amdsbwd_identify(driver_t *driver, device_t parent);
104 static int	amdsbwd_probe(device_t dev);
105 static int	amdsbwd_attach(device_t dev);
106 static int	amdsbwd_detach(device_t dev);
107 static int	amdsbwd_suspend(device_t dev);
108 static int	amdsbwd_resume(device_t dev);
109 
110 static device_method_t amdsbwd_methods[] = {
111 	DEVMETHOD(device_identify,	amdsbwd_identify),
112 	DEVMETHOD(device_probe,		amdsbwd_probe),
113 	DEVMETHOD(device_attach,	amdsbwd_attach),
114 	DEVMETHOD(device_detach,	amdsbwd_detach),
115 	DEVMETHOD(device_suspend,	amdsbwd_suspend),
116 	DEVMETHOD(device_resume,	amdsbwd_resume),
117 #if 0
118 	DEVMETHOD(device_shutdown,	amdsbwd_detach),
119 #endif
120 	DEVMETHOD_END
121 };
122 
123 static devclass_t	amdsbwd_devclass;
124 static driver_t		amdsbwd_driver = {
125 	"amdsbwd",
126 	amdsbwd_methods,
127 	sizeof(struct amdsbwd_softc)
128 };
129 
130 DRIVER_MODULE(amdsbwd, isa, amdsbwd_driver, amdsbwd_devclass, NULL, NULL);
131 
132 
133 static uint8_t
134 pmio_read(struct resource *res, uint8_t reg)
135 {
136 	bus_write_1(res, 0, reg);	/* Index */
137 	return (bus_read_1(res, 1));	/* Data */
138 }
139 
140 static void
141 pmio_write(struct resource *res, uint8_t reg, uint8_t val)
142 {
143 	bus_write_1(res, 0, reg);	/* Index */
144 	bus_write_1(res, 1, val);	/* Data */
145 }
146 
147 static uint32_t
148 wdctrl_read(struct amdsbwd_softc *sc)
149 {
150 	return (bus_read_4(sc->res_ctrl, 0));
151 }
152 
153 static void
154 wdctrl_write(struct amdsbwd_softc *sc, uint32_t val)
155 {
156 	bus_write_4(sc->res_ctrl, 0, val);
157 }
158 
159 static __unused uint32_t
160 wdcount_read(struct amdsbwd_softc *sc)
161 {
162 	return (bus_read_4(sc->res_count, 0));
163 }
164 
165 static void
166 wdcount_write(struct amdsbwd_softc *sc, uint32_t val)
167 {
168 	bus_write_4(sc->res_count, 0, val);
169 }
170 
171 static void
172 amdsbwd_tmr_enable(struct amdsbwd_softc *sc)
173 {
174 	uint32_t val;
175 
176 	val = wdctrl_read(sc);
177 	val |= AMDSB_WD_RUN;
178 	wdctrl_write(sc, val);
179 	sc->active = 1;
180 	amdsbwd_verbose_printf(sc->dev, "timer enabled\n");
181 }
182 
183 static void
184 amdsbwd_tmr_disable(struct amdsbwd_softc *sc)
185 {
186 	uint32_t val;
187 
188 	val = wdctrl_read(sc);
189 	val &= ~AMDSB_WD_RUN;
190 	wdctrl_write(sc, val);
191 	sc->active = 0;
192 	amdsbwd_verbose_printf(sc->dev, "timer disabled\n");
193 }
194 
195 static void
196 amdsbwd_tmr_reload(struct amdsbwd_softc *sc)
197 {
198 	uint32_t val;
199 
200 	val = wdctrl_read(sc);
201 	val |= AMDSB_WD_RELOAD;
202 	wdctrl_write(sc, val);
203 }
204 
205 static void
206 amdsbwd_tmr_set(struct amdsbwd_softc *sc, uint16_t timeout)
207 {
208 
209 	timeout &= AMDSB_WD_COUNT_MASK;
210 	wdcount_write(sc, timeout);
211 	sc->timeout = timeout;
212 	amdsbwd_verbose_printf(sc->dev, "timeout set to %u ticks\n", timeout);
213 }
214 
215 static void
216 amdsbwd_event(void *arg, unsigned int cmd, int *error)
217 {
218 	struct amdsbwd_softc *sc = arg;
219 	uint64_t timeout;
220 
221 	if (cmd != 0) {
222 		timeout = 0;
223 		cmd &= WD_INTERVAL;
224 		if (cmd >= WD_TO_1MS) {
225 			timeout = (uint64_t)1 << (cmd - WD_TO_1MS);
226 			timeout = timeout / sc->ms_per_tick;
227 		}
228 		/* For a too short timeout use 1 tick. */
229 		if (timeout == 0)
230 			timeout = 1;
231 		/* For a too long timeout stop the timer. */
232 		if (timeout > sc->max_ticks)
233 			timeout = 0;
234 	} else {
235 		timeout = 0;
236 	}
237 
238 	if (timeout != 0) {
239 		if (timeout != sc->timeout)
240 			amdsbwd_tmr_set(sc, timeout);
241 		if (!sc->active)
242 			amdsbwd_tmr_enable(sc);
243 		amdsbwd_tmr_reload(sc);
244 		*error = 0;
245 	} else {
246 		if (sc->active)
247 			amdsbwd_tmr_disable(sc);
248 	}
249 }
250 
251 static void
252 amdsbwd_identify(driver_t *driver, device_t parent)
253 {
254 	device_t		child;
255 	device_t		smb_dev;
256 
257 	if (resource_disabled("amdsbwd", 0))
258 		return;
259 	if (device_find_child(parent, "amdsbwd", -1) != NULL)
260 		return;
261 
262 	/*
263 	 * Try to identify SB600/SB7xx by PCI Device ID of SMBus device
264 	 * that should be present at bus 0, device 20, function 0.
265 	 */
266 	smb_dev = pci_find_bsf(0, 20, 0);
267 	if (smb_dev == NULL)
268 		return;
269 	if (pci_get_devid(smb_dev) != AMDSB_SMBUS_DEVID &&
270 	    pci_get_devid(smb_dev) != AMDFCH_SMBUS_DEVID &&
271 	    pci_get_devid(smb_dev) != AMDCZ_SMBUS_DEVID)
272 		return;
273 
274 	child = BUS_ADD_CHILD(parent, ISA_ORDER_SPECULATIVE, "amdsbwd", -1);
275 	if (child == NULL)
276 		device_printf(parent, "add amdsbwd child failed\n");
277 }
278 
279 
280 static void
281 amdsbwd_probe_sb7xx(device_t dev, struct resource *pmres, uint32_t *addr)
282 {
283 	uint8_t	val;
284 	int	i;
285 
286 	/* Report cause of previous reset for user's convenience. */
287 	val = pmio_read(pmres, AMDSB_PM_RESET_STATUS0);
288 	if (val != 0)
289 		amdsbwd_verbose_printf(dev, "ResetStatus0 = %#04x\n", val);
290 	val = pmio_read(pmres, AMDSB_PM_RESET_STATUS1);
291 	if (val != 0)
292 		amdsbwd_verbose_printf(dev, "ResetStatus1 = %#04x\n", val);
293 	if ((val & AMDSB_WD_RST_STS) != 0)
294 		device_printf(dev, "Previous Reset was caused by Watchdog\n");
295 
296 	/* Find base address of memory mapped WDT registers. */
297 	for (*addr = 0, i = 0; i < 4; i++) {
298 		*addr <<= 8;
299 		*addr |= pmio_read(pmres, AMDSB_PM_WDT_BASE_MSB - i);
300 	}
301 	*addr &= ~0x07u;
302 
303 	/* Set watchdog timer tick to 1s. */
304 	val = pmio_read(pmres, AMDSB_PM_WDT_CTRL);
305 	val &= ~AMDSB_WDT_RES_MASK;
306 	val |= AMDSB_WDT_RES_1S;
307 	pmio_write(pmres, AMDSB_PM_WDT_CTRL, val);
308 
309 	/* Enable watchdog device (in stopped state). */
310 	val = pmio_read(pmres, AMDSB_PM_WDT_CTRL);
311 	val &= ~AMDSB_WDT_DISABLE;
312 	pmio_write(pmres, AMDSB_PM_WDT_CTRL, val);
313 
314 	/*
315 	 * XXX TODO: Ensure that watchdog decode is enabled
316 	 * (register 0x41, bit 3).
317 	 */
318 	device_set_desc(dev, "AMD SB600/SB7xx Watchdog Timer");
319 }
320 
321 static void
322 amdsbwd_probe_sb8xx(device_t dev, struct resource *pmres, uint32_t *addr)
323 {
324 	uint32_t	val;
325 	int		i;
326 
327 	/* Report cause of previous reset for user's convenience. */
328 
329 	val = pmio_read(pmres, AMDSB8_PM_RESET_CTRL);
330 	if ((val & AMDSB8_RST_STS_DIS) != 0) {
331 		val &= ~AMDSB8_RST_STS_DIS;
332 		pmio_write(pmres, AMDSB8_PM_RESET_CTRL, val);
333 	}
334 	val = 0;
335 	for (i = 3; i >= 0; i--) {
336 		val <<= 8;
337 		val |= pmio_read(pmres, AMDSB8_PM_RESET_STATUS + i);
338 	}
339 	if (val != 0)
340 		amdsbwd_verbose_printf(dev, "ResetStatus = 0x%08x\n", val);
341 	if ((val & AMDSB8_WD_RST_STS) != 0)
342 		device_printf(dev, "Previous Reset was caused by Watchdog\n");
343 
344 	/* Find base address of memory mapped WDT registers. */
345 	for (*addr = 0, i = 0; i < 4; i++) {
346 		*addr <<= 8;
347 		*addr |= pmio_read(pmres, AMDSB8_PM_WDT_EN + 3 - i);
348 	}
349 	*addr &= ~0x07u;
350 
351 	/* Set watchdog timer tick to 1s. */
352 	val = pmio_read(pmres, AMDSB8_PM_WDT_CTRL);
353 	val &= ~AMDSB8_WDT_RES_MASK;
354 	val |= AMDSB8_WDT_1HZ;
355 	pmio_write(pmres, AMDSB8_PM_WDT_CTRL, val);
356 #ifdef AMDSBWD_DEBUG
357 	val = pmio_read(pmres, AMDSB8_PM_WDT_CTRL);
358 	amdsbwd_verbose_printf(dev, "AMDSB8_PM_WDT_CTRL value = %#04x\n", val);
359 #endif
360 
361 	/*
362 	 * Enable watchdog device (in stopped state)
363 	 * and decoding of its address.
364 	 */
365 	val = pmio_read(pmres, AMDSB8_PM_WDT_EN);
366 	val &= ~AMDSB8_WDT_DISABLE;
367 	val |= AMDSB8_WDT_DEC_EN;
368 	pmio_write(pmres, AMDSB8_PM_WDT_EN, val);
369 #ifdef AMDSBWD_DEBUG
370 	val = pmio_read(pmres, AMDSB8_PM_WDT_EN);
371 	device_printf(dev, "AMDSB8_PM_WDT_EN value = %#04x\n", val);
372 #endif
373 	device_set_desc(dev, "AMD SB8xx/SB9xx/Axx Watchdog Timer");
374 }
375 
376 static void
377 amdsbwd_probe_fch41(device_t dev, struct resource *pmres, uint32_t *addr)
378 {
379 	uint8_t	val;
380 
381 	val = pmio_read(pmres, AMDFCH41_PM_ISA_CTRL);
382 	if ((val & AMDFCH41_MMIO_EN) != 0) {
383 		/* Fixed offset for the watchdog within ACPI MMIO range. */
384 		amdsbwd_verbose_printf(dev, "ACPI MMIO range is enabled\n");
385 		*addr = AMDFCH41_MMIO_ADDR + AMDFCH41_MMIO_WDT_OFF;
386 	} else {
387 		/*
388 		 * Enable decoding of watchdog MMIO address.
389 		 */
390 		val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN0);
391 		val |= AMDFCH41_WDT_EN;
392 		pmio_write(pmres, AMDFCH41_PM_DECODE_EN0, val);
393 #ifdef AMDSBWD_DEBUG
394 		val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN0);
395 		device_printf(dev, "AMDFCH41_PM_DECODE_EN0 value = %#04x\n",
396 		    val);
397 #endif
398 
399 		/* Special fixed MMIO range for the watchdog. */
400 		*addr = AMDFCH41_WDT_FIXED_ADDR;
401 	}
402 
403 	/*
404 	 * Set watchdog timer tick to 1s and
405 	 * enable the watchdog device (in stopped state).
406 	 */
407 	val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN3);
408 	val &= ~AMDFCH41_WDT_RES_MASK;
409 	val |= AMDFCH41_WDT_RES_1S;
410 	val &= ~AMDFCH41_WDT_EN_MASK;
411 	val |= AMDFCH41_WDT_ENABLE;
412 	pmio_write(pmres, AMDFCH41_PM_DECODE_EN3, val);
413 #ifdef AMDSBWD_DEBUG
414 	val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN3);
415 	amdsbwd_verbose_printf(dev, "AMDFCH41_PM_DECODE_EN3 value = %#04x\n",
416 	    val);
417 #endif
418 	device_set_desc(dev, "AMD FCH Rev 41h+ Watchdog Timer");
419 }
420 
421 static int
422 amdsbwd_probe(device_t dev)
423 {
424 	struct resource		*res;
425 	device_t		smb_dev;
426 	uint32_t		addr;
427 	int			rid;
428 	int			rc;
429 	uint32_t		devid;
430 	uint8_t			revid;
431 
432 	/* Do not claim some ISA PnP device by accident. */
433 	if (isa_get_logicalid(dev) != 0)
434 		return (ENXIO);
435 
436 	rc = bus_set_resource(dev, SYS_RES_IOPORT, 0, AMDSB_PMIO_INDEX,
437 	    AMDSB_PMIO_WIDTH);
438 	if (rc != 0) {
439 		device_printf(dev, "bus_set_resource for IO failed\n");
440 		return (ENXIO);
441 	}
442 	rid = 0;
443 	res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &rid,
444 	    RF_ACTIVE | RF_SHAREABLE);
445 	if (res == NULL) {
446 		device_printf(dev, "bus_alloc_resource for IO failed\n");
447 		return (ENXIO);
448 	}
449 
450 	smb_dev = pci_find_bsf(0, 20, 0);
451 	KASSERT(smb_dev != NULL, ("can't find SMBus PCI device\n"));
452 	devid = pci_get_devid(smb_dev);
453 	revid = pci_get_revid(smb_dev);
454 	if (devid == AMDSB_SMBUS_DEVID && revid < AMDSB8_SMBUS_REVID)
455 		amdsbwd_probe_sb7xx(dev, res, &addr);
456 	else if (devid == AMDSB_SMBUS_DEVID ||
457 	    (devid == AMDFCH_SMBUS_DEVID && revid < AMDFCH41_SMBUS_REVID) ||
458 	    (devid == AMDCZ_SMBUS_DEVID  && revid < AMDCZ49_SMBUS_REVID))
459 		amdsbwd_probe_sb8xx(dev, res, &addr);
460 	else
461 		amdsbwd_probe_fch41(dev, res, &addr);
462 
463 	bus_release_resource(dev, SYS_RES_IOPORT, rid, res);
464 	bus_delete_resource(dev, SYS_RES_IOPORT, rid);
465 
466 	amdsbwd_verbose_printf(dev, "memory base address = %#010x\n", addr);
467 	rc = bus_set_resource(dev, SYS_RES_MEMORY, 0, addr + AMDSB_WD_CTRL,
468 	    AMDSB_WDIO_REG_WIDTH);
469 	if (rc != 0) {
470 		device_printf(dev, "bus_set_resource for control failed\n");
471 		return (ENXIO);
472 	}
473 	rc = bus_set_resource(dev, SYS_RES_MEMORY, 1, addr + AMDSB_WD_COUNT,
474 	    AMDSB_WDIO_REG_WIDTH);
475 	if (rc != 0) {
476 		device_printf(dev, "bus_set_resource for count failed\n");
477 		return (ENXIO);
478 	}
479 
480 	return (0);
481 }
482 
483 static int
484 amdsbwd_attach_sb(device_t dev, struct amdsbwd_softc *sc)
485 {
486 
487 	sc->max_ticks = UINT16_MAX;
488 	sc->rid_ctrl = 0;
489 	sc->rid_count = 1;
490 
491 	sc->ms_per_tick = 1000;
492 
493 	sc->res_ctrl = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
494 	    &sc->rid_ctrl, RF_ACTIVE);
495 	if (sc->res_ctrl == NULL) {
496 		device_printf(dev, "bus_alloc_resource for ctrl failed\n");
497 		return (ENXIO);
498 	}
499 	sc->res_count = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
500 	    &sc->rid_count, RF_ACTIVE);
501 	if (sc->res_count == NULL) {
502 		device_printf(dev, "bus_alloc_resource for count failed\n");
503 		return (ENXIO);
504 	}
505 	return (0);
506 }
507 
508 static int
509 amdsbwd_attach(device_t dev)
510 {
511 	struct amdsbwd_softc	*sc;
512 	int			rc;
513 
514 	sc = device_get_softc(dev);
515 	sc->dev = dev;
516 
517 	rc = amdsbwd_attach_sb(dev, sc);
518 	if (rc != 0)
519 		goto fail;
520 
521 #ifdef AMDSBWD_DEBUG
522 	device_printf(dev, "wd ctrl = %#04x\n", wdctrl_read(sc));
523 	device_printf(dev, "wd count = %#04x\n", wdcount_read(sc));
524 #endif
525 
526 	/* Setup initial state of Watchdog Control. */
527 	wdctrl_write(sc, AMDSB_WD_FIRED);
528 
529 	if (wdctrl_read(sc) & AMDSB_WD_DISABLE) {
530 		device_printf(dev, "watchdog hardware is disabled\n");
531 		goto fail;
532 	}
533 
534 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, amdsbwd_event, sc,
535 	    EVENTHANDLER_PRI_ANY);
536 
537 	return (0);
538 
539 fail:
540 	amdsbwd_detach(dev);
541 	return (ENXIO);
542 }
543 
544 static int
545 amdsbwd_detach(device_t dev)
546 {
547 	struct amdsbwd_softc *sc;
548 
549 	sc = device_get_softc(dev);
550 	if (sc->ev_tag != NULL)
551 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
552 
553 	if (sc->active)
554 		amdsbwd_tmr_disable(sc);
555 
556 	if (sc->res_ctrl != NULL)
557 		bus_release_resource(dev, SYS_RES_MEMORY, sc->rid_ctrl,
558 		    sc->res_ctrl);
559 
560 	if (sc->res_count != NULL)
561 		bus_release_resource(dev, SYS_RES_MEMORY, sc->rid_count,
562 		    sc->res_count);
563 
564 	return (0);
565 }
566 
567 static int
568 amdsbwd_suspend(device_t dev)
569 {
570 	struct amdsbwd_softc *sc;
571 	uint32_t val;
572 
573 	sc = device_get_softc(dev);
574 	val = wdctrl_read(sc);
575 	val &= ~AMDSB_WD_RUN;
576 	wdctrl_write(sc, val);
577 	return (0);
578 }
579 
580 static int
581 amdsbwd_resume(device_t dev)
582 {
583 	struct amdsbwd_softc *sc;
584 
585 	sc = device_get_softc(dev);
586 	wdctrl_write(sc, AMDSB_WD_FIRED);
587 	if (sc->active) {
588 		amdsbwd_tmr_set(sc, sc->timeout);
589 		amdsbwd_tmr_enable(sc);
590 		amdsbwd_tmr_reload(sc);
591 	}
592 	return (0);
593 }
594