xref: /freebsd/sys/dev/amdsbwd/amdsbwd.c (revision f6a3b357e9be4c6423c85eff9a847163a0d307c8)
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/eventhandler.h>
56 #include <sys/kernel.h>
57 #include <sys/module.h>
58 #include <sys/systm.h>
59 #include <sys/sysctl.h>
60 #include <sys/bus.h>
61 #include <machine/bus.h>
62 #include <sys/rman.h>
63 #include <machine/resource.h>
64 #include <sys/watchdog.h>
65 
66 #include <dev/pci/pcivar.h>
67 #include <dev/amdsbwd/amd_chipset.h>
68 #include <isa/isavar.h>
69 
70 /*
71  * Registers in the Watchdog IO space.
72  * See SB7xx RRG 2.3.4, WDRT.
73  */
74 #define	AMDSB_WD_CTRL			0x00
75 #define		AMDSB_WD_RUN		0x01
76 #define		AMDSB_WD_FIRED		0x02
77 #define		AMDSB_WD_SHUTDOWN	0x04
78 #define		AMDSB_WD_DISABLE	0x08
79 #define		AMDSB_WD_RESERVED	0x70
80 #define		AMDSB_WD_RELOAD		0x80
81 #define	AMDSB_WD_COUNT			0x04
82 #define		AMDSB_WD_COUNT_MASK	0xffff
83 #define	AMDSB_WDIO_REG_WIDTH		4
84 
85 #define	amdsbwd_verbose_printf(dev, ...)	\
86 	do {						\
87 		if (bootverbose)			\
88 			device_printf(dev, __VA_ARGS__);\
89 	} while (0)
90 
91 struct amdsbwd_softc {
92 	device_t		dev;
93 	eventhandler_tag	ev_tag;
94 	struct resource		*res_ctrl;
95 	struct resource		*res_count;
96 	int			rid_ctrl;
97 	int			rid_count;
98 	int			ms_per_tick;
99 	int			max_ticks;
100 	int			active;
101 	unsigned int		timeout;
102 };
103 
104 static void	amdsbwd_identify(driver_t *driver, device_t parent);
105 static int	amdsbwd_probe(device_t dev);
106 static int	amdsbwd_attach(device_t dev);
107 static int	amdsbwd_detach(device_t dev);
108 static int	amdsbwd_suspend(device_t dev);
109 static int	amdsbwd_resume(device_t dev);
110 
111 static device_method_t amdsbwd_methods[] = {
112 	DEVMETHOD(device_identify,	amdsbwd_identify),
113 	DEVMETHOD(device_probe,		amdsbwd_probe),
114 	DEVMETHOD(device_attach,	amdsbwd_attach),
115 	DEVMETHOD(device_detach,	amdsbwd_detach),
116 	DEVMETHOD(device_suspend,	amdsbwd_suspend),
117 	DEVMETHOD(device_resume,	amdsbwd_resume),
118 #if 0
119 	DEVMETHOD(device_shutdown,	amdsbwd_detach),
120 #endif
121 	DEVMETHOD_END
122 };
123 
124 static devclass_t	amdsbwd_devclass;
125 static driver_t		amdsbwd_driver = {
126 	"amdsbwd",
127 	amdsbwd_methods,
128 	sizeof(struct amdsbwd_softc)
129 };
130 
131 DRIVER_MODULE(amdsbwd, isa, amdsbwd_driver, amdsbwd_devclass, NULL, NULL);
132 
133 
134 static uint8_t
135 pmio_read(struct resource *res, uint8_t reg)
136 {
137 	bus_write_1(res, 0, reg);	/* Index */
138 	return (bus_read_1(res, 1));	/* Data */
139 }
140 
141 static void
142 pmio_write(struct resource *res, uint8_t reg, uint8_t val)
143 {
144 	bus_write_1(res, 0, reg);	/* Index */
145 	bus_write_1(res, 1, val);	/* Data */
146 }
147 
148 static uint32_t
149 wdctrl_read(struct amdsbwd_softc *sc)
150 {
151 	return (bus_read_4(sc->res_ctrl, 0));
152 }
153 
154 static void
155 wdctrl_write(struct amdsbwd_softc *sc, uint32_t val)
156 {
157 	bus_write_4(sc->res_ctrl, 0, val);
158 }
159 
160 static __unused uint32_t
161 wdcount_read(struct amdsbwd_softc *sc)
162 {
163 	return (bus_read_4(sc->res_count, 0));
164 }
165 
166 static void
167 wdcount_write(struct amdsbwd_softc *sc, uint32_t val)
168 {
169 	bus_write_4(sc->res_count, 0, val);
170 }
171 
172 static void
173 amdsbwd_tmr_enable(struct amdsbwd_softc *sc)
174 {
175 	uint32_t val;
176 
177 	val = wdctrl_read(sc);
178 	val |= AMDSB_WD_RUN;
179 	wdctrl_write(sc, val);
180 	sc->active = 1;
181 	amdsbwd_verbose_printf(sc->dev, "timer enabled\n");
182 }
183 
184 static void
185 amdsbwd_tmr_disable(struct amdsbwd_softc *sc)
186 {
187 	uint32_t val;
188 
189 	val = wdctrl_read(sc);
190 	val &= ~AMDSB_WD_RUN;
191 	wdctrl_write(sc, val);
192 	sc->active = 0;
193 	amdsbwd_verbose_printf(sc->dev, "timer disabled\n");
194 }
195 
196 static void
197 amdsbwd_tmr_reload(struct amdsbwd_softc *sc)
198 {
199 	uint32_t val;
200 
201 	val = wdctrl_read(sc);
202 	val |= AMDSB_WD_RELOAD;
203 	wdctrl_write(sc, val);
204 }
205 
206 static void
207 amdsbwd_tmr_set(struct amdsbwd_softc *sc, uint16_t timeout)
208 {
209 
210 	timeout &= AMDSB_WD_COUNT_MASK;
211 	wdcount_write(sc, timeout);
212 	sc->timeout = timeout;
213 	amdsbwd_verbose_printf(sc->dev, "timeout set to %u ticks\n", timeout);
214 }
215 
216 static void
217 amdsbwd_event(void *arg, unsigned int cmd, int *error)
218 {
219 	struct amdsbwd_softc *sc = arg;
220 	uint64_t timeout;
221 
222 	if (cmd != 0) {
223 		timeout = 0;
224 		cmd &= WD_INTERVAL;
225 		if (cmd >= WD_TO_1MS) {
226 			timeout = (uint64_t)1 << (cmd - WD_TO_1MS);
227 			timeout = timeout / sc->ms_per_tick;
228 		}
229 		/* For a too short timeout use 1 tick. */
230 		if (timeout == 0)
231 			timeout = 1;
232 		/* For a too long timeout stop the timer. */
233 		if (timeout > sc->max_ticks)
234 			timeout = 0;
235 	} else {
236 		timeout = 0;
237 	}
238 
239 	if (timeout != 0) {
240 		if (timeout != sc->timeout)
241 			amdsbwd_tmr_set(sc, timeout);
242 		if (!sc->active)
243 			amdsbwd_tmr_enable(sc);
244 		amdsbwd_tmr_reload(sc);
245 		*error = 0;
246 	} else {
247 		if (sc->active)
248 			amdsbwd_tmr_disable(sc);
249 	}
250 }
251 
252 static void
253 amdsbwd_identify(driver_t *driver, device_t parent)
254 {
255 	device_t		child;
256 	device_t		smb_dev;
257 
258 	if (resource_disabled("amdsbwd", 0))
259 		return;
260 	if (device_find_child(parent, "amdsbwd", -1) != NULL)
261 		return;
262 
263 	/*
264 	 * Try to identify SB600/SB7xx by PCI Device ID of SMBus device
265 	 * that should be present at bus 0, device 20, function 0.
266 	 */
267 	smb_dev = pci_find_bsf(0, 20, 0);
268 	if (smb_dev == NULL)
269 		return;
270 	if (pci_get_devid(smb_dev) != AMDSB_SMBUS_DEVID &&
271 	    pci_get_devid(smb_dev) != AMDFCH_SMBUS_DEVID &&
272 	    pci_get_devid(smb_dev) != AMDCZ_SMBUS_DEVID)
273 		return;
274 
275 	child = BUS_ADD_CHILD(parent, ISA_ORDER_SPECULATIVE, "amdsbwd", -1);
276 	if (child == NULL)
277 		device_printf(parent, "add amdsbwd child failed\n");
278 }
279 
280 
281 static void
282 amdsbwd_probe_sb7xx(device_t dev, struct resource *pmres, uint32_t *addr)
283 {
284 	uint8_t	val;
285 	int	i;
286 
287 	/* Report cause of previous reset for user's convenience. */
288 	val = pmio_read(pmres, AMDSB_PM_RESET_STATUS0);
289 	if (val != 0)
290 		amdsbwd_verbose_printf(dev, "ResetStatus0 = %#04x\n", val);
291 	val = pmio_read(pmres, AMDSB_PM_RESET_STATUS1);
292 	if (val != 0)
293 		amdsbwd_verbose_printf(dev, "ResetStatus1 = %#04x\n", val);
294 	if ((val & AMDSB_WD_RST_STS) != 0)
295 		device_printf(dev, "Previous Reset was caused by Watchdog\n");
296 
297 	/* Find base address of memory mapped WDT registers. */
298 	for (*addr = 0, i = 0; i < 4; i++) {
299 		*addr <<= 8;
300 		*addr |= pmio_read(pmres, AMDSB_PM_WDT_BASE_MSB - i);
301 	}
302 	*addr &= ~0x07u;
303 
304 	/* Set watchdog timer tick to 1s. */
305 	val = pmio_read(pmres, AMDSB_PM_WDT_CTRL);
306 	val &= ~AMDSB_WDT_RES_MASK;
307 	val |= AMDSB_WDT_RES_1S;
308 	pmio_write(pmres, AMDSB_PM_WDT_CTRL, val);
309 
310 	/* Enable watchdog device (in stopped state). */
311 	val = pmio_read(pmres, AMDSB_PM_WDT_CTRL);
312 	val &= ~AMDSB_WDT_DISABLE;
313 	pmio_write(pmres, AMDSB_PM_WDT_CTRL, val);
314 
315 	/*
316 	 * XXX TODO: Ensure that watchdog decode is enabled
317 	 * (register 0x41, bit 3).
318 	 */
319 	device_set_desc(dev, "AMD SB600/SB7xx Watchdog Timer");
320 }
321 
322 static void
323 amdsbwd_probe_sb8xx(device_t dev, struct resource *pmres, uint32_t *addr)
324 {
325 	uint32_t	val;
326 	int		i;
327 
328 	/* Report cause of previous reset for user's convenience. */
329 
330 	val = pmio_read(pmres, AMDSB8_PM_RESET_CTRL);
331 	if ((val & AMDSB8_RST_STS_DIS) != 0) {
332 		val &= ~AMDSB8_RST_STS_DIS;
333 		pmio_write(pmres, AMDSB8_PM_RESET_CTRL, val);
334 	}
335 	val = 0;
336 	for (i = 3; i >= 0; i--) {
337 		val <<= 8;
338 		val |= pmio_read(pmres, AMDSB8_PM_RESET_STATUS + i);
339 	}
340 	if (val != 0)
341 		amdsbwd_verbose_printf(dev, "ResetStatus = 0x%08x\n", val);
342 	if ((val & AMDSB8_WD_RST_STS) != 0)
343 		device_printf(dev, "Previous Reset was caused by Watchdog\n");
344 
345 	/* Find base address of memory mapped WDT registers. */
346 	for (*addr = 0, i = 0; i < 4; i++) {
347 		*addr <<= 8;
348 		*addr |= pmio_read(pmres, AMDSB8_PM_WDT_EN + 3 - i);
349 	}
350 	*addr &= ~0x07u;
351 
352 	/* Set watchdog timer tick to 1s. */
353 	val = pmio_read(pmres, AMDSB8_PM_WDT_CTRL);
354 	val &= ~AMDSB8_WDT_RES_MASK;
355 	val |= AMDSB8_WDT_1HZ;
356 	pmio_write(pmres, AMDSB8_PM_WDT_CTRL, val);
357 #ifdef AMDSBWD_DEBUG
358 	val = pmio_read(pmres, AMDSB8_PM_WDT_CTRL);
359 	amdsbwd_verbose_printf(dev, "AMDSB8_PM_WDT_CTRL value = %#04x\n", val);
360 #endif
361 
362 	/*
363 	 * Enable watchdog device (in stopped state)
364 	 * and decoding of its address.
365 	 */
366 	val = pmio_read(pmres, AMDSB8_PM_WDT_EN);
367 	val &= ~AMDSB8_WDT_DISABLE;
368 	val |= AMDSB8_WDT_DEC_EN;
369 	pmio_write(pmres, AMDSB8_PM_WDT_EN, val);
370 #ifdef AMDSBWD_DEBUG
371 	val = pmio_read(pmres, AMDSB8_PM_WDT_EN);
372 	device_printf(dev, "AMDSB8_PM_WDT_EN value = %#04x\n", val);
373 #endif
374 	device_set_desc(dev, "AMD SB8xx/SB9xx/Axx Watchdog Timer");
375 }
376 
377 static void
378 amdsbwd_probe_fch41(device_t dev, struct resource *pmres, uint32_t *addr)
379 {
380 	uint8_t	val;
381 
382 	val = pmio_read(pmres, AMDFCH41_PM_ISA_CTRL);
383 	if ((val & AMDFCH41_MMIO_EN) != 0) {
384 		/* Fixed offset for the watchdog within ACPI MMIO range. */
385 		amdsbwd_verbose_printf(dev, "ACPI MMIO range is enabled\n");
386 		*addr = AMDFCH41_MMIO_ADDR + AMDFCH41_MMIO_WDT_OFF;
387 	} else {
388 		/*
389 		 * Enable decoding of watchdog MMIO address.
390 		 */
391 		val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN0);
392 		val |= AMDFCH41_WDT_EN;
393 		pmio_write(pmres, AMDFCH41_PM_DECODE_EN0, val);
394 #ifdef AMDSBWD_DEBUG
395 		val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN0);
396 		device_printf(dev, "AMDFCH41_PM_DECODE_EN0 value = %#04x\n",
397 		    val);
398 #endif
399 
400 		/* Special fixed MMIO range for the watchdog. */
401 		*addr = AMDFCH41_WDT_FIXED_ADDR;
402 	}
403 
404 	/*
405 	 * Set watchdog timer tick to 1s and
406 	 * enable the watchdog device (in stopped state).
407 	 */
408 	val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN3);
409 	val &= ~AMDFCH41_WDT_RES_MASK;
410 	val |= AMDFCH41_WDT_RES_1S;
411 	val &= ~AMDFCH41_WDT_EN_MASK;
412 	val |= AMDFCH41_WDT_ENABLE;
413 	pmio_write(pmres, AMDFCH41_PM_DECODE_EN3, val);
414 #ifdef AMDSBWD_DEBUG
415 	val = pmio_read(pmres, AMDFCH41_PM_DECODE_EN3);
416 	amdsbwd_verbose_printf(dev, "AMDFCH41_PM_DECODE_EN3 value = %#04x\n",
417 	    val);
418 #endif
419 	device_set_desc(dev, "AMD FCH Rev 41h+ Watchdog Timer");
420 }
421 
422 static int
423 amdsbwd_probe(device_t dev)
424 {
425 	struct resource		*res;
426 	device_t		smb_dev;
427 	uint32_t		addr;
428 	int			rid;
429 	int			rc;
430 	uint32_t		devid;
431 	uint8_t			revid;
432 
433 	/* Do not claim some ISA PnP device by accident. */
434 	if (isa_get_logicalid(dev) != 0)
435 		return (ENXIO);
436 
437 	rc = bus_set_resource(dev, SYS_RES_IOPORT, 0, AMDSB_PMIO_INDEX,
438 	    AMDSB_PMIO_WIDTH);
439 	if (rc != 0) {
440 		device_printf(dev, "bus_set_resource for IO failed\n");
441 		return (ENXIO);
442 	}
443 	rid = 0;
444 	res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &rid,
445 	    RF_ACTIVE | RF_SHAREABLE);
446 	if (res == NULL) {
447 		device_printf(dev, "bus_alloc_resource for IO failed\n");
448 		return (ENXIO);
449 	}
450 
451 	smb_dev = pci_find_bsf(0, 20, 0);
452 	KASSERT(smb_dev != NULL, ("can't find SMBus PCI device\n"));
453 	devid = pci_get_devid(smb_dev);
454 	revid = pci_get_revid(smb_dev);
455 	if (devid == AMDSB_SMBUS_DEVID && revid < AMDSB8_SMBUS_REVID)
456 		amdsbwd_probe_sb7xx(dev, res, &addr);
457 	else if (devid == AMDSB_SMBUS_DEVID ||
458 	    (devid == AMDFCH_SMBUS_DEVID && revid < AMDFCH41_SMBUS_REVID) ||
459 	    (devid == AMDCZ_SMBUS_DEVID  && revid < AMDCZ49_SMBUS_REVID))
460 		amdsbwd_probe_sb8xx(dev, res, &addr);
461 	else
462 		amdsbwd_probe_fch41(dev, res, &addr);
463 
464 	bus_release_resource(dev, SYS_RES_IOPORT, rid, res);
465 	bus_delete_resource(dev, SYS_RES_IOPORT, rid);
466 
467 	amdsbwd_verbose_printf(dev, "memory base address = %#010x\n", addr);
468 	rc = bus_set_resource(dev, SYS_RES_MEMORY, 0, addr + AMDSB_WD_CTRL,
469 	    AMDSB_WDIO_REG_WIDTH);
470 	if (rc != 0) {
471 		device_printf(dev, "bus_set_resource for control failed\n");
472 		return (ENXIO);
473 	}
474 	rc = bus_set_resource(dev, SYS_RES_MEMORY, 1, addr + AMDSB_WD_COUNT,
475 	    AMDSB_WDIO_REG_WIDTH);
476 	if (rc != 0) {
477 		device_printf(dev, "bus_set_resource for count failed\n");
478 		return (ENXIO);
479 	}
480 
481 	return (0);
482 }
483 
484 static int
485 amdsbwd_attach_sb(device_t dev, struct amdsbwd_softc *sc)
486 {
487 
488 	sc->max_ticks = UINT16_MAX;
489 	sc->rid_ctrl = 0;
490 	sc->rid_count = 1;
491 
492 	sc->ms_per_tick = 1000;
493 
494 	sc->res_ctrl = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
495 	    &sc->rid_ctrl, RF_ACTIVE);
496 	if (sc->res_ctrl == NULL) {
497 		device_printf(dev, "bus_alloc_resource for ctrl failed\n");
498 		return (ENXIO);
499 	}
500 	sc->res_count = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
501 	    &sc->rid_count, RF_ACTIVE);
502 	if (sc->res_count == NULL) {
503 		device_printf(dev, "bus_alloc_resource for count failed\n");
504 		return (ENXIO);
505 	}
506 	return (0);
507 }
508 
509 static int
510 amdsbwd_attach(device_t dev)
511 {
512 	struct amdsbwd_softc	*sc;
513 	int			rc;
514 
515 	sc = device_get_softc(dev);
516 	sc->dev = dev;
517 
518 	rc = amdsbwd_attach_sb(dev, sc);
519 	if (rc != 0)
520 		goto fail;
521 
522 #ifdef AMDSBWD_DEBUG
523 	device_printf(dev, "wd ctrl = %#04x\n", wdctrl_read(sc));
524 	device_printf(dev, "wd count = %#04x\n", wdcount_read(sc));
525 #endif
526 
527 	/* Setup initial state of Watchdog Control. */
528 	wdctrl_write(sc, AMDSB_WD_FIRED);
529 
530 	if (wdctrl_read(sc) & AMDSB_WD_DISABLE) {
531 		device_printf(dev, "watchdog hardware is disabled\n");
532 		goto fail;
533 	}
534 
535 	sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, amdsbwd_event, sc,
536 	    EVENTHANDLER_PRI_ANY);
537 
538 	return (0);
539 
540 fail:
541 	amdsbwd_detach(dev);
542 	return (ENXIO);
543 }
544 
545 static int
546 amdsbwd_detach(device_t dev)
547 {
548 	struct amdsbwd_softc *sc;
549 
550 	sc = device_get_softc(dev);
551 	if (sc->ev_tag != NULL)
552 		EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
553 
554 	if (sc->active)
555 		amdsbwd_tmr_disable(sc);
556 
557 	if (sc->res_ctrl != NULL)
558 		bus_release_resource(dev, SYS_RES_MEMORY, sc->rid_ctrl,
559 		    sc->res_ctrl);
560 
561 	if (sc->res_count != NULL)
562 		bus_release_resource(dev, SYS_RES_MEMORY, sc->rid_count,
563 		    sc->res_count);
564 
565 	return (0);
566 }
567 
568 static int
569 amdsbwd_suspend(device_t dev)
570 {
571 	struct amdsbwd_softc *sc;
572 	uint32_t val;
573 
574 	sc = device_get_softc(dev);
575 	val = wdctrl_read(sc);
576 	val &= ~AMDSB_WD_RUN;
577 	wdctrl_write(sc, val);
578 	return (0);
579 }
580 
581 static int
582 amdsbwd_resume(device_t dev)
583 {
584 	struct amdsbwd_softc *sc;
585 
586 	sc = device_get_softc(dev);
587 	wdctrl_write(sc, AMDSB_WD_FIRED);
588 	if (sc->active) {
589 		amdsbwd_tmr_set(sc, sc->timeout);
590 		amdsbwd_tmr_enable(sc);
591 		amdsbwd_tmr_reload(sc);
592 	}
593 	return (0);
594 }
595