xref: /netbsd/sys/dev/acpi/wmi/wmi_acpi.c (revision 6550d01e)
1 /*	$NetBSD: wmi_acpi.c,v 1.11 2010/10/28 15:55:04 jruoho Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009, 2010 Jukka Ruohonen <jruohonen@iki.fi>
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  *
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 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: wmi_acpi.c,v 1.11 2010/10/28 15:55:04 jruoho Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/device.h>
34 #include <sys/endian.h>
35 #include <sys/kmem.h>
36 #include <sys/systm.h>
37 #include <sys/module.h>
38 
39 #include <dev/acpi/acpireg.h>
40 #include <dev/acpi/acpivar.h>
41 #include <dev/acpi/acpi_ecvar.h>
42 #include <dev/acpi/wmi/wmi_acpivar.h>
43 
44 #define _COMPONENT          ACPI_RESOURCE_COMPONENT
45 ACPI_MODULE_NAME            ("wmi_acpi")
46 
47 /*
48  * This implements something called "Microsoft Windows Management
49  * Instrumentation" (WMI). This subset of ACPI is desribed in:
50  *
51  * http://www.microsoft.com/whdc/system/pnppwr/wmi/wmi-acpi.mspx
52  *
53  * (Obtained on Thu Feb 12 18:21:44 EET 2009.)
54  */
55 
56 static int		acpi_wmi_match(device_t, cfdata_t, void *);
57 static void		acpi_wmi_attach(device_t, device_t, void *);
58 static int		acpi_wmi_detach(device_t, int);
59 static int		acpi_wmi_rescan(device_t, const char *, const int *);
60 static void		acpi_wmi_childdet(device_t, device_t);
61 static int		acpi_wmi_print(void *, const char *);
62 static bool		acpi_wmi_init(struct acpi_wmi_softc *);
63 static void		acpi_wmi_init_ec(struct acpi_wmi_softc *);
64 static bool		acpi_wmi_add(struct acpi_wmi_softc *, ACPI_OBJECT *);
65 static void		acpi_wmi_del(struct acpi_wmi_softc *);
66 static void		acpi_wmi_dump(struct acpi_wmi_softc *);
67 static ACPI_STATUS	acpi_wmi_guid_get(struct acpi_wmi_softc *,
68 				const char *, struct wmi_t **);
69 static void		acpi_wmi_event_add(struct acpi_wmi_softc *);
70 static void		acpi_wmi_event_del(struct acpi_wmi_softc *);
71 static void		acpi_wmi_event_handler(ACPI_HANDLE, uint32_t, void *);
72 static ACPI_STATUS	acpi_wmi_ec_handler(uint32_t, ACPI_PHYSICAL_ADDRESS,
73 				uint32_t, ACPI_INTEGER *, void *, void *);
74 static bool		acpi_wmi_suspend(device_t, const pmf_qual_t *);
75 static bool		acpi_wmi_resume(device_t, const pmf_qual_t *);
76 static ACPI_STATUS	acpi_wmi_enable(ACPI_HANDLE, const char *, bool, bool);
77 static bool		acpi_wmi_input(struct wmi_t *, uint8_t, uint8_t);
78 
79 const char * const acpi_wmi_ids[] = {
80 	"PNP0C14",
81 	"pnp0c14",
82 	NULL
83 };
84 
85 CFATTACH_DECL2_NEW(acpiwmi, sizeof(struct acpi_wmi_softc),
86     acpi_wmi_match, acpi_wmi_attach, acpi_wmi_detach, NULL,
87     acpi_wmi_rescan, acpi_wmi_childdet);
88 
89 static int
90 acpi_wmi_match(device_t parent, cfdata_t match, void *aux)
91 {
92 	struct acpi_attach_args *aa = aux;
93 
94 	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
95 		return 0;
96 
97 	return acpi_match_hid(aa->aa_node->ad_devinfo, acpi_wmi_ids);
98 }
99 
100 static void
101 acpi_wmi_attach(device_t parent, device_t self, void *aux)
102 {
103 	struct acpi_wmi_softc *sc = device_private(self);
104 	struct acpi_attach_args *aa = aux;
105 
106 	sc->sc_dev = self;
107 	sc->sc_node = aa->aa_node;
108 
109 	sc->sc_child = NULL;
110 	sc->sc_ecdev = NULL;
111 	sc->sc_handler = NULL;
112 
113 	aprint_naive("\n");
114 	aprint_normal(": ACPI WMI Interface\n");
115 
116 	if (acpi_wmi_init(sc) != true)
117 		return;
118 
119 	acpi_wmi_dump(sc);
120 	acpi_wmi_init_ec(sc);
121 	acpi_wmi_event_add(sc);
122 	acpi_wmi_rescan(self, NULL, NULL);
123 
124 	(void)pmf_device_register(self, acpi_wmi_suspend, acpi_wmi_resume);
125 }
126 
127 static int
128 acpi_wmi_detach(device_t self, int flags)
129 {
130 	struct acpi_wmi_softc *sc = device_private(self);
131 
132 	acpi_wmi_event_del(sc);
133 
134 	if (sc->sc_ecdev != NULL) {
135 
136 		(void)AcpiRemoveAddressSpaceHandler(sc->sc_node->ad_handle,
137 		    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler);
138 	}
139 
140 	if (sc->sc_child != NULL)
141 		(void)config_detach(sc->sc_child, flags);
142 
143 	acpi_wmi_del(sc);
144 	pmf_device_deregister(self);
145 
146 	return 0;
147 }
148 
149 static int
150 acpi_wmi_rescan(device_t self, const char *ifattr, const int *locators)
151 {
152 	struct acpi_wmi_softc *sc = device_private(self);
153 
154 	if (ifattr_match(ifattr, "acpiwmibus") && sc->sc_child == NULL)
155 		sc->sc_child = config_found_ia(self, "acpiwmibus",
156 		    NULL, acpi_wmi_print);
157 
158 	return 0;
159 }
160 
161 static void
162 acpi_wmi_childdet(device_t self, device_t child)
163 {
164 	struct acpi_wmi_softc *sc = device_private(self);
165 
166 	if (sc->sc_child == child)
167 		sc->sc_child = NULL;
168 }
169 
170 static int
171 acpi_wmi_print(void *aux, const char *pnp)
172 {
173 
174 	if (pnp != NULL)
175 		aprint_normal("acpiwmibus at %s", pnp);
176 
177 	return UNCONF;
178 }
179 
180 static bool
181 acpi_wmi_init(struct acpi_wmi_softc *sc)
182 {
183 	ACPI_OBJECT *obj;
184 	ACPI_BUFFER buf;
185 	ACPI_STATUS rv;
186 	uint32_t len;
187 
188 	rv = acpi_eval_struct(sc->sc_node->ad_handle, "_WDG", &buf);
189 
190 	if (ACPI_FAILURE(rv))
191 		goto fail;
192 
193 	obj = buf.Pointer;
194 
195 	if (obj->Type != ACPI_TYPE_BUFFER) {
196 		rv = AE_TYPE;
197 		goto fail;
198 	}
199 
200 	len = obj->Buffer.Length;
201 
202 	if (len != obj->Package.Count) {
203 		rv = AE_BAD_VALUE;
204 		goto fail;
205 	}
206 
207 	CTASSERT(sizeof(struct guid_t) == 20);
208 
209 	if (len < sizeof(struct guid_t) ||
210 	    len % sizeof(struct guid_t) != 0) {
211 		rv = AE_BAD_DATA;
212 		goto fail;
213 	}
214 
215 	return acpi_wmi_add(sc, obj);
216 
217 fail:
218 	aprint_error_dev(sc->sc_dev, "failed to evaluate _WDG: %s\n",
219 	    AcpiFormatException(rv));
220 
221 	if (buf.Pointer != NULL)
222 		ACPI_FREE(buf.Pointer);
223 
224 	return false;
225 }
226 
227 static bool
228 acpi_wmi_add(struct acpi_wmi_softc *sc, ACPI_OBJECT *obj)
229 {
230 	struct wmi_t *wmi;
231 	size_t i, n, offset, siz;
232 
233 	siz = sizeof(struct guid_t);
234 	n = obj->Buffer.Length / siz;
235 
236 	SIMPLEQ_INIT(&sc->wmi_head);
237 
238 	for (i = offset = 0; i < n; ++i) {
239 
240 		if ((wmi = kmem_zalloc(sizeof(*wmi), KM_NOSLEEP)) == NULL)
241 			goto fail;
242 
243 		(void)memcpy(&wmi->guid, obj->Buffer.Pointer + offset, siz);
244 
245 		wmi->eevent = false;
246 		offset = offset + siz;
247 
248 		SIMPLEQ_INSERT_TAIL(&sc->wmi_head, wmi, wmi_link);
249 	}
250 
251 	ACPI_FREE(obj);
252 
253 	return true;
254 
255 fail:
256 	ACPI_FREE(obj);
257 	acpi_wmi_del(sc);
258 
259 	return false;
260 }
261 
262 static void
263 acpi_wmi_del(struct acpi_wmi_softc *sc)
264 {
265 	struct wmi_t *wmi;
266 
267 	if (SIMPLEQ_EMPTY(&sc->wmi_head) != 0)
268 		return;
269 
270 	while (SIMPLEQ_FIRST(&sc->wmi_head) != NULL) {
271 
272 		wmi = SIMPLEQ_FIRST(&sc->wmi_head);
273 		SIMPLEQ_REMOVE_HEAD(&sc->wmi_head, wmi_link);
274 
275 		KASSERT(wmi != NULL);
276 
277 		kmem_free(wmi, sizeof(*wmi));
278 	}
279 }
280 
281 static void
282 acpi_wmi_dump(struct acpi_wmi_softc *sc)
283 {
284 	struct wmi_t *wmi;
285 
286 	KASSERT(SIMPLEQ_EMPTY(&sc->wmi_head) == 0);
287 
288 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
289 
290 		aprint_debug_dev(sc->sc_dev, "{%08X-%04X-%04X-",
291 		    wmi->guid.data1, wmi->guid.data2, wmi->guid.data3);
292 
293 		aprint_debug("%02X%02X-%02X%02X%02X%02X%02X%02X} ",
294 		    wmi->guid.data4[0], wmi->guid.data4[1],
295 		    wmi->guid.data4[2], wmi->guid.data4[3],
296 		    wmi->guid.data4[4], wmi->guid.data4[5],
297 		    wmi->guid.data4[6], wmi->guid.data4[7]);
298 
299 		aprint_debug("oid %04X count %02X flags %02X\n",
300 		    UGET16(wmi->guid.oid), wmi->guid.count, wmi->guid.flags);
301 	}
302 }
303 
304 static void
305 acpi_wmi_init_ec(struct acpi_wmi_softc *sc)
306 {
307 	ACPI_STATUS rv;
308 	deviter_t i;
309 	device_t d;
310 
311 	d = deviter_first(&i, DEVITER_F_ROOT_FIRST);
312 
313 	for (; d != NULL; d = deviter_next(&i)) {
314 
315 		if (device_is_a(d, "acpiec") != false ||
316 		    device_is_a(d, "acpiecdt") != false) {
317 			sc->sc_ecdev = d;
318 			break;
319 		}
320 	}
321 
322 	deviter_release(&i);
323 
324 	if (sc->sc_ecdev == NULL)
325 		return;
326 
327 	rv = AcpiInstallAddressSpaceHandler(sc->sc_node->ad_handle,
328 	    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler, NULL, sc);
329 
330 	if (ACPI_FAILURE(rv))
331 		sc->sc_ecdev = NULL;
332 }
333 
334 static ACPI_STATUS
335 acpi_wmi_guid_get(struct acpi_wmi_softc *sc,
336     const char *src, struct wmi_t **out)
337 {
338 	struct wmi_t *wmi;
339 	struct guid_t *guid;
340 	char bin[16];
341 	char hex[2];
342 	const char *ptr;
343 	uint8_t i;
344 
345 	if (sc == NULL || src == NULL || strlen(src) != 36)
346 		return AE_BAD_PARAMETER;
347 
348 	for (ptr = src, i = 0; i < 16; i++) {
349 
350 		if (*ptr == '-')
351 			ptr++;
352 
353 		(void)memcpy(hex, ptr, 2);
354 
355 		if (HEXCHAR(hex[0]) == 0 || HEXCHAR(hex[1]) == 0)
356 			return AE_BAD_HEX_CONSTANT;
357 
358 		bin[i] = strtoul(hex, NULL, 16) & 0xFF;
359 
360 		ptr++;
361 		ptr++;
362 	}
363 
364 	guid = (struct guid_t *)bin;
365 	guid->data1 = be32toh(guid->data1);
366 	guid->data2 = be16toh(guid->data2);
367 	guid->data3 = be16toh(guid->data3);
368 
369 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
370 
371 		if (GUIDCMP(guid, &wmi->guid) != 0) {
372 
373 			if (out != NULL)
374 				*out = wmi;
375 
376 			return AE_OK;
377 		}
378 	}
379 
380 	return AE_NOT_FOUND;
381 }
382 
383 /*
384  * Checks if a GUID is present. Child devices
385  * can use this in their autoconf(9) routines.
386  */
387 int
388 acpi_wmi_guid_match(device_t self, const char *guid)
389 {
390 	struct acpi_wmi_softc *sc = device_private(self);
391 	ACPI_STATUS rv;
392 
393 	rv = acpi_wmi_guid_get(sc, guid, NULL);
394 
395 	if (ACPI_SUCCESS(rv))
396 		return 1;
397 
398 	return 0;
399 }
400 
401 /*
402  * Adds internal event handler.
403  */
404 static void
405 acpi_wmi_event_add(struct acpi_wmi_softc *sc)
406 {
407 	struct wmi_t *wmi;
408 	ACPI_STATUS rv;
409 
410 	if (acpi_register_notify(sc->sc_node, acpi_wmi_event_handler) != true)
411 		return;
412 
413 	/*
414 	 * Enable possible expensive events.
415 	 */
416 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
417 
418 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0 &&
419 		    (wmi->guid.flags & ACPI_WMI_FLAG_EXPENSIVE) != 0) {
420 
421 			rv = acpi_wmi_enable(sc->sc_node->ad_handle,
422 			    wmi->guid.oid, false, true);
423 
424 			if (ACPI_SUCCESS(rv)) {
425 				wmi->eevent = true;
426 				continue;
427 			}
428 
429 			aprint_debug_dev(sc->sc_dev, "failed to enable "
430 			    "expensive WExx: %s\n", AcpiFormatException(rv));
431 		}
432 	}
433 }
434 
435 /*
436  * Removes the internal event handler.
437  */
438 static void
439 acpi_wmi_event_del(struct acpi_wmi_softc *sc)
440 {
441 	struct wmi_t *wmi;
442 	ACPI_STATUS rv;
443 
444 	acpi_deregister_notify(sc->sc_node);
445 
446 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
447 
448 		if (wmi->eevent != true)
449 			continue;
450 
451 		KASSERT((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0);
452 		KASSERT((wmi->guid.flags & ACPI_WMI_FLAG_EXPENSIVE) != 0);
453 
454 		rv = acpi_wmi_enable(sc->sc_node->ad_handle,
455 		    wmi->guid.oid, false, false);
456 
457 		if (ACPI_SUCCESS(rv)) {
458 			wmi->eevent = false;
459 			continue;
460 		}
461 
462 		aprint_debug_dev(sc->sc_dev, "failed to disable "
463 		    "expensive WExx: %s\n", AcpiFormatException(rv));
464 	}
465 }
466 
467 /*
468  * Returns extra information possibly associated with an event.
469  */
470 ACPI_STATUS
471 acpi_wmi_event_get(device_t self, uint32_t event, ACPI_BUFFER *obuf)
472 {
473 	struct acpi_wmi_softc *sc = device_private(self);
474 	struct wmi_t *wmi;
475 	ACPI_OBJECT_LIST arg;
476 	ACPI_OBJECT obj;
477 	ACPI_HANDLE hdl;
478 
479 	if (sc == NULL || obuf == NULL)
480 		return AE_BAD_PARAMETER;
481 
482 	if (sc->sc_handler == NULL)
483 		return AE_ABORT_METHOD;
484 
485 	hdl = sc->sc_node->ad_handle;
486 
487 	obj.Type = ACPI_TYPE_INTEGER;
488 	obj.Integer.Value = event;
489 
490 	arg.Count = 0x01;
491 	arg.Pointer = &obj;
492 
493 	obuf->Pointer = NULL;
494 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
495 
496 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
497 
498 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) == 0)
499 			continue;
500 
501 		if (wmi->guid.nid != event)
502 			continue;
503 
504 		return AcpiEvaluateObject(hdl, "_WED", &arg, obuf);
505 	}
506 
507 	return AE_NOT_FOUND;
508 }
509 
510 /*
511  * Forwards events to the external handler through the internal one.
512  */
513 static void
514 acpi_wmi_event_handler(ACPI_HANDLE hdl, uint32_t evt, void *aux)
515 {
516 	struct acpi_wmi_softc *sc;
517 	device_t self = aux;
518 
519 	sc = device_private(self);
520 
521 	if (sc->sc_child == NULL)
522 		return;
523 
524 	if (sc->sc_handler == NULL)
525 		return;
526 
527 	(*sc->sc_handler)(NULL, evt, sc->sc_child);
528 }
529 
530 ACPI_STATUS
531 acpi_wmi_event_register(device_t self, ACPI_NOTIFY_HANDLER handler)
532 {
533 	struct acpi_wmi_softc *sc = device_private(self);
534 
535 	if (sc == NULL)
536 		return AE_BAD_PARAMETER;
537 
538 	if (handler != NULL && sc->sc_handler != NULL)
539 		return AE_ALREADY_EXISTS;
540 
541 	sc->sc_handler = handler;
542 
543 	return AE_OK;
544 }
545 
546 ACPI_STATUS
547 acpi_wmi_event_deregister(device_t self)
548 {
549 	return acpi_wmi_event_register(self, NULL);
550 }
551 
552 /*
553  * Handler for EC regions, which may be embedded in WMI.
554  */
555 static ACPI_STATUS
556 acpi_wmi_ec_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS addr,
557     uint32_t width, ACPI_INTEGER *val, void *setup, void *aux)
558 {
559 	struct acpi_wmi_softc *sc = aux;
560 
561 	if (aux == NULL || val == NULL)
562 		return AE_BAD_PARAMETER;
563 
564 	if (addr > 0xFF || width % 8 != 0)
565 		return AE_BAD_ADDRESS;
566 
567 	switch (func) {
568 
569 	case ACPI_READ:
570 		(void)acpiec_bus_read(sc->sc_ecdev, addr, val, width);
571 		break;
572 
573 	case ACPI_WRITE:
574 		(void)acpiec_bus_write(sc->sc_ecdev, addr, *val, width);
575 		break;
576 
577 	default:
578 		return AE_BAD_PARAMETER;
579 	}
580 
581 	return AE_OK;
582 }
583 
584 /*
585  * As there is no prior knowledge about the expensive
586  * events that cause "significant overhead", try to
587  * disable (enable) these before suspending (resuming).
588  */
589 static bool
590 acpi_wmi_suspend(device_t self, const pmf_qual_t *qual)
591 {
592 	struct acpi_wmi_softc *sc = device_private(self);
593 
594 	acpi_wmi_event_del(sc);
595 
596 	return true;
597 }
598 
599 static bool
600 acpi_wmi_resume(device_t self, const pmf_qual_t *qual)
601 {
602 	struct acpi_wmi_softc *sc = device_private(self);
603 
604 	acpi_wmi_event_add(sc);
605 
606 	return true;
607 }
608 
609 /*
610  * Enables or disables data collection (WCxx) or an event (WExx).
611  */
612 static ACPI_STATUS
613 acpi_wmi_enable(ACPI_HANDLE hdl, const char *oid, bool data, bool flag)
614 {
615 	char path[5];
616 	const char *str;
617 
618 	str = (data != false) ? "WC" : "WE";
619 
620 	(void)strlcpy(path, str, sizeof(path));
621 	(void)strlcat(path, oid, sizeof(path));
622 
623 	return acpi_eval_set_integer(hdl, path, (flag != false) ? 0x01 : 0x00);
624 }
625 
626 static bool
627 acpi_wmi_input(struct wmi_t *wmi, uint8_t flag, uint8_t idx)
628 {
629 
630 	if ((wmi->guid.flags & flag) == 0)
631 		return false;
632 
633 	if (wmi->guid.count == 0x00)
634 		return false;
635 
636 	if (wmi->guid.count < idx)
637 		return false;
638 
639 	return true;
640 }
641 
642 /*
643  * Makes a WMI data block query (WQxx). The corresponding control
644  * method for data collection will be invoked if it is available.
645  */
646 ACPI_STATUS
647 acpi_wmi_data_query(device_t self, const char *guid,
648     uint8_t idx, ACPI_BUFFER *obuf)
649 {
650 	struct acpi_wmi_softc *sc = device_private(self);
651 	struct wmi_t *wmi;
652 	char path[5] = "WQ";
653 	ACPI_OBJECT_LIST arg;
654 	ACPI_STATUS rv, rvxx;
655 	ACPI_OBJECT obj;
656 
657 	rvxx = AE_SUPPORT;
658 
659 	if (obuf == NULL)
660 		return AE_BAD_PARAMETER;
661 
662 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
663 
664 	if (ACPI_FAILURE(rv))
665 		return rv;
666 
667 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
668 		return AE_BAD_DATA;
669 
670 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
671 
672 	obj.Type = ACPI_TYPE_INTEGER;
673 	obj.Integer.Value = idx;
674 
675 	arg.Count = 0x01;
676 	arg.Pointer = &obj;
677 
678 	obuf->Pointer = NULL;
679 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
680 
681 	/*
682 	 * If the expensive flag is set, we should enable
683 	 * data collection before evaluating the WQxx buffer.
684 	 */
685 	if ((wmi->guid.flags & ACPI_WMI_FLAG_EXPENSIVE) != 0) {
686 
687 		rvxx = acpi_wmi_enable(sc->sc_node->ad_handle,
688 		    wmi->guid.oid, true, true);
689 	}
690 
691 	rv = AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
692 
693 	/* No longer needed. */
694 	if (ACPI_SUCCESS(rvxx)) {
695 
696 		(void)acpi_wmi_enable(sc->sc_node->ad_handle,
697 		    wmi->guid.oid, true, false);
698 	}
699 
700 #ifdef DIAGNOSTIC
701 	/*
702 	 * XXX: It appears that quite a few laptops have WQxx
703 	 * methods that are declared as expensive, but lack the
704 	 * corresponding WCxx control method.
705 	 *
706 	 * -- Acer Aspire One is one example <jruohonen@iki.fi>.
707 	 */
708 	if (ACPI_FAILURE(rvxx) && rvxx != AE_SUPPORT)
709 		aprint_error_dev(sc->sc_dev, "failed to evaluate WCxx "
710 		    "for %s: %s\n", path, AcpiFormatException(rvxx));
711 #endif
712 	return rv;
713 }
714 
715 /*
716  * Writes to a data block (WSxx).
717  */
718 ACPI_STATUS
719 acpi_wmi_data_write(device_t self, const char *guid,
720     uint8_t idx, ACPI_BUFFER *ibuf)
721 {
722 	struct acpi_wmi_softc *sc = device_private(self);
723 	struct wmi_t *wmi;
724 	ACPI_OBJECT_LIST arg;
725 	ACPI_OBJECT obj[2];
726 	char path[5] = "WS";
727 	ACPI_STATUS rv;
728 
729 	if (ibuf == NULL)
730 		return AE_BAD_PARAMETER;
731 
732 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
733 
734 	if (ACPI_FAILURE(rv))
735 		return rv;
736 
737 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
738 		return AE_BAD_DATA;
739 
740 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
741 
742 	obj[0].Integer.Value = idx;
743 	obj[0].Type = ACPI_TYPE_INTEGER;
744 
745 	obj[1].Buffer.Length = ibuf->Length;
746 	obj[1].Buffer.Pointer = ibuf->Pointer;
747 
748 	obj[1].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
749 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
750 
751 	arg.Count = 0x02;
752 	arg.Pointer = obj;
753 
754 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, NULL);
755 }
756 
757 /*
758  * Executes a method (WMxx).
759  */
760 ACPI_STATUS
761 acpi_wmi_method(device_t self, const char *guid, uint8_t idx,
762     uint32_t mid, ACPI_BUFFER *ibuf, ACPI_BUFFER *obuf)
763 {
764 	struct acpi_wmi_softc *sc = device_private(self);
765 	struct wmi_t *wmi;
766 	ACPI_OBJECT_LIST arg;
767 	ACPI_OBJECT obj[3];
768 	char path[5] = "WM";
769 	ACPI_STATUS rv;
770 
771 	if (ibuf == NULL || obuf == NULL)
772 		return AE_BAD_PARAMETER;
773 
774 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
775 
776 	if (ACPI_FAILURE(rv))
777 		return rv;
778 
779 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_METHOD, idx) != true)
780 		return AE_BAD_DATA;
781 
782 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
783 
784 	obj[0].Integer.Value = idx;
785 	obj[1].Integer.Value = mid;
786 	obj[0].Type = obj[1].Type = ACPI_TYPE_INTEGER;
787 
788 	obj[2].Buffer.Length = ibuf->Length;
789 	obj[2].Buffer.Pointer = ibuf->Pointer;
790 
791 	obj[2].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
792 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
793 
794 	arg.Count = 0x03;
795 	arg.Pointer = obj;
796 
797 	obuf->Pointer = NULL;
798 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
799 
800 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
801 }
802 
803 #ifdef _MODULE
804 
805 MODULE(MODULE_CLASS_DRIVER, acpiwmi, NULL);
806 CFDRIVER_DECL(acpiwmi, DV_DULL, NULL);
807 
808 static int acpiwmiloc[] = { -1 };
809 extern struct cfattach acpiwmi_ca;
810 
811 static struct cfparent acpiparent = {
812 	"acpinodebus", NULL, DVUNIT_ANY
813 };
814 
815 static struct cfdata acpiwmi_cfdata[] = {
816 	{
817 		.cf_name = "acpiwmi",
818 		.cf_atname = "acpiwmi",
819 		.cf_unit = 0,
820 		.cf_fstate = FSTATE_STAR,
821 		.cf_loc = acpiwmiloc,
822 		.cf_flags = 0,
823 		.cf_pspec = &acpiparent,
824 	},
825 
826 	{ NULL, NULL, 0, 0, NULL, 0, NULL }
827 };
828 
829 static int
830 acpiwmi_modcmd(modcmd_t cmd, void *opaque)
831 {
832 	int err;
833 
834 	switch (cmd) {
835 
836 	case MODULE_CMD_INIT:
837 
838 		err = config_cfdriver_attach(&acpiwmi_cd);
839 
840 		if (err != 0)
841 			return err;
842 
843 		err = config_cfattach_attach("acpiwmi", &acpiwmi_ca);
844 
845 		if (err != 0) {
846 			config_cfdriver_detach(&acpiwmi_cd);
847 			return err;
848 		}
849 
850 		err = config_cfdata_attach(acpiwmi_cfdata, 1);
851 
852 		if (err != 0) {
853 			config_cfattach_detach("acpiwmi", &acpiwmi_ca);
854 			config_cfdriver_detach(&acpiwmi_cd);
855 			return err;
856 		}
857 
858 		return 0;
859 
860 	case MODULE_CMD_FINI:
861 
862 		err = config_cfdata_detach(acpiwmi_cfdata);
863 
864 		if (err != 0)
865 			return err;
866 
867 		config_cfattach_detach("acpiwmi", &acpiwmi_ca);
868 		config_cfdriver_detach(&acpiwmi_cd);
869 
870 		return 0;
871 
872 	default:
873 		return ENOTTY;
874 	}
875 }
876 
877 #endif	/* _MODULE */
878