xref: /netbsd-src/sys/dev/acpi/wmi/wmi_acpi.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: wmi_acpi.c,v 1.14 2012/08/14 14:38:02 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 1.14 2012/08/14 14:38:02 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_event(ACPI_HANDLE, uint8_t, bool);
77 static ACPI_STATUS	acpi_wmi_enable_collection(ACPI_HANDLE, const char *, bool);
78 static bool		acpi_wmi_input(struct wmi_t *, uint8_t, uint8_t);
79 
80 const char * const acpi_wmi_ids[] = {
81 	"PNP0C14",
82 	"pnp0c14",
83 	NULL
84 };
85 
86 CFATTACH_DECL2_NEW(acpiwmi, sizeof(struct acpi_wmi_softc),
87     acpi_wmi_match, acpi_wmi_attach, acpi_wmi_detach, NULL,
88     acpi_wmi_rescan, acpi_wmi_childdet);
89 
90 static int
91 acpi_wmi_match(device_t parent, cfdata_t match, void *aux)
92 {
93 	struct acpi_attach_args *aa = aux;
94 
95 	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
96 		return 0;
97 
98 	return acpi_match_hid(aa->aa_node->ad_devinfo, acpi_wmi_ids);
99 }
100 
101 static void
102 acpi_wmi_attach(device_t parent, device_t self, void *aux)
103 {
104 	struct acpi_wmi_softc *sc = device_private(self);
105 	struct acpi_attach_args *aa = aux;
106 
107 	sc->sc_dev = self;
108 	sc->sc_node = aa->aa_node;
109 
110 	sc->sc_child = NULL;
111 	sc->sc_ecdev = NULL;
112 	sc->sc_handler = NULL;
113 
114 	aprint_naive("\n");
115 	aprint_normal(": ACPI WMI Interface\n");
116 
117 	if (acpi_wmi_init(sc) != true)
118 		return;
119 
120 	acpi_wmi_dump(sc);
121 	acpi_wmi_init_ec(sc);
122 	acpi_wmi_event_add(sc);
123 	acpi_wmi_rescan(self, NULL, NULL);
124 
125 	(void)pmf_device_register(self, acpi_wmi_suspend, acpi_wmi_resume);
126 }
127 
128 static int
129 acpi_wmi_detach(device_t self, int flags)
130 {
131 	struct acpi_wmi_softc *sc = device_private(self);
132 
133 	acpi_wmi_event_del(sc);
134 
135 	if (sc->sc_ecdev != NULL) {
136 
137 		(void)AcpiRemoveAddressSpaceHandler(sc->sc_node->ad_handle,
138 		    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler);
139 	}
140 
141 	if (sc->sc_child != NULL)
142 		(void)config_detach(sc->sc_child, flags);
143 
144 	acpi_wmi_del(sc);
145 	pmf_device_deregister(self);
146 
147 	return 0;
148 }
149 
150 static int
151 acpi_wmi_rescan(device_t self, const char *ifattr, const int *locators)
152 {
153 	struct acpi_wmi_softc *sc = device_private(self);
154 
155 	if (ifattr_match(ifattr, "acpiwmibus") && sc->sc_child == NULL)
156 		sc->sc_child = config_found_ia(self, "acpiwmibus",
157 		    NULL, acpi_wmi_print);
158 
159 	return 0;
160 }
161 
162 static void
163 acpi_wmi_childdet(device_t self, device_t child)
164 {
165 	struct acpi_wmi_softc *sc = device_private(self);
166 
167 	if (sc->sc_child == child)
168 		sc->sc_child = NULL;
169 }
170 
171 static int
172 acpi_wmi_print(void *aux, const char *pnp)
173 {
174 
175 	if (pnp != NULL)
176 		aprint_normal("acpiwmibus at %s", pnp);
177 
178 	return UNCONF;
179 }
180 
181 static bool
182 acpi_wmi_init(struct acpi_wmi_softc *sc)
183 {
184 	ACPI_OBJECT *obj;
185 	ACPI_BUFFER buf;
186 	ACPI_STATUS rv;
187 	uint32_t len;
188 
189 	rv = acpi_eval_struct(sc->sc_node->ad_handle, "_WDG", &buf);
190 
191 	if (ACPI_FAILURE(rv))
192 		goto fail;
193 
194 	obj = buf.Pointer;
195 
196 	if (obj->Type != ACPI_TYPE_BUFFER) {
197 		rv = AE_TYPE;
198 		goto fail;
199 	}
200 
201 	len = obj->Buffer.Length;
202 
203 	if (len != obj->Package.Count) {
204 		rv = AE_BAD_VALUE;
205 		goto fail;
206 	}
207 
208 	CTASSERT(sizeof(struct guid_t) == 20);
209 
210 	if (len < sizeof(struct guid_t) ||
211 	    len % sizeof(struct guid_t) != 0) {
212 		rv = AE_BAD_DATA;
213 		goto fail;
214 	}
215 
216 	return acpi_wmi_add(sc, obj);
217 
218 fail:
219 	aprint_error_dev(sc->sc_dev, "failed to evaluate _WDG: %s\n",
220 	    AcpiFormatException(rv));
221 
222 	if (buf.Pointer != NULL)
223 		ACPI_FREE(buf.Pointer);
224 
225 	return false;
226 }
227 
228 static bool
229 acpi_wmi_add(struct acpi_wmi_softc *sc, ACPI_OBJECT *obj)
230 {
231 	struct wmi_t *wmi;
232 	size_t i, n, offset, siz;
233 
234 	siz = sizeof(struct guid_t);
235 	n = obj->Buffer.Length / siz;
236 
237 	SIMPLEQ_INIT(&sc->wmi_head);
238 
239 	for (i = offset = 0; i < n; ++i) {
240 
241 		if ((wmi = kmem_zalloc(sizeof(*wmi), KM_SLEEP)) == NULL)
242 			goto fail;
243 
244 		(void)memcpy(&wmi->guid, obj->Buffer.Pointer + offset, siz);
245 
246 		wmi->eevent = false;
247 		offset = offset + siz;
248 
249 		SIMPLEQ_INSERT_TAIL(&sc->wmi_head, wmi, wmi_link);
250 	}
251 
252 	ACPI_FREE(obj);
253 
254 	return true;
255 
256 fail:
257 	ACPI_FREE(obj);
258 	acpi_wmi_del(sc);
259 
260 	return false;
261 }
262 
263 static void
264 acpi_wmi_del(struct acpi_wmi_softc *sc)
265 {
266 	struct wmi_t *wmi;
267 
268 	while (SIMPLEQ_FIRST(&sc->wmi_head) != NULL) {
269 		wmi = SIMPLEQ_FIRST(&sc->wmi_head);
270 		SIMPLEQ_REMOVE_HEAD(&sc->wmi_head, wmi_link);
271 		kmem_free(wmi, sizeof(*wmi));
272 	}
273 }
274 
275 static void
276 acpi_wmi_dump(struct acpi_wmi_softc *sc)
277 {
278 	struct wmi_t *wmi;
279 
280 	KASSERT(SIMPLEQ_EMPTY(&sc->wmi_head) == 0);
281 
282 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
283 
284 		aprint_debug_dev(sc->sc_dev, "{%08X-%04X-%04X-",
285 		    wmi->guid.data1, wmi->guid.data2, wmi->guid.data3);
286 
287 		aprint_debug("%02X%02X-%02X%02X%02X%02X%02X%02X} ",
288 		    wmi->guid.data4[0], wmi->guid.data4[1],
289 		    wmi->guid.data4[2], wmi->guid.data4[3],
290 		    wmi->guid.data4[4], wmi->guid.data4[5],
291 		    wmi->guid.data4[6], wmi->guid.data4[7]);
292 
293 		aprint_debug("oid %04X count %02X flags %02X\n",
294 		    UGET16(wmi->guid.oid), wmi->guid.count, wmi->guid.flags);
295 	}
296 }
297 
298 static void
299 acpi_wmi_init_ec(struct acpi_wmi_softc *sc)
300 {
301 	ACPI_STATUS rv;
302 	deviter_t i;
303 	device_t d;
304 
305 	d = deviter_first(&i, DEVITER_F_ROOT_FIRST);
306 
307 	for (; d != NULL; d = deviter_next(&i)) {
308 
309 		if (device_is_a(d, "acpiec") != false ||
310 		    device_is_a(d, "acpiecdt") != false) {
311 			sc->sc_ecdev = d;
312 			break;
313 		}
314 	}
315 
316 	deviter_release(&i);
317 
318 	if (sc->sc_ecdev == NULL)
319 		return;
320 
321 	rv = AcpiInstallAddressSpaceHandler(sc->sc_node->ad_handle,
322 	    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler, NULL, sc);
323 
324 	if (ACPI_FAILURE(rv))
325 		sc->sc_ecdev = NULL;
326 }
327 
328 static ACPI_STATUS
329 acpi_wmi_guid_get(struct acpi_wmi_softc *sc,
330     const char *src, struct wmi_t **out)
331 {
332 	struct wmi_t *wmi;
333 	struct guid_t *guid;
334 	char bin[16];
335 	char hex[2];
336 	const char *ptr;
337 	uint8_t i;
338 
339 	if (sc == NULL || src == NULL || strlen(src) != 36)
340 		return AE_BAD_PARAMETER;
341 
342 	for (ptr = src, i = 0; i < 16; i++) {
343 
344 		if (*ptr == '-')
345 			ptr++;
346 
347 		(void)memcpy(hex, ptr, 2);
348 
349 		if (HEXCHAR(hex[0]) == 0 || HEXCHAR(hex[1]) == 0)
350 			return AE_BAD_HEX_CONSTANT;
351 
352 		bin[i] = strtoul(hex, NULL, 16) & 0xFF;
353 
354 		ptr++;
355 		ptr++;
356 	}
357 
358 	guid = (struct guid_t *)bin;
359 	guid->data1 = be32toh(guid->data1);
360 	guid->data2 = be16toh(guid->data2);
361 	guid->data3 = be16toh(guid->data3);
362 
363 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
364 
365 		if (GUIDCMP(guid, &wmi->guid) != 0) {
366 
367 			if (out != NULL)
368 				*out = wmi;
369 
370 			return AE_OK;
371 		}
372 	}
373 
374 	return AE_NOT_FOUND;
375 }
376 
377 /*
378  * Checks if a GUID is present. Child devices
379  * can use this in their autoconf(9) routines.
380  */
381 int
382 acpi_wmi_guid_match(device_t self, const char *guid)
383 {
384 	struct acpi_wmi_softc *sc = device_private(self);
385 	ACPI_STATUS rv;
386 
387 	rv = acpi_wmi_guid_get(sc, guid, NULL);
388 
389 	if (ACPI_SUCCESS(rv))
390 		return 1;
391 
392 	return 0;
393 }
394 
395 /*
396  * Adds internal event handler.
397  */
398 static void
399 acpi_wmi_event_add(struct acpi_wmi_softc *sc)
400 {
401 	struct wmi_t *wmi;
402 	ACPI_STATUS rv;
403 
404 	if (acpi_register_notify(sc->sc_node, acpi_wmi_event_handler) != true)
405 		return;
406 
407 	/*
408 	 * Enable possible events, expensive or otherwise.
409 	 */
410 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
411 
412 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0) {
413 
414 			rv = acpi_wmi_enable_event(sc->sc_node->ad_handle,
415 			    wmi->guid.nid, true);
416 
417 			if (ACPI_SUCCESS(rv)) {
418 				wmi->eevent = true;
419 				continue;
420 			}
421 
422 			aprint_debug_dev(sc->sc_dev, "failed to enable "
423 			    "expensive WExx: %s\n", AcpiFormatException(rv));
424 		}
425 	}
426 }
427 
428 /*
429  * Removes the internal event handler.
430  */
431 static void
432 acpi_wmi_event_del(struct acpi_wmi_softc *sc)
433 {
434 	struct wmi_t *wmi;
435 	ACPI_STATUS rv;
436 
437 	acpi_deregister_notify(sc->sc_node);
438 
439 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
440 
441 		if (wmi->eevent != true)
442 			continue;
443 
444 		KASSERT((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0);
445 
446 		rv = acpi_wmi_enable_event(sc->sc_node->ad_handle,
447 		    wmi->guid.nid, false);
448 
449 		if (ACPI_SUCCESS(rv)) {
450 			wmi->eevent = false;
451 			continue;
452 		}
453 
454 		aprint_debug_dev(sc->sc_dev, "failed to disable "
455 		    "expensive WExx: %s\n", AcpiFormatException(rv));
456 	}
457 }
458 
459 /*
460  * Returns extra information possibly associated with an event.
461  */
462 ACPI_STATUS
463 acpi_wmi_event_get(device_t self, uint32_t event, ACPI_BUFFER *obuf)
464 {
465 	struct acpi_wmi_softc *sc = device_private(self);
466 	struct wmi_t *wmi;
467 	ACPI_OBJECT_LIST arg;
468 	ACPI_OBJECT obj;
469 	ACPI_HANDLE hdl;
470 
471 	if (sc == NULL || obuf == NULL)
472 		return AE_BAD_PARAMETER;
473 
474 	if (sc->sc_handler == NULL)
475 		return AE_ABORT_METHOD;
476 
477 	hdl = sc->sc_node->ad_handle;
478 
479 	obj.Type = ACPI_TYPE_INTEGER;
480 	obj.Integer.Value = event;
481 
482 	arg.Count = 0x01;
483 	arg.Pointer = &obj;
484 
485 	obuf->Pointer = NULL;
486 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
487 
488 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
489 
490 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) == 0)
491 			continue;
492 
493 		if (wmi->guid.nid != event)
494 			continue;
495 
496 		return AcpiEvaluateObject(hdl, "_WED", &arg, obuf);
497 	}
498 
499 	return AE_NOT_FOUND;
500 }
501 
502 /*
503  * Forwards events to the external handler through the internal one.
504  */
505 static void
506 acpi_wmi_event_handler(ACPI_HANDLE hdl, uint32_t evt, void *aux)
507 {
508 	struct acpi_wmi_softc *sc;
509 	device_t self = aux;
510 
511 	sc = device_private(self);
512 
513 	if (sc->sc_child == NULL)
514 		return;
515 
516 	if (sc->sc_handler == NULL)
517 		return;
518 
519 	(*sc->sc_handler)(NULL, evt, sc->sc_child);
520 }
521 
522 ACPI_STATUS
523 acpi_wmi_event_register(device_t self, ACPI_NOTIFY_HANDLER handler)
524 {
525 	struct acpi_wmi_softc *sc = device_private(self);
526 
527 	if (sc == NULL)
528 		return AE_BAD_PARAMETER;
529 
530 	if (handler != NULL && sc->sc_handler != NULL)
531 		return AE_ALREADY_EXISTS;
532 
533 	sc->sc_handler = handler;
534 
535 	return AE_OK;
536 }
537 
538 ACPI_STATUS
539 acpi_wmi_event_deregister(device_t self)
540 {
541 	return acpi_wmi_event_register(self, NULL);
542 }
543 
544 /*
545  * Handler for EC regions, which may be embedded in WMI.
546  */
547 static ACPI_STATUS
548 acpi_wmi_ec_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS addr,
549     uint32_t width, ACPI_INTEGER *val, void *setup, void *aux)
550 {
551 	struct acpi_wmi_softc *sc = aux;
552 
553 	if (aux == NULL || val == NULL)
554 		return AE_BAD_PARAMETER;
555 
556 	if (addr > 0xFF || width % 8 != 0)
557 		return AE_BAD_ADDRESS;
558 
559 	switch (func) {
560 
561 	case ACPI_READ:
562 		(void)acpiec_bus_read(sc->sc_ecdev, addr, val, width);
563 		break;
564 
565 	case ACPI_WRITE:
566 		(void)acpiec_bus_write(sc->sc_ecdev, addr, *val, width);
567 		break;
568 
569 	default:
570 		return AE_BAD_PARAMETER;
571 	}
572 
573 	return AE_OK;
574 }
575 
576 /*
577  * As there is no prior knowledge about the expensive
578  * events that cause "significant overhead", try to
579  * disable (enable) these before suspending (resuming).
580  */
581 static bool
582 acpi_wmi_suspend(device_t self, const pmf_qual_t *qual)
583 {
584 	struct acpi_wmi_softc *sc = device_private(self);
585 
586 	acpi_wmi_event_del(sc);
587 
588 	return true;
589 }
590 
591 static bool
592 acpi_wmi_resume(device_t self, const pmf_qual_t *qual)
593 {
594 	struct acpi_wmi_softc *sc = device_private(self);
595 
596 	acpi_wmi_event_add(sc);
597 
598 	return true;
599 }
600 
601 static ACPI_STATUS
602 acpi_wmi_enable_event(ACPI_HANDLE hdl, uint8_t nid, bool flag)
603 {
604 	char path[5];
605 
606 	snprintf(path, sizeof(path), "WE%02X", nid);
607 
608 	return acpi_eval_set_integer(hdl, path, (flag != false) ? 0x01 : 0x00);
609 }
610 
611 static ACPI_STATUS
612 acpi_wmi_enable_collection(ACPI_HANDLE hdl, const char *oid, bool flag)
613 {
614 	char path[5];
615 
616 	strlcpy(path, "WC", sizeof(path));
617 	strlcat(path, oid, sizeof(path));
618 
619 	return acpi_eval_set_integer(hdl, path, (flag != false) ? 0x01 : 0x00);
620 }
621 
622 static bool
623 acpi_wmi_input(struct wmi_t *wmi, uint8_t flag, uint8_t idx)
624 {
625 
626 	if ((wmi->guid.flags & flag) == 0)
627 		return false;
628 
629 	if (wmi->guid.count == 0x00)
630 		return false;
631 
632 	if (wmi->guid.count < idx)
633 		return false;
634 
635 	return true;
636 }
637 
638 /*
639  * Makes a WMI data block query (WQxx). The corresponding control
640  * method for data collection will be invoked if it is available.
641  */
642 ACPI_STATUS
643 acpi_wmi_data_query(device_t self, const char *guid,
644     uint8_t idx, ACPI_BUFFER *obuf)
645 {
646 	struct acpi_wmi_softc *sc = device_private(self);
647 	struct wmi_t *wmi;
648 	char path[5] = "WQ";
649 	ACPI_OBJECT_LIST arg;
650 	ACPI_STATUS rv, rvxx;
651 	ACPI_OBJECT obj;
652 
653 	rvxx = AE_SUPPORT;
654 
655 	if (obuf == NULL)
656 		return AE_BAD_PARAMETER;
657 
658 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
659 
660 	if (ACPI_FAILURE(rv))
661 		return rv;
662 
663 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
664 		return AE_BAD_DATA;
665 
666 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
667 
668 	obj.Type = ACPI_TYPE_INTEGER;
669 	obj.Integer.Value = idx;
670 
671 	arg.Count = 0x01;
672 	arg.Pointer = &obj;
673 
674 	obuf->Pointer = NULL;
675 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
676 
677 	/*
678 	 * If the expensive flag is set, we should enable
679 	 * data collection before evaluating the WQxx buffer.
680 	 */
681 	if ((wmi->guid.flags & ACPI_WMI_FLAG_EXPENSIVE) != 0) {
682 
683 		rvxx = acpi_wmi_enable_collection(sc->sc_node->ad_handle,
684 		    wmi->guid.oid, true);
685 	}
686 
687 	rv = AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
688 
689 	/* No longer needed. */
690 	if (ACPI_SUCCESS(rvxx)) {
691 
692 		(void)acpi_wmi_enable_collection(sc->sc_node->ad_handle,
693 		    wmi->guid.oid, false);
694 	}
695 
696 #ifdef DIAGNOSTIC
697 	/*
698 	 * XXX: It appears that quite a few laptops have WQxx
699 	 * methods that are declared as expensive, but lack the
700 	 * corresponding WCxx control method.
701 	 *
702 	 * -- Acer Aspire One is one example <jruohonen@iki.fi>.
703 	 */
704 	if (ACPI_FAILURE(rvxx) && rvxx != AE_SUPPORT)
705 		aprint_error_dev(sc->sc_dev, "failed to evaluate WCxx "
706 		    "for %s: %s\n", path, AcpiFormatException(rvxx));
707 #endif
708 	return rv;
709 }
710 
711 /*
712  * Writes to a data block (WSxx).
713  */
714 ACPI_STATUS
715 acpi_wmi_data_write(device_t self, const char *guid,
716     uint8_t idx, ACPI_BUFFER *ibuf)
717 {
718 	struct acpi_wmi_softc *sc = device_private(self);
719 	struct wmi_t *wmi;
720 	ACPI_OBJECT_LIST arg;
721 	ACPI_OBJECT obj[2];
722 	char path[5] = "WS";
723 	ACPI_STATUS rv;
724 
725 	if (ibuf == NULL)
726 		return AE_BAD_PARAMETER;
727 
728 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
729 
730 	if (ACPI_FAILURE(rv))
731 		return rv;
732 
733 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
734 		return AE_BAD_DATA;
735 
736 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
737 
738 	obj[0].Integer.Value = idx;
739 	obj[0].Type = ACPI_TYPE_INTEGER;
740 
741 	obj[1].Buffer.Length = ibuf->Length;
742 	obj[1].Buffer.Pointer = ibuf->Pointer;
743 
744 	obj[1].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
745 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
746 
747 	arg.Count = 0x02;
748 	arg.Pointer = obj;
749 
750 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, NULL);
751 }
752 
753 /*
754  * Executes a method (WMxx).
755  */
756 ACPI_STATUS
757 acpi_wmi_method(device_t self, const char *guid, uint8_t idx,
758     uint32_t mid, ACPI_BUFFER *ibuf, ACPI_BUFFER *obuf)
759 {
760 	struct acpi_wmi_softc *sc = device_private(self);
761 	struct wmi_t *wmi;
762 	ACPI_OBJECT_LIST arg;
763 	ACPI_OBJECT obj[3];
764 	char path[5] = "WM";
765 	ACPI_STATUS rv;
766 
767 	if (ibuf == NULL || obuf == NULL)
768 		return AE_BAD_PARAMETER;
769 
770 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
771 
772 	if (ACPI_FAILURE(rv))
773 		return rv;
774 
775 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_METHOD, idx) != true)
776 		return AE_BAD_DATA;
777 
778 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
779 
780 	obj[0].Integer.Value = idx;
781 	obj[1].Integer.Value = mid;
782 	obj[0].Type = obj[1].Type = ACPI_TYPE_INTEGER;
783 
784 	obj[2].Buffer.Length = ibuf->Length;
785 	obj[2].Buffer.Pointer = ibuf->Pointer;
786 
787 	obj[2].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
788 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
789 
790 	arg.Count = 0x03;
791 	arg.Pointer = obj;
792 
793 	obuf->Pointer = NULL;
794 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
795 
796 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
797 }
798 
799 MODULE(MODULE_CLASS_DRIVER, acpiwmi, NULL);
800 
801 #ifdef _MODULE
802 #include "ioconf.c"
803 #endif
804 
805 static int
806 acpiwmi_modcmd(modcmd_t cmd, void *aux)
807 {
808 	int rv = 0;
809 
810 	switch (cmd) {
811 
812 	case MODULE_CMD_INIT:
813 
814 #ifdef _MODULE
815 		rv = config_init_component(cfdriver_ioconf_acpiwmi,
816 		    cfattach_ioconf_acpiwmi, cfdata_ioconf_acpiwmi);
817 #endif
818 		break;
819 
820 	case MODULE_CMD_FINI:
821 
822 #ifdef _MODULE
823 		rv = config_fini_component(cfdriver_ioconf_acpiwmi,
824 		    cfattach_ioconf_acpiwmi, cfdata_ioconf_acpiwmi);
825 #endif
826 		break;
827 
828 	default:
829 		rv = ENOTTY;
830 	}
831 
832 	return rv;
833 }
834