xref: /netbsd-src/sys/dev/acpi/wmi/wmi_acpi.c (revision 9fb66d812c00ebfb445c0b47dea128f32aa6fe96)
1 /*	$NetBSD: wmi_acpi.c,v 1.17 2021/01/29 15:49:55 thorpej 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 1.17 2021/01/29 15:49:55 thorpej 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 void		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 static const struct device_compatible_entry compat_data[] = {
81 	{ .compat = "PNP0C14" },
82 	{ .compat = "pnp0c14" },
83 	DEVICE_COMPAT_EOL
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 	return acpi_compatible_match(aa, compat_data);
96 }
97 
98 static void
99 acpi_wmi_attach(device_t parent, device_t self, void *aux)
100 {
101 	struct acpi_wmi_softc *sc = device_private(self);
102 	struct acpi_attach_args *aa = aux;
103 
104 	sc->sc_dev = self;
105 	sc->sc_node = aa->aa_node;
106 
107 	sc->sc_child = NULL;
108 	sc->sc_ecdev = NULL;
109 	sc->sc_handler = NULL;
110 
111 	aprint_naive("\n");
112 	aprint_normal(": ACPI WMI Interface\n");
113 
114 	if (acpi_wmi_init(sc) != true)
115 		return;
116 
117 	acpi_wmi_dump(sc);
118 	acpi_wmi_init_ec(sc);
119 	acpi_wmi_event_add(sc);
120 	acpi_wmi_rescan(self, NULL, NULL);
121 
122 	(void)pmf_device_register(self, acpi_wmi_suspend, acpi_wmi_resume);
123 }
124 
125 static int
126 acpi_wmi_detach(device_t self, int flags)
127 {
128 	struct acpi_wmi_softc *sc = device_private(self);
129 
130 	acpi_wmi_event_del(sc);
131 
132 	if (sc->sc_ecdev != NULL) {
133 
134 		(void)AcpiRemoveAddressSpaceHandler(sc->sc_node->ad_handle,
135 		    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler);
136 	}
137 
138 	if (sc->sc_child != NULL)
139 		(void)config_detach(sc->sc_child, flags);
140 
141 	acpi_wmi_del(sc);
142 	pmf_device_deregister(self);
143 
144 	return 0;
145 }
146 
147 static int
148 acpi_wmi_rescan(device_t self, const char *ifattr, const int *locators)
149 {
150 	struct acpi_wmi_softc *sc = device_private(self);
151 
152 	if (ifattr_match(ifattr, "acpiwmibus") && sc->sc_child == NULL)
153 		sc->sc_child = config_found_ia(self, "acpiwmibus",
154 		    NULL, acpi_wmi_print);
155 
156 	return 0;
157 }
158 
159 static void
160 acpi_wmi_childdet(device_t self, device_t child)
161 {
162 	struct acpi_wmi_softc *sc = device_private(self);
163 
164 	if (sc->sc_child == child)
165 		sc->sc_child = NULL;
166 }
167 
168 static int
169 acpi_wmi_print(void *aux, const char *pnp)
170 {
171 
172 	if (pnp != NULL)
173 		aprint_normal("acpiwmibus at %s", pnp);
174 
175 	return UNCONF;
176 }
177 
178 static bool
179 acpi_wmi_init(struct acpi_wmi_softc *sc)
180 {
181 	ACPI_OBJECT *obj;
182 	ACPI_BUFFER buf;
183 	ACPI_STATUS rv;
184 	uint32_t len;
185 
186 	rv = acpi_eval_struct(sc->sc_node->ad_handle, "_WDG", &buf);
187 
188 	if (ACPI_FAILURE(rv))
189 		goto fail;
190 
191 	obj = buf.Pointer;
192 
193 	if (obj->Type != ACPI_TYPE_BUFFER) {
194 		rv = AE_TYPE;
195 		goto fail;
196 	}
197 
198 	len = obj->Buffer.Length;
199 
200 	if (len != obj->Package.Count) {
201 		rv = AE_BAD_VALUE;
202 		goto fail;
203 	}
204 
205 	CTASSERT(sizeof(struct guid_t) == 20);
206 
207 	if (len < sizeof(struct guid_t) ||
208 	    len % sizeof(struct guid_t) != 0) {
209 		rv = AE_BAD_DATA;
210 		goto fail;
211 	}
212 
213 	acpi_wmi_add(sc, obj);
214 	return true;
215 
216 fail:
217 	aprint_error_dev(sc->sc_dev, "failed to evaluate _WDG: %s\n",
218 	    AcpiFormatException(rv));
219 
220 	if (buf.Pointer != NULL)
221 		ACPI_FREE(buf.Pointer);
222 
223 	return false;
224 }
225 
226 static void
227 acpi_wmi_add(struct acpi_wmi_softc *sc, ACPI_OBJECT *obj)
228 {
229 	struct wmi_t *wmi;
230 	size_t i, n, offset, siz;
231 
232 	siz = sizeof(struct guid_t);
233 	n = obj->Buffer.Length / siz;
234 
235 	SIMPLEQ_INIT(&sc->wmi_head);
236 
237 	for (i = offset = 0; i < n; ++i) {
238 
239 		wmi = kmem_zalloc(sizeof(*wmi), KM_SLEEP);
240 		(void)memcpy(&wmi->guid, obj->Buffer.Pointer + offset, siz);
241 
242 		wmi->eevent = false;
243 		offset = offset + siz;
244 
245 		SIMPLEQ_INSERT_TAIL(&sc->wmi_head, wmi, wmi_link);
246 	}
247 
248 	ACPI_FREE(obj);
249 }
250 
251 static void
252 acpi_wmi_del(struct acpi_wmi_softc *sc)
253 {
254 	struct wmi_t *wmi;
255 
256 	while (SIMPLEQ_FIRST(&sc->wmi_head) != NULL) {
257 		wmi = SIMPLEQ_FIRST(&sc->wmi_head);
258 		SIMPLEQ_REMOVE_HEAD(&sc->wmi_head, wmi_link);
259 		kmem_free(wmi, sizeof(*wmi));
260 	}
261 }
262 
263 static void
264 acpi_wmi_dump(struct acpi_wmi_softc *sc)
265 {
266 	struct wmi_t *wmi;
267 
268 	KASSERT(SIMPLEQ_EMPTY(&sc->wmi_head) == 0);
269 
270 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
271 
272 		aprint_debug_dev(sc->sc_dev, "{%08X-%04X-%04X-",
273 		    wmi->guid.data1, wmi->guid.data2, wmi->guid.data3);
274 
275 		aprint_debug("%02X%02X-%02X%02X%02X%02X%02X%02X} ",
276 		    wmi->guid.data4[0], wmi->guid.data4[1],
277 		    wmi->guid.data4[2], wmi->guid.data4[3],
278 		    wmi->guid.data4[4], wmi->guid.data4[5],
279 		    wmi->guid.data4[6], wmi->guid.data4[7]);
280 
281 		aprint_debug("oid %04X count %02X flags %02X\n",
282 		    UGET16(wmi->guid.oid), wmi->guid.count, wmi->guid.flags);
283 	}
284 }
285 
286 static void
287 acpi_wmi_init_ec(struct acpi_wmi_softc *sc)
288 {
289 	ACPI_STATUS rv;
290 	deviter_t i;
291 	device_t d;
292 
293 	d = deviter_first(&i, DEVITER_F_ROOT_FIRST);
294 
295 	for (; d != NULL; d = deviter_next(&i)) {
296 
297 		if (device_is_a(d, "acpiec") != false ||
298 		    device_is_a(d, "acpiecdt") != false) {
299 			sc->sc_ecdev = d;
300 			break;
301 		}
302 	}
303 
304 	deviter_release(&i);
305 
306 	if (sc->sc_ecdev == NULL)
307 		return;
308 
309 	rv = AcpiInstallAddressSpaceHandler(sc->sc_node->ad_handle,
310 	    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler, NULL, sc);
311 
312 	if (ACPI_FAILURE(rv))
313 		sc->sc_ecdev = NULL;
314 }
315 
316 static ACPI_STATUS
317 acpi_wmi_guid_get(struct acpi_wmi_softc *sc,
318     const char *src, struct wmi_t **out)
319 {
320 	struct wmi_t *wmi;
321 	struct guid_t *guid;
322 	char bin[16];
323 	char hex[3];
324 	const char *ptr;
325 	uint8_t i;
326 
327 	if (sc == NULL || src == NULL || strlen(src) != 36)
328 		return AE_BAD_PARAMETER;
329 
330 	for (ptr = src, i = 0; i < 16; i++) {
331 
332 		if (*ptr == '-')
333 			ptr++;
334 
335 		(void)memcpy(hex, ptr, 2);
336 		hex[2] = '\0';
337 
338 		if (HEXCHAR(hex[0]) == 0 || HEXCHAR(hex[1]) == 0)
339 			return AE_BAD_HEX_CONSTANT;
340 
341 		bin[i] = strtoul(hex, NULL, 16) & 0xFF;
342 
343 		ptr++;
344 		ptr++;
345 	}
346 
347 	guid = (struct guid_t *)bin;
348 	guid->data1 = be32toh(guid->data1);
349 	guid->data2 = be16toh(guid->data2);
350 	guid->data3 = be16toh(guid->data3);
351 
352 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
353 
354 		if (GUIDCMP(guid, &wmi->guid) != 0) {
355 
356 			if (out != NULL)
357 				*out = wmi;
358 
359 			return AE_OK;
360 		}
361 	}
362 
363 	return AE_NOT_FOUND;
364 }
365 
366 /*
367  * Checks if a GUID is present. Child devices
368  * can use this in their autoconf(9) routines.
369  */
370 int
371 acpi_wmi_guid_match(device_t self, const char *guid)
372 {
373 	struct acpi_wmi_softc *sc = device_private(self);
374 	ACPI_STATUS rv;
375 
376 	rv = acpi_wmi_guid_get(sc, guid, NULL);
377 
378 	if (ACPI_SUCCESS(rv))
379 		return 1;
380 
381 	return 0;
382 }
383 
384 /*
385  * Adds internal event handler.
386  */
387 static void
388 acpi_wmi_event_add(struct acpi_wmi_softc *sc)
389 {
390 	struct wmi_t *wmi;
391 	ACPI_STATUS rv;
392 
393 	if (acpi_register_notify(sc->sc_node, acpi_wmi_event_handler) != true)
394 		return;
395 
396 	/*
397 	 * Enable possible events, expensive or otherwise.
398 	 */
399 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
400 
401 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0) {
402 
403 			rv = acpi_wmi_enable_event(sc->sc_node->ad_handle,
404 			    wmi->guid.nid, true);
405 
406 			if (ACPI_SUCCESS(rv)) {
407 				wmi->eevent = true;
408 				continue;
409 			}
410 
411 			aprint_debug_dev(sc->sc_dev, "failed to enable "
412 			    "expensive WExx: %s\n", AcpiFormatException(rv));
413 		}
414 	}
415 }
416 
417 /*
418  * Removes the internal event handler.
419  */
420 static void
421 acpi_wmi_event_del(struct acpi_wmi_softc *sc)
422 {
423 	struct wmi_t *wmi;
424 	ACPI_STATUS rv;
425 
426 	acpi_deregister_notify(sc->sc_node);
427 
428 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
429 
430 		if (wmi->eevent != true)
431 			continue;
432 
433 		KASSERT((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0);
434 
435 		rv = acpi_wmi_enable_event(sc->sc_node->ad_handle,
436 		    wmi->guid.nid, false);
437 
438 		if (ACPI_SUCCESS(rv)) {
439 			wmi->eevent = false;
440 			continue;
441 		}
442 
443 		aprint_debug_dev(sc->sc_dev, "failed to disable "
444 		    "expensive WExx: %s\n", AcpiFormatException(rv));
445 	}
446 }
447 
448 /*
449  * Returns extra information possibly associated with an event.
450  */
451 ACPI_STATUS
452 acpi_wmi_event_get(device_t self, uint32_t event, ACPI_BUFFER *obuf)
453 {
454 	struct acpi_wmi_softc *sc = device_private(self);
455 	struct wmi_t *wmi;
456 	ACPI_OBJECT_LIST arg;
457 	ACPI_OBJECT obj;
458 	ACPI_HANDLE hdl;
459 
460 	if (sc == NULL || obuf == NULL)
461 		return AE_BAD_PARAMETER;
462 
463 	if (sc->sc_handler == NULL)
464 		return AE_ABORT_METHOD;
465 
466 	hdl = sc->sc_node->ad_handle;
467 
468 	obj.Type = ACPI_TYPE_INTEGER;
469 	obj.Integer.Value = event;
470 
471 	arg.Count = 0x01;
472 	arg.Pointer = &obj;
473 
474 	obuf->Pointer = NULL;
475 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
476 
477 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
478 
479 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) == 0)
480 			continue;
481 
482 		if (wmi->guid.nid != event)
483 			continue;
484 
485 		return AcpiEvaluateObject(hdl, "_WED", &arg, obuf);
486 	}
487 
488 	return AE_NOT_FOUND;
489 }
490 
491 /*
492  * Forwards events to the external handler through the internal one.
493  */
494 static void
495 acpi_wmi_event_handler(ACPI_HANDLE hdl, uint32_t evt, void *aux)
496 {
497 	struct acpi_wmi_softc *sc;
498 	device_t self = aux;
499 
500 	sc = device_private(self);
501 
502 	if (sc->sc_child == NULL)
503 		return;
504 
505 	if (sc->sc_handler == NULL)
506 		return;
507 
508 	(*sc->sc_handler)(NULL, evt, sc->sc_child);
509 }
510 
511 ACPI_STATUS
512 acpi_wmi_event_register(device_t self, ACPI_NOTIFY_HANDLER handler)
513 {
514 	struct acpi_wmi_softc *sc = device_private(self);
515 
516 	if (sc == NULL)
517 		return AE_BAD_PARAMETER;
518 
519 	if (handler != NULL && sc->sc_handler != NULL)
520 		return AE_ALREADY_EXISTS;
521 
522 	sc->sc_handler = handler;
523 
524 	return AE_OK;
525 }
526 
527 ACPI_STATUS
528 acpi_wmi_event_deregister(device_t self)
529 {
530 	return acpi_wmi_event_register(self, NULL);
531 }
532 
533 /*
534  * Handler for EC regions, which may be embedded in WMI.
535  */
536 static ACPI_STATUS
537 acpi_wmi_ec_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS addr,
538     uint32_t width, ACPI_INTEGER *val, void *setup, void *aux)
539 {
540 	struct acpi_wmi_softc *sc = aux;
541 
542 	if (aux == NULL || val == NULL)
543 		return AE_BAD_PARAMETER;
544 
545 	if (addr > 0xFF || width % 8 != 0)
546 		return AE_BAD_ADDRESS;
547 
548 	switch (func) {
549 
550 	case ACPI_READ:
551 		(void)acpiec_bus_read(sc->sc_ecdev, addr, val, width);
552 		break;
553 
554 	case ACPI_WRITE:
555 		(void)acpiec_bus_write(sc->sc_ecdev, addr, *val, width);
556 		break;
557 
558 	default:
559 		return AE_BAD_PARAMETER;
560 	}
561 
562 	return AE_OK;
563 }
564 
565 /*
566  * As there is no prior knowledge about the expensive
567  * events that cause "significant overhead", try to
568  * disable (enable) these before suspending (resuming).
569  */
570 static bool
571 acpi_wmi_suspend(device_t self, const pmf_qual_t *qual)
572 {
573 	struct acpi_wmi_softc *sc = device_private(self);
574 
575 	acpi_wmi_event_del(sc);
576 
577 	return true;
578 }
579 
580 static bool
581 acpi_wmi_resume(device_t self, const pmf_qual_t *qual)
582 {
583 	struct acpi_wmi_softc *sc = device_private(self);
584 
585 	acpi_wmi_event_add(sc);
586 
587 	return true;
588 }
589 
590 static ACPI_STATUS
591 acpi_wmi_enable_event(ACPI_HANDLE hdl, uint8_t nid, bool flag)
592 {
593 	char path[5];
594 
595 	snprintf(path, sizeof(path), "WE%02X", nid);
596 
597 	return acpi_eval_set_integer(hdl, path, (flag != false) ? 0x01 : 0x00);
598 }
599 
600 static ACPI_STATUS
601 acpi_wmi_enable_collection(ACPI_HANDLE hdl, const char *oid, bool flag)
602 {
603 	char path[5];
604 
605 	strlcpy(path, "WC", sizeof(path));
606 	strlcat(path, oid, sizeof(path));
607 
608 	return acpi_eval_set_integer(hdl, path, (flag != false) ? 0x01 : 0x00);
609 }
610 
611 static bool
612 acpi_wmi_input(struct wmi_t *wmi, uint8_t flag, uint8_t idx)
613 {
614 	/* A data block may have no flags at all */
615 	if ((wmi->guid.flags & flag) == 0 &&
616 	    (flag == ACPI_WMI_FLAG_DATA  &&
617 	     (wmi->guid.flags & ~ACPI_WMI_FLAG_EXPENSIVE) != 0))
618 		return false;
619 
620 	if (wmi->guid.count == 0x00)
621 		return false;
622 
623 	if (wmi->guid.count < idx)
624 		return false;
625 
626 	return true;
627 }
628 
629 /*
630  * Makes a WMI data block query (WQxx). The corresponding control
631  * method for data collection will be invoked if it is available.
632  */
633 ACPI_STATUS
634 acpi_wmi_data_query(device_t self, const char *guid,
635     uint8_t idx, ACPI_BUFFER *obuf)
636 {
637 	struct acpi_wmi_softc *sc = device_private(self);
638 	struct wmi_t *wmi;
639 	char path[5] = "WQ";
640 	ACPI_OBJECT_LIST arg;
641 	ACPI_STATUS rv, rvxx;
642 	ACPI_OBJECT obj;
643 
644 	rvxx = AE_SUPPORT;
645 
646 	if (obuf == NULL)
647 		return AE_BAD_PARAMETER;
648 
649 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
650 
651 	if (ACPI_FAILURE(rv))
652 		return rv;
653 
654 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
655 		return AE_BAD_DATA;
656 
657 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
658 
659 	obj.Type = ACPI_TYPE_INTEGER;
660 	obj.Integer.Value = idx;
661 
662 	arg.Count = 0x01;
663 	arg.Pointer = &obj;
664 
665 	obuf->Pointer = NULL;
666 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
667 
668 	/*
669 	 * If the expensive flag is set, we should enable
670 	 * data collection before evaluating the WQxx buffer.
671 	 */
672 	if ((wmi->guid.flags & ACPI_WMI_FLAG_EXPENSIVE) != 0) {
673 
674 		rvxx = acpi_wmi_enable_collection(sc->sc_node->ad_handle,
675 		    wmi->guid.oid, true);
676 	}
677 
678 	rv = AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
679 
680 	/* No longer needed. */
681 	if (ACPI_SUCCESS(rvxx)) {
682 
683 		(void)acpi_wmi_enable_collection(sc->sc_node->ad_handle,
684 		    wmi->guid.oid, false);
685 	}
686 
687 #ifdef DIAGNOSTIC
688 	/*
689 	 * XXX: It appears that quite a few laptops have WQxx
690 	 * methods that are declared as expensive, but lack the
691 	 * corresponding WCxx control method.
692 	 *
693 	 * -- Acer Aspire One is one example <jruohonen@iki.fi>.
694 	 */
695 	if (ACPI_FAILURE(rvxx) && rvxx != AE_SUPPORT)
696 		aprint_error_dev(sc->sc_dev, "failed to evaluate WCxx "
697 		    "for %s: %s\n", path, AcpiFormatException(rvxx));
698 #endif
699 	return rv;
700 }
701 
702 /*
703  * Writes to a data block (WSxx).
704  */
705 ACPI_STATUS
706 acpi_wmi_data_write(device_t self, const char *guid,
707     uint8_t idx, ACPI_BUFFER *ibuf)
708 {
709 	struct acpi_wmi_softc *sc = device_private(self);
710 	struct wmi_t *wmi;
711 	ACPI_OBJECT_LIST arg;
712 	ACPI_OBJECT obj[2];
713 	char path[5] = "WS";
714 	ACPI_STATUS rv;
715 
716 	if (ibuf == NULL)
717 		return AE_BAD_PARAMETER;
718 
719 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
720 
721 	if (ACPI_FAILURE(rv))
722 		return rv;
723 
724 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
725 		return AE_BAD_DATA;
726 
727 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
728 
729 	obj[0].Integer.Value = idx;
730 	obj[0].Type = ACPI_TYPE_INTEGER;
731 
732 	obj[1].Buffer.Length = ibuf->Length;
733 	obj[1].Buffer.Pointer = ibuf->Pointer;
734 
735 	obj[1].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
736 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
737 
738 	arg.Count = 0x02;
739 	arg.Pointer = obj;
740 
741 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, NULL);
742 }
743 
744 /*
745  * Executes a method (WMxx).
746  */
747 ACPI_STATUS
748 acpi_wmi_method(device_t self, const char *guid, uint8_t idx,
749     uint32_t mid, ACPI_BUFFER *ibuf, ACPI_BUFFER *obuf)
750 {
751 	struct acpi_wmi_softc *sc = device_private(self);
752 	struct wmi_t *wmi;
753 	ACPI_OBJECT_LIST arg;
754 	ACPI_OBJECT obj[3];
755 	char path[5] = "WM";
756 	ACPI_STATUS rv;
757 
758 	if (ibuf == NULL || obuf == NULL)
759 		return AE_BAD_PARAMETER;
760 
761 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
762 
763 	if (ACPI_FAILURE(rv))
764 		return rv;
765 
766 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_METHOD, idx) != true)
767 		return AE_BAD_DATA;
768 
769 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
770 
771 	obj[0].Integer.Value = idx;
772 	obj[1].Integer.Value = mid;
773 	obj[0].Type = obj[1].Type = ACPI_TYPE_INTEGER;
774 
775 	obj[2].Buffer.Length = ibuf->Length;
776 	obj[2].Buffer.Pointer = ibuf->Pointer;
777 
778 	obj[2].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
779 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
780 
781 	arg.Count = 0x03;
782 	arg.Pointer = obj;
783 
784 	obuf->Pointer = NULL;
785 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
786 
787 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
788 }
789 
790 MODULE(MODULE_CLASS_DRIVER, acpiwmi, NULL);
791 
792 #ifdef _MODULE
793 #include "ioconf.c"
794 #endif
795 
796 static int
797 acpiwmi_modcmd(modcmd_t cmd, void *aux)
798 {
799 	int rv = 0;
800 
801 	switch (cmd) {
802 
803 	case MODULE_CMD_INIT:
804 
805 #ifdef _MODULE
806 		rv = config_init_component(cfdriver_ioconf_acpiwmi,
807 		    cfattach_ioconf_acpiwmi, cfdata_ioconf_acpiwmi);
808 #endif
809 		break;
810 
811 	case MODULE_CMD_FINI:
812 
813 #ifdef _MODULE
814 		rv = config_fini_component(cfdriver_ioconf_acpiwmi,
815 		    cfattach_ioconf_acpiwmi, cfdata_ioconf_acpiwmi);
816 #endif
817 		break;
818 
819 	default:
820 		rv = ENOTTY;
821 	}
822 
823 	return rv;
824 }
825