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      1 /*	$NetBSD: wmi_acpi.c,v 1.23 2023/08/11 08:36:59 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2009, 2010 Jukka Ruohonen <jruohonen (at) 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 1.23 2023/08/11 08:36:59 riastradh 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 described 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 	int error;
    130 
    131 	error = config_detach_children(self, flags);
    132 	if (error)
    133 		return error;
    134 
    135 	acpi_wmi_event_del(sc);
    136 
    137 	if (sc->sc_ecdev != NULL) {
    138 		(void)AcpiRemoveAddressSpaceHandler(sc->sc_node->ad_handle,
    139 		    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler);
    140 	}
    141 
    142 	acpi_wmi_del(sc);
    143 	pmf_device_deregister(self);
    144 
    145 	return 0;
    146 }
    147 
    148 static int
    149 acpi_wmi_rescan(device_t self, const char *ifattr, const int *locators)
    150 {
    151 	struct acpi_wmi_softc *sc = device_private(self);
    152 
    153 	if (sc->sc_child == NULL) {
    154 		sc->sc_child =
    155 		    config_found(self, NULL, acpi_wmi_print, CFARGS_NONE);
    156 	}
    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 	acpi_wmi_add(sc, obj);
    216 	return true;
    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 void
    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 		wmi = kmem_zalloc(sizeof(*wmi), KM_SLEEP);
    242 		(void)memcpy(&wmi->guid, obj->Buffer.Pointer + offset, siz);
    243 
    244 		wmi->eevent = false;
    245 		offset = offset + siz;
    246 
    247 		SIMPLEQ_INSERT_TAIL(&sc->wmi_head, wmi, wmi_link);
    248 	}
    249 
    250 	ACPI_FREE(obj);
    251 }
    252 
    253 static void
    254 acpi_wmi_del(struct acpi_wmi_softc *sc)
    255 {
    256 	struct wmi_t *wmi;
    257 
    258 	while (SIMPLEQ_FIRST(&sc->wmi_head) != NULL) {
    259 		wmi = SIMPLEQ_FIRST(&sc->wmi_head);
    260 		SIMPLEQ_REMOVE_HEAD(&sc->wmi_head, wmi_link);
    261 		kmem_free(wmi, sizeof(*wmi));
    262 	}
    263 }
    264 
    265 static void
    266 acpi_wmi_dump(struct acpi_wmi_softc *sc)
    267 {
    268 	struct wmi_t *wmi;
    269 
    270 	KASSERT(SIMPLEQ_EMPTY(&sc->wmi_head) == 0);
    271 
    272 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
    273 
    274 		aprint_debug_dev(sc->sc_dev, "{%08X-%04X-%04X-",
    275 		    wmi->guid.data1, wmi->guid.data2, wmi->guid.data3);
    276 
    277 		aprint_debug("%02X%02X-%02X%02X%02X%02X%02X%02X} ",
    278 		    wmi->guid.data4[0], wmi->guid.data4[1],
    279 		    wmi->guid.data4[2], wmi->guid.data4[3],
    280 		    wmi->guid.data4[4], wmi->guid.data4[5],
    281 		    wmi->guid.data4[6], wmi->guid.data4[7]);
    282 
    283 		aprint_debug("oid %04X count %02X flags %02X\n",
    284 		    UGET16(wmi->guid.oid), wmi->guid.count, wmi->guid.flags);
    285 	}
    286 }
    287 
    288 static void
    289 acpi_wmi_init_ec(struct acpi_wmi_softc *sc)
    290 {
    291 	ACPI_STATUS rv;
    292 	deviter_t i;
    293 	device_t d;
    294 
    295 	d = deviter_first(&i, DEVITER_F_ROOT_FIRST);
    296 
    297 	for (; d != NULL; d = deviter_next(&i)) {
    298 
    299 		if (device_is_a(d, "acpiec") != false ||
    300 		    device_is_a(d, "acpiecdt") != false) {
    301 			sc->sc_ecdev = d;
    302 			break;
    303 		}
    304 	}
    305 
    306 	deviter_release(&i);
    307 
    308 	if (sc->sc_ecdev == NULL)
    309 		return;
    310 
    311 	rv = AcpiInstallAddressSpaceHandler(sc->sc_node->ad_handle,
    312 	    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler, NULL, sc);
    313 
    314 	if (ACPI_FAILURE(rv))
    315 		sc->sc_ecdev = NULL;
    316 }
    317 
    318 static ACPI_STATUS
    319 acpi_wmi_guid_get(struct acpi_wmi_softc *sc,
    320     const char *src, struct wmi_t **out)
    321 {
    322 	struct wmi_t *wmi;
    323 	struct guid_t guid;
    324 	char bin[16];
    325 	char hex[3];
    326 	const char *ptr;
    327 	uint8_t i;
    328 
    329 	if (sc == NULL || src == NULL || strlen(src) != 36)
    330 		return AE_BAD_PARAMETER;
    331 
    332 	for (ptr = src, i = 0; i < 16; i++) {
    333 
    334 		if (*ptr == '-')
    335 			ptr++;
    336 
    337 		(void)memcpy(hex, ptr, 2);
    338 		hex[2] = '\0';
    339 
    340 		if (HEXCHAR(hex[0]) == 0 || HEXCHAR(hex[1]) == 0)
    341 			return AE_BAD_HEX_CONSTANT;
    342 
    343 		bin[i] = strtoul(hex, NULL, 16) & 0xFF;
    344 
    345 		ptr++;
    346 		ptr++;
    347 	}
    348 
    349 	guid.data1 = be32dec(&bin[0]);
    350 	guid.data2 = be16dec(&bin[4]);
    351 	guid.data3 = be16dec(&bin[6]);
    352 	memcpy(guid.data4, &bin[8], 8);
    353 
    354 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
    355 
    356 		if (GUIDCMP(&guid, &wmi->guid) != 0) {
    357 
    358 			if (out != NULL)
    359 				*out = wmi;
    360 
    361 			return AE_OK;
    362 		}
    363 	}
    364 
    365 	return AE_NOT_FOUND;
    366 }
    367 
    368 /*
    369  * Checks if a GUID is present. Child devices
    370  * can use this in their autoconf(9) routines.
    371  */
    372 int
    373 acpi_wmi_guid_match(device_t self, const char *guid)
    374 {
    375 	struct acpi_wmi_softc *sc = device_private(self);
    376 	ACPI_STATUS rv;
    377 
    378 	rv = acpi_wmi_guid_get(sc, guid, NULL);
    379 
    380 	if (ACPI_SUCCESS(rv))
    381 		return 1;
    382 
    383 	return 0;
    384 }
    385 
    386 /*
    387  * Adds internal event handler.
    388  */
    389 static void
    390 acpi_wmi_event_add(struct acpi_wmi_softc *sc)
    391 {
    392 	struct wmi_t *wmi;
    393 	ACPI_STATUS rv;
    394 
    395 	if (acpi_register_notify(sc->sc_node, acpi_wmi_event_handler) != true)
    396 		return;
    397 
    398 	/*
    399 	 * Enable possible events, expensive or otherwise.
    400 	 */
    401 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
    402 
    403 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0) {
    404 
    405 			rv = acpi_wmi_enable_event(sc->sc_node->ad_handle,
    406 			    wmi->guid.nid, true);
    407 
    408 			if (ACPI_SUCCESS(rv)) {
    409 				wmi->eevent = true;
    410 				continue;
    411 			}
    412 
    413 			aprint_debug_dev(sc->sc_dev, "failed to enable "
    414 			    "expensive WExx: %s\n", AcpiFormatException(rv));
    415 		}
    416 	}
    417 }
    418 
    419 /*
    420  * Removes the internal event handler.
    421  */
    422 static void
    423 acpi_wmi_event_del(struct acpi_wmi_softc *sc)
    424 {
    425 	struct wmi_t *wmi;
    426 	ACPI_STATUS rv;
    427 
    428 	acpi_deregister_notify(sc->sc_node);
    429 
    430 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
    431 
    432 		if (wmi->eevent != true)
    433 			continue;
    434 
    435 		KASSERT((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) != 0);
    436 
    437 		rv = acpi_wmi_enable_event(sc->sc_node->ad_handle,
    438 		    wmi->guid.nid, false);
    439 
    440 		if (ACPI_SUCCESS(rv)) {
    441 			wmi->eevent = false;
    442 			continue;
    443 		}
    444 
    445 		aprint_debug_dev(sc->sc_dev, "failed to disable "
    446 		    "expensive WExx: %s\n", AcpiFormatException(rv));
    447 	}
    448 }
    449 
    450 /*
    451  * Returns extra information possibly associated with an event.
    452  */
    453 ACPI_STATUS
    454 acpi_wmi_event_get(device_t self, uint32_t event, ACPI_BUFFER *obuf)
    455 {
    456 	struct acpi_wmi_softc *sc = device_private(self);
    457 	struct wmi_t *wmi;
    458 	ACPI_OBJECT_LIST arg;
    459 	ACPI_OBJECT obj;
    460 	ACPI_HANDLE hdl;
    461 
    462 	if (sc == NULL || obuf == NULL)
    463 		return AE_BAD_PARAMETER;
    464 
    465 	if (sc->sc_handler == NULL)
    466 		return AE_ABORT_METHOD;
    467 
    468 	hdl = sc->sc_node->ad_handle;
    469 
    470 	obj.Type = ACPI_TYPE_INTEGER;
    471 	obj.Integer.Value = event;
    472 
    473 	arg.Count = 0x01;
    474 	arg.Pointer = &obj;
    475 
    476 	obuf->Pointer = NULL;
    477 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
    478 
    479 	SIMPLEQ_FOREACH(wmi, &sc->wmi_head, wmi_link) {
    480 
    481 		if ((wmi->guid.flags & ACPI_WMI_FLAG_EVENT) == 0)
    482 			continue;
    483 
    484 		if (wmi->guid.nid != event)
    485 			continue;
    486 
    487 		return AcpiEvaluateObject(hdl, "_WED", &arg, obuf);
    488 	}
    489 
    490 	return AE_NOT_FOUND;
    491 }
    492 
    493 /*
    494  * Forwards events to the external handler through the internal one.
    495  */
    496 static void
    497 acpi_wmi_event_handler(ACPI_HANDLE hdl, uint32_t evt, void *aux)
    498 {
    499 	struct acpi_wmi_softc *sc;
    500 	device_t self = aux;
    501 
    502 	sc = device_private(self);
    503 
    504 	if (sc->sc_child == NULL)
    505 		return;
    506 
    507 	if (sc->sc_handler == NULL)
    508 		return;
    509 
    510 	(*sc->sc_handler)(NULL, evt, sc->sc_child);
    511 }
    512 
    513 ACPI_STATUS
    514 acpi_wmi_event_register(device_t self, ACPI_NOTIFY_HANDLER handler)
    515 {
    516 	struct acpi_wmi_softc *sc = device_private(self);
    517 
    518 	if (sc == NULL)
    519 		return AE_BAD_PARAMETER;
    520 
    521 	if (handler != NULL && sc->sc_handler != NULL)
    522 		return AE_ALREADY_EXISTS;
    523 
    524 	sc->sc_handler = handler;
    525 
    526 	return AE_OK;
    527 }
    528 
    529 ACPI_STATUS
    530 acpi_wmi_event_deregister(device_t self)
    531 {
    532 	return acpi_wmi_event_register(self, NULL);
    533 }
    534 
    535 /*
    536  * Handler for EC regions, which may be embedded in WMI.
    537  */
    538 static ACPI_STATUS
    539 acpi_wmi_ec_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS addr,
    540     uint32_t width, ACPI_INTEGER *val, void *setup, void *aux)
    541 {
    542 	struct acpi_wmi_softc *sc = aux;
    543 
    544 	if (aux == NULL || val == NULL)
    545 		return AE_BAD_PARAMETER;
    546 
    547 	if (addr > 0xFF || width % 8 != 0)
    548 		return AE_BAD_ADDRESS;
    549 
    550 	switch (func) {
    551 
    552 	case ACPI_READ:
    553 		(void)acpiec_bus_read(sc->sc_ecdev, addr, val, width);
    554 		break;
    555 
    556 	case ACPI_WRITE:
    557 		(void)acpiec_bus_write(sc->sc_ecdev, addr, *val, width);
    558 		break;
    559 
    560 	default:
    561 		return AE_BAD_PARAMETER;
    562 	}
    563 
    564 	return AE_OK;
    565 }
    566 
    567 /*
    568  * As there is no prior knowledge about the expensive
    569  * events that cause "significant overhead", try to
    570  * disable (enable) these before suspending (resuming).
    571  */
    572 static bool
    573 acpi_wmi_suspend(device_t self, const pmf_qual_t *qual)
    574 {
    575 	struct acpi_wmi_softc *sc = device_private(self);
    576 
    577 	acpi_wmi_event_del(sc);
    578 
    579 	return true;
    580 }
    581 
    582 static bool
    583 acpi_wmi_resume(device_t self, const pmf_qual_t *qual)
    584 {
    585 	struct acpi_wmi_softc *sc = device_private(self);
    586 
    587 	acpi_wmi_event_add(sc);
    588 
    589 	return true;
    590 }
    591 
    592 static ACPI_STATUS
    593 acpi_wmi_enable_event(ACPI_HANDLE hdl, uint8_t nid, bool flag)
    594 {
    595 	char path[5];
    596 
    597 	snprintf(path, sizeof(path), "WE%02X", nid);
    598 
    599 	return acpi_eval_set_integer(hdl, path, (flag != false) ? 0x01 : 0x00);
    600 }
    601 
    602 static ACPI_STATUS
    603 acpi_wmi_enable_collection(ACPI_HANDLE hdl, const char *oid, bool flag)
    604 {
    605 	char path[5];
    606 
    607 	strlcpy(path, "WC", sizeof(path));
    608 	strlcat(path, oid, sizeof(path));
    609 
    610 	return acpi_eval_set_integer(hdl, path, (flag != false) ? 0x01 : 0x00);
    611 }
    612 
    613 static bool
    614 acpi_wmi_input(struct wmi_t *wmi, uint8_t flag, uint8_t idx)
    615 {
    616 	/* A data block may have no flags at all */
    617 	if ((wmi->guid.flags & flag) == 0 &&
    618 	    (flag == ACPI_WMI_FLAG_DATA  &&
    619 	     (wmi->guid.flags & ~ACPI_WMI_FLAG_EXPENSIVE) != 0))
    620 		return false;
    621 
    622 	if (wmi->guid.count == 0x00)
    623 		return false;
    624 
    625 	if (wmi->guid.count < idx)
    626 		return false;
    627 
    628 	return true;
    629 }
    630 
    631 /*
    632  * Makes a WMI data block query (WQxx). The corresponding control
    633  * method for data collection will be invoked if it is available.
    634  */
    635 ACPI_STATUS
    636 acpi_wmi_data_query(device_t self, const char *guid,
    637     uint8_t idx, ACPI_BUFFER *obuf)
    638 {
    639 	struct acpi_wmi_softc *sc = device_private(self);
    640 	struct wmi_t *wmi;
    641 	char path[5] = "WQ";
    642 	ACPI_OBJECT_LIST arg;
    643 	ACPI_STATUS rv, rvxx;
    644 	ACPI_OBJECT obj;
    645 
    646 	rvxx = AE_SUPPORT;
    647 
    648 	if (obuf == NULL)
    649 		return AE_BAD_PARAMETER;
    650 
    651 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
    652 
    653 	if (ACPI_FAILURE(rv))
    654 		return rv;
    655 
    656 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
    657 		return AE_BAD_DATA;
    658 
    659 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
    660 
    661 	obj.Type = ACPI_TYPE_INTEGER;
    662 	obj.Integer.Value = idx;
    663 
    664 	arg.Count = 0x01;
    665 	arg.Pointer = &obj;
    666 
    667 	obuf->Pointer = NULL;
    668 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
    669 
    670 	/*
    671 	 * If the expensive flag is set, we should enable
    672 	 * data collection before evaluating the WQxx buffer.
    673 	 */
    674 	if ((wmi->guid.flags & ACPI_WMI_FLAG_EXPENSIVE) != 0) {
    675 
    676 		rvxx = acpi_wmi_enable_collection(sc->sc_node->ad_handle,
    677 		    wmi->guid.oid, true);
    678 	}
    679 
    680 	rv = AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
    681 
    682 	/* No longer needed. */
    683 	if (ACPI_SUCCESS(rvxx)) {
    684 
    685 		(void)acpi_wmi_enable_collection(sc->sc_node->ad_handle,
    686 		    wmi->guid.oid, false);
    687 	}
    688 
    689 #ifdef DIAGNOSTIC
    690 	/*
    691 	 * XXX: It appears that quite a few laptops have WQxx
    692 	 * methods that are declared as expensive, but lack the
    693 	 * corresponding WCxx control method.
    694 	 *
    695 	 * -- Acer Aspire One is one example <jruohonen (at) iki.fi>.
    696 	 */
    697 	if (ACPI_FAILURE(rvxx) && rvxx != AE_SUPPORT)
    698 		aprint_error_dev(sc->sc_dev, "failed to evaluate WCxx "
    699 		    "for %s: %s\n", path, AcpiFormatException(rvxx));
    700 #endif
    701 	return rv;
    702 }
    703 
    704 /*
    705  * Writes to a data block (WSxx).
    706  */
    707 ACPI_STATUS
    708 acpi_wmi_data_write(device_t self, const char *guid,
    709     uint8_t idx, ACPI_BUFFER *ibuf)
    710 {
    711 	struct acpi_wmi_softc *sc = device_private(self);
    712 	struct wmi_t *wmi;
    713 	ACPI_OBJECT_LIST arg;
    714 	ACPI_OBJECT obj[2];
    715 	char path[5] = "WS";
    716 	ACPI_STATUS rv;
    717 
    718 	if (ibuf == NULL)
    719 		return AE_BAD_PARAMETER;
    720 
    721 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
    722 
    723 	if (ACPI_FAILURE(rv))
    724 		return rv;
    725 
    726 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_DATA, idx) != true)
    727 		return AE_BAD_DATA;
    728 
    729 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
    730 
    731 	obj[0].Integer.Value = idx;
    732 	obj[0].Type = ACPI_TYPE_INTEGER;
    733 
    734 	obj[1].Buffer.Length = ibuf->Length;
    735 	obj[1].Buffer.Pointer = ibuf->Pointer;
    736 
    737 	obj[1].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
    738 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
    739 
    740 	arg.Count = 0x02;
    741 	arg.Pointer = obj;
    742 
    743 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, NULL);
    744 }
    745 
    746 /*
    747  * Executes a method (WMxx).
    748  */
    749 ACPI_STATUS
    750 acpi_wmi_method(device_t self, const char *guid, uint8_t idx,
    751     uint32_t mid, ACPI_BUFFER *ibuf, ACPI_BUFFER *obuf)
    752 {
    753 	struct acpi_wmi_softc *sc = device_private(self);
    754 	struct wmi_t *wmi;
    755 	ACPI_OBJECT_LIST arg;
    756 	ACPI_OBJECT obj[3];
    757 	char path[5] = "WM";
    758 	ACPI_STATUS rv;
    759 
    760 	if (ibuf == NULL || obuf == NULL)
    761 		return AE_BAD_PARAMETER;
    762 
    763 	rv = acpi_wmi_guid_get(sc, guid, &wmi);
    764 
    765 	if (ACPI_FAILURE(rv))
    766 		return rv;
    767 
    768 	if (acpi_wmi_input(wmi, ACPI_WMI_FLAG_METHOD, idx) != true)
    769 		return AE_BAD_DATA;
    770 
    771 	(void)strlcat(path, wmi->guid.oid, sizeof(path));
    772 
    773 	obj[0].Integer.Value = idx;
    774 	obj[1].Integer.Value = mid;
    775 	obj[0].Type = obj[1].Type = ACPI_TYPE_INTEGER;
    776 
    777 	obj[2].Buffer.Length = ibuf->Length;
    778 	obj[2].Buffer.Pointer = ibuf->Pointer;
    779 
    780 	obj[2].Type = ((wmi->guid.flags & ACPI_WMI_FLAG_STRING) != 0) ?
    781 	    ACPI_TYPE_STRING : ACPI_TYPE_BUFFER;
    782 
    783 	arg.Count = 0x03;
    784 	arg.Pointer = obj;
    785 
    786 	obuf->Pointer = NULL;
    787 	obuf->Length = ACPI_ALLOCATE_LOCAL_BUFFER;
    788 
    789 	return AcpiEvaluateObject(sc->sc_node->ad_handle, path, &arg, obuf);
    790 }
    791 
    792 MODULE(MODULE_CLASS_DRIVER, acpiwmi, NULL);
    793 
    794 #ifdef _MODULE
    795 #include "ioconf.c"
    796 #endif
    797 
    798 static int
    799 acpiwmi_modcmd(modcmd_t cmd, void *aux)
    800 {
    801 	int rv = 0;
    802 
    803 	switch (cmd) {
    804 
    805 	case MODULE_CMD_INIT:
    806 
    807 #ifdef _MODULE
    808 		rv = config_init_component(cfdriver_ioconf_acpiwmi,
    809 		    cfattach_ioconf_acpiwmi, cfdata_ioconf_acpiwmi);
    810 #endif
    811 		break;
    812 
    813 	case MODULE_CMD_FINI:
    814 
    815 #ifdef _MODULE
    816 		rv = config_fini_component(cfdriver_ioconf_acpiwmi,
    817 		    cfattach_ioconf_acpiwmi, cfdata_ioconf_acpiwmi);
    818 #endif
    819 		break;
    820 
    821 	default:
    822 		rv = ENOTTY;
    823 	}
    824 
    825 	return rv;
    826 }
    827