xref: /freebsd/sys/dev/acpi_support/acpi_wmi.c (revision 0f454b93f8502e85e8d2b26a383e40b5dc50cd27)
1 /*-
2  * Copyright (c) 2009 Michael Gmelin <freebsd@grem.de>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * Driver for acpi-wmi mapping, provides an interface for vendor specific
32  * implementations (e.g. HP and Acer laptops).
33  * Inspired by the ACPI-WMI mapping driver (c) 2008-2008 Carlos Corbacho which
34  * implements this functionality for Linux.
35  *
36  * WMI and ACPI: http://www.microsoft.com/whdc/system/pnppwr/wmi/wmi-acpi.mspx
37  * acpi-wmi for Linux: http://www.kernel.org
38  */
39 
40 #include "opt_acpi.h"
41 #include <sys/param.h>
42 #include <sys/conf.h>
43 #include <sys/uio.h>
44 #include <sys/proc.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/sbuf.h>
48 #include <sys/module.h>
49 #include <sys/bus.h>
50 
51 #include <contrib/dev/acpica/include/acpi.h>
52 #include <contrib/dev/acpica/include/accommon.h>
53 #include <dev/acpica/acpivar.h>
54 #include "acpi_wmi_if.h"
55 
56 MALLOC_DEFINE(M_ACPIWMI, "acpiwmi", "ACPI-WMI mapping");
57 
58 #define _COMPONENT	ACPI_OEM
59 ACPI_MODULE_NAME("ACPI_WMI");
60 
61 #define ACPI_WMI_REGFLAG_EXPENSIVE	0x1 /* GUID flag: Expensive operation */
62 #define ACPI_WMI_REGFLAG_METHOD		0x2	/* GUID flag: Method call */
63 #define ACPI_WMI_REGFLAG_STRING		0x4	/* GUID flag: String */
64 #define ACPI_WMI_REGFLAG_EVENT		0x8	/* GUID flag: Event */
65 
66 /*
67  * acpi_wmi driver private structure
68  */
69 struct acpi_wmi_softc {
70 	device_t	wmi_dev;	/* wmi device id */
71 	ACPI_HANDLE	wmi_handle;	/* handle of the PNP0C14 node */
72 	device_t	ec_dev;		/* acpi_ec0 */
73 	struct cdev	*wmistat_dev_t;	/* wmistat device handle */
74 	struct sbuf	wmistat_sbuf;	/* sbuf for /dev/wmistat output */
75 	pid_t		wmistat_open_pid; /* pid operating on /dev/wmistat */
76 	int		wmistat_bufptr;	/* /dev/wmistat ptr to buffer position */
77 };
78 
79 /*
80  * Struct that holds information about
81  * about a single GUID entry in _WDG
82  */
83 struct guid_info {
84 	char	guid[16];	/* 16 byte non human readable GUID */
85 	char	oid[2];		/* object id or event notify id (first byte) */
86 	UINT8	max_instance;	/* highest instance known for this GUID */
87 	UINT8	flags;		/* ACPI_WMI_REGFLAG_%s */
88 };
89 
90 /* WExx event generation state (on/off) */
91 enum event_generation_state {
92 	EVENT_GENERATION_ON = 1,
93 	EVENT_GENERATION_OFF = 0
94 };
95 
96 
97 /*
98  * Information about one entry in _WDG.
99  * List of those is used to lookup information by GUID.
100  */
101 struct wmi_info {
102 	TAILQ_ENTRY(wmi_info)	wmi_list;
103 	struct guid_info	ginfo;		/* information on guid */
104 	ACPI_NOTIFY_HANDLER	event_handler;/* client provided event handler */
105 	void			*event_handler_user_data; /* ev handler cookie  */
106 };
107 
108 TAILQ_HEAD(wmi_info_list_head, wmi_info)
109     wmi_info_list = TAILQ_HEAD_INITIALIZER(wmi_info_list);
110 
111 ACPI_SERIAL_DECL(acpi_wmi, "ACPI-WMI Mapping");
112 
113 /* public interface - declaration */
114 /* standard device interface*/
115 static int		acpi_wmi_probe(device_t dev);
116 static int		acpi_wmi_attach(device_t dev);
117 static int		acpi_wmi_detach(device_t dev);
118 /* see acpi_wmi_if.m */
119 static int		acpi_wmi_provides_guid_string_method(device_t dev,
120 			    const char *guid_string);
121 static ACPI_STATUS	acpi_wmi_evaluate_call_method(device_t dev,
122 			    const char *guid_string, UINT8 instance,
123 			    UINT32 method_id, const ACPI_BUFFER *in,
124 			    ACPI_BUFFER *out);
125 static ACPI_STATUS	acpi_wmi_install_event_handler_method(device_t dev,
126 			    const char *guid_string, ACPI_NOTIFY_HANDLER handler,
127 			    void *data);
128 static ACPI_STATUS	acpi_wmi_remove_event_handler_method(device_t dev,
129 			    const char *guid_string);
130 static ACPI_STATUS	acpi_wmi_get_event_data_method(device_t dev,
131 			    UINT32 event_id, ACPI_BUFFER *out);
132 static ACPI_STATUS	acpi_wmi_get_block_method(device_t dev,
133 			    const char *guid_string,
134 			    UINT8 instance, ACPI_BUFFER *out);
135 static ACPI_STATUS	acpi_wmi_set_block_method(device_t dev,
136 			    const char *guid_string,
137 			    UINT8 instance, const ACPI_BUFFER *in);
138 /* private interface - declaration */
139 /* callbacks */
140 static void		acpi_wmi_notify_handler(ACPI_HANDLE h, UINT32 notify,
141 			    void *context);
142 static ACPI_STATUS	acpi_wmi_ec_handler(UINT32 function,
143 			    ACPI_PHYSICAL_ADDRESS address, UINT32 width,
144 			    ACPI_INTEGER *value, void *context,
145 			    void *region_context);
146 /* helpers */
147 static ACPI_STATUS	acpi_wmi_read_wdg_blocks(ACPI_HANDLE h);
148 static ACPI_STATUS	acpi_wmi_toggle_we_event_generation(device_t dev,
149 			    struct wmi_info *winfo,
150 			    enum event_generation_state state);
151 static int		acpi_wmi_guid_string_to_guid(const UINT8 *guid_string,
152 			    UINT8 *guid);
153 static struct wmi_info* acpi_wmi_lookup_wmi_info_by_guid_string(
154 			    const char *guid_string);
155 
156 static d_open_t acpi_wmi_wmistat_open;
157 static d_close_t acpi_wmi_wmistat_close;
158 static d_read_t acpi_wmi_wmistat_read;
159 
160 /* handler /dev/wmistat device */
161 static struct cdevsw wmistat_cdevsw = {
162 	.d_version = D_VERSION,
163 	.d_open = acpi_wmi_wmistat_open,
164 	.d_close = acpi_wmi_wmistat_close,
165 	.d_read = acpi_wmi_wmistat_read,
166 	.d_name = "wmistat",
167 };
168 
169 
170 static device_method_t acpi_wmi_methods[] = {
171 	/* Device interface */
172 	DEVMETHOD(device_probe,	acpi_wmi_probe),
173 	DEVMETHOD(device_attach, acpi_wmi_attach),
174 	DEVMETHOD(device_detach, acpi_wmi_detach),
175 
176 	/* acpi_wmi interface */
177 	DEVMETHOD(acpi_wmi_provides_guid_string,
178 		    acpi_wmi_provides_guid_string_method),
179 	DEVMETHOD(acpi_wmi_evaluate_call, acpi_wmi_evaluate_call_method),
180 	DEVMETHOD(acpi_wmi_install_event_handler,
181 		    acpi_wmi_install_event_handler_method),
182 	DEVMETHOD(acpi_wmi_remove_event_handler,
183 		    acpi_wmi_remove_event_handler_method),
184 	DEVMETHOD(acpi_wmi_get_event_data, acpi_wmi_get_event_data_method),
185 	DEVMETHOD(acpi_wmi_get_block, acpi_wmi_get_block_method),
186 	DEVMETHOD(acpi_wmi_set_block, acpi_wmi_set_block_method),
187 
188 	{0, 0}
189 };
190 
191 static driver_t acpi_wmi_driver = {
192 	"acpi_wmi",
193 	acpi_wmi_methods,
194 	sizeof(struct acpi_wmi_softc),
195 };
196 
197 static devclass_t acpi_wmi_devclass;
198 DRIVER_MODULE(acpi_wmi, acpi, acpi_wmi_driver, acpi_wmi_devclass, 0, 0);
199 MODULE_VERSION(acpi_wmi, 1);
200 MODULE_DEPEND(acpi_wmi, acpi, 1, 1, 1);
201 static char *wmi_ids[] = {"PNP0C14", "PNP0c14", NULL};
202 
203 /*
204  * Probe for the PNP0C14 ACPI node
205  */
206 static int
207 acpi_wmi_probe(device_t dev)
208 {
209 	if (acpi_disabled("wmi") ||
210 	    ACPI_ID_PROBE(device_get_parent(dev), dev, wmi_ids) == NULL)
211 		return (ENXIO);
212 	device_set_desc(dev, "ACPI-WMI mapping");
213 
214 	return (0);
215 }
216 
217 /*
218  * Attach the device by:
219  * - Looking for the first ACPI EC device
220  * - Install the notify handler
221  * - Install the EC address space handler
222  * - Look for the _WDG node and read GUID information blocks
223  */
224 static int
225 acpi_wmi_attach(device_t dev)
226 {
227 	struct acpi_wmi_softc *sc;
228 	int ret;
229 	ACPI_STATUS status;
230 
231 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
232 	sc = device_get_softc(dev);
233 	ret = ENXIO;
234 
235 	ACPI_SERIAL_BEGIN(acpi_wmi);
236 	sc->wmi_dev = dev;
237 	sc->wmi_handle = acpi_get_handle(dev);
238 	TAILQ_INIT(&wmi_info_list);
239 	/* XXX Only works with one EC, but nearly all systems only have one. */
240 	if ((sc->ec_dev = devclass_get_device(devclass_find("acpi_ec"), 0))
241 	    == NULL)
242 		device_printf(dev, "cannot find EC device\n");
243 	else if (ACPI_FAILURE((status = AcpiInstallNotifyHandler(sc->wmi_handle,
244 		    ACPI_DEVICE_NOTIFY, acpi_wmi_notify_handler, sc))))
245 		device_printf(sc->wmi_dev, "couldn't install notify handler - %s\n",
246 		    AcpiFormatException(status));
247 	else if (ACPI_FAILURE((status = AcpiInstallAddressSpaceHandler(
248 		    sc->wmi_handle, ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler,
249 		    NULL, sc)))) {
250 		device_printf(sc->wmi_dev, "couldn't install EC handler - %s\n",
251 		    AcpiFormatException(status));
252 		AcpiRemoveNotifyHandler(sc->wmi_handle, ACPI_DEVICE_NOTIFY,
253 		    acpi_wmi_notify_handler);
254 	} else if (ACPI_FAILURE((status = acpi_wmi_read_wdg_blocks(
255 		    sc->wmi_handle)))) {
256 		device_printf(sc->wmi_dev, "couldn't parse _WDG - %s\n",
257 		    AcpiFormatException(status));
258 		AcpiRemoveNotifyHandler(sc->wmi_handle, ACPI_DEVICE_NOTIFY,
259 		    acpi_wmi_notify_handler);
260 		AcpiRemoveAddressSpaceHandler(sc->wmi_handle, ACPI_ADR_SPACE_EC,
261 		    acpi_wmi_ec_handler);
262 	} else {
263 		sc->wmistat_dev_t = make_dev(&wmistat_cdevsw, 0, UID_ROOT,
264 		    GID_WHEEL, 0644, "wmistat");
265 		sc->wmistat_dev_t->si_drv1 = sc;
266 		sc->wmistat_open_pid = 0;
267 		sc->wmistat_bufptr = -1;
268 		ret = 0;
269 	}
270 	ACPI_SERIAL_END(acpi_wmi);
271 
272 	return (ret);
273 }
274 
275 /*
276  * Detach the driver by:
277  * - Removing notification handler
278  * - Removing address space handler
279  * - Turning off event generation for all WExx event activated by
280  *   child drivers
281  */
282 static int
283 acpi_wmi_detach(device_t dev)
284 {
285 	struct wmi_info *winfo, *tmp;
286 	struct acpi_wmi_softc *sc;
287 	int ret;
288 
289 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
290 	sc = device_get_softc(dev);
291 	ACPI_SERIAL_BEGIN(acpi_wmi);
292 
293 	if (sc->wmistat_open_pid != 0) {
294 		ret = EBUSY;
295 	} else {
296 		AcpiRemoveNotifyHandler(sc->wmi_handle, ACPI_DEVICE_NOTIFY,
297 		    acpi_wmi_notify_handler);
298 		AcpiRemoveAddressSpaceHandler(sc->wmi_handle,
299 		    ACPI_ADR_SPACE_EC, acpi_wmi_ec_handler);
300 		TAILQ_FOREACH_SAFE(winfo, &wmi_info_list, wmi_list, tmp) {
301 			if (winfo->event_handler)
302 				acpi_wmi_toggle_we_event_generation(dev,
303 				    winfo, EVENT_GENERATION_OFF);
304 			TAILQ_REMOVE(&wmi_info_list, winfo, wmi_list);
305 			free(winfo, M_ACPIWMI);
306 		}
307 		if (sc->wmistat_bufptr != -1) {
308 			sbuf_delete(&sc->wmistat_sbuf);
309 			sc->wmistat_bufptr = -1;
310 		}
311 		sc->wmistat_open_pid = 0;
312 		destroy_dev(sc->wmistat_dev_t);
313 		ret = 0;
314 	}
315 	ACPI_SERIAL_END(acpi_wmi);
316 
317 	return (ret);
318 }
319 
320 
321 /*
322  * Check if the given GUID string (human readable format
323  * AABBCCDD-EEFF-GGHH-IIJJ-KKLLMMNNOOPP)
324  * exists within _WDG
325  */
326 static int
327 acpi_wmi_provides_guid_string_method(device_t dev, const char *guid_string)
328 {
329 	struct wmi_info *winfo;
330 	int ret;
331 
332 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
333 	ACPI_SERIAL_BEGIN(acpi_wmi);
334 	winfo = acpi_wmi_lookup_wmi_info_by_guid_string(guid_string);
335 	ret = (winfo == NULL)?0:winfo->ginfo.max_instance+1;
336 	ACPI_SERIAL_END(acpi_wmi);
337 
338 	return (ret);
339 }
340 
341 /*
342  * Call a method "method_id" on the given GUID block
343  * write result into user provided output buffer
344  */
345 static ACPI_STATUS
346 acpi_wmi_evaluate_call_method(device_t dev, const char *guid_string,
347     UINT8 instance, UINT32 method_id, const ACPI_BUFFER *in, ACPI_BUFFER *out)
348 {
349 	ACPI_OBJECT params[3];
350 	ACPI_OBJECT_LIST input;
351 	char method[5] = "WMxx";
352 	struct wmi_info *winfo;
353 	struct acpi_wmi_softc *sc;
354 	ACPI_STATUS status;
355 
356 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
357 
358 	sc = device_get_softc(dev);
359 	ACPI_SERIAL_BEGIN(acpi_wmi);
360 	if ((winfo = acpi_wmi_lookup_wmi_info_by_guid_string(guid_string))
361 		    == NULL)
362 		status = AE_NOT_FOUND;
363 	else if (!(winfo->ginfo.flags & ACPI_WMI_REGFLAG_METHOD))
364 		status = AE_BAD_DATA;
365 	else if (instance > winfo->ginfo.max_instance)
366 		status = AE_BAD_PARAMETER;
367 	else {
368 		params[0].Type = ACPI_TYPE_INTEGER;
369 		params[0].Integer.Value = instance;
370 		params[1].Type = ACPI_TYPE_INTEGER;
371 		params[1].Integer.Value = method_id;
372 		input.Pointer = params;
373 		input.Count = 2;
374 		if (in) {
375 			params[2].Type =
376 			    (winfo->ginfo.flags & ACPI_WMI_REGFLAG_STRING)
377 			    ?ACPI_TYPE_STRING:ACPI_TYPE_BUFFER;
378 			params[2].Buffer.Length = in->Length;
379 			params[2].Buffer.Pointer = in->Pointer;
380 			input.Count = 3;
381 		}
382 		method[2] = winfo->ginfo.oid[0];
383 		method[3] = winfo->ginfo.oid[1];
384 		status = AcpiEvaluateObject(sc->wmi_handle, method,
385 			    &input, out);
386 	}
387 	ACPI_SERIAL_END(acpi_wmi);
388 
389 	return (status);
390 }
391 
392 /*
393  * Install a user provided event_handler on the given GUID
394  * provided *data will be passed on callback
395  * If there is already an existing event handler registered it will be silently
396  * discarded
397  */
398 static ACPI_STATUS
399 acpi_wmi_install_event_handler_method(device_t dev, const char *guid_string,
400     ACPI_NOTIFY_HANDLER event_handler, void *data)
401 {
402 	struct wmi_info *winfo;
403 	ACPI_STATUS status;
404 
405 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
406 
407 	status = AE_OK;
408 	ACPI_SERIAL_BEGIN(acpi_wmi);
409 	if (guid_string == NULL || event_handler == NULL)
410 		status = AE_BAD_PARAMETER;
411 	else if ((winfo = acpi_wmi_lookup_wmi_info_by_guid_string(guid_string))
412 		    == NULL)
413 		status = AE_NOT_EXIST;
414 	else if (winfo->event_handler != NULL ||
415 		(status = acpi_wmi_toggle_we_event_generation(dev, winfo,
416 		    EVENT_GENERATION_ON)) == AE_OK) {
417 		winfo->event_handler = event_handler;
418 		winfo->event_handler_user_data = data;
419 	}
420 	ACPI_SERIAL_END(acpi_wmi);
421 
422 	return (status);
423 }
424 
425 /*
426  * Remove a previously installed event handler from the given GUID
427  * If there was none installed, this call is silently discarded and
428  * reported as AE_OK
429  */
430 static ACPI_STATUS
431 acpi_wmi_remove_event_handler_method(device_t dev, const char *guid_string)
432 {
433 	struct wmi_info *winfo;
434 	ACPI_STATUS status;
435 
436 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
437 
438 	status = AE_OK;
439 	ACPI_SERIAL_BEGIN(acpi_wmi);
440 	if (guid_string &&
441 	    (winfo = acpi_wmi_lookup_wmi_info_by_guid_string(guid_string))
442 	    != NULL && winfo->event_handler) {
443 		status = acpi_wmi_toggle_we_event_generation(dev, winfo,
444 			    EVENT_GENERATION_OFF);
445 		winfo->event_handler = NULL;
446 		winfo->event_handler_user_data = NULL;
447 	}
448 	ACPI_SERIAL_END(acpi_wmi);
449 
450 	return (status);
451 }
452 
453 /*
454  * Get details on an event received through a callback registered
455  * through ACPI_WMI_REMOVE_EVENT_HANDLER into a user provided output buffer.
456  * (event_id equals "notify" passed in the callback)
457  */
458 static ACPI_STATUS
459 acpi_wmi_get_event_data_method(device_t dev, UINT32 event_id, ACPI_BUFFER *out)
460 {
461 	ACPI_OBJECT_LIST input;
462 	ACPI_OBJECT params[1];
463 	struct acpi_wmi_softc *sc;
464 	struct wmi_info *winfo;
465 	ACPI_STATUS status;
466 
467 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
468 
469 	sc = device_get_softc(dev);
470 	status = AE_NOT_FOUND;
471 	ACPI_SERIAL_BEGIN(acpi_wmi);
472 	params[0].Type = ACPI_TYPE_INTEGER;
473 	params[0].Integer.Value = event_id;
474 	input.Pointer = params;
475 	input.Count = 1;
476 	TAILQ_FOREACH(winfo, &wmi_info_list, wmi_list) {
477 		if ((winfo->ginfo.flags & ACPI_WMI_REGFLAG_EVENT) &&
478 		    ((UINT8) winfo->ginfo.oid[0] == event_id)) {
479 			status = AcpiEvaluateObject(sc->wmi_handle, "_WED",
480 				    &input, out);
481 			break;
482 		}
483 	}
484 	ACPI_SERIAL_END(acpi_wmi);
485 
486 	return (status);
487 }
488 
489 /*
490  * Read a block of data from the given GUID (using WQxx (query))
491  * Will be returned in a user provided buffer (out).
492  * If the method is marked as expensive (ACPI_WMI_REGFLAG_EXPENSIVE)
493  * we will first call the WCxx control method to lock the node to
494  * lock the node for data collection and release it afterwards.
495  * (Failed WCxx calls are ignored to "support" broken implementations)
496  */
497 static ACPI_STATUS
498 acpi_wmi_get_block_method(device_t dev, const char *guid_string, UINT8 instance,
499 	ACPI_BUFFER *out)
500 {
501 	char wc_method[5] = "WCxx";
502 	char wq_method[5] = "WQxx";
503 	ACPI_OBJECT_LIST wc_input;
504 	ACPI_OBJECT_LIST wq_input;
505 	ACPI_OBJECT wc_params[1];
506 	ACPI_OBJECT wq_params[1];
507 	ACPI_HANDLE wc_handle;
508 	struct acpi_wmi_softc *sc;
509 	struct wmi_info *winfo;
510 	ACPI_STATUS status;
511 	ACPI_STATUS wc_status;
512 
513 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
514 
515 	sc = device_get_softc(dev);
516 	wc_status = AE_ERROR;
517 	ACPI_SERIAL_BEGIN(acpi_wmi);
518 	if (guid_string == NULL || out == NULL)
519 		status = AE_BAD_PARAMETER;
520 	else if ((winfo = acpi_wmi_lookup_wmi_info_by_guid_string(guid_string))
521 		    == NULL)
522 		status = AE_ERROR;
523 	else if (instance > winfo->ginfo.max_instance)
524 		status = AE_BAD_PARAMETER;
525 	else if ((winfo->ginfo.flags & ACPI_WMI_REGFLAG_EVENT) ||
526 	    (winfo->ginfo.flags & ACPI_WMI_REGFLAG_METHOD))
527 		status = AE_ERROR;
528 	else {
529 		wq_params[0].Type = ACPI_TYPE_INTEGER;
530 		wq_params[0].Integer.Value = instance;
531 		wq_input.Pointer = wq_params;
532 		wq_input.Count = 1;
533 		if (winfo->ginfo.flags & ACPI_WMI_REGFLAG_EXPENSIVE) {
534 			wc_params[0].Type = ACPI_TYPE_INTEGER;
535 			wc_params[0].Integer.Value = 1;
536 			wc_input.Pointer = wc_params;
537 			wc_input.Count = 1;
538 			wc_method[2] = winfo->ginfo.oid[0];
539 			wc_method[3] = winfo->ginfo.oid[1];
540 			wc_status = AcpiGetHandle(sc->wmi_handle, wc_method,
541 				    &wc_handle);
542 			if (ACPI_SUCCESS(wc_status))
543 				wc_status = AcpiEvaluateObject(wc_handle,
544 						wc_method, &wc_input, NULL);
545 		}
546 		wq_method[2] = winfo->ginfo.oid[0];
547 		wq_method[3] = winfo->ginfo.oid[1];
548 		status = AcpiEvaluateObject(sc->wmi_handle, wq_method,
549 			    &wq_input, out);
550 		if ((winfo->ginfo.flags & ACPI_WMI_REGFLAG_EXPENSIVE)
551 		    && ACPI_SUCCESS(wc_status)) {
552 			wc_params[0].Integer.Value = 0;
553 			status = AcpiEvaluateObject(wc_handle, wc_method,
554 				    &wc_input, NULL);  /* XXX this might be
555 				    			 the wrong status to
556 				    			 return? */
557 		}
558 	}
559 	ACPI_SERIAL_END(acpi_wmi);
560 
561 	return (status);
562 }
563 
564 /*
565  * Write a block of data to the given GUID (using WSxx)
566  */
567 static ACPI_STATUS
568 acpi_wmi_set_block_method(device_t dev, const char *guid_string, UINT8 instance,
569 	const ACPI_BUFFER *in)
570 {
571 	char method[5] = "WSxx";
572 	ACPI_OBJECT_LIST input;
573 	ACPI_OBJECT params[2];
574 	struct wmi_info *winfo;
575 	struct acpi_wmi_softc *sc;
576 	ACPI_STATUS status;
577 
578 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
579 
580 	sc = device_get_softc(dev);
581 	ACPI_SERIAL_BEGIN(acpi_wmi);
582 	if (guid_string == NULL || in == NULL)
583 		status = AE_BAD_DATA;
584 	else if ((winfo = acpi_wmi_lookup_wmi_info_by_guid_string(guid_string))
585 		    == NULL)
586 		status = AE_ERROR;
587 	else if (instance > winfo->ginfo.max_instance)
588 		status = AE_BAD_PARAMETER;
589 	else if ((winfo->ginfo.flags & ACPI_WMI_REGFLAG_EVENT) ||
590 		    (winfo->ginfo.flags & ACPI_WMI_REGFLAG_METHOD))
591 		status = AE_ERROR;
592 	else {
593 		params[0].Type = ACPI_TYPE_INTEGER;
594 		params[0].Integer.Value = instance;
595 		input.Pointer = params;
596 		input.Count = 2;
597 		params[1].Type = (winfo->ginfo.flags & ACPI_WMI_REGFLAG_STRING)
598 		    ?ACPI_TYPE_STRING:ACPI_TYPE_BUFFER;
599 		params[1].Buffer.Length = in->Length;
600 		params[1].Buffer.Pointer = in->Pointer;
601 		method[2] = winfo->ginfo.oid[0];
602 		method[3] = winfo->ginfo.oid[1];
603 		status = AcpiEvaluateObject(sc->wmi_handle, method,
604 			    &input, NULL);
605 	}
606 	ACPI_SERIAL_END(acpi_wmi);
607 
608 	return (status);
609 }
610 
611 /*
612  * Handle events received and dispatch them to
613  * stakeholders that registered through ACPI_WMI_INSTALL_EVENT_HANDLER
614  */
615 static void
616 acpi_wmi_notify_handler(ACPI_HANDLE h, UINT32 notify, void *context)
617 {
618 	ACPI_NOTIFY_HANDLER handler;
619 	void *handler_data;
620 	struct wmi_info *winfo;
621 
622 	ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, notify);
623 
624 	handler = NULL;
625 	handler_data = NULL;
626 	ACPI_SERIAL_BEGIN(acpi_wmi);
627 	TAILQ_FOREACH(winfo, &wmi_info_list, wmi_list) {
628 		if ((winfo->ginfo.flags & ACPI_WMI_REGFLAG_EVENT) &&
629 				((UINT8) winfo->ginfo.oid[0] == notify)) {
630 			if (winfo->event_handler) {
631 				handler = winfo->event_handler;
632 				handler_data = winfo->event_handler_user_data;
633 				break;
634 			}
635 		}
636 	}
637 	ACPI_SERIAL_END(acpi_wmi);
638 	if (handler) {
639 		handler(h, notify, handler_data);
640 	}
641 }
642 
643 /*
644  * Handle EC address space notifications reveived on the WDG node
645  * (this mimics EcAddressSpaceHandler in acpi_ec.c)
646  */
647 static ACPI_STATUS
648 acpi_wmi_ec_handler(UINT32 function, ACPI_PHYSICAL_ADDRESS address,
649     UINT32 width, ACPI_INTEGER *value, void *context,
650     void *region_context)
651 {
652 	struct acpi_wmi_softc *sc;
653 	int i;
654 	ACPI_INTEGER ec_data;
655 	UINT8 ec_addr;
656 	ACPI_STATUS status;
657 
658 	ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)address);
659 
660 	sc = (struct acpi_wmi_softc *)context;
661 	if (width % 8 != 0 || value == NULL || context == NULL)
662 		return (AE_BAD_PARAMETER);
663 	if (address + (width / 8) - 1 > 0xFF)
664 		return (AE_BAD_ADDRESS);
665 	if (function == ACPI_READ)
666 		*value = 0;
667 	ec_addr = address;
668 	status = AE_ERROR;
669 
670 	for (i = 0; i < width; i += 8, ++ec_addr) {
671 		switch (function) {
672 		case ACPI_READ:
673 			status = ACPI_EC_READ(sc->ec_dev, ec_addr, &ec_data, 1);
674 			if (ACPI_SUCCESS(status))
675 				*value |= ((ACPI_INTEGER)ec_data) << i;
676 		break;
677 		case ACPI_WRITE:
678 			ec_data = (UINT8)((*value) >> i);
679 			status = ACPI_EC_WRITE(sc->ec_dev, ec_addr, ec_data, 1);
680 			break;
681 		default:
682 			device_printf(sc->wmi_dev,
683 			    "invalid acpi_wmi_ec_handler function %d\n",
684 			    function);
685 			status = AE_BAD_PARAMETER;
686 			break;
687 		}
688 		if (ACPI_FAILURE(status))
689 			break;
690 	}
691 
692 	return (status);
693 }
694 
695 /*
696  * Read GUID blocks from the _WDG node
697  * into wmi_info_list.
698  */
699 static ACPI_STATUS
700 acpi_wmi_read_wdg_blocks(ACPI_HANDLE h)
701 {
702 	ACPI_BUFFER out = {ACPI_ALLOCATE_BUFFER, NULL};
703 	struct guid_info *ginfo;
704 	ACPI_OBJECT *obj;
705 	struct wmi_info *winfo;
706 	UINT32 i;
707 	UINT32 wdg_block_count;
708 	ACPI_STATUS status;
709 
710 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
711 
712 	ACPI_SERIAL_ASSERT(acpi_wmi);
713 	if (ACPI_FAILURE(status = AcpiEvaluateObject(h, "_WDG", NULL, &out)))
714 		return (status);
715 	obj = (ACPI_OBJECT*) out.Pointer;
716 	wdg_block_count = obj->Buffer.Length / sizeof(struct guid_info);
717 	if ((ginfo = malloc(obj->Buffer.Length, M_ACPIWMI, M_NOWAIT))
718 		    == NULL) {
719 		AcpiOsFree(out.Pointer);
720 		return (AE_NO_MEMORY);
721 	}
722 	memcpy(ginfo, obj->Buffer.Pointer, obj->Buffer.Length);
723 	for (i = 0; i < wdg_block_count; ++i) {
724 		if ((winfo = malloc(sizeof(struct wmi_info), M_ACPIWMI,
725 			    M_NOWAIT | M_ZERO)) == NULL) {
726 			AcpiOsFree(out.Pointer);
727 			free(ginfo, M_ACPIWMI);
728 			return (AE_NO_MEMORY);
729 		}
730 		winfo->ginfo = ginfo[i];
731 		TAILQ_INSERT_TAIL(&wmi_info_list, winfo, wmi_list);
732 	}
733 	AcpiOsFree(out.Pointer);
734 	free(ginfo, M_ACPIWMI);
735 
736 	return (status);
737 }
738 
739 /*
740  * Toggle event generation in for the given GUID (passed by winfo)
741  * Turn on to get notified (through acpi_wmi_notify_handler) if events happen
742  * on the given GUID.
743  */
744 static ACPI_STATUS
745 acpi_wmi_toggle_we_event_generation(device_t dev, struct wmi_info *winfo,
746     enum event_generation_state state)
747 {
748 	char method[5] = "WExx";
749 	ACPI_OBJECT_LIST input;
750 	ACPI_OBJECT params[1];
751 	struct acpi_wmi_softc *sc;
752 	ACPI_STATUS status;
753 
754 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
755 
756 	sc = device_get_softc(dev);
757 	ACPI_SERIAL_ASSERT(acpi_wmi);
758 	params[0].Type = ACPI_TYPE_INTEGER;
759 	params[0].Integer.Value = state==EVENT_GENERATION_ON?1:0;
760 	input.Pointer = params;
761 	input.Count = 1;
762 
763 	UINT8 hi = ((UINT8) winfo->ginfo.oid[0]) >> 4;
764 	UINT8 lo = ((UINT8) winfo->ginfo.oid[0]) & 0xf;
765 	method[2] = (hi > 9 ? hi + 55: hi + 48);
766 	method[3] = (lo > 9 ? lo + 55: lo + 48);
767 	status = AcpiEvaluateObject(sc->wmi_handle, method, &input, NULL);
768 	if (status == AE_NOT_FOUND) status = AE_OK;
769 
770 	return (status);
771 }
772 
773 /*
774  * Convert given two digit hex string (hexin) to an UINT8 referenced
775  * by byteout.
776  * Return != 0 if the was a problem (invalid input)
777  */
778 static __inline int acpi_wmi_hex_to_int(const UINT8 *hexin, UINT8 *byteout)
779 {
780 	unsigned int hi;
781 	unsigned int lo;
782 
783 	hi = hexin[0];
784 	lo = hexin[1];
785 	if ('0' <= hi && hi <= '9')
786 		hi -= '0';
787 	else if ('A' <= hi && hi <= 'F')
788 		hi -= ('A' - 10);
789 	else if ('a' <= hi && hi <= 'f')
790 		hi -= ('a' - 10);
791 	else
792 		return (1);
793 	if ('0' <= lo && lo <= '9')
794 		lo -= '0';
795 	else if ('A' <= lo && lo <= 'F')
796 		lo -= ('A' - 10);
797 	else if ('a' <= lo && lo <= 'f')
798 		lo -= ('a' - 10);
799 	else
800 		return (1);
801 	*byteout = (hi << 4) + lo;
802 
803 	return (0);
804 }
805 
806 /*
807  * Convert a human readable 36 character GUID into a 16byte
808  * machine readable one.
809  * The basic algorithm looks as follows:
810  * Input:  AABBCCDD-EEFF-GGHH-IIJJ-KKLLMMNNOOPP
811  * Output: DCBAFEHGIJKLMNOP
812  * (AA BB CC etc. represent two digit hex numbers == bytes)
813  * Return != 0 if passed guid string is invalid
814  */
815 static int
816 acpi_wmi_guid_string_to_guid(const UINT8 *guid_string, UINT8 *guid)
817 {
818 	static const int mapping[20] = {3, 2, 1, 0, -1, 5, 4, -1, 7, 6, -1,
819 	    8, 9, -1, 10, 11, 12, 13, 14, 15};
820 	int i;
821 
822 	for (i = 0; i < 20; ++i, ++guid_string) {
823 		if (mapping[i] >= 0) {
824 			if (acpi_wmi_hex_to_int(guid_string,
825 			    &guid[mapping[i]]))
826 				return (-1);
827 			++guid_string;
828 		} else if (*guid_string != '-')
829 			return (-1);
830 	}
831 
832 	return (0);
833 }
834 
835 /*
836  * Lookup a wmi_info structure in wmi_list based on a
837  * human readable GUID
838  * Return NULL if the GUID is unknown in the _WDG
839  */
840 static struct wmi_info*
841 acpi_wmi_lookup_wmi_info_by_guid_string(const char *guid_string)
842 {
843 	char guid[16];
844 	struct wmi_info *winfo;
845 
846 	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
847 
848 	ACPI_SERIAL_ASSERT(acpi_wmi);
849 
850 	if (!acpi_wmi_guid_string_to_guid(guid_string, guid)) {
851 		TAILQ_FOREACH(winfo, &wmi_info_list, wmi_list) {
852 			if (!memcmp(winfo->ginfo.guid, guid, 16)) {
853 				return (winfo);
854 			}
855 		}
856 	}
857 
858 	return (NULL);
859 }
860 
861 /*
862  * open wmistat device
863  */
864 static int
865 acpi_wmi_wmistat_open(struct cdev* dev, int flags, int mode, struct thread *td)
866 {
867 	struct acpi_wmi_softc *sc;
868 	int ret;
869 
870 	if (dev == NULL || dev->si_drv1 == NULL)
871 		return (EBADF);
872 	sc = dev->si_drv1;
873 
874 	ACPI_SERIAL_BEGIN(acpi_wmi);
875 	if (sc->wmistat_open_pid != 0) {
876 		ret = EBUSY;
877 	}
878 	else {
879 		if (sbuf_new(&sc->wmistat_sbuf, NULL, 4096, SBUF_AUTOEXTEND)
880 			    == NULL) {
881 			ret = ENXIO;
882 		} else {
883 			sc->wmistat_open_pid = td->td_proc->p_pid;
884 			sc->wmistat_bufptr = 0;
885 			ret = 0;
886 		}
887 	}
888 	ACPI_SERIAL_END(acpi_wmi);
889 
890 	return (ret);
891 }
892 
893 /*
894  * close wmistat device
895  */
896 static int
897 acpi_wmi_wmistat_close(struct cdev* dev, int flags, int mode,
898     struct thread *td)
899 {
900 	struct acpi_wmi_softc *sc;
901 	int ret;
902 
903 	if (dev == NULL || dev->si_drv1 == NULL)
904 		return (EBADF);
905 	sc = dev->si_drv1;
906 
907 	ACPI_SERIAL_BEGIN(acpi_wmi);
908 	if (sc->wmistat_open_pid == 0) {
909 		ret = EBADF;
910 	}
911 	else {
912 		if (sc->wmistat_bufptr != -1) {
913 			sbuf_delete(&sc->wmistat_sbuf);
914 			sc->wmistat_bufptr = -1;
915 		}
916 		sc->wmistat_open_pid = 0;
917 		ret = 0;
918 	}
919 	ACPI_SERIAL_END(acpi_wmi);
920 
921 	return (ret);
922 }
923 
924 /*
925  * Read from wmistat guid information
926  */
927 static int
928 acpi_wmi_wmistat_read(struct cdev *dev, struct uio *buf, int flag)
929 {
930 	struct acpi_wmi_softc *sc;
931 	struct wmi_info *winfo;
932 	int l;
933 	int ret;
934 	UINT8* guid;
935 
936 	if (dev == NULL || dev->si_drv1 == NULL)
937 		return (EBADF);
938 	sc = dev->si_drv1;
939 
940 	ACPI_SERIAL_BEGIN(acpi_wmi);
941 	if (sc->wmistat_open_pid != buf->uio_td->td_proc->p_pid ||
942 			sc->wmistat_bufptr == -1) {
943 		ret = EBADF;
944 	}
945 	else {
946 		if (!sbuf_done(&sc->wmistat_sbuf)) {
947 			sbuf_printf(&sc->wmistat_sbuf, "GUID                 "
948 				    "                 INST EXPE METH STR "
949 				    "EVENT OID\n");
950 			TAILQ_FOREACH(winfo, &wmi_info_list, wmi_list) {
951 				guid = (UINT8*)winfo->ginfo.guid;
952 				sbuf_printf(&sc->wmistat_sbuf,
953 					    "{%02X%02X%02X%02X-%02X%02X-"
954 					    "%02X%02X-%02X%02X-%02X%02X"
955 					    "%02X%02X%02X%02X} %3d %-5s",
956 					guid[3], guid[2], guid[1], guid[0],
957 					guid[5], guid[4],
958 					guid[7], guid[6],
959 					guid[8], guid[9],
960 					guid[10], guid[11], guid[12],
961 					guid[13], guid[14], guid[15],
962 					winfo->ginfo.max_instance,
963 					(winfo->ginfo.flags&
964 						ACPI_WMI_REGFLAG_EXPENSIVE)?
965 						"YES":"NO"
966 					);
967 				if (winfo->ginfo.flags&ACPI_WMI_REGFLAG_METHOD)
968 					sbuf_printf(&sc->wmistat_sbuf,
969 						    "WM%c%c ",
970 						    winfo->ginfo.oid[0],
971 						    winfo->ginfo.oid[1]);
972 				else
973 					sbuf_printf(&sc->wmistat_sbuf, "NO   ");
974 				sbuf_printf(&sc->wmistat_sbuf, "%-4s",
975 					    (winfo->ginfo.flags&
976 					    ACPI_WMI_REGFLAG_STRING)?"YES":"NO"
977 					);
978 				if (winfo->ginfo.flags&ACPI_WMI_REGFLAG_EVENT)
979 					sbuf_printf(&sc->wmistat_sbuf,
980 						    "0x%02X%s -\n",
981 						    (UINT8)winfo->ginfo.oid[0],
982 						    winfo->event_handler==NULL?
983 						    " ":"+");
984 				else
985 					sbuf_printf(&sc->wmistat_sbuf,
986 						    "NO    %c%c\n",
987 						    winfo->ginfo.oid[0],
988 						    winfo->ginfo.oid[1]);
989 			}
990 			sbuf_finish(&sc->wmistat_sbuf);
991 		}
992 		if (sbuf_len(&sc->wmistat_sbuf) <= 0) {
993 			sbuf_delete(&sc->wmistat_sbuf);
994 			sc->wmistat_bufptr = -1;
995 			sc->wmistat_open_pid = 0;
996 			ret = ENOMEM;
997 		} else {
998 			l = min(buf->uio_resid, sbuf_len(&sc->wmistat_sbuf) -
999 				    sc->wmistat_bufptr);
1000 			ret = (l > 0)?uiomove(sbuf_data(&sc->wmistat_sbuf) +
1001 				    sc->wmistat_bufptr, l, buf) : 0;
1002 			sc->wmistat_bufptr += l;
1003 		}
1004 	}
1005 	ACPI_SERIAL_END(acpi_wmi);
1006 
1007 	return (ret);
1008 }
1009