xref: /netbsd-src/sys/dev/acpi/acpi_ec.c (revision d20841bb642898112fe68f0ad3f7b26dddf56f07)
1 /*	$NetBSD: acpi_ec.c,v 1.20 2003/11/12 13:59:23 yamt Exp $	*/
2 
3 /*
4  * Copyright 2001 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed for the NetBSD Project by
20  *	Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*-
39  * Copyright (c) 2000 Michael Smith
40  * Copyright (c) 2000 BSDi
41  * All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62  * SUCH DAMAGE.
63  */
64 
65 /******************************************************************************
66  *
67  * 1. Copyright Notice
68  *
69  * Some or all of this work - Copyright (c) 1999, Intel Corp.  All rights
70  * reserved.
71  *
72  * 2. License
73  *
74  * 2.1. This is your license from Intel Corp. under its intellectual property
75  * rights.  You may have additional license terms from the party that provided
76  * you this software, covering your right to use that party's intellectual
77  * property rights.
78  *
79  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
80  * copy of the source code appearing in this file ("Covered Code") an
81  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
82  * base code distributed originally by Intel ("Original Intel Code") to copy,
83  * make derivatives, distribute, use and display any portion of the Covered
84  * Code in any form, with the right to sublicense such rights; and
85  *
86  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
87  * license (with the right to sublicense), under only those claims of Intel
88  * patents that are infringed by the Original Intel Code, to make, use, sell,
89  * offer to sell, and import the Covered Code and derivative works thereof
90  * solely to the minimum extent necessary to exercise the above copyright
91  * license, and in no event shall the patent license extend to any additions
92  * to or modifications of the Original Intel Code.  No other license or right
93  * is granted directly or by implication, estoppel or otherwise;
94  *
95  * The above copyright and patent license is granted only if the following
96  * conditions are met:
97  *
98  * 3. Conditions
99  *
100  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
101  * Redistribution of source code of any substantial portion of the Covered
102  * Code or modification with rights to further distribute source must include
103  * the above Copyright Notice, the above License, this list of Conditions,
104  * and the following Disclaimer and Export Compliance provision.  In addition,
105  * Licensee must cause all Covered Code to which Licensee contributes to
106  * contain a file documenting the changes Licensee made to create that Covered
107  * Code and the date of any change.  Licensee must include in that file the
108  * documentation of any changes made by any predecessor Licensee.  Licensee
109  * must include a prominent statement that the modification is derived,
110  * directly or indirectly, from Original Intel Code.
111  *
112  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
113  * Redistribution of source code of any substantial portion of the Covered
114  * Code or modification without rights to further distribute source must
115  * include the following Disclaimer and Export Compliance provision in the
116  * documentation and/or other materials provided with distribution.  In
117  * addition, Licensee may not authorize further sublicense of source of any
118  * portion of the Covered Code, and must include terms to the effect that the
119  * license from Licensee to its licensee is limited to the intellectual
120  * property embodied in the software Licensee provides to its licensee, and
121  * not to intellectual property embodied in modifications its licensee may
122  * make.
123  *
124  * 3.3. Redistribution of Executable. Redistribution in executable form of any
125  * substantial portion of the Covered Code or modification must reproduce the
126  * above Copyright Notice, and the following Disclaimer and Export Compliance
127  * provision in the documentation and/or other materials provided with the
128  * distribution.
129  *
130  * 3.4. Intel retains all right, title, and interest in and to the Original
131  * Intel Code.
132  *
133  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
134  * Intel shall be used in advertising or otherwise to promote the sale, use or
135  * other dealings in products derived from or relating to the Covered Code
136  * without prior written authorization from Intel.
137  *
138  * 4. Disclaimer and Export Compliance
139  *
140  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
141  * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
142  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,
143  * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY
144  * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY
145  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
146  * PARTICULAR PURPOSE.
147  *
148  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
149  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
150  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
151  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
152  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
153  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS
154  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
155  * LIMITED REMEDY.
156  *
157  * 4.3. Licensee shall not export, either directly or indirectly, any of this
158  * software or system incorporating such software without first obtaining any
159  * required license or other approval from the U. S. Department of Commerce or
160  * any other agency or department of the United States Government.  In the
161  * event Licensee exports any such software from the United States or
162  * re-exports any such software from a foreign destination, Licensee shall
163  * ensure that the distribution and export/re-export of the software is in
164  * compliance with all laws, regulations, orders, or other restrictions of the
165  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
166  * any of its subsidiaries will export/re-export any technical data, process,
167  * software, or service, directly or indirectly, to any country for which the
168  * United States government or any agency thereof requires an export license,
169  * other governmental approval, or letter of assurance, without first obtaining
170  * such license, approval or letter.
171  *
172  *****************************************************************************/
173 
174 #include <sys/cdefs.h>
175 __KERNEL_RCSID(0, "$NetBSD: acpi_ec.c,v 1.20 2003/11/12 13:59:23 yamt Exp $");
176 
177 #include <sys/param.h>
178 #include <sys/systm.h>
179 #include <sys/device.h>
180 #include <sys/proc.h>
181 #include <sys/kernel.h>
182 
183 #include <machine/bus.h>
184 
185 #include <dev/acpi/acpica.h>
186 #include <dev/acpi/acpireg.h>
187 #include <dev/acpi/acpivar.h>
188 #include <dev/acpi/acpi_ecreg.h>
189 
190 #define _COMPONENT	ACPI_EC_COMPONENT
191 ACPI_MODULE_NAME("EC")
192 
193 struct acpi_ec_softc {
194 	struct device	sc_dev;		/* base device glue */
195 	struct acpi_devnode *sc_node;	/* our ACPI devnode */
196 
197 	struct acpi_resources sc_res;	/* our bus resources */
198 
199 	UINT32		sc_gpebit;	/* our GPE interrupt bit */
200 
201 	bus_space_tag_t	sc_data_st;	/* space tag for data register */
202 	bus_space_handle_t sc_data_sh;	/* space handle for data register */
203 
204 	bus_space_tag_t	sc_csr_st;	/* space tag for control register */
205 	bus_space_handle_t sc_csr_sh;	/* space handle for control register */
206 
207 	int		sc_flags;	/* see below */
208 
209 	uint32_t	sc_csrvalue;	/* saved control register */
210 
211 	struct lock	sc_lock;	/* serialize operations to this EC */
212 	struct simplelock sc_slock;	/* protect against interrupts */
213 	UINT32		sc_glkhandle;	/* global lock handle */
214 	UINT32		sc_glk;		/* need global lock? */
215 } *acpiec_ecdt_softc;
216 
217 static const char * const ec_hid[] = {
218 	"PNP0C09",
219 	NULL
220 };
221 
222 #define	EC_F_TRANSACTION	0x01	/* doing transaction */
223 #define	EC_F_PENDQUERY		0x02	/* query is pending */
224 
225 /*
226  * how long to wait to acquire global lock.
227  * the value is taken from FreeBSD driver.
228  */
229 #define	EC_LOCK_TIMEOUT	1000
230 
231 #define	EC_DATA_READ(sc)						\
232 	bus_space_read_1((sc)->sc_data_st, (sc)->sc_data_sh, 0)
233 #define	EC_DATA_WRITE(sc, v)						\
234 	bus_space_write_1((sc)->sc_data_st, (sc)->sc_data_sh, 0, (v))
235 
236 #define	EC_CSR_READ(sc)							\
237 	bus_space_read_1((sc)->sc_csr_st, (sc)->sc_csr_sh, 0)
238 #define	EC_CSR_WRITE(sc, v)						\
239 	bus_space_write_1((sc)->sc_csr_st, (sc)->sc_csr_sh, 0, (v))
240 
241 typedef struct {
242 	EC_COMMAND	Command;
243 	UINT8		Address;
244 	UINT8		Data;
245 } EC_REQUEST;
246 
247 static void		EcGpeHandler(void *Context);
248 static ACPI_STATUS	EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
249 			    void *Context, void **return_Context);
250 static ACPI_STATUS	EcSpaceHandler(UINT32 Function,
251 			    ACPI_PHYSICAL_ADDRESS Address, UINT32 width,
252 			    ACPI_INTEGER *Value, void *Context,
253 			    void *RegionContext);
254 
255 static ACPI_STATUS	EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event);
256 static ACPI_STATUS	EcQuery(struct acpi_ec_softc *sc, UINT8 *Data);
257 static ACPI_STATUS	EcTransaction(struct acpi_ec_softc *sc,
258 			    EC_REQUEST *EcRequest);
259 static ACPI_STATUS	EcRead(struct acpi_ec_softc *sc, UINT8 Address,
260 			    UINT8 *Data);
261 static ACPI_STATUS	EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
262 			    UINT8 *Data);
263 static void		EcGpeQueryHandler(void *);
264 static __inline int	EcIsLocked(struct acpi_ec_softc *);
265 static __inline void	EcLock(struct acpi_ec_softc *);
266 static __inline void	EcUnlock(struct acpi_ec_softc *);
267 
268 
269 int	acpiec_match(struct device *, struct cfdata *, void *);
270 void	acpiec_attach(struct device *, struct device *, void *);
271 
272 CFATTACH_DECL(acpiec, sizeof(struct acpi_ec_softc),
273     acpiec_match, acpiec_attach, NULL, NULL);
274 
275 static __inline int
276 EcIsLocked(struct acpi_ec_softc *sc)
277 {
278 
279 	return (lockstatus(&sc->sc_lock) == LK_EXCLUSIVE);
280 }
281 
282 static __inline void
283 EcLock(struct acpi_ec_softc *sc)
284 {
285 	ACPI_STATUS status;
286 	int s;
287 
288 	lockmgr(&sc->sc_lock, LK_EXCLUSIVE, NULL);
289 	if (sc->sc_glk) {
290 		status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT,
291 		    &sc->sc_glkhandle);
292 		if (ACPI_FAILURE(status)) {
293 			printf("%s: failed to acquire global lock\n",
294 			    sc->sc_dev.dv_xname);
295 			lockmgr(&sc->sc_lock, LK_RELEASE, NULL);
296 			return;
297 		}
298 	}
299 
300 	s = splvm(); /* XXX */
301 	simple_lock(&sc->sc_slock);
302 	sc->sc_flags |= EC_F_TRANSACTION;
303 	simple_unlock(&sc->sc_slock);
304 	splx(s);
305 }
306 
307 static __inline void
308 EcUnlock(struct acpi_ec_softc *sc)
309 {
310 	ACPI_STATUS status;
311 	int s;
312 
313 	/*
314 	 * Clear & Re-Enable the EC GPE:
315 	 * -----------------------------
316 	 * 'Consume' any EC GPE events that we generated while performing
317 	 * the transaction (e.g. IBF/OBF). Clearing the GPE here shouldn't
318 	 * have an adverse affect on outstanding EC-SCI's, as the source
319 	 * (EC-SCI) will still be high and thus should trigger the GPE
320 	 * immediately after we re-enabling it.
321 	 */
322 	s = splvm(); /* XXX */
323 	simple_lock(&sc->sc_slock);
324 	if (sc->sc_flags & EC_F_PENDQUERY) {
325 		ACPI_STATUS Status2;
326 
327 		Status2 = AcpiOsQueueForExecution(OSD_PRIORITY_HIGH,
328 		    EcGpeQueryHandler, sc);
329 		if (ACPI_FAILURE(Status2))
330 			printf("%s: unable to queue pending query: %s\n",
331 			    sc->sc_dev.dv_xname, AcpiFormatException(Status2));
332 		sc->sc_flags &= ~EC_F_PENDQUERY;
333 	}
334 	sc->sc_flags &= ~EC_F_TRANSACTION;
335 	simple_unlock(&sc->sc_slock);
336 	splx(s);
337 
338 	if (sc->sc_glk) {
339 		status = AcpiReleaseGlobalLock(sc->sc_glkhandle);
340 		if (ACPI_FAILURE(status))
341 			printf("%s: failed to release global lock\n",
342 			    sc->sc_dev.dv_xname);
343 	}
344 	lockmgr(&sc->sc_lock, LK_RELEASE, NULL);
345 }
346 
347 /*
348  * acpiec_match:
349  *
350  *	Autoconfiguration `match' routine.
351  */
352 int
353 acpiec_match(struct device *parent, struct cfdata *match, void *aux)
354 {
355 	struct acpi_attach_args *aa = aux;
356 
357 	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
358 		return (0);
359 
360 	return (acpi_match_hid(aa->aa_node->ad_devinfo, ec_hid));
361 }
362 
363 #if 0
364 void
365 acpiec_early_attach(struct device *parent)
366 {
367 	EC_BOOT_RESOURCES *ep;
368 	ACPI_HANDLE handle;
369 
370 	status = AcpiGetFirmwareTable("ECDT", 1, ACPI_LOGICAL_ADDRESSING,
371 	    (ACPI_TABLE_HEADER **)&ep;
372 	if (ACPI_FAILURE(status))
373 		return;
374 
375 	if (ep->EcControl.RegisterBitWidth != 8 ||
376 	    ep->EcData.RegisterBitWidth != 8) {
377 		printf("%s: ECDT data is invalid, RegisterBitWidth=%d/%d\n",
378 		    ep->EcControl.RegisterBitWidth, ep->EcData.RegisterBitWidth);
379 		return;
380 	}
381 
382 	status = AcpiGetHandle(ACPI_ROOT_OBJECT, ep->EcId, &handle);
383 	if (ACPI_FAILURE(status)) {
384 		printf("%s: failed to look up EC object %s: %s\n", ep->EcId,
385 		    AcpiFormatExeception(status));
386 		return (status);
387 	}
388 }
389 #endif
390 
391 /*
392  * acpiec_attach:
393  *
394  *	Autoconfiguration `attach' routine.
395  */
396 void
397 acpiec_attach(struct device *parent, struct device *self, void *aux)
398 {
399 	struct acpi_ec_softc *sc = (void *) self;
400 	struct acpi_attach_args *aa = aux;
401 	struct acpi_io *io0, *io1;
402 	ACPI_STATUS rv;
403 
404 	ACPI_FUNCTION_TRACE(__FUNCTION__);
405 
406 	printf(": ACPI Embedded Controller\n");
407 
408 	lockinit(&sc->sc_lock, PWAIT, "eclock", 0, 0);
409 	simple_lock_init(&sc->sc_slock);
410 
411 	sc->sc_node = aa->aa_node;
412 
413 	/* Parse our resources. */
414 	ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "parsing EC resources\n"));
415 	rv = acpi_resource_parse(&sc->sc_dev, sc->sc_node, &sc->sc_res,
416 	    &acpi_resource_parse_ops_default);
417 	if (ACPI_FAILURE(rv))
418 		return;
419 
420 	sc->sc_data_st = aa->aa_iot;
421 	io0 = acpi_res_io(&sc->sc_res, 0);
422 	if (io0 == NULL) {
423 		printf("%s: unable to find data register resource\n",
424 		    sc->sc_dev.dv_xname);
425 		return;
426 	}
427 	if (bus_space_map(sc->sc_data_st, io0->ar_base, io0->ar_length,
428 	    0, &sc->sc_data_sh) != 0) {
429 		printf("%s: unable to map data register\n",
430 		    sc->sc_dev.dv_xname);
431 		return;
432 	}
433 
434 	sc->sc_csr_st = aa->aa_iot;
435 	io1 = acpi_res_io(&sc->sc_res, 1);
436 	if (io1 == NULL) {
437 		printf("%s: unable to find csr register resource\n",
438 		    sc->sc_dev.dv_xname);
439 		return;
440 	}
441 	if (bus_space_map(sc->sc_csr_st, io1->ar_base, io1->ar_length,
442 	    0, &sc->sc_csr_sh) != 0) {
443 		printf("%s: unable to map csr register\n",
444 		    sc->sc_dev.dv_xname);
445 		return;
446 	}
447 
448 	/*
449 	 * Install GPE handler.
450 	 *
451 	 * We evaluate the _GPE method to find the GPE bit used by the
452 	 * Embedded Controller to signal status (SCI).
453 	 */
454 	rv = acpi_eval_integer(sc->sc_node->ad_handle, "_GPE", &sc->sc_gpebit);
455 	if (ACPI_FAILURE(rv)) {
456 		printf("%s: unable to evaluate _GPE: %s\n",
457 		    sc->sc_dev.dv_xname, AcpiFormatException(rv));
458 		return;
459 	}
460 
461 	/*
462 	 * evaluate _GLK to see if we should acquire global lock
463 	 * when accessing the EC.
464 	 */
465 	rv = acpi_eval_integer(sc->sc_node->ad_handle, "_GLK", &sc->sc_glk);
466 	if (ACPI_FAILURE(rv)) {
467 		if (rv != AE_NOT_FOUND)
468 			printf("%s: unable to evaluate _GLK: %s\n",
469 			    sc->sc_dev.dv_xname, AcpiFormatException(rv));
470 		sc->sc_glk = 0;
471 	}
472 
473 	/*
474 	 * Install a handler for this EC's GPE bit.  Note that EC SCIs are
475 	 * treated as both edge- and level-triggered interrupts; in other words
476 	 * we clear the status bit immediately after getting an EC-SCI, then
477 	 * again after we're done processing the event.  This guarantees that
478 	 * events we cause while performing a transaction (e.g. IBE/OBF) get
479 	 * cleared before re-enabling the GPE.
480 	 */
481 	rv = AcpiInstallGpeHandler(NULL, sc->sc_gpebit,
482 	     ACPI_EVENT_EDGE_TRIGGERED, EcGpeHandler, sc);
483 	if (ACPI_FAILURE(rv)) {
484 		printf("%s: unable to install GPE handler: %s\n",
485 		    sc->sc_dev.dv_xname, AcpiFormatException(rv));
486 		return;
487 	}
488 
489 	/* Install address space handler. */
490 	rv = AcpiInstallAddressSpaceHandler(sc->sc_node->ad_handle,
491 	     ACPI_ADR_SPACE_EC, EcSpaceHandler, EcSpaceSetup, sc);
492 	if (ACPI_FAILURE(rv)) {
493 		printf("%s: unable to install address space handler: %s\n",
494 		    sc->sc_dev.dv_xname, AcpiFormatException(rv));
495 		return;
496 	}
497 
498 	return_VOID;
499 }
500 
501 static void
502 EcGpeQueryHandler(void *Context)
503 {
504 	struct acpi_ec_softc *sc = Context;
505 	UINT8 Data;
506 	ACPI_STATUS Status;
507 	char qxx[5];
508 
509 	ACPI_FUNCTION_TRACE(__FUNCTION__);
510 
511 	for (;;) {
512 		/*
513 		 * Check EC_SCI.
514 		 *
515 		 * Bail out if the EC_SCI bit of the status register is not
516 		 * set. Note that this function should only be called when
517 		 * this bit is set (polling is used to detect IBE/OBF events).
518 		 *
519 		 * It is safe to do this without locking the controller, as
520 		 * it's OK to call EcQuery when there's no data ready; in the
521 		 * worst case we should just find nothing waiting for us and
522 		 * bail.
523 		 */
524 		if ((EC_CSR_READ(sc) & EC_EVENT_SCI) == 0)
525 			break;
526 
527 		EcLock(sc);
528 
529 		/*
530 		 * Find out why the EC is signalling us
531 		 */
532 		Status = EcQuery(sc, &Data);
533 
534 		EcUnlock(sc);
535 
536 		/*
537 		 * If we failed to get anything from the EC, give up.
538 		 */
539 		if (ACPI_FAILURE(Status)) {
540 			printf("%s: GPE query failed: %s\n",
541 			    sc->sc_dev.dv_xname, AcpiFormatException(Status));
542 			break;
543 		}
544 
545 		/*
546 		 * Evaluate _Qxx to respond to the controller.
547 		 */
548 		sprintf(qxx, "_Q%02X", Data);
549 		Status = AcpiEvaluateObject(sc->sc_node->ad_handle, qxx,
550 		    NULL, NULL);
551 
552 		/*
553 		 * Ignore spurious query requests.
554 		 */
555 		if (ACPI_FAILURE(Status) &&
556 		    (Data != 0 || Status != AE_NOT_FOUND)) {
557 			printf("%s: evaluation of GPE query method %s "
558 			    "failed: %s\n", sc->sc_dev.dv_xname, qxx,
559 			    AcpiFormatException(Status));
560 		}
561 	}
562 
563 	/* I know I request Level trigger cleanup */
564 	Status = AcpiClearGpe(NULL, sc->sc_gpebit, ACPI_NOT_ISR);
565 	if (ACPI_FAILURE(Status))
566 		printf("%s: AcpiClearGpe failed: %s\n", sc->sc_dev.dv_xname,
567 		    AcpiFormatException(Status));
568 
569 	return_VOID;
570 }
571 
572 static void
573 EcGpeHandler(void *Context)
574 {
575 	struct acpi_ec_softc *sc = Context;
576 	uint32_t csrvalue;
577 	ACPI_STATUS Status;
578 
579 	/*
580 	 * If EC is locked, the intr must process EcRead/Write wait only.
581 	 * Query request must be pending.
582 	 */
583 	simple_lock(&sc->sc_slock);
584 	if (sc->sc_flags & EC_F_TRANSACTION) {
585 		csrvalue = EC_CSR_READ(sc);
586 		if (csrvalue & EC_EVENT_SCI)
587 			sc->sc_flags |= EC_F_PENDQUERY;
588 
589 		if ((csrvalue & EC_FLAG_OUTPUT_BUFFER) != 0 ||
590 		    (csrvalue & EC_FLAG_INPUT_BUFFER) == 0) {
591 			sc->sc_csrvalue = csrvalue;
592 			wakeup(&sc->sc_csrvalue);
593 		}
594 		simple_unlock(&sc->sc_slock);
595 	} else {
596 		simple_unlock(&sc->sc_slock);
597 		/* Enqueue GpeQuery handler. */
598 		Status = AcpiOsQueueForExecution(OSD_PRIORITY_HIGH,
599 		    EcGpeQueryHandler, Context);
600 		if (ACPI_FAILURE(Status))
601 			printf("%s: failed to enqueue query handler: %s\n",
602 			    sc->sc_dev.dv_xname, AcpiFormatException(Status));
603 	}
604 }
605 
606 static ACPI_STATUS
607 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
608     void **RegionContext)
609 {
610 
611 	ACPI_FUNCTION_TRACE(__FUNCTION__);
612 
613 	/*
614 	 * Just pass the context through, there's nothing to do here.
615 	 */
616 	*RegionContext = Context;
617 
618 	return_ACPI_STATUS(AE_OK);
619 }
620 
621 static ACPI_STATUS
622 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 width,
623     ACPI_INTEGER *Value, void *Context, void *RegionContext)
624 {
625 	struct acpi_ec_softc *sc = Context;
626 	ACPI_STATUS Status = AE_OK;
627 	EC_REQUEST EcRequest;
628 	int i;
629 
630 	ACPI_FUNCTION_TRACE_U32(__FUNCTION__, (UINT32)Address);
631 
632 	if ((Address > 0xFF) || (width % 8 != 0) || (Value == NULL) ||
633 	    (Context == NULL))
634 		return_ACPI_STATUS(AE_BAD_PARAMETER);
635 
636 	switch (Function) {
637 	case ACPI_READ:
638 		EcRequest.Command = EC_COMMAND_READ;
639 		EcRequest.Address = Address;
640 		(*Value) = 0;
641 		break;
642 
643 	case ACPI_WRITE:
644 		EcRequest.Command = EC_COMMAND_WRITE;
645 		EcRequest.Address = Address;
646 		break;
647 
648 	default:
649 		printf("%s: invalid Address Space function: %d\n",
650 		    sc->sc_dev.dv_xname, Function);
651 		return_ACPI_STATUS(AE_BAD_PARAMETER);
652 	}
653 
654 	/*
655 	 * Perform the transaction.
656 	 */
657 	for (i = 0; i < width; i += 8) {
658 		if (Function == ACPI_READ)
659 			EcRequest.Data = 0;
660 		else
661 			EcRequest.Data = (UINT8)((*Value) >> i);
662 
663 		Status = EcTransaction(sc, &EcRequest);
664 		if (ACPI_FAILURE(Status))
665 			break;
666 
667 		(*Value) |= (UINT32)EcRequest.Data << i;
668 		if (++EcRequest.Address == 0)
669 			return_ACPI_STATUS(AE_BAD_PARAMETER);
670 	}
671 
672 	return_ACPI_STATUS(Status);
673 }
674 
675 static ACPI_STATUS
676 EcWaitEventIntr(struct acpi_ec_softc *sc, EC_EVENT Event)
677 {
678 	EC_STATUS EcStatus;
679 	int i;
680 
681 	ACPI_FUNCTION_TRACE_U32(__FUNCTION__, (UINT32)Event);
682 
683 	/* XXX Need better test for "yes, you have interrupts". */
684 	if (cold)
685 		return_ACPI_STATUS(EcWaitEvent(sc, Event));
686 
687 	if (EcIsLocked(sc) == 0)
688 		printf("%s: EcWaitEventIntr called without EC lock!\n",
689 		    sc->sc_dev.dv_xname);
690 
691 	EcStatus = EC_CSR_READ(sc);
692 
693 	/* Too long? */
694 	for (i = 0; i < 10; i++) {
695 		/* Check EC status against the desired event. */
696 		if ((Event == EC_EVENT_OUTPUT_BUFFER_FULL) &&
697 		    (EcStatus & EC_FLAG_OUTPUT_BUFFER) != 0)
698 			return_ACPI_STATUS(AE_OK);
699 
700 		if ((Event == EC_EVENT_INPUT_BUFFER_EMPTY) &&
701 		    (EcStatus & EC_FLAG_INPUT_BUFFER) == 0)
702 			return_ACPI_STATUS(AE_OK);
703 
704 		sc->sc_csrvalue = 0;
705 		/* XXXJRT Sleeping with a lock held? */
706 		if (tsleep(&sc->sc_csrvalue, 0, "EcWait", 1) != EWOULDBLOCK)
707 			EcStatus = sc->sc_csrvalue;
708 		else
709 			EcStatus = EC_CSR_READ(sc);
710 	}
711 	return_ACPI_STATUS(AE_ERROR);
712 }
713 
714 static ACPI_STATUS
715 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event)
716 {
717 	EC_STATUS EcStatus;
718 	UINT32 i = 0;
719 
720 	if (EcIsLocked(sc) == 0)
721 		printf("%s: EcWaitEvent called without EC lock!\n",
722 		    sc->sc_dev.dv_xname);
723 
724 	/*
725 	 * Stall 1us:
726 	 * ----------
727 	 * Stall for 1 microsecond before reading the status register
728 	 * for the first time.  This allows the EC to set the IBF/OBF
729 	 * bit to its proper state.
730 	 *
731 	 * XXX it is not clear why we read the CSR twice.
732 	 */
733 	AcpiOsStall(1);
734 	EcStatus = EC_CSR_READ(sc);
735 
736 	/*
737 	 * Wait For Event:
738 	 * ---------------
739 	 * Poll the EC status register to detect completion of the last
740 	 * command.  Wait up to 10ms (in 100us chunks) for this to occur.
741 	 */
742 	for (i = 0; i < 100; i++) {
743 		EcStatus = EC_CSR_READ(sc);
744 
745 		if ((Event == EC_EVENT_OUTPUT_BUFFER_FULL) &&
746 		    (EcStatus & EC_FLAG_OUTPUT_BUFFER) != 0)
747 			return (AE_OK);
748 
749 		if ((Event == EC_EVENT_INPUT_BUFFER_EMPTY) &&
750 		    (EcStatus & EC_FLAG_INPUT_BUFFER) == 0)
751 			return (AE_OK);
752 
753 		AcpiOsStall(10);
754 	}
755 
756 	return (AE_ERROR);
757 }
758 
759 static ACPI_STATUS
760 EcQuery(struct acpi_ec_softc *sc, UINT8 *Data)
761 {
762 	ACPI_STATUS Status;
763 
764 	if (EcIsLocked(sc) == 0)
765 		printf("%s: EcQuery called without EC lock!\n",
766 		    sc->sc_dev.dv_xname);
767 
768 	EC_CSR_WRITE(sc, EC_COMMAND_QUERY);
769 	Status = EcWaitEventIntr(sc, EC_EVENT_OUTPUT_BUFFER_FULL);
770 	if (ACPI_SUCCESS(Status))
771 		*Data = EC_DATA_READ(sc);
772 
773 	if (ACPI_FAILURE(Status))
774 		printf("%s: timed out waiting for EC to respond to "
775 		    "EC_COMMAND_QUERY\n", sc->sc_dev.dv_xname);
776 
777 	return (Status);
778 }
779 
780 static ACPI_STATUS
781 EcTransaction(struct acpi_ec_softc *sc, EC_REQUEST *EcRequest)
782 {
783 	ACPI_STATUS Status;
784 
785 	EcLock(sc);
786 
787 	/*
788 	 * Perform the transaction.
789 	 */
790 	switch (EcRequest->Command) {
791 	case EC_COMMAND_READ:
792 		Status = EcRead(sc, EcRequest->Address, &(EcRequest->Data));
793 		break;
794 
795 	case EC_COMMAND_WRITE:
796 		Status = EcWrite(sc, EcRequest->Address, &(EcRequest->Data));
797 		break;
798 
799 	default:
800 		Status = AE_SUPPORT;
801 		break;
802 	}
803 
804 	EcUnlock(sc);
805 
806 	return(Status);
807 }
808 
809 static ACPI_STATUS
810 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
811 {
812 	ACPI_STATUS Status;
813 
814 	if (EcIsLocked(sc) == 0)
815 		printf("%s: EcRead called without EC lock!\n",
816 		    sc->sc_dev.dv_xname);
817 
818 	/* EcBurstEnable(EmbeddedController); */
819 
820 	EC_CSR_WRITE(sc, EC_COMMAND_READ);
821 	if ((Status = EcWaitEventIntr(sc, EC_EVENT_INPUT_BUFFER_EMPTY)) !=
822 	    AE_OK) {
823 		printf("%s: EcRead: timeout waiting for EC to process "
824 		    "read command\n", sc->sc_dev.dv_xname);
825 		return (Status);
826 	}
827 
828 	EC_DATA_WRITE(sc, Address);
829 	if ((Status = EcWaitEventIntr(sc, EC_EVENT_OUTPUT_BUFFER_FULL)) !=
830 	    AE_OK) {
831 		printf("%s: EcRead: timeout waiting for EC to send data\n",
832 		    sc->sc_dev.dv_xname);
833 		return (Status);
834 	}
835 
836 	(*Data) = EC_DATA_READ(sc);
837 
838 	/* EcBurstDisable(EmbeddedController); */
839 
840 	return (AE_OK);
841 }
842 
843 static ACPI_STATUS
844 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
845 {
846 	ACPI_STATUS Status;
847 
848 	if (EcIsLocked(sc) == 0)
849 		printf("%s: EcWrite called without EC lock!\n",
850 		    sc->sc_dev.dv_xname);
851 
852 	/* EcBurstEnable(EmbeddedController); */
853 
854 	EC_CSR_WRITE(sc, EC_COMMAND_WRITE);
855 	if ((Status = EcWaitEventIntr(sc, EC_EVENT_INPUT_BUFFER_EMPTY)) !=
856 	    AE_OK) {
857 		printf("%s: EcWrite: timeout waiting for EC to process "
858 		    "write command\n", sc->sc_dev.dv_xname);
859 		return (Status);
860 	}
861 
862 	EC_DATA_WRITE(sc, Address);
863 	if ((Status = EcWaitEventIntr(sc, EC_EVENT_INPUT_BUFFER_EMPTY)) !=
864 	    AE_OK) {
865 		printf("%s: EcWrite: timeout waiting for EC to process "
866 		    "address\n", sc->sc_dev.dv_xname);
867 		return (Status);
868 	}
869 
870 	EC_DATA_WRITE(sc, *Data);
871 	if ((Status = EcWaitEventIntr(sc, EC_EVENT_INPUT_BUFFER_EMPTY)) !=
872 	    AE_OK) {
873 		printf("%s: EcWrite: timeout waiting for EC to process "
874 		    "data\n", sc->sc_dev.dv_xname);
875 		return (Status);
876 	}
877 
878 	/* EcBurstDisable(EmbeddedController); */
879 
880 	return (AE_OK);
881 }
882