xref: /freebsd/sys/dev/acpica/acpi_ec.c (revision b28624fde638caadd4a89f50c9b7e7da0f98c4d2)
1 /*-
2  * Copyright (c) 2003 Nate Lawson
3  * Copyright (c) 2000 Michael Smith
4  * Copyright (c) 2000 BSDi
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  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 /*-
29  ******************************************************************************
30  *
31  * 1. Copyright Notice
32  *
33  * Some or all of this work - Copyright (c) 1999, Intel Corp.  All rights
34  * reserved.
35  *
36  * 2. License
37  *
38  * 2.1. This is your license from Intel Corp. under its intellectual property
39  * rights.  You may have additional license terms from the party that provided
40  * you this software, covering your right to use that party's intellectual
41  * property rights.
42  *
43  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
44  * copy of the source code appearing in this file ("Covered Code") an
45  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
46  * base code distributed originally by Intel ("Original Intel Code") to copy,
47  * make derivatives, distribute, use and display any portion of the Covered
48  * Code in any form, with the right to sublicense such rights; and
49  *
50  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
51  * license (with the right to sublicense), under only those claims of Intel
52  * patents that are infringed by the Original Intel Code, to make, use, sell,
53  * offer to sell, and import the Covered Code and derivative works thereof
54  * solely to the minimum extent necessary to exercise the above copyright
55  * license, and in no event shall the patent license extend to any additions
56  * to or modifications of the Original Intel Code.  No other license or right
57  * is granted directly or by implication, estoppel or otherwise;
58  *
59  * The above copyright and patent license is granted only if the following
60  * conditions are met:
61  *
62  * 3. Conditions
63  *
64  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
65  * Redistribution of source code of any substantial portion of the Covered
66  * Code or modification with rights to further distribute source must include
67  * the above Copyright Notice, the above License, this list of Conditions,
68  * and the following Disclaimer and Export Compliance provision.  In addition,
69  * Licensee must cause all Covered Code to which Licensee contributes to
70  * contain a file documenting the changes Licensee made to create that Covered
71  * Code and the date of any change.  Licensee must include in that file the
72  * documentation of any changes made by any predecessor Licensee.  Licensee
73  * must include a prominent statement that the modification is derived,
74  * directly or indirectly, from Original Intel Code.
75  *
76  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
77  * Redistribution of source code of any substantial portion of the Covered
78  * Code or modification without rights to further distribute source must
79  * include the following Disclaimer and Export Compliance provision in the
80  * documentation and/or other materials provided with distribution.  In
81  * addition, Licensee may not authorize further sublicense of source of any
82  * portion of the Covered Code, and must include terms to the effect that the
83  * license from Licensee to its licensee is limited to the intellectual
84  * property embodied in the software Licensee provides to its licensee, and
85  * not to intellectual property embodied in modifications its licensee may
86  * make.
87  *
88  * 3.3. Redistribution of Executable. Redistribution in executable form of any
89  * substantial portion of the Covered Code or modification must reproduce the
90  * above Copyright Notice, and the following Disclaimer and Export Compliance
91  * provision in the documentation and/or other materials provided with the
92  * distribution.
93  *
94  * 3.4. Intel retains all right, title, and interest in and to the Original
95  * Intel Code.
96  *
97  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
98  * Intel shall be used in advertising or otherwise to promote the sale, use or
99  * other dealings in products derived from or relating to the Covered Code
100  * without prior written authorization from Intel.
101  *
102  * 4. Disclaimer and Export Compliance
103  *
104  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
105  * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
106  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,
107  * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY
108  * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY
109  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
110  * PARTICULAR PURPOSE.
111  *
112  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
113  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
114  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
115  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
116  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
117  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS
118  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
119  * LIMITED REMEDY.
120  *
121  * 4.3. Licensee shall not export, either directly or indirectly, any of this
122  * software or system incorporating such software without first obtaining any
123  * required license or other approval from the U. S. Department of Commerce or
124  * any other agency or department of the United States Government.  In the
125  * event Licensee exports any such software from the United States or
126  * re-exports any such software from a foreign destination, Licensee shall
127  * ensure that the distribution and export/re-export of the software is in
128  * compliance with all laws, regulations, orders, or other restrictions of the
129  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
130  * any of its subsidiaries will export/re-export any technical data, process,
131  * software, or service, directly or indirectly, to any country for which the
132  * United States government or any agency thereof requires an export license,
133  * other governmental approval, or letter of assurance, without first obtaining
134  * such license, approval or letter.
135  *
136  *****************************************************************************/
137 
138 #include <sys/cdefs.h>
139 __FBSDID("$FreeBSD$");
140 
141 #include "opt_acpi.h"
142 #include <sys/param.h>
143 #include <sys/kernel.h>
144 #include <sys/bus.h>
145 #include <sys/lock.h>
146 #include <sys/malloc.h>
147 #include <sys/module.h>
148 #include <sys/sx.h>
149 
150 #include <machine/bus.h>
151 #include <machine/resource.h>
152 #include <sys/rman.h>
153 
154 #include <contrib/dev/acpica/acpi.h>
155 #include <dev/acpica/acpivar.h>
156 
157 /* Hooks for the ACPI CA debugging infrastructure */
158 #define _COMPONENT	ACPI_EC
159 ACPI_MODULE_NAME("EC")
160 
161 /*
162  * EC_COMMAND:
163  * -----------
164  */
165 typedef UINT8				EC_COMMAND;
166 
167 #define EC_COMMAND_UNKNOWN		((EC_COMMAND) 0x00)
168 #define EC_COMMAND_READ			((EC_COMMAND) 0x80)
169 #define EC_COMMAND_WRITE		((EC_COMMAND) 0x81)
170 #define EC_COMMAND_BURST_ENABLE		((EC_COMMAND) 0x82)
171 #define EC_COMMAND_BURST_DISABLE	((EC_COMMAND) 0x83)
172 #define EC_COMMAND_QUERY		((EC_COMMAND) 0x84)
173 
174 /*
175  * EC_STATUS:
176  * ----------
177  * The encoding of the EC status register is illustrated below.
178  * Note that a set bit (1) indicates the property is TRUE
179  * (e.g. if bit 0 is set then the output buffer is full).
180  * +-+-+-+-+-+-+-+-+
181  * |7|6|5|4|3|2|1|0|
182  * +-+-+-+-+-+-+-+-+
183  *  | | | | | | | |
184  *  | | | | | | | +- Output Buffer Full?
185  *  | | | | | | +--- Input Buffer Full?
186  *  | | | | | +----- <reserved>
187  *  | | | | +------- Data Register is Command Byte?
188  *  | | | +--------- Burst Mode Enabled?
189  *  | | +----------- SCI Event?
190  *  | +------------- SMI Event?
191  *  +--------------- <reserved>
192  *
193  */
194 typedef UINT8				EC_STATUS;
195 
196 #define EC_FLAG_OUTPUT_BUFFER		((EC_STATUS) 0x01)
197 #define EC_FLAG_INPUT_BUFFER		((EC_STATUS) 0x02)
198 #define EC_FLAG_DATA_IS_CMD		((EC_STATUS) 0x08)
199 #define EC_FLAG_BURST_MODE		((EC_STATUS) 0x10)
200 
201 /*
202  * EC_EVENT:
203  * ---------
204  */
205 typedef UINT8				EC_EVENT;
206 
207 #define EC_EVENT_UNKNOWN		((EC_EVENT) 0x00)
208 #define EC_EVENT_OUTPUT_BUFFER_FULL	((EC_EVENT) 0x01)
209 #define EC_EVENT_INPUT_BUFFER_EMPTY	((EC_EVENT) 0x02)
210 #define EC_EVENT_SCI			((EC_EVENT) 0x20)
211 #define EC_EVENT_SMI			((EC_EVENT) 0x40)
212 
213 /* Data byte returned after burst enable indicating it was successful. */
214 #define EC_BURST_ACK			0x90
215 
216 /*
217  * Register access primitives
218  */
219 #define EC_GET_DATA(sc)							\
220 	bus_space_read_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0)
221 
222 #define EC_SET_DATA(sc, v)						\
223 	bus_space_write_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0, (v))
224 
225 #define EC_GET_CSR(sc)							\
226 	bus_space_read_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0)
227 
228 #define EC_SET_CSR(sc, v)						\
229 	bus_space_write_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0, (v))
230 
231 /* Additional params to pass from the probe routine */
232 struct acpi_ec_params {
233     int		glk;
234     int		gpe_bit;
235     ACPI_HANDLE	gpe_handle;
236     int		uid;
237 };
238 
239 /* Indicate that this device has already been probed via ECDT. */
240 #define DEV_ECDT(x)	(acpi_get_magic(x) == (uintptr_t)&acpi_ec_devclass)
241 
242 /*
243  * Driver softc.
244  */
245 struct acpi_ec_softc {
246     device_t		ec_dev;
247     ACPI_HANDLE		ec_handle;
248     int			ec_uid;
249     ACPI_HANDLE		ec_gpehandle;
250     UINT8		ec_gpebit;
251     UINT8		ec_csrvalue;
252 
253     int			ec_data_rid;
254     struct resource	*ec_data_res;
255     bus_space_tag_t	ec_data_tag;
256     bus_space_handle_t	ec_data_handle;
257 
258     int			ec_csr_rid;
259     struct resource	*ec_csr_res;
260     bus_space_tag_t	ec_csr_tag;
261     bus_space_handle_t	ec_csr_handle;
262 
263     struct mtx		ec_mtx;
264     int			ec_glk;
265     int			ec_glkhandle;
266     int			ec_burstactive;
267     int			ec_sci_pend;
268 };
269 
270 /*
271  * XXX njl
272  * I couldn't find it in the spec but other implementations also use a
273  * value of 1 ms for the time to acquire global lock.
274  */
275 #define EC_LOCK_TIMEOUT	1000
276 
277 /* Default delay in microseconds between each run of the status polling loop. */
278 #define EC_POLL_DELAY	10
279 
280 /* Default time in microseconds spent polling before sleep waiting. */
281 #define EC_POLL_TIME	500
282 
283 /* Total time in ms spent waiting for a response from EC. */
284 #define EC_TIMEOUT	500
285 
286 #define EVENT_READY(event, status)			\
287 	(((event) == EC_EVENT_OUTPUT_BUFFER_FULL &&	\
288 	 ((status) & EC_FLAG_OUTPUT_BUFFER) != 0) ||	\
289 	 ((event) == EC_EVENT_INPUT_BUFFER_EMPTY && 	\
290 	 ((status) & EC_FLAG_INPUT_BUFFER) == 0))
291 
292 ACPI_SERIAL_DECL(ec, "ACPI embedded controller");
293 
294 SYSCTL_DECL(_debug_acpi);
295 SYSCTL_NODE(_debug_acpi, OID_AUTO, ec, CTLFLAG_RD, NULL, "EC debugging");
296 
297 static int	ec_burst_mode;
298 TUNABLE_INT("debug.acpi.ec.burst", &ec_burst_mode);
299 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, burst, CTLFLAG_RW, &ec_burst_mode, 0,
300     "Enable use of burst mode (faster for nearly all systems)");
301 static int	ec_poll_time = EC_POLL_TIME;
302 TUNABLE_INT("debug.acpi.ec.poll_time", &ec_poll_time);
303 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, poll_time, CTLFLAG_RW, &ec_poll_time,
304     EC_POLL_TIME, "Time spent polling vs. sleeping (CPU intensive)");
305 static int	ec_timeout = EC_TIMEOUT;
306 TUNABLE_INT("debug.acpi.ec.timeout", &ec_timeout);
307 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, timeout, CTLFLAG_RW, &ec_timeout,
308     EC_TIMEOUT, "Total time spent waiting for a response (poll+sleep)");
309 
310 static __inline ACPI_STATUS
311 EcLock(struct acpi_ec_softc *sc, int serialize)
312 {
313     ACPI_STATUS	status;
314 
315     /* If _GLK is non-zero, acquire the global lock. */
316     status = AE_OK;
317     if (sc->ec_glk) {
318 	status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->ec_glkhandle);
319 	if (ACPI_FAILURE(status))
320 	    return (status);
321     }
322 
323     /*
324      * If caller is executing a series of commands, acquire the exclusive lock
325      * to serialize with other users.
326      * To sync with bottom-half interrupt handler, always acquire the mutex.
327      */
328     if (serialize)
329 	ACPI_SERIAL_BEGIN(ec);
330     mtx_lock(&sc->ec_mtx);
331 
332     return (status);
333 }
334 
335 static __inline void
336 EcUnlock(struct acpi_ec_softc *sc)
337 {
338     mtx_unlock(&sc->ec_mtx);
339     if (sx_xlocked(&ec_sxlock))
340 	ACPI_SERIAL_END(ec);
341     if (sc->ec_glk)
342 	AcpiReleaseGlobalLock(sc->ec_glkhandle);
343 }
344 
345 static uint32_t		EcGpeHandler(void *Context);
346 static ACPI_STATUS	EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
347 				void *Context, void **return_Context);
348 static ACPI_STATUS	EcSpaceHandler(UINT32 Function,
349 				ACPI_PHYSICAL_ADDRESS Address,
350 				UINT32 width, ACPI_INTEGER *Value,
351 				void *Context, void *RegionContext);
352 static ACPI_STATUS	EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event);
353 static ACPI_STATUS	EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
354 static ACPI_STATUS	EcRead(struct acpi_ec_softc *sc, UINT8 Address,
355 				UINT8 *Data);
356 static ACPI_STATUS	EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
357 				UINT8 *Data);
358 static int		acpi_ec_probe(device_t dev);
359 static int		acpi_ec_attach(device_t dev);
360 static int		acpi_ec_shutdown(device_t dev);
361 static int		acpi_ec_read_method(device_t dev, u_int addr,
362 				ACPI_INTEGER *val, int width);
363 static int		acpi_ec_write_method(device_t dev, u_int addr,
364 				ACPI_INTEGER val, int width);
365 
366 static device_method_t acpi_ec_methods[] = {
367     /* Device interface */
368     DEVMETHOD(device_probe,	acpi_ec_probe),
369     DEVMETHOD(device_attach,	acpi_ec_attach),
370     DEVMETHOD(device_shutdown,	acpi_ec_shutdown),
371 
372     /* Embedded controller interface */
373     DEVMETHOD(acpi_ec_read,	acpi_ec_read_method),
374     DEVMETHOD(acpi_ec_write,	acpi_ec_write_method),
375 
376     {0, 0}
377 };
378 
379 static driver_t acpi_ec_driver = {
380     "acpi_ec",
381     acpi_ec_methods,
382     sizeof(struct acpi_ec_softc),
383 };
384 
385 static devclass_t acpi_ec_devclass;
386 DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, acpi_ec_devclass, 0, 0);
387 MODULE_DEPEND(acpi_ec, acpi, 1, 1, 1);
388 
389 /*
390  * Look for an ECDT and if we find one, set up default GPE and
391  * space handlers to catch attempts to access EC space before
392  * we have a real driver instance in place.
393  * TODO: if people report invalid ECDTs, add a tunable to disable them.
394  */
395 void
396 acpi_ec_ecdt_probe(device_t parent)
397 {
398     ACPI_TABLE_ECDT *ecdt;
399     ACPI_STATUS	     status;
400     device_t	     child;
401     ACPI_HANDLE	     h;
402     struct acpi_ec_params *params;
403 
404     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
405 
406     /* Find and validate the ECDT. */
407     status = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
408     if (ACPI_FAILURE(status) ||
409 	ecdt->Control.BitWidth != 8 ||
410 	ecdt->Data.BitWidth != 8) {
411 	return;
412     }
413 
414     /* Create the child device with the given unit number. */
415     child = BUS_ADD_CHILD(parent, 0, "acpi_ec", ecdt->Uid);
416     if (child == NULL) {
417 	printf("%s: can't add child\n", __func__);
418 	return;
419     }
420 
421     /* Find and save the ACPI handle for this device. */
422     status = AcpiGetHandle(NULL, ecdt->Id, &h);
423     if (ACPI_FAILURE(status)) {
424 	device_delete_child(parent, child);
425 	printf("%s: can't get handle\n", __func__);
426 	return;
427     }
428     acpi_set_handle(child, h);
429 
430     /* Set the data and CSR register addresses. */
431     bus_set_resource(child, SYS_RES_IOPORT, 0, ecdt->Data.Address,
432 	/*count*/1);
433     bus_set_resource(child, SYS_RES_IOPORT, 1, ecdt->Control.Address,
434 	/*count*/1);
435 
436     /*
437      * Store values for the probe/attach routines to use.  Store the
438      * ECDT GPE bit and set the global lock flag according to _GLK.
439      * Note that it is not perfectly correct to be evaluating a method
440      * before initializing devices, but in practice this function
441      * should be safe to call at this point.
442      */
443     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
444     params->gpe_handle = NULL;
445     params->gpe_bit = ecdt->Gpe;
446     params->uid = ecdt->Uid;
447     acpi_GetInteger(h, "_GLK", &params->glk);
448     acpi_set_private(child, params);
449     acpi_set_magic(child, (uintptr_t)&acpi_ec_devclass);
450 
451     /* Finish the attach process. */
452     if (device_probe_and_attach(child) != 0)
453 	device_delete_child(parent, child);
454 }
455 
456 static int
457 acpi_ec_probe(device_t dev)
458 {
459     ACPI_BUFFER buf;
460     ACPI_HANDLE h;
461     ACPI_OBJECT *obj;
462     ACPI_STATUS status;
463     device_t	peer;
464     char	desc[64];
465     int		ret;
466     struct acpi_ec_params *params;
467     static char *ec_ids[] = { "PNP0C09", NULL };
468 
469     /* Check that this is a device and that EC is not disabled. */
470     if (acpi_get_type(dev) != ACPI_TYPE_DEVICE || acpi_disabled("ec"))
471 	return (ENXIO);
472 
473     /*
474      * If probed via ECDT, set description and continue.  Otherwise,
475      * we can access the namespace and make sure this is not a
476      * duplicate probe.
477      */
478     ret = ENXIO;
479     params = NULL;
480     buf.Pointer = NULL;
481     buf.Length = ACPI_ALLOCATE_BUFFER;
482     if (DEV_ECDT(dev)) {
483 	params = acpi_get_private(dev);
484 	ret = 0;
485     } else if (!acpi_disabled("ec") &&
486 	ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids)) {
487 	params = malloc(sizeof(struct acpi_ec_params), M_TEMP,
488 			M_WAITOK | M_ZERO);
489 	h = acpi_get_handle(dev);
490 
491 	/*
492 	 * Read the unit ID to check for duplicate attach and the
493 	 * global lock value to see if we should acquire it when
494 	 * accessing the EC.
495 	 */
496 	status = acpi_GetInteger(h, "_UID", &params->uid);
497 	if (ACPI_FAILURE(status))
498 	    params->uid = 0;
499 	status = acpi_GetInteger(h, "_GLK", &params->glk);
500 	if (ACPI_FAILURE(status))
501 	    params->glk = 0;
502 
503 	/*
504 	 * Evaluate the _GPE method to find the GPE bit used by the EC to
505 	 * signal status (SCI).  If it's a package, it contains a reference
506 	 * and GPE bit, similar to _PRW.
507 	 */
508 	status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
509 	if (ACPI_FAILURE(status)) {
510 	    device_printf(dev, "can't evaluate _GPE - %s\n",
511 			  AcpiFormatException(status));
512 	    goto out;
513 	}
514 	obj = (ACPI_OBJECT *)buf.Pointer;
515 	if (obj == NULL)
516 	    goto out;
517 
518 	switch (obj->Type) {
519 	case ACPI_TYPE_INTEGER:
520 	    params->gpe_handle = NULL;
521 	    params->gpe_bit = obj->Integer.Value;
522 	    break;
523 	case ACPI_TYPE_PACKAGE:
524 	    if (!ACPI_PKG_VALID(obj, 2))
525 		goto out;
526 	    params->gpe_handle =
527 		acpi_GetReference(NULL, &obj->Package.Elements[0]);
528 	    if (params->gpe_handle == NULL ||
529 		acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
530 		goto out;
531 	    break;
532 	default:
533 	    device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
534 	    goto out;
535 	}
536 
537 	/* Store the values we got from the namespace for attach. */
538 	acpi_set_private(dev, params);
539 
540 	/*
541 	 * Check for a duplicate probe.  This can happen when a probe
542 	 * via ECDT succeeded already.  If this is a duplicate, disable
543 	 * this device.
544 	 */
545 	peer = devclass_get_device(acpi_ec_devclass, params->uid);
546 	if (peer == NULL || !device_is_alive(peer))
547 	    ret = 0;
548 	else
549 	    device_disable(dev);
550     }
551 
552 out:
553     if (ret == 0) {
554 	snprintf(desc, sizeof(desc), "Embedded Controller: GPE %#x%s%s",
555 		 params->gpe_bit, (params->glk) ? ", GLK" : "",
556 		 DEV_ECDT(dev) ? ", ECDT" : "");
557 	device_set_desc_copy(dev, desc);
558     }
559 
560     if (ret > 0 && params)
561 	free(params, M_TEMP);
562     if (buf.Pointer)
563 	AcpiOsFree(buf.Pointer);
564     return (ret);
565 }
566 
567 static int
568 acpi_ec_attach(device_t dev)
569 {
570     struct acpi_ec_softc	*sc;
571     struct acpi_ec_params	*params;
572     ACPI_STATUS			Status;
573 
574     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
575 
576     /* Fetch/initialize softc (assumes softc is pre-zeroed). */
577     sc = device_get_softc(dev);
578     params = acpi_get_private(dev);
579     sc->ec_dev = dev;
580     sc->ec_handle = acpi_get_handle(dev);
581     mtx_init(&sc->ec_mtx, "ACPI EC lock", NULL, MTX_DEF);
582 
583     /* Retrieve previously probed values via device ivars. */
584     sc->ec_glk = params->glk;
585     sc->ec_gpebit = params->gpe_bit;
586     sc->ec_gpehandle = params->gpe_handle;
587     sc->ec_uid = params->uid;
588     free(params, M_TEMP);
589 
590     /* Attach bus resources for data and command/status ports. */
591     sc->ec_data_rid = 0;
592     sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
593 			&sc->ec_data_rid, RF_ACTIVE);
594     if (sc->ec_data_res == NULL) {
595 	device_printf(dev, "can't allocate data port\n");
596 	goto error;
597     }
598     sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
599     sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
600 
601     sc->ec_csr_rid = 1;
602     sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
603 			&sc->ec_csr_rid, RF_ACTIVE);
604     if (sc->ec_csr_res == NULL) {
605 	device_printf(dev, "can't allocate command/status port\n");
606 	goto error;
607     }
608     sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
609     sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
610 
611     /*
612      * Install a handler for this EC's GPE bit.  We want edge-triggered
613      * behavior.
614      */
615     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
616     Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
617 		ACPI_GPE_EDGE_TRIGGERED, &EcGpeHandler, sc);
618     if (ACPI_FAILURE(Status)) {
619 	device_printf(dev, "can't install GPE handler for %s - %s\n",
620 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
621 	goto error;
622     }
623 
624     /*
625      * Install address space handler
626      */
627     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
628     Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
629 		&EcSpaceHandler, &EcSpaceSetup, sc);
630     if (ACPI_FAILURE(Status)) {
631 	device_printf(dev, "can't install address space handler for %s - %s\n",
632 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
633 	goto error;
634     }
635 
636     /* Enable runtime GPEs for the handler. */
637     Status = AcpiSetGpeType(sc->ec_gpehandle, sc->ec_gpebit,
638 			    ACPI_GPE_TYPE_RUNTIME);
639     if (ACPI_FAILURE(Status)) {
640 	device_printf(dev, "AcpiSetGpeType failed: %s\n",
641 		      AcpiFormatException(Status));
642 	goto error;
643     }
644     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit, ACPI_NOT_ISR);
645     if (ACPI_FAILURE(Status)) {
646 	device_printf(dev, "AcpiEnableGpe failed: %s\n",
647 		      AcpiFormatException(Status));
648 	goto error;
649     }
650 
651     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
652     return (0);
653 
654 error:
655     AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, &EcGpeHandler);
656     AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
657 	EcSpaceHandler);
658     if (sc->ec_csr_res)
659 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
660 			     sc->ec_csr_res);
661     if (sc->ec_data_res)
662 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
663 			     sc->ec_data_res);
664     mtx_destroy(&sc->ec_mtx);
665     return (ENXIO);
666 }
667 
668 static int
669 acpi_ec_shutdown(device_t dev)
670 {
671     struct acpi_ec_softc	*sc;
672 
673     /* Disable the GPE so we don't get EC events during shutdown. */
674     sc = device_get_softc(dev);
675     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit, ACPI_NOT_ISR);
676     return (0);
677 }
678 
679 /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
680 static int
681 acpi_ec_read_method(device_t dev, u_int addr, ACPI_INTEGER *val, int width)
682 {
683     struct acpi_ec_softc *sc;
684     ACPI_STATUS status;
685 
686     sc = device_get_softc(dev);
687     status = EcSpaceHandler(ACPI_READ, addr, width * 8, val, sc, NULL);
688     if (ACPI_FAILURE(status))
689 	return (ENXIO);
690     return (0);
691 }
692 
693 static int
694 acpi_ec_write_method(device_t dev, u_int addr, ACPI_INTEGER val, int width)
695 {
696     struct acpi_ec_softc *sc;
697     ACPI_STATUS status;
698 
699     sc = device_get_softc(dev);
700     status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
701     if (ACPI_FAILURE(status))
702 	return (ENXIO);
703     return (0);
704 }
705 
706 static void
707 EcGpeQueryHandler(void *Context)
708 {
709     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
710     UINT8			Data;
711     ACPI_STATUS			Status;
712     char			qxx[5];
713 
714     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
715     KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
716 
717     /* Serialize user access with EcSpaceHandler(). */
718     Status = EcLock(sc, TRUE);
719     if (ACPI_FAILURE(Status)) {
720 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
721 		    "GpeQuery lock error: %s\n", AcpiFormatException(Status));
722 	return;
723     }
724 
725     /*
726      * Send a query command to the EC to find out which _Qxx call it
727      * wants to make.  This command clears the SCI bit and also the
728      * interrupt source since we are edge-triggered.
729      */
730     Status = EcCommand(sc, EC_COMMAND_QUERY);
731     if (ACPI_FAILURE(Status)) {
732 	EcUnlock(sc);
733 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
734 		    "GPE query failed - %s\n", AcpiFormatException(Status));
735 	goto re_enable;
736     }
737     Data = EC_GET_DATA(sc);
738     sc->ec_sci_pend = FALSE;
739 
740     /* Drop locks before evaluating _Qxx method since it may trigger GPEs. */
741     EcUnlock(sc);
742 
743     /* Ignore the value for "no outstanding event". (13.3.5) */
744     CTR2(KTR_ACPI, "ec query ok,%s running _Q%02x", Data ? "" : " not", Data);
745     if (Data == 0)
746 	goto re_enable;
747 
748     /* Evaluate _Qxx to respond to the controller. */
749     snprintf(qxx, sizeof(qxx), "_Q%02x", Data);
750     AcpiUtStrupr(qxx);
751     Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
752     if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
753 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
754 		    "evaluation of GPE query method %s failed - %s\n",
755 		    qxx, AcpiFormatException(Status));
756     }
757 
758 re_enable:
759     /* Re-enable the GPE event so we'll get future requests. */
760     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit, ACPI_ISR);
761     if (ACPI_FAILURE(Status))
762 	printf("EcGpeQueryHandler: AcpiEnableEvent failed\n");
763 }
764 
765 /*
766  * Handle a GPE.  Currently we only handle SCI events as others must
767  * be handled by polling in EcWaitEvent().  This is because some ECs
768  * treat events as level when they should be edge-triggered.
769  */
770 static uint32_t
771 EcGpeHandler(void *Context)
772 {
773     struct acpi_ec_softc *sc = Context;
774     ACPI_STATUS		       Status;
775     EC_STATUS		       EcStatus;
776     int			       query_pend;
777 
778     KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
779 
780     /*
781      * Disable further GPEs while we handle this one.  Since we are directly
782      * called by ACPI-CA and it may have unknown locks held, we specify the
783      * ACPI_ISR flag to keep it from acquiring any more mutexes (although
784      * sleeping would be ok since we're in an ithread.)
785      */
786     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit, ACPI_ISR);
787 
788     /* For interrupt (GPE) handler, don't acquire serialization lock. */
789     Status = EcLock(sc, FALSE);
790     if (ACPI_FAILURE(Status)) {
791 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
792 		    "GpeQuery lock error: %s\n", AcpiFormatException(Status));
793 	return (-1);
794     }
795 
796     /*
797      * If burst was active, but the status bit was cleared, the EC had to
798      * exit burst mode for some reason.  Record this for later.
799      */
800     EcStatus = EC_GET_CSR(sc);
801     if (sc->ec_burstactive && (EcStatus & EC_FLAG_BURST_MODE) == 0) {
802 	CTR0(KTR_ACPI, "ec burst disabled in query handler");
803 	sc->ec_burstactive = FALSE;
804     }
805 
806     /*
807      * If the EC_SCI bit of the status register is not set, then pass
808      * it along to any potential waiters as it may be an IBE/OBF event.
809      * If it is set, queue a query handler.
810      */
811     query_pend = FALSE;
812     if ((EcStatus & EC_EVENT_SCI) == 0) {
813 	CTR1(KTR_ACPI, "ec event was IBE/OBF, status %#x", EcStatus);
814 	sc->ec_csrvalue = EcStatus;
815 	wakeup(&sc->ec_csrvalue);
816     } else if (!sc->ec_sci_pend) {
817 	/* SCI bit set and no pending query handler, so schedule one. */
818 	CTR0(KTR_ACPI, "ec queueing gpe handler");
819 	Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
820 	if (ACPI_SUCCESS(Status)) {
821 	    sc->ec_sci_pend = TRUE;
822 	    query_pend = TRUE;
823 	} else
824 	    printf("Queuing GPE query handler failed.\n");
825     }
826 
827     /*
828      * If we didn't queue a query handler, which will eventually re-enable
829      * the GPE, re-enable it right now so we can get more events.
830      */
831     if (!query_pend) {
832 	Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit, ACPI_ISR);
833 	if (ACPI_FAILURE(Status))
834 	    printf("EcGpeHandler: AcpiEnableGpe failed\n");
835     }
836 
837     EcUnlock(sc);
838     return (0);
839 }
840 
841 static ACPI_STATUS
842 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
843 	     void **RegionContext)
844 {
845 
846     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
847 
848     /*
849      * If deactivating a region, always set the output to NULL.  Otherwise,
850      * just pass the context through.
851      */
852     if (Function == ACPI_REGION_DEACTIVATE)
853 	*RegionContext = NULL;
854     else
855 	*RegionContext = Context;
856 
857     return_ACPI_STATUS (AE_OK);
858 }
859 
860 static ACPI_STATUS
861 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 width,
862 	       ACPI_INTEGER *Value, void *Context, void *RegionContext)
863 {
864     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
865     ACPI_STATUS			Status;
866     UINT8			EcAddr, EcData;
867     int				i;
868 
869     ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
870 
871     if (width % 8 != 0 || Value == NULL || Context == NULL)
872 	return_ACPI_STATUS (AE_BAD_PARAMETER);
873     if (Address + (width / 8) - 1 > 0xFF)
874 	return_ACPI_STATUS (AE_BAD_ADDRESS);
875 
876     if (Function == ACPI_READ)
877 	*Value = 0;
878     EcAddr = Address;
879     Status = AE_ERROR;
880 
881     /* Grab serialization lock to hold across command sequence. */
882     Status = EcLock(sc, TRUE);
883     if (ACPI_FAILURE(Status))
884 	return_ACPI_STATUS (Status);
885 
886     /* Perform the transaction(s), based on width. */
887     for (i = 0; i < width; i += 8, EcAddr++) {
888 	switch (Function) {
889 	case ACPI_READ:
890 	    Status = EcRead(sc, EcAddr, &EcData);
891 	    if (ACPI_SUCCESS(Status))
892 		*Value |= ((ACPI_INTEGER)EcData) << i;
893 	    break;
894 	case ACPI_WRITE:
895 	    EcData = (UINT8)((*Value) >> i);
896 	    Status = EcWrite(sc, EcAddr, &EcData);
897 	    break;
898 	default:
899 	    device_printf(sc->ec_dev, "invalid EcSpaceHandler function %d\n",
900 			  Function);
901 	    Status = AE_BAD_PARAMETER;
902 	    break;
903 	}
904 	if (ACPI_FAILURE(Status))
905 	    break;
906     }
907 
908     EcUnlock(sc);
909     return_ACPI_STATUS (Status);
910 }
911 
912 static ACPI_STATUS
913 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event)
914 {
915     EC_STATUS	EcStatus;
916     ACPI_STATUS	Status;
917     int		count, i, retval, slp_ival;
918 
919     ACPI_SERIAL_ASSERT(ec);
920     Status = AE_NO_HARDWARE_RESPONSE;
921     EcStatus = 0;
922 
923     /*
924      * Poll for up to ec_poll_time microseconds since many ECs complete
925      * the command quickly, especially if in burst mode.
926      */
927 #if 0 /* Enable this as a possible workaround if EC times out. */
928     AcpiOsStall(EC_POLL_DELAY);
929 #endif
930     count = ec_poll_time / EC_POLL_DELAY;
931     if (count <= 0)
932 	count = 1;
933     for (i = 0; i < count; i++) {
934 	EcStatus = EC_GET_CSR(sc);
935 	if (sc->ec_burstactive && (EcStatus & EC_FLAG_BURST_MODE) == 0) {
936 	    CTR0(KTR_ACPI, "ec burst disabled in waitevent (poll)");
937 	    sc->ec_burstactive = FALSE;
938 	}
939 	if (EVENT_READY(Event, EcStatus)) {
940 	    CTR1(KTR_ACPI, "ec poll wait ready, status %#x", EcStatus);
941 	    Status = AE_OK;
942 	    break;
943 	}
944 	AcpiOsStall(EC_POLL_DELAY);
945     }
946 
947     /*
948      * If we still don't have a response and we're up and running, wait up
949      * to ec_timeout ms for completion, sleeping for chunks of 1 ms or the
950      * smallest resolution hz supports.
951      */
952     slp_ival = 0;
953     if (Status != AE_OK) {
954 	retval = ENXIO;
955 	if (!cold) {
956 	    slp_ival = hz / 1000;
957 	    if (slp_ival != 0) {
958 		count = ec_timeout / slp_ival;
959 	    } else {
960 		/* hz has less than 1000 Hz resolution so scale timeout. */
961 		slp_ival = 1;
962 		count = ec_timeout / (1000 / hz);
963 	    }
964 	} else
965 	    count = ec_timeout;
966 	for (i = 0; i < count; i++) {
967 	    if (retval != 0)
968 		EcStatus = EC_GET_CSR(sc);
969 	    else
970 		EcStatus = sc->ec_csrvalue;
971 	    if (sc->ec_burstactive && (EcStatus & EC_FLAG_BURST_MODE) == 0) {
972 		CTR0(KTR_ACPI, "ec burst disabled in waitevent (slp)");
973 		sc->ec_burstactive = FALSE;
974 	    }
975 	    if (EVENT_READY(Event, EcStatus)) {
976 		CTR1(KTR_ACPI, "ec sleep wait ready, status %#x", EcStatus);
977 		Status = AE_OK;
978 		break;
979 	    }
980 	    if (!cold) {
981 		retval = msleep(&sc->ec_csrvalue, &sc->ec_mtx, PZERO, "ecpoll",
982 		    slp_ival);
983 	    } else
984 		AcpiOsStall(1000);
985 	}
986     }
987 
988     return (Status);
989 }
990 
991 static ACPI_STATUS
992 EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
993 {
994     ACPI_STATUS	status;
995     EC_EVENT	event;
996     EC_STATUS	ec_status;
997 
998     ACPI_SERIAL_ASSERT(ec);
999 
1000     /* Don't use burst mode if user disabled it. */
1001     if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
1002 	return (AE_ERROR);
1003 
1004     /* Decide what to wait for based on command type. */
1005     switch (cmd) {
1006     case EC_COMMAND_READ:
1007     case EC_COMMAND_WRITE:
1008     case EC_COMMAND_BURST_DISABLE:
1009 	event = EC_EVENT_INPUT_BUFFER_EMPTY;
1010 	break;
1011     case EC_COMMAND_QUERY:
1012     case EC_COMMAND_BURST_ENABLE:
1013 	event = EC_EVENT_OUTPUT_BUFFER_FULL;
1014 	break;
1015     default:
1016 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
1017 		    "EcCommand: Invalid command %#x\n", cmd);
1018 	return (AE_BAD_PARAMETER);
1019     }
1020 
1021     /* Run the command and wait for the chosen event. */
1022     CTR1(KTR_ACPI, "ec running command %#x", cmd);
1023     EC_SET_CSR(sc, cmd);
1024     status = EcWaitEvent(sc, event);
1025     if (ACPI_SUCCESS(status)) {
1026 	/* If we succeeded, burst flag should now be present. */
1027 	if (cmd == EC_COMMAND_BURST_ENABLE) {
1028 	    ec_status = EC_GET_CSR(sc);
1029 	    if ((ec_status & EC_FLAG_BURST_MODE) == 0)
1030 		status = AE_ERROR;
1031 	}
1032     } else {
1033 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
1034 		    "EcCommand: no response to %#x\n", cmd);
1035     }
1036 
1037     return (status);
1038 }
1039 
1040 static ACPI_STATUS
1041 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
1042 {
1043     ACPI_STATUS	status;
1044     UINT8 data;
1045 
1046     ACPI_SERIAL_ASSERT(ec);
1047     CTR1(KTR_ACPI, "ec read from %#x", Address);
1048 
1049     /* If we can't start burst mode, continue anyway. */
1050     status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
1051     if (status == AE_OK) {
1052     	data = EC_GET_DATA(sc);
1053 	if (data == EC_BURST_ACK) {
1054 	    CTR0(KTR_ACPI, "ec burst enabled");
1055 	    sc->ec_burstactive = TRUE;
1056 	}
1057     }
1058 
1059     status = EcCommand(sc, EC_COMMAND_READ);
1060     if (ACPI_FAILURE(status))
1061 	return (status);
1062 
1063     EC_SET_DATA(sc, Address);
1064     status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL);
1065     if (ACPI_FAILURE(status)) {
1066 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
1067 		    "EcRead: Failed waiting for EC to send data.\n");
1068 	return (status);
1069     }
1070 
1071     *Data = EC_GET_DATA(sc);
1072 
1073     if (sc->ec_burstactive) {
1074 	status = EcCommand(sc, EC_COMMAND_BURST_DISABLE);
1075 	if (ACPI_FAILURE(status))
1076 	    return (status);
1077 	sc->ec_burstactive = FALSE;
1078 	CTR0(KTR_ACPI, "ec disabled burst ok");
1079     }
1080 
1081     return (AE_OK);
1082 }
1083 
1084 static ACPI_STATUS
1085 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
1086 {
1087     ACPI_STATUS	status;
1088     UINT8 data;
1089 
1090     ACPI_SERIAL_ASSERT(ec);
1091     CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, *Data);
1092 
1093     /* If we can't start burst mode, continue anyway. */
1094     status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
1095     if (status == AE_OK) {
1096     	data = EC_GET_DATA(sc);
1097 	if (data == EC_BURST_ACK) {
1098 	    CTR0(KTR_ACPI, "ec burst enabled");
1099 	    sc->ec_burstactive = TRUE;
1100 	}
1101     }
1102 
1103     status = EcCommand(sc, EC_COMMAND_WRITE);
1104     if (ACPI_FAILURE(status))
1105 	return (status);
1106 
1107     EC_SET_DATA(sc, Address);
1108     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY);
1109     if (ACPI_FAILURE(status)) {
1110 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
1111 		    "EcRead: Failed waiting for EC to process address\n");
1112 	return (status);
1113     }
1114 
1115     EC_SET_DATA(sc, *Data);
1116     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY);
1117     if (ACPI_FAILURE(status)) {
1118 	ACPI_VPRINT(sc->ec_dev, acpi_device_get_parent_softc(sc->ec_dev),
1119 		    "EcWrite: Failed waiting for EC to process data\n");
1120 	return (status);
1121     }
1122 
1123     if (sc->ec_burstactive) {
1124 	status = EcCommand(sc, EC_COMMAND_BURST_DISABLE);
1125 	if (ACPI_FAILURE(status))
1126 	    return (status);
1127 	sc->ec_burstactive = FALSE;
1128 	CTR0(KTR_ACPI, "ec disabled burst ok");
1129     }
1130 
1131     return (AE_OK);
1132 }
1133