xref: /netbsd-src/sys/dev/acpi/acpi_ec.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /*	$NetBSD: acpi_ec.c,v 1.58 2010/01/08 20:40:41 dyoung Exp $	*/
2 
3 /*-
4  * Copyright (c) 2007 Joerg Sonnenberger <joerg@NetBSD.org>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
22  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
28  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * The ACPI Embedded Controller (EC) driver serves two different purposes:
34  * - read and write access from ASL, e.g. to read battery state
35  * - notification of ASL of System Control Interrupts.
36  *
37  * Access to the EC is serialised by sc_access_mtx and optionally the
38  * ACPI global mutex.  Both locks are held until the request is fulfilled.
39  * All access to the softc has to hold sc_mtx to serialise against the GPE
40  * handler and the callout.  sc_mtx is also used for wakeup conditions.
41  *
42  * SCIs are processed in a kernel thread. Handling gets a bit complicated
43  * by the lock order (sc_mtx must be acquired after sc_access_mtx and the
44  * ACPI global mutex).
45  *
46  * Read and write requests spin around for a short time as many requests
47  * can be handled instantly by the EC.  During normal processing interrupt
48  * mode is used exclusively.  At boot and resume time interrupts are not
49  * working and the handlers just busy loop.
50  *
51  * A callout is scheduled to compensate for missing interrupts on some
52  * hardware.  If the EC doesn't process a request for 5s, it is most likely
53  * in a wedged state.  No method to reset the EC is currently known.
54  *
55  * Special care has to be taken to not poll the EC in a busy loop without
56  * delay.  This can prevent processing of Power Button events. At least some
57  * Lenovo Thinkpads seem to be implement the Power Button Override in the EC
58  * and the only option to recover on those models is to cut off all power.
59  */
60 
61 #include <sys/cdefs.h>
62 __KERNEL_RCSID(0, "$NetBSD: acpi_ec.c,v 1.58 2010/01/08 20:40:41 dyoung Exp $");
63 
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/condvar.h>
67 #include <sys/device.h>
68 #include <sys/kernel.h>
69 #include <sys/kthread.h>
70 #include <sys/mutex.h>
71 
72 #include <sys/bus.h>
73 
74 #include <dev/acpi/acpireg.h>
75 #include <dev/acpi/acpivar.h>
76 #include <dev/acpi/acpi_ecvar.h>
77 
78 #define _COMPONENT          ACPI_EC_COMPONENT
79 ACPI_MODULE_NAME            ("acpi_ec")
80 
81 /* Maximum time to wait for global ACPI lock in ms */
82 #define	EC_LOCK_TIMEOUT		5
83 
84 /* Maximum time to poll for completion of a command  in ms */
85 #define	EC_POLL_TIMEOUT		5
86 
87 /* Maximum time to give a single EC command in s */
88 #define EC_CMD_TIMEOUT		10
89 
90 /* From ACPI 3.0b, chapter 12.3 */
91 #define EC_COMMAND_READ		0x80
92 #define	EC_COMMAND_WRITE	0x81
93 #define	EC_COMMAND_BURST_EN	0x82
94 #define	EC_COMMAND_BURST_DIS	0x83
95 #define	EC_COMMAND_QUERY	0x84
96 
97 /* From ACPI 3.0b, chapter 12.2.1 */
98 #define	EC_STATUS_OBF		0x01
99 #define	EC_STATUS_IBF		0x02
100 #define	EC_STATUS_CMD		0x08
101 #define	EC_STATUS_BURST		0x10
102 #define	EC_STATUS_SCI		0x20
103 #define	EC_STATUS_SMI		0x40
104 
105 static const char *ec_hid[] = {
106 	"PNP0C09",
107 	NULL,
108 };
109 
110 enum ec_state_t {
111 	EC_STATE_QUERY,
112 	EC_STATE_QUERY_VAL,
113 	EC_STATE_READ,
114 	EC_STATE_READ_ADDR,
115 	EC_STATE_READ_VAL,
116 	EC_STATE_WRITE,
117 	EC_STATE_WRITE_ADDR,
118 	EC_STATE_WRITE_VAL,
119 	EC_STATE_FREE
120 };
121 
122 struct acpiec_softc {
123 	ACPI_HANDLE sc_ech;
124 
125 	ACPI_HANDLE sc_gpeh;
126 	UINT8 sc_gpebit;
127 
128 	bus_space_tag_t sc_data_st;
129 	bus_space_handle_t sc_data_sh;
130 
131 	bus_space_tag_t sc_csr_st;
132 	bus_space_handle_t sc_csr_sh;
133 
134 	bool sc_need_global_lock;
135 	UINT32 sc_global_lock;
136 
137 	kmutex_t sc_mtx, sc_access_mtx;
138 	kcondvar_t sc_cv, sc_cv_sci;
139 	enum ec_state_t sc_state;
140 	bool sc_got_sci;
141 	callout_t sc_pseudo_intr;
142 
143 	uint8_t sc_cur_addr, sc_cur_val;
144 };
145 
146 static int acpiecdt_match(device_t, cfdata_t, void *);
147 static void acpiecdt_attach(device_t, device_t, void *);
148 
149 static int acpiec_match(device_t, cfdata_t, void *);
150 static void acpiec_attach(device_t, device_t, void *);
151 
152 static void acpiec_common_attach(device_t, device_t, ACPI_HANDLE,
153     bus_addr_t, bus_addr_t, ACPI_HANDLE, uint8_t);
154 
155 static bool acpiec_suspend(device_t, pmf_qual_t);
156 static bool acpiec_resume(device_t, pmf_qual_t);
157 static bool acpiec_shutdown(device_t, int);
158 
159 static bool acpiec_parse_gpe_package(device_t, ACPI_HANDLE,
160     ACPI_HANDLE *, uint8_t *);
161 
162 static void acpiec_callout(void *);
163 static void acpiec_gpe_query(void *);
164 static UINT32 acpiec_gpe_handler(void *);
165 static ACPI_STATUS acpiec_space_setup(ACPI_HANDLE, UINT32, void *, void **);
166 static ACPI_STATUS acpiec_space_handler(UINT32, ACPI_PHYSICAL_ADDRESS,
167     UINT32, ACPI_INTEGER *, void *, void *);
168 
169 static void acpiec_gpe_state_machine(device_t);
170 
171 CFATTACH_DECL_NEW(acpiec, sizeof(struct acpiec_softc),
172     acpiec_match, acpiec_attach, NULL, NULL);
173 
174 CFATTACH_DECL_NEW(acpiecdt, sizeof(struct acpiec_softc),
175     acpiecdt_match, acpiecdt_attach, NULL, NULL);
176 
177 static device_t ec_singleton = NULL;
178 static bool acpiec_cold = false;
179 
180 static bool
181 acpiecdt_find(device_t parent, ACPI_HANDLE *ec_handle,
182     bus_addr_t *cmd_reg, bus_addr_t *data_reg, uint8_t *gpebit)
183 {
184 	ACPI_TABLE_ECDT *ecdt;
185 	ACPI_STATUS rv;
186 
187 	rv = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
188 	if (ACPI_FAILURE(rv))
189 		return false;
190 
191 	if (ecdt->Control.BitWidth != 8 || ecdt->Data.BitWidth != 8) {
192 		aprint_error_dev(parent,
193 		    "ECDT register width invalid (%d/%d)\n",
194 		    ecdt->Control.BitWidth, ecdt->Data.BitWidth);
195 		return false;
196 	}
197 
198 	rv = AcpiGetHandle(ACPI_ROOT_OBJECT, ecdt->Id, ec_handle);
199 	if (ACPI_FAILURE(rv)) {
200 		aprint_error_dev(parent,
201 		    "failed to look up EC object %s: %s\n",
202 		    ecdt->Id, AcpiFormatException(rv));
203 		return false;
204 	}
205 
206 	*cmd_reg = ecdt->Control.Address;
207 	*data_reg = ecdt->Data.Address;
208 	*gpebit = ecdt->Gpe;
209 
210 	return true;
211 }
212 
213 static int
214 acpiecdt_match(device_t parent, cfdata_t match, void *aux)
215 {
216 	ACPI_HANDLE ec_handle;
217 	bus_addr_t cmd_reg, data_reg;
218 	uint8_t gpebit;
219 
220 	if (acpiecdt_find(parent, &ec_handle, &cmd_reg, &data_reg, &gpebit))
221 		return 1;
222 	else
223 		return 0;
224 }
225 
226 static void
227 acpiecdt_attach(device_t parent, device_t self, void *aux)
228 {
229 	ACPI_HANDLE ec_handle;
230 	bus_addr_t cmd_reg, data_reg;
231 	uint8_t gpebit;
232 
233 	if (!acpiecdt_find(parent, &ec_handle, &cmd_reg, &data_reg, &gpebit))
234 		panic("ECDT disappeared");
235 
236 	aprint_naive("\n");
237 	aprint_normal(": ACPI Embedded Controller via ECDT\n");
238 
239 	acpiec_common_attach(parent, self, ec_handle, cmd_reg, data_reg,
240 	    NULL, gpebit);
241 }
242 
243 static int
244 acpiec_match(device_t parent, cfdata_t match, void *aux)
245 {
246 	struct acpi_attach_args *aa = aux;
247 
248 	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
249 		return 0;
250 
251 	return acpi_match_hid(aa->aa_node->ad_devinfo, ec_hid);
252 }
253 
254 static void
255 acpiec_attach(device_t parent, device_t self, void *aux)
256 {
257 	struct acpi_attach_args *aa = aux;
258 	struct acpi_resources ec_res;
259 	struct acpi_io *io0, *io1;
260 	ACPI_HANDLE gpe_handle;
261 	uint8_t gpebit;
262 	ACPI_STATUS rv;
263 
264 	if (ec_singleton != NULL) {
265 		aprint_naive(": using %s\n", device_xname(ec_singleton));
266 		aprint_normal(": using %s\n", device_xname(ec_singleton));
267 		if (!pmf_device_register(self, NULL, NULL))
268 			aprint_error_dev(self, "couldn't establish power handler\n");
269 		return;
270 	}
271 
272 	if (!acpiec_parse_gpe_package(self, aa->aa_node->ad_handle,
273 				      &gpe_handle, &gpebit))
274 		return;
275 
276 	rv = acpi_resource_parse(self, aa->aa_node->ad_handle, "_CRS",
277 	    &ec_res, &acpi_resource_parse_ops_default);
278 	if (rv != AE_OK) {
279 		aprint_error_dev(self, "resource parsing failed: %s\n",
280 		    AcpiFormatException(rv));
281 		return;
282 	}
283 
284 	if ((io0 = acpi_res_io(&ec_res, 0)) == NULL) {
285 		aprint_error_dev(self, "no data register resource\n");
286 		goto free_res;
287 	}
288 	if ((io1 = acpi_res_io(&ec_res, 1)) == NULL) {
289 		aprint_error_dev(self, "no CSR register resource\n");
290 		goto free_res;
291 	}
292 
293 	acpiec_common_attach(parent, self, aa->aa_node->ad_handle,
294 	    io1->ar_base, io0->ar_base, gpe_handle, gpebit);
295 
296 free_res:
297 	acpi_resource_cleanup(&ec_res);
298 }
299 
300 static void
301 acpiec_common_attach(device_t parent, device_t self,
302     ACPI_HANDLE ec_handle, bus_addr_t cmd_reg, bus_addr_t data_reg,
303     ACPI_HANDLE gpe_handle, uint8_t gpebit)
304 {
305 	struct acpiec_softc *sc = device_private(self);
306 	ACPI_STATUS rv;
307 	ACPI_INTEGER val;
308 
309 	sc->sc_ech = ec_handle;
310 	sc->sc_gpeh = gpe_handle;
311 	sc->sc_gpebit = gpebit;
312 
313 	sc->sc_state = EC_STATE_FREE;
314 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
315 	mutex_init(&sc->sc_access_mtx, MUTEX_DEFAULT, IPL_NONE);
316 	cv_init(&sc->sc_cv, "eccv");
317 	cv_init(&sc->sc_cv_sci, "ecsci");
318 
319 	if (bus_space_map(sc->sc_data_st, data_reg, 1, 0,
320 	    &sc->sc_data_sh) != 0) {
321 		aprint_error_dev(self, "unable to map data register\n");
322 		return;
323 	}
324 
325 	if (bus_space_map(sc->sc_csr_st, cmd_reg, 1, 0, &sc->sc_csr_sh) != 0) {
326 		aprint_error_dev(self, "unable to map CSR register\n");
327 		goto post_data_map;
328 	}
329 
330 	rv = acpi_eval_integer(sc->sc_ech, "_GLK", &val);
331 	if (rv == AE_OK) {
332 		sc->sc_need_global_lock = val != 0;
333 	} else if (rv != AE_NOT_FOUND) {
334 		aprint_error_dev(self, "unable to evaluate _GLK: %s\n",
335 		    AcpiFormatException(rv));
336 		goto post_csr_map;
337 	} else {
338 		sc->sc_need_global_lock = false;
339 	}
340 	if (sc->sc_need_global_lock)
341 		aprint_normal_dev(self, "using global ACPI lock\n");
342 
343 	callout_init(&sc->sc_pseudo_intr, CALLOUT_MPSAFE);
344 	callout_setfunc(&sc->sc_pseudo_intr, acpiec_callout, self);
345 
346 	rv = AcpiInstallAddressSpaceHandler(sc->sc_ech, ACPI_ADR_SPACE_EC,
347 	    acpiec_space_handler, acpiec_space_setup, self);
348 	if (rv != AE_OK) {
349 		aprint_error_dev(self,
350 		    "unable to install address space handler: %s\n",
351 		    AcpiFormatException(rv));
352 		goto post_csr_map;
353 	}
354 
355 	rv = AcpiInstallGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
356 	    ACPI_GPE_EDGE_TRIGGERED, acpiec_gpe_handler, self);
357 	if (rv != AE_OK) {
358 		aprint_error_dev(self, "unable to install GPE handler: %s\n",
359 		    AcpiFormatException(rv));
360 		goto post_csr_map;
361 	}
362 
363 	rv = AcpiSetGpeType(sc->sc_gpeh, sc->sc_gpebit, ACPI_GPE_TYPE_RUNTIME);
364 	if (rv != AE_OK) {
365 		aprint_error_dev(self, "unable to set GPE type: %s\n",
366 		    AcpiFormatException(rv));
367 		goto post_csr_map;
368 	}
369 
370 	rv = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
371 	if (rv != AE_OK) {
372 		aprint_error_dev(self, "unable to enable GPE: %s\n",
373 		    AcpiFormatException(rv));
374 		goto post_csr_map;
375 	}
376 
377 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, acpiec_gpe_query,
378 		           self, NULL, "acpiec sci thread")) {
379 		aprint_error_dev(self, "unable to create query kthread\n");
380 		goto post_csr_map;
381 	}
382 
383 	ec_singleton = self;
384 
385 	if (!pmf_device_register1(self, acpiec_suspend, acpiec_resume,
386 	    acpiec_shutdown))
387 		aprint_error_dev(self, "couldn't establish power handler\n");
388 
389 	return;
390 
391 post_csr_map:
392 	(void)AcpiRemoveGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
393 	    acpiec_gpe_handler);
394 	(void)AcpiRemoveAddressSpaceHandler(sc->sc_ech,
395 	    ACPI_ADR_SPACE_EC, acpiec_space_handler);
396 	bus_space_unmap(sc->sc_csr_st, sc->sc_csr_sh, 1);
397 post_data_map:
398 	bus_space_unmap(sc->sc_data_st, sc->sc_data_sh, 1);
399 }
400 
401 static bool
402 acpiec_suspend(device_t dv, pmf_qual_t qual)
403 {
404 	acpiec_cold = true;
405 
406 	return true;
407 }
408 
409 static bool
410 acpiec_resume(device_t dv, pmf_qual_t qual)
411 {
412 	acpiec_cold = false;
413 
414 	return true;
415 }
416 
417 static bool
418 acpiec_shutdown(device_t dv, int how)
419 {
420 
421 	acpiec_cold = true;
422 	return true;
423 }
424 
425 static bool
426 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
427     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
428 {
429 	ACPI_BUFFER buf;
430 	ACPI_OBJECT *p, *c;
431 	ACPI_STATUS rv;
432 
433 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
434 	if (rv != AE_OK) {
435 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
436 		    AcpiFormatException(rv));
437 		return false;
438 	}
439 
440 	p = buf.Pointer;
441 
442 	if (p->Type == ACPI_TYPE_INTEGER) {
443 		*gpe_handle = NULL;
444 		*gpebit = p->Integer.Value;
445 		ACPI_FREE(p);
446 		return true;
447 	}
448 
449 	if (p->Type != ACPI_TYPE_PACKAGE) {
450 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
451 		ACPI_FREE(p);
452 		return false;
453 	}
454 
455 	if (p->Package.Count != 2) {
456 		aprint_error_dev(self, "_GPE package does not contain 2 elements\n");
457 		ACPI_FREE(p);
458 		return false;
459 	}
460 
461 	c = &p->Package.Elements[0];
462 	switch (c->Type) {
463 	case ACPI_TYPE_LOCAL_REFERENCE:
464 	case ACPI_TYPE_ANY:
465 		*gpe_handle = c->Reference.Handle;
466 		break;
467 	case ACPI_TYPE_STRING:
468 		/* XXX should be using real scope here */
469 		rv = AcpiGetHandle(NULL, p->String.Pointer, gpe_handle);
470 		if (rv != AE_OK) {
471 			aprint_error_dev(self,
472 			    "_GPE device reference unresolvable\n");
473 			ACPI_FREE(p);
474 			return false;
475 		}
476 		break;
477 	default:
478 		aprint_error_dev(self, "_GPE device reference incorrect\n");
479 		ACPI_FREE(p);
480 		return false;
481 	}
482 	c = &p->Package.Elements[1];
483 	if (c->Type != ACPI_TYPE_INTEGER) {
484 		aprint_error_dev(self,
485 		    "_GPE package needs integer as 2nd field\n");
486 		ACPI_FREE(p);
487 		return false;
488 	}
489 	*gpebit = c->Integer.Value;
490 	ACPI_FREE(p);
491 	return true;
492 }
493 
494 static uint8_t
495 acpiec_read_data(struct acpiec_softc *sc)
496 {
497 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
498 }
499 
500 static void
501 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
502 {
503 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
504 }
505 
506 static uint8_t
507 acpiec_read_status(struct acpiec_softc *sc)
508 {
509 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
510 }
511 
512 static void
513 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
514 {
515 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
516 }
517 
518 static ACPI_STATUS
519 acpiec_space_setup(ACPI_HANDLE region, UINT32 func, void *arg,
520     void **region_arg)
521 {
522 	if (func == ACPI_REGION_DEACTIVATE)
523 		*region_arg = NULL;
524 	else
525 		*region_arg = arg;
526 
527 	return AE_OK;
528 }
529 
530 static void
531 acpiec_lock(device_t dv)
532 {
533 	struct acpiec_softc *sc = device_private(dv);
534 	ACPI_STATUS rv;
535 
536 	mutex_enter(&sc->sc_access_mtx);
537 
538 	if (sc->sc_need_global_lock) {
539 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->sc_global_lock);
540 		if (rv != AE_OK) {
541 			aprint_error_dev(dv, "failed to acquire global lock: %s\n",
542 			    AcpiFormatException(rv));
543 			return;
544 		}
545 	}
546 }
547 
548 static void
549 acpiec_unlock(device_t dv)
550 {
551 	struct acpiec_softc *sc = device_private(dv);
552 	ACPI_STATUS rv;
553 
554 	if (sc->sc_need_global_lock) {
555 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
556 		if (rv != AE_OK) {
557 			aprint_error_dev(dv, "failed to release global lock: %s\n",
558 			    AcpiFormatException(rv));
559 		}
560 	}
561 	mutex_exit(&sc->sc_access_mtx);
562 }
563 
564 static ACPI_STATUS
565 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
566 {
567 	struct acpiec_softc *sc = device_private(dv);
568 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
569 
570 	acpiec_lock(dv);
571 	mutex_enter(&sc->sc_mtx);
572 
573 	sc->sc_cur_addr = addr;
574 	sc->sc_state = EC_STATE_READ;
575 
576 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
577 		acpiec_gpe_state_machine(dv);
578 		if (sc->sc_state == EC_STATE_FREE)
579 			goto done;
580 		delay(1);
581 	}
582 
583 	if (cold || acpiec_cold) {
584 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
585 			delay(1000);
586 			acpiec_gpe_state_machine(dv);
587 		}
588 		if (sc->sc_state != EC_STATE_FREE) {
589 			mutex_exit(&sc->sc_mtx);
590 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
591 			acpiec_unlock(dv);
592 			aprint_error_dev(dv, "command timed out, state %d\n",
593 			    sc->sc_state);
594 			return AE_ERROR;
595 		}
596 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
597 		mutex_exit(&sc->sc_mtx);
598 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
599 		acpiec_unlock(dv);
600 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
601 		return AE_ERROR;
602 	}
603 
604 done:
605 	*val = sc->sc_cur_val;
606 
607 	mutex_exit(&sc->sc_mtx);
608 	acpiec_unlock(dv);
609 	return AE_OK;
610 }
611 
612 static ACPI_STATUS
613 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
614 {
615 	struct acpiec_softc *sc = device_private(dv);
616 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
617 
618 	acpiec_lock(dv);
619 	mutex_enter(&sc->sc_mtx);
620 
621 	sc->sc_cur_addr = addr;
622 	sc->sc_cur_val = val;
623 	sc->sc_state = EC_STATE_WRITE;
624 
625 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
626 		acpiec_gpe_state_machine(dv);
627 		if (sc->sc_state == EC_STATE_FREE)
628 			goto done;
629 		delay(1);
630 	}
631 
632 	if (cold || acpiec_cold) {
633 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
634 			delay(1000);
635 			acpiec_gpe_state_machine(dv);
636 		}
637 		if (sc->sc_state != EC_STATE_FREE) {
638 			mutex_exit(&sc->sc_mtx);
639 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
640 			acpiec_unlock(dv);
641 			aprint_error_dev(dv, "command timed out, state %d\n",
642 			    sc->sc_state);
643 			return AE_ERROR;
644 		}
645 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
646 		mutex_exit(&sc->sc_mtx);
647 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
648 		acpiec_unlock(dv);
649 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
650 		return AE_ERROR;
651 	}
652 
653 done:
654 	mutex_exit(&sc->sc_mtx);
655 	acpiec_unlock(dv);
656 	return AE_OK;
657 }
658 
659 static ACPI_STATUS
660 acpiec_space_handler(UINT32 func, ACPI_PHYSICAL_ADDRESS paddr,
661     UINT32 width, ACPI_INTEGER *value, void *arg, void *region_arg)
662 {
663 	device_t dv;
664 	struct acpiec_softc *sc;
665 	ACPI_STATUS rv;
666 	uint8_t addr, reg;
667 	unsigned int i;
668 
669 	if (paddr > 0xff || width % 8 != 0 || value == NULL || arg == NULL ||
670 	    paddr + width / 8 > 0xff)
671 		return AE_BAD_PARAMETER;
672 
673 	addr = paddr;
674 	dv = arg;
675 	sc = device_private(dv);
676 
677 	rv = AE_OK;
678 
679 	switch (func) {
680 	case ACPI_READ:
681 		*value = 0;
682 		for (i = 0; i < width; i += 8, ++addr) {
683 			rv = acpiec_read(dv, addr, &reg);
684 			if (rv != AE_OK)
685 				break;
686 			*value |= (ACPI_INTEGER)reg << i;
687 		}
688 		break;
689 	case ACPI_WRITE:
690 		for (i = 0; i < width; i += 8, ++addr) {
691 			reg = (*value >>i) & 0xff;
692 			rv = acpiec_write(dv, addr, reg);
693 			if (rv != AE_OK)
694 				break;
695 		}
696 		break;
697 	default:
698 		aprint_error("%s: invalid Address Space function called: %x\n",
699 		    device_xname(dv), (unsigned int)func);
700 		return AE_BAD_PARAMETER;
701 	}
702 
703 	return rv;
704 }
705 
706 static void
707 acpiec_gpe_query(void *arg)
708 {
709 	device_t dv = arg;
710 	struct acpiec_softc *sc = device_private(dv);
711 	uint8_t reg;
712 	char qxx[5];
713 	ACPI_STATUS rv;
714 	int i;
715 
716 loop:
717 	mutex_enter(&sc->sc_mtx);
718 
719 	if (sc->sc_got_sci == false)
720 		cv_wait(&sc->sc_cv_sci, &sc->sc_mtx);
721 	mutex_exit(&sc->sc_mtx);
722 
723 	acpiec_lock(dv);
724 	mutex_enter(&sc->sc_mtx);
725 
726 	/* The Query command can always be issued, so be defensive here. */
727 	sc->sc_got_sci = false;
728 	sc->sc_state = EC_STATE_QUERY;
729 
730 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
731 		acpiec_gpe_state_machine(dv);
732 		if (sc->sc_state == EC_STATE_FREE)
733 			goto done;
734 		delay(1);
735 	}
736 
737 	cv_wait(&sc->sc_cv, &sc->sc_mtx);
738 
739 done:
740 	reg = sc->sc_cur_val;
741 
742 	mutex_exit(&sc->sc_mtx);
743 	acpiec_unlock(dv);
744 
745 	if (reg == 0)
746 		goto loop; /* Spurious query result */
747 
748 	/*
749 	 * Evaluate _Qxx to respond to the controller.
750 	 */
751 	snprintf(qxx, sizeof(qxx), "_Q%02X", (unsigned int)reg);
752 	rv = AcpiEvaluateObject(sc->sc_ech, qxx, NULL, NULL);
753 	if (rv != AE_OK && rv != AE_NOT_FOUND) {
754 		aprint_error("%s: GPE query method %s failed: %s",
755 		    device_xname(dv), qxx, AcpiFormatException(rv));
756 	}
757 
758 	goto loop;
759 }
760 
761 static void
762 acpiec_gpe_state_machine(device_t dv)
763 {
764 	struct acpiec_softc *sc = device_private(dv);
765 	uint8_t reg;
766 
767 	reg = acpiec_read_status(sc);
768 
769 	if (reg & EC_STATUS_SCI)
770 		sc->sc_got_sci = true;
771 
772 	switch (sc->sc_state) {
773 	case EC_STATE_QUERY:
774 		if ((reg & EC_STATUS_IBF) != 0)
775 			break; /* Nothing of interest here. */
776 		acpiec_write_command(sc, EC_COMMAND_QUERY);
777 		sc->sc_state = EC_STATE_QUERY_VAL;
778 		break;
779 
780 	case EC_STATE_QUERY_VAL:
781 		if ((reg & EC_STATUS_OBF) == 0)
782 			break; /* Nothing of interest here. */
783 
784 		sc->sc_cur_val = acpiec_read_data(sc);
785 		sc->sc_state = EC_STATE_FREE;
786 
787 		cv_signal(&sc->sc_cv);
788 		break;
789 
790 	case EC_STATE_READ:
791 		if ((reg & EC_STATUS_IBF) != 0)
792 			break; /* Nothing of interest here. */
793 
794 		acpiec_write_command(sc, EC_COMMAND_READ);
795 		sc->sc_state = EC_STATE_READ_ADDR;
796 		break;
797 
798 	case EC_STATE_READ_ADDR:
799 		if ((reg & EC_STATUS_IBF) != 0)
800 			break; /* Nothing of interest here. */
801 
802 		acpiec_write_data(sc, sc->sc_cur_addr);
803 		sc->sc_state = EC_STATE_READ_VAL;
804 		break;
805 
806 	case EC_STATE_READ_VAL:
807 		if ((reg & EC_STATUS_OBF) == 0)
808 			break; /* Nothing of interest here. */
809 		sc->sc_cur_val = acpiec_read_data(sc);
810 		sc->sc_state = EC_STATE_FREE;
811 
812 		cv_signal(&sc->sc_cv);
813 		break;
814 
815 	case EC_STATE_WRITE:
816 		if ((reg & EC_STATUS_IBF) != 0)
817 			break; /* Nothing of interest here. */
818 
819 		acpiec_write_command(sc, EC_COMMAND_WRITE);
820 		sc->sc_state = EC_STATE_WRITE_ADDR;
821 		break;
822 
823 	case EC_STATE_WRITE_ADDR:
824 		if ((reg & EC_STATUS_IBF) != 0)
825 			break; /* Nothing of interest here. */
826 		acpiec_write_data(sc, sc->sc_cur_addr);
827 		sc->sc_state = EC_STATE_WRITE_VAL;
828 		break;
829 
830 	case EC_STATE_WRITE_VAL:
831 		if ((reg & EC_STATUS_IBF) != 0)
832 			break; /* Nothing of interest here. */
833 		sc->sc_state = EC_STATE_FREE;
834 		cv_signal(&sc->sc_cv);
835 
836 		acpiec_write_data(sc, sc->sc_cur_val);
837 		break;
838 
839 	case EC_STATE_FREE:
840 		if (sc->sc_got_sci)
841 			cv_signal(&sc->sc_cv_sci);
842 		break;
843 	default:
844 		panic("invalid state");
845 	}
846 
847 	if (sc->sc_state != EC_STATE_FREE)
848 		callout_schedule(&sc->sc_pseudo_intr, 1);
849 }
850 
851 static void
852 acpiec_callout(void *arg)
853 {
854 	device_t dv = arg;
855 	struct acpiec_softc *sc = device_private(dv);
856 
857 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
858 
859 	mutex_enter(&sc->sc_mtx);
860 	acpiec_gpe_state_machine(dv);
861 	mutex_exit(&sc->sc_mtx);
862 }
863 
864 static UINT32
865 acpiec_gpe_handler(void *arg)
866 {
867 	device_t dv = arg;
868 	struct acpiec_softc *sc = device_private(dv);
869 
870 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
871 
872 	mutex_enter(&sc->sc_mtx);
873 	acpiec_gpe_state_machine(dv);
874 	mutex_exit(&sc->sc_mtx);
875 
876 	return 0;
877 }
878 
879 ACPI_STATUS
880 acpiec_bus_read(device_t dv, u_int addr, ACPI_INTEGER *val, int width)
881 {
882 	return acpiec_space_handler(ACPI_READ, addr, width * 8, val, dv, NULL);
883 }
884 
885 ACPI_STATUS
886 acpiec_bus_write(device_t dv, u_int addr, ACPI_INTEGER val, int width)
887 {
888 	return acpiec_space_handler(ACPI_WRITE, addr, width * 8, &val, dv, NULL);
889 }
890 
891 ACPI_HANDLE
892 acpiec_get_handle(device_t dv)
893 {
894 	struct acpiec_softc *sc = device_private(dv);
895 
896 	return sc->sc_ech;
897 }
898