xref: /netbsd-src/sys/dev/acpi/acpi_ec.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: acpi_ec.c,v 1.46 2007/12/15 09:30:59 joerg 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 1.46 2007/12/15 09:30:59 joerg 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/acpivar.h>
75 
76 /* Maximum time to wait for global ACPI lock in ms */
77 #define	EC_LOCK_TIMEOUT		5
78 
79 /* Maximum time to poll for completion of a command  in ms */
80 #define	EC_POLL_TIMEOUT		5
81 
82 /* Maximum time to give a single EC command in s */
83 #define EC_CMD_TIMEOUT		10
84 
85 /* From ACPI 3.0b, chapter 12.3 */
86 #define EC_COMMAND_READ		0x80
87 #define	EC_COMMAND_WRITE	0x81
88 #define	EC_COMMAND_BURST_EN	0x82
89 #define	EC_COMMAND_BURST_DIS	0x83
90 #define	EC_COMMAND_QUERY	0x84
91 
92 /* From ACPI 3.0b, chapter 12.2.1 */
93 #define	EC_STATUS_OBF		0x01
94 #define	EC_STATUS_IBF		0x02
95 #define	EC_STATUS_CMD		0x08
96 #define	EC_STATUS_BURST		0x10
97 #define	EC_STATUS_SCI		0x20
98 #define	EC_STATUS_SMI		0x40
99 
100 static const char *ec_hid[] = {
101 	"PNP0C09",
102 	NULL,
103 };
104 
105 enum ec_state_t {
106 	EC_STATE_QUERY,
107 	EC_STATE_QUERY_VAL,
108 	EC_STATE_READ,
109 	EC_STATE_READ_ADDR,
110 	EC_STATE_READ_VAL,
111 	EC_STATE_WRITE,
112 	EC_STATE_WRITE_ADDR,
113 	EC_STATE_WRITE_VAL,
114 	EC_STATE_FREE
115 };
116 
117 struct acpiec_softc {
118 	ACPI_HANDLE sc_ech;
119 
120 	ACPI_HANDLE sc_gpeh;
121 	UINT8 sc_gpebit;
122 
123 	bus_space_tag_t sc_data_st;
124 	bus_space_handle_t sc_data_sh;
125 
126 	bus_space_tag_t sc_csr_st;
127 	bus_space_handle_t sc_csr_sh;
128 
129 	bool sc_need_global_lock;
130 	UINT32 sc_global_lock;
131 
132 	kmutex_t sc_mtx, sc_access_mtx;
133 	kcondvar_t sc_cv, sc_cv_sci;
134 	enum ec_state_t sc_state;
135 	bool sc_got_sci;
136 	callout_t sc_pseudo_intr;
137 
138 	uint8_t sc_cur_addr, sc_cur_val;
139 };
140 
141 static int acpiecdt_match(device_t, struct cfdata *, void *);
142 static void acpiecdt_attach(device_t, device_t, void *);
143 
144 static int acpiec_match(device_t, struct cfdata *, void *);
145 static void acpiec_attach(device_t, device_t, void *);
146 
147 static void acpiec_common_attach(device_t, device_t, ACPI_HANDLE,
148     bus_addr_t, bus_addr_t, ACPI_HANDLE, uint8_t);
149 
150 static bool acpiec_resume(device_t);
151 static bool acpiec_suspend(device_t);
152 
153 static bool acpiec_parse_gpe_package(device_t, ACPI_HANDLE,
154     ACPI_HANDLE *, uint8_t *);
155 
156 static void acpiec_callout(void *);
157 static void acpiec_gpe_query(void *);
158 static UINT32 acpiec_gpe_handler(void *);
159 static ACPI_STATUS acpiec_space_setup(ACPI_HANDLE, UINT32, void *, void **);
160 static ACPI_STATUS acpiec_space_handler(UINT32, ACPI_PHYSICAL_ADDRESS,
161     UINT32, ACPI_INTEGER *, void *, void *);
162 
163 static void acpiec_gpe_state_machine(device_t);
164 
165 CFATTACH_DECL_NEW(acpiec, sizeof(struct acpiec_softc),
166     acpiec_match, acpiec_attach, NULL, NULL);
167 
168 CFATTACH_DECL_NEW(acpiecdt, sizeof(struct acpiec_softc),
169     acpiecdt_match, acpiecdt_attach, NULL, NULL);
170 
171 static device_t ec_singleton = NULL;
172 static bool acpiec_cold = false;
173 
174 static bool
175 acpiecdt_find(device_t parent, ACPI_HANDLE *ec_handle,
176     bus_addr_t *cmd_reg, bus_addr_t *data_reg, uint8_t *gpebit)
177 {
178 	ACPI_TABLE_ECDT *ecdt;
179 	ACPI_STATUS rv;
180 
181 	rv = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
182 	if (ACPI_FAILURE(rv))
183 		return false;
184 
185 	if (ecdt->Control.BitWidth != 8 || ecdt->Data.BitWidth != 8) {
186 		aprint_error_dev(parent,
187 		    "ECDT register width invalid (%d/%d)\n",
188 		    ecdt->Control.BitWidth, ecdt->Data.BitWidth);
189 		return false;
190 	}
191 
192 	rv = AcpiGetHandle(ACPI_ROOT_OBJECT, ecdt->Id, ec_handle);
193 	if (ACPI_FAILURE(rv)) {
194 		aprint_error_dev(parent,
195 		    "failed to look up EC object %s: %s\n",
196 		    ecdt->Id, AcpiFormatException(rv));
197 		return false;
198 	}
199 
200 	*cmd_reg = ecdt->Control.Address;
201 	*data_reg = ecdt->Data.Address;
202 	*gpebit = ecdt->Gpe;
203 
204 	return true;
205 }
206 
207 static int
208 acpiecdt_match(device_t parent, struct cfdata *match, void *aux)
209 {
210 	ACPI_HANDLE ec_handle;
211 	bus_addr_t cmd_reg, data_reg;
212 	uint8_t gpebit;
213 
214 	if (acpiecdt_find(parent, &ec_handle, &cmd_reg, &data_reg, &gpebit))
215 		return 1;
216 	else
217 		return 0;
218 }
219 
220 static void
221 acpiecdt_attach(device_t parent, device_t self, void *aux)
222 {
223 	ACPI_HANDLE ec_handle;
224 	bus_addr_t cmd_reg, data_reg;
225 	uint8_t gpebit;
226 
227 	if (!acpiecdt_find(parent, &ec_handle, &cmd_reg, &data_reg, &gpebit))
228 		panic("ECDT disappeared");
229 
230 	aprint_naive(": ACPI Embedded Controller via ECDT\n");
231 	aprint_normal(": ACPI Embedded Controller via ECDT\n");
232 
233 	acpiec_common_attach(parent, self, ec_handle, cmd_reg, data_reg,
234 	    NULL, gpebit);
235 }
236 
237 static int
238 acpiec_match(device_t parent, struct cfdata *match, void *aux)
239 {
240 	struct acpi_attach_args *aa = aux;
241 
242 	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
243 		return 0;
244 
245 	return acpi_match_hid(aa->aa_node->ad_devinfo, ec_hid);
246 }
247 
248 static void
249 acpiec_attach(device_t parent, device_t self, void *aux)
250 {
251 	struct acpi_attach_args *aa = aux;
252 	struct acpi_resources ec_res;
253 	struct acpi_io *io0, *io1;
254 	ACPI_HANDLE gpe_handle;
255 	uint8_t gpebit;
256 	ACPI_STATUS rv;
257 
258 	if (ec_singleton != NULL) {
259 		aprint_naive(": ACPI Embedded Controller (disabled)\n");
260 		aprint_normal(": ACPI Embedded Controller (disabled)\n");
261 		if (!pmf_device_register(self, NULL, NULL))
262 			aprint_error_dev(self, "couldn't establish power handler\n");
263 		return;
264 	}
265 
266 	aprint_naive(": ACPI Embedded Controller\n");
267 	aprint_normal(": ACPI Embedded Controller\n");
268 
269 	if (!acpiec_parse_gpe_package(self, aa->aa_node->ad_handle,
270 				      &gpe_handle, &gpebit))
271 		return;
272 
273 	rv = acpi_resource_parse(self, aa->aa_node->ad_handle, "_CRS",
274 	    &ec_res, &acpi_resource_parse_ops_default);
275 	if (rv != AE_OK) {
276 		aprint_error_dev(self, "resource parsing failed: %s\n",
277 		    AcpiFormatException(rv));
278 		return;
279 	}
280 
281 	if ((io0 = acpi_res_io(&ec_res, 0)) == NULL) {
282 		aprint_error_dev(self, "no data register resource\n");
283 		goto free_res;
284 	}
285 	if ((io1 = acpi_res_io(&ec_res, 1)) == NULL) {
286 		aprint_error_dev(self, "no CSR register resource\n");
287 		goto free_res;
288 	}
289 
290 	acpiec_common_attach(parent, self, aa->aa_node->ad_handle,
291 	    io1->ar_base, io0->ar_base, gpe_handle, gpebit);
292 
293 free_res:
294 	acpi_resource_cleanup(&ec_res);
295 }
296 
297 static void
298 acpiec_common_attach(device_t parent, device_t self,
299     ACPI_HANDLE ec_handle, bus_addr_t cmd_reg, bus_addr_t data_reg,
300     ACPI_HANDLE gpe_handle, uint8_t gpebit)
301 {
302 	struct acpiec_softc *sc = device_private(self);
303 	ACPI_STATUS rv;
304 	ACPI_INTEGER val;
305 
306 	sc->sc_ech = ec_handle;
307 	sc->sc_gpeh = gpe_handle;
308 	sc->sc_gpebit = gpebit;
309 
310 	sc->sc_state = EC_STATE_FREE;
311 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
312 	mutex_init(&sc->sc_access_mtx, MUTEX_DEFAULT, IPL_NONE);
313 	cv_init(&sc->sc_cv, "eccv");
314 	cv_init(&sc->sc_cv_sci, "ecsci");
315 
316 	if (bus_space_map(sc->sc_data_st, data_reg, 1, 0,
317 	    &sc->sc_data_sh) != 0) {
318 		aprint_error_dev(self, "unable to map data register\n");
319 		return;
320 	}
321 
322 	if (bus_space_map(sc->sc_csr_st, cmd_reg, 1, 0, &sc->sc_csr_sh) != 0) {
323 		aprint_error_dev(self, "unable to map CSR register\n");
324 		goto post_data_map;
325 	}
326 
327 	rv = acpi_eval_integer(sc->sc_ech, "_GLK", &val);
328 	if (rv == AE_OK) {
329 		sc->sc_need_global_lock = val != 0;
330 	} else if (rv != AE_NOT_FOUND) {
331 		aprint_error_dev(self, "unable to evaluate _GLK: %s\n",
332 		    AcpiFormatException(rv));
333 		goto post_csr_map;
334 	} else {
335 		sc->sc_need_global_lock = false;
336 	}
337 	if (sc->sc_need_global_lock)
338 		aprint_normal_dev(self, "using global ACPI lock\n");
339 
340 	callout_init(&sc->sc_pseudo_intr, CALLOUT_MPSAFE);
341 	callout_setfunc(&sc->sc_pseudo_intr, acpiec_callout, self);
342 
343 	rv = AcpiInstallAddressSpaceHandler(sc->sc_ech, ACPI_ADR_SPACE_EC,
344 	    acpiec_space_handler, acpiec_space_setup, self);
345 	if (rv != AE_OK) {
346 		aprint_error_dev(self,
347 		    "unable to install address space handler: %s\n",
348 		    AcpiFormatException(rv));
349 		goto post_csr_map;
350 	}
351 
352 	rv = AcpiInstallGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
353 	    ACPI_GPE_EDGE_TRIGGERED, acpiec_gpe_handler, self);
354 	if (rv != AE_OK) {
355 		aprint_error_dev(self, "unable to install GPE handler: %s\n",
356 		    AcpiFormatException(rv));
357 		goto post_csr_map;
358 	}
359 
360 	rv = AcpiSetGpeType(sc->sc_gpeh, sc->sc_gpebit, ACPI_GPE_TYPE_RUNTIME);
361 	if (rv != AE_OK) {
362 		aprint_error_dev(self, "unable to set GPE type: %s\n",
363 		    AcpiFormatException(rv));
364 		goto post_csr_map;
365 	}
366 
367 	rv = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
368 	if (rv != AE_OK) {
369 		aprint_error_dev(self, "unable to enable GPE: %s\n",
370 		    AcpiFormatException(rv));
371 		goto post_csr_map;
372 	}
373 
374 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, acpiec_gpe_query,
375 		           self, NULL, "acpiec sci thread")) {
376 		aprint_error_dev(self, "unable to create query kthread\n");
377 		goto post_csr_map;
378 	}
379 
380 	ec_singleton = self;
381 
382 	if (!pmf_device_register(self, acpiec_suspend, acpiec_resume))
383 		aprint_error_dev(self, "couldn't establish power handler\n");
384 
385 	return;
386 
387 post_csr_map:
388 	(void)AcpiRemoveGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
389 	    acpiec_gpe_handler);
390 	(void)AcpiRemoveAddressSpaceHandler(sc->sc_ech,
391 	    ACPI_ADR_SPACE_EC, acpiec_space_handler);
392 	bus_space_unmap(sc->sc_csr_st, sc->sc_csr_sh, 1);
393 post_data_map:
394 	bus_space_unmap(sc->sc_data_st, sc->sc_data_sh, 1);
395 }
396 
397 static bool
398 acpiec_suspend(device_t dv)
399 {
400 	acpiec_cold = true;
401 
402 	return true;
403 }
404 
405 static bool
406 acpiec_resume(device_t dv)
407 {
408 	acpiec_cold = false;
409 
410 	return true;
411 }
412 
413 static bool
414 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
415     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
416 {
417 	ACPI_BUFFER buf;
418 	ACPI_OBJECT *p, *c;
419 	ACPI_STATUS rv;
420 
421 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
422 	if (rv != AE_OK) {
423 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
424 		    AcpiFormatException(rv));
425 		return false;
426 	}
427 
428 	p = buf.Pointer;
429 
430 	if (p->Type == ACPI_TYPE_INTEGER) {
431 		*gpe_handle = NULL;
432 		*gpebit = p->Integer.Value;
433 		AcpiOsFree(p);
434 		return true;
435 	}
436 
437 	if (p->Type != ACPI_TYPE_PACKAGE) {
438 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
439 		AcpiOsFree(p);
440 		return false;
441 	}
442 
443 	if (p->Package.Count != 2) {
444 		aprint_error_dev(self, "_GPE package does not contain 2 elements\n");
445 		AcpiOsFree(p);
446 		return false;
447 	}
448 
449 	c = &p->Package.Elements[0];
450 	switch (c->Type) {
451 	case ACPI_TYPE_LOCAL_REFERENCE:
452 	case ACPI_TYPE_ANY:
453 		*gpe_handle = c->Reference.Handle;
454 		break;
455 	case ACPI_TYPE_STRING:
456 		/* XXX should be using real scope here */
457 		rv = AcpiGetHandle(NULL, p->String.Pointer, gpe_handle);
458 		if (rv != AE_OK) {
459 			aprint_error_dev(self,
460 			    "_GPE device reference unresolvable\n");
461 			AcpiOsFree(p);
462 			return false;
463 		}
464 		break;
465 	default:
466 		aprint_error_dev(self, "_GPE device reference incorrect\n");
467 		AcpiOsFree(p);
468 		return false;
469 	}
470 	c = &p->Package.Elements[1];
471 	if (c->Type != ACPI_TYPE_INTEGER) {
472 		aprint_error_dev(self,
473 		    "_GPE package needs integer as 2nd field\n");
474 		AcpiOsFree(p);
475 		return false;
476 	}
477 	*gpebit = c->Integer.Value;
478 	AcpiOsFree(p);
479 	return true;
480 }
481 
482 static uint8_t
483 acpiec_read_data(struct acpiec_softc *sc)
484 {
485 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
486 }
487 
488 static void
489 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
490 {
491 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
492 }
493 
494 static uint8_t
495 acpiec_read_status(struct acpiec_softc *sc)
496 {
497 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
498 }
499 
500 static void
501 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
502 {
503 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
504 }
505 
506 static ACPI_STATUS
507 acpiec_space_setup(ACPI_HANDLE region, UINT32 func, void *arg,
508     void **region_arg)
509 {
510 	if (func == ACPI_REGION_DEACTIVATE)
511 		*region_arg = NULL;
512 	else
513 		*region_arg = arg;
514 
515 	return AE_OK;
516 }
517 
518 static void
519 acpiec_lock(device_t dv)
520 {
521 	struct acpiec_softc *sc = device_private(dv);
522 	ACPI_STATUS rv;
523 
524 	mutex_enter(&sc->sc_access_mtx);
525 
526 	if (sc->sc_need_global_lock) {
527 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->sc_global_lock);
528 		if (rv != AE_OK) {
529 			aprint_error_dev(dv, "failed to acquire global lock: %s\n",
530 			    AcpiFormatException(rv));
531 			return;
532 		}
533 	}
534 }
535 
536 static void
537 acpiec_unlock(device_t dv)
538 {
539 	struct acpiec_softc *sc = device_private(dv);
540 	ACPI_STATUS rv;
541 
542 	if (sc->sc_need_global_lock) {
543 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
544 		if (rv != AE_OK) {
545 			aprint_error_dev(dv, "failed to release global lock: %s\n",
546 			    AcpiFormatException(rv));
547 		}
548 	}
549 	mutex_exit(&sc->sc_access_mtx);
550 }
551 
552 static ACPI_STATUS
553 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
554 {
555 	struct acpiec_softc *sc = device_private(dv);
556 	int i;
557 
558 	acpiec_lock(dv);
559 	mutex_enter(&sc->sc_mtx);
560 
561 	sc->sc_cur_addr = addr;
562 	sc->sc_state = EC_STATE_READ;
563 
564 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
565 		acpiec_gpe_state_machine(dv);
566 		if (sc->sc_state == EC_STATE_FREE)
567 			goto done;
568 		delay(1);
569 	}
570 
571 	if (cold || acpiec_cold) {
572 		while (sc->sc_state != EC_STATE_FREE) {
573 			delay(1);
574 			acpiec_gpe_state_machine(dv);
575 		}
576 	} else while (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
577 		mutex_exit(&sc->sc_mtx);
578 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
579 		acpiec_unlock(dv);
580 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
581 		return AE_ERROR;
582 	}
583 
584 done:
585 	*val = sc->sc_cur_val;
586 
587 	mutex_exit(&sc->sc_mtx);
588 	acpiec_unlock(dv);
589 	return AE_OK;
590 }
591 
592 static ACPI_STATUS
593 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
594 {
595 	struct acpiec_softc *sc = device_private(dv);
596 	int i;
597 
598 	acpiec_lock(dv);
599 	mutex_enter(&sc->sc_mtx);
600 
601 	sc->sc_cur_addr = addr;
602 	sc->sc_cur_val = val;
603 	sc->sc_state = EC_STATE_WRITE;
604 
605 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
606 		acpiec_gpe_state_machine(dv);
607 		if (sc->sc_state == EC_STATE_FREE)
608 			goto done;
609 		delay(1);
610 	}
611 
612 	if (cold || acpiec_cold) {
613 		while (sc->sc_state != EC_STATE_FREE) {
614 			delay(1);
615 			acpiec_gpe_state_machine(dv);
616 		}
617 	} else while (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
618 		mutex_exit(&sc->sc_mtx);
619 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
620 		acpiec_unlock(dv);
621 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
622 		return AE_ERROR;
623 	}
624 
625 done:
626 	mutex_exit(&sc->sc_mtx);
627 	acpiec_unlock(dv);
628 	return AE_OK;
629 }
630 
631 static ACPI_STATUS
632 acpiec_space_handler(UINT32 func, ACPI_PHYSICAL_ADDRESS paddr,
633     UINT32 width, ACPI_INTEGER *value, void *arg, void *region_arg)
634 {
635 	device_t dv;
636 	struct acpiec_softc *sc;
637 	ACPI_STATUS rv;
638 	uint8_t addr, reg;
639 	unsigned int i;
640 
641 	if (paddr > 0xff || width % 8 != 0 || value == NULL || arg == NULL ||
642 	    paddr + width / 8 > 0xff)
643 		return AE_BAD_PARAMETER;
644 
645 	addr = paddr;
646 	dv = arg;
647 	sc = device_private(dv);
648 
649 	rv = AE_OK;
650 
651 	switch (func) {
652 	case ACPI_READ:
653 		*value = 0;
654 		for (i = 0; i < width; i += 8, ++addr) {
655 			rv = acpiec_read(dv, addr, &reg);
656 			if (rv != AE_OK)
657 				break;
658 			*value |= (ACPI_INTEGER)reg << i;
659 		}
660 		break;
661 	case ACPI_WRITE:
662 		for (i = 0; i < width; i += 8, ++addr) {
663 			reg = (*value >>i) & 0xff;
664 			rv = acpiec_write(dv, addr, reg);
665 			if (rv != AE_OK)
666 				break;
667 		}
668 		break;
669 	default:
670 		aprint_error("%s: invalid Address Space function called: %x\n",
671 		    device_xname(dv), (unsigned int)func);
672 		return AE_BAD_PARAMETER;
673 	}
674 
675 	return rv;
676 }
677 
678 static void
679 acpiec_gpe_query(void *arg)
680 {
681 	device_t dv = arg;
682 	struct acpiec_softc *sc = device_private(dv);
683 	uint8_t reg;
684 	char qxx[5];
685 	ACPI_STATUS rv;
686 	int i;
687 
688 loop:
689 	mutex_enter(&sc->sc_mtx);
690 
691 	if (sc->sc_got_sci == false)
692 		cv_wait(&sc->sc_cv_sci, &sc->sc_mtx);
693 	mutex_exit(&sc->sc_mtx);
694 
695 	acpiec_lock(dv);
696 	mutex_enter(&sc->sc_mtx);
697 
698 	/* The Query command can always be issued, so be defensive here. */
699 	sc->sc_got_sci = false;
700 	sc->sc_state = EC_STATE_QUERY;
701 
702 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
703 		acpiec_gpe_state_machine(dv);
704 		if (sc->sc_state == EC_STATE_FREE)
705 			goto done;
706 		delay(1);
707 	}
708 
709 	cv_wait(&sc->sc_cv, &sc->sc_mtx);
710 
711 done:
712 	reg = sc->sc_cur_val;
713 
714 	mutex_exit(&sc->sc_mtx);
715 	acpiec_unlock(dv);
716 
717 	if (reg == 0)
718 		goto loop; /* Spurious query result */
719 
720 	/*
721 	 * Evaluate _Qxx to respond to the controller.
722 	 */
723 	snprintf(qxx, sizeof(qxx), "_Q%02X", (unsigned int)reg);
724 	rv = AcpiEvaluateObject(sc->sc_ech, qxx, NULL, NULL);
725 	if (rv != AE_OK && rv != AE_NOT_FOUND) {
726 		aprint_error("%s: GPE query method %s failed: %s",
727 		    device_xname(dv), qxx, AcpiFormatException(rv));
728 	}
729 
730 	goto loop;
731 }
732 
733 static void
734 acpiec_gpe_state_machine(device_t dv)
735 {
736 	struct acpiec_softc *sc = device_private(dv);
737 	uint8_t reg;
738 
739 	reg = acpiec_read_status(sc);
740 
741 	if (reg & EC_STATUS_SCI)
742 		sc->sc_got_sci = true;
743 
744 	switch (sc->sc_state) {
745 	case EC_STATE_QUERY:
746 		if ((reg & EC_STATUS_IBF) != 0)
747 			break; /* Nothing of interest here. */
748 		acpiec_write_command(sc, EC_COMMAND_QUERY);
749 		sc->sc_state = EC_STATE_QUERY_VAL;
750 		break;
751 
752 	case EC_STATE_QUERY_VAL:
753 		if ((reg & EC_STATUS_OBF) == 0)
754 			break; /* Nothing of interest here. */
755 
756 		sc->sc_cur_val = acpiec_read_data(sc);
757 		sc->sc_state = EC_STATE_FREE;
758 
759 		cv_signal(&sc->sc_cv);
760 		break;
761 
762 	case EC_STATE_READ:
763 		if ((reg & EC_STATUS_IBF) != 0)
764 			break; /* Nothing of interest here. */
765 
766 		acpiec_write_command(sc, EC_COMMAND_READ);
767 		sc->sc_state = EC_STATE_READ_ADDR;
768 		break;
769 
770 	case EC_STATE_READ_ADDR:
771 		if ((reg & EC_STATUS_IBF) != 0)
772 			break; /* Nothing of interest here. */
773 
774 		acpiec_write_data(sc, sc->sc_cur_addr);
775 		sc->sc_state = EC_STATE_READ_VAL;
776 		break;
777 
778 	case EC_STATE_READ_VAL:
779 		if ((reg & EC_STATUS_OBF) == 0)
780 			break; /* Nothing of interest here. */
781 		sc->sc_cur_val = acpiec_read_data(sc);
782 		sc->sc_state = EC_STATE_FREE;
783 
784 		cv_signal(&sc->sc_cv);
785 		break;
786 
787 	case EC_STATE_WRITE:
788 		if ((reg & EC_STATUS_IBF) != 0)
789 			break; /* Nothing of interest here. */
790 
791 		acpiec_write_command(sc, EC_COMMAND_WRITE);
792 		sc->sc_state = EC_STATE_WRITE_ADDR;
793 		break;
794 
795 	case EC_STATE_WRITE_ADDR:
796 		if ((reg & EC_STATUS_IBF) != 0)
797 			break; /* Nothing of interest here. */
798 		acpiec_write_data(sc, sc->sc_cur_addr);
799 		sc->sc_state = EC_STATE_WRITE_VAL;
800 		break;
801 
802 	case EC_STATE_WRITE_VAL:
803 		if ((reg & EC_STATUS_IBF) != 0)
804 			break; /* Nothing of interest here. */
805 		sc->sc_state = EC_STATE_FREE;
806 		cv_signal(&sc->sc_cv);
807 
808 		acpiec_write_data(sc, sc->sc_cur_val);
809 		break;
810 
811 	case EC_STATE_FREE:
812 		if (sc->sc_got_sci)
813 			cv_signal(&sc->sc_cv_sci);
814 		break;
815 	default:
816 		panic("invalid state");
817 	}
818 
819 	if (sc->sc_state != EC_STATE_FREE)
820 		callout_schedule(&sc->sc_pseudo_intr, 1);
821 }
822 
823 static void
824 acpiec_callout(void *arg)
825 {
826 	device_t dv = arg;
827 	struct acpiec_softc *sc = device_private(dv);
828 
829 	mutex_enter(&sc->sc_mtx);
830 	acpiec_gpe_state_machine(dv);
831 	mutex_exit(&sc->sc_mtx);
832 }
833 
834 static UINT32
835 acpiec_gpe_handler(void *arg)
836 {
837 	device_t dv = arg;
838 	struct acpiec_softc *sc = device_private(dv);
839 
840 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
841 
842 	mutex_enter(&sc->sc_mtx);
843 	acpiec_gpe_state_machine(dv);
844 	mutex_exit(&sc->sc_mtx);
845 
846 	return 0;
847 }
848