xref: /netbsd-src/sys/dev/acpi/acpi_ec.c (revision da9817918ec7e88db2912a2882967c7570a83f47)
1 /*	$NetBSD: acpi_ec.c,v 1.55 2009/05/12 09:29:46 cegger 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 1.55 2009/05/12 09:29:46 cegger 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 #include <dev/acpi/acpi_ecvar.h>
76 
77 /* Maximum time to wait for global ACPI lock in ms */
78 #define	EC_LOCK_TIMEOUT		5
79 
80 /* Maximum time to poll for completion of a command  in ms */
81 #define	EC_POLL_TIMEOUT		5
82 
83 /* Maximum time to give a single EC command in s */
84 #define EC_CMD_TIMEOUT		10
85 
86 /* From ACPI 3.0b, chapter 12.3 */
87 #define EC_COMMAND_READ		0x80
88 #define	EC_COMMAND_WRITE	0x81
89 #define	EC_COMMAND_BURST_EN	0x82
90 #define	EC_COMMAND_BURST_DIS	0x83
91 #define	EC_COMMAND_QUERY	0x84
92 
93 /* From ACPI 3.0b, chapter 12.2.1 */
94 #define	EC_STATUS_OBF		0x01
95 #define	EC_STATUS_IBF		0x02
96 #define	EC_STATUS_CMD		0x08
97 #define	EC_STATUS_BURST		0x10
98 #define	EC_STATUS_SCI		0x20
99 #define	EC_STATUS_SMI		0x40
100 
101 static const char *ec_hid[] = {
102 	"PNP0C09",
103 	NULL,
104 };
105 
106 enum ec_state_t {
107 	EC_STATE_QUERY,
108 	EC_STATE_QUERY_VAL,
109 	EC_STATE_READ,
110 	EC_STATE_READ_ADDR,
111 	EC_STATE_READ_VAL,
112 	EC_STATE_WRITE,
113 	EC_STATE_WRITE_ADDR,
114 	EC_STATE_WRITE_VAL,
115 	EC_STATE_FREE
116 };
117 
118 struct acpiec_softc {
119 	ACPI_HANDLE sc_ech;
120 
121 	ACPI_HANDLE sc_gpeh;
122 	UINT8 sc_gpebit;
123 
124 	bus_space_tag_t sc_data_st;
125 	bus_space_handle_t sc_data_sh;
126 
127 	bus_space_tag_t sc_csr_st;
128 	bus_space_handle_t sc_csr_sh;
129 
130 	bool sc_need_global_lock;
131 	UINT32 sc_global_lock;
132 
133 	kmutex_t sc_mtx, sc_access_mtx;
134 	kcondvar_t sc_cv, sc_cv_sci;
135 	enum ec_state_t sc_state;
136 	bool sc_got_sci;
137 	callout_t sc_pseudo_intr;
138 
139 	uint8_t sc_cur_addr, sc_cur_val;
140 };
141 
142 static int acpiecdt_match(device_t, cfdata_t, void *);
143 static void acpiecdt_attach(device_t, device_t, void *);
144 
145 static int acpiec_match(device_t, cfdata_t, void *);
146 static void acpiec_attach(device_t, device_t, void *);
147 
148 static void acpiec_common_attach(device_t, device_t, ACPI_HANDLE,
149     bus_addr_t, bus_addr_t, ACPI_HANDLE, uint8_t);
150 
151 static bool acpiec_resume(device_t PMF_FN_PROTO);
152 static bool acpiec_suspend(device_t PMF_FN_PROTO);
153 
154 static bool acpiec_parse_gpe_package(device_t, ACPI_HANDLE,
155     ACPI_HANDLE *, uint8_t *);
156 
157 static void acpiec_callout(void *);
158 static void acpiec_gpe_query(void *);
159 static UINT32 acpiec_gpe_handler(void *);
160 static ACPI_STATUS acpiec_space_setup(ACPI_HANDLE, UINT32, void *, void **);
161 static ACPI_STATUS acpiec_space_handler(UINT32, ACPI_PHYSICAL_ADDRESS,
162     UINT32, ACPI_INTEGER *, void *, void *);
163 
164 static void acpiec_gpe_state_machine(device_t);
165 
166 CFATTACH_DECL_NEW(acpiec, sizeof(struct acpiec_softc),
167     acpiec_match, acpiec_attach, NULL, NULL);
168 
169 CFATTACH_DECL_NEW(acpiecdt, sizeof(struct acpiec_softc),
170     acpiecdt_match, acpiecdt_attach, NULL, NULL);
171 
172 static device_t ec_singleton = NULL;
173 static bool acpiec_cold = false;
174 
175 static bool
176 acpiecdt_find(device_t parent, ACPI_HANDLE *ec_handle,
177     bus_addr_t *cmd_reg, bus_addr_t *data_reg, uint8_t *gpebit)
178 {
179 	ACPI_TABLE_ECDT *ecdt;
180 	ACPI_STATUS rv;
181 
182 	rv = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
183 	if (ACPI_FAILURE(rv))
184 		return false;
185 
186 	if (ecdt->Control.BitWidth != 8 || ecdt->Data.BitWidth != 8) {
187 		aprint_error_dev(parent,
188 		    "ECDT register width invalid (%d/%d)\n",
189 		    ecdt->Control.BitWidth, ecdt->Data.BitWidth);
190 		return false;
191 	}
192 
193 	rv = AcpiGetHandle(ACPI_ROOT_OBJECT, ecdt->Id, ec_handle);
194 	if (ACPI_FAILURE(rv)) {
195 		aprint_error_dev(parent,
196 		    "failed to look up EC object %s: %s\n",
197 		    ecdt->Id, AcpiFormatException(rv));
198 		return false;
199 	}
200 
201 	*cmd_reg = ecdt->Control.Address;
202 	*data_reg = ecdt->Data.Address;
203 	*gpebit = ecdt->Gpe;
204 
205 	return true;
206 }
207 
208 static int
209 acpiecdt_match(device_t parent, cfdata_t match, void *aux)
210 {
211 	ACPI_HANDLE ec_handle;
212 	bus_addr_t cmd_reg, data_reg;
213 	uint8_t gpebit;
214 
215 	if (acpiecdt_find(parent, &ec_handle, &cmd_reg, &data_reg, &gpebit))
216 		return 1;
217 	else
218 		return 0;
219 }
220 
221 static void
222 acpiecdt_attach(device_t parent, device_t self, void *aux)
223 {
224 	ACPI_HANDLE ec_handle;
225 	bus_addr_t cmd_reg, data_reg;
226 	uint8_t gpebit;
227 
228 	if (!acpiecdt_find(parent, &ec_handle, &cmd_reg, &data_reg, &gpebit))
229 		panic("ECDT disappeared");
230 
231 	aprint_naive("\n");
232 	aprint_normal(": ACPI Embedded Controller via ECDT\n");
233 
234 	acpiec_common_attach(parent, self, ec_handle, cmd_reg, data_reg,
235 	    NULL, gpebit);
236 }
237 
238 static int
239 acpiec_match(device_t parent, cfdata_t match, void *aux)
240 {
241 	struct acpi_attach_args *aa = aux;
242 
243 	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
244 		return 0;
245 
246 	return acpi_match_hid(aa->aa_node->ad_devinfo, ec_hid);
247 }
248 
249 static void
250 acpiec_attach(device_t parent, device_t self, void *aux)
251 {
252 	struct acpi_attach_args *aa = aux;
253 	struct acpi_resources ec_res;
254 	struct acpi_io *io0, *io1;
255 	ACPI_HANDLE gpe_handle;
256 	uint8_t gpebit;
257 	ACPI_STATUS rv;
258 
259 	if (ec_singleton != NULL) {
260 		aprint_naive(": using %s\n", device_xname(ec_singleton));
261 		aprint_normal(": using %s\n", device_xname(ec_singleton));
262 		if (!pmf_device_register(self, NULL, NULL))
263 			aprint_error_dev(self, "couldn't establish power handler\n");
264 		return;
265 	}
266 
267 	if (!acpiec_parse_gpe_package(self, aa->aa_node->ad_handle,
268 				      &gpe_handle, &gpebit))
269 		return;
270 
271 	rv = acpi_resource_parse(self, aa->aa_node->ad_handle, "_CRS",
272 	    &ec_res, &acpi_resource_parse_ops_default);
273 	if (rv != AE_OK) {
274 		aprint_error_dev(self, "resource parsing failed: %s\n",
275 		    AcpiFormatException(rv));
276 		return;
277 	}
278 
279 	if ((io0 = acpi_res_io(&ec_res, 0)) == NULL) {
280 		aprint_error_dev(self, "no data register resource\n");
281 		goto free_res;
282 	}
283 	if ((io1 = acpi_res_io(&ec_res, 1)) == NULL) {
284 		aprint_error_dev(self, "no CSR register resource\n");
285 		goto free_res;
286 	}
287 
288 	acpiec_common_attach(parent, self, aa->aa_node->ad_handle,
289 	    io1->ar_base, io0->ar_base, gpe_handle, gpebit);
290 
291 free_res:
292 	acpi_resource_cleanup(&ec_res);
293 }
294 
295 static void
296 acpiec_common_attach(device_t parent, device_t self,
297     ACPI_HANDLE ec_handle, bus_addr_t cmd_reg, bus_addr_t data_reg,
298     ACPI_HANDLE gpe_handle, uint8_t gpebit)
299 {
300 	struct acpiec_softc *sc = device_private(self);
301 	ACPI_STATUS rv;
302 	ACPI_INTEGER val;
303 
304 	sc->sc_ech = ec_handle;
305 	sc->sc_gpeh = gpe_handle;
306 	sc->sc_gpebit = gpebit;
307 
308 	sc->sc_state = EC_STATE_FREE;
309 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
310 	mutex_init(&sc->sc_access_mtx, MUTEX_DEFAULT, IPL_NONE);
311 	cv_init(&sc->sc_cv, "eccv");
312 	cv_init(&sc->sc_cv_sci, "ecsci");
313 
314 	if (bus_space_map(sc->sc_data_st, data_reg, 1, 0,
315 	    &sc->sc_data_sh) != 0) {
316 		aprint_error_dev(self, "unable to map data register\n");
317 		return;
318 	}
319 
320 	if (bus_space_map(sc->sc_csr_st, cmd_reg, 1, 0, &sc->sc_csr_sh) != 0) {
321 		aprint_error_dev(self, "unable to map CSR register\n");
322 		goto post_data_map;
323 	}
324 
325 	rv = acpi_eval_integer(sc->sc_ech, "_GLK", &val);
326 	if (rv == AE_OK) {
327 		sc->sc_need_global_lock = val != 0;
328 	} else if (rv != AE_NOT_FOUND) {
329 		aprint_error_dev(self, "unable to evaluate _GLK: %s\n",
330 		    AcpiFormatException(rv));
331 		goto post_csr_map;
332 	} else {
333 		sc->sc_need_global_lock = false;
334 	}
335 	if (sc->sc_need_global_lock)
336 		aprint_normal_dev(self, "using global ACPI lock\n");
337 
338 	callout_init(&sc->sc_pseudo_intr, CALLOUT_MPSAFE);
339 	callout_setfunc(&sc->sc_pseudo_intr, acpiec_callout, self);
340 
341 	rv = AcpiInstallAddressSpaceHandler(sc->sc_ech, ACPI_ADR_SPACE_EC,
342 	    acpiec_space_handler, acpiec_space_setup, self);
343 	if (rv != AE_OK) {
344 		aprint_error_dev(self,
345 		    "unable to install address space handler: %s\n",
346 		    AcpiFormatException(rv));
347 		goto post_csr_map;
348 	}
349 
350 	rv = AcpiInstallGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
351 	    ACPI_GPE_EDGE_TRIGGERED, acpiec_gpe_handler, self);
352 	if (rv != AE_OK) {
353 		aprint_error_dev(self, "unable to install GPE handler: %s\n",
354 		    AcpiFormatException(rv));
355 		goto post_csr_map;
356 	}
357 
358 	rv = AcpiSetGpeType(sc->sc_gpeh, sc->sc_gpebit, ACPI_GPE_TYPE_RUNTIME);
359 	if (rv != AE_OK) {
360 		aprint_error_dev(self, "unable to set GPE type: %s\n",
361 		    AcpiFormatException(rv));
362 		goto post_csr_map;
363 	}
364 
365 	rv = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
366 	if (rv != AE_OK) {
367 		aprint_error_dev(self, "unable to enable GPE: %s\n",
368 		    AcpiFormatException(rv));
369 		goto post_csr_map;
370 	}
371 
372 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, acpiec_gpe_query,
373 		           self, NULL, "acpiec sci thread")) {
374 		aprint_error_dev(self, "unable to create query kthread\n");
375 		goto post_csr_map;
376 	}
377 
378 	ec_singleton = self;
379 
380 	if (!pmf_device_register(self, acpiec_suspend, acpiec_resume))
381 		aprint_error_dev(self, "couldn't establish power handler\n");
382 
383 	return;
384 
385 post_csr_map:
386 	(void)AcpiRemoveGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
387 	    acpiec_gpe_handler);
388 	(void)AcpiRemoveAddressSpaceHandler(sc->sc_ech,
389 	    ACPI_ADR_SPACE_EC, acpiec_space_handler);
390 	bus_space_unmap(sc->sc_csr_st, sc->sc_csr_sh, 1);
391 post_data_map:
392 	bus_space_unmap(sc->sc_data_st, sc->sc_data_sh, 1);
393 }
394 
395 static bool
396 acpiec_suspend(device_t dv PMF_FN_ARGS)
397 {
398 	acpiec_cold = true;
399 
400 	return true;
401 }
402 
403 static bool
404 acpiec_resume(device_t dv PMF_FN_ARGS)
405 {
406 	acpiec_cold = false;
407 
408 	return true;
409 }
410 
411 static bool
412 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
413     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
414 {
415 	ACPI_BUFFER buf;
416 	ACPI_OBJECT *p, *c;
417 	ACPI_STATUS rv;
418 
419 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
420 	if (rv != AE_OK) {
421 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
422 		    AcpiFormatException(rv));
423 		return false;
424 	}
425 
426 	p = buf.Pointer;
427 
428 	if (p->Type == ACPI_TYPE_INTEGER) {
429 		*gpe_handle = NULL;
430 		*gpebit = p->Integer.Value;
431 		AcpiOsFree(p);
432 		return true;
433 	}
434 
435 	if (p->Type != ACPI_TYPE_PACKAGE) {
436 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
437 		AcpiOsFree(p);
438 		return false;
439 	}
440 
441 	if (p->Package.Count != 2) {
442 		aprint_error_dev(self, "_GPE package does not contain 2 elements\n");
443 		AcpiOsFree(p);
444 		return false;
445 	}
446 
447 	c = &p->Package.Elements[0];
448 	switch (c->Type) {
449 	case ACPI_TYPE_LOCAL_REFERENCE:
450 	case ACPI_TYPE_ANY:
451 		*gpe_handle = c->Reference.Handle;
452 		break;
453 	case ACPI_TYPE_STRING:
454 		/* XXX should be using real scope here */
455 		rv = AcpiGetHandle(NULL, p->String.Pointer, gpe_handle);
456 		if (rv != AE_OK) {
457 			aprint_error_dev(self,
458 			    "_GPE device reference unresolvable\n");
459 			AcpiOsFree(p);
460 			return false;
461 		}
462 		break;
463 	default:
464 		aprint_error_dev(self, "_GPE device reference incorrect\n");
465 		AcpiOsFree(p);
466 		return false;
467 	}
468 	c = &p->Package.Elements[1];
469 	if (c->Type != ACPI_TYPE_INTEGER) {
470 		aprint_error_dev(self,
471 		    "_GPE package needs integer as 2nd field\n");
472 		AcpiOsFree(p);
473 		return false;
474 	}
475 	*gpebit = c->Integer.Value;
476 	AcpiOsFree(p);
477 	return true;
478 }
479 
480 static uint8_t
481 acpiec_read_data(struct acpiec_softc *sc)
482 {
483 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
484 }
485 
486 static void
487 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
488 {
489 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
490 }
491 
492 static uint8_t
493 acpiec_read_status(struct acpiec_softc *sc)
494 {
495 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
496 }
497 
498 static void
499 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
500 {
501 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
502 }
503 
504 static ACPI_STATUS
505 acpiec_space_setup(ACPI_HANDLE region, UINT32 func, void *arg,
506     void **region_arg)
507 {
508 	if (func == ACPI_REGION_DEACTIVATE)
509 		*region_arg = NULL;
510 	else
511 		*region_arg = arg;
512 
513 	return AE_OK;
514 }
515 
516 static void
517 acpiec_lock(device_t dv)
518 {
519 	struct acpiec_softc *sc = device_private(dv);
520 	ACPI_STATUS rv;
521 
522 	mutex_enter(&sc->sc_access_mtx);
523 
524 	if (sc->sc_need_global_lock) {
525 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->sc_global_lock);
526 		if (rv != AE_OK) {
527 			aprint_error_dev(dv, "failed to acquire global lock: %s\n",
528 			    AcpiFormatException(rv));
529 			return;
530 		}
531 	}
532 }
533 
534 static void
535 acpiec_unlock(device_t dv)
536 {
537 	struct acpiec_softc *sc = device_private(dv);
538 	ACPI_STATUS rv;
539 
540 	if (sc->sc_need_global_lock) {
541 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
542 		if (rv != AE_OK) {
543 			aprint_error_dev(dv, "failed to release global lock: %s\n",
544 			    AcpiFormatException(rv));
545 		}
546 	}
547 	mutex_exit(&sc->sc_access_mtx);
548 }
549 
550 static ACPI_STATUS
551 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
552 {
553 	struct acpiec_softc *sc = device_private(dv);
554 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
555 
556 	acpiec_lock(dv);
557 	mutex_enter(&sc->sc_mtx);
558 
559 	sc->sc_cur_addr = addr;
560 	sc->sc_state = EC_STATE_READ;
561 
562 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
563 		acpiec_gpe_state_machine(dv);
564 		if (sc->sc_state == EC_STATE_FREE)
565 			goto done;
566 		delay(1);
567 	}
568 
569 	if (cold || acpiec_cold) {
570 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
571 			delay(1000);
572 			acpiec_gpe_state_machine(dv);
573 		}
574 		if (sc->sc_state != EC_STATE_FREE) {
575 			mutex_exit(&sc->sc_mtx);
576 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
577 			acpiec_unlock(dv);
578 			aprint_error_dev(dv, "command timed out, state %d\n",
579 			    sc->sc_state);
580 			return AE_ERROR;
581 		}
582 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
583 		mutex_exit(&sc->sc_mtx);
584 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
585 		acpiec_unlock(dv);
586 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
587 		return AE_ERROR;
588 	}
589 
590 done:
591 	*val = sc->sc_cur_val;
592 
593 	mutex_exit(&sc->sc_mtx);
594 	acpiec_unlock(dv);
595 	return AE_OK;
596 }
597 
598 static ACPI_STATUS
599 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
600 {
601 	struct acpiec_softc *sc = device_private(dv);
602 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
603 
604 	acpiec_lock(dv);
605 	mutex_enter(&sc->sc_mtx);
606 
607 	sc->sc_cur_addr = addr;
608 	sc->sc_cur_val = val;
609 	sc->sc_state = EC_STATE_WRITE;
610 
611 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
612 		acpiec_gpe_state_machine(dv);
613 		if (sc->sc_state == EC_STATE_FREE)
614 			goto done;
615 		delay(1);
616 	}
617 
618 	if (cold || acpiec_cold) {
619 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
620 			delay(1000);
621 			acpiec_gpe_state_machine(dv);
622 		}
623 		if (sc->sc_state != EC_STATE_FREE) {
624 			mutex_exit(&sc->sc_mtx);
625 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
626 			acpiec_unlock(dv);
627 			aprint_error_dev(dv, "command timed out, state %d\n",
628 			    sc->sc_state);
629 			return AE_ERROR;
630 		}
631 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
632 		mutex_exit(&sc->sc_mtx);
633 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
634 		acpiec_unlock(dv);
635 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
636 		return AE_ERROR;
637 	}
638 
639 done:
640 	mutex_exit(&sc->sc_mtx);
641 	acpiec_unlock(dv);
642 	return AE_OK;
643 }
644 
645 static ACPI_STATUS
646 acpiec_space_handler(UINT32 func, ACPI_PHYSICAL_ADDRESS paddr,
647     UINT32 width, ACPI_INTEGER *value, void *arg, void *region_arg)
648 {
649 	device_t dv;
650 	struct acpiec_softc *sc;
651 	ACPI_STATUS rv;
652 	uint8_t addr, reg;
653 	unsigned int i;
654 
655 	if (paddr > 0xff || width % 8 != 0 || value == NULL || arg == NULL ||
656 	    paddr + width / 8 > 0xff)
657 		return AE_BAD_PARAMETER;
658 
659 	addr = paddr;
660 	dv = arg;
661 	sc = device_private(dv);
662 
663 	rv = AE_OK;
664 
665 	switch (func) {
666 	case ACPI_READ:
667 		*value = 0;
668 		for (i = 0; i < width; i += 8, ++addr) {
669 			rv = acpiec_read(dv, addr, &reg);
670 			if (rv != AE_OK)
671 				break;
672 			*value |= (ACPI_INTEGER)reg << i;
673 		}
674 		break;
675 	case ACPI_WRITE:
676 		for (i = 0; i < width; i += 8, ++addr) {
677 			reg = (*value >>i) & 0xff;
678 			rv = acpiec_write(dv, addr, reg);
679 			if (rv != AE_OK)
680 				break;
681 		}
682 		break;
683 	default:
684 		aprint_error("%s: invalid Address Space function called: %x\n",
685 		    device_xname(dv), (unsigned int)func);
686 		return AE_BAD_PARAMETER;
687 	}
688 
689 	return rv;
690 }
691 
692 static void
693 acpiec_gpe_query(void *arg)
694 {
695 	device_t dv = arg;
696 	struct acpiec_softc *sc = device_private(dv);
697 	uint8_t reg;
698 	char qxx[5];
699 	ACPI_STATUS rv;
700 	int i;
701 
702 loop:
703 	mutex_enter(&sc->sc_mtx);
704 
705 	if (sc->sc_got_sci == false)
706 		cv_wait(&sc->sc_cv_sci, &sc->sc_mtx);
707 	mutex_exit(&sc->sc_mtx);
708 
709 	acpiec_lock(dv);
710 	mutex_enter(&sc->sc_mtx);
711 
712 	/* The Query command can always be issued, so be defensive here. */
713 	sc->sc_got_sci = false;
714 	sc->sc_state = EC_STATE_QUERY;
715 
716 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
717 		acpiec_gpe_state_machine(dv);
718 		if (sc->sc_state == EC_STATE_FREE)
719 			goto done;
720 		delay(1);
721 	}
722 
723 	cv_wait(&sc->sc_cv, &sc->sc_mtx);
724 
725 done:
726 	reg = sc->sc_cur_val;
727 
728 	mutex_exit(&sc->sc_mtx);
729 	acpiec_unlock(dv);
730 
731 	if (reg == 0)
732 		goto loop; /* Spurious query result */
733 
734 	/*
735 	 * Evaluate _Qxx to respond to the controller.
736 	 */
737 	snprintf(qxx, sizeof(qxx), "_Q%02X", (unsigned int)reg);
738 	rv = AcpiEvaluateObject(sc->sc_ech, qxx, NULL, NULL);
739 	if (rv != AE_OK && rv != AE_NOT_FOUND) {
740 		aprint_error("%s: GPE query method %s failed: %s",
741 		    device_xname(dv), qxx, AcpiFormatException(rv));
742 	}
743 
744 	goto loop;
745 }
746 
747 static void
748 acpiec_gpe_state_machine(device_t dv)
749 {
750 	struct acpiec_softc *sc = device_private(dv);
751 	uint8_t reg;
752 
753 	reg = acpiec_read_status(sc);
754 
755 	if (reg & EC_STATUS_SCI)
756 		sc->sc_got_sci = true;
757 
758 	switch (sc->sc_state) {
759 	case EC_STATE_QUERY:
760 		if ((reg & EC_STATUS_IBF) != 0)
761 			break; /* Nothing of interest here. */
762 		acpiec_write_command(sc, EC_COMMAND_QUERY);
763 		sc->sc_state = EC_STATE_QUERY_VAL;
764 		break;
765 
766 	case EC_STATE_QUERY_VAL:
767 		if ((reg & EC_STATUS_OBF) == 0)
768 			break; /* Nothing of interest here. */
769 
770 		sc->sc_cur_val = acpiec_read_data(sc);
771 		sc->sc_state = EC_STATE_FREE;
772 
773 		cv_signal(&sc->sc_cv);
774 		break;
775 
776 	case EC_STATE_READ:
777 		if ((reg & EC_STATUS_IBF) != 0)
778 			break; /* Nothing of interest here. */
779 
780 		acpiec_write_command(sc, EC_COMMAND_READ);
781 		sc->sc_state = EC_STATE_READ_ADDR;
782 		break;
783 
784 	case EC_STATE_READ_ADDR:
785 		if ((reg & EC_STATUS_IBF) != 0)
786 			break; /* Nothing of interest here. */
787 
788 		acpiec_write_data(sc, sc->sc_cur_addr);
789 		sc->sc_state = EC_STATE_READ_VAL;
790 		break;
791 
792 	case EC_STATE_READ_VAL:
793 		if ((reg & EC_STATUS_OBF) == 0)
794 			break; /* Nothing of interest here. */
795 		sc->sc_cur_val = acpiec_read_data(sc);
796 		sc->sc_state = EC_STATE_FREE;
797 
798 		cv_signal(&sc->sc_cv);
799 		break;
800 
801 	case EC_STATE_WRITE:
802 		if ((reg & EC_STATUS_IBF) != 0)
803 			break; /* Nothing of interest here. */
804 
805 		acpiec_write_command(sc, EC_COMMAND_WRITE);
806 		sc->sc_state = EC_STATE_WRITE_ADDR;
807 		break;
808 
809 	case EC_STATE_WRITE_ADDR:
810 		if ((reg & EC_STATUS_IBF) != 0)
811 			break; /* Nothing of interest here. */
812 		acpiec_write_data(sc, sc->sc_cur_addr);
813 		sc->sc_state = EC_STATE_WRITE_VAL;
814 		break;
815 
816 	case EC_STATE_WRITE_VAL:
817 		if ((reg & EC_STATUS_IBF) != 0)
818 			break; /* Nothing of interest here. */
819 		sc->sc_state = EC_STATE_FREE;
820 		cv_signal(&sc->sc_cv);
821 
822 		acpiec_write_data(sc, sc->sc_cur_val);
823 		break;
824 
825 	case EC_STATE_FREE:
826 		if (sc->sc_got_sci)
827 			cv_signal(&sc->sc_cv_sci);
828 		break;
829 	default:
830 		panic("invalid state");
831 	}
832 
833 	if (sc->sc_state != EC_STATE_FREE)
834 		callout_schedule(&sc->sc_pseudo_intr, 1);
835 }
836 
837 static void
838 acpiec_callout(void *arg)
839 {
840 	device_t dv = arg;
841 	struct acpiec_softc *sc = device_private(dv);
842 
843 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
844 
845 	mutex_enter(&sc->sc_mtx);
846 	acpiec_gpe_state_machine(dv);
847 	mutex_exit(&sc->sc_mtx);
848 }
849 
850 static UINT32
851 acpiec_gpe_handler(void *arg)
852 {
853 	device_t dv = arg;
854 	struct acpiec_softc *sc = device_private(dv);
855 
856 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
857 
858 	mutex_enter(&sc->sc_mtx);
859 	acpiec_gpe_state_machine(dv);
860 	mutex_exit(&sc->sc_mtx);
861 
862 	return 0;
863 }
864 
865 ACPI_STATUS
866 acpiec_bus_read(device_t dv, u_int addr, ACPI_INTEGER *val, int width)
867 {
868 	return acpiec_space_handler(ACPI_READ, addr, width * 8, val, dv, NULL);
869 }
870 
871 ACPI_STATUS
872 acpiec_bus_write(device_t dv, u_int addr, ACPI_INTEGER val, int width)
873 {
874 	return acpiec_space_handler(ACPI_WRITE, addr, width * 8, &val, dv, NULL);
875 }
876 
877 ACPI_HANDLE
878 acpiec_get_handle(device_t dv)
879 {
880 	struct acpiec_softc *sc = device_private(dv);
881 
882 	return sc->sc_ech;
883 }
884