xref: /netbsd-src/sys/dev/acpi/acpi_ec.c (revision bbde328be4e75ea9ad02e9715ea13ca54b797ada)
1 /*	$NetBSD: acpi_ec.c,v 1.65 2010/04/14 19:27:28 jruoho 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 1.65 2010/04/14 19:27:28 jruoho Exp $");
63 
64 #include <sys/param.h>
65 #include <sys/callout.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 #include <sys/systm.h>
72 
73 #include <dev/acpi/acpireg.h>
74 #include <dev/acpi/acpivar.h>
75 #include <dev/acpi/acpi_ecvar.h>
76 
77 #define _COMPONENT          ACPI_EC_COMPONENT
78 ACPI_MODULE_NAME            ("acpi_ec")
79 
80 /* Maximum time to wait for global ACPI lock in ms */
81 #define	EC_LOCK_TIMEOUT		5
82 
83 /* Maximum time to poll for completion of a command  in ms */
84 #define	EC_POLL_TIMEOUT		5
85 
86 /* Maximum time to give a single EC command in s */
87 #define EC_CMD_TIMEOUT		10
88 
89 /* From ACPI 3.0b, chapter 12.3 */
90 #define EC_COMMAND_READ		0x80
91 #define	EC_COMMAND_WRITE	0x81
92 #define	EC_COMMAND_BURST_EN	0x82
93 #define	EC_COMMAND_BURST_DIS	0x83
94 #define	EC_COMMAND_QUERY	0x84
95 
96 /* From ACPI 3.0b, chapter 12.2.1 */
97 #define	EC_STATUS_OBF		0x01
98 #define	EC_STATUS_IBF		0x02
99 #define	EC_STATUS_CMD		0x08
100 #define	EC_STATUS_BURST		0x10
101 #define	EC_STATUS_SCI		0x20
102 #define	EC_STATUS_SMI		0x40
103 
104 static const char *ec_hid[] = {
105 	"PNP0C09",
106 	NULL,
107 };
108 
109 enum ec_state_t {
110 	EC_STATE_QUERY,
111 	EC_STATE_QUERY_VAL,
112 	EC_STATE_READ,
113 	EC_STATE_READ_ADDR,
114 	EC_STATE_READ_VAL,
115 	EC_STATE_WRITE,
116 	EC_STATE_WRITE_ADDR,
117 	EC_STATE_WRITE_VAL,
118 	EC_STATE_FREE
119 };
120 
121 struct acpiec_softc {
122 	ACPI_HANDLE sc_ech;
123 
124 	ACPI_HANDLE sc_gpeh;
125 	uint8_t sc_gpebit;
126 
127 	bus_space_tag_t sc_data_st;
128 	bus_space_handle_t sc_data_sh;
129 
130 	bus_space_tag_t sc_csr_st;
131 	bus_space_handle_t sc_csr_sh;
132 
133 	bool sc_need_global_lock;
134 	uint32_t sc_global_lock;
135 
136 	kmutex_t sc_mtx, sc_access_mtx;
137 	kcondvar_t sc_cv, sc_cv_sci;
138 	enum ec_state_t sc_state;
139 	bool sc_got_sci;
140 	callout_t sc_pseudo_intr;
141 
142 	uint8_t sc_cur_addr, sc_cur_val;
143 };
144 
145 static int acpiecdt_match(device_t, cfdata_t, void *);
146 static void acpiecdt_attach(device_t, device_t, void *);
147 
148 static int acpiec_match(device_t, cfdata_t, void *);
149 static void acpiec_attach(device_t, device_t, void *);
150 
151 static void acpiec_common_attach(device_t, device_t, ACPI_HANDLE,
152     bus_space_tag_t, bus_addr_t, bus_space_tag_t, bus_addr_t,
153     ACPI_HANDLE, uint8_t);
154 
155 static bool acpiec_suspend(device_t, const pmf_qual_t *);
156 static bool acpiec_resume(device_t, const 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_t acpiec_gpe_handler(void *);
165 static ACPI_STATUS acpiec_space_setup(ACPI_HANDLE, uint32_t, void *, void **);
166 static ACPI_STATUS acpiec_space_handler(uint32_t, ACPI_PHYSICAL_ADDRESS,
167     uint32_t, 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 (%u/%u)\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 	struct acpibus_attach_args *aa = aux;
230 	ACPI_HANDLE ec_handle;
231 	bus_addr_t cmd_reg, data_reg;
232 	uint8_t gpebit;
233 
234 	if (!acpiecdt_find(parent, &ec_handle, &cmd_reg, &data_reg, &gpebit))
235 		panic("ECDT disappeared");
236 
237 	aprint_naive("\n");
238 	aprint_normal(": ACPI Embedded Controller via ECDT\n");
239 
240 	acpiec_common_attach(parent, self, ec_handle, aa->aa_iot, cmd_reg,
241 	    aa->aa_iot, data_reg, NULL, gpebit);
242 }
243 
244 static int
245 acpiec_match(device_t parent, cfdata_t match, void *aux)
246 {
247 	struct acpi_attach_args *aa = aux;
248 
249 	if (aa->aa_node->ad_type != ACPI_TYPE_DEVICE)
250 		return 0;
251 
252 	return acpi_match_hid(aa->aa_node->ad_devinfo, ec_hid);
253 }
254 
255 static void
256 acpiec_attach(device_t parent, device_t self, void *aux)
257 {
258 	struct acpi_attach_args *aa = aux;
259 	struct acpi_resources ec_res;
260 	struct acpi_io *io0, *io1;
261 	ACPI_HANDLE gpe_handle;
262 	uint8_t gpebit;
263 	ACPI_STATUS rv;
264 
265 	if (ec_singleton != NULL) {
266 		aprint_naive(": using %s\n", device_xname(ec_singleton));
267 		aprint_normal(": using %s\n", device_xname(ec_singleton));
268 		if (!pmf_device_register(self, NULL, NULL))
269 			aprint_error_dev(self, "couldn't establish power handler\n");
270 		return;
271 	}
272 
273 	if (!acpiec_parse_gpe_package(self, aa->aa_node->ad_handle,
274 				      &gpe_handle, &gpebit))
275 		return;
276 
277 	rv = acpi_resource_parse(self, aa->aa_node->ad_handle, "_CRS",
278 	    &ec_res, &acpi_resource_parse_ops_default);
279 	if (rv != AE_OK) {
280 		aprint_error_dev(self, "resource parsing failed: %s\n",
281 		    AcpiFormatException(rv));
282 		return;
283 	}
284 
285 	if ((io0 = acpi_res_io(&ec_res, 0)) == NULL) {
286 		aprint_error_dev(self, "no data register resource\n");
287 		goto free_res;
288 	}
289 	if ((io1 = acpi_res_io(&ec_res, 1)) == NULL) {
290 		aprint_error_dev(self, "no CSR register resource\n");
291 		goto free_res;
292 	}
293 
294 	acpiec_common_attach(parent, self, aa->aa_node->ad_handle,
295 	    aa->aa_iot, io1->ar_base, aa->aa_iot, io0->ar_base,
296 	    gpe_handle, gpebit);
297 
298 free_res:
299 	acpi_resource_cleanup(&ec_res);
300 }
301 
302 static void
303 acpiec_common_attach(device_t parent, device_t self,
304     ACPI_HANDLE ec_handle, bus_space_tag_t cmdt, bus_addr_t cmd_reg,
305     bus_space_tag_t datat, bus_addr_t data_reg,
306     ACPI_HANDLE gpe_handle, uint8_t gpebit)
307 {
308 	struct acpiec_softc *sc = device_private(self);
309 	ACPI_STATUS rv;
310 	ACPI_INTEGER val;
311 
312 	sc->sc_csr_st = cmdt;
313 	sc->sc_data_st = datat;
314 
315 	sc->sc_ech = ec_handle;
316 	sc->sc_gpeh = gpe_handle;
317 	sc->sc_gpebit = gpebit;
318 
319 	sc->sc_state = EC_STATE_FREE;
320 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
321 	mutex_init(&sc->sc_access_mtx, MUTEX_DEFAULT, IPL_NONE);
322 	cv_init(&sc->sc_cv, "eccv");
323 	cv_init(&sc->sc_cv_sci, "ecsci");
324 
325 	if (bus_space_map(sc->sc_data_st, data_reg, 1, 0,
326 	    &sc->sc_data_sh) != 0) {
327 		aprint_error_dev(self, "unable to map data register\n");
328 		return;
329 	}
330 
331 	if (bus_space_map(sc->sc_csr_st, cmd_reg, 1, 0, &sc->sc_csr_sh) != 0) {
332 		aprint_error_dev(self, "unable to map CSR register\n");
333 		goto post_data_map;
334 	}
335 
336 	rv = acpi_eval_integer(sc->sc_ech, "_GLK", &val);
337 	if (rv == AE_OK) {
338 		sc->sc_need_global_lock = val != 0;
339 	} else if (rv != AE_NOT_FOUND) {
340 		aprint_error_dev(self, "unable to evaluate _GLK: %s\n",
341 		    AcpiFormatException(rv));
342 		goto post_csr_map;
343 	} else {
344 		sc->sc_need_global_lock = false;
345 	}
346 	if (sc->sc_need_global_lock)
347 		aprint_normal_dev(self, "using global ACPI lock\n");
348 
349 	callout_init(&sc->sc_pseudo_intr, CALLOUT_MPSAFE);
350 	callout_setfunc(&sc->sc_pseudo_intr, acpiec_callout, self);
351 
352 	rv = AcpiInstallAddressSpaceHandler(sc->sc_ech, ACPI_ADR_SPACE_EC,
353 	    acpiec_space_handler, acpiec_space_setup, self);
354 	if (rv != AE_OK) {
355 		aprint_error_dev(self,
356 		    "unable to install address space handler: %s\n",
357 		    AcpiFormatException(rv));
358 		goto post_csr_map;
359 	}
360 
361 	rv = AcpiInstallGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
362 	    ACPI_GPE_EDGE_TRIGGERED, acpiec_gpe_handler, self);
363 	if (rv != AE_OK) {
364 		aprint_error_dev(self, "unable to install GPE handler: %s\n",
365 		    AcpiFormatException(rv));
366 		goto post_csr_map;
367 	}
368 
369 	rv = AcpiSetGpeType(sc->sc_gpeh, sc->sc_gpebit, ACPI_GPE_TYPE_RUNTIME);
370 	if (rv != AE_OK) {
371 		aprint_error_dev(self, "unable to set GPE type: %s\n",
372 		    AcpiFormatException(rv));
373 		goto post_csr_map;
374 	}
375 
376 	rv = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
377 	if (rv != AE_OK) {
378 		aprint_error_dev(self, "unable to enable GPE: %s\n",
379 		    AcpiFormatException(rv));
380 		goto post_csr_map;
381 	}
382 
383 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, acpiec_gpe_query,
384 		           self, NULL, "acpiec sci thread")) {
385 		aprint_error_dev(self, "unable to create query kthread\n");
386 		goto post_csr_map;
387 	}
388 
389 	ec_singleton = self;
390 
391 	if (!pmf_device_register1(self, acpiec_suspend, acpiec_resume,
392 	    acpiec_shutdown))
393 		aprint_error_dev(self, "couldn't establish power handler\n");
394 
395 	return;
396 
397 post_csr_map:
398 	(void)AcpiRemoveGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
399 	    acpiec_gpe_handler);
400 	(void)AcpiRemoveAddressSpaceHandler(sc->sc_ech,
401 	    ACPI_ADR_SPACE_EC, acpiec_space_handler);
402 	bus_space_unmap(sc->sc_csr_st, sc->sc_csr_sh, 1);
403 post_data_map:
404 	bus_space_unmap(sc->sc_data_st, sc->sc_data_sh, 1);
405 }
406 
407 static bool
408 acpiec_suspend(device_t dv, const pmf_qual_t *qual)
409 {
410 	acpiec_cold = true;
411 
412 	return true;
413 }
414 
415 static bool
416 acpiec_resume(device_t dv, const pmf_qual_t *qual)
417 {
418 	acpiec_cold = false;
419 
420 	return true;
421 }
422 
423 static bool
424 acpiec_shutdown(device_t dv, int how)
425 {
426 
427 	acpiec_cold = true;
428 	return true;
429 }
430 
431 static bool
432 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
433     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
434 {
435 	ACPI_BUFFER buf;
436 	ACPI_OBJECT *p, *c;
437 	ACPI_STATUS rv;
438 
439 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
440 	if (rv != AE_OK) {
441 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
442 		    AcpiFormatException(rv));
443 		return false;
444 	}
445 
446 	p = buf.Pointer;
447 
448 	if (p->Type == ACPI_TYPE_INTEGER) {
449 		*gpe_handle = NULL;
450 		*gpebit = p->Integer.Value;
451 		ACPI_FREE(p);
452 		return true;
453 	}
454 
455 	if (p->Type != ACPI_TYPE_PACKAGE) {
456 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
457 		ACPI_FREE(p);
458 		return false;
459 	}
460 
461 	if (p->Package.Count != 2) {
462 		aprint_error_dev(self, "_GPE package does not contain 2 elements\n");
463 		ACPI_FREE(p);
464 		return false;
465 	}
466 
467 	c = &p->Package.Elements[0];
468 	rv = acpi_eval_reference_handle(c, gpe_handle);
469 
470 	if (ACPI_FAILURE(rv)) {
471 		aprint_error_dev(self, "failed to evaluate _GPE handle\n");
472 		ACPI_FREE(p);
473 		return false;
474 	}
475 
476 	c = &p->Package.Elements[1];
477 
478 	if (c->Type != ACPI_TYPE_INTEGER) {
479 		aprint_error_dev(self,
480 		    "_GPE package needs integer as 2nd field\n");
481 		ACPI_FREE(p);
482 		return false;
483 	}
484 	*gpebit = c->Integer.Value;
485 	ACPI_FREE(p);
486 	return true;
487 }
488 
489 static uint8_t
490 acpiec_read_data(struct acpiec_softc *sc)
491 {
492 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
493 }
494 
495 static void
496 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
497 {
498 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
499 }
500 
501 static uint8_t
502 acpiec_read_status(struct acpiec_softc *sc)
503 {
504 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
505 }
506 
507 static void
508 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
509 {
510 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
511 }
512 
513 static ACPI_STATUS
514 acpiec_space_setup(ACPI_HANDLE region, uint32_t func, void *arg,
515     void **region_arg)
516 {
517 	if (func == ACPI_REGION_DEACTIVATE)
518 		*region_arg = NULL;
519 	else
520 		*region_arg = arg;
521 
522 	return AE_OK;
523 }
524 
525 static void
526 acpiec_lock(device_t dv)
527 {
528 	struct acpiec_softc *sc = device_private(dv);
529 	ACPI_STATUS rv;
530 
531 	mutex_enter(&sc->sc_access_mtx);
532 
533 	if (sc->sc_need_global_lock) {
534 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->sc_global_lock);
535 		if (rv != AE_OK) {
536 			aprint_error_dev(dv, "failed to acquire global lock: %s\n",
537 			    AcpiFormatException(rv));
538 			return;
539 		}
540 	}
541 }
542 
543 static void
544 acpiec_unlock(device_t dv)
545 {
546 	struct acpiec_softc *sc = device_private(dv);
547 	ACPI_STATUS rv;
548 
549 	if (sc->sc_need_global_lock) {
550 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
551 		if (rv != AE_OK) {
552 			aprint_error_dev(dv, "failed to release global lock: %s\n",
553 			    AcpiFormatException(rv));
554 		}
555 	}
556 	mutex_exit(&sc->sc_access_mtx);
557 }
558 
559 static ACPI_STATUS
560 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
561 {
562 	struct acpiec_softc *sc = device_private(dv);
563 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
564 
565 	acpiec_lock(dv);
566 	mutex_enter(&sc->sc_mtx);
567 
568 	sc->sc_cur_addr = addr;
569 	sc->sc_state = EC_STATE_READ;
570 
571 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
572 		acpiec_gpe_state_machine(dv);
573 		if (sc->sc_state == EC_STATE_FREE)
574 			goto done;
575 		delay(1);
576 	}
577 
578 	if (cold || acpiec_cold) {
579 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
580 			delay(1000);
581 			acpiec_gpe_state_machine(dv);
582 		}
583 		if (sc->sc_state != EC_STATE_FREE) {
584 			mutex_exit(&sc->sc_mtx);
585 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
586 			acpiec_unlock(dv);
587 			aprint_error_dev(dv, "command timed out, state %d\n",
588 			    sc->sc_state);
589 			return AE_ERROR;
590 		}
591 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
592 		mutex_exit(&sc->sc_mtx);
593 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
594 		acpiec_unlock(dv);
595 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
596 		return AE_ERROR;
597 	}
598 
599 done:
600 	*val = sc->sc_cur_val;
601 
602 	mutex_exit(&sc->sc_mtx);
603 	acpiec_unlock(dv);
604 	return AE_OK;
605 }
606 
607 static ACPI_STATUS
608 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
609 {
610 	struct acpiec_softc *sc = device_private(dv);
611 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
612 
613 	acpiec_lock(dv);
614 	mutex_enter(&sc->sc_mtx);
615 
616 	sc->sc_cur_addr = addr;
617 	sc->sc_cur_val = val;
618 	sc->sc_state = EC_STATE_WRITE;
619 
620 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
621 		acpiec_gpe_state_machine(dv);
622 		if (sc->sc_state == EC_STATE_FREE)
623 			goto done;
624 		delay(1);
625 	}
626 
627 	if (cold || acpiec_cold) {
628 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
629 			delay(1000);
630 			acpiec_gpe_state_machine(dv);
631 		}
632 		if (sc->sc_state != EC_STATE_FREE) {
633 			mutex_exit(&sc->sc_mtx);
634 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
635 			acpiec_unlock(dv);
636 			aprint_error_dev(dv, "command timed out, state %d\n",
637 			    sc->sc_state);
638 			return AE_ERROR;
639 		}
640 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
641 		mutex_exit(&sc->sc_mtx);
642 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
643 		acpiec_unlock(dv);
644 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
645 		return AE_ERROR;
646 	}
647 
648 done:
649 	mutex_exit(&sc->sc_mtx);
650 	acpiec_unlock(dv);
651 	return AE_OK;
652 }
653 
654 static ACPI_STATUS
655 acpiec_space_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS paddr,
656     uint32_t width, ACPI_INTEGER *value, void *arg, void *region_arg)
657 {
658 	device_t dv;
659 	struct acpiec_softc *sc;
660 	ACPI_STATUS rv;
661 	uint8_t addr, reg;
662 	unsigned int i;
663 
664 	if (paddr > 0xff || width % 8 != 0 || value == NULL || arg == NULL ||
665 	    paddr + width / 8 > 0xff)
666 		return AE_BAD_PARAMETER;
667 
668 	addr = paddr;
669 	dv = arg;
670 	sc = device_private(dv);
671 
672 	rv = AE_OK;
673 
674 	switch (func) {
675 	case ACPI_READ:
676 		*value = 0;
677 		for (i = 0; i < width; i += 8, ++addr) {
678 			rv = acpiec_read(dv, addr, &reg);
679 			if (rv != AE_OK)
680 				break;
681 			*value |= (ACPI_INTEGER)reg << i;
682 		}
683 		break;
684 	case ACPI_WRITE:
685 		for (i = 0; i < width; i += 8, ++addr) {
686 			reg = (*value >>i) & 0xff;
687 			rv = acpiec_write(dv, addr, reg);
688 			if (rv != AE_OK)
689 				break;
690 		}
691 		break;
692 	default:
693 		aprint_error("%s: invalid Address Space function called: %x\n",
694 		    device_xname(dv), (unsigned int)func);
695 		return AE_BAD_PARAMETER;
696 	}
697 
698 	return rv;
699 }
700 
701 static void
702 acpiec_gpe_query(void *arg)
703 {
704 	device_t dv = arg;
705 	struct acpiec_softc *sc = device_private(dv);
706 	uint8_t reg;
707 	char qxx[5];
708 	ACPI_STATUS rv;
709 	int i;
710 
711 loop:
712 	mutex_enter(&sc->sc_mtx);
713 
714 	if (sc->sc_got_sci == false)
715 		cv_wait(&sc->sc_cv_sci, &sc->sc_mtx);
716 	mutex_exit(&sc->sc_mtx);
717 
718 	acpiec_lock(dv);
719 	mutex_enter(&sc->sc_mtx);
720 
721 	/* The Query command can always be issued, so be defensive here. */
722 	sc->sc_got_sci = false;
723 	sc->sc_state = EC_STATE_QUERY;
724 
725 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
726 		acpiec_gpe_state_machine(dv);
727 		if (sc->sc_state == EC_STATE_FREE)
728 			goto done;
729 		delay(1);
730 	}
731 
732 	cv_wait(&sc->sc_cv, &sc->sc_mtx);
733 
734 done:
735 	reg = sc->sc_cur_val;
736 
737 	mutex_exit(&sc->sc_mtx);
738 	acpiec_unlock(dv);
739 
740 	if (reg == 0)
741 		goto loop; /* Spurious query result */
742 
743 	/*
744 	 * Evaluate _Qxx to respond to the controller.
745 	 */
746 	snprintf(qxx, sizeof(qxx), "_Q%02X", (unsigned int)reg);
747 	rv = AcpiEvaluateObject(sc->sc_ech, qxx, NULL, NULL);
748 	if (rv != AE_OK && rv != AE_NOT_FOUND) {
749 		aprint_error("%s: GPE query method %s failed: %s",
750 		    device_xname(dv), qxx, AcpiFormatException(rv));
751 	}
752 
753 	goto loop;
754 }
755 
756 static void
757 acpiec_gpe_state_machine(device_t dv)
758 {
759 	struct acpiec_softc *sc = device_private(dv);
760 	uint8_t reg;
761 
762 	reg = acpiec_read_status(sc);
763 
764 	if (reg & EC_STATUS_SCI)
765 		sc->sc_got_sci = true;
766 
767 	switch (sc->sc_state) {
768 	case EC_STATE_QUERY:
769 		if ((reg & EC_STATUS_IBF) != 0)
770 			break; /* Nothing of interest here. */
771 		acpiec_write_command(sc, EC_COMMAND_QUERY);
772 		sc->sc_state = EC_STATE_QUERY_VAL;
773 		break;
774 
775 	case EC_STATE_QUERY_VAL:
776 		if ((reg & EC_STATUS_OBF) == 0)
777 			break; /* Nothing of interest here. */
778 
779 		sc->sc_cur_val = acpiec_read_data(sc);
780 		sc->sc_state = EC_STATE_FREE;
781 
782 		cv_signal(&sc->sc_cv);
783 		break;
784 
785 	case EC_STATE_READ:
786 		if ((reg & EC_STATUS_IBF) != 0)
787 			break; /* Nothing of interest here. */
788 
789 		acpiec_write_command(sc, EC_COMMAND_READ);
790 		sc->sc_state = EC_STATE_READ_ADDR;
791 		break;
792 
793 	case EC_STATE_READ_ADDR:
794 		if ((reg & EC_STATUS_IBF) != 0)
795 			break; /* Nothing of interest here. */
796 
797 		acpiec_write_data(sc, sc->sc_cur_addr);
798 		sc->sc_state = EC_STATE_READ_VAL;
799 		break;
800 
801 	case EC_STATE_READ_VAL:
802 		if ((reg & EC_STATUS_OBF) == 0)
803 			break; /* Nothing of interest here. */
804 		sc->sc_cur_val = acpiec_read_data(sc);
805 		sc->sc_state = EC_STATE_FREE;
806 
807 		cv_signal(&sc->sc_cv);
808 		break;
809 
810 	case EC_STATE_WRITE:
811 		if ((reg & EC_STATUS_IBF) != 0)
812 			break; /* Nothing of interest here. */
813 
814 		acpiec_write_command(sc, EC_COMMAND_WRITE);
815 		sc->sc_state = EC_STATE_WRITE_ADDR;
816 		break;
817 
818 	case EC_STATE_WRITE_ADDR:
819 		if ((reg & EC_STATUS_IBF) != 0)
820 			break; /* Nothing of interest here. */
821 		acpiec_write_data(sc, sc->sc_cur_addr);
822 		sc->sc_state = EC_STATE_WRITE_VAL;
823 		break;
824 
825 	case EC_STATE_WRITE_VAL:
826 		if ((reg & EC_STATUS_IBF) != 0)
827 			break; /* Nothing of interest here. */
828 		sc->sc_state = EC_STATE_FREE;
829 		cv_signal(&sc->sc_cv);
830 
831 		acpiec_write_data(sc, sc->sc_cur_val);
832 		break;
833 
834 	case EC_STATE_FREE:
835 		if (sc->sc_got_sci)
836 			cv_signal(&sc->sc_cv_sci);
837 		break;
838 	default:
839 		panic("invalid state");
840 	}
841 
842 	if (sc->sc_state != EC_STATE_FREE)
843 		callout_schedule(&sc->sc_pseudo_intr, 1);
844 }
845 
846 static void
847 acpiec_callout(void *arg)
848 {
849 	device_t dv = arg;
850 	struct acpiec_softc *sc = device_private(dv);
851 
852 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_NOT_ISR);
853 
854 	mutex_enter(&sc->sc_mtx);
855 	acpiec_gpe_state_machine(dv);
856 	mutex_exit(&sc->sc_mtx);
857 }
858 
859 static uint32_t
860 acpiec_gpe_handler(void *arg)
861 {
862 	device_t dv = arg;
863 	struct acpiec_softc *sc = device_private(dv);
864 
865 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_ISR);
866 
867 	mutex_enter(&sc->sc_mtx);
868 	acpiec_gpe_state_machine(dv);
869 	mutex_exit(&sc->sc_mtx);
870 
871 	return 0;
872 }
873 
874 ACPI_STATUS
875 acpiec_bus_read(device_t dv, u_int addr, ACPI_INTEGER *val, int width)
876 {
877 	return acpiec_space_handler(ACPI_READ, addr, width * 8, val, dv, NULL);
878 }
879 
880 ACPI_STATUS
881 acpiec_bus_write(device_t dv, u_int addr, ACPI_INTEGER val, int width)
882 {
883 	return acpiec_space_handler(ACPI_WRITE, addr, width * 8, &val, dv, NULL);
884 }
885 
886 ACPI_HANDLE
887 acpiec_get_handle(device_t dv)
888 {
889 	struct acpiec_softc *sc = device_private(dv);
890 
891 	return sc->sc_ech;
892 }
893