xref: /netbsd-src/sys/dev/acpi/acpi_ec.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: acpi_ec.c,v 1.74 2014/12/08 16:16:45 msaitoh 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 1.74 2014/12/08 16:16:45 msaitoh 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(ACPI_HANDLE, uint32_t, 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 		goto fail0;
269 	}
270 	aprint_naive("\n");
271 	aprint_normal("\n");
272 
273 	if (!acpiec_parse_gpe_package(self, aa->aa_node->ad_handle,
274 				      &gpe_handle, &gpebit))
275 		goto fail0;
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 		goto fail0;
283 	}
284 
285 	if ((io0 = acpi_res_io(&ec_res, 0)) == NULL) {
286 		aprint_error_dev(self, "no data register resource\n");
287 		goto fail1;
288 	}
289 	if ((io1 = acpi_res_io(&ec_res, 1)) == NULL) {
290 		aprint_error_dev(self, "no CSR register resource\n");
291 		goto fail1;
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 	acpi_resource_cleanup(&ec_res);
299 	return;
300 
301 fail1:	acpi_resource_cleanup(&ec_res);
302 fail0:	if (!pmf_device_register(self, NULL, NULL))
303 		aprint_error_dev(self, "couldn't establish power handler\n");
304 }
305 
306 static void
307 acpiec_common_attach(device_t parent, device_t self,
308     ACPI_HANDLE ec_handle, bus_space_tag_t cmdt, bus_addr_t cmd_reg,
309     bus_space_tag_t datat, bus_addr_t data_reg,
310     ACPI_HANDLE gpe_handle, uint8_t gpebit)
311 {
312 	struct acpiec_softc *sc = device_private(self);
313 	ACPI_STATUS rv;
314 	ACPI_INTEGER val;
315 
316 	sc->sc_csr_st = cmdt;
317 	sc->sc_data_st = datat;
318 
319 	sc->sc_ech = ec_handle;
320 	sc->sc_gpeh = gpe_handle;
321 	sc->sc_gpebit = gpebit;
322 
323 	sc->sc_state = EC_STATE_FREE;
324 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
325 	mutex_init(&sc->sc_access_mtx, MUTEX_DEFAULT, IPL_NONE);
326 	cv_init(&sc->sc_cv, "eccv");
327 	cv_init(&sc->sc_cv_sci, "ecsci");
328 
329 	if (bus_space_map(sc->sc_data_st, data_reg, 1, 0,
330 	    &sc->sc_data_sh) != 0) {
331 		aprint_error_dev(self, "unable to map data register\n");
332 		return;
333 	}
334 
335 	if (bus_space_map(sc->sc_csr_st, cmd_reg, 1, 0, &sc->sc_csr_sh) != 0) {
336 		aprint_error_dev(self, "unable to map CSR register\n");
337 		goto post_data_map;
338 	}
339 
340 	rv = acpi_eval_integer(sc->sc_ech, "_GLK", &val);
341 	if (rv == AE_OK) {
342 		sc->sc_need_global_lock = val != 0;
343 	} else if (rv != AE_NOT_FOUND) {
344 		aprint_error_dev(self, "unable to evaluate _GLK: %s\n",
345 		    AcpiFormatException(rv));
346 		goto post_csr_map;
347 	} else {
348 		sc->sc_need_global_lock = false;
349 	}
350 	if (sc->sc_need_global_lock)
351 		aprint_normal_dev(self, "using global ACPI lock\n");
352 
353 	callout_init(&sc->sc_pseudo_intr, CALLOUT_MPSAFE);
354 	callout_setfunc(&sc->sc_pseudo_intr, acpiec_callout, self);
355 
356 	rv = AcpiInstallAddressSpaceHandler(sc->sc_ech, ACPI_ADR_SPACE_EC,
357 	    acpiec_space_handler, acpiec_space_setup, self);
358 	if (rv != AE_OK) {
359 		aprint_error_dev(self,
360 		    "unable to install address space handler: %s\n",
361 		    AcpiFormatException(rv));
362 		goto post_csr_map;
363 	}
364 
365 	rv = AcpiInstallGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
366 	    ACPI_GPE_EDGE_TRIGGERED, acpiec_gpe_handler, self);
367 	if (rv != AE_OK) {
368 		aprint_error_dev(self, "unable to install GPE handler: %s\n",
369 		    AcpiFormatException(rv));
370 		goto post_csr_map;
371 	}
372 
373 	rv = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit);
374 	if (rv != AE_OK) {
375 		aprint_error_dev(self, "unable to enable GPE: %s\n",
376 		    AcpiFormatException(rv));
377 		goto post_csr_map;
378 	}
379 
380 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, acpiec_gpe_query,
381 		           self, NULL, "acpiec sci thread")) {
382 		aprint_error_dev(self, "unable to create query kthread\n");
383 		goto post_csr_map;
384 	}
385 
386 	ec_singleton = self;
387 
388 	if (!pmf_device_register1(self, acpiec_suspend, acpiec_resume,
389 	    acpiec_shutdown))
390 		aprint_error_dev(self, "couldn't establish power handler\n");
391 
392 	return;
393 
394 post_csr_map:
395 	(void)AcpiRemoveGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
396 	    acpiec_gpe_handler);
397 	(void)AcpiRemoveAddressSpaceHandler(sc->sc_ech,
398 	    ACPI_ADR_SPACE_EC, acpiec_space_handler);
399 	bus_space_unmap(sc->sc_csr_st, sc->sc_csr_sh, 1);
400 post_data_map:
401 	bus_space_unmap(sc->sc_data_st, sc->sc_data_sh, 1);
402 	if (!pmf_device_register(self, NULL, NULL))
403 		aprint_error_dev(self, "couldn't establish power handler\n");
404 }
405 
406 static bool
407 acpiec_suspend(device_t dv, const pmf_qual_t *qual)
408 {
409 	acpiec_cold = true;
410 
411 	return true;
412 }
413 
414 static bool
415 acpiec_resume(device_t dv, const pmf_qual_t *qual)
416 {
417 	acpiec_cold = false;
418 
419 	return true;
420 }
421 
422 static bool
423 acpiec_shutdown(device_t dv, int how)
424 {
425 
426 	acpiec_cold = true;
427 	return true;
428 }
429 
430 static bool
431 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
432     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
433 {
434 	ACPI_BUFFER buf;
435 	ACPI_OBJECT *p, *c;
436 	ACPI_STATUS rv;
437 
438 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
439 	if (rv != AE_OK) {
440 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
441 		    AcpiFormatException(rv));
442 		return false;
443 	}
444 
445 	p = buf.Pointer;
446 
447 	if (p->Type == ACPI_TYPE_INTEGER) {
448 		*gpe_handle = NULL;
449 		*gpebit = p->Integer.Value;
450 		ACPI_FREE(p);
451 		return true;
452 	}
453 
454 	if (p->Type != ACPI_TYPE_PACKAGE) {
455 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
456 		ACPI_FREE(p);
457 		return false;
458 	}
459 
460 	if (p->Package.Count != 2) {
461 		aprint_error_dev(self, "_GPE package does not contain 2 elements\n");
462 		ACPI_FREE(p);
463 		return false;
464 	}
465 
466 	c = &p->Package.Elements[0];
467 	rv = acpi_eval_reference_handle(c, gpe_handle);
468 
469 	if (ACPI_FAILURE(rv)) {
470 		aprint_error_dev(self, "failed to evaluate _GPE handle\n");
471 		ACPI_FREE(p);
472 		return false;
473 	}
474 
475 	c = &p->Package.Elements[1];
476 
477 	if (c->Type != ACPI_TYPE_INTEGER) {
478 		aprint_error_dev(self,
479 		    "_GPE package needs integer as 2nd field\n");
480 		ACPI_FREE(p);
481 		return false;
482 	}
483 	*gpebit = c->Integer.Value;
484 	ACPI_FREE(p);
485 	return true;
486 }
487 
488 static uint8_t
489 acpiec_read_data(struct acpiec_softc *sc)
490 {
491 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
492 }
493 
494 static void
495 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
496 {
497 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
498 }
499 
500 static uint8_t
501 acpiec_read_status(struct acpiec_softc *sc)
502 {
503 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
504 }
505 
506 static void
507 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
508 {
509 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
510 }
511 
512 static ACPI_STATUS
513 acpiec_space_setup(ACPI_HANDLE region, uint32_t func, void *arg,
514     void **region_arg)
515 {
516 	if (func == ACPI_REGION_DEACTIVATE)
517 		*region_arg = NULL;
518 	else
519 		*region_arg = arg;
520 
521 	return AE_OK;
522 }
523 
524 static void
525 acpiec_lock(device_t dv)
526 {
527 	struct acpiec_softc *sc = device_private(dv);
528 	ACPI_STATUS rv;
529 
530 	mutex_enter(&sc->sc_access_mtx);
531 
532 	if (sc->sc_need_global_lock) {
533 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->sc_global_lock);
534 		if (rv != AE_OK) {
535 			aprint_error_dev(dv, "failed to acquire global lock: %s\n",
536 			    AcpiFormatException(rv));
537 			return;
538 		}
539 	}
540 }
541 
542 static void
543 acpiec_unlock(device_t dv)
544 {
545 	struct acpiec_softc *sc = device_private(dv);
546 	ACPI_STATUS rv;
547 
548 	if (sc->sc_need_global_lock) {
549 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
550 		if (rv != AE_OK) {
551 			aprint_error_dev(dv, "failed to release global lock: %s\n",
552 			    AcpiFormatException(rv));
553 		}
554 	}
555 	mutex_exit(&sc->sc_access_mtx);
556 }
557 
558 static ACPI_STATUS
559 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
560 {
561 	struct acpiec_softc *sc = device_private(dv);
562 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
563 
564 	acpiec_lock(dv);
565 	mutex_enter(&sc->sc_mtx);
566 
567 	sc->sc_cur_addr = addr;
568 	sc->sc_state = EC_STATE_READ;
569 
570 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
571 		acpiec_gpe_state_machine(dv);
572 		if (sc->sc_state == EC_STATE_FREE)
573 			goto done;
574 		delay(1);
575 	}
576 
577 	if (cold || acpiec_cold) {
578 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
579 			delay(1000);
580 			acpiec_gpe_state_machine(dv);
581 		}
582 		if (sc->sc_state != EC_STATE_FREE) {
583 			mutex_exit(&sc->sc_mtx);
584 			acpiec_unlock(dv);
585 			aprint_error_dev(dv, "command timed out, state %d\n",
586 			    sc->sc_state);
587 			return AE_ERROR;
588 		}
589 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
590 		mutex_exit(&sc->sc_mtx);
591 		acpiec_unlock(dv);
592 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
593 		return AE_ERROR;
594 	}
595 
596 done:
597 	*val = sc->sc_cur_val;
598 
599 	mutex_exit(&sc->sc_mtx);
600 	acpiec_unlock(dv);
601 	return AE_OK;
602 }
603 
604 static ACPI_STATUS
605 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
606 {
607 	struct acpiec_softc *sc = device_private(dv);
608 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
609 
610 	acpiec_lock(dv);
611 	mutex_enter(&sc->sc_mtx);
612 
613 	sc->sc_cur_addr = addr;
614 	sc->sc_cur_val = val;
615 	sc->sc_state = EC_STATE_WRITE;
616 
617 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
618 		acpiec_gpe_state_machine(dv);
619 		if (sc->sc_state == EC_STATE_FREE)
620 			goto done;
621 		delay(1);
622 	}
623 
624 	if (cold || acpiec_cold) {
625 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
626 			delay(1000);
627 			acpiec_gpe_state_machine(dv);
628 		}
629 		if (sc->sc_state != EC_STATE_FREE) {
630 			mutex_exit(&sc->sc_mtx);
631 			acpiec_unlock(dv);
632 			aprint_error_dev(dv, "command timed out, state %d\n",
633 			    sc->sc_state);
634 			return AE_ERROR;
635 		}
636 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
637 		mutex_exit(&sc->sc_mtx);
638 		acpiec_unlock(dv);
639 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
640 		return AE_ERROR;
641 	}
642 
643 done:
644 	mutex_exit(&sc->sc_mtx);
645 	acpiec_unlock(dv);
646 	return AE_OK;
647 }
648 
649 static ACPI_STATUS
650 acpiec_space_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS paddr,
651     uint32_t width, ACPI_INTEGER *value, void *arg, void *region_arg)
652 {
653 	device_t dv;
654 	ACPI_STATUS rv;
655 	uint8_t addr, reg;
656 	unsigned int i;
657 
658 	if (paddr > 0xff || width % 8 != 0 || value == NULL || arg == NULL ||
659 	    paddr + width / 8 > 0x100)
660 		return AE_BAD_PARAMETER;
661 
662 	addr = paddr;
663 	dv = arg;
664 
665 	rv = AE_OK;
666 
667 	switch (func) {
668 	case ACPI_READ:
669 		*value = 0;
670 		for (i = 0; i < width; i += 8, ++addr) {
671 			rv = acpiec_read(dv, addr, &reg);
672 			if (rv != AE_OK)
673 				break;
674 			*value |= (ACPI_INTEGER)reg << i;
675 		}
676 		break;
677 	case ACPI_WRITE:
678 		for (i = 0; i < width; i += 8, ++addr) {
679 			reg = (*value >>i) & 0xff;
680 			rv = acpiec_write(dv, addr, reg);
681 			if (rv != AE_OK)
682 				break;
683 		}
684 		break;
685 	default:
686 		aprint_error("%s: invalid Address Space function called: %x\n",
687 		    device_xname(dv), (unsigned int)func);
688 		return AE_BAD_PARAMETER;
689 	}
690 
691 	return rv;
692 }
693 
694 static void
695 acpiec_gpe_query(void *arg)
696 {
697 	device_t dv = arg;
698 	struct acpiec_softc *sc = device_private(dv);
699 	uint8_t reg;
700 	char qxx[5];
701 	ACPI_STATUS rv;
702 	int i;
703 
704 loop:
705 	mutex_enter(&sc->sc_mtx);
706 
707 	if (sc->sc_got_sci == false)
708 		cv_wait(&sc->sc_cv_sci, &sc->sc_mtx);
709 	mutex_exit(&sc->sc_mtx);
710 
711 	acpiec_lock(dv);
712 	mutex_enter(&sc->sc_mtx);
713 
714 	/* The Query command can always be issued, so be defensive here. */
715 	sc->sc_got_sci = false;
716 	sc->sc_state = EC_STATE_QUERY;
717 
718 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
719 		acpiec_gpe_state_machine(dv);
720 		if (sc->sc_state == EC_STATE_FREE)
721 			goto done;
722 		delay(1);
723 	}
724 
725 	cv_wait(&sc->sc_cv, &sc->sc_mtx);
726 
727 done:
728 	reg = sc->sc_cur_val;
729 
730 	mutex_exit(&sc->sc_mtx);
731 	acpiec_unlock(dv);
732 
733 	if (reg == 0)
734 		goto loop; /* Spurious query result */
735 
736 	/*
737 	 * Evaluate _Qxx to respond to the controller.
738 	 */
739 	snprintf(qxx, sizeof(qxx), "_Q%02X", (unsigned int)reg);
740 	rv = AcpiEvaluateObject(sc->sc_ech, qxx, NULL, NULL);
741 	if (rv != AE_OK && rv != AE_NOT_FOUND) {
742 		aprint_error_dev(dv, "GPE query method %s failed: %s",
743 		    qxx, AcpiFormatException(rv));
744 	}
745 
746 	goto loop;
747 }
748 
749 static void
750 acpiec_gpe_state_machine(device_t dv)
751 {
752 	struct acpiec_softc *sc = device_private(dv);
753 	uint8_t reg;
754 
755 	reg = acpiec_read_status(sc);
756 
757 	if (reg & EC_STATUS_SCI)
758 		sc->sc_got_sci = true;
759 
760 	switch (sc->sc_state) {
761 	case EC_STATE_QUERY:
762 		if ((reg & EC_STATUS_IBF) != 0)
763 			break; /* Nothing of interest here. */
764 		acpiec_write_command(sc, EC_COMMAND_QUERY);
765 		sc->sc_state = EC_STATE_QUERY_VAL;
766 		break;
767 
768 	case EC_STATE_QUERY_VAL:
769 		if ((reg & EC_STATUS_OBF) == 0)
770 			break; /* Nothing of interest here. */
771 
772 		sc->sc_cur_val = acpiec_read_data(sc);
773 		sc->sc_state = EC_STATE_FREE;
774 
775 		cv_signal(&sc->sc_cv);
776 		break;
777 
778 	case EC_STATE_READ:
779 		if ((reg & EC_STATUS_IBF) != 0)
780 			break; /* Nothing of interest here. */
781 
782 		acpiec_write_command(sc, EC_COMMAND_READ);
783 		sc->sc_state = EC_STATE_READ_ADDR;
784 		break;
785 
786 	case EC_STATE_READ_ADDR:
787 		if ((reg & EC_STATUS_IBF) != 0)
788 			break; /* Nothing of interest here. */
789 
790 		acpiec_write_data(sc, sc->sc_cur_addr);
791 		sc->sc_state = EC_STATE_READ_VAL;
792 		break;
793 
794 	case EC_STATE_READ_VAL:
795 		if ((reg & EC_STATUS_OBF) == 0)
796 			break; /* Nothing of interest here. */
797 		sc->sc_cur_val = acpiec_read_data(sc);
798 		sc->sc_state = EC_STATE_FREE;
799 
800 		cv_signal(&sc->sc_cv);
801 		break;
802 
803 	case EC_STATE_WRITE:
804 		if ((reg & EC_STATUS_IBF) != 0)
805 			break; /* Nothing of interest here. */
806 
807 		acpiec_write_command(sc, EC_COMMAND_WRITE);
808 		sc->sc_state = EC_STATE_WRITE_ADDR;
809 		break;
810 
811 	case EC_STATE_WRITE_ADDR:
812 		if ((reg & EC_STATUS_IBF) != 0)
813 			break; /* Nothing of interest here. */
814 		acpiec_write_data(sc, sc->sc_cur_addr);
815 		sc->sc_state = EC_STATE_WRITE_VAL;
816 		break;
817 
818 	case EC_STATE_WRITE_VAL:
819 		if ((reg & EC_STATUS_IBF) != 0)
820 			break; /* Nothing of interest here. */
821 		sc->sc_state = EC_STATE_FREE;
822 		cv_signal(&sc->sc_cv);
823 
824 		acpiec_write_data(sc, sc->sc_cur_val);
825 		break;
826 
827 	case EC_STATE_FREE:
828 		if (sc->sc_got_sci)
829 			cv_signal(&sc->sc_cv_sci);
830 		break;
831 	default:
832 		panic("invalid state");
833 	}
834 
835 	if (sc->sc_state != EC_STATE_FREE)
836 		callout_schedule(&sc->sc_pseudo_intr, 1);
837 }
838 
839 static void
840 acpiec_callout(void *arg)
841 {
842 	device_t dv = arg;
843 	struct acpiec_softc *sc = device_private(dv);
844 
845 	mutex_enter(&sc->sc_mtx);
846 	acpiec_gpe_state_machine(dv);
847 	mutex_exit(&sc->sc_mtx);
848 }
849 
850 static uint32_t
851 acpiec_gpe_handler(ACPI_HANDLE hdl, uint32_t gpebit, void *arg)
852 {
853 	device_t dv = arg;
854 	struct acpiec_softc *sc = device_private(dv);
855 
856 	mutex_enter(&sc->sc_mtx);
857 	acpiec_gpe_state_machine(dv);
858 	mutex_exit(&sc->sc_mtx);
859 
860 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
861 }
862 
863 ACPI_STATUS
864 acpiec_bus_read(device_t dv, u_int addr, ACPI_INTEGER *val, int width)
865 {
866 	return acpiec_space_handler(ACPI_READ, addr, width * 8, val, dv, NULL);
867 }
868 
869 ACPI_STATUS
870 acpiec_bus_write(device_t dv, u_int addr, ACPI_INTEGER val, int width)
871 {
872 	return acpiec_space_handler(ACPI_WRITE, addr, width * 8, &val, dv, NULL);
873 }
874 
875 ACPI_HANDLE
876 acpiec_get_handle(device_t dv)
877 {
878 	struct acpiec_softc *sc = device_private(dv);
879 
880 	return sc->sc_ech;
881 }
882