xref: /netbsd-src/sys/dev/acpi/acpi_ec.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: acpi_ec.c,v 1.75 2017/03/11 08:26:23 tsutsui 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 1.75 2017/03/11 08:26:23 tsutsui 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 
271 	if (!acpiec_parse_gpe_package(self, aa->aa_node->ad_handle,
272 				      &gpe_handle, &gpebit))
273 		goto fail0;
274 
275 	rv = acpi_resource_parse(self, aa->aa_node->ad_handle, "_CRS",
276 	    &ec_res, &acpi_resource_parse_ops_default);
277 	if (rv != AE_OK) {
278 		aprint_error_dev(self, "resource parsing failed: %s\n",
279 		    AcpiFormatException(rv));
280 		goto fail0;
281 	}
282 
283 	if ((io0 = acpi_res_io(&ec_res, 0)) == NULL) {
284 		aprint_error_dev(self, "no data register resource\n");
285 		goto fail1;
286 	}
287 	if ((io1 = acpi_res_io(&ec_res, 1)) == NULL) {
288 		aprint_error_dev(self, "no CSR register resource\n");
289 		goto fail1;
290 	}
291 
292 	acpiec_common_attach(parent, self, aa->aa_node->ad_handle,
293 	    aa->aa_iot, io1->ar_base, aa->aa_iot, io0->ar_base,
294 	    gpe_handle, gpebit);
295 
296 	acpi_resource_cleanup(&ec_res);
297 	return;
298 
299 fail1:	acpi_resource_cleanup(&ec_res);
300 fail0:	if (!pmf_device_register(self, NULL, NULL))
301 		aprint_error_dev(self, "couldn't establish power handler\n");
302 }
303 
304 static void
305 acpiec_common_attach(device_t parent, device_t self,
306     ACPI_HANDLE ec_handle, bus_space_tag_t cmdt, bus_addr_t cmd_reg,
307     bus_space_tag_t datat, bus_addr_t data_reg,
308     ACPI_HANDLE gpe_handle, uint8_t gpebit)
309 {
310 	struct acpiec_softc *sc = device_private(self);
311 	ACPI_STATUS rv;
312 	ACPI_INTEGER val;
313 
314 	sc->sc_csr_st = cmdt;
315 	sc->sc_data_st = datat;
316 
317 	sc->sc_ech = ec_handle;
318 	sc->sc_gpeh = gpe_handle;
319 	sc->sc_gpebit = gpebit;
320 
321 	sc->sc_state = EC_STATE_FREE;
322 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
323 	mutex_init(&sc->sc_access_mtx, MUTEX_DEFAULT, IPL_NONE);
324 	cv_init(&sc->sc_cv, "eccv");
325 	cv_init(&sc->sc_cv_sci, "ecsci");
326 
327 	if (bus_space_map(sc->sc_data_st, data_reg, 1, 0,
328 	    &sc->sc_data_sh) != 0) {
329 		aprint_error_dev(self, "unable to map data register\n");
330 		return;
331 	}
332 
333 	if (bus_space_map(sc->sc_csr_st, cmd_reg, 1, 0, &sc->sc_csr_sh) != 0) {
334 		aprint_error_dev(self, "unable to map CSR register\n");
335 		goto post_data_map;
336 	}
337 
338 	rv = acpi_eval_integer(sc->sc_ech, "_GLK", &val);
339 	if (rv == AE_OK) {
340 		sc->sc_need_global_lock = val != 0;
341 	} else if (rv != AE_NOT_FOUND) {
342 		aprint_error_dev(self, "unable to evaluate _GLK: %s\n",
343 		    AcpiFormatException(rv));
344 		goto post_csr_map;
345 	} else {
346 		sc->sc_need_global_lock = false;
347 	}
348 	if (sc->sc_need_global_lock)
349 		aprint_normal_dev(self, "using global ACPI lock\n");
350 
351 	callout_init(&sc->sc_pseudo_intr, CALLOUT_MPSAFE);
352 	callout_setfunc(&sc->sc_pseudo_intr, acpiec_callout, self);
353 
354 	rv = AcpiInstallAddressSpaceHandler(sc->sc_ech, ACPI_ADR_SPACE_EC,
355 	    acpiec_space_handler, acpiec_space_setup, self);
356 	if (rv != AE_OK) {
357 		aprint_error_dev(self,
358 		    "unable to install address space handler: %s\n",
359 		    AcpiFormatException(rv));
360 		goto post_csr_map;
361 	}
362 
363 	rv = AcpiInstallGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
364 	    ACPI_GPE_EDGE_TRIGGERED, acpiec_gpe_handler, self);
365 	if (rv != AE_OK) {
366 		aprint_error_dev(self, "unable to install GPE handler: %s\n",
367 		    AcpiFormatException(rv));
368 		goto post_csr_map;
369 	}
370 
371 	rv = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit);
372 	if (rv != AE_OK) {
373 		aprint_error_dev(self, "unable to enable GPE: %s\n",
374 		    AcpiFormatException(rv));
375 		goto post_csr_map;
376 	}
377 
378 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, acpiec_gpe_query,
379 		           self, NULL, "acpiec sci thread")) {
380 		aprint_error_dev(self, "unable to create query kthread\n");
381 		goto post_csr_map;
382 	}
383 
384 	ec_singleton = self;
385 
386 	if (!pmf_device_register1(self, acpiec_suspend, acpiec_resume,
387 	    acpiec_shutdown))
388 		aprint_error_dev(self, "couldn't establish power handler\n");
389 
390 	return;
391 
392 post_csr_map:
393 	(void)AcpiRemoveGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
394 	    acpiec_gpe_handler);
395 	(void)AcpiRemoveAddressSpaceHandler(sc->sc_ech,
396 	    ACPI_ADR_SPACE_EC, acpiec_space_handler);
397 	bus_space_unmap(sc->sc_csr_st, sc->sc_csr_sh, 1);
398 post_data_map:
399 	bus_space_unmap(sc->sc_data_st, sc->sc_data_sh, 1);
400 	if (!pmf_device_register(self, NULL, NULL))
401 		aprint_error_dev(self, "couldn't establish power handler\n");
402 }
403 
404 static bool
405 acpiec_suspend(device_t dv, const pmf_qual_t *qual)
406 {
407 	acpiec_cold = true;
408 
409 	return true;
410 }
411 
412 static bool
413 acpiec_resume(device_t dv, const pmf_qual_t *qual)
414 {
415 	acpiec_cold = false;
416 
417 	return true;
418 }
419 
420 static bool
421 acpiec_shutdown(device_t dv, int how)
422 {
423 
424 	acpiec_cold = true;
425 	return true;
426 }
427 
428 static bool
429 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
430     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
431 {
432 	ACPI_BUFFER buf;
433 	ACPI_OBJECT *p, *c;
434 	ACPI_STATUS rv;
435 
436 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
437 	if (rv != AE_OK) {
438 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
439 		    AcpiFormatException(rv));
440 		return false;
441 	}
442 
443 	p = buf.Pointer;
444 
445 	if (p->Type == ACPI_TYPE_INTEGER) {
446 		*gpe_handle = NULL;
447 		*gpebit = p->Integer.Value;
448 		ACPI_FREE(p);
449 		return true;
450 	}
451 
452 	if (p->Type != ACPI_TYPE_PACKAGE) {
453 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
454 		ACPI_FREE(p);
455 		return false;
456 	}
457 
458 	if (p->Package.Count != 2) {
459 		aprint_error_dev(self, "_GPE package does not contain 2 elements\n");
460 		ACPI_FREE(p);
461 		return false;
462 	}
463 
464 	c = &p->Package.Elements[0];
465 	rv = acpi_eval_reference_handle(c, gpe_handle);
466 
467 	if (ACPI_FAILURE(rv)) {
468 		aprint_error_dev(self, "failed to evaluate _GPE handle\n");
469 		ACPI_FREE(p);
470 		return false;
471 	}
472 
473 	c = &p->Package.Elements[1];
474 
475 	if (c->Type != ACPI_TYPE_INTEGER) {
476 		aprint_error_dev(self,
477 		    "_GPE package needs integer as 2nd field\n");
478 		ACPI_FREE(p);
479 		return false;
480 	}
481 	*gpebit = c->Integer.Value;
482 	ACPI_FREE(p);
483 	return true;
484 }
485 
486 static uint8_t
487 acpiec_read_data(struct acpiec_softc *sc)
488 {
489 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
490 }
491 
492 static void
493 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
494 {
495 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
496 }
497 
498 static uint8_t
499 acpiec_read_status(struct acpiec_softc *sc)
500 {
501 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
502 }
503 
504 static void
505 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
506 {
507 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
508 }
509 
510 static ACPI_STATUS
511 acpiec_space_setup(ACPI_HANDLE region, uint32_t func, void *arg,
512     void **region_arg)
513 {
514 	if (func == ACPI_REGION_DEACTIVATE)
515 		*region_arg = NULL;
516 	else
517 		*region_arg = arg;
518 
519 	return AE_OK;
520 }
521 
522 static void
523 acpiec_lock(device_t dv)
524 {
525 	struct acpiec_softc *sc = device_private(dv);
526 	ACPI_STATUS rv;
527 
528 	mutex_enter(&sc->sc_access_mtx);
529 
530 	if (sc->sc_need_global_lock) {
531 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->sc_global_lock);
532 		if (rv != AE_OK) {
533 			aprint_error_dev(dv, "failed to acquire global lock: %s\n",
534 			    AcpiFormatException(rv));
535 			return;
536 		}
537 	}
538 }
539 
540 static void
541 acpiec_unlock(device_t dv)
542 {
543 	struct acpiec_softc *sc = device_private(dv);
544 	ACPI_STATUS rv;
545 
546 	if (sc->sc_need_global_lock) {
547 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
548 		if (rv != AE_OK) {
549 			aprint_error_dev(dv, "failed to release global lock: %s\n",
550 			    AcpiFormatException(rv));
551 		}
552 	}
553 	mutex_exit(&sc->sc_access_mtx);
554 }
555 
556 static ACPI_STATUS
557 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
558 {
559 	struct acpiec_softc *sc = device_private(dv);
560 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
561 
562 	acpiec_lock(dv);
563 	mutex_enter(&sc->sc_mtx);
564 
565 	sc->sc_cur_addr = addr;
566 	sc->sc_state = EC_STATE_READ;
567 
568 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
569 		acpiec_gpe_state_machine(dv);
570 		if (sc->sc_state == EC_STATE_FREE)
571 			goto done;
572 		delay(1);
573 	}
574 
575 	if (cold || acpiec_cold) {
576 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
577 			delay(1000);
578 			acpiec_gpe_state_machine(dv);
579 		}
580 		if (sc->sc_state != EC_STATE_FREE) {
581 			mutex_exit(&sc->sc_mtx);
582 			acpiec_unlock(dv);
583 			aprint_error_dev(dv, "command timed out, state %d\n",
584 			    sc->sc_state);
585 			return AE_ERROR;
586 		}
587 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
588 		mutex_exit(&sc->sc_mtx);
589 		acpiec_unlock(dv);
590 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
591 		return AE_ERROR;
592 	}
593 
594 done:
595 	*val = sc->sc_cur_val;
596 
597 	mutex_exit(&sc->sc_mtx);
598 	acpiec_unlock(dv);
599 	return AE_OK;
600 }
601 
602 static ACPI_STATUS
603 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
604 {
605 	struct acpiec_softc *sc = device_private(dv);
606 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
607 
608 	acpiec_lock(dv);
609 	mutex_enter(&sc->sc_mtx);
610 
611 	sc->sc_cur_addr = addr;
612 	sc->sc_cur_val = val;
613 	sc->sc_state = EC_STATE_WRITE;
614 
615 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
616 		acpiec_gpe_state_machine(dv);
617 		if (sc->sc_state == EC_STATE_FREE)
618 			goto done;
619 		delay(1);
620 	}
621 
622 	if (cold || acpiec_cold) {
623 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
624 			delay(1000);
625 			acpiec_gpe_state_machine(dv);
626 		}
627 		if (sc->sc_state != EC_STATE_FREE) {
628 			mutex_exit(&sc->sc_mtx);
629 			acpiec_unlock(dv);
630 			aprint_error_dev(dv, "command timed out, state %d\n",
631 			    sc->sc_state);
632 			return AE_ERROR;
633 		}
634 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
635 		mutex_exit(&sc->sc_mtx);
636 		acpiec_unlock(dv);
637 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
638 		return AE_ERROR;
639 	}
640 
641 done:
642 	mutex_exit(&sc->sc_mtx);
643 	acpiec_unlock(dv);
644 	return AE_OK;
645 }
646 
647 static ACPI_STATUS
648 acpiec_space_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS paddr,
649     uint32_t width, ACPI_INTEGER *value, void *arg, void *region_arg)
650 {
651 	device_t dv;
652 	ACPI_STATUS rv;
653 	uint8_t addr, reg;
654 	unsigned int i;
655 
656 	if (paddr > 0xff || width % 8 != 0 || value == NULL || arg == NULL ||
657 	    paddr + width / 8 > 0x100)
658 		return AE_BAD_PARAMETER;
659 
660 	addr = paddr;
661 	dv = arg;
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_dev(dv, "GPE query method %s failed: %s",
741 		    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 	mutex_enter(&sc->sc_mtx);
844 	acpiec_gpe_state_machine(dv);
845 	mutex_exit(&sc->sc_mtx);
846 }
847 
848 static uint32_t
849 acpiec_gpe_handler(ACPI_HANDLE hdl, uint32_t gpebit, void *arg)
850 {
851 	device_t dv = arg;
852 	struct acpiec_softc *sc = device_private(dv);
853 
854 	mutex_enter(&sc->sc_mtx);
855 	acpiec_gpe_state_machine(dv);
856 	mutex_exit(&sc->sc_mtx);
857 
858 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
859 }
860 
861 ACPI_STATUS
862 acpiec_bus_read(device_t dv, u_int addr, ACPI_INTEGER *val, int width)
863 {
864 	return acpiec_space_handler(ACPI_READ, addr, width * 8, val, dv, NULL);
865 }
866 
867 ACPI_STATUS
868 acpiec_bus_write(device_t dv, u_int addr, ACPI_INTEGER val, int width)
869 {
870 	return acpiec_space_handler(ACPI_WRITE, addr, width * 8, &val, dv, NULL);
871 }
872 
873 ACPI_HANDLE
874 acpiec_get_handle(device_t dv)
875 {
876 	struct acpiec_softc *sc = device_private(dv);
877 
878 	return sc->sc_ech;
879 }
880