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acpi_ec.c revision 1.66
      1 /*	$NetBSD: acpi_ec.c,v 1.66 2010/06/06 18:40:51 jruoho Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2007 Joerg Sonnenberger <joerg (at) 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 1.66 2010/06/06 18:40:51 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 = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit, ACPI_GPE_TYPE_RUNTIME);
    370 	if (rv != AE_OK) {
    371 		aprint_error_dev(self, "unable to enable GPE: %s\n",
    372 		    AcpiFormatException(rv));
    373 		goto post_csr_map;
    374 	}
    375 
    376 	if (kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, acpiec_gpe_query,
    377 		           self, NULL, "acpiec sci thread")) {
    378 		aprint_error_dev(self, "unable to create query kthread\n");
    379 		goto post_csr_map;
    380 	}
    381 
    382 	ec_singleton = self;
    383 
    384 	if (!pmf_device_register1(self, acpiec_suspend, acpiec_resume,
    385 	    acpiec_shutdown))
    386 		aprint_error_dev(self, "couldn't establish power handler\n");
    387 
    388 	return;
    389 
    390 post_csr_map:
    391 	(void)AcpiRemoveGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
    392 	    acpiec_gpe_handler);
    393 	(void)AcpiRemoveAddressSpaceHandler(sc->sc_ech,
    394 	    ACPI_ADR_SPACE_EC, acpiec_space_handler);
    395 	bus_space_unmap(sc->sc_csr_st, sc->sc_csr_sh, 1);
    396 post_data_map:
    397 	bus_space_unmap(sc->sc_data_st, sc->sc_data_sh, 1);
    398 }
    399 
    400 static bool
    401 acpiec_suspend(device_t dv, const pmf_qual_t *qual)
    402 {
    403 	acpiec_cold = true;
    404 
    405 	return true;
    406 }
    407 
    408 static bool
    409 acpiec_resume(device_t dv, const pmf_qual_t *qual)
    410 {
    411 	acpiec_cold = false;
    412 
    413 	return true;
    414 }
    415 
    416 static bool
    417 acpiec_shutdown(device_t dv, int how)
    418 {
    419 
    420 	acpiec_cold = true;
    421 	return true;
    422 }
    423 
    424 static bool
    425 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
    426     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
    427 {
    428 	ACPI_BUFFER buf;
    429 	ACPI_OBJECT *p, *c;
    430 	ACPI_STATUS rv;
    431 
    432 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
    433 	if (rv != AE_OK) {
    434 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
    435 		    AcpiFormatException(rv));
    436 		return false;
    437 	}
    438 
    439 	p = buf.Pointer;
    440 
    441 	if (p->Type == ACPI_TYPE_INTEGER) {
    442 		*gpe_handle = NULL;
    443 		*gpebit = p->Integer.Value;
    444 		ACPI_FREE(p);
    445 		return true;
    446 	}
    447 
    448 	if (p->Type != ACPI_TYPE_PACKAGE) {
    449 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
    450 		ACPI_FREE(p);
    451 		return false;
    452 	}
    453 
    454 	if (p->Package.Count != 2) {
    455 		aprint_error_dev(self, "_GPE package does not contain 2 elements\n");
    456 		ACPI_FREE(p);
    457 		return false;
    458 	}
    459 
    460 	c = &p->Package.Elements[0];
    461 	rv = acpi_eval_reference_handle(c, gpe_handle);
    462 
    463 	if (ACPI_FAILURE(rv)) {
    464 		aprint_error_dev(self, "failed to evaluate _GPE handle\n");
    465 		ACPI_FREE(p);
    466 		return false;
    467 	}
    468 
    469 	c = &p->Package.Elements[1];
    470 
    471 	if (c->Type != ACPI_TYPE_INTEGER) {
    472 		aprint_error_dev(self,
    473 		    "_GPE package needs integer as 2nd field\n");
    474 		ACPI_FREE(p);
    475 		return false;
    476 	}
    477 	*gpebit = c->Integer.Value;
    478 	ACPI_FREE(p);
    479 	return true;
    480 }
    481 
    482 static uint8_t
    483 acpiec_read_data(struct acpiec_softc *sc)
    484 {
    485 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
    486 }
    487 
    488 static void
    489 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
    490 {
    491 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
    492 }
    493 
    494 static uint8_t
    495 acpiec_read_status(struct acpiec_softc *sc)
    496 {
    497 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
    498 }
    499 
    500 static void
    501 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
    502 {
    503 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
    504 }
    505 
    506 static ACPI_STATUS
    507 acpiec_space_setup(ACPI_HANDLE region, uint32_t func, void *arg,
    508     void **region_arg)
    509 {
    510 	if (func == ACPI_REGION_DEACTIVATE)
    511 		*region_arg = NULL;
    512 	else
    513 		*region_arg = arg;
    514 
    515 	return AE_OK;
    516 }
    517 
    518 static void
    519 acpiec_lock(device_t dv)
    520 {
    521 	struct acpiec_softc *sc = device_private(dv);
    522 	ACPI_STATUS rv;
    523 
    524 	mutex_enter(&sc->sc_access_mtx);
    525 
    526 	if (sc->sc_need_global_lock) {
    527 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->sc_global_lock);
    528 		if (rv != AE_OK) {
    529 			aprint_error_dev(dv, "failed to acquire global lock: %s\n",
    530 			    AcpiFormatException(rv));
    531 			return;
    532 		}
    533 	}
    534 }
    535 
    536 static void
    537 acpiec_unlock(device_t dv)
    538 {
    539 	struct acpiec_softc *sc = device_private(dv);
    540 	ACPI_STATUS rv;
    541 
    542 	if (sc->sc_need_global_lock) {
    543 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
    544 		if (rv != AE_OK) {
    545 			aprint_error_dev(dv, "failed to release global lock: %s\n",
    546 			    AcpiFormatException(rv));
    547 		}
    548 	}
    549 	mutex_exit(&sc->sc_access_mtx);
    550 }
    551 
    552 static ACPI_STATUS
    553 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
    554 {
    555 	struct acpiec_softc *sc = device_private(dv);
    556 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
    557 
    558 	acpiec_lock(dv);
    559 	mutex_enter(&sc->sc_mtx);
    560 
    561 	sc->sc_cur_addr = addr;
    562 	sc->sc_state = EC_STATE_READ;
    563 
    564 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
    565 		acpiec_gpe_state_machine(dv);
    566 		if (sc->sc_state == EC_STATE_FREE)
    567 			goto done;
    568 		delay(1);
    569 	}
    570 
    571 	if (cold || acpiec_cold) {
    572 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
    573 			delay(1000);
    574 			acpiec_gpe_state_machine(dv);
    575 		}
    576 		if (sc->sc_state != EC_STATE_FREE) {
    577 			mutex_exit(&sc->sc_mtx);
    578 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit);
    579 			acpiec_unlock(dv);
    580 			aprint_error_dev(dv, "command timed out, state %d\n",
    581 			    sc->sc_state);
    582 			return AE_ERROR;
    583 		}
    584 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
    585 		mutex_exit(&sc->sc_mtx);
    586 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit);
    587 		acpiec_unlock(dv);
    588 		aprint_error_dev(dv, "command takes over %d sec...\n", EC_CMD_TIMEOUT);
    589 		return AE_ERROR;
    590 	}
    591 
    592 done:
    593 	*val = sc->sc_cur_val;
    594 
    595 	mutex_exit(&sc->sc_mtx);
    596 	acpiec_unlock(dv);
    597 	return AE_OK;
    598 }
    599 
    600 static ACPI_STATUS
    601 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
    602 {
    603 	struct acpiec_softc *sc = device_private(dv);
    604 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
    605 
    606 	acpiec_lock(dv);
    607 	mutex_enter(&sc->sc_mtx);
    608 
    609 	sc->sc_cur_addr = addr;
    610 	sc->sc_cur_val = val;
    611 	sc->sc_state = EC_STATE_WRITE;
    612 
    613 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
    614 		acpiec_gpe_state_machine(dv);
    615 		if (sc->sc_state == EC_STATE_FREE)
    616 			goto done;
    617 		delay(1);
    618 	}
    619 
    620 	if (cold || acpiec_cold) {
    621 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
    622 			delay(1000);
    623 			acpiec_gpe_state_machine(dv);
    624 		}
    625 		if (sc->sc_state != EC_STATE_FREE) {
    626 			mutex_exit(&sc->sc_mtx);
    627 			AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit);
    628 			acpiec_unlock(dv);
    629 			aprint_error_dev(dv, "command timed out, state %d\n",
    630 			    sc->sc_state);
    631 			return AE_ERROR;
    632 		}
    633 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
    634 		mutex_exit(&sc->sc_mtx);
    635 		AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit);
    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 	struct acpiec_softc *sc;
    653 	ACPI_STATUS rv;
    654 	uint8_t addr, reg;
    655 	unsigned int i;
    656 
    657 	if (paddr > 0xff || width % 8 != 0 || value == NULL || arg == NULL ||
    658 	    paddr + width / 8 > 0xff)
    659 		return AE_BAD_PARAMETER;
    660 
    661 	addr = paddr;
    662 	dv = arg;
    663 	sc = device_private(dv);
    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("%s: GPE query method %s failed: %s",
    743 		    device_xname(dv), 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 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit);
    846 
    847 	mutex_enter(&sc->sc_mtx);
    848 	acpiec_gpe_state_machine(dv);
    849 	mutex_exit(&sc->sc_mtx);
    850 }
    851 
    852 static uint32_t
    853 acpiec_gpe_handler(void *arg)
    854 {
    855 	device_t dv = arg;
    856 	struct acpiec_softc *sc = device_private(dv);
    857 
    858 	AcpiClearGpe(sc->sc_gpeh, sc->sc_gpebit);
    859 
    860 	mutex_enter(&sc->sc_mtx);
    861 	acpiec_gpe_state_machine(dv);
    862 	mutex_exit(&sc->sc_mtx);
    863 
    864 	return 0;
    865 }
    866 
    867 ACPI_STATUS
    868 acpiec_bus_read(device_t dv, u_int addr, ACPI_INTEGER *val, int width)
    869 {
    870 	return acpiec_space_handler(ACPI_READ, addr, width * 8, val, dv, NULL);
    871 }
    872 
    873 ACPI_STATUS
    874 acpiec_bus_write(device_t dv, u_int addr, ACPI_INTEGER val, int width)
    875 {
    876 	return acpiec_space_handler(ACPI_WRITE, addr, width * 8, &val, dv, NULL);
    877 }
    878 
    879 ACPI_HANDLE
    880 acpiec_get_handle(device_t dv)
    881 {
    882 	struct acpiec_softc *sc = device_private(dv);
    883 
    884 	return sc->sc_ech;
    885 }
    886