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acpi_ec.c revision 1.84
      1 /*	$NetBSD: acpi_ec.c,v 1.84 2020/06/15 15:29:46 jdolecek 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 1.84 2020/06/15 15:29:46 jdolecek 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 * const 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 (!acpi_device_present(aa->aa_node->ad_handle)) {
    272 		aprint_normal(": not present\n");
    273 		goto fail0;
    274 	}
    275 
    276 	if (!acpiec_parse_gpe_package(self, aa->aa_node->ad_handle,
    277 				      &gpe_handle, &gpebit))
    278 		goto fail0;
    279 
    280 	rv = acpi_resource_parse(self, aa->aa_node->ad_handle, "_CRS",
    281 	    &ec_res, &acpi_resource_parse_ops_default);
    282 	if (rv != AE_OK) {
    283 		aprint_error_dev(self, "resource parsing failed: %s\n",
    284 		    AcpiFormatException(rv));
    285 		goto fail0;
    286 	}
    287 
    288 	if ((io0 = acpi_res_io(&ec_res, 0)) == NULL) {
    289 		aprint_error_dev(self, "no data register resource\n");
    290 		goto fail1;
    291 	}
    292 	if ((io1 = acpi_res_io(&ec_res, 1)) == NULL) {
    293 		aprint_error_dev(self, "no CSR register resource\n");
    294 		goto fail1;
    295 	}
    296 
    297 	acpiec_common_attach(parent, self, aa->aa_node->ad_handle,
    298 	    aa->aa_iot, io1->ar_base, aa->aa_iot, io0->ar_base,
    299 	    gpe_handle, gpebit);
    300 
    301 	acpi_resource_cleanup(&ec_res);
    302 	return;
    303 
    304 fail1:	acpi_resource_cleanup(&ec_res);
    305 fail0:	if (!pmf_device_register(self, NULL, NULL))
    306 		aprint_error_dev(self, "couldn't establish power handler\n");
    307 }
    308 
    309 static void
    310 acpiec_common_attach(device_t parent, device_t self,
    311     ACPI_HANDLE ec_handle, bus_space_tag_t cmdt, bus_addr_t cmd_reg,
    312     bus_space_tag_t datat, bus_addr_t data_reg,
    313     ACPI_HANDLE gpe_handle, uint8_t gpebit)
    314 {
    315 	struct acpiec_softc *sc = device_private(self);
    316 	ACPI_STATUS rv;
    317 	ACPI_INTEGER val;
    318 
    319 	sc->sc_csr_st = cmdt;
    320 	sc->sc_data_st = datat;
    321 
    322 	sc->sc_ech = ec_handle;
    323 	sc->sc_gpeh = gpe_handle;
    324 	sc->sc_gpebit = gpebit;
    325 
    326 	sc->sc_state = EC_STATE_FREE;
    327 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_TTY);
    328 	mutex_init(&sc->sc_access_mtx, MUTEX_DEFAULT, IPL_NONE);
    329 	cv_init(&sc->sc_cv, "eccv");
    330 	cv_init(&sc->sc_cv_sci, "ecsci");
    331 
    332 	if (bus_space_map(sc->sc_data_st, data_reg, 1, 0,
    333 	    &sc->sc_data_sh) != 0) {
    334 		aprint_error_dev(self, "unable to map data register\n");
    335 		return;
    336 	}
    337 
    338 	if (bus_space_map(sc->sc_csr_st, cmd_reg, 1, 0, &sc->sc_csr_sh) != 0) {
    339 		aprint_error_dev(self, "unable to map CSR register\n");
    340 		goto post_data_map;
    341 	}
    342 
    343 	rv = acpi_eval_integer(sc->sc_ech, "_GLK", &val);
    344 	if (rv == AE_OK) {
    345 		sc->sc_need_global_lock = val != 0;
    346 	} else if (rv != AE_NOT_FOUND) {
    347 		aprint_error_dev(self, "unable to evaluate _GLK: %s\n",
    348 		    AcpiFormatException(rv));
    349 		goto post_csr_map;
    350 	} else {
    351 		sc->sc_need_global_lock = false;
    352 	}
    353 	if (sc->sc_need_global_lock)
    354 		aprint_normal_dev(self, "using global ACPI lock\n");
    355 
    356 	callout_init(&sc->sc_pseudo_intr, CALLOUT_MPSAFE);
    357 	callout_setfunc(&sc->sc_pseudo_intr, acpiec_callout, self);
    358 
    359 	rv = AcpiInstallAddressSpaceHandler(sc->sc_ech, ACPI_ADR_SPACE_EC,
    360 	    acpiec_space_handler, acpiec_space_setup, self);
    361 	if (rv != AE_OK) {
    362 		aprint_error_dev(self,
    363 		    "unable to install address space handler: %s\n",
    364 		    AcpiFormatException(rv));
    365 		goto post_csr_map;
    366 	}
    367 
    368 	rv = AcpiInstallGpeHandler(sc->sc_gpeh, sc->sc_gpebit,
    369 	    ACPI_GPE_EDGE_TRIGGERED, acpiec_gpe_handler, self);
    370 	if (rv != AE_OK) {
    371 		aprint_error_dev(self, "unable to install GPE handler: %s\n",
    372 		    AcpiFormatException(rv));
    373 		goto post_csr_map;
    374 	}
    375 
    376 	rv = AcpiEnableGpe(sc->sc_gpeh, sc->sc_gpebit);
    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 	if (!pmf_device_register(self, NULL, NULL))
    406 		aprint_error_dev(self, "couldn't establish power handler\n");
    407 }
    408 
    409 static bool
    410 acpiec_suspend(device_t dv, const pmf_qual_t *qual)
    411 {
    412 
    413 	acpiec_cold = true;
    414 
    415 	return true;
    416 }
    417 
    418 static bool
    419 acpiec_resume(device_t dv, const pmf_qual_t *qual)
    420 {
    421 
    422 	acpiec_cold = false;
    423 
    424 	return true;
    425 }
    426 
    427 static bool
    428 acpiec_shutdown(device_t dv, int how)
    429 {
    430 
    431 	acpiec_cold = true;
    432 	return true;
    433 }
    434 
    435 static bool
    436 acpiec_parse_gpe_package(device_t self, ACPI_HANDLE ec_handle,
    437     ACPI_HANDLE *gpe_handle, uint8_t *gpebit)
    438 {
    439 	ACPI_BUFFER buf;
    440 	ACPI_OBJECT *p, *c;
    441 	ACPI_STATUS rv;
    442 
    443 	rv = acpi_eval_struct(ec_handle, "_GPE", &buf);
    444 	if (rv != AE_OK) {
    445 		aprint_error_dev(self, "unable to evaluate _GPE: %s\n",
    446 		    AcpiFormatException(rv));
    447 		return false;
    448 	}
    449 
    450 	p = buf.Pointer;
    451 
    452 	if (p->Type == ACPI_TYPE_INTEGER) {
    453 		*gpe_handle = NULL;
    454 		*gpebit = p->Integer.Value;
    455 		ACPI_FREE(p);
    456 		return true;
    457 	}
    458 
    459 	if (p->Type != ACPI_TYPE_PACKAGE) {
    460 		aprint_error_dev(self, "_GPE is neither integer nor package\n");
    461 		ACPI_FREE(p);
    462 		return false;
    463 	}
    464 
    465 	if (p->Package.Count != 2) {
    466 		aprint_error_dev(self,
    467 		    "_GPE package does not contain 2 elements\n");
    468 		ACPI_FREE(p);
    469 		return false;
    470 	}
    471 
    472 	c = &p->Package.Elements[0];
    473 	rv = acpi_eval_reference_handle(c, gpe_handle);
    474 
    475 	if (ACPI_FAILURE(rv)) {
    476 		aprint_error_dev(self, "failed to evaluate _GPE handle\n");
    477 		ACPI_FREE(p);
    478 		return false;
    479 	}
    480 
    481 	c = &p->Package.Elements[1];
    482 
    483 	if (c->Type != ACPI_TYPE_INTEGER) {
    484 		aprint_error_dev(self,
    485 		    "_GPE package needs integer as 2nd field\n");
    486 		ACPI_FREE(p);
    487 		return false;
    488 	}
    489 	*gpebit = c->Integer.Value;
    490 	ACPI_FREE(p);
    491 	return true;
    492 }
    493 
    494 static uint8_t
    495 acpiec_read_data(struct acpiec_softc *sc)
    496 {
    497 	return bus_space_read_1(sc->sc_data_st, sc->sc_data_sh, 0);
    498 }
    499 
    500 static void
    501 acpiec_write_data(struct acpiec_softc *sc, uint8_t val)
    502 {
    503 	bus_space_write_1(sc->sc_data_st, sc->sc_data_sh, 0, val);
    504 }
    505 
    506 static uint8_t
    507 acpiec_read_status(struct acpiec_softc *sc)
    508 {
    509 	return bus_space_read_1(sc->sc_csr_st, sc->sc_csr_sh, 0);
    510 }
    511 
    512 static void
    513 acpiec_write_command(struct acpiec_softc *sc, uint8_t cmd)
    514 {
    515 	bus_space_write_1(sc->sc_csr_st, sc->sc_csr_sh, 0, cmd);
    516 }
    517 
    518 static ACPI_STATUS
    519 acpiec_space_setup(ACPI_HANDLE region, uint32_t func, void *arg,
    520     void **region_arg)
    521 {
    522 
    523 	if (func == ACPI_REGION_DEACTIVATE)
    524 		*region_arg = NULL;
    525 	else
    526 		*region_arg = arg;
    527 
    528 	return AE_OK;
    529 }
    530 
    531 static void
    532 acpiec_lock(device_t dv)
    533 {
    534 	struct acpiec_softc *sc = device_private(dv);
    535 	ACPI_STATUS rv;
    536 
    537 	mutex_enter(&sc->sc_access_mtx);
    538 
    539 	if (sc->sc_need_global_lock) {
    540 		rv = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT,
    541 		    &sc->sc_global_lock);
    542 		if (rv != AE_OK) {
    543 			aprint_error_dev(dv,
    544 			    "failed to acquire global lock: %s\n",
    545 			    AcpiFormatException(rv));
    546 			return;
    547 		}
    548 	}
    549 }
    550 
    551 static void
    552 acpiec_unlock(device_t dv)
    553 {
    554 	struct acpiec_softc *sc = device_private(dv);
    555 	ACPI_STATUS rv;
    556 
    557 	if (sc->sc_need_global_lock) {
    558 		rv = AcpiReleaseGlobalLock(sc->sc_global_lock);
    559 		if (rv != AE_OK) {
    560 			aprint_error_dev(dv,
    561 			    "failed to release global lock: %s\n",
    562 			    AcpiFormatException(rv));
    563 		}
    564 	}
    565 	mutex_exit(&sc->sc_access_mtx);
    566 }
    567 
    568 static ACPI_STATUS
    569 acpiec_read(device_t dv, uint8_t addr, uint8_t *val)
    570 {
    571 	struct acpiec_softc *sc = device_private(dv);
    572 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
    573 
    574 	acpiec_lock(dv);
    575 	mutex_enter(&sc->sc_mtx);
    576 
    577 	sc->sc_cur_addr = addr;
    578 	sc->sc_state = EC_STATE_READ;
    579 
    580 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
    581 		acpiec_gpe_state_machine(dv);
    582 		if (sc->sc_state == EC_STATE_FREE)
    583 			goto done;
    584 		delay(1);
    585 	}
    586 
    587 	if (cold || acpiec_cold) {
    588 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
    589 			delay(1000);
    590 			acpiec_gpe_state_machine(dv);
    591 		}
    592 		if (sc->sc_state != EC_STATE_FREE) {
    593 			mutex_exit(&sc->sc_mtx);
    594 			acpiec_unlock(dv);
    595 			aprint_error_dev(dv, "command timed out, state %d\n",
    596 			    sc->sc_state);
    597 			return AE_ERROR;
    598 		}
    599 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
    600 		mutex_exit(&sc->sc_mtx);
    601 		acpiec_unlock(dv);
    602 		aprint_error_dev(dv,
    603 		    "command takes over %d sec...\n", EC_CMD_TIMEOUT);
    604 		return AE_ERROR;
    605 	}
    606 
    607 done:
    608 	*val = sc->sc_cur_val;
    609 
    610 	mutex_exit(&sc->sc_mtx);
    611 	acpiec_unlock(dv);
    612 	return AE_OK;
    613 }
    614 
    615 static ACPI_STATUS
    616 acpiec_write(device_t dv, uint8_t addr, uint8_t val)
    617 {
    618 	struct acpiec_softc *sc = device_private(dv);
    619 	int i, timeo = 1000 * EC_CMD_TIMEOUT;
    620 
    621 	acpiec_lock(dv);
    622 	mutex_enter(&sc->sc_mtx);
    623 
    624 	sc->sc_cur_addr = addr;
    625 	sc->sc_cur_val = val;
    626 	sc->sc_state = EC_STATE_WRITE;
    627 
    628 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
    629 		acpiec_gpe_state_machine(dv);
    630 		if (sc->sc_state == EC_STATE_FREE)
    631 			goto done;
    632 		delay(1);
    633 	}
    634 
    635 	if (cold || acpiec_cold) {
    636 		while (sc->sc_state != EC_STATE_FREE && timeo-- > 0) {
    637 			delay(1000);
    638 			acpiec_gpe_state_machine(dv);
    639 		}
    640 		if (sc->sc_state != EC_STATE_FREE) {
    641 			mutex_exit(&sc->sc_mtx);
    642 			acpiec_unlock(dv);
    643 			aprint_error_dev(dv, "command timed out, state %d\n",
    644 			    sc->sc_state);
    645 			return AE_ERROR;
    646 		}
    647 	} else if (cv_timedwait(&sc->sc_cv, &sc->sc_mtx, EC_CMD_TIMEOUT * hz)) {
    648 		mutex_exit(&sc->sc_mtx);
    649 		acpiec_unlock(dv);
    650 		aprint_error_dev(dv,
    651 		    "command takes over %d sec...\n", EC_CMD_TIMEOUT);
    652 		return AE_ERROR;
    653 	}
    654 
    655 done:
    656 	mutex_exit(&sc->sc_mtx);
    657 	acpiec_unlock(dv);
    658 	return AE_OK;
    659 }
    660 
    661 static ACPI_STATUS
    662 acpiec_space_handler(uint32_t func, ACPI_PHYSICAL_ADDRESS paddr,
    663     uint32_t width, ACPI_INTEGER *value, void *arg, void *region_arg)
    664 {
    665 	device_t dv;
    666 	ACPI_STATUS rv;
    667 	uint8_t addr, *buf;
    668 	unsigned int i;
    669 
    670 	if (paddr > 0xff || width % 8 != 0 ||
    671 	    value == NULL || arg == NULL || paddr + width / 8 > 0x100)
    672 		return AE_BAD_PARAMETER;
    673 
    674 	addr = paddr;
    675 	dv = arg;
    676 	buf = (uint8_t *)value;
    677 
    678 	rv = AE_OK;
    679 
    680 	switch (func) {
    681 	case ACPI_READ:
    682 		for (i = 0; i < width; i += 8, ++addr, ++buf) {
    683 			rv = acpiec_read(dv, addr, buf);
    684 			if (rv != AE_OK)
    685 				break;
    686 		}
    687 		break;
    688 	case ACPI_WRITE:
    689 		for (i = 0; i < width; i += 8, ++addr, ++buf) {
    690 			rv = acpiec_write(dv, addr, *buf);
    691 			if (rv != AE_OK)
    692 				break;
    693 		}
    694 		break;
    695 	default:
    696 		aprint_error("%s: invalid Address Space function called: %x\n",
    697 		    device_xname(dv), (unsigned int)func);
    698 		return AE_BAD_PARAMETER;
    699 	}
    700 
    701 	return rv;
    702 }
    703 
    704 static void
    705 acpiec_gpe_query(void *arg)
    706 {
    707 	device_t dv = arg;
    708 	struct acpiec_softc *sc = device_private(dv);
    709 	uint8_t reg;
    710 	char qxx[5];
    711 	ACPI_STATUS rv;
    712 	int i;
    713 
    714 loop:
    715 	mutex_enter(&sc->sc_mtx);
    716 
    717 	if (sc->sc_got_sci == false)
    718 		cv_wait(&sc->sc_cv_sci, &sc->sc_mtx);
    719 	mutex_exit(&sc->sc_mtx);
    720 
    721 	acpiec_lock(dv);
    722 	mutex_enter(&sc->sc_mtx);
    723 
    724 	/* The Query command can always be issued, so be defensive here. */
    725 	sc->sc_got_sci = false;
    726 	sc->sc_state = EC_STATE_QUERY;
    727 
    728 	for (i = 0; i < EC_POLL_TIMEOUT; ++i) {
    729 		acpiec_gpe_state_machine(dv);
    730 		if (sc->sc_state == EC_STATE_FREE)
    731 			goto done;
    732 		delay(1);
    733 	}
    734 
    735 	cv_wait(&sc->sc_cv, &sc->sc_mtx);
    736 
    737 done:
    738 	reg = sc->sc_cur_val;
    739 
    740 	mutex_exit(&sc->sc_mtx);
    741 	acpiec_unlock(dv);
    742 
    743 	if (reg == 0)
    744 		goto loop; /* Spurious query result */
    745 
    746 	/*
    747 	 * Evaluate _Qxx to respond to the controller.
    748 	 */
    749 	snprintf(qxx, sizeof(qxx), "_Q%02X", (unsigned int)reg);
    750 	rv = AcpiEvaluateObject(sc->sc_ech, qxx, NULL, NULL);
    751 	if (rv != AE_OK && rv != AE_NOT_FOUND) {
    752 		aprint_error_dev(dv, "GPE query method %s failed: %s",
    753 		    qxx, AcpiFormatException(rv));
    754 	}
    755 
    756 	goto loop;
    757 }
    758 
    759 static void
    760 acpiec_gpe_state_machine(device_t dv)
    761 {
    762 	struct acpiec_softc *sc = device_private(dv);
    763 	uint8_t reg;
    764 
    765 	reg = acpiec_read_status(sc);
    766 
    767 	if (reg & EC_STATUS_SCI)
    768 		sc->sc_got_sci = true;
    769 
    770 	switch (sc->sc_state) {
    771 	case EC_STATE_QUERY:
    772 		if ((reg & EC_STATUS_IBF) != 0)
    773 			break; /* Nothing of interest here. */
    774 		acpiec_write_command(sc, EC_COMMAND_QUERY);
    775 		sc->sc_state = EC_STATE_QUERY_VAL;
    776 		break;
    777 
    778 	case EC_STATE_QUERY_VAL:
    779 		if ((reg & EC_STATUS_OBF) == 0)
    780 			break; /* Nothing of interest here. */
    781 
    782 		sc->sc_cur_val = acpiec_read_data(sc);
    783 		sc->sc_state = EC_STATE_FREE;
    784 
    785 		cv_signal(&sc->sc_cv);
    786 		break;
    787 
    788 	case EC_STATE_READ:
    789 		if ((reg & EC_STATUS_IBF) != 0)
    790 			break; /* Nothing of interest here. */
    791 
    792 		acpiec_write_command(sc, EC_COMMAND_READ);
    793 		sc->sc_state = EC_STATE_READ_ADDR;
    794 		break;
    795 
    796 	case EC_STATE_READ_ADDR:
    797 		if ((reg & EC_STATUS_IBF) != 0)
    798 			break; /* Nothing of interest here. */
    799 
    800 		acpiec_write_data(sc, sc->sc_cur_addr);
    801 		sc->sc_state = EC_STATE_READ_VAL;
    802 		break;
    803 
    804 	case EC_STATE_READ_VAL:
    805 		if ((reg & EC_STATUS_OBF) == 0)
    806 			break; /* Nothing of interest here. */
    807 		sc->sc_cur_val = acpiec_read_data(sc);
    808 		sc->sc_state = EC_STATE_FREE;
    809 
    810 		cv_signal(&sc->sc_cv);
    811 		break;
    812 
    813 	case EC_STATE_WRITE:
    814 		if ((reg & EC_STATUS_IBF) != 0)
    815 			break; /* Nothing of interest here. */
    816 
    817 		acpiec_write_command(sc, EC_COMMAND_WRITE);
    818 		sc->sc_state = EC_STATE_WRITE_ADDR;
    819 		break;
    820 
    821 	case EC_STATE_WRITE_ADDR:
    822 		if ((reg & EC_STATUS_IBF) != 0)
    823 			break; /* Nothing of interest here. */
    824 		acpiec_write_data(sc, sc->sc_cur_addr);
    825 		sc->sc_state = EC_STATE_WRITE_VAL;
    826 		break;
    827 
    828 	case EC_STATE_WRITE_VAL:
    829 		if ((reg & EC_STATUS_IBF) != 0)
    830 			break; /* Nothing of interest here. */
    831 		sc->sc_state = EC_STATE_FREE;
    832 		cv_signal(&sc->sc_cv);
    833 
    834 		acpiec_write_data(sc, sc->sc_cur_val);
    835 		break;
    836 
    837 	case EC_STATE_FREE:
    838 		if (sc->sc_got_sci)
    839 			cv_signal(&sc->sc_cv_sci);
    840 		break;
    841 	default:
    842 		panic("invalid state");
    843 	}
    844 
    845 	if (sc->sc_state != EC_STATE_FREE)
    846 		callout_schedule(&sc->sc_pseudo_intr, 1);
    847 }
    848 
    849 static void
    850 acpiec_callout(void *arg)
    851 {
    852 	device_t dv = arg;
    853 	struct acpiec_softc *sc = device_private(dv);
    854 
    855 	mutex_enter(&sc->sc_mtx);
    856 	acpiec_gpe_state_machine(dv);
    857 	mutex_exit(&sc->sc_mtx);
    858 }
    859 
    860 static uint32_t
    861 acpiec_gpe_handler(ACPI_HANDLE hdl, uint32_t gpebit, void *arg)
    862 {
    863 	device_t dv = arg;
    864 	struct acpiec_softc *sc = device_private(dv);
    865 
    866 	mutex_enter(&sc->sc_mtx);
    867 	acpiec_gpe_state_machine(dv);
    868 	mutex_exit(&sc->sc_mtx);
    869 
    870 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
    871 }
    872 
    873 ACPI_STATUS
    874 acpiec_bus_read(device_t dv, u_int addr, ACPI_INTEGER *val, int width)
    875 {
    876 	return acpiec_space_handler(ACPI_READ, addr, width * 8, val, dv, NULL);
    877 }
    878 
    879 ACPI_STATUS
    880 acpiec_bus_write(device_t dv, u_int addr, ACPI_INTEGER val, int width)
    881 {
    882 	return acpiec_space_handler(ACPI_WRITE, addr, width * 8, &val, dv,
    883 	    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