xref: /freebsd/sys/dev/acpica/acpi_ec.c (revision 93e779a26c651610ac6e7986d67ecc9ed2cadcbf)
1 /*-
2  * Copyright (c) 2003-2007 Nate Lawson
3  * Copyright (c) 2000 Michael Smith
4  * Copyright (c) 2000 BSDi
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  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_acpi.h"
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/bus.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/sx.h>
40 
41 #include <machine/bus.h>
42 #include <machine/resource.h>
43 #include <sys/rman.h>
44 
45 #include <contrib/dev/acpica/include/acpi.h>
46 #include <contrib/dev/acpica/include/accommon.h>
47 
48 #include <dev/acpica/acpivar.h>
49 
50 /* Hooks for the ACPI CA debugging infrastructure */
51 #define _COMPONENT	ACPI_EC
52 ACPI_MODULE_NAME("EC")
53 
54 /*
55  * EC_COMMAND:
56  * -----------
57  */
58 typedef UINT8				EC_COMMAND;
59 
60 #define EC_COMMAND_UNKNOWN		((EC_COMMAND) 0x00)
61 #define EC_COMMAND_READ			((EC_COMMAND) 0x80)
62 #define EC_COMMAND_WRITE		((EC_COMMAND) 0x81)
63 #define EC_COMMAND_BURST_ENABLE		((EC_COMMAND) 0x82)
64 #define EC_COMMAND_BURST_DISABLE	((EC_COMMAND) 0x83)
65 #define EC_COMMAND_QUERY		((EC_COMMAND) 0x84)
66 
67 /*
68  * EC_STATUS:
69  * ----------
70  * The encoding of the EC status register is illustrated below.
71  * Note that a set bit (1) indicates the property is TRUE
72  * (e.g. if bit 0 is set then the output buffer is full).
73  * +-+-+-+-+-+-+-+-+
74  * |7|6|5|4|3|2|1|0|
75  * +-+-+-+-+-+-+-+-+
76  *  | | | | | | | |
77  *  | | | | | | | +- Output Buffer Full?
78  *  | | | | | | +--- Input Buffer Full?
79  *  | | | | | +----- <reserved>
80  *  | | | | +------- Data Register is Command Byte?
81  *  | | | +--------- Burst Mode Enabled?
82  *  | | +----------- SCI Event?
83  *  | +------------- SMI Event?
84  *  +--------------- <reserved>
85  *
86  */
87 typedef UINT8				EC_STATUS;
88 
89 #define EC_FLAG_OUTPUT_BUFFER		((EC_STATUS) 0x01)
90 #define EC_FLAG_INPUT_BUFFER		((EC_STATUS) 0x02)
91 #define EC_FLAG_DATA_IS_CMD		((EC_STATUS) 0x08)
92 #define EC_FLAG_BURST_MODE		((EC_STATUS) 0x10)
93 
94 /*
95  * EC_EVENT:
96  * ---------
97  */
98 typedef UINT8				EC_EVENT;
99 
100 #define EC_EVENT_UNKNOWN		((EC_EVENT) 0x00)
101 #define EC_EVENT_OUTPUT_BUFFER_FULL	((EC_EVENT) 0x01)
102 #define EC_EVENT_INPUT_BUFFER_EMPTY	((EC_EVENT) 0x02)
103 #define EC_EVENT_SCI			((EC_EVENT) 0x20)
104 #define EC_EVENT_SMI			((EC_EVENT) 0x40)
105 
106 /* Data byte returned after burst enable indicating it was successful. */
107 #define EC_BURST_ACK			0x90
108 
109 /*
110  * Register access primitives
111  */
112 #define EC_GET_DATA(sc)							\
113 	bus_space_read_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0)
114 
115 #define EC_SET_DATA(sc, v)						\
116 	bus_space_write_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0, (v))
117 
118 #define EC_GET_CSR(sc)							\
119 	bus_space_read_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0)
120 
121 #define EC_SET_CSR(sc, v)						\
122 	bus_space_write_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0, (v))
123 
124 /* Additional params to pass from the probe routine */
125 struct acpi_ec_params {
126     int		glk;
127     int		gpe_bit;
128     ACPI_HANDLE	gpe_handle;
129     int		uid;
130 };
131 
132 /*
133  * Driver softc.
134  */
135 struct acpi_ec_softc {
136     device_t		ec_dev;
137     ACPI_HANDLE		ec_handle;
138     int			ec_uid;
139     ACPI_HANDLE		ec_gpehandle;
140     UINT8		ec_gpebit;
141 
142     int			ec_data_rid;
143     struct resource	*ec_data_res;
144     bus_space_tag_t	ec_data_tag;
145     bus_space_handle_t	ec_data_handle;
146 
147     int			ec_csr_rid;
148     struct resource	*ec_csr_res;
149     bus_space_tag_t	ec_csr_tag;
150     bus_space_handle_t	ec_csr_handle;
151 
152     int			ec_glk;
153     int			ec_glkhandle;
154     int			ec_burstactive;
155     int			ec_sci_pend;
156     volatile u_int	ec_gencount;
157     int			ec_suspending;
158 };
159 
160 /*
161  * XXX njl
162  * I couldn't find it in the spec but other implementations also use a
163  * value of 1 ms for the time to acquire global lock.
164  */
165 #define EC_LOCK_TIMEOUT	1000
166 
167 /* Default delay in microseconds between each run of the status polling loop. */
168 #define EC_POLL_DELAY	50
169 
170 /* Total time in ms spent waiting for a response from EC. */
171 #define EC_TIMEOUT	750
172 
173 #define EVENT_READY(event, status)			\
174 	(((event) == EC_EVENT_OUTPUT_BUFFER_FULL &&	\
175 	 ((status) & EC_FLAG_OUTPUT_BUFFER) != 0) ||	\
176 	 ((event) == EC_EVENT_INPUT_BUFFER_EMPTY && 	\
177 	 ((status) & EC_FLAG_INPUT_BUFFER) == 0))
178 
179 ACPI_SERIAL_DECL(ec, "ACPI embedded controller");
180 
181 static SYSCTL_NODE(_debug_acpi, OID_AUTO, ec, CTLFLAG_RD, NULL, "EC debugging");
182 
183 static int	ec_burst_mode;
184 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, burst, CTLFLAG_RWTUN, &ec_burst_mode, 0,
185     "Enable use of burst mode (faster for nearly all systems)");
186 static int	ec_polled_mode;
187 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, polled, CTLFLAG_RWTUN, &ec_polled_mode, 0,
188     "Force use of polled mode (only if interrupt mode doesn't work)");
189 static int	ec_timeout = EC_TIMEOUT;
190 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, timeout, CTLFLAG_RWTUN, &ec_timeout,
191     EC_TIMEOUT, "Total time spent waiting for a response (poll+sleep)");
192 
193 static ACPI_STATUS
194 EcLock(struct acpi_ec_softc *sc)
195 {
196     ACPI_STATUS	status;
197 
198     /* If _GLK is non-zero, acquire the global lock. */
199     status = AE_OK;
200     if (sc->ec_glk) {
201 	status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->ec_glkhandle);
202 	if (ACPI_FAILURE(status))
203 	    return (status);
204     }
205     ACPI_SERIAL_BEGIN(ec);
206     return (status);
207 }
208 
209 static void
210 EcUnlock(struct acpi_ec_softc *sc)
211 {
212     ACPI_SERIAL_END(ec);
213     if (sc->ec_glk)
214 	AcpiReleaseGlobalLock(sc->ec_glkhandle);
215 }
216 
217 static UINT32		EcGpeHandler(ACPI_HANDLE, UINT32, void *);
218 static ACPI_STATUS	EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
219 				void *Context, void **return_Context);
220 static ACPI_STATUS	EcSpaceHandler(UINT32 Function,
221 				ACPI_PHYSICAL_ADDRESS Address,
222 				UINT32 Width, UINT64 *Value,
223 				void *Context, void *RegionContext);
224 static ACPI_STATUS	EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event,
225 				u_int gen_count);
226 static ACPI_STATUS	EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
227 static ACPI_STATUS	EcRead(struct acpi_ec_softc *sc, UINT8 Address,
228 				UINT8 *Data);
229 static ACPI_STATUS	EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
230 				UINT8 Data);
231 static int		acpi_ec_probe(device_t dev);
232 static int		acpi_ec_attach(device_t dev);
233 static int		acpi_ec_suspend(device_t dev);
234 static int		acpi_ec_resume(device_t dev);
235 static int		acpi_ec_shutdown(device_t dev);
236 static int		acpi_ec_read_method(device_t dev, u_int addr,
237 				UINT64 *val, int width);
238 static int		acpi_ec_write_method(device_t dev, u_int addr,
239 				UINT64 val, int width);
240 
241 static device_method_t acpi_ec_methods[] = {
242     /* Device interface */
243     DEVMETHOD(device_probe,	acpi_ec_probe),
244     DEVMETHOD(device_attach,	acpi_ec_attach),
245     DEVMETHOD(device_suspend,	acpi_ec_suspend),
246     DEVMETHOD(device_resume,	acpi_ec_resume),
247     DEVMETHOD(device_shutdown,	acpi_ec_shutdown),
248 
249     /* Embedded controller interface */
250     DEVMETHOD(acpi_ec_read,	acpi_ec_read_method),
251     DEVMETHOD(acpi_ec_write,	acpi_ec_write_method),
252 
253     DEVMETHOD_END
254 };
255 
256 static driver_t acpi_ec_driver = {
257     "acpi_ec",
258     acpi_ec_methods,
259     sizeof(struct acpi_ec_softc),
260 };
261 
262 static devclass_t acpi_ec_devclass;
263 DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, acpi_ec_devclass, 0, 0);
264 MODULE_DEPEND(acpi_ec, acpi, 1, 1, 1);
265 
266 /*
267  * Look for an ECDT and if we find one, set up default GPE and
268  * space handlers to catch attempts to access EC space before
269  * we have a real driver instance in place.
270  *
271  * TODO: Some old Gateway laptops need us to fake up an ECDT or
272  * otherwise attach early so that _REG methods can run.
273  */
274 void
275 acpi_ec_ecdt_probe(device_t parent)
276 {
277     ACPI_TABLE_ECDT *ecdt;
278     ACPI_STATUS	     status;
279     device_t	     child;
280     ACPI_HANDLE	     h;
281     struct acpi_ec_params *params;
282 
283     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
284 
285     /* Find and validate the ECDT. */
286     status = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
287     if (ACPI_FAILURE(status) ||
288 	ecdt->Control.BitWidth != 8 ||
289 	ecdt->Data.BitWidth != 8) {
290 	return;
291     }
292 
293     /* Create the child device with the given unit number. */
294     child = BUS_ADD_CHILD(parent, 3, "acpi_ec", ecdt->Uid);
295     if (child == NULL) {
296 	printf("%s: can't add child\n", __func__);
297 	return;
298     }
299 
300     /* Find and save the ACPI handle for this device. */
301     status = AcpiGetHandle(NULL, ecdt->Id, &h);
302     if (ACPI_FAILURE(status)) {
303 	device_delete_child(parent, child);
304 	printf("%s: can't get handle\n", __func__);
305 	return;
306     }
307     acpi_set_handle(child, h);
308 
309     /* Set the data and CSR register addresses. */
310     bus_set_resource(child, SYS_RES_IOPORT, 0, ecdt->Data.Address,
311 	/*count*/1);
312     bus_set_resource(child, SYS_RES_IOPORT, 1, ecdt->Control.Address,
313 	/*count*/1);
314 
315     /*
316      * Store values for the probe/attach routines to use.  Store the
317      * ECDT GPE bit and set the global lock flag according to _GLK.
318      * Note that it is not perfectly correct to be evaluating a method
319      * before initializing devices, but in practice this function
320      * should be safe to call at this point.
321      */
322     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
323     params->gpe_handle = NULL;
324     params->gpe_bit = ecdt->Gpe;
325     params->uid = ecdt->Uid;
326     acpi_GetInteger(h, "_GLK", &params->glk);
327     acpi_set_private(child, params);
328 
329     /* Finish the attach process. */
330     if (device_probe_and_attach(child) != 0)
331 	device_delete_child(parent, child);
332 }
333 
334 static int
335 acpi_ec_probe(device_t dev)
336 {
337     ACPI_BUFFER buf;
338     ACPI_HANDLE h;
339     ACPI_OBJECT *obj;
340     ACPI_STATUS status;
341     device_t	peer;
342     char	desc[64];
343     int		ecdt;
344     int		ret;
345     struct acpi_ec_params *params;
346     static char *ec_ids[] = { "PNP0C09", NULL };
347 
348     /* Check that this is a device and that EC is not disabled. */
349     if (acpi_get_type(dev) != ACPI_TYPE_DEVICE || acpi_disabled("ec"))
350 	return (ENXIO);
351 
352     /*
353      * If probed via ECDT, set description and continue.  Otherwise,
354      * we can access the namespace and make sure this is not a
355      * duplicate probe.
356      */
357     ret = ENXIO;
358     ecdt = 0;
359     buf.Pointer = NULL;
360     buf.Length = ACPI_ALLOCATE_BUFFER;
361     params = acpi_get_private(dev);
362     if (params != NULL) {
363 	ecdt = 1;
364 	ret = 0;
365     } else if (ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids)) {
366 	params = malloc(sizeof(struct acpi_ec_params), M_TEMP,
367 			M_WAITOK | M_ZERO);
368 	h = acpi_get_handle(dev);
369 
370 	/*
371 	 * Read the unit ID to check for duplicate attach and the
372 	 * global lock value to see if we should acquire it when
373 	 * accessing the EC.
374 	 */
375 	status = acpi_GetInteger(h, "_UID", &params->uid);
376 	if (ACPI_FAILURE(status))
377 	    params->uid = 0;
378 	status = acpi_GetInteger(h, "_GLK", &params->glk);
379 	if (ACPI_FAILURE(status))
380 	    params->glk = 0;
381 
382 	/*
383 	 * Evaluate the _GPE method to find the GPE bit used by the EC to
384 	 * signal status (SCI).  If it's a package, it contains a reference
385 	 * and GPE bit, similar to _PRW.
386 	 */
387 	status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
388 	if (ACPI_FAILURE(status)) {
389 	    device_printf(dev, "can't evaluate _GPE - %s\n",
390 			  AcpiFormatException(status));
391 	    goto out;
392 	}
393 	obj = (ACPI_OBJECT *)buf.Pointer;
394 	if (obj == NULL)
395 	    goto out;
396 
397 	switch (obj->Type) {
398 	case ACPI_TYPE_INTEGER:
399 	    params->gpe_handle = NULL;
400 	    params->gpe_bit = obj->Integer.Value;
401 	    break;
402 	case ACPI_TYPE_PACKAGE:
403 	    if (!ACPI_PKG_VALID(obj, 2))
404 		goto out;
405 	    params->gpe_handle =
406 		acpi_GetReference(NULL, &obj->Package.Elements[0]);
407 	    if (params->gpe_handle == NULL ||
408 		acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
409 		goto out;
410 	    break;
411 	default:
412 	    device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
413 	    goto out;
414 	}
415 
416 	/* Store the values we got from the namespace for attach. */
417 	acpi_set_private(dev, params);
418 
419 	/*
420 	 * Check for a duplicate probe.  This can happen when a probe
421 	 * via ECDT succeeded already.  If this is a duplicate, disable
422 	 * this device.
423 	 */
424 	peer = devclass_get_device(acpi_ec_devclass, params->uid);
425 	if (peer == NULL || !device_is_alive(peer))
426 	    ret = 0;
427 	else
428 	    device_disable(dev);
429     }
430 
431 out:
432     if (ret == 0) {
433 	snprintf(desc, sizeof(desc), "Embedded Controller: GPE %#x%s%s",
434 		 params->gpe_bit, (params->glk) ? ", GLK" : "",
435 		 ecdt ? ", ECDT" : "");
436 	device_set_desc_copy(dev, desc);
437     }
438 
439     if (ret > 0 && params)
440 	free(params, M_TEMP);
441     if (buf.Pointer)
442 	AcpiOsFree(buf.Pointer);
443     return (ret);
444 }
445 
446 static int
447 acpi_ec_attach(device_t dev)
448 {
449     struct acpi_ec_softc	*sc;
450     struct acpi_ec_params	*params;
451     ACPI_STATUS			Status;
452 
453     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
454 
455     /* Fetch/initialize softc (assumes softc is pre-zeroed). */
456     sc = device_get_softc(dev);
457     params = acpi_get_private(dev);
458     sc->ec_dev = dev;
459     sc->ec_handle = acpi_get_handle(dev);
460 
461     /* Retrieve previously probed values via device ivars. */
462     sc->ec_glk = params->glk;
463     sc->ec_gpebit = params->gpe_bit;
464     sc->ec_gpehandle = params->gpe_handle;
465     sc->ec_uid = params->uid;
466     sc->ec_suspending = FALSE;
467     acpi_set_private(dev, NULL);
468     free(params, M_TEMP);
469 
470     /* Attach bus resources for data and command/status ports. */
471     sc->ec_data_rid = 0;
472     sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
473 			&sc->ec_data_rid, RF_ACTIVE);
474     if (sc->ec_data_res == NULL) {
475 	device_printf(dev, "can't allocate data port\n");
476 	goto error;
477     }
478     sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
479     sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
480 
481     sc->ec_csr_rid = 1;
482     sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
483 			&sc->ec_csr_rid, RF_ACTIVE);
484     if (sc->ec_csr_res == NULL) {
485 	device_printf(dev, "can't allocate command/status port\n");
486 	goto error;
487     }
488     sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
489     sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
490 
491     /*
492      * Install a handler for this EC's GPE bit.  We want edge-triggered
493      * behavior.
494      */
495     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
496     Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
497 		ACPI_GPE_EDGE_TRIGGERED, EcGpeHandler, sc);
498     if (ACPI_FAILURE(Status)) {
499 	device_printf(dev, "can't install GPE handler for %s - %s\n",
500 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
501 	goto error;
502     }
503 
504     /*
505      * Install address space handler
506      */
507     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
508     Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
509 		&EcSpaceHandler, &EcSpaceSetup, sc);
510     if (ACPI_FAILURE(Status)) {
511 	device_printf(dev, "can't install address space handler for %s - %s\n",
512 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
513 	goto error;
514     }
515 
516     /* Enable runtime GPEs for the handler. */
517     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit);
518     if (ACPI_FAILURE(Status)) {
519 	device_printf(dev, "AcpiEnableGpe failed: %s\n",
520 		      AcpiFormatException(Status));
521 	goto error;
522     }
523 
524     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
525     return (0);
526 
527 error:
528     AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, EcGpeHandler);
529     AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
530 	EcSpaceHandler);
531     if (sc->ec_csr_res)
532 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
533 			     sc->ec_csr_res);
534     if (sc->ec_data_res)
535 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
536 			     sc->ec_data_res);
537     return (ENXIO);
538 }
539 
540 static int
541 acpi_ec_suspend(device_t dev)
542 {
543     struct acpi_ec_softc	*sc;
544 
545     sc = device_get_softc(dev);
546     sc->ec_suspending = TRUE;
547     return (0);
548 }
549 
550 static int
551 acpi_ec_resume(device_t dev)
552 {
553     struct acpi_ec_softc	*sc;
554 
555     sc = device_get_softc(dev);
556     sc->ec_suspending = FALSE;
557     return (0);
558 }
559 
560 static int
561 acpi_ec_shutdown(device_t dev)
562 {
563     struct acpi_ec_softc	*sc;
564 
565     /* Disable the GPE so we don't get EC events during shutdown. */
566     sc = device_get_softc(dev);
567     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit);
568     return (0);
569 }
570 
571 /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
572 static int
573 acpi_ec_read_method(device_t dev, u_int addr, UINT64 *val, int width)
574 {
575     struct acpi_ec_softc *sc;
576     ACPI_STATUS status;
577 
578     sc = device_get_softc(dev);
579     status = EcSpaceHandler(ACPI_READ, addr, width * 8, val, sc, NULL);
580     if (ACPI_FAILURE(status))
581 	return (ENXIO);
582     return (0);
583 }
584 
585 static int
586 acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
587 {
588     struct acpi_ec_softc *sc;
589     ACPI_STATUS status;
590 
591     sc = device_get_softc(dev);
592     status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
593     if (ACPI_FAILURE(status))
594 	return (ENXIO);
595     return (0);
596 }
597 
598 static ACPI_STATUS
599 EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
600 {
601     ACPI_STATUS status;
602     EC_STATUS ec_status;
603 
604     status = AE_NO_HARDWARE_RESPONSE;
605     ec_status = EC_GET_CSR(sc);
606     if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
607 	CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
608 	sc->ec_burstactive = FALSE;
609     }
610     if (EVENT_READY(event, ec_status)) {
611 	CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
612 	status = AE_OK;
613     }
614     return (status);
615 }
616 
617 static void
618 EcGpeQueryHandler(void *Context)
619 {
620     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
621     UINT8			Data;
622     ACPI_STATUS			Status;
623     int				retry;
624     char			qxx[5];
625 
626     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
627     KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
628 
629     /* Serialize user access with EcSpaceHandler(). */
630     Status = EcLock(sc);
631     if (ACPI_FAILURE(Status)) {
632 	device_printf(sc->ec_dev, "GpeQuery lock error: %s\n",
633 	    AcpiFormatException(Status));
634 	return;
635     }
636 
637     /*
638      * Send a query command to the EC to find out which _Qxx call it
639      * wants to make.  This command clears the SCI bit and also the
640      * interrupt source since we are edge-triggered.  To prevent the GPE
641      * that may arise from running the query from causing another query
642      * to be queued, we clear the pending flag only after running it.
643      */
644     for (retry = 0; retry < 2; retry++) {
645 	Status = EcCommand(sc, EC_COMMAND_QUERY);
646 	if (ACPI_SUCCESS(Status))
647 	    break;
648 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
649 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
650 	    break;
651     }
652     sc->ec_sci_pend = FALSE;
653     if (ACPI_FAILURE(Status)) {
654 	EcUnlock(sc);
655 	device_printf(sc->ec_dev, "GPE query failed: %s\n",
656 	    AcpiFormatException(Status));
657 	return;
658     }
659     Data = EC_GET_DATA(sc);
660 
661     /*
662      * We have to unlock before running the _Qxx method below since that
663      * method may attempt to read/write from EC address space, causing
664      * recursive acquisition of the lock.
665      */
666     EcUnlock(sc);
667 
668     /* Ignore the value for "no outstanding event". (13.3.5) */
669     CTR2(KTR_ACPI, "ec query ok,%s running _Q%02X", Data ? "" : " not", Data);
670     if (Data == 0)
671 	return;
672 
673     /* Evaluate _Qxx to respond to the controller. */
674     snprintf(qxx, sizeof(qxx), "_Q%02X", Data);
675     AcpiUtStrupr(qxx);
676     Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
677     if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
678 	device_printf(sc->ec_dev, "evaluation of query method %s failed: %s\n",
679 	    qxx, AcpiFormatException(Status));
680     }
681 }
682 
683 /*
684  * The GPE handler is called when IBE/OBF or SCI events occur.  We are
685  * called from an unknown lock context.
686  */
687 static UINT32
688 EcGpeHandler(ACPI_HANDLE GpeDevice, UINT32 GpeNumber, void *Context)
689 {
690     struct acpi_ec_softc *sc = Context;
691     ACPI_STATUS		       Status;
692     EC_STATUS		       EcStatus;
693 
694     KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
695     CTR0(KTR_ACPI, "ec gpe handler start");
696 
697     /*
698      * Notify EcWaitEvent() that the status register is now fresh.  If we
699      * didn't do this, it wouldn't be possible to distinguish an old IBE
700      * from a new one, for example when doing a write transaction (writing
701      * address and then data values.)
702      */
703     atomic_add_int(&sc->ec_gencount, 1);
704     wakeup(sc);
705 
706     /*
707      * If the EC_SCI bit of the status register is set, queue a query handler.
708      * It will run the query and _Qxx method later, under the lock.
709      */
710     EcStatus = EC_GET_CSR(sc);
711     if ((EcStatus & EC_EVENT_SCI) && !sc->ec_sci_pend) {
712 	CTR0(KTR_ACPI, "ec gpe queueing query handler");
713 	Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
714 	if (ACPI_SUCCESS(Status))
715 	    sc->ec_sci_pend = TRUE;
716 	else
717 	    printf("EcGpeHandler: queuing GPE query handler failed\n");
718     }
719     return (ACPI_REENABLE_GPE);
720 }
721 
722 static ACPI_STATUS
723 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
724 	     void **RegionContext)
725 {
726 
727     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
728 
729     /*
730      * If deactivating a region, always set the output to NULL.  Otherwise,
731      * just pass the context through.
732      */
733     if (Function == ACPI_REGION_DEACTIVATE)
734 	*RegionContext = NULL;
735     else
736 	*RegionContext = Context;
737 
738     return_ACPI_STATUS (AE_OK);
739 }
740 
741 static ACPI_STATUS
742 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 Width,
743 	       UINT64 *Value, void *Context, void *RegionContext)
744 {
745     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
746     ACPI_PHYSICAL_ADDRESS	EcAddr;
747     UINT8			*EcData;
748     ACPI_STATUS			Status;
749 
750     ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
751 
752     if (Function != ACPI_READ && Function != ACPI_WRITE)
753 	return_ACPI_STATUS (AE_BAD_PARAMETER);
754     if (Width % 8 != 0 || Value == NULL || Context == NULL)
755 	return_ACPI_STATUS (AE_BAD_PARAMETER);
756     if (Address + Width / 8 > 256)
757 	return_ACPI_STATUS (AE_BAD_ADDRESS);
758 
759     /*
760      * If booting, check if we need to run the query handler.  If so, we
761      * we call it directly here since our thread taskq is not active yet.
762      */
763     if (cold || rebooting || sc->ec_suspending) {
764 	if ((EC_GET_CSR(sc) & EC_EVENT_SCI)) {
765 	    CTR0(KTR_ACPI, "ec running gpe handler directly");
766 	    EcGpeQueryHandler(sc);
767 	}
768     }
769 
770     /* Serialize with EcGpeQueryHandler() at transaction granularity. */
771     Status = EcLock(sc);
772     if (ACPI_FAILURE(Status))
773 	return_ACPI_STATUS (Status);
774 
775     /* If we can't start burst mode, continue anyway. */
776     Status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
777     if (ACPI_SUCCESS(Status)) {
778 	if (EC_GET_DATA(sc) == EC_BURST_ACK) {
779 	    CTR0(KTR_ACPI, "ec burst enabled");
780 	    sc->ec_burstactive = TRUE;
781 	}
782     }
783 
784     /* Perform the transaction(s), based on Width. */
785     EcAddr = Address;
786     EcData = (UINT8 *)Value;
787     if (Function == ACPI_READ)
788 	*Value = 0;
789     do {
790 	switch (Function) {
791 	case ACPI_READ:
792 	    Status = EcRead(sc, EcAddr, EcData);
793 	    break;
794 	case ACPI_WRITE:
795 	    Status = EcWrite(sc, EcAddr, *EcData);
796 	    break;
797 	}
798 	if (ACPI_FAILURE(Status))
799 	    break;
800 	EcAddr++;
801 	EcData++;
802     } while (EcAddr < Address + Width / 8);
803 
804     if (sc->ec_burstactive) {
805 	sc->ec_burstactive = FALSE;
806 	if (ACPI_SUCCESS(EcCommand(sc, EC_COMMAND_BURST_DISABLE)))
807 	    CTR0(KTR_ACPI, "ec disabled burst ok");
808     }
809 
810     EcUnlock(sc);
811     return_ACPI_STATUS (Status);
812 }
813 
814 static ACPI_STATUS
815 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
816 {
817     static int	no_intr = 0;
818     ACPI_STATUS	Status;
819     int		count, i, need_poll, slp_ival;
820 
821     ACPI_SERIAL_ASSERT(ec);
822     Status = AE_NO_HARDWARE_RESPONSE;
823     need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
824 
825     /* Wait for event by polling or GPE (interrupt). */
826     if (need_poll) {
827 	count = (ec_timeout * 1000) / EC_POLL_DELAY;
828 	if (count == 0)
829 	    count = 1;
830 	DELAY(10);
831 	for (i = 0; i < count; i++) {
832 	    Status = EcCheckStatus(sc, "poll", Event);
833 	    if (ACPI_SUCCESS(Status))
834 		break;
835 	    DELAY(EC_POLL_DELAY);
836 	}
837     } else {
838 	slp_ival = hz / 1000;
839 	if (slp_ival != 0) {
840 	    count = ec_timeout;
841 	} else {
842 	    /* hz has less than 1 ms resolution so scale timeout. */
843 	    slp_ival = 1;
844 	    count = ec_timeout / (1000 / hz);
845 	}
846 
847 	/*
848 	 * Wait for the GPE to signal the status changed, checking the
849 	 * status register each time we get one.  It's possible to get a
850 	 * GPE for an event we're not interested in here (i.e., SCI for
851 	 * EC query).
852 	 */
853 	for (i = 0; i < count; i++) {
854 	    if (gen_count == sc->ec_gencount)
855 		tsleep(sc, 0, "ecgpe", slp_ival);
856 	    /*
857 	     * Record new generation count.  It's possible the GPE was
858 	     * just to notify us that a query is needed and we need to
859 	     * wait for a second GPE to signal the completion of the
860 	     * event we are actually waiting for.
861 	     */
862 	    Status = EcCheckStatus(sc, "sleep", Event);
863 	    if (ACPI_SUCCESS(Status)) {
864 		if (gen_count == sc->ec_gencount)
865 		    no_intr++;
866 		else
867 		    no_intr = 0;
868 		break;
869 	    }
870 	    gen_count = sc->ec_gencount;
871 	}
872 
873 	/*
874 	 * We finished waiting for the GPE and it never arrived.  Try to
875 	 * read the register once and trust whatever value we got.  This is
876 	 * the best we can do at this point.
877 	 */
878 	if (ACPI_FAILURE(Status))
879 	    Status = EcCheckStatus(sc, "sleep_end", Event);
880     }
881     if (!need_poll && no_intr > 10) {
882 	device_printf(sc->ec_dev,
883 	    "not getting interrupts, switched to polled mode\n");
884 	ec_polled_mode = 1;
885     }
886     if (ACPI_FAILURE(Status))
887 	    CTR0(KTR_ACPI, "error: ec wait timed out");
888     return (Status);
889 }
890 
891 static ACPI_STATUS
892 EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
893 {
894     ACPI_STATUS	status;
895     EC_EVENT	event;
896     EC_STATUS	ec_status;
897     u_int	gen_count;
898 
899     ACPI_SERIAL_ASSERT(ec);
900 
901     /* Don't use burst mode if user disabled it. */
902     if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
903 	return (AE_ERROR);
904 
905     /* Decide what to wait for based on command type. */
906     switch (cmd) {
907     case EC_COMMAND_READ:
908     case EC_COMMAND_WRITE:
909     case EC_COMMAND_BURST_DISABLE:
910 	event = EC_EVENT_INPUT_BUFFER_EMPTY;
911 	break;
912     case EC_COMMAND_QUERY:
913     case EC_COMMAND_BURST_ENABLE:
914 	event = EC_EVENT_OUTPUT_BUFFER_FULL;
915 	break;
916     default:
917 	device_printf(sc->ec_dev, "EcCommand: invalid command %#x\n", cmd);
918 	return (AE_BAD_PARAMETER);
919     }
920 
921     /*
922      * Ensure empty input buffer before issuing command.
923      * Use generation count of zero to force a quick check.
924      */
925     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, 0);
926     if (ACPI_FAILURE(status))
927 	return (status);
928 
929     /* Run the command and wait for the chosen event. */
930     CTR1(KTR_ACPI, "ec running command %#x", cmd);
931     gen_count = sc->ec_gencount;
932     EC_SET_CSR(sc, cmd);
933     status = EcWaitEvent(sc, event, gen_count);
934     if (ACPI_SUCCESS(status)) {
935 	/* If we succeeded, burst flag should now be present. */
936 	if (cmd == EC_COMMAND_BURST_ENABLE) {
937 	    ec_status = EC_GET_CSR(sc);
938 	    if ((ec_status & EC_FLAG_BURST_MODE) == 0)
939 		status = AE_ERROR;
940 	}
941     } else
942 	device_printf(sc->ec_dev, "EcCommand: no response to %#x\n", cmd);
943     return (status);
944 }
945 
946 static ACPI_STATUS
947 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
948 {
949     ACPI_STATUS	status;
950     u_int gen_count;
951     int retry;
952 
953     ACPI_SERIAL_ASSERT(ec);
954     CTR1(KTR_ACPI, "ec read from %#x", Address);
955 
956     for (retry = 0; retry < 2; retry++) {
957 	status = EcCommand(sc, EC_COMMAND_READ);
958 	if (ACPI_FAILURE(status))
959 	    return (status);
960 
961 	gen_count = sc->ec_gencount;
962 	EC_SET_DATA(sc, Address);
963 	status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
964 	if (ACPI_SUCCESS(status)) {
965 	    *Data = EC_GET_DATA(sc);
966 	    return (AE_OK);
967 	}
968 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
969 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
970 	    break;
971     }
972     device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
973     return (status);
974 }
975 
976 static ACPI_STATUS
977 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 Data)
978 {
979     ACPI_STATUS	status;
980     u_int gen_count;
981 
982     ACPI_SERIAL_ASSERT(ec);
983     CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, Data);
984 
985     status = EcCommand(sc, EC_COMMAND_WRITE);
986     if (ACPI_FAILURE(status))
987 	return (status);
988 
989     gen_count = sc->ec_gencount;
990     EC_SET_DATA(sc, Address);
991     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
992     if (ACPI_FAILURE(status)) {
993 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent address\n");
994 	return (status);
995     }
996 
997     gen_count = sc->ec_gencount;
998     EC_SET_DATA(sc, Data);
999     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1000     if (ACPI_FAILURE(status)) {
1001 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent data\n");
1002 	return (status);
1003     }
1004 
1005     return (AE_OK);
1006 }
1007