xref: /freebsd/sys/dev/acpica/acpi_ec.c (revision 66e576525d35c68fcb86f142ebaa5a448555c0c7)
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     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	5
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 SYSCTL_DECL(_debug_acpi);
182 SYSCTL_NODE(_debug_acpi, OID_AUTO, ec, CTLFLAG_RD, NULL, "EC debugging");
183 
184 static int	ec_burst_mode;
185 TUNABLE_INT("debug.acpi.ec.burst", &ec_burst_mode);
186 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, burst, CTLFLAG_RW, &ec_burst_mode, 0,
187     "Enable use of burst mode (faster for nearly all systems)");
188 static int	ec_polled_mode;
189 TUNABLE_INT("debug.acpi.ec.polled", &ec_polled_mode);
190 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, polled, CTLFLAG_RW, &ec_polled_mode, 0,
191     "Force use of polled mode (only if interrupt mode doesn't work)");
192 static int	ec_timeout = EC_TIMEOUT;
193 TUNABLE_INT("debug.acpi.ec.timeout", &ec_timeout);
194 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, timeout, CTLFLAG_RW, &ec_timeout,
195     EC_TIMEOUT, "Total time spent waiting for a response (poll+sleep)");
196 
197 static ACPI_STATUS
198 EcLock(struct acpi_ec_softc *sc)
199 {
200     ACPI_STATUS	status;
201 
202     /* If _GLK is non-zero, acquire the global lock. */
203     status = AE_OK;
204     if (sc->ec_glk) {
205 	status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->ec_glkhandle);
206 	if (ACPI_FAILURE(status))
207 	    return (status);
208     }
209     ACPI_SERIAL_BEGIN(ec);
210     return (status);
211 }
212 
213 static void
214 EcUnlock(struct acpi_ec_softc *sc)
215 {
216     ACPI_SERIAL_END(ec);
217     if (sc->ec_glk)
218 	AcpiReleaseGlobalLock(sc->ec_glkhandle);
219 }
220 
221 static uint32_t		EcGpeHandler(void *Context);
222 static ACPI_STATUS	EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
223 				void *Context, void **return_Context);
224 static ACPI_STATUS	EcSpaceHandler(UINT32 Function,
225 				ACPI_PHYSICAL_ADDRESS Address,
226 				UINT32 Width, UINT64 *Value,
227 				void *Context, void *RegionContext);
228 static ACPI_STATUS	EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event,
229 				u_int gen_count);
230 static ACPI_STATUS	EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
231 static ACPI_STATUS	EcRead(struct acpi_ec_softc *sc, UINT8 Address,
232 				UINT8 *Data);
233 static ACPI_STATUS	EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
234 				UINT8 Data);
235 static int		acpi_ec_probe(device_t dev);
236 static int		acpi_ec_attach(device_t dev);
237 static int		acpi_ec_suspend(device_t dev);
238 static int		acpi_ec_resume(device_t dev);
239 static int		acpi_ec_shutdown(device_t dev);
240 static int		acpi_ec_read_method(device_t dev, u_int addr,
241 				UINT64 *val, int width);
242 static int		acpi_ec_write_method(device_t dev, u_int addr,
243 				UINT64 val, int width);
244 
245 static device_method_t acpi_ec_methods[] = {
246     /* Device interface */
247     DEVMETHOD(device_probe,	acpi_ec_probe),
248     DEVMETHOD(device_attach,	acpi_ec_attach),
249     DEVMETHOD(device_suspend,	acpi_ec_suspend),
250     DEVMETHOD(device_resume,	acpi_ec_resume),
251     DEVMETHOD(device_shutdown,	acpi_ec_shutdown),
252 
253     /* Embedded controller interface */
254     DEVMETHOD(acpi_ec_read,	acpi_ec_read_method),
255     DEVMETHOD(acpi_ec_write,	acpi_ec_write_method),
256 
257     {0, 0}
258 };
259 
260 static driver_t acpi_ec_driver = {
261     "acpi_ec",
262     acpi_ec_methods,
263     sizeof(struct acpi_ec_softc),
264 };
265 
266 static devclass_t acpi_ec_devclass;
267 DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, acpi_ec_devclass, 0, 0);
268 MODULE_DEPEND(acpi_ec, acpi, 1, 1, 1);
269 
270 /*
271  * Look for an ECDT and if we find one, set up default GPE and
272  * space handlers to catch attempts to access EC space before
273  * we have a real driver instance in place.
274  *
275  * TODO: Some old Gateway laptops need us to fake up an ECDT or
276  * otherwise attach early so that _REG methods can run.
277  */
278 void
279 acpi_ec_ecdt_probe(device_t parent)
280 {
281     ACPI_TABLE_ECDT *ecdt;
282     ACPI_STATUS	     status;
283     device_t	     child;
284     ACPI_HANDLE	     h;
285     struct acpi_ec_params *params;
286 
287     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
288 
289     /* Find and validate the ECDT. */
290     status = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
291     if (ACPI_FAILURE(status) ||
292 	ecdt->Control.BitWidth != 8 ||
293 	ecdt->Data.BitWidth != 8) {
294 	return;
295     }
296 
297     /* Create the child device with the given unit number. */
298     child = BUS_ADD_CHILD(parent, 0, "acpi_ec", ecdt->Uid);
299     if (child == NULL) {
300 	printf("%s: can't add child\n", __func__);
301 	return;
302     }
303 
304     /* Find and save the ACPI handle for this device. */
305     status = AcpiGetHandle(NULL, ecdt->Id, &h);
306     if (ACPI_FAILURE(status)) {
307 	device_delete_child(parent, child);
308 	printf("%s: can't get handle\n", __func__);
309 	return;
310     }
311     acpi_set_handle(child, h);
312 
313     /* Set the data and CSR register addresses. */
314     bus_set_resource(child, SYS_RES_IOPORT, 0, ecdt->Data.Address,
315 	/*count*/1);
316     bus_set_resource(child, SYS_RES_IOPORT, 1, ecdt->Control.Address,
317 	/*count*/1);
318 
319     /*
320      * Store values for the probe/attach routines to use.  Store the
321      * ECDT GPE bit and set the global lock flag according to _GLK.
322      * Note that it is not perfectly correct to be evaluating a method
323      * before initializing devices, but in practice this function
324      * should be safe to call at this point.
325      */
326     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
327     params->gpe_handle = NULL;
328     params->gpe_bit = ecdt->Gpe;
329     params->uid = ecdt->Uid;
330     acpi_GetInteger(h, "_GLK", &params->glk);
331     acpi_set_private(child, params);
332 
333     /* Finish the attach process. */
334     if (device_probe_and_attach(child) != 0)
335 	device_delete_child(parent, child);
336 }
337 
338 static int
339 acpi_ec_probe(device_t dev)
340 {
341     ACPI_BUFFER buf;
342     ACPI_HANDLE h;
343     ACPI_OBJECT *obj;
344     ACPI_STATUS status;
345     device_t	peer;
346     char	desc[64];
347     int		ecdt;
348     int		ret;
349     struct acpi_ec_params *params;
350     static char *ec_ids[] = { "PNP0C09", NULL };
351 
352     /* Check that this is a device and that EC is not disabled. */
353     if (acpi_get_type(dev) != ACPI_TYPE_DEVICE || acpi_disabled("ec"))
354 	return (ENXIO);
355 
356     /*
357      * If probed via ECDT, set description and continue.  Otherwise,
358      * we can access the namespace and make sure this is not a
359      * duplicate probe.
360      */
361     ret = ENXIO;
362     ecdt = 0;
363     buf.Pointer = NULL;
364     buf.Length = ACPI_ALLOCATE_BUFFER;
365     params = acpi_get_private(dev);
366     if (params != NULL) {
367 	ecdt = 1;
368 	ret = 0;
369     } else if (ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids)) {
370 	params = malloc(sizeof(struct acpi_ec_params), M_TEMP,
371 			M_WAITOK | M_ZERO);
372 	h = acpi_get_handle(dev);
373 
374 	/*
375 	 * Read the unit ID to check for duplicate attach and the
376 	 * global lock value to see if we should acquire it when
377 	 * accessing the EC.
378 	 */
379 	status = acpi_GetInteger(h, "_UID", &params->uid);
380 	if (ACPI_FAILURE(status))
381 	    params->uid = 0;
382 	status = acpi_GetInteger(h, "_GLK", &params->glk);
383 	if (ACPI_FAILURE(status))
384 	    params->glk = 0;
385 
386 	/*
387 	 * Evaluate the _GPE method to find the GPE bit used by the EC to
388 	 * signal status (SCI).  If it's a package, it contains a reference
389 	 * and GPE bit, similar to _PRW.
390 	 */
391 	status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
392 	if (ACPI_FAILURE(status)) {
393 	    device_printf(dev, "can't evaluate _GPE - %s\n",
394 			  AcpiFormatException(status));
395 	    goto out;
396 	}
397 	obj = (ACPI_OBJECT *)buf.Pointer;
398 	if (obj == NULL)
399 	    goto out;
400 
401 	switch (obj->Type) {
402 	case ACPI_TYPE_INTEGER:
403 	    params->gpe_handle = NULL;
404 	    params->gpe_bit = obj->Integer.Value;
405 	    break;
406 	case ACPI_TYPE_PACKAGE:
407 	    if (!ACPI_PKG_VALID(obj, 2))
408 		goto out;
409 	    params->gpe_handle =
410 		acpi_GetReference(NULL, &obj->Package.Elements[0]);
411 	    if (params->gpe_handle == NULL ||
412 		acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
413 		goto out;
414 	    break;
415 	default:
416 	    device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
417 	    goto out;
418 	}
419 
420 	/* Store the values we got from the namespace for attach. */
421 	acpi_set_private(dev, params);
422 
423 	/*
424 	 * Check for a duplicate probe.  This can happen when a probe
425 	 * via ECDT succeeded already.  If this is a duplicate, disable
426 	 * this device.
427 	 */
428 	peer = devclass_get_device(acpi_ec_devclass, params->uid);
429 	if (peer == NULL || !device_is_alive(peer))
430 	    ret = 0;
431 	else
432 	    device_disable(dev);
433     }
434 
435 out:
436     if (ret == 0) {
437 	snprintf(desc, sizeof(desc), "Embedded Controller: GPE %#x%s%s",
438 		 params->gpe_bit, (params->glk) ? ", GLK" : "",
439 		 ecdt ? ", ECDT" : "");
440 	device_set_desc_copy(dev, desc);
441     }
442 
443     if (ret > 0 && params)
444 	free(params, M_TEMP);
445     if (buf.Pointer)
446 	AcpiOsFree(buf.Pointer);
447     return (ret);
448 }
449 
450 static int
451 acpi_ec_attach(device_t dev)
452 {
453     struct acpi_ec_softc	*sc;
454     struct acpi_ec_params	*params;
455     ACPI_STATUS			Status;
456 
457     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
458 
459     /* Fetch/initialize softc (assumes softc is pre-zeroed). */
460     sc = device_get_softc(dev);
461     params = acpi_get_private(dev);
462     sc->ec_dev = dev;
463     sc->ec_handle = acpi_get_handle(dev);
464 
465     /* Retrieve previously probed values via device ivars. */
466     sc->ec_glk = params->glk;
467     sc->ec_gpebit = params->gpe_bit;
468     sc->ec_gpehandle = params->gpe_handle;
469     sc->ec_uid = params->uid;
470     sc->ec_suspending = FALSE;
471     acpi_set_private(dev, NULL);
472     free(params, M_TEMP);
473 
474     /* Attach bus resources for data and command/status ports. */
475     sc->ec_data_rid = 0;
476     sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
477 			&sc->ec_data_rid, RF_ACTIVE);
478     if (sc->ec_data_res == NULL) {
479 	device_printf(dev, "can't allocate data port\n");
480 	goto error;
481     }
482     sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
483     sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
484 
485     sc->ec_csr_rid = 1;
486     sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
487 			&sc->ec_csr_rid, RF_ACTIVE);
488     if (sc->ec_csr_res == NULL) {
489 	device_printf(dev, "can't allocate command/status port\n");
490 	goto error;
491     }
492     sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
493     sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
494 
495     /*
496      * Install a handler for this EC's GPE bit.  We want edge-triggered
497      * behavior.
498      */
499     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
500     Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
501 		ACPI_GPE_EDGE_TRIGGERED, &EcGpeHandler, sc);
502     if (ACPI_FAILURE(Status)) {
503 	device_printf(dev, "can't install GPE handler for %s - %s\n",
504 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
505 	goto error;
506     }
507 
508     /*
509      * Install address space handler
510      */
511     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
512     Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
513 		&EcSpaceHandler, &EcSpaceSetup, sc);
514     if (ACPI_FAILURE(Status)) {
515 	device_printf(dev, "can't install address space handler for %s - %s\n",
516 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
517 	goto error;
518     }
519 
520     /* Enable runtime GPEs for the handler. */
521     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit);
522     if (ACPI_FAILURE(Status)) {
523 	device_printf(dev, "AcpiEnableGpe failed: %s\n",
524 		      AcpiFormatException(Status));
525 	goto error;
526     }
527 
528     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
529     return (0);
530 
531 error:
532     AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, &EcGpeHandler);
533     AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
534 	EcSpaceHandler);
535     if (sc->ec_csr_res)
536 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
537 			     sc->ec_csr_res);
538     if (sc->ec_data_res)
539 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
540 			     sc->ec_data_res);
541     return (ENXIO);
542 }
543 
544 static int
545 acpi_ec_suspend(device_t dev)
546 {
547     struct acpi_ec_softc	*sc;
548 
549     sc = device_get_softc(dev);
550     sc->ec_suspending = TRUE;
551     return (0);
552 }
553 
554 static int
555 acpi_ec_resume(device_t dev)
556 {
557     struct acpi_ec_softc	*sc;
558 
559     sc = device_get_softc(dev);
560     sc->ec_suspending = FALSE;
561     return (0);
562 }
563 
564 static int
565 acpi_ec_shutdown(device_t dev)
566 {
567     struct acpi_ec_softc	*sc;
568 
569     /* Disable the GPE so we don't get EC events during shutdown. */
570     sc = device_get_softc(dev);
571     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit);
572     return (0);
573 }
574 
575 /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
576 static int
577 acpi_ec_read_method(device_t dev, u_int addr, UINT64 *val, int width)
578 {
579     struct acpi_ec_softc *sc;
580     ACPI_STATUS status;
581 
582     sc = device_get_softc(dev);
583     status = EcSpaceHandler(ACPI_READ, addr, width * 8, val, sc, NULL);
584     if (ACPI_FAILURE(status))
585 	return (ENXIO);
586     return (0);
587 }
588 
589 static int
590 acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
591 {
592     struct acpi_ec_softc *sc;
593     ACPI_STATUS status;
594 
595     sc = device_get_softc(dev);
596     status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
597     if (ACPI_FAILURE(status))
598 	return (ENXIO);
599     return (0);
600 }
601 
602 static void
603 EcGpeQueryHandler(void *Context)
604 {
605     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
606     UINT8			Data;
607     ACPI_STATUS			Status;
608     char			qxx[5];
609 
610     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
611     KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
612 
613     /* Serialize user access with EcSpaceHandler(). */
614     Status = EcLock(sc);
615     if (ACPI_FAILURE(Status)) {
616 	device_printf(sc->ec_dev, "GpeQuery lock error: %s\n",
617 	    AcpiFormatException(Status));
618 	return;
619     }
620 
621     /*
622      * Send a query command to the EC to find out which _Qxx call it
623      * wants to make.  This command clears the SCI bit and also the
624      * interrupt source since we are edge-triggered.  To prevent the GPE
625      * that may arise from running the query from causing another query
626      * to be queued, we clear the pending flag only after running it.
627      */
628     Status = EcCommand(sc, EC_COMMAND_QUERY);
629     sc->ec_sci_pend = FALSE;
630     if (ACPI_FAILURE(Status)) {
631 	EcUnlock(sc);
632 	device_printf(sc->ec_dev, "GPE query failed: %s\n",
633 	    AcpiFormatException(Status));
634 	return;
635     }
636     Data = EC_GET_DATA(sc);
637 
638     /*
639      * We have to unlock before running the _Qxx method below since that
640      * method may attempt to read/write from EC address space, causing
641      * recursive acquisition of the lock.
642      */
643     EcUnlock(sc);
644 
645     /* Ignore the value for "no outstanding event". (13.3.5) */
646     CTR2(KTR_ACPI, "ec query ok,%s running _Q%02X", Data ? "" : " not", Data);
647     if (Data == 0)
648 	return;
649 
650     /* Evaluate _Qxx to respond to the controller. */
651     snprintf(qxx, sizeof(qxx), "_Q%02X", Data);
652     AcpiUtStrupr(qxx);
653     Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
654     if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
655 	device_printf(sc->ec_dev, "evaluation of query method %s failed: %s\n",
656 	    qxx, AcpiFormatException(Status));
657     }
658 }
659 
660 /*
661  * The GPE handler is called when IBE/OBF or SCI events occur.  We are
662  * called from an unknown lock context.
663  */
664 static uint32_t
665 EcGpeHandler(void *Context)
666 {
667     struct acpi_ec_softc *sc = Context;
668     ACPI_STATUS		       Status;
669     EC_STATUS		       EcStatus;
670 
671     KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
672     CTR0(KTR_ACPI, "ec gpe handler start");
673 
674     /*
675      * Notify EcWaitEvent() that the status register is now fresh.  If we
676      * didn't do this, it wouldn't be possible to distinguish an old IBE
677      * from a new one, for example when doing a write transaction (writing
678      * address and then data values.)
679      */
680     atomic_add_int(&sc->ec_gencount, 1);
681     wakeup(&sc->ec_gencount);
682 
683     /*
684      * If the EC_SCI bit of the status register is set, queue a query handler.
685      * It will run the query and _Qxx method later, under the lock.
686      */
687     EcStatus = EC_GET_CSR(sc);
688     if ((EcStatus & EC_EVENT_SCI) && !sc->ec_sci_pend) {
689 	CTR0(KTR_ACPI, "ec gpe queueing query handler");
690 	Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
691 	if (ACPI_SUCCESS(Status))
692 	    sc->ec_sci_pend = TRUE;
693 	else
694 	    printf("EcGpeHandler: queuing GPE query handler failed\n");
695     }
696     return (0);
697 }
698 
699 static ACPI_STATUS
700 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
701 	     void **RegionContext)
702 {
703 
704     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
705 
706     /*
707      * If deactivating a region, always set the output to NULL.  Otherwise,
708      * just pass the context through.
709      */
710     if (Function == ACPI_REGION_DEACTIVATE)
711 	*RegionContext = NULL;
712     else
713 	*RegionContext = Context;
714 
715     return_ACPI_STATUS (AE_OK);
716 }
717 
718 static ACPI_STATUS
719 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 Width,
720 	       UINT64 *Value, void *Context, void *RegionContext)
721 {
722     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
723     ACPI_PHYSICAL_ADDRESS	EcAddr;
724     UINT8			*EcData;
725     ACPI_STATUS			Status;
726 
727     ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
728 
729     if (Function != ACPI_READ && Function != ACPI_WRITE)
730 	return_ACPI_STATUS (AE_BAD_PARAMETER);
731     if (Width % 8 != 0 || Value == NULL || Context == NULL)
732 	return_ACPI_STATUS (AE_BAD_PARAMETER);
733     if (Address + Width / 8 > 256)
734 	return_ACPI_STATUS (AE_BAD_ADDRESS);
735 
736     /*
737      * If booting, check if we need to run the query handler.  If so, we
738      * we call it directly here since our thread taskq is not active yet.
739      */
740     if (cold || rebooting || sc->ec_suspending) {
741 	if ((EC_GET_CSR(sc) & EC_EVENT_SCI)) {
742 	    CTR0(KTR_ACPI, "ec running gpe handler directly");
743 	    EcGpeQueryHandler(sc);
744 	}
745     }
746 
747     /* Serialize with EcGpeQueryHandler() at transaction granularity. */
748     Status = EcLock(sc);
749     if (ACPI_FAILURE(Status))
750 	return_ACPI_STATUS (Status);
751 
752     /* If we can't start burst mode, continue anyway. */
753     Status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
754     if (ACPI_SUCCESS(Status)) {
755 	if (EC_GET_DATA(sc) == EC_BURST_ACK) {
756 	    CTR0(KTR_ACPI, "ec burst enabled");
757 	    sc->ec_burstactive = TRUE;
758 	}
759     }
760 
761     /* Perform the transaction(s), based on Width. */
762     EcAddr = Address;
763     EcData = (UINT8 *)Value;
764     if (Function == ACPI_READ)
765 	*Value = 0;
766     do {
767 	switch (Function) {
768 	case ACPI_READ:
769 	    Status = EcRead(sc, EcAddr, EcData);
770 	    break;
771 	case ACPI_WRITE:
772 	    Status = EcWrite(sc, EcAddr, *EcData);
773 	    break;
774 	}
775 	if (ACPI_FAILURE(Status))
776 	    break;
777 	EcAddr++;
778 	EcData++;
779     } while (EcAddr < Address + Width / 8);
780 
781     if (sc->ec_burstactive) {
782 	sc->ec_burstactive = FALSE;
783 	if (ACPI_SUCCESS(EcCommand(sc, EC_COMMAND_BURST_DISABLE)))
784 	    CTR0(KTR_ACPI, "ec disabled burst ok");
785     }
786 
787     EcUnlock(sc);
788     return_ACPI_STATUS (Status);
789 }
790 
791 static ACPI_STATUS
792 EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
793 {
794     ACPI_STATUS status;
795     EC_STATUS ec_status;
796 
797     status = AE_NO_HARDWARE_RESPONSE;
798     ec_status = EC_GET_CSR(sc);
799     if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
800 	CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
801 	sc->ec_burstactive = FALSE;
802     }
803     if (EVENT_READY(event, ec_status)) {
804 	CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
805 	status = AE_OK;
806     }
807     return (status);
808 }
809 
810 static ACPI_STATUS
811 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
812 {
813     ACPI_STATUS	Status;
814     int		count, i, slp_ival;
815 
816     ACPI_SERIAL_ASSERT(ec);
817     Status = AE_NO_HARDWARE_RESPONSE;
818     int need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
819     /*
820      * The main CPU should be much faster than the EC.  So the status should
821      * be "not ready" when we start waiting.  But if the main CPU is really
822      * slow, it's possible we see the current "ready" response.  Since that
823      * can't be distinguished from the previous response in polled mode,
824      * this is a potential issue.  We really should have interrupts enabled
825      * during boot so there is no ambiguity in polled mode.
826      *
827      * If this occurs, we add an additional delay before actually entering
828      * the status checking loop, hopefully to allow the EC to go to work
829      * and produce a non-stale status.
830      */
831     if (need_poll) {
832 	static int	once;
833 
834 	if (EcCheckStatus(sc, "pre-check", Event) == AE_OK) {
835 	    if (!once) {
836 		device_printf(sc->ec_dev,
837 		    "warning: EC done before starting event wait\n");
838 		once = 1;
839 	    }
840 	    AcpiOsStall(10);
841 	}
842     }
843 
844     /* Wait for event by polling or GPE (interrupt). */
845     if (need_poll) {
846 	count = (ec_timeout * 1000) / EC_POLL_DELAY;
847 	if (count == 0)
848 	    count = 1;
849 	for (i = 0; i < count; i++) {
850 	    Status = EcCheckStatus(sc, "poll", Event);
851 	    if (Status == AE_OK)
852 		break;
853 	    AcpiOsStall(EC_POLL_DELAY);
854 	}
855     } else {
856 	slp_ival = hz / 1000;
857 	if (slp_ival != 0) {
858 	    count = ec_timeout;
859 	} else {
860 	    /* hz has less than 1 ms resolution so scale timeout. */
861 	    slp_ival = 1;
862 	    count = ec_timeout / (1000 / hz);
863 	}
864 
865 	/*
866 	 * Wait for the GPE to signal the status changed, checking the
867 	 * status register each time we get one.  It's possible to get a
868 	 * GPE for an event we're not interested in here (i.e., SCI for
869 	 * EC query).
870 	 */
871 	for (i = 0; i < count; i++) {
872 	    if (gen_count != sc->ec_gencount) {
873 		/*
874 		 * Record new generation count.  It's possible the GPE was
875 		 * just to notify us that a query is needed and we need to
876 		 * wait for a second GPE to signal the completion of the
877 		 * event we are actually waiting for.
878 		 */
879 		gen_count = sc->ec_gencount;
880 		Status = EcCheckStatus(sc, "sleep", Event);
881 		if (Status == AE_OK)
882 		    break;
883 	    }
884 	    tsleep(&sc->ec_gencount, PZERO, "ecgpe", slp_ival);
885 	}
886 
887 	/*
888 	 * We finished waiting for the GPE and it never arrived.  Try to
889 	 * read the register once and trust whatever value we got.  This is
890 	 * the best we can do at this point.  Then, force polled mode on
891 	 * since this system doesn't appear to generate GPEs.
892 	 */
893 	if (Status != AE_OK) {
894 	    Status = EcCheckStatus(sc, "sleep_end", Event);
895 	    device_printf(sc->ec_dev,
896 		"wait timed out (%sresponse), forcing polled mode\n",
897 		Status == AE_OK ? "" : "no ");
898 	    ec_polled_mode = TRUE;
899 	}
900     }
901     if (Status != AE_OK)
902 	    CTR0(KTR_ACPI, "error: ec wait timed out");
903     return (Status);
904 }
905 
906 static ACPI_STATUS
907 EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
908 {
909     ACPI_STATUS	status;
910     EC_EVENT	event;
911     EC_STATUS	ec_status;
912     u_int	gen_count;
913 
914     ACPI_SERIAL_ASSERT(ec);
915 
916     /* Don't use burst mode if user disabled it. */
917     if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
918 	return (AE_ERROR);
919 
920     /* Decide what to wait for based on command type. */
921     switch (cmd) {
922     case EC_COMMAND_READ:
923     case EC_COMMAND_WRITE:
924     case EC_COMMAND_BURST_DISABLE:
925 	event = EC_EVENT_INPUT_BUFFER_EMPTY;
926 	break;
927     case EC_COMMAND_QUERY:
928     case EC_COMMAND_BURST_ENABLE:
929 	event = EC_EVENT_OUTPUT_BUFFER_FULL;
930 	break;
931     default:
932 	device_printf(sc->ec_dev, "EcCommand: invalid command %#x\n", cmd);
933 	return (AE_BAD_PARAMETER);
934     }
935 
936     /* Run the command and wait for the chosen event. */
937     CTR1(KTR_ACPI, "ec running command %#x", cmd);
938     gen_count = sc->ec_gencount;
939     EC_SET_CSR(sc, cmd);
940     status = EcWaitEvent(sc, event, gen_count);
941     if (ACPI_SUCCESS(status)) {
942 	/* If we succeeded, burst flag should now be present. */
943 	if (cmd == EC_COMMAND_BURST_ENABLE) {
944 	    ec_status = EC_GET_CSR(sc);
945 	    if ((ec_status & EC_FLAG_BURST_MODE) == 0)
946 		status = AE_ERROR;
947 	}
948     } else
949 	device_printf(sc->ec_dev, "EcCommand: no response to %#x\n", cmd);
950     return (status);
951 }
952 
953 static ACPI_STATUS
954 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
955 {
956     ACPI_STATUS	status;
957     u_int gen_count;
958 
959     ACPI_SERIAL_ASSERT(ec);
960     CTR1(KTR_ACPI, "ec read from %#x", Address);
961 
962     status = EcCommand(sc, EC_COMMAND_READ);
963     if (ACPI_FAILURE(status))
964 	return (status);
965 
966     gen_count = sc->ec_gencount;
967     EC_SET_DATA(sc, Address);
968     status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
969     if (ACPI_FAILURE(status)) {
970 	device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
971 	return (status);
972     }
973     *Data = EC_GET_DATA(sc);
974 
975     return (AE_OK);
976 }
977 
978 static ACPI_STATUS
979 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 Data)
980 {
981     ACPI_STATUS	status;
982     u_int gen_count;
983 
984     ACPI_SERIAL_ASSERT(ec);
985     CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, Data);
986 
987     status = EcCommand(sc, EC_COMMAND_WRITE);
988     if (ACPI_FAILURE(status))
989 	return (status);
990 
991     gen_count = sc->ec_gencount;
992     EC_SET_DATA(sc, Address);
993     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
994     if (ACPI_FAILURE(status)) {
995 	device_printf(sc->ec_dev, "EcRead: failed waiting for sent address\n");
996 	return (status);
997     }
998 
999     gen_count = sc->ec_gencount;
1000     EC_SET_DATA(sc, Data);
1001     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1002     if (ACPI_FAILURE(status)) {
1003 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent data\n");
1004 	return (status);
1005     }
1006 
1007     return (AE_OK);
1008 }
1009