xref: /freebsd/sys/dev/acpica/acpi_ec.c (revision bad36a49985c3cd7bfcb1b35ce3ae37f007843ce)
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 #include "opt_acpi.h"
31 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/ktr.h>
34 #include <sys/bus.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/sx.h>
39 
40 #include <machine/bus.h>
41 #include <machine/resource.h>
42 #include <sys/rman.h>
43 
44 #include <contrib/dev/acpica/include/acpi.h>
45 #include <contrib/dev/acpica/include/accommon.h>
46 
47 #include <dev/acpica/acpivar.h>
48 
49 /* Hooks for the ACPI CA debugging infrastructure */
50 #define _COMPONENT	ACPI_EC
51 ACPI_MODULE_NAME("EC")
52 
53 /*
54  * EC_COMMAND:
55  * -----------
56  */
57 typedef UINT8				EC_COMMAND;
58 
59 #define EC_COMMAND_UNKNOWN		((EC_COMMAND) 0x00)
60 #define EC_COMMAND_READ			((EC_COMMAND) 0x80)
61 #define EC_COMMAND_WRITE		((EC_COMMAND) 0x81)
62 #define EC_COMMAND_BURST_ENABLE		((EC_COMMAND) 0x82)
63 #define EC_COMMAND_BURST_DISABLE	((EC_COMMAND) 0x83)
64 #define EC_COMMAND_QUERY		((EC_COMMAND) 0x84)
65 
66 /*
67  * EC_STATUS:
68  * ----------
69  * The encoding of the EC status register is illustrated below.
70  * Note that a set bit (1) indicates the property is TRUE
71  * (e.g. if bit 0 is set then the output buffer is full).
72  * +-+-+-+-+-+-+-+-+
73  * |7|6|5|4|3|2|1|0|
74  * +-+-+-+-+-+-+-+-+
75  *  | | | | | | | |
76  *  | | | | | | | +- Output Buffer Full?
77  *  | | | | | | +--- Input Buffer Full?
78  *  | | | | | +----- <reserved>
79  *  | | | | +------- Data Register is Command Byte?
80  *  | | | +--------- Burst Mode Enabled?
81  *  | | +----------- SCI Event?
82  *  | +------------- SMI Event?
83  *  +--------------- <reserved>
84  *
85  */
86 typedef UINT8				EC_STATUS;
87 
88 #define EC_FLAG_OUTPUT_BUFFER		((EC_STATUS) 0x01)
89 #define EC_FLAG_INPUT_BUFFER		((EC_STATUS) 0x02)
90 #define EC_FLAG_DATA_IS_CMD		((EC_STATUS) 0x08)
91 #define EC_FLAG_BURST_MODE		((EC_STATUS) 0x10)
92 
93 /*
94  * EC_EVENT:
95  * ---------
96  */
97 typedef UINT8				EC_EVENT;
98 
99 #define EC_EVENT_UNKNOWN		((EC_EVENT) 0x00)
100 #define EC_EVENT_OUTPUT_BUFFER_FULL	((EC_EVENT) 0x01)
101 #define EC_EVENT_INPUT_BUFFER_EMPTY	((EC_EVENT) 0x02)
102 #define EC_EVENT_SCI			((EC_EVENT) 0x20)
103 #define EC_EVENT_SMI			((EC_EVENT) 0x40)
104 
105 /* Data byte returned after burst enable indicating it was successful. */
106 #define EC_BURST_ACK			0x90
107 
108 /*
109  * Register access primitives
110  */
111 #define EC_GET_DATA(sc)							\
112 	bus_space_read_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0)
113 
114 #define EC_SET_DATA(sc, v)						\
115 	bus_space_write_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0, (v))
116 
117 #define EC_GET_CSR(sc)							\
118 	bus_space_read_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0)
119 
120 #define EC_SET_CSR(sc, v)						\
121 	bus_space_write_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0, (v))
122 
123 /* Additional params to pass from the probe routine */
124 struct acpi_ec_params {
125     int		glk;
126     int		gpe_bit;
127     ACPI_HANDLE	gpe_handle;
128     int		uid;
129 };
130 
131 /*
132  * Driver softc.
133  */
134 struct acpi_ec_softc {
135     device_t		ec_dev;
136     ACPI_HANDLE		ec_handle;
137     int			ec_uid;
138     ACPI_HANDLE		ec_gpehandle;
139     UINT8		ec_gpebit;
140 
141     int			ec_data_rid;
142     struct resource	*ec_data_res;
143     bus_space_tag_t	ec_data_tag;
144     bus_space_handle_t	ec_data_handle;
145 
146     int			ec_csr_rid;
147     struct resource	*ec_csr_res;
148     bus_space_tag_t	ec_csr_tag;
149     bus_space_handle_t	ec_csr_handle;
150 
151     int			ec_glk;
152     int			ec_glkhandle;
153     int			ec_burstactive;
154     int			ec_sci_pend;
155     volatile u_int	ec_gencount;
156     int			ec_suspending;
157 };
158 
159 /*
160  * XXX njl
161  * I couldn't find it in the spec but other implementations also use a
162  * value of 1 ms for the time to acquire global lock.
163  */
164 #define EC_LOCK_TIMEOUT	1000
165 
166 /* Default delay in microseconds between each run of the status polling loop. */
167 #define EC_POLL_DELAY	50
168 
169 /* Total time in ms spent waiting for a response from EC. */
170 #define EC_TIMEOUT	750
171 
172 #define EVENT_READY(event, status)			\
173 	(((event) == EC_EVENT_OUTPUT_BUFFER_FULL &&	\
174 	 ((status) & EC_FLAG_OUTPUT_BUFFER) != 0) ||	\
175 	 ((event) == EC_EVENT_INPUT_BUFFER_EMPTY && 	\
176 	 ((status) & EC_FLAG_INPUT_BUFFER) == 0))
177 
178 ACPI_SERIAL_DECL(ec, "ACPI embedded controller");
179 
180 static SYSCTL_NODE(_debug_acpi, OID_AUTO, ec,
181     CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
182     "EC debugging");
183 
184 static int	ec_burst_mode;
185 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, burst, CTLFLAG_RWTUN, &ec_burst_mode, 0,
186     "Enable use of burst mode (faster for nearly all systems)");
187 static int	ec_polled_mode;
188 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, polled, CTLFLAG_RWTUN, &ec_polled_mode, 0,
189     "Force use of polled mode (only if interrupt mode doesn't work)");
190 static int	ec_timeout = EC_TIMEOUT;
191 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, timeout, CTLFLAG_RWTUN, &ec_timeout,
192     EC_TIMEOUT, "Total time spent waiting for a response (poll+sleep)");
193 
194 static ACPI_STATUS
195 EcLock(struct acpi_ec_softc *sc)
196 {
197     ACPI_STATUS	status;
198 
199     /* If _GLK is non-zero, acquire the global lock. */
200     status = AE_OK;
201     if (sc->ec_glk) {
202 	status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->ec_glkhandle);
203 	if (ACPI_FAILURE(status))
204 	    return (status);
205     }
206     ACPI_SERIAL_BEGIN(ec);
207     return (status);
208 }
209 
210 static void
211 EcUnlock(struct acpi_ec_softc *sc)
212 {
213     ACPI_SERIAL_END(ec);
214     if (sc->ec_glk)
215 	AcpiReleaseGlobalLock(sc->ec_glkhandle);
216 }
217 
218 static UINT32		EcGpeHandler(ACPI_HANDLE, UINT32, void *);
219 static ACPI_STATUS	EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
220 				void *Context, void **return_Context);
221 static ACPI_STATUS	EcSpaceHandler(UINT32 Function,
222 				ACPI_PHYSICAL_ADDRESS Address,
223 				UINT32 Width, UINT64 *Value,
224 				void *Context, void *RegionContext);
225 static ACPI_STATUS	EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event,
226 				u_int gen_count);
227 static ACPI_STATUS	EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
228 static ACPI_STATUS	EcRead(struct acpi_ec_softc *sc, UINT8 Address,
229 				UINT8 *Data);
230 static ACPI_STATUS	EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
231 				UINT8 Data);
232 static int		acpi_ec_probe(device_t dev);
233 static int		acpi_ec_attach(device_t dev);
234 static int		acpi_ec_suspend(device_t dev);
235 static int		acpi_ec_resume(device_t dev);
236 static int		acpi_ec_shutdown(device_t dev);
237 static int		acpi_ec_read_method(device_t dev, u_int addr,
238 				UINT64 *val, int width);
239 static int		acpi_ec_write_method(device_t dev, u_int addr,
240 				UINT64 val, int width);
241 
242 static device_method_t acpi_ec_methods[] = {
243     /* Device interface */
244     DEVMETHOD(device_probe,	acpi_ec_probe),
245     DEVMETHOD(device_attach,	acpi_ec_attach),
246     DEVMETHOD(device_suspend,	acpi_ec_suspend),
247     DEVMETHOD(device_resume,	acpi_ec_resume),
248     DEVMETHOD(device_shutdown,	acpi_ec_shutdown),
249 
250     /* Embedded controller interface */
251     DEVMETHOD(acpi_ec_read,	acpi_ec_read_method),
252     DEVMETHOD(acpi_ec_write,	acpi_ec_write_method),
253 
254     DEVMETHOD_END
255 };
256 
257 static driver_t acpi_ec_driver = {
258     "acpi_ec",
259     acpi_ec_methods,
260     sizeof(struct acpi_ec_softc),
261 };
262 
263 DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, 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     int		ecdt;
343     int		ret, rc;
344     struct acpi_ec_params *params;
345     static char *ec_ids[] = { "PNP0C09", NULL };
346 
347     ret = ENXIO;
348 
349     /* Check that this is a device and that EC is not disabled. */
350     if (acpi_get_type(dev) != ACPI_TYPE_DEVICE || acpi_disabled("ec"))
351 	return (ret);
352 
353     if (device_is_devclass_fixed(dev)) {
354 	/*
355 	 * If probed via ECDT, set description and continue. Otherwise, we can
356 	 * access the namespace and make sure this is not a duplicate probe.
357 	 */
358         ecdt = 1;
359         params = acpi_get_private(dev);
360 	if (params != NULL)
361 	    ret = 0;
362 
363 	goto out;
364     } else
365 	ecdt = 0;
366 
367     rc = ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids, NULL);
368     if (rc > 0)
369 	return (rc);
370 
371     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
372 
373     buf.Pointer = NULL;
374     buf.Length = ACPI_ALLOCATE_BUFFER;
375     h = acpi_get_handle(dev);
376 
377     /*
378      * Read the unit ID to check for duplicate attach and the global lock value
379      * to see if we should acquire it when accessing the EC.
380      */
381     status = acpi_GetInteger(h, "_UID", &params->uid);
382     if (ACPI_FAILURE(status))
383 	params->uid = 0;
384 
385     /*
386      * Check for a duplicate probe. This can happen when a probe via ECDT
387      * succeeded already. If this is a duplicate, disable this device.
388      *
389      * NB: It would seem device_disable would be sufficient to not get
390      * duplicated devices, and ENXIO isn't needed, however, device_probe() only
391      * checks DF_ENABLED at the start and so disabling it here is too late to
392      * prevent device_attach() from being called.
393      */
394     peer = devclass_get_device(device_get_devclass(dev), params->uid);
395     if (peer != NULL && device_is_alive(peer)) {
396 	device_disable(dev);
397 	goto out;
398     }
399 
400     status = acpi_GetInteger(h, "_GLK", &params->glk);
401     if (ACPI_FAILURE(status))
402 	params->glk = 0;
403 
404     /*
405      * Evaluate the _GPE method to find the GPE bit used by the EC to signal
406      * status (SCI).  If it's a package, it contains a reference and GPE bit,
407      * similar to _PRW.
408      */
409     status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
410     if (ACPI_FAILURE(status)) {
411 	device_printf(dev, "can't evaluate _GPE - %s\n", AcpiFormatException(status));
412 	goto out;
413     }
414 
415     obj = (ACPI_OBJECT *)buf.Pointer;
416     if (obj == NULL)
417 	goto out;
418 
419     switch (obj->Type) {
420     case ACPI_TYPE_INTEGER:
421 	params->gpe_handle = NULL;
422 	params->gpe_bit = obj->Integer.Value;
423 	break;
424     case ACPI_TYPE_PACKAGE:
425 	if (!ACPI_PKG_VALID(obj, 2))
426 	    goto out;
427 	params->gpe_handle = acpi_GetReference(NULL, &obj->Package.Elements[0]);
428 	if (params->gpe_handle == NULL ||
429 	    acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
430 		goto out;
431 	break;
432     default:
433 	device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
434 	goto out;
435     }
436 
437     /* Store the values we got from the namespace for attach. */
438     acpi_set_private(dev, params);
439 
440     if (buf.Pointer)
441 	AcpiOsFree(buf.Pointer);
442 
443     ret = rc;
444 out:
445     if (ret <= 0) {
446 	device_set_descf(dev, "Embedded Controller: GPE %#x%s%s",
447 			 params->gpe_bit, (params->glk) ? ", GLK" : "",
448 			 ecdt ? ", ECDT" : "");
449     } else
450 	free(params, M_TEMP);
451 
452     return (ret);
453 }
454 
455 static int
456 acpi_ec_attach(device_t dev)
457 {
458     struct acpi_ec_softc	*sc;
459     struct acpi_ec_params	*params;
460     ACPI_STATUS			Status;
461 
462     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
463 
464     /* Fetch/initialize softc (assumes softc is pre-zeroed). */
465     sc = device_get_softc(dev);
466     params = acpi_get_private(dev);
467     sc->ec_dev = dev;
468     sc->ec_handle = acpi_get_handle(dev);
469 
470     /* Retrieve previously probed values via device ivars. */
471     sc->ec_glk = params->glk;
472     sc->ec_gpebit = params->gpe_bit;
473     sc->ec_gpehandle = params->gpe_handle;
474     sc->ec_uid = params->uid;
475     sc->ec_suspending = FALSE;
476     acpi_set_private(dev, NULL);
477     free(params, M_TEMP);
478 
479     /* Attach bus resources for data and command/status ports. */
480     sc->ec_data_rid = 0;
481     sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
482 			&sc->ec_data_rid, RF_ACTIVE);
483     if (sc->ec_data_res == NULL) {
484 	device_printf(dev, "can't allocate data port\n");
485 	goto error;
486     }
487     sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
488     sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
489 
490     sc->ec_csr_rid = 1;
491     sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
492 			&sc->ec_csr_rid, RF_ACTIVE);
493     if (sc->ec_csr_res == NULL) {
494 	device_printf(dev, "can't allocate command/status port\n");
495 	goto error;
496     }
497     sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
498     sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
499 
500     /*
501      * Install a handler for this EC's GPE bit.  We want edge-triggered
502      * behavior.
503      */
504     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
505     Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
506 		ACPI_GPE_EDGE_TRIGGERED, EcGpeHandler, sc);
507     if (ACPI_FAILURE(Status)) {
508 	device_printf(dev, "can't install GPE handler for %s - %s\n",
509 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
510 	goto error;
511     }
512 
513     /*
514      * Install address space handler
515      */
516     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
517     Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
518 		&EcSpaceHandler, &EcSpaceSetup, sc);
519     if (ACPI_FAILURE(Status)) {
520 	device_printf(dev, "can't install address space handler for %s - %s\n",
521 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
522 	goto error;
523     }
524 
525     /* Enable runtime GPEs for the handler. */
526     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit);
527     if (ACPI_FAILURE(Status)) {
528 	device_printf(dev, "AcpiEnableGpe failed: %s\n",
529 		      AcpiFormatException(Status));
530 	goto error;
531     }
532 
533     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
534     return (0);
535 
536 error:
537     AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, EcGpeHandler);
538     AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
539 	EcSpaceHandler);
540     if (sc->ec_csr_res)
541 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
542 			     sc->ec_csr_res);
543     if (sc->ec_data_res)
544 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
545 			     sc->ec_data_res);
546     return (ENXIO);
547 }
548 
549 static int
550 acpi_ec_suspend(device_t dev)
551 {
552     struct acpi_ec_softc	*sc;
553 
554     sc = device_get_softc(dev);
555     sc->ec_suspending = TRUE;
556     return (0);
557 }
558 
559 static int
560 acpi_ec_resume(device_t dev)
561 {
562     struct acpi_ec_softc	*sc;
563 
564     sc = device_get_softc(dev);
565     sc->ec_suspending = FALSE;
566     return (0);
567 }
568 
569 static int
570 acpi_ec_shutdown(device_t dev)
571 {
572     struct acpi_ec_softc	*sc;
573 
574     /* Disable the GPE so we don't get EC events during shutdown. */
575     sc = device_get_softc(dev);
576     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit);
577     return (0);
578 }
579 
580 /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
581 static int
582 acpi_ec_read_method(device_t dev, u_int addr, UINT64 *val, int width)
583 {
584     struct acpi_ec_softc *sc;
585     ACPI_STATUS status;
586 
587     sc = device_get_softc(dev);
588     status = EcSpaceHandler(ACPI_READ, addr, width * 8, val, sc, NULL);
589     if (ACPI_FAILURE(status))
590 	return (ENXIO);
591     return (0);
592 }
593 
594 static int
595 acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
596 {
597     struct acpi_ec_softc *sc;
598     ACPI_STATUS status;
599 
600     sc = device_get_softc(dev);
601     status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
602     if (ACPI_FAILURE(status))
603 	return (ENXIO);
604     return (0);
605 }
606 
607 static ACPI_STATUS
608 EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
609 {
610     ACPI_STATUS status;
611     EC_STATUS ec_status;
612 
613     status = AE_NO_HARDWARE_RESPONSE;
614     ec_status = EC_GET_CSR(sc);
615     if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
616 	CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
617 	sc->ec_burstactive = FALSE;
618     }
619     if (EVENT_READY(event, ec_status)) {
620 	CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
621 	status = AE_OK;
622     }
623     return (status);
624 }
625 
626 static void
627 EcGpeQueryHandlerSub(struct acpi_ec_softc *sc)
628 {
629     UINT8			Data;
630     ACPI_STATUS			Status;
631     int				retry;
632     char			qxx[5];
633 
634     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
635 
636     /* Serialize user access with EcSpaceHandler(). */
637     Status = EcLock(sc);
638     if (ACPI_FAILURE(Status)) {
639 	device_printf(sc->ec_dev, "GpeQuery lock error: %s\n",
640 	    AcpiFormatException(Status));
641 	return;
642     }
643 
644     /*
645      * Send a query command to the EC to find out which _Qxx call it
646      * wants to make.  This command clears the SCI bit and also the
647      * interrupt source since we are edge-triggered.  To prevent the GPE
648      * that may arise from running the query from causing another query
649      * to be queued, we clear the pending flag only after running it.
650      */
651     for (retry = 0; retry < 2; retry++) {
652 	Status = EcCommand(sc, EC_COMMAND_QUERY);
653 	if (ACPI_SUCCESS(Status))
654 	    break;
655 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
656 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
657 	    break;
658     }
659     if (ACPI_FAILURE(Status)) {
660 	EcUnlock(sc);
661 	device_printf(sc->ec_dev, "GPE query failed: %s\n",
662 	    AcpiFormatException(Status));
663 	return;
664     }
665     Data = EC_GET_DATA(sc);
666 
667     /*
668      * We have to unlock before running the _Qxx method below since that
669      * method may attempt to read/write from EC address space, causing
670      * recursive acquisition of the lock.
671      */
672     EcUnlock(sc);
673 
674     /* Ignore the value for "no outstanding event". (13.3.5) */
675     CTR2(KTR_ACPI, "ec query ok,%s running _Q%02X", Data ? "" : " not", Data);
676     if (Data == 0)
677 	return;
678 
679     /* Evaluate _Qxx to respond to the controller. */
680     snprintf(qxx, sizeof(qxx), "_Q%02X", Data);
681     AcpiUtStrupr(qxx);
682     Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
683     if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
684 	device_printf(sc->ec_dev, "evaluation of query method %s failed: %s\n",
685 	    qxx, AcpiFormatException(Status));
686     }
687 }
688 
689 static void
690 EcGpeQueryHandler(void *Context)
691 {
692     struct acpi_ec_softc *sc = (struct acpi_ec_softc *)Context;
693     int pending;
694 
695     KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
696 
697     do {
698 	/* Read the current pending count */
699 	pending = atomic_load_acq_int(&sc->ec_sci_pend);
700 
701 	/* Call GPE handler function */
702 	EcGpeQueryHandlerSub(sc);
703 
704 	/*
705 	 * Try to reset the pending count to zero. If this fails we
706 	 * know another GPE event has occurred while handling the
707 	 * current GPE event and need to loop.
708 	 */
709     } while (!atomic_cmpset_int(&sc->ec_sci_pend, pending, 0));
710 }
711 
712 /*
713  * The GPE handler is called when IBE/OBF or SCI events occur.  We are
714  * called from an unknown lock context.
715  */
716 static UINT32
717 EcGpeHandler(ACPI_HANDLE GpeDevice, UINT32 GpeNumber, void *Context)
718 {
719     struct acpi_ec_softc *sc = Context;
720     ACPI_STATUS		       Status;
721     EC_STATUS		       EcStatus;
722 
723     KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
724     CTR0(KTR_ACPI, "ec gpe handler start");
725 
726     /*
727      * Notify EcWaitEvent() that the status register is now fresh.  If we
728      * didn't do this, it wouldn't be possible to distinguish an old IBE
729      * from a new one, for example when doing a write transaction (writing
730      * address and then data values.)
731      */
732     atomic_add_int(&sc->ec_gencount, 1);
733     wakeup(sc);
734 
735     /*
736      * If the EC_SCI bit of the status register is set, queue a query handler.
737      * It will run the query and _Qxx method later, under the lock.
738      */
739     EcStatus = EC_GET_CSR(sc);
740     if ((EcStatus & EC_EVENT_SCI) &&
741 	atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
742 	CTR0(KTR_ACPI, "ec gpe queueing query handler");
743 	Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
744 	if (ACPI_FAILURE(Status)) {
745 	    printf("EcGpeHandler: queuing GPE query handler failed\n");
746 	    atomic_store_rel_int(&sc->ec_sci_pend, 0);
747 	}
748     }
749     return (ACPI_REENABLE_GPE);
750 }
751 
752 static ACPI_STATUS
753 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
754 	     void **RegionContext)
755 {
756 
757     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
758 
759     /*
760      * If deactivating a region, always set the output to NULL.  Otherwise,
761      * just pass the context through.
762      */
763     if (Function == ACPI_REGION_DEACTIVATE)
764 	*RegionContext = NULL;
765     else
766 	*RegionContext = Context;
767 
768     return_ACPI_STATUS (AE_OK);
769 }
770 
771 static ACPI_STATUS
772 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 Width,
773 	       UINT64 *Value, void *Context, void *RegionContext)
774 {
775     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
776     ACPI_PHYSICAL_ADDRESS	EcAddr;
777     UINT8			*EcData;
778     ACPI_STATUS			Status;
779 
780     ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
781 
782     if (Function != ACPI_READ && Function != ACPI_WRITE)
783 	return_ACPI_STATUS (AE_BAD_PARAMETER);
784     if (Width % 8 != 0 || Value == NULL || Context == NULL)
785 	return_ACPI_STATUS (AE_BAD_PARAMETER);
786     if (Address + Width / 8 > 256)
787 	return_ACPI_STATUS (AE_BAD_ADDRESS);
788 
789     /*
790      * If booting, check if we need to run the query handler.  If so, we
791      * we call it directly here since our thread taskq is not active yet.
792      */
793     if (cold || rebooting || sc->ec_suspending) {
794 	if ((EC_GET_CSR(sc) & EC_EVENT_SCI) &&
795 	    atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
796 	    CTR0(KTR_ACPI, "ec running gpe handler directly");
797 	    EcGpeQueryHandler(sc);
798 	}
799     }
800 
801     /* Serialize with EcGpeQueryHandler() at transaction granularity. */
802     Status = EcLock(sc);
803     if (ACPI_FAILURE(Status))
804 	return_ACPI_STATUS (Status);
805 
806     /* If we can't start burst mode, continue anyway. */
807     Status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
808     if (ACPI_SUCCESS(Status)) {
809 	if (EC_GET_DATA(sc) == EC_BURST_ACK) {
810 	    CTR0(KTR_ACPI, "ec burst enabled");
811 	    sc->ec_burstactive = TRUE;
812 	}
813     }
814 
815     /* Perform the transaction(s), based on Width. */
816     EcAddr = Address;
817     EcData = (UINT8 *)Value;
818     if (Function == ACPI_READ)
819 	*Value = 0;
820     do {
821 	switch (Function) {
822 	case ACPI_READ:
823 	    Status = EcRead(sc, EcAddr, EcData);
824 	    break;
825 	case ACPI_WRITE:
826 	    Status = EcWrite(sc, EcAddr, *EcData);
827 	    break;
828 	}
829 	if (ACPI_FAILURE(Status))
830 	    break;
831 	EcAddr++;
832 	EcData++;
833     } while (EcAddr < Address + Width / 8);
834 
835     if (sc->ec_burstactive) {
836 	sc->ec_burstactive = FALSE;
837 	if (ACPI_SUCCESS(EcCommand(sc, EC_COMMAND_BURST_DISABLE)))
838 	    CTR0(KTR_ACPI, "ec disabled burst ok");
839     }
840 
841     EcUnlock(sc);
842     return_ACPI_STATUS (Status);
843 }
844 
845 static ACPI_STATUS
846 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
847 {
848     static int	no_intr = 0;
849     ACPI_STATUS	Status;
850     int		count, i, need_poll, slp_ival;
851 
852     ACPI_SERIAL_ASSERT(ec);
853     Status = AE_NO_HARDWARE_RESPONSE;
854     need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
855 
856     /* Wait for event by polling or GPE (interrupt). */
857     if (need_poll) {
858 	count = (ec_timeout * 1000) / EC_POLL_DELAY;
859 	if (count == 0)
860 	    count = 1;
861 	DELAY(10);
862 	for (i = 0; i < count; i++) {
863 	    Status = EcCheckStatus(sc, "poll", Event);
864 	    if (ACPI_SUCCESS(Status))
865 		break;
866 	    DELAY(EC_POLL_DELAY);
867 	}
868     } else {
869 	slp_ival = hz / 1000;
870 	if (slp_ival != 0) {
871 	    count = ec_timeout;
872 	} else {
873 	    /* hz has less than 1 ms resolution so scale timeout. */
874 	    slp_ival = 1;
875 	    count = ec_timeout / (1000 / hz);
876 	}
877 
878 	/*
879 	 * Wait for the GPE to signal the status changed, checking the
880 	 * status register each time we get one.  It's possible to get a
881 	 * GPE for an event we're not interested in here (i.e., SCI for
882 	 * EC query).
883 	 */
884 	for (i = 0; i < count; i++) {
885 	    if (gen_count == sc->ec_gencount)
886 		tsleep(sc, 0, "ecgpe", slp_ival);
887 	    /*
888 	     * Record new generation count.  It's possible the GPE was
889 	     * just to notify us that a query is needed and we need to
890 	     * wait for a second GPE to signal the completion of the
891 	     * event we are actually waiting for.
892 	     */
893 	    Status = EcCheckStatus(sc, "sleep", Event);
894 	    if (ACPI_SUCCESS(Status)) {
895 		if (gen_count == sc->ec_gencount)
896 		    no_intr++;
897 		else
898 		    no_intr = 0;
899 		break;
900 	    }
901 	    gen_count = sc->ec_gencount;
902 	}
903 
904 	/*
905 	 * We finished waiting for the GPE and it never arrived.  Try to
906 	 * read the register once and trust whatever value we got.  This is
907 	 * the best we can do at this point.
908 	 */
909 	if (ACPI_FAILURE(Status))
910 	    Status = EcCheckStatus(sc, "sleep_end", Event);
911     }
912     if (!need_poll && no_intr > 10) {
913 	device_printf(sc->ec_dev,
914 	    "not getting interrupts, switched to polled mode\n");
915 	ec_polled_mode = 1;
916     }
917     if (ACPI_FAILURE(Status))
918 	    CTR0(KTR_ACPI, "error: ec wait timed out");
919     return (Status);
920 }
921 
922 static ACPI_STATUS
923 EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
924 {
925     ACPI_STATUS	status;
926     EC_EVENT	event;
927     EC_STATUS	ec_status;
928     u_int	gen_count;
929 
930     ACPI_SERIAL_ASSERT(ec);
931 
932     /* Don't use burst mode if user disabled it. */
933     if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
934 	return (AE_ERROR);
935 
936     /* Decide what to wait for based on command type. */
937     switch (cmd) {
938     case EC_COMMAND_READ:
939     case EC_COMMAND_WRITE:
940     case EC_COMMAND_BURST_DISABLE:
941 	event = EC_EVENT_INPUT_BUFFER_EMPTY;
942 	break;
943     case EC_COMMAND_QUERY:
944     case EC_COMMAND_BURST_ENABLE:
945 	event = EC_EVENT_OUTPUT_BUFFER_FULL;
946 	break;
947     default:
948 	device_printf(sc->ec_dev, "EcCommand: invalid command %#x\n", cmd);
949 	return (AE_BAD_PARAMETER);
950     }
951 
952     /*
953      * Ensure empty input buffer before issuing command.
954      * Use generation count of zero to force a quick check.
955      */
956     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, 0);
957     if (ACPI_FAILURE(status))
958 	return (status);
959 
960     /* Run the command and wait for the chosen event. */
961     CTR1(KTR_ACPI, "ec running command %#x", cmd);
962     gen_count = sc->ec_gencount;
963     EC_SET_CSR(sc, cmd);
964     status = EcWaitEvent(sc, event, gen_count);
965     if (ACPI_SUCCESS(status)) {
966 	/* If we succeeded, burst flag should now be present. */
967 	if (cmd == EC_COMMAND_BURST_ENABLE) {
968 	    ec_status = EC_GET_CSR(sc);
969 	    if ((ec_status & EC_FLAG_BURST_MODE) == 0)
970 		status = AE_ERROR;
971 	}
972     } else
973 	device_printf(sc->ec_dev, "EcCommand: no response to %#x\n", cmd);
974     return (status);
975 }
976 
977 static ACPI_STATUS
978 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
979 {
980     ACPI_STATUS	status;
981     u_int gen_count;
982     int retry;
983 
984     ACPI_SERIAL_ASSERT(ec);
985     CTR1(KTR_ACPI, "ec read from %#x", Address);
986 
987     for (retry = 0; retry < 2; retry++) {
988 	status = EcCommand(sc, EC_COMMAND_READ);
989 	if (ACPI_FAILURE(status))
990 	    return (status);
991 
992 	gen_count = sc->ec_gencount;
993 	EC_SET_DATA(sc, Address);
994 	status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
995 	if (ACPI_SUCCESS(status)) {
996 	    *Data = EC_GET_DATA(sc);
997 	    return (AE_OK);
998 	}
999 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
1000 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
1001 	    break;
1002     }
1003     device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
1004     return (status);
1005 }
1006 
1007 static ACPI_STATUS
1008 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 Data)
1009 {
1010     ACPI_STATUS	status;
1011     u_int gen_count;
1012 
1013     ACPI_SERIAL_ASSERT(ec);
1014     CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, Data);
1015 
1016     status = EcCommand(sc, EC_COMMAND_WRITE);
1017     if (ACPI_FAILURE(status))
1018 	return (status);
1019 
1020     gen_count = sc->ec_gencount;
1021     EC_SET_DATA(sc, Address);
1022     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1023     if (ACPI_FAILURE(status)) {
1024 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent address\n");
1025 	return (status);
1026     }
1027 
1028     gen_count = sc->ec_gencount;
1029     EC_SET_DATA(sc, Data);
1030     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1031     if (ACPI_FAILURE(status)) {
1032 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent data\n");
1033 	return (status);
1034     }
1035 
1036     return (AE_OK);
1037 }
1038