xref: /freebsd/sys/dev/acpica/acpi_ec.c (revision d9a42747950146bf03cda7f6e25d219253f8a57a)
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/ktr.h>
36 #include <sys/bus.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/sx.h>
41 
42 #include <machine/bus.h>
43 #include <machine/resource.h>
44 #include <sys/rman.h>
45 
46 #include <contrib/dev/acpica/include/acpi.h>
47 #include <contrib/dev/acpica/include/accommon.h>
48 
49 #include <dev/acpica/acpivar.h>
50 
51 /* Hooks for the ACPI CA debugging infrastructure */
52 #define _COMPONENT	ACPI_EC
53 ACPI_MODULE_NAME("EC")
54 
55 /*
56  * EC_COMMAND:
57  * -----------
58  */
59 typedef UINT8				EC_COMMAND;
60 
61 #define EC_COMMAND_UNKNOWN		((EC_COMMAND) 0x00)
62 #define EC_COMMAND_READ			((EC_COMMAND) 0x80)
63 #define EC_COMMAND_WRITE		((EC_COMMAND) 0x81)
64 #define EC_COMMAND_BURST_ENABLE		((EC_COMMAND) 0x82)
65 #define EC_COMMAND_BURST_DISABLE	((EC_COMMAND) 0x83)
66 #define EC_COMMAND_QUERY		((EC_COMMAND) 0x84)
67 
68 /*
69  * EC_STATUS:
70  * ----------
71  * The encoding of the EC status register is illustrated below.
72  * Note that a set bit (1) indicates the property is TRUE
73  * (e.g. if bit 0 is set then the output buffer is full).
74  * +-+-+-+-+-+-+-+-+
75  * |7|6|5|4|3|2|1|0|
76  * +-+-+-+-+-+-+-+-+
77  *  | | | | | | | |
78  *  | | | | | | | +- Output Buffer Full?
79  *  | | | | | | +--- Input Buffer Full?
80  *  | | | | | +----- <reserved>
81  *  | | | | +------- Data Register is Command Byte?
82  *  | | | +--------- Burst Mode Enabled?
83  *  | | +----------- SCI Event?
84  *  | +------------- SMI Event?
85  *  +--------------- <reserved>
86  *
87  */
88 typedef UINT8				EC_STATUS;
89 
90 #define EC_FLAG_OUTPUT_BUFFER		((EC_STATUS) 0x01)
91 #define EC_FLAG_INPUT_BUFFER		((EC_STATUS) 0x02)
92 #define EC_FLAG_DATA_IS_CMD		((EC_STATUS) 0x08)
93 #define EC_FLAG_BURST_MODE		((EC_STATUS) 0x10)
94 
95 /*
96  * EC_EVENT:
97  * ---------
98  */
99 typedef UINT8				EC_EVENT;
100 
101 #define EC_EVENT_UNKNOWN		((EC_EVENT) 0x00)
102 #define EC_EVENT_OUTPUT_BUFFER_FULL	((EC_EVENT) 0x01)
103 #define EC_EVENT_INPUT_BUFFER_EMPTY	((EC_EVENT) 0x02)
104 #define EC_EVENT_SCI			((EC_EVENT) 0x20)
105 #define EC_EVENT_SMI			((EC_EVENT) 0x40)
106 
107 /* Data byte returned after burst enable indicating it was successful. */
108 #define EC_BURST_ACK			0x90
109 
110 /*
111  * Register access primitives
112  */
113 #define EC_GET_DATA(sc)							\
114 	bus_space_read_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0)
115 
116 #define EC_SET_DATA(sc, v)						\
117 	bus_space_write_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0, (v))
118 
119 #define EC_GET_CSR(sc)							\
120 	bus_space_read_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0)
121 
122 #define EC_SET_CSR(sc, v)						\
123 	bus_space_write_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0, (v))
124 
125 /* Additional params to pass from the probe routine */
126 struct acpi_ec_params {
127     int		glk;
128     int		gpe_bit;
129     ACPI_HANDLE	gpe_handle;
130     int		uid;
131 };
132 
133 /*
134  * Driver softc.
135  */
136 struct acpi_ec_softc {
137     device_t		ec_dev;
138     ACPI_HANDLE		ec_handle;
139     int			ec_uid;
140     ACPI_HANDLE		ec_gpehandle;
141     UINT8		ec_gpebit;
142 
143     int			ec_data_rid;
144     struct resource	*ec_data_res;
145     bus_space_tag_t	ec_data_tag;
146     bus_space_handle_t	ec_data_handle;
147 
148     int			ec_csr_rid;
149     struct resource	*ec_csr_res;
150     bus_space_tag_t	ec_csr_tag;
151     bus_space_handle_t	ec_csr_handle;
152 
153     int			ec_glk;
154     int			ec_glkhandle;
155     int			ec_burstactive;
156     int			ec_sci_pend;
157     volatile u_int	ec_gencount;
158     int			ec_suspending;
159 };
160 
161 /*
162  * XXX njl
163  * I couldn't find it in the spec but other implementations also use a
164  * value of 1 ms for the time to acquire global lock.
165  */
166 #define EC_LOCK_TIMEOUT	1000
167 
168 /* Default delay in microseconds between each run of the status polling loop. */
169 #define EC_POLL_DELAY	50
170 
171 /* Total time in ms spent waiting for a response from EC. */
172 #define EC_TIMEOUT	750
173 
174 #define EVENT_READY(event, status)			\
175 	(((event) == EC_EVENT_OUTPUT_BUFFER_FULL &&	\
176 	 ((status) & EC_FLAG_OUTPUT_BUFFER) != 0) ||	\
177 	 ((event) == EC_EVENT_INPUT_BUFFER_EMPTY && 	\
178 	 ((status) & EC_FLAG_INPUT_BUFFER) == 0))
179 
180 ACPI_SERIAL_DECL(ec, "ACPI embedded controller");
181 
182 static SYSCTL_NODE(_debug_acpi, OID_AUTO, ec,
183     CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
184     "EC debugging");
185 
186 static int	ec_burst_mode;
187 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, burst, CTLFLAG_RWTUN, &ec_burst_mode, 0,
188     "Enable use of burst mode (faster for nearly all systems)");
189 static int	ec_polled_mode;
190 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, polled, CTLFLAG_RWTUN, &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 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, timeout, CTLFLAG_RWTUN, &ec_timeout,
194     EC_TIMEOUT, "Total time spent waiting for a response (poll+sleep)");
195 
196 static ACPI_STATUS
197 EcLock(struct acpi_ec_softc *sc)
198 {
199     ACPI_STATUS	status;
200 
201     /* If _GLK is non-zero, acquire the global lock. */
202     status = AE_OK;
203     if (sc->ec_glk) {
204 	status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->ec_glkhandle);
205 	if (ACPI_FAILURE(status))
206 	    return (status);
207     }
208     ACPI_SERIAL_BEGIN(ec);
209     return (status);
210 }
211 
212 static void
213 EcUnlock(struct acpi_ec_softc *sc)
214 {
215     ACPI_SERIAL_END(ec);
216     if (sc->ec_glk)
217 	AcpiReleaseGlobalLock(sc->ec_glkhandle);
218 }
219 
220 static UINT32		EcGpeHandler(ACPI_HANDLE, UINT32, void *);
221 static ACPI_STATUS	EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
222 				void *Context, void **return_Context);
223 static ACPI_STATUS	EcSpaceHandler(UINT32 Function,
224 				ACPI_PHYSICAL_ADDRESS Address,
225 				UINT32 Width, UINT64 *Value,
226 				void *Context, void *RegionContext);
227 static ACPI_STATUS	EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event,
228 				u_int gen_count);
229 static ACPI_STATUS	EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
230 static ACPI_STATUS	EcRead(struct acpi_ec_softc *sc, UINT8 Address,
231 				UINT8 *Data);
232 static ACPI_STATUS	EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
233 				UINT8 Data);
234 static int		acpi_ec_probe(device_t dev);
235 static int		acpi_ec_attach(device_t dev);
236 static int		acpi_ec_suspend(device_t dev);
237 static int		acpi_ec_resume(device_t dev);
238 static int		acpi_ec_shutdown(device_t dev);
239 static int		acpi_ec_read_method(device_t dev, u_int addr,
240 				UINT64 *val, int width);
241 static int		acpi_ec_write_method(device_t dev, u_int addr,
242 				UINT64 val, int width);
243 
244 static device_method_t acpi_ec_methods[] = {
245     /* Device interface */
246     DEVMETHOD(device_probe,	acpi_ec_probe),
247     DEVMETHOD(device_attach,	acpi_ec_attach),
248     DEVMETHOD(device_suspend,	acpi_ec_suspend),
249     DEVMETHOD(device_resume,	acpi_ec_resume),
250     DEVMETHOD(device_shutdown,	acpi_ec_shutdown),
251 
252     /* Embedded controller interface */
253     DEVMETHOD(acpi_ec_read,	acpi_ec_read_method),
254     DEVMETHOD(acpi_ec_write,	acpi_ec_write_method),
255 
256     DEVMETHOD_END
257 };
258 
259 static driver_t acpi_ec_driver = {
260     "acpi_ec",
261     acpi_ec_methods,
262     sizeof(struct acpi_ec_softc),
263 };
264 
265 DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, 0, 0);
266 MODULE_DEPEND(acpi_ec, acpi, 1, 1, 1);
267 
268 /*
269  * Look for an ECDT and if we find one, set up default GPE and
270  * space handlers to catch attempts to access EC space before
271  * we have a real driver instance in place.
272  *
273  * TODO: Some old Gateway laptops need us to fake up an ECDT or
274  * otherwise attach early so that _REG methods can run.
275  */
276 void
277 acpi_ec_ecdt_probe(device_t parent)
278 {
279     ACPI_TABLE_ECDT *ecdt;
280     ACPI_STATUS	     status;
281     device_t	     child;
282     ACPI_HANDLE	     h;
283     struct acpi_ec_params *params;
284 
285     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
286 
287     /* Find and validate the ECDT. */
288     status = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
289     if (ACPI_FAILURE(status) ||
290 	ecdt->Control.BitWidth != 8 ||
291 	ecdt->Data.BitWidth != 8) {
292 	return;
293     }
294 
295     /* Create the child device with the given unit number. */
296     child = BUS_ADD_CHILD(parent, 3, "acpi_ec", ecdt->Uid);
297     if (child == NULL) {
298 	printf("%s: can't add child\n", __func__);
299 	return;
300     }
301 
302     /* Find and save the ACPI handle for this device. */
303     status = AcpiGetHandle(NULL, ecdt->Id, &h);
304     if (ACPI_FAILURE(status)) {
305 	device_delete_child(parent, child);
306 	printf("%s: can't get handle\n", __func__);
307 	return;
308     }
309     acpi_set_handle(child, h);
310 
311     /* Set the data and CSR register addresses. */
312     bus_set_resource(child, SYS_RES_IOPORT, 0, ecdt->Data.Address,
313 	/*count*/1);
314     bus_set_resource(child, SYS_RES_IOPORT, 1, ecdt->Control.Address,
315 	/*count*/1);
316 
317     /*
318      * Store values for the probe/attach routines to use.  Store the
319      * ECDT GPE bit and set the global lock flag according to _GLK.
320      * Note that it is not perfectly correct to be evaluating a method
321      * before initializing devices, but in practice this function
322      * should be safe to call at this point.
323      */
324     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
325     params->gpe_handle = NULL;
326     params->gpe_bit = ecdt->Gpe;
327     params->uid = ecdt->Uid;
328     acpi_GetInteger(h, "_GLK", &params->glk);
329     acpi_set_private(child, params);
330 
331     /* Finish the attach process. */
332     if (device_probe_and_attach(child) != 0)
333 	device_delete_child(parent, child);
334 }
335 
336 static int
337 acpi_ec_probe(device_t dev)
338 {
339     ACPI_BUFFER buf;
340     ACPI_HANDLE h;
341     ACPI_OBJECT *obj;
342     ACPI_STATUS status;
343     device_t	peer;
344     char	desc[64];
345     int		ecdt;
346     int		ret, rc;
347     struct acpi_ec_params *params;
348     static char *ec_ids[] = { "PNP0C09", NULL };
349 
350     ret = ENXIO;
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 (ret);
355 
356     if (device_is_devclass_fixed(dev)) {
357 	/*
358 	 * If probed via ECDT, set description and continue. Otherwise, we can
359 	 * access the namespace and make sure this is not a duplicate probe.
360 	 */
361         ecdt = 1;
362         params = acpi_get_private(dev);
363 	if (params != NULL)
364 	    ret = 0;
365 
366 	goto out;
367     } else
368 	ecdt = 0;
369 
370     rc = ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids, NULL);
371     if (rc > 0)
372 	return (rc);
373 
374     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
375 
376     buf.Pointer = NULL;
377     buf.Length = ACPI_ALLOCATE_BUFFER;
378     h = acpi_get_handle(dev);
379 
380     /*
381      * Read the unit ID to check for duplicate attach and the global lock value
382      * to see if we should acquire it when accessing the EC.
383      */
384     status = acpi_GetInteger(h, "_UID", &params->uid);
385     if (ACPI_FAILURE(status))
386 	params->uid = 0;
387 
388     /*
389      * Check for a duplicate probe. This can happen when a probe via ECDT
390      * succeeded already. If this is a duplicate, disable this device.
391      *
392      * NB: It would seem device_disable would be sufficient to not get
393      * duplicated devices, and ENXIO isn't needed, however, device_probe() only
394      * checks DF_ENABLED at the start and so disabling it here is too late to
395      * prevent device_attach() from being called.
396      */
397     peer = devclass_get_device(device_get_devclass(dev), params->uid);
398     if (peer != NULL && device_is_alive(peer)) {
399 	device_disable(dev);
400 	goto out;
401     }
402 
403     status = acpi_GetInteger(h, "_GLK", &params->glk);
404     if (ACPI_FAILURE(status))
405 	params->glk = 0;
406 
407     /*
408      * Evaluate the _GPE method to find the GPE bit used by the EC to signal
409      * status (SCI).  If it's a package, it contains a reference and GPE bit,
410      * similar to _PRW.
411      */
412     status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
413     if (ACPI_FAILURE(status)) {
414 	device_printf(dev, "can't evaluate _GPE - %s\n", AcpiFormatException(status));
415 	goto out;
416     }
417 
418     obj = (ACPI_OBJECT *)buf.Pointer;
419     if (obj == NULL)
420 	goto out;
421 
422     switch (obj->Type) {
423     case ACPI_TYPE_INTEGER:
424 	params->gpe_handle = NULL;
425 	params->gpe_bit = obj->Integer.Value;
426 	break;
427     case ACPI_TYPE_PACKAGE:
428 	if (!ACPI_PKG_VALID(obj, 2))
429 	    goto out;
430 	params->gpe_handle = acpi_GetReference(NULL, &obj->Package.Elements[0]);
431 	if (params->gpe_handle == NULL ||
432 	    acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
433 		goto out;
434 	break;
435     default:
436 	device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
437 	goto out;
438     }
439 
440     /* Store the values we got from the namespace for attach. */
441     acpi_set_private(dev, params);
442 
443     if (buf.Pointer)
444 	AcpiOsFree(buf.Pointer);
445 
446     ret = rc;
447 out:
448     if (ret <= 0) {
449 	snprintf(desc, sizeof(desc), "Embedded Controller: GPE %#x%s%s",
450 		 params->gpe_bit, (params->glk) ? ", GLK" : "",
451 		 ecdt ? ", ECDT" : "");
452 	device_set_desc_copy(dev, desc);
453     } else
454 	free(params, M_TEMP);
455 
456     return (ret);
457 }
458 
459 static int
460 acpi_ec_attach(device_t dev)
461 {
462     struct acpi_ec_softc	*sc;
463     struct acpi_ec_params	*params;
464     ACPI_STATUS			Status;
465 
466     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
467 
468     /* Fetch/initialize softc (assumes softc is pre-zeroed). */
469     sc = device_get_softc(dev);
470     params = acpi_get_private(dev);
471     sc->ec_dev = dev;
472     sc->ec_handle = acpi_get_handle(dev);
473 
474     /* Retrieve previously probed values via device ivars. */
475     sc->ec_glk = params->glk;
476     sc->ec_gpebit = params->gpe_bit;
477     sc->ec_gpehandle = params->gpe_handle;
478     sc->ec_uid = params->uid;
479     sc->ec_suspending = FALSE;
480     acpi_set_private(dev, NULL);
481     free(params, M_TEMP);
482 
483     /* Attach bus resources for data and command/status ports. */
484     sc->ec_data_rid = 0;
485     sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
486 			&sc->ec_data_rid, RF_ACTIVE);
487     if (sc->ec_data_res == NULL) {
488 	device_printf(dev, "can't allocate data port\n");
489 	goto error;
490     }
491     sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
492     sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
493 
494     sc->ec_csr_rid = 1;
495     sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
496 			&sc->ec_csr_rid, RF_ACTIVE);
497     if (sc->ec_csr_res == NULL) {
498 	device_printf(dev, "can't allocate command/status port\n");
499 	goto error;
500     }
501     sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
502     sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
503 
504     /*
505      * Install a handler for this EC's GPE bit.  We want edge-triggered
506      * behavior.
507      */
508     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
509     Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
510 		ACPI_GPE_EDGE_TRIGGERED, EcGpeHandler, sc);
511     if (ACPI_FAILURE(Status)) {
512 	device_printf(dev, "can't install GPE handler for %s - %s\n",
513 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
514 	goto error;
515     }
516 
517     /*
518      * Install address space handler
519      */
520     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
521     Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
522 		&EcSpaceHandler, &EcSpaceSetup, sc);
523     if (ACPI_FAILURE(Status)) {
524 	device_printf(dev, "can't install address space handler for %s - %s\n",
525 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
526 	goto error;
527     }
528 
529     /* Enable runtime GPEs for the handler. */
530     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit);
531     if (ACPI_FAILURE(Status)) {
532 	device_printf(dev, "AcpiEnableGpe failed: %s\n",
533 		      AcpiFormatException(Status));
534 	goto error;
535     }
536 
537     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
538     return (0);
539 
540 error:
541     AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, EcGpeHandler);
542     AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
543 	EcSpaceHandler);
544     if (sc->ec_csr_res)
545 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
546 			     sc->ec_csr_res);
547     if (sc->ec_data_res)
548 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
549 			     sc->ec_data_res);
550     return (ENXIO);
551 }
552 
553 static int
554 acpi_ec_suspend(device_t dev)
555 {
556     struct acpi_ec_softc	*sc;
557 
558     sc = device_get_softc(dev);
559     sc->ec_suspending = TRUE;
560     return (0);
561 }
562 
563 static int
564 acpi_ec_resume(device_t dev)
565 {
566     struct acpi_ec_softc	*sc;
567 
568     sc = device_get_softc(dev);
569     sc->ec_suspending = FALSE;
570     return (0);
571 }
572 
573 static int
574 acpi_ec_shutdown(device_t dev)
575 {
576     struct acpi_ec_softc	*sc;
577 
578     /* Disable the GPE so we don't get EC events during shutdown. */
579     sc = device_get_softc(dev);
580     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit);
581     return (0);
582 }
583 
584 /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
585 static int
586 acpi_ec_read_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_READ, addr, width * 8, val, sc, NULL);
593     if (ACPI_FAILURE(status))
594 	return (ENXIO);
595     return (0);
596 }
597 
598 static int
599 acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
600 {
601     struct acpi_ec_softc *sc;
602     ACPI_STATUS status;
603 
604     sc = device_get_softc(dev);
605     status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
606     if (ACPI_FAILURE(status))
607 	return (ENXIO);
608     return (0);
609 }
610 
611 static ACPI_STATUS
612 EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
613 {
614     ACPI_STATUS status;
615     EC_STATUS ec_status;
616 
617     status = AE_NO_HARDWARE_RESPONSE;
618     ec_status = EC_GET_CSR(sc);
619     if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
620 	CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
621 	sc->ec_burstactive = FALSE;
622     }
623     if (EVENT_READY(event, ec_status)) {
624 	CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
625 	status = AE_OK;
626     }
627     return (status);
628 }
629 
630 static void
631 EcGpeQueryHandlerSub(struct acpi_ec_softc *sc)
632 {
633     UINT8			Data;
634     ACPI_STATUS			Status;
635     int				retry;
636     char			qxx[5];
637 
638     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
639 
640     /* Serialize user access with EcSpaceHandler(). */
641     Status = EcLock(sc);
642     if (ACPI_FAILURE(Status)) {
643 	device_printf(sc->ec_dev, "GpeQuery lock error: %s\n",
644 	    AcpiFormatException(Status));
645 	return;
646     }
647 
648     /*
649      * Send a query command to the EC to find out which _Qxx call it
650      * wants to make.  This command clears the SCI bit and also the
651      * interrupt source since we are edge-triggered.  To prevent the GPE
652      * that may arise from running the query from causing another query
653      * to be queued, we clear the pending flag only after running it.
654      */
655     for (retry = 0; retry < 2; retry++) {
656 	Status = EcCommand(sc, EC_COMMAND_QUERY);
657 	if (ACPI_SUCCESS(Status))
658 	    break;
659 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
660 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
661 	    break;
662     }
663     if (ACPI_FAILURE(Status)) {
664 	EcUnlock(sc);
665 	device_printf(sc->ec_dev, "GPE query failed: %s\n",
666 	    AcpiFormatException(Status));
667 	return;
668     }
669     Data = EC_GET_DATA(sc);
670 
671     /*
672      * We have to unlock before running the _Qxx method below since that
673      * method may attempt to read/write from EC address space, causing
674      * recursive acquisition of the lock.
675      */
676     EcUnlock(sc);
677 
678     /* Ignore the value for "no outstanding event". (13.3.5) */
679     CTR2(KTR_ACPI, "ec query ok,%s running _Q%02X", Data ? "" : " not", Data);
680     if (Data == 0)
681 	return;
682 
683     /* Evaluate _Qxx to respond to the controller. */
684     snprintf(qxx, sizeof(qxx), "_Q%02X", Data);
685     AcpiUtStrupr(qxx);
686     Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
687     if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
688 	device_printf(sc->ec_dev, "evaluation of query method %s failed: %s\n",
689 	    qxx, AcpiFormatException(Status));
690     }
691 }
692 
693 static void
694 EcGpeQueryHandler(void *Context)
695 {
696     struct acpi_ec_softc *sc = (struct acpi_ec_softc *)Context;
697     int pending;
698 
699     KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
700 
701     do {
702 	/* Read the current pending count */
703 	pending = atomic_load_acq_int(&sc->ec_sci_pend);
704 
705 	/* Call GPE handler function */
706 	EcGpeQueryHandlerSub(sc);
707 
708 	/*
709 	 * Try to reset the pending count to zero. If this fails we
710 	 * know another GPE event has occurred while handling the
711 	 * current GPE event and need to loop.
712 	 */
713     } while (!atomic_cmpset_int(&sc->ec_sci_pend, pending, 0));
714 }
715 
716 /*
717  * The GPE handler is called when IBE/OBF or SCI events occur.  We are
718  * called from an unknown lock context.
719  */
720 static UINT32
721 EcGpeHandler(ACPI_HANDLE GpeDevice, UINT32 GpeNumber, void *Context)
722 {
723     struct acpi_ec_softc *sc = Context;
724     ACPI_STATUS		       Status;
725     EC_STATUS		       EcStatus;
726 
727     KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
728     CTR0(KTR_ACPI, "ec gpe handler start");
729 
730     /*
731      * Notify EcWaitEvent() that the status register is now fresh.  If we
732      * didn't do this, it wouldn't be possible to distinguish an old IBE
733      * from a new one, for example when doing a write transaction (writing
734      * address and then data values.)
735      */
736     atomic_add_int(&sc->ec_gencount, 1);
737     wakeup(sc);
738 
739     /*
740      * If the EC_SCI bit of the status register is set, queue a query handler.
741      * It will run the query and _Qxx method later, under the lock.
742      */
743     EcStatus = EC_GET_CSR(sc);
744     if ((EcStatus & EC_EVENT_SCI) &&
745 	atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
746 	CTR0(KTR_ACPI, "ec gpe queueing query handler");
747 	Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
748 	if (ACPI_FAILURE(Status)) {
749 	    printf("EcGpeHandler: queuing GPE query handler failed\n");
750 	    atomic_store_rel_int(&sc->ec_sci_pend, 0);
751 	}
752     }
753     return (ACPI_REENABLE_GPE);
754 }
755 
756 static ACPI_STATUS
757 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
758 	     void **RegionContext)
759 {
760 
761     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
762 
763     /*
764      * If deactivating a region, always set the output to NULL.  Otherwise,
765      * just pass the context through.
766      */
767     if (Function == ACPI_REGION_DEACTIVATE)
768 	*RegionContext = NULL;
769     else
770 	*RegionContext = Context;
771 
772     return_ACPI_STATUS (AE_OK);
773 }
774 
775 static ACPI_STATUS
776 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 Width,
777 	       UINT64 *Value, void *Context, void *RegionContext)
778 {
779     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
780     ACPI_PHYSICAL_ADDRESS	EcAddr;
781     UINT8			*EcData;
782     ACPI_STATUS			Status;
783 
784     ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
785 
786     if (Function != ACPI_READ && Function != ACPI_WRITE)
787 	return_ACPI_STATUS (AE_BAD_PARAMETER);
788     if (Width % 8 != 0 || Value == NULL || Context == NULL)
789 	return_ACPI_STATUS (AE_BAD_PARAMETER);
790     if (Address + Width / 8 > 256)
791 	return_ACPI_STATUS (AE_BAD_ADDRESS);
792 
793     /*
794      * If booting, check if we need to run the query handler.  If so, we
795      * we call it directly here since our thread taskq is not active yet.
796      */
797     if (cold || rebooting || sc->ec_suspending) {
798 	if ((EC_GET_CSR(sc) & EC_EVENT_SCI) &&
799 	    atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
800 	    CTR0(KTR_ACPI, "ec running gpe handler directly");
801 	    EcGpeQueryHandler(sc);
802 	}
803     }
804 
805     /* Serialize with EcGpeQueryHandler() at transaction granularity. */
806     Status = EcLock(sc);
807     if (ACPI_FAILURE(Status))
808 	return_ACPI_STATUS (Status);
809 
810     /* If we can't start burst mode, continue anyway. */
811     Status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
812     if (ACPI_SUCCESS(Status)) {
813 	if (EC_GET_DATA(sc) == EC_BURST_ACK) {
814 	    CTR0(KTR_ACPI, "ec burst enabled");
815 	    sc->ec_burstactive = TRUE;
816 	}
817     }
818 
819     /* Perform the transaction(s), based on Width. */
820     EcAddr = Address;
821     EcData = (UINT8 *)Value;
822     if (Function == ACPI_READ)
823 	*Value = 0;
824     do {
825 	switch (Function) {
826 	case ACPI_READ:
827 	    Status = EcRead(sc, EcAddr, EcData);
828 	    break;
829 	case ACPI_WRITE:
830 	    Status = EcWrite(sc, EcAddr, *EcData);
831 	    break;
832 	}
833 	if (ACPI_FAILURE(Status))
834 	    break;
835 	EcAddr++;
836 	EcData++;
837     } while (EcAddr < Address + Width / 8);
838 
839     if (sc->ec_burstactive) {
840 	sc->ec_burstactive = FALSE;
841 	if (ACPI_SUCCESS(EcCommand(sc, EC_COMMAND_BURST_DISABLE)))
842 	    CTR0(KTR_ACPI, "ec disabled burst ok");
843     }
844 
845     EcUnlock(sc);
846     return_ACPI_STATUS (Status);
847 }
848 
849 static ACPI_STATUS
850 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
851 {
852     static int	no_intr = 0;
853     ACPI_STATUS	Status;
854     int		count, i, need_poll, slp_ival;
855 
856     ACPI_SERIAL_ASSERT(ec);
857     Status = AE_NO_HARDWARE_RESPONSE;
858     need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
859 
860     /* Wait for event by polling or GPE (interrupt). */
861     if (need_poll) {
862 	count = (ec_timeout * 1000) / EC_POLL_DELAY;
863 	if (count == 0)
864 	    count = 1;
865 	DELAY(10);
866 	for (i = 0; i < count; i++) {
867 	    Status = EcCheckStatus(sc, "poll", Event);
868 	    if (ACPI_SUCCESS(Status))
869 		break;
870 	    DELAY(EC_POLL_DELAY);
871 	}
872     } else {
873 	slp_ival = hz / 1000;
874 	if (slp_ival != 0) {
875 	    count = ec_timeout;
876 	} else {
877 	    /* hz has less than 1 ms resolution so scale timeout. */
878 	    slp_ival = 1;
879 	    count = ec_timeout / (1000 / hz);
880 	}
881 
882 	/*
883 	 * Wait for the GPE to signal the status changed, checking the
884 	 * status register each time we get one.  It's possible to get a
885 	 * GPE for an event we're not interested in here (i.e., SCI for
886 	 * EC query).
887 	 */
888 	for (i = 0; i < count; i++) {
889 	    if (gen_count == sc->ec_gencount)
890 		tsleep(sc, 0, "ecgpe", slp_ival);
891 	    /*
892 	     * Record new generation count.  It's possible the GPE was
893 	     * just to notify us that a query is needed and we need to
894 	     * wait for a second GPE to signal the completion of the
895 	     * event we are actually waiting for.
896 	     */
897 	    Status = EcCheckStatus(sc, "sleep", Event);
898 	    if (ACPI_SUCCESS(Status)) {
899 		if (gen_count == sc->ec_gencount)
900 		    no_intr++;
901 		else
902 		    no_intr = 0;
903 		break;
904 	    }
905 	    gen_count = sc->ec_gencount;
906 	}
907 
908 	/*
909 	 * We finished waiting for the GPE and it never arrived.  Try to
910 	 * read the register once and trust whatever value we got.  This is
911 	 * the best we can do at this point.
912 	 */
913 	if (ACPI_FAILURE(Status))
914 	    Status = EcCheckStatus(sc, "sleep_end", Event);
915     }
916     if (!need_poll && no_intr > 10) {
917 	device_printf(sc->ec_dev,
918 	    "not getting interrupts, switched to polled mode\n");
919 	ec_polled_mode = 1;
920     }
921     if (ACPI_FAILURE(Status))
922 	    CTR0(KTR_ACPI, "error: ec wait timed out");
923     return (Status);
924 }
925 
926 static ACPI_STATUS
927 EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
928 {
929     ACPI_STATUS	status;
930     EC_EVENT	event;
931     EC_STATUS	ec_status;
932     u_int	gen_count;
933 
934     ACPI_SERIAL_ASSERT(ec);
935 
936     /* Don't use burst mode if user disabled it. */
937     if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
938 	return (AE_ERROR);
939 
940     /* Decide what to wait for based on command type. */
941     switch (cmd) {
942     case EC_COMMAND_READ:
943     case EC_COMMAND_WRITE:
944     case EC_COMMAND_BURST_DISABLE:
945 	event = EC_EVENT_INPUT_BUFFER_EMPTY;
946 	break;
947     case EC_COMMAND_QUERY:
948     case EC_COMMAND_BURST_ENABLE:
949 	event = EC_EVENT_OUTPUT_BUFFER_FULL;
950 	break;
951     default:
952 	device_printf(sc->ec_dev, "EcCommand: invalid command %#x\n", cmd);
953 	return (AE_BAD_PARAMETER);
954     }
955 
956     /*
957      * Ensure empty input buffer before issuing command.
958      * Use generation count of zero to force a quick check.
959      */
960     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, 0);
961     if (ACPI_FAILURE(status))
962 	return (status);
963 
964     /* Run the command and wait for the chosen event. */
965     CTR1(KTR_ACPI, "ec running command %#x", cmd);
966     gen_count = sc->ec_gencount;
967     EC_SET_CSR(sc, cmd);
968     status = EcWaitEvent(sc, event, gen_count);
969     if (ACPI_SUCCESS(status)) {
970 	/* If we succeeded, burst flag should now be present. */
971 	if (cmd == EC_COMMAND_BURST_ENABLE) {
972 	    ec_status = EC_GET_CSR(sc);
973 	    if ((ec_status & EC_FLAG_BURST_MODE) == 0)
974 		status = AE_ERROR;
975 	}
976     } else
977 	device_printf(sc->ec_dev, "EcCommand: no response to %#x\n", cmd);
978     return (status);
979 }
980 
981 static ACPI_STATUS
982 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
983 {
984     ACPI_STATUS	status;
985     u_int gen_count;
986     int retry;
987 
988     ACPI_SERIAL_ASSERT(ec);
989     CTR1(KTR_ACPI, "ec read from %#x", Address);
990 
991     for (retry = 0; retry < 2; retry++) {
992 	status = EcCommand(sc, EC_COMMAND_READ);
993 	if (ACPI_FAILURE(status))
994 	    return (status);
995 
996 	gen_count = sc->ec_gencount;
997 	EC_SET_DATA(sc, Address);
998 	status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
999 	if (ACPI_SUCCESS(status)) {
1000 	    *Data = EC_GET_DATA(sc);
1001 	    return (AE_OK);
1002 	}
1003 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
1004 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
1005 	    break;
1006     }
1007     device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
1008     return (status);
1009 }
1010 
1011 static ACPI_STATUS
1012 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 Data)
1013 {
1014     ACPI_STATUS	status;
1015     u_int gen_count;
1016 
1017     ACPI_SERIAL_ASSERT(ec);
1018     CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, Data);
1019 
1020     status = EcCommand(sc, EC_COMMAND_WRITE);
1021     if (ACPI_FAILURE(status))
1022 	return (status);
1023 
1024     gen_count = sc->ec_gencount;
1025     EC_SET_DATA(sc, Address);
1026     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1027     if (ACPI_FAILURE(status)) {
1028 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent address\n");
1029 	return (status);
1030     }
1031 
1032     gen_count = sc->ec_gencount;
1033     EC_SET_DATA(sc, Data);
1034     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1035     if (ACPI_FAILURE(status)) {
1036 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent data\n");
1037 	return (status);
1038     }
1039 
1040     return (AE_OK);
1041 }
1042