xref: /freebsd/sys/dev/acpica/acpi_ec.c (revision ee2e9f4dbc195bf07bfc8e8ab2faed357d617e81)
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 static devclass_t acpi_ec_devclass;
266 DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, acpi_ec_devclass, 0, 0);
267 MODULE_DEPEND(acpi_ec, acpi, 1, 1, 1);
268 
269 /*
270  * Look for an ECDT and if we find one, set up default GPE and
271  * space handlers to catch attempts to access EC space before
272  * we have a real driver instance in place.
273  *
274  * TODO: Some old Gateway laptops need us to fake up an ECDT or
275  * otherwise attach early so that _REG methods can run.
276  */
277 void
278 acpi_ec_ecdt_probe(device_t parent)
279 {
280     ACPI_TABLE_ECDT *ecdt;
281     ACPI_STATUS	     status;
282     device_t	     child;
283     ACPI_HANDLE	     h;
284     struct acpi_ec_params *params;
285 
286     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
287 
288     /* Find and validate the ECDT. */
289     status = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
290     if (ACPI_FAILURE(status) ||
291 	ecdt->Control.BitWidth != 8 ||
292 	ecdt->Data.BitWidth != 8) {
293 	return;
294     }
295 
296     /* Create the child device with the given unit number. */
297     child = BUS_ADD_CHILD(parent, 3, "acpi_ec", ecdt->Uid);
298     if (child == NULL) {
299 	printf("%s: can't add child\n", __func__);
300 	return;
301     }
302 
303     /* Find and save the ACPI handle for this device. */
304     status = AcpiGetHandle(NULL, ecdt->Id, &h);
305     if (ACPI_FAILURE(status)) {
306 	device_delete_child(parent, child);
307 	printf("%s: can't get handle\n", __func__);
308 	return;
309     }
310     acpi_set_handle(child, h);
311 
312     /* Set the data and CSR register addresses. */
313     bus_set_resource(child, SYS_RES_IOPORT, 0, ecdt->Data.Address,
314 	/*count*/1);
315     bus_set_resource(child, SYS_RES_IOPORT, 1, ecdt->Control.Address,
316 	/*count*/1);
317 
318     /*
319      * Store values for the probe/attach routines to use.  Store the
320      * ECDT GPE bit and set the global lock flag according to _GLK.
321      * Note that it is not perfectly correct to be evaluating a method
322      * before initializing devices, but in practice this function
323      * should be safe to call at this point.
324      */
325     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
326     params->gpe_handle = NULL;
327     params->gpe_bit = ecdt->Gpe;
328     params->uid = ecdt->Uid;
329     acpi_GetInteger(h, "_GLK", &params->glk);
330     acpi_set_private(child, params);
331 
332     /* Finish the attach process. */
333     if (device_probe_and_attach(child) != 0)
334 	device_delete_child(parent, child);
335 }
336 
337 static int
338 acpi_ec_probe(device_t dev)
339 {
340     ACPI_BUFFER buf;
341     ACPI_HANDLE h;
342     ACPI_OBJECT *obj;
343     ACPI_STATUS status;
344     device_t	peer;
345     char	desc[64];
346     int		ecdt;
347     int		ret, rc;
348     struct acpi_ec_params *params;
349     static char *ec_ids[] = { "PNP0C09", NULL };
350 
351     ret = ENXIO;
352 
353     /* Check that this is a device and that EC is not disabled. */
354     if (acpi_get_type(dev) != ACPI_TYPE_DEVICE || acpi_disabled("ec"))
355 	return (ret);
356 
357     if (device_is_devclass_fixed(dev)) {
358 	/*
359 	 * If probed via ECDT, set description and continue. Otherwise, we can
360 	 * access the namespace and make sure this is not a duplicate probe.
361 	 */
362         ecdt = 1;
363         params = acpi_get_private(dev);
364 	if (params != NULL)
365 	    ret = 0;
366 
367 	goto out;
368     } else
369 	ecdt = 0;
370 
371     rc = ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids, NULL);
372     if (rc > 0)
373 	return (rc);
374 
375     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
376 
377     buf.Pointer = NULL;
378     buf.Length = ACPI_ALLOCATE_BUFFER;
379     h = acpi_get_handle(dev);
380 
381     /*
382      * Read the unit ID to check for duplicate attach and the global lock value
383      * to see if we should acquire it when accessing the EC.
384      */
385     status = acpi_GetInteger(h, "_UID", &params->uid);
386     if (ACPI_FAILURE(status))
387 	params->uid = 0;
388 
389     /*
390      * Check for a duplicate probe. This can happen when a probe via ECDT
391      * succeeded already. If this is a duplicate, disable this device.
392      *
393      * NB: It would seem device_disable would be sufficient to not get
394      * duplicated devices, and ENXIO isn't needed, however, device_probe() only
395      * checks DF_ENABLED at the start and so disabling it here is too late to
396      * prevent device_attach() from being called.
397      */
398     peer = devclass_get_device(acpi_ec_devclass, params->uid);
399     if (peer != NULL && device_is_alive(peer)) {
400 	device_disable(dev);
401 	goto out;
402     }
403 
404     status = acpi_GetInteger(h, "_GLK", &params->glk);
405     if (ACPI_FAILURE(status))
406 	params->glk = 0;
407 
408     /*
409      * Evaluate the _GPE method to find the GPE bit used by the EC to signal
410      * status (SCI).  If it's a package, it contains a reference and GPE bit,
411      * similar to _PRW.
412      */
413     status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
414     if (ACPI_FAILURE(status)) {
415 	device_printf(dev, "can't evaluate _GPE - %s\n", AcpiFormatException(status));
416 	goto out;
417     }
418 
419     obj = (ACPI_OBJECT *)buf.Pointer;
420     if (obj == NULL)
421 	goto out;
422 
423     switch (obj->Type) {
424     case ACPI_TYPE_INTEGER:
425 	params->gpe_handle = NULL;
426 	params->gpe_bit = obj->Integer.Value;
427 	break;
428     case ACPI_TYPE_PACKAGE:
429 	if (!ACPI_PKG_VALID(obj, 2))
430 	    goto out;
431 	params->gpe_handle = acpi_GetReference(NULL, &obj->Package.Elements[0]);
432 	if (params->gpe_handle == NULL ||
433 	    acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
434 		goto out;
435 	break;
436     default:
437 	device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
438 	goto out;
439     }
440 
441     /* Store the values we got from the namespace for attach. */
442     acpi_set_private(dev, params);
443 
444     if (buf.Pointer)
445 	AcpiOsFree(buf.Pointer);
446 out:
447     if (ret <= 0) {
448 	snprintf(desc, sizeof(desc), "Embedded Controller: GPE %#x%s%s",
449 		 params->gpe_bit, (params->glk) ? ", GLK" : "",
450 		 ecdt ? ", ECDT" : "");
451 	device_set_desc_copy(dev, desc);
452     } else
453 	free(params, M_TEMP);
454 
455     return (ret);
456 }
457 
458 static int
459 acpi_ec_attach(device_t dev)
460 {
461     struct acpi_ec_softc	*sc;
462     struct acpi_ec_params	*params;
463     ACPI_STATUS			Status;
464 
465     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
466 
467     /* Fetch/initialize softc (assumes softc is pre-zeroed). */
468     sc = device_get_softc(dev);
469     params = acpi_get_private(dev);
470     sc->ec_dev = dev;
471     sc->ec_handle = acpi_get_handle(dev);
472 
473     /* Retrieve previously probed values via device ivars. */
474     sc->ec_glk = params->glk;
475     sc->ec_gpebit = params->gpe_bit;
476     sc->ec_gpehandle = params->gpe_handle;
477     sc->ec_uid = params->uid;
478     sc->ec_suspending = FALSE;
479     acpi_set_private(dev, NULL);
480     free(params, M_TEMP);
481 
482     /* Attach bus resources for data and command/status ports. */
483     sc->ec_data_rid = 0;
484     sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
485 			&sc->ec_data_rid, RF_ACTIVE);
486     if (sc->ec_data_res == NULL) {
487 	device_printf(dev, "can't allocate data port\n");
488 	goto error;
489     }
490     sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
491     sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
492 
493     sc->ec_csr_rid = 1;
494     sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
495 			&sc->ec_csr_rid, RF_ACTIVE);
496     if (sc->ec_csr_res == NULL) {
497 	device_printf(dev, "can't allocate command/status port\n");
498 	goto error;
499     }
500     sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
501     sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
502 
503     /*
504      * Install a handler for this EC's GPE bit.  We want edge-triggered
505      * behavior.
506      */
507     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
508     Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
509 		ACPI_GPE_EDGE_TRIGGERED, EcGpeHandler, sc);
510     if (ACPI_FAILURE(Status)) {
511 	device_printf(dev, "can't install GPE handler for %s - %s\n",
512 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
513 	goto error;
514     }
515 
516     /*
517      * Install address space handler
518      */
519     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
520     Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
521 		&EcSpaceHandler, &EcSpaceSetup, sc);
522     if (ACPI_FAILURE(Status)) {
523 	device_printf(dev, "can't install address space handler for %s - %s\n",
524 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
525 	goto error;
526     }
527 
528     /* Enable runtime GPEs for the handler. */
529     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit);
530     if (ACPI_FAILURE(Status)) {
531 	device_printf(dev, "AcpiEnableGpe failed: %s\n",
532 		      AcpiFormatException(Status));
533 	goto error;
534     }
535 
536     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
537     return (0);
538 
539 error:
540     AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, EcGpeHandler);
541     AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
542 	EcSpaceHandler);
543     if (sc->ec_csr_res)
544 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
545 			     sc->ec_csr_res);
546     if (sc->ec_data_res)
547 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
548 			     sc->ec_data_res);
549     return (ENXIO);
550 }
551 
552 static int
553 acpi_ec_suspend(device_t dev)
554 {
555     struct acpi_ec_softc	*sc;
556 
557     sc = device_get_softc(dev);
558     sc->ec_suspending = TRUE;
559     return (0);
560 }
561 
562 static int
563 acpi_ec_resume(device_t dev)
564 {
565     struct acpi_ec_softc	*sc;
566 
567     sc = device_get_softc(dev);
568     sc->ec_suspending = FALSE;
569     return (0);
570 }
571 
572 static int
573 acpi_ec_shutdown(device_t dev)
574 {
575     struct acpi_ec_softc	*sc;
576 
577     /* Disable the GPE so we don't get EC events during shutdown. */
578     sc = device_get_softc(dev);
579     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit);
580     return (0);
581 }
582 
583 /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
584 static int
585 acpi_ec_read_method(device_t dev, u_int addr, UINT64 *val, int width)
586 {
587     struct acpi_ec_softc *sc;
588     ACPI_STATUS status;
589 
590     sc = device_get_softc(dev);
591     status = EcSpaceHandler(ACPI_READ, addr, width * 8, val, sc, NULL);
592     if (ACPI_FAILURE(status))
593 	return (ENXIO);
594     return (0);
595 }
596 
597 static int
598 acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
599 {
600     struct acpi_ec_softc *sc;
601     ACPI_STATUS status;
602 
603     sc = device_get_softc(dev);
604     status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
605     if (ACPI_FAILURE(status))
606 	return (ENXIO);
607     return (0);
608 }
609 
610 static ACPI_STATUS
611 EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
612 {
613     ACPI_STATUS status;
614     EC_STATUS ec_status;
615 
616     status = AE_NO_HARDWARE_RESPONSE;
617     ec_status = EC_GET_CSR(sc);
618     if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
619 	CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
620 	sc->ec_burstactive = FALSE;
621     }
622     if (EVENT_READY(event, ec_status)) {
623 	CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
624 	status = AE_OK;
625     }
626     return (status);
627 }
628 
629 static void
630 EcGpeQueryHandlerSub(struct acpi_ec_softc *sc)
631 {
632     UINT8			Data;
633     ACPI_STATUS			Status;
634     int				retry;
635     char			qxx[5];
636 
637     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
638 
639     /* Serialize user access with EcSpaceHandler(). */
640     Status = EcLock(sc);
641     if (ACPI_FAILURE(Status)) {
642 	device_printf(sc->ec_dev, "GpeQuery lock error: %s\n",
643 	    AcpiFormatException(Status));
644 	return;
645     }
646 
647     /*
648      * Send a query command to the EC to find out which _Qxx call it
649      * wants to make.  This command clears the SCI bit and also the
650      * interrupt source since we are edge-triggered.  To prevent the GPE
651      * that may arise from running the query from causing another query
652      * to be queued, we clear the pending flag only after running it.
653      */
654     for (retry = 0; retry < 2; retry++) {
655 	Status = EcCommand(sc, EC_COMMAND_QUERY);
656 	if (ACPI_SUCCESS(Status))
657 	    break;
658 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
659 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
660 	    break;
661     }
662     if (ACPI_FAILURE(Status)) {
663 	EcUnlock(sc);
664 	device_printf(sc->ec_dev, "GPE query failed: %s\n",
665 	    AcpiFormatException(Status));
666 	return;
667     }
668     Data = EC_GET_DATA(sc);
669 
670     /*
671      * We have to unlock before running the _Qxx method below since that
672      * method may attempt to read/write from EC address space, causing
673      * recursive acquisition of the lock.
674      */
675     EcUnlock(sc);
676 
677     /* Ignore the value for "no outstanding event". (13.3.5) */
678     CTR2(KTR_ACPI, "ec query ok,%s running _Q%02X", Data ? "" : " not", Data);
679     if (Data == 0)
680 	return;
681 
682     /* Evaluate _Qxx to respond to the controller. */
683     snprintf(qxx, sizeof(qxx), "_Q%02X", Data);
684     AcpiUtStrupr(qxx);
685     Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
686     if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
687 	device_printf(sc->ec_dev, "evaluation of query method %s failed: %s\n",
688 	    qxx, AcpiFormatException(Status));
689     }
690 }
691 
692 static void
693 EcGpeQueryHandler(void *Context)
694 {
695     struct acpi_ec_softc *sc = (struct acpi_ec_softc *)Context;
696     int pending;
697 
698     KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
699 
700     do {
701 	/* Read the current pending count */
702 	pending = atomic_load_acq_int(&sc->ec_sci_pend);
703 
704 	/* Call GPE handler function */
705 	EcGpeQueryHandlerSub(sc);
706 
707 	/*
708 	 * Try to reset the pending count to zero. If this fails we
709 	 * know another GPE event has occurred while handling the
710 	 * current GPE event and need to loop.
711 	 */
712     } while (!atomic_cmpset_int(&sc->ec_sci_pend, pending, 0));
713 }
714 
715 /*
716  * The GPE handler is called when IBE/OBF or SCI events occur.  We are
717  * called from an unknown lock context.
718  */
719 static UINT32
720 EcGpeHandler(ACPI_HANDLE GpeDevice, UINT32 GpeNumber, void *Context)
721 {
722     struct acpi_ec_softc *sc = Context;
723     ACPI_STATUS		       Status;
724     EC_STATUS		       EcStatus;
725 
726     KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
727     CTR0(KTR_ACPI, "ec gpe handler start");
728 
729     /*
730      * Notify EcWaitEvent() that the status register is now fresh.  If we
731      * didn't do this, it wouldn't be possible to distinguish an old IBE
732      * from a new one, for example when doing a write transaction (writing
733      * address and then data values.)
734      */
735     atomic_add_int(&sc->ec_gencount, 1);
736     wakeup(sc);
737 
738     /*
739      * If the EC_SCI bit of the status register is set, queue a query handler.
740      * It will run the query and _Qxx method later, under the lock.
741      */
742     EcStatus = EC_GET_CSR(sc);
743     if ((EcStatus & EC_EVENT_SCI) &&
744 	atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
745 	CTR0(KTR_ACPI, "ec gpe queueing query handler");
746 	Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
747 	if (ACPI_FAILURE(Status)) {
748 	    printf("EcGpeHandler: queuing GPE query handler failed\n");
749 	    atomic_store_rel_int(&sc->ec_sci_pend, 0);
750 	}
751     }
752     return (ACPI_REENABLE_GPE);
753 }
754 
755 static ACPI_STATUS
756 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
757 	     void **RegionContext)
758 {
759 
760     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
761 
762     /*
763      * If deactivating a region, always set the output to NULL.  Otherwise,
764      * just pass the context through.
765      */
766     if (Function == ACPI_REGION_DEACTIVATE)
767 	*RegionContext = NULL;
768     else
769 	*RegionContext = Context;
770 
771     return_ACPI_STATUS (AE_OK);
772 }
773 
774 static ACPI_STATUS
775 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 Width,
776 	       UINT64 *Value, void *Context, void *RegionContext)
777 {
778     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
779     ACPI_PHYSICAL_ADDRESS	EcAddr;
780     UINT8			*EcData;
781     ACPI_STATUS			Status;
782 
783     ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
784 
785     if (Function != ACPI_READ && Function != ACPI_WRITE)
786 	return_ACPI_STATUS (AE_BAD_PARAMETER);
787     if (Width % 8 != 0 || Value == NULL || Context == NULL)
788 	return_ACPI_STATUS (AE_BAD_PARAMETER);
789     if (Address + Width / 8 > 256)
790 	return_ACPI_STATUS (AE_BAD_ADDRESS);
791 
792     /*
793      * If booting, check if we need to run the query handler.  If so, we
794      * we call it directly here since our thread taskq is not active yet.
795      */
796     if (cold || rebooting || sc->ec_suspending) {
797 	if ((EC_GET_CSR(sc) & EC_EVENT_SCI) &&
798 	    atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
799 	    CTR0(KTR_ACPI, "ec running gpe handler directly");
800 	    EcGpeQueryHandler(sc);
801 	}
802     }
803 
804     /* Serialize with EcGpeQueryHandler() at transaction granularity. */
805     Status = EcLock(sc);
806     if (ACPI_FAILURE(Status))
807 	return_ACPI_STATUS (Status);
808 
809     /* If we can't start burst mode, continue anyway. */
810     Status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
811     if (ACPI_SUCCESS(Status)) {
812 	if (EC_GET_DATA(sc) == EC_BURST_ACK) {
813 	    CTR0(KTR_ACPI, "ec burst enabled");
814 	    sc->ec_burstactive = TRUE;
815 	}
816     }
817 
818     /* Perform the transaction(s), based on Width. */
819     EcAddr = Address;
820     EcData = (UINT8 *)Value;
821     if (Function == ACPI_READ)
822 	*Value = 0;
823     do {
824 	switch (Function) {
825 	case ACPI_READ:
826 	    Status = EcRead(sc, EcAddr, EcData);
827 	    break;
828 	case ACPI_WRITE:
829 	    Status = EcWrite(sc, EcAddr, *EcData);
830 	    break;
831 	}
832 	if (ACPI_FAILURE(Status))
833 	    break;
834 	EcAddr++;
835 	EcData++;
836     } while (EcAddr < Address + Width / 8);
837 
838     if (sc->ec_burstactive) {
839 	sc->ec_burstactive = FALSE;
840 	if (ACPI_SUCCESS(EcCommand(sc, EC_COMMAND_BURST_DISABLE)))
841 	    CTR0(KTR_ACPI, "ec disabled burst ok");
842     }
843 
844     EcUnlock(sc);
845     return_ACPI_STATUS (Status);
846 }
847 
848 static ACPI_STATUS
849 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
850 {
851     static int	no_intr = 0;
852     ACPI_STATUS	Status;
853     int		count, i, need_poll, slp_ival;
854 
855     ACPI_SERIAL_ASSERT(ec);
856     Status = AE_NO_HARDWARE_RESPONSE;
857     need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
858 
859     /* Wait for event by polling or GPE (interrupt). */
860     if (need_poll) {
861 	count = (ec_timeout * 1000) / EC_POLL_DELAY;
862 	if (count == 0)
863 	    count = 1;
864 	DELAY(10);
865 	for (i = 0; i < count; i++) {
866 	    Status = EcCheckStatus(sc, "poll", Event);
867 	    if (ACPI_SUCCESS(Status))
868 		break;
869 	    DELAY(EC_POLL_DELAY);
870 	}
871     } else {
872 	slp_ival = hz / 1000;
873 	if (slp_ival != 0) {
874 	    count = ec_timeout;
875 	} else {
876 	    /* hz has less than 1 ms resolution so scale timeout. */
877 	    slp_ival = 1;
878 	    count = ec_timeout / (1000 / hz);
879 	}
880 
881 	/*
882 	 * Wait for the GPE to signal the status changed, checking the
883 	 * status register each time we get one.  It's possible to get a
884 	 * GPE for an event we're not interested in here (i.e., SCI for
885 	 * EC query).
886 	 */
887 	for (i = 0; i < count; i++) {
888 	    if (gen_count == sc->ec_gencount)
889 		tsleep(sc, 0, "ecgpe", slp_ival);
890 	    /*
891 	     * Record new generation count.  It's possible the GPE was
892 	     * just to notify us that a query is needed and we need to
893 	     * wait for a second GPE to signal the completion of the
894 	     * event we are actually waiting for.
895 	     */
896 	    Status = EcCheckStatus(sc, "sleep", Event);
897 	    if (ACPI_SUCCESS(Status)) {
898 		if (gen_count == sc->ec_gencount)
899 		    no_intr++;
900 		else
901 		    no_intr = 0;
902 		break;
903 	    }
904 	    gen_count = sc->ec_gencount;
905 	}
906 
907 	/*
908 	 * We finished waiting for the GPE and it never arrived.  Try to
909 	 * read the register once and trust whatever value we got.  This is
910 	 * the best we can do at this point.
911 	 */
912 	if (ACPI_FAILURE(Status))
913 	    Status = EcCheckStatus(sc, "sleep_end", Event);
914     }
915     if (!need_poll && no_intr > 10) {
916 	device_printf(sc->ec_dev,
917 	    "not getting interrupts, switched to polled mode\n");
918 	ec_polled_mode = 1;
919     }
920     if (ACPI_FAILURE(Status))
921 	    CTR0(KTR_ACPI, "error: ec wait timed out");
922     return (Status);
923 }
924 
925 static ACPI_STATUS
926 EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
927 {
928     ACPI_STATUS	status;
929     EC_EVENT	event;
930     EC_STATUS	ec_status;
931     u_int	gen_count;
932 
933     ACPI_SERIAL_ASSERT(ec);
934 
935     /* Don't use burst mode if user disabled it. */
936     if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
937 	return (AE_ERROR);
938 
939     /* Decide what to wait for based on command type. */
940     switch (cmd) {
941     case EC_COMMAND_READ:
942     case EC_COMMAND_WRITE:
943     case EC_COMMAND_BURST_DISABLE:
944 	event = EC_EVENT_INPUT_BUFFER_EMPTY;
945 	break;
946     case EC_COMMAND_QUERY:
947     case EC_COMMAND_BURST_ENABLE:
948 	event = EC_EVENT_OUTPUT_BUFFER_FULL;
949 	break;
950     default:
951 	device_printf(sc->ec_dev, "EcCommand: invalid command %#x\n", cmd);
952 	return (AE_BAD_PARAMETER);
953     }
954 
955     /*
956      * Ensure empty input buffer before issuing command.
957      * Use generation count of zero to force a quick check.
958      */
959     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, 0);
960     if (ACPI_FAILURE(status))
961 	return (status);
962 
963     /* Run the command and wait for the chosen event. */
964     CTR1(KTR_ACPI, "ec running command %#x", cmd);
965     gen_count = sc->ec_gencount;
966     EC_SET_CSR(sc, cmd);
967     status = EcWaitEvent(sc, event, gen_count);
968     if (ACPI_SUCCESS(status)) {
969 	/* If we succeeded, burst flag should now be present. */
970 	if (cmd == EC_COMMAND_BURST_ENABLE) {
971 	    ec_status = EC_GET_CSR(sc);
972 	    if ((ec_status & EC_FLAG_BURST_MODE) == 0)
973 		status = AE_ERROR;
974 	}
975     } else
976 	device_printf(sc->ec_dev, "EcCommand: no response to %#x\n", cmd);
977     return (status);
978 }
979 
980 static ACPI_STATUS
981 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
982 {
983     ACPI_STATUS	status;
984     u_int gen_count;
985     int retry;
986 
987     ACPI_SERIAL_ASSERT(ec);
988     CTR1(KTR_ACPI, "ec read from %#x", Address);
989 
990     for (retry = 0; retry < 2; retry++) {
991 	status = EcCommand(sc, EC_COMMAND_READ);
992 	if (ACPI_FAILURE(status))
993 	    return (status);
994 
995 	gen_count = sc->ec_gencount;
996 	EC_SET_DATA(sc, Address);
997 	status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
998 	if (ACPI_SUCCESS(status)) {
999 	    *Data = EC_GET_DATA(sc);
1000 	    return (AE_OK);
1001 	}
1002 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
1003 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
1004 	    break;
1005     }
1006     device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
1007     return (status);
1008 }
1009 
1010 static ACPI_STATUS
1011 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 Data)
1012 {
1013     ACPI_STATUS	status;
1014     u_int gen_count;
1015 
1016     ACPI_SERIAL_ASSERT(ec);
1017     CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, Data);
1018 
1019     status = EcCommand(sc, EC_COMMAND_WRITE);
1020     if (ACPI_FAILURE(status))
1021 	return (status);
1022 
1023     gen_count = sc->ec_gencount;
1024     EC_SET_DATA(sc, Address);
1025     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1026     if (ACPI_FAILURE(status)) {
1027 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent address\n");
1028 	return (status);
1029     }
1030 
1031     gen_count = sc->ec_gencount;
1032     EC_SET_DATA(sc, Data);
1033     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1034     if (ACPI_FAILURE(status)) {
1035 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent data\n");
1036 	return (status);
1037     }
1038 
1039     return (AE_OK);
1040 }
1041