xref: /freebsd/sys/dev/acpica/acpi_ec.c (revision efe3b0de1438e7a8473d92f2be57072394559e3c)
1 /*-
2  * Copyright (c) 2003-2007 Nate Lawson
3  * Copyright (c) 2000 Michael Smith
4  * Copyright (c) 2000 BSDi
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_acpi.h"
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/bus.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/sx.h>
40 
41 #include <machine/bus.h>
42 #include <machine/resource.h>
43 #include <sys/rman.h>
44 
45 #include <contrib/dev/acpica/include/acpi.h>
46 #include <contrib/dev/acpica/include/accommon.h>
47 
48 #include <dev/acpica/acpivar.h>
49 
50 /* Hooks for the ACPI CA debugging infrastructure */
51 #define _COMPONENT	ACPI_EC
52 ACPI_MODULE_NAME("EC")
53 
54 /*
55  * EC_COMMAND:
56  * -----------
57  */
58 typedef UINT8				EC_COMMAND;
59 
60 #define EC_COMMAND_UNKNOWN		((EC_COMMAND) 0x00)
61 #define EC_COMMAND_READ			((EC_COMMAND) 0x80)
62 #define EC_COMMAND_WRITE		((EC_COMMAND) 0x81)
63 #define EC_COMMAND_BURST_ENABLE		((EC_COMMAND) 0x82)
64 #define EC_COMMAND_BURST_DISABLE	((EC_COMMAND) 0x83)
65 #define EC_COMMAND_QUERY		((EC_COMMAND) 0x84)
66 
67 /*
68  * EC_STATUS:
69  * ----------
70  * The encoding of the EC status register is illustrated below.
71  * Note that a set bit (1) indicates the property is TRUE
72  * (e.g. if bit 0 is set then the output buffer is full).
73  * +-+-+-+-+-+-+-+-+
74  * |7|6|5|4|3|2|1|0|
75  * +-+-+-+-+-+-+-+-+
76  *  | | | | | | | |
77  *  | | | | | | | +- Output Buffer Full?
78  *  | | | | | | +--- Input Buffer Full?
79  *  | | | | | +----- <reserved>
80  *  | | | | +------- Data Register is Command Byte?
81  *  | | | +--------- Burst Mode Enabled?
82  *  | | +----------- SCI Event?
83  *  | +------------- SMI Event?
84  *  +--------------- <reserved>
85  *
86  */
87 typedef UINT8				EC_STATUS;
88 
89 #define EC_FLAG_OUTPUT_BUFFER		((EC_STATUS) 0x01)
90 #define EC_FLAG_INPUT_BUFFER		((EC_STATUS) 0x02)
91 #define EC_FLAG_DATA_IS_CMD		((EC_STATUS) 0x08)
92 #define EC_FLAG_BURST_MODE		((EC_STATUS) 0x10)
93 
94 /*
95  * EC_EVENT:
96  * ---------
97  */
98 typedef UINT8				EC_EVENT;
99 
100 #define EC_EVENT_UNKNOWN		((EC_EVENT) 0x00)
101 #define EC_EVENT_OUTPUT_BUFFER_FULL	((EC_EVENT) 0x01)
102 #define EC_EVENT_INPUT_BUFFER_EMPTY	((EC_EVENT) 0x02)
103 #define EC_EVENT_SCI			((EC_EVENT) 0x20)
104 #define EC_EVENT_SMI			((EC_EVENT) 0x40)
105 
106 /* Data byte returned after burst enable indicating it was successful. */
107 #define EC_BURST_ACK			0x90
108 
109 /*
110  * Register access primitives
111  */
112 #define EC_GET_DATA(sc)							\
113 	bus_space_read_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0)
114 
115 #define EC_SET_DATA(sc, v)						\
116 	bus_space_write_1((sc)->ec_data_tag, (sc)->ec_data_handle, 0, (v))
117 
118 #define EC_GET_CSR(sc)							\
119 	bus_space_read_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0)
120 
121 #define EC_SET_CSR(sc, v)						\
122 	bus_space_write_1((sc)->ec_csr_tag, (sc)->ec_csr_handle, 0, (v))
123 
124 /* Additional params to pass from the probe routine */
125 struct acpi_ec_params {
126     int		glk;
127     int		gpe_bit;
128     ACPI_HANDLE	gpe_handle;
129     int		uid;
130 };
131 
132 /*
133  * Driver softc.
134  */
135 struct acpi_ec_softc {
136     device_t		ec_dev;
137     ACPI_HANDLE		ec_handle;
138     int			ec_uid;
139     ACPI_HANDLE		ec_gpehandle;
140     UINT8		ec_gpebit;
141 
142     int			ec_data_rid;
143     struct resource	*ec_data_res;
144     bus_space_tag_t	ec_data_tag;
145     bus_space_handle_t	ec_data_handle;
146 
147     int			ec_csr_rid;
148     struct resource	*ec_csr_res;
149     bus_space_tag_t	ec_csr_tag;
150     bus_space_handle_t	ec_csr_handle;
151 
152     int			ec_glk;
153     int			ec_glkhandle;
154     int			ec_burstactive;
155     int			ec_sci_pend;
156     volatile u_int	ec_gencount;
157     int			ec_suspending;
158 };
159 
160 /*
161  * XXX njl
162  * I couldn't find it in the spec but other implementations also use a
163  * value of 1 ms for the time to acquire global lock.
164  */
165 #define EC_LOCK_TIMEOUT	1000
166 
167 /* Default delay in microseconds between each run of the status polling loop. */
168 #define EC_POLL_DELAY	50
169 
170 /* Total time in ms spent waiting for a response from EC. */
171 #define EC_TIMEOUT	750
172 
173 #define EVENT_READY(event, status)			\
174 	(((event) == EC_EVENT_OUTPUT_BUFFER_FULL &&	\
175 	 ((status) & EC_FLAG_OUTPUT_BUFFER) != 0) ||	\
176 	 ((event) == EC_EVENT_INPUT_BUFFER_EMPTY && 	\
177 	 ((status) & EC_FLAG_INPUT_BUFFER) == 0))
178 
179 ACPI_SERIAL_DECL(ec, "ACPI embedded controller");
180 
181 static SYSCTL_NODE(_debug_acpi, OID_AUTO, ec, CTLFLAG_RD, NULL, "EC debugging");
182 
183 static int	ec_burst_mode;
184 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, burst, CTLFLAG_RWTUN, &ec_burst_mode, 0,
185     "Enable use of burst mode (faster for nearly all systems)");
186 static int	ec_polled_mode;
187 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, polled, CTLFLAG_RWTUN, &ec_polled_mode, 0,
188     "Force use of polled mode (only if interrupt mode doesn't work)");
189 static int	ec_timeout = EC_TIMEOUT;
190 SYSCTL_INT(_debug_acpi_ec, OID_AUTO, timeout, CTLFLAG_RWTUN, &ec_timeout,
191     EC_TIMEOUT, "Total time spent waiting for a response (poll+sleep)");
192 
193 static ACPI_STATUS
194 EcLock(struct acpi_ec_softc *sc)
195 {
196     ACPI_STATUS	status;
197 
198     /* If _GLK is non-zero, acquire the global lock. */
199     status = AE_OK;
200     if (sc->ec_glk) {
201 	status = AcpiAcquireGlobalLock(EC_LOCK_TIMEOUT, &sc->ec_glkhandle);
202 	if (ACPI_FAILURE(status))
203 	    return (status);
204     }
205     ACPI_SERIAL_BEGIN(ec);
206     return (status);
207 }
208 
209 static void
210 EcUnlock(struct acpi_ec_softc *sc)
211 {
212     ACPI_SERIAL_END(ec);
213     if (sc->ec_glk)
214 	AcpiReleaseGlobalLock(sc->ec_glkhandle);
215 }
216 
217 static UINT32		EcGpeHandler(ACPI_HANDLE, UINT32, void *);
218 static ACPI_STATUS	EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function,
219 				void *Context, void **return_Context);
220 static ACPI_STATUS	EcSpaceHandler(UINT32 Function,
221 				ACPI_PHYSICAL_ADDRESS Address,
222 				UINT32 Width, UINT64 *Value,
223 				void *Context, void *RegionContext);
224 static ACPI_STATUS	EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event,
225 				u_int gen_count);
226 static ACPI_STATUS	EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd);
227 static ACPI_STATUS	EcRead(struct acpi_ec_softc *sc, UINT8 Address,
228 				UINT8 *Data);
229 static ACPI_STATUS	EcWrite(struct acpi_ec_softc *sc, UINT8 Address,
230 				UINT8 Data);
231 static int		acpi_ec_probe(device_t dev);
232 static int		acpi_ec_attach(device_t dev);
233 static int		acpi_ec_suspend(device_t dev);
234 static int		acpi_ec_resume(device_t dev);
235 static int		acpi_ec_shutdown(device_t dev);
236 static int		acpi_ec_read_method(device_t dev, u_int addr,
237 				UINT64 *val, int width);
238 static int		acpi_ec_write_method(device_t dev, u_int addr,
239 				UINT64 val, int width);
240 
241 static device_method_t acpi_ec_methods[] = {
242     /* Device interface */
243     DEVMETHOD(device_probe,	acpi_ec_probe),
244     DEVMETHOD(device_attach,	acpi_ec_attach),
245     DEVMETHOD(device_suspend,	acpi_ec_suspend),
246     DEVMETHOD(device_resume,	acpi_ec_resume),
247     DEVMETHOD(device_shutdown,	acpi_ec_shutdown),
248 
249     /* Embedded controller interface */
250     DEVMETHOD(acpi_ec_read,	acpi_ec_read_method),
251     DEVMETHOD(acpi_ec_write,	acpi_ec_write_method),
252 
253     DEVMETHOD_END
254 };
255 
256 static driver_t acpi_ec_driver = {
257     "acpi_ec",
258     acpi_ec_methods,
259     sizeof(struct acpi_ec_softc),
260 };
261 
262 static devclass_t acpi_ec_devclass;
263 DRIVER_MODULE(acpi_ec, acpi, acpi_ec_driver, acpi_ec_devclass, 0, 0);
264 MODULE_DEPEND(acpi_ec, acpi, 1, 1, 1);
265 
266 /*
267  * Look for an ECDT and if we find one, set up default GPE and
268  * space handlers to catch attempts to access EC space before
269  * we have a real driver instance in place.
270  *
271  * TODO: Some old Gateway laptops need us to fake up an ECDT or
272  * otherwise attach early so that _REG methods can run.
273  */
274 void
275 acpi_ec_ecdt_probe(device_t parent)
276 {
277     ACPI_TABLE_ECDT *ecdt;
278     ACPI_STATUS	     status;
279     device_t	     child;
280     ACPI_HANDLE	     h;
281     struct acpi_ec_params *params;
282 
283     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
284 
285     /* Find and validate the ECDT. */
286     status = AcpiGetTable(ACPI_SIG_ECDT, 1, (ACPI_TABLE_HEADER **)&ecdt);
287     if (ACPI_FAILURE(status) ||
288 	ecdt->Control.BitWidth != 8 ||
289 	ecdt->Data.BitWidth != 8) {
290 	return;
291     }
292 
293     /* Create the child device with the given unit number. */
294     child = BUS_ADD_CHILD(parent, 3, "acpi_ec", ecdt->Uid);
295     if (child == NULL) {
296 	printf("%s: can't add child\n", __func__);
297 	return;
298     }
299 
300     /* Find and save the ACPI handle for this device. */
301     status = AcpiGetHandle(NULL, ecdt->Id, &h);
302     if (ACPI_FAILURE(status)) {
303 	device_delete_child(parent, child);
304 	printf("%s: can't get handle\n", __func__);
305 	return;
306     }
307     acpi_set_handle(child, h);
308 
309     /* Set the data and CSR register addresses. */
310     bus_set_resource(child, SYS_RES_IOPORT, 0, ecdt->Data.Address,
311 	/*count*/1);
312     bus_set_resource(child, SYS_RES_IOPORT, 1, ecdt->Control.Address,
313 	/*count*/1);
314 
315     /*
316      * Store values for the probe/attach routines to use.  Store the
317      * ECDT GPE bit and set the global lock flag according to _GLK.
318      * Note that it is not perfectly correct to be evaluating a method
319      * before initializing devices, but in practice this function
320      * should be safe to call at this point.
321      */
322     params = malloc(sizeof(struct acpi_ec_params), M_TEMP, M_WAITOK | M_ZERO);
323     params->gpe_handle = NULL;
324     params->gpe_bit = ecdt->Gpe;
325     params->uid = ecdt->Uid;
326     acpi_GetInteger(h, "_GLK", &params->glk);
327     acpi_set_private(child, params);
328 
329     /* Finish the attach process. */
330     if (device_probe_and_attach(child) != 0)
331 	device_delete_child(parent, child);
332 }
333 
334 static int
335 acpi_ec_probe(device_t dev)
336 {
337     ACPI_BUFFER buf;
338     ACPI_HANDLE h;
339     ACPI_OBJECT *obj;
340     ACPI_STATUS status;
341     device_t	peer;
342     char	desc[64];
343     int		ecdt;
344     int		ret;
345     struct acpi_ec_params *params;
346     static char *ec_ids[] = { "PNP0C09", NULL };
347 
348     /* Check that this is a device and that EC is not disabled. */
349     if (acpi_get_type(dev) != ACPI_TYPE_DEVICE || acpi_disabled("ec"))
350 	return (ENXIO);
351 
352     /*
353      * If probed via ECDT, set description and continue.  Otherwise,
354      * we can access the namespace and make sure this is not a
355      * duplicate probe.
356      */
357     ret = ENXIO;
358     ecdt = 0;
359     buf.Pointer = NULL;
360     buf.Length = ACPI_ALLOCATE_BUFFER;
361     params = acpi_get_private(dev);
362     if (params != NULL) {
363 	ecdt = 1;
364 	ret = 0;
365     } else if (ACPI_ID_PROBE(device_get_parent(dev), dev, ec_ids)) {
366 	params = malloc(sizeof(struct acpi_ec_params), M_TEMP,
367 			M_WAITOK | M_ZERO);
368 	h = acpi_get_handle(dev);
369 
370 	/*
371 	 * Read the unit ID to check for duplicate attach and the
372 	 * global lock value to see if we should acquire it when
373 	 * accessing the EC.
374 	 */
375 	status = acpi_GetInteger(h, "_UID", &params->uid);
376 	if (ACPI_FAILURE(status))
377 	    params->uid = 0;
378 	status = acpi_GetInteger(h, "_GLK", &params->glk);
379 	if (ACPI_FAILURE(status))
380 	    params->glk = 0;
381 
382 	/*
383 	 * Evaluate the _GPE method to find the GPE bit used by the EC to
384 	 * signal status (SCI).  If it's a package, it contains a reference
385 	 * and GPE bit, similar to _PRW.
386 	 */
387 	status = AcpiEvaluateObject(h, "_GPE", NULL, &buf);
388 	if (ACPI_FAILURE(status)) {
389 	    device_printf(dev, "can't evaluate _GPE - %s\n",
390 			  AcpiFormatException(status));
391 	    goto out;
392 	}
393 	obj = (ACPI_OBJECT *)buf.Pointer;
394 	if (obj == NULL)
395 	    goto out;
396 
397 	switch (obj->Type) {
398 	case ACPI_TYPE_INTEGER:
399 	    params->gpe_handle = NULL;
400 	    params->gpe_bit = obj->Integer.Value;
401 	    break;
402 	case ACPI_TYPE_PACKAGE:
403 	    if (!ACPI_PKG_VALID(obj, 2))
404 		goto out;
405 	    params->gpe_handle =
406 		acpi_GetReference(NULL, &obj->Package.Elements[0]);
407 	    if (params->gpe_handle == NULL ||
408 		acpi_PkgInt32(obj, 1, &params->gpe_bit) != 0)
409 		goto out;
410 	    break;
411 	default:
412 	    device_printf(dev, "_GPE has invalid type %d\n", obj->Type);
413 	    goto out;
414 	}
415 
416 	/* Store the values we got from the namespace for attach. */
417 	acpi_set_private(dev, params);
418 
419 	/*
420 	 * Check for a duplicate probe.  This can happen when a probe
421 	 * via ECDT succeeded already.  If this is a duplicate, disable
422 	 * this device.
423 	 */
424 	peer = devclass_get_device(acpi_ec_devclass, params->uid);
425 	if (peer == NULL || !device_is_alive(peer))
426 	    ret = 0;
427 	else
428 	    device_disable(dev);
429     }
430 
431 out:
432     if (ret == 0) {
433 	snprintf(desc, sizeof(desc), "Embedded Controller: GPE %#x%s%s",
434 		 params->gpe_bit, (params->glk) ? ", GLK" : "",
435 		 ecdt ? ", ECDT" : "");
436 	device_set_desc_copy(dev, desc);
437     } else
438 	free(params, M_TEMP);
439     if (buf.Pointer)
440 	AcpiOsFree(buf.Pointer);
441     return (ret);
442 }
443 
444 static int
445 acpi_ec_attach(device_t dev)
446 {
447     struct acpi_ec_softc	*sc;
448     struct acpi_ec_params	*params;
449     ACPI_STATUS			Status;
450 
451     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
452 
453     /* Fetch/initialize softc (assumes softc is pre-zeroed). */
454     sc = device_get_softc(dev);
455     params = acpi_get_private(dev);
456     sc->ec_dev = dev;
457     sc->ec_handle = acpi_get_handle(dev);
458 
459     /* Retrieve previously probed values via device ivars. */
460     sc->ec_glk = params->glk;
461     sc->ec_gpebit = params->gpe_bit;
462     sc->ec_gpehandle = params->gpe_handle;
463     sc->ec_uid = params->uid;
464     sc->ec_suspending = FALSE;
465     acpi_set_private(dev, NULL);
466     free(params, M_TEMP);
467 
468     /* Attach bus resources for data and command/status ports. */
469     sc->ec_data_rid = 0;
470     sc->ec_data_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
471 			&sc->ec_data_rid, RF_ACTIVE);
472     if (sc->ec_data_res == NULL) {
473 	device_printf(dev, "can't allocate data port\n");
474 	goto error;
475     }
476     sc->ec_data_tag = rman_get_bustag(sc->ec_data_res);
477     sc->ec_data_handle = rman_get_bushandle(sc->ec_data_res);
478 
479     sc->ec_csr_rid = 1;
480     sc->ec_csr_res = bus_alloc_resource_any(sc->ec_dev, SYS_RES_IOPORT,
481 			&sc->ec_csr_rid, RF_ACTIVE);
482     if (sc->ec_csr_res == NULL) {
483 	device_printf(dev, "can't allocate command/status port\n");
484 	goto error;
485     }
486     sc->ec_csr_tag = rman_get_bustag(sc->ec_csr_res);
487     sc->ec_csr_handle = rman_get_bushandle(sc->ec_csr_res);
488 
489     /*
490      * Install a handler for this EC's GPE bit.  We want edge-triggered
491      * behavior.
492      */
493     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching GPE handler\n"));
494     Status = AcpiInstallGpeHandler(sc->ec_gpehandle, sc->ec_gpebit,
495 		ACPI_GPE_EDGE_TRIGGERED, EcGpeHandler, sc);
496     if (ACPI_FAILURE(Status)) {
497 	device_printf(dev, "can't install GPE handler for %s - %s\n",
498 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
499 	goto error;
500     }
501 
502     /*
503      * Install address space handler
504      */
505     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "attaching address space handler\n"));
506     Status = AcpiInstallAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
507 		&EcSpaceHandler, &EcSpaceSetup, sc);
508     if (ACPI_FAILURE(Status)) {
509 	device_printf(dev, "can't install address space handler for %s - %s\n",
510 		      acpi_name(sc->ec_handle), AcpiFormatException(Status));
511 	goto error;
512     }
513 
514     /* Enable runtime GPEs for the handler. */
515     Status = AcpiEnableGpe(sc->ec_gpehandle, sc->ec_gpebit);
516     if (ACPI_FAILURE(Status)) {
517 	device_printf(dev, "AcpiEnableGpe failed: %s\n",
518 		      AcpiFormatException(Status));
519 	goto error;
520     }
521 
522     ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES, "acpi_ec_attach complete\n"));
523     return (0);
524 
525 error:
526     AcpiRemoveGpeHandler(sc->ec_gpehandle, sc->ec_gpebit, EcGpeHandler);
527     AcpiRemoveAddressSpaceHandler(sc->ec_handle, ACPI_ADR_SPACE_EC,
528 	EcSpaceHandler);
529     if (sc->ec_csr_res)
530 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_csr_rid,
531 			     sc->ec_csr_res);
532     if (sc->ec_data_res)
533 	bus_release_resource(sc->ec_dev, SYS_RES_IOPORT, sc->ec_data_rid,
534 			     sc->ec_data_res);
535     return (ENXIO);
536 }
537 
538 static int
539 acpi_ec_suspend(device_t dev)
540 {
541     struct acpi_ec_softc	*sc;
542 
543     sc = device_get_softc(dev);
544     sc->ec_suspending = TRUE;
545     return (0);
546 }
547 
548 static int
549 acpi_ec_resume(device_t dev)
550 {
551     struct acpi_ec_softc	*sc;
552 
553     sc = device_get_softc(dev);
554     sc->ec_suspending = FALSE;
555     return (0);
556 }
557 
558 static int
559 acpi_ec_shutdown(device_t dev)
560 {
561     struct acpi_ec_softc	*sc;
562 
563     /* Disable the GPE so we don't get EC events during shutdown. */
564     sc = device_get_softc(dev);
565     AcpiDisableGpe(sc->ec_gpehandle, sc->ec_gpebit);
566     return (0);
567 }
568 
569 /* Methods to allow other devices (e.g., smbat) to read/write EC space. */
570 static int
571 acpi_ec_read_method(device_t dev, u_int addr, UINT64 *val, int width)
572 {
573     struct acpi_ec_softc *sc;
574     ACPI_STATUS status;
575 
576     sc = device_get_softc(dev);
577     status = EcSpaceHandler(ACPI_READ, addr, width * 8, val, sc, NULL);
578     if (ACPI_FAILURE(status))
579 	return (ENXIO);
580     return (0);
581 }
582 
583 static int
584 acpi_ec_write_method(device_t dev, u_int addr, UINT64 val, int width)
585 {
586     struct acpi_ec_softc *sc;
587     ACPI_STATUS status;
588 
589     sc = device_get_softc(dev);
590     status = EcSpaceHandler(ACPI_WRITE, addr, width * 8, &val, sc, NULL);
591     if (ACPI_FAILURE(status))
592 	return (ENXIO);
593     return (0);
594 }
595 
596 static ACPI_STATUS
597 EcCheckStatus(struct acpi_ec_softc *sc, const char *msg, EC_EVENT event)
598 {
599     ACPI_STATUS status;
600     EC_STATUS ec_status;
601 
602     status = AE_NO_HARDWARE_RESPONSE;
603     ec_status = EC_GET_CSR(sc);
604     if (sc->ec_burstactive && !(ec_status & EC_FLAG_BURST_MODE)) {
605 	CTR1(KTR_ACPI, "ec burst disabled in waitevent (%s)", msg);
606 	sc->ec_burstactive = FALSE;
607     }
608     if (EVENT_READY(event, ec_status)) {
609 	CTR2(KTR_ACPI, "ec %s wait ready, status %#x", msg, ec_status);
610 	status = AE_OK;
611     }
612     return (status);
613 }
614 
615 static void
616 EcGpeQueryHandlerSub(struct acpi_ec_softc *sc)
617 {
618     UINT8			Data;
619     ACPI_STATUS			Status;
620     int				retry;
621     char			qxx[5];
622 
623     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
624 
625     /* Serialize user access with EcSpaceHandler(). */
626     Status = EcLock(sc);
627     if (ACPI_FAILURE(Status)) {
628 	device_printf(sc->ec_dev, "GpeQuery lock error: %s\n",
629 	    AcpiFormatException(Status));
630 	return;
631     }
632 
633     /*
634      * Send a query command to the EC to find out which _Qxx call it
635      * wants to make.  This command clears the SCI bit and also the
636      * interrupt source since we are edge-triggered.  To prevent the GPE
637      * that may arise from running the query from causing another query
638      * to be queued, we clear the pending flag only after running it.
639      */
640     for (retry = 0; retry < 2; retry++) {
641 	Status = EcCommand(sc, EC_COMMAND_QUERY);
642 	if (ACPI_SUCCESS(Status))
643 	    break;
644 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
645 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
646 	    break;
647     }
648     if (ACPI_FAILURE(Status)) {
649 	EcUnlock(sc);
650 	device_printf(sc->ec_dev, "GPE query failed: %s\n",
651 	    AcpiFormatException(Status));
652 	return;
653     }
654     Data = EC_GET_DATA(sc);
655 
656     /*
657      * We have to unlock before running the _Qxx method below since that
658      * method may attempt to read/write from EC address space, causing
659      * recursive acquisition of the lock.
660      */
661     EcUnlock(sc);
662 
663     /* Ignore the value for "no outstanding event". (13.3.5) */
664     CTR2(KTR_ACPI, "ec query ok,%s running _Q%02X", Data ? "" : " not", Data);
665     if (Data == 0)
666 	return;
667 
668     /* Evaluate _Qxx to respond to the controller. */
669     snprintf(qxx, sizeof(qxx), "_Q%02X", Data);
670     AcpiUtStrupr(qxx);
671     Status = AcpiEvaluateObject(sc->ec_handle, qxx, NULL, NULL);
672     if (ACPI_FAILURE(Status) && Status != AE_NOT_FOUND) {
673 	device_printf(sc->ec_dev, "evaluation of query method %s failed: %s\n",
674 	    qxx, AcpiFormatException(Status));
675     }
676 }
677 
678 static void
679 EcGpeQueryHandler(void *Context)
680 {
681     struct acpi_ec_softc *sc = (struct acpi_ec_softc *)Context;
682     int pending;
683 
684     KASSERT(Context != NULL, ("EcGpeQueryHandler called with NULL"));
685 
686     do {
687 	/* Read the current pending count */
688 	pending = atomic_load_acq_int(&sc->ec_sci_pend);
689 
690 	/* Call GPE handler function */
691 	EcGpeQueryHandlerSub(sc);
692 
693 	/*
694 	 * Try to reset the pending count to zero. If this fails we
695 	 * know another GPE event has occurred while handling the
696 	 * current GPE event and need to loop.
697 	 */
698     } while (!atomic_cmpset_int(&sc->ec_sci_pend, pending, 0));
699 }
700 
701 /*
702  * The GPE handler is called when IBE/OBF or SCI events occur.  We are
703  * called from an unknown lock context.
704  */
705 static UINT32
706 EcGpeHandler(ACPI_HANDLE GpeDevice, UINT32 GpeNumber, void *Context)
707 {
708     struct acpi_ec_softc *sc = Context;
709     ACPI_STATUS		       Status;
710     EC_STATUS		       EcStatus;
711 
712     KASSERT(Context != NULL, ("EcGpeHandler called with NULL"));
713     CTR0(KTR_ACPI, "ec gpe handler start");
714 
715     /*
716      * Notify EcWaitEvent() that the status register is now fresh.  If we
717      * didn't do this, it wouldn't be possible to distinguish an old IBE
718      * from a new one, for example when doing a write transaction (writing
719      * address and then data values.)
720      */
721     atomic_add_int(&sc->ec_gencount, 1);
722     wakeup(sc);
723 
724     /*
725      * If the EC_SCI bit of the status register is set, queue a query handler.
726      * It will run the query and _Qxx method later, under the lock.
727      */
728     EcStatus = EC_GET_CSR(sc);
729     if ((EcStatus & EC_EVENT_SCI) &&
730 	atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
731 	CTR0(KTR_ACPI, "ec gpe queueing query handler");
732 	Status = AcpiOsExecute(OSL_GPE_HANDLER, EcGpeQueryHandler, Context);
733 	if (ACPI_FAILURE(Status)) {
734 	    printf("EcGpeHandler: queuing GPE query handler failed\n");
735 	    atomic_store_rel_int(&sc->ec_sci_pend, 0);
736 	}
737     }
738     return (ACPI_REENABLE_GPE);
739 }
740 
741 static ACPI_STATUS
742 EcSpaceSetup(ACPI_HANDLE Region, UINT32 Function, void *Context,
743 	     void **RegionContext)
744 {
745 
746     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
747 
748     /*
749      * If deactivating a region, always set the output to NULL.  Otherwise,
750      * just pass the context through.
751      */
752     if (Function == ACPI_REGION_DEACTIVATE)
753 	*RegionContext = NULL;
754     else
755 	*RegionContext = Context;
756 
757     return_ACPI_STATUS (AE_OK);
758 }
759 
760 static ACPI_STATUS
761 EcSpaceHandler(UINT32 Function, ACPI_PHYSICAL_ADDRESS Address, UINT32 Width,
762 	       UINT64 *Value, void *Context, void *RegionContext)
763 {
764     struct acpi_ec_softc	*sc = (struct acpi_ec_softc *)Context;
765     ACPI_PHYSICAL_ADDRESS	EcAddr;
766     UINT8			*EcData;
767     ACPI_STATUS			Status;
768 
769     ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, (UINT32)Address);
770 
771     if (Function != ACPI_READ && Function != ACPI_WRITE)
772 	return_ACPI_STATUS (AE_BAD_PARAMETER);
773     if (Width % 8 != 0 || Value == NULL || Context == NULL)
774 	return_ACPI_STATUS (AE_BAD_PARAMETER);
775     if (Address + Width / 8 > 256)
776 	return_ACPI_STATUS (AE_BAD_ADDRESS);
777 
778     /*
779      * If booting, check if we need to run the query handler.  If so, we
780      * we call it directly here since our thread taskq is not active yet.
781      */
782     if (cold || rebooting || sc->ec_suspending) {
783 	if ((EC_GET_CSR(sc) & EC_EVENT_SCI) &&
784 	    atomic_fetchadd_int(&sc->ec_sci_pend, 1) == 0) {
785 	    CTR0(KTR_ACPI, "ec running gpe handler directly");
786 	    EcGpeQueryHandler(sc);
787 	}
788     }
789 
790     /* Serialize with EcGpeQueryHandler() at transaction granularity. */
791     Status = EcLock(sc);
792     if (ACPI_FAILURE(Status))
793 	return_ACPI_STATUS (Status);
794 
795     /* If we can't start burst mode, continue anyway. */
796     Status = EcCommand(sc, EC_COMMAND_BURST_ENABLE);
797     if (ACPI_SUCCESS(Status)) {
798 	if (EC_GET_DATA(sc) == EC_BURST_ACK) {
799 	    CTR0(KTR_ACPI, "ec burst enabled");
800 	    sc->ec_burstactive = TRUE;
801 	}
802     }
803 
804     /* Perform the transaction(s), based on Width. */
805     EcAddr = Address;
806     EcData = (UINT8 *)Value;
807     if (Function == ACPI_READ)
808 	*Value = 0;
809     do {
810 	switch (Function) {
811 	case ACPI_READ:
812 	    Status = EcRead(sc, EcAddr, EcData);
813 	    break;
814 	case ACPI_WRITE:
815 	    Status = EcWrite(sc, EcAddr, *EcData);
816 	    break;
817 	}
818 	if (ACPI_FAILURE(Status))
819 	    break;
820 	EcAddr++;
821 	EcData++;
822     } while (EcAddr < Address + Width / 8);
823 
824     if (sc->ec_burstactive) {
825 	sc->ec_burstactive = FALSE;
826 	if (ACPI_SUCCESS(EcCommand(sc, EC_COMMAND_BURST_DISABLE)))
827 	    CTR0(KTR_ACPI, "ec disabled burst ok");
828     }
829 
830     EcUnlock(sc);
831     return_ACPI_STATUS (Status);
832 }
833 
834 static ACPI_STATUS
835 EcWaitEvent(struct acpi_ec_softc *sc, EC_EVENT Event, u_int gen_count)
836 {
837     static int	no_intr = 0;
838     ACPI_STATUS	Status;
839     int		count, i, need_poll, slp_ival;
840 
841     ACPI_SERIAL_ASSERT(ec);
842     Status = AE_NO_HARDWARE_RESPONSE;
843     need_poll = cold || rebooting || ec_polled_mode || sc->ec_suspending;
844 
845     /* Wait for event by polling or GPE (interrupt). */
846     if (need_poll) {
847 	count = (ec_timeout * 1000) / EC_POLL_DELAY;
848 	if (count == 0)
849 	    count = 1;
850 	DELAY(10);
851 	for (i = 0; i < count; i++) {
852 	    Status = EcCheckStatus(sc, "poll", Event);
853 	    if (ACPI_SUCCESS(Status))
854 		break;
855 	    DELAY(EC_POLL_DELAY);
856 	}
857     } else {
858 	slp_ival = hz / 1000;
859 	if (slp_ival != 0) {
860 	    count = ec_timeout;
861 	} else {
862 	    /* hz has less than 1 ms resolution so scale timeout. */
863 	    slp_ival = 1;
864 	    count = ec_timeout / (1000 / hz);
865 	}
866 
867 	/*
868 	 * Wait for the GPE to signal the status changed, checking the
869 	 * status register each time we get one.  It's possible to get a
870 	 * GPE for an event we're not interested in here (i.e., SCI for
871 	 * EC query).
872 	 */
873 	for (i = 0; i < count; i++) {
874 	    if (gen_count == sc->ec_gencount)
875 		tsleep(sc, 0, "ecgpe", slp_ival);
876 	    /*
877 	     * Record new generation count.  It's possible the GPE was
878 	     * just to notify us that a query is needed and we need to
879 	     * wait for a second GPE to signal the completion of the
880 	     * event we are actually waiting for.
881 	     */
882 	    Status = EcCheckStatus(sc, "sleep", Event);
883 	    if (ACPI_SUCCESS(Status)) {
884 		if (gen_count == sc->ec_gencount)
885 		    no_intr++;
886 		else
887 		    no_intr = 0;
888 		break;
889 	    }
890 	    gen_count = sc->ec_gencount;
891 	}
892 
893 	/*
894 	 * We finished waiting for the GPE and it never arrived.  Try to
895 	 * read the register once and trust whatever value we got.  This is
896 	 * the best we can do at this point.
897 	 */
898 	if (ACPI_FAILURE(Status))
899 	    Status = EcCheckStatus(sc, "sleep_end", Event);
900     }
901     if (!need_poll && no_intr > 10) {
902 	device_printf(sc->ec_dev,
903 	    "not getting interrupts, switched to polled mode\n");
904 	ec_polled_mode = 1;
905     }
906     if (ACPI_FAILURE(Status))
907 	    CTR0(KTR_ACPI, "error: ec wait timed out");
908     return (Status);
909 }
910 
911 static ACPI_STATUS
912 EcCommand(struct acpi_ec_softc *sc, EC_COMMAND cmd)
913 {
914     ACPI_STATUS	status;
915     EC_EVENT	event;
916     EC_STATUS	ec_status;
917     u_int	gen_count;
918 
919     ACPI_SERIAL_ASSERT(ec);
920 
921     /* Don't use burst mode if user disabled it. */
922     if (!ec_burst_mode && cmd == EC_COMMAND_BURST_ENABLE)
923 	return (AE_ERROR);
924 
925     /* Decide what to wait for based on command type. */
926     switch (cmd) {
927     case EC_COMMAND_READ:
928     case EC_COMMAND_WRITE:
929     case EC_COMMAND_BURST_DISABLE:
930 	event = EC_EVENT_INPUT_BUFFER_EMPTY;
931 	break;
932     case EC_COMMAND_QUERY:
933     case EC_COMMAND_BURST_ENABLE:
934 	event = EC_EVENT_OUTPUT_BUFFER_FULL;
935 	break;
936     default:
937 	device_printf(sc->ec_dev, "EcCommand: invalid command %#x\n", cmd);
938 	return (AE_BAD_PARAMETER);
939     }
940 
941     /*
942      * Ensure empty input buffer before issuing command.
943      * Use generation count of zero to force a quick check.
944      */
945     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, 0);
946     if (ACPI_FAILURE(status))
947 	return (status);
948 
949     /* Run the command and wait for the chosen event. */
950     CTR1(KTR_ACPI, "ec running command %#x", cmd);
951     gen_count = sc->ec_gencount;
952     EC_SET_CSR(sc, cmd);
953     status = EcWaitEvent(sc, event, gen_count);
954     if (ACPI_SUCCESS(status)) {
955 	/* If we succeeded, burst flag should now be present. */
956 	if (cmd == EC_COMMAND_BURST_ENABLE) {
957 	    ec_status = EC_GET_CSR(sc);
958 	    if ((ec_status & EC_FLAG_BURST_MODE) == 0)
959 		status = AE_ERROR;
960 	}
961     } else
962 	device_printf(sc->ec_dev, "EcCommand: no response to %#x\n", cmd);
963     return (status);
964 }
965 
966 static ACPI_STATUS
967 EcRead(struct acpi_ec_softc *sc, UINT8 Address, UINT8 *Data)
968 {
969     ACPI_STATUS	status;
970     u_int gen_count;
971     int retry;
972 
973     ACPI_SERIAL_ASSERT(ec);
974     CTR1(KTR_ACPI, "ec read from %#x", Address);
975 
976     for (retry = 0; retry < 2; retry++) {
977 	status = EcCommand(sc, EC_COMMAND_READ);
978 	if (ACPI_FAILURE(status))
979 	    return (status);
980 
981 	gen_count = sc->ec_gencount;
982 	EC_SET_DATA(sc, Address);
983 	status = EcWaitEvent(sc, EC_EVENT_OUTPUT_BUFFER_FULL, gen_count);
984 	if (ACPI_SUCCESS(status)) {
985 	    *Data = EC_GET_DATA(sc);
986 	    return (AE_OK);
987 	}
988 	if (ACPI_FAILURE(EcCheckStatus(sc, "retr_check",
989 	    EC_EVENT_INPUT_BUFFER_EMPTY)))
990 	    break;
991     }
992     device_printf(sc->ec_dev, "EcRead: failed waiting to get data\n");
993     return (status);
994 }
995 
996 static ACPI_STATUS
997 EcWrite(struct acpi_ec_softc *sc, UINT8 Address, UINT8 Data)
998 {
999     ACPI_STATUS	status;
1000     u_int gen_count;
1001 
1002     ACPI_SERIAL_ASSERT(ec);
1003     CTR2(KTR_ACPI, "ec write to %#x, data %#x", Address, Data);
1004 
1005     status = EcCommand(sc, EC_COMMAND_WRITE);
1006     if (ACPI_FAILURE(status))
1007 	return (status);
1008 
1009     gen_count = sc->ec_gencount;
1010     EC_SET_DATA(sc, Address);
1011     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1012     if (ACPI_FAILURE(status)) {
1013 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent address\n");
1014 	return (status);
1015     }
1016 
1017     gen_count = sc->ec_gencount;
1018     EC_SET_DATA(sc, Data);
1019     status = EcWaitEvent(sc, EC_EVENT_INPUT_BUFFER_EMPTY, gen_count);
1020     if (ACPI_FAILURE(status)) {
1021 	device_printf(sc->ec_dev, "EcWrite: failed waiting for sent data\n");
1022 	return (status);
1023     }
1024 
1025     return (AE_OK);
1026 }
1027