xref: /linux/drivers/acpi/ec.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
1 /*
2  *  ec.c - ACPI Embedded Controller Driver (v2.1)
3  *
4  *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or (at
15  *  your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful, but
18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20  *  General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License along
23  *  with this program; if not, write to the Free Software Foundation, Inc.,
24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25  *
26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27  */
28 
29 /* Uncomment next line to get verbose printout */
30 /* #define DEBUG */
31 
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/init.h>
35 #include <linux/types.h>
36 #include <linux/delay.h>
37 #include <linux/interrupt.h>
38 #include <linux/list.h>
39 #include <linux/spinlock.h>
40 #include <linux/slab.h>
41 #include <asm/io.h>
42 #include <acpi/acpi_bus.h>
43 #include <acpi/acpi_drivers.h>
44 #include <linux/dmi.h>
45 
46 #include "internal.h"
47 
48 #define ACPI_EC_CLASS			"embedded_controller"
49 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
50 #define ACPI_EC_FILE_INFO		"info"
51 
52 #undef PREFIX
53 #define PREFIX				"ACPI: EC: "
54 
55 /* EC status register */
56 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
57 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
58 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
59 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
60 
61 /* EC commands */
62 enum ec_command {
63 	ACPI_EC_COMMAND_READ = 0x80,
64 	ACPI_EC_COMMAND_WRITE = 0x81,
65 	ACPI_EC_BURST_ENABLE = 0x82,
66 	ACPI_EC_BURST_DISABLE = 0x83,
67 	ACPI_EC_COMMAND_QUERY = 0x84,
68 };
69 
70 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
71 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
72 #define ACPI_EC_CDELAY		10	/* Wait 10us before polling EC */
73 #define ACPI_EC_MSI_UDELAY	550	/* Wait 550us for MSI EC */
74 
75 #define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
76 					   per one transaction */
77 
78 enum {
79 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
80 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
81 	EC_FLAGS_HANDLERS_INSTALLED,	/* Handlers for GPE and
82 					 * OpReg are installed */
83 	EC_FLAGS_BLOCKED,		/* Transactions are blocked */
84 };
85 
86 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
87 /* External interfaces use first EC only, so remember */
88 typedef int (*acpi_ec_query_func) (void *data);
89 
90 struct acpi_ec_query_handler {
91 	struct list_head node;
92 	acpi_ec_query_func func;
93 	acpi_handle handle;
94 	void *data;
95 	u8 query_bit;
96 };
97 
98 struct transaction {
99 	const u8 *wdata;
100 	u8 *rdata;
101 	unsigned short irq_count;
102 	u8 command;
103 	u8 wi;
104 	u8 ri;
105 	u8 wlen;
106 	u8 rlen;
107 	bool done;
108 };
109 
110 struct acpi_ec *boot_ec, *first_ec;
111 EXPORT_SYMBOL(first_ec);
112 
113 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
114 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
115 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
116 
117 /* --------------------------------------------------------------------------
118                              Transaction Management
119    -------------------------------------------------------------------------- */
120 
121 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
122 {
123 	u8 x = inb(ec->command_addr);
124 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
125 	return x;
126 }
127 
128 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
129 {
130 	u8 x = inb(ec->data_addr);
131 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
132 	return x;
133 }
134 
135 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
136 {
137 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
138 	outb(command, ec->command_addr);
139 }
140 
141 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
142 {
143 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
144 	outb(data, ec->data_addr);
145 }
146 
147 static int ec_transaction_done(struct acpi_ec *ec)
148 {
149 	unsigned long flags;
150 	int ret = 0;
151 	spin_lock_irqsave(&ec->curr_lock, flags);
152 	if (!ec->curr || ec->curr->done)
153 		ret = 1;
154 	spin_unlock_irqrestore(&ec->curr_lock, flags);
155 	return ret;
156 }
157 
158 static void start_transaction(struct acpi_ec *ec)
159 {
160 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
161 	ec->curr->done = false;
162 	acpi_ec_write_cmd(ec, ec->curr->command);
163 }
164 
165 static void advance_transaction(struct acpi_ec *ec, u8 status)
166 {
167 	unsigned long flags;
168 	spin_lock_irqsave(&ec->curr_lock, flags);
169 	if (!ec->curr)
170 		goto unlock;
171 	if (ec->curr->wlen > ec->curr->wi) {
172 		if ((status & ACPI_EC_FLAG_IBF) == 0)
173 			acpi_ec_write_data(ec,
174 				ec->curr->wdata[ec->curr->wi++]);
175 		else
176 			goto err;
177 	} else if (ec->curr->rlen > ec->curr->ri) {
178 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
179 			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
180 			if (ec->curr->rlen == ec->curr->ri)
181 				ec->curr->done = true;
182 		} else
183 			goto err;
184 	} else if (ec->curr->wlen == ec->curr->wi &&
185 		   (status & ACPI_EC_FLAG_IBF) == 0)
186 		ec->curr->done = true;
187 	goto unlock;
188 err:
189 	/* false interrupt, state didn't change */
190 	if (in_interrupt())
191 		++ec->curr->irq_count;
192 unlock:
193 	spin_unlock_irqrestore(&ec->curr_lock, flags);
194 }
195 
196 static int acpi_ec_sync_query(struct acpi_ec *ec);
197 
198 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
199 {
200 	if (state & ACPI_EC_FLAG_SCI) {
201 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
202 			return acpi_ec_sync_query(ec);
203 	}
204 	return 0;
205 }
206 
207 static int ec_poll(struct acpi_ec *ec)
208 {
209 	unsigned long flags;
210 	int repeat = 2; /* number of command restarts */
211 	while (repeat--) {
212 		unsigned long delay = jiffies +
213 			msecs_to_jiffies(ACPI_EC_DELAY);
214 		do {
215 			/* don't sleep with disabled interrupts */
216 			if (EC_FLAGS_MSI || irqs_disabled()) {
217 				udelay(ACPI_EC_MSI_UDELAY);
218 				if (ec_transaction_done(ec))
219 					return 0;
220 			} else {
221 				if (wait_event_timeout(ec->wait,
222 						ec_transaction_done(ec),
223 						msecs_to_jiffies(1)))
224 					return 0;
225 			}
226 			advance_transaction(ec, acpi_ec_read_status(ec));
227 		} while (time_before(jiffies, delay));
228 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
229 			break;
230 		pr_debug(PREFIX "controller reset, restart transaction\n");
231 		spin_lock_irqsave(&ec->curr_lock, flags);
232 		start_transaction(ec);
233 		spin_unlock_irqrestore(&ec->curr_lock, flags);
234 	}
235 	return -ETIME;
236 }
237 
238 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
239 					struct transaction *t)
240 {
241 	unsigned long tmp;
242 	int ret = 0;
243 	if (EC_FLAGS_MSI)
244 		udelay(ACPI_EC_MSI_UDELAY);
245 	/* start transaction */
246 	spin_lock_irqsave(&ec->curr_lock, tmp);
247 	/* following two actions should be kept atomic */
248 	ec->curr = t;
249 	start_transaction(ec);
250 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
251 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
252 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
253 	ret = ec_poll(ec);
254 	spin_lock_irqsave(&ec->curr_lock, tmp);
255 	ec->curr = NULL;
256 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
257 	return ret;
258 }
259 
260 static int ec_check_ibf0(struct acpi_ec *ec)
261 {
262 	u8 status = acpi_ec_read_status(ec);
263 	return (status & ACPI_EC_FLAG_IBF) == 0;
264 }
265 
266 static int ec_wait_ibf0(struct acpi_ec *ec)
267 {
268 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
269 	/* interrupt wait manually if GPE mode is not active */
270 	while (time_before(jiffies, delay))
271 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
272 					msecs_to_jiffies(1)))
273 			return 0;
274 	return -ETIME;
275 }
276 
277 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
278 {
279 	int status;
280 	u32 glk;
281 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
282 		return -EINVAL;
283 	if (t->rdata)
284 		memset(t->rdata, 0, t->rlen);
285 	mutex_lock(&ec->lock);
286 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
287 		status = -EINVAL;
288 		goto unlock;
289 	}
290 	if (ec->global_lock) {
291 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
292 		if (ACPI_FAILURE(status)) {
293 			status = -ENODEV;
294 			goto unlock;
295 		}
296 	}
297 	if (ec_wait_ibf0(ec)) {
298 		pr_err(PREFIX "input buffer is not empty, "
299 				"aborting transaction\n");
300 		status = -ETIME;
301 		goto end;
302 	}
303 	pr_debug(PREFIX "transaction start\n");
304 	/* disable GPE during transaction if storm is detected */
305 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
306 		/* It has to be disabled, so that it doesn't trigger. */
307 		acpi_disable_gpe(NULL, ec->gpe);
308 	}
309 
310 	status = acpi_ec_transaction_unlocked(ec, t);
311 
312 	/* check if we received SCI during transaction */
313 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
314 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
315 		msleep(1);
316 		/* It is safe to enable the GPE outside of the transaction. */
317 		acpi_enable_gpe(NULL, ec->gpe);
318 	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
319 		pr_info(PREFIX "GPE storm detected, "
320 			"transactions will use polling mode\n");
321 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
322 	}
323 	pr_debug(PREFIX "transaction end\n");
324 end:
325 	if (ec->global_lock)
326 		acpi_release_global_lock(glk);
327 unlock:
328 	mutex_unlock(&ec->lock);
329 	return status;
330 }
331 
332 static int acpi_ec_burst_enable(struct acpi_ec *ec)
333 {
334 	u8 d;
335 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
336 				.wdata = NULL, .rdata = &d,
337 				.wlen = 0, .rlen = 1};
338 
339 	return acpi_ec_transaction(ec, &t);
340 }
341 
342 static int acpi_ec_burst_disable(struct acpi_ec *ec)
343 {
344 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
345 				.wdata = NULL, .rdata = NULL,
346 				.wlen = 0, .rlen = 0};
347 
348 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
349 				acpi_ec_transaction(ec, &t) : 0;
350 }
351 
352 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
353 {
354 	int result;
355 	u8 d;
356 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
357 				.wdata = &address, .rdata = &d,
358 				.wlen = 1, .rlen = 1};
359 
360 	result = acpi_ec_transaction(ec, &t);
361 	*data = d;
362 	return result;
363 }
364 
365 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
366 {
367 	u8 wdata[2] = { address, data };
368 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
369 				.wdata = wdata, .rdata = NULL,
370 				.wlen = 2, .rlen = 0};
371 
372 	return acpi_ec_transaction(ec, &t);
373 }
374 
375 /*
376  * Externally callable EC access functions. For now, assume 1 EC only
377  */
378 int ec_burst_enable(void)
379 {
380 	if (!first_ec)
381 		return -ENODEV;
382 	return acpi_ec_burst_enable(first_ec);
383 }
384 
385 EXPORT_SYMBOL(ec_burst_enable);
386 
387 int ec_burst_disable(void)
388 {
389 	if (!first_ec)
390 		return -ENODEV;
391 	return acpi_ec_burst_disable(first_ec);
392 }
393 
394 EXPORT_SYMBOL(ec_burst_disable);
395 
396 int ec_read(u8 addr, u8 * val)
397 {
398 	int err;
399 	u8 temp_data;
400 
401 	if (!first_ec)
402 		return -ENODEV;
403 
404 	err = acpi_ec_read(first_ec, addr, &temp_data);
405 
406 	if (!err) {
407 		*val = temp_data;
408 		return 0;
409 	} else
410 		return err;
411 }
412 
413 EXPORT_SYMBOL(ec_read);
414 
415 int ec_write(u8 addr, u8 val)
416 {
417 	int err;
418 
419 	if (!first_ec)
420 		return -ENODEV;
421 
422 	err = acpi_ec_write(first_ec, addr, val);
423 
424 	return err;
425 }
426 
427 EXPORT_SYMBOL(ec_write);
428 
429 int ec_transaction(u8 command,
430 		   const u8 * wdata, unsigned wdata_len,
431 		   u8 * rdata, unsigned rdata_len,
432 		   int force_poll)
433 {
434 	struct transaction t = {.command = command,
435 				.wdata = wdata, .rdata = rdata,
436 				.wlen = wdata_len, .rlen = rdata_len};
437 	if (!first_ec)
438 		return -ENODEV;
439 
440 	return acpi_ec_transaction(first_ec, &t);
441 }
442 
443 EXPORT_SYMBOL(ec_transaction);
444 
445 void acpi_ec_block_transactions(void)
446 {
447 	struct acpi_ec *ec = first_ec;
448 
449 	if (!ec)
450 		return;
451 
452 	mutex_lock(&ec->lock);
453 	/* Prevent transactions from being carried out */
454 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
455 	mutex_unlock(&ec->lock);
456 }
457 
458 void acpi_ec_unblock_transactions(void)
459 {
460 	struct acpi_ec *ec = first_ec;
461 
462 	if (!ec)
463 		return;
464 
465 	mutex_lock(&ec->lock);
466 	/* Allow transactions to be carried out again */
467 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
468 	mutex_unlock(&ec->lock);
469 }
470 
471 void acpi_ec_unblock_transactions_early(void)
472 {
473 	/*
474 	 * Allow transactions to happen again (this function is called from
475 	 * atomic context during wakeup, so we don't need to acquire the mutex).
476 	 */
477 	if (first_ec)
478 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
479 }
480 
481 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
482 {
483 	int result;
484 	u8 d;
485 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
486 				.wdata = NULL, .rdata = &d,
487 				.wlen = 0, .rlen = 1};
488 	if (!ec || !data)
489 		return -EINVAL;
490 	/*
491 	 * Query the EC to find out which _Qxx method we need to evaluate.
492 	 * Note that successful completion of the query causes the ACPI_EC_SCI
493 	 * bit to be cleared (and thus clearing the interrupt source).
494 	 */
495 	result = acpi_ec_transaction_unlocked(ec, &t);
496 	if (result)
497 		return result;
498 	if (!d)
499 		return -ENODATA;
500 	*data = d;
501 	return 0;
502 }
503 
504 /* --------------------------------------------------------------------------
505                                 Event Management
506    -------------------------------------------------------------------------- */
507 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
508 			      acpi_handle handle, acpi_ec_query_func func,
509 			      void *data)
510 {
511 	struct acpi_ec_query_handler *handler =
512 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
513 	if (!handler)
514 		return -ENOMEM;
515 
516 	handler->query_bit = query_bit;
517 	handler->handle = handle;
518 	handler->func = func;
519 	handler->data = data;
520 	mutex_lock(&ec->lock);
521 	list_add(&handler->node, &ec->list);
522 	mutex_unlock(&ec->lock);
523 	return 0;
524 }
525 
526 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
527 
528 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
529 {
530 	struct acpi_ec_query_handler *handler, *tmp;
531 	mutex_lock(&ec->lock);
532 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
533 		if (query_bit == handler->query_bit) {
534 			list_del(&handler->node);
535 			kfree(handler);
536 		}
537 	}
538 	mutex_unlock(&ec->lock);
539 }
540 
541 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
542 
543 static void acpi_ec_run(void *cxt)
544 {
545 	struct acpi_ec_query_handler *handler = cxt;
546 	if (!handler)
547 		return;
548 	pr_debug(PREFIX "start query execution\n");
549 	if (handler->func)
550 		handler->func(handler->data);
551 	else if (handler->handle)
552 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
553 	pr_debug(PREFIX "stop query execution\n");
554 	kfree(handler);
555 }
556 
557 static int acpi_ec_sync_query(struct acpi_ec *ec)
558 {
559 	u8 value = 0;
560 	int status;
561 	struct acpi_ec_query_handler *handler, *copy;
562 	if ((status = acpi_ec_query_unlocked(ec, &value)))
563 		return status;
564 	list_for_each_entry(handler, &ec->list, node) {
565 		if (value == handler->query_bit) {
566 			/* have custom handler for this bit */
567 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
568 			if (!copy)
569 				return -ENOMEM;
570 			memcpy(copy, handler, sizeof(*copy));
571 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
572 			return acpi_os_execute((copy->func) ?
573 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
574 				acpi_ec_run, copy);
575 		}
576 	}
577 	return 0;
578 }
579 
580 static void acpi_ec_gpe_query(void *ec_cxt)
581 {
582 	struct acpi_ec *ec = ec_cxt;
583 	if (!ec)
584 		return;
585 	mutex_lock(&ec->lock);
586 	acpi_ec_sync_query(ec);
587 	mutex_unlock(&ec->lock);
588 }
589 
590 static void acpi_ec_gpe_query(void *ec_cxt);
591 
592 static int ec_check_sci(struct acpi_ec *ec, u8 state)
593 {
594 	if (state & ACPI_EC_FLAG_SCI) {
595 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
596 			pr_debug(PREFIX "push gpe query to the queue\n");
597 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
598 				acpi_ec_gpe_query, ec);
599 		}
600 	}
601 	return 0;
602 }
603 
604 static u32 acpi_ec_gpe_handler(void *data)
605 {
606 	struct acpi_ec *ec = data;
607 
608 	pr_debug(PREFIX "~~~> interrupt\n");
609 
610 	advance_transaction(ec, acpi_ec_read_status(ec));
611 	if (ec_transaction_done(ec) &&
612 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
613 		wake_up(&ec->wait);
614 		ec_check_sci(ec, acpi_ec_read_status(ec));
615 	}
616 	return ACPI_INTERRUPT_HANDLED;
617 }
618 
619 /* --------------------------------------------------------------------------
620                              Address Space Management
621    -------------------------------------------------------------------------- */
622 
623 static acpi_status
624 acpi_ec_space_handler(u32 function, acpi_physical_address address,
625 		      u32 bits, u64 *value64,
626 		      void *handler_context, void *region_context)
627 {
628 	struct acpi_ec *ec = handler_context;
629 	int result = 0, i, bytes = bits / 8;
630 	u8 *value = (u8 *)value64;
631 
632 	if ((address > 0xFF) || !value || !handler_context)
633 		return AE_BAD_PARAMETER;
634 
635 	if (function != ACPI_READ && function != ACPI_WRITE)
636 		return AE_BAD_PARAMETER;
637 
638 	if (EC_FLAGS_MSI || bits > 8)
639 		acpi_ec_burst_enable(ec);
640 
641 	for (i = 0; i < bytes; ++i, ++address, ++value)
642 		result = (function == ACPI_READ) ?
643 			acpi_ec_read(ec, address, value) :
644 			acpi_ec_write(ec, address, *value);
645 
646 	if (EC_FLAGS_MSI || bits > 8)
647 		acpi_ec_burst_disable(ec);
648 
649 	switch (result) {
650 	case -EINVAL:
651 		return AE_BAD_PARAMETER;
652 		break;
653 	case -ENODEV:
654 		return AE_NOT_FOUND;
655 		break;
656 	case -ETIME:
657 		return AE_TIME;
658 		break;
659 	default:
660 		return AE_OK;
661 	}
662 }
663 
664 /* --------------------------------------------------------------------------
665                                Driver Interface
666    -------------------------------------------------------------------------- */
667 static acpi_status
668 ec_parse_io_ports(struct acpi_resource *resource, void *context);
669 
670 static struct acpi_ec *make_acpi_ec(void)
671 {
672 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
673 	if (!ec)
674 		return NULL;
675 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
676 	mutex_init(&ec->lock);
677 	init_waitqueue_head(&ec->wait);
678 	INIT_LIST_HEAD(&ec->list);
679 	spin_lock_init(&ec->curr_lock);
680 	return ec;
681 }
682 
683 static acpi_status
684 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
685 			       void *context, void **return_value)
686 {
687 	char node_name[5];
688 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
689 	struct acpi_ec *ec = context;
690 	int value = 0;
691 	acpi_status status;
692 
693 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
694 
695 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
696 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
697 	}
698 	return AE_OK;
699 }
700 
701 static acpi_status
702 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
703 {
704 	acpi_status status;
705 	unsigned long long tmp = 0;
706 
707 	struct acpi_ec *ec = context;
708 
709 	/* clear addr values, ec_parse_io_ports depend on it */
710 	ec->command_addr = ec->data_addr = 0;
711 
712 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
713 				     ec_parse_io_ports, ec);
714 	if (ACPI_FAILURE(status))
715 		return status;
716 
717 	/* Get GPE bit assignment (EC events). */
718 	/* TODO: Add support for _GPE returning a package */
719 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
720 	if (ACPI_FAILURE(status))
721 		return status;
722 	ec->gpe = tmp;
723 	/* Use the global lock for all EC transactions? */
724 	tmp = 0;
725 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
726 	ec->global_lock = tmp;
727 	ec->handle = handle;
728 	return AE_CTRL_TERMINATE;
729 }
730 
731 static int ec_install_handlers(struct acpi_ec *ec)
732 {
733 	acpi_status status;
734 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
735 		return 0;
736 	status = acpi_install_gpe_handler(NULL, ec->gpe,
737 				  ACPI_GPE_EDGE_TRIGGERED,
738 				  &acpi_ec_gpe_handler, ec);
739 	if (ACPI_FAILURE(status))
740 		return -ENODEV;
741 
742 	acpi_enable_gpe(NULL, ec->gpe);
743 	status = acpi_install_address_space_handler(ec->handle,
744 						    ACPI_ADR_SPACE_EC,
745 						    &acpi_ec_space_handler,
746 						    NULL, ec);
747 	if (ACPI_FAILURE(status)) {
748 		if (status == AE_NOT_FOUND) {
749 			/*
750 			 * Maybe OS fails in evaluating the _REG object.
751 			 * The AE_NOT_FOUND error will be ignored and OS
752 			 * continue to initialize EC.
753 			 */
754 			printk(KERN_ERR "Fail in evaluating the _REG object"
755 				" of EC device. Broken bios is suspected.\n");
756 		} else {
757 			acpi_remove_gpe_handler(NULL, ec->gpe,
758 				&acpi_ec_gpe_handler);
759 			acpi_disable_gpe(NULL, ec->gpe);
760 			return -ENODEV;
761 		}
762 	}
763 
764 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
765 	return 0;
766 }
767 
768 static void ec_remove_handlers(struct acpi_ec *ec)
769 {
770 	acpi_disable_gpe(NULL, ec->gpe);
771 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
772 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
773 		pr_err(PREFIX "failed to remove space handler\n");
774 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
775 				&acpi_ec_gpe_handler)))
776 		pr_err(PREFIX "failed to remove gpe handler\n");
777 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
778 }
779 
780 static int acpi_ec_add(struct acpi_device *device)
781 {
782 	struct acpi_ec *ec = NULL;
783 	int ret;
784 
785 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
786 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
787 
788 	/* Check for boot EC */
789 	if (boot_ec &&
790 	    (boot_ec->handle == device->handle ||
791 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
792 		ec = boot_ec;
793 		boot_ec = NULL;
794 	} else {
795 		ec = make_acpi_ec();
796 		if (!ec)
797 			return -ENOMEM;
798 	}
799 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
800 		AE_CTRL_TERMINATE) {
801 			kfree(ec);
802 			return -EINVAL;
803 	}
804 
805 	ec->handle = device->handle;
806 
807 	/* Find and register all query methods */
808 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
809 			    acpi_ec_register_query_methods, NULL, ec, NULL);
810 
811 	if (!first_ec)
812 		first_ec = ec;
813 	device->driver_data = ec;
814 
815 	WARN(!request_region(ec->data_addr, 1, "EC data"),
816 	     "Could not request EC data io port 0x%lx", ec->data_addr);
817 	WARN(!request_region(ec->command_addr, 1, "EC cmd"),
818 	     "Could not request EC cmd io port 0x%lx", ec->command_addr);
819 
820 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
821 			  ec->gpe, ec->command_addr, ec->data_addr);
822 
823 	ret = ec_install_handlers(ec);
824 
825 	/* EC is fully operational, allow queries */
826 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
827 	return ret;
828 }
829 
830 static int acpi_ec_remove(struct acpi_device *device, int type)
831 {
832 	struct acpi_ec *ec;
833 	struct acpi_ec_query_handler *handler, *tmp;
834 
835 	if (!device)
836 		return -EINVAL;
837 
838 	ec = acpi_driver_data(device);
839 	ec_remove_handlers(ec);
840 	mutex_lock(&ec->lock);
841 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
842 		list_del(&handler->node);
843 		kfree(handler);
844 	}
845 	mutex_unlock(&ec->lock);
846 	release_region(ec->data_addr, 1);
847 	release_region(ec->command_addr, 1);
848 	device->driver_data = NULL;
849 	if (ec == first_ec)
850 		first_ec = NULL;
851 	kfree(ec);
852 	return 0;
853 }
854 
855 static acpi_status
856 ec_parse_io_ports(struct acpi_resource *resource, void *context)
857 {
858 	struct acpi_ec *ec = context;
859 
860 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
861 		return AE_OK;
862 
863 	/*
864 	 * The first address region returned is the data port, and
865 	 * the second address region returned is the status/command
866 	 * port.
867 	 */
868 	if (ec->data_addr == 0)
869 		ec->data_addr = resource->data.io.minimum;
870 	else if (ec->command_addr == 0)
871 		ec->command_addr = resource->data.io.minimum;
872 	else
873 		return AE_CTRL_TERMINATE;
874 
875 	return AE_OK;
876 }
877 
878 int __init acpi_boot_ec_enable(void)
879 {
880 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
881 		return 0;
882 	if (!ec_install_handlers(boot_ec)) {
883 		first_ec = boot_ec;
884 		return 0;
885 	}
886 	return -EFAULT;
887 }
888 
889 static const struct acpi_device_id ec_device_ids[] = {
890 	{"PNP0C09", 0},
891 	{"", 0},
892 };
893 
894 /* Some BIOS do not survive early DSDT scan, skip it */
895 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
896 {
897 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
898 	return 0;
899 }
900 
901 /* ASUStek often supplies us with broken ECDT, validate it */
902 static int ec_validate_ecdt(const struct dmi_system_id *id)
903 {
904 	EC_FLAGS_VALIDATE_ECDT = 1;
905 	return 0;
906 }
907 
908 /* MSI EC needs special treatment, enable it */
909 static int ec_flag_msi(const struct dmi_system_id *id)
910 {
911 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
912 	EC_FLAGS_MSI = 1;
913 	EC_FLAGS_VALIDATE_ECDT = 1;
914 	return 0;
915 }
916 
917 static struct dmi_system_id __initdata ec_dmi_table[] = {
918 	{
919 	ec_skip_dsdt_scan, "Compal JFL92", {
920 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
921 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
922 	{
923 	ec_flag_msi, "MSI hardware", {
924 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
925 	{
926 	ec_flag_msi, "MSI hardware", {
927 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
928 	{
929 	ec_flag_msi, "MSI hardware", {
930 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
931 	{
932 	ec_validate_ecdt, "ASUS hardware", {
933 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
934 	{},
935 };
936 
937 
938 int __init acpi_ec_ecdt_probe(void)
939 {
940 	acpi_status status;
941 	struct acpi_ec *saved_ec = NULL;
942 	struct acpi_table_ecdt *ecdt_ptr;
943 
944 	boot_ec = make_acpi_ec();
945 	if (!boot_ec)
946 		return -ENOMEM;
947 	/*
948 	 * Generate a boot ec context
949 	 */
950 	dmi_check_system(ec_dmi_table);
951 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
952 				(struct acpi_table_header **)&ecdt_ptr);
953 	if (ACPI_SUCCESS(status)) {
954 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
955 		boot_ec->command_addr = ecdt_ptr->control.address;
956 		boot_ec->data_addr = ecdt_ptr->data.address;
957 		boot_ec->gpe = ecdt_ptr->gpe;
958 		boot_ec->handle = ACPI_ROOT_OBJECT;
959 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
960 		/* Don't trust ECDT, which comes from ASUSTek */
961 		if (!EC_FLAGS_VALIDATE_ECDT)
962 			goto install;
963 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
964 		if (!saved_ec)
965 			return -ENOMEM;
966 	/* fall through */
967 	}
968 
969 	if (EC_FLAGS_SKIP_DSDT_SCAN)
970 		return -ENODEV;
971 
972 	/* This workaround is needed only on some broken machines,
973 	 * which require early EC, but fail to provide ECDT */
974 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
975 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
976 					boot_ec, NULL);
977 	/* Check that acpi_get_devices actually find something */
978 	if (ACPI_FAILURE(status) || !boot_ec->handle)
979 		goto error;
980 	if (saved_ec) {
981 		/* try to find good ECDT from ASUSTek */
982 		if (saved_ec->command_addr != boot_ec->command_addr ||
983 		    saved_ec->data_addr != boot_ec->data_addr ||
984 		    saved_ec->gpe != boot_ec->gpe ||
985 		    saved_ec->handle != boot_ec->handle)
986 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
987 			"ECDT tables, which are very hard to workaround. "
988 			"Trying to use DSDT EC info instead. Please send "
989 			"output of acpidump to linux-acpi@vger.kernel.org\n");
990 		kfree(saved_ec);
991 		saved_ec = NULL;
992 	} else {
993 		/* We really need to limit this workaround, the only ASUS,
994 		* which needs it, has fake EC._INI method, so use it as flag.
995 		* Keep boot_ec struct as it will be needed soon.
996 		*/
997 		acpi_handle dummy;
998 		if (!dmi_name_in_vendors("ASUS") ||
999 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1000 							&dummy)))
1001 			return -ENODEV;
1002 	}
1003 install:
1004 	if (!ec_install_handlers(boot_ec)) {
1005 		first_ec = boot_ec;
1006 		return 0;
1007 	}
1008 error:
1009 	kfree(boot_ec);
1010 	boot_ec = NULL;
1011 	return -ENODEV;
1012 }
1013 
1014 static struct acpi_driver acpi_ec_driver = {
1015 	.name = "ec",
1016 	.class = ACPI_EC_CLASS,
1017 	.ids = ec_device_ids,
1018 	.ops = {
1019 		.add = acpi_ec_add,
1020 		.remove = acpi_ec_remove,
1021 		},
1022 };
1023 
1024 int __init acpi_ec_init(void)
1025 {
1026 	int result = 0;
1027 
1028 	/* Now register the driver for the EC */
1029 	result = acpi_bus_register_driver(&acpi_ec_driver);
1030 	if (result < 0)
1031 		return -ENODEV;
1032 
1033 	return result;
1034 }
1035 
1036 /* EC driver currently not unloadable */
1037 #if 0
1038 static void __exit acpi_ec_exit(void)
1039 {
1040 
1041 	acpi_bus_unregister_driver(&acpi_ec_driver);
1042 	return;
1043 }
1044 #endif	/* 0 */
1045