xref: /linux/drivers/acpi/ec.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
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/proc_fs.h>
38 #include <linux/seq_file.h>
39 #include <linux/interrupt.h>
40 #include <linux/list.h>
41 #include <linux/spinlock.h>
42 #include <asm/io.h>
43 #include <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
45 #include <linux/dmi.h>
46 
47 #define ACPI_EC_CLASS			"embedded_controller"
48 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
49 #define ACPI_EC_FILE_INFO		"info"
50 
51 #define PREFIX				"ACPI: EC: "
52 
53 /* EC status register */
54 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
55 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
56 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
57 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
58 
59 /* EC commands */
60 enum ec_command {
61 	ACPI_EC_COMMAND_READ = 0x80,
62 	ACPI_EC_COMMAND_WRITE = 0x81,
63 	ACPI_EC_BURST_ENABLE = 0x82,
64 	ACPI_EC_BURST_DISABLE = 0x83,
65 	ACPI_EC_COMMAND_QUERY = 0x84,
66 };
67 
68 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
69 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
70 #define ACPI_EC_CDELAY		10	/* Wait 10us before polling EC */
71 #define ACPI_EC_MSI_UDELAY	550	/* Wait 550us for MSI EC */
72 
73 #define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
74 					   per one transaction */
75 
76 enum {
77 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
78 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
79 	EC_FLAGS_HANDLERS_INSTALLED	/* Handlers for GPE and
80 					 * OpReg are installed */
81 };
82 
83 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
84 /* External interfaces use first EC only, so remember */
85 typedef int (*acpi_ec_query_func) (void *data);
86 
87 struct acpi_ec_query_handler {
88 	struct list_head node;
89 	acpi_ec_query_func func;
90 	acpi_handle handle;
91 	void *data;
92 	u8 query_bit;
93 };
94 
95 struct transaction {
96 	const u8 *wdata;
97 	u8 *rdata;
98 	unsigned short irq_count;
99 	u8 command;
100 	u8 wi;
101 	u8 ri;
102 	u8 wlen;
103 	u8 rlen;
104 	bool done;
105 };
106 
107 static struct acpi_ec {
108 	acpi_handle handle;
109 	unsigned long gpe;
110 	unsigned long command_addr;
111 	unsigned long data_addr;
112 	unsigned long global_lock;
113 	unsigned long flags;
114 	struct mutex lock;
115 	wait_queue_head_t wait;
116 	struct list_head list;
117 	struct transaction *curr;
118 	spinlock_t curr_lock;
119 } *boot_ec, *first_ec;
120 
121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
124 
125 /* --------------------------------------------------------------------------
126                              Transaction Management
127    -------------------------------------------------------------------------- */
128 
129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
130 {
131 	u8 x = inb(ec->command_addr);
132 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
133 	return x;
134 }
135 
136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
137 {
138 	u8 x = inb(ec->data_addr);
139 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
140 	return x;
141 }
142 
143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
144 {
145 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
146 	outb(command, ec->command_addr);
147 }
148 
149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
150 {
151 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
152 	outb(data, ec->data_addr);
153 }
154 
155 static int ec_transaction_done(struct acpi_ec *ec)
156 {
157 	unsigned long flags;
158 	int ret = 0;
159 	spin_lock_irqsave(&ec->curr_lock, flags);
160 	if (!ec->curr || ec->curr->done)
161 		ret = 1;
162 	spin_unlock_irqrestore(&ec->curr_lock, flags);
163 	return ret;
164 }
165 
166 static void start_transaction(struct acpi_ec *ec)
167 {
168 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
169 	ec->curr->done = false;
170 	acpi_ec_write_cmd(ec, ec->curr->command);
171 }
172 
173 static void advance_transaction(struct acpi_ec *ec, u8 status)
174 {
175 	unsigned long flags;
176 	spin_lock_irqsave(&ec->curr_lock, flags);
177 	if (!ec->curr)
178 		goto unlock;
179 	if (ec->curr->wlen > ec->curr->wi) {
180 		if ((status & ACPI_EC_FLAG_IBF) == 0)
181 			acpi_ec_write_data(ec,
182 				ec->curr->wdata[ec->curr->wi++]);
183 		else
184 			goto err;
185 	} else if (ec->curr->rlen > ec->curr->ri) {
186 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
187 			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
188 			if (ec->curr->rlen == ec->curr->ri)
189 				ec->curr->done = true;
190 		} else
191 			goto err;
192 	} else if (ec->curr->wlen == ec->curr->wi &&
193 		   (status & ACPI_EC_FLAG_IBF) == 0)
194 		ec->curr->done = true;
195 	goto unlock;
196 err:
197 	/* false interrupt, state didn't change */
198 	if (in_interrupt())
199 		++ec->curr->irq_count;
200 unlock:
201 	spin_unlock_irqrestore(&ec->curr_lock, flags);
202 }
203 
204 static int acpi_ec_sync_query(struct acpi_ec *ec);
205 
206 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
207 {
208 	if (state & ACPI_EC_FLAG_SCI) {
209 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
210 			return acpi_ec_sync_query(ec);
211 	}
212 	return 0;
213 }
214 
215 static int ec_poll(struct acpi_ec *ec)
216 {
217 	unsigned long flags;
218 	int repeat = 2; /* number of command restarts */
219 	while (repeat--) {
220 		unsigned long delay = jiffies +
221 			msecs_to_jiffies(ACPI_EC_DELAY);
222 		do {
223 			/* don't sleep with disabled interrupts */
224 			if (EC_FLAGS_MSI || irqs_disabled()) {
225 				udelay(ACPI_EC_MSI_UDELAY);
226 				if (ec_transaction_done(ec))
227 					return 0;
228 			} else {
229 				if (wait_event_timeout(ec->wait,
230 						ec_transaction_done(ec),
231 						msecs_to_jiffies(1)))
232 					return 0;
233 			}
234 			advance_transaction(ec, acpi_ec_read_status(ec));
235 		} while (time_before(jiffies, delay));
236 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
237 			break;
238 		pr_debug(PREFIX "controller reset, restart transaction\n");
239 		spin_lock_irqsave(&ec->curr_lock, flags);
240 		start_transaction(ec);
241 		spin_unlock_irqrestore(&ec->curr_lock, flags);
242 	}
243 	return -ETIME;
244 }
245 
246 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
247 					struct transaction *t)
248 {
249 	unsigned long tmp;
250 	int ret = 0;
251 	if (EC_FLAGS_MSI)
252 		udelay(ACPI_EC_MSI_UDELAY);
253 	/* start transaction */
254 	spin_lock_irqsave(&ec->curr_lock, tmp);
255 	/* following two actions should be kept atomic */
256 	ec->curr = t;
257 	start_transaction(ec);
258 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
259 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
260 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
261 	ret = ec_poll(ec);
262 	spin_lock_irqsave(&ec->curr_lock, tmp);
263 	ec->curr = NULL;
264 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
265 	return ret;
266 }
267 
268 static int ec_check_ibf0(struct acpi_ec *ec)
269 {
270 	u8 status = acpi_ec_read_status(ec);
271 	return (status & ACPI_EC_FLAG_IBF) == 0;
272 }
273 
274 static int ec_wait_ibf0(struct acpi_ec *ec)
275 {
276 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
277 	/* interrupt wait manually if GPE mode is not active */
278 	while (time_before(jiffies, delay))
279 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
280 					msecs_to_jiffies(1)))
281 			return 0;
282 	return -ETIME;
283 }
284 
285 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
286 {
287 	int status;
288 	u32 glk;
289 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
290 		return -EINVAL;
291 	if (t->rdata)
292 		memset(t->rdata, 0, t->rlen);
293 	mutex_lock(&ec->lock);
294 	if (ec->global_lock) {
295 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
296 		if (ACPI_FAILURE(status)) {
297 			status = -ENODEV;
298 			goto unlock;
299 		}
300 	}
301 	if (ec_wait_ibf0(ec)) {
302 		pr_err(PREFIX "input buffer is not empty, "
303 				"aborting transaction\n");
304 		status = -ETIME;
305 		goto end;
306 	}
307 	pr_debug(PREFIX "transaction start\n");
308 	/* disable GPE during transaction if storm is detected */
309 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
310 		/*
311 		 * It has to be disabled at the hardware level regardless of the
312 		 * GPE reference counting, so that it doesn't trigger.
313 		 */
314 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
315 	}
316 
317 	status = acpi_ec_transaction_unlocked(ec, t);
318 
319 	/* check if we received SCI during transaction */
320 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
321 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
322 		msleep(1);
323 		/*
324 		 * It is safe to enable the GPE outside of the transaction.  Use
325 		 * acpi_set_gpe() for that, since we used it to disable the GPE
326 		 * above.
327 		 */
328 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
329 	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
330 		pr_info(PREFIX "GPE storm detected, "
331 			"transactions will use polling mode\n");
332 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
333 	}
334 	pr_debug(PREFIX "transaction end\n");
335 end:
336 	if (ec->global_lock)
337 		acpi_release_global_lock(glk);
338 unlock:
339 	mutex_unlock(&ec->lock);
340 	return status;
341 }
342 
343 static int acpi_ec_burst_enable(struct acpi_ec *ec)
344 {
345 	u8 d;
346 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
347 				.wdata = NULL, .rdata = &d,
348 				.wlen = 0, .rlen = 1};
349 
350 	return acpi_ec_transaction(ec, &t);
351 }
352 
353 static int acpi_ec_burst_disable(struct acpi_ec *ec)
354 {
355 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
356 				.wdata = NULL, .rdata = NULL,
357 				.wlen = 0, .rlen = 0};
358 
359 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
360 				acpi_ec_transaction(ec, &t) : 0;
361 }
362 
363 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
364 {
365 	int result;
366 	u8 d;
367 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
368 				.wdata = &address, .rdata = &d,
369 				.wlen = 1, .rlen = 1};
370 
371 	result = acpi_ec_transaction(ec, &t);
372 	*data = d;
373 	return result;
374 }
375 
376 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
377 {
378 	u8 wdata[2] = { address, data };
379 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
380 				.wdata = wdata, .rdata = NULL,
381 				.wlen = 2, .rlen = 0};
382 
383 	return acpi_ec_transaction(ec, &t);
384 }
385 
386 /*
387  * Externally callable EC access functions. For now, assume 1 EC only
388  */
389 int ec_burst_enable(void)
390 {
391 	if (!first_ec)
392 		return -ENODEV;
393 	return acpi_ec_burst_enable(first_ec);
394 }
395 
396 EXPORT_SYMBOL(ec_burst_enable);
397 
398 int ec_burst_disable(void)
399 {
400 	if (!first_ec)
401 		return -ENODEV;
402 	return acpi_ec_burst_disable(first_ec);
403 }
404 
405 EXPORT_SYMBOL(ec_burst_disable);
406 
407 int ec_read(u8 addr, u8 * val)
408 {
409 	int err;
410 	u8 temp_data;
411 
412 	if (!first_ec)
413 		return -ENODEV;
414 
415 	err = acpi_ec_read(first_ec, addr, &temp_data);
416 
417 	if (!err) {
418 		*val = temp_data;
419 		return 0;
420 	} else
421 		return err;
422 }
423 
424 EXPORT_SYMBOL(ec_read);
425 
426 int ec_write(u8 addr, u8 val)
427 {
428 	int err;
429 
430 	if (!first_ec)
431 		return -ENODEV;
432 
433 	err = acpi_ec_write(first_ec, addr, val);
434 
435 	return err;
436 }
437 
438 EXPORT_SYMBOL(ec_write);
439 
440 int ec_transaction(u8 command,
441 		   const u8 * wdata, unsigned wdata_len,
442 		   u8 * rdata, unsigned rdata_len,
443 		   int force_poll)
444 {
445 	struct transaction t = {.command = command,
446 				.wdata = wdata, .rdata = rdata,
447 				.wlen = wdata_len, .rlen = rdata_len};
448 	if (!first_ec)
449 		return -ENODEV;
450 
451 	return acpi_ec_transaction(first_ec, &t);
452 }
453 
454 EXPORT_SYMBOL(ec_transaction);
455 
456 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
457 {
458 	int result;
459 	u8 d;
460 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
461 				.wdata = NULL, .rdata = &d,
462 				.wlen = 0, .rlen = 1};
463 	if (!ec || !data)
464 		return -EINVAL;
465 	/*
466 	 * Query the EC to find out which _Qxx method we need to evaluate.
467 	 * Note that successful completion of the query causes the ACPI_EC_SCI
468 	 * bit to be cleared (and thus clearing the interrupt source).
469 	 */
470 	result = acpi_ec_transaction_unlocked(ec, &t);
471 	if (result)
472 		return result;
473 	if (!d)
474 		return -ENODATA;
475 	*data = d;
476 	return 0;
477 }
478 
479 /* --------------------------------------------------------------------------
480                                 Event Management
481    -------------------------------------------------------------------------- */
482 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
483 			      acpi_handle handle, acpi_ec_query_func func,
484 			      void *data)
485 {
486 	struct acpi_ec_query_handler *handler =
487 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
488 	if (!handler)
489 		return -ENOMEM;
490 
491 	handler->query_bit = query_bit;
492 	handler->handle = handle;
493 	handler->func = func;
494 	handler->data = data;
495 	mutex_lock(&ec->lock);
496 	list_add(&handler->node, &ec->list);
497 	mutex_unlock(&ec->lock);
498 	return 0;
499 }
500 
501 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
502 
503 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
504 {
505 	struct acpi_ec_query_handler *handler, *tmp;
506 	mutex_lock(&ec->lock);
507 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
508 		if (query_bit == handler->query_bit) {
509 			list_del(&handler->node);
510 			kfree(handler);
511 		}
512 	}
513 	mutex_unlock(&ec->lock);
514 }
515 
516 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
517 
518 static void acpi_ec_run(void *cxt)
519 {
520 	struct acpi_ec_query_handler *handler = cxt;
521 	if (!handler)
522 		return;
523 	pr_debug(PREFIX "start query execution\n");
524 	if (handler->func)
525 		handler->func(handler->data);
526 	else if (handler->handle)
527 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
528 	pr_debug(PREFIX "stop query execution\n");
529 	kfree(handler);
530 }
531 
532 static int acpi_ec_sync_query(struct acpi_ec *ec)
533 {
534 	u8 value = 0;
535 	int status;
536 	struct acpi_ec_query_handler *handler, *copy;
537 	if ((status = acpi_ec_query_unlocked(ec, &value)))
538 		return status;
539 	list_for_each_entry(handler, &ec->list, node) {
540 		if (value == handler->query_bit) {
541 			/* have custom handler for this bit */
542 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
543 			if (!copy)
544 				return -ENOMEM;
545 			memcpy(copy, handler, sizeof(*copy));
546 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
547 			return acpi_os_execute((copy->func) ?
548 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
549 				acpi_ec_run, copy);
550 		}
551 	}
552 	return 0;
553 }
554 
555 static void acpi_ec_gpe_query(void *ec_cxt)
556 {
557 	struct acpi_ec *ec = ec_cxt;
558 	if (!ec)
559 		return;
560 	mutex_lock(&ec->lock);
561 	acpi_ec_sync_query(ec);
562 	mutex_unlock(&ec->lock);
563 }
564 
565 static void acpi_ec_gpe_query(void *ec_cxt);
566 
567 static int ec_check_sci(struct acpi_ec *ec, u8 state)
568 {
569 	if (state & ACPI_EC_FLAG_SCI) {
570 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
571 			pr_debug(PREFIX "push gpe query to the queue\n");
572 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
573 				acpi_ec_gpe_query, ec);
574 		}
575 	}
576 	return 0;
577 }
578 
579 static u32 acpi_ec_gpe_handler(void *data)
580 {
581 	struct acpi_ec *ec = data;
582 
583 	pr_debug(PREFIX "~~~> interrupt\n");
584 
585 	advance_transaction(ec, acpi_ec_read_status(ec));
586 	if (ec_transaction_done(ec) &&
587 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
588 		wake_up(&ec->wait);
589 		ec_check_sci(ec, acpi_ec_read_status(ec));
590 	}
591 	return ACPI_INTERRUPT_HANDLED;
592 }
593 
594 /* --------------------------------------------------------------------------
595                              Address Space Management
596    -------------------------------------------------------------------------- */
597 
598 static acpi_status
599 acpi_ec_space_handler(u32 function, acpi_physical_address address,
600 		      u32 bits, acpi_integer *value,
601 		      void *handler_context, void *region_context)
602 {
603 	struct acpi_ec *ec = handler_context;
604 	int result = 0, i;
605 	u8 temp = 0;
606 
607 	if ((address > 0xFF) || !value || !handler_context)
608 		return AE_BAD_PARAMETER;
609 
610 	if (function != ACPI_READ && function != ACPI_WRITE)
611 		return AE_BAD_PARAMETER;
612 
613 	if (bits != 8 && acpi_strict)
614 		return AE_BAD_PARAMETER;
615 
616 	if (EC_FLAGS_MSI)
617 		acpi_ec_burst_enable(ec);
618 
619 	if (function == ACPI_READ) {
620 		result = acpi_ec_read(ec, address, &temp);
621 		*value = temp;
622 	} else {
623 		temp = 0xff & (*value);
624 		result = acpi_ec_write(ec, address, temp);
625 	}
626 
627 	for (i = 8; unlikely(bits - i > 0); i += 8) {
628 		++address;
629 		if (function == ACPI_READ) {
630 			result = acpi_ec_read(ec, address, &temp);
631 			(*value) |= ((acpi_integer)temp) << i;
632 		} else {
633 			temp = 0xff & ((*value) >> i);
634 			result = acpi_ec_write(ec, address, temp);
635 		}
636 	}
637 
638 	if (EC_FLAGS_MSI)
639 		acpi_ec_burst_disable(ec);
640 
641 	switch (result) {
642 	case -EINVAL:
643 		return AE_BAD_PARAMETER;
644 		break;
645 	case -ENODEV:
646 		return AE_NOT_FOUND;
647 		break;
648 	case -ETIME:
649 		return AE_TIME;
650 		break;
651 	default:
652 		return AE_OK;
653 	}
654 }
655 
656 /* --------------------------------------------------------------------------
657                               FS Interface (/proc)
658    -------------------------------------------------------------------------- */
659 
660 static struct proc_dir_entry *acpi_ec_dir;
661 
662 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
663 {
664 	struct acpi_ec *ec = seq->private;
665 
666 	if (!ec)
667 		goto end;
668 
669 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
670 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
671 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
672 	seq_printf(seq, "use global lock:\t%s\n",
673 		   ec->global_lock ? "yes" : "no");
674       end:
675 	return 0;
676 }
677 
678 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
679 {
680 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
681 }
682 
683 static const struct file_operations acpi_ec_info_ops = {
684 	.open = acpi_ec_info_open_fs,
685 	.read = seq_read,
686 	.llseek = seq_lseek,
687 	.release = single_release,
688 	.owner = THIS_MODULE,
689 };
690 
691 static int acpi_ec_add_fs(struct acpi_device *device)
692 {
693 	struct proc_dir_entry *entry = NULL;
694 
695 	if (!acpi_device_dir(device)) {
696 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
697 						     acpi_ec_dir);
698 		if (!acpi_device_dir(device))
699 			return -ENODEV;
700 	}
701 
702 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
703 				 acpi_device_dir(device),
704 				 &acpi_ec_info_ops, acpi_driver_data(device));
705 	if (!entry)
706 		return -ENODEV;
707 	return 0;
708 }
709 
710 static int acpi_ec_remove_fs(struct acpi_device *device)
711 {
712 
713 	if (acpi_device_dir(device)) {
714 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
715 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
716 		acpi_device_dir(device) = NULL;
717 	}
718 
719 	return 0;
720 }
721 
722 /* --------------------------------------------------------------------------
723                                Driver Interface
724    -------------------------------------------------------------------------- */
725 static acpi_status
726 ec_parse_io_ports(struct acpi_resource *resource, void *context);
727 
728 static struct acpi_ec *make_acpi_ec(void)
729 {
730 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
731 	if (!ec)
732 		return NULL;
733 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
734 	mutex_init(&ec->lock);
735 	init_waitqueue_head(&ec->wait);
736 	INIT_LIST_HEAD(&ec->list);
737 	spin_lock_init(&ec->curr_lock);
738 	return ec;
739 }
740 
741 static acpi_status
742 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
743 			       void *context, void **return_value)
744 {
745 	char node_name[5];
746 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
747 	struct acpi_ec *ec = context;
748 	int value = 0;
749 	acpi_status status;
750 
751 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
752 
753 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
754 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
755 	}
756 	return AE_OK;
757 }
758 
759 static acpi_status
760 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
761 {
762 	acpi_status status;
763 	unsigned long long tmp = 0;
764 
765 	struct acpi_ec *ec = context;
766 
767 	/* clear addr values, ec_parse_io_ports depend on it */
768 	ec->command_addr = ec->data_addr = 0;
769 
770 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
771 				     ec_parse_io_ports, ec);
772 	if (ACPI_FAILURE(status))
773 		return status;
774 
775 	/* Get GPE bit assignment (EC events). */
776 	/* TODO: Add support for _GPE returning a package */
777 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
778 	if (ACPI_FAILURE(status))
779 		return status;
780 	ec->gpe = tmp;
781 	/* Use the global lock for all EC transactions? */
782 	tmp = 0;
783 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
784 	ec->global_lock = tmp;
785 	ec->handle = handle;
786 	return AE_CTRL_TERMINATE;
787 }
788 
789 static int ec_install_handlers(struct acpi_ec *ec)
790 {
791 	acpi_status status;
792 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
793 		return 0;
794 	status = acpi_install_gpe_handler(NULL, ec->gpe,
795 				  ACPI_GPE_EDGE_TRIGGERED,
796 				  &acpi_ec_gpe_handler, ec);
797 	if (ACPI_FAILURE(status))
798 		return -ENODEV;
799 
800 	acpi_enable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
801 	status = acpi_install_address_space_handler(ec->handle,
802 						    ACPI_ADR_SPACE_EC,
803 						    &acpi_ec_space_handler,
804 						    NULL, ec);
805 	if (ACPI_FAILURE(status)) {
806 		if (status == AE_NOT_FOUND) {
807 			/*
808 			 * Maybe OS fails in evaluating the _REG object.
809 			 * The AE_NOT_FOUND error will be ignored and OS
810 			 * continue to initialize EC.
811 			 */
812 			printk(KERN_ERR "Fail in evaluating the _REG object"
813 				" of EC device. Broken bios is suspected.\n");
814 		} else {
815 			acpi_remove_gpe_handler(NULL, ec->gpe,
816 				&acpi_ec_gpe_handler);
817 			acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
818 			return -ENODEV;
819 		}
820 	}
821 
822 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
823 	return 0;
824 }
825 
826 static void ec_remove_handlers(struct acpi_ec *ec)
827 {
828 	acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
829 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
830 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
831 		pr_err(PREFIX "failed to remove space handler\n");
832 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
833 				&acpi_ec_gpe_handler)))
834 		pr_err(PREFIX "failed to remove gpe handler\n");
835 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
836 }
837 
838 static int acpi_ec_add(struct acpi_device *device)
839 {
840 	struct acpi_ec *ec = NULL;
841 	int ret;
842 
843 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
844 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
845 
846 	/* Check for boot EC */
847 	if (boot_ec &&
848 	    (boot_ec->handle == device->handle ||
849 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
850 		ec = boot_ec;
851 		boot_ec = NULL;
852 	} else {
853 		ec = make_acpi_ec();
854 		if (!ec)
855 			return -ENOMEM;
856 	}
857 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
858 		AE_CTRL_TERMINATE) {
859 			kfree(ec);
860 			return -EINVAL;
861 	}
862 
863 	ec->handle = device->handle;
864 
865 	/* Find and register all query methods */
866 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
867 			    acpi_ec_register_query_methods, NULL, ec, NULL);
868 
869 	if (!first_ec)
870 		first_ec = ec;
871 	device->driver_data = ec;
872 	acpi_ec_add_fs(device);
873 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
874 			  ec->gpe, ec->command_addr, ec->data_addr);
875 
876 	ret = ec_install_handlers(ec);
877 
878 	/* EC is fully operational, allow queries */
879 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
880 	return ret;
881 }
882 
883 static int acpi_ec_remove(struct acpi_device *device, int type)
884 {
885 	struct acpi_ec *ec;
886 	struct acpi_ec_query_handler *handler, *tmp;
887 
888 	if (!device)
889 		return -EINVAL;
890 
891 	ec = acpi_driver_data(device);
892 	ec_remove_handlers(ec);
893 	mutex_lock(&ec->lock);
894 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
895 		list_del(&handler->node);
896 		kfree(handler);
897 	}
898 	mutex_unlock(&ec->lock);
899 	acpi_ec_remove_fs(device);
900 	device->driver_data = NULL;
901 	if (ec == first_ec)
902 		first_ec = NULL;
903 	kfree(ec);
904 	return 0;
905 }
906 
907 static acpi_status
908 ec_parse_io_ports(struct acpi_resource *resource, void *context)
909 {
910 	struct acpi_ec *ec = context;
911 
912 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
913 		return AE_OK;
914 
915 	/*
916 	 * The first address region returned is the data port, and
917 	 * the second address region returned is the status/command
918 	 * port.
919 	 */
920 	if (ec->data_addr == 0)
921 		ec->data_addr = resource->data.io.minimum;
922 	else if (ec->command_addr == 0)
923 		ec->command_addr = resource->data.io.minimum;
924 	else
925 		return AE_CTRL_TERMINATE;
926 
927 	return AE_OK;
928 }
929 
930 int __init acpi_boot_ec_enable(void)
931 {
932 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
933 		return 0;
934 	if (!ec_install_handlers(boot_ec)) {
935 		first_ec = boot_ec;
936 		return 0;
937 	}
938 	return -EFAULT;
939 }
940 
941 static const struct acpi_device_id ec_device_ids[] = {
942 	{"PNP0C09", 0},
943 	{"", 0},
944 };
945 
946 /* Some BIOS do not survive early DSDT scan, skip it */
947 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
948 {
949 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
950 	return 0;
951 }
952 
953 /* ASUStek often supplies us with broken ECDT, validate it */
954 static int ec_validate_ecdt(const struct dmi_system_id *id)
955 {
956 	EC_FLAGS_VALIDATE_ECDT = 1;
957 	return 0;
958 }
959 
960 /* MSI EC needs special treatment, enable it */
961 static int ec_flag_msi(const struct dmi_system_id *id)
962 {
963 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
964 	EC_FLAGS_MSI = 1;
965 	EC_FLAGS_VALIDATE_ECDT = 1;
966 	return 0;
967 }
968 
969 static struct dmi_system_id __initdata ec_dmi_table[] = {
970 	{
971 	ec_skip_dsdt_scan, "Compal JFL92", {
972 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
973 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
974 	{
975 	ec_flag_msi, "MSI hardware", {
976 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
977 	{
978 	ec_flag_msi, "MSI hardware", {
979 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
980 	{
981 	ec_flag_msi, "MSI hardware", {
982 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
983 	{
984 	ec_validate_ecdt, "ASUS hardware", {
985 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
986 	{},
987 };
988 
989 
990 int __init acpi_ec_ecdt_probe(void)
991 {
992 	acpi_status status;
993 	struct acpi_ec *saved_ec = NULL;
994 	struct acpi_table_ecdt *ecdt_ptr;
995 
996 	boot_ec = make_acpi_ec();
997 	if (!boot_ec)
998 		return -ENOMEM;
999 	/*
1000 	 * Generate a boot ec context
1001 	 */
1002 	dmi_check_system(ec_dmi_table);
1003 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1004 				(struct acpi_table_header **)&ecdt_ptr);
1005 	if (ACPI_SUCCESS(status)) {
1006 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1007 		boot_ec->command_addr = ecdt_ptr->control.address;
1008 		boot_ec->data_addr = ecdt_ptr->data.address;
1009 		boot_ec->gpe = ecdt_ptr->gpe;
1010 		boot_ec->handle = ACPI_ROOT_OBJECT;
1011 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1012 		/* Don't trust ECDT, which comes from ASUSTek */
1013 		if (!EC_FLAGS_VALIDATE_ECDT)
1014 			goto install;
1015 		saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1016 		if (!saved_ec)
1017 			return -ENOMEM;
1018 		memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1019 	/* fall through */
1020 	}
1021 
1022 	if (EC_FLAGS_SKIP_DSDT_SCAN)
1023 		return -ENODEV;
1024 
1025 	/* This workaround is needed only on some broken machines,
1026 	 * which require early EC, but fail to provide ECDT */
1027 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1028 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1029 					boot_ec, NULL);
1030 	/* Check that acpi_get_devices actually find something */
1031 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1032 		goto error;
1033 	if (saved_ec) {
1034 		/* try to find good ECDT from ASUSTek */
1035 		if (saved_ec->command_addr != boot_ec->command_addr ||
1036 		    saved_ec->data_addr != boot_ec->data_addr ||
1037 		    saved_ec->gpe != boot_ec->gpe ||
1038 		    saved_ec->handle != boot_ec->handle)
1039 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1040 			"ECDT tables, which are very hard to workaround. "
1041 			"Trying to use DSDT EC info instead. Please send "
1042 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1043 		kfree(saved_ec);
1044 		saved_ec = NULL;
1045 	} else {
1046 		/* We really need to limit this workaround, the only ASUS,
1047 		* which needs it, has fake EC._INI method, so use it as flag.
1048 		* Keep boot_ec struct as it will be needed soon.
1049 		*/
1050 		acpi_handle dummy;
1051 		if (!dmi_name_in_vendors("ASUS") ||
1052 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1053 							&dummy)))
1054 			return -ENODEV;
1055 	}
1056 install:
1057 	if (!ec_install_handlers(boot_ec)) {
1058 		first_ec = boot_ec;
1059 		return 0;
1060 	}
1061 error:
1062 	kfree(boot_ec);
1063 	boot_ec = NULL;
1064 	return -ENODEV;
1065 }
1066 
1067 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1068 {
1069 	struct acpi_ec *ec = acpi_driver_data(device);
1070 	/* Stop using the GPE, but keep it reference counted. */
1071 	acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1072 	return 0;
1073 }
1074 
1075 static int acpi_ec_resume(struct acpi_device *device)
1076 {
1077 	struct acpi_ec *ec = acpi_driver_data(device);
1078 	/* Enable the GPE again, but don't reference count it once more. */
1079 	acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1080 	return 0;
1081 }
1082 
1083 static struct acpi_driver acpi_ec_driver = {
1084 	.name = "ec",
1085 	.class = ACPI_EC_CLASS,
1086 	.ids = ec_device_ids,
1087 	.ops = {
1088 		.add = acpi_ec_add,
1089 		.remove = acpi_ec_remove,
1090 		.suspend = acpi_ec_suspend,
1091 		.resume = acpi_ec_resume,
1092 		},
1093 };
1094 
1095 int __init acpi_ec_init(void)
1096 {
1097 	int result = 0;
1098 
1099 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1100 	if (!acpi_ec_dir)
1101 		return -ENODEV;
1102 
1103 	/* Now register the driver for the EC */
1104 	result = acpi_bus_register_driver(&acpi_ec_driver);
1105 	if (result < 0) {
1106 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1107 		return -ENODEV;
1108 	}
1109 
1110 	return result;
1111 }
1112 
1113 /* EC driver currently not unloadable */
1114 #if 0
1115 static void __exit acpi_ec_exit(void)
1116 {
1117 
1118 	acpi_bus_unregister_driver(&acpi_ec_driver);
1119 
1120 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1121 
1122 	return;
1123 }
1124 #endif	/* 0 */
1125