xref: /openbmc/linux/drivers/acpi/ec.c (revision df388556)
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 
46 #define ACPI_EC_CLASS			"embedded_controller"
47 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
48 #define ACPI_EC_FILE_INFO		"info"
49 
50 #undef PREFIX
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_UDELAY		100	/* Wait 100us before polling EC again */
71 
72 #define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
73 					   per one transaction */
74 
75 enum {
76 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
77 	EC_FLAGS_GPE_MODE,		/* Expect GPE to be sent
78 					 * for status change */
79 	EC_FLAGS_NO_GPE,		/* Don't use GPE mode */
80 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
81 	EC_FLAGS_HANDLERS_INSTALLED	/* Handlers for GPE and
82 					 * OpReg are installed */
83 };
84 
85 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
86 /* External interfaces use first EC only, so remember */
87 typedef int (*acpi_ec_query_func) (void *data);
88 
89 struct acpi_ec_query_handler {
90 	struct list_head node;
91 	acpi_ec_query_func func;
92 	acpi_handle handle;
93 	void *data;
94 	u8 query_bit;
95 };
96 
97 struct transaction {
98 	const u8 *wdata;
99 	u8 *rdata;
100 	unsigned short irq_count;
101 	u8 command;
102 	u8 wi;
103 	u8 ri;
104 	u8 wlen;
105 	u8 rlen;
106 	bool done;
107 };
108 
109 static struct acpi_ec {
110 	acpi_handle handle;
111 	unsigned long gpe;
112 	unsigned long command_addr;
113 	unsigned long data_addr;
114 	unsigned long global_lock;
115 	unsigned long flags;
116 	struct mutex lock;
117 	wait_queue_head_t wait;
118 	struct list_head list;
119 	struct transaction *curr;
120 	spinlock_t curr_lock;
121 } *boot_ec, *first_ec;
122 
123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
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 gpe_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_wait(struct acpi_ec *ec)
205 {
206 	if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
207 			       msecs_to_jiffies(ACPI_EC_DELAY)))
208 		return 0;
209 	/* try restart command if we get any false interrupts */
210 	if (ec->curr->irq_count &&
211 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
212 		pr_debug(PREFIX "controller reset, restart transaction\n");
213 		start_transaction(ec);
214 		if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
215 					msecs_to_jiffies(ACPI_EC_DELAY)))
216 			return 0;
217 	}
218 	/* missing GPEs, switch back to poll mode */
219 	if (printk_ratelimit())
220 		pr_info(PREFIX "missing confirmations, "
221 				"switch off interrupt mode.\n");
222 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
223 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
224 	return 1;
225 }
226 
227 static void acpi_ec_gpe_query(void *ec_cxt);
228 
229 static int ec_check_sci(struct acpi_ec *ec, u8 state)
230 {
231 	if (state & ACPI_EC_FLAG_SCI) {
232 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
233 			return acpi_os_execute(OSL_EC_BURST_HANDLER,
234 				acpi_ec_gpe_query, ec);
235 	}
236 	return 0;
237 }
238 
239 static int ec_poll(struct acpi_ec *ec)
240 {
241 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
242 	udelay(ACPI_EC_UDELAY);
243 	while (time_before(jiffies, delay)) {
244 		gpe_transaction(ec, acpi_ec_read_status(ec));
245 		udelay(ACPI_EC_UDELAY);
246 		if (ec_transaction_done(ec))
247 			return 0;
248 	}
249 	return -ETIME;
250 }
251 
252 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
253 					struct transaction *t,
254 					int force_poll)
255 {
256 	unsigned long tmp;
257 	int ret = 0;
258 	pr_debug(PREFIX "transaction start\n");
259 	/* disable GPE during transaction if storm is detected */
260 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
261 		clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
262 		acpi_disable_gpe(NULL, ec->gpe);
263 	}
264 	if (EC_FLAGS_MSI)
265 		udelay(ACPI_EC_DELAY);
266 	/* start transaction */
267 	spin_lock_irqsave(&ec->curr_lock, tmp);
268 	/* following two actions should be kept atomic */
269 	ec->curr = t;
270 	start_transaction(ec);
271 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
272 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
273 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
274 	/* if we selected poll mode or failed in GPE-mode do a poll loop */
275 	if (force_poll ||
276 	    !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
277 	    acpi_ec_wait(ec))
278 		ret = ec_poll(ec);
279 	pr_debug(PREFIX "transaction end\n");
280 	spin_lock_irqsave(&ec->curr_lock, tmp);
281 	ec->curr = NULL;
282 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
283 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
284 		/* check if we received SCI during transaction */
285 		ec_check_sci(ec, acpi_ec_read_status(ec));
286 		/* it is safe to enable GPE outside of transaction */
287 		acpi_enable_gpe(NULL, ec->gpe);
288 	} else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
289 		   t->irq_count > ACPI_EC_STORM_THRESHOLD) {
290 		pr_info(PREFIX "GPE storm detected, "
291 			"transactions will use polling mode\n");
292 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
293 	}
294 	return ret;
295 }
296 
297 static int ec_check_ibf0(struct acpi_ec *ec)
298 {
299 	u8 status = acpi_ec_read_status(ec);
300 	return (status & ACPI_EC_FLAG_IBF) == 0;
301 }
302 
303 static int ec_wait_ibf0(struct acpi_ec *ec)
304 {
305 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
306 	/* interrupt wait manually if GPE mode is not active */
307 	unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
308 		msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
309 	while (time_before(jiffies, delay))
310 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
311 			return 0;
312 	return -ETIME;
313 }
314 
315 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
316 			       int force_poll)
317 {
318 	int status;
319 	u32 glk;
320 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
321 		return -EINVAL;
322 	if (t->rdata)
323 		memset(t->rdata, 0, t->rlen);
324 	mutex_lock(&ec->lock);
325 	if (ec->global_lock) {
326 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
327 		if (ACPI_FAILURE(status)) {
328 			status = -ENODEV;
329 			goto unlock;
330 		}
331 	}
332 	if (ec_wait_ibf0(ec)) {
333 		pr_err(PREFIX "input buffer is not empty, "
334 				"aborting transaction\n");
335 		status = -ETIME;
336 		goto end;
337 	}
338 	status = acpi_ec_transaction_unlocked(ec, t, force_poll);
339 end:
340 	if (ec->global_lock)
341 		acpi_release_global_lock(glk);
342 unlock:
343 	mutex_unlock(&ec->lock);
344 	return status;
345 }
346 
347 /*
348  * Note: samsung nv5000 doesn't work with ec burst mode.
349  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
350  */
351 static int acpi_ec_burst_enable(struct acpi_ec *ec)
352 {
353 	u8 d;
354 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
355 				.wdata = NULL, .rdata = &d,
356 				.wlen = 0, .rlen = 1};
357 
358 	return acpi_ec_transaction(ec, &t, 0);
359 }
360 
361 static int acpi_ec_burst_disable(struct acpi_ec *ec)
362 {
363 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
364 				.wdata = NULL, .rdata = NULL,
365 				.wlen = 0, .rlen = 0};
366 
367 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
368 				acpi_ec_transaction(ec, &t, 0) : 0;
369 }
370 
371 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
372 {
373 	int result;
374 	u8 d;
375 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
376 				.wdata = &address, .rdata = &d,
377 				.wlen = 1, .rlen = 1};
378 
379 	result = acpi_ec_transaction(ec, &t, 0);
380 	*data = d;
381 	return result;
382 }
383 
384 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
385 {
386 	u8 wdata[2] = { address, data };
387 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
388 				.wdata = wdata, .rdata = NULL,
389 				.wlen = 2, .rlen = 0};
390 
391 	return acpi_ec_transaction(ec, &t, 0);
392 }
393 
394 /*
395  * Externally callable EC access functions. For now, assume 1 EC only
396  */
397 int ec_burst_enable(void)
398 {
399 	if (!first_ec)
400 		return -ENODEV;
401 	return acpi_ec_burst_enable(first_ec);
402 }
403 
404 EXPORT_SYMBOL(ec_burst_enable);
405 
406 int ec_burst_disable(void)
407 {
408 	if (!first_ec)
409 		return -ENODEV;
410 	return acpi_ec_burst_disable(first_ec);
411 }
412 
413 EXPORT_SYMBOL(ec_burst_disable);
414 
415 int ec_read(u8 addr, u8 * val)
416 {
417 	int err;
418 	u8 temp_data;
419 
420 	if (!first_ec)
421 		return -ENODEV;
422 
423 	err = acpi_ec_read(first_ec, addr, &temp_data);
424 
425 	if (!err) {
426 		*val = temp_data;
427 		return 0;
428 	} else
429 		return err;
430 }
431 
432 EXPORT_SYMBOL(ec_read);
433 
434 int ec_write(u8 addr, u8 val)
435 {
436 	int err;
437 
438 	if (!first_ec)
439 		return -ENODEV;
440 
441 	err = acpi_ec_write(first_ec, addr, val);
442 
443 	return err;
444 }
445 
446 EXPORT_SYMBOL(ec_write);
447 
448 int ec_transaction(u8 command,
449 		   const u8 * wdata, unsigned wdata_len,
450 		   u8 * rdata, unsigned rdata_len,
451 		   int force_poll)
452 {
453 	struct transaction t = {.command = command,
454 				.wdata = wdata, .rdata = rdata,
455 				.wlen = wdata_len, .rlen = rdata_len};
456 	if (!first_ec)
457 		return -ENODEV;
458 
459 	return acpi_ec_transaction(first_ec, &t, force_poll);
460 }
461 
462 EXPORT_SYMBOL(ec_transaction);
463 
464 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
465 {
466 	int result;
467 	u8 d;
468 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
469 				.wdata = NULL, .rdata = &d,
470 				.wlen = 0, .rlen = 1};
471 	if (!ec || !data)
472 		return -EINVAL;
473 
474 	/*
475 	 * Query the EC to find out which _Qxx method we need to evaluate.
476 	 * Note that successful completion of the query causes the ACPI_EC_SCI
477 	 * bit to be cleared (and thus clearing the interrupt source).
478 	 */
479 
480 	result = acpi_ec_transaction(ec, &t, 0);
481 	if (result)
482 		return result;
483 
484 	if (!d)
485 		return -ENODATA;
486 
487 	*data = d;
488 	return 0;
489 }
490 
491 /* --------------------------------------------------------------------------
492                                 Event Management
493    -------------------------------------------------------------------------- */
494 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
495 			      acpi_handle handle, acpi_ec_query_func func,
496 			      void *data)
497 {
498 	struct acpi_ec_query_handler *handler =
499 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
500 	if (!handler)
501 		return -ENOMEM;
502 
503 	handler->query_bit = query_bit;
504 	handler->handle = handle;
505 	handler->func = func;
506 	handler->data = data;
507 	mutex_lock(&ec->lock);
508 	list_add(&handler->node, &ec->list);
509 	mutex_unlock(&ec->lock);
510 	return 0;
511 }
512 
513 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
514 
515 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
516 {
517 	struct acpi_ec_query_handler *handler, *tmp;
518 	mutex_lock(&ec->lock);
519 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
520 		if (query_bit == handler->query_bit) {
521 			list_del(&handler->node);
522 			kfree(handler);
523 		}
524 	}
525 	mutex_unlock(&ec->lock);
526 }
527 
528 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
529 
530 static void acpi_ec_gpe_query(void *ec_cxt)
531 {
532 	struct acpi_ec *ec = ec_cxt;
533 	u8 value = 0;
534 	struct acpi_ec_query_handler *handler, copy;
535 
536 	if (!ec || acpi_ec_query(ec, &value))
537 		return;
538 	mutex_lock(&ec->lock);
539 	list_for_each_entry(handler, &ec->list, node) {
540 		if (value == handler->query_bit) {
541 			/* have custom handler for this bit */
542 			memcpy(&copy, handler, sizeof(copy));
543 			mutex_unlock(&ec->lock);
544 			if (copy.func) {
545 				copy.func(copy.data);
546 			} else if (copy.handle) {
547 				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
548 			}
549 			return;
550 		}
551 	}
552 	mutex_unlock(&ec->lock);
553 }
554 
555 static u32 acpi_ec_gpe_handler(void *data)
556 {
557 	struct acpi_ec *ec = data;
558 	u8 status;
559 
560 	pr_debug(PREFIX "~~~> interrupt\n");
561 	status = acpi_ec_read_status(ec);
562 
563 	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
564 		gpe_transaction(ec, status);
565 		if (ec_transaction_done(ec) &&
566 		    (status & ACPI_EC_FLAG_IBF) == 0)
567 			wake_up(&ec->wait);
568 	}
569 
570 	ec_check_sci(ec, status);
571 	if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
572 	    !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
573 		/* this is non-query, must be confirmation */
574 		if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
575 			if (printk_ratelimit())
576 				pr_info(PREFIX "non-query interrupt received,"
577 					" switching to interrupt mode\n");
578 		} else {
579 			/* hush, STORM switches the mode every transaction */
580 			pr_debug(PREFIX "non-query interrupt received,"
581 				" switching to interrupt mode\n");
582 		}
583 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
584 	}
585 	return ACPI_INTERRUPT_HANDLED;
586 }
587 
588 /* --------------------------------------------------------------------------
589                              Address Space Management
590    -------------------------------------------------------------------------- */
591 
592 static acpi_status
593 acpi_ec_space_handler(u32 function, acpi_physical_address address,
594 		      u32 bits, acpi_integer *value,
595 		      void *handler_context, void *region_context)
596 {
597 	struct acpi_ec *ec = handler_context;
598 	int result = 0, i;
599 	u8 temp = 0;
600 
601 	if ((address > 0xFF) || !value || !handler_context)
602 		return AE_BAD_PARAMETER;
603 
604 	if (function != ACPI_READ && function != ACPI_WRITE)
605 		return AE_BAD_PARAMETER;
606 
607 	if (bits != 8 && acpi_strict)
608 		return AE_BAD_PARAMETER;
609 
610 	acpi_ec_burst_enable(ec);
611 
612 	if (function == ACPI_READ) {
613 		result = acpi_ec_read(ec, address, &temp);
614 		*value = temp;
615 	} else {
616 		temp = 0xff & (*value);
617 		result = acpi_ec_write(ec, address, temp);
618 	}
619 
620 	for (i = 8; unlikely(bits - i > 0); i += 8) {
621 		++address;
622 		if (function == ACPI_READ) {
623 			result = acpi_ec_read(ec, address, &temp);
624 			(*value) |= ((acpi_integer)temp) << i;
625 		} else {
626 			temp = 0xff & ((*value) >> i);
627 			result = acpi_ec_write(ec, address, temp);
628 		}
629 	}
630 
631 	acpi_ec_burst_disable(ec);
632 
633 	switch (result) {
634 	case -EINVAL:
635 		return AE_BAD_PARAMETER;
636 		break;
637 	case -ENODEV:
638 		return AE_NOT_FOUND;
639 		break;
640 	case -ETIME:
641 		return AE_TIME;
642 		break;
643 	default:
644 		return AE_OK;
645 	}
646 }
647 
648 /* --------------------------------------------------------------------------
649                               FS Interface (/proc)
650    -------------------------------------------------------------------------- */
651 
652 static struct proc_dir_entry *acpi_ec_dir;
653 
654 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
655 {
656 	struct acpi_ec *ec = seq->private;
657 
658 	if (!ec)
659 		goto end;
660 
661 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
662 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
663 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
664 	seq_printf(seq, "use global lock:\t%s\n",
665 		   ec->global_lock ? "yes" : "no");
666       end:
667 	return 0;
668 }
669 
670 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
671 {
672 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
673 }
674 
675 static struct file_operations acpi_ec_info_ops = {
676 	.open = acpi_ec_info_open_fs,
677 	.read = seq_read,
678 	.llseek = seq_lseek,
679 	.release = single_release,
680 	.owner = THIS_MODULE,
681 };
682 
683 static int acpi_ec_add_fs(struct acpi_device *device)
684 {
685 	struct proc_dir_entry *entry = NULL;
686 
687 	if (!acpi_device_dir(device)) {
688 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
689 						     acpi_ec_dir);
690 		if (!acpi_device_dir(device))
691 			return -ENODEV;
692 	}
693 
694 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
695 				 acpi_device_dir(device),
696 				 &acpi_ec_info_ops, acpi_driver_data(device));
697 	if (!entry)
698 		return -ENODEV;
699 	return 0;
700 }
701 
702 static int acpi_ec_remove_fs(struct acpi_device *device)
703 {
704 
705 	if (acpi_device_dir(device)) {
706 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
707 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
708 		acpi_device_dir(device) = NULL;
709 	}
710 
711 	return 0;
712 }
713 
714 /* --------------------------------------------------------------------------
715                                Driver Interface
716    -------------------------------------------------------------------------- */
717 static acpi_status
718 ec_parse_io_ports(struct acpi_resource *resource, void *context);
719 
720 static struct acpi_ec *make_acpi_ec(void)
721 {
722 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
723 	if (!ec)
724 		return NULL;
725 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
726 	mutex_init(&ec->lock);
727 	init_waitqueue_head(&ec->wait);
728 	INIT_LIST_HEAD(&ec->list);
729 	spin_lock_init(&ec->curr_lock);
730 	return ec;
731 }
732 
733 static acpi_status
734 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
735 			       void *context, void **return_value)
736 {
737 	char node_name[5];
738 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
739 	struct acpi_ec *ec = context;
740 	int value = 0;
741 	acpi_status status;
742 
743 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
744 
745 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
746 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
747 	}
748 	return AE_OK;
749 }
750 
751 static acpi_status
752 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
753 {
754 	acpi_status status;
755 	unsigned long long tmp = 0;
756 
757 	struct acpi_ec *ec = context;
758 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
759 				     ec_parse_io_ports, ec);
760 	if (ACPI_FAILURE(status))
761 		return status;
762 
763 	/* Get GPE bit assignment (EC events). */
764 	/* TODO: Add support for _GPE returning a package */
765 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
766 	if (ACPI_FAILURE(status))
767 		return status;
768 	ec->gpe = tmp;
769 	/* Use the global lock for all EC transactions? */
770 	tmp = 0;
771 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
772 	ec->global_lock = tmp;
773 	ec->handle = handle;
774 	return AE_CTRL_TERMINATE;
775 }
776 
777 static void ec_remove_handlers(struct acpi_ec *ec)
778 {
779 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
780 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
781 		pr_err(PREFIX "failed to remove space handler\n");
782 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
783 				&acpi_ec_gpe_handler)))
784 		pr_err(PREFIX "failed to remove gpe handler\n");
785 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
786 }
787 
788 static int acpi_ec_add(struct acpi_device *device)
789 {
790 	struct acpi_ec *ec = NULL;
791 
792 	if (!device)
793 		return -EINVAL;
794 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
795 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
796 
797 	/* Check for boot EC */
798 	if (boot_ec &&
799 	    (boot_ec->handle == device->handle ||
800 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
801 		ec = boot_ec;
802 		boot_ec = NULL;
803 	} else {
804 		ec = make_acpi_ec();
805 		if (!ec)
806 			return -ENOMEM;
807 		if (ec_parse_device(device->handle, 0, ec, NULL) !=
808 		    AE_CTRL_TERMINATE) {
809 			kfree(ec);
810 			return -EINVAL;
811 		}
812 	}
813 
814 	ec->handle = device->handle;
815 
816 	/* Find and register all query methods */
817 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
818 			    acpi_ec_register_query_methods, ec, NULL);
819 
820 	if (!first_ec)
821 		first_ec = ec;
822 	device->driver_data = ec;
823 	acpi_ec_add_fs(device);
824 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
825 			  ec->gpe, ec->command_addr, ec->data_addr);
826 	pr_info(PREFIX "driver started in %s mode\n",
827 		(test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
828 	return 0;
829 }
830 
831 static int acpi_ec_remove(struct acpi_device *device, int type)
832 {
833 	struct acpi_ec *ec;
834 	struct acpi_ec_query_handler *handler, *tmp;
835 
836 	if (!device)
837 		return -EINVAL;
838 
839 	ec = acpi_driver_data(device);
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 	acpi_ec_remove_fs(device);
847 	device->driver_data = NULL;
848 	if (ec == first_ec)
849 		first_ec = NULL;
850 	kfree(ec);
851 	return 0;
852 }
853 
854 static acpi_status
855 ec_parse_io_ports(struct acpi_resource *resource, void *context)
856 {
857 	struct acpi_ec *ec = context;
858 
859 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
860 		return AE_OK;
861 
862 	/*
863 	 * The first address region returned is the data port, and
864 	 * the second address region returned is the status/command
865 	 * port.
866 	 */
867 	if (ec->data_addr == 0)
868 		ec->data_addr = resource->data.io.minimum;
869 	else if (ec->command_addr == 0)
870 		ec->command_addr = resource->data.io.minimum;
871 	else
872 		return AE_CTRL_TERMINATE;
873 
874 	return AE_OK;
875 }
876 
877 static int ec_install_handlers(struct acpi_ec *ec)
878 {
879 	acpi_status status;
880 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
881 		return 0;
882 	status = acpi_install_gpe_handler(NULL, ec->gpe,
883 				  ACPI_GPE_EDGE_TRIGGERED,
884 				  &acpi_ec_gpe_handler, ec);
885 	if (ACPI_FAILURE(status))
886 		return -ENODEV;
887 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
888 	acpi_enable_gpe(NULL, ec->gpe);
889 	status = acpi_install_address_space_handler(ec->handle,
890 						    ACPI_ADR_SPACE_EC,
891 						    &acpi_ec_space_handler,
892 						    NULL, ec);
893 	if (ACPI_FAILURE(status)) {
894 		if (status == AE_NOT_FOUND) {
895 			/*
896 			 * Maybe OS fails in evaluating the _REG object.
897 			 * The AE_NOT_FOUND error will be ignored and OS
898 			 * continue to initialize EC.
899 			 */
900 			printk(KERN_ERR "Fail in evaluating the _REG object"
901 				" of EC device. Broken bios is suspected.\n");
902 		} else {
903 			acpi_remove_gpe_handler(NULL, ec->gpe,
904 				&acpi_ec_gpe_handler);
905 			return -ENODEV;
906 		}
907 	}
908 
909 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
910 	return 0;
911 }
912 
913 static int acpi_ec_start(struct acpi_device *device)
914 {
915 	struct acpi_ec *ec;
916 	int ret = 0;
917 
918 	if (!device)
919 		return -EINVAL;
920 
921 	ec = acpi_driver_data(device);
922 
923 	if (!ec)
924 		return -EINVAL;
925 
926 	ret = ec_install_handlers(ec);
927 
928 	/* EC is fully operational, allow queries */
929 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
930 	return ret;
931 }
932 
933 static int acpi_ec_stop(struct acpi_device *device, int type)
934 {
935 	struct acpi_ec *ec;
936 	if (!device)
937 		return -EINVAL;
938 	ec = acpi_driver_data(device);
939 	if (!ec)
940 		return -EINVAL;
941 	ec_remove_handlers(ec);
942 
943 	return 0;
944 }
945 
946 int __init acpi_boot_ec_enable(void)
947 {
948 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
949 		return 0;
950 	if (!ec_install_handlers(boot_ec)) {
951 		first_ec = boot_ec;
952 		return 0;
953 	}
954 	return -EFAULT;
955 }
956 
957 static const struct acpi_device_id ec_device_ids[] = {
958 	{"PNP0C09", 0},
959 	{"", 0},
960 };
961 
962 int __init acpi_ec_ecdt_probe(void)
963 {
964 	acpi_status status;
965 	struct acpi_ec *saved_ec = NULL;
966 	struct acpi_table_ecdt *ecdt_ptr;
967 
968 	boot_ec = make_acpi_ec();
969 	if (!boot_ec)
970 		return -ENOMEM;
971 	/*
972 	 * Generate a boot ec context
973 	 */
974 	if (dmi_name_in_vendors("Micro-Star") ||
975 	    dmi_name_in_vendors("Notebook")) {
976 		pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
977 		EC_FLAGS_MSI = 1;
978 	}
979 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
980 				(struct acpi_table_header **)&ecdt_ptr);
981 	if (ACPI_SUCCESS(status)) {
982 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
983 		boot_ec->command_addr = ecdt_ptr->control.address;
984 		boot_ec->data_addr = ecdt_ptr->data.address;
985 		boot_ec->gpe = ecdt_ptr->gpe;
986 		boot_ec->handle = ACPI_ROOT_OBJECT;
987 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
988 		/* Don't trust ECDT, which comes from ASUSTek */
989 		if (!dmi_name_in_vendors("ASUS"))
990 			goto install;
991 		saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
992 		if (!saved_ec)
993 			return -ENOMEM;
994 		memcpy(saved_ec, boot_ec, sizeof(*saved_ec));
995 	/* fall through */
996 	}
997 	/* This workaround is needed only on some broken machines,
998 	 * which require early EC, but fail to provide ECDT */
999 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1000 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1001 					boot_ec, NULL);
1002 	/* Check that acpi_get_devices actually find something */
1003 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1004 		goto error;
1005 	if (saved_ec) {
1006 		/* try to find good ECDT from ASUSTek */
1007 		if (saved_ec->command_addr != boot_ec->command_addr ||
1008 		    saved_ec->data_addr != boot_ec->data_addr ||
1009 		    saved_ec->gpe != boot_ec->gpe ||
1010 		    saved_ec->handle != boot_ec->handle)
1011 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1012 			"ECDT tables, which are very hard to workaround. "
1013 			"Trying to use DSDT EC info instead. Please send "
1014 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1015 		kfree(saved_ec);
1016 		saved_ec = NULL;
1017 	} else {
1018 		/* We really need to limit this workaround, the only ASUS,
1019 		* which needs it, has fake EC._INI method, so use it as flag.
1020 		* Keep boot_ec struct as it will be needed soon.
1021 		*/
1022 		acpi_handle dummy;
1023 		if (!dmi_name_in_vendors("ASUS") ||
1024 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1025 							&dummy)))
1026 			return -ENODEV;
1027 	}
1028 install:
1029 	if (!ec_install_handlers(boot_ec)) {
1030 		first_ec = boot_ec;
1031 		return 0;
1032 	}
1033 error:
1034 	kfree(boot_ec);
1035 	boot_ec = NULL;
1036 	return -ENODEV;
1037 }
1038 
1039 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1040 {
1041 	struct acpi_ec *ec = acpi_driver_data(device);
1042 	/* Stop using GPE */
1043 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1044 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1045 	acpi_disable_gpe(NULL, ec->gpe);
1046 	return 0;
1047 }
1048 
1049 static int acpi_ec_resume(struct acpi_device *device)
1050 {
1051 	struct acpi_ec *ec = acpi_driver_data(device);
1052 	/* Enable use of GPE back */
1053 	clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1054 	acpi_enable_gpe(NULL, ec->gpe);
1055 	return 0;
1056 }
1057 
1058 static struct acpi_driver acpi_ec_driver = {
1059 	.name = "ec",
1060 	.class = ACPI_EC_CLASS,
1061 	.ids = ec_device_ids,
1062 	.ops = {
1063 		.add = acpi_ec_add,
1064 		.remove = acpi_ec_remove,
1065 		.start = acpi_ec_start,
1066 		.stop = acpi_ec_stop,
1067 		.suspend = acpi_ec_suspend,
1068 		.resume = acpi_ec_resume,
1069 		},
1070 };
1071 
1072 static int __init acpi_ec_init(void)
1073 {
1074 	int result = 0;
1075 
1076 	if (acpi_disabled)
1077 		return 0;
1078 
1079 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1080 	if (!acpi_ec_dir)
1081 		return -ENODEV;
1082 
1083 	/* Now register the driver for the EC */
1084 	result = acpi_bus_register_driver(&acpi_ec_driver);
1085 	if (result < 0) {
1086 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1087 		return -ENODEV;
1088 	}
1089 
1090 	return result;
1091 }
1092 
1093 subsys_initcall(acpi_ec_init);
1094 
1095 /* EC driver currently not unloadable */
1096 #if 0
1097 static void __exit acpi_ec_exit(void)
1098 {
1099 
1100 	acpi_bus_unregister_driver(&acpi_ec_driver);
1101 
1102 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1103 
1104 	return;
1105 }
1106 #endif	/* 0 */
1107