xref: /openbmc/linux/drivers/acpi/ec.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
87 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
88 module_param(ec_delay, uint, 0644);
89 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
90 
91 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
92 /* External interfaces use first EC only, so remember */
93 typedef int (*acpi_ec_query_func) (void *data);
94 
95 struct acpi_ec_query_handler {
96 	struct list_head node;
97 	acpi_ec_query_func func;
98 	acpi_handle handle;
99 	void *data;
100 	u8 query_bit;
101 };
102 
103 struct transaction {
104 	const u8 *wdata;
105 	u8 *rdata;
106 	unsigned short irq_count;
107 	u8 command;
108 	u8 wi;
109 	u8 ri;
110 	u8 wlen;
111 	u8 rlen;
112 	bool done;
113 };
114 
115 struct acpi_ec *boot_ec, *first_ec;
116 EXPORT_SYMBOL(first_ec);
117 
118 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
119 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
120 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
121 
122 /* --------------------------------------------------------------------------
123                              Transaction Management
124    -------------------------------------------------------------------------- */
125 
126 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
127 {
128 	u8 x = inb(ec->command_addr);
129 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
130 	return x;
131 }
132 
133 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
134 {
135 	u8 x = inb(ec->data_addr);
136 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
137 	return x;
138 }
139 
140 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
141 {
142 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
143 	outb(command, ec->command_addr);
144 }
145 
146 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
147 {
148 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
149 	outb(data, ec->data_addr);
150 }
151 
152 static int ec_transaction_done(struct acpi_ec *ec)
153 {
154 	unsigned long flags;
155 	int ret = 0;
156 	spin_lock_irqsave(&ec->curr_lock, flags);
157 	if (!ec->curr || ec->curr->done)
158 		ret = 1;
159 	spin_unlock_irqrestore(&ec->curr_lock, flags);
160 	return ret;
161 }
162 
163 static void start_transaction(struct acpi_ec *ec)
164 {
165 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
166 	ec->curr->done = false;
167 	acpi_ec_write_cmd(ec, ec->curr->command);
168 }
169 
170 static void advance_transaction(struct acpi_ec *ec, u8 status)
171 {
172 	unsigned long flags;
173 	spin_lock_irqsave(&ec->curr_lock, flags);
174 	if (!ec->curr)
175 		goto unlock;
176 	if (ec->curr->wlen > ec->curr->wi) {
177 		if ((status & ACPI_EC_FLAG_IBF) == 0)
178 			acpi_ec_write_data(ec,
179 				ec->curr->wdata[ec->curr->wi++]);
180 		else
181 			goto err;
182 	} else if (ec->curr->rlen > ec->curr->ri) {
183 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
184 			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
185 			if (ec->curr->rlen == ec->curr->ri)
186 				ec->curr->done = true;
187 		} else
188 			goto err;
189 	} else if (ec->curr->wlen == ec->curr->wi &&
190 		   (status & ACPI_EC_FLAG_IBF) == 0)
191 		ec->curr->done = true;
192 	goto unlock;
193 err:
194 	/* false interrupt, state didn't change */
195 	if (in_interrupt())
196 		++ec->curr->irq_count;
197 unlock:
198 	spin_unlock_irqrestore(&ec->curr_lock, flags);
199 }
200 
201 static int acpi_ec_sync_query(struct acpi_ec *ec);
202 
203 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
204 {
205 	if (state & ACPI_EC_FLAG_SCI) {
206 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
207 			return acpi_ec_sync_query(ec);
208 	}
209 	return 0;
210 }
211 
212 static int ec_poll(struct acpi_ec *ec)
213 {
214 	unsigned long flags;
215 	int repeat = 2; /* number of command restarts */
216 	while (repeat--) {
217 		unsigned long delay = jiffies +
218 			msecs_to_jiffies(ec_delay);
219 		do {
220 			/* don't sleep with disabled interrupts */
221 			if (EC_FLAGS_MSI || irqs_disabled()) {
222 				udelay(ACPI_EC_MSI_UDELAY);
223 				if (ec_transaction_done(ec))
224 					return 0;
225 			} else {
226 				if (wait_event_timeout(ec->wait,
227 						ec_transaction_done(ec),
228 						msecs_to_jiffies(1)))
229 					return 0;
230 			}
231 			advance_transaction(ec, acpi_ec_read_status(ec));
232 		} while (time_before(jiffies, delay));
233 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
234 			break;
235 		pr_debug(PREFIX "controller reset, restart transaction\n");
236 		spin_lock_irqsave(&ec->curr_lock, flags);
237 		start_transaction(ec);
238 		spin_unlock_irqrestore(&ec->curr_lock, flags);
239 	}
240 	return -ETIME;
241 }
242 
243 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
244 					struct transaction *t)
245 {
246 	unsigned long tmp;
247 	int ret = 0;
248 	if (EC_FLAGS_MSI)
249 		udelay(ACPI_EC_MSI_UDELAY);
250 	/* start transaction */
251 	spin_lock_irqsave(&ec->curr_lock, tmp);
252 	/* following two actions should be kept atomic */
253 	ec->curr = t;
254 	start_transaction(ec);
255 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
256 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
257 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
258 	ret = ec_poll(ec);
259 	spin_lock_irqsave(&ec->curr_lock, tmp);
260 	ec->curr = NULL;
261 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
262 	return ret;
263 }
264 
265 static int ec_check_ibf0(struct acpi_ec *ec)
266 {
267 	u8 status = acpi_ec_read_status(ec);
268 	return (status & ACPI_EC_FLAG_IBF) == 0;
269 }
270 
271 static int ec_wait_ibf0(struct acpi_ec *ec)
272 {
273 	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
274 	/* interrupt wait manually if GPE mode is not active */
275 	while (time_before(jiffies, delay))
276 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
277 					msecs_to_jiffies(1)))
278 			return 0;
279 	return -ETIME;
280 }
281 
282 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
283 {
284 	int status;
285 	u32 glk;
286 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
287 		return -EINVAL;
288 	if (t->rdata)
289 		memset(t->rdata, 0, t->rlen);
290 	mutex_lock(&ec->lock);
291 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
292 		status = -EINVAL;
293 		goto unlock;
294 	}
295 	if (ec->global_lock) {
296 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
297 		if (ACPI_FAILURE(status)) {
298 			status = -ENODEV;
299 			goto unlock;
300 		}
301 	}
302 	if (ec_wait_ibf0(ec)) {
303 		pr_err(PREFIX "input buffer is not empty, "
304 				"aborting transaction\n");
305 		status = -ETIME;
306 		goto end;
307 	}
308 	pr_debug(PREFIX "transaction start\n");
309 	/* disable GPE during transaction if storm is detected */
310 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
311 		/* It has to be disabled, so that it doesn't trigger. */
312 		acpi_disable_gpe(NULL, ec->gpe);
313 	}
314 
315 	status = acpi_ec_transaction_unlocked(ec, t);
316 
317 	/* check if we received SCI during transaction */
318 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
319 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
320 		msleep(1);
321 		/* It is safe to enable the GPE outside of the transaction. */
322 		acpi_enable_gpe(NULL, ec->gpe);
323 	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
324 		pr_info(PREFIX "GPE storm detected, "
325 			"transactions will use polling mode\n");
326 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
327 	}
328 	pr_debug(PREFIX "transaction end\n");
329 end:
330 	if (ec->global_lock)
331 		acpi_release_global_lock(glk);
332 unlock:
333 	mutex_unlock(&ec->lock);
334 	return status;
335 }
336 
337 static int acpi_ec_burst_enable(struct acpi_ec *ec)
338 {
339 	u8 d;
340 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
341 				.wdata = NULL, .rdata = &d,
342 				.wlen = 0, .rlen = 1};
343 
344 	return acpi_ec_transaction(ec, &t);
345 }
346 
347 static int acpi_ec_burst_disable(struct acpi_ec *ec)
348 {
349 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
350 				.wdata = NULL, .rdata = NULL,
351 				.wlen = 0, .rlen = 0};
352 
353 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
354 				acpi_ec_transaction(ec, &t) : 0;
355 }
356 
357 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
358 {
359 	int result;
360 	u8 d;
361 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
362 				.wdata = &address, .rdata = &d,
363 				.wlen = 1, .rlen = 1};
364 
365 	result = acpi_ec_transaction(ec, &t);
366 	*data = d;
367 	return result;
368 }
369 
370 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
371 {
372 	u8 wdata[2] = { address, data };
373 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
374 				.wdata = wdata, .rdata = NULL,
375 				.wlen = 2, .rlen = 0};
376 
377 	return acpi_ec_transaction(ec, &t);
378 }
379 
380 /*
381  * Externally callable EC access functions. For now, assume 1 EC only
382  */
383 int ec_burst_enable(void)
384 {
385 	if (!first_ec)
386 		return -ENODEV;
387 	return acpi_ec_burst_enable(first_ec);
388 }
389 
390 EXPORT_SYMBOL(ec_burst_enable);
391 
392 int ec_burst_disable(void)
393 {
394 	if (!first_ec)
395 		return -ENODEV;
396 	return acpi_ec_burst_disable(first_ec);
397 }
398 
399 EXPORT_SYMBOL(ec_burst_disable);
400 
401 int ec_read(u8 addr, u8 * val)
402 {
403 	int err;
404 	u8 temp_data;
405 
406 	if (!first_ec)
407 		return -ENODEV;
408 
409 	err = acpi_ec_read(first_ec, addr, &temp_data);
410 
411 	if (!err) {
412 		*val = temp_data;
413 		return 0;
414 	} else
415 		return err;
416 }
417 
418 EXPORT_SYMBOL(ec_read);
419 
420 int ec_write(u8 addr, u8 val)
421 {
422 	int err;
423 
424 	if (!first_ec)
425 		return -ENODEV;
426 
427 	err = acpi_ec_write(first_ec, addr, val);
428 
429 	return err;
430 }
431 
432 EXPORT_SYMBOL(ec_write);
433 
434 int ec_transaction(u8 command,
435 		   const u8 * wdata, unsigned wdata_len,
436 		   u8 * rdata, unsigned rdata_len,
437 		   int force_poll)
438 {
439 	struct transaction t = {.command = command,
440 				.wdata = wdata, .rdata = rdata,
441 				.wlen = wdata_len, .rlen = rdata_len};
442 	if (!first_ec)
443 		return -ENODEV;
444 
445 	return acpi_ec_transaction(first_ec, &t);
446 }
447 
448 EXPORT_SYMBOL(ec_transaction);
449 
450 void acpi_ec_block_transactions(void)
451 {
452 	struct acpi_ec *ec = first_ec;
453 
454 	if (!ec)
455 		return;
456 
457 	mutex_lock(&ec->lock);
458 	/* Prevent transactions from being carried out */
459 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
460 	mutex_unlock(&ec->lock);
461 }
462 
463 void acpi_ec_unblock_transactions(void)
464 {
465 	struct acpi_ec *ec = first_ec;
466 
467 	if (!ec)
468 		return;
469 
470 	mutex_lock(&ec->lock);
471 	/* Allow transactions to be carried out again */
472 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
473 	mutex_unlock(&ec->lock);
474 }
475 
476 void acpi_ec_unblock_transactions_early(void)
477 {
478 	/*
479 	 * Allow transactions to happen again (this function is called from
480 	 * atomic context during wakeup, so we don't need to acquire the mutex).
481 	 */
482 	if (first_ec)
483 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
484 }
485 
486 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
487 {
488 	int result;
489 	u8 d;
490 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
491 				.wdata = NULL, .rdata = &d,
492 				.wlen = 0, .rlen = 1};
493 	if (!ec || !data)
494 		return -EINVAL;
495 	/*
496 	 * Query the EC to find out which _Qxx method we need to evaluate.
497 	 * Note that successful completion of the query causes the ACPI_EC_SCI
498 	 * bit to be cleared (and thus clearing the interrupt source).
499 	 */
500 	result = acpi_ec_transaction_unlocked(ec, &t);
501 	if (result)
502 		return result;
503 	if (!d)
504 		return -ENODATA;
505 	*data = d;
506 	return 0;
507 }
508 
509 /* --------------------------------------------------------------------------
510                                 Event Management
511    -------------------------------------------------------------------------- */
512 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
513 			      acpi_handle handle, acpi_ec_query_func func,
514 			      void *data)
515 {
516 	struct acpi_ec_query_handler *handler =
517 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
518 	if (!handler)
519 		return -ENOMEM;
520 
521 	handler->query_bit = query_bit;
522 	handler->handle = handle;
523 	handler->func = func;
524 	handler->data = data;
525 	mutex_lock(&ec->lock);
526 	list_add(&handler->node, &ec->list);
527 	mutex_unlock(&ec->lock);
528 	return 0;
529 }
530 
531 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
532 
533 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
534 {
535 	struct acpi_ec_query_handler *handler, *tmp;
536 	mutex_lock(&ec->lock);
537 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
538 		if (query_bit == handler->query_bit) {
539 			list_del(&handler->node);
540 			kfree(handler);
541 		}
542 	}
543 	mutex_unlock(&ec->lock);
544 }
545 
546 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
547 
548 static void acpi_ec_run(void *cxt)
549 {
550 	struct acpi_ec_query_handler *handler = cxt;
551 	if (!handler)
552 		return;
553 	pr_debug(PREFIX "start query execution\n");
554 	if (handler->func)
555 		handler->func(handler->data);
556 	else if (handler->handle)
557 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
558 	pr_debug(PREFIX "stop query execution\n");
559 	kfree(handler);
560 }
561 
562 static int acpi_ec_sync_query(struct acpi_ec *ec)
563 {
564 	u8 value = 0;
565 	int status;
566 	struct acpi_ec_query_handler *handler, *copy;
567 	if ((status = acpi_ec_query_unlocked(ec, &value)))
568 		return status;
569 	list_for_each_entry(handler, &ec->list, node) {
570 		if (value == handler->query_bit) {
571 			/* have custom handler for this bit */
572 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
573 			if (!copy)
574 				return -ENOMEM;
575 			memcpy(copy, handler, sizeof(*copy));
576 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
577 			return acpi_os_execute((copy->func) ?
578 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
579 				acpi_ec_run, copy);
580 		}
581 	}
582 	return 0;
583 }
584 
585 static void acpi_ec_gpe_query(void *ec_cxt)
586 {
587 	struct acpi_ec *ec = ec_cxt;
588 	if (!ec)
589 		return;
590 	mutex_lock(&ec->lock);
591 	acpi_ec_sync_query(ec);
592 	mutex_unlock(&ec->lock);
593 }
594 
595 static void acpi_ec_gpe_query(void *ec_cxt);
596 
597 static int ec_check_sci(struct acpi_ec *ec, u8 state)
598 {
599 	if (state & ACPI_EC_FLAG_SCI) {
600 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
601 			pr_debug(PREFIX "push gpe query to the queue\n");
602 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
603 				acpi_ec_gpe_query, ec);
604 		}
605 	}
606 	return 0;
607 }
608 
609 static u32 acpi_ec_gpe_handler(void *data)
610 {
611 	struct acpi_ec *ec = data;
612 
613 	pr_debug(PREFIX "~~~> interrupt\n");
614 
615 	advance_transaction(ec, acpi_ec_read_status(ec));
616 	if (ec_transaction_done(ec) &&
617 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
618 		wake_up(&ec->wait);
619 		ec_check_sci(ec, acpi_ec_read_status(ec));
620 	}
621 	return ACPI_INTERRUPT_HANDLED;
622 }
623 
624 /* --------------------------------------------------------------------------
625                              Address Space Management
626    -------------------------------------------------------------------------- */
627 
628 static acpi_status
629 acpi_ec_space_handler(u32 function, acpi_physical_address address,
630 		      u32 bits, u64 *value64,
631 		      void *handler_context, void *region_context)
632 {
633 	struct acpi_ec *ec = handler_context;
634 	int result = 0, i, bytes = bits / 8;
635 	u8 *value = (u8 *)value64;
636 
637 	if ((address > 0xFF) || !value || !handler_context)
638 		return AE_BAD_PARAMETER;
639 
640 	if (function != ACPI_READ && function != ACPI_WRITE)
641 		return AE_BAD_PARAMETER;
642 
643 	if (EC_FLAGS_MSI || bits > 8)
644 		acpi_ec_burst_enable(ec);
645 
646 	for (i = 0; i < bytes; ++i, ++address, ++value)
647 		result = (function == ACPI_READ) ?
648 			acpi_ec_read(ec, address, value) :
649 			acpi_ec_write(ec, address, *value);
650 
651 	if (EC_FLAGS_MSI || bits > 8)
652 		acpi_ec_burst_disable(ec);
653 
654 	switch (result) {
655 	case -EINVAL:
656 		return AE_BAD_PARAMETER;
657 		break;
658 	case -ENODEV:
659 		return AE_NOT_FOUND;
660 		break;
661 	case -ETIME:
662 		return AE_TIME;
663 		break;
664 	default:
665 		return AE_OK;
666 	}
667 }
668 
669 /* --------------------------------------------------------------------------
670                                Driver Interface
671    -------------------------------------------------------------------------- */
672 static acpi_status
673 ec_parse_io_ports(struct acpi_resource *resource, void *context);
674 
675 static struct acpi_ec *make_acpi_ec(void)
676 {
677 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
678 	if (!ec)
679 		return NULL;
680 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
681 	mutex_init(&ec->lock);
682 	init_waitqueue_head(&ec->wait);
683 	INIT_LIST_HEAD(&ec->list);
684 	spin_lock_init(&ec->curr_lock);
685 	return ec;
686 }
687 
688 static acpi_status
689 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
690 			       void *context, void **return_value)
691 {
692 	char node_name[5];
693 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
694 	struct acpi_ec *ec = context;
695 	int value = 0;
696 	acpi_status status;
697 
698 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
699 
700 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
701 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
702 	}
703 	return AE_OK;
704 }
705 
706 static acpi_status
707 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
708 {
709 	acpi_status status;
710 	unsigned long long tmp = 0;
711 
712 	struct acpi_ec *ec = context;
713 
714 	/* clear addr values, ec_parse_io_ports depend on it */
715 	ec->command_addr = ec->data_addr = 0;
716 
717 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
718 				     ec_parse_io_ports, ec);
719 	if (ACPI_FAILURE(status))
720 		return status;
721 
722 	/* Get GPE bit assignment (EC events). */
723 	/* TODO: Add support for _GPE returning a package */
724 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
725 	if (ACPI_FAILURE(status))
726 		return status;
727 	ec->gpe = tmp;
728 	/* Use the global lock for all EC transactions? */
729 	tmp = 0;
730 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
731 	ec->global_lock = tmp;
732 	ec->handle = handle;
733 	return AE_CTRL_TERMINATE;
734 }
735 
736 static int ec_install_handlers(struct acpi_ec *ec)
737 {
738 	acpi_status status;
739 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
740 		return 0;
741 	status = acpi_install_gpe_handler(NULL, ec->gpe,
742 				  ACPI_GPE_EDGE_TRIGGERED,
743 				  &acpi_ec_gpe_handler, ec);
744 	if (ACPI_FAILURE(status))
745 		return -ENODEV;
746 
747 	acpi_enable_gpe(NULL, ec->gpe);
748 	status = acpi_install_address_space_handler(ec->handle,
749 						    ACPI_ADR_SPACE_EC,
750 						    &acpi_ec_space_handler,
751 						    NULL, ec);
752 	if (ACPI_FAILURE(status)) {
753 		if (status == AE_NOT_FOUND) {
754 			/*
755 			 * Maybe OS fails in evaluating the _REG object.
756 			 * The AE_NOT_FOUND error will be ignored and OS
757 			 * continue to initialize EC.
758 			 */
759 			printk(KERN_ERR "Fail in evaluating the _REG object"
760 				" of EC device. Broken bios is suspected.\n");
761 		} else {
762 			acpi_remove_gpe_handler(NULL, ec->gpe,
763 				&acpi_ec_gpe_handler);
764 			acpi_disable_gpe(NULL, ec->gpe);
765 			return -ENODEV;
766 		}
767 	}
768 
769 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
770 	return 0;
771 }
772 
773 static void ec_remove_handlers(struct acpi_ec *ec)
774 {
775 	acpi_disable_gpe(NULL, ec->gpe);
776 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
777 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
778 		pr_err(PREFIX "failed to remove space handler\n");
779 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
780 				&acpi_ec_gpe_handler)))
781 		pr_err(PREFIX "failed to remove gpe handler\n");
782 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
783 }
784 
785 static int acpi_ec_add(struct acpi_device *device)
786 {
787 	struct acpi_ec *ec = NULL;
788 	int ret;
789 
790 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
791 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
792 
793 	/* Check for boot EC */
794 	if (boot_ec &&
795 	    (boot_ec->handle == device->handle ||
796 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
797 		ec = boot_ec;
798 		boot_ec = NULL;
799 	} else {
800 		ec = make_acpi_ec();
801 		if (!ec)
802 			return -ENOMEM;
803 	}
804 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
805 		AE_CTRL_TERMINATE) {
806 			kfree(ec);
807 			return -EINVAL;
808 	}
809 
810 	ec->handle = device->handle;
811 
812 	/* Find and register all query methods */
813 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
814 			    acpi_ec_register_query_methods, NULL, ec, NULL);
815 
816 	if (!first_ec)
817 		first_ec = ec;
818 	device->driver_data = ec;
819 
820 	WARN(!request_region(ec->data_addr, 1, "EC data"),
821 	     "Could not request EC data io port 0x%lx", ec->data_addr);
822 	WARN(!request_region(ec->command_addr, 1, "EC cmd"),
823 	     "Could not request EC cmd io port 0x%lx", ec->command_addr);
824 
825 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
826 			  ec->gpe, ec->command_addr, ec->data_addr);
827 
828 	ret = ec_install_handlers(ec);
829 
830 	/* EC is fully operational, allow queries */
831 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
832 	return ret;
833 }
834 
835 static int acpi_ec_remove(struct acpi_device *device, int type)
836 {
837 	struct acpi_ec *ec;
838 	struct acpi_ec_query_handler *handler, *tmp;
839 
840 	if (!device)
841 		return -EINVAL;
842 
843 	ec = acpi_driver_data(device);
844 	ec_remove_handlers(ec);
845 	mutex_lock(&ec->lock);
846 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
847 		list_del(&handler->node);
848 		kfree(handler);
849 	}
850 	mutex_unlock(&ec->lock);
851 	release_region(ec->data_addr, 1);
852 	release_region(ec->command_addr, 1);
853 	device->driver_data = NULL;
854 	if (ec == first_ec)
855 		first_ec = NULL;
856 	kfree(ec);
857 	return 0;
858 }
859 
860 static acpi_status
861 ec_parse_io_ports(struct acpi_resource *resource, void *context)
862 {
863 	struct acpi_ec *ec = context;
864 
865 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
866 		return AE_OK;
867 
868 	/*
869 	 * The first address region returned is the data port, and
870 	 * the second address region returned is the status/command
871 	 * port.
872 	 */
873 	if (ec->data_addr == 0)
874 		ec->data_addr = resource->data.io.minimum;
875 	else if (ec->command_addr == 0)
876 		ec->command_addr = resource->data.io.minimum;
877 	else
878 		return AE_CTRL_TERMINATE;
879 
880 	return AE_OK;
881 }
882 
883 int __init acpi_boot_ec_enable(void)
884 {
885 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
886 		return 0;
887 	if (!ec_install_handlers(boot_ec)) {
888 		first_ec = boot_ec;
889 		return 0;
890 	}
891 	return -EFAULT;
892 }
893 
894 static const struct acpi_device_id ec_device_ids[] = {
895 	{"PNP0C09", 0},
896 	{"", 0},
897 };
898 
899 /* Some BIOS do not survive early DSDT scan, skip it */
900 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
901 {
902 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
903 	return 0;
904 }
905 
906 /* ASUStek often supplies us with broken ECDT, validate it */
907 static int ec_validate_ecdt(const struct dmi_system_id *id)
908 {
909 	EC_FLAGS_VALIDATE_ECDT = 1;
910 	return 0;
911 }
912 
913 /* MSI EC needs special treatment, enable it */
914 static int ec_flag_msi(const struct dmi_system_id *id)
915 {
916 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
917 	EC_FLAGS_MSI = 1;
918 	EC_FLAGS_VALIDATE_ECDT = 1;
919 	return 0;
920 }
921 
922 static struct dmi_system_id __initdata ec_dmi_table[] = {
923 	{
924 	ec_skip_dsdt_scan, "Compal JFL92", {
925 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
926 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
927 	{
928 	ec_flag_msi, "MSI hardware", {
929 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
930 	{
931 	ec_flag_msi, "MSI hardware", {
932 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
933 	{
934 	ec_flag_msi, "MSI hardware", {
935 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
936 	{
937 	ec_flag_msi, "MSI hardware", {
938 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
939 	{
940 	ec_validate_ecdt, "ASUS hardware", {
941 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
942 	{},
943 };
944 
945 
946 int __init acpi_ec_ecdt_probe(void)
947 {
948 	acpi_status status;
949 	struct acpi_ec *saved_ec = NULL;
950 	struct acpi_table_ecdt *ecdt_ptr;
951 
952 	boot_ec = make_acpi_ec();
953 	if (!boot_ec)
954 		return -ENOMEM;
955 	/*
956 	 * Generate a boot ec context
957 	 */
958 	dmi_check_system(ec_dmi_table);
959 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
960 				(struct acpi_table_header **)&ecdt_ptr);
961 	if (ACPI_SUCCESS(status)) {
962 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
963 		boot_ec->command_addr = ecdt_ptr->control.address;
964 		boot_ec->data_addr = ecdt_ptr->data.address;
965 		boot_ec->gpe = ecdt_ptr->gpe;
966 		boot_ec->handle = ACPI_ROOT_OBJECT;
967 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
968 		/* Don't trust ECDT, which comes from ASUSTek */
969 		if (!EC_FLAGS_VALIDATE_ECDT)
970 			goto install;
971 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
972 		if (!saved_ec)
973 			return -ENOMEM;
974 	/* fall through */
975 	}
976 
977 	if (EC_FLAGS_SKIP_DSDT_SCAN)
978 		return -ENODEV;
979 
980 	/* This workaround is needed only on some broken machines,
981 	 * which require early EC, but fail to provide ECDT */
982 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
983 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
984 					boot_ec, NULL);
985 	/* Check that acpi_get_devices actually find something */
986 	if (ACPI_FAILURE(status) || !boot_ec->handle)
987 		goto error;
988 	if (saved_ec) {
989 		/* try to find good ECDT from ASUSTek */
990 		if (saved_ec->command_addr != boot_ec->command_addr ||
991 		    saved_ec->data_addr != boot_ec->data_addr ||
992 		    saved_ec->gpe != boot_ec->gpe ||
993 		    saved_ec->handle != boot_ec->handle)
994 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
995 			"ECDT tables, which are very hard to workaround. "
996 			"Trying to use DSDT EC info instead. Please send "
997 			"output of acpidump to linux-acpi@vger.kernel.org\n");
998 		kfree(saved_ec);
999 		saved_ec = NULL;
1000 	} else {
1001 		/* We really need to limit this workaround, the only ASUS,
1002 		* which needs it, has fake EC._INI method, so use it as flag.
1003 		* Keep boot_ec struct as it will be needed soon.
1004 		*/
1005 		acpi_handle dummy;
1006 		if (!dmi_name_in_vendors("ASUS") ||
1007 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1008 							&dummy)))
1009 			return -ENODEV;
1010 	}
1011 install:
1012 	if (!ec_install_handlers(boot_ec)) {
1013 		first_ec = boot_ec;
1014 		return 0;
1015 	}
1016 error:
1017 	kfree(boot_ec);
1018 	boot_ec = NULL;
1019 	return -ENODEV;
1020 }
1021 
1022 static struct acpi_driver acpi_ec_driver = {
1023 	.name = "ec",
1024 	.class = ACPI_EC_CLASS,
1025 	.ids = ec_device_ids,
1026 	.ops = {
1027 		.add = acpi_ec_add,
1028 		.remove = acpi_ec_remove,
1029 		},
1030 };
1031 
1032 int __init acpi_ec_init(void)
1033 {
1034 	int result = 0;
1035 
1036 	/* Now register the driver for the EC */
1037 	result = acpi_bus_register_driver(&acpi_ec_driver);
1038 	if (result < 0)
1039 		return -ENODEV;
1040 
1041 	return result;
1042 }
1043 
1044 /* EC driver currently not unloadable */
1045 #if 0
1046 static void __exit acpi_ec_exit(void)
1047 {
1048 
1049 	acpi_bus_unregister_driver(&acpi_ec_driver);
1050 	return;
1051 }
1052 #endif	/* 0 */
1053