xref: /openbmc/linux/drivers/acpi/ec.c (revision 54cbac81)
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_MSI_UDELAY	550	/* Wait 550us for MSI EC */
73 
74 enum {
75 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
76 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
77 	EC_FLAGS_HANDLERS_INSTALLED,	/* Handlers for GPE and
78 					 * OpReg are installed */
79 	EC_FLAGS_BLOCKED,		/* Transactions are blocked */
80 };
81 
82 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
83 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
84 module_param(ec_delay, uint, 0644);
85 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
86 
87 /*
88  * If the number of false interrupts per one transaction exceeds
89  * this threshold, will think there is a GPE storm happened and
90  * will disable the GPE for normal transaction.
91  */
92 static unsigned int ec_storm_threshold  __read_mostly = 8;
93 module_param(ec_storm_threshold, uint, 0644);
94 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
95 
96 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
97 /* External interfaces use first EC only, so remember */
98 typedef int (*acpi_ec_query_func) (void *data);
99 
100 struct acpi_ec_query_handler {
101 	struct list_head node;
102 	acpi_ec_query_func func;
103 	acpi_handle handle;
104 	void *data;
105 	u8 query_bit;
106 };
107 
108 struct transaction {
109 	const u8 *wdata;
110 	u8 *rdata;
111 	unsigned short irq_count;
112 	u8 command;
113 	u8 wi;
114 	u8 ri;
115 	u8 wlen;
116 	u8 rlen;
117 	bool done;
118 };
119 
120 struct acpi_ec *boot_ec, *first_ec;
121 EXPORT_SYMBOL(first_ec);
122 
123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
124 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
125 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
126 
127 /* --------------------------------------------------------------------------
128                              Transaction Management
129    -------------------------------------------------------------------------- */
130 
131 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
132 {
133 	u8 x = inb(ec->command_addr);
134 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
135 	return x;
136 }
137 
138 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
139 {
140 	u8 x = inb(ec->data_addr);
141 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
142 	return x;
143 }
144 
145 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
146 {
147 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
148 	outb(command, ec->command_addr);
149 }
150 
151 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
152 {
153 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
154 	outb(data, ec->data_addr);
155 }
156 
157 static int ec_transaction_done(struct acpi_ec *ec)
158 {
159 	unsigned long flags;
160 	int ret = 0;
161 	spin_lock_irqsave(&ec->lock, flags);
162 	if (!ec->curr || ec->curr->done)
163 		ret = 1;
164 	spin_unlock_irqrestore(&ec->lock, flags);
165 	return ret;
166 }
167 
168 static void start_transaction(struct acpi_ec *ec)
169 {
170 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
171 	ec->curr->done = false;
172 	acpi_ec_write_cmd(ec, ec->curr->command);
173 }
174 
175 static void advance_transaction(struct acpi_ec *ec, u8 status)
176 {
177 	unsigned long flags;
178 	struct transaction *t = ec->curr;
179 
180 	spin_lock_irqsave(&ec->lock, flags);
181 	if (!t)
182 		goto unlock;
183 	if (t->wlen > t->wi) {
184 		if ((status & ACPI_EC_FLAG_IBF) == 0)
185 			acpi_ec_write_data(ec,
186 				t->wdata[t->wi++]);
187 		else
188 			goto err;
189 	} else if (t->rlen > t->ri) {
190 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
191 			t->rdata[t->ri++] = acpi_ec_read_data(ec);
192 			if (t->rlen == t->ri)
193 				t->done = true;
194 		} else
195 			goto err;
196 	} else if (t->wlen == t->wi &&
197 		   (status & ACPI_EC_FLAG_IBF) == 0)
198 		t->done = true;
199 	goto unlock;
200 err:
201 	/*
202 	 * If SCI bit is set, then don't think it's a false IRQ
203 	 * otherwise will take a not handled IRQ as a false one.
204 	 */
205 	if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
206 		++t->irq_count;
207 
208 unlock:
209 	spin_unlock_irqrestore(&ec->lock, flags);
210 }
211 
212 static int acpi_ec_sync_query(struct acpi_ec *ec);
213 
214 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
215 {
216 	if (state & ACPI_EC_FLAG_SCI) {
217 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
218 			return acpi_ec_sync_query(ec);
219 	}
220 	return 0;
221 }
222 
223 static int ec_poll(struct acpi_ec *ec)
224 {
225 	unsigned long flags;
226 	int repeat = 2; /* number of command restarts */
227 	while (repeat--) {
228 		unsigned long delay = jiffies +
229 			msecs_to_jiffies(ec_delay);
230 		do {
231 			/* don't sleep with disabled interrupts */
232 			if (EC_FLAGS_MSI || irqs_disabled()) {
233 				udelay(ACPI_EC_MSI_UDELAY);
234 				if (ec_transaction_done(ec))
235 					return 0;
236 			} else {
237 				if (wait_event_timeout(ec->wait,
238 						ec_transaction_done(ec),
239 						msecs_to_jiffies(1)))
240 					return 0;
241 			}
242 			advance_transaction(ec, acpi_ec_read_status(ec));
243 		} while (time_before(jiffies, delay));
244 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
245 			break;
246 		pr_debug(PREFIX "controller reset, restart transaction\n");
247 		spin_lock_irqsave(&ec->lock, flags);
248 		start_transaction(ec);
249 		spin_unlock_irqrestore(&ec->lock, flags);
250 	}
251 	return -ETIME;
252 }
253 
254 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
255 					struct transaction *t)
256 {
257 	unsigned long tmp;
258 	int ret = 0;
259 	if (EC_FLAGS_MSI)
260 		udelay(ACPI_EC_MSI_UDELAY);
261 	/* start transaction */
262 	spin_lock_irqsave(&ec->lock, tmp);
263 	/* following two actions should be kept atomic */
264 	ec->curr = t;
265 	start_transaction(ec);
266 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
267 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
268 	spin_unlock_irqrestore(&ec->lock, tmp);
269 	ret = ec_poll(ec);
270 	spin_lock_irqsave(&ec->lock, tmp);
271 	ec->curr = NULL;
272 	spin_unlock_irqrestore(&ec->lock, tmp);
273 	return ret;
274 }
275 
276 static int ec_check_ibf0(struct acpi_ec *ec)
277 {
278 	u8 status = acpi_ec_read_status(ec);
279 	return (status & ACPI_EC_FLAG_IBF) == 0;
280 }
281 
282 static int ec_wait_ibf0(struct acpi_ec *ec)
283 {
284 	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
285 	/* interrupt wait manually if GPE mode is not active */
286 	while (time_before(jiffies, delay))
287 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
288 					msecs_to_jiffies(1)))
289 			return 0;
290 	return -ETIME;
291 }
292 
293 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
294 {
295 	int status;
296 	u32 glk;
297 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
298 		return -EINVAL;
299 	if (t->rdata)
300 		memset(t->rdata, 0, t->rlen);
301 	mutex_lock(&ec->mutex);
302 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
303 		status = -EINVAL;
304 		goto unlock;
305 	}
306 	if (ec->global_lock) {
307 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
308 		if (ACPI_FAILURE(status)) {
309 			status = -ENODEV;
310 			goto unlock;
311 		}
312 	}
313 	if (ec_wait_ibf0(ec)) {
314 		pr_err(PREFIX "input buffer is not empty, "
315 				"aborting transaction\n");
316 		status = -ETIME;
317 		goto end;
318 	}
319 	pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
320 			t->command, t->wdata ? t->wdata[0] : 0);
321 	/* disable GPE during transaction if storm is detected */
322 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
323 		/* It has to be disabled, so that it doesn't trigger. */
324 		acpi_disable_gpe(NULL, ec->gpe);
325 	}
326 
327 	status = acpi_ec_transaction_unlocked(ec, t);
328 
329 	/* check if we received SCI during transaction */
330 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
331 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
332 		msleep(1);
333 		/* It is safe to enable the GPE outside of the transaction. */
334 		acpi_enable_gpe(NULL, ec->gpe);
335 	} else if (t->irq_count > ec_storm_threshold) {
336 		pr_info(PREFIX "GPE storm detected(%d GPEs), "
337 			"transactions will use polling mode\n",
338 			t->irq_count);
339 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
340 	}
341 	pr_debug(PREFIX "transaction end\n");
342 end:
343 	if (ec->global_lock)
344 		acpi_release_global_lock(glk);
345 unlock:
346 	mutex_unlock(&ec->mutex);
347 	return status;
348 }
349 
350 static int acpi_ec_burst_enable(struct acpi_ec *ec)
351 {
352 	u8 d;
353 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
354 				.wdata = NULL, .rdata = &d,
355 				.wlen = 0, .rlen = 1};
356 
357 	return acpi_ec_transaction(ec, &t);
358 }
359 
360 static int acpi_ec_burst_disable(struct acpi_ec *ec)
361 {
362 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
363 				.wdata = NULL, .rdata = NULL,
364 				.wlen = 0, .rlen = 0};
365 
366 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
367 				acpi_ec_transaction(ec, &t) : 0;
368 }
369 
370 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
371 {
372 	int result;
373 	u8 d;
374 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
375 				.wdata = &address, .rdata = &d,
376 				.wlen = 1, .rlen = 1};
377 
378 	result = acpi_ec_transaction(ec, &t);
379 	*data = d;
380 	return result;
381 }
382 
383 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
384 {
385 	u8 wdata[2] = { address, data };
386 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
387 				.wdata = wdata, .rdata = NULL,
388 				.wlen = 2, .rlen = 0};
389 
390 	return acpi_ec_transaction(ec, &t);
391 }
392 
393 /*
394  * Externally callable EC access functions. For now, assume 1 EC only
395  */
396 int ec_burst_enable(void)
397 {
398 	if (!first_ec)
399 		return -ENODEV;
400 	return acpi_ec_burst_enable(first_ec);
401 }
402 
403 EXPORT_SYMBOL(ec_burst_enable);
404 
405 int ec_burst_disable(void)
406 {
407 	if (!first_ec)
408 		return -ENODEV;
409 	return acpi_ec_burst_disable(first_ec);
410 }
411 
412 EXPORT_SYMBOL(ec_burst_disable);
413 
414 int ec_read(u8 addr, u8 *val)
415 {
416 	int err;
417 	u8 temp_data;
418 
419 	if (!first_ec)
420 		return -ENODEV;
421 
422 	err = acpi_ec_read(first_ec, addr, &temp_data);
423 
424 	if (!err) {
425 		*val = temp_data;
426 		return 0;
427 	} else
428 		return err;
429 }
430 
431 EXPORT_SYMBOL(ec_read);
432 
433 int ec_write(u8 addr, u8 val)
434 {
435 	int err;
436 
437 	if (!first_ec)
438 		return -ENODEV;
439 
440 	err = acpi_ec_write(first_ec, addr, val);
441 
442 	return err;
443 }
444 
445 EXPORT_SYMBOL(ec_write);
446 
447 int ec_transaction(u8 command,
448 		   const u8 * wdata, unsigned wdata_len,
449 		   u8 * rdata, unsigned rdata_len)
450 {
451 	struct transaction t = {.command = command,
452 				.wdata = wdata, .rdata = rdata,
453 				.wlen = wdata_len, .rlen = rdata_len};
454 	if (!first_ec)
455 		return -ENODEV;
456 
457 	return acpi_ec_transaction(first_ec, &t);
458 }
459 
460 EXPORT_SYMBOL(ec_transaction);
461 
462 /* Get the handle to the EC device */
463 acpi_handle ec_get_handle(void)
464 {
465 	if (!first_ec)
466 		return NULL;
467 	return first_ec->handle;
468 }
469 
470 EXPORT_SYMBOL(ec_get_handle);
471 
472 void acpi_ec_block_transactions(void)
473 {
474 	struct acpi_ec *ec = first_ec;
475 
476 	if (!ec)
477 		return;
478 
479 	mutex_lock(&ec->mutex);
480 	/* Prevent transactions from being carried out */
481 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
482 	mutex_unlock(&ec->mutex);
483 }
484 
485 void acpi_ec_unblock_transactions(void)
486 {
487 	struct acpi_ec *ec = first_ec;
488 
489 	if (!ec)
490 		return;
491 
492 	mutex_lock(&ec->mutex);
493 	/* Allow transactions to be carried out again */
494 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
495 	mutex_unlock(&ec->mutex);
496 }
497 
498 void acpi_ec_unblock_transactions_early(void)
499 {
500 	/*
501 	 * Allow transactions to happen again (this function is called from
502 	 * atomic context during wakeup, so we don't need to acquire the mutex).
503 	 */
504 	if (first_ec)
505 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
506 }
507 
508 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
509 {
510 	int result;
511 	u8 d;
512 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
513 				.wdata = NULL, .rdata = &d,
514 				.wlen = 0, .rlen = 1};
515 	if (!ec || !data)
516 		return -EINVAL;
517 	/*
518 	 * Query the EC to find out which _Qxx method we need to evaluate.
519 	 * Note that successful completion of the query causes the ACPI_EC_SCI
520 	 * bit to be cleared (and thus clearing the interrupt source).
521 	 */
522 	result = acpi_ec_transaction_unlocked(ec, &t);
523 	if (result)
524 		return result;
525 	if (!d)
526 		return -ENODATA;
527 	*data = d;
528 	return 0;
529 }
530 
531 /* --------------------------------------------------------------------------
532                                 Event Management
533    -------------------------------------------------------------------------- */
534 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
535 			      acpi_handle handle, acpi_ec_query_func func,
536 			      void *data)
537 {
538 	struct acpi_ec_query_handler *handler =
539 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
540 	if (!handler)
541 		return -ENOMEM;
542 
543 	handler->query_bit = query_bit;
544 	handler->handle = handle;
545 	handler->func = func;
546 	handler->data = data;
547 	mutex_lock(&ec->mutex);
548 	list_add(&handler->node, &ec->list);
549 	mutex_unlock(&ec->mutex);
550 	return 0;
551 }
552 
553 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
554 
555 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
556 {
557 	struct acpi_ec_query_handler *handler, *tmp;
558 	mutex_lock(&ec->mutex);
559 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
560 		if (query_bit == handler->query_bit) {
561 			list_del(&handler->node);
562 			kfree(handler);
563 		}
564 	}
565 	mutex_unlock(&ec->mutex);
566 }
567 
568 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
569 
570 static void acpi_ec_run(void *cxt)
571 {
572 	struct acpi_ec_query_handler *handler = cxt;
573 	if (!handler)
574 		return;
575 	pr_debug(PREFIX "start query execution\n");
576 	if (handler->func)
577 		handler->func(handler->data);
578 	else if (handler->handle)
579 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
580 	pr_debug(PREFIX "stop query execution\n");
581 	kfree(handler);
582 }
583 
584 static int acpi_ec_sync_query(struct acpi_ec *ec)
585 {
586 	u8 value = 0;
587 	int status;
588 	struct acpi_ec_query_handler *handler, *copy;
589 	if ((status = acpi_ec_query_unlocked(ec, &value)))
590 		return status;
591 	list_for_each_entry(handler, &ec->list, node) {
592 		if (value == handler->query_bit) {
593 			/* have custom handler for this bit */
594 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
595 			if (!copy)
596 				return -ENOMEM;
597 			memcpy(copy, handler, sizeof(*copy));
598 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
599 			return acpi_os_execute((copy->func) ?
600 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
601 				acpi_ec_run, copy);
602 		}
603 	}
604 	return 0;
605 }
606 
607 static void acpi_ec_gpe_query(void *ec_cxt)
608 {
609 	struct acpi_ec *ec = ec_cxt;
610 	if (!ec)
611 		return;
612 	mutex_lock(&ec->mutex);
613 	acpi_ec_sync_query(ec);
614 	mutex_unlock(&ec->mutex);
615 }
616 
617 static int ec_check_sci(struct acpi_ec *ec, u8 state)
618 {
619 	if (state & ACPI_EC_FLAG_SCI) {
620 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
621 			pr_debug(PREFIX "push gpe query to the queue\n");
622 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
623 				acpi_ec_gpe_query, ec);
624 		}
625 	}
626 	return 0;
627 }
628 
629 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
630 	u32 gpe_number, void *data)
631 {
632 	struct acpi_ec *ec = data;
633 	u8 status = acpi_ec_read_status(ec);
634 
635 	pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status);
636 
637 	advance_transaction(ec, status);
638 	if (ec_transaction_done(ec) &&
639 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
640 		wake_up(&ec->wait);
641 		ec_check_sci(ec, acpi_ec_read_status(ec));
642 	}
643 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
644 }
645 
646 /* --------------------------------------------------------------------------
647                              Address Space Management
648    -------------------------------------------------------------------------- */
649 
650 static acpi_status
651 acpi_ec_space_handler(u32 function, acpi_physical_address address,
652 		      u32 bits, u64 *value64,
653 		      void *handler_context, void *region_context)
654 {
655 	struct acpi_ec *ec = handler_context;
656 	int result = 0, i, bytes = bits / 8;
657 	u8 *value = (u8 *)value64;
658 
659 	if ((address > 0xFF) || !value || !handler_context)
660 		return AE_BAD_PARAMETER;
661 
662 	if (function != ACPI_READ && function != ACPI_WRITE)
663 		return AE_BAD_PARAMETER;
664 
665 	if (EC_FLAGS_MSI || bits > 8)
666 		acpi_ec_burst_enable(ec);
667 
668 	for (i = 0; i < bytes; ++i, ++address, ++value)
669 		result = (function == ACPI_READ) ?
670 			acpi_ec_read(ec, address, value) :
671 			acpi_ec_write(ec, address, *value);
672 
673 	if (EC_FLAGS_MSI || bits > 8)
674 		acpi_ec_burst_disable(ec);
675 
676 	switch (result) {
677 	case -EINVAL:
678 		return AE_BAD_PARAMETER;
679 		break;
680 	case -ENODEV:
681 		return AE_NOT_FOUND;
682 		break;
683 	case -ETIME:
684 		return AE_TIME;
685 		break;
686 	default:
687 		return AE_OK;
688 	}
689 }
690 
691 /* --------------------------------------------------------------------------
692                                Driver Interface
693    -------------------------------------------------------------------------- */
694 static acpi_status
695 ec_parse_io_ports(struct acpi_resource *resource, void *context);
696 
697 static struct acpi_ec *make_acpi_ec(void)
698 {
699 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
700 	if (!ec)
701 		return NULL;
702 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
703 	mutex_init(&ec->mutex);
704 	init_waitqueue_head(&ec->wait);
705 	INIT_LIST_HEAD(&ec->list);
706 	spin_lock_init(&ec->lock);
707 	return ec;
708 }
709 
710 static acpi_status
711 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
712 			       void *context, void **return_value)
713 {
714 	char node_name[5];
715 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
716 	struct acpi_ec *ec = context;
717 	int value = 0;
718 	acpi_status status;
719 
720 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
721 
722 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
723 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
724 	}
725 	return AE_OK;
726 }
727 
728 static acpi_status
729 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
730 {
731 	acpi_status status;
732 	unsigned long long tmp = 0;
733 
734 	struct acpi_ec *ec = context;
735 
736 	/* clear addr values, ec_parse_io_ports depend on it */
737 	ec->command_addr = ec->data_addr = 0;
738 
739 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
740 				     ec_parse_io_ports, ec);
741 	if (ACPI_FAILURE(status))
742 		return status;
743 
744 	/* Get GPE bit assignment (EC events). */
745 	/* TODO: Add support for _GPE returning a package */
746 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
747 	if (ACPI_FAILURE(status))
748 		return status;
749 	ec->gpe = tmp;
750 	/* Use the global lock for all EC transactions? */
751 	tmp = 0;
752 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
753 	ec->global_lock = tmp;
754 	ec->handle = handle;
755 	return AE_CTRL_TERMINATE;
756 }
757 
758 static int ec_install_handlers(struct acpi_ec *ec)
759 {
760 	acpi_status status;
761 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
762 		return 0;
763 	status = acpi_install_gpe_handler(NULL, ec->gpe,
764 				  ACPI_GPE_EDGE_TRIGGERED,
765 				  &acpi_ec_gpe_handler, ec);
766 	if (ACPI_FAILURE(status))
767 		return -ENODEV;
768 
769 	acpi_enable_gpe(NULL, ec->gpe);
770 	status = acpi_install_address_space_handler(ec->handle,
771 						    ACPI_ADR_SPACE_EC,
772 						    &acpi_ec_space_handler,
773 						    NULL, ec);
774 	if (ACPI_FAILURE(status)) {
775 		if (status == AE_NOT_FOUND) {
776 			/*
777 			 * Maybe OS fails in evaluating the _REG object.
778 			 * The AE_NOT_FOUND error will be ignored and OS
779 			 * continue to initialize EC.
780 			 */
781 			printk(KERN_ERR "Fail in evaluating the _REG object"
782 				" of EC device. Broken bios is suspected.\n");
783 		} else {
784 			acpi_remove_gpe_handler(NULL, ec->gpe,
785 				&acpi_ec_gpe_handler);
786 			acpi_disable_gpe(NULL, ec->gpe);
787 			return -ENODEV;
788 		}
789 	}
790 
791 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
792 	return 0;
793 }
794 
795 static void ec_remove_handlers(struct acpi_ec *ec)
796 {
797 	acpi_disable_gpe(NULL, ec->gpe);
798 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
799 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
800 		pr_err(PREFIX "failed to remove space handler\n");
801 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
802 				&acpi_ec_gpe_handler)))
803 		pr_err(PREFIX "failed to remove gpe handler\n");
804 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
805 }
806 
807 static int acpi_ec_add(struct acpi_device *device)
808 {
809 	struct acpi_ec *ec = NULL;
810 	int ret;
811 
812 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
813 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
814 
815 	/* Check for boot EC */
816 	if (boot_ec &&
817 	    (boot_ec->handle == device->handle ||
818 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
819 		ec = boot_ec;
820 		boot_ec = NULL;
821 	} else {
822 		ec = make_acpi_ec();
823 		if (!ec)
824 			return -ENOMEM;
825 	}
826 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
827 		AE_CTRL_TERMINATE) {
828 			kfree(ec);
829 			return -EINVAL;
830 	}
831 
832 	/* Find and register all query methods */
833 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
834 			    acpi_ec_register_query_methods, NULL, ec, NULL);
835 
836 	if (!first_ec)
837 		first_ec = ec;
838 	device->driver_data = ec;
839 
840 	ret = !!request_region(ec->data_addr, 1, "EC data");
841 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
842 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
843 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
844 
845 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
846 			  ec->gpe, ec->command_addr, ec->data_addr);
847 
848 	ret = ec_install_handlers(ec);
849 
850 	/* EC is fully operational, allow queries */
851 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
852 	return ret;
853 }
854 
855 static int acpi_ec_remove(struct acpi_device *device, int type)
856 {
857 	struct acpi_ec *ec;
858 	struct acpi_ec_query_handler *handler, *tmp;
859 
860 	if (!device)
861 		return -EINVAL;
862 
863 	ec = acpi_driver_data(device);
864 	ec_remove_handlers(ec);
865 	mutex_lock(&ec->mutex);
866 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
867 		list_del(&handler->node);
868 		kfree(handler);
869 	}
870 	mutex_unlock(&ec->mutex);
871 	release_region(ec->data_addr, 1);
872 	release_region(ec->command_addr, 1);
873 	device->driver_data = NULL;
874 	if (ec == first_ec)
875 		first_ec = NULL;
876 	kfree(ec);
877 	return 0;
878 }
879 
880 static acpi_status
881 ec_parse_io_ports(struct acpi_resource *resource, void *context)
882 {
883 	struct acpi_ec *ec = context;
884 
885 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
886 		return AE_OK;
887 
888 	/*
889 	 * The first address region returned is the data port, and
890 	 * the second address region returned is the status/command
891 	 * port.
892 	 */
893 	if (ec->data_addr == 0)
894 		ec->data_addr = resource->data.io.minimum;
895 	else if (ec->command_addr == 0)
896 		ec->command_addr = resource->data.io.minimum;
897 	else
898 		return AE_CTRL_TERMINATE;
899 
900 	return AE_OK;
901 }
902 
903 int __init acpi_boot_ec_enable(void)
904 {
905 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
906 		return 0;
907 	if (!ec_install_handlers(boot_ec)) {
908 		first_ec = boot_ec;
909 		return 0;
910 	}
911 	return -EFAULT;
912 }
913 
914 static const struct acpi_device_id ec_device_ids[] = {
915 	{"PNP0C09", 0},
916 	{"", 0},
917 };
918 
919 /* Some BIOS do not survive early DSDT scan, skip it */
920 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
921 {
922 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
923 	return 0;
924 }
925 
926 /* ASUStek often supplies us with broken ECDT, validate it */
927 static int ec_validate_ecdt(const struct dmi_system_id *id)
928 {
929 	EC_FLAGS_VALIDATE_ECDT = 1;
930 	return 0;
931 }
932 
933 /* MSI EC needs special treatment, enable it */
934 static int ec_flag_msi(const struct dmi_system_id *id)
935 {
936 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
937 	EC_FLAGS_MSI = 1;
938 	EC_FLAGS_VALIDATE_ECDT = 1;
939 	return 0;
940 }
941 
942 /*
943  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
944  * the GPE storm threshold back to 20
945  */
946 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
947 {
948 	pr_debug("Setting the EC GPE storm threshold to 20\n");
949 	ec_storm_threshold  = 20;
950 	return 0;
951 }
952 
953 static struct dmi_system_id __initdata ec_dmi_table[] = {
954 	{
955 	ec_skip_dsdt_scan, "Compal JFL92", {
956 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
957 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
958 	{
959 	ec_flag_msi, "MSI hardware", {
960 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
961 	{
962 	ec_flag_msi, "MSI hardware", {
963 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
964 	{
965 	ec_flag_msi, "MSI hardware", {
966 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
967 	{
968 	ec_flag_msi, "MSI hardware", {
969 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
970 	{
971 	ec_flag_msi, "Quanta hardware", {
972 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
973 	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
974 	{
975 	ec_flag_msi, "Quanta hardware", {
976 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
977 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
978 	{
979 	ec_validate_ecdt, "ASUS hardware", {
980 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
981 	{
982 	ec_validate_ecdt, "ASUS hardware", {
983 	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
984 	{
985 	ec_enlarge_storm_threshold, "CLEVO hardware", {
986 	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
987 	DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
988 	{},
989 };
990 
991 int __init acpi_ec_ecdt_probe(void)
992 {
993 	acpi_status status;
994 	struct acpi_ec *saved_ec = NULL;
995 	struct acpi_table_ecdt *ecdt_ptr;
996 
997 	boot_ec = make_acpi_ec();
998 	if (!boot_ec)
999 		return -ENOMEM;
1000 	/*
1001 	 * Generate a boot ec context
1002 	 */
1003 	dmi_check_system(ec_dmi_table);
1004 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1005 				(struct acpi_table_header **)&ecdt_ptr);
1006 	if (ACPI_SUCCESS(status)) {
1007 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1008 		boot_ec->command_addr = ecdt_ptr->control.address;
1009 		boot_ec->data_addr = ecdt_ptr->data.address;
1010 		boot_ec->gpe = ecdt_ptr->gpe;
1011 		boot_ec->handle = ACPI_ROOT_OBJECT;
1012 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1013 		/* Don't trust ECDT, which comes from ASUSTek */
1014 		if (!EC_FLAGS_VALIDATE_ECDT)
1015 			goto install;
1016 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1017 		if (!saved_ec)
1018 			return -ENOMEM;
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 struct acpi_driver acpi_ec_driver = {
1068 	.name = "ec",
1069 	.class = ACPI_EC_CLASS,
1070 	.ids = ec_device_ids,
1071 	.ops = {
1072 		.add = acpi_ec_add,
1073 		.remove = acpi_ec_remove,
1074 		},
1075 };
1076 
1077 int __init acpi_ec_init(void)
1078 {
1079 	int result = 0;
1080 
1081 	/* Now register the driver for the EC */
1082 	result = acpi_bus_register_driver(&acpi_ec_driver);
1083 	if (result < 0)
1084 		return -ENODEV;
1085 
1086 	return result;
1087 }
1088 
1089 /* EC driver currently not unloadable */
1090 #if 0
1091 static void __exit acpi_ec_exit(void)
1092 {
1093 
1094 	acpi_bus_unregister_driver(&acpi_ec_driver);
1095 	return;
1096 }
1097 #endif	/* 0 */
1098