xref: /linux/drivers/acpi/ec.c (revision 08ec212c0f92cbf30e3ecc7349f18151714041d6)
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->curr_lock, flags);
162 	if (!ec->curr || ec->curr->done)
163 		ret = 1;
164 	spin_unlock_irqrestore(&ec->curr_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 	spin_lock_irqsave(&ec->curr_lock, flags);
179 	if (!ec->curr)
180 		goto unlock;
181 	if (ec->curr->wlen > ec->curr->wi) {
182 		if ((status & ACPI_EC_FLAG_IBF) == 0)
183 			acpi_ec_write_data(ec,
184 				ec->curr->wdata[ec->curr->wi++]);
185 		else
186 			goto err;
187 	} else if (ec->curr->rlen > ec->curr->ri) {
188 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
189 			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
190 			if (ec->curr->rlen == ec->curr->ri)
191 				ec->curr->done = true;
192 		} else
193 			goto err;
194 	} else if (ec->curr->wlen == ec->curr->wi &&
195 		   (status & ACPI_EC_FLAG_IBF) == 0)
196 		ec->curr->done = true;
197 	goto unlock;
198 err:
199 	/* false interrupt, state didn't change */
200 	if (in_interrupt())
201 		++ec->curr->irq_count;
202 unlock:
203 	spin_unlock_irqrestore(&ec->curr_lock, flags);
204 }
205 
206 static int acpi_ec_sync_query(struct acpi_ec *ec);
207 
208 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
209 {
210 	if (state & ACPI_EC_FLAG_SCI) {
211 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
212 			return acpi_ec_sync_query(ec);
213 	}
214 	return 0;
215 }
216 
217 static int ec_poll(struct acpi_ec *ec)
218 {
219 	unsigned long flags;
220 	int repeat = 2; /* number of command restarts */
221 	while (repeat--) {
222 		unsigned long delay = jiffies +
223 			msecs_to_jiffies(ec_delay);
224 		do {
225 			/* don't sleep with disabled interrupts */
226 			if (EC_FLAGS_MSI || irqs_disabled()) {
227 				udelay(ACPI_EC_MSI_UDELAY);
228 				if (ec_transaction_done(ec))
229 					return 0;
230 			} else {
231 				if (wait_event_timeout(ec->wait,
232 						ec_transaction_done(ec),
233 						msecs_to_jiffies(1)))
234 					return 0;
235 			}
236 			advance_transaction(ec, acpi_ec_read_status(ec));
237 		} while (time_before(jiffies, delay));
238 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
239 			break;
240 		pr_debug(PREFIX "controller reset, restart transaction\n");
241 		spin_lock_irqsave(&ec->curr_lock, flags);
242 		start_transaction(ec);
243 		spin_unlock_irqrestore(&ec->curr_lock, flags);
244 	}
245 	return -ETIME;
246 }
247 
248 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
249 					struct transaction *t)
250 {
251 	unsigned long tmp;
252 	int ret = 0;
253 	if (EC_FLAGS_MSI)
254 		udelay(ACPI_EC_MSI_UDELAY);
255 	/* start transaction */
256 	spin_lock_irqsave(&ec->curr_lock, tmp);
257 	/* following two actions should be kept atomic */
258 	ec->curr = t;
259 	start_transaction(ec);
260 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
261 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
262 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
263 	ret = ec_poll(ec);
264 	spin_lock_irqsave(&ec->curr_lock, tmp);
265 	ec->curr = NULL;
266 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
267 	return ret;
268 }
269 
270 static int ec_check_ibf0(struct acpi_ec *ec)
271 {
272 	u8 status = acpi_ec_read_status(ec);
273 	return (status & ACPI_EC_FLAG_IBF) == 0;
274 }
275 
276 static int ec_wait_ibf0(struct acpi_ec *ec)
277 {
278 	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
279 	/* interrupt wait manually if GPE mode is not active */
280 	while (time_before(jiffies, delay))
281 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
282 					msecs_to_jiffies(1)))
283 			return 0;
284 	return -ETIME;
285 }
286 
287 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
288 {
289 	int status;
290 	u32 glk;
291 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
292 		return -EINVAL;
293 	if (t->rdata)
294 		memset(t->rdata, 0, t->rlen);
295 	mutex_lock(&ec->lock);
296 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
297 		status = -EINVAL;
298 		goto unlock;
299 	}
300 	if (ec->global_lock) {
301 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
302 		if (ACPI_FAILURE(status)) {
303 			status = -ENODEV;
304 			goto unlock;
305 		}
306 	}
307 	if (ec_wait_ibf0(ec)) {
308 		pr_err(PREFIX "input buffer is not empty, "
309 				"aborting transaction\n");
310 		status = -ETIME;
311 		goto end;
312 	}
313 	pr_debug(PREFIX "transaction start\n");
314 	/* disable GPE during transaction if storm is detected */
315 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
316 		/* It has to be disabled, so that it doesn't trigger. */
317 		acpi_disable_gpe(NULL, ec->gpe);
318 	}
319 
320 	status = acpi_ec_transaction_unlocked(ec, t);
321 
322 	/* check if we received SCI during transaction */
323 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
324 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
325 		msleep(1);
326 		/* It is safe to enable the GPE outside of the transaction. */
327 		acpi_enable_gpe(NULL, ec->gpe);
328 	} else if (t->irq_count > ec_storm_threshold) {
329 		pr_info(PREFIX "GPE storm detected, "
330 			"transactions will use polling mode\n");
331 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
332 	}
333 	pr_debug(PREFIX "transaction end\n");
334 end:
335 	if (ec->global_lock)
336 		acpi_release_global_lock(glk);
337 unlock:
338 	mutex_unlock(&ec->lock);
339 	return status;
340 }
341 
342 static int acpi_ec_burst_enable(struct acpi_ec *ec)
343 {
344 	u8 d;
345 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
346 				.wdata = NULL, .rdata = &d,
347 				.wlen = 0, .rlen = 1};
348 
349 	return acpi_ec_transaction(ec, &t);
350 }
351 
352 static int acpi_ec_burst_disable(struct acpi_ec *ec)
353 {
354 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
355 				.wdata = NULL, .rdata = NULL,
356 				.wlen = 0, .rlen = 0};
357 
358 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
359 				acpi_ec_transaction(ec, &t) : 0;
360 }
361 
362 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
363 {
364 	int result;
365 	u8 d;
366 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
367 				.wdata = &address, .rdata = &d,
368 				.wlen = 1, .rlen = 1};
369 
370 	result = acpi_ec_transaction(ec, &t);
371 	*data = d;
372 	return result;
373 }
374 
375 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
376 {
377 	u8 wdata[2] = { address, data };
378 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
379 				.wdata = wdata, .rdata = NULL,
380 				.wlen = 2, .rlen = 0};
381 
382 	return acpi_ec_transaction(ec, &t);
383 }
384 
385 /*
386  * Externally callable EC access functions. For now, assume 1 EC only
387  */
388 int ec_burst_enable(void)
389 {
390 	if (!first_ec)
391 		return -ENODEV;
392 	return acpi_ec_burst_enable(first_ec);
393 }
394 
395 EXPORT_SYMBOL(ec_burst_enable);
396 
397 int ec_burst_disable(void)
398 {
399 	if (!first_ec)
400 		return -ENODEV;
401 	return acpi_ec_burst_disable(first_ec);
402 }
403 
404 EXPORT_SYMBOL(ec_burst_disable);
405 
406 int ec_read(u8 addr, u8 * val)
407 {
408 	int err;
409 	u8 temp_data;
410 
411 	if (!first_ec)
412 		return -ENODEV;
413 
414 	err = acpi_ec_read(first_ec, addr, &temp_data);
415 
416 	if (!err) {
417 		*val = temp_data;
418 		return 0;
419 	} else
420 		return err;
421 }
422 
423 EXPORT_SYMBOL(ec_read);
424 
425 int ec_write(u8 addr, u8 val)
426 {
427 	int err;
428 
429 	if (!first_ec)
430 		return -ENODEV;
431 
432 	err = acpi_ec_write(first_ec, addr, val);
433 
434 	return err;
435 }
436 
437 EXPORT_SYMBOL(ec_write);
438 
439 int ec_transaction(u8 command,
440 		   const u8 * wdata, unsigned wdata_len,
441 		   u8 * rdata, unsigned rdata_len)
442 {
443 	struct transaction t = {.command = command,
444 				.wdata = wdata, .rdata = rdata,
445 				.wlen = wdata_len, .rlen = rdata_len};
446 	if (!first_ec)
447 		return -ENODEV;
448 
449 	return acpi_ec_transaction(first_ec, &t);
450 }
451 
452 EXPORT_SYMBOL(ec_transaction);
453 
454 /* Get the handle to the EC device */
455 acpi_handle ec_get_handle(void)
456 {
457 	if (!first_ec)
458 		return NULL;
459 	return first_ec->handle;
460 }
461 
462 EXPORT_SYMBOL(ec_get_handle);
463 
464 void acpi_ec_block_transactions(void)
465 {
466 	struct acpi_ec *ec = first_ec;
467 
468 	if (!ec)
469 		return;
470 
471 	mutex_lock(&ec->lock);
472 	/* Prevent transactions from being carried out */
473 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
474 	mutex_unlock(&ec->lock);
475 }
476 
477 void acpi_ec_unblock_transactions(void)
478 {
479 	struct acpi_ec *ec = first_ec;
480 
481 	if (!ec)
482 		return;
483 
484 	mutex_lock(&ec->lock);
485 	/* Allow transactions to be carried out again */
486 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
487 	mutex_unlock(&ec->lock);
488 }
489 
490 void acpi_ec_unblock_transactions_early(void)
491 {
492 	/*
493 	 * Allow transactions to happen again (this function is called from
494 	 * atomic context during wakeup, so we don't need to acquire the mutex).
495 	 */
496 	if (first_ec)
497 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
498 }
499 
500 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
501 {
502 	int result;
503 	u8 d;
504 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
505 				.wdata = NULL, .rdata = &d,
506 				.wlen = 0, .rlen = 1};
507 	if (!ec || !data)
508 		return -EINVAL;
509 	/*
510 	 * Query the EC to find out which _Qxx method we need to evaluate.
511 	 * Note that successful completion of the query causes the ACPI_EC_SCI
512 	 * bit to be cleared (and thus clearing the interrupt source).
513 	 */
514 	result = acpi_ec_transaction_unlocked(ec, &t);
515 	if (result)
516 		return result;
517 	if (!d)
518 		return -ENODATA;
519 	*data = d;
520 	return 0;
521 }
522 
523 /* --------------------------------------------------------------------------
524                                 Event Management
525    -------------------------------------------------------------------------- */
526 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
527 			      acpi_handle handle, acpi_ec_query_func func,
528 			      void *data)
529 {
530 	struct acpi_ec_query_handler *handler =
531 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
532 	if (!handler)
533 		return -ENOMEM;
534 
535 	handler->query_bit = query_bit;
536 	handler->handle = handle;
537 	handler->func = func;
538 	handler->data = data;
539 	mutex_lock(&ec->lock);
540 	list_add(&handler->node, &ec->list);
541 	mutex_unlock(&ec->lock);
542 	return 0;
543 }
544 
545 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
546 
547 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
548 {
549 	struct acpi_ec_query_handler *handler, *tmp;
550 	mutex_lock(&ec->lock);
551 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
552 		if (query_bit == handler->query_bit) {
553 			list_del(&handler->node);
554 			kfree(handler);
555 		}
556 	}
557 	mutex_unlock(&ec->lock);
558 }
559 
560 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
561 
562 static void acpi_ec_run(void *cxt)
563 {
564 	struct acpi_ec_query_handler *handler = cxt;
565 	if (!handler)
566 		return;
567 	pr_debug(PREFIX "start query execution\n");
568 	if (handler->func)
569 		handler->func(handler->data);
570 	else if (handler->handle)
571 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
572 	pr_debug(PREFIX "stop query execution\n");
573 	kfree(handler);
574 }
575 
576 static int acpi_ec_sync_query(struct acpi_ec *ec)
577 {
578 	u8 value = 0;
579 	int status;
580 	struct acpi_ec_query_handler *handler, *copy;
581 	if ((status = acpi_ec_query_unlocked(ec, &value)))
582 		return status;
583 	list_for_each_entry(handler, &ec->list, node) {
584 		if (value == handler->query_bit) {
585 			/* have custom handler for this bit */
586 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
587 			if (!copy)
588 				return -ENOMEM;
589 			memcpy(copy, handler, sizeof(*copy));
590 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
591 			return acpi_os_execute((copy->func) ?
592 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
593 				acpi_ec_run, copy);
594 		}
595 	}
596 	return 0;
597 }
598 
599 static void acpi_ec_gpe_query(void *ec_cxt)
600 {
601 	struct acpi_ec *ec = ec_cxt;
602 	if (!ec)
603 		return;
604 	mutex_lock(&ec->lock);
605 	acpi_ec_sync_query(ec);
606 	mutex_unlock(&ec->lock);
607 }
608 
609 static int ec_check_sci(struct acpi_ec *ec, u8 state)
610 {
611 	if (state & ACPI_EC_FLAG_SCI) {
612 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
613 			pr_debug(PREFIX "push gpe query to the queue\n");
614 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
615 				acpi_ec_gpe_query, ec);
616 		}
617 	}
618 	return 0;
619 }
620 
621 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
622 	u32 gpe_number, void *data)
623 {
624 	struct acpi_ec *ec = data;
625 
626 	pr_debug(PREFIX "~~~> interrupt\n");
627 
628 	advance_transaction(ec, acpi_ec_read_status(ec));
629 	if (ec_transaction_done(ec) &&
630 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
631 		wake_up(&ec->wait);
632 		ec_check_sci(ec, acpi_ec_read_status(ec));
633 	}
634 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
635 }
636 
637 /* --------------------------------------------------------------------------
638                              Address Space Management
639    -------------------------------------------------------------------------- */
640 
641 static acpi_status
642 acpi_ec_space_handler(u32 function, acpi_physical_address address,
643 		      u32 bits, u64 *value64,
644 		      void *handler_context, void *region_context)
645 {
646 	struct acpi_ec *ec = handler_context;
647 	int result = 0, i, bytes = bits / 8;
648 	u8 *value = (u8 *)value64;
649 
650 	if ((address > 0xFF) || !value || !handler_context)
651 		return AE_BAD_PARAMETER;
652 
653 	if (function != ACPI_READ && function != ACPI_WRITE)
654 		return AE_BAD_PARAMETER;
655 
656 	if (EC_FLAGS_MSI || bits > 8)
657 		acpi_ec_burst_enable(ec);
658 
659 	for (i = 0; i < bytes; ++i, ++address, ++value)
660 		result = (function == ACPI_READ) ?
661 			acpi_ec_read(ec, address, value) :
662 			acpi_ec_write(ec, address, *value);
663 
664 	if (EC_FLAGS_MSI || bits > 8)
665 		acpi_ec_burst_disable(ec);
666 
667 	switch (result) {
668 	case -EINVAL:
669 		return AE_BAD_PARAMETER;
670 		break;
671 	case -ENODEV:
672 		return AE_NOT_FOUND;
673 		break;
674 	case -ETIME:
675 		return AE_TIME;
676 		break;
677 	default:
678 		return AE_OK;
679 	}
680 }
681 
682 /* --------------------------------------------------------------------------
683                                Driver Interface
684    -------------------------------------------------------------------------- */
685 static acpi_status
686 ec_parse_io_ports(struct acpi_resource *resource, void *context);
687 
688 static struct acpi_ec *make_acpi_ec(void)
689 {
690 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
691 	if (!ec)
692 		return NULL;
693 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
694 	mutex_init(&ec->lock);
695 	init_waitqueue_head(&ec->wait);
696 	INIT_LIST_HEAD(&ec->list);
697 	spin_lock_init(&ec->curr_lock);
698 	return ec;
699 }
700 
701 static acpi_status
702 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
703 			       void *context, void **return_value)
704 {
705 	char node_name[5];
706 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
707 	struct acpi_ec *ec = context;
708 	int value = 0;
709 	acpi_status status;
710 
711 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
712 
713 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
714 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
715 	}
716 	return AE_OK;
717 }
718 
719 static acpi_status
720 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
721 {
722 	acpi_status status;
723 	unsigned long long tmp = 0;
724 
725 	struct acpi_ec *ec = context;
726 
727 	/* clear addr values, ec_parse_io_ports depend on it */
728 	ec->command_addr = ec->data_addr = 0;
729 
730 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
731 				     ec_parse_io_ports, ec);
732 	if (ACPI_FAILURE(status))
733 		return status;
734 
735 	/* Get GPE bit assignment (EC events). */
736 	/* TODO: Add support for _GPE returning a package */
737 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
738 	if (ACPI_FAILURE(status))
739 		return status;
740 	ec->gpe = tmp;
741 	/* Use the global lock for all EC transactions? */
742 	tmp = 0;
743 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
744 	ec->global_lock = tmp;
745 	ec->handle = handle;
746 	return AE_CTRL_TERMINATE;
747 }
748 
749 static int ec_install_handlers(struct acpi_ec *ec)
750 {
751 	acpi_status status;
752 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
753 		return 0;
754 	status = acpi_install_gpe_handler(NULL, ec->gpe,
755 				  ACPI_GPE_EDGE_TRIGGERED,
756 				  &acpi_ec_gpe_handler, ec);
757 	if (ACPI_FAILURE(status))
758 		return -ENODEV;
759 
760 	acpi_enable_gpe(NULL, ec->gpe);
761 	status = acpi_install_address_space_handler(ec->handle,
762 						    ACPI_ADR_SPACE_EC,
763 						    &acpi_ec_space_handler,
764 						    NULL, ec);
765 	if (ACPI_FAILURE(status)) {
766 		if (status == AE_NOT_FOUND) {
767 			/*
768 			 * Maybe OS fails in evaluating the _REG object.
769 			 * The AE_NOT_FOUND error will be ignored and OS
770 			 * continue to initialize EC.
771 			 */
772 			printk(KERN_ERR "Fail in evaluating the _REG object"
773 				" of EC device. Broken bios is suspected.\n");
774 		} else {
775 			acpi_remove_gpe_handler(NULL, ec->gpe,
776 				&acpi_ec_gpe_handler);
777 			acpi_disable_gpe(NULL, ec->gpe);
778 			return -ENODEV;
779 		}
780 	}
781 
782 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
783 	return 0;
784 }
785 
786 static void ec_remove_handlers(struct acpi_ec *ec)
787 {
788 	acpi_disable_gpe(NULL, ec->gpe);
789 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
790 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
791 		pr_err(PREFIX "failed to remove space handler\n");
792 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
793 				&acpi_ec_gpe_handler)))
794 		pr_err(PREFIX "failed to remove gpe handler\n");
795 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
796 }
797 
798 static int acpi_ec_add(struct acpi_device *device)
799 {
800 	struct acpi_ec *ec = NULL;
801 	int ret;
802 
803 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
804 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
805 
806 	/* Check for boot EC */
807 	if (boot_ec &&
808 	    (boot_ec->handle == device->handle ||
809 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
810 		ec = boot_ec;
811 		boot_ec = NULL;
812 	} else {
813 		ec = make_acpi_ec();
814 		if (!ec)
815 			return -ENOMEM;
816 	}
817 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
818 		AE_CTRL_TERMINATE) {
819 			kfree(ec);
820 			return -EINVAL;
821 	}
822 
823 	/* Find and register all query methods */
824 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
825 			    acpi_ec_register_query_methods, NULL, ec, NULL);
826 
827 	if (!first_ec)
828 		first_ec = ec;
829 	device->driver_data = ec;
830 
831 	ret = !!request_region(ec->data_addr, 1, "EC data");
832 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
833 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
834 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
835 
836 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
837 			  ec->gpe, ec->command_addr, ec->data_addr);
838 
839 	ret = ec_install_handlers(ec);
840 
841 	/* EC is fully operational, allow queries */
842 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
843 	return ret;
844 }
845 
846 static int acpi_ec_remove(struct acpi_device *device, int type)
847 {
848 	struct acpi_ec *ec;
849 	struct acpi_ec_query_handler *handler, *tmp;
850 
851 	if (!device)
852 		return -EINVAL;
853 
854 	ec = acpi_driver_data(device);
855 	ec_remove_handlers(ec);
856 	mutex_lock(&ec->lock);
857 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
858 		list_del(&handler->node);
859 		kfree(handler);
860 	}
861 	mutex_unlock(&ec->lock);
862 	release_region(ec->data_addr, 1);
863 	release_region(ec->command_addr, 1);
864 	device->driver_data = NULL;
865 	if (ec == first_ec)
866 		first_ec = NULL;
867 	kfree(ec);
868 	return 0;
869 }
870 
871 static acpi_status
872 ec_parse_io_ports(struct acpi_resource *resource, void *context)
873 {
874 	struct acpi_ec *ec = context;
875 
876 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
877 		return AE_OK;
878 
879 	/*
880 	 * The first address region returned is the data port, and
881 	 * the second address region returned is the status/command
882 	 * port.
883 	 */
884 	if (ec->data_addr == 0)
885 		ec->data_addr = resource->data.io.minimum;
886 	else if (ec->command_addr == 0)
887 		ec->command_addr = resource->data.io.minimum;
888 	else
889 		return AE_CTRL_TERMINATE;
890 
891 	return AE_OK;
892 }
893 
894 int __init acpi_boot_ec_enable(void)
895 {
896 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
897 		return 0;
898 	if (!ec_install_handlers(boot_ec)) {
899 		first_ec = boot_ec;
900 		return 0;
901 	}
902 	return -EFAULT;
903 }
904 
905 static const struct acpi_device_id ec_device_ids[] = {
906 	{"PNP0C09", 0},
907 	{"", 0},
908 };
909 
910 /* Some BIOS do not survive early DSDT scan, skip it */
911 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
912 {
913 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
914 	return 0;
915 }
916 
917 /* ASUStek often supplies us with broken ECDT, validate it */
918 static int ec_validate_ecdt(const struct dmi_system_id *id)
919 {
920 	EC_FLAGS_VALIDATE_ECDT = 1;
921 	return 0;
922 }
923 
924 /* MSI EC needs special treatment, enable it */
925 static int ec_flag_msi(const struct dmi_system_id *id)
926 {
927 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
928 	EC_FLAGS_MSI = 1;
929 	EC_FLAGS_VALIDATE_ECDT = 1;
930 	return 0;
931 }
932 
933 /*
934  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
935  * the GPE storm threshold back to 20
936  */
937 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
938 {
939 	pr_debug("Setting the EC GPE storm threshold to 20\n");
940 	ec_storm_threshold  = 20;
941 	return 0;
942 }
943 
944 static struct dmi_system_id __initdata ec_dmi_table[] = {
945 	{
946 	ec_skip_dsdt_scan, "Compal JFL92", {
947 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
948 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
949 	{
950 	ec_flag_msi, "MSI hardware", {
951 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
952 	{
953 	ec_flag_msi, "MSI hardware", {
954 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
955 	{
956 	ec_flag_msi, "MSI hardware", {
957 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
958 	{
959 	ec_flag_msi, "MSI hardware", {
960 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
961 	{
962 	ec_flag_msi, "Quanta hardware", {
963 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
964 	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
965 	{
966 	ec_flag_msi, "Quanta hardware", {
967 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
968 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
969 	{
970 	ec_validate_ecdt, "ASUS hardware", {
971 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
972 	{
973 	ec_validate_ecdt, "ASUS hardware", {
974 	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
975 	{
976 	ec_enlarge_storm_threshold, "CLEVO hardware", {
977 	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
978 	DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
979 	{},
980 };
981 
982 int __init acpi_ec_ecdt_probe(void)
983 {
984 	acpi_status status;
985 	struct acpi_ec *saved_ec = NULL;
986 	struct acpi_table_ecdt *ecdt_ptr;
987 
988 	boot_ec = make_acpi_ec();
989 	if (!boot_ec)
990 		return -ENOMEM;
991 	/*
992 	 * Generate a boot ec context
993 	 */
994 	dmi_check_system(ec_dmi_table);
995 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
996 				(struct acpi_table_header **)&ecdt_ptr);
997 	if (ACPI_SUCCESS(status)) {
998 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
999 		boot_ec->command_addr = ecdt_ptr->control.address;
1000 		boot_ec->data_addr = ecdt_ptr->data.address;
1001 		boot_ec->gpe = ecdt_ptr->gpe;
1002 		boot_ec->handle = ACPI_ROOT_OBJECT;
1003 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1004 		/* Don't trust ECDT, which comes from ASUSTek */
1005 		if (!EC_FLAGS_VALIDATE_ECDT)
1006 			goto install;
1007 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1008 		if (!saved_ec)
1009 			return -ENOMEM;
1010 	/* fall through */
1011 	}
1012 
1013 	if (EC_FLAGS_SKIP_DSDT_SCAN)
1014 		return -ENODEV;
1015 
1016 	/* This workaround is needed only on some broken machines,
1017 	 * which require early EC, but fail to provide ECDT */
1018 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1019 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1020 					boot_ec, NULL);
1021 	/* Check that acpi_get_devices actually find something */
1022 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1023 		goto error;
1024 	if (saved_ec) {
1025 		/* try to find good ECDT from ASUSTek */
1026 		if (saved_ec->command_addr != boot_ec->command_addr ||
1027 		    saved_ec->data_addr != boot_ec->data_addr ||
1028 		    saved_ec->gpe != boot_ec->gpe ||
1029 		    saved_ec->handle != boot_ec->handle)
1030 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1031 			"ECDT tables, which are very hard to workaround. "
1032 			"Trying to use DSDT EC info instead. Please send "
1033 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1034 		kfree(saved_ec);
1035 		saved_ec = NULL;
1036 	} else {
1037 		/* We really need to limit this workaround, the only ASUS,
1038 		* which needs it, has fake EC._INI method, so use it as flag.
1039 		* Keep boot_ec struct as it will be needed soon.
1040 		*/
1041 		acpi_handle dummy;
1042 		if (!dmi_name_in_vendors("ASUS") ||
1043 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1044 							&dummy)))
1045 			return -ENODEV;
1046 	}
1047 install:
1048 	if (!ec_install_handlers(boot_ec)) {
1049 		first_ec = boot_ec;
1050 		return 0;
1051 	}
1052 error:
1053 	kfree(boot_ec);
1054 	boot_ec = NULL;
1055 	return -ENODEV;
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 		},
1066 };
1067 
1068 int __init acpi_ec_init(void)
1069 {
1070 	int result = 0;
1071 
1072 	/* Now register the driver for the EC */
1073 	result = acpi_bus_register_driver(&acpi_ec_driver);
1074 	if (result < 0)
1075 		return -ENODEV;
1076 
1077 	return result;
1078 }
1079 
1080 /* EC driver currently not unloadable */
1081 #if 0
1082 static void __exit acpi_ec_exit(void)
1083 {
1084 
1085 	acpi_bus_unregister_driver(&acpi_ec_driver);
1086 	return;
1087 }
1088 #endif	/* 0 */
1089