xref: /openbmc/linux/drivers/acpi/ec.c (revision 73eb94a0)
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 #define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
75 					   per one transaction */
76 
77 enum {
78 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
79 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
80 	EC_FLAGS_HANDLERS_INSTALLED,	/* Handlers for GPE and
81 					 * OpReg are installed */
82 	EC_FLAGS_BLOCKED,		/* Transactions are blocked */
83 };
84 
85 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
86 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
87 module_param(ec_delay, uint, 0644);
88 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
89 
90 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
91 /* External interfaces use first EC only, so remember */
92 typedef int (*acpi_ec_query_func) (void *data);
93 
94 struct acpi_ec_query_handler {
95 	struct list_head node;
96 	acpi_ec_query_func func;
97 	acpi_handle handle;
98 	void *data;
99 	u8 query_bit;
100 };
101 
102 struct transaction {
103 	const u8 *wdata;
104 	u8 *rdata;
105 	unsigned short irq_count;
106 	u8 command;
107 	u8 wi;
108 	u8 ri;
109 	u8 wlen;
110 	u8 rlen;
111 	bool done;
112 };
113 
114 struct acpi_ec *boot_ec, *first_ec;
115 EXPORT_SYMBOL(first_ec);
116 
117 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
118 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
119 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
120 
121 /* --------------------------------------------------------------------------
122                              Transaction Management
123    -------------------------------------------------------------------------- */
124 
125 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
126 {
127 	u8 x = inb(ec->command_addr);
128 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
129 	return x;
130 }
131 
132 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
133 {
134 	u8 x = inb(ec->data_addr);
135 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
136 	return x;
137 }
138 
139 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
140 {
141 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
142 	outb(command, ec->command_addr);
143 }
144 
145 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
146 {
147 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
148 	outb(data, ec->data_addr);
149 }
150 
151 static int ec_transaction_done(struct acpi_ec *ec)
152 {
153 	unsigned long flags;
154 	int ret = 0;
155 	spin_lock_irqsave(&ec->curr_lock, flags);
156 	if (!ec->curr || ec->curr->done)
157 		ret = 1;
158 	spin_unlock_irqrestore(&ec->curr_lock, flags);
159 	return ret;
160 }
161 
162 static void start_transaction(struct acpi_ec *ec)
163 {
164 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
165 	ec->curr->done = false;
166 	acpi_ec_write_cmd(ec, ec->curr->command);
167 }
168 
169 static void advance_transaction(struct acpi_ec *ec, u8 status)
170 {
171 	unsigned long flags;
172 	spin_lock_irqsave(&ec->curr_lock, flags);
173 	if (!ec->curr)
174 		goto unlock;
175 	if (ec->curr->wlen > ec->curr->wi) {
176 		if ((status & ACPI_EC_FLAG_IBF) == 0)
177 			acpi_ec_write_data(ec,
178 				ec->curr->wdata[ec->curr->wi++]);
179 		else
180 			goto err;
181 	} else if (ec->curr->rlen > ec->curr->ri) {
182 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
183 			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
184 			if (ec->curr->rlen == ec->curr->ri)
185 				ec->curr->done = true;
186 		} else
187 			goto err;
188 	} else if (ec->curr->wlen == ec->curr->wi &&
189 		   (status & ACPI_EC_FLAG_IBF) == 0)
190 		ec->curr->done = true;
191 	goto unlock;
192 err:
193 	/* false interrupt, state didn't change */
194 	if (in_interrupt())
195 		++ec->curr->irq_count;
196 unlock:
197 	spin_unlock_irqrestore(&ec->curr_lock, flags);
198 }
199 
200 static int acpi_ec_sync_query(struct acpi_ec *ec);
201 
202 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
203 {
204 	if (state & ACPI_EC_FLAG_SCI) {
205 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
206 			return acpi_ec_sync_query(ec);
207 	}
208 	return 0;
209 }
210 
211 static int ec_poll(struct acpi_ec *ec)
212 {
213 	unsigned long flags;
214 	int repeat = 2; /* number of command restarts */
215 	while (repeat--) {
216 		unsigned long delay = jiffies +
217 			msecs_to_jiffies(ec_delay);
218 		do {
219 			/* don't sleep with disabled interrupts */
220 			if (EC_FLAGS_MSI || irqs_disabled()) {
221 				udelay(ACPI_EC_MSI_UDELAY);
222 				if (ec_transaction_done(ec))
223 					return 0;
224 			} else {
225 				if (wait_event_timeout(ec->wait,
226 						ec_transaction_done(ec),
227 						msecs_to_jiffies(1)))
228 					return 0;
229 			}
230 			advance_transaction(ec, acpi_ec_read_status(ec));
231 		} while (time_before(jiffies, delay));
232 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
233 			break;
234 		pr_debug(PREFIX "controller reset, restart transaction\n");
235 		spin_lock_irqsave(&ec->curr_lock, flags);
236 		start_transaction(ec);
237 		spin_unlock_irqrestore(&ec->curr_lock, flags);
238 	}
239 	return -ETIME;
240 }
241 
242 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
243 					struct transaction *t)
244 {
245 	unsigned long tmp;
246 	int ret = 0;
247 	if (EC_FLAGS_MSI)
248 		udelay(ACPI_EC_MSI_UDELAY);
249 	/* start transaction */
250 	spin_lock_irqsave(&ec->curr_lock, tmp);
251 	/* following two actions should be kept atomic */
252 	ec->curr = t;
253 	start_transaction(ec);
254 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
255 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
256 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
257 	ret = ec_poll(ec);
258 	spin_lock_irqsave(&ec->curr_lock, tmp);
259 	ec->curr = NULL;
260 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
261 	return ret;
262 }
263 
264 static int ec_check_ibf0(struct acpi_ec *ec)
265 {
266 	u8 status = acpi_ec_read_status(ec);
267 	return (status & ACPI_EC_FLAG_IBF) == 0;
268 }
269 
270 static int ec_wait_ibf0(struct acpi_ec *ec)
271 {
272 	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
273 	/* interrupt wait manually if GPE mode is not active */
274 	while (time_before(jiffies, delay))
275 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
276 					msecs_to_jiffies(1)))
277 			return 0;
278 	return -ETIME;
279 }
280 
281 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
282 {
283 	int status;
284 	u32 glk;
285 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
286 		return -EINVAL;
287 	if (t->rdata)
288 		memset(t->rdata, 0, t->rlen);
289 	mutex_lock(&ec->lock);
290 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
291 		status = -EINVAL;
292 		goto unlock;
293 	}
294 	if (ec->global_lock) {
295 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
296 		if (ACPI_FAILURE(status)) {
297 			status = -ENODEV;
298 			goto unlock;
299 		}
300 	}
301 	if (ec_wait_ibf0(ec)) {
302 		pr_err(PREFIX "input buffer is not empty, "
303 				"aborting transaction\n");
304 		status = -ETIME;
305 		goto end;
306 	}
307 	pr_debug(PREFIX "transaction start\n");
308 	/* disable GPE during transaction if storm is detected */
309 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
310 		/* It has to be disabled, so that it doesn't trigger. */
311 		acpi_disable_gpe(NULL, ec->gpe);
312 	}
313 
314 	status = acpi_ec_transaction_unlocked(ec, t);
315 
316 	/* check if we received SCI during transaction */
317 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
318 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
319 		msleep(1);
320 		/* It is safe to enable the GPE outside of the transaction. */
321 		acpi_enable_gpe(NULL, ec->gpe);
322 	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
323 		pr_info(PREFIX "GPE storm detected, "
324 			"transactions will use polling mode\n");
325 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
326 	}
327 	pr_debug(PREFIX "transaction end\n");
328 end:
329 	if (ec->global_lock)
330 		acpi_release_global_lock(glk);
331 unlock:
332 	mutex_unlock(&ec->lock);
333 	return status;
334 }
335 
336 static int acpi_ec_burst_enable(struct acpi_ec *ec)
337 {
338 	u8 d;
339 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
340 				.wdata = NULL, .rdata = &d,
341 				.wlen = 0, .rlen = 1};
342 
343 	return acpi_ec_transaction(ec, &t);
344 }
345 
346 static int acpi_ec_burst_disable(struct acpi_ec *ec)
347 {
348 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
349 				.wdata = NULL, .rdata = NULL,
350 				.wlen = 0, .rlen = 0};
351 
352 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
353 				acpi_ec_transaction(ec, &t) : 0;
354 }
355 
356 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
357 {
358 	int result;
359 	u8 d;
360 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
361 				.wdata = &address, .rdata = &d,
362 				.wlen = 1, .rlen = 1};
363 
364 	result = acpi_ec_transaction(ec, &t);
365 	*data = d;
366 	return result;
367 }
368 
369 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
370 {
371 	u8 wdata[2] = { address, data };
372 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
373 				.wdata = wdata, .rdata = NULL,
374 				.wlen = 2, .rlen = 0};
375 
376 	return acpi_ec_transaction(ec, &t);
377 }
378 
379 /*
380  * Externally callable EC access functions. For now, assume 1 EC only
381  */
382 int ec_burst_enable(void)
383 {
384 	if (!first_ec)
385 		return -ENODEV;
386 	return acpi_ec_burst_enable(first_ec);
387 }
388 
389 EXPORT_SYMBOL(ec_burst_enable);
390 
391 int ec_burst_disable(void)
392 {
393 	if (!first_ec)
394 		return -ENODEV;
395 	return acpi_ec_burst_disable(first_ec);
396 }
397 
398 EXPORT_SYMBOL(ec_burst_disable);
399 
400 int ec_read(u8 addr, u8 * val)
401 {
402 	int err;
403 	u8 temp_data;
404 
405 	if (!first_ec)
406 		return -ENODEV;
407 
408 	err = acpi_ec_read(first_ec, addr, &temp_data);
409 
410 	if (!err) {
411 		*val = temp_data;
412 		return 0;
413 	} else
414 		return err;
415 }
416 
417 EXPORT_SYMBOL(ec_read);
418 
419 int ec_write(u8 addr, u8 val)
420 {
421 	int err;
422 
423 	if (!first_ec)
424 		return -ENODEV;
425 
426 	err = acpi_ec_write(first_ec, addr, val);
427 
428 	return err;
429 }
430 
431 EXPORT_SYMBOL(ec_write);
432 
433 int ec_transaction(u8 command,
434 		   const u8 * wdata, unsigned wdata_len,
435 		   u8 * rdata, unsigned rdata_len)
436 {
437 	struct transaction t = {.command = command,
438 				.wdata = wdata, .rdata = rdata,
439 				.wlen = wdata_len, .rlen = rdata_len};
440 	if (!first_ec)
441 		return -ENODEV;
442 
443 	return acpi_ec_transaction(first_ec, &t);
444 }
445 
446 EXPORT_SYMBOL(ec_transaction);
447 
448 /* Get the handle to the EC device */
449 acpi_handle ec_get_handle(void)
450 {
451 	if (!first_ec)
452 		return NULL;
453 	return first_ec->handle;
454 }
455 
456 EXPORT_SYMBOL(ec_get_handle);
457 
458 void acpi_ec_block_transactions(void)
459 {
460 	struct acpi_ec *ec = first_ec;
461 
462 	if (!ec)
463 		return;
464 
465 	mutex_lock(&ec->lock);
466 	/* Prevent transactions from being carried out */
467 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
468 	mutex_unlock(&ec->lock);
469 }
470 
471 void acpi_ec_unblock_transactions(void)
472 {
473 	struct acpi_ec *ec = first_ec;
474 
475 	if (!ec)
476 		return;
477 
478 	mutex_lock(&ec->lock);
479 	/* Allow transactions to be carried out again */
480 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
481 	mutex_unlock(&ec->lock);
482 }
483 
484 void acpi_ec_unblock_transactions_early(void)
485 {
486 	/*
487 	 * Allow transactions to happen again (this function is called from
488 	 * atomic context during wakeup, so we don't need to acquire the mutex).
489 	 */
490 	if (first_ec)
491 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
492 }
493 
494 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
495 {
496 	int result;
497 	u8 d;
498 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
499 				.wdata = NULL, .rdata = &d,
500 				.wlen = 0, .rlen = 1};
501 	if (!ec || !data)
502 		return -EINVAL;
503 	/*
504 	 * Query the EC to find out which _Qxx method we need to evaluate.
505 	 * Note that successful completion of the query causes the ACPI_EC_SCI
506 	 * bit to be cleared (and thus clearing the interrupt source).
507 	 */
508 	result = acpi_ec_transaction_unlocked(ec, &t);
509 	if (result)
510 		return result;
511 	if (!d)
512 		return -ENODATA;
513 	*data = d;
514 	return 0;
515 }
516 
517 /* --------------------------------------------------------------------------
518                                 Event Management
519    -------------------------------------------------------------------------- */
520 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
521 			      acpi_handle handle, acpi_ec_query_func func,
522 			      void *data)
523 {
524 	struct acpi_ec_query_handler *handler =
525 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
526 	if (!handler)
527 		return -ENOMEM;
528 
529 	handler->query_bit = query_bit;
530 	handler->handle = handle;
531 	handler->func = func;
532 	handler->data = data;
533 	mutex_lock(&ec->lock);
534 	list_add(&handler->node, &ec->list);
535 	mutex_unlock(&ec->lock);
536 	return 0;
537 }
538 
539 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
540 
541 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
542 {
543 	struct acpi_ec_query_handler *handler, *tmp;
544 	mutex_lock(&ec->lock);
545 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
546 		if (query_bit == handler->query_bit) {
547 			list_del(&handler->node);
548 			kfree(handler);
549 		}
550 	}
551 	mutex_unlock(&ec->lock);
552 }
553 
554 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
555 
556 static void acpi_ec_run(void *cxt)
557 {
558 	struct acpi_ec_query_handler *handler = cxt;
559 	if (!handler)
560 		return;
561 	pr_debug(PREFIX "start query execution\n");
562 	if (handler->func)
563 		handler->func(handler->data);
564 	else if (handler->handle)
565 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
566 	pr_debug(PREFIX "stop query execution\n");
567 	kfree(handler);
568 }
569 
570 static int acpi_ec_sync_query(struct acpi_ec *ec)
571 {
572 	u8 value = 0;
573 	int status;
574 	struct acpi_ec_query_handler *handler, *copy;
575 	if ((status = acpi_ec_query_unlocked(ec, &value)))
576 		return status;
577 	list_for_each_entry(handler, &ec->list, node) {
578 		if (value == handler->query_bit) {
579 			/* have custom handler for this bit */
580 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
581 			if (!copy)
582 				return -ENOMEM;
583 			memcpy(copy, handler, sizeof(*copy));
584 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
585 			return acpi_os_execute((copy->func) ?
586 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
587 				acpi_ec_run, copy);
588 		}
589 	}
590 	return 0;
591 }
592 
593 static void acpi_ec_gpe_query(void *ec_cxt)
594 {
595 	struct acpi_ec *ec = ec_cxt;
596 	if (!ec)
597 		return;
598 	mutex_lock(&ec->lock);
599 	acpi_ec_sync_query(ec);
600 	mutex_unlock(&ec->lock);
601 }
602 
603 static int ec_check_sci(struct acpi_ec *ec, u8 state)
604 {
605 	if (state & ACPI_EC_FLAG_SCI) {
606 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
607 			pr_debug(PREFIX "push gpe query to the queue\n");
608 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
609 				acpi_ec_gpe_query, ec);
610 		}
611 	}
612 	return 0;
613 }
614 
615 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
616 	u32 gpe_number, void *data)
617 {
618 	struct acpi_ec *ec = data;
619 
620 	pr_debug(PREFIX "~~~> interrupt\n");
621 
622 	advance_transaction(ec, acpi_ec_read_status(ec));
623 	if (ec_transaction_done(ec) &&
624 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
625 		wake_up(&ec->wait);
626 		ec_check_sci(ec, acpi_ec_read_status(ec));
627 	}
628 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
629 }
630 
631 /* --------------------------------------------------------------------------
632                              Address Space Management
633    -------------------------------------------------------------------------- */
634 
635 static acpi_status
636 acpi_ec_space_handler(u32 function, acpi_physical_address address,
637 		      u32 bits, u64 *value64,
638 		      void *handler_context, void *region_context)
639 {
640 	struct acpi_ec *ec = handler_context;
641 	int result = 0, i, bytes = bits / 8;
642 	u8 *value = (u8 *)value64;
643 
644 	if ((address > 0xFF) || !value || !handler_context)
645 		return AE_BAD_PARAMETER;
646 
647 	if (function != ACPI_READ && function != ACPI_WRITE)
648 		return AE_BAD_PARAMETER;
649 
650 	if (EC_FLAGS_MSI || bits > 8)
651 		acpi_ec_burst_enable(ec);
652 
653 	for (i = 0; i < bytes; ++i, ++address, ++value)
654 		result = (function == ACPI_READ) ?
655 			acpi_ec_read(ec, address, value) :
656 			acpi_ec_write(ec, address, *value);
657 
658 	if (EC_FLAGS_MSI || bits > 8)
659 		acpi_ec_burst_disable(ec);
660 
661 	switch (result) {
662 	case -EINVAL:
663 		return AE_BAD_PARAMETER;
664 		break;
665 	case -ENODEV:
666 		return AE_NOT_FOUND;
667 		break;
668 	case -ETIME:
669 		return AE_TIME;
670 		break;
671 	default:
672 		return AE_OK;
673 	}
674 }
675 
676 /* --------------------------------------------------------------------------
677                                Driver Interface
678    -------------------------------------------------------------------------- */
679 static acpi_status
680 ec_parse_io_ports(struct acpi_resource *resource, void *context);
681 
682 static struct acpi_ec *make_acpi_ec(void)
683 {
684 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
685 	if (!ec)
686 		return NULL;
687 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
688 	mutex_init(&ec->lock);
689 	init_waitqueue_head(&ec->wait);
690 	INIT_LIST_HEAD(&ec->list);
691 	spin_lock_init(&ec->curr_lock);
692 	return ec;
693 }
694 
695 static acpi_status
696 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
697 			       void *context, void **return_value)
698 {
699 	char node_name[5];
700 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
701 	struct acpi_ec *ec = context;
702 	int value = 0;
703 	acpi_status status;
704 
705 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
706 
707 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
708 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
709 	}
710 	return AE_OK;
711 }
712 
713 static acpi_status
714 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
715 {
716 	acpi_status status;
717 	unsigned long long tmp = 0;
718 
719 	struct acpi_ec *ec = context;
720 
721 	/* clear addr values, ec_parse_io_ports depend on it */
722 	ec->command_addr = ec->data_addr = 0;
723 
724 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
725 				     ec_parse_io_ports, ec);
726 	if (ACPI_FAILURE(status))
727 		return status;
728 
729 	/* Get GPE bit assignment (EC events). */
730 	/* TODO: Add support for _GPE returning a package */
731 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
732 	if (ACPI_FAILURE(status))
733 		return status;
734 	ec->gpe = tmp;
735 	/* Use the global lock for all EC transactions? */
736 	tmp = 0;
737 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
738 	ec->global_lock = tmp;
739 	ec->handle = handle;
740 	return AE_CTRL_TERMINATE;
741 }
742 
743 static int ec_install_handlers(struct acpi_ec *ec)
744 {
745 	acpi_status status;
746 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
747 		return 0;
748 	status = acpi_install_gpe_handler(NULL, ec->gpe,
749 				  ACPI_GPE_EDGE_TRIGGERED,
750 				  &acpi_ec_gpe_handler, ec);
751 	if (ACPI_FAILURE(status))
752 		return -ENODEV;
753 
754 	acpi_enable_gpe(NULL, ec->gpe);
755 	status = acpi_install_address_space_handler(ec->handle,
756 						    ACPI_ADR_SPACE_EC,
757 						    &acpi_ec_space_handler,
758 						    NULL, ec);
759 	if (ACPI_FAILURE(status)) {
760 		if (status == AE_NOT_FOUND) {
761 			/*
762 			 * Maybe OS fails in evaluating the _REG object.
763 			 * The AE_NOT_FOUND error will be ignored and OS
764 			 * continue to initialize EC.
765 			 */
766 			printk(KERN_ERR "Fail in evaluating the _REG object"
767 				" of EC device. Broken bios is suspected.\n");
768 		} else {
769 			acpi_remove_gpe_handler(NULL, ec->gpe,
770 				&acpi_ec_gpe_handler);
771 			acpi_disable_gpe(NULL, ec->gpe);
772 			return -ENODEV;
773 		}
774 	}
775 
776 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
777 	return 0;
778 }
779 
780 static void ec_remove_handlers(struct acpi_ec *ec)
781 {
782 	acpi_disable_gpe(NULL, ec->gpe);
783 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
784 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
785 		pr_err(PREFIX "failed to remove space handler\n");
786 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
787 				&acpi_ec_gpe_handler)))
788 		pr_err(PREFIX "failed to remove gpe handler\n");
789 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
790 }
791 
792 static int acpi_ec_add(struct acpi_device *device)
793 {
794 	struct acpi_ec *ec = NULL;
795 	int ret;
796 
797 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
798 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
799 
800 	/* Check for boot EC */
801 	if (boot_ec &&
802 	    (boot_ec->handle == device->handle ||
803 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
804 		ec = boot_ec;
805 		boot_ec = NULL;
806 	} else {
807 		ec = make_acpi_ec();
808 		if (!ec)
809 			return -ENOMEM;
810 	}
811 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
812 		AE_CTRL_TERMINATE) {
813 			kfree(ec);
814 			return -EINVAL;
815 	}
816 
817 	/* Find and register all query methods */
818 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
819 			    acpi_ec_register_query_methods, NULL, ec, NULL);
820 
821 	if (!first_ec)
822 		first_ec = ec;
823 	device->driver_data = ec;
824 
825 	ret = !!request_region(ec->data_addr, 1, "EC data");
826 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
827 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
828 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
829 
830 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
831 			  ec->gpe, ec->command_addr, ec->data_addr);
832 
833 	ret = ec_install_handlers(ec);
834 
835 	/* EC is fully operational, allow queries */
836 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
837 	return ret;
838 }
839 
840 static int acpi_ec_remove(struct acpi_device *device, int type)
841 {
842 	struct acpi_ec *ec;
843 	struct acpi_ec_query_handler *handler, *tmp;
844 
845 	if (!device)
846 		return -EINVAL;
847 
848 	ec = acpi_driver_data(device);
849 	ec_remove_handlers(ec);
850 	mutex_lock(&ec->lock);
851 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
852 		list_del(&handler->node);
853 		kfree(handler);
854 	}
855 	mutex_unlock(&ec->lock);
856 	release_region(ec->data_addr, 1);
857 	release_region(ec->command_addr, 1);
858 	device->driver_data = NULL;
859 	if (ec == first_ec)
860 		first_ec = NULL;
861 	kfree(ec);
862 	return 0;
863 }
864 
865 static acpi_status
866 ec_parse_io_ports(struct acpi_resource *resource, void *context)
867 {
868 	struct acpi_ec *ec = context;
869 
870 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
871 		return AE_OK;
872 
873 	/*
874 	 * The first address region returned is the data port, and
875 	 * the second address region returned is the status/command
876 	 * port.
877 	 */
878 	if (ec->data_addr == 0)
879 		ec->data_addr = resource->data.io.minimum;
880 	else if (ec->command_addr == 0)
881 		ec->command_addr = resource->data.io.minimum;
882 	else
883 		return AE_CTRL_TERMINATE;
884 
885 	return AE_OK;
886 }
887 
888 int __init acpi_boot_ec_enable(void)
889 {
890 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
891 		return 0;
892 	if (!ec_install_handlers(boot_ec)) {
893 		first_ec = boot_ec;
894 		return 0;
895 	}
896 	return -EFAULT;
897 }
898 
899 static const struct acpi_device_id ec_device_ids[] = {
900 	{"PNP0C09", 0},
901 	{"", 0},
902 };
903 
904 /* Some BIOS do not survive early DSDT scan, skip it */
905 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
906 {
907 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
908 	return 0;
909 }
910 
911 /* ASUStek often supplies us with broken ECDT, validate it */
912 static int ec_validate_ecdt(const struct dmi_system_id *id)
913 {
914 	EC_FLAGS_VALIDATE_ECDT = 1;
915 	return 0;
916 }
917 
918 /* MSI EC needs special treatment, enable it */
919 static int ec_flag_msi(const struct dmi_system_id *id)
920 {
921 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
922 	EC_FLAGS_MSI = 1;
923 	EC_FLAGS_VALIDATE_ECDT = 1;
924 	return 0;
925 }
926 
927 static struct dmi_system_id __initdata ec_dmi_table[] = {
928 	{
929 	ec_skip_dsdt_scan, "Compal JFL92", {
930 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
931 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
932 	{
933 	ec_flag_msi, "MSI hardware", {
934 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
935 	{
936 	ec_flag_msi, "MSI hardware", {
937 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
938 	{
939 	ec_flag_msi, "MSI hardware", {
940 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
941 	{
942 	ec_flag_msi, "MSI hardware", {
943 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
944 	{
945 	ec_flag_msi, "Quanta hardware", {
946 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
947 	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
948 	{
949 	ec_flag_msi, "Quanta hardware", {
950 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
951 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
952 	{
953 	ec_validate_ecdt, "ASUS hardware", {
954 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
955 	{
956 	ec_validate_ecdt, "ASUS hardware", {
957 	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
958 	{},
959 };
960 
961 
962 int __init acpi_ec_ecdt_probe(void)
963 {
964 	acpi_status status;
965 	struct acpi_ec *saved_ec = NULL;
966 	struct acpi_table_ecdt *ecdt_ptr;
967 
968 	boot_ec = make_acpi_ec();
969 	if (!boot_ec)
970 		return -ENOMEM;
971 	/*
972 	 * Generate a boot ec context
973 	 */
974 	dmi_check_system(ec_dmi_table);
975 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
976 				(struct acpi_table_header **)&ecdt_ptr);
977 	if (ACPI_SUCCESS(status)) {
978 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
979 		boot_ec->command_addr = ecdt_ptr->control.address;
980 		boot_ec->data_addr = ecdt_ptr->data.address;
981 		boot_ec->gpe = ecdt_ptr->gpe;
982 		boot_ec->handle = ACPI_ROOT_OBJECT;
983 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
984 		/* Don't trust ECDT, which comes from ASUSTek */
985 		if (!EC_FLAGS_VALIDATE_ECDT)
986 			goto install;
987 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
988 		if (!saved_ec)
989 			return -ENOMEM;
990 	/* fall through */
991 	}
992 
993 	if (EC_FLAGS_SKIP_DSDT_SCAN)
994 		return -ENODEV;
995 
996 	/* This workaround is needed only on some broken machines,
997 	 * which require early EC, but fail to provide ECDT */
998 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
999 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1000 					boot_ec, NULL);
1001 	/* Check that acpi_get_devices actually find something */
1002 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1003 		goto error;
1004 	if (saved_ec) {
1005 		/* try to find good ECDT from ASUSTek */
1006 		if (saved_ec->command_addr != boot_ec->command_addr ||
1007 		    saved_ec->data_addr != boot_ec->data_addr ||
1008 		    saved_ec->gpe != boot_ec->gpe ||
1009 		    saved_ec->handle != boot_ec->handle)
1010 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1011 			"ECDT tables, which are very hard to workaround. "
1012 			"Trying to use DSDT EC info instead. Please send "
1013 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1014 		kfree(saved_ec);
1015 		saved_ec = NULL;
1016 	} else {
1017 		/* We really need to limit this workaround, the only ASUS,
1018 		* which needs it, has fake EC._INI method, so use it as flag.
1019 		* Keep boot_ec struct as it will be needed soon.
1020 		*/
1021 		acpi_handle dummy;
1022 		if (!dmi_name_in_vendors("ASUS") ||
1023 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1024 							&dummy)))
1025 			return -ENODEV;
1026 	}
1027 install:
1028 	if (!ec_install_handlers(boot_ec)) {
1029 		first_ec = boot_ec;
1030 		return 0;
1031 	}
1032 error:
1033 	kfree(boot_ec);
1034 	boot_ec = NULL;
1035 	return -ENODEV;
1036 }
1037 
1038 static struct acpi_driver acpi_ec_driver = {
1039 	.name = "ec",
1040 	.class = ACPI_EC_CLASS,
1041 	.ids = ec_device_ids,
1042 	.ops = {
1043 		.add = acpi_ec_add,
1044 		.remove = acpi_ec_remove,
1045 		},
1046 };
1047 
1048 int __init acpi_ec_init(void)
1049 {
1050 	int result = 0;
1051 
1052 	/* Now register the driver for the EC */
1053 	result = acpi_bus_register_driver(&acpi_ec_driver);
1054 	if (result < 0)
1055 		return -ENODEV;
1056 
1057 	return result;
1058 }
1059 
1060 /* EC driver currently not unloadable */
1061 #if 0
1062 static void __exit acpi_ec_exit(void)
1063 {
1064 
1065 	acpi_bus_unregister_driver(&acpi_ec_driver);
1066 	return;
1067 }
1068 #endif	/* 0 */
1069