xref: /linux/drivers/acpi/ec.c (revision f8324e20f8289dffc646d64366332e05eaacab25)
1 /*
2  *  ec.c - ACPI Embedded Controller Driver (v2.1)
3  *
4  *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or (at
15  *  your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful, but
18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20  *  General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License along
23  *  with this program; if not, write to the Free Software Foundation, Inc.,
24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25  *
26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27  */
28 
29 /* Uncomment next line to get verbose printout */
30 /* #define DEBUG */
31 
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/init.h>
35 #include <linux/types.h>
36 #include <linux/delay.h>
37 #include <linux/proc_fs.h>
38 #include <linux/seq_file.h>
39 #include <linux/interrupt.h>
40 #include <linux/list.h>
41 #include <linux/spinlock.h>
42 #include <linux/slab.h>
43 #include <asm/io.h>
44 #include <acpi/acpi_bus.h>
45 #include <acpi/acpi_drivers.h>
46 #include <linux/dmi.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 #define PREFIX				"ACPI: EC: "
53 
54 /* EC status register */
55 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
56 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
57 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
58 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
59 
60 /* EC commands */
61 enum ec_command {
62 	ACPI_EC_COMMAND_READ = 0x80,
63 	ACPI_EC_COMMAND_WRITE = 0x81,
64 	ACPI_EC_BURST_ENABLE = 0x82,
65 	ACPI_EC_BURST_DISABLE = 0x83,
66 	ACPI_EC_COMMAND_QUERY = 0x84,
67 };
68 
69 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
70 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
71 #define ACPI_EC_CDELAY		10	/* Wait 10us before polling EC */
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 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
86 /* External interfaces use first EC only, so remember */
87 typedef int (*acpi_ec_query_func) (void *data);
88 
89 struct acpi_ec_query_handler {
90 	struct list_head node;
91 	acpi_ec_query_func func;
92 	acpi_handle handle;
93 	void *data;
94 	u8 query_bit;
95 };
96 
97 struct transaction {
98 	const u8 *wdata;
99 	u8 *rdata;
100 	unsigned short irq_count;
101 	u8 command;
102 	u8 wi;
103 	u8 ri;
104 	u8 wlen;
105 	u8 rlen;
106 	bool done;
107 };
108 
109 static struct acpi_ec {
110 	acpi_handle handle;
111 	unsigned long gpe;
112 	unsigned long command_addr;
113 	unsigned long data_addr;
114 	unsigned long global_lock;
115 	unsigned long flags;
116 	struct mutex lock;
117 	wait_queue_head_t wait;
118 	struct list_head list;
119 	struct transaction *curr;
120 	spinlock_t curr_lock;
121 } *boot_ec, *first_ec;
122 
123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
124 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(ACPI_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(ACPI_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 		/*
317 		 * It has to be disabled at the hardware level regardless of the
318 		 * GPE reference counting, so that it doesn't trigger.
319 		 */
320 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
321 	}
322 
323 	status = acpi_ec_transaction_unlocked(ec, t);
324 
325 	/* check if we received SCI during transaction */
326 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
327 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
328 		msleep(1);
329 		/*
330 		 * It is safe to enable the GPE outside of the transaction.  Use
331 		 * acpi_set_gpe() for that, since we used it to disable the GPE
332 		 * above.
333 		 */
334 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
335 	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
336 		pr_info(PREFIX "GPE storm detected, "
337 			"transactions will use polling mode\n");
338 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
339 	}
340 	pr_debug(PREFIX "transaction end\n");
341 end:
342 	if (ec->global_lock)
343 		acpi_release_global_lock(glk);
344 unlock:
345 	mutex_unlock(&ec->lock);
346 	return status;
347 }
348 
349 static int acpi_ec_burst_enable(struct acpi_ec *ec)
350 {
351 	u8 d;
352 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
353 				.wdata = NULL, .rdata = &d,
354 				.wlen = 0, .rlen = 1};
355 
356 	return acpi_ec_transaction(ec, &t);
357 }
358 
359 static int acpi_ec_burst_disable(struct acpi_ec *ec)
360 {
361 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
362 				.wdata = NULL, .rdata = NULL,
363 				.wlen = 0, .rlen = 0};
364 
365 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
366 				acpi_ec_transaction(ec, &t) : 0;
367 }
368 
369 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
370 {
371 	int result;
372 	u8 d;
373 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
374 				.wdata = &address, .rdata = &d,
375 				.wlen = 1, .rlen = 1};
376 
377 	result = acpi_ec_transaction(ec, &t);
378 	*data = d;
379 	return result;
380 }
381 
382 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
383 {
384 	u8 wdata[2] = { address, data };
385 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
386 				.wdata = wdata, .rdata = NULL,
387 				.wlen = 2, .rlen = 0};
388 
389 	return acpi_ec_transaction(ec, &t);
390 }
391 
392 /*
393  * Externally callable EC access functions. For now, assume 1 EC only
394  */
395 int ec_burst_enable(void)
396 {
397 	if (!first_ec)
398 		return -ENODEV;
399 	return acpi_ec_burst_enable(first_ec);
400 }
401 
402 EXPORT_SYMBOL(ec_burst_enable);
403 
404 int ec_burst_disable(void)
405 {
406 	if (!first_ec)
407 		return -ENODEV;
408 	return acpi_ec_burst_disable(first_ec);
409 }
410 
411 EXPORT_SYMBOL(ec_burst_disable);
412 
413 int ec_read(u8 addr, u8 * val)
414 {
415 	int err;
416 	u8 temp_data;
417 
418 	if (!first_ec)
419 		return -ENODEV;
420 
421 	err = acpi_ec_read(first_ec, addr, &temp_data);
422 
423 	if (!err) {
424 		*val = temp_data;
425 		return 0;
426 	} else
427 		return err;
428 }
429 
430 EXPORT_SYMBOL(ec_read);
431 
432 int ec_write(u8 addr, u8 val)
433 {
434 	int err;
435 
436 	if (!first_ec)
437 		return -ENODEV;
438 
439 	err = acpi_ec_write(first_ec, addr, val);
440 
441 	return err;
442 }
443 
444 EXPORT_SYMBOL(ec_write);
445 
446 int ec_transaction(u8 command,
447 		   const u8 * wdata, unsigned wdata_len,
448 		   u8 * rdata, unsigned rdata_len,
449 		   int force_poll)
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 void acpi_ec_block_transactions(void)
463 {
464 	struct acpi_ec *ec = first_ec;
465 
466 	if (!ec)
467 		return;
468 
469 	mutex_lock(&ec->lock);
470 	/* Prevent transactions from being carried out */
471 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
472 	mutex_unlock(&ec->lock);
473 }
474 
475 void acpi_ec_unblock_transactions(void)
476 {
477 	struct acpi_ec *ec = first_ec;
478 
479 	if (!ec)
480 		return;
481 
482 	mutex_lock(&ec->lock);
483 	/* Allow transactions to be carried out again */
484 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
485 	mutex_unlock(&ec->lock);
486 }
487 
488 void acpi_ec_unblock_transactions_early(void)
489 {
490 	/*
491 	 * Allow transactions to happen again (this function is called from
492 	 * atomic context during wakeup, so we don't need to acquire the mutex).
493 	 */
494 	if (first_ec)
495 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
496 }
497 
498 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
499 {
500 	int result;
501 	u8 d;
502 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
503 				.wdata = NULL, .rdata = &d,
504 				.wlen = 0, .rlen = 1};
505 	if (!ec || !data)
506 		return -EINVAL;
507 	/*
508 	 * Query the EC to find out which _Qxx method we need to evaluate.
509 	 * Note that successful completion of the query causes the ACPI_EC_SCI
510 	 * bit to be cleared (and thus clearing the interrupt source).
511 	 */
512 	result = acpi_ec_transaction_unlocked(ec, &t);
513 	if (result)
514 		return result;
515 	if (!d)
516 		return -ENODATA;
517 	*data = d;
518 	return 0;
519 }
520 
521 /* --------------------------------------------------------------------------
522                                 Event Management
523    -------------------------------------------------------------------------- */
524 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
525 			      acpi_handle handle, acpi_ec_query_func func,
526 			      void *data)
527 {
528 	struct acpi_ec_query_handler *handler =
529 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
530 	if (!handler)
531 		return -ENOMEM;
532 
533 	handler->query_bit = query_bit;
534 	handler->handle = handle;
535 	handler->func = func;
536 	handler->data = data;
537 	mutex_lock(&ec->lock);
538 	list_add(&handler->node, &ec->list);
539 	mutex_unlock(&ec->lock);
540 	return 0;
541 }
542 
543 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
544 
545 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
546 {
547 	struct acpi_ec_query_handler *handler, *tmp;
548 	mutex_lock(&ec->lock);
549 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
550 		if (query_bit == handler->query_bit) {
551 			list_del(&handler->node);
552 			kfree(handler);
553 		}
554 	}
555 	mutex_unlock(&ec->lock);
556 }
557 
558 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
559 
560 static void acpi_ec_run(void *cxt)
561 {
562 	struct acpi_ec_query_handler *handler = cxt;
563 	if (!handler)
564 		return;
565 	pr_debug(PREFIX "start query execution\n");
566 	if (handler->func)
567 		handler->func(handler->data);
568 	else if (handler->handle)
569 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
570 	pr_debug(PREFIX "stop query execution\n");
571 	kfree(handler);
572 }
573 
574 static int acpi_ec_sync_query(struct acpi_ec *ec)
575 {
576 	u8 value = 0;
577 	int status;
578 	struct acpi_ec_query_handler *handler, *copy;
579 	if ((status = acpi_ec_query_unlocked(ec, &value)))
580 		return status;
581 	list_for_each_entry(handler, &ec->list, node) {
582 		if (value == handler->query_bit) {
583 			/* have custom handler for this bit */
584 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
585 			if (!copy)
586 				return -ENOMEM;
587 			memcpy(copy, handler, sizeof(*copy));
588 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
589 			return acpi_os_execute((copy->func) ?
590 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
591 				acpi_ec_run, copy);
592 		}
593 	}
594 	return 0;
595 }
596 
597 static void acpi_ec_gpe_query(void *ec_cxt)
598 {
599 	struct acpi_ec *ec = ec_cxt;
600 	if (!ec)
601 		return;
602 	mutex_lock(&ec->lock);
603 	acpi_ec_sync_query(ec);
604 	mutex_unlock(&ec->lock);
605 }
606 
607 static void acpi_ec_gpe_query(void *ec_cxt);
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(void *data)
622 {
623 	struct acpi_ec *ec = data;
624 
625 	pr_debug(PREFIX "~~~> interrupt\n");
626 
627 	advance_transaction(ec, acpi_ec_read_status(ec));
628 	if (ec_transaction_done(ec) &&
629 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
630 		wake_up(&ec->wait);
631 		ec_check_sci(ec, acpi_ec_read_status(ec));
632 	}
633 	return ACPI_INTERRUPT_HANDLED;
634 }
635 
636 /* --------------------------------------------------------------------------
637                              Address Space Management
638    -------------------------------------------------------------------------- */
639 
640 static acpi_status
641 acpi_ec_space_handler(u32 function, acpi_physical_address address,
642 		      u32 bits, u64 *value64,
643 		      void *handler_context, void *region_context)
644 {
645 	struct acpi_ec *ec = handler_context;
646 	int result = 0, i, bytes = bits / 8;
647 	u8 *value = (u8 *)value64;
648 
649 	if ((address > 0xFF) || !value || !handler_context)
650 		return AE_BAD_PARAMETER;
651 
652 	if (function != ACPI_READ && function != ACPI_WRITE)
653 		return AE_BAD_PARAMETER;
654 
655 	if (EC_FLAGS_MSI || bits > 8)
656 		acpi_ec_burst_enable(ec);
657 
658 	for (i = 0; i < bytes; ++i, ++address, ++value)
659 		result = (function == ACPI_READ) ?
660 			acpi_ec_read(ec, address, value) :
661 			acpi_ec_write(ec, address, *value);
662 
663 	if (EC_FLAGS_MSI || bits > 8)
664 		acpi_ec_burst_disable(ec);
665 
666 	switch (result) {
667 	case -EINVAL:
668 		return AE_BAD_PARAMETER;
669 		break;
670 	case -ENODEV:
671 		return AE_NOT_FOUND;
672 		break;
673 	case -ETIME:
674 		return AE_TIME;
675 		break;
676 	default:
677 		return AE_OK;
678 	}
679 }
680 
681 /* --------------------------------------------------------------------------
682                               FS Interface (/proc)
683    -------------------------------------------------------------------------- */
684 
685 static struct proc_dir_entry *acpi_ec_dir;
686 
687 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
688 {
689 	struct acpi_ec *ec = seq->private;
690 
691 	if (!ec)
692 		goto end;
693 
694 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
695 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
696 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
697 	seq_printf(seq, "use global lock:\t%s\n",
698 		   ec->global_lock ? "yes" : "no");
699       end:
700 	return 0;
701 }
702 
703 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
704 {
705 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
706 }
707 
708 static const struct file_operations acpi_ec_info_ops = {
709 	.open = acpi_ec_info_open_fs,
710 	.read = seq_read,
711 	.llseek = seq_lseek,
712 	.release = single_release,
713 	.owner = THIS_MODULE,
714 };
715 
716 static int acpi_ec_add_fs(struct acpi_device *device)
717 {
718 	struct proc_dir_entry *entry = NULL;
719 
720 	if (!acpi_device_dir(device)) {
721 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
722 						     acpi_ec_dir);
723 		if (!acpi_device_dir(device))
724 			return -ENODEV;
725 	}
726 
727 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
728 				 acpi_device_dir(device),
729 				 &acpi_ec_info_ops, acpi_driver_data(device));
730 	if (!entry)
731 		return -ENODEV;
732 	return 0;
733 }
734 
735 static int acpi_ec_remove_fs(struct acpi_device *device)
736 {
737 
738 	if (acpi_device_dir(device)) {
739 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
740 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
741 		acpi_device_dir(device) = NULL;
742 	}
743 
744 	return 0;
745 }
746 
747 /* --------------------------------------------------------------------------
748                                Driver Interface
749    -------------------------------------------------------------------------- */
750 static acpi_status
751 ec_parse_io_ports(struct acpi_resource *resource, void *context);
752 
753 static struct acpi_ec *make_acpi_ec(void)
754 {
755 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
756 	if (!ec)
757 		return NULL;
758 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
759 	mutex_init(&ec->lock);
760 	init_waitqueue_head(&ec->wait);
761 	INIT_LIST_HEAD(&ec->list);
762 	spin_lock_init(&ec->curr_lock);
763 	return ec;
764 }
765 
766 static acpi_status
767 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
768 			       void *context, void **return_value)
769 {
770 	char node_name[5];
771 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
772 	struct acpi_ec *ec = context;
773 	int value = 0;
774 	acpi_status status;
775 
776 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
777 
778 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
779 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
780 	}
781 	return AE_OK;
782 }
783 
784 static acpi_status
785 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
786 {
787 	acpi_status status;
788 	unsigned long long tmp = 0;
789 
790 	struct acpi_ec *ec = context;
791 
792 	/* clear addr values, ec_parse_io_ports depend on it */
793 	ec->command_addr = ec->data_addr = 0;
794 
795 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
796 				     ec_parse_io_ports, ec);
797 	if (ACPI_FAILURE(status))
798 		return status;
799 
800 	/* Get GPE bit assignment (EC events). */
801 	/* TODO: Add support for _GPE returning a package */
802 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
803 	if (ACPI_FAILURE(status))
804 		return status;
805 	ec->gpe = tmp;
806 	/* Use the global lock for all EC transactions? */
807 	tmp = 0;
808 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
809 	ec->global_lock = tmp;
810 	ec->handle = handle;
811 	return AE_CTRL_TERMINATE;
812 }
813 
814 static int ec_install_handlers(struct acpi_ec *ec)
815 {
816 	acpi_status status;
817 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
818 		return 0;
819 	status = acpi_install_gpe_handler(NULL, ec->gpe,
820 				  ACPI_GPE_EDGE_TRIGGERED,
821 				  &acpi_ec_gpe_handler, ec);
822 	if (ACPI_FAILURE(status))
823 		return -ENODEV;
824 
825 	acpi_enable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
826 	status = acpi_install_address_space_handler(ec->handle,
827 						    ACPI_ADR_SPACE_EC,
828 						    &acpi_ec_space_handler,
829 						    NULL, ec);
830 	if (ACPI_FAILURE(status)) {
831 		if (status == AE_NOT_FOUND) {
832 			/*
833 			 * Maybe OS fails in evaluating the _REG object.
834 			 * The AE_NOT_FOUND error will be ignored and OS
835 			 * continue to initialize EC.
836 			 */
837 			printk(KERN_ERR "Fail in evaluating the _REG object"
838 				" of EC device. Broken bios is suspected.\n");
839 		} else {
840 			acpi_remove_gpe_handler(NULL, ec->gpe,
841 				&acpi_ec_gpe_handler);
842 			acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
843 			return -ENODEV;
844 		}
845 	}
846 
847 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
848 	return 0;
849 }
850 
851 static void ec_remove_handlers(struct acpi_ec *ec)
852 {
853 	acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
854 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
855 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
856 		pr_err(PREFIX "failed to remove space handler\n");
857 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
858 				&acpi_ec_gpe_handler)))
859 		pr_err(PREFIX "failed to remove gpe handler\n");
860 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
861 }
862 
863 static int acpi_ec_add(struct acpi_device *device)
864 {
865 	struct acpi_ec *ec = NULL;
866 	int ret;
867 
868 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
869 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
870 
871 	/* Check for boot EC */
872 	if (boot_ec &&
873 	    (boot_ec->handle == device->handle ||
874 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
875 		ec = boot_ec;
876 		boot_ec = NULL;
877 	} else {
878 		ec = make_acpi_ec();
879 		if (!ec)
880 			return -ENOMEM;
881 	}
882 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
883 		AE_CTRL_TERMINATE) {
884 			kfree(ec);
885 			return -EINVAL;
886 	}
887 
888 	ec->handle = device->handle;
889 
890 	/* Find and register all query methods */
891 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
892 			    acpi_ec_register_query_methods, NULL, ec, NULL);
893 
894 	if (!first_ec)
895 		first_ec = ec;
896 	device->driver_data = ec;
897 	acpi_ec_add_fs(device);
898 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
899 			  ec->gpe, ec->command_addr, ec->data_addr);
900 
901 	ret = ec_install_handlers(ec);
902 
903 	/* EC is fully operational, allow queries */
904 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
905 	return ret;
906 }
907 
908 static int acpi_ec_remove(struct acpi_device *device, int type)
909 {
910 	struct acpi_ec *ec;
911 	struct acpi_ec_query_handler *handler, *tmp;
912 
913 	if (!device)
914 		return -EINVAL;
915 
916 	ec = acpi_driver_data(device);
917 	ec_remove_handlers(ec);
918 	mutex_lock(&ec->lock);
919 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
920 		list_del(&handler->node);
921 		kfree(handler);
922 	}
923 	mutex_unlock(&ec->lock);
924 	acpi_ec_remove_fs(device);
925 	device->driver_data = NULL;
926 	if (ec == first_ec)
927 		first_ec = NULL;
928 	kfree(ec);
929 	return 0;
930 }
931 
932 static acpi_status
933 ec_parse_io_ports(struct acpi_resource *resource, void *context)
934 {
935 	struct acpi_ec *ec = context;
936 
937 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
938 		return AE_OK;
939 
940 	/*
941 	 * The first address region returned is the data port, and
942 	 * the second address region returned is the status/command
943 	 * port.
944 	 */
945 	if (ec->data_addr == 0)
946 		ec->data_addr = resource->data.io.minimum;
947 	else if (ec->command_addr == 0)
948 		ec->command_addr = resource->data.io.minimum;
949 	else
950 		return AE_CTRL_TERMINATE;
951 
952 	return AE_OK;
953 }
954 
955 int __init acpi_boot_ec_enable(void)
956 {
957 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
958 		return 0;
959 	if (!ec_install_handlers(boot_ec)) {
960 		first_ec = boot_ec;
961 		return 0;
962 	}
963 	return -EFAULT;
964 }
965 
966 static const struct acpi_device_id ec_device_ids[] = {
967 	{"PNP0C09", 0},
968 	{"", 0},
969 };
970 
971 /* Some BIOS do not survive early DSDT scan, skip it */
972 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
973 {
974 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
975 	return 0;
976 }
977 
978 /* ASUStek often supplies us with broken ECDT, validate it */
979 static int ec_validate_ecdt(const struct dmi_system_id *id)
980 {
981 	EC_FLAGS_VALIDATE_ECDT = 1;
982 	return 0;
983 }
984 
985 /* MSI EC needs special treatment, enable it */
986 static int ec_flag_msi(const struct dmi_system_id *id)
987 {
988 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
989 	EC_FLAGS_MSI = 1;
990 	EC_FLAGS_VALIDATE_ECDT = 1;
991 	return 0;
992 }
993 
994 static struct dmi_system_id __initdata ec_dmi_table[] = {
995 	{
996 	ec_skip_dsdt_scan, "Compal JFL92", {
997 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
998 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
999 	{
1000 	ec_flag_msi, "MSI hardware", {
1001 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1002 	{
1003 	ec_flag_msi, "MSI hardware", {
1004 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1005 	{
1006 	ec_flag_msi, "MSI hardware", {
1007 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1008 	{
1009 	ec_validate_ecdt, "ASUS hardware", {
1010 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1011 	{},
1012 };
1013 
1014 
1015 int __init acpi_ec_ecdt_probe(void)
1016 {
1017 	acpi_status status;
1018 	struct acpi_ec *saved_ec = NULL;
1019 	struct acpi_table_ecdt *ecdt_ptr;
1020 
1021 	boot_ec = make_acpi_ec();
1022 	if (!boot_ec)
1023 		return -ENOMEM;
1024 	/*
1025 	 * Generate a boot ec context
1026 	 */
1027 	dmi_check_system(ec_dmi_table);
1028 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1029 				(struct acpi_table_header **)&ecdt_ptr);
1030 	if (ACPI_SUCCESS(status)) {
1031 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1032 		boot_ec->command_addr = ecdt_ptr->control.address;
1033 		boot_ec->data_addr = ecdt_ptr->data.address;
1034 		boot_ec->gpe = ecdt_ptr->gpe;
1035 		boot_ec->handle = ACPI_ROOT_OBJECT;
1036 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1037 		/* Don't trust ECDT, which comes from ASUSTek */
1038 		if (!EC_FLAGS_VALIDATE_ECDT)
1039 			goto install;
1040 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1041 		if (!saved_ec)
1042 			return -ENOMEM;
1043 	/* fall through */
1044 	}
1045 
1046 	if (EC_FLAGS_SKIP_DSDT_SCAN)
1047 		return -ENODEV;
1048 
1049 	/* This workaround is needed only on some broken machines,
1050 	 * which require early EC, but fail to provide ECDT */
1051 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1052 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1053 					boot_ec, NULL);
1054 	/* Check that acpi_get_devices actually find something */
1055 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1056 		goto error;
1057 	if (saved_ec) {
1058 		/* try to find good ECDT from ASUSTek */
1059 		if (saved_ec->command_addr != boot_ec->command_addr ||
1060 		    saved_ec->data_addr != boot_ec->data_addr ||
1061 		    saved_ec->gpe != boot_ec->gpe ||
1062 		    saved_ec->handle != boot_ec->handle)
1063 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1064 			"ECDT tables, which are very hard to workaround. "
1065 			"Trying to use DSDT EC info instead. Please send "
1066 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1067 		kfree(saved_ec);
1068 		saved_ec = NULL;
1069 	} else {
1070 		/* We really need to limit this workaround, the only ASUS,
1071 		* which needs it, has fake EC._INI method, so use it as flag.
1072 		* Keep boot_ec struct as it will be needed soon.
1073 		*/
1074 		acpi_handle dummy;
1075 		if (!dmi_name_in_vendors("ASUS") ||
1076 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1077 							&dummy)))
1078 			return -ENODEV;
1079 	}
1080 install:
1081 	if (!ec_install_handlers(boot_ec)) {
1082 		first_ec = boot_ec;
1083 		return 0;
1084 	}
1085 error:
1086 	kfree(boot_ec);
1087 	boot_ec = NULL;
1088 	return -ENODEV;
1089 }
1090 
1091 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1092 {
1093 	struct acpi_ec *ec = acpi_driver_data(device);
1094 	/* Stop using the GPE, but keep it reference counted. */
1095 	acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1096 	return 0;
1097 }
1098 
1099 static int acpi_ec_resume(struct acpi_device *device)
1100 {
1101 	struct acpi_ec *ec = acpi_driver_data(device);
1102 	/* Enable the GPE again, but don't reference count it once more. */
1103 	acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1104 	return 0;
1105 }
1106 
1107 static struct acpi_driver acpi_ec_driver = {
1108 	.name = "ec",
1109 	.class = ACPI_EC_CLASS,
1110 	.ids = ec_device_ids,
1111 	.ops = {
1112 		.add = acpi_ec_add,
1113 		.remove = acpi_ec_remove,
1114 		.suspend = acpi_ec_suspend,
1115 		.resume = acpi_ec_resume,
1116 		},
1117 };
1118 
1119 int __init acpi_ec_init(void)
1120 {
1121 	int result = 0;
1122 
1123 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1124 	if (!acpi_ec_dir)
1125 		return -ENODEV;
1126 
1127 	/* Now register the driver for the EC */
1128 	result = acpi_bus_register_driver(&acpi_ec_driver);
1129 	if (result < 0) {
1130 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1131 		return -ENODEV;
1132 	}
1133 
1134 	return result;
1135 }
1136 
1137 /* EC driver currently not unloadable */
1138 #if 0
1139 static void __exit acpi_ec_exit(void)
1140 {
1141 
1142 	acpi_bus_unregister_driver(&acpi_ec_driver);
1143 
1144 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1145 
1146 	return;
1147 }
1148 #endif	/* 0 */
1149