xref: /openbmc/linux/drivers/acpi/ec.c (revision b6dcefde)
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 <asm/io.h>
43 #include <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
45 #include <linux/dmi.h>
46 
47 #define ACPI_EC_CLASS			"embedded_controller"
48 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
49 #define ACPI_EC_FILE_INFO		"info"
50 
51 #define PREFIX				"ACPI: EC: "
52 
53 /* EC status register */
54 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
55 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
56 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
57 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
58 
59 /* EC commands */
60 enum ec_command {
61 	ACPI_EC_COMMAND_READ = 0x80,
62 	ACPI_EC_COMMAND_WRITE = 0x81,
63 	ACPI_EC_BURST_ENABLE = 0x82,
64 	ACPI_EC_BURST_DISABLE = 0x83,
65 	ACPI_EC_COMMAND_QUERY = 0x84,
66 };
67 
68 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
69 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
70 #define ACPI_EC_CDELAY		10	/* Wait 10us before polling EC */
71 #define ACPI_EC_MSI_UDELAY	550	/* Wait 550us for MSI EC */
72 
73 #define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
74 					   per one transaction */
75 
76 enum {
77 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
78 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
79 	EC_FLAGS_HANDLERS_INSTALLED	/* Handlers for GPE and
80 					 * OpReg are installed */
81 };
82 
83 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
84 /* External interfaces use first EC only, so remember */
85 typedef int (*acpi_ec_query_func) (void *data);
86 
87 struct acpi_ec_query_handler {
88 	struct list_head node;
89 	acpi_ec_query_func func;
90 	acpi_handle handle;
91 	void *data;
92 	u8 query_bit;
93 };
94 
95 struct transaction {
96 	const u8 *wdata;
97 	u8 *rdata;
98 	unsigned short irq_count;
99 	u8 command;
100 	u8 wi;
101 	u8 ri;
102 	u8 wlen;
103 	u8 rlen;
104 	bool done;
105 };
106 
107 static struct acpi_ec {
108 	acpi_handle handle;
109 	unsigned long gpe;
110 	unsigned long command_addr;
111 	unsigned long data_addr;
112 	unsigned long global_lock;
113 	unsigned long flags;
114 	struct mutex lock;
115 	wait_queue_head_t wait;
116 	struct list_head list;
117 	struct transaction *curr;
118 	spinlock_t curr_lock;
119 } *boot_ec, *first_ec;
120 
121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
124 
125 /* --------------------------------------------------------------------------
126                              Transaction Management
127    -------------------------------------------------------------------------- */
128 
129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
130 {
131 	u8 x = inb(ec->command_addr);
132 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
133 	return x;
134 }
135 
136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
137 {
138 	u8 x = inb(ec->data_addr);
139 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
140 	return x;
141 }
142 
143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
144 {
145 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
146 	outb(command, ec->command_addr);
147 }
148 
149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
150 {
151 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
152 	outb(data, ec->data_addr);
153 }
154 
155 static int ec_transaction_done(struct acpi_ec *ec)
156 {
157 	unsigned long flags;
158 	int ret = 0;
159 	spin_lock_irqsave(&ec->curr_lock, flags);
160 	if (!ec->curr || ec->curr->done)
161 		ret = 1;
162 	spin_unlock_irqrestore(&ec->curr_lock, flags);
163 	return ret;
164 }
165 
166 static void start_transaction(struct acpi_ec *ec)
167 {
168 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
169 	ec->curr->done = false;
170 	acpi_ec_write_cmd(ec, ec->curr->command);
171 }
172 
173 static void advance_transaction(struct acpi_ec *ec, u8 status)
174 {
175 	unsigned long flags;
176 	spin_lock_irqsave(&ec->curr_lock, flags);
177 	if (!ec->curr)
178 		goto unlock;
179 	if (ec->curr->wlen > ec->curr->wi) {
180 		if ((status & ACPI_EC_FLAG_IBF) == 0)
181 			acpi_ec_write_data(ec,
182 				ec->curr->wdata[ec->curr->wi++]);
183 		else
184 			goto err;
185 	} else if (ec->curr->rlen > ec->curr->ri) {
186 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
187 			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
188 			if (ec->curr->rlen == ec->curr->ri)
189 				ec->curr->done = true;
190 		} else
191 			goto err;
192 	} else if (ec->curr->wlen == ec->curr->wi &&
193 		   (status & ACPI_EC_FLAG_IBF) == 0)
194 		ec->curr->done = true;
195 	goto unlock;
196 err:
197 	/* false interrupt, state didn't change */
198 	if (in_interrupt())
199 		++ec->curr->irq_count;
200 unlock:
201 	spin_unlock_irqrestore(&ec->curr_lock, flags);
202 }
203 
204 static int acpi_ec_sync_query(struct acpi_ec *ec);
205 
206 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
207 {
208 	if (state & ACPI_EC_FLAG_SCI) {
209 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
210 			return acpi_ec_sync_query(ec);
211 	}
212 	return 0;
213 }
214 
215 static int ec_poll(struct acpi_ec *ec)
216 {
217 	unsigned long flags;
218 	int repeat = 2; /* number of command restarts */
219 	while (repeat--) {
220 		unsigned long delay = jiffies +
221 			msecs_to_jiffies(ACPI_EC_DELAY);
222 		do {
223 			/* don't sleep with disabled interrupts */
224 			if (EC_FLAGS_MSI || irqs_disabled()) {
225 				udelay(ACPI_EC_MSI_UDELAY);
226 				if (ec_transaction_done(ec))
227 					return 0;
228 			} else {
229 				if (wait_event_timeout(ec->wait,
230 						ec_transaction_done(ec),
231 						msecs_to_jiffies(1)))
232 					return 0;
233 			}
234 			advance_transaction(ec, acpi_ec_read_status(ec));
235 		} while (time_before(jiffies, delay));
236 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
237 			break;
238 		pr_debug(PREFIX "controller reset, restart transaction\n");
239 		spin_lock_irqsave(&ec->curr_lock, flags);
240 		start_transaction(ec);
241 		spin_unlock_irqrestore(&ec->curr_lock, flags);
242 	}
243 	return -ETIME;
244 }
245 
246 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
247 					struct transaction *t)
248 {
249 	unsigned long tmp;
250 	int ret = 0;
251 	if (EC_FLAGS_MSI)
252 		udelay(ACPI_EC_MSI_UDELAY);
253 	/* start transaction */
254 	spin_lock_irqsave(&ec->curr_lock, tmp);
255 	/* following two actions should be kept atomic */
256 	ec->curr = t;
257 	start_transaction(ec);
258 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
259 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
260 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
261 	ret = ec_poll(ec);
262 	spin_lock_irqsave(&ec->curr_lock, tmp);
263 	ec->curr = NULL;
264 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
265 	return ret;
266 }
267 
268 static int ec_check_ibf0(struct acpi_ec *ec)
269 {
270 	u8 status = acpi_ec_read_status(ec);
271 	return (status & ACPI_EC_FLAG_IBF) == 0;
272 }
273 
274 static int ec_wait_ibf0(struct acpi_ec *ec)
275 {
276 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
277 	/* interrupt wait manually if GPE mode is not active */
278 	while (time_before(jiffies, delay))
279 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
280 					msecs_to_jiffies(1)))
281 			return 0;
282 	return -ETIME;
283 }
284 
285 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
286 {
287 	int status;
288 	u32 glk;
289 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
290 		return -EINVAL;
291 	if (t->rdata)
292 		memset(t->rdata, 0, t->rlen);
293 	mutex_lock(&ec->lock);
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 		acpi_disable_gpe(NULL, ec->gpe);
311 	}
312 
313 	status = acpi_ec_transaction_unlocked(ec, t);
314 
315 	/* check if we received SCI during transaction */
316 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
317 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
318 		msleep(1);
319 		/* it is safe to enable GPE outside of transaction */
320 		acpi_enable_gpe(NULL, ec->gpe);
321 	} else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
322 		pr_info(PREFIX "GPE storm detected, "
323 			"transactions will use polling mode\n");
324 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
325 	}
326 	pr_debug(PREFIX "transaction end\n");
327 end:
328 	if (ec->global_lock)
329 		acpi_release_global_lock(glk);
330 unlock:
331 	mutex_unlock(&ec->lock);
332 	return status;
333 }
334 
335 static int acpi_ec_burst_enable(struct acpi_ec *ec)
336 {
337 	u8 d;
338 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
339 				.wdata = NULL, .rdata = &d,
340 				.wlen = 0, .rlen = 1};
341 
342 	return acpi_ec_transaction(ec, &t);
343 }
344 
345 static int acpi_ec_burst_disable(struct acpi_ec *ec)
346 {
347 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
348 				.wdata = NULL, .rdata = NULL,
349 				.wlen = 0, .rlen = 0};
350 
351 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
352 				acpi_ec_transaction(ec, &t) : 0;
353 }
354 
355 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
356 {
357 	int result;
358 	u8 d;
359 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
360 				.wdata = &address, .rdata = &d,
361 				.wlen = 1, .rlen = 1};
362 
363 	result = acpi_ec_transaction(ec, &t);
364 	*data = d;
365 	return result;
366 }
367 
368 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
369 {
370 	u8 wdata[2] = { address, data };
371 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
372 				.wdata = wdata, .rdata = NULL,
373 				.wlen = 2, .rlen = 0};
374 
375 	return acpi_ec_transaction(ec, &t);
376 }
377 
378 /*
379  * Externally callable EC access functions. For now, assume 1 EC only
380  */
381 int ec_burst_enable(void)
382 {
383 	if (!first_ec)
384 		return -ENODEV;
385 	return acpi_ec_burst_enable(first_ec);
386 }
387 
388 EXPORT_SYMBOL(ec_burst_enable);
389 
390 int ec_burst_disable(void)
391 {
392 	if (!first_ec)
393 		return -ENODEV;
394 	return acpi_ec_burst_disable(first_ec);
395 }
396 
397 EXPORT_SYMBOL(ec_burst_disable);
398 
399 int ec_read(u8 addr, u8 * val)
400 {
401 	int err;
402 	u8 temp_data;
403 
404 	if (!first_ec)
405 		return -ENODEV;
406 
407 	err = acpi_ec_read(first_ec, addr, &temp_data);
408 
409 	if (!err) {
410 		*val = temp_data;
411 		return 0;
412 	} else
413 		return err;
414 }
415 
416 EXPORT_SYMBOL(ec_read);
417 
418 int ec_write(u8 addr, u8 val)
419 {
420 	int err;
421 
422 	if (!first_ec)
423 		return -ENODEV;
424 
425 	err = acpi_ec_write(first_ec, addr, val);
426 
427 	return err;
428 }
429 
430 EXPORT_SYMBOL(ec_write);
431 
432 int ec_transaction(u8 command,
433 		   const u8 * wdata, unsigned wdata_len,
434 		   u8 * rdata, unsigned rdata_len,
435 		   int force_poll)
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 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
449 {
450 	int result;
451 	u8 d;
452 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
453 				.wdata = NULL, .rdata = &d,
454 				.wlen = 0, .rlen = 1};
455 	if (!ec || !data)
456 		return -EINVAL;
457 	/*
458 	 * Query the EC to find out which _Qxx method we need to evaluate.
459 	 * Note that successful completion of the query causes the ACPI_EC_SCI
460 	 * bit to be cleared (and thus clearing the interrupt source).
461 	 */
462 	result = acpi_ec_transaction_unlocked(ec, &t);
463 	if (result)
464 		return result;
465 	if (!d)
466 		return -ENODATA;
467 	*data = d;
468 	return 0;
469 }
470 
471 /* --------------------------------------------------------------------------
472                                 Event Management
473    -------------------------------------------------------------------------- */
474 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
475 			      acpi_handle handle, acpi_ec_query_func func,
476 			      void *data)
477 {
478 	struct acpi_ec_query_handler *handler =
479 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
480 	if (!handler)
481 		return -ENOMEM;
482 
483 	handler->query_bit = query_bit;
484 	handler->handle = handle;
485 	handler->func = func;
486 	handler->data = data;
487 	mutex_lock(&ec->lock);
488 	list_add(&handler->node, &ec->list);
489 	mutex_unlock(&ec->lock);
490 	return 0;
491 }
492 
493 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
494 
495 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
496 {
497 	struct acpi_ec_query_handler *handler, *tmp;
498 	mutex_lock(&ec->lock);
499 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
500 		if (query_bit == handler->query_bit) {
501 			list_del(&handler->node);
502 			kfree(handler);
503 		}
504 	}
505 	mutex_unlock(&ec->lock);
506 }
507 
508 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
509 
510 static void acpi_ec_run(void *cxt)
511 {
512 	struct acpi_ec_query_handler *handler = cxt;
513 	if (!handler)
514 		return;
515 	pr_debug(PREFIX "start query execution\n");
516 	if (handler->func)
517 		handler->func(handler->data);
518 	else if (handler->handle)
519 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
520 	pr_debug(PREFIX "stop query execution\n");
521 	kfree(handler);
522 }
523 
524 static int acpi_ec_sync_query(struct acpi_ec *ec)
525 {
526 	u8 value = 0;
527 	int status;
528 	struct acpi_ec_query_handler *handler, *copy;
529 	if ((status = acpi_ec_query_unlocked(ec, &value)))
530 		return status;
531 	list_for_each_entry(handler, &ec->list, node) {
532 		if (value == handler->query_bit) {
533 			/* have custom handler for this bit */
534 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
535 			if (!copy)
536 				return -ENOMEM;
537 			memcpy(copy, handler, sizeof(*copy));
538 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
539 			return acpi_os_execute((copy->func) ?
540 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
541 				acpi_ec_run, copy);
542 		}
543 	}
544 	return 0;
545 }
546 
547 static void acpi_ec_gpe_query(void *ec_cxt)
548 {
549 	struct acpi_ec *ec = ec_cxt;
550 	if (!ec)
551 		return;
552 	mutex_lock(&ec->lock);
553 	acpi_ec_sync_query(ec);
554 	mutex_unlock(&ec->lock);
555 }
556 
557 static void acpi_ec_gpe_query(void *ec_cxt);
558 
559 static int ec_check_sci(struct acpi_ec *ec, u8 state)
560 {
561 	if (state & ACPI_EC_FLAG_SCI) {
562 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
563 			pr_debug(PREFIX "push gpe query to the queue\n");
564 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
565 				acpi_ec_gpe_query, ec);
566 		}
567 	}
568 	return 0;
569 }
570 
571 static u32 acpi_ec_gpe_handler(void *data)
572 {
573 	struct acpi_ec *ec = data;
574 
575 	pr_debug(PREFIX "~~~> interrupt\n");
576 
577 	advance_transaction(ec, acpi_ec_read_status(ec));
578 	if (ec_transaction_done(ec) &&
579 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
580 		wake_up(&ec->wait);
581 		ec_check_sci(ec, acpi_ec_read_status(ec));
582 	}
583 	return ACPI_INTERRUPT_HANDLED;
584 }
585 
586 /* --------------------------------------------------------------------------
587                              Address Space Management
588    -------------------------------------------------------------------------- */
589 
590 static acpi_status
591 acpi_ec_space_handler(u32 function, acpi_physical_address address,
592 		      u32 bits, acpi_integer *value,
593 		      void *handler_context, void *region_context)
594 {
595 	struct acpi_ec *ec = handler_context;
596 	int result = 0, i;
597 	u8 temp = 0;
598 
599 	if ((address > 0xFF) || !value || !handler_context)
600 		return AE_BAD_PARAMETER;
601 
602 	if (function != ACPI_READ && function != ACPI_WRITE)
603 		return AE_BAD_PARAMETER;
604 
605 	if (bits != 8 && acpi_strict)
606 		return AE_BAD_PARAMETER;
607 
608 	if (EC_FLAGS_MSI)
609 		acpi_ec_burst_enable(ec);
610 
611 	if (function == ACPI_READ) {
612 		result = acpi_ec_read(ec, address, &temp);
613 		*value = temp;
614 	} else {
615 		temp = 0xff & (*value);
616 		result = acpi_ec_write(ec, address, temp);
617 	}
618 
619 	for (i = 8; unlikely(bits - i > 0); i += 8) {
620 		++address;
621 		if (function == ACPI_READ) {
622 			result = acpi_ec_read(ec, address, &temp);
623 			(*value) |= ((acpi_integer)temp) << i;
624 		} else {
625 			temp = 0xff & ((*value) >> i);
626 			result = acpi_ec_write(ec, address, temp);
627 		}
628 	}
629 
630 	if (EC_FLAGS_MSI)
631 		acpi_ec_burst_disable(ec);
632 
633 	switch (result) {
634 	case -EINVAL:
635 		return AE_BAD_PARAMETER;
636 		break;
637 	case -ENODEV:
638 		return AE_NOT_FOUND;
639 		break;
640 	case -ETIME:
641 		return AE_TIME;
642 		break;
643 	default:
644 		return AE_OK;
645 	}
646 }
647 
648 /* --------------------------------------------------------------------------
649                               FS Interface (/proc)
650    -------------------------------------------------------------------------- */
651 
652 static struct proc_dir_entry *acpi_ec_dir;
653 
654 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
655 {
656 	struct acpi_ec *ec = seq->private;
657 
658 	if (!ec)
659 		goto end;
660 
661 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
662 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
663 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
664 	seq_printf(seq, "use global lock:\t%s\n",
665 		   ec->global_lock ? "yes" : "no");
666       end:
667 	return 0;
668 }
669 
670 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
671 {
672 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
673 }
674 
675 static const struct file_operations acpi_ec_info_ops = {
676 	.open = acpi_ec_info_open_fs,
677 	.read = seq_read,
678 	.llseek = seq_lseek,
679 	.release = single_release,
680 	.owner = THIS_MODULE,
681 };
682 
683 static int acpi_ec_add_fs(struct acpi_device *device)
684 {
685 	struct proc_dir_entry *entry = NULL;
686 
687 	if (!acpi_device_dir(device)) {
688 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
689 						     acpi_ec_dir);
690 		if (!acpi_device_dir(device))
691 			return -ENODEV;
692 	}
693 
694 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
695 				 acpi_device_dir(device),
696 				 &acpi_ec_info_ops, acpi_driver_data(device));
697 	if (!entry)
698 		return -ENODEV;
699 	return 0;
700 }
701 
702 static int acpi_ec_remove_fs(struct acpi_device *device)
703 {
704 
705 	if (acpi_device_dir(device)) {
706 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
707 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
708 		acpi_device_dir(device) = NULL;
709 	}
710 
711 	return 0;
712 }
713 
714 /* --------------------------------------------------------------------------
715                                Driver Interface
716    -------------------------------------------------------------------------- */
717 static acpi_status
718 ec_parse_io_ports(struct acpi_resource *resource, void *context);
719 
720 static struct acpi_ec *make_acpi_ec(void)
721 {
722 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
723 	if (!ec)
724 		return NULL;
725 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
726 	mutex_init(&ec->lock);
727 	init_waitqueue_head(&ec->wait);
728 	INIT_LIST_HEAD(&ec->list);
729 	spin_lock_init(&ec->curr_lock);
730 	return ec;
731 }
732 
733 static acpi_status
734 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
735 			       void *context, void **return_value)
736 {
737 	char node_name[5];
738 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
739 	struct acpi_ec *ec = context;
740 	int value = 0;
741 	acpi_status status;
742 
743 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
744 
745 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
746 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
747 	}
748 	return AE_OK;
749 }
750 
751 static acpi_status
752 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
753 {
754 	acpi_status status;
755 	unsigned long long tmp = 0;
756 
757 	struct acpi_ec *ec = context;
758 
759 	/* clear addr values, ec_parse_io_ports depend on it */
760 	ec->command_addr = ec->data_addr = 0;
761 
762 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
763 				     ec_parse_io_ports, ec);
764 	if (ACPI_FAILURE(status))
765 		return status;
766 
767 	/* Get GPE bit assignment (EC events). */
768 	/* TODO: Add support for _GPE returning a package */
769 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
770 	if (ACPI_FAILURE(status))
771 		return status;
772 	ec->gpe = tmp;
773 	/* Use the global lock for all EC transactions? */
774 	tmp = 0;
775 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
776 	ec->global_lock = tmp;
777 	ec->handle = handle;
778 	return AE_CTRL_TERMINATE;
779 }
780 
781 static int ec_install_handlers(struct acpi_ec *ec)
782 {
783 	acpi_status status;
784 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
785 		return 0;
786 	status = acpi_install_gpe_handler(NULL, ec->gpe,
787 				  ACPI_GPE_EDGE_TRIGGERED,
788 				  &acpi_ec_gpe_handler, ec);
789 	if (ACPI_FAILURE(status))
790 		return -ENODEV;
791 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
792 	acpi_enable_gpe(NULL, ec->gpe);
793 	status = acpi_install_address_space_handler(ec->handle,
794 						    ACPI_ADR_SPACE_EC,
795 						    &acpi_ec_space_handler,
796 						    NULL, ec);
797 	if (ACPI_FAILURE(status)) {
798 		if (status == AE_NOT_FOUND) {
799 			/*
800 			 * Maybe OS fails in evaluating the _REG object.
801 			 * The AE_NOT_FOUND error will be ignored and OS
802 			 * continue to initialize EC.
803 			 */
804 			printk(KERN_ERR "Fail in evaluating the _REG object"
805 				" of EC device. Broken bios is suspected.\n");
806 		} else {
807 			acpi_remove_gpe_handler(NULL, ec->gpe,
808 				&acpi_ec_gpe_handler);
809 			return -ENODEV;
810 		}
811 	}
812 
813 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
814 	return 0;
815 }
816 
817 static void ec_remove_handlers(struct acpi_ec *ec)
818 {
819 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
820 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
821 		pr_err(PREFIX "failed to remove space handler\n");
822 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
823 				&acpi_ec_gpe_handler)))
824 		pr_err(PREFIX "failed to remove gpe handler\n");
825 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
826 }
827 
828 static int acpi_ec_add(struct acpi_device *device)
829 {
830 	struct acpi_ec *ec = NULL;
831 	int ret;
832 
833 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
834 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
835 
836 	/* Check for boot EC */
837 	if (boot_ec &&
838 	    (boot_ec->handle == device->handle ||
839 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
840 		ec = boot_ec;
841 		boot_ec = NULL;
842 	} else {
843 		ec = make_acpi_ec();
844 		if (!ec)
845 			return -ENOMEM;
846 	}
847 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
848 		AE_CTRL_TERMINATE) {
849 			kfree(ec);
850 			return -EINVAL;
851 	}
852 
853 	ec->handle = device->handle;
854 
855 	/* Find and register all query methods */
856 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
857 			    acpi_ec_register_query_methods, NULL, ec, NULL);
858 
859 	if (!first_ec)
860 		first_ec = ec;
861 	device->driver_data = ec;
862 	acpi_ec_add_fs(device);
863 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
864 			  ec->gpe, ec->command_addr, ec->data_addr);
865 
866 	ret = ec_install_handlers(ec);
867 
868 	/* EC is fully operational, allow queries */
869 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
870 	return ret;
871 }
872 
873 static int acpi_ec_remove(struct acpi_device *device, int type)
874 {
875 	struct acpi_ec *ec;
876 	struct acpi_ec_query_handler *handler, *tmp;
877 
878 	if (!device)
879 		return -EINVAL;
880 
881 	ec = acpi_driver_data(device);
882 	ec_remove_handlers(ec);
883 	mutex_lock(&ec->lock);
884 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
885 		list_del(&handler->node);
886 		kfree(handler);
887 	}
888 	mutex_unlock(&ec->lock);
889 	acpi_ec_remove_fs(device);
890 	device->driver_data = NULL;
891 	if (ec == first_ec)
892 		first_ec = NULL;
893 	kfree(ec);
894 	return 0;
895 }
896 
897 static acpi_status
898 ec_parse_io_ports(struct acpi_resource *resource, void *context)
899 {
900 	struct acpi_ec *ec = context;
901 
902 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
903 		return AE_OK;
904 
905 	/*
906 	 * The first address region returned is the data port, and
907 	 * the second address region returned is the status/command
908 	 * port.
909 	 */
910 	if (ec->data_addr == 0)
911 		ec->data_addr = resource->data.io.minimum;
912 	else if (ec->command_addr == 0)
913 		ec->command_addr = resource->data.io.minimum;
914 	else
915 		return AE_CTRL_TERMINATE;
916 
917 	return AE_OK;
918 }
919 
920 int __init acpi_boot_ec_enable(void)
921 {
922 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
923 		return 0;
924 	if (!ec_install_handlers(boot_ec)) {
925 		first_ec = boot_ec;
926 		return 0;
927 	}
928 	return -EFAULT;
929 }
930 
931 static const struct acpi_device_id ec_device_ids[] = {
932 	{"PNP0C09", 0},
933 	{"", 0},
934 };
935 
936 /* Some BIOS do not survive early DSDT scan, skip it */
937 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
938 {
939 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
940 	return 0;
941 }
942 
943 /* ASUStek often supplies us with broken ECDT, validate it */
944 static int ec_validate_ecdt(const struct dmi_system_id *id)
945 {
946 	EC_FLAGS_VALIDATE_ECDT = 1;
947 	return 0;
948 }
949 
950 /* MSI EC needs special treatment, enable it */
951 static int ec_flag_msi(const struct dmi_system_id *id)
952 {
953 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
954 	EC_FLAGS_MSI = 1;
955 	EC_FLAGS_VALIDATE_ECDT = 1;
956 	return 0;
957 }
958 
959 static struct dmi_system_id __initdata ec_dmi_table[] = {
960 	{
961 	ec_skip_dsdt_scan, "Compal JFL92", {
962 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
963 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
964 	{
965 	ec_flag_msi, "MSI hardware", {
966 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
967 	{
968 	ec_flag_msi, "MSI hardware", {
969 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
970 	{
971 	ec_flag_msi, "MSI hardware", {
972 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
973 	{
974 	ec_validate_ecdt, "ASUS hardware", {
975 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
976 	{},
977 };
978 
979 
980 int __init acpi_ec_ecdt_probe(void)
981 {
982 	acpi_status status;
983 	struct acpi_ec *saved_ec = NULL;
984 	struct acpi_table_ecdt *ecdt_ptr;
985 
986 	boot_ec = make_acpi_ec();
987 	if (!boot_ec)
988 		return -ENOMEM;
989 	/*
990 	 * Generate a boot ec context
991 	 */
992 	dmi_check_system(ec_dmi_table);
993 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
994 				(struct acpi_table_header **)&ecdt_ptr);
995 	if (ACPI_SUCCESS(status)) {
996 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
997 		boot_ec->command_addr = ecdt_ptr->control.address;
998 		boot_ec->data_addr = ecdt_ptr->data.address;
999 		boot_ec->gpe = ecdt_ptr->gpe;
1000 		boot_ec->handle = ACPI_ROOT_OBJECT;
1001 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1002 		/* Don't trust ECDT, which comes from ASUSTek */
1003 		if (!EC_FLAGS_VALIDATE_ECDT)
1004 			goto install;
1005 		saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1006 		if (!saved_ec)
1007 			return -ENOMEM;
1008 		memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1009 	/* fall through */
1010 	}
1011 
1012 	if (EC_FLAGS_SKIP_DSDT_SCAN)
1013 		return -ENODEV;
1014 
1015 	/* This workaround is needed only on some broken machines,
1016 	 * which require early EC, but fail to provide ECDT */
1017 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1018 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1019 					boot_ec, NULL);
1020 	/* Check that acpi_get_devices actually find something */
1021 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1022 		goto error;
1023 	if (saved_ec) {
1024 		/* try to find good ECDT from ASUSTek */
1025 		if (saved_ec->command_addr != boot_ec->command_addr ||
1026 		    saved_ec->data_addr != boot_ec->data_addr ||
1027 		    saved_ec->gpe != boot_ec->gpe ||
1028 		    saved_ec->handle != boot_ec->handle)
1029 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1030 			"ECDT tables, which are very hard to workaround. "
1031 			"Trying to use DSDT EC info instead. Please send "
1032 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1033 		kfree(saved_ec);
1034 		saved_ec = NULL;
1035 	} else {
1036 		/* We really need to limit this workaround, the only ASUS,
1037 		* which needs it, has fake EC._INI method, so use it as flag.
1038 		* Keep boot_ec struct as it will be needed soon.
1039 		*/
1040 		acpi_handle dummy;
1041 		if (!dmi_name_in_vendors("ASUS") ||
1042 		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1043 							&dummy)))
1044 			return -ENODEV;
1045 	}
1046 install:
1047 	if (!ec_install_handlers(boot_ec)) {
1048 		first_ec = boot_ec;
1049 		return 0;
1050 	}
1051 error:
1052 	kfree(boot_ec);
1053 	boot_ec = NULL;
1054 	return -ENODEV;
1055 }
1056 
1057 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1058 {
1059 	struct acpi_ec *ec = acpi_driver_data(device);
1060 	/* Stop using GPE */
1061 	acpi_disable_gpe(NULL, ec->gpe);
1062 	return 0;
1063 }
1064 
1065 static int acpi_ec_resume(struct acpi_device *device)
1066 {
1067 	struct acpi_ec *ec = acpi_driver_data(device);
1068 	/* Enable use of GPE back */
1069 	acpi_enable_gpe(NULL, ec->gpe);
1070 	return 0;
1071 }
1072 
1073 static struct acpi_driver acpi_ec_driver = {
1074 	.name = "ec",
1075 	.class = ACPI_EC_CLASS,
1076 	.ids = ec_device_ids,
1077 	.ops = {
1078 		.add = acpi_ec_add,
1079 		.remove = acpi_ec_remove,
1080 		.suspend = acpi_ec_suspend,
1081 		.resume = acpi_ec_resume,
1082 		},
1083 };
1084 
1085 int __init acpi_ec_init(void)
1086 {
1087 	int result = 0;
1088 
1089 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1090 	if (!acpi_ec_dir)
1091 		return -ENODEV;
1092 
1093 	/* Now register the driver for the EC */
1094 	result = acpi_bus_register_driver(&acpi_ec_driver);
1095 	if (result < 0) {
1096 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1097 		return -ENODEV;
1098 	}
1099 
1100 	return result;
1101 }
1102 
1103 /* EC driver currently not unloadable */
1104 #if 0
1105 static void __exit acpi_ec_exit(void)
1106 {
1107 
1108 	acpi_bus_unregister_driver(&acpi_ec_driver);
1109 
1110 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1111 
1112 	return;
1113 }
1114 #endif	/* 0 */
1115