xref: /openbmc/linux/drivers/acpi/ec.c (revision 089a49b6)
1 /*
2  *  ec.c - ACPI Embedded Controller Driver (v2.1)
3  *
4  *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or (at
15  *  your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful, but
18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20  *  General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License along
23  *  with this program; if not, write to the Free Software Foundation, Inc.,
24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25  *
26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27  */
28 
29 /* Uncomment next line to get verbose printout */
30 /* #define DEBUG */
31 
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/init.h>
35 #include <linux/types.h>
36 #include <linux/delay.h>
37 #include <linux/interrupt.h>
38 #include <linux/list.h>
39 #include <linux/spinlock.h>
40 #include <linux/slab.h>
41 #include <asm/io.h>
42 #include <acpi/acpi_bus.h>
43 #include <acpi/acpi_drivers.h>
44 #include <linux/dmi.h>
45 
46 #include "internal.h"
47 
48 #define ACPI_EC_CLASS			"embedded_controller"
49 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
50 #define ACPI_EC_FILE_INFO		"info"
51 
52 #undef PREFIX
53 #define PREFIX				"ACPI: EC: "
54 
55 /* EC status register */
56 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
57 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
58 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
59 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
60 
61 /* EC commands */
62 enum ec_command {
63 	ACPI_EC_COMMAND_READ = 0x80,
64 	ACPI_EC_COMMAND_WRITE = 0x81,
65 	ACPI_EC_BURST_ENABLE = 0x82,
66 	ACPI_EC_BURST_DISABLE = 0x83,
67 	ACPI_EC_COMMAND_QUERY = 0x84,
68 };
69 
70 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
71 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
72 #define ACPI_EC_MSI_UDELAY	550	/* Wait 550us for MSI EC */
73 
74 enum {
75 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
76 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
77 	EC_FLAGS_HANDLERS_INSTALLED,	/* Handlers for GPE and
78 					 * OpReg are installed */
79 	EC_FLAGS_BLOCKED,		/* Transactions are blocked */
80 };
81 
82 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
83 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
84 module_param(ec_delay, uint, 0644);
85 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
86 
87 /*
88  * If the number of false interrupts per one transaction exceeds
89  * this threshold, will think there is a GPE storm happened and
90  * will disable the GPE for normal transaction.
91  */
92 static unsigned int ec_storm_threshold  __read_mostly = 8;
93 module_param(ec_storm_threshold, uint, 0644);
94 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
95 
96 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
97 /* External interfaces use first EC only, so remember */
98 typedef int (*acpi_ec_query_func) (void *data);
99 
100 struct acpi_ec_query_handler {
101 	struct list_head node;
102 	acpi_ec_query_func func;
103 	acpi_handle handle;
104 	void *data;
105 	u8 query_bit;
106 };
107 
108 struct transaction {
109 	const u8 *wdata;
110 	u8 *rdata;
111 	unsigned short irq_count;
112 	u8 command;
113 	u8 wi;
114 	u8 ri;
115 	u8 wlen;
116 	u8 rlen;
117 	bool done;
118 };
119 
120 struct acpi_ec *boot_ec, *first_ec;
121 EXPORT_SYMBOL(first_ec);
122 
123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
124 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
125 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
126 
127 /* --------------------------------------------------------------------------
128                              Transaction Management
129    -------------------------------------------------------------------------- */
130 
131 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
132 {
133 	u8 x = inb(ec->command_addr);
134 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
135 	return x;
136 }
137 
138 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
139 {
140 	u8 x = inb(ec->data_addr);
141 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
142 	return x;
143 }
144 
145 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
146 {
147 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
148 	outb(command, ec->command_addr);
149 }
150 
151 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
152 {
153 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
154 	outb(data, ec->data_addr);
155 }
156 
157 static int ec_transaction_done(struct acpi_ec *ec)
158 {
159 	unsigned long flags;
160 	int ret = 0;
161 	spin_lock_irqsave(&ec->lock, flags);
162 	if (!ec->curr || ec->curr->done)
163 		ret = 1;
164 	spin_unlock_irqrestore(&ec->lock, flags);
165 	return ret;
166 }
167 
168 static void start_transaction(struct acpi_ec *ec)
169 {
170 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
171 	ec->curr->done = false;
172 	acpi_ec_write_cmd(ec, ec->curr->command);
173 }
174 
175 static void advance_transaction(struct acpi_ec *ec, u8 status)
176 {
177 	unsigned long flags;
178 	struct transaction *t = ec->curr;
179 
180 	spin_lock_irqsave(&ec->lock, flags);
181 	if (!t)
182 		goto unlock;
183 	if (t->wlen > t->wi) {
184 		if ((status & ACPI_EC_FLAG_IBF) == 0)
185 			acpi_ec_write_data(ec,
186 				t->wdata[t->wi++]);
187 		else
188 			goto err;
189 	} else if (t->rlen > t->ri) {
190 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
191 			t->rdata[t->ri++] = acpi_ec_read_data(ec);
192 			if (t->rlen == t->ri)
193 				t->done = true;
194 		} else
195 			goto err;
196 	} else if (t->wlen == t->wi &&
197 		   (status & ACPI_EC_FLAG_IBF) == 0)
198 		t->done = true;
199 	goto unlock;
200 err:
201 	/*
202 	 * If SCI bit is set, then don't think it's a false IRQ
203 	 * otherwise will take a not handled IRQ as a false one.
204 	 */
205 	if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
206 		++t->irq_count;
207 
208 unlock:
209 	spin_unlock_irqrestore(&ec->lock, flags);
210 }
211 
212 static int acpi_ec_sync_query(struct acpi_ec *ec);
213 
214 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
215 {
216 	if (state & ACPI_EC_FLAG_SCI) {
217 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
218 			return acpi_ec_sync_query(ec);
219 	}
220 	return 0;
221 }
222 
223 static int ec_poll(struct acpi_ec *ec)
224 {
225 	unsigned long flags;
226 	int repeat = 5; /* number of command restarts */
227 	while (repeat--) {
228 		unsigned long delay = jiffies +
229 			msecs_to_jiffies(ec_delay);
230 		do {
231 			/* don't sleep with disabled interrupts */
232 			if (EC_FLAGS_MSI || irqs_disabled()) {
233 				udelay(ACPI_EC_MSI_UDELAY);
234 				if (ec_transaction_done(ec))
235 					return 0;
236 			} else {
237 				if (wait_event_timeout(ec->wait,
238 						ec_transaction_done(ec),
239 						msecs_to_jiffies(1)))
240 					return 0;
241 			}
242 			advance_transaction(ec, acpi_ec_read_status(ec));
243 		} while (time_before(jiffies, delay));
244 		pr_debug(PREFIX "controller reset, restart transaction\n");
245 		spin_lock_irqsave(&ec->lock, flags);
246 		start_transaction(ec);
247 		spin_unlock_irqrestore(&ec->lock, flags);
248 	}
249 	return -ETIME;
250 }
251 
252 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
253 					struct transaction *t)
254 {
255 	unsigned long tmp;
256 	int ret = 0;
257 	if (EC_FLAGS_MSI)
258 		udelay(ACPI_EC_MSI_UDELAY);
259 	/* start transaction */
260 	spin_lock_irqsave(&ec->lock, tmp);
261 	/* following two actions should be kept atomic */
262 	ec->curr = t;
263 	start_transaction(ec);
264 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
265 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
266 	spin_unlock_irqrestore(&ec->lock, tmp);
267 	ret = ec_poll(ec);
268 	spin_lock_irqsave(&ec->lock, tmp);
269 	ec->curr = NULL;
270 	spin_unlock_irqrestore(&ec->lock, tmp);
271 	return ret;
272 }
273 
274 static int ec_check_ibf0(struct acpi_ec *ec)
275 {
276 	u8 status = acpi_ec_read_status(ec);
277 	return (status & ACPI_EC_FLAG_IBF) == 0;
278 }
279 
280 static int ec_wait_ibf0(struct acpi_ec *ec)
281 {
282 	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
283 	/* interrupt wait manually if GPE mode is not active */
284 	while (time_before(jiffies, delay))
285 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
286 					msecs_to_jiffies(1)))
287 			return 0;
288 	return -ETIME;
289 }
290 
291 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
292 {
293 	int status;
294 	u32 glk;
295 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
296 		return -EINVAL;
297 	if (t->rdata)
298 		memset(t->rdata, 0, t->rlen);
299 	mutex_lock(&ec->mutex);
300 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
301 		status = -EINVAL;
302 		goto unlock;
303 	}
304 	if (ec->global_lock) {
305 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
306 		if (ACPI_FAILURE(status)) {
307 			status = -ENODEV;
308 			goto unlock;
309 		}
310 	}
311 	if (ec_wait_ibf0(ec)) {
312 		pr_err(PREFIX "input buffer is not empty, "
313 				"aborting transaction\n");
314 		status = -ETIME;
315 		goto end;
316 	}
317 	pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
318 			t->command, t->wdata ? t->wdata[0] : 0);
319 	/* disable GPE during transaction if storm is detected */
320 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
321 		/* It has to be disabled, so that it doesn't trigger. */
322 		acpi_disable_gpe(NULL, ec->gpe);
323 	}
324 
325 	status = acpi_ec_transaction_unlocked(ec, t);
326 
327 	/* check if we received SCI during transaction */
328 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
329 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
330 		msleep(1);
331 		/* It is safe to enable the GPE outside of the transaction. */
332 		acpi_enable_gpe(NULL, ec->gpe);
333 	} else if (t->irq_count > ec_storm_threshold) {
334 		pr_info(PREFIX "GPE storm detected(%d GPEs), "
335 			"transactions will use polling mode\n",
336 			t->irq_count);
337 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
338 	}
339 	pr_debug(PREFIX "transaction end\n");
340 end:
341 	if (ec->global_lock)
342 		acpi_release_global_lock(glk);
343 unlock:
344 	mutex_unlock(&ec->mutex);
345 	return status;
346 }
347 
348 static int acpi_ec_burst_enable(struct acpi_ec *ec)
349 {
350 	u8 d;
351 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
352 				.wdata = NULL, .rdata = &d,
353 				.wlen = 0, .rlen = 1};
354 
355 	return acpi_ec_transaction(ec, &t);
356 }
357 
358 static int acpi_ec_burst_disable(struct acpi_ec *ec)
359 {
360 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
361 				.wdata = NULL, .rdata = NULL,
362 				.wlen = 0, .rlen = 0};
363 
364 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
365 				acpi_ec_transaction(ec, &t) : 0;
366 }
367 
368 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
369 {
370 	int result;
371 	u8 d;
372 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
373 				.wdata = &address, .rdata = &d,
374 				.wlen = 1, .rlen = 1};
375 
376 	result = acpi_ec_transaction(ec, &t);
377 	*data = d;
378 	return result;
379 }
380 
381 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
382 {
383 	u8 wdata[2] = { address, data };
384 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
385 				.wdata = wdata, .rdata = NULL,
386 				.wlen = 2, .rlen = 0};
387 
388 	return acpi_ec_transaction(ec, &t);
389 }
390 
391 /*
392  * Externally callable EC access functions. For now, assume 1 EC only
393  */
394 int ec_burst_enable(void)
395 {
396 	if (!first_ec)
397 		return -ENODEV;
398 	return acpi_ec_burst_enable(first_ec);
399 }
400 
401 EXPORT_SYMBOL(ec_burst_enable);
402 
403 int ec_burst_disable(void)
404 {
405 	if (!first_ec)
406 		return -ENODEV;
407 	return acpi_ec_burst_disable(first_ec);
408 }
409 
410 EXPORT_SYMBOL(ec_burst_disable);
411 
412 int ec_read(u8 addr, u8 *val)
413 {
414 	int err;
415 	u8 temp_data;
416 
417 	if (!first_ec)
418 		return -ENODEV;
419 
420 	err = acpi_ec_read(first_ec, addr, &temp_data);
421 
422 	if (!err) {
423 		*val = temp_data;
424 		return 0;
425 	} else
426 		return err;
427 }
428 
429 EXPORT_SYMBOL(ec_read);
430 
431 int ec_write(u8 addr, u8 val)
432 {
433 	int err;
434 
435 	if (!first_ec)
436 		return -ENODEV;
437 
438 	err = acpi_ec_write(first_ec, addr, val);
439 
440 	return err;
441 }
442 
443 EXPORT_SYMBOL(ec_write);
444 
445 int ec_transaction(u8 command,
446 		   const u8 * wdata, unsigned wdata_len,
447 		   u8 * rdata, unsigned rdata_len)
448 {
449 	struct transaction t = {.command = command,
450 				.wdata = wdata, .rdata = rdata,
451 				.wlen = wdata_len, .rlen = rdata_len};
452 	if (!first_ec)
453 		return -ENODEV;
454 
455 	return acpi_ec_transaction(first_ec, &t);
456 }
457 
458 EXPORT_SYMBOL(ec_transaction);
459 
460 /* Get the handle to the EC device */
461 acpi_handle ec_get_handle(void)
462 {
463 	if (!first_ec)
464 		return NULL;
465 	return first_ec->handle;
466 }
467 
468 EXPORT_SYMBOL(ec_get_handle);
469 
470 void acpi_ec_block_transactions(void)
471 {
472 	struct acpi_ec *ec = first_ec;
473 
474 	if (!ec)
475 		return;
476 
477 	mutex_lock(&ec->mutex);
478 	/* Prevent transactions from being carried out */
479 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
480 	mutex_unlock(&ec->mutex);
481 }
482 
483 void acpi_ec_unblock_transactions(void)
484 {
485 	struct acpi_ec *ec = first_ec;
486 
487 	if (!ec)
488 		return;
489 
490 	mutex_lock(&ec->mutex);
491 	/* Allow transactions to be carried out again */
492 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
493 	mutex_unlock(&ec->mutex);
494 }
495 
496 void acpi_ec_unblock_transactions_early(void)
497 {
498 	/*
499 	 * Allow transactions to happen again (this function is called from
500 	 * atomic context during wakeup, so we don't need to acquire the mutex).
501 	 */
502 	if (first_ec)
503 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
504 }
505 
506 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
507 {
508 	int result;
509 	u8 d;
510 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
511 				.wdata = NULL, .rdata = &d,
512 				.wlen = 0, .rlen = 1};
513 	if (!ec || !data)
514 		return -EINVAL;
515 	/*
516 	 * Query the EC to find out which _Qxx method we need to evaluate.
517 	 * Note that successful completion of the query causes the ACPI_EC_SCI
518 	 * bit to be cleared (and thus clearing the interrupt source).
519 	 */
520 	result = acpi_ec_transaction_unlocked(ec, &t);
521 	if (result)
522 		return result;
523 	if (!d)
524 		return -ENODATA;
525 	*data = d;
526 	return 0;
527 }
528 
529 /* --------------------------------------------------------------------------
530                                 Event Management
531    -------------------------------------------------------------------------- */
532 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
533 			      acpi_handle handle, acpi_ec_query_func func,
534 			      void *data)
535 {
536 	struct acpi_ec_query_handler *handler =
537 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
538 	if (!handler)
539 		return -ENOMEM;
540 
541 	handler->query_bit = query_bit;
542 	handler->handle = handle;
543 	handler->func = func;
544 	handler->data = data;
545 	mutex_lock(&ec->mutex);
546 	list_add(&handler->node, &ec->list);
547 	mutex_unlock(&ec->mutex);
548 	return 0;
549 }
550 
551 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
552 
553 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
554 {
555 	struct acpi_ec_query_handler *handler, *tmp;
556 	mutex_lock(&ec->mutex);
557 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
558 		if (query_bit == handler->query_bit) {
559 			list_del(&handler->node);
560 			kfree(handler);
561 		}
562 	}
563 	mutex_unlock(&ec->mutex);
564 }
565 
566 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
567 
568 static void acpi_ec_run(void *cxt)
569 {
570 	struct acpi_ec_query_handler *handler = cxt;
571 	if (!handler)
572 		return;
573 	pr_debug(PREFIX "start query execution\n");
574 	if (handler->func)
575 		handler->func(handler->data);
576 	else if (handler->handle)
577 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
578 	pr_debug(PREFIX "stop query execution\n");
579 	kfree(handler);
580 }
581 
582 static int acpi_ec_sync_query(struct acpi_ec *ec)
583 {
584 	u8 value = 0;
585 	int status;
586 	struct acpi_ec_query_handler *handler, *copy;
587 	if ((status = acpi_ec_query_unlocked(ec, &value)))
588 		return status;
589 	list_for_each_entry(handler, &ec->list, node) {
590 		if (value == handler->query_bit) {
591 			/* have custom handler for this bit */
592 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
593 			if (!copy)
594 				return -ENOMEM;
595 			memcpy(copy, handler, sizeof(*copy));
596 			pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
597 			return acpi_os_execute((copy->func) ?
598 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
599 				acpi_ec_run, copy);
600 		}
601 	}
602 	return 0;
603 }
604 
605 static void acpi_ec_gpe_query(void *ec_cxt)
606 {
607 	struct acpi_ec *ec = ec_cxt;
608 	if (!ec)
609 		return;
610 	mutex_lock(&ec->mutex);
611 	acpi_ec_sync_query(ec);
612 	mutex_unlock(&ec->mutex);
613 }
614 
615 static int ec_check_sci(struct acpi_ec *ec, u8 state)
616 {
617 	if (state & ACPI_EC_FLAG_SCI) {
618 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
619 			pr_debug(PREFIX "push gpe query to the queue\n");
620 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
621 				acpi_ec_gpe_query, ec);
622 		}
623 	}
624 	return 0;
625 }
626 
627 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
628 	u32 gpe_number, void *data)
629 {
630 	struct acpi_ec *ec = data;
631 	u8 status = acpi_ec_read_status(ec);
632 
633 	pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status);
634 
635 	advance_transaction(ec, status);
636 	if (ec_transaction_done(ec) &&
637 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
638 		wake_up(&ec->wait);
639 		ec_check_sci(ec, acpi_ec_read_status(ec));
640 	}
641 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
642 }
643 
644 /* --------------------------------------------------------------------------
645                              Address Space Management
646    -------------------------------------------------------------------------- */
647 
648 static acpi_status
649 acpi_ec_space_handler(u32 function, acpi_physical_address address,
650 		      u32 bits, u64 *value64,
651 		      void *handler_context, void *region_context)
652 {
653 	struct acpi_ec *ec = handler_context;
654 	int result = 0, i, bytes = bits / 8;
655 	u8 *value = (u8 *)value64;
656 
657 	if ((address > 0xFF) || !value || !handler_context)
658 		return AE_BAD_PARAMETER;
659 
660 	if (function != ACPI_READ && function != ACPI_WRITE)
661 		return AE_BAD_PARAMETER;
662 
663 	if (EC_FLAGS_MSI || bits > 8)
664 		acpi_ec_burst_enable(ec);
665 
666 	for (i = 0; i < bytes; ++i, ++address, ++value)
667 		result = (function == ACPI_READ) ?
668 			acpi_ec_read(ec, address, value) :
669 			acpi_ec_write(ec, address, *value);
670 
671 	if (EC_FLAGS_MSI || bits > 8)
672 		acpi_ec_burst_disable(ec);
673 
674 	switch (result) {
675 	case -EINVAL:
676 		return AE_BAD_PARAMETER;
677 		break;
678 	case -ENODEV:
679 		return AE_NOT_FOUND;
680 		break;
681 	case -ETIME:
682 		return AE_TIME;
683 		break;
684 	default:
685 		return AE_OK;
686 	}
687 }
688 
689 /* --------------------------------------------------------------------------
690                                Driver Interface
691    -------------------------------------------------------------------------- */
692 static acpi_status
693 ec_parse_io_ports(struct acpi_resource *resource, void *context);
694 
695 static struct acpi_ec *make_acpi_ec(void)
696 {
697 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
698 	if (!ec)
699 		return NULL;
700 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
701 	mutex_init(&ec->mutex);
702 	init_waitqueue_head(&ec->wait);
703 	INIT_LIST_HEAD(&ec->list);
704 	spin_lock_init(&ec->lock);
705 	return ec;
706 }
707 
708 static acpi_status
709 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
710 			       void *context, void **return_value)
711 {
712 	char node_name[5];
713 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
714 	struct acpi_ec *ec = context;
715 	int value = 0;
716 	acpi_status status;
717 
718 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
719 
720 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
721 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
722 	}
723 	return AE_OK;
724 }
725 
726 static acpi_status
727 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
728 {
729 	acpi_status status;
730 	unsigned long long tmp = 0;
731 
732 	struct acpi_ec *ec = context;
733 
734 	/* clear addr values, ec_parse_io_ports depend on it */
735 	ec->command_addr = ec->data_addr = 0;
736 
737 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
738 				     ec_parse_io_ports, ec);
739 	if (ACPI_FAILURE(status))
740 		return status;
741 
742 	/* Get GPE bit assignment (EC events). */
743 	/* TODO: Add support for _GPE returning a package */
744 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
745 	if (ACPI_FAILURE(status))
746 		return status;
747 	ec->gpe = tmp;
748 	/* Use the global lock for all EC transactions? */
749 	tmp = 0;
750 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
751 	ec->global_lock = tmp;
752 	ec->handle = handle;
753 	return AE_CTRL_TERMINATE;
754 }
755 
756 static int ec_install_handlers(struct acpi_ec *ec)
757 {
758 	acpi_status status;
759 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
760 		return 0;
761 	status = acpi_install_gpe_handler(NULL, ec->gpe,
762 				  ACPI_GPE_EDGE_TRIGGERED,
763 				  &acpi_ec_gpe_handler, ec);
764 	if (ACPI_FAILURE(status))
765 		return -ENODEV;
766 
767 	acpi_enable_gpe(NULL, ec->gpe);
768 	status = acpi_install_address_space_handler(ec->handle,
769 						    ACPI_ADR_SPACE_EC,
770 						    &acpi_ec_space_handler,
771 						    NULL, ec);
772 	if (ACPI_FAILURE(status)) {
773 		if (status == AE_NOT_FOUND) {
774 			/*
775 			 * Maybe OS fails in evaluating the _REG object.
776 			 * The AE_NOT_FOUND error will be ignored and OS
777 			 * continue to initialize EC.
778 			 */
779 			printk(KERN_ERR "Fail in evaluating the _REG object"
780 				" of EC device. Broken bios is suspected.\n");
781 		} else {
782 			acpi_remove_gpe_handler(NULL, ec->gpe,
783 				&acpi_ec_gpe_handler);
784 			acpi_disable_gpe(NULL, ec->gpe);
785 			return -ENODEV;
786 		}
787 	}
788 
789 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
790 	return 0;
791 }
792 
793 static void ec_remove_handlers(struct acpi_ec *ec)
794 {
795 	acpi_disable_gpe(NULL, ec->gpe);
796 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
797 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
798 		pr_err(PREFIX "failed to remove space handler\n");
799 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
800 				&acpi_ec_gpe_handler)))
801 		pr_err(PREFIX "failed to remove gpe handler\n");
802 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
803 }
804 
805 static int acpi_ec_add(struct acpi_device *device)
806 {
807 	struct acpi_ec *ec = NULL;
808 	int ret;
809 
810 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
811 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
812 
813 	/* Check for boot EC */
814 	if (boot_ec &&
815 	    (boot_ec->handle == device->handle ||
816 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
817 		ec = boot_ec;
818 		boot_ec = NULL;
819 	} else {
820 		ec = make_acpi_ec();
821 		if (!ec)
822 			return -ENOMEM;
823 	}
824 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
825 		AE_CTRL_TERMINATE) {
826 			kfree(ec);
827 			return -EINVAL;
828 	}
829 
830 	/* Find and register all query methods */
831 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
832 			    acpi_ec_register_query_methods, NULL, ec, NULL);
833 
834 	if (!first_ec)
835 		first_ec = ec;
836 	device->driver_data = ec;
837 
838 	ret = !!request_region(ec->data_addr, 1, "EC data");
839 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
840 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
841 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
842 
843 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
844 			  ec->gpe, ec->command_addr, ec->data_addr);
845 
846 	ret = ec_install_handlers(ec);
847 
848 	/* EC is fully operational, allow queries */
849 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
850 	return ret;
851 }
852 
853 static int acpi_ec_remove(struct acpi_device *device)
854 {
855 	struct acpi_ec *ec;
856 	struct acpi_ec_query_handler *handler, *tmp;
857 
858 	if (!device)
859 		return -EINVAL;
860 
861 	ec = acpi_driver_data(device);
862 	ec_remove_handlers(ec);
863 	mutex_lock(&ec->mutex);
864 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
865 		list_del(&handler->node);
866 		kfree(handler);
867 	}
868 	mutex_unlock(&ec->mutex);
869 	release_region(ec->data_addr, 1);
870 	release_region(ec->command_addr, 1);
871 	device->driver_data = NULL;
872 	if (ec == first_ec)
873 		first_ec = NULL;
874 	kfree(ec);
875 	return 0;
876 }
877 
878 static acpi_status
879 ec_parse_io_ports(struct acpi_resource *resource, void *context)
880 {
881 	struct acpi_ec *ec = context;
882 
883 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
884 		return AE_OK;
885 
886 	/*
887 	 * The first address region returned is the data port, and
888 	 * the second address region returned is the status/command
889 	 * port.
890 	 */
891 	if (ec->data_addr == 0)
892 		ec->data_addr = resource->data.io.minimum;
893 	else if (ec->command_addr == 0)
894 		ec->command_addr = resource->data.io.minimum;
895 	else
896 		return AE_CTRL_TERMINATE;
897 
898 	return AE_OK;
899 }
900 
901 int __init acpi_boot_ec_enable(void)
902 {
903 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
904 		return 0;
905 	if (!ec_install_handlers(boot_ec)) {
906 		first_ec = boot_ec;
907 		return 0;
908 	}
909 	return -EFAULT;
910 }
911 
912 static const struct acpi_device_id ec_device_ids[] = {
913 	{"PNP0C09", 0},
914 	{"", 0},
915 };
916 
917 /* Some BIOS do not survive early DSDT scan, skip it */
918 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
919 {
920 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
921 	return 0;
922 }
923 
924 /* ASUStek often supplies us with broken ECDT, validate it */
925 static int ec_validate_ecdt(const struct dmi_system_id *id)
926 {
927 	EC_FLAGS_VALIDATE_ECDT = 1;
928 	return 0;
929 }
930 
931 /* MSI EC needs special treatment, enable it */
932 static int ec_flag_msi(const struct dmi_system_id *id)
933 {
934 	printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
935 	EC_FLAGS_MSI = 1;
936 	EC_FLAGS_VALIDATE_ECDT = 1;
937 	return 0;
938 }
939 
940 /*
941  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
942  * the GPE storm threshold back to 20
943  */
944 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
945 {
946 	pr_debug("Setting the EC GPE storm threshold to 20\n");
947 	ec_storm_threshold  = 20;
948 	return 0;
949 }
950 
951 static struct dmi_system_id ec_dmi_table[] __initdata = {
952 	{
953 	ec_skip_dsdt_scan, "Compal JFL92", {
954 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
955 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
956 	{
957 	ec_flag_msi, "MSI hardware", {
958 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
959 	{
960 	ec_flag_msi, "MSI hardware", {
961 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
962 	{
963 	ec_flag_msi, "MSI hardware", {
964 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
965 	{
966 	ec_flag_msi, "MSI hardware", {
967 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
968 	{
969 	ec_flag_msi, "Quanta hardware", {
970 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
971 	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
972 	{
973 	ec_flag_msi, "Quanta hardware", {
974 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
975 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
976 	{
977 	ec_validate_ecdt, "ASUS hardware", {
978 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
979 	{
980 	ec_validate_ecdt, "ASUS hardware", {
981 	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
982 	{
983 	ec_enlarge_storm_threshold, "CLEVO hardware", {
984 	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
985 	DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
986 	{
987 	ec_skip_dsdt_scan, "HP Folio 13", {
988 	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
989 	DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
990 	{
991 	ec_validate_ecdt, "ASUS hardware", {
992 	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
993 	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
994 	{},
995 };
996 
997 int __init acpi_ec_ecdt_probe(void)
998 {
999 	acpi_status status;
1000 	struct acpi_ec *saved_ec = NULL;
1001 	struct acpi_table_ecdt *ecdt_ptr;
1002 
1003 	boot_ec = make_acpi_ec();
1004 	if (!boot_ec)
1005 		return -ENOMEM;
1006 	/*
1007 	 * Generate a boot ec context
1008 	 */
1009 	dmi_check_system(ec_dmi_table);
1010 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1011 				(struct acpi_table_header **)&ecdt_ptr);
1012 	if (ACPI_SUCCESS(status)) {
1013 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1014 		boot_ec->command_addr = ecdt_ptr->control.address;
1015 		boot_ec->data_addr = ecdt_ptr->data.address;
1016 		boot_ec->gpe = ecdt_ptr->gpe;
1017 		boot_ec->handle = ACPI_ROOT_OBJECT;
1018 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1019 		/* Don't trust ECDT, which comes from ASUSTek */
1020 		if (!EC_FLAGS_VALIDATE_ECDT)
1021 			goto install;
1022 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1023 		if (!saved_ec)
1024 			return -ENOMEM;
1025 	/* fall through */
1026 	}
1027 
1028 	if (EC_FLAGS_SKIP_DSDT_SCAN)
1029 		return -ENODEV;
1030 
1031 	/* This workaround is needed only on some broken machines,
1032 	 * which require early EC, but fail to provide ECDT */
1033 	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1034 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1035 					boot_ec, NULL);
1036 	/* Check that acpi_get_devices actually find something */
1037 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1038 		goto error;
1039 	if (saved_ec) {
1040 		/* try to find good ECDT from ASUSTek */
1041 		if (saved_ec->command_addr != boot_ec->command_addr ||
1042 		    saved_ec->data_addr != boot_ec->data_addr ||
1043 		    saved_ec->gpe != boot_ec->gpe ||
1044 		    saved_ec->handle != boot_ec->handle)
1045 			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1046 			"ECDT tables, which are very hard to workaround. "
1047 			"Trying to use DSDT EC info instead. Please send "
1048 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1049 		kfree(saved_ec);
1050 		saved_ec = NULL;
1051 	} else {
1052 		/* We really need to limit this workaround, the only ASUS,
1053 		* which needs it, has fake EC._INI method, so use it as flag.
1054 		* Keep boot_ec struct as it will be needed soon.
1055 		*/
1056 		if (!dmi_name_in_vendors("ASUS") ||
1057 		    !acpi_has_method(boot_ec->handle, "_INI"))
1058 			return -ENODEV;
1059 	}
1060 install:
1061 	if (!ec_install_handlers(boot_ec)) {
1062 		first_ec = boot_ec;
1063 		return 0;
1064 	}
1065 error:
1066 	kfree(boot_ec);
1067 	boot_ec = NULL;
1068 	return -ENODEV;
1069 }
1070 
1071 static struct acpi_driver acpi_ec_driver = {
1072 	.name = "ec",
1073 	.class = ACPI_EC_CLASS,
1074 	.ids = ec_device_ids,
1075 	.ops = {
1076 		.add = acpi_ec_add,
1077 		.remove = acpi_ec_remove,
1078 		},
1079 };
1080 
1081 int __init acpi_ec_init(void)
1082 {
1083 	int result = 0;
1084 
1085 	/* Now register the driver for the EC */
1086 	result = acpi_bus_register_driver(&acpi_ec_driver);
1087 	if (result < 0)
1088 		return -ENODEV;
1089 
1090 	return result;
1091 }
1092 
1093 /* EC driver currently not unloadable */
1094 #if 0
1095 static void __exit acpi_ec_exit(void)
1096 {
1097 
1098 	acpi_bus_unregister_driver(&acpi_ec_driver);
1099 	return;
1100 }
1101 #endif	/* 0 */
1102