xref: /linux/drivers/acpi/ec.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
1 /*
2  *  ec.c - ACPI Embedded Controller Driver (v2.0)
3  *
4  *  Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
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 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/types.h>
33 #include <linux/delay.h>
34 #include <linux/proc_fs.h>
35 #include <linux/seq_file.h>
36 #include <linux/interrupt.h>
37 #include <linux/list.h>
38 #include <asm/io.h>
39 #include <acpi/acpi_bus.h>
40 #include <acpi/acpi_drivers.h>
41 #include <acpi/actypes.h>
42 
43 #define ACPI_EC_CLASS			"embedded_controller"
44 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
45 #define ACPI_EC_FILE_INFO		"info"
46 
47 #undef PREFIX
48 #define PREFIX				"ACPI: EC: "
49 
50 /* EC status register */
51 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
52 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
53 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
54 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
55 
56 /* EC commands */
57 enum ec_command {
58 	ACPI_EC_COMMAND_READ = 0x80,
59 	ACPI_EC_COMMAND_WRITE = 0x81,
60 	ACPI_EC_BURST_ENABLE = 0x82,
61 	ACPI_EC_BURST_DISABLE = 0x83,
62 	ACPI_EC_COMMAND_QUERY = 0x84,
63 };
64 
65 /* EC events */
66 enum ec_event {
67 	ACPI_EC_EVENT_OBF_1 = 1,	/* Output buffer full */
68 	ACPI_EC_EVENT_IBF_0,	/* Input buffer empty */
69 };
70 
71 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
72 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
73 
74 static enum ec_mode {
75 	EC_INTR = 1,		/* Output buffer full */
76 	EC_POLL,		/* Input buffer empty */
77 } acpi_ec_mode = EC_INTR;
78 
79 static int acpi_ec_remove(struct acpi_device *device, int type);
80 static int acpi_ec_start(struct acpi_device *device);
81 static int acpi_ec_stop(struct acpi_device *device, int type);
82 static int acpi_ec_add(struct acpi_device *device);
83 
84 static const struct acpi_device_id ec_device_ids[] = {
85 	{"PNP0C09", 0},
86 	{"", 0},
87 };
88 
89 static struct acpi_driver acpi_ec_driver = {
90 	.name = "ec",
91 	.class = ACPI_EC_CLASS,
92 	.ids = ec_device_ids,
93 	.ops = {
94 		.add = acpi_ec_add,
95 		.remove = acpi_ec_remove,
96 		.start = acpi_ec_start,
97 		.stop = acpi_ec_stop,
98 		},
99 };
100 
101 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
102 /* External interfaces use first EC only, so remember */
103 typedef int (*acpi_ec_query_func) (void *data);
104 
105 struct acpi_ec_query_handler {
106 	struct list_head node;
107 	acpi_ec_query_func func;
108 	acpi_handle handle;
109 	void *data;
110 	u8 query_bit;
111 };
112 
113 static struct acpi_ec {
114 	acpi_handle handle;
115 	unsigned long gpe;
116 	unsigned long command_addr;
117 	unsigned long data_addr;
118 	unsigned long global_lock;
119 	struct mutex lock;
120 	atomic_t query_pending;
121 	atomic_t event_count;
122 	wait_queue_head_t wait;
123 	struct list_head list;
124 } *boot_ec, *first_ec;
125 
126 /* --------------------------------------------------------------------------
127                              Transaction Management
128    -------------------------------------------------------------------------- */
129 
130 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
131 {
132 	return inb(ec->command_addr);
133 }
134 
135 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
136 {
137 	return inb(ec->data_addr);
138 }
139 
140 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
141 {
142 	outb(command, ec->command_addr);
143 }
144 
145 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
146 {
147 	outb(data, ec->data_addr);
148 }
149 
150 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event,
151 				       unsigned old_count)
152 {
153 	u8 status = acpi_ec_read_status(ec);
154 	if (old_count == atomic_read(&ec->event_count))
155 		return 0;
156 	if (event == ACPI_EC_EVENT_OBF_1) {
157 		if (status & ACPI_EC_FLAG_OBF)
158 			return 1;
159 	} else if (event == ACPI_EC_EVENT_IBF_0) {
160 		if (!(status & ACPI_EC_FLAG_IBF))
161 			return 1;
162 	}
163 
164 	return 0;
165 }
166 
167 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event,
168                         unsigned count, int force_poll)
169 {
170 	if (unlikely(force_poll) || acpi_ec_mode == EC_POLL) {
171 		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
172 		while (time_before(jiffies, delay)) {
173 			if (acpi_ec_check_status(ec, event, 0))
174 				return 0;
175 		}
176 	} else {
177 		if (wait_event_timeout(ec->wait,
178 				       acpi_ec_check_status(ec, event, count),
179 				       msecs_to_jiffies(ACPI_EC_DELAY)) ||
180 		    acpi_ec_check_status(ec, event, 0)) {
181 			return 0;
182 		} else {
183 			printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
184 			       " status = %d, expect_event = %d\n",
185 			       acpi_ec_read_status(ec), event);
186 		}
187 	}
188 
189 	return -ETIME;
190 }
191 
192 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
193 					const u8 * wdata, unsigned wdata_len,
194 					u8 * rdata, unsigned rdata_len,
195 					int force_poll)
196 {
197 	int result = 0;
198 	unsigned count = atomic_read(&ec->event_count);
199 	acpi_ec_write_cmd(ec, command);
200 
201 	for (; wdata_len > 0; --wdata_len) {
202 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
203 		if (result) {
204 			printk(KERN_ERR PREFIX
205 			       "write_cmd timeout, command = %d\n", command);
206 			goto end;
207 		}
208 		count = atomic_read(&ec->event_count);
209 		acpi_ec_write_data(ec, *(wdata++));
210 	}
211 
212 	if (!rdata_len) {
213 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
214 		if (result) {
215 			printk(KERN_ERR PREFIX
216 			       "finish-write timeout, command = %d\n", command);
217 			goto end;
218 		}
219 	} else if (command == ACPI_EC_COMMAND_QUERY) {
220 		atomic_set(&ec->query_pending, 0);
221 	}
222 
223 	for (; rdata_len > 0; --rdata_len) {
224 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count, force_poll);
225 		if (result) {
226 			printk(KERN_ERR PREFIX "read timeout, command = %d\n",
227 			       command);
228 			goto end;
229 		}
230 		count = atomic_read(&ec->event_count);
231 		*(rdata++) = acpi_ec_read_data(ec);
232 	}
233       end:
234 	return result;
235 }
236 
237 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
238 			       const u8 * wdata, unsigned wdata_len,
239 			       u8 * rdata, unsigned rdata_len,
240 			       int force_poll)
241 {
242 	int status;
243 	u32 glk;
244 
245 	if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
246 		return -EINVAL;
247 
248 	if (rdata)
249 		memset(rdata, 0, rdata_len);
250 
251 	mutex_lock(&ec->lock);
252 	if (ec->global_lock) {
253 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
254 		if (ACPI_FAILURE(status)) {
255 			mutex_unlock(&ec->lock);
256 			return -ENODEV;
257 		}
258 	}
259 
260 	/* Make sure GPE is enabled before doing transaction */
261 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
262 
263 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0, 0);
264 	if (status) {
265 		printk(KERN_ERR PREFIX
266 		       "input buffer is not empty, aborting transaction\n");
267 		goto end;
268 	}
269 
270 	status = acpi_ec_transaction_unlocked(ec, command,
271 					      wdata, wdata_len,
272 					      rdata, rdata_len,
273 					      force_poll);
274 
275       end:
276 
277 	if (ec->global_lock)
278 		acpi_release_global_lock(glk);
279 	mutex_unlock(&ec->lock);
280 
281 	return status;
282 }
283 
284 /*
285  * Note: samsung nv5000 doesn't work with ec burst mode.
286  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
287  */
288 int acpi_ec_burst_enable(struct acpi_ec *ec)
289 {
290 	u8 d;
291 	return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
292 }
293 
294 int acpi_ec_burst_disable(struct acpi_ec *ec)
295 {
296 	return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
297 }
298 
299 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
300 {
301 	int result;
302 	u8 d;
303 
304 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
305 				     &address, 1, &d, 1, 0);
306 	*data = d;
307 	return result;
308 }
309 
310 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
311 {
312 	u8 wdata[2] = { address, data };
313 	return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
314 				   wdata, 2, NULL, 0, 0);
315 }
316 
317 /*
318  * Externally callable EC access functions. For now, assume 1 EC only
319  */
320 int ec_burst_enable(void)
321 {
322 	if (!first_ec)
323 		return -ENODEV;
324 	return acpi_ec_burst_enable(first_ec);
325 }
326 
327 EXPORT_SYMBOL(ec_burst_enable);
328 
329 int ec_burst_disable(void)
330 {
331 	if (!first_ec)
332 		return -ENODEV;
333 	return acpi_ec_burst_disable(first_ec);
334 }
335 
336 EXPORT_SYMBOL(ec_burst_disable);
337 
338 int ec_read(u8 addr, u8 * val)
339 {
340 	int err;
341 	u8 temp_data;
342 
343 	if (!first_ec)
344 		return -ENODEV;
345 
346 	err = acpi_ec_read(first_ec, addr, &temp_data);
347 
348 	if (!err) {
349 		*val = temp_data;
350 		return 0;
351 	} else
352 		return err;
353 }
354 
355 EXPORT_SYMBOL(ec_read);
356 
357 int ec_write(u8 addr, u8 val)
358 {
359 	int err;
360 
361 	if (!first_ec)
362 		return -ENODEV;
363 
364 	err = acpi_ec_write(first_ec, addr, val);
365 
366 	return err;
367 }
368 
369 EXPORT_SYMBOL(ec_write);
370 
371 int ec_transaction(u8 command,
372 		   const u8 * wdata, unsigned wdata_len,
373 		   u8 * rdata, unsigned rdata_len,
374 		   int force_poll)
375 {
376 	if (!first_ec)
377 		return -ENODEV;
378 
379 	return acpi_ec_transaction(first_ec, command, wdata,
380 				   wdata_len, rdata, rdata_len,
381 				   force_poll);
382 }
383 
384 EXPORT_SYMBOL(ec_transaction);
385 
386 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
387 {
388 	int result;
389 	u8 d;
390 
391 	if (!ec || !data)
392 		return -EINVAL;
393 
394 	/*
395 	 * Query the EC to find out which _Qxx method we need to evaluate.
396 	 * Note that successful completion of the query causes the ACPI_EC_SCI
397 	 * bit to be cleared (and thus clearing the interrupt source).
398 	 */
399 
400 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
401 	if (result)
402 		return result;
403 
404 	if (!d)
405 		return -ENODATA;
406 
407 	*data = d;
408 	return 0;
409 }
410 
411 /* --------------------------------------------------------------------------
412                                 Event Management
413    -------------------------------------------------------------------------- */
414 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
415 			      acpi_handle handle, acpi_ec_query_func func,
416 			      void *data)
417 {
418 	struct acpi_ec_query_handler *handler =
419 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
420 	if (!handler)
421 		return -ENOMEM;
422 
423 	handler->query_bit = query_bit;
424 	handler->handle = handle;
425 	handler->func = func;
426 	handler->data = data;
427 	mutex_lock(&ec->lock);
428 	list_add_tail(&handler->node, &ec->list);
429 	mutex_unlock(&ec->lock);
430 	return 0;
431 }
432 
433 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
434 
435 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
436 {
437 	struct acpi_ec_query_handler *handler;
438 	mutex_lock(&ec->lock);
439 	list_for_each_entry(handler, &ec->list, node) {
440 		if (query_bit == handler->query_bit) {
441 			list_del(&handler->node);
442 			kfree(handler);
443 			break;
444 		}
445 	}
446 	mutex_unlock(&ec->lock);
447 }
448 
449 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
450 
451 static void acpi_ec_gpe_query(void *ec_cxt)
452 {
453 	struct acpi_ec *ec = ec_cxt;
454 	u8 value = 0;
455 	struct acpi_ec_query_handler *handler, copy;
456 
457 	if (!ec || acpi_ec_query(ec, &value))
458 		return;
459 	mutex_lock(&ec->lock);
460 	list_for_each_entry(handler, &ec->list, node) {
461 		if (value == handler->query_bit) {
462 			/* have custom handler for this bit */
463 			memcpy(&copy, handler, sizeof(copy));
464 			mutex_unlock(&ec->lock);
465 			if (copy.func) {
466 				copy.func(copy.data);
467 			} else if (copy.handle) {
468 				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
469 			}
470 			return;
471 		}
472 	}
473 	mutex_unlock(&ec->lock);
474 }
475 
476 static u32 acpi_ec_gpe_handler(void *data)
477 {
478 	acpi_status status = AE_OK;
479 	u8 value;
480 	struct acpi_ec *ec = data;
481 
482 	atomic_inc(&ec->event_count);
483 
484 	if (acpi_ec_mode == EC_INTR) {
485 		wake_up(&ec->wait);
486 	}
487 
488 	value = acpi_ec_read_status(ec);
489 	if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
490 		atomic_set(&ec->query_pending, 1);
491 		status =
492 		    acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
493 	}
494 
495 	return status == AE_OK ?
496 	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
497 }
498 
499 /* --------------------------------------------------------------------------
500                              Address Space Management
501    -------------------------------------------------------------------------- */
502 
503 static acpi_status
504 acpi_ec_space_setup(acpi_handle region_handle,
505 		    u32 function, void *handler_context, void **return_context)
506 {
507 	/*
508 	 * The EC object is in the handler context and is needed
509 	 * when calling the acpi_ec_space_handler.
510 	 */
511 	*return_context = (function != ACPI_REGION_DEACTIVATE) ?
512 	    handler_context : NULL;
513 
514 	return AE_OK;
515 }
516 
517 static acpi_status
518 acpi_ec_space_handler(u32 function, acpi_physical_address address,
519 		      u32 bits, acpi_integer *value,
520 		      void *handler_context, void *region_context)
521 {
522 	struct acpi_ec *ec = handler_context;
523 	int result = 0, i = 0;
524 	u8 temp = 0;
525 
526 	if ((address > 0xFF) || !value || !handler_context)
527 		return AE_BAD_PARAMETER;
528 
529 	if (function != ACPI_READ && function != ACPI_WRITE)
530 		return AE_BAD_PARAMETER;
531 
532 	if (bits != 8 && acpi_strict)
533 		return AE_BAD_PARAMETER;
534 
535 	while (bits - i > 0) {
536 		if (function == ACPI_READ) {
537 			result = acpi_ec_read(ec, address, &temp);
538 			(*value) |= ((acpi_integer)temp) << i;
539 		} else {
540 			temp = 0xff & ((*value) >> i);
541 			result = acpi_ec_write(ec, address, temp);
542 		}
543 		i += 8;
544 		++address;
545 	}
546 
547 	switch (result) {
548 	case -EINVAL:
549 		return AE_BAD_PARAMETER;
550 		break;
551 	case -ENODEV:
552 		return AE_NOT_FOUND;
553 		break;
554 	case -ETIME:
555 		return AE_TIME;
556 		break;
557 	default:
558 		return AE_OK;
559 	}
560 }
561 
562 /* --------------------------------------------------------------------------
563                               FS Interface (/proc)
564    -------------------------------------------------------------------------- */
565 
566 static struct proc_dir_entry *acpi_ec_dir;
567 
568 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
569 {
570 	struct acpi_ec *ec = seq->private;
571 
572 	if (!ec)
573 		goto end;
574 
575 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
576 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
577 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
578 	seq_printf(seq, "use global lock:\t%s\n",
579 		   ec->global_lock ? "yes" : "no");
580       end:
581 	return 0;
582 }
583 
584 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
585 {
586 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
587 }
588 
589 static struct file_operations acpi_ec_info_ops = {
590 	.open = acpi_ec_info_open_fs,
591 	.read = seq_read,
592 	.llseek = seq_lseek,
593 	.release = single_release,
594 	.owner = THIS_MODULE,
595 };
596 
597 static int acpi_ec_add_fs(struct acpi_device *device)
598 {
599 	struct proc_dir_entry *entry = NULL;
600 
601 	if (!acpi_device_dir(device)) {
602 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
603 						     acpi_ec_dir);
604 		if (!acpi_device_dir(device))
605 			return -ENODEV;
606 	}
607 
608 	entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
609 				  acpi_device_dir(device));
610 	if (!entry)
611 		return -ENODEV;
612 	else {
613 		entry->proc_fops = &acpi_ec_info_ops;
614 		entry->data = acpi_driver_data(device);
615 		entry->owner = THIS_MODULE;
616 	}
617 
618 	return 0;
619 }
620 
621 static int acpi_ec_remove_fs(struct acpi_device *device)
622 {
623 
624 	if (acpi_device_dir(device)) {
625 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
626 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
627 		acpi_device_dir(device) = NULL;
628 	}
629 
630 	return 0;
631 }
632 
633 /* --------------------------------------------------------------------------
634                                Driver Interface
635    -------------------------------------------------------------------------- */
636 static acpi_status
637 ec_parse_io_ports(struct acpi_resource *resource, void *context);
638 
639 static struct acpi_ec *make_acpi_ec(void)
640 {
641 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
642 	if (!ec)
643 		return NULL;
644 
645 	atomic_set(&ec->query_pending, 1);
646 	atomic_set(&ec->event_count, 1);
647 	mutex_init(&ec->lock);
648 	init_waitqueue_head(&ec->wait);
649 	INIT_LIST_HEAD(&ec->list);
650 
651 	return ec;
652 }
653 
654 static acpi_status
655 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
656 			       void *context, void **return_value)
657 {
658 	struct acpi_namespace_node *node = handle;
659 	struct acpi_ec *ec = context;
660 	int value = 0;
661 	if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
662 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
663 	}
664 	return AE_OK;
665 }
666 
667 static acpi_status
668 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
669 {
670 	acpi_status status;
671 
672 	struct acpi_ec *ec = context;
673 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
674 				     ec_parse_io_ports, ec);
675 	if (ACPI_FAILURE(status))
676 		return status;
677 
678 	/* Get GPE bit assignment (EC events). */
679 	/* TODO: Add support for _GPE returning a package */
680 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
681 	if (ACPI_FAILURE(status))
682 		return status;
683 
684 	/* Find and register all query methods */
685 	acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
686 			    acpi_ec_register_query_methods, ec, NULL);
687 
688 	/* Use the global lock for all EC transactions? */
689 	acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
690 
691 	ec->handle = handle;
692 
693 	printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
694 			  ec->gpe, ec->command_addr, ec->data_addr);
695 
696 	return AE_CTRL_TERMINATE;
697 }
698 
699 static int acpi_ec_add(struct acpi_device *device)
700 {
701 	struct acpi_ec *ec = NULL;
702 
703 	if (!device)
704 		return -EINVAL;
705 
706 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
707 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
708 
709 	ec = make_acpi_ec();
710 	if (!ec)
711 		return -ENOMEM;
712 
713 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
714 	    AE_CTRL_TERMINATE) {
715 		kfree(ec);
716 		return -EINVAL;
717 	}
718 
719 	/* Check if we found the boot EC */
720 	if (boot_ec) {
721 		if (boot_ec->gpe == ec->gpe) {
722 			/* We might have incorrect info for GL at boot time */
723 			mutex_lock(&boot_ec->lock);
724 			boot_ec->global_lock = ec->global_lock;
725 			/* Copy handlers from new ec into boot ec */
726 			list_splice(&ec->list, &boot_ec->list);
727 			mutex_unlock(&boot_ec->lock);
728 			kfree(ec);
729 			ec = boot_ec;
730 		}
731 	} else
732 		first_ec = ec;
733 	ec->handle = device->handle;
734 	acpi_driver_data(device) = ec;
735 
736 	acpi_ec_add_fs(device);
737 	return 0;
738 }
739 
740 static int acpi_ec_remove(struct acpi_device *device, int type)
741 {
742 	struct acpi_ec *ec;
743 	struct acpi_ec_query_handler *handler, *tmp;
744 
745 	if (!device)
746 		return -EINVAL;
747 
748 	ec = acpi_driver_data(device);
749 	mutex_lock(&ec->lock);
750 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
751 		list_del(&handler->node);
752 		kfree(handler);
753 	}
754 	mutex_unlock(&ec->lock);
755 	acpi_ec_remove_fs(device);
756 	acpi_driver_data(device) = NULL;
757 	if (ec == first_ec)
758 		first_ec = NULL;
759 
760 	/* Don't touch boot EC */
761 	if (boot_ec != ec)
762 		kfree(ec);
763 	return 0;
764 }
765 
766 static acpi_status
767 ec_parse_io_ports(struct acpi_resource *resource, void *context)
768 {
769 	struct acpi_ec *ec = context;
770 
771 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
772 		return AE_OK;
773 
774 	/*
775 	 * The first address region returned is the data port, and
776 	 * the second address region returned is the status/command
777 	 * port.
778 	 */
779 	if (ec->data_addr == 0)
780 		ec->data_addr = resource->data.io.minimum;
781 	else if (ec->command_addr == 0)
782 		ec->command_addr = resource->data.io.minimum;
783 	else
784 		return AE_CTRL_TERMINATE;
785 
786 	return AE_OK;
787 }
788 
789 static int ec_install_handlers(struct acpi_ec *ec)
790 {
791 	acpi_status status;
792 	status = acpi_install_gpe_handler(NULL, ec->gpe,
793 					  ACPI_GPE_EDGE_TRIGGERED,
794 					  &acpi_ec_gpe_handler, ec);
795 	if (ACPI_FAILURE(status))
796 		return -ENODEV;
797 
798 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
799 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
800 
801 	status = acpi_install_address_space_handler(ec->handle,
802 						    ACPI_ADR_SPACE_EC,
803 						    &acpi_ec_space_handler,
804 						    &acpi_ec_space_setup, ec);
805 	if (ACPI_FAILURE(status)) {
806 		acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
807 		return -ENODEV;
808 	}
809 
810 	return 0;
811 }
812 
813 static int acpi_ec_start(struct acpi_device *device)
814 {
815 	struct acpi_ec *ec;
816 	int ret = 0;
817 
818 	if (!device)
819 		return -EINVAL;
820 
821 	ec = acpi_driver_data(device);
822 
823 	if (!ec)
824 		return -EINVAL;
825 
826 	/* Boot EC is already working */
827 	if (ec != boot_ec)
828 		ret = ec_install_handlers(ec);
829 
830 	/* EC is fully operational, allow queries */
831 	atomic_set(&ec->query_pending, 0);
832 
833 	return ret;
834 }
835 
836 static int acpi_ec_stop(struct acpi_device *device, int type)
837 {
838 	acpi_status status;
839 	struct acpi_ec *ec;
840 
841 	if (!device)
842 		return -EINVAL;
843 
844 	ec = acpi_driver_data(device);
845 	if (!ec)
846 		return -EINVAL;
847 
848 	/* Don't touch boot EC */
849 	if (ec == boot_ec)
850 		return 0;
851 
852 	status = acpi_remove_address_space_handler(ec->handle,
853 						   ACPI_ADR_SPACE_EC,
854 						   &acpi_ec_space_handler);
855 	if (ACPI_FAILURE(status))
856 		return -ENODEV;
857 
858 	status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
859 	if (ACPI_FAILURE(status))
860 		return -ENODEV;
861 
862 	return 0;
863 }
864 
865 int __init acpi_ec_ecdt_probe(void)
866 {
867 	int ret;
868 	acpi_status status;
869 	struct acpi_table_ecdt *ecdt_ptr;
870 
871 	boot_ec = make_acpi_ec();
872 	if (!boot_ec)
873 		return -ENOMEM;
874 	/*
875 	 * Generate a boot ec context
876 	 */
877 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
878 				(struct acpi_table_header **)&ecdt_ptr);
879 	if (ACPI_SUCCESS(status)) {
880 		printk(KERN_INFO PREFIX "EC description table is found, configuring boot EC\n\n");
881 		boot_ec->command_addr = ecdt_ptr->control.address;
882 		boot_ec->data_addr = ecdt_ptr->data.address;
883 		boot_ec->gpe = ecdt_ptr->gpe;
884 		boot_ec->handle = ACPI_ROOT_OBJECT;
885 	} else {
886 		printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
887 		status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
888 						boot_ec, NULL);
889 		/* Check that acpi_get_devices actually find something */
890 		if (ACPI_FAILURE(status) || !boot_ec->handle)
891 			goto error;
892 	}
893 
894 	ret = ec_install_handlers(boot_ec);
895 	if (!ret) {
896 		first_ec = boot_ec;
897 		return 0;
898 	}
899       error:
900 	kfree(boot_ec);
901 	boot_ec = NULL;
902 
903 	return -ENODEV;
904 }
905 
906 static int __init acpi_ec_init(void)
907 {
908 	int result = 0;
909 
910 	if (acpi_disabled)
911 		return 0;
912 
913 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
914 	if (!acpi_ec_dir)
915 		return -ENODEV;
916 
917 	/* Now register the driver for the EC */
918 	result = acpi_bus_register_driver(&acpi_ec_driver);
919 	if (result < 0) {
920 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
921 		return -ENODEV;
922 	}
923 
924 	return result;
925 }
926 
927 subsys_initcall(acpi_ec_init);
928 
929 /* EC driver currently not unloadable */
930 #if 0
931 static void __exit acpi_ec_exit(void)
932 {
933 
934 	acpi_bus_unregister_driver(&acpi_ec_driver);
935 
936 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
937 
938 	return;
939 }
940 #endif				/* 0 */
941 
942 static int __init acpi_ec_set_intr_mode(char *str)
943 {
944 	int intr;
945 
946 	if (!get_option(&str, &intr))
947 		return 0;
948 
949 	acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
950 
951 	printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
952 
953 	return 1;
954 }
955 
956 __setup("ec_intr=", acpi_ec_set_intr_mode);
957