xref: /openbmc/linux/drivers/acpi/ec.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 <asm/io.h>
38 #include <acpi/acpi_bus.h>
39 #include <acpi/acpi_drivers.h>
40 #include <acpi/actypes.h>
41 
42 #define _COMPONENT		ACPI_EC_COMPONENT
43 ACPI_MODULE_NAME("ec");
44 #define ACPI_EC_COMPONENT		0x00100000
45 #define ACPI_EC_CLASS			"embedded_controller"
46 #define ACPI_EC_HID			"PNP0C09"
47 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
48 #define ACPI_EC_FILE_INFO		"info"
49 #undef PREFIX
50 #define PREFIX				"ACPI: EC: "
51 /* EC status register */
52 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
53 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
54 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
55 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
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 /* EC events */
65 enum ec_event {
66 	ACPI_EC_EVENT_OBF_1 = 1,	/* Output buffer full */
67 	ACPI_EC_EVENT_IBF_0,	/* Input buffer empty */
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 
73 static enum ec_mode {
74 	EC_INTR = 1,		/* Output buffer full */
75 	EC_POLL,		/* Input buffer empty */
76 } acpi_ec_mode = EC_INTR;
77 
78 static int acpi_ec_remove(struct acpi_device *device, int type);
79 static int acpi_ec_start(struct acpi_device *device);
80 static int acpi_ec_stop(struct acpi_device *device, int type);
81 static int acpi_ec_add(struct acpi_device *device);
82 
83 static struct acpi_driver acpi_ec_driver = {
84 	.name = "ec",
85 	.class = ACPI_EC_CLASS,
86 	.ids = ACPI_EC_HID,
87 	.ops = {
88 		.add = acpi_ec_add,
89 		.remove = acpi_ec_remove,
90 		.start = acpi_ec_start,
91 		.stop = acpi_ec_stop,
92 		},
93 };
94 
95 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
96 /* External interfaces use first EC only, so remember */
97 static struct acpi_ec {
98 	acpi_handle handle;
99 	unsigned long gpe;
100 	unsigned long command_addr;
101 	unsigned long data_addr;
102 	unsigned long global_lock;
103 	struct mutex lock;
104 	atomic_t query_pending;
105 	atomic_t event_count;
106 	wait_queue_head_t wait;
107 } *boot_ec, *first_ec;
108 
109 /* --------------------------------------------------------------------------
110                              Transaction Management
111    -------------------------------------------------------------------------- */
112 
113 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
114 {
115 	return inb(ec->command_addr);
116 }
117 
118 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
119 {
120 	return inb(ec->data_addr);
121 }
122 
123 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
124 {
125 	outb(command, ec->command_addr);
126 }
127 
128 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
129 {
130 	outb(data, ec->data_addr);
131 }
132 
133 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event,
134 				       unsigned old_count)
135 {
136 	u8 status = acpi_ec_read_status(ec);
137 	if (old_count == atomic_read(&ec->event_count))
138 		return 0;
139 	if (event == ACPI_EC_EVENT_OBF_1) {
140 		if (status & ACPI_EC_FLAG_OBF)
141 			return 1;
142 	} else if (event == ACPI_EC_EVENT_IBF_0) {
143 		if (!(status & ACPI_EC_FLAG_IBF))
144 			return 1;
145 	}
146 
147 	return 0;
148 }
149 
150 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event,
151                         unsigned count, int force_poll)
152 {
153 	if (unlikely(force_poll) || acpi_ec_mode == EC_POLL) {
154 		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
155 		while (time_before(jiffies, delay)) {
156 			if (acpi_ec_check_status(ec, event, 0))
157 				return 0;
158 		}
159 	} else {
160 		if (wait_event_timeout(ec->wait,
161 				       acpi_ec_check_status(ec, event, count),
162 				       msecs_to_jiffies(ACPI_EC_DELAY)) ||
163 		    acpi_ec_check_status(ec, event, 0)) {
164 			return 0;
165 		} else {
166 			printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
167 			       " status = %d, expect_event = %d\n",
168 			       acpi_ec_read_status(ec), event);
169 		}
170 	}
171 
172 	return -ETIME;
173 }
174 
175 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
176 					const u8 * wdata, unsigned wdata_len,
177 					u8 * rdata, unsigned rdata_len,
178 					int force_poll)
179 {
180 	int result = 0;
181 	unsigned count = atomic_read(&ec->event_count);
182 	acpi_ec_write_cmd(ec, command);
183 
184 	for (; wdata_len > 0; --wdata_len) {
185 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
186 		if (result) {
187 			printk(KERN_ERR PREFIX
188 			       "write_cmd timeout, command = %d\n", command);
189 			goto end;
190 		}
191 		count = atomic_read(&ec->event_count);
192 		acpi_ec_write_data(ec, *(wdata++));
193 	}
194 
195 	if (!rdata_len) {
196 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
197 		if (result) {
198 			printk(KERN_ERR PREFIX
199 			       "finish-write timeout, command = %d\n", command);
200 			goto end;
201 		}
202 	} else if (command == ACPI_EC_COMMAND_QUERY) {
203 		atomic_set(&ec->query_pending, 0);
204 	}
205 
206 	for (; rdata_len > 0; --rdata_len) {
207 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count, force_poll);
208 		if (result) {
209 			printk(KERN_ERR PREFIX "read timeout, command = %d\n",
210 			       command);
211 			goto end;
212 		}
213 		count = atomic_read(&ec->event_count);
214 		*(rdata++) = acpi_ec_read_data(ec);
215 	}
216       end:
217 	return result;
218 }
219 
220 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
221 			       const u8 * wdata, unsigned wdata_len,
222 			       u8 * rdata, unsigned rdata_len,
223 			       int force_poll)
224 {
225 	int status;
226 	u32 glk;
227 
228 	if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
229 		return -EINVAL;
230 
231 	if (rdata)
232 		memset(rdata, 0, rdata_len);
233 
234 	mutex_lock(&ec->lock);
235 	if (ec->global_lock) {
236 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
237 		if (ACPI_FAILURE(status)) {
238 			mutex_unlock(&ec->lock);
239 			return -ENODEV;
240 		}
241 	}
242 
243 	/* Make sure GPE is enabled before doing transaction */
244 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
245 
246 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0, 0);
247 	if (status) {
248 		printk(KERN_DEBUG PREFIX
249 		       "input buffer is not empty, aborting transaction\n");
250 		goto end;
251 	}
252 
253 	status = acpi_ec_transaction_unlocked(ec, command,
254 					      wdata, wdata_len,
255 					      rdata, rdata_len,
256 					      force_poll);
257 
258       end:
259 
260 	if (ec->global_lock)
261 		acpi_release_global_lock(glk);
262 	mutex_unlock(&ec->lock);
263 
264 	return status;
265 }
266 
267 /*
268  * Note: samsung nv5000 doesn't work with ec burst mode.
269  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
270  */
271 int acpi_ec_burst_enable(struct acpi_ec *ec)
272 {
273 	u8 d;
274 	return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
275 }
276 
277 int acpi_ec_burst_disable(struct acpi_ec *ec)
278 {
279 	return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
280 }
281 
282 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
283 {
284 	int result;
285 	u8 d;
286 
287 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
288 				     &address, 1, &d, 1, 0);
289 	*data = d;
290 	return result;
291 }
292 
293 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
294 {
295 	u8 wdata[2] = { address, data };
296 	return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
297 				   wdata, 2, NULL, 0, 0);
298 }
299 
300 /*
301  * Externally callable EC access functions. For now, assume 1 EC only
302  */
303 int ec_burst_enable(void)
304 {
305 	if (!first_ec)
306 		return -ENODEV;
307 	return acpi_ec_burst_enable(first_ec);
308 }
309 
310 EXPORT_SYMBOL(ec_burst_enable);
311 
312 int ec_burst_disable(void)
313 {
314 	if (!first_ec)
315 		return -ENODEV;
316 	return acpi_ec_burst_disable(first_ec);
317 }
318 
319 EXPORT_SYMBOL(ec_burst_disable);
320 
321 int ec_read(u8 addr, u8 * val)
322 {
323 	int err;
324 	u8 temp_data;
325 
326 	if (!first_ec)
327 		return -ENODEV;
328 
329 	err = acpi_ec_read(first_ec, addr, &temp_data);
330 
331 	if (!err) {
332 		*val = temp_data;
333 		return 0;
334 	} else
335 		return err;
336 }
337 
338 EXPORT_SYMBOL(ec_read);
339 
340 int ec_write(u8 addr, u8 val)
341 {
342 	int err;
343 
344 	if (!first_ec)
345 		return -ENODEV;
346 
347 	err = acpi_ec_write(first_ec, addr, val);
348 
349 	return err;
350 }
351 
352 EXPORT_SYMBOL(ec_write);
353 
354 int ec_transaction(u8 command,
355 		   const u8 * wdata, unsigned wdata_len,
356 		   u8 * rdata, unsigned rdata_len,
357 		   int force_poll)
358 {
359 	if (!first_ec)
360 		return -ENODEV;
361 
362 	return acpi_ec_transaction(first_ec, command, wdata,
363 				   wdata_len, rdata, rdata_len,
364 				   force_poll);
365 }
366 
367 EXPORT_SYMBOL(ec_transaction);
368 
369 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
370 {
371 	int result;
372 	u8 d;
373 
374 	if (!ec || !data)
375 		return -EINVAL;
376 
377 	/*
378 	 * Query the EC to find out which _Qxx method we need to evaluate.
379 	 * Note that successful completion of the query causes the ACPI_EC_SCI
380 	 * bit to be cleared (and thus clearing the interrupt source).
381 	 */
382 
383 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
384 	if (result)
385 		return result;
386 
387 	if (!d)
388 		return -ENODATA;
389 
390 	*data = d;
391 	return 0;
392 }
393 
394 /* --------------------------------------------------------------------------
395                                 Event Management
396    -------------------------------------------------------------------------- */
397 
398 static void acpi_ec_gpe_query(void *ec_cxt)
399 {
400 	struct acpi_ec *ec = ec_cxt;
401 	u8 value = 0;
402 	char object_name[8];
403 
404 	if (!ec || acpi_ec_query(ec, &value))
405 		return;
406 
407 	snprintf(object_name, 8, "_Q%2.2X", value);
408 
409 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
410 
411 	acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
412 }
413 
414 static u32 acpi_ec_gpe_handler(void *data)
415 {
416 	acpi_status status = AE_OK;
417 	u8 value;
418 	struct acpi_ec *ec = data;
419 
420 	atomic_inc(&ec->event_count);
421 
422 	if (acpi_ec_mode == EC_INTR) {
423 		wake_up(&ec->wait);
424 	}
425 
426 	value = acpi_ec_read_status(ec);
427 	if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
428 		atomic_set(&ec->query_pending, 1);
429 		status =
430 		    acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query,
431 				    ec);
432 	}
433 
434 	return status == AE_OK ?
435 	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
436 }
437 
438 /* --------------------------------------------------------------------------
439                              Address Space Management
440    -------------------------------------------------------------------------- */
441 
442 static acpi_status
443 acpi_ec_space_setup(acpi_handle region_handle,
444 		    u32 function, void *handler_context, void **return_context)
445 {
446 	/*
447 	 * The EC object is in the handler context and is needed
448 	 * when calling the acpi_ec_space_handler.
449 	 */
450 	*return_context = (function != ACPI_REGION_DEACTIVATE) ?
451 	    handler_context : NULL;
452 
453 	return AE_OK;
454 }
455 
456 static acpi_status
457 acpi_ec_space_handler(u32 function,
458 		      acpi_physical_address address,
459 		      u32 bit_width,
460 		      acpi_integer * value,
461 		      void *handler_context, void *region_context)
462 {
463 	int result = 0;
464 	struct acpi_ec *ec = handler_context;
465 	u64 temp = *value;
466 	acpi_integer f_v = 0;
467 	int i = 0;
468 
469 	if ((address > 0xFF) || !value || !handler_context)
470 		return AE_BAD_PARAMETER;
471 
472 	if (bit_width != 8 && acpi_strict) {
473 		return AE_BAD_PARAMETER;
474 	}
475 
476       next_byte:
477 	switch (function) {
478 	case ACPI_READ:
479 		temp = 0;
480 		result = acpi_ec_read(ec, (u8) address, (u8 *) & temp);
481 		break;
482 	case ACPI_WRITE:
483 		result = acpi_ec_write(ec, (u8) address, (u8) temp);
484 		break;
485 	default:
486 		result = -EINVAL;
487 		goto out;
488 		break;
489 	}
490 
491 	bit_width -= 8;
492 	if (bit_width) {
493 		if (function == ACPI_READ)
494 			f_v |= temp << 8 * i;
495 		if (function == ACPI_WRITE)
496 			temp >>= 8;
497 		i++;
498 		address++;
499 		goto next_byte;
500 	}
501 
502 	if (function == ACPI_READ) {
503 		f_v |= temp << 8 * i;
504 		*value = f_v;
505 	}
506 
507       out:
508 	switch (result) {
509 	case -EINVAL:
510 		return AE_BAD_PARAMETER;
511 		break;
512 	case -ENODEV:
513 		return AE_NOT_FOUND;
514 		break;
515 	case -ETIME:
516 		return AE_TIME;
517 		break;
518 	default:
519 		return AE_OK;
520 	}
521 }
522 
523 /* --------------------------------------------------------------------------
524                               FS Interface (/proc)
525    -------------------------------------------------------------------------- */
526 
527 static struct proc_dir_entry *acpi_ec_dir;
528 
529 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
530 {
531 	struct acpi_ec *ec = seq->private;
532 
533 	if (!ec)
534 		goto end;
535 
536 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
537 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
538 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
539 	seq_printf(seq, "use global lock:\t%s\n",
540 		   ec->global_lock ? "yes" : "no");
541       end:
542 	return 0;
543 }
544 
545 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
546 {
547 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
548 }
549 
550 static struct file_operations acpi_ec_info_ops = {
551 	.open = acpi_ec_info_open_fs,
552 	.read = seq_read,
553 	.llseek = seq_lseek,
554 	.release = single_release,
555 	.owner = THIS_MODULE,
556 };
557 
558 static int acpi_ec_add_fs(struct acpi_device *device)
559 {
560 	struct proc_dir_entry *entry = NULL;
561 
562 	if (!acpi_device_dir(device)) {
563 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
564 						     acpi_ec_dir);
565 		if (!acpi_device_dir(device))
566 			return -ENODEV;
567 	}
568 
569 	entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
570 				  acpi_device_dir(device));
571 	if (!entry)
572 		return -ENODEV;
573 	else {
574 		entry->proc_fops = &acpi_ec_info_ops;
575 		entry->data = acpi_driver_data(device);
576 		entry->owner = THIS_MODULE;
577 	}
578 
579 	return 0;
580 }
581 
582 static int acpi_ec_remove_fs(struct acpi_device *device)
583 {
584 
585 	if (acpi_device_dir(device)) {
586 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
587 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
588 		acpi_device_dir(device) = NULL;
589 	}
590 
591 	return 0;
592 }
593 
594 /* --------------------------------------------------------------------------
595                                Driver Interface
596    -------------------------------------------------------------------------- */
597 static acpi_status
598 ec_parse_io_ports(struct acpi_resource *resource, void *context);
599 
600 static acpi_status
601 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval);
602 
603 static struct acpi_ec *make_acpi_ec(void)
604 {
605 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
606 	if (!ec)
607 		return NULL;
608 
609 	atomic_set(&ec->query_pending, 1);
610 	atomic_set(&ec->event_count, 1);
611 	mutex_init(&ec->lock);
612 	init_waitqueue_head(&ec->wait);
613 
614 	return ec;
615 }
616 
617 static int acpi_ec_add(struct acpi_device *device)
618 {
619 	acpi_status status = AE_OK;
620 	struct acpi_ec *ec = NULL;
621 
622 	if (!device)
623 		return -EINVAL;
624 
625 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
626 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
627 
628 	ec = make_acpi_ec();
629 	if (!ec)
630 		return -ENOMEM;
631 
632 	status = ec_parse_device(device->handle, 0, ec, NULL);
633 	if (status != AE_CTRL_TERMINATE) {
634 		kfree(ec);
635 		return -EINVAL;
636 	}
637 
638 	/* Check if we found the boot EC */
639 	if (boot_ec) {
640 		if (boot_ec->gpe == ec->gpe) {
641 			/* We might have incorrect info for GL at boot time */
642 			mutex_lock(&boot_ec->lock);
643 			boot_ec->global_lock = ec->global_lock;
644 			mutex_unlock(&boot_ec->lock);
645 			kfree(ec);
646 			ec = boot_ec;
647 		}
648 	} else
649 		first_ec = ec;
650 	ec->handle = device->handle;
651 	acpi_driver_data(device) = ec;
652 
653 	acpi_ec_add_fs(device);
654 
655 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
656 			  acpi_device_name(device), acpi_device_bid(device),
657 			  (u32) ec->gpe));
658 
659 	return 0;
660 }
661 
662 static int acpi_ec_remove(struct acpi_device *device, int type)
663 {
664 	struct acpi_ec *ec;
665 
666 	if (!device)
667 		return -EINVAL;
668 
669 	ec = acpi_driver_data(device);
670 	acpi_ec_remove_fs(device);
671 	acpi_driver_data(device) = NULL;
672 	if (ec == first_ec)
673 		first_ec = NULL;
674 
675 	/* Don't touch boot EC */
676 	if (boot_ec != ec)
677 		kfree(ec);
678 	return 0;
679 }
680 
681 static acpi_status
682 ec_parse_io_ports(struct acpi_resource *resource, void *context)
683 {
684 	struct acpi_ec *ec = context;
685 
686 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
687 		return AE_OK;
688 
689 	/*
690 	 * The first address region returned is the data port, and
691 	 * the second address region returned is the status/command
692 	 * port.
693 	 */
694 	if (ec->data_addr == 0)
695 		ec->data_addr = resource->data.io.minimum;
696 	else if (ec->command_addr == 0)
697 		ec->command_addr = resource->data.io.minimum;
698 	else
699 		return AE_CTRL_TERMINATE;
700 
701 	return AE_OK;
702 }
703 
704 static int ec_install_handlers(struct acpi_ec *ec)
705 {
706 	acpi_status status;
707 	status = acpi_install_gpe_handler(NULL, ec->gpe,
708 					  ACPI_GPE_EDGE_TRIGGERED,
709 					  &acpi_ec_gpe_handler, ec);
710 	if (ACPI_FAILURE(status))
711 		return -ENODEV;
712 
713 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
714 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
715 
716 	status = acpi_install_address_space_handler(ec->handle,
717 						    ACPI_ADR_SPACE_EC,
718 						    &acpi_ec_space_handler,
719 						    &acpi_ec_space_setup, ec);
720 	if (ACPI_FAILURE(status)) {
721 		acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
722 		return -ENODEV;
723 	}
724 
725 	/* EC is fully operational, allow queries */
726 	atomic_set(&ec->query_pending, 0);
727 
728 	return 0;
729 }
730 
731 static int acpi_ec_start(struct acpi_device *device)
732 {
733 	struct acpi_ec *ec;
734 
735 	if (!device)
736 		return -EINVAL;
737 
738 	ec = acpi_driver_data(device);
739 
740 	if (!ec)
741 		return -EINVAL;
742 
743 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
744 			  ec->gpe, ec->command_addr, ec->data_addr));
745 
746 	/* Boot EC is already working */
747 	if (ec == boot_ec)
748 		return 0;
749 
750 	return ec_install_handlers(ec);
751 }
752 
753 static int acpi_ec_stop(struct acpi_device *device, int type)
754 {
755 	acpi_status status;
756 	struct acpi_ec *ec;
757 
758 	if (!device)
759 		return -EINVAL;
760 
761 	ec = acpi_driver_data(device);
762 	if (!ec)
763 		return -EINVAL;
764 
765 	/* Don't touch boot EC */
766 	if (ec == boot_ec)
767 		return 0;
768 
769 	status = acpi_remove_address_space_handler(ec->handle,
770 						   ACPI_ADR_SPACE_EC,
771 						   &acpi_ec_space_handler);
772 	if (ACPI_FAILURE(status))
773 		return -ENODEV;
774 
775 	status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
776 	if (ACPI_FAILURE(status))
777 		return -ENODEV;
778 
779 	return 0;
780 }
781 
782 static acpi_status
783 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
784 {
785 	acpi_status status;
786 
787 	struct acpi_ec *ec = context;
788 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
789 				     ec_parse_io_ports, ec);
790 	if (ACPI_FAILURE(status))
791 		return status;
792 
793 	/* Get GPE bit assignment (EC events). */
794 	/* TODO: Add support for _GPE returning a package */
795 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
796 	if (ACPI_FAILURE(status))
797 		return status;
798 
799 	/* Use the global lock for all EC transactions? */
800 	acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
801 
802 	ec->handle = handle;
803 
804 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
805 			  ec->gpe, ec->command_addr, ec->data_addr));
806 
807 	return AE_CTRL_TERMINATE;
808 }
809 
810 int __init acpi_ec_ecdt_probe(void)
811 {
812 	int ret;
813 	acpi_status status;
814 	struct acpi_table_ecdt *ecdt_ptr;
815 
816 	boot_ec = make_acpi_ec();
817 	if (!boot_ec)
818 		return -ENOMEM;
819 	/*
820 	 * Generate a boot ec context
821 	 */
822 
823 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
824 				(struct acpi_table_header **)&ecdt_ptr);
825 	if (ACPI_FAILURE(status))
826 		goto error;
827 
828 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
829 
830 	boot_ec->command_addr = ecdt_ptr->control.address;
831 	boot_ec->data_addr = ecdt_ptr->data.address;
832 	boot_ec->gpe = ecdt_ptr->gpe;
833 	boot_ec->handle = ACPI_ROOT_OBJECT;
834 
835 	ret = ec_install_handlers(boot_ec);
836 	if (!ret) {
837 		first_ec = boot_ec;
838 		return 0;
839 	}
840       error:
841 	kfree(boot_ec);
842 	boot_ec = NULL;
843 
844 	return -ENODEV;
845 }
846 
847 static int __init acpi_ec_init(void)
848 {
849 	int result = 0;
850 
851 	if (acpi_disabled)
852 		return 0;
853 
854 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
855 	if (!acpi_ec_dir)
856 		return -ENODEV;
857 
858 	/* Now register the driver for the EC */
859 	result = acpi_bus_register_driver(&acpi_ec_driver);
860 	if (result < 0) {
861 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
862 		return -ENODEV;
863 	}
864 
865 	return result;
866 }
867 
868 subsys_initcall(acpi_ec_init);
869 
870 /* EC driver currently not unloadable */
871 #if 0
872 static void __exit acpi_ec_exit(void)
873 {
874 
875 	acpi_bus_unregister_driver(&acpi_ec_driver);
876 
877 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
878 
879 	return;
880 }
881 #endif				/* 0 */
882 
883 static int __init acpi_ec_set_intr_mode(char *str)
884 {
885 	int intr;
886 
887 	if (!get_option(&str, &intr))
888 		return 0;
889 
890 	acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
891 
892 	printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
893 
894 	return 1;
895 }
896 
897 __setup("ec_intr=", acpi_ec_set_intr_mode);
898