ec.c revision 9fd9f8e8bdcfc9aa309dae5bccc55d02804337d0 
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
43ACPI_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 */
57enum 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 */
65enum 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
73static enum ec_mode {
74	EC_INTR = 1,		/* Output buffer full */
75	EC_POLL,		/* Input buffer empty */
76} acpi_ec_mode = EC_INTR;
77
78static int acpi_ec_remove(struct acpi_device *device, int type);
79static int acpi_ec_start(struct acpi_device *device);
80static int acpi_ec_stop(struct acpi_device *device, int type);
81static int acpi_ec_add(struct acpi_device *device);
82
83static 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 */
97static 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
113static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
114{
115	return inb(ec->command_addr);
116}
117
118static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
119{
120	return inb(ec->data_addr);
121}
122
123static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
124{
125	outb(command, ec->command_addr);
126}
127
128static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
129{
130	outb(data, ec->data_addr);
131}
132
133static 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
150static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, unsigned count)
151{
152	if (acpi_ec_mode == EC_POLL) {
153		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
154		while (time_before(jiffies, delay)) {
155			if (acpi_ec_check_status(ec, event, 0))
156				return 0;
157		}
158	} else {
159		if (wait_event_timeout(ec->wait,
160				       acpi_ec_check_status(ec, event, count),
161				       msecs_to_jiffies(ACPI_EC_DELAY)) ||
162		    acpi_ec_check_status(ec, event, 0)) {
163			return 0;
164		} else {
165			printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
166			       " status = %d, expect_event = %d\n",
167			       acpi_ec_read_status(ec), event);
168		}
169	}
170
171	return -ETIME;
172}
173
174static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
175					const u8 * wdata, unsigned wdata_len,
176					u8 * rdata, unsigned rdata_len)
177{
178	int result = 0;
179	unsigned count = atomic_read(&ec->event_count);
180	acpi_ec_write_cmd(ec, command);
181
182	for (; wdata_len > 0; --wdata_len) {
183		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count);
184		if (result) {
185			printk(KERN_ERR PREFIX
186			       "write_cmd timeout, command = %d\n", command);
187			goto end;
188		}
189		count = atomic_read(&ec->event_count);
190		acpi_ec_write_data(ec, *(wdata++));
191	}
192
193	if (!rdata_len) {
194		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count);
195		if (result) {
196			printk(KERN_ERR PREFIX
197			       "finish-write timeout, command = %d\n", command);
198			goto end;
199		}
200	} else if (command == ACPI_EC_COMMAND_QUERY) {
201		atomic_set(&ec->query_pending, 0);
202	}
203
204	for (; rdata_len > 0; --rdata_len) {
205		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count);
206		if (result) {
207			printk(KERN_ERR PREFIX "read timeout, command = %d\n",
208			       command);
209			goto end;
210		}
211		count = atomic_read(&ec->event_count);
212		*(rdata++) = acpi_ec_read_data(ec);
213	}
214      end:
215	return result;
216}
217
218static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
219			       const u8 * wdata, unsigned wdata_len,
220			       u8 * rdata, unsigned rdata_len)
221{
222	int status;
223	u32 glk;
224
225	if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
226		return -EINVAL;
227
228	if (rdata)
229		memset(rdata, 0, rdata_len);
230
231	mutex_lock(&ec->lock);
232	if (ec->global_lock) {
233		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
234		if (ACPI_FAILURE(status)) {
235			mutex_unlock(&ec->lock);
236			return -ENODEV;
237		}
238	}
239
240	/* Make sure GPE is enabled before doing transaction */
241	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
242
243	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
244	if (status) {
245		printk(KERN_DEBUG PREFIX
246		       "input buffer is not empty, aborting transaction\n");
247		goto end;
248	}
249
250	status = acpi_ec_transaction_unlocked(ec, command,
251					      wdata, wdata_len,
252					      rdata, rdata_len);
253
254      end:
255
256	if (ec->global_lock)
257		acpi_release_global_lock(glk);
258	mutex_unlock(&ec->lock);
259
260	return status;
261}
262
263/*
264 * Note: samsung nv5000 doesn't work with ec burst mode.
265 * http://bugzilla.kernel.org/show_bug.cgi?id=4980
266 */
267int acpi_ec_burst_enable(struct acpi_ec *ec)
268{
269	u8 d;
270	return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1);
271}
272
273int acpi_ec_burst_disable(struct acpi_ec *ec)
274{
275	return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0);
276}
277
278static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
279{
280	int result;
281	u8 d;
282
283	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
284				     &address, 1, &d, 1);
285	*data = d;
286	return result;
287}
288
289static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
290{
291	u8 wdata[2] = { address, data };
292	return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
293				   wdata, 2, NULL, 0);
294}
295
296/*
297 * Externally callable EC access functions. For now, assume 1 EC only
298 */
299int ec_burst_enable(void)
300{
301	if (!first_ec)
302		return -ENODEV;
303	return acpi_ec_burst_enable(first_ec);
304}
305
306EXPORT_SYMBOL(ec_burst_enable);
307
308int ec_burst_disable(void)
309{
310	if (!first_ec)
311		return -ENODEV;
312	return acpi_ec_burst_disable(first_ec);
313}
314
315EXPORT_SYMBOL(ec_burst_disable);
316
317int ec_read(u8 addr, u8 * val)
318{
319	int err;
320	u8 temp_data;
321
322	if (!first_ec)
323		return -ENODEV;
324
325	err = acpi_ec_read(first_ec, addr, &temp_data);
326
327	if (!err) {
328		*val = temp_data;
329		return 0;
330	} else
331		return err;
332}
333
334EXPORT_SYMBOL(ec_read);
335
336int ec_write(u8 addr, u8 val)
337{
338	int err;
339
340	if (!first_ec)
341		return -ENODEV;
342
343	err = acpi_ec_write(first_ec, addr, val);
344
345	return err;
346}
347
348EXPORT_SYMBOL(ec_write);
349
350int ec_transaction(u8 command,
351		   const u8 * wdata, unsigned wdata_len,
352		   u8 * rdata, unsigned rdata_len)
353{
354	if (!first_ec)
355		return -ENODEV;
356
357	return acpi_ec_transaction(first_ec, command, wdata,
358				   wdata_len, rdata, rdata_len);
359}
360
361EXPORT_SYMBOL(ec_transaction);
362
363static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
364{
365	int result;
366	u8 d;
367
368	if (!ec || !data)
369		return -EINVAL;
370
371	/*
372	 * Query the EC to find out which _Qxx method we need to evaluate.
373	 * Note that successful completion of the query causes the ACPI_EC_SCI
374	 * bit to be cleared (and thus clearing the interrupt source).
375	 */
376
377	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1);
378	if (result)
379		return result;
380
381	if (!d)
382		return -ENODATA;
383
384	*data = d;
385	return 0;
386}
387
388/* --------------------------------------------------------------------------
389                                Event Management
390   -------------------------------------------------------------------------- */
391
392static void acpi_ec_gpe_query(void *ec_cxt)
393{
394	struct acpi_ec *ec = ec_cxt;
395	u8 value = 0;
396	char object_name[8];
397
398	if (!ec || acpi_ec_query(ec, &value))
399		return;
400
401	snprintf(object_name, 8, "_Q%2.2X", value);
402
403	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
404
405	acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
406}
407
408static u32 acpi_ec_gpe_handler(void *data)
409{
410	acpi_status status = AE_OK;
411	u8 value;
412	struct acpi_ec *ec = data;
413	atomic_inc(&ec->event_count);
414
415	if (acpi_ec_mode == EC_INTR) {
416		wake_up(&ec->wait);
417	}
418
419	value = acpi_ec_read_status(ec);
420	if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
421		atomic_set(&ec->query_pending, 1);
422		status =
423		    acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query,
424				    ec);
425	}
426
427	return status == AE_OK ?
428	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
429}
430
431/* --------------------------------------------------------------------------
432                             Address Space Management
433   -------------------------------------------------------------------------- */
434
435static acpi_status
436acpi_ec_space_setup(acpi_handle region_handle,
437		    u32 function, void *handler_context, void **return_context)
438{
439	/*
440	 * The EC object is in the handler context and is needed
441	 * when calling the acpi_ec_space_handler.
442	 */
443	*return_context = (function != ACPI_REGION_DEACTIVATE) ?
444	    handler_context : NULL;
445
446	return AE_OK;
447}
448
449static acpi_status
450acpi_ec_space_handler(u32 function,
451		      acpi_physical_address address,
452		      u32 bit_width,
453		      acpi_integer * value,
454		      void *handler_context, void *region_context)
455{
456	int result = 0;
457	struct acpi_ec *ec = handler_context;
458	u64 temp = *value;
459	acpi_integer f_v = 0;
460	int i = 0;
461
462	if ((address > 0xFF) || !value || !handler_context)
463		return AE_BAD_PARAMETER;
464
465	if (bit_width != 8 && acpi_strict) {
466		return AE_BAD_PARAMETER;
467	}
468
469      next_byte:
470	switch (function) {
471	case ACPI_READ:
472		temp = 0;
473		result = acpi_ec_read(ec, (u8) address, (u8 *) & temp);
474		break;
475	case ACPI_WRITE:
476		result = acpi_ec_write(ec, (u8) address, (u8) temp);
477		break;
478	default:
479		result = -EINVAL;
480		goto out;
481		break;
482	}
483
484	bit_width -= 8;
485	if (bit_width) {
486		if (function == ACPI_READ)
487			f_v |= temp << 8 * i;
488		if (function == ACPI_WRITE)
489			temp >>= 8;
490		i++;
491		address++;
492		goto next_byte;
493	}
494
495	if (function == ACPI_READ) {
496		f_v |= temp << 8 * i;
497		*value = f_v;
498	}
499
500      out:
501	switch (result) {
502	case -EINVAL:
503		return AE_BAD_PARAMETER;
504		break;
505	case -ENODEV:
506		return AE_NOT_FOUND;
507		break;
508	case -ETIME:
509		return AE_TIME;
510		break;
511	default:
512		return AE_OK;
513	}
514}
515
516/* --------------------------------------------------------------------------
517                              FS Interface (/proc)
518   -------------------------------------------------------------------------- */
519
520static struct proc_dir_entry *acpi_ec_dir;
521
522static int acpi_ec_read_info(struct seq_file *seq, void *offset)
523{
524	struct acpi_ec *ec = seq->private;
525
526	if (!ec)
527		goto end;
528
529	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
530	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
531		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
532	seq_printf(seq, "use global lock:\t%s\n",
533		   ec->global_lock ? "yes" : "no");
534      end:
535	return 0;
536}
537
538static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
539{
540	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
541}
542
543static struct file_operations acpi_ec_info_ops = {
544	.open = acpi_ec_info_open_fs,
545	.read = seq_read,
546	.llseek = seq_lseek,
547	.release = single_release,
548	.owner = THIS_MODULE,
549};
550
551static int acpi_ec_add_fs(struct acpi_device *device)
552{
553	struct proc_dir_entry *entry = NULL;
554
555	if (!acpi_device_dir(device)) {
556		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
557						     acpi_ec_dir);
558		if (!acpi_device_dir(device))
559			return -ENODEV;
560	}
561
562	entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
563				  acpi_device_dir(device));
564	if (!entry)
565		return -ENODEV;
566	else {
567		entry->proc_fops = &acpi_ec_info_ops;
568		entry->data = acpi_driver_data(device);
569		entry->owner = THIS_MODULE;
570	}
571
572	return 0;
573}
574
575static int acpi_ec_remove_fs(struct acpi_device *device)
576{
577
578	if (acpi_device_dir(device)) {
579		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
580		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
581		acpi_device_dir(device) = NULL;
582	}
583
584	return 0;
585}
586
587/* --------------------------------------------------------------------------
588                               Driver Interface
589   -------------------------------------------------------------------------- */
590static acpi_status
591ec_parse_io_ports(struct acpi_resource *resource, void *context);
592
593static acpi_status
594ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval);
595
596static struct acpi_ec *make_acpi_ec(void)
597{
598	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
599	if (!ec)
600		return NULL;
601
602	atomic_set(&ec->query_pending, 1);
603	atomic_set(&ec->event_count, 1);
604	mutex_init(&ec->lock);
605	init_waitqueue_head(&ec->wait);
606
607	return ec;
608}
609
610static int acpi_ec_add(struct acpi_device *device)
611{
612	acpi_status status = AE_OK;
613	struct acpi_ec *ec = NULL;
614
615	if (!device)
616		return -EINVAL;
617
618	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
619	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
620
621	ec = make_acpi_ec();
622	if (!ec)
623		return -ENOMEM;
624
625	status = ec_parse_device(device->handle, 0, ec, NULL);
626	if (status != AE_CTRL_TERMINATE) {
627		kfree(ec);
628		return -EINVAL;
629	}
630
631	/* Check if we found the boot EC */
632	if (boot_ec) {
633		if (boot_ec->gpe == ec->gpe) {
634			/* We might have incorrect info for GL at boot time */
635			mutex_lock(&boot_ec->lock);
636			boot_ec->global_lock = ec->global_lock;
637			mutex_unlock(&boot_ec->lock);
638			kfree(ec);
639			ec = boot_ec;
640		}
641	} else
642		first_ec = ec;
643	ec->handle = device->handle;
644	acpi_driver_data(device) = ec;
645
646	acpi_ec_add_fs(device);
647
648	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
649			  acpi_device_name(device), acpi_device_bid(device),
650			  (u32) ec->gpe));
651
652	return 0;
653}
654
655static int acpi_ec_remove(struct acpi_device *device, int type)
656{
657	struct acpi_ec *ec;
658
659	if (!device)
660		return -EINVAL;
661
662	ec = acpi_driver_data(device);
663	acpi_ec_remove_fs(device);
664	acpi_driver_data(device) = NULL;
665	if (ec == first_ec)
666		first_ec = NULL;
667
668	/* Don't touch boot EC */
669	if (boot_ec != ec)
670		kfree(ec);
671	return 0;
672}
673
674static acpi_status
675ec_parse_io_ports(struct acpi_resource *resource, void *context)
676{
677	struct acpi_ec *ec = context;
678
679	if (resource->type != ACPI_RESOURCE_TYPE_IO)
680		return AE_OK;
681
682	/*
683	 * The first address region returned is the data port, and
684	 * the second address region returned is the status/command
685	 * port.
686	 */
687	if (ec->data_addr == 0)
688		ec->data_addr = resource->data.io.minimum;
689	else if (ec->command_addr == 0)
690		ec->command_addr = resource->data.io.minimum;
691	else
692		return AE_CTRL_TERMINATE;
693
694	return AE_OK;
695}
696
697static int ec_install_handlers(struct acpi_ec *ec)
698{
699	acpi_status status;
700	status = acpi_install_gpe_handler(NULL, ec->gpe,
701					  ACPI_GPE_EDGE_TRIGGERED,
702					  &acpi_ec_gpe_handler, ec);
703	if (ACPI_FAILURE(status))
704		return -ENODEV;
705
706	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
707	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
708
709	status = acpi_install_address_space_handler(ec->handle,
710						    ACPI_ADR_SPACE_EC,
711						    &acpi_ec_space_handler,
712						    &acpi_ec_space_setup, ec);
713	if (ACPI_FAILURE(status)) {
714		acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
715		return -ENODEV;
716	}
717
718	/* EC is fully operational, allow queries */
719	atomic_set(&ec->query_pending, 0);
720
721	return 0;
722}
723
724static int acpi_ec_start(struct acpi_device *device)
725{
726	struct acpi_ec *ec;
727
728	if (!device)
729		return -EINVAL;
730
731	ec = acpi_driver_data(device);
732
733	if (!ec)
734		return -EINVAL;
735
736	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
737			  ec->gpe, ec->command_addr, ec->data_addr));
738
739	/* Boot EC is already working */
740	if (ec == boot_ec)
741		return 0;
742
743	return ec_install_handlers(ec);
744}
745
746static int acpi_ec_stop(struct acpi_device *device, int type)
747{
748	acpi_status status;
749	struct acpi_ec *ec;
750
751	if (!device)
752		return -EINVAL;
753
754	ec = acpi_driver_data(device);
755	if (!ec)
756		return -EINVAL;
757
758	/* Don't touch boot EC */
759	if (ec == boot_ec)
760		return 0;
761
762	status = acpi_remove_address_space_handler(ec->handle,
763						   ACPI_ADR_SPACE_EC,
764						   &acpi_ec_space_handler);
765	if (ACPI_FAILURE(status))
766		return -ENODEV;
767
768	status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
769	if (ACPI_FAILURE(status))
770		return -ENODEV;
771
772	return 0;
773}
774
775static acpi_status
776ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
777{
778	acpi_status status;
779
780	struct acpi_ec *ec = context;
781	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
782				     ec_parse_io_ports, ec);
783	if (ACPI_FAILURE(status))
784		return status;
785
786	/* Get GPE bit assignment (EC events). */
787	/* TODO: Add support for _GPE returning a package */
788	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
789	if (ACPI_FAILURE(status))
790		return status;
791
792	/* Use the global lock for all EC transactions? */
793	acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
794
795	ec->handle = handle;
796
797	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
798			  ec->gpe, ec->command_addr, ec->data_addr));
799
800	return AE_CTRL_TERMINATE;
801}
802
803int __init acpi_ec_ecdt_probe(void)
804{
805	int ret;
806	acpi_status status;
807	struct acpi_table_ecdt *ecdt_ptr;
808
809	boot_ec = make_acpi_ec();
810	if (!boot_ec)
811		return -ENOMEM;
812	/*
813	 * Generate a boot ec context
814	 */
815
816	status = acpi_get_table(ACPI_SIG_ECDT, 1,
817				(struct acpi_table_header **)&ecdt_ptr);
818	if (ACPI_FAILURE(status))
819		goto error;
820
821	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
822
823	boot_ec->command_addr = ecdt_ptr->control.address;
824	boot_ec->data_addr = ecdt_ptr->data.address;
825	boot_ec->gpe = ecdt_ptr->gpe;
826	boot_ec->handle = ACPI_ROOT_OBJECT;
827
828	ret = ec_install_handlers(boot_ec);
829	if (!ret) {
830		first_ec = boot_ec;
831		return 0;
832	}
833      error:
834	kfree(boot_ec);
835	boot_ec = NULL;
836
837	return -ENODEV;
838}
839
840static int __init acpi_ec_init(void)
841{
842	int result = 0;
843
844	if (acpi_disabled)
845		return 0;
846
847	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
848	if (!acpi_ec_dir)
849		return -ENODEV;
850
851	/* Now register the driver for the EC */
852	result = acpi_bus_register_driver(&acpi_ec_driver);
853	if (result < 0) {
854		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
855		return -ENODEV;
856	}
857
858	return result;
859}
860
861subsys_initcall(acpi_ec_init);
862
863/* EC driver currently not unloadable */
864#if 0
865static void __exit acpi_ec_exit(void)
866{
867
868	acpi_bus_unregister_driver(&acpi_ec_driver);
869
870	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
871
872	return;
873}
874#endif				/* 0 */
875
876static int __init acpi_ec_set_intr_mode(char *str)
877{
878	int intr;
879
880	if (!get_option(&str, &intr))
881		return 0;
882
883	acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
884
885	printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
886
887	return 1;
888}
889
890__setup("ec_intr=", acpi_ec_set_intr_mode);
891