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,
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
175static 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
220static 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 */
271int 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
277int 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
282static 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
293static 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 */
303int ec_burst_enable(void)
304{
305	if (!first_ec)
306		return -ENODEV;
307	return acpi_ec_burst_enable(first_ec);
308}
309
310EXPORT_SYMBOL(ec_burst_enable);
311
312int ec_burst_disable(void)
313{
314	if (!first_ec)
315		return -ENODEV;
316	return acpi_ec_burst_disable(first_ec);
317}
318
319EXPORT_SYMBOL(ec_burst_disable);
320
321int 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
338EXPORT_SYMBOL(ec_read);
339
340int 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
352EXPORT_SYMBOL(ec_write);
353
354int 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
367EXPORT_SYMBOL(ec_transaction);
368
369static 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
398static 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
414static 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
442static acpi_status
443acpi_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
456static acpi_status
457acpi_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
527static struct proc_dir_entry *acpi_ec_dir;
528
529static 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
545static 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
550static 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
558static 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
582static 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   -------------------------------------------------------------------------- */
597static acpi_status
598ec_parse_io_ports(struct acpi_resource *resource, void *context);
599
600static acpi_status
601ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval);
602
603static 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
617static 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
662static 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
681static acpi_status
682ec_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
704static 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
731static 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
753static 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
782static acpi_status
783ec_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
810int __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
847static 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
868subsys_initcall(acpi_ec_init);
869
870/* EC driver currently not unloadable */
871
872static int __init acpi_ec_set_intr_mode(char *str)
873{
874	int intr;
875
876	if (!get_option(&str, &intr))
877		return 0;
878
879	acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
880
881	printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
882
883	return 1;
884}
885
886__setup("ec_intr=", acpi_ec_set_intr_mode);
887