ec.c revision a5f820feb54a59fcdaf4a67a6381ea1ddb36cc6e 
1/*
2 *  ec.c - ACPI Embedded Controller Driver (v2.1)
3 *
4 *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
5 *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
6 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
7 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
8 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9 *
10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11 *
12 *  This program is free software; you can redistribute it and/or modify
13 *  it under the terms of the GNU General Public License as published by
14 *  the Free Software Foundation; either version 2 of the License, or (at
15 *  your option) any later version.
16 *
17 *  This program is distributed in the hope that it will be useful, but
18 *  WITHOUT ANY WARRANTY; without even the implied warranty of
19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20 *  General Public License for more details.
21 *
22 *  You should have received a copy of the GNU General Public License along
23 *  with this program; if not, write to the Free Software Foundation, Inc.,
24 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25 *
26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27 */
28
29/* Uncomment next line to get verbose printout */
30/* #define DEBUG */
31
32#include <linux/kernel.h>
33#include <linux/module.h>
34#include <linux/init.h>
35#include <linux/types.h>
36#include <linux/delay.h>
37#include <linux/proc_fs.h>
38#include <linux/seq_file.h>
39#include <linux/interrupt.h>
40#include <linux/list.h>
41#include <linux/spinlock.h>
42#include <asm/io.h>
43#include <acpi/acpi_bus.h>
44#include <acpi/acpi_drivers.h>
45
46#define ACPI_EC_CLASS			"embedded_controller"
47#define ACPI_EC_DEVICE_NAME		"Embedded Controller"
48#define ACPI_EC_FILE_INFO		"info"
49
50#undef PREFIX
51#define PREFIX				"ACPI: EC: "
52
53/* EC status register */
54#define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
55#define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
56#define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
57#define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
58
59/* EC commands */
60enum ec_command {
61	ACPI_EC_COMMAND_READ = 0x80,
62	ACPI_EC_COMMAND_WRITE = 0x81,
63	ACPI_EC_BURST_ENABLE = 0x82,
64	ACPI_EC_BURST_DISABLE = 0x83,
65	ACPI_EC_COMMAND_QUERY = 0x84,
66};
67
68#define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
69#define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
70#define ACPI_EC_UDELAY		100	/* Wait 100us before polling EC again */
71
72#define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
73					   per one transaction */
74
75enum {
76	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
77	EC_FLAGS_GPE_MODE,		/* Expect GPE to be sent
78					 * for status change */
79	EC_FLAGS_NO_GPE,		/* Don't use GPE mode */
80	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
81	EC_FLAGS_HANDLERS_INSTALLED	/* Handlers for GPE and
82					 * OpReg are installed */
83};
84
85/* If we find an EC via the ECDT, we need to keep a ptr to its context */
86/* External interfaces use first EC only, so remember */
87typedef int (*acpi_ec_query_func) (void *data);
88
89struct acpi_ec_query_handler {
90	struct list_head node;
91	acpi_ec_query_func func;
92	acpi_handle handle;
93	void *data;
94	u8 query_bit;
95};
96
97struct transaction {
98	const u8 *wdata;
99	u8 *rdata;
100	unsigned short irq_count;
101	u8 command;
102	u8 wi;
103	u8 ri;
104	u8 wlen;
105	u8 rlen;
106	bool done;
107};
108
109static struct acpi_ec {
110	acpi_handle handle;
111	unsigned long gpe;
112	unsigned long command_addr;
113	unsigned long data_addr;
114	unsigned long global_lock;
115	unsigned long flags;
116	struct mutex lock;
117	wait_queue_head_t wait;
118	struct list_head list;
119	struct transaction *curr;
120	spinlock_t curr_lock;
121} *boot_ec, *first_ec;
122
123static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
124
125/* --------------------------------------------------------------------------
126                             Transaction Management
127   -------------------------------------------------------------------------- */
128
129static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
130{
131	u8 x = inb(ec->command_addr);
132	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
133	return x;
134}
135
136static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
137{
138	u8 x = inb(ec->data_addr);
139	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
140	return x;
141}
142
143static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
144{
145	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
146	outb(command, ec->command_addr);
147}
148
149static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
150{
151	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
152	outb(data, ec->data_addr);
153}
154
155static int ec_transaction_done(struct acpi_ec *ec)
156{
157	unsigned long flags;
158	int ret = 0;
159	spin_lock_irqsave(&ec->curr_lock, flags);
160	if (!ec->curr || ec->curr->done)
161		ret = 1;
162	spin_unlock_irqrestore(&ec->curr_lock, flags);
163	return ret;
164}
165
166static void start_transaction(struct acpi_ec *ec)
167{
168	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
169	ec->curr->done = false;
170	acpi_ec_write_cmd(ec, ec->curr->command);
171}
172
173static void gpe_transaction(struct acpi_ec *ec, u8 status)
174{
175	unsigned long flags;
176	spin_lock_irqsave(&ec->curr_lock, flags);
177	if (!ec->curr)
178		goto unlock;
179	if (ec->curr->wlen > ec->curr->wi) {
180		if ((status & ACPI_EC_FLAG_IBF) == 0)
181			acpi_ec_write_data(ec,
182				ec->curr->wdata[ec->curr->wi++]);
183		else
184			goto err;
185	} else if (ec->curr->rlen > ec->curr->ri) {
186		if ((status & ACPI_EC_FLAG_OBF) == 1) {
187			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
188			if (ec->curr->rlen == ec->curr->ri)
189				ec->curr->done = true;
190		} else
191			goto err;
192	} else if (ec->curr->wlen == ec->curr->wi &&
193		   (status & ACPI_EC_FLAG_IBF) == 0)
194		ec->curr->done = true;
195	goto unlock;
196err:
197	/* false interrupt, state didn't change */
198	if (in_interrupt())
199		++ec->curr->irq_count;
200unlock:
201	spin_unlock_irqrestore(&ec->curr_lock, flags);
202}
203
204static int acpi_ec_wait(struct acpi_ec *ec)
205{
206	if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
207			       msecs_to_jiffies(ACPI_EC_DELAY)))
208		return 0;
209	/* try restart command if we get any false interrupts */
210	if (ec->curr->irq_count &&
211	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
212		pr_debug(PREFIX "controller reset, restart transaction\n");
213		start_transaction(ec);
214		if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
215					msecs_to_jiffies(ACPI_EC_DELAY)))
216			return 0;
217	}
218	/* missing GPEs, switch back to poll mode */
219	if (printk_ratelimit())
220		pr_info(PREFIX "missing confirmations, "
221				"switch off interrupt mode.\n");
222	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
223	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
224	return 1;
225}
226
227static void acpi_ec_gpe_query(void *ec_cxt);
228
229static int ec_check_sci(struct acpi_ec *ec, u8 state)
230{
231	if (state & ACPI_EC_FLAG_SCI) {
232		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
233			return acpi_os_execute(OSL_EC_BURST_HANDLER,
234				acpi_ec_gpe_query, ec);
235	}
236	return 0;
237}
238
239static int ec_poll(struct acpi_ec *ec)
240{
241	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
242	udelay(ACPI_EC_UDELAY);
243	while (time_before(jiffies, delay)) {
244		gpe_transaction(ec, acpi_ec_read_status(ec));
245		udelay(ACPI_EC_UDELAY);
246		if (ec_transaction_done(ec))
247			return 0;
248	}
249	return -ETIME;
250}
251
252static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
253					struct transaction *t,
254					int force_poll)
255{
256	unsigned long tmp;
257	int ret = 0;
258	pr_debug(PREFIX "transaction start\n");
259	/* disable GPE during transaction if storm is detected */
260	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
261		clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
262		acpi_disable_gpe(NULL, ec->gpe);
263	}
264	if (EC_FLAGS_MSI)
265		udelay(ACPI_EC_DELAY);
266	/* start transaction */
267	spin_lock_irqsave(&ec->curr_lock, tmp);
268	/* following two actions should be kept atomic */
269	ec->curr = t;
270	start_transaction(ec);
271	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
272		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
273	spin_unlock_irqrestore(&ec->curr_lock, tmp);
274	/* if we selected poll mode or failed in GPE-mode do a poll loop */
275	if (force_poll ||
276	    !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
277	    acpi_ec_wait(ec))
278		ret = ec_poll(ec);
279	pr_debug(PREFIX "transaction end\n");
280	spin_lock_irqsave(&ec->curr_lock, tmp);
281	ec->curr = NULL;
282	spin_unlock_irqrestore(&ec->curr_lock, tmp);
283	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
284		/* check if we received SCI during transaction */
285		ec_check_sci(ec, acpi_ec_read_status(ec));
286		/* it is safe to enable GPE outside of transaction */
287		acpi_enable_gpe(NULL, ec->gpe);
288	} else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
289		   t->irq_count > ACPI_EC_STORM_THRESHOLD) {
290		pr_info(PREFIX "GPE storm detected, "
291			"transactions will use polling mode\n");
292		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
293	}
294	return ret;
295}
296
297static int ec_check_ibf0(struct acpi_ec *ec)
298{
299	u8 status = acpi_ec_read_status(ec);
300	return (status & ACPI_EC_FLAG_IBF) == 0;
301}
302
303static int ec_wait_ibf0(struct acpi_ec *ec)
304{
305	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
306	/* interrupt wait manually if GPE mode is not active */
307	unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
308		msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
309	while (time_before(jiffies, delay))
310		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
311			return 0;
312	return -ETIME;
313}
314
315static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
316			       int force_poll)
317{
318	int status;
319	u32 glk;
320	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
321		return -EINVAL;
322	if (t->rdata)
323		memset(t->rdata, 0, t->rlen);
324	mutex_lock(&ec->lock);
325	if (ec->global_lock) {
326		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
327		if (ACPI_FAILURE(status)) {
328			status = -ENODEV;
329			goto unlock;
330		}
331	}
332	if (ec_wait_ibf0(ec)) {
333		pr_err(PREFIX "input buffer is not empty, "
334				"aborting transaction\n");
335		status = -ETIME;
336		goto end;
337	}
338	status = acpi_ec_transaction_unlocked(ec, t, force_poll);
339end:
340	if (ec->global_lock)
341		acpi_release_global_lock(glk);
342unlock:
343	mutex_unlock(&ec->lock);
344	return status;
345}
346
347/*
348 * Note: samsung nv5000 doesn't work with ec burst mode.
349 * http://bugzilla.kernel.org/show_bug.cgi?id=4980
350 */
351static int acpi_ec_burst_enable(struct acpi_ec *ec)
352{
353	u8 d;
354	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
355				.wdata = NULL, .rdata = &d,
356				.wlen = 0, .rlen = 1};
357
358	return acpi_ec_transaction(ec, &t, 0);
359}
360
361static int acpi_ec_burst_disable(struct acpi_ec *ec)
362{
363	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
364				.wdata = NULL, .rdata = NULL,
365				.wlen = 0, .rlen = 0};
366
367	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
368				acpi_ec_transaction(ec, &t, 0) : 0;
369}
370
371static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
372{
373	int result;
374	u8 d;
375	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
376				.wdata = &address, .rdata = &d,
377				.wlen = 1, .rlen = 1};
378
379	result = acpi_ec_transaction(ec, &t, 0);
380	*data = d;
381	return result;
382}
383
384static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
385{
386	u8 wdata[2] = { address, data };
387	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
388				.wdata = wdata, .rdata = NULL,
389				.wlen = 2, .rlen = 0};
390
391	return acpi_ec_transaction(ec, &t, 0);
392}
393
394/*
395 * Externally callable EC access functions. For now, assume 1 EC only
396 */
397int ec_burst_enable(void)
398{
399	if (!first_ec)
400		return -ENODEV;
401	return acpi_ec_burst_enable(first_ec);
402}
403
404EXPORT_SYMBOL(ec_burst_enable);
405
406int ec_burst_disable(void)
407{
408	if (!first_ec)
409		return -ENODEV;
410	return acpi_ec_burst_disable(first_ec);
411}
412
413EXPORT_SYMBOL(ec_burst_disable);
414
415int ec_read(u8 addr, u8 * val)
416{
417	int err;
418	u8 temp_data;
419
420	if (!first_ec)
421		return -ENODEV;
422
423	err = acpi_ec_read(first_ec, addr, &temp_data);
424
425	if (!err) {
426		*val = temp_data;
427		return 0;
428	} else
429		return err;
430}
431
432EXPORT_SYMBOL(ec_read);
433
434int ec_write(u8 addr, u8 val)
435{
436	int err;
437
438	if (!first_ec)
439		return -ENODEV;
440
441	err = acpi_ec_write(first_ec, addr, val);
442
443	return err;
444}
445
446EXPORT_SYMBOL(ec_write);
447
448int ec_transaction(u8 command,
449		   const u8 * wdata, unsigned wdata_len,
450		   u8 * rdata, unsigned rdata_len,
451		   int force_poll)
452{
453	struct transaction t = {.command = command,
454				.wdata = wdata, .rdata = rdata,
455				.wlen = wdata_len, .rlen = rdata_len};
456	if (!first_ec)
457		return -ENODEV;
458
459	return acpi_ec_transaction(first_ec, &t, force_poll);
460}
461
462EXPORT_SYMBOL(ec_transaction);
463
464static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
465{
466	int result;
467	u8 d;
468	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
469				.wdata = NULL, .rdata = &d,
470				.wlen = 0, .rlen = 1};
471	if (!ec || !data)
472		return -EINVAL;
473
474	/*
475	 * Query the EC to find out which _Qxx method we need to evaluate.
476	 * Note that successful completion of the query causes the ACPI_EC_SCI
477	 * bit to be cleared (and thus clearing the interrupt source).
478	 */
479
480	result = acpi_ec_transaction(ec, &t, 0);
481	if (result)
482		return result;
483
484	if (!d)
485		return -ENODATA;
486
487	*data = d;
488	return 0;
489}
490
491/* --------------------------------------------------------------------------
492                                Event Management
493   -------------------------------------------------------------------------- */
494int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
495			      acpi_handle handle, acpi_ec_query_func func,
496			      void *data)
497{
498	struct acpi_ec_query_handler *handler =
499	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
500	if (!handler)
501		return -ENOMEM;
502
503	handler->query_bit = query_bit;
504	handler->handle = handle;
505	handler->func = func;
506	handler->data = data;
507	mutex_lock(&ec->lock);
508	list_add(&handler->node, &ec->list);
509	mutex_unlock(&ec->lock);
510	return 0;
511}
512
513EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
514
515void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
516{
517	struct acpi_ec_query_handler *handler, *tmp;
518	mutex_lock(&ec->lock);
519	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
520		if (query_bit == handler->query_bit) {
521			list_del(&handler->node);
522			kfree(handler);
523		}
524	}
525	mutex_unlock(&ec->lock);
526}
527
528EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
529
530static void acpi_ec_gpe_query(void *ec_cxt)
531{
532	struct acpi_ec *ec = ec_cxt;
533	u8 value = 0;
534	struct acpi_ec_query_handler *handler, copy;
535
536	if (!ec || acpi_ec_query(ec, &value))
537		return;
538	mutex_lock(&ec->lock);
539	list_for_each_entry(handler, &ec->list, node) {
540		if (value == handler->query_bit) {
541			/* have custom handler for this bit */
542			memcpy(&copy, handler, sizeof(copy));
543			mutex_unlock(&ec->lock);
544			if (copy.func) {
545				copy.func(copy.data);
546			} else if (copy.handle) {
547				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
548			}
549			return;
550		}
551	}
552	mutex_unlock(&ec->lock);
553}
554
555static u32 acpi_ec_gpe_handler(void *data)
556{
557	struct acpi_ec *ec = data;
558	u8 status;
559
560	pr_debug(PREFIX "~~~> interrupt\n");
561	status = acpi_ec_read_status(ec);
562
563	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
564		gpe_transaction(ec, status);
565		if (ec_transaction_done(ec) &&
566		    (status & ACPI_EC_FLAG_IBF) == 0)
567			wake_up(&ec->wait);
568	}
569
570	ec_check_sci(ec, status);
571	if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
572	    !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
573		/* this is non-query, must be confirmation */
574		if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
575			if (printk_ratelimit())
576				pr_info(PREFIX "non-query interrupt received,"
577					" switching to interrupt mode\n");
578		} else {
579			/* hush, STORM switches the mode every transaction */
580			pr_debug(PREFIX "non-query interrupt received,"
581				" switching to interrupt mode\n");
582		}
583		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
584	}
585	return ACPI_INTERRUPT_HANDLED;
586}
587
588/* --------------------------------------------------------------------------
589                             Address Space Management
590   -------------------------------------------------------------------------- */
591
592static acpi_status
593acpi_ec_space_handler(u32 function, acpi_physical_address address,
594		      u32 bits, acpi_integer *value,
595		      void *handler_context, void *region_context)
596{
597	struct acpi_ec *ec = handler_context;
598	int result = 0, i;
599	u8 temp = 0;
600
601	if ((address > 0xFF) || !value || !handler_context)
602		return AE_BAD_PARAMETER;
603
604	if (function != ACPI_READ && function != ACPI_WRITE)
605		return AE_BAD_PARAMETER;
606
607	if (bits != 8 && acpi_strict)
608		return AE_BAD_PARAMETER;
609
610	acpi_ec_burst_enable(ec);
611
612	if (function == ACPI_READ) {
613		result = acpi_ec_read(ec, address, &temp);
614		*value = temp;
615	} else {
616		temp = 0xff & (*value);
617		result = acpi_ec_write(ec, address, temp);
618	}
619
620	for (i = 8; unlikely(bits - i > 0); i += 8) {
621		++address;
622		if (function == ACPI_READ) {
623			result = acpi_ec_read(ec, address, &temp);
624			(*value) |= ((acpi_integer)temp) << i;
625		} else {
626			temp = 0xff & ((*value) >> i);
627			result = acpi_ec_write(ec, address, temp);
628		}
629	}
630
631	acpi_ec_burst_disable(ec);
632
633	switch (result) {
634	case -EINVAL:
635		return AE_BAD_PARAMETER;
636		break;
637	case -ENODEV:
638		return AE_NOT_FOUND;
639		break;
640	case -ETIME:
641		return AE_TIME;
642		break;
643	default:
644		return AE_OK;
645	}
646}
647
648/* --------------------------------------------------------------------------
649                              FS Interface (/proc)
650   -------------------------------------------------------------------------- */
651
652static struct proc_dir_entry *acpi_ec_dir;
653
654static int acpi_ec_read_info(struct seq_file *seq, void *offset)
655{
656	struct acpi_ec *ec = seq->private;
657
658	if (!ec)
659		goto end;
660
661	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
662	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
663		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
664	seq_printf(seq, "use global lock:\t%s\n",
665		   ec->global_lock ? "yes" : "no");
666      end:
667	return 0;
668}
669
670static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
671{
672	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
673}
674
675static struct file_operations acpi_ec_info_ops = {
676	.open = acpi_ec_info_open_fs,
677	.read = seq_read,
678	.llseek = seq_lseek,
679	.release = single_release,
680	.owner = THIS_MODULE,
681};
682
683static int acpi_ec_add_fs(struct acpi_device *device)
684{
685	struct proc_dir_entry *entry = NULL;
686
687	if (!acpi_device_dir(device)) {
688		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
689						     acpi_ec_dir);
690		if (!acpi_device_dir(device))
691			return -ENODEV;
692	}
693
694	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
695				 acpi_device_dir(device),
696				 &acpi_ec_info_ops, acpi_driver_data(device));
697	if (!entry)
698		return -ENODEV;
699	return 0;
700}
701
702static int acpi_ec_remove_fs(struct acpi_device *device)
703{
704
705	if (acpi_device_dir(device)) {
706		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
707		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
708		acpi_device_dir(device) = NULL;
709	}
710
711	return 0;
712}
713
714/* --------------------------------------------------------------------------
715                               Driver Interface
716   -------------------------------------------------------------------------- */
717static acpi_status
718ec_parse_io_ports(struct acpi_resource *resource, void *context);
719
720static struct acpi_ec *make_acpi_ec(void)
721{
722	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
723	if (!ec)
724		return NULL;
725	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
726	mutex_init(&ec->lock);
727	init_waitqueue_head(&ec->wait);
728	INIT_LIST_HEAD(&ec->list);
729	spin_lock_init(&ec->curr_lock);
730	return ec;
731}
732
733static acpi_status
734acpi_ec_register_query_methods(acpi_handle handle, u32 level,
735			       void *context, void **return_value)
736{
737	char node_name[5];
738	struct acpi_buffer buffer = { sizeof(node_name), node_name };
739	struct acpi_ec *ec = context;
740	int value = 0;
741	acpi_status status;
742
743	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
744
745	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
746		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
747	}
748	return AE_OK;
749}
750
751static acpi_status
752ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
753{
754	acpi_status status;
755	unsigned long long tmp = 0;
756
757	struct acpi_ec *ec = context;
758	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
759				     ec_parse_io_ports, ec);
760	if (ACPI_FAILURE(status))
761		return status;
762
763	/* Get GPE bit assignment (EC events). */
764	/* TODO: Add support for _GPE returning a package */
765	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
766	if (ACPI_FAILURE(status))
767		return status;
768	ec->gpe = tmp;
769	/* Use the global lock for all EC transactions? */
770	tmp = 0;
771	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
772	ec->global_lock = tmp;
773	ec->handle = handle;
774	return AE_CTRL_TERMINATE;
775}
776
777static void ec_remove_handlers(struct acpi_ec *ec)
778{
779	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
780				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
781		pr_err(PREFIX "failed to remove space handler\n");
782	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
783				&acpi_ec_gpe_handler)))
784		pr_err(PREFIX "failed to remove gpe handler\n");
785	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
786}
787
788static int acpi_ec_add(struct acpi_device *device)
789{
790	struct acpi_ec *ec = NULL;
791
792	if (!device)
793		return -EINVAL;
794	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
795	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
796
797	/* Check for boot EC */
798	if (boot_ec &&
799	    (boot_ec->handle == device->handle ||
800	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
801		ec = boot_ec;
802		boot_ec = NULL;
803	} else {
804		ec = make_acpi_ec();
805		if (!ec)
806			return -ENOMEM;
807		if (ec_parse_device(device->handle, 0, ec, NULL) !=
808		    AE_CTRL_TERMINATE) {
809			kfree(ec);
810			return -EINVAL;
811		}
812	}
813
814	ec->handle = device->handle;
815
816	/* Find and register all query methods */
817	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
818			    acpi_ec_register_query_methods, ec, NULL);
819
820	if (!first_ec)
821		first_ec = ec;
822	device->driver_data = ec;
823	acpi_ec_add_fs(device);
824	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
825			  ec->gpe, ec->command_addr, ec->data_addr);
826	pr_info(PREFIX "driver started in %s mode\n",
827		(test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
828	return 0;
829}
830
831static int acpi_ec_remove(struct acpi_device *device, int type)
832{
833	struct acpi_ec *ec;
834	struct acpi_ec_query_handler *handler, *tmp;
835
836	if (!device)
837		return -EINVAL;
838
839	ec = acpi_driver_data(device);
840	mutex_lock(&ec->lock);
841	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
842		list_del(&handler->node);
843		kfree(handler);
844	}
845	mutex_unlock(&ec->lock);
846	acpi_ec_remove_fs(device);
847	device->driver_data = NULL;
848	if (ec == first_ec)
849		first_ec = NULL;
850	kfree(ec);
851	return 0;
852}
853
854static acpi_status
855ec_parse_io_ports(struct acpi_resource *resource, void *context)
856{
857	struct acpi_ec *ec = context;
858
859	if (resource->type != ACPI_RESOURCE_TYPE_IO)
860		return AE_OK;
861
862	/*
863	 * The first address region returned is the data port, and
864	 * the second address region returned is the status/command
865	 * port.
866	 */
867	if (ec->data_addr == 0)
868		ec->data_addr = resource->data.io.minimum;
869	else if (ec->command_addr == 0)
870		ec->command_addr = resource->data.io.minimum;
871	else
872		return AE_CTRL_TERMINATE;
873
874	return AE_OK;
875}
876
877static int ec_install_handlers(struct acpi_ec *ec)
878{
879	acpi_status status;
880	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
881		return 0;
882	status = acpi_install_gpe_handler(NULL, ec->gpe,
883				  ACPI_GPE_EDGE_TRIGGERED,
884				  &acpi_ec_gpe_handler, ec);
885	if (ACPI_FAILURE(status))
886		return -ENODEV;
887	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
888	acpi_enable_gpe(NULL, ec->gpe);
889	status = acpi_install_address_space_handler(ec->handle,
890						    ACPI_ADR_SPACE_EC,
891						    &acpi_ec_space_handler,
892						    NULL, ec);
893	if (ACPI_FAILURE(status)) {
894		if (status == AE_NOT_FOUND) {
895			/*
896			 * Maybe OS fails in evaluating the _REG object.
897			 * The AE_NOT_FOUND error will be ignored and OS
898			 * continue to initialize EC.
899			 */
900			printk(KERN_ERR "Fail in evaluating the _REG object"
901				" of EC device. Broken bios is suspected.\n");
902		} else {
903			acpi_remove_gpe_handler(NULL, ec->gpe,
904				&acpi_ec_gpe_handler);
905			return -ENODEV;
906		}
907	}
908
909	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
910	return 0;
911}
912
913static int acpi_ec_start(struct acpi_device *device)
914{
915	struct acpi_ec *ec;
916	int ret = 0;
917
918	if (!device)
919		return -EINVAL;
920
921	ec = acpi_driver_data(device);
922
923	if (!ec)
924		return -EINVAL;
925
926	ret = ec_install_handlers(ec);
927
928	/* EC is fully operational, allow queries */
929	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
930	return ret;
931}
932
933static int acpi_ec_stop(struct acpi_device *device, int type)
934{
935	struct acpi_ec *ec;
936	if (!device)
937		return -EINVAL;
938	ec = acpi_driver_data(device);
939	if (!ec)
940		return -EINVAL;
941	ec_remove_handlers(ec);
942
943	return 0;
944}
945
946int __init acpi_boot_ec_enable(void)
947{
948	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
949		return 0;
950	if (!ec_install_handlers(boot_ec)) {
951		first_ec = boot_ec;
952		return 0;
953	}
954	return -EFAULT;
955}
956
957static const struct acpi_device_id ec_device_ids[] = {
958	{"PNP0C09", 0},
959	{"", 0},
960};
961
962int __init acpi_ec_ecdt_probe(void)
963{
964	acpi_status status;
965	struct acpi_ec *saved_ec = NULL;
966	struct acpi_table_ecdt *ecdt_ptr;
967
968	boot_ec = make_acpi_ec();
969	if (!boot_ec)
970		return -ENOMEM;
971	/*
972	 * Generate a boot ec context
973	 */
974	if (dmi_name_in_vendors("Micro-Star") ||
975	    dmi_name_in_vendors("Notebook")) {
976		pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
977		EC_FLAGS_MSI = 1;
978	}
979	status = acpi_get_table(ACPI_SIG_ECDT, 1,
980				(struct acpi_table_header **)&ecdt_ptr);
981	if (ACPI_SUCCESS(status)) {
982		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
983		boot_ec->command_addr = ecdt_ptr->control.address;
984		boot_ec->data_addr = ecdt_ptr->data.address;
985		boot_ec->gpe = ecdt_ptr->gpe;
986		boot_ec->handle = ACPI_ROOT_OBJECT;
987		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
988		/* Don't trust ECDT, which comes from ASUSTek */
989		if (!dmi_name_in_vendors("ASUS"))
990			goto install;
991		saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
992		if (!saved_ec)
993			return -ENOMEM;
994		memcpy(saved_ec, boot_ec, sizeof(*saved_ec));
995	/* fall through */
996	}
997	/* This workaround is needed only on some broken machines,
998	 * which require early EC, but fail to provide ECDT */
999	printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1000	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1001					boot_ec, NULL);
1002	/* Check that acpi_get_devices actually find something */
1003	if (ACPI_FAILURE(status) || !boot_ec->handle)
1004		goto error;
1005	if (saved_ec) {
1006		/* try to find good ECDT from ASUSTek */
1007		if (saved_ec->command_addr != boot_ec->command_addr ||
1008		    saved_ec->data_addr != boot_ec->data_addr ||
1009		    saved_ec->gpe != boot_ec->gpe ||
1010		    saved_ec->handle != boot_ec->handle)
1011			pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1012			"ECDT tables, which are very hard to workaround. "
1013			"Trying to use DSDT EC info instead. Please send "
1014			"output of acpidump to linux-acpi@vger.kernel.org\n");
1015		kfree(saved_ec);
1016		saved_ec = NULL;
1017	} else {
1018		/* We really need to limit this workaround, the only ASUS,
1019		* which needs it, has fake EC._INI method, so use it as flag.
1020		* Keep boot_ec struct as it will be needed soon.
1021		*/
1022		acpi_handle dummy;
1023		if (!dmi_name_in_vendors("ASUS") ||
1024		    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1025							&dummy)))
1026			return -ENODEV;
1027	}
1028install:
1029	if (!ec_install_handlers(boot_ec)) {
1030		first_ec = boot_ec;
1031		return 0;
1032	}
1033error:
1034	kfree(boot_ec);
1035	boot_ec = NULL;
1036	return -ENODEV;
1037}
1038
1039static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1040{
1041	struct acpi_ec *ec = acpi_driver_data(device);
1042	/* Stop using GPE */
1043	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1044	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1045	acpi_disable_gpe(NULL, ec->gpe);
1046	return 0;
1047}
1048
1049static int acpi_ec_resume(struct acpi_device *device)
1050{
1051	struct acpi_ec *ec = acpi_driver_data(device);
1052	/* Enable use of GPE back */
1053	clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1054	acpi_enable_gpe(NULL, ec->gpe);
1055	return 0;
1056}
1057
1058static struct acpi_driver acpi_ec_driver = {
1059	.name = "ec",
1060	.class = ACPI_EC_CLASS,
1061	.ids = ec_device_ids,
1062	.ops = {
1063		.add = acpi_ec_add,
1064		.remove = acpi_ec_remove,
1065		.start = acpi_ec_start,
1066		.stop = acpi_ec_stop,
1067		.suspend = acpi_ec_suspend,
1068		.resume = acpi_ec_resume,
1069		},
1070};
1071
1072int __init acpi_ec_init(void)
1073{
1074	int result = 0;
1075
1076	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1077	if (!acpi_ec_dir)
1078		return -ENODEV;
1079
1080	/* Now register the driver for the EC */
1081	result = acpi_bus_register_driver(&acpi_ec_driver);
1082	if (result < 0) {
1083		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1084		return -ENODEV;
1085	}
1086
1087	return result;
1088}
1089
1090/* EC driver currently not unloadable */
1091#if 0
1092static void __exit acpi_ec_exit(void)
1093{
1094
1095	acpi_bus_unregister_driver(&acpi_ec_driver);
1096
1097	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1098
1099	return;
1100}
1101#endif	/* 0 */
1102