Merge branch 'bkl_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[linux-2.6.git] / drivers / acpi / ec.c
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/interrupt.h>
38 #include <linux/list.h>
39 #include <linux/spinlock.h>
40 #include <linux/slab.h>
41 #include <asm/io.h>
42 #include <acpi/acpi_bus.h>
43 #include <acpi/acpi_drivers.h>
44 #include <linux/dmi.h>
45
46 #include "internal.h"
47
48 #define ACPI_EC_CLASS                   "embedded_controller"
49 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
50 #define ACPI_EC_FILE_INFO               "info"
51
52 #undef PREFIX
53 #define PREFIX                          "ACPI: EC: "
54
55 /* EC status register */
56 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
57 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
58 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
59 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
60
61 /* EC commands */
62 enum ec_command {
63         ACPI_EC_COMMAND_READ = 0x80,
64         ACPI_EC_COMMAND_WRITE = 0x81,
65         ACPI_EC_BURST_ENABLE = 0x82,
66         ACPI_EC_BURST_DISABLE = 0x83,
67         ACPI_EC_COMMAND_QUERY = 0x84,
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 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
73 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
74
75 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
76                                            per one transaction */
77
78 enum {
79         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
80         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
81         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
82                                          * OpReg are installed */
83         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
84 };
85
86 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
87 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
88 module_param(ec_delay, uint, 0644);
89 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
90
91 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
92 /* External interfaces use first EC only, so remember */
93 typedef int (*acpi_ec_query_func) (void *data);
94
95 struct acpi_ec_query_handler {
96         struct list_head node;
97         acpi_ec_query_func func;
98         acpi_handle handle;
99         void *data;
100         u8 query_bit;
101 };
102
103 struct transaction {
104         const u8 *wdata;
105         u8 *rdata;
106         unsigned short irq_count;
107         u8 command;
108         u8 wi;
109         u8 ri;
110         u8 wlen;
111         u8 rlen;
112         bool done;
113 };
114
115 struct acpi_ec *boot_ec, *first_ec;
116 EXPORT_SYMBOL(first_ec);
117
118 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
119 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
120 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
121
122 /* --------------------------------------------------------------------------
123                              Transaction Management
124    -------------------------------------------------------------------------- */
125
126 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
127 {
128         u8 x = inb(ec->command_addr);
129         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
130         return x;
131 }
132
133 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
134 {
135         u8 x = inb(ec->data_addr);
136         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
137         return x;
138 }
139
140 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
141 {
142         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
143         outb(command, ec->command_addr);
144 }
145
146 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
147 {
148         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
149         outb(data, ec->data_addr);
150 }
151
152 static int ec_transaction_done(struct acpi_ec *ec)
153 {
154         unsigned long flags;
155         int ret = 0;
156         spin_lock_irqsave(&ec->curr_lock, flags);
157         if (!ec->curr || ec->curr->done)
158                 ret = 1;
159         spin_unlock_irqrestore(&ec->curr_lock, flags);
160         return ret;
161 }
162
163 static void start_transaction(struct acpi_ec *ec)
164 {
165         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
166         ec->curr->done = false;
167         acpi_ec_write_cmd(ec, ec->curr->command);
168 }
169
170 static void advance_transaction(struct acpi_ec *ec, u8 status)
171 {
172         unsigned long flags;
173         spin_lock_irqsave(&ec->curr_lock, flags);
174         if (!ec->curr)
175                 goto unlock;
176         if (ec->curr->wlen > ec->curr->wi) {
177                 if ((status & ACPI_EC_FLAG_IBF) == 0)
178                         acpi_ec_write_data(ec,
179                                 ec->curr->wdata[ec->curr->wi++]);
180                 else
181                         goto err;
182         } else if (ec->curr->rlen > ec->curr->ri) {
183                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
184                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
185                         if (ec->curr->rlen == ec->curr->ri)
186                                 ec->curr->done = true;
187                 } else
188                         goto err;
189         } else if (ec->curr->wlen == ec->curr->wi &&
190                    (status & ACPI_EC_FLAG_IBF) == 0)
191                 ec->curr->done = true;
192         goto unlock;
193 err:
194         /* false interrupt, state didn't change */
195         if (in_interrupt())
196                 ++ec->curr->irq_count;
197 unlock:
198         spin_unlock_irqrestore(&ec->curr_lock, flags);
199 }
200
201 static int acpi_ec_sync_query(struct acpi_ec *ec);
202
203 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
204 {
205         if (state & ACPI_EC_FLAG_SCI) {
206                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
207                         return acpi_ec_sync_query(ec);
208         }
209         return 0;
210 }
211
212 static int ec_poll(struct acpi_ec *ec)
213 {
214         unsigned long flags;
215         int repeat = 2; /* number of command restarts */
216         while (repeat--) {
217                 unsigned long delay = jiffies +
218                         msecs_to_jiffies(ec_delay);
219                 do {
220                         /* don't sleep with disabled interrupts */
221                         if (EC_FLAGS_MSI || irqs_disabled()) {
222                                 udelay(ACPI_EC_MSI_UDELAY);
223                                 if (ec_transaction_done(ec))
224                                         return 0;
225                         } else {
226                                 if (wait_event_timeout(ec->wait,
227                                                 ec_transaction_done(ec),
228                                                 msecs_to_jiffies(1)))
229                                         return 0;
230                         }
231                         advance_transaction(ec, acpi_ec_read_status(ec));
232                 } while (time_before(jiffies, delay));
233                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
234                         break;
235                 pr_debug(PREFIX "controller reset, restart transaction\n");
236                 spin_lock_irqsave(&ec->curr_lock, flags);
237                 start_transaction(ec);
238                 spin_unlock_irqrestore(&ec->curr_lock, flags);
239         }
240         return -ETIME;
241 }
242
243 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
244                                         struct transaction *t)
245 {
246         unsigned long tmp;
247         int ret = 0;
248         if (EC_FLAGS_MSI)
249                 udelay(ACPI_EC_MSI_UDELAY);
250         /* start transaction */
251         spin_lock_irqsave(&ec->curr_lock, tmp);
252         /* following two actions should be kept atomic */
253         ec->curr = t;
254         start_transaction(ec);
255         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
256                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
257         spin_unlock_irqrestore(&ec->curr_lock, tmp);
258         ret = ec_poll(ec);
259         spin_lock_irqsave(&ec->curr_lock, tmp);
260         ec->curr = NULL;
261         spin_unlock_irqrestore(&ec->curr_lock, tmp);
262         return ret;
263 }
264
265 static int ec_check_ibf0(struct acpi_ec *ec)
266 {
267         u8 status = acpi_ec_read_status(ec);
268         return (status & ACPI_EC_FLAG_IBF) == 0;
269 }
270
271 static int ec_wait_ibf0(struct acpi_ec *ec)
272 {
273         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
274         /* interrupt wait manually if GPE mode is not active */
275         while (time_before(jiffies, delay))
276                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
277                                         msecs_to_jiffies(1)))
278                         return 0;
279         return -ETIME;
280 }
281
282 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
283 {
284         int status;
285         u32 glk;
286         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
287                 return -EINVAL;
288         if (t->rdata)
289                 memset(t->rdata, 0, t->rlen);
290         mutex_lock(&ec->lock);
291         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
292                 status = -EINVAL;
293                 goto unlock;
294         }
295         if (ec->global_lock) {
296                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
297                 if (ACPI_FAILURE(status)) {
298                         status = -ENODEV;
299                         goto unlock;
300                 }
301         }
302         if (ec_wait_ibf0(ec)) {
303                 pr_err(PREFIX "input buffer is not empty, "
304                                 "aborting transaction\n");
305                 status = -ETIME;
306                 goto end;
307         }
308         pr_debug(PREFIX "transaction start\n");
309         /* disable GPE during transaction if storm is detected */
310         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
311                 /* It has to be disabled, so that it doesn't trigger. */
312                 acpi_disable_gpe(NULL, ec->gpe);
313         }
314
315         status = acpi_ec_transaction_unlocked(ec, t);
316
317         /* check if we received SCI during transaction */
318         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
319         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
320                 msleep(1);
321                 /* It is safe to enable the GPE outside of the transaction. */
322                 acpi_enable_gpe(NULL, ec->gpe);
323         } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
324                 pr_info(PREFIX "GPE storm detected, "
325                         "transactions will use polling mode\n");
326                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
327         }
328         pr_debug(PREFIX "transaction end\n");
329 end:
330         if (ec->global_lock)
331                 acpi_release_global_lock(glk);
332 unlock:
333         mutex_unlock(&ec->lock);
334         return status;
335 }
336
337 static int acpi_ec_burst_enable(struct acpi_ec *ec)
338 {
339         u8 d;
340         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
341                                 .wdata = NULL, .rdata = &d,
342                                 .wlen = 0, .rlen = 1};
343
344         return acpi_ec_transaction(ec, &t);
345 }
346
347 static int acpi_ec_burst_disable(struct acpi_ec *ec)
348 {
349         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
350                                 .wdata = NULL, .rdata = NULL,
351                                 .wlen = 0, .rlen = 0};
352
353         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
354                                 acpi_ec_transaction(ec, &t) : 0;
355 }
356
357 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
358 {
359         int result;
360         u8 d;
361         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
362                                 .wdata = &address, .rdata = &d,
363                                 .wlen = 1, .rlen = 1};
364
365         result = acpi_ec_transaction(ec, &t);
366         *data = d;
367         return result;
368 }
369
370 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
371 {
372         u8 wdata[2] = { address, data };
373         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
374                                 .wdata = wdata, .rdata = NULL,
375                                 .wlen = 2, .rlen = 0};
376
377         return acpi_ec_transaction(ec, &t);
378 }
379
380 /*
381  * Externally callable EC access functions. For now, assume 1 EC only
382  */
383 int ec_burst_enable(void)
384 {
385         if (!first_ec)
386                 return -ENODEV;
387         return acpi_ec_burst_enable(first_ec);
388 }
389
390 EXPORT_SYMBOL(ec_burst_enable);
391
392 int ec_burst_disable(void)
393 {
394         if (!first_ec)
395                 return -ENODEV;
396         return acpi_ec_burst_disable(first_ec);
397 }
398
399 EXPORT_SYMBOL(ec_burst_disable);
400
401 int ec_read(u8 addr, u8 * val)
402 {
403         int err;
404         u8 temp_data;
405
406         if (!first_ec)
407                 return -ENODEV;
408
409         err = acpi_ec_read(first_ec, addr, &temp_data);
410
411         if (!err) {
412                 *val = temp_data;
413                 return 0;
414         } else
415                 return err;
416 }
417
418 EXPORT_SYMBOL(ec_read);
419
420 int ec_write(u8 addr, u8 val)
421 {
422         int err;
423
424         if (!first_ec)
425                 return -ENODEV;
426
427         err = acpi_ec_write(first_ec, addr, val);
428
429         return err;
430 }
431
432 EXPORT_SYMBOL(ec_write);
433
434 int ec_transaction(u8 command,
435                    const u8 * wdata, unsigned wdata_len,
436                    u8 * rdata, unsigned rdata_len,
437                    int force_poll)
438 {
439         struct transaction t = {.command = command,
440                                 .wdata = wdata, .rdata = rdata,
441                                 .wlen = wdata_len, .rlen = rdata_len};
442         if (!first_ec)
443                 return -ENODEV;
444
445         return acpi_ec_transaction(first_ec, &t);
446 }
447
448 EXPORT_SYMBOL(ec_transaction);
449
450 void acpi_ec_block_transactions(void)
451 {
452         struct acpi_ec *ec = first_ec;
453
454         if (!ec)
455                 return;
456
457         mutex_lock(&ec->lock);
458         /* Prevent transactions from being carried out */
459         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
460         mutex_unlock(&ec->lock);
461 }
462
463 void acpi_ec_unblock_transactions(void)
464 {
465         struct acpi_ec *ec = first_ec;
466
467         if (!ec)
468                 return;
469
470         mutex_lock(&ec->lock);
471         /* Allow transactions to be carried out again */
472         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
473         mutex_unlock(&ec->lock);
474 }
475
476 void acpi_ec_unblock_transactions_early(void)
477 {
478         /*
479          * Allow transactions to happen again (this function is called from
480          * atomic context during wakeup, so we don't need to acquire the mutex).
481          */
482         if (first_ec)
483                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
484 }
485
486 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
487 {
488         int result;
489         u8 d;
490         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
491                                 .wdata = NULL, .rdata = &d,
492                                 .wlen = 0, .rlen = 1};
493         if (!ec || !data)
494                 return -EINVAL;
495         /*
496          * Query the EC to find out which _Qxx method we need to evaluate.
497          * Note that successful completion of the query causes the ACPI_EC_SCI
498          * bit to be cleared (and thus clearing the interrupt source).
499          */
500         result = acpi_ec_transaction_unlocked(ec, &t);
501         if (result)
502                 return result;
503         if (!d)
504                 return -ENODATA;
505         *data = d;
506         return 0;
507 }
508
509 /* --------------------------------------------------------------------------
510                                 Event Management
511    -------------------------------------------------------------------------- */
512 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
513                               acpi_handle handle, acpi_ec_query_func func,
514                               void *data)
515 {
516         struct acpi_ec_query_handler *handler =
517             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
518         if (!handler)
519                 return -ENOMEM;
520
521         handler->query_bit = query_bit;
522         handler->handle = handle;
523         handler->func = func;
524         handler->data = data;
525         mutex_lock(&ec->lock);
526         list_add(&handler->node, &ec->list);
527         mutex_unlock(&ec->lock);
528         return 0;
529 }
530
531 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
532
533 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
534 {
535         struct acpi_ec_query_handler *handler, *tmp;
536         mutex_lock(&ec->lock);
537         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
538                 if (query_bit == handler->query_bit) {
539                         list_del(&handler->node);
540                         kfree(handler);
541                 }
542         }
543         mutex_unlock(&ec->lock);
544 }
545
546 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
547
548 static void acpi_ec_run(void *cxt)
549 {
550         struct acpi_ec_query_handler *handler = cxt;
551         if (!handler)
552                 return;
553         pr_debug(PREFIX "start query execution\n");
554         if (handler->func)
555                 handler->func(handler->data);
556         else if (handler->handle)
557                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
558         pr_debug(PREFIX "stop query execution\n");
559         kfree(handler);
560 }
561
562 static int acpi_ec_sync_query(struct acpi_ec *ec)
563 {
564         u8 value = 0;
565         int status;
566         struct acpi_ec_query_handler *handler, *copy;
567         if ((status = acpi_ec_query_unlocked(ec, &value)))
568                 return status;
569         list_for_each_entry(handler, &ec->list, node) {
570                 if (value == handler->query_bit) {
571                         /* have custom handler for this bit */
572                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
573                         if (!copy)
574                                 return -ENOMEM;
575                         memcpy(copy, handler, sizeof(*copy));
576                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
577                         return acpi_os_execute((copy->func) ?
578                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
579                                 acpi_ec_run, copy);
580                 }
581         }
582         return 0;
583 }
584
585 static void acpi_ec_gpe_query(void *ec_cxt)
586 {
587         struct acpi_ec *ec = ec_cxt;
588         if (!ec)
589                 return;
590         mutex_lock(&ec->lock);
591         acpi_ec_sync_query(ec);
592         mutex_unlock(&ec->lock);
593 }
594
595 static void acpi_ec_gpe_query(void *ec_cxt);
596
597 static int ec_check_sci(struct acpi_ec *ec, u8 state)
598 {
599         if (state & ACPI_EC_FLAG_SCI) {
600                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
601                         pr_debug(PREFIX "push gpe query to the queue\n");
602                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
603                                 acpi_ec_gpe_query, ec);
604                 }
605         }
606         return 0;
607 }
608
609 static u32 acpi_ec_gpe_handler(void *data)
610 {
611         struct acpi_ec *ec = data;
612
613         pr_debug(PREFIX "~~~> interrupt\n");
614
615         advance_transaction(ec, acpi_ec_read_status(ec));
616         if (ec_transaction_done(ec) &&
617             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
618                 wake_up(&ec->wait);
619                 ec_check_sci(ec, acpi_ec_read_status(ec));
620         }
621         return ACPI_INTERRUPT_HANDLED;
622 }
623
624 /* --------------------------------------------------------------------------
625                              Address Space Management
626    -------------------------------------------------------------------------- */
627
628 static acpi_status
629 acpi_ec_space_handler(u32 function, acpi_physical_address address,
630                       u32 bits, u64 *value64,
631                       void *handler_context, void *region_context)
632 {
633         struct acpi_ec *ec = handler_context;
634         int result = 0, i, bytes = bits / 8;
635         u8 *value = (u8 *)value64;
636
637         if ((address > 0xFF) || !value || !handler_context)
638                 return AE_BAD_PARAMETER;
639
640         if (function != ACPI_READ && function != ACPI_WRITE)
641                 return AE_BAD_PARAMETER;
642
643         if (EC_FLAGS_MSI || bits > 8)
644                 acpi_ec_burst_enable(ec);
645
646         for (i = 0; i < bytes; ++i, ++address, ++value)
647                 result = (function == ACPI_READ) ?
648                         acpi_ec_read(ec, address, value) :
649                         acpi_ec_write(ec, address, *value);
650
651         if (EC_FLAGS_MSI || bits > 8)
652                 acpi_ec_burst_disable(ec);
653
654         switch (result) {
655         case -EINVAL:
656                 return AE_BAD_PARAMETER;
657                 break;
658         case -ENODEV:
659                 return AE_NOT_FOUND;
660                 break;
661         case -ETIME:
662                 return AE_TIME;
663                 break;
664         default:
665                 return AE_OK;
666         }
667 }
668
669 /* --------------------------------------------------------------------------
670                                Driver Interface
671    -------------------------------------------------------------------------- */
672 static acpi_status
673 ec_parse_io_ports(struct acpi_resource *resource, void *context);
674
675 static struct acpi_ec *make_acpi_ec(void)
676 {
677         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
678         if (!ec)
679                 return NULL;
680         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
681         mutex_init(&ec->lock);
682         init_waitqueue_head(&ec->wait);
683         INIT_LIST_HEAD(&ec->list);
684         spin_lock_init(&ec->curr_lock);
685         return ec;
686 }
687
688 static acpi_status
689 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
690                                void *context, void **return_value)
691 {
692         char node_name[5];
693         struct acpi_buffer buffer = { sizeof(node_name), node_name };
694         struct acpi_ec *ec = context;
695         int value = 0;
696         acpi_status status;
697
698         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
699
700         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
701                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
702         }
703         return AE_OK;
704 }
705
706 static acpi_status
707 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
708 {
709         acpi_status status;
710         unsigned long long tmp = 0;
711
712         struct acpi_ec *ec = context;
713
714         /* clear addr values, ec_parse_io_ports depend on it */
715         ec->command_addr = ec->data_addr = 0;
716
717         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
718                                      ec_parse_io_ports, ec);
719         if (ACPI_FAILURE(status))
720                 return status;
721
722         /* Get GPE bit assignment (EC events). */
723         /* TODO: Add support for _GPE returning a package */
724         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
725         if (ACPI_FAILURE(status))
726                 return status;
727         ec->gpe = tmp;
728         /* Use the global lock for all EC transactions? */
729         tmp = 0;
730         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
731         ec->global_lock = tmp;
732         ec->handle = handle;
733         return AE_CTRL_TERMINATE;
734 }
735
736 static int ec_install_handlers(struct acpi_ec *ec)
737 {
738         acpi_status status;
739         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
740                 return 0;
741         status = acpi_install_gpe_handler(NULL, ec->gpe,
742                                   ACPI_GPE_EDGE_TRIGGERED,
743                                   &acpi_ec_gpe_handler, ec);
744         if (ACPI_FAILURE(status))
745                 return -ENODEV;
746
747         acpi_enable_gpe(NULL, ec->gpe);
748         status = acpi_install_address_space_handler(ec->handle,
749                                                     ACPI_ADR_SPACE_EC,
750                                                     &acpi_ec_space_handler,
751                                                     NULL, ec);
752         if (ACPI_FAILURE(status)) {
753                 if (status == AE_NOT_FOUND) {
754                         /*
755                          * Maybe OS fails in evaluating the _REG object.
756                          * The AE_NOT_FOUND error will be ignored and OS
757                          * continue to initialize EC.
758                          */
759                         printk(KERN_ERR "Fail in evaluating the _REG object"
760                                 " of EC device. Broken bios is suspected.\n");
761                 } else {
762                         acpi_remove_gpe_handler(NULL, ec->gpe,
763                                 &acpi_ec_gpe_handler);
764                         acpi_disable_gpe(NULL, ec->gpe);
765                         return -ENODEV;
766                 }
767         }
768
769         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
770         return 0;
771 }
772
773 static void ec_remove_handlers(struct acpi_ec *ec)
774 {
775         acpi_disable_gpe(NULL, ec->gpe);
776         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
777                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
778                 pr_err(PREFIX "failed to remove space handler\n");
779         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
780                                 &acpi_ec_gpe_handler)))
781                 pr_err(PREFIX "failed to remove gpe handler\n");
782         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
783 }
784
785 static int acpi_ec_add(struct acpi_device *device)
786 {
787         struct acpi_ec *ec = NULL;
788         int ret;
789
790         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
791         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
792
793         /* Check for boot EC */
794         if (boot_ec &&
795             (boot_ec->handle == device->handle ||
796              boot_ec->handle == ACPI_ROOT_OBJECT)) {
797                 ec = boot_ec;
798                 boot_ec = NULL;
799         } else {
800                 ec = make_acpi_ec();
801                 if (!ec)
802                         return -ENOMEM;
803         }
804         if (ec_parse_device(device->handle, 0, ec, NULL) !=
805                 AE_CTRL_TERMINATE) {
806                         kfree(ec);
807                         return -EINVAL;
808         }
809
810         ec->handle = device->handle;
811
812         /* Find and register all query methods */
813         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
814                             acpi_ec_register_query_methods, NULL, ec, NULL);
815
816         if (!first_ec)
817                 first_ec = ec;
818         device->driver_data = ec;
819
820         WARN(!request_region(ec->data_addr, 1, "EC data"),
821              "Could not request EC data io port 0x%lx", ec->data_addr);
822         WARN(!request_region(ec->command_addr, 1, "EC cmd"),
823              "Could not request EC cmd io port 0x%lx", ec->command_addr);
824
825         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
826                           ec->gpe, ec->command_addr, ec->data_addr);
827
828         ret = ec_install_handlers(ec);
829
830         /* EC is fully operational, allow queries */
831         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
832         return ret;
833 }
834
835 static int acpi_ec_remove(struct acpi_device *device, int type)
836 {
837         struct acpi_ec *ec;
838         struct acpi_ec_query_handler *handler, *tmp;
839
840         if (!device)
841                 return -EINVAL;
842
843         ec = acpi_driver_data(device);
844         ec_remove_handlers(ec);
845         mutex_lock(&ec->lock);
846         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
847                 list_del(&handler->node);
848                 kfree(handler);
849         }
850         mutex_unlock(&ec->lock);
851         release_region(ec->data_addr, 1);
852         release_region(ec->command_addr, 1);
853         device->driver_data = NULL;
854         if (ec == first_ec)
855                 first_ec = NULL;
856         kfree(ec);
857         return 0;
858 }
859
860 static acpi_status
861 ec_parse_io_ports(struct acpi_resource *resource, void *context)
862 {
863         struct acpi_ec *ec = context;
864
865         if (resource->type != ACPI_RESOURCE_TYPE_IO)
866                 return AE_OK;
867
868         /*
869          * The first address region returned is the data port, and
870          * the second address region returned is the status/command
871          * port.
872          */
873         if (ec->data_addr == 0)
874                 ec->data_addr = resource->data.io.minimum;
875         else if (ec->command_addr == 0)
876                 ec->command_addr = resource->data.io.minimum;
877         else
878                 return AE_CTRL_TERMINATE;
879
880         return AE_OK;
881 }
882
883 int __init acpi_boot_ec_enable(void)
884 {
885         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
886                 return 0;
887         if (!ec_install_handlers(boot_ec)) {
888                 first_ec = boot_ec;
889                 return 0;
890         }
891         return -EFAULT;
892 }
893
894 static const struct acpi_device_id ec_device_ids[] = {
895         {"PNP0C09", 0},
896         {"", 0},
897 };
898
899 /* Some BIOS do not survive early DSDT scan, skip it */
900 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
901 {
902         EC_FLAGS_SKIP_DSDT_SCAN = 1;
903         return 0;
904 }
905
906 /* ASUStek often supplies us with broken ECDT, validate it */
907 static int ec_validate_ecdt(const struct dmi_system_id *id)
908 {
909         EC_FLAGS_VALIDATE_ECDT = 1;
910         return 0;
911 }
912
913 /* MSI EC needs special treatment, enable it */
914 static int ec_flag_msi(const struct dmi_system_id *id)
915 {
916         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
917         EC_FLAGS_MSI = 1;
918         EC_FLAGS_VALIDATE_ECDT = 1;
919         return 0;
920 }
921
922 static struct dmi_system_id __initdata ec_dmi_table[] = {
923         {
924         ec_skip_dsdt_scan, "Compal JFL92", {
925         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
926         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
927         {
928         ec_flag_msi, "MSI hardware", {
929         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
930         {
931         ec_flag_msi, "MSI hardware", {
932         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
933         {
934         ec_flag_msi, "MSI hardware", {
935         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
936         {
937         ec_flag_msi, "MSI hardware", {
938         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
939         {
940         ec_validate_ecdt, "ASUS hardware", {
941         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
942         {},
943 };
944
945
946 int __init acpi_ec_ecdt_probe(void)
947 {
948         acpi_status status;
949         struct acpi_ec *saved_ec = NULL;
950         struct acpi_table_ecdt *ecdt_ptr;
951
952         boot_ec = make_acpi_ec();
953         if (!boot_ec)
954                 return -ENOMEM;
955         /*
956          * Generate a boot ec context
957          */
958         dmi_check_system(ec_dmi_table);
959         status = acpi_get_table(ACPI_SIG_ECDT, 1,
960                                 (struct acpi_table_header **)&ecdt_ptr);
961         if (ACPI_SUCCESS(status)) {
962                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
963                 boot_ec->command_addr = ecdt_ptr->control.address;
964                 boot_ec->data_addr = ecdt_ptr->data.address;
965                 boot_ec->gpe = ecdt_ptr->gpe;
966                 boot_ec->handle = ACPI_ROOT_OBJECT;
967                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
968                 /* Don't trust ECDT, which comes from ASUSTek */
969                 if (!EC_FLAGS_VALIDATE_ECDT)
970                         goto install;
971                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
972                 if (!saved_ec)
973                         return -ENOMEM;
974         /* fall through */
975         }
976
977         if (EC_FLAGS_SKIP_DSDT_SCAN)
978                 return -ENODEV;
979
980         /* This workaround is needed only on some broken machines,
981          * which require early EC, but fail to provide ECDT */
982         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
983         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
984                                         boot_ec, NULL);
985         /* Check that acpi_get_devices actually find something */
986         if (ACPI_FAILURE(status) || !boot_ec->handle)
987                 goto error;
988         if (saved_ec) {
989                 /* try to find good ECDT from ASUSTek */
990                 if (saved_ec->command_addr != boot_ec->command_addr ||
991                     saved_ec->data_addr != boot_ec->data_addr ||
992                     saved_ec->gpe != boot_ec->gpe ||
993                     saved_ec->handle != boot_ec->handle)
994                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
995                         "ECDT tables, which are very hard to workaround. "
996                         "Trying to use DSDT EC info instead. Please send "
997                         "output of acpidump to linux-acpi@vger.kernel.org\n");
998                 kfree(saved_ec);
999                 saved_ec = NULL;
1000         } else {
1001                 /* We really need to limit this workaround, the only ASUS,
1002                 * which needs it, has fake EC._INI method, so use it as flag.
1003                 * Keep boot_ec struct as it will be needed soon.
1004                 */
1005                 acpi_handle dummy;
1006                 if (!dmi_name_in_vendors("ASUS") ||
1007                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1008                                                         &dummy)))
1009                         return -ENODEV;
1010         }
1011 install:
1012         if (!ec_install_handlers(boot_ec)) {
1013                 first_ec = boot_ec;
1014                 return 0;
1015         }
1016 error:
1017         kfree(boot_ec);
1018         boot_ec = NULL;
1019         return -ENODEV;
1020 }
1021
1022 static struct acpi_driver acpi_ec_driver = {
1023         .name = "ec",
1024         .class = ACPI_EC_CLASS,
1025         .ids = ec_device_ids,
1026         .ops = {
1027                 .add = acpi_ec_add,
1028                 .remove = acpi_ec_remove,
1029                 },
1030 };
1031
1032 int __init acpi_ec_init(void)
1033 {
1034         int result = 0;
1035
1036         /* Now register the driver for the EC */
1037         result = acpi_bus_register_driver(&acpi_ec_driver);
1038         if (result < 0)
1039                 return -ENODEV;
1040
1041         return result;
1042 }
1043
1044 /* EC driver currently not unloadable */
1045 #if 0
1046 static void __exit acpi_ec_exit(void)
1047 {
1048
1049         acpi_bus_unregister_driver(&acpi_ec_driver);
1050         return;
1051 }
1052 #endif  /* 0 */