ce1f07fd7241c3fd82deb80c19c122639abf7b69
[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 #define ACPI_EC_CLASS                   "embedded_controller"
47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
48 #define ACPI_EC_FILE_INFO               "info"
49
50 #define PREFIX                          "ACPI: EC: "
51
52 /* EC status register */
53 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
54 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
55 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
56 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
57
58 /* EC commands */
59 enum ec_command {
60         ACPI_EC_COMMAND_READ = 0x80,
61         ACPI_EC_COMMAND_WRITE = 0x81,
62         ACPI_EC_BURST_ENABLE = 0x82,
63         ACPI_EC_BURST_DISABLE = 0x83,
64         ACPI_EC_COMMAND_QUERY = 0x84,
65 };
66
67 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
68 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
69 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
70 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
71
72 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
73                                            per one transaction */
74
75 enum {
76         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
77         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
78         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
79                                          * OpReg are installed */
80         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
81 };
82
83 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
84 /* External interfaces use first EC only, so remember */
85 typedef int (*acpi_ec_query_func) (void *data);
86
87 struct acpi_ec_query_handler {
88         struct list_head node;
89         acpi_ec_query_func func;
90         acpi_handle handle;
91         void *data;
92         u8 query_bit;
93 };
94
95 struct transaction {
96         const u8 *wdata;
97         u8 *rdata;
98         unsigned short irq_count;
99         u8 command;
100         u8 wi;
101         u8 ri;
102         u8 wlen;
103         u8 rlen;
104         bool done;
105 };
106
107 static struct acpi_ec {
108         acpi_handle handle;
109         unsigned long gpe;
110         unsigned long command_addr;
111         unsigned long data_addr;
112         unsigned long global_lock;
113         unsigned long flags;
114         struct mutex lock;
115         wait_queue_head_t wait;
116         struct list_head list;
117         struct transaction *curr;
118         spinlock_t curr_lock;
119 } *boot_ec, *first_ec;
120
121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
124
125 /* --------------------------------------------------------------------------
126                              Transaction Management
127    -------------------------------------------------------------------------- */
128
129 static 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
136 static 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
143 static 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
149 static 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
155 static 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
166 static 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
173 static void advance_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;
196 err:
197         /* false interrupt, state didn't change */
198         if (in_interrupt())
199                 ++ec->curr->irq_count;
200 unlock:
201         spin_unlock_irqrestore(&ec->curr_lock, flags);
202 }
203
204 static int acpi_ec_sync_query(struct acpi_ec *ec);
205
206 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
207 {
208         if (state & ACPI_EC_FLAG_SCI) {
209                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
210                         return acpi_ec_sync_query(ec);
211         }
212         return 0;
213 }
214
215 static int ec_poll(struct acpi_ec *ec)
216 {
217         unsigned long flags;
218         int repeat = 2; /* number of command restarts */
219         while (repeat--) {
220                 unsigned long delay = jiffies +
221                         msecs_to_jiffies(ACPI_EC_DELAY);
222                 do {
223                         /* don't sleep with disabled interrupts */
224                         if (EC_FLAGS_MSI || irqs_disabled()) {
225                                 udelay(ACPI_EC_MSI_UDELAY);
226                                 if (ec_transaction_done(ec))
227                                         return 0;
228                         } else {
229                                 if (wait_event_timeout(ec->wait,
230                                                 ec_transaction_done(ec),
231                                                 msecs_to_jiffies(1)))
232                                         return 0;
233                         }
234                         advance_transaction(ec, acpi_ec_read_status(ec));
235                 } while (time_before(jiffies, delay));
236                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
237                         break;
238                 pr_debug(PREFIX "controller reset, restart transaction\n");
239                 spin_lock_irqsave(&ec->curr_lock, flags);
240                 start_transaction(ec);
241                 spin_unlock_irqrestore(&ec->curr_lock, flags);
242         }
243         return -ETIME;
244 }
245
246 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
247                                         struct transaction *t)
248 {
249         unsigned long tmp;
250         int ret = 0;
251         if (EC_FLAGS_MSI)
252                 udelay(ACPI_EC_MSI_UDELAY);
253         /* start transaction */
254         spin_lock_irqsave(&ec->curr_lock, tmp);
255         /* following two actions should be kept atomic */
256         ec->curr = t;
257         start_transaction(ec);
258         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
259                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
260         spin_unlock_irqrestore(&ec->curr_lock, tmp);
261         ret = ec_poll(ec);
262         spin_lock_irqsave(&ec->curr_lock, tmp);
263         ec->curr = NULL;
264         spin_unlock_irqrestore(&ec->curr_lock, tmp);
265         return ret;
266 }
267
268 static int ec_check_ibf0(struct acpi_ec *ec)
269 {
270         u8 status = acpi_ec_read_status(ec);
271         return (status & ACPI_EC_FLAG_IBF) == 0;
272 }
273
274 static int ec_wait_ibf0(struct acpi_ec *ec)
275 {
276         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
277         /* interrupt wait manually if GPE mode is not active */
278         while (time_before(jiffies, delay))
279                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
280                                         msecs_to_jiffies(1)))
281                         return 0;
282         return -ETIME;
283 }
284
285 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
286 {
287         int status;
288         u32 glk;
289         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
290                 return -EINVAL;
291         if (t->rdata)
292                 memset(t->rdata, 0, t->rlen);
293         mutex_lock(&ec->lock);
294         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
295                 status = -EINVAL;
296                 goto unlock;
297         }
298         if (ec->global_lock) {
299                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
300                 if (ACPI_FAILURE(status)) {
301                         status = -ENODEV;
302                         goto unlock;
303                 }
304         }
305         if (ec_wait_ibf0(ec)) {
306                 pr_err(PREFIX "input buffer is not empty, "
307                                 "aborting transaction\n");
308                 status = -ETIME;
309                 goto end;
310         }
311         pr_debug(PREFIX "transaction start\n");
312         /* disable GPE during transaction if storm is detected */
313         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
314                 /*
315                  * It has to be disabled at the hardware level regardless of the
316                  * GPE reference counting, so that it doesn't trigger.
317                  */
318                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
319         }
320
321         status = acpi_ec_transaction_unlocked(ec, t);
322
323         /* check if we received SCI during transaction */
324         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
325         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
326                 msleep(1);
327                 /*
328                  * It is safe to enable the GPE outside of the transaction.  Use
329                  * acpi_set_gpe() for that, since we used it to disable the GPE
330                  * above.
331                  */
332                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
333         } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
334                 pr_info(PREFIX "GPE storm detected, "
335                         "transactions will use polling mode\n");
336                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
337         }
338         pr_debug(PREFIX "transaction end\n");
339 end:
340         if (ec->global_lock)
341                 acpi_release_global_lock(glk);
342 unlock:
343         mutex_unlock(&ec->lock);
344         return status;
345 }
346
347 static int acpi_ec_burst_enable(struct acpi_ec *ec)
348 {
349         u8 d;
350         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
351                                 .wdata = NULL, .rdata = &d,
352                                 .wlen = 0, .rlen = 1};
353
354         return acpi_ec_transaction(ec, &t);
355 }
356
357 static int acpi_ec_burst_disable(struct acpi_ec *ec)
358 {
359         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
360                                 .wdata = NULL, .rdata = NULL,
361                                 .wlen = 0, .rlen = 0};
362
363         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
364                                 acpi_ec_transaction(ec, &t) : 0;
365 }
366
367 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
368 {
369         int result;
370         u8 d;
371         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
372                                 .wdata = &address, .rdata = &d,
373                                 .wlen = 1, .rlen = 1};
374
375         result = acpi_ec_transaction(ec, &t);
376         *data = d;
377         return result;
378 }
379
380 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
381 {
382         u8 wdata[2] = { address, data };
383         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
384                                 .wdata = wdata, .rdata = NULL,
385                                 .wlen = 2, .rlen = 0};
386
387         return acpi_ec_transaction(ec, &t);
388 }
389
390 /*
391  * Externally callable EC access functions. For now, assume 1 EC only
392  */
393 int ec_burst_enable(void)
394 {
395         if (!first_ec)
396                 return -ENODEV;
397         return acpi_ec_burst_enable(first_ec);
398 }
399
400 EXPORT_SYMBOL(ec_burst_enable);
401
402 int ec_burst_disable(void)
403 {
404         if (!first_ec)
405                 return -ENODEV;
406         return acpi_ec_burst_disable(first_ec);
407 }
408
409 EXPORT_SYMBOL(ec_burst_disable);
410
411 int ec_read(u8 addr, u8 * val)
412 {
413         int err;
414         u8 temp_data;
415
416         if (!first_ec)
417                 return -ENODEV;
418
419         err = acpi_ec_read(first_ec, addr, &temp_data);
420
421         if (!err) {
422                 *val = temp_data;
423                 return 0;
424         } else
425                 return err;
426 }
427
428 EXPORT_SYMBOL(ec_read);
429
430 int ec_write(u8 addr, u8 val)
431 {
432         int err;
433
434         if (!first_ec)
435                 return -ENODEV;
436
437         err = acpi_ec_write(first_ec, addr, val);
438
439         return err;
440 }
441
442 EXPORT_SYMBOL(ec_write);
443
444 int ec_transaction(u8 command,
445                    const u8 * wdata, unsigned wdata_len,
446                    u8 * rdata, unsigned rdata_len,
447                    int force_poll)
448 {
449         struct transaction t = {.command = command,
450                                 .wdata = wdata, .rdata = rdata,
451                                 .wlen = wdata_len, .rlen = rdata_len};
452         if (!first_ec)
453                 return -ENODEV;
454
455         return acpi_ec_transaction(first_ec, &t);
456 }
457
458 EXPORT_SYMBOL(ec_transaction);
459
460 void acpi_ec_block_transactions(void)
461 {
462         struct acpi_ec *ec = first_ec;
463
464         if (!ec)
465                 return;
466
467         mutex_lock(&ec->lock);
468         /* Prevent transactions from being carried out */
469         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
470         mutex_unlock(&ec->lock);
471 }
472
473 void acpi_ec_unblock_transactions(void)
474 {
475         struct acpi_ec *ec = first_ec;
476
477         if (!ec)
478                 return;
479
480         mutex_lock(&ec->lock);
481         /* Allow transactions to be carried out again */
482         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
483         mutex_unlock(&ec->lock);
484 }
485
486 void acpi_ec_unblock_transactions_early(void)
487 {
488         /*
489          * Allow transactions to happen again (this function is called from
490          * atomic context during wakeup, so we don't need to acquire the mutex).
491          */
492         if (first_ec)
493                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
494 }
495
496 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
497 {
498         int result;
499         u8 d;
500         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
501                                 .wdata = NULL, .rdata = &d,
502                                 .wlen = 0, .rlen = 1};
503         if (!ec || !data)
504                 return -EINVAL;
505         /*
506          * Query the EC to find out which _Qxx method we need to evaluate.
507          * Note that successful completion of the query causes the ACPI_EC_SCI
508          * bit to be cleared (and thus clearing the interrupt source).
509          */
510         result = acpi_ec_transaction_unlocked(ec, &t);
511         if (result)
512                 return result;
513         if (!d)
514                 return -ENODATA;
515         *data = d;
516         return 0;
517 }
518
519 /* --------------------------------------------------------------------------
520                                 Event Management
521    -------------------------------------------------------------------------- */
522 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
523                               acpi_handle handle, acpi_ec_query_func func,
524                               void *data)
525 {
526         struct acpi_ec_query_handler *handler =
527             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
528         if (!handler)
529                 return -ENOMEM;
530
531         handler->query_bit = query_bit;
532         handler->handle = handle;
533         handler->func = func;
534         handler->data = data;
535         mutex_lock(&ec->lock);
536         list_add(&handler->node, &ec->list);
537         mutex_unlock(&ec->lock);
538         return 0;
539 }
540
541 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
542
543 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
544 {
545         struct acpi_ec_query_handler *handler, *tmp;
546         mutex_lock(&ec->lock);
547         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
548                 if (query_bit == handler->query_bit) {
549                         list_del(&handler->node);
550                         kfree(handler);
551                 }
552         }
553         mutex_unlock(&ec->lock);
554 }
555
556 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
557
558 static void acpi_ec_run(void *cxt)
559 {
560         struct acpi_ec_query_handler *handler = cxt;
561         if (!handler)
562                 return;
563         pr_debug(PREFIX "start query execution\n");
564         if (handler->func)
565                 handler->func(handler->data);
566         else if (handler->handle)
567                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
568         pr_debug(PREFIX "stop query execution\n");
569         kfree(handler);
570 }
571
572 static int acpi_ec_sync_query(struct acpi_ec *ec)
573 {
574         u8 value = 0;
575         int status;
576         struct acpi_ec_query_handler *handler, *copy;
577         if ((status = acpi_ec_query_unlocked(ec, &value)))
578                 return status;
579         list_for_each_entry(handler, &ec->list, node) {
580                 if (value == handler->query_bit) {
581                         /* have custom handler for this bit */
582                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
583                         if (!copy)
584                                 return -ENOMEM;
585                         memcpy(copy, handler, sizeof(*copy));
586                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
587                         return acpi_os_execute((copy->func) ?
588                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
589                                 acpi_ec_run, copy);
590                 }
591         }
592         return 0;
593 }
594
595 static void acpi_ec_gpe_query(void *ec_cxt)
596 {
597         struct acpi_ec *ec = ec_cxt;
598         if (!ec)
599                 return;
600         mutex_lock(&ec->lock);
601         acpi_ec_sync_query(ec);
602         mutex_unlock(&ec->lock);
603 }
604
605 static void acpi_ec_gpe_query(void *ec_cxt);
606
607 static int ec_check_sci(struct acpi_ec *ec, u8 state)
608 {
609         if (state & ACPI_EC_FLAG_SCI) {
610                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
611                         pr_debug(PREFIX "push gpe query to the queue\n");
612                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
613                                 acpi_ec_gpe_query, ec);
614                 }
615         }
616         return 0;
617 }
618
619 static u32 acpi_ec_gpe_handler(void *data)
620 {
621         struct acpi_ec *ec = data;
622
623         pr_debug(PREFIX "~~~> interrupt\n");
624
625         advance_transaction(ec, acpi_ec_read_status(ec));
626         if (ec_transaction_done(ec) &&
627             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
628                 wake_up(&ec->wait);
629                 ec_check_sci(ec, acpi_ec_read_status(ec));
630         }
631         return ACPI_INTERRUPT_HANDLED;
632 }
633
634 /* --------------------------------------------------------------------------
635                              Address Space Management
636    -------------------------------------------------------------------------- */
637
638 static acpi_status
639 acpi_ec_space_handler(u32 function, acpi_physical_address address,
640                       u32 bits, u64 *value64,
641                       void *handler_context, void *region_context)
642 {
643         struct acpi_ec *ec = handler_context;
644         int result = 0, i, bytes = bits / 8;
645         u8 *value = (u8 *)value64;
646
647         if ((address > 0xFF) || !value || !handler_context)
648                 return AE_BAD_PARAMETER;
649
650         if (function != ACPI_READ && function != ACPI_WRITE)
651                 return AE_BAD_PARAMETER;
652
653         if (EC_FLAGS_MSI || bits > 8)
654                 acpi_ec_burst_enable(ec);
655
656         for (i = 0; i < bytes; ++i, ++address, ++value)
657                 result = (function == ACPI_READ) ?
658                         acpi_ec_read(ec, address, value) :
659                         acpi_ec_write(ec, address, *value);
660
661         if (EC_FLAGS_MSI || bits > 8)
662                 acpi_ec_burst_disable(ec);
663
664         switch (result) {
665         case -EINVAL:
666                 return AE_BAD_PARAMETER;
667                 break;
668         case -ENODEV:
669                 return AE_NOT_FOUND;
670                 break;
671         case -ETIME:
672                 return AE_TIME;
673                 break;
674         default:
675                 return AE_OK;
676         }
677 }
678
679 /* --------------------------------------------------------------------------
680                                Driver Interface
681    -------------------------------------------------------------------------- */
682 static acpi_status
683 ec_parse_io_ports(struct acpi_resource *resource, void *context);
684
685 static struct acpi_ec *make_acpi_ec(void)
686 {
687         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
688         if (!ec)
689                 return NULL;
690         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
691         mutex_init(&ec->lock);
692         init_waitqueue_head(&ec->wait);
693         INIT_LIST_HEAD(&ec->list);
694         spin_lock_init(&ec->curr_lock);
695         return ec;
696 }
697
698 static acpi_status
699 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
700                                void *context, void **return_value)
701 {
702         char node_name[5];
703         struct acpi_buffer buffer = { sizeof(node_name), node_name };
704         struct acpi_ec *ec = context;
705         int value = 0;
706         acpi_status status;
707
708         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
709
710         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
711                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
712         }
713         return AE_OK;
714 }
715
716 static acpi_status
717 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
718 {
719         acpi_status status;
720         unsigned long long tmp = 0;
721
722         struct acpi_ec *ec = context;
723
724         /* clear addr values, ec_parse_io_ports depend on it */
725         ec->command_addr = ec->data_addr = 0;
726
727         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
728                                      ec_parse_io_ports, ec);
729         if (ACPI_FAILURE(status))
730                 return status;
731
732         /* Get GPE bit assignment (EC events). */
733         /* TODO: Add support for _GPE returning a package */
734         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
735         if (ACPI_FAILURE(status))
736                 return status;
737         ec->gpe = tmp;
738         /* Use the global lock for all EC transactions? */
739         tmp = 0;
740         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
741         ec->global_lock = tmp;
742         ec->handle = handle;
743         return AE_CTRL_TERMINATE;
744 }
745
746 static int ec_install_handlers(struct acpi_ec *ec)
747 {
748         acpi_status status;
749         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
750                 return 0;
751         status = acpi_install_gpe_handler(NULL, ec->gpe,
752                                   ACPI_GPE_EDGE_TRIGGERED,
753                                   &acpi_ec_gpe_handler, ec);
754         if (ACPI_FAILURE(status))
755                 return -ENODEV;
756
757         acpi_enable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
758         status = acpi_install_address_space_handler(ec->handle,
759                                                     ACPI_ADR_SPACE_EC,
760                                                     &acpi_ec_space_handler,
761                                                     NULL, ec);
762         if (ACPI_FAILURE(status)) {
763                 if (status == AE_NOT_FOUND) {
764                         /*
765                          * Maybe OS fails in evaluating the _REG object.
766                          * The AE_NOT_FOUND error will be ignored and OS
767                          * continue to initialize EC.
768                          */
769                         printk(KERN_ERR "Fail in evaluating the _REG object"
770                                 " of EC device. Broken bios is suspected.\n");
771                 } else {
772                         acpi_remove_gpe_handler(NULL, ec->gpe,
773                                 &acpi_ec_gpe_handler);
774                         acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
775                         return -ENODEV;
776                 }
777         }
778
779         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
780         return 0;
781 }
782
783 static void ec_remove_handlers(struct acpi_ec *ec)
784 {
785         acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
786         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
787                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
788                 pr_err(PREFIX "failed to remove space handler\n");
789         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
790                                 &acpi_ec_gpe_handler)))
791                 pr_err(PREFIX "failed to remove gpe handler\n");
792         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
793 }
794
795 static int acpi_ec_add(struct acpi_device *device)
796 {
797         struct acpi_ec *ec = NULL;
798         int ret;
799
800         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
801         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
802
803         /* Check for boot EC */
804         if (boot_ec &&
805             (boot_ec->handle == device->handle ||
806              boot_ec->handle == ACPI_ROOT_OBJECT)) {
807                 ec = boot_ec;
808                 boot_ec = NULL;
809         } else {
810                 ec = make_acpi_ec();
811                 if (!ec)
812                         return -ENOMEM;
813         }
814         if (ec_parse_device(device->handle, 0, ec, NULL) !=
815                 AE_CTRL_TERMINATE) {
816                         kfree(ec);
817                         return -EINVAL;
818         }
819
820         ec->handle = device->handle;
821
822         /* Find and register all query methods */
823         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
824                             acpi_ec_register_query_methods, NULL, ec, NULL);
825
826         if (!first_ec)
827                 first_ec = ec;
828         device->driver_data = ec;
829         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
830                           ec->gpe, ec->command_addr, ec->data_addr);
831
832         ret = ec_install_handlers(ec);
833
834         /* EC is fully operational, allow queries */
835         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
836         return ret;
837 }
838
839 static int acpi_ec_remove(struct acpi_device *device, int type)
840 {
841         struct acpi_ec *ec;
842         struct acpi_ec_query_handler *handler, *tmp;
843
844         if (!device)
845                 return -EINVAL;
846
847         ec = acpi_driver_data(device);
848         ec_remove_handlers(ec);
849         mutex_lock(&ec->lock);
850         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
851                 list_del(&handler->node);
852                 kfree(handler);
853         }
854         mutex_unlock(&ec->lock);
855         device->driver_data = NULL;
856         if (ec == first_ec)
857                 first_ec = NULL;
858         kfree(ec);
859         return 0;
860 }
861
862 static acpi_status
863 ec_parse_io_ports(struct acpi_resource *resource, void *context)
864 {
865         struct acpi_ec *ec = context;
866
867         if (resource->type != ACPI_RESOURCE_TYPE_IO)
868                 return AE_OK;
869
870         /*
871          * The first address region returned is the data port, and
872          * the second address region returned is the status/command
873          * port.
874          */
875         if (ec->data_addr == 0)
876                 ec->data_addr = resource->data.io.minimum;
877         else if (ec->command_addr == 0)
878                 ec->command_addr = resource->data.io.minimum;
879         else
880                 return AE_CTRL_TERMINATE;
881
882         return AE_OK;
883 }
884
885 int __init acpi_boot_ec_enable(void)
886 {
887         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
888                 return 0;
889         if (!ec_install_handlers(boot_ec)) {
890                 first_ec = boot_ec;
891                 return 0;
892         }
893         return -EFAULT;
894 }
895
896 static const struct acpi_device_id ec_device_ids[] = {
897         {"PNP0C09", 0},
898         {"", 0},
899 };
900
901 /* Some BIOS do not survive early DSDT scan, skip it */
902 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
903 {
904         EC_FLAGS_SKIP_DSDT_SCAN = 1;
905         return 0;
906 }
907
908 /* ASUStek often supplies us with broken ECDT, validate it */
909 static int ec_validate_ecdt(const struct dmi_system_id *id)
910 {
911         EC_FLAGS_VALIDATE_ECDT = 1;
912         return 0;
913 }
914
915 /* MSI EC needs special treatment, enable it */
916 static int ec_flag_msi(const struct dmi_system_id *id)
917 {
918         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
919         EC_FLAGS_MSI = 1;
920         EC_FLAGS_VALIDATE_ECDT = 1;
921         return 0;
922 }
923
924 static struct dmi_system_id __initdata ec_dmi_table[] = {
925         {
926         ec_skip_dsdt_scan, "Compal JFL92", {
927         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
928         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
929         {
930         ec_flag_msi, "MSI hardware", {
931         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
932         {
933         ec_flag_msi, "MSI hardware", {
934         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
935         {
936         ec_flag_msi, "MSI hardware", {
937         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
938         {
939         ec_validate_ecdt, "ASUS hardware", {
940         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
941         {},
942 };
943
944
945 int __init acpi_ec_ecdt_probe(void)
946 {
947         acpi_status status;
948         struct acpi_ec *saved_ec = NULL;
949         struct acpi_table_ecdt *ecdt_ptr;
950
951         boot_ec = make_acpi_ec();
952         if (!boot_ec)
953                 return -ENOMEM;
954         /*
955          * Generate a boot ec context
956          */
957         dmi_check_system(ec_dmi_table);
958         status = acpi_get_table(ACPI_SIG_ECDT, 1,
959                                 (struct acpi_table_header **)&ecdt_ptr);
960         if (ACPI_SUCCESS(status)) {
961                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
962                 boot_ec->command_addr = ecdt_ptr->control.address;
963                 boot_ec->data_addr = ecdt_ptr->data.address;
964                 boot_ec->gpe = ecdt_ptr->gpe;
965                 boot_ec->handle = ACPI_ROOT_OBJECT;
966                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
967                 /* Don't trust ECDT, which comes from ASUSTek */
968                 if (!EC_FLAGS_VALIDATE_ECDT)
969                         goto install;
970                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
971                 if (!saved_ec)
972                         return -ENOMEM;
973         /* fall through */
974         }
975
976         if (EC_FLAGS_SKIP_DSDT_SCAN)
977                 return -ENODEV;
978
979         /* This workaround is needed only on some broken machines,
980          * which require early EC, but fail to provide ECDT */
981         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
982         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
983                                         boot_ec, NULL);
984         /* Check that acpi_get_devices actually find something */
985         if (ACPI_FAILURE(status) || !boot_ec->handle)
986                 goto error;
987         if (saved_ec) {
988                 /* try to find good ECDT from ASUSTek */
989                 if (saved_ec->command_addr != boot_ec->command_addr ||
990                     saved_ec->data_addr != boot_ec->data_addr ||
991                     saved_ec->gpe != boot_ec->gpe ||
992                     saved_ec->handle != boot_ec->handle)
993                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
994                         "ECDT tables, which are very hard to workaround. "
995                         "Trying to use DSDT EC info instead. Please send "
996                         "output of acpidump to linux-acpi@vger.kernel.org\n");
997                 kfree(saved_ec);
998                 saved_ec = NULL;
999         } else {
1000                 /* We really need to limit this workaround, the only ASUS,
1001                 * which needs it, has fake EC._INI method, so use it as flag.
1002                 * Keep boot_ec struct as it will be needed soon.
1003                 */
1004                 acpi_handle dummy;
1005                 if (!dmi_name_in_vendors("ASUS") ||
1006                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1007                                                         &dummy)))
1008                         return -ENODEV;
1009         }
1010 install:
1011         if (!ec_install_handlers(boot_ec)) {
1012                 first_ec = boot_ec;
1013                 return 0;
1014         }
1015 error:
1016         kfree(boot_ec);
1017         boot_ec = NULL;
1018         return -ENODEV;
1019 }
1020
1021 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1022 {
1023         struct acpi_ec *ec = acpi_driver_data(device);
1024         /* Stop using the GPE, but keep it reference counted. */
1025         acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1026         return 0;
1027 }
1028
1029 static int acpi_ec_resume(struct acpi_device *device)
1030 {
1031         struct acpi_ec *ec = acpi_driver_data(device);
1032         /* Enable the GPE again, but don't reference count it once more. */
1033         acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1034         return 0;
1035 }
1036
1037 static struct acpi_driver acpi_ec_driver = {
1038         .name = "ec",
1039         .class = ACPI_EC_CLASS,
1040         .ids = ec_device_ids,
1041         .ops = {
1042                 .add = acpi_ec_add,
1043                 .remove = acpi_ec_remove,
1044                 .suspend = acpi_ec_suspend,
1045                 .resume = acpi_ec_resume,
1046                 },
1047 };
1048
1049 int __init acpi_ec_init(void)
1050 {
1051         int result = 0;
1052
1053         /* Now register the driver for the EC */
1054         result = acpi_bus_register_driver(&acpi_ec_driver);
1055         if (result < 0)
1056                 return -ENODEV;
1057
1058         return result;
1059 }
1060
1061 /* EC driver currently not unloadable */
1062 #if 0
1063 static void __exit acpi_ec_exit(void)
1064 {
1065
1066         acpi_bus_unregister_driver(&acpi_ec_driver);
1067         return;
1068 }
1069 #endif  /* 0 */