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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_MSI_UDELAY      550     /* Wait 550us for MSI EC */
73
74 enum {
75         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
76         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
77         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
78                                          * OpReg are installed */
79         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
80 };
81
82 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
83 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
84 module_param(ec_delay, uint, 0644);
85 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
86
87 /*
88  * If the number of false interrupts per one transaction exceeds
89  * this threshold, will think there is a GPE storm happened and
90  * will disable the GPE for normal transaction.
91  */
92 static unsigned int ec_storm_threshold  __read_mostly = 8;
93 module_param(ec_storm_threshold, uint, 0644);
94 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
95
96 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
97 /* External interfaces use first EC only, so remember */
98 typedef int (*acpi_ec_query_func) (void *data);
99
100 struct acpi_ec_query_handler {
101         struct list_head node;
102         acpi_ec_query_func func;
103         acpi_handle handle;
104         void *data;
105         u8 query_bit;
106 };
107
108 struct transaction {
109         const u8 *wdata;
110         u8 *rdata;
111         unsigned short irq_count;
112         u8 command;
113         u8 wi;
114         u8 ri;
115         u8 wlen;
116         u8 rlen;
117         bool done;
118 };
119
120 struct acpi_ec *boot_ec, *first_ec;
121 EXPORT_SYMBOL(first_ec);
122
123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
124 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
125 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
126
127 /* --------------------------------------------------------------------------
128                              Transaction Management
129    -------------------------------------------------------------------------- */
130
131 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
132 {
133         u8 x = inb(ec->command_addr);
134         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
135         return x;
136 }
137
138 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
139 {
140         u8 x = inb(ec->data_addr);
141         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
142         return x;
143 }
144
145 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
146 {
147         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
148         outb(command, ec->command_addr);
149 }
150
151 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
152 {
153         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
154         outb(data, ec->data_addr);
155 }
156
157 static int ec_transaction_done(struct acpi_ec *ec)
158 {
159         unsigned long flags;
160         int ret = 0;
161         spin_lock_irqsave(&ec->lock, flags);
162         if (!ec->curr || ec->curr->done)
163                 ret = 1;
164         spin_unlock_irqrestore(&ec->lock, flags);
165         return ret;
166 }
167
168 static void start_transaction(struct acpi_ec *ec)
169 {
170         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
171         ec->curr->done = false;
172         acpi_ec_write_cmd(ec, ec->curr->command);
173 }
174
175 static void advance_transaction(struct acpi_ec *ec, u8 status)
176 {
177         unsigned long flags;
178         struct transaction *t = ec->curr;
179
180         spin_lock_irqsave(&ec->lock, flags);
181         if (!t)
182                 goto unlock;
183         if (t->wlen > t->wi) {
184                 if ((status & ACPI_EC_FLAG_IBF) == 0)
185                         acpi_ec_write_data(ec,
186                                 t->wdata[t->wi++]);
187                 else
188                         goto err;
189         } else if (t->rlen > t->ri) {
190                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
191                         t->rdata[t->ri++] = acpi_ec_read_data(ec);
192                         if (t->rlen == t->ri)
193                                 t->done = true;
194                 } else
195                         goto err;
196         } else if (t->wlen == t->wi &&
197                    (status & ACPI_EC_FLAG_IBF) == 0)
198                 t->done = true;
199         goto unlock;
200 err:
201         /*
202          * If SCI bit is set, then don't think it's a false IRQ
203          * otherwise will take a not handled IRQ as a false one.
204          */
205         if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
206                 ++t->irq_count;
207
208 unlock:
209         spin_unlock_irqrestore(&ec->lock, flags);
210 }
211
212 static int acpi_ec_sync_query(struct acpi_ec *ec);
213
214 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
215 {
216         if (state & ACPI_EC_FLAG_SCI) {
217                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
218                         return acpi_ec_sync_query(ec);
219         }
220         return 0;
221 }
222
223 static int ec_poll(struct acpi_ec *ec)
224 {
225         unsigned long flags;
226         int repeat = 2; /* number of command restarts */
227         while (repeat--) {
228                 unsigned long delay = jiffies +
229                         msecs_to_jiffies(ec_delay);
230                 do {
231                         /* don't sleep with disabled interrupts */
232                         if (EC_FLAGS_MSI || irqs_disabled()) {
233                                 udelay(ACPI_EC_MSI_UDELAY);
234                                 if (ec_transaction_done(ec))
235                                         return 0;
236                         } else {
237                                 if (wait_event_timeout(ec->wait,
238                                                 ec_transaction_done(ec),
239                                                 msecs_to_jiffies(1)))
240                                         return 0;
241                         }
242                         advance_transaction(ec, acpi_ec_read_status(ec));
243                 } while (time_before(jiffies, delay));
244                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
245                         break;
246                 pr_debug(PREFIX "controller reset, restart transaction\n");
247                 spin_lock_irqsave(&ec->lock, flags);
248                 start_transaction(ec);
249                 spin_unlock_irqrestore(&ec->lock, flags);
250         }
251         return -ETIME;
252 }
253
254 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
255                                         struct transaction *t)
256 {
257         unsigned long tmp;
258         int ret = 0;
259         if (EC_FLAGS_MSI)
260                 udelay(ACPI_EC_MSI_UDELAY);
261         /* start transaction */
262         spin_lock_irqsave(&ec->lock, tmp);
263         /* following two actions should be kept atomic */
264         ec->curr = t;
265         start_transaction(ec);
266         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
267                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
268         spin_unlock_irqrestore(&ec->lock, tmp);
269         ret = ec_poll(ec);
270         spin_lock_irqsave(&ec->lock, tmp);
271         ec->curr = NULL;
272         spin_unlock_irqrestore(&ec->lock, tmp);
273         return ret;
274 }
275
276 static int ec_check_ibf0(struct acpi_ec *ec)
277 {
278         u8 status = acpi_ec_read_status(ec);
279         return (status & ACPI_EC_FLAG_IBF) == 0;
280 }
281
282 static int ec_wait_ibf0(struct acpi_ec *ec)
283 {
284         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
285         /* interrupt wait manually if GPE mode is not active */
286         while (time_before(jiffies, delay))
287                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
288                                         msecs_to_jiffies(1)))
289                         return 0;
290         return -ETIME;
291 }
292
293 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
294 {
295         int status;
296         u32 glk;
297         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
298                 return -EINVAL;
299         if (t->rdata)
300                 memset(t->rdata, 0, t->rlen);
301         mutex_lock(&ec->mutex);
302         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
303                 status = -EINVAL;
304                 goto unlock;
305         }
306         if (ec->global_lock) {
307                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
308                 if (ACPI_FAILURE(status)) {
309                         status = -ENODEV;
310                         goto unlock;
311                 }
312         }
313         if (ec_wait_ibf0(ec)) {
314                 pr_err(PREFIX "input buffer is not empty, "
315                                 "aborting transaction\n");
316                 status = -ETIME;
317                 goto end;
318         }
319         pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
320                         t->command, t->wdata ? t->wdata[0] : 0);
321         /* disable GPE during transaction if storm is detected */
322         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
323                 /* It has to be disabled, so that it doesn't trigger. */
324                 acpi_disable_gpe(NULL, ec->gpe);
325         }
326
327         status = acpi_ec_transaction_unlocked(ec, t);
328
329         /* check if we received SCI during transaction */
330         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
331         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
332                 msleep(1);
333                 /* It is safe to enable the GPE outside of the transaction. */
334                 acpi_enable_gpe(NULL, ec->gpe);
335         } else if (t->irq_count > ec_storm_threshold) {
336                 pr_info(PREFIX "GPE storm detected(%d GPEs), "
337                         "transactions will use polling mode\n",
338                         t->irq_count);
339                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
340         }
341         pr_debug(PREFIX "transaction end\n");
342 end:
343         if (ec->global_lock)
344                 acpi_release_global_lock(glk);
345 unlock:
346         mutex_unlock(&ec->mutex);
347         return status;
348 }
349
350 static int acpi_ec_burst_enable(struct acpi_ec *ec)
351 {
352         u8 d;
353         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
354                                 .wdata = NULL, .rdata = &d,
355                                 .wlen = 0, .rlen = 1};
356
357         return acpi_ec_transaction(ec, &t);
358 }
359
360 static int acpi_ec_burst_disable(struct acpi_ec *ec)
361 {
362         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
363                                 .wdata = NULL, .rdata = NULL,
364                                 .wlen = 0, .rlen = 0};
365
366         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
367                                 acpi_ec_transaction(ec, &t) : 0;
368 }
369
370 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
371 {
372         int result;
373         u8 d;
374         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
375                                 .wdata = &address, .rdata = &d,
376                                 .wlen = 1, .rlen = 1};
377
378         result = acpi_ec_transaction(ec, &t);
379         *data = d;
380         return result;
381 }
382
383 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
384 {
385         u8 wdata[2] = { address, data };
386         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
387                                 .wdata = wdata, .rdata = NULL,
388                                 .wlen = 2, .rlen = 0};
389
390         return acpi_ec_transaction(ec, &t);
391 }
392
393 /*
394  * Externally callable EC access functions. For now, assume 1 EC only
395  */
396 int ec_burst_enable(void)
397 {
398         if (!first_ec)
399                 return -ENODEV;
400         return acpi_ec_burst_enable(first_ec);
401 }
402
403 EXPORT_SYMBOL(ec_burst_enable);
404
405 int ec_burst_disable(void)
406 {
407         if (!first_ec)
408                 return -ENODEV;
409         return acpi_ec_burst_disable(first_ec);
410 }
411
412 EXPORT_SYMBOL(ec_burst_disable);
413
414 int ec_read(u8 addr, u8 *val)
415 {
416         int err;
417         u8 temp_data;
418
419         if (!first_ec)
420                 return -ENODEV;
421
422         err = acpi_ec_read(first_ec, addr, &temp_data);
423
424         if (!err) {
425                 *val = temp_data;
426                 return 0;
427         } else
428                 return err;
429 }
430
431 EXPORT_SYMBOL(ec_read);
432
433 int ec_write(u8 addr, u8 val)
434 {
435         int err;
436
437         if (!first_ec)
438                 return -ENODEV;
439
440         err = acpi_ec_write(first_ec, addr, val);
441
442         return err;
443 }
444
445 EXPORT_SYMBOL(ec_write);
446
447 int ec_transaction(u8 command,
448                    const u8 * wdata, unsigned wdata_len,
449                    u8 * rdata, unsigned rdata_len)
450 {
451         struct transaction t = {.command = command,
452                                 .wdata = wdata, .rdata = rdata,
453                                 .wlen = wdata_len, .rlen = rdata_len};
454         if (!first_ec)
455                 return -ENODEV;
456
457         return acpi_ec_transaction(first_ec, &t);
458 }
459
460 EXPORT_SYMBOL(ec_transaction);
461
462 /* Get the handle to the EC device */
463 acpi_handle ec_get_handle(void)
464 {
465         if (!first_ec)
466                 return NULL;
467         return first_ec->handle;
468 }
469
470 EXPORT_SYMBOL(ec_get_handle);
471
472 void acpi_ec_block_transactions(void)
473 {
474         struct acpi_ec *ec = first_ec;
475
476         if (!ec)
477                 return;
478
479         mutex_lock(&ec->mutex);
480         /* Prevent transactions from being carried out */
481         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
482         mutex_unlock(&ec->mutex);
483 }
484
485 void acpi_ec_unblock_transactions(void)
486 {
487         struct acpi_ec *ec = first_ec;
488
489         if (!ec)
490                 return;
491
492         mutex_lock(&ec->mutex);
493         /* Allow transactions to be carried out again */
494         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
495         mutex_unlock(&ec->mutex);
496 }
497
498 void acpi_ec_unblock_transactions_early(void)
499 {
500         /*
501          * Allow transactions to happen again (this function is called from
502          * atomic context during wakeup, so we don't need to acquire the mutex).
503          */
504         if (first_ec)
505                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
506 }
507
508 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
509 {
510         int result;
511         u8 d;
512         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
513                                 .wdata = NULL, .rdata = &d,
514                                 .wlen = 0, .rlen = 1};
515         if (!ec || !data)
516                 return -EINVAL;
517         /*
518          * Query the EC to find out which _Qxx method we need to evaluate.
519          * Note that successful completion of the query causes the ACPI_EC_SCI
520          * bit to be cleared (and thus clearing the interrupt source).
521          */
522         result = acpi_ec_transaction_unlocked(ec, &t);
523         if (result)
524                 return result;
525         if (!d)
526                 return -ENODATA;
527         *data = d;
528         return 0;
529 }
530
531 /* --------------------------------------------------------------------------
532                                 Event Management
533    -------------------------------------------------------------------------- */
534 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
535                               acpi_handle handle, acpi_ec_query_func func,
536                               void *data)
537 {
538         struct acpi_ec_query_handler *handler =
539             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
540         if (!handler)
541                 return -ENOMEM;
542
543         handler->query_bit = query_bit;
544         handler->handle = handle;
545         handler->func = func;
546         handler->data = data;
547         mutex_lock(&ec->mutex);
548         list_add(&handler->node, &ec->list);
549         mutex_unlock(&ec->mutex);
550         return 0;
551 }
552
553 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
554
555 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
556 {
557         struct acpi_ec_query_handler *handler, *tmp;
558         mutex_lock(&ec->mutex);
559         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
560                 if (query_bit == handler->query_bit) {
561                         list_del(&handler->node);
562                         kfree(handler);
563                 }
564         }
565         mutex_unlock(&ec->mutex);
566 }
567
568 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
569
570 static void acpi_ec_run(void *cxt)
571 {
572         struct acpi_ec_query_handler *handler = cxt;
573         if (!handler)
574                 return;
575         pr_debug(PREFIX "start query execution\n");
576         if (handler->func)
577                 handler->func(handler->data);
578         else if (handler->handle)
579                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
580         pr_debug(PREFIX "stop query execution\n");
581         kfree(handler);
582 }
583
584 static int acpi_ec_sync_query(struct acpi_ec *ec)
585 {
586         u8 value = 0;
587         int status;
588         struct acpi_ec_query_handler *handler, *copy;
589         if ((status = acpi_ec_query_unlocked(ec, &value)))
590                 return status;
591         list_for_each_entry(handler, &ec->list, node) {
592                 if (value == handler->query_bit) {
593                         /* have custom handler for this bit */
594                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
595                         if (!copy)
596                                 return -ENOMEM;
597                         memcpy(copy, handler, sizeof(*copy));
598                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
599                         return acpi_os_execute((copy->func) ?
600                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
601                                 acpi_ec_run, copy);
602                 }
603         }
604         return 0;
605 }
606
607 static void acpi_ec_gpe_query(void *ec_cxt)
608 {
609         struct acpi_ec *ec = ec_cxt;
610         if (!ec)
611                 return;
612         mutex_lock(&ec->mutex);
613         acpi_ec_sync_query(ec);
614         mutex_unlock(&ec->mutex);
615 }
616
617 static int ec_check_sci(struct acpi_ec *ec, u8 state)
618 {
619         if (state & ACPI_EC_FLAG_SCI) {
620                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
621                         pr_debug(PREFIX "push gpe query to the queue\n");
622                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
623                                 acpi_ec_gpe_query, ec);
624                 }
625         }
626         return 0;
627 }
628
629 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
630         u32 gpe_number, void *data)
631 {
632         struct acpi_ec *ec = data;
633         u8 status = acpi_ec_read_status(ec);
634
635         pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status);
636
637         advance_transaction(ec, status);
638         if (ec_transaction_done(ec) &&
639             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
640                 wake_up(&ec->wait);
641                 ec_check_sci(ec, acpi_ec_read_status(ec));
642         }
643         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
644 }
645
646 /* --------------------------------------------------------------------------
647                              Address Space Management
648    -------------------------------------------------------------------------- */
649
650 static acpi_status
651 acpi_ec_space_handler(u32 function, acpi_physical_address address,
652                       u32 bits, u64 *value64,
653                       void *handler_context, void *region_context)
654 {
655         struct acpi_ec *ec = handler_context;
656         int result = 0, i, bytes = bits / 8;
657         u8 *value = (u8 *)value64;
658
659         if ((address > 0xFF) || !value || !handler_context)
660                 return AE_BAD_PARAMETER;
661
662         if (function != ACPI_READ && function != ACPI_WRITE)
663                 return AE_BAD_PARAMETER;
664
665         if (EC_FLAGS_MSI || bits > 8)
666                 acpi_ec_burst_enable(ec);
667
668         for (i = 0; i < bytes; ++i, ++address, ++value)
669                 result = (function == ACPI_READ) ?
670                         acpi_ec_read(ec, address, value) :
671                         acpi_ec_write(ec, address, *value);
672
673         if (EC_FLAGS_MSI || bits > 8)
674                 acpi_ec_burst_disable(ec);
675
676         switch (result) {
677         case -EINVAL:
678                 return AE_BAD_PARAMETER;
679                 break;
680         case -ENODEV:
681                 return AE_NOT_FOUND;
682                 break;
683         case -ETIME:
684                 return AE_TIME;
685                 break;
686         default:
687                 return AE_OK;
688         }
689 }
690
691 /* --------------------------------------------------------------------------
692                                Driver Interface
693    -------------------------------------------------------------------------- */
694 static acpi_status
695 ec_parse_io_ports(struct acpi_resource *resource, void *context);
696
697 static struct acpi_ec *make_acpi_ec(void)
698 {
699         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
700         if (!ec)
701                 return NULL;
702         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
703         mutex_init(&ec->mutex);
704         init_waitqueue_head(&ec->wait);
705         INIT_LIST_HEAD(&ec->list);
706         spin_lock_init(&ec->lock);
707         return ec;
708 }
709
710 static acpi_status
711 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
712                                void *context, void **return_value)
713 {
714         char node_name[5];
715         struct acpi_buffer buffer = { sizeof(node_name), node_name };
716         struct acpi_ec *ec = context;
717         int value = 0;
718         acpi_status status;
719
720         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
721
722         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
723                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
724         }
725         return AE_OK;
726 }
727
728 static acpi_status
729 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
730 {
731         acpi_status status;
732         unsigned long long tmp = 0;
733
734         struct acpi_ec *ec = context;
735
736         /* clear addr values, ec_parse_io_ports depend on it */
737         ec->command_addr = ec->data_addr = 0;
738
739         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
740                                      ec_parse_io_ports, ec);
741         if (ACPI_FAILURE(status))
742                 return status;
743
744         /* Get GPE bit assignment (EC events). */
745         /* TODO: Add support for _GPE returning a package */
746         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
747         if (ACPI_FAILURE(status))
748                 return status;
749         ec->gpe = tmp;
750         /* Use the global lock for all EC transactions? */
751         tmp = 0;
752         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
753         ec->global_lock = tmp;
754         ec->handle = handle;
755         return AE_CTRL_TERMINATE;
756 }
757
758 static int ec_install_handlers(struct acpi_ec *ec)
759 {
760         acpi_status status;
761         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
762                 return 0;
763         status = acpi_install_gpe_handler(NULL, ec->gpe,
764                                   ACPI_GPE_EDGE_TRIGGERED,
765                                   &acpi_ec_gpe_handler, ec);
766         if (ACPI_FAILURE(status))
767                 return -ENODEV;
768
769         acpi_enable_gpe(NULL, ec->gpe);
770         status = acpi_install_address_space_handler(ec->handle,
771                                                     ACPI_ADR_SPACE_EC,
772                                                     &acpi_ec_space_handler,
773                                                     NULL, ec);
774         if (ACPI_FAILURE(status)) {
775                 if (status == AE_NOT_FOUND) {
776                         /*
777                          * Maybe OS fails in evaluating the _REG object.
778                          * The AE_NOT_FOUND error will be ignored and OS
779                          * continue to initialize EC.
780                          */
781                         printk(KERN_ERR "Fail in evaluating the _REG object"
782                                 " of EC device. Broken bios is suspected.\n");
783                 } else {
784                         acpi_remove_gpe_handler(NULL, ec->gpe,
785                                 &acpi_ec_gpe_handler);
786                         acpi_disable_gpe(NULL, ec->gpe);
787                         return -ENODEV;
788                 }
789         }
790
791         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
792         return 0;
793 }
794
795 static void ec_remove_handlers(struct acpi_ec *ec)
796 {
797         acpi_disable_gpe(NULL, ec->gpe);
798         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
799                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
800                 pr_err(PREFIX "failed to remove space handler\n");
801         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
802                                 &acpi_ec_gpe_handler)))
803                 pr_err(PREFIX "failed to remove gpe handler\n");
804         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
805 }
806
807 static int acpi_ec_add(struct acpi_device *device)
808 {
809         struct acpi_ec *ec = NULL;
810         int ret;
811
812         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
813         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
814
815         /* Check for boot EC */
816         if (boot_ec &&
817             (boot_ec->handle == device->handle ||
818              boot_ec->handle == ACPI_ROOT_OBJECT)) {
819                 ec = boot_ec;
820                 boot_ec = NULL;
821         } else {
822                 ec = make_acpi_ec();
823                 if (!ec)
824                         return -ENOMEM;
825         }
826         if (ec_parse_device(device->handle, 0, ec, NULL) !=
827                 AE_CTRL_TERMINATE) {
828                         kfree(ec);
829                         return -EINVAL;
830         }
831
832         /* Find and register all query methods */
833         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
834                             acpi_ec_register_query_methods, NULL, ec, NULL);
835
836         if (!first_ec)
837                 first_ec = ec;
838         device->driver_data = ec;
839
840         ret = !!request_region(ec->data_addr, 1, "EC data");
841         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
842         ret = !!request_region(ec->command_addr, 1, "EC cmd");
843         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
844
845         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
846                           ec->gpe, ec->command_addr, ec->data_addr);
847
848         ret = ec_install_handlers(ec);
849
850         /* EC is fully operational, allow queries */
851         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
852         return ret;
853 }
854
855 static int acpi_ec_remove(struct acpi_device *device)
856 {
857         struct acpi_ec *ec;
858         struct acpi_ec_query_handler *handler, *tmp;
859
860         if (!device)
861                 return -EINVAL;
862
863         ec = acpi_driver_data(device);
864         ec_remove_handlers(ec);
865         mutex_lock(&ec->mutex);
866         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
867                 list_del(&handler->node);
868                 kfree(handler);
869         }
870         mutex_unlock(&ec->mutex);
871         release_region(ec->data_addr, 1);
872         release_region(ec->command_addr, 1);
873         device->driver_data = NULL;
874         if (ec == first_ec)
875                 first_ec = NULL;
876         kfree(ec);
877         return 0;
878 }
879
880 static acpi_status
881 ec_parse_io_ports(struct acpi_resource *resource, void *context)
882 {
883         struct acpi_ec *ec = context;
884
885         if (resource->type != ACPI_RESOURCE_TYPE_IO)
886                 return AE_OK;
887
888         /*
889          * The first address region returned is the data port, and
890          * the second address region returned is the status/command
891          * port.
892          */
893         if (ec->data_addr == 0)
894                 ec->data_addr = resource->data.io.minimum;
895         else if (ec->command_addr == 0)
896                 ec->command_addr = resource->data.io.minimum;
897         else
898                 return AE_CTRL_TERMINATE;
899
900         return AE_OK;
901 }
902
903 int __init acpi_boot_ec_enable(void)
904 {
905         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
906                 return 0;
907         if (!ec_install_handlers(boot_ec)) {
908                 first_ec = boot_ec;
909                 return 0;
910         }
911         return -EFAULT;
912 }
913
914 static const struct acpi_device_id ec_device_ids[] = {
915         {"PNP0C09", 0},
916         {"", 0},
917 };
918
919 /* Some BIOS do not survive early DSDT scan, skip it */
920 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
921 {
922         EC_FLAGS_SKIP_DSDT_SCAN = 1;
923         return 0;
924 }
925
926 /* ASUStek often supplies us with broken ECDT, validate it */
927 static int ec_validate_ecdt(const struct dmi_system_id *id)
928 {
929         EC_FLAGS_VALIDATE_ECDT = 1;
930         return 0;
931 }
932
933 /* MSI EC needs special treatment, enable it */
934 static int ec_flag_msi(const struct dmi_system_id *id)
935 {
936         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
937         EC_FLAGS_MSI = 1;
938         EC_FLAGS_VALIDATE_ECDT = 1;
939         return 0;
940 }
941
942 /*
943  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
944  * the GPE storm threshold back to 20
945  */
946 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
947 {
948         pr_debug("Setting the EC GPE storm threshold to 20\n");
949         ec_storm_threshold  = 20;
950         return 0;
951 }
952
953 static struct dmi_system_id __initdata ec_dmi_table[] = {
954         {
955         ec_skip_dsdt_scan, "Compal JFL92", {
956         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
957         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
958         {
959         ec_flag_msi, "MSI hardware", {
960         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
961         {
962         ec_flag_msi, "MSI hardware", {
963         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
964         {
965         ec_flag_msi, "MSI hardware", {
966         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
967         {
968         ec_flag_msi, "MSI hardware", {
969         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
970         {
971         ec_flag_msi, "Quanta hardware", {
972         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
973         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
974         {
975         ec_flag_msi, "Quanta hardware", {
976         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
977         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
978         {
979         ec_validate_ecdt, "ASUS hardware", {
980         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
981         {
982         ec_validate_ecdt, "ASUS hardware", {
983         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
984         {
985         ec_enlarge_storm_threshold, "CLEVO hardware", {
986         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
987         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
988         {},
989 };
990
991 int __init acpi_ec_ecdt_probe(void)
992 {
993         acpi_status status;
994         struct acpi_ec *saved_ec = NULL;
995         struct acpi_table_ecdt *ecdt_ptr;
996
997         boot_ec = make_acpi_ec();
998         if (!boot_ec)
999                 return -ENOMEM;
1000         /*
1001          * Generate a boot ec context
1002          */
1003         dmi_check_system(ec_dmi_table);
1004         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1005                                 (struct acpi_table_header **)&ecdt_ptr);
1006         if (ACPI_SUCCESS(status)) {
1007                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1008                 boot_ec->command_addr = ecdt_ptr->control.address;
1009                 boot_ec->data_addr = ecdt_ptr->data.address;
1010                 boot_ec->gpe = ecdt_ptr->gpe;
1011                 boot_ec->handle = ACPI_ROOT_OBJECT;
1012                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1013                 /* Don't trust ECDT, which comes from ASUSTek */
1014                 if (!EC_FLAGS_VALIDATE_ECDT)
1015                         goto install;
1016                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1017                 if (!saved_ec)
1018                         return -ENOMEM;
1019         /* fall through */
1020         }
1021
1022         if (EC_FLAGS_SKIP_DSDT_SCAN)
1023                 return -ENODEV;
1024
1025         /* This workaround is needed only on some broken machines,
1026          * which require early EC, but fail to provide ECDT */
1027         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1028         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1029                                         boot_ec, NULL);
1030         /* Check that acpi_get_devices actually find something */
1031         if (ACPI_FAILURE(status) || !boot_ec->handle)
1032                 goto error;
1033         if (saved_ec) {
1034                 /* try to find good ECDT from ASUSTek */
1035                 if (saved_ec->command_addr != boot_ec->command_addr ||
1036                     saved_ec->data_addr != boot_ec->data_addr ||
1037                     saved_ec->gpe != boot_ec->gpe ||
1038                     saved_ec->handle != boot_ec->handle)
1039                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1040                         "ECDT tables, which are very hard to workaround. "
1041                         "Trying to use DSDT EC info instead. Please send "
1042                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1043                 kfree(saved_ec);
1044                 saved_ec = NULL;
1045         } else {
1046                 /* We really need to limit this workaround, the only ASUS,
1047                 * which needs it, has fake EC._INI method, so use it as flag.
1048                 * Keep boot_ec struct as it will be needed soon.
1049                 */
1050                 acpi_handle dummy;
1051                 if (!dmi_name_in_vendors("ASUS") ||
1052                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1053                                                         &dummy)))
1054                         return -ENODEV;
1055         }
1056 install:
1057         if (!ec_install_handlers(boot_ec)) {
1058                 first_ec = boot_ec;
1059                 return 0;
1060         }
1061 error:
1062         kfree(boot_ec);
1063         boot_ec = NULL;
1064         return -ENODEV;
1065 }
1066
1067 static struct acpi_driver acpi_ec_driver = {
1068         .name = "ec",
1069         .class = ACPI_EC_CLASS,
1070         .ids = ec_device_ids,
1071         .ops = {
1072                 .add = acpi_ec_add,
1073                 .remove = acpi_ec_remove,
1074                 },
1075 };
1076
1077 int __init acpi_ec_init(void)
1078 {
1079         int result = 0;
1080
1081         /* Now register the driver for the EC */
1082         result = acpi_bus_register_driver(&acpi_ec_driver);
1083         if (result < 0)
1084                 return -ENODEV;
1085
1086         return result;
1087 }
1088
1089 /* EC driver currently not unloadable */
1090 #if 0
1091 static void __exit acpi_ec_exit(void)
1092 {
1093
1094         acpi_bus_unregister_driver(&acpi_ec_driver);
1095         return;
1096 }
1097 #endif  /* 0 */