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