ACPI / EC: Restart transaction even when the IBF flag set
[linux-3.10.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->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 = 5; /* 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                 pr_debug(PREFIX "controller reset, restart transaction\n");
245                 spin_lock_irqsave(&ec->lock, flags);
246                 start_transaction(ec);
247                 spin_unlock_irqrestore(&ec->lock, flags);
248         }
249         return -ETIME;
250 }
251
252 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
253                                         struct transaction *t)
254 {
255         unsigned long tmp;
256         int ret = 0;
257         if (EC_FLAGS_MSI)
258                 udelay(ACPI_EC_MSI_UDELAY);
259         /* start transaction */
260         spin_lock_irqsave(&ec->lock, tmp);
261         /* following two actions should be kept atomic */
262         ec->curr = t;
263         start_transaction(ec);
264         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
265                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
266         spin_unlock_irqrestore(&ec->lock, tmp);
267         ret = ec_poll(ec);
268         spin_lock_irqsave(&ec->lock, tmp);
269         ec->curr = NULL;
270         spin_unlock_irqrestore(&ec->lock, tmp);
271         return ret;
272 }
273
274 static int ec_check_ibf0(struct acpi_ec *ec)
275 {
276         u8 status = acpi_ec_read_status(ec);
277         return (status & ACPI_EC_FLAG_IBF) == 0;
278 }
279
280 static int ec_wait_ibf0(struct acpi_ec *ec)
281 {
282         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
283         /* interrupt wait manually if GPE mode is not active */
284         while (time_before(jiffies, delay))
285                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
286                                         msecs_to_jiffies(1)))
287                         return 0;
288         return -ETIME;
289 }
290
291 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
292 {
293         int status;
294         u32 glk;
295         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
296                 return -EINVAL;
297         if (t->rdata)
298                 memset(t->rdata, 0, t->rlen);
299         mutex_lock(&ec->mutex);
300         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
301                 status = -EINVAL;
302                 goto unlock;
303         }
304         if (ec->global_lock) {
305                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
306                 if (ACPI_FAILURE(status)) {
307                         status = -ENODEV;
308                         goto unlock;
309                 }
310         }
311         if (ec_wait_ibf0(ec)) {
312                 pr_err(PREFIX "input buffer is not empty, "
313                                 "aborting transaction\n");
314                 status = -ETIME;
315                 goto end;
316         }
317         pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
318                         t->command, t->wdata ? t->wdata[0] : 0);
319         /* disable GPE during transaction if storm is detected */
320         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
321                 /* It has to be disabled, so that it doesn't trigger. */
322                 acpi_disable_gpe(NULL, ec->gpe);
323         }
324
325         status = acpi_ec_transaction_unlocked(ec, t);
326
327         /* check if we received SCI during transaction */
328         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
329         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
330                 msleep(1);
331                 /* It is safe to enable the GPE outside of the transaction. */
332                 acpi_enable_gpe(NULL, ec->gpe);
333         } else if (t->irq_count > ec_storm_threshold) {
334                 pr_info(PREFIX "GPE storm detected(%d GPEs), "
335                         "transactions will use polling mode\n",
336                         t->irq_count);
337                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
338         }
339         pr_debug(PREFIX "transaction end\n");
340 end:
341         if (ec->global_lock)
342                 acpi_release_global_lock(glk);
343 unlock:
344         mutex_unlock(&ec->mutex);
345         return status;
346 }
347
348 static int acpi_ec_burst_enable(struct acpi_ec *ec)
349 {
350         u8 d;
351         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
352                                 .wdata = NULL, .rdata = &d,
353                                 .wlen = 0, .rlen = 1};
354
355         return acpi_ec_transaction(ec, &t);
356 }
357
358 static int acpi_ec_burst_disable(struct acpi_ec *ec)
359 {
360         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
361                                 .wdata = NULL, .rdata = NULL,
362                                 .wlen = 0, .rlen = 0};
363
364         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
365                                 acpi_ec_transaction(ec, &t) : 0;
366 }
367
368 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
369 {
370         int result;
371         u8 d;
372         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
373                                 .wdata = &address, .rdata = &d,
374                                 .wlen = 1, .rlen = 1};
375
376         result = acpi_ec_transaction(ec, &t);
377         *data = d;
378         return result;
379 }
380
381 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
382 {
383         u8 wdata[2] = { address, data };
384         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
385                                 .wdata = wdata, .rdata = NULL,
386                                 .wlen = 2, .rlen = 0};
387
388         return acpi_ec_transaction(ec, &t);
389 }
390
391 /*
392  * Externally callable EC access functions. For now, assume 1 EC only
393  */
394 int ec_burst_enable(void)
395 {
396         if (!first_ec)
397                 return -ENODEV;
398         return acpi_ec_burst_enable(first_ec);
399 }
400
401 EXPORT_SYMBOL(ec_burst_enable);
402
403 int ec_burst_disable(void)
404 {
405         if (!first_ec)
406                 return -ENODEV;
407         return acpi_ec_burst_disable(first_ec);
408 }
409
410 EXPORT_SYMBOL(ec_burst_disable);
411
412 int ec_read(u8 addr, u8 *val)
413 {
414         int err;
415         u8 temp_data;
416
417         if (!first_ec)
418                 return -ENODEV;
419
420         err = acpi_ec_read(first_ec, addr, &temp_data);
421
422         if (!err) {
423                 *val = temp_data;
424                 return 0;
425         } else
426                 return err;
427 }
428
429 EXPORT_SYMBOL(ec_read);
430
431 int ec_write(u8 addr, u8 val)
432 {
433         int err;
434
435         if (!first_ec)
436                 return -ENODEV;
437
438         err = acpi_ec_write(first_ec, addr, val);
439
440         return err;
441 }
442
443 EXPORT_SYMBOL(ec_write);
444
445 int ec_transaction(u8 command,
446                    const u8 * wdata, unsigned wdata_len,
447                    u8 * rdata, unsigned rdata_len)
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 /* Get the handle to the EC device */
461 acpi_handle ec_get_handle(void)
462 {
463         if (!first_ec)
464                 return NULL;
465         return first_ec->handle;
466 }
467
468 EXPORT_SYMBOL(ec_get_handle);
469
470 void acpi_ec_block_transactions(void)
471 {
472         struct acpi_ec *ec = first_ec;
473
474         if (!ec)
475                 return;
476
477         mutex_lock(&ec->mutex);
478         /* Prevent transactions from being carried out */
479         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
480         mutex_unlock(&ec->mutex);
481 }
482
483 void acpi_ec_unblock_transactions(void)
484 {
485         struct acpi_ec *ec = first_ec;
486
487         if (!ec)
488                 return;
489
490         mutex_lock(&ec->mutex);
491         /* Allow transactions to be carried out again */
492         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
493         mutex_unlock(&ec->mutex);
494 }
495
496 void acpi_ec_unblock_transactions_early(void)
497 {
498         /*
499          * Allow transactions to happen again (this function is called from
500          * atomic context during wakeup, so we don't need to acquire the mutex).
501          */
502         if (first_ec)
503                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
504 }
505
506 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
507 {
508         int result;
509         u8 d;
510         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
511                                 .wdata = NULL, .rdata = &d,
512                                 .wlen = 0, .rlen = 1};
513         if (!ec || !data)
514                 return -EINVAL;
515         /*
516          * Query the EC to find out which _Qxx method we need to evaluate.
517          * Note that successful completion of the query causes the ACPI_EC_SCI
518          * bit to be cleared (and thus clearing the interrupt source).
519          */
520         result = acpi_ec_transaction_unlocked(ec, &t);
521         if (result)
522                 return result;
523         if (!d)
524                 return -ENODATA;
525         *data = d;
526         return 0;
527 }
528
529 /* --------------------------------------------------------------------------
530                                 Event Management
531    -------------------------------------------------------------------------- */
532 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
533                               acpi_handle handle, acpi_ec_query_func func,
534                               void *data)
535 {
536         struct acpi_ec_query_handler *handler =
537             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
538         if (!handler)
539                 return -ENOMEM;
540
541         handler->query_bit = query_bit;
542         handler->handle = handle;
543         handler->func = func;
544         handler->data = data;
545         mutex_lock(&ec->mutex);
546         list_add(&handler->node, &ec->list);
547         mutex_unlock(&ec->mutex);
548         return 0;
549 }
550
551 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
552
553 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
554 {
555         struct acpi_ec_query_handler *handler, *tmp;
556         mutex_lock(&ec->mutex);
557         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
558                 if (query_bit == handler->query_bit) {
559                         list_del(&handler->node);
560                         kfree(handler);
561                 }
562         }
563         mutex_unlock(&ec->mutex);
564 }
565
566 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
567
568 static void acpi_ec_run(void *cxt)
569 {
570         struct acpi_ec_query_handler *handler = cxt;
571         if (!handler)
572                 return;
573         pr_debug(PREFIX "start query execution\n");
574         if (handler->func)
575                 handler->func(handler->data);
576         else if (handler->handle)
577                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
578         pr_debug(PREFIX "stop query execution\n");
579         kfree(handler);
580 }
581
582 static int acpi_ec_sync_query(struct acpi_ec *ec)
583 {
584         u8 value = 0;
585         int status;
586         struct acpi_ec_query_handler *handler, *copy;
587         if ((status = acpi_ec_query_unlocked(ec, &value)))
588                 return status;
589         list_for_each_entry(handler, &ec->list, node) {
590                 if (value == handler->query_bit) {
591                         /* have custom handler for this bit */
592                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
593                         if (!copy)
594                                 return -ENOMEM;
595                         memcpy(copy, handler, sizeof(*copy));
596                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
597                         return acpi_os_execute((copy->func) ?
598                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
599                                 acpi_ec_run, copy);
600                 }
601         }
602         return 0;
603 }
604
605 static void acpi_ec_gpe_query(void *ec_cxt)
606 {
607         struct acpi_ec *ec = ec_cxt;
608         if (!ec)
609                 return;
610         mutex_lock(&ec->mutex);
611         acpi_ec_sync_query(ec);
612         mutex_unlock(&ec->mutex);
613 }
614
615 static int ec_check_sci(struct acpi_ec *ec, u8 state)
616 {
617         if (state & ACPI_EC_FLAG_SCI) {
618                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
619                         pr_debug(PREFIX "push gpe query to the queue\n");
620                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
621                                 acpi_ec_gpe_query, ec);
622                 }
623         }
624         return 0;
625 }
626
627 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
628         u32 gpe_number, void *data)
629 {
630         struct acpi_ec *ec = data;
631         u8 status = acpi_ec_read_status(ec);
632
633         pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status);
634
635         advance_transaction(ec, status);
636         if (ec_transaction_done(ec) &&
637             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
638                 wake_up(&ec->wait);
639                 ec_check_sci(ec, acpi_ec_read_status(ec));
640         }
641         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
642 }
643
644 /* --------------------------------------------------------------------------
645                              Address Space Management
646    -------------------------------------------------------------------------- */
647
648 static acpi_status
649 acpi_ec_space_handler(u32 function, acpi_physical_address address,
650                       u32 bits, u64 *value64,
651                       void *handler_context, void *region_context)
652 {
653         struct acpi_ec *ec = handler_context;
654         int result = 0, i, bytes = bits / 8;
655         u8 *value = (u8 *)value64;
656
657         if ((address > 0xFF) || !value || !handler_context)
658                 return AE_BAD_PARAMETER;
659
660         if (function != ACPI_READ && function != ACPI_WRITE)
661                 return AE_BAD_PARAMETER;
662
663         if (EC_FLAGS_MSI || bits > 8)
664                 acpi_ec_burst_enable(ec);
665
666         for (i = 0; i < bytes; ++i, ++address, ++value)
667                 result = (function == ACPI_READ) ?
668                         acpi_ec_read(ec, address, value) :
669                         acpi_ec_write(ec, address, *value);
670
671         if (EC_FLAGS_MSI || bits > 8)
672                 acpi_ec_burst_disable(ec);
673
674         switch (result) {
675         case -EINVAL:
676                 return AE_BAD_PARAMETER;
677                 break;
678         case -ENODEV:
679                 return AE_NOT_FOUND;
680                 break;
681         case -ETIME:
682                 return AE_TIME;
683                 break;
684         default:
685                 return AE_OK;
686         }
687 }
688
689 /* --------------------------------------------------------------------------
690                                Driver Interface
691    -------------------------------------------------------------------------- */
692 static acpi_status
693 ec_parse_io_ports(struct acpi_resource *resource, void *context);
694
695 static struct acpi_ec *make_acpi_ec(void)
696 {
697         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
698         if (!ec)
699                 return NULL;
700         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
701         mutex_init(&ec->mutex);
702         init_waitqueue_head(&ec->wait);
703         INIT_LIST_HEAD(&ec->list);
704         spin_lock_init(&ec->lock);
705         return ec;
706 }
707
708 static acpi_status
709 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
710                                void *context, void **return_value)
711 {
712         char node_name[5];
713         struct acpi_buffer buffer = { sizeof(node_name), node_name };
714         struct acpi_ec *ec = context;
715         int value = 0;
716         acpi_status status;
717
718         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
719
720         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
721                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
722         }
723         return AE_OK;
724 }
725
726 static acpi_status
727 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
728 {
729         acpi_status status;
730         unsigned long long tmp = 0;
731
732         struct acpi_ec *ec = context;
733
734         /* clear addr values, ec_parse_io_ports depend on it */
735         ec->command_addr = ec->data_addr = 0;
736
737         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
738                                      ec_parse_io_ports, ec);
739         if (ACPI_FAILURE(status))
740                 return status;
741
742         /* Get GPE bit assignment (EC events). */
743         /* TODO: Add support for _GPE returning a package */
744         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
745         if (ACPI_FAILURE(status))
746                 return status;
747         ec->gpe = tmp;
748         /* Use the global lock for all EC transactions? */
749         tmp = 0;
750         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
751         ec->global_lock = tmp;
752         ec->handle = handle;
753         return AE_CTRL_TERMINATE;
754 }
755
756 static int ec_install_handlers(struct acpi_ec *ec)
757 {
758         acpi_status status;
759         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
760                 return 0;
761         status = acpi_install_gpe_handler(NULL, ec->gpe,
762                                   ACPI_GPE_EDGE_TRIGGERED,
763                                   &acpi_ec_gpe_handler, ec);
764         if (ACPI_FAILURE(status))
765                 return -ENODEV;
766
767         acpi_enable_gpe(NULL, ec->gpe);
768         status = acpi_install_address_space_handler(ec->handle,
769                                                     ACPI_ADR_SPACE_EC,
770                                                     &acpi_ec_space_handler,
771                                                     NULL, ec);
772         if (ACPI_FAILURE(status)) {
773                 if (status == AE_NOT_FOUND) {
774                         /*
775                          * Maybe OS fails in evaluating the _REG object.
776                          * The AE_NOT_FOUND error will be ignored and OS
777                          * continue to initialize EC.
778                          */
779                         printk(KERN_ERR "Fail in evaluating the _REG object"
780                                 " of EC device. Broken bios is suspected.\n");
781                 } else {
782                         acpi_remove_gpe_handler(NULL, ec->gpe,
783                                 &acpi_ec_gpe_handler);
784                         acpi_disable_gpe(NULL, ec->gpe);
785                         return -ENODEV;
786                 }
787         }
788
789         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
790         return 0;
791 }
792
793 static void ec_remove_handlers(struct acpi_ec *ec)
794 {
795         acpi_disable_gpe(NULL, ec->gpe);
796         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
797                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
798                 pr_err(PREFIX "failed to remove space handler\n");
799         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
800                                 &acpi_ec_gpe_handler)))
801                 pr_err(PREFIX "failed to remove gpe handler\n");
802         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
803 }
804
805 static int acpi_ec_add(struct acpi_device *device)
806 {
807         struct acpi_ec *ec = NULL;
808         int ret;
809
810         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
811         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
812
813         /* Check for boot EC */
814         if (boot_ec &&
815             (boot_ec->handle == device->handle ||
816              boot_ec->handle == ACPI_ROOT_OBJECT)) {
817                 ec = boot_ec;
818                 boot_ec = NULL;
819         } else {
820                 ec = make_acpi_ec();
821                 if (!ec)
822                         return -ENOMEM;
823         }
824         if (ec_parse_device(device->handle, 0, ec, NULL) !=
825                 AE_CTRL_TERMINATE) {
826                         kfree(ec);
827                         return -EINVAL;
828         }
829
830         /* Find and register all query methods */
831         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
832                             acpi_ec_register_query_methods, NULL, ec, NULL);
833
834         if (!first_ec)
835                 first_ec = ec;
836         device->driver_data = ec;
837
838         ret = !!request_region(ec->data_addr, 1, "EC data");
839         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
840         ret = !!request_region(ec->command_addr, 1, "EC cmd");
841         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
842
843         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
844                           ec->gpe, ec->command_addr, ec->data_addr);
845
846         ret = ec_install_handlers(ec);
847
848         /* EC is fully operational, allow queries */
849         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
850         return ret;
851 }
852
853 static int acpi_ec_remove(struct acpi_device *device)
854 {
855         struct acpi_ec *ec;
856         struct acpi_ec_query_handler *handler, *tmp;
857
858         if (!device)
859                 return -EINVAL;
860
861         ec = acpi_driver_data(device);
862         ec_remove_handlers(ec);
863         mutex_lock(&ec->mutex);
864         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
865                 list_del(&handler->node);
866                 kfree(handler);
867         }
868         mutex_unlock(&ec->mutex);
869         release_region(ec->data_addr, 1);
870         release_region(ec->command_addr, 1);
871         device->driver_data = NULL;
872         if (ec == first_ec)
873                 first_ec = NULL;
874         kfree(ec);
875         return 0;
876 }
877
878 static acpi_status
879 ec_parse_io_ports(struct acpi_resource *resource, void *context)
880 {
881         struct acpi_ec *ec = context;
882
883         if (resource->type != ACPI_RESOURCE_TYPE_IO)
884                 return AE_OK;
885
886         /*
887          * The first address region returned is the data port, and
888          * the second address region returned is the status/command
889          * port.
890          */
891         if (ec->data_addr == 0)
892                 ec->data_addr = resource->data.io.minimum;
893         else if (ec->command_addr == 0)
894                 ec->command_addr = resource->data.io.minimum;
895         else
896                 return AE_CTRL_TERMINATE;
897
898         return AE_OK;
899 }
900
901 int __init acpi_boot_ec_enable(void)
902 {
903         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
904                 return 0;
905         if (!ec_install_handlers(boot_ec)) {
906                 first_ec = boot_ec;
907                 return 0;
908         }
909         return -EFAULT;
910 }
911
912 static const struct acpi_device_id ec_device_ids[] = {
913         {"PNP0C09", 0},
914         {"", 0},
915 };
916
917 /* Some BIOS do not survive early DSDT scan, skip it */
918 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
919 {
920         EC_FLAGS_SKIP_DSDT_SCAN = 1;
921         return 0;
922 }
923
924 /* ASUStek often supplies us with broken ECDT, validate it */
925 static int ec_validate_ecdt(const struct dmi_system_id *id)
926 {
927         EC_FLAGS_VALIDATE_ECDT = 1;
928         return 0;
929 }
930
931 /* MSI EC needs special treatment, enable it */
932 static int ec_flag_msi(const struct dmi_system_id *id)
933 {
934         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
935         EC_FLAGS_MSI = 1;
936         EC_FLAGS_VALIDATE_ECDT = 1;
937         return 0;
938 }
939
940 /*
941  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
942  * the GPE storm threshold back to 20
943  */
944 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
945 {
946         pr_debug("Setting the EC GPE storm threshold to 20\n");
947         ec_storm_threshold  = 20;
948         return 0;
949 }
950
951 static struct dmi_system_id __initdata ec_dmi_table[] = {
952         {
953         ec_skip_dsdt_scan, "Compal JFL92", {
954         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
955         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
956         {
957         ec_flag_msi, "MSI hardware", {
958         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
959         {
960         ec_flag_msi, "MSI hardware", {
961         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
962         {
963         ec_flag_msi, "MSI hardware", {
964         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
965         {
966         ec_flag_msi, "MSI hardware", {
967         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
968         {
969         ec_flag_msi, "Quanta hardware", {
970         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
971         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
972         {
973         ec_flag_msi, "Quanta hardware", {
974         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
975         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
976         {
977         ec_validate_ecdt, "ASUS hardware", {
978         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
979         {
980         ec_validate_ecdt, "ASUS hardware", {
981         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
982         {
983         ec_enlarge_storm_threshold, "CLEVO hardware", {
984         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
985         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
986         {},
987 };
988
989 int __init acpi_ec_ecdt_probe(void)
990 {
991         acpi_status status;
992         struct acpi_ec *saved_ec = NULL;
993         struct acpi_table_ecdt *ecdt_ptr;
994
995         boot_ec = make_acpi_ec();
996         if (!boot_ec)
997                 return -ENOMEM;
998         /*
999          * Generate a boot ec context
1000          */
1001         dmi_check_system(ec_dmi_table);
1002         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1003                                 (struct acpi_table_header **)&ecdt_ptr);
1004         if (ACPI_SUCCESS(status)) {
1005                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1006                 boot_ec->command_addr = ecdt_ptr->control.address;
1007                 boot_ec->data_addr = ecdt_ptr->data.address;
1008                 boot_ec->gpe = ecdt_ptr->gpe;
1009                 boot_ec->handle = ACPI_ROOT_OBJECT;
1010                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1011                 /* Don't trust ECDT, which comes from ASUSTek */
1012                 if (!EC_FLAGS_VALIDATE_ECDT)
1013                         goto install;
1014                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1015                 if (!saved_ec)
1016                         return -ENOMEM;
1017         /* fall through */
1018         }
1019
1020         if (EC_FLAGS_SKIP_DSDT_SCAN)
1021                 return -ENODEV;
1022
1023         /* This workaround is needed only on some broken machines,
1024          * which require early EC, but fail to provide ECDT */
1025         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1026         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1027                                         boot_ec, NULL);
1028         /* Check that acpi_get_devices actually find something */
1029         if (ACPI_FAILURE(status) || !boot_ec->handle)
1030                 goto error;
1031         if (saved_ec) {
1032                 /* try to find good ECDT from ASUSTek */
1033                 if (saved_ec->command_addr != boot_ec->command_addr ||
1034                     saved_ec->data_addr != boot_ec->data_addr ||
1035                     saved_ec->gpe != boot_ec->gpe ||
1036                     saved_ec->handle != boot_ec->handle)
1037                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1038                         "ECDT tables, which are very hard to workaround. "
1039                         "Trying to use DSDT EC info instead. Please send "
1040                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1041                 kfree(saved_ec);
1042                 saved_ec = NULL;
1043         } else {
1044                 /* We really need to limit this workaround, the only ASUS,
1045                 * which needs it, has fake EC._INI method, so use it as flag.
1046                 * Keep boot_ec struct as it will be needed soon.
1047                 */
1048                 acpi_handle dummy;
1049                 if (!dmi_name_in_vendors("ASUS") ||
1050                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1051                                                         &dummy)))
1052                         return -ENODEV;
1053         }
1054 install:
1055         if (!ec_install_handlers(boot_ec)) {
1056                 first_ec = boot_ec;
1057                 return 0;
1058         }
1059 error:
1060         kfree(boot_ec);
1061         boot_ec = NULL;
1062         return -ENODEV;
1063 }
1064
1065 static struct acpi_driver acpi_ec_driver = {
1066         .name = "ec",
1067         .class = ACPI_EC_CLASS,
1068         .ids = ec_device_ids,
1069         .ops = {
1070                 .add = acpi_ec_add,
1071                 .remove = acpi_ec_remove,
1072                 },
1073 };
1074
1075 int __init acpi_ec_init(void)
1076 {
1077         int result = 0;
1078
1079         /* Now register the driver for the EC */
1080         result = acpi_bus_register_driver(&acpi_ec_driver);
1081         if (result < 0)
1082                 return -ENODEV;
1083
1084         return result;
1085 }
1086
1087 /* EC driver currently not unloadable */
1088 #if 0
1089 static void __exit acpi_ec_exit(void)
1090 {
1091
1092         acpi_bus_unregister_driver(&acpi_ec_driver);
1093         return;
1094 }
1095 #endif  /* 0 */