ACPI: EC: Don't do transaction from GPE handler in poll mode.
[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/proc_fs.h>
38 #include <linux/seq_file.h>
39 #include <linux/interrupt.h>
40 #include <linux/list.h>
41 #include <linux/spinlock.h>
42 #include <asm/io.h>
43 #include <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
45 #include <acpi/actypes.h>
46
47 #define ACPI_EC_CLASS                   "embedded_controller"
48 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
49 #define ACPI_EC_FILE_INFO               "info"
50
51 #undef PREFIX
52 #define PREFIX                          "ACPI: EC: "
53
54 /* EC status register */
55 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
56 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
57 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
58 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
59
60 /* EC commands */
61 enum ec_command {
62         ACPI_EC_COMMAND_READ = 0x80,
63         ACPI_EC_COMMAND_WRITE = 0x81,
64         ACPI_EC_BURST_ENABLE = 0x82,
65         ACPI_EC_BURST_DISABLE = 0x83,
66         ACPI_EC_COMMAND_QUERY = 0x84,
67 };
68
69 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
70 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
71 #define ACPI_EC_UDELAY          100     /* Wait 100us before polling EC again */
72
73 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
74                                            per one transaction */
75
76 enum {
77         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
78         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent
79                                          * for status change */
80         EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
81         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
82         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
83                                          * OpReg are installed */
84 };
85
86 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
87 /* External interfaces use first EC only, so remember */
88 typedef int (*acpi_ec_query_func) (void *data);
89
90 struct acpi_ec_query_handler {
91         struct list_head node;
92         acpi_ec_query_func func;
93         acpi_handle handle;
94         void *data;
95         u8 query_bit;
96 };
97
98 struct transaction {
99         const u8 *wdata;
100         u8 *rdata;
101         unsigned short irq_count;
102         u8 command;
103         u8 wi;
104         u8 ri;
105         u8 wlen;
106         u8 rlen;
107         bool done;
108 };
109
110 static struct acpi_ec {
111         acpi_handle handle;
112         unsigned long gpe;
113         unsigned long command_addr;
114         unsigned long data_addr;
115         unsigned long global_lock;
116         unsigned long flags;
117         struct mutex lock;
118         wait_queue_head_t wait;
119         struct list_head list;
120         struct transaction *curr;
121         spinlock_t curr_lock;
122 } *boot_ec, *first_ec;
123
124 /* 
125  * Some Asus system have exchanged ECDT data/command IO addresses.
126  */
127 static int print_ecdt_error(const struct dmi_system_id *id)
128 {
129         printk(KERN_NOTICE PREFIX "%s detected - "
130                 "ECDT has exchanged control/data I/O address\n",
131                 id->ident);
132         return 0;
133 }
134
135 static struct dmi_system_id __cpuinitdata ec_dmi_table[] = {
136         {
137         print_ecdt_error, "Asus L4R", {
138         DMI_MATCH(DMI_BIOS_VERSION, "1008.006"),
139         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),
140         DMI_MATCH(DMI_BOARD_NAME, "L4R") }, NULL},
141         {
142         print_ecdt_error, "Asus M6R", {
143         DMI_MATCH(DMI_BIOS_VERSION, "0207"),
144         DMI_MATCH(DMI_PRODUCT_NAME, "M6R"),
145         DMI_MATCH(DMI_BOARD_NAME, "M6R") }, NULL},
146         {},
147 };
148
149 /* --------------------------------------------------------------------------
150                              Transaction Management
151    -------------------------------------------------------------------------- */
152
153 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
154 {
155         u8 x = inb(ec->command_addr);
156         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
157         return x;
158 }
159
160 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
161 {
162         u8 x = inb(ec->data_addr);
163         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
164         return x;
165 }
166
167 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
168 {
169         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
170         outb(command, ec->command_addr);
171 }
172
173 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
174 {
175         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
176         outb(data, ec->data_addr);
177 }
178
179 static int ec_transaction_done(struct acpi_ec *ec)
180 {
181         unsigned long flags;
182         int ret = 0;
183         spin_lock_irqsave(&ec->curr_lock, flags);
184         if (!ec->curr || ec->curr->done)
185                 ret = 1;
186         spin_unlock_irqrestore(&ec->curr_lock, flags);
187         return ret;
188 }
189
190 static void start_transaction(struct acpi_ec *ec)
191 {
192         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
193         ec->curr->done = false;
194         acpi_ec_write_cmd(ec, ec->curr->command);
195 }
196
197 static void gpe_transaction(struct acpi_ec *ec, u8 status)
198 {
199         unsigned long flags;
200         spin_lock_irqsave(&ec->curr_lock, flags);
201         if (!ec->curr)
202                 goto unlock;
203         if (ec->curr->wlen > ec->curr->wi) {
204                 if ((status & ACPI_EC_FLAG_IBF) == 0)
205                         acpi_ec_write_data(ec,
206                                 ec->curr->wdata[ec->curr->wi++]);
207                 else
208                         goto err;
209         } else if (ec->curr->rlen > ec->curr->ri) {
210                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
211                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
212                         if (ec->curr->rlen == ec->curr->ri)
213                                 ec->curr->done = true;
214                 } else
215                         goto err;
216         } else if (ec->curr->wlen == ec->curr->wi &&
217                    (status & ACPI_EC_FLAG_IBF) == 0)
218                 ec->curr->done = true;
219         goto unlock;
220 err:
221         /* false interrupt, state didn't change */
222         ++ec->curr->irq_count;
223 unlock:
224         spin_unlock_irqrestore(&ec->curr_lock, flags);
225 }
226
227 static int acpi_ec_wait(struct acpi_ec *ec)
228 {
229         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
230                                msecs_to_jiffies(ACPI_EC_DELAY)))
231                 return 0;
232         /* try restart command if we get any false interrupts */
233         if (ec->curr->irq_count &&
234             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
235                 pr_debug(PREFIX "controller reset, restart transaction\n");
236                 start_transaction(ec);
237                 if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
238                                         msecs_to_jiffies(ACPI_EC_DELAY)))
239                         return 0;
240         }
241         /* missing GPEs, switch back to poll mode */
242         if (printk_ratelimit())
243                 pr_info(PREFIX "missing confirmations, "
244                                 "switch off interrupt mode.\n");
245         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
246         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
247         return 1;
248 }
249
250 static void acpi_ec_gpe_query(void *ec_cxt);
251
252 static int ec_check_sci(struct acpi_ec *ec, u8 state)
253 {
254         if (state & ACPI_EC_FLAG_SCI) {
255                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
256                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
257                                 acpi_ec_gpe_query, ec);
258         }
259         return 0;
260 }
261
262 static int ec_poll(struct acpi_ec *ec)
263 {
264         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
265         udelay(ACPI_EC_UDELAY);
266         while (time_before(jiffies, delay)) {
267                 gpe_transaction(ec, acpi_ec_read_status(ec));
268                 udelay(ACPI_EC_UDELAY);
269                 if (ec_transaction_done(ec))
270                         return 0;
271         }
272         return -ETIME;
273 }
274
275 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
276                                         struct transaction *t,
277                                         int force_poll)
278 {
279         unsigned long tmp;
280         int ret = 0;
281         pr_debug(PREFIX "transaction start\n");
282         /* disable GPE during transaction if storm is detected */
283         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
284                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
285                 acpi_disable_gpe(NULL, ec->gpe);
286         }
287         /* start transaction */
288         spin_lock_irqsave(&ec->curr_lock, tmp);
289         /* following two actions should be kept atomic */
290         ec->curr = t;
291         start_transaction(ec);
292         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
293                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
294         spin_unlock_irqrestore(&ec->curr_lock, tmp);
295         /* if we selected poll mode or failed in GPE-mode do a poll loop */
296         if (force_poll ||
297             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
298             acpi_ec_wait(ec))
299                 ret = ec_poll(ec);
300         pr_debug(PREFIX "transaction end\n");
301         spin_lock_irqsave(&ec->curr_lock, tmp);
302         ec->curr = NULL;
303         spin_unlock_irqrestore(&ec->curr_lock, tmp);
304         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
305                 /* check if we received SCI during transaction */
306                 ec_check_sci(ec, acpi_ec_read_status(ec));
307                 /* it is safe to enable GPE outside of transaction */
308                 acpi_enable_gpe(NULL, ec->gpe);
309         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
310                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
311                 pr_info(PREFIX "GPE storm detected, "
312                         "transactions will use polling mode\n");
313                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
314         }
315         return ret;
316 }
317
318 static int ec_check_ibf0(struct acpi_ec *ec)
319 {
320         u8 status = acpi_ec_read_status(ec);
321         return (status & ACPI_EC_FLAG_IBF) == 0;
322 }
323
324 static int ec_wait_ibf0(struct acpi_ec *ec)
325 {
326         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
327         /* interrupt wait manually if GPE mode is not active */
328         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
329                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
330         while (time_before(jiffies, delay))
331                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
332                         return 0;
333         return -ETIME;
334 }
335
336 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
337                                int force_poll)
338 {
339         int status;
340         u32 glk;
341         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
342                 return -EINVAL;
343         if (t->rdata)
344                 memset(t->rdata, 0, t->rlen);
345         mutex_lock(&ec->lock);
346         if (ec->global_lock) {
347                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
348                 if (ACPI_FAILURE(status)) {
349                         status = -ENODEV;
350                         goto unlock;
351                 }
352         }
353         if (ec_wait_ibf0(ec)) {
354                 pr_err(PREFIX "input buffer is not empty, "
355                                 "aborting transaction\n");
356                 status = -ETIME;
357                 goto end;
358         }
359         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
360 end:
361         if (ec->global_lock)
362                 acpi_release_global_lock(glk);
363 unlock:
364         mutex_unlock(&ec->lock);
365         return status;
366 }
367
368 /*
369  * Note: samsung nv5000 doesn't work with ec burst mode.
370  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
371  */
372 int acpi_ec_burst_enable(struct acpi_ec *ec)
373 {
374         u8 d;
375         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
376                                 .wdata = NULL, .rdata = &d,
377                                 .wlen = 0, .rlen = 1};
378
379         return acpi_ec_transaction(ec, &t, 0);
380 }
381
382 int acpi_ec_burst_disable(struct acpi_ec *ec)
383 {
384         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
385                                 .wdata = NULL, .rdata = NULL,
386                                 .wlen = 0, .rlen = 0};
387
388         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
389                                 acpi_ec_transaction(ec, &t, 0) : 0;
390 }
391
392 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
393 {
394         int result;
395         u8 d;
396         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
397                                 .wdata = &address, .rdata = &d,
398                                 .wlen = 1, .rlen = 1};
399
400         result = acpi_ec_transaction(ec, &t, 0);
401         *data = d;
402         return result;
403 }
404
405 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
406 {
407         u8 wdata[2] = { address, data };
408         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
409                                 .wdata = wdata, .rdata = NULL,
410                                 .wlen = 2, .rlen = 0};
411
412         return acpi_ec_transaction(ec, &t, 0);
413 }
414
415 /*
416  * Externally callable EC access functions. For now, assume 1 EC only
417  */
418 int ec_burst_enable(void)
419 {
420         if (!first_ec)
421                 return -ENODEV;
422         return acpi_ec_burst_enable(first_ec);
423 }
424
425 EXPORT_SYMBOL(ec_burst_enable);
426
427 int ec_burst_disable(void)
428 {
429         if (!first_ec)
430                 return -ENODEV;
431         return acpi_ec_burst_disable(first_ec);
432 }
433
434 EXPORT_SYMBOL(ec_burst_disable);
435
436 int ec_read(u8 addr, u8 * val)
437 {
438         int err;
439         u8 temp_data;
440
441         if (!first_ec)
442                 return -ENODEV;
443
444         err = acpi_ec_read(first_ec, addr, &temp_data);
445
446         if (!err) {
447                 *val = temp_data;
448                 return 0;
449         } else
450                 return err;
451 }
452
453 EXPORT_SYMBOL(ec_read);
454
455 int ec_write(u8 addr, u8 val)
456 {
457         int err;
458
459         if (!first_ec)
460                 return -ENODEV;
461
462         err = acpi_ec_write(first_ec, addr, val);
463
464         return err;
465 }
466
467 EXPORT_SYMBOL(ec_write);
468
469 int ec_transaction(u8 command,
470                    const u8 * wdata, unsigned wdata_len,
471                    u8 * rdata, unsigned rdata_len,
472                    int force_poll)
473 {
474         struct transaction t = {.command = command,
475                                 .wdata = wdata, .rdata = rdata,
476                                 .wlen = wdata_len, .rlen = rdata_len};
477         if (!first_ec)
478                 return -ENODEV;
479
480         return acpi_ec_transaction(first_ec, &t, force_poll);
481 }
482
483 EXPORT_SYMBOL(ec_transaction);
484
485 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
486 {
487         int result;
488         u8 d;
489         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
490                                 .wdata = NULL, .rdata = &d,
491                                 .wlen = 0, .rlen = 1};
492         if (!ec || !data)
493                 return -EINVAL;
494
495         /*
496          * Query the EC to find out which _Qxx method we need to evaluate.
497          * Note that successful completion of the query causes the ACPI_EC_SCI
498          * bit to be cleared (and thus clearing the interrupt source).
499          */
500
501         result = acpi_ec_transaction(ec, &t, 0);
502         if (result)
503                 return result;
504
505         if (!d)
506                 return -ENODATA;
507
508         *data = d;
509         return 0;
510 }
511
512 /* --------------------------------------------------------------------------
513                                 Event Management
514    -------------------------------------------------------------------------- */
515 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
516                               acpi_handle handle, acpi_ec_query_func func,
517                               void *data)
518 {
519         struct acpi_ec_query_handler *handler =
520             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
521         if (!handler)
522                 return -ENOMEM;
523
524         handler->query_bit = query_bit;
525         handler->handle = handle;
526         handler->func = func;
527         handler->data = data;
528         mutex_lock(&ec->lock);
529         list_add(&handler->node, &ec->list);
530         mutex_unlock(&ec->lock);
531         return 0;
532 }
533
534 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
535
536 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
537 {
538         struct acpi_ec_query_handler *handler, *tmp;
539         mutex_lock(&ec->lock);
540         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
541                 if (query_bit == handler->query_bit) {
542                         list_del(&handler->node);
543                         kfree(handler);
544                 }
545         }
546         mutex_unlock(&ec->lock);
547 }
548
549 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
550
551 static void acpi_ec_gpe_query(void *ec_cxt)
552 {
553         struct acpi_ec *ec = ec_cxt;
554         u8 value = 0;
555         struct acpi_ec_query_handler *handler, copy;
556
557         if (!ec || acpi_ec_query(ec, &value))
558                 return;
559         mutex_lock(&ec->lock);
560         list_for_each_entry(handler, &ec->list, node) {
561                 if (value == handler->query_bit) {
562                         /* have custom handler for this bit */
563                         memcpy(&copy, handler, sizeof(copy));
564                         mutex_unlock(&ec->lock);
565                         if (copy.func) {
566                                 copy.func(copy.data);
567                         } else if (copy.handle) {
568                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
569                         }
570                         return;
571                 }
572         }
573         mutex_unlock(&ec->lock);
574 }
575
576 static u32 acpi_ec_gpe_handler(void *data)
577 {
578         struct acpi_ec *ec = data;
579         u8 status;
580
581         pr_debug(PREFIX "~~~> interrupt\n");
582         status = acpi_ec_read_status(ec);
583
584         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
585                 gpe_transaction(ec, status);
586                 if (ec_transaction_done(ec) &&
587                     (status & ACPI_EC_FLAG_IBF) == 0)
588                         wake_up(&ec->wait);
589         }
590
591         ec_check_sci(ec, status);
592         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
593             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
594                 /* this is non-query, must be confirmation */
595                 if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
596                         if (printk_ratelimit())
597                                 pr_info(PREFIX "non-query interrupt received,"
598                                         " switching to interrupt mode\n");
599                 } else {
600                         /* hush, STORM switches the mode every transaction */
601                         pr_debug(PREFIX "non-query interrupt received,"
602                                 " switching to interrupt mode\n");
603                 }
604                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
605         }
606         return ACPI_INTERRUPT_HANDLED;
607 }
608
609 /* --------------------------------------------------------------------------
610                              Address Space Management
611    -------------------------------------------------------------------------- */
612
613 static acpi_status
614 acpi_ec_space_handler(u32 function, acpi_physical_address address,
615                       u32 bits, acpi_integer *value,
616                       void *handler_context, void *region_context)
617 {
618         struct acpi_ec *ec = handler_context;
619         int result = 0, i;
620         u8 temp = 0;
621
622         if ((address > 0xFF) || !value || !handler_context)
623                 return AE_BAD_PARAMETER;
624
625         if (function != ACPI_READ && function != ACPI_WRITE)
626                 return AE_BAD_PARAMETER;
627
628         if (bits != 8 && acpi_strict)
629                 return AE_BAD_PARAMETER;
630
631         acpi_ec_burst_enable(ec);
632
633         if (function == ACPI_READ) {
634                 result = acpi_ec_read(ec, address, &temp);
635                 *value = temp;
636         } else {
637                 temp = 0xff & (*value);
638                 result = acpi_ec_write(ec, address, temp);
639         }
640
641         for (i = 8; unlikely(bits - i > 0); i += 8) {
642                 ++address;
643                 if (function == ACPI_READ) {
644                         result = acpi_ec_read(ec, address, &temp);
645                         (*value) |= ((acpi_integer)temp) << i;
646                 } else {
647                         temp = 0xff & ((*value) >> i);
648                         result = acpi_ec_write(ec, address, temp);
649                 }
650         }
651
652         acpi_ec_burst_disable(ec);
653
654         switch (result) {
655         case -EINVAL:
656                 return AE_BAD_PARAMETER;
657                 break;
658         case -ENODEV:
659                 return AE_NOT_FOUND;
660                 break;
661         case -ETIME:
662                 return AE_TIME;
663                 break;
664         default:
665                 return AE_OK;
666         }
667 }
668
669 /* --------------------------------------------------------------------------
670                               FS Interface (/proc)
671    -------------------------------------------------------------------------- */
672
673 static struct proc_dir_entry *acpi_ec_dir;
674
675 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
676 {
677         struct acpi_ec *ec = seq->private;
678
679         if (!ec)
680                 goto end;
681
682         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
683         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
684                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
685         seq_printf(seq, "use global lock:\t%s\n",
686                    ec->global_lock ? "yes" : "no");
687       end:
688         return 0;
689 }
690
691 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
692 {
693         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
694 }
695
696 static struct file_operations acpi_ec_info_ops = {
697         .open = acpi_ec_info_open_fs,
698         .read = seq_read,
699         .llseek = seq_lseek,
700         .release = single_release,
701         .owner = THIS_MODULE,
702 };
703
704 static int acpi_ec_add_fs(struct acpi_device *device)
705 {
706         struct proc_dir_entry *entry = NULL;
707
708         if (!acpi_device_dir(device)) {
709                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
710                                                      acpi_ec_dir);
711                 if (!acpi_device_dir(device))
712                         return -ENODEV;
713         }
714
715         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
716                                  acpi_device_dir(device),
717                                  &acpi_ec_info_ops, acpi_driver_data(device));
718         if (!entry)
719                 return -ENODEV;
720         return 0;
721 }
722
723 static int acpi_ec_remove_fs(struct acpi_device *device)
724 {
725
726         if (acpi_device_dir(device)) {
727                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
728                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
729                 acpi_device_dir(device) = NULL;
730         }
731
732         return 0;
733 }
734
735 /* --------------------------------------------------------------------------
736                                Driver Interface
737    -------------------------------------------------------------------------- */
738 static acpi_status
739 ec_parse_io_ports(struct acpi_resource *resource, void *context);
740
741 static struct acpi_ec *make_acpi_ec(void)
742 {
743         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
744         if (!ec)
745                 return NULL;
746         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
747         mutex_init(&ec->lock);
748         init_waitqueue_head(&ec->wait);
749         INIT_LIST_HEAD(&ec->list);
750         spin_lock_init(&ec->curr_lock);
751         return ec;
752 }
753
754 static acpi_status
755 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
756                                void *context, void **return_value)
757 {
758         struct acpi_namespace_node *node = handle;
759         struct acpi_ec *ec = context;
760         int value = 0;
761         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
762                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
763         }
764         return AE_OK;
765 }
766
767 static acpi_status
768 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
769 {
770         acpi_status status;
771         unsigned long long tmp;
772
773         struct acpi_ec *ec = context;
774         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
775                                      ec_parse_io_ports, ec);
776         if (ACPI_FAILURE(status))
777                 return status;
778
779         /* Get GPE bit assignment (EC events). */
780         /* TODO: Add support for _GPE returning a package */
781         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
782         if (ACPI_FAILURE(status))
783                 return status;
784         ec->gpe = tmp;
785         /* Use the global lock for all EC transactions? */
786         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
787         ec->global_lock = tmp;
788         ec->handle = handle;
789         return AE_CTRL_TERMINATE;
790 }
791
792 static void ec_remove_handlers(struct acpi_ec *ec)
793 {
794         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
795                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
796                 pr_err(PREFIX "failed to remove space handler\n");
797         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
798                                 &acpi_ec_gpe_handler)))
799                 pr_err(PREFIX "failed to remove gpe handler\n");
800         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
801 }
802
803 static int acpi_ec_add(struct acpi_device *device)
804 {
805         struct acpi_ec *ec = NULL;
806
807         if (!device)
808                 return -EINVAL;
809         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
810         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
811
812         /* Check for boot EC */
813         if (boot_ec &&
814             (boot_ec->handle == device->handle ||
815              boot_ec->handle == ACPI_ROOT_OBJECT)) {
816                 ec = boot_ec;
817                 boot_ec = NULL;
818         } else {
819                 ec = make_acpi_ec();
820                 if (!ec)
821                         return -ENOMEM;
822                 if (ec_parse_device(device->handle, 0, ec, NULL) !=
823                     AE_CTRL_TERMINATE) {
824                         kfree(ec);
825                         return -EINVAL;
826                 }
827         }
828
829         ec->handle = device->handle;
830
831         /* Find and register all query methods */
832         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
833                             acpi_ec_register_query_methods, ec, NULL);
834
835         if (!first_ec)
836                 first_ec = ec;
837         device->driver_data = ec;
838         acpi_ec_add_fs(device);
839         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
840                           ec->gpe, ec->command_addr, ec->data_addr);
841         pr_info(PREFIX "driver started in %s mode\n",
842                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
843         return 0;
844 }
845
846 static int acpi_ec_remove(struct acpi_device *device, int type)
847 {
848         struct acpi_ec *ec;
849         struct acpi_ec_query_handler *handler, *tmp;
850
851         if (!device)
852                 return -EINVAL;
853
854         ec = acpi_driver_data(device);
855         mutex_lock(&ec->lock);
856         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
857                 list_del(&handler->node);
858                 kfree(handler);
859         }
860         mutex_unlock(&ec->lock);
861         acpi_ec_remove_fs(device);
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 static int ec_install_handlers(struct acpi_ec *ec)
893 {
894         acpi_status status;
895         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
896                 return 0;
897         status = acpi_install_gpe_handler(NULL, ec->gpe,
898                                   ACPI_GPE_EDGE_TRIGGERED,
899                                   &acpi_ec_gpe_handler, ec);
900         if (ACPI_FAILURE(status))
901                 return -ENODEV;
902         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
903         acpi_enable_gpe(NULL, ec->gpe);
904         status = acpi_install_address_space_handler(ec->handle,
905                                                     ACPI_ADR_SPACE_EC,
906                                                     &acpi_ec_space_handler,
907                                                     NULL, ec);
908         if (ACPI_FAILURE(status)) {
909                 if (status == AE_NOT_FOUND) {
910                         /*
911                          * Maybe OS fails in evaluating the _REG object.
912                          * The AE_NOT_FOUND error will be ignored and OS
913                          * continue to initialize EC.
914                          */
915                         printk(KERN_ERR "Fail in evaluating the _REG object"
916                                 " of EC device. Broken bios is suspected.\n");
917                 } else {
918                         acpi_remove_gpe_handler(NULL, ec->gpe,
919                                 &acpi_ec_gpe_handler);
920                         return -ENODEV;
921                 }
922         }
923
924         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
925         return 0;
926 }
927
928 static int acpi_ec_start(struct acpi_device *device)
929 {
930         struct acpi_ec *ec;
931         int ret = 0;
932
933         if (!device)
934                 return -EINVAL;
935
936         ec = acpi_driver_data(device);
937
938         if (!ec)
939                 return -EINVAL;
940
941         ret = ec_install_handlers(ec);
942
943         /* EC is fully operational, allow queries */
944         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
945         return ret;
946 }
947
948 static int acpi_ec_stop(struct acpi_device *device, int type)
949 {
950         struct acpi_ec *ec;
951         if (!device)
952                 return -EINVAL;
953         ec = acpi_driver_data(device);
954         if (!ec)
955                 return -EINVAL;
956         ec_remove_handlers(ec);
957
958         return 0;
959 }
960
961 int __init acpi_boot_ec_enable(void)
962 {
963         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
964                 return 0;
965         if (!ec_install_handlers(boot_ec)) {
966                 first_ec = boot_ec;
967                 return 0;
968         }
969         return -EFAULT;
970 }
971
972 static const struct acpi_device_id ec_device_ids[] = {
973         {"PNP0C09", 0},
974         {"", 0},
975 };
976
977 int __init acpi_ec_ecdt_probe(void)
978 {
979         int ret;
980         acpi_status status;
981         struct acpi_table_ecdt *ecdt_ptr;
982
983         boot_ec = make_acpi_ec();
984         if (!boot_ec)
985                 return -ENOMEM;
986         /*
987          * Generate a boot ec context
988          */
989         status = acpi_get_table(ACPI_SIG_ECDT, 1,
990                                 (struct acpi_table_header **)&ecdt_ptr);
991         if (ACPI_SUCCESS(status)) {
992                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
993                 boot_ec->command_addr = ecdt_ptr->control.address;
994                 boot_ec->data_addr = ecdt_ptr->data.address;
995                 if (dmi_check_system(ec_dmi_table)) {
996                         /*
997                          * If the board falls into ec_dmi_table, it means
998                          * that ECDT table gives the incorrect command/status
999                          * & data I/O address. Just fix it.
1000                          */
1001                         boot_ec->data_addr = ecdt_ptr->control.address;
1002                         boot_ec->command_addr = ecdt_ptr->data.address;
1003                 }
1004                 boot_ec->gpe = ecdt_ptr->gpe;
1005                 boot_ec->handle = ACPI_ROOT_OBJECT;
1006                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1007         } else {
1008                 /* This workaround is needed only on some broken machines,
1009                  * which require early EC, but fail to provide ECDT */
1010                 acpi_handle x;
1011                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1012                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1013                                                 boot_ec, NULL);
1014                 /* Check that acpi_get_devices actually find something */
1015                 if (ACPI_FAILURE(status) || !boot_ec->handle)
1016                         goto error;
1017                 /* We really need to limit this workaround, the only ASUS,
1018                  * which needs it, has fake EC._INI method, so use it as flag.
1019                  * Keep boot_ec struct as it will be needed soon.
1020                  */
1021                 if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
1022                         return -ENODEV;
1023         }
1024
1025         ret = ec_install_handlers(boot_ec);
1026         if (!ret) {
1027                 first_ec = boot_ec;
1028                 return 0;
1029         }
1030       error:
1031         kfree(boot_ec);
1032         boot_ec = NULL;
1033         return -ENODEV;
1034 }
1035
1036 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1037 {
1038         struct acpi_ec *ec = acpi_driver_data(device);
1039         /* Stop using GPE */
1040         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1041         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1042         acpi_disable_gpe(NULL, ec->gpe);
1043         return 0;
1044 }
1045
1046 static int acpi_ec_resume(struct acpi_device *device)
1047 {
1048         struct acpi_ec *ec = acpi_driver_data(device);
1049         /* Enable use of GPE back */
1050         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1051         acpi_enable_gpe(NULL, ec->gpe);
1052         return 0;
1053 }
1054
1055 static struct acpi_driver acpi_ec_driver = {
1056         .name = "ec",
1057         .class = ACPI_EC_CLASS,
1058         .ids = ec_device_ids,
1059         .ops = {
1060                 .add = acpi_ec_add,
1061                 .remove = acpi_ec_remove,
1062                 .start = acpi_ec_start,
1063                 .stop = acpi_ec_stop,
1064                 .suspend = acpi_ec_suspend,
1065                 .resume = acpi_ec_resume,
1066                 },
1067 };
1068
1069 static int __init acpi_ec_init(void)
1070 {
1071         int result = 0;
1072
1073         if (acpi_disabled)
1074                 return 0;
1075
1076         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1077         if (!acpi_ec_dir)
1078                 return -ENODEV;
1079
1080         /* Now register the driver for the EC */
1081         result = acpi_bus_register_driver(&acpi_ec_driver);
1082         if (result < 0) {
1083                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1084                 return -ENODEV;
1085         }
1086
1087         return result;
1088 }
1089
1090 subsys_initcall(acpi_ec_init);
1091
1092 /* EC driver currently not unloadable */
1093 #if 0
1094 static void __exit acpi_ec_exit(void)
1095 {
1096
1097         acpi_bus_unregister_driver(&acpi_ec_driver);
1098
1099         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1100
1101         return;
1102 }
1103 #endif  /* 0 */