ACPI: EC: Always parse EC device
[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
46 #define ACPI_EC_CLASS                   "embedded_controller"
47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
48 #define ACPI_EC_FILE_INFO               "info"
49
50 #undef PREFIX
51 #define PREFIX                          "ACPI: EC: "
52
53 /* EC status register */
54 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
55 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
56 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
57 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
58
59 /* EC commands */
60 enum ec_command {
61         ACPI_EC_COMMAND_READ = 0x80,
62         ACPI_EC_COMMAND_WRITE = 0x81,
63         ACPI_EC_BURST_ENABLE = 0x82,
64         ACPI_EC_BURST_DISABLE = 0x83,
65         ACPI_EC_COMMAND_QUERY = 0x84,
66 };
67
68 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
69 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
70 #define ACPI_EC_UDELAY          100     /* Wait 100us before polling EC again */
71
72 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
73                                            per one transaction */
74
75 enum {
76         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
77         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent
78                                          * for status change */
79         EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
80         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
81         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
82                                          * OpReg are installed */
83 };
84
85 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
86 /* External interfaces use first EC only, so remember */
87 typedef int (*acpi_ec_query_func) (void *data);
88
89 struct acpi_ec_query_handler {
90         struct list_head node;
91         acpi_ec_query_func func;
92         acpi_handle handle;
93         void *data;
94         u8 query_bit;
95 };
96
97 struct transaction {
98         const u8 *wdata;
99         u8 *rdata;
100         unsigned short irq_count;
101         u8 command;
102         u8 wi;
103         u8 ri;
104         u8 wlen;
105         u8 rlen;
106         bool done;
107 };
108
109 static struct acpi_ec {
110         acpi_handle handle;
111         unsigned long gpe;
112         unsigned long command_addr;
113         unsigned long data_addr;
114         unsigned long global_lock;
115         unsigned long flags;
116         struct mutex lock;
117         wait_queue_head_t wait;
118         struct list_head list;
119         struct transaction *curr;
120         spinlock_t curr_lock;
121 } *boot_ec, *first_ec;
122
123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
124
125 /* --------------------------------------------------------------------------
126                              Transaction Management
127    -------------------------------------------------------------------------- */
128
129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
130 {
131         u8 x = inb(ec->command_addr);
132         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
133         return x;
134 }
135
136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
137 {
138         u8 x = inb(ec->data_addr);
139         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
140         return x;
141 }
142
143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
144 {
145         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
146         outb(command, ec->command_addr);
147 }
148
149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
150 {
151         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
152         outb(data, ec->data_addr);
153 }
154
155 static int ec_transaction_done(struct acpi_ec *ec)
156 {
157         unsigned long flags;
158         int ret = 0;
159         spin_lock_irqsave(&ec->curr_lock, flags);
160         if (!ec->curr || ec->curr->done)
161                 ret = 1;
162         spin_unlock_irqrestore(&ec->curr_lock, flags);
163         return ret;
164 }
165
166 static void start_transaction(struct acpi_ec *ec)
167 {
168         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
169         ec->curr->done = false;
170         acpi_ec_write_cmd(ec, ec->curr->command);
171 }
172
173 static void gpe_transaction(struct acpi_ec *ec, u8 status)
174 {
175         unsigned long flags;
176         spin_lock_irqsave(&ec->curr_lock, flags);
177         if (!ec->curr)
178                 goto unlock;
179         if (ec->curr->wlen > ec->curr->wi) {
180                 if ((status & ACPI_EC_FLAG_IBF) == 0)
181                         acpi_ec_write_data(ec,
182                                 ec->curr->wdata[ec->curr->wi++]);
183                 else
184                         goto err;
185         } else if (ec->curr->rlen > ec->curr->ri) {
186                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
187                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
188                         if (ec->curr->rlen == ec->curr->ri)
189                                 ec->curr->done = true;
190                 } else
191                         goto err;
192         } else if (ec->curr->wlen == ec->curr->wi &&
193                    (status & ACPI_EC_FLAG_IBF) == 0)
194                 ec->curr->done = true;
195         goto unlock;
196 err:
197         /* false interrupt, state didn't change */
198         if (in_interrupt())
199                 ++ec->curr->irq_count;
200 unlock:
201         spin_unlock_irqrestore(&ec->curr_lock, flags);
202 }
203
204 static int acpi_ec_wait(struct acpi_ec *ec)
205 {
206         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
207                                msecs_to_jiffies(ACPI_EC_DELAY)))
208                 return 0;
209         /* try restart command if we get any false interrupts */
210         if (ec->curr->irq_count &&
211             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
212                 pr_debug(PREFIX "controller reset, restart transaction\n");
213                 start_transaction(ec);
214                 if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
215                                         msecs_to_jiffies(ACPI_EC_DELAY)))
216                         return 0;
217         }
218         /* missing GPEs, switch back to poll mode */
219         if (printk_ratelimit())
220                 pr_info(PREFIX "missing confirmations, "
221                                 "switch off interrupt mode.\n");
222         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
223         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
224         return 1;
225 }
226
227 static void acpi_ec_gpe_query(void *ec_cxt);
228
229 static int ec_check_sci(struct acpi_ec *ec, u8 state)
230 {
231         if (state & ACPI_EC_FLAG_SCI) {
232                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
233                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
234                                 acpi_ec_gpe_query, ec);
235         }
236         return 0;
237 }
238
239 static int ec_poll(struct acpi_ec *ec)
240 {
241         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
242         udelay(ACPI_EC_UDELAY);
243         while (time_before(jiffies, delay)) {
244                 gpe_transaction(ec, acpi_ec_read_status(ec));
245                 udelay(ACPI_EC_UDELAY);
246                 if (ec_transaction_done(ec))
247                         return 0;
248         }
249         return -ETIME;
250 }
251
252 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
253                                         struct transaction *t,
254                                         int force_poll)
255 {
256         unsigned long tmp;
257         int ret = 0;
258         pr_debug(PREFIX "transaction start\n");
259         /* disable GPE during transaction if storm is detected */
260         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
261                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
262                 acpi_disable_gpe(NULL, ec->gpe);
263         }
264         if (EC_FLAGS_MSI)
265                 udelay(ACPI_EC_DELAY);
266         /* start transaction */
267         spin_lock_irqsave(&ec->curr_lock, tmp);
268         /* following two actions should be kept atomic */
269         ec->curr = t;
270         start_transaction(ec);
271         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
272                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
273         spin_unlock_irqrestore(&ec->curr_lock, tmp);
274         /* if we selected poll mode or failed in GPE-mode do a poll loop */
275         if (force_poll ||
276             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
277             acpi_ec_wait(ec))
278                 ret = ec_poll(ec);
279         pr_debug(PREFIX "transaction end\n");
280         spin_lock_irqsave(&ec->curr_lock, tmp);
281         ec->curr = NULL;
282         spin_unlock_irqrestore(&ec->curr_lock, tmp);
283         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
284                 /* check if we received SCI during transaction */
285                 ec_check_sci(ec, acpi_ec_read_status(ec));
286                 /* it is safe to enable GPE outside of transaction */
287                 acpi_enable_gpe(NULL, ec->gpe);
288         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
289                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
290                 pr_info(PREFIX "GPE storm detected, "
291                         "transactions will use polling mode\n");
292                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
293         }
294         return ret;
295 }
296
297 static int ec_check_ibf0(struct acpi_ec *ec)
298 {
299         u8 status = acpi_ec_read_status(ec);
300         return (status & ACPI_EC_FLAG_IBF) == 0;
301 }
302
303 static int ec_wait_ibf0(struct acpi_ec *ec)
304 {
305         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
306         /* interrupt wait manually if GPE mode is not active */
307         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
308                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
309         while (time_before(jiffies, delay))
310                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
311                         return 0;
312         return -ETIME;
313 }
314
315 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
316                                int force_poll)
317 {
318         int status;
319         u32 glk;
320         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
321                 return -EINVAL;
322         if (t->rdata)
323                 memset(t->rdata, 0, t->rlen);
324         mutex_lock(&ec->lock);
325         if (ec->global_lock) {
326                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
327                 if (ACPI_FAILURE(status)) {
328                         status = -ENODEV;
329                         goto unlock;
330                 }
331         }
332         if (ec_wait_ibf0(ec)) {
333                 pr_err(PREFIX "input buffer is not empty, "
334                                 "aborting transaction\n");
335                 status = -ETIME;
336                 goto end;
337         }
338         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
339 end:
340         if (ec->global_lock)
341                 acpi_release_global_lock(glk);
342 unlock:
343         mutex_unlock(&ec->lock);
344         return status;
345 }
346
347 /*
348  * Note: samsung nv5000 doesn't work with ec burst mode.
349  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
350  */
351 static int acpi_ec_burst_enable(struct acpi_ec *ec)
352 {
353         u8 d;
354         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
355                                 .wdata = NULL, .rdata = &d,
356                                 .wlen = 0, .rlen = 1};
357
358         return acpi_ec_transaction(ec, &t, 0);
359 }
360
361 static int acpi_ec_burst_disable(struct acpi_ec *ec)
362 {
363         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
364                                 .wdata = NULL, .rdata = NULL,
365                                 .wlen = 0, .rlen = 0};
366
367         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
368                                 acpi_ec_transaction(ec, &t, 0) : 0;
369 }
370
371 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
372 {
373         int result;
374         u8 d;
375         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
376                                 .wdata = &address, .rdata = &d,
377                                 .wlen = 1, .rlen = 1};
378
379         result = acpi_ec_transaction(ec, &t, 0);
380         *data = d;
381         return result;
382 }
383
384 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
385 {
386         u8 wdata[2] = { address, data };
387         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
388                                 .wdata = wdata, .rdata = NULL,
389                                 .wlen = 2, .rlen = 0};
390
391         return acpi_ec_transaction(ec, &t, 0);
392 }
393
394 /*
395  * Externally callable EC access functions. For now, assume 1 EC only
396  */
397 int ec_burst_enable(void)
398 {
399         if (!first_ec)
400                 return -ENODEV;
401         return acpi_ec_burst_enable(first_ec);
402 }
403
404 EXPORT_SYMBOL(ec_burst_enable);
405
406 int ec_burst_disable(void)
407 {
408         if (!first_ec)
409                 return -ENODEV;
410         return acpi_ec_burst_disable(first_ec);
411 }
412
413 EXPORT_SYMBOL(ec_burst_disable);
414
415 int ec_read(u8 addr, u8 * val)
416 {
417         int err;
418         u8 temp_data;
419
420         if (!first_ec)
421                 return -ENODEV;
422
423         err = acpi_ec_read(first_ec, addr, &temp_data);
424
425         if (!err) {
426                 *val = temp_data;
427                 return 0;
428         } else
429                 return err;
430 }
431
432 EXPORT_SYMBOL(ec_read);
433
434 int ec_write(u8 addr, u8 val)
435 {
436         int err;
437
438         if (!first_ec)
439                 return -ENODEV;
440
441         err = acpi_ec_write(first_ec, addr, val);
442
443         return err;
444 }
445
446 EXPORT_SYMBOL(ec_write);
447
448 int ec_transaction(u8 command,
449                    const u8 * wdata, unsigned wdata_len,
450                    u8 * rdata, unsigned rdata_len,
451                    int force_poll)
452 {
453         struct transaction t = {.command = command,
454                                 .wdata = wdata, .rdata = rdata,
455                                 .wlen = wdata_len, .rlen = rdata_len};
456         if (!first_ec)
457                 return -ENODEV;
458
459         return acpi_ec_transaction(first_ec, &t, force_poll);
460 }
461
462 EXPORT_SYMBOL(ec_transaction);
463
464 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
465 {
466         int result;
467         u8 d;
468         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
469                                 .wdata = NULL, .rdata = &d,
470                                 .wlen = 0, .rlen = 1};
471         if (!ec || !data)
472                 return -EINVAL;
473
474         /*
475          * Query the EC to find out which _Qxx method we need to evaluate.
476          * Note that successful completion of the query causes the ACPI_EC_SCI
477          * bit to be cleared (and thus clearing the interrupt source).
478          */
479
480         result = acpi_ec_transaction(ec, &t, 0);
481         if (result)
482                 return result;
483
484         if (!d)
485                 return -ENODATA;
486
487         *data = d;
488         return 0;
489 }
490
491 /* --------------------------------------------------------------------------
492                                 Event Management
493    -------------------------------------------------------------------------- */
494 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
495                               acpi_handle handle, acpi_ec_query_func func,
496                               void *data)
497 {
498         struct acpi_ec_query_handler *handler =
499             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
500         if (!handler)
501                 return -ENOMEM;
502
503         handler->query_bit = query_bit;
504         handler->handle = handle;
505         handler->func = func;
506         handler->data = data;
507         mutex_lock(&ec->lock);
508         list_add(&handler->node, &ec->list);
509         mutex_unlock(&ec->lock);
510         return 0;
511 }
512
513 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
514
515 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
516 {
517         struct acpi_ec_query_handler *handler, *tmp;
518         mutex_lock(&ec->lock);
519         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
520                 if (query_bit == handler->query_bit) {
521                         list_del(&handler->node);
522                         kfree(handler);
523                 }
524         }
525         mutex_unlock(&ec->lock);
526 }
527
528 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
529
530 static void acpi_ec_gpe_query(void *ec_cxt)
531 {
532         struct acpi_ec *ec = ec_cxt;
533         u8 value = 0;
534         struct acpi_ec_query_handler *handler, copy;
535
536         if (!ec || acpi_ec_query(ec, &value))
537                 return;
538         mutex_lock(&ec->lock);
539         list_for_each_entry(handler, &ec->list, node) {
540                 if (value == handler->query_bit) {
541                         /* have custom handler for this bit */
542                         memcpy(&copy, handler, sizeof(copy));
543                         mutex_unlock(&ec->lock);
544                         if (copy.func) {
545                                 copy.func(copy.data);
546                         } else if (copy.handle) {
547                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
548                         }
549                         return;
550                 }
551         }
552         mutex_unlock(&ec->lock);
553 }
554
555 static u32 acpi_ec_gpe_handler(void *data)
556 {
557         struct acpi_ec *ec = data;
558         u8 status;
559
560         pr_debug(PREFIX "~~~> interrupt\n");
561         status = acpi_ec_read_status(ec);
562
563         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
564                 gpe_transaction(ec, status);
565                 if (ec_transaction_done(ec) &&
566                     (status & ACPI_EC_FLAG_IBF) == 0)
567                         wake_up(&ec->wait);
568         }
569
570         ec_check_sci(ec, status);
571         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
572             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
573                 /* this is non-query, must be confirmation */
574                 if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
575                         if (printk_ratelimit())
576                                 pr_info(PREFIX "non-query interrupt received,"
577                                         " switching to interrupt mode\n");
578                 } else {
579                         /* hush, STORM switches the mode every transaction */
580                         pr_debug(PREFIX "non-query interrupt received,"
581                                 " switching to interrupt mode\n");
582                 }
583                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
584         }
585         return ACPI_INTERRUPT_HANDLED;
586 }
587
588 /* --------------------------------------------------------------------------
589                              Address Space Management
590    -------------------------------------------------------------------------- */
591
592 static acpi_status
593 acpi_ec_space_handler(u32 function, acpi_physical_address address,
594                       u32 bits, acpi_integer *value,
595                       void *handler_context, void *region_context)
596 {
597         struct acpi_ec *ec = handler_context;
598         int result = 0, i;
599         u8 temp = 0;
600
601         if ((address > 0xFF) || !value || !handler_context)
602                 return AE_BAD_PARAMETER;
603
604         if (function != ACPI_READ && function != ACPI_WRITE)
605                 return AE_BAD_PARAMETER;
606
607         if (bits != 8 && acpi_strict)
608                 return AE_BAD_PARAMETER;
609
610         acpi_ec_burst_enable(ec);
611
612         if (function == ACPI_READ) {
613                 result = acpi_ec_read(ec, address, &temp);
614                 *value = temp;
615         } else {
616                 temp = 0xff & (*value);
617                 result = acpi_ec_write(ec, address, temp);
618         }
619
620         for (i = 8; unlikely(bits - i > 0); i += 8) {
621                 ++address;
622                 if (function == ACPI_READ) {
623                         result = acpi_ec_read(ec, address, &temp);
624                         (*value) |= ((acpi_integer)temp) << i;
625                 } else {
626                         temp = 0xff & ((*value) >> i);
627                         result = acpi_ec_write(ec, address, temp);
628                 }
629         }
630
631         acpi_ec_burst_disable(ec);
632
633         switch (result) {
634         case -EINVAL:
635                 return AE_BAD_PARAMETER;
636                 break;
637         case -ENODEV:
638                 return AE_NOT_FOUND;
639                 break;
640         case -ETIME:
641                 return AE_TIME;
642                 break;
643         default:
644                 return AE_OK;
645         }
646 }
647
648 /* --------------------------------------------------------------------------
649                               FS Interface (/proc)
650    -------------------------------------------------------------------------- */
651
652 static struct proc_dir_entry *acpi_ec_dir;
653
654 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
655 {
656         struct acpi_ec *ec = seq->private;
657
658         if (!ec)
659                 goto end;
660
661         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
662         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
663                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
664         seq_printf(seq, "use global lock:\t%s\n",
665                    ec->global_lock ? "yes" : "no");
666       end:
667         return 0;
668 }
669
670 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
671 {
672         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
673 }
674
675 static struct file_operations acpi_ec_info_ops = {
676         .open = acpi_ec_info_open_fs,
677         .read = seq_read,
678         .llseek = seq_lseek,
679         .release = single_release,
680         .owner = THIS_MODULE,
681 };
682
683 static int acpi_ec_add_fs(struct acpi_device *device)
684 {
685         struct proc_dir_entry *entry = NULL;
686
687         if (!acpi_device_dir(device)) {
688                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
689                                                      acpi_ec_dir);
690                 if (!acpi_device_dir(device))
691                         return -ENODEV;
692         }
693
694         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
695                                  acpi_device_dir(device),
696                                  &acpi_ec_info_ops, acpi_driver_data(device));
697         if (!entry)
698                 return -ENODEV;
699         return 0;
700 }
701
702 static int acpi_ec_remove_fs(struct acpi_device *device)
703 {
704
705         if (acpi_device_dir(device)) {
706                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
707                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
708                 acpi_device_dir(device) = NULL;
709         }
710
711         return 0;
712 }
713
714 /* --------------------------------------------------------------------------
715                                Driver Interface
716    -------------------------------------------------------------------------- */
717 static acpi_status
718 ec_parse_io_ports(struct acpi_resource *resource, void *context);
719
720 static struct acpi_ec *make_acpi_ec(void)
721 {
722         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
723         if (!ec)
724                 return NULL;
725         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
726         mutex_init(&ec->lock);
727         init_waitqueue_head(&ec->wait);
728         INIT_LIST_HEAD(&ec->list);
729         spin_lock_init(&ec->curr_lock);
730         return ec;
731 }
732
733 static acpi_status
734 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
735                                void *context, void **return_value)
736 {
737         char node_name[5];
738         struct acpi_buffer buffer = { sizeof(node_name), node_name };
739         struct acpi_ec *ec = context;
740         int value = 0;
741         acpi_status status;
742
743         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
744
745         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
746                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
747         }
748         return AE_OK;
749 }
750
751 static acpi_status
752 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
753 {
754         acpi_status status;
755         unsigned long long tmp = 0;
756
757         struct acpi_ec *ec = context;
758
759         /* clear addr values, ec_parse_io_ports depend on it */
760         ec->command_addr = ec->data_addr = 0;
761
762         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
763                                      ec_parse_io_ports, ec);
764         if (ACPI_FAILURE(status))
765                 return status;
766
767         /* Get GPE bit assignment (EC events). */
768         /* TODO: Add support for _GPE returning a package */
769         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
770         if (ACPI_FAILURE(status))
771                 return status;
772         ec->gpe = tmp;
773         /* Use the global lock for all EC transactions? */
774         tmp = 0;
775         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
776         ec->global_lock = tmp;
777         ec->handle = handle;
778         return AE_CTRL_TERMINATE;
779 }
780
781 static void ec_remove_handlers(struct acpi_ec *ec)
782 {
783         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
784                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
785                 pr_err(PREFIX "failed to remove space handler\n");
786         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
787                                 &acpi_ec_gpe_handler)))
788                 pr_err(PREFIX "failed to remove gpe handler\n");
789         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
790 }
791
792 static int acpi_ec_add(struct acpi_device *device)
793 {
794         struct acpi_ec *ec = NULL;
795
796         if (!device)
797                 return -EINVAL;
798         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
799         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
800
801         /* Check for boot EC */
802         if (boot_ec &&
803             (boot_ec->handle == device->handle ||
804              boot_ec->handle == ACPI_ROOT_OBJECT)) {
805                 ec = boot_ec;
806                 boot_ec = NULL;
807         } else {
808                 ec = make_acpi_ec();
809                 if (!ec)
810                         return -ENOMEM;
811         }
812         if (ec_parse_device(device->handle, 0, ec, NULL) !=
813                 AE_CTRL_TERMINATE) {
814                         kfree(ec);
815                         return -EINVAL;
816         }
817
818         ec->handle = device->handle;
819
820         /* Find and register all query methods */
821         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
822                             acpi_ec_register_query_methods, ec, NULL);
823
824         if (!first_ec)
825                 first_ec = ec;
826         device->driver_data = ec;
827         acpi_ec_add_fs(device);
828         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
829                           ec->gpe, ec->command_addr, ec->data_addr);
830         pr_info(PREFIX "driver started in %s mode\n",
831                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
832         return 0;
833 }
834
835 static int acpi_ec_remove(struct acpi_device *device, int type)
836 {
837         struct acpi_ec *ec;
838         struct acpi_ec_query_handler *handler, *tmp;
839
840         if (!device)
841                 return -EINVAL;
842
843         ec = acpi_driver_data(device);
844         mutex_lock(&ec->lock);
845         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
846                 list_del(&handler->node);
847                 kfree(handler);
848         }
849         mutex_unlock(&ec->lock);
850         acpi_ec_remove_fs(device);
851         device->driver_data = NULL;
852         if (ec == first_ec)
853                 first_ec = NULL;
854         kfree(ec);
855         return 0;
856 }
857
858 static acpi_status
859 ec_parse_io_ports(struct acpi_resource *resource, void *context)
860 {
861         struct acpi_ec *ec = context;
862
863         if (resource->type != ACPI_RESOURCE_TYPE_IO)
864                 return AE_OK;
865
866         /*
867          * The first address region returned is the data port, and
868          * the second address region returned is the status/command
869          * port.
870          */
871         if (ec->data_addr == 0)
872                 ec->data_addr = resource->data.io.minimum;
873         else if (ec->command_addr == 0)
874                 ec->command_addr = resource->data.io.minimum;
875         else
876                 return AE_CTRL_TERMINATE;
877
878         return AE_OK;
879 }
880
881 static int ec_install_handlers(struct acpi_ec *ec)
882 {
883         acpi_status status;
884         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
885                 return 0;
886         status = acpi_install_gpe_handler(NULL, ec->gpe,
887                                   ACPI_GPE_EDGE_TRIGGERED,
888                                   &acpi_ec_gpe_handler, ec);
889         if (ACPI_FAILURE(status))
890                 return -ENODEV;
891         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
892         acpi_enable_gpe(NULL, ec->gpe);
893         status = acpi_install_address_space_handler(ec->handle,
894                                                     ACPI_ADR_SPACE_EC,
895                                                     &acpi_ec_space_handler,
896                                                     NULL, ec);
897         if (ACPI_FAILURE(status)) {
898                 if (status == AE_NOT_FOUND) {
899                         /*
900                          * Maybe OS fails in evaluating the _REG object.
901                          * The AE_NOT_FOUND error will be ignored and OS
902                          * continue to initialize EC.
903                          */
904                         printk(KERN_ERR "Fail in evaluating the _REG object"
905                                 " of EC device. Broken bios is suspected.\n");
906                 } else {
907                         acpi_remove_gpe_handler(NULL, ec->gpe,
908                                 &acpi_ec_gpe_handler);
909                         return -ENODEV;
910                 }
911         }
912
913         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
914         return 0;
915 }
916
917 static int acpi_ec_start(struct acpi_device *device)
918 {
919         struct acpi_ec *ec;
920         int ret = 0;
921
922         if (!device)
923                 return -EINVAL;
924
925         ec = acpi_driver_data(device);
926
927         if (!ec)
928                 return -EINVAL;
929
930         ret = ec_install_handlers(ec);
931
932         /* EC is fully operational, allow queries */
933         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
934         return ret;
935 }
936
937 static int acpi_ec_stop(struct acpi_device *device, int type)
938 {
939         struct acpi_ec *ec;
940         if (!device)
941                 return -EINVAL;
942         ec = acpi_driver_data(device);
943         if (!ec)
944                 return -EINVAL;
945         ec_remove_handlers(ec);
946
947         return 0;
948 }
949
950 int __init acpi_boot_ec_enable(void)
951 {
952         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
953                 return 0;
954         if (!ec_install_handlers(boot_ec)) {
955                 first_ec = boot_ec;
956                 return 0;
957         }
958         return -EFAULT;
959 }
960
961 static const struct acpi_device_id ec_device_ids[] = {
962         {"PNP0C09", 0},
963         {"", 0},
964 };
965
966 int __init acpi_ec_ecdt_probe(void)
967 {
968         acpi_status status;
969         struct acpi_ec *saved_ec = NULL;
970         struct acpi_table_ecdt *ecdt_ptr;
971
972         boot_ec = make_acpi_ec();
973         if (!boot_ec)
974                 return -ENOMEM;
975         /*
976          * Generate a boot ec context
977          */
978         if (dmi_name_in_vendors("Micro-Star") ||
979             dmi_name_in_vendors("Notebook")) {
980                 pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
981                 EC_FLAGS_MSI = 1;
982         }
983         status = acpi_get_table(ACPI_SIG_ECDT, 1,
984                                 (struct acpi_table_header **)&ecdt_ptr);
985         if (ACPI_SUCCESS(status)) {
986                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
987                 boot_ec->command_addr = ecdt_ptr->control.address;
988                 boot_ec->data_addr = ecdt_ptr->data.address;
989                 boot_ec->gpe = ecdt_ptr->gpe;
990                 boot_ec->handle = ACPI_ROOT_OBJECT;
991                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
992                 /* Don't trust ECDT, which comes from ASUSTek */
993                 if (!dmi_name_in_vendors("ASUS") && EC_FLAGS_MSI == 0)
994                         goto install;
995                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
996                 if (!saved_ec)
997                         return -ENOMEM;
998                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
999         /* fall through */
1000         }
1001         /* This workaround is needed only on some broken machines,
1002          * which require early EC, but fail to provide ECDT */
1003         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1004         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1005                                         boot_ec, NULL);
1006         /* Check that acpi_get_devices actually find something */
1007         if (ACPI_FAILURE(status) || !boot_ec->handle)
1008                 goto error;
1009         if (saved_ec) {
1010                 /* try to find good ECDT from ASUSTek */
1011                 if (saved_ec->command_addr != boot_ec->command_addr ||
1012                     saved_ec->data_addr != boot_ec->data_addr ||
1013                     saved_ec->gpe != boot_ec->gpe ||
1014                     saved_ec->handle != boot_ec->handle)
1015                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1016                         "ECDT tables, which are very hard to workaround. "
1017                         "Trying to use DSDT EC info instead. Please send "
1018                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1019                 kfree(saved_ec);
1020                 saved_ec = NULL;
1021         } else {
1022                 /* We really need to limit this workaround, the only ASUS,
1023                 * which needs it, has fake EC._INI method, so use it as flag.
1024                 * Keep boot_ec struct as it will be needed soon.
1025                 */
1026                 acpi_handle dummy;
1027                 if (!dmi_name_in_vendors("ASUS") ||
1028                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1029                                                         &dummy)))
1030                         return -ENODEV;
1031         }
1032 install:
1033         if (!ec_install_handlers(boot_ec)) {
1034                 first_ec = boot_ec;
1035                 return 0;
1036         }
1037 error:
1038         kfree(boot_ec);
1039         boot_ec = NULL;
1040         return -ENODEV;
1041 }
1042
1043 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1044 {
1045         struct acpi_ec *ec = acpi_driver_data(device);
1046         /* Stop using GPE */
1047         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1048         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1049         acpi_disable_gpe(NULL, ec->gpe);
1050         return 0;
1051 }
1052
1053 static int acpi_ec_resume(struct acpi_device *device)
1054 {
1055         struct acpi_ec *ec = acpi_driver_data(device);
1056         /* Enable use of GPE back */
1057         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1058         acpi_enable_gpe(NULL, ec->gpe);
1059         return 0;
1060 }
1061
1062 static struct acpi_driver acpi_ec_driver = {
1063         .name = "ec",
1064         .class = ACPI_EC_CLASS,
1065         .ids = ec_device_ids,
1066         .ops = {
1067                 .add = acpi_ec_add,
1068                 .remove = acpi_ec_remove,
1069                 .start = acpi_ec_start,
1070                 .stop = acpi_ec_stop,
1071                 .suspend = acpi_ec_suspend,
1072                 .resume = acpi_ec_resume,
1073                 },
1074 };
1075
1076 static int __init acpi_ec_init(void)
1077 {
1078         int result = 0;
1079
1080         if (acpi_disabled)
1081                 return 0;
1082
1083         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1084         if (!acpi_ec_dir)
1085                 return -ENODEV;
1086
1087         /* Now register the driver for the EC */
1088         result = acpi_bus_register_driver(&acpi_ec_driver);
1089         if (result < 0) {
1090                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1091                 return -ENODEV;
1092         }
1093
1094         return result;
1095 }
1096
1097 subsys_initcall(acpi_ec_init);
1098
1099 /* EC driver currently not unloadable */
1100 #if 0
1101 static void __exit acpi_ec_exit(void)
1102 {
1103
1104         acpi_bus_unregister_driver(&acpi_ec_driver);
1105
1106         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1107
1108         return;
1109 }
1110 #endif  /* 0 */