ACPI: EC: Drop orphan comment
[sfrench/cifs-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_CDELAY          10      /* Wait 10us before polling EC */
71 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
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_STORM,             /* GPE storm detected */
79         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
80                                          * OpReg are installed */
81 };
82
83 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
84 /* External interfaces use first EC only, so remember */
85 typedef int (*acpi_ec_query_func) (void *data);
86
87 struct acpi_ec_query_handler {
88         struct list_head node;
89         acpi_ec_query_func func;
90         acpi_handle handle;
91         void *data;
92         u8 query_bit;
93 };
94
95 struct transaction {
96         const u8 *wdata;
97         u8 *rdata;
98         unsigned short irq_count;
99         u8 command;
100         u8 wi;
101         u8 ri;
102         u8 wlen;
103         u8 rlen;
104         bool done;
105 };
106
107 static struct acpi_ec {
108         acpi_handle handle;
109         unsigned long gpe;
110         unsigned long command_addr;
111         unsigned long data_addr;
112         unsigned long global_lock;
113         unsigned long flags;
114         struct mutex lock;
115         wait_queue_head_t wait;
116         struct list_head list;
117         struct transaction *curr;
118         spinlock_t curr_lock;
119 } *boot_ec, *first_ec;
120
121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
122
123 /* --------------------------------------------------------------------------
124                              Transaction Management
125    -------------------------------------------------------------------------- */
126
127 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
128 {
129         u8 x = inb(ec->command_addr);
130         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
131         return x;
132 }
133
134 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
135 {
136         u8 x = inb(ec->data_addr);
137         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
138         return x;
139 }
140
141 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
142 {
143         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
144         outb(command, ec->command_addr);
145 }
146
147 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
148 {
149         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
150         outb(data, ec->data_addr);
151 }
152
153 static int ec_transaction_done(struct acpi_ec *ec)
154 {
155         unsigned long flags;
156         int ret = 0;
157         spin_lock_irqsave(&ec->curr_lock, flags);
158         if (!ec->curr || ec->curr->done)
159                 ret = 1;
160         spin_unlock_irqrestore(&ec->curr_lock, flags);
161         return ret;
162 }
163
164 static void start_transaction(struct acpi_ec *ec)
165 {
166         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
167         ec->curr->done = false;
168         acpi_ec_write_cmd(ec, ec->curr->command);
169 }
170
171 static void advance_transaction(struct acpi_ec *ec, u8 status)
172 {
173         unsigned long flags;
174         spin_lock_irqsave(&ec->curr_lock, flags);
175         if (!ec->curr)
176                 goto unlock;
177         if (ec->curr->wlen > ec->curr->wi) {
178                 if ((status & ACPI_EC_FLAG_IBF) == 0)
179                         acpi_ec_write_data(ec,
180                                 ec->curr->wdata[ec->curr->wi++]);
181                 else
182                         goto err;
183         } else if (ec->curr->rlen > ec->curr->ri) {
184                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
185                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
186                         if (ec->curr->rlen == ec->curr->ri)
187                                 ec->curr->done = true;
188                 } else
189                         goto err;
190         } else if (ec->curr->wlen == ec->curr->wi &&
191                    (status & ACPI_EC_FLAG_IBF) == 0)
192                 ec->curr->done = true;
193         goto unlock;
194 err:
195         /* false interrupt, state didn't change */
196         if (in_interrupt())
197                 ++ec->curr->irq_count;
198 unlock:
199         spin_unlock_irqrestore(&ec->curr_lock, flags);
200 }
201
202 static void acpi_ec_gpe_query(void *ec_cxt);
203
204 static int ec_check_sci(struct acpi_ec *ec, u8 state)
205 {
206         if (state & ACPI_EC_FLAG_SCI) {
207                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
208                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
209                                 acpi_ec_gpe_query, ec);
210         }
211         return 0;
212 }
213
214 static int ec_poll(struct acpi_ec *ec)
215 {
216         unsigned long flags;
217         int repeat = 2; /* number of command restarts */
218         while (repeat--) {
219                 unsigned long delay = jiffies +
220                         msecs_to_jiffies(ACPI_EC_DELAY);
221                 do {
222                         /* don't sleep with disabled interrupts */
223                         if (EC_FLAGS_MSI || irqs_disabled()) {
224                                 udelay(ACPI_EC_MSI_UDELAY);
225                                 if (ec_transaction_done(ec))
226                                         return 0;
227                         } else {
228                                 if (wait_event_timeout(ec->wait,
229                                                 ec_transaction_done(ec),
230                                                 msecs_to_jiffies(1)))
231                                         return 0;
232                         }
233                         advance_transaction(ec, acpi_ec_read_status(ec));
234                 } while (time_before(jiffies, delay));
235                 if (!ec->curr->irq_count ||
236                     (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
237                         break;
238                 /* try restart command if we get any false interrupts */
239                 pr_debug(PREFIX "controller reset, restart transaction\n");
240                 spin_lock_irqsave(&ec->curr_lock, flags);
241                 start_transaction(ec);
242                 spin_unlock_irqrestore(&ec->curr_lock, flags);
243         }
244         return -ETIME;
245 }
246
247 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
248                                         struct transaction *t)
249 {
250         unsigned long tmp;
251         int ret = 0;
252         pr_debug(PREFIX "transaction start\n");
253         /* disable GPE during transaction if storm is detected */
254         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
255                 acpi_disable_gpe(NULL, ec->gpe);
256         }
257         if (EC_FLAGS_MSI)
258                 udelay(ACPI_EC_MSI_UDELAY);
259         /* start transaction */
260         spin_lock_irqsave(&ec->curr_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->curr_lock, tmp);
267         ret = ec_poll(ec);
268         pr_debug(PREFIX "transaction end\n");
269         spin_lock_irqsave(&ec->curr_lock, tmp);
270         ec->curr = NULL;
271         spin_unlock_irqrestore(&ec->curr_lock, tmp);
272         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
273                 /* check if we received SCI during transaction */
274                 ec_check_sci(ec, acpi_ec_read_status(ec));
275                 /* it is safe to enable GPE outside of transaction */
276                 acpi_enable_gpe(NULL, ec->gpe);
277         } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
278                 pr_info(PREFIX "GPE storm detected, "
279                         "transactions will use polling mode\n");
280                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
281         }
282         return ret;
283 }
284
285 static int ec_check_ibf0(struct acpi_ec *ec)
286 {
287         u8 status = acpi_ec_read_status(ec);
288         return (status & ACPI_EC_FLAG_IBF) == 0;
289 }
290
291 static int ec_wait_ibf0(struct acpi_ec *ec)
292 {
293         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
294         /* interrupt wait manually if GPE mode is not active */
295         while (time_before(jiffies, delay))
296                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
297                                         msecs_to_jiffies(1)))
298                         return 0;
299         return -ETIME;
300 }
301
302 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
303 {
304         int status;
305         u32 glk;
306         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
307                 return -EINVAL;
308         if (t->rdata)
309                 memset(t->rdata, 0, t->rlen);
310         mutex_lock(&ec->lock);
311         if (ec->global_lock) {
312                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
313                 if (ACPI_FAILURE(status)) {
314                         status = -ENODEV;
315                         goto unlock;
316                 }
317         }
318         if (ec_wait_ibf0(ec)) {
319                 pr_err(PREFIX "input buffer is not empty, "
320                                 "aborting transaction\n");
321                 status = -ETIME;
322                 goto end;
323         }
324         status = acpi_ec_transaction_unlocked(ec, t);
325 end:
326         if (ec->global_lock)
327                 acpi_release_global_lock(glk);
328 unlock:
329         mutex_unlock(&ec->lock);
330         return status;
331 }
332
333 static int acpi_ec_burst_enable(struct acpi_ec *ec)
334 {
335         u8 d;
336         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
337                                 .wdata = NULL, .rdata = &d,
338                                 .wlen = 0, .rlen = 1};
339
340         return acpi_ec_transaction(ec, &t);
341 }
342
343 static int acpi_ec_burst_disable(struct acpi_ec *ec)
344 {
345         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
346                                 .wdata = NULL, .rdata = NULL,
347                                 .wlen = 0, .rlen = 0};
348
349         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
350                                 acpi_ec_transaction(ec, &t) : 0;
351 }
352
353 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
354 {
355         int result;
356         u8 d;
357         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
358                                 .wdata = &address, .rdata = &d,
359                                 .wlen = 1, .rlen = 1};
360
361         result = acpi_ec_transaction(ec, &t);
362         *data = d;
363         return result;
364 }
365
366 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
367 {
368         u8 wdata[2] = { address, data };
369         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
370                                 .wdata = wdata, .rdata = NULL,
371                                 .wlen = 2, .rlen = 0};
372
373         return acpi_ec_transaction(ec, &t);
374 }
375
376 /*
377  * Externally callable EC access functions. For now, assume 1 EC only
378  */
379 int ec_burst_enable(void)
380 {
381         if (!first_ec)
382                 return -ENODEV;
383         return acpi_ec_burst_enable(first_ec);
384 }
385
386 EXPORT_SYMBOL(ec_burst_enable);
387
388 int ec_burst_disable(void)
389 {
390         if (!first_ec)
391                 return -ENODEV;
392         return acpi_ec_burst_disable(first_ec);
393 }
394
395 EXPORT_SYMBOL(ec_burst_disable);
396
397 int ec_read(u8 addr, u8 * val)
398 {
399         int err;
400         u8 temp_data;
401
402         if (!first_ec)
403                 return -ENODEV;
404
405         err = acpi_ec_read(first_ec, addr, &temp_data);
406
407         if (!err) {
408                 *val = temp_data;
409                 return 0;
410         } else
411                 return err;
412 }
413
414 EXPORT_SYMBOL(ec_read);
415
416 int ec_write(u8 addr, u8 val)
417 {
418         int err;
419
420         if (!first_ec)
421                 return -ENODEV;
422
423         err = acpi_ec_write(first_ec, addr, val);
424
425         return err;
426 }
427
428 EXPORT_SYMBOL(ec_write);
429
430 int ec_transaction(u8 command,
431                    const u8 * wdata, unsigned wdata_len,
432                    u8 * rdata, unsigned rdata_len,
433                    int force_poll)
434 {
435         struct transaction t = {.command = command,
436                                 .wdata = wdata, .rdata = rdata,
437                                 .wlen = wdata_len, .rlen = rdata_len};
438         if (!first_ec)
439                 return -ENODEV;
440
441         return acpi_ec_transaction(first_ec, &t);
442 }
443
444 EXPORT_SYMBOL(ec_transaction);
445
446 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
447 {
448         int result;
449         u8 d;
450         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
451                                 .wdata = NULL, .rdata = &d,
452                                 .wlen = 0, .rlen = 1};
453         if (!ec || !data)
454                 return -EINVAL;
455
456         /*
457          * Query the EC to find out which _Qxx method we need to evaluate.
458          * Note that successful completion of the query causes the ACPI_EC_SCI
459          * bit to be cleared (and thus clearing the interrupt source).
460          */
461
462         result = acpi_ec_transaction(ec, &t);
463         if (result)
464                 return result;
465
466         if (!d)
467                 return -ENODATA;
468
469         *data = d;
470         return 0;
471 }
472
473 /* --------------------------------------------------------------------------
474                                 Event Management
475    -------------------------------------------------------------------------- */
476 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
477                               acpi_handle handle, acpi_ec_query_func func,
478                               void *data)
479 {
480         struct acpi_ec_query_handler *handler =
481             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
482         if (!handler)
483                 return -ENOMEM;
484
485         handler->query_bit = query_bit;
486         handler->handle = handle;
487         handler->func = func;
488         handler->data = data;
489         mutex_lock(&ec->lock);
490         list_add(&handler->node, &ec->list);
491         mutex_unlock(&ec->lock);
492         return 0;
493 }
494
495 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
496
497 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
498 {
499         struct acpi_ec_query_handler *handler, *tmp;
500         mutex_lock(&ec->lock);
501         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
502                 if (query_bit == handler->query_bit) {
503                         list_del(&handler->node);
504                         kfree(handler);
505                 }
506         }
507         mutex_unlock(&ec->lock);
508 }
509
510 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
511
512 static void acpi_ec_gpe_query(void *ec_cxt)
513 {
514         struct acpi_ec *ec = ec_cxt;
515         u8 value = 0;
516         struct acpi_ec_query_handler *handler, copy;
517
518         if (!ec || acpi_ec_query(ec, &value))
519                 return;
520         mutex_lock(&ec->lock);
521         list_for_each_entry(handler, &ec->list, node) {
522                 if (value == handler->query_bit) {
523                         /* have custom handler for this bit */
524                         memcpy(&copy, handler, sizeof(copy));
525                         mutex_unlock(&ec->lock);
526                         if (copy.func) {
527                                 copy.func(copy.data);
528                         } else if (copy.handle) {
529                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
530                         }
531                         return;
532                 }
533         }
534         mutex_unlock(&ec->lock);
535 }
536
537 static u32 acpi_ec_gpe_handler(void *data)
538 {
539         struct acpi_ec *ec = data;
540         u8 status;
541
542         pr_debug(PREFIX "~~~> interrupt\n");
543         status = acpi_ec_read_status(ec);
544
545         advance_transaction(ec, status);
546         if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0)
547                 wake_up(&ec->wait);
548         ec_check_sci(ec, status);
549         return ACPI_INTERRUPT_HANDLED;
550 }
551
552 /* --------------------------------------------------------------------------
553                              Address Space Management
554    -------------------------------------------------------------------------- */
555
556 static acpi_status
557 acpi_ec_space_handler(u32 function, acpi_physical_address address,
558                       u32 bits, acpi_integer *value,
559                       void *handler_context, void *region_context)
560 {
561         struct acpi_ec *ec = handler_context;
562         int result = 0, i;
563         u8 temp = 0;
564
565         if ((address > 0xFF) || !value || !handler_context)
566                 return AE_BAD_PARAMETER;
567
568         if (function != ACPI_READ && function != ACPI_WRITE)
569                 return AE_BAD_PARAMETER;
570
571         if (bits != 8 && acpi_strict)
572                 return AE_BAD_PARAMETER;
573
574         if (EC_FLAGS_MSI)
575                 acpi_ec_burst_enable(ec);
576
577         if (function == ACPI_READ) {
578                 result = acpi_ec_read(ec, address, &temp);
579                 *value = temp;
580         } else {
581                 temp = 0xff & (*value);
582                 result = acpi_ec_write(ec, address, temp);
583         }
584
585         for (i = 8; unlikely(bits - i > 0); i += 8) {
586                 ++address;
587                 if (function == ACPI_READ) {
588                         result = acpi_ec_read(ec, address, &temp);
589                         (*value) |= ((acpi_integer)temp) << i;
590                 } else {
591                         temp = 0xff & ((*value) >> i);
592                         result = acpi_ec_write(ec, address, temp);
593                 }
594         }
595
596         if (EC_FLAGS_MSI)
597                 acpi_ec_burst_disable(ec);
598
599         switch (result) {
600         case -EINVAL:
601                 return AE_BAD_PARAMETER;
602                 break;
603         case -ENODEV:
604                 return AE_NOT_FOUND;
605                 break;
606         case -ETIME:
607                 return AE_TIME;
608                 break;
609         default:
610                 return AE_OK;
611         }
612 }
613
614 /* --------------------------------------------------------------------------
615                               FS Interface (/proc)
616    -------------------------------------------------------------------------- */
617
618 static struct proc_dir_entry *acpi_ec_dir;
619
620 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
621 {
622         struct acpi_ec *ec = seq->private;
623
624         if (!ec)
625                 goto end;
626
627         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
628         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
629                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
630         seq_printf(seq, "use global lock:\t%s\n",
631                    ec->global_lock ? "yes" : "no");
632       end:
633         return 0;
634 }
635
636 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
637 {
638         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
639 }
640
641 static const struct file_operations acpi_ec_info_ops = {
642         .open = acpi_ec_info_open_fs,
643         .read = seq_read,
644         .llseek = seq_lseek,
645         .release = single_release,
646         .owner = THIS_MODULE,
647 };
648
649 static int acpi_ec_add_fs(struct acpi_device *device)
650 {
651         struct proc_dir_entry *entry = NULL;
652
653         if (!acpi_device_dir(device)) {
654                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
655                                                      acpi_ec_dir);
656                 if (!acpi_device_dir(device))
657                         return -ENODEV;
658         }
659
660         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
661                                  acpi_device_dir(device),
662                                  &acpi_ec_info_ops, acpi_driver_data(device));
663         if (!entry)
664                 return -ENODEV;
665         return 0;
666 }
667
668 static int acpi_ec_remove_fs(struct acpi_device *device)
669 {
670
671         if (acpi_device_dir(device)) {
672                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
673                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
674                 acpi_device_dir(device) = NULL;
675         }
676
677         return 0;
678 }
679
680 /* --------------------------------------------------------------------------
681                                Driver Interface
682    -------------------------------------------------------------------------- */
683 static acpi_status
684 ec_parse_io_ports(struct acpi_resource *resource, void *context);
685
686 static struct acpi_ec *make_acpi_ec(void)
687 {
688         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
689         if (!ec)
690                 return NULL;
691         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
692         mutex_init(&ec->lock);
693         init_waitqueue_head(&ec->wait);
694         INIT_LIST_HEAD(&ec->list);
695         spin_lock_init(&ec->curr_lock);
696         return ec;
697 }
698
699 static acpi_status
700 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
701                                void *context, void **return_value)
702 {
703         char node_name[5];
704         struct acpi_buffer buffer = { sizeof(node_name), node_name };
705         struct acpi_ec *ec = context;
706         int value = 0;
707         acpi_status status;
708
709         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
710
711         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
712                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
713         }
714         return AE_OK;
715 }
716
717 static acpi_status
718 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
719 {
720         acpi_status status;
721         unsigned long long tmp = 0;
722
723         struct acpi_ec *ec = context;
724
725         /* clear addr values, ec_parse_io_ports depend on it */
726         ec->command_addr = ec->data_addr = 0;
727
728         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
729                                      ec_parse_io_ports, ec);
730         if (ACPI_FAILURE(status))
731                 return status;
732
733         /* Get GPE bit assignment (EC events). */
734         /* TODO: Add support for _GPE returning a package */
735         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
736         if (ACPI_FAILURE(status))
737                 return status;
738         ec->gpe = tmp;
739         /* Use the global lock for all EC transactions? */
740         tmp = 0;
741         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
742         ec->global_lock = tmp;
743         ec->handle = handle;
744         return AE_CTRL_TERMINATE;
745 }
746
747 static void ec_remove_handlers(struct acpi_ec *ec)
748 {
749         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
750                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
751                 pr_err(PREFIX "failed to remove space handler\n");
752         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
753                                 &acpi_ec_gpe_handler)))
754                 pr_err(PREFIX "failed to remove gpe handler\n");
755         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
756 }
757
758 static int acpi_ec_add(struct acpi_device *device)
759 {
760         struct acpi_ec *ec = NULL;
761
762         if (!device)
763                 return -EINVAL;
764         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
765         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
766
767         /* Check for boot EC */
768         if (boot_ec &&
769             (boot_ec->handle == device->handle ||
770              boot_ec->handle == ACPI_ROOT_OBJECT)) {
771                 ec = boot_ec;
772                 boot_ec = NULL;
773         } else {
774                 ec = make_acpi_ec();
775                 if (!ec)
776                         return -ENOMEM;
777         }
778         if (ec_parse_device(device->handle, 0, ec, NULL) !=
779                 AE_CTRL_TERMINATE) {
780                         kfree(ec);
781                         return -EINVAL;
782         }
783
784         ec->handle = device->handle;
785
786         /* Find and register all query methods */
787         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
788                             acpi_ec_register_query_methods, ec, NULL);
789
790         if (!first_ec)
791                 first_ec = ec;
792         device->driver_data = ec;
793         acpi_ec_add_fs(device);
794         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
795                           ec->gpe, ec->command_addr, ec->data_addr);
796         return 0;
797 }
798
799 static int acpi_ec_remove(struct acpi_device *device, int type)
800 {
801         struct acpi_ec *ec;
802         struct acpi_ec_query_handler *handler, *tmp;
803
804         if (!device)
805                 return -EINVAL;
806
807         ec = acpi_driver_data(device);
808         mutex_lock(&ec->lock);
809         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
810                 list_del(&handler->node);
811                 kfree(handler);
812         }
813         mutex_unlock(&ec->lock);
814         acpi_ec_remove_fs(device);
815         device->driver_data = NULL;
816         if (ec == first_ec)
817                 first_ec = NULL;
818         kfree(ec);
819         return 0;
820 }
821
822 static acpi_status
823 ec_parse_io_ports(struct acpi_resource *resource, void *context)
824 {
825         struct acpi_ec *ec = context;
826
827         if (resource->type != ACPI_RESOURCE_TYPE_IO)
828                 return AE_OK;
829
830         /*
831          * The first address region returned is the data port, and
832          * the second address region returned is the status/command
833          * port.
834          */
835         if (ec->data_addr == 0)
836                 ec->data_addr = resource->data.io.minimum;
837         else if (ec->command_addr == 0)
838                 ec->command_addr = resource->data.io.minimum;
839         else
840                 return AE_CTRL_TERMINATE;
841
842         return AE_OK;
843 }
844
845 static int ec_install_handlers(struct acpi_ec *ec)
846 {
847         acpi_status status;
848         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
849                 return 0;
850         status = acpi_install_gpe_handler(NULL, ec->gpe,
851                                   ACPI_GPE_EDGE_TRIGGERED,
852                                   &acpi_ec_gpe_handler, ec);
853         if (ACPI_FAILURE(status))
854                 return -ENODEV;
855         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
856         acpi_enable_gpe(NULL, ec->gpe);
857         status = acpi_install_address_space_handler(ec->handle,
858                                                     ACPI_ADR_SPACE_EC,
859                                                     &acpi_ec_space_handler,
860                                                     NULL, ec);
861         if (ACPI_FAILURE(status)) {
862                 if (status == AE_NOT_FOUND) {
863                         /*
864                          * Maybe OS fails in evaluating the _REG object.
865                          * The AE_NOT_FOUND error will be ignored and OS
866                          * continue to initialize EC.
867                          */
868                         printk(KERN_ERR "Fail in evaluating the _REG object"
869                                 " of EC device. Broken bios is suspected.\n");
870                 } else {
871                         acpi_remove_gpe_handler(NULL, ec->gpe,
872                                 &acpi_ec_gpe_handler);
873                         return -ENODEV;
874                 }
875         }
876
877         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
878         return 0;
879 }
880
881 static int acpi_ec_start(struct acpi_device *device)
882 {
883         struct acpi_ec *ec;
884         int ret = 0;
885
886         if (!device)
887                 return -EINVAL;
888
889         ec = acpi_driver_data(device);
890
891         if (!ec)
892                 return -EINVAL;
893
894         ret = ec_install_handlers(ec);
895
896         /* EC is fully operational, allow queries */
897         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
898         return ret;
899 }
900
901 static int acpi_ec_stop(struct acpi_device *device, int type)
902 {
903         struct acpi_ec *ec;
904         if (!device)
905                 return -EINVAL;
906         ec = acpi_driver_data(device);
907         if (!ec)
908                 return -EINVAL;
909         ec_remove_handlers(ec);
910
911         return 0;
912 }
913
914 int __init acpi_boot_ec_enable(void)
915 {
916         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
917                 return 0;
918         if (!ec_install_handlers(boot_ec)) {
919                 first_ec = boot_ec;
920                 return 0;
921         }
922         return -EFAULT;
923 }
924
925 static const struct acpi_device_id ec_device_ids[] = {
926         {"PNP0C09", 0},
927         {"", 0},
928 };
929
930 int __init acpi_ec_ecdt_probe(void)
931 {
932         acpi_status status;
933         struct acpi_ec *saved_ec = NULL;
934         struct acpi_table_ecdt *ecdt_ptr;
935
936         boot_ec = make_acpi_ec();
937         if (!boot_ec)
938                 return -ENOMEM;
939         /*
940          * Generate a boot ec context
941          */
942         if (dmi_name_in_vendors("Micro-Star") ||
943             dmi_name_in_vendors("Notebook")) {
944                 pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
945                 EC_FLAGS_MSI = 1;
946         }
947         status = acpi_get_table(ACPI_SIG_ECDT, 1,
948                                 (struct acpi_table_header **)&ecdt_ptr);
949         if (ACPI_SUCCESS(status)) {
950                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
951                 boot_ec->command_addr = ecdt_ptr->control.address;
952                 boot_ec->data_addr = ecdt_ptr->data.address;
953                 boot_ec->gpe = ecdt_ptr->gpe;
954                 boot_ec->handle = ACPI_ROOT_OBJECT;
955                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
956                 /* Don't trust ECDT, which comes from ASUSTek */
957                 if (!dmi_name_in_vendors("ASUS") && EC_FLAGS_MSI == 0)
958                         goto install;
959                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
960                 if (!saved_ec)
961                         return -ENOMEM;
962                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
963         /* fall through */
964         }
965         /* This workaround is needed only on some broken machines,
966          * which require early EC, but fail to provide ECDT */
967         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
968         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
969                                         boot_ec, NULL);
970         /* Check that acpi_get_devices actually find something */
971         if (ACPI_FAILURE(status) || !boot_ec->handle)
972                 goto error;
973         if (saved_ec) {
974                 /* try to find good ECDT from ASUSTek */
975                 if (saved_ec->command_addr != boot_ec->command_addr ||
976                     saved_ec->data_addr != boot_ec->data_addr ||
977                     saved_ec->gpe != boot_ec->gpe ||
978                     saved_ec->handle != boot_ec->handle)
979                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
980                         "ECDT tables, which are very hard to workaround. "
981                         "Trying to use DSDT EC info instead. Please send "
982                         "output of acpidump to linux-acpi@vger.kernel.org\n");
983                 kfree(saved_ec);
984                 saved_ec = NULL;
985         } else {
986                 /* We really need to limit this workaround, the only ASUS,
987                 * which needs it, has fake EC._INI method, so use it as flag.
988                 * Keep boot_ec struct as it will be needed soon.
989                 */
990                 acpi_handle dummy;
991                 if (!dmi_name_in_vendors("ASUS") ||
992                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
993                                                         &dummy)))
994                         return -ENODEV;
995         }
996 install:
997         if (!ec_install_handlers(boot_ec)) {
998                 first_ec = boot_ec;
999                 return 0;
1000         }
1001 error:
1002         kfree(boot_ec);
1003         boot_ec = NULL;
1004         return -ENODEV;
1005 }
1006
1007 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1008 {
1009         struct acpi_ec *ec = acpi_driver_data(device);
1010         /* Stop using GPE */
1011         acpi_disable_gpe(NULL, ec->gpe);
1012         return 0;
1013 }
1014
1015 static int acpi_ec_resume(struct acpi_device *device)
1016 {
1017         struct acpi_ec *ec = acpi_driver_data(device);
1018         /* Enable use of GPE back */
1019         acpi_enable_gpe(NULL, ec->gpe);
1020         return 0;
1021 }
1022
1023 static struct acpi_driver acpi_ec_driver = {
1024         .name = "ec",
1025         .class = ACPI_EC_CLASS,
1026         .ids = ec_device_ids,
1027         .ops = {
1028                 .add = acpi_ec_add,
1029                 .remove = acpi_ec_remove,
1030                 .start = acpi_ec_start,
1031                 .stop = acpi_ec_stop,
1032                 .suspend = acpi_ec_suspend,
1033                 .resume = acpi_ec_resume,
1034                 },
1035 };
1036
1037 int __init acpi_ec_init(void)
1038 {
1039         int result = 0;
1040
1041         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1042         if (!acpi_ec_dir)
1043                 return -ENODEV;
1044
1045         /* Now register the driver for the EC */
1046         result = acpi_bus_register_driver(&acpi_ec_driver);
1047         if (result < 0) {
1048                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1049                 return -ENODEV;
1050         }
1051
1052         return result;
1053 }
1054
1055 /* EC driver currently not unloadable */
1056 #if 0
1057 static void __exit acpi_ec_exit(void)
1058 {
1059
1060         acpi_bus_unregister_driver(&acpi_ec_driver);
1061
1062         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1063
1064         return;
1065 }
1066 #endif  /* 0 */