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ACPI / EC: Fix a code path that global lock is not held
[deliverable/linux.git] / drivers / acpi / ec.c
1 /*
2 * ec.c - ACPI Embedded Controller Driver (v2.2)
3 *
4 * Copyright (C) 2001-2014 Intel Corporation
5 * Author: 2014 Lv Zheng <lv.zheng@intel.com>
6 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
7 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
8 * 2004 Luming Yu <luming.yu@intel.com>
9 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
10 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
11 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
12 *
13 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or (at
18 * your option) any later version.
19 *
20 * This program is distributed in the hope that it will be useful, but
21 * WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 * General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License along
26 * with this program; if not, write to the Free Software Foundation, Inc.,
27 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
28 *
29 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
30 */
31
32 /* Uncomment next line to get verbose printout */
33 /* #define DEBUG */
34 #define pr_fmt(fmt) "ACPI : EC: " fmt
35
36 #include <linux/kernel.h>
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/types.h>
40 #include <linux/delay.h>
41 #include <linux/interrupt.h>
42 #include <linux/list.h>
43 #include <linux/spinlock.h>
44 #include <linux/slab.h>
45 #include <linux/acpi.h>
46 #include <linux/dmi.h>
47 #include <asm/io.h>
48
49 #include "internal.h"
50
51 #define ACPI_EC_CLASS "embedded_controller"
52 #define ACPI_EC_DEVICE_NAME "Embedded Controller"
53 #define ACPI_EC_FILE_INFO "info"
54
55 /* EC status register */
56 #define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
57 #define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
58 #define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
59 #define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
60 #define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
61
62 /* EC commands */
63 enum ec_command {
64 ACPI_EC_COMMAND_READ = 0x80,
65 ACPI_EC_COMMAND_WRITE = 0x81,
66 ACPI_EC_BURST_ENABLE = 0x82,
67 ACPI_EC_BURST_DISABLE = 0x83,
68 ACPI_EC_COMMAND_QUERY = 0x84,
69 };
70
71 #define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
72 #define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
73 #define ACPI_EC_MSI_UDELAY 550 /* Wait 550us for MSI EC */
74 #define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
75 * when trying to clear the EC */
76
77 enum {
78 EC_FLAGS_QUERY_PENDING, /* Query is pending */
79 EC_FLAGS_GPE_STORM, /* GPE storm detected */
80 EC_FLAGS_HANDLERS_INSTALLED, /* Handlers for GPE and
81 * OpReg are installed */
82 EC_FLAGS_BLOCKED, /* Transactions are blocked */
83 };
84
85 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
86 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
87
88 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
89 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
90 module_param(ec_delay, uint, 0644);
91 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
92
93 /*
94 * If the number of false interrupts per one transaction exceeds
95 * this threshold, will think there is a GPE storm happened and
96 * will disable the GPE for normal transaction.
97 */
98 static unsigned int ec_storm_threshold __read_mostly = 8;
99 module_param(ec_storm_threshold, uint, 0644);
100 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
101
102 struct acpi_ec_query_handler {
103 struct list_head node;
104 acpi_ec_query_func func;
105 acpi_handle handle;
106 void *data;
107 u8 query_bit;
108 struct kref kref;
109 };
110
111 struct transaction {
112 const u8 *wdata;
113 u8 *rdata;
114 unsigned short irq_count;
115 u8 command;
116 u8 wi;
117 u8 ri;
118 u8 wlen;
119 u8 rlen;
120 u8 flags;
121 };
122
123 struct acpi_ec *boot_ec, *first_ec;
124 EXPORT_SYMBOL(first_ec);
125
126 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
127 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
128 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
129 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
130 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
131
132 /* --------------------------------------------------------------------------
133 * Transaction Management
134 * -------------------------------------------------------------------------- */
135
136 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
137 {
138 u8 x = inb(ec->command_addr);
139
140 pr_debug("EC_SC(R) = 0x%2.2x "
141 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
142 x,
143 !!(x & ACPI_EC_FLAG_SCI),
144 !!(x & ACPI_EC_FLAG_BURST),
145 !!(x & ACPI_EC_FLAG_CMD),
146 !!(x & ACPI_EC_FLAG_IBF),
147 !!(x & ACPI_EC_FLAG_OBF));
148 return x;
149 }
150
151 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
152 {
153 u8 x = inb(ec->data_addr);
154
155 pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
156 return x;
157 }
158
159 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
160 {
161 pr_debug("EC_SC(W) = 0x%2.2x\n", command);
162 outb(command, ec->command_addr);
163 }
164
165 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
166 {
167 pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
168 outb(data, ec->data_addr);
169 }
170
171 #ifdef DEBUG
172 static const char *acpi_ec_cmd_string(u8 cmd)
173 {
174 switch (cmd) {
175 case 0x80:
176 return "RD_EC";
177 case 0x81:
178 return "WR_EC";
179 case 0x82:
180 return "BE_EC";
181 case 0x83:
182 return "BD_EC";
183 case 0x84:
184 return "QR_EC";
185 }
186 return "UNKNOWN";
187 }
188 #else
189 #define acpi_ec_cmd_string(cmd) "UNDEF"
190 #endif
191
192 static int ec_transaction_completed(struct acpi_ec *ec)
193 {
194 unsigned long flags;
195 int ret = 0;
196
197 spin_lock_irqsave(&ec->lock, flags);
198 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
199 ret = 1;
200 spin_unlock_irqrestore(&ec->lock, flags);
201 return ret;
202 }
203
204 static void advance_transaction(struct acpi_ec *ec)
205 {
206 struct transaction *t;
207 u8 status;
208 bool wakeup = false;
209
210 pr_debug("===== %s (%d) =====\n",
211 in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
212 status = acpi_ec_read_status(ec);
213 t = ec->curr;
214 if (!t)
215 goto err;
216 if (t->flags & ACPI_EC_COMMAND_POLL) {
217 if (t->wlen > t->wi) {
218 if ((status & ACPI_EC_FLAG_IBF) == 0)
219 acpi_ec_write_data(ec, t->wdata[t->wi++]);
220 else
221 goto err;
222 } else if (t->rlen > t->ri) {
223 if ((status & ACPI_EC_FLAG_OBF) == 1) {
224 t->rdata[t->ri++] = acpi_ec_read_data(ec);
225 if (t->rlen == t->ri) {
226 t->flags |= ACPI_EC_COMMAND_COMPLETE;
227 if (t->command == ACPI_EC_COMMAND_QUERY)
228 pr_debug("***** Command(%s) hardware completion *****\n",
229 acpi_ec_cmd_string(t->command));
230 wakeup = true;
231 }
232 } else
233 goto err;
234 } else if (t->wlen == t->wi &&
235 (status & ACPI_EC_FLAG_IBF) == 0) {
236 t->flags |= ACPI_EC_COMMAND_COMPLETE;
237 wakeup = true;
238 }
239 goto out;
240 } else {
241 if (EC_FLAGS_QUERY_HANDSHAKE &&
242 !(status & ACPI_EC_FLAG_SCI) &&
243 (t->command == ACPI_EC_COMMAND_QUERY)) {
244 t->flags |= ACPI_EC_COMMAND_POLL;
245 t->rdata[t->ri++] = 0x00;
246 t->flags |= ACPI_EC_COMMAND_COMPLETE;
247 pr_debug("***** Command(%s) software completion *****\n",
248 acpi_ec_cmd_string(t->command));
249 wakeup = true;
250 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
251 acpi_ec_write_cmd(ec, t->command);
252 t->flags |= ACPI_EC_COMMAND_POLL;
253 } else
254 goto err;
255 goto out;
256 }
257 err:
258 /*
259 * If SCI bit is set, then don't think it's a false IRQ
260 * otherwise will take a not handled IRQ as a false one.
261 */
262 if (!(status & ACPI_EC_FLAG_SCI)) {
263 if (in_interrupt() && t)
264 ++t->irq_count;
265 }
266 out:
267 if (wakeup && in_interrupt())
268 wake_up(&ec->wait);
269 }
270
271 static void start_transaction(struct acpi_ec *ec)
272 {
273 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
274 ec->curr->flags = 0;
275 advance_transaction(ec);
276 }
277
278 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
279
280 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
281 {
282 if (state & ACPI_EC_FLAG_SCI) {
283 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
284 return acpi_ec_sync_query(ec, NULL);
285 }
286 return 0;
287 }
288
289 static int ec_poll(struct acpi_ec *ec)
290 {
291 unsigned long flags;
292 int repeat = 5; /* number of command restarts */
293
294 while (repeat--) {
295 unsigned long delay = jiffies +
296 msecs_to_jiffies(ec_delay);
297 do {
298 /* don't sleep with disabled interrupts */
299 if (EC_FLAGS_MSI || irqs_disabled()) {
300 udelay(ACPI_EC_MSI_UDELAY);
301 if (ec_transaction_completed(ec))
302 return 0;
303 } else {
304 if (wait_event_timeout(ec->wait,
305 ec_transaction_completed(ec),
306 msecs_to_jiffies(1)))
307 return 0;
308 }
309 spin_lock_irqsave(&ec->lock, flags);
310 advance_transaction(ec);
311 spin_unlock_irqrestore(&ec->lock, flags);
312 } while (time_before(jiffies, delay));
313 pr_debug("controller reset, restart transaction\n");
314 spin_lock_irqsave(&ec->lock, flags);
315 start_transaction(ec);
316 spin_unlock_irqrestore(&ec->lock, flags);
317 }
318 return -ETIME;
319 }
320
321 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
322 struct transaction *t)
323 {
324 unsigned long tmp;
325 int ret = 0;
326
327 if (EC_FLAGS_MSI)
328 udelay(ACPI_EC_MSI_UDELAY);
329 /* start transaction */
330 spin_lock_irqsave(&ec->lock, tmp);
331 /* following two actions should be kept atomic */
332 ec->curr = t;
333 pr_debug("***** Command(%s) started *****\n",
334 acpi_ec_cmd_string(t->command));
335 start_transaction(ec);
336 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
337 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
338 pr_debug("***** Event stopped *****\n");
339 }
340 spin_unlock_irqrestore(&ec->lock, tmp);
341 ret = ec_poll(ec);
342 spin_lock_irqsave(&ec->lock, tmp);
343 pr_debug("***** Command(%s) stopped *****\n",
344 acpi_ec_cmd_string(t->command));
345 ec->curr = NULL;
346 spin_unlock_irqrestore(&ec->lock, tmp);
347 return ret;
348 }
349
350 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
351 {
352 int status;
353 u32 glk;
354
355 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
356 return -EINVAL;
357 if (t->rdata)
358 memset(t->rdata, 0, t->rlen);
359 mutex_lock(&ec->mutex);
360 if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
361 status = -EINVAL;
362 goto unlock;
363 }
364 if (ec->global_lock) {
365 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
366 if (ACPI_FAILURE(status)) {
367 status = -ENODEV;
368 goto unlock;
369 }
370 }
371 /* disable GPE during transaction if storm is detected */
372 if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
373 /* It has to be disabled, so that it doesn't trigger. */
374 acpi_disable_gpe(NULL, ec->gpe);
375 }
376
377 status = acpi_ec_transaction_unlocked(ec, t);
378
379 /* check if we received SCI during transaction */
380 ec_check_sci_sync(ec, acpi_ec_read_status(ec));
381 if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
382 msleep(1);
383 /* It is safe to enable the GPE outside of the transaction. */
384 acpi_enable_gpe(NULL, ec->gpe);
385 } else if (t->irq_count > ec_storm_threshold) {
386 pr_info("GPE storm detected(%d GPEs), "
387 "transactions will use polling mode\n",
388 t->irq_count);
389 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
390 }
391 if (ec->global_lock)
392 acpi_release_global_lock(glk);
393 unlock:
394 mutex_unlock(&ec->mutex);
395 return status;
396 }
397
398 static int acpi_ec_burst_enable(struct acpi_ec *ec)
399 {
400 u8 d;
401 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
402 .wdata = NULL, .rdata = &d,
403 .wlen = 0, .rlen = 1};
404
405 return acpi_ec_transaction(ec, &t);
406 }
407
408 static int acpi_ec_burst_disable(struct acpi_ec *ec)
409 {
410 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
411 .wdata = NULL, .rdata = NULL,
412 .wlen = 0, .rlen = 0};
413
414 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
415 acpi_ec_transaction(ec, &t) : 0;
416 }
417
418 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
419 {
420 int result;
421 u8 d;
422 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
423 .wdata = &address, .rdata = &d,
424 .wlen = 1, .rlen = 1};
425
426 result = acpi_ec_transaction(ec, &t);
427 *data = d;
428 return result;
429 }
430
431 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
432 {
433 u8 wdata[2] = { address, data };
434 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
435 .wdata = wdata, .rdata = NULL,
436 .wlen = 2, .rlen = 0};
437
438 return acpi_ec_transaction(ec, &t);
439 }
440
441 int ec_read(u8 addr, u8 *val)
442 {
443 int err;
444 u8 temp_data;
445
446 if (!first_ec)
447 return -ENODEV;
448
449 err = acpi_ec_read(first_ec, addr, &temp_data);
450
451 if (!err) {
452 *val = temp_data;
453 return 0;
454 }
455 return err;
456 }
457 EXPORT_SYMBOL(ec_read);
458
459 int ec_write(u8 addr, u8 val)
460 {
461 int err;
462
463 if (!first_ec)
464 return -ENODEV;
465
466 err = acpi_ec_write(first_ec, addr, val);
467
468 return err;
469 }
470 EXPORT_SYMBOL(ec_write);
471
472 int ec_transaction(u8 command,
473 const u8 *wdata, unsigned wdata_len,
474 u8 *rdata, unsigned rdata_len)
475 {
476 struct transaction t = {.command = command,
477 .wdata = wdata, .rdata = rdata,
478 .wlen = wdata_len, .rlen = rdata_len};
479
480 if (!first_ec)
481 return -ENODEV;
482
483 return acpi_ec_transaction(first_ec, &t);
484 }
485 EXPORT_SYMBOL(ec_transaction);
486
487 /* Get the handle to the EC device */
488 acpi_handle ec_get_handle(void)
489 {
490 if (!first_ec)
491 return NULL;
492 return first_ec->handle;
493 }
494 EXPORT_SYMBOL(ec_get_handle);
495
496 /*
497 * Process _Q events that might have accumulated in the EC.
498 * Run with locked ec mutex.
499 */
500 static void acpi_ec_clear(struct acpi_ec *ec)
501 {
502 int i, status;
503 u8 value = 0;
504
505 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
506 status = acpi_ec_sync_query(ec, &value);
507 if (status || !value)
508 break;
509 }
510
511 if (unlikely(i == ACPI_EC_CLEAR_MAX))
512 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
513 else
514 pr_info("%d stale EC events cleared\n", i);
515 }
516
517 void acpi_ec_block_transactions(void)
518 {
519 struct acpi_ec *ec = first_ec;
520
521 if (!ec)
522 return;
523
524 mutex_lock(&ec->mutex);
525 /* Prevent transactions from being carried out */
526 set_bit(EC_FLAGS_BLOCKED, &ec->flags);
527 mutex_unlock(&ec->mutex);
528 }
529
530 void acpi_ec_unblock_transactions(void)
531 {
532 struct acpi_ec *ec = first_ec;
533
534 if (!ec)
535 return;
536
537 mutex_lock(&ec->mutex);
538 /* Allow transactions to be carried out again */
539 clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
540
541 if (EC_FLAGS_CLEAR_ON_RESUME)
542 acpi_ec_clear(ec);
543
544 mutex_unlock(&ec->mutex);
545 }
546
547 void acpi_ec_unblock_transactions_early(void)
548 {
549 /*
550 * Allow transactions to happen again (this function is called from
551 * atomic context during wakeup, so we don't need to acquire the mutex).
552 */
553 if (first_ec)
554 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
555 }
556
557 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data)
558 {
559 int result;
560 u8 d;
561 struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
562 .wdata = NULL, .rdata = &d,
563 .wlen = 0, .rlen = 1};
564
565 if (!ec || !data)
566 return -EINVAL;
567 /*
568 * Query the EC to find out which _Qxx method we need to evaluate.
569 * Note that successful completion of the query causes the ACPI_EC_SCI
570 * bit to be cleared (and thus clearing the interrupt source).
571 */
572 result = acpi_ec_transaction_unlocked(ec, &t);
573 if (result)
574 return result;
575 if (!d)
576 return -ENODATA;
577 *data = d;
578 return 0;
579 }
580
581 /* --------------------------------------------------------------------------
582 Event Management
583 -------------------------------------------------------------------------- */
584 static struct acpi_ec_query_handler *
585 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
586 {
587 if (handler)
588 kref_get(&handler->kref);
589 return handler;
590 }
591
592 static void acpi_ec_query_handler_release(struct kref *kref)
593 {
594 struct acpi_ec_query_handler *handler =
595 container_of(kref, struct acpi_ec_query_handler, kref);
596
597 kfree(handler);
598 }
599
600 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
601 {
602 kref_put(&handler->kref, acpi_ec_query_handler_release);
603 }
604
605 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
606 acpi_handle handle, acpi_ec_query_func func,
607 void *data)
608 {
609 struct acpi_ec_query_handler *handler =
610 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
611
612 if (!handler)
613 return -ENOMEM;
614
615 handler->query_bit = query_bit;
616 handler->handle = handle;
617 handler->func = func;
618 handler->data = data;
619 mutex_lock(&ec->mutex);
620 kref_init(&handler->kref);
621 list_add(&handler->node, &ec->list);
622 mutex_unlock(&ec->mutex);
623 return 0;
624 }
625 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
626
627 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
628 {
629 struct acpi_ec_query_handler *handler, *tmp;
630 LIST_HEAD(free_list);
631
632 mutex_lock(&ec->mutex);
633 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
634 if (query_bit == handler->query_bit) {
635 list_del_init(&handler->node);
636 list_add(&handler->node, &free_list);
637 }
638 }
639 mutex_unlock(&ec->mutex);
640 list_for_each_entry(handler, &free_list, node)
641 acpi_ec_put_query_handler(handler);
642 }
643 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
644
645 static void acpi_ec_run(void *cxt)
646 {
647 struct acpi_ec_query_handler *handler = cxt;
648
649 if (!handler)
650 return;
651 pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
652 if (handler->func)
653 handler->func(handler->data);
654 else if (handler->handle)
655 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
656 pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
657 acpi_ec_put_query_handler(handler);
658 }
659
660 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
661 {
662 u8 value = 0;
663 int result;
664 acpi_status status;
665 struct acpi_ec_query_handler *handler;
666
667 result = acpi_ec_query_unlocked(ec, &value);
668 if (data)
669 *data = value;
670 if (result)
671 return result;
672
673 list_for_each_entry(handler, &ec->list, node) {
674 if (value == handler->query_bit) {
675 /* have custom handler for this bit */
676 handler = acpi_ec_get_query_handler(handler);
677 pr_debug("##### Query(0x%02x) scheduled #####\n",
678 handler->query_bit);
679 status = acpi_os_execute((handler->func) ?
680 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
681 acpi_ec_run, handler);
682 if (ACPI_FAILURE(status))
683 result = -EBUSY;
684 break;
685 }
686 }
687 return result;
688 }
689
690 static void acpi_ec_gpe_query(void *ec_cxt)
691 {
692 struct acpi_ec *ec = ec_cxt;
693 acpi_status status;
694 u32 glk;
695
696 if (!ec)
697 return;
698 mutex_lock(&ec->mutex);
699 if (ec->global_lock) {
700 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
701 if (ACPI_FAILURE(status))
702 goto unlock;
703 }
704 acpi_ec_sync_query(ec, NULL);
705 if (ec->global_lock)
706 acpi_release_global_lock(glk);
707 unlock:
708 mutex_unlock(&ec->mutex);
709 }
710
711 static int ec_check_sci(struct acpi_ec *ec, u8 state)
712 {
713 if (state & ACPI_EC_FLAG_SCI) {
714 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
715 pr_debug("***** Event started *****\n");
716 return acpi_os_execute(OSL_NOTIFY_HANDLER,
717 acpi_ec_gpe_query, ec);
718 }
719 }
720 return 0;
721 }
722
723 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
724 u32 gpe_number, void *data)
725 {
726 unsigned long flags;
727 struct acpi_ec *ec = data;
728
729 spin_lock_irqsave(&ec->lock, flags);
730 advance_transaction(ec);
731 spin_unlock_irqrestore(&ec->lock, flags);
732 ec_check_sci(ec, acpi_ec_read_status(ec));
733 return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
734 }
735
736 /* --------------------------------------------------------------------------
737 * Address Space Management
738 * -------------------------------------------------------------------------- */
739
740 static acpi_status
741 acpi_ec_space_handler(u32 function, acpi_physical_address address,
742 u32 bits, u64 *value64,
743 void *handler_context, void *region_context)
744 {
745 struct acpi_ec *ec = handler_context;
746 int result = 0, i, bytes = bits / 8;
747 u8 *value = (u8 *)value64;
748
749 if ((address > 0xFF) || !value || !handler_context)
750 return AE_BAD_PARAMETER;
751
752 if (function != ACPI_READ && function != ACPI_WRITE)
753 return AE_BAD_PARAMETER;
754
755 if (EC_FLAGS_MSI || bits > 8)
756 acpi_ec_burst_enable(ec);
757
758 for (i = 0; i < bytes; ++i, ++address, ++value)
759 result = (function == ACPI_READ) ?
760 acpi_ec_read(ec, address, value) :
761 acpi_ec_write(ec, address, *value);
762
763 if (EC_FLAGS_MSI || bits > 8)
764 acpi_ec_burst_disable(ec);
765
766 switch (result) {
767 case -EINVAL:
768 return AE_BAD_PARAMETER;
769 case -ENODEV:
770 return AE_NOT_FOUND;
771 case -ETIME:
772 return AE_TIME;
773 default:
774 return AE_OK;
775 }
776 }
777
778 /* --------------------------------------------------------------------------
779 * Driver Interface
780 * -------------------------------------------------------------------------- */
781
782 static acpi_status
783 ec_parse_io_ports(struct acpi_resource *resource, void *context);
784
785 static struct acpi_ec *make_acpi_ec(void)
786 {
787 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
788
789 if (!ec)
790 return NULL;
791 ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
792 mutex_init(&ec->mutex);
793 init_waitqueue_head(&ec->wait);
794 INIT_LIST_HEAD(&ec->list);
795 spin_lock_init(&ec->lock);
796 return ec;
797 }
798
799 static acpi_status
800 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
801 void *context, void **return_value)
802 {
803 char node_name[5];
804 struct acpi_buffer buffer = { sizeof(node_name), node_name };
805 struct acpi_ec *ec = context;
806 int value = 0;
807 acpi_status status;
808
809 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
810
811 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
812 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
813 return AE_OK;
814 }
815
816 static acpi_status
817 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
818 {
819 acpi_status status;
820 unsigned long long tmp = 0;
821 struct acpi_ec *ec = context;
822
823 /* clear addr values, ec_parse_io_ports depend on it */
824 ec->command_addr = ec->data_addr = 0;
825
826 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
827 ec_parse_io_ports, ec);
828 if (ACPI_FAILURE(status))
829 return status;
830
831 /* Get GPE bit assignment (EC events). */
832 /* TODO: Add support for _GPE returning a package */
833 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
834 if (ACPI_FAILURE(status))
835 return status;
836 ec->gpe = tmp;
837 /* Use the global lock for all EC transactions? */
838 tmp = 0;
839 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
840 ec->global_lock = tmp;
841 ec->handle = handle;
842 return AE_CTRL_TERMINATE;
843 }
844
845 static int ec_install_handlers(struct acpi_ec *ec)
846 {
847 acpi_status status;
848
849 if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
850 return 0;
851 status = acpi_install_gpe_handler(NULL, ec->gpe,
852 ACPI_GPE_EDGE_TRIGGERED,
853 &acpi_ec_gpe_handler, ec);
854 if (ACPI_FAILURE(status))
855 return -ENODEV;
856
857 acpi_enable_gpe(NULL, ec->gpe);
858 status = acpi_install_address_space_handler(ec->handle,
859 ACPI_ADR_SPACE_EC,
860 &acpi_ec_space_handler,
861 NULL, ec);
862 if (ACPI_FAILURE(status)) {
863 if (status == AE_NOT_FOUND) {
864 /*
865 * Maybe OS fails in evaluating the _REG object.
866 * The AE_NOT_FOUND error will be ignored and OS
867 * continue to initialize EC.
868 */
869 pr_err("Fail in evaluating the _REG object"
870 " of EC device. Broken bios is suspected.\n");
871 } else {
872 acpi_disable_gpe(NULL, ec->gpe);
873 acpi_remove_gpe_handler(NULL, ec->gpe,
874 &acpi_ec_gpe_handler);
875 return -ENODEV;
876 }
877 }
878
879 set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
880 return 0;
881 }
882
883 static void ec_remove_handlers(struct acpi_ec *ec)
884 {
885 if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
886 return;
887 acpi_disable_gpe(NULL, ec->gpe);
888 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
889 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
890 pr_err("failed to remove space handler\n");
891 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
892 &acpi_ec_gpe_handler)))
893 pr_err("failed to remove gpe handler\n");
894 clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
895 }
896
897 static int acpi_ec_add(struct acpi_device *device)
898 {
899 struct acpi_ec *ec = NULL;
900 int ret;
901
902 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
903 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
904
905 /* Check for boot EC */
906 if (boot_ec &&
907 (boot_ec->handle == device->handle ||
908 boot_ec->handle == ACPI_ROOT_OBJECT)) {
909 ec = boot_ec;
910 boot_ec = NULL;
911 } else {
912 ec = make_acpi_ec();
913 if (!ec)
914 return -ENOMEM;
915 }
916 if (ec_parse_device(device->handle, 0, ec, NULL) !=
917 AE_CTRL_TERMINATE) {
918 kfree(ec);
919 return -EINVAL;
920 }
921
922 /* Find and register all query methods */
923 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
924 acpi_ec_register_query_methods, NULL, ec, NULL);
925
926 if (!first_ec)
927 first_ec = ec;
928 device->driver_data = ec;
929
930 ret = !!request_region(ec->data_addr, 1, "EC data");
931 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
932 ret = !!request_region(ec->command_addr, 1, "EC cmd");
933 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
934
935 pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
936 ec->gpe, ec->command_addr, ec->data_addr);
937
938 ret = ec_install_handlers(ec);
939
940 /* EC is fully operational, allow queries */
941 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
942
943 /* Clear stale _Q events if hardware might require that */
944 if (EC_FLAGS_CLEAR_ON_RESUME) {
945 mutex_lock(&ec->mutex);
946 acpi_ec_clear(ec);
947 mutex_unlock(&ec->mutex);
948 }
949 return ret;
950 }
951
952 static int acpi_ec_remove(struct acpi_device *device)
953 {
954 struct acpi_ec *ec;
955 struct acpi_ec_query_handler *handler, *tmp;
956
957 if (!device)
958 return -EINVAL;
959
960 ec = acpi_driver_data(device);
961 ec_remove_handlers(ec);
962 mutex_lock(&ec->mutex);
963 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
964 list_del(&handler->node);
965 kfree(handler);
966 }
967 mutex_unlock(&ec->mutex);
968 release_region(ec->data_addr, 1);
969 release_region(ec->command_addr, 1);
970 device->driver_data = NULL;
971 if (ec == first_ec)
972 first_ec = NULL;
973 kfree(ec);
974 return 0;
975 }
976
977 static acpi_status
978 ec_parse_io_ports(struct acpi_resource *resource, void *context)
979 {
980 struct acpi_ec *ec = context;
981
982 if (resource->type != ACPI_RESOURCE_TYPE_IO)
983 return AE_OK;
984
985 /*
986 * The first address region returned is the data port, and
987 * the second address region returned is the status/command
988 * port.
989 */
990 if (ec->data_addr == 0)
991 ec->data_addr = resource->data.io.minimum;
992 else if (ec->command_addr == 0)
993 ec->command_addr = resource->data.io.minimum;
994 else
995 return AE_CTRL_TERMINATE;
996
997 return AE_OK;
998 }
999
1000 int __init acpi_boot_ec_enable(void)
1001 {
1002 if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1003 return 0;
1004 if (!ec_install_handlers(boot_ec)) {
1005 first_ec = boot_ec;
1006 return 0;
1007 }
1008 return -EFAULT;
1009 }
1010
1011 static const struct acpi_device_id ec_device_ids[] = {
1012 {"PNP0C09", 0},
1013 {"", 0},
1014 };
1015
1016 /* Some BIOS do not survive early DSDT scan, skip it */
1017 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1018 {
1019 EC_FLAGS_SKIP_DSDT_SCAN = 1;
1020 return 0;
1021 }
1022
1023 /* ASUStek often supplies us with broken ECDT, validate it */
1024 static int ec_validate_ecdt(const struct dmi_system_id *id)
1025 {
1026 EC_FLAGS_VALIDATE_ECDT = 1;
1027 return 0;
1028 }
1029
1030 /* MSI EC needs special treatment, enable it */
1031 static int ec_flag_msi(const struct dmi_system_id *id)
1032 {
1033 pr_debug("Detected MSI hardware, enabling workarounds.\n");
1034 EC_FLAGS_MSI = 1;
1035 EC_FLAGS_VALIDATE_ECDT = 1;
1036 return 0;
1037 }
1038
1039 /*
1040 * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1041 * the GPE storm threshold back to 20
1042 */
1043 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1044 {
1045 pr_debug("Setting the EC GPE storm threshold to 20\n");
1046 ec_storm_threshold = 20;
1047 return 0;
1048 }
1049
1050 /*
1051 * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1052 * which case, we complete the QR_EC without issuing it to the firmware.
1053 * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1054 */
1055 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1056 {
1057 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1058 EC_FLAGS_QUERY_HANDSHAKE = 1;
1059 return 0;
1060 }
1061
1062 /*
1063 * On some hardware it is necessary to clear events accumulated by the EC during
1064 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1065 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1066 *
1067 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1068 *
1069 * Ideally, the EC should also be instructed NOT to accumulate events during
1070 * sleep (which Windows seems to do somehow), but the interface to control this
1071 * behaviour is not known at this time.
1072 *
1073 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1074 * however it is very likely that other Samsung models are affected.
1075 *
1076 * On systems which don't accumulate _Q events during sleep, this extra check
1077 * should be harmless.
1078 */
1079 static int ec_clear_on_resume(const struct dmi_system_id *id)
1080 {
1081 pr_debug("Detected system needing EC poll on resume.\n");
1082 EC_FLAGS_CLEAR_ON_RESUME = 1;
1083 return 0;
1084 }
1085
1086 static struct dmi_system_id ec_dmi_table[] __initdata = {
1087 {
1088 ec_skip_dsdt_scan, "Compal JFL92", {
1089 DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1090 DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1091 {
1092 ec_flag_msi, "MSI hardware", {
1093 DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1094 {
1095 ec_flag_msi, "MSI hardware", {
1096 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1097 {
1098 ec_flag_msi, "MSI hardware", {
1099 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1100 {
1101 ec_flag_msi, "MSI hardware", {
1102 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1103 {
1104 ec_flag_msi, "Quanta hardware", {
1105 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1106 DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1107 {
1108 ec_flag_msi, "Quanta hardware", {
1109 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1110 DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1111 {
1112 ec_flag_msi, "Clevo W350etq", {
1113 DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1114 DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1115 {
1116 ec_validate_ecdt, "ASUS hardware", {
1117 DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1118 {
1119 ec_validate_ecdt, "ASUS hardware", {
1120 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1121 {
1122 ec_enlarge_storm_threshold, "CLEVO hardware", {
1123 DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1124 DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1125 {
1126 ec_skip_dsdt_scan, "HP Folio 13", {
1127 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1128 DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1129 {
1130 ec_validate_ecdt, "ASUS hardware", {
1131 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1132 DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1133 {
1134 ec_clear_on_resume, "Samsung hardware", {
1135 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1136 {
1137 ec_flag_query_handshake, "Acer hardware", {
1138 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1139 {},
1140 };
1141
1142 int __init acpi_ec_ecdt_probe(void)
1143 {
1144 acpi_status status;
1145 struct acpi_ec *saved_ec = NULL;
1146 struct acpi_table_ecdt *ecdt_ptr;
1147
1148 boot_ec = make_acpi_ec();
1149 if (!boot_ec)
1150 return -ENOMEM;
1151 /*
1152 * Generate a boot ec context
1153 */
1154 dmi_check_system(ec_dmi_table);
1155 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1156 (struct acpi_table_header **)&ecdt_ptr);
1157 if (ACPI_SUCCESS(status)) {
1158 pr_info("EC description table is found, configuring boot EC\n");
1159 boot_ec->command_addr = ecdt_ptr->control.address;
1160 boot_ec->data_addr = ecdt_ptr->data.address;
1161 boot_ec->gpe = ecdt_ptr->gpe;
1162 boot_ec->handle = ACPI_ROOT_OBJECT;
1163 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1164 &boot_ec->handle);
1165 /* Don't trust ECDT, which comes from ASUSTek */
1166 if (!EC_FLAGS_VALIDATE_ECDT)
1167 goto install;
1168 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1169 if (!saved_ec)
1170 return -ENOMEM;
1171 /* fall through */
1172 }
1173
1174 if (EC_FLAGS_SKIP_DSDT_SCAN) {
1175 kfree(saved_ec);
1176 return -ENODEV;
1177 }
1178
1179 /* This workaround is needed only on some broken machines,
1180 * which require early EC, but fail to provide ECDT */
1181 pr_debug("Look up EC in DSDT\n");
1182 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1183 boot_ec, NULL);
1184 /* Check that acpi_get_devices actually find something */
1185 if (ACPI_FAILURE(status) || !boot_ec->handle)
1186 goto error;
1187 if (saved_ec) {
1188 /* try to find good ECDT from ASUSTek */
1189 if (saved_ec->command_addr != boot_ec->command_addr ||
1190 saved_ec->data_addr != boot_ec->data_addr ||
1191 saved_ec->gpe != boot_ec->gpe ||
1192 saved_ec->handle != boot_ec->handle)
1193 pr_info("ASUSTek keeps feeding us with broken "
1194 "ECDT tables, which are very hard to workaround. "
1195 "Trying to use DSDT EC info instead. Please send "
1196 "output of acpidump to linux-acpi@vger.kernel.org\n");
1197 kfree(saved_ec);
1198 saved_ec = NULL;
1199 } else {
1200 /* We really need to limit this workaround, the only ASUS,
1201 * which needs it, has fake EC._INI method, so use it as flag.
1202 * Keep boot_ec struct as it will be needed soon.
1203 */
1204 if (!dmi_name_in_vendors("ASUS") ||
1205 !acpi_has_method(boot_ec->handle, "_INI"))
1206 return -ENODEV;
1207 }
1208 install:
1209 if (!ec_install_handlers(boot_ec)) {
1210 first_ec = boot_ec;
1211 return 0;
1212 }
1213 error:
1214 kfree(boot_ec);
1215 kfree(saved_ec);
1216 boot_ec = NULL;
1217 return -ENODEV;
1218 }
1219
1220 static struct acpi_driver acpi_ec_driver = {
1221 .name = "ec",
1222 .class = ACPI_EC_CLASS,
1223 .ids = ec_device_ids,
1224 .ops = {
1225 .add = acpi_ec_add,
1226 .remove = acpi_ec_remove,
1227 },
1228 };
1229
1230 int __init acpi_ec_init(void)
1231 {
1232 int result = 0;
1233
1234 /* Now register the driver for the EC */
1235 result = acpi_bus_register_driver(&acpi_ec_driver);
1236 if (result < 0)
1237 return -ENODEV;
1238
1239 return result;
1240 }
1241
1242 /* EC driver currently not unloadable */
1243 #if 0
1244 static void __exit acpi_ec_exit(void)
1245 {
1246
1247 acpi_bus_unregister_driver(&acpi_ec_driver);
1248 }
1249 #endif /* 0 */
Linux kernel - Deliverables
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