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Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming...
[mirror_ubuntu-focal-kernel.git] / drivers / acpi / ec.c
1 /*
2 * ec.c - ACPI Embedded Controller Driver (v3)
3 *
4 * Copyright (C) 2001-2015 Intel Corporation
5 * Author: 2014, 2015 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_UDELAY_POLL 1000 /* Wait 1ms for EC transaction polling */
75 #define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
76 * when trying to clear the EC */
77
78 enum {
79 EC_FLAGS_QUERY_PENDING, /* Query is pending */
80 EC_FLAGS_HANDLERS_INSTALLED, /* Handlers for GPE and
81 * OpReg are installed */
82 EC_FLAGS_STARTED, /* Driver is started */
83 EC_FLAGS_STOPPED, /* Driver is stopped */
84 EC_FLAGS_COMMAND_STORM, /* GPE storms occurred to the
85 * current command processing */
86 };
87
88 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
89 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
90
91 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
92 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
93 module_param(ec_delay, uint, 0644);
94 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
95
96 /*
97 * If the number of false interrupts per one transaction exceeds
98 * this threshold, will think there is a GPE storm happened and
99 * will disable the GPE for normal transaction.
100 */
101 static unsigned int ec_storm_threshold __read_mostly = 8;
102 module_param(ec_storm_threshold, uint, 0644);
103 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
104
105 struct acpi_ec_query_handler {
106 struct list_head node;
107 acpi_ec_query_func func;
108 acpi_handle handle;
109 void *data;
110 u8 query_bit;
111 struct kref kref;
112 };
113
114 struct transaction {
115 const u8 *wdata;
116 u8 *rdata;
117 unsigned short irq_count;
118 u8 command;
119 u8 wi;
120 u8 ri;
121 u8 wlen;
122 u8 rlen;
123 u8 flags;
124 unsigned long timestamp;
125 };
126
127 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
128 static void advance_transaction(struct acpi_ec *ec);
129
130 struct acpi_ec *boot_ec, *first_ec;
131 EXPORT_SYMBOL(first_ec);
132
133 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
134 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
135 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
136 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
137 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
138
139 /* --------------------------------------------------------------------------
140 * Device Flags
141 * -------------------------------------------------------------------------- */
142
143 static bool acpi_ec_started(struct acpi_ec *ec)
144 {
145 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
146 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
147 }
148
149 static bool acpi_ec_flushed(struct acpi_ec *ec)
150 {
151 return ec->reference_count == 1;
152 }
153
154 /* --------------------------------------------------------------------------
155 * EC Registers
156 * -------------------------------------------------------------------------- */
157
158 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
159 {
160 u8 x = inb(ec->command_addr);
161
162 pr_debug("EC_SC(R) = 0x%2.2x "
163 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
164 x,
165 !!(x & ACPI_EC_FLAG_SCI),
166 !!(x & ACPI_EC_FLAG_BURST),
167 !!(x & ACPI_EC_FLAG_CMD),
168 !!(x & ACPI_EC_FLAG_IBF),
169 !!(x & ACPI_EC_FLAG_OBF));
170 return x;
171 }
172
173 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
174 {
175 u8 x = inb(ec->data_addr);
176
177 ec->curr->timestamp = jiffies;
178 pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
179 return x;
180 }
181
182 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
183 {
184 pr_debug("EC_SC(W) = 0x%2.2x\n", command);
185 outb(command, ec->command_addr);
186 ec->curr->timestamp = jiffies;
187 }
188
189 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
190 {
191 pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
192 outb(data, ec->data_addr);
193 ec->curr->timestamp = jiffies;
194 }
195
196 #ifdef DEBUG
197 static const char *acpi_ec_cmd_string(u8 cmd)
198 {
199 switch (cmd) {
200 case 0x80:
201 return "RD_EC";
202 case 0x81:
203 return "WR_EC";
204 case 0x82:
205 return "BE_EC";
206 case 0x83:
207 return "BD_EC";
208 case 0x84:
209 return "QR_EC";
210 }
211 return "UNKNOWN";
212 }
213 #else
214 #define acpi_ec_cmd_string(cmd) "UNDEF"
215 #endif
216
217 /* --------------------------------------------------------------------------
218 * GPE Registers
219 * -------------------------------------------------------------------------- */
220
221 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
222 {
223 acpi_event_status gpe_status = 0;
224
225 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
226 return (gpe_status & ACPI_EVENT_FLAG_SET) ? true : false;
227 }
228
229 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
230 {
231 if (open)
232 acpi_enable_gpe(NULL, ec->gpe);
233 else {
234 BUG_ON(ec->reference_count < 1);
235 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
236 }
237 if (acpi_ec_is_gpe_raised(ec)) {
238 /*
239 * On some platforms, EN=1 writes cannot trigger GPE. So
240 * software need to manually trigger a pseudo GPE event on
241 * EN=1 writes.
242 */
243 pr_debug("***** Polling quirk *****\n");
244 advance_transaction(ec);
245 }
246 }
247
248 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
249 {
250 if (close)
251 acpi_disable_gpe(NULL, ec->gpe);
252 else {
253 BUG_ON(ec->reference_count < 1);
254 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
255 }
256 }
257
258 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
259 {
260 /*
261 * GPE STS is a W1C register, which means:
262 * 1. Software can clear it without worrying about clearing other
263 * GPEs' STS bits when the hardware sets them in parallel.
264 * 2. As long as software can ensure only clearing it when it is
265 * set, hardware won't set it in parallel.
266 * So software can clear GPE in any contexts.
267 * Warning: do not move the check into advance_transaction() as the
268 * EC commands will be sent without GPE raised.
269 */
270 if (!acpi_ec_is_gpe_raised(ec))
271 return;
272 acpi_clear_gpe(NULL, ec->gpe);
273 }
274
275 /* --------------------------------------------------------------------------
276 * Transaction Management
277 * -------------------------------------------------------------------------- */
278
279 static void acpi_ec_submit_request(struct acpi_ec *ec)
280 {
281 ec->reference_count++;
282 if (ec->reference_count == 1)
283 acpi_ec_enable_gpe(ec, true);
284 }
285
286 static void acpi_ec_complete_request(struct acpi_ec *ec)
287 {
288 bool flushed = false;
289
290 ec->reference_count--;
291 if (ec->reference_count == 0)
292 acpi_ec_disable_gpe(ec, true);
293 flushed = acpi_ec_flushed(ec);
294 if (flushed)
295 wake_up(&ec->wait);
296 }
297
298 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
299 {
300 if (!test_bit(flag, &ec->flags)) {
301 acpi_ec_disable_gpe(ec, false);
302 pr_debug("+++++ Polling enabled +++++\n");
303 set_bit(flag, &ec->flags);
304 }
305 }
306
307 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
308 {
309 if (test_bit(flag, &ec->flags)) {
310 clear_bit(flag, &ec->flags);
311 acpi_ec_enable_gpe(ec, false);
312 pr_debug("+++++ Polling disabled +++++\n");
313 }
314 }
315
316 /*
317 * acpi_ec_submit_flushable_request() - Increase the reference count unless
318 * the flush operation is not in
319 * progress
320 * @ec: the EC device
321 *
322 * This function must be used before taking a new action that should hold
323 * the reference count. If this function returns false, then the action
324 * must be discarded or it will prevent the flush operation from being
325 * completed.
326 */
327 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
328 {
329 if (!acpi_ec_started(ec))
330 return false;
331 acpi_ec_submit_request(ec);
332 return true;
333 }
334
335 static void acpi_ec_submit_query(struct acpi_ec *ec)
336 {
337 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
338 pr_debug("***** Event started *****\n");
339 schedule_work(&ec->work);
340 }
341 }
342
343 static void acpi_ec_complete_query(struct acpi_ec *ec)
344 {
345 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
346 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
347 pr_debug("***** Event stopped *****\n");
348 }
349 }
350
351 static int ec_transaction_completed(struct acpi_ec *ec)
352 {
353 unsigned long flags;
354 int ret = 0;
355
356 spin_lock_irqsave(&ec->lock, flags);
357 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
358 ret = 1;
359 spin_unlock_irqrestore(&ec->lock, flags);
360 return ret;
361 }
362
363 static void advance_transaction(struct acpi_ec *ec)
364 {
365 struct transaction *t;
366 u8 status;
367 bool wakeup = false;
368
369 pr_debug("===== %s (%d) =====\n",
370 in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
371 /*
372 * By always clearing STS before handling all indications, we can
373 * ensure a hardware STS 0->1 change after this clearing can always
374 * trigger a GPE interrupt.
375 */
376 acpi_ec_clear_gpe(ec);
377 status = acpi_ec_read_status(ec);
378 t = ec->curr;
379 if (!t)
380 goto err;
381 if (t->flags & ACPI_EC_COMMAND_POLL) {
382 if (t->wlen > t->wi) {
383 if ((status & ACPI_EC_FLAG_IBF) == 0)
384 acpi_ec_write_data(ec, t->wdata[t->wi++]);
385 else
386 goto err;
387 } else if (t->rlen > t->ri) {
388 if ((status & ACPI_EC_FLAG_OBF) == 1) {
389 t->rdata[t->ri++] = acpi_ec_read_data(ec);
390 if (t->rlen == t->ri) {
391 t->flags |= ACPI_EC_COMMAND_COMPLETE;
392 if (t->command == ACPI_EC_COMMAND_QUERY)
393 pr_debug("***** Command(%s) hardware completion *****\n",
394 acpi_ec_cmd_string(t->command));
395 wakeup = true;
396 }
397 } else
398 goto err;
399 } else if (t->wlen == t->wi &&
400 (status & ACPI_EC_FLAG_IBF) == 0) {
401 t->flags |= ACPI_EC_COMMAND_COMPLETE;
402 wakeup = true;
403 }
404 goto out;
405 } else {
406 if (EC_FLAGS_QUERY_HANDSHAKE &&
407 !(status & ACPI_EC_FLAG_SCI) &&
408 (t->command == ACPI_EC_COMMAND_QUERY)) {
409 t->flags |= ACPI_EC_COMMAND_POLL;
410 acpi_ec_complete_query(ec);
411 t->rdata[t->ri++] = 0x00;
412 t->flags |= ACPI_EC_COMMAND_COMPLETE;
413 pr_debug("***** Command(%s) software completion *****\n",
414 acpi_ec_cmd_string(t->command));
415 wakeup = true;
416 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
417 acpi_ec_write_cmd(ec, t->command);
418 t->flags |= ACPI_EC_COMMAND_POLL;
419 acpi_ec_complete_query(ec);
420 } else
421 goto err;
422 goto out;
423 }
424 err:
425 /*
426 * If SCI bit is set, then don't think it's a false IRQ
427 * otherwise will take a not handled IRQ as a false one.
428 */
429 if (!(status & ACPI_EC_FLAG_SCI)) {
430 if (in_interrupt() && t) {
431 if (t->irq_count < ec_storm_threshold)
432 ++t->irq_count;
433 /* Allow triggering on 0 threshold */
434 if (t->irq_count == ec_storm_threshold)
435 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
436 }
437 }
438 out:
439 if (status & ACPI_EC_FLAG_SCI)
440 acpi_ec_submit_query(ec);
441 if (wakeup && in_interrupt())
442 wake_up(&ec->wait);
443 }
444
445 static void start_transaction(struct acpi_ec *ec)
446 {
447 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
448 ec->curr->flags = 0;
449 ec->curr->timestamp = jiffies;
450 advance_transaction(ec);
451 }
452
453 static int ec_poll(struct acpi_ec *ec)
454 {
455 unsigned long flags;
456 int repeat = 5; /* number of command restarts */
457
458 while (repeat--) {
459 unsigned long delay = jiffies +
460 msecs_to_jiffies(ec_delay);
461 unsigned long usecs = ACPI_EC_UDELAY_POLL;
462 do {
463 /* don't sleep with disabled interrupts */
464 if (EC_FLAGS_MSI || irqs_disabled()) {
465 usecs = ACPI_EC_MSI_UDELAY;
466 udelay(usecs);
467 if (ec_transaction_completed(ec))
468 return 0;
469 } else {
470 if (wait_event_timeout(ec->wait,
471 ec_transaction_completed(ec),
472 usecs_to_jiffies(usecs)))
473 return 0;
474 }
475 spin_lock_irqsave(&ec->lock, flags);
476 if (time_after(jiffies,
477 ec->curr->timestamp +
478 usecs_to_jiffies(usecs)))
479 advance_transaction(ec);
480 spin_unlock_irqrestore(&ec->lock, flags);
481 } while (time_before(jiffies, delay));
482 pr_debug("controller reset, restart transaction\n");
483 spin_lock_irqsave(&ec->lock, flags);
484 start_transaction(ec);
485 spin_unlock_irqrestore(&ec->lock, flags);
486 }
487 return -ETIME;
488 }
489
490 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
491 struct transaction *t)
492 {
493 unsigned long tmp;
494 int ret = 0;
495
496 if (EC_FLAGS_MSI)
497 udelay(ACPI_EC_MSI_UDELAY);
498 /* start transaction */
499 spin_lock_irqsave(&ec->lock, tmp);
500 /* Enable GPE for command processing (IBF=0/OBF=1) */
501 if (!acpi_ec_submit_flushable_request(ec)) {
502 ret = -EINVAL;
503 goto unlock;
504 }
505 /* following two actions should be kept atomic */
506 ec->curr = t;
507 pr_debug("***** Command(%s) started *****\n",
508 acpi_ec_cmd_string(t->command));
509 start_transaction(ec);
510 spin_unlock_irqrestore(&ec->lock, tmp);
511 ret = ec_poll(ec);
512 spin_lock_irqsave(&ec->lock, tmp);
513 if (t->irq_count == ec_storm_threshold)
514 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
515 pr_debug("***** Command(%s) stopped *****\n",
516 acpi_ec_cmd_string(t->command));
517 ec->curr = NULL;
518 /* Disable GPE for command processing (IBF=0/OBF=1) */
519 acpi_ec_complete_request(ec);
520 unlock:
521 spin_unlock_irqrestore(&ec->lock, tmp);
522 return ret;
523 }
524
525 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
526 {
527 int status;
528 u32 glk;
529
530 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
531 return -EINVAL;
532 if (t->rdata)
533 memset(t->rdata, 0, t->rlen);
534 mutex_lock(&ec->mutex);
535 if (ec->global_lock) {
536 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
537 if (ACPI_FAILURE(status)) {
538 status = -ENODEV;
539 goto unlock;
540 }
541 }
542
543 status = acpi_ec_transaction_unlocked(ec, t);
544
545 if (test_bit(EC_FLAGS_COMMAND_STORM, &ec->flags))
546 msleep(1);
547 if (ec->global_lock)
548 acpi_release_global_lock(glk);
549 unlock:
550 mutex_unlock(&ec->mutex);
551 return status;
552 }
553
554 static int acpi_ec_burst_enable(struct acpi_ec *ec)
555 {
556 u8 d;
557 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
558 .wdata = NULL, .rdata = &d,
559 .wlen = 0, .rlen = 1};
560
561 return acpi_ec_transaction(ec, &t);
562 }
563
564 static int acpi_ec_burst_disable(struct acpi_ec *ec)
565 {
566 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
567 .wdata = NULL, .rdata = NULL,
568 .wlen = 0, .rlen = 0};
569
570 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
571 acpi_ec_transaction(ec, &t) : 0;
572 }
573
574 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
575 {
576 int result;
577 u8 d;
578 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
579 .wdata = &address, .rdata = &d,
580 .wlen = 1, .rlen = 1};
581
582 result = acpi_ec_transaction(ec, &t);
583 *data = d;
584 return result;
585 }
586
587 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
588 {
589 u8 wdata[2] = { address, data };
590 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
591 .wdata = wdata, .rdata = NULL,
592 .wlen = 2, .rlen = 0};
593
594 return acpi_ec_transaction(ec, &t);
595 }
596
597 int ec_read(u8 addr, u8 *val)
598 {
599 int err;
600 u8 temp_data;
601
602 if (!first_ec)
603 return -ENODEV;
604
605 err = acpi_ec_read(first_ec, addr, &temp_data);
606
607 if (!err) {
608 *val = temp_data;
609 return 0;
610 }
611 return err;
612 }
613 EXPORT_SYMBOL(ec_read);
614
615 int ec_write(u8 addr, u8 val)
616 {
617 int err;
618
619 if (!first_ec)
620 return -ENODEV;
621
622 err = acpi_ec_write(first_ec, addr, val);
623
624 return err;
625 }
626 EXPORT_SYMBOL(ec_write);
627
628 int ec_transaction(u8 command,
629 const u8 *wdata, unsigned wdata_len,
630 u8 *rdata, unsigned rdata_len)
631 {
632 struct transaction t = {.command = command,
633 .wdata = wdata, .rdata = rdata,
634 .wlen = wdata_len, .rlen = rdata_len};
635
636 if (!first_ec)
637 return -ENODEV;
638
639 return acpi_ec_transaction(first_ec, &t);
640 }
641 EXPORT_SYMBOL(ec_transaction);
642
643 /* Get the handle to the EC device */
644 acpi_handle ec_get_handle(void)
645 {
646 if (!first_ec)
647 return NULL;
648 return first_ec->handle;
649 }
650 EXPORT_SYMBOL(ec_get_handle);
651
652 /*
653 * Process _Q events that might have accumulated in the EC.
654 * Run with locked ec mutex.
655 */
656 static void acpi_ec_clear(struct acpi_ec *ec)
657 {
658 int i, status;
659 u8 value = 0;
660
661 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
662 status = acpi_ec_query(ec, &value);
663 if (status || !value)
664 break;
665 }
666
667 if (unlikely(i == ACPI_EC_CLEAR_MAX))
668 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
669 else
670 pr_info("%d stale EC events cleared\n", i);
671 }
672
673 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
674 {
675 unsigned long flags;
676
677 spin_lock_irqsave(&ec->lock, flags);
678 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
679 pr_debug("+++++ Starting EC +++++\n");
680 /* Enable GPE for event processing (SCI_EVT=1) */
681 if (!resuming)
682 acpi_ec_submit_request(ec);
683 pr_debug("EC started\n");
684 }
685 spin_unlock_irqrestore(&ec->lock, flags);
686 }
687
688 static bool acpi_ec_stopped(struct acpi_ec *ec)
689 {
690 unsigned long flags;
691 bool flushed;
692
693 spin_lock_irqsave(&ec->lock, flags);
694 flushed = acpi_ec_flushed(ec);
695 spin_unlock_irqrestore(&ec->lock, flags);
696 return flushed;
697 }
698
699 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
700 {
701 unsigned long flags;
702
703 spin_lock_irqsave(&ec->lock, flags);
704 if (acpi_ec_started(ec)) {
705 pr_debug("+++++ Stopping EC +++++\n");
706 set_bit(EC_FLAGS_STOPPED, &ec->flags);
707 spin_unlock_irqrestore(&ec->lock, flags);
708 wait_event(ec->wait, acpi_ec_stopped(ec));
709 spin_lock_irqsave(&ec->lock, flags);
710 /* Disable GPE for event processing (SCI_EVT=1) */
711 if (!suspending)
712 acpi_ec_complete_request(ec);
713 clear_bit(EC_FLAGS_STARTED, &ec->flags);
714 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
715 pr_debug("EC stopped\n");
716 }
717 spin_unlock_irqrestore(&ec->lock, flags);
718 }
719
720 void acpi_ec_block_transactions(void)
721 {
722 struct acpi_ec *ec = first_ec;
723
724 if (!ec)
725 return;
726
727 mutex_lock(&ec->mutex);
728 /* Prevent transactions from being carried out */
729 acpi_ec_stop(ec, true);
730 mutex_unlock(&ec->mutex);
731 }
732
733 void acpi_ec_unblock_transactions(void)
734 {
735 struct acpi_ec *ec = first_ec;
736
737 if (!ec)
738 return;
739
740 /* Allow transactions to be carried out again */
741 acpi_ec_start(ec, true);
742
743 if (EC_FLAGS_CLEAR_ON_RESUME)
744 acpi_ec_clear(ec);
745 }
746
747 void acpi_ec_unblock_transactions_early(void)
748 {
749 /*
750 * Allow transactions to happen again (this function is called from
751 * atomic context during wakeup, so we don't need to acquire the mutex).
752 */
753 if (first_ec)
754 acpi_ec_start(first_ec, true);
755 }
756
757 /* --------------------------------------------------------------------------
758 Event Management
759 -------------------------------------------------------------------------- */
760 static struct acpi_ec_query_handler *
761 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
762 {
763 if (handler)
764 kref_get(&handler->kref);
765 return handler;
766 }
767
768 static void acpi_ec_query_handler_release(struct kref *kref)
769 {
770 struct acpi_ec_query_handler *handler =
771 container_of(kref, struct acpi_ec_query_handler, kref);
772
773 kfree(handler);
774 }
775
776 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
777 {
778 kref_put(&handler->kref, acpi_ec_query_handler_release);
779 }
780
781 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
782 acpi_handle handle, acpi_ec_query_func func,
783 void *data)
784 {
785 struct acpi_ec_query_handler *handler =
786 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
787
788 if (!handler)
789 return -ENOMEM;
790
791 handler->query_bit = query_bit;
792 handler->handle = handle;
793 handler->func = func;
794 handler->data = data;
795 mutex_lock(&ec->mutex);
796 kref_init(&handler->kref);
797 list_add(&handler->node, &ec->list);
798 mutex_unlock(&ec->mutex);
799 return 0;
800 }
801 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
802
803 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
804 {
805 struct acpi_ec_query_handler *handler, *tmp;
806 LIST_HEAD(free_list);
807
808 mutex_lock(&ec->mutex);
809 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
810 if (query_bit == handler->query_bit) {
811 list_del_init(&handler->node);
812 list_add(&handler->node, &free_list);
813 }
814 }
815 mutex_unlock(&ec->mutex);
816 list_for_each_entry(handler, &free_list, node)
817 acpi_ec_put_query_handler(handler);
818 }
819 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
820
821 static void acpi_ec_run(void *cxt)
822 {
823 struct acpi_ec_query_handler *handler = cxt;
824
825 if (!handler)
826 return;
827 pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
828 if (handler->func)
829 handler->func(handler->data);
830 else if (handler->handle)
831 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
832 pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
833 acpi_ec_put_query_handler(handler);
834 }
835
836 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
837 {
838 u8 value = 0;
839 int result;
840 acpi_status status;
841 struct acpi_ec_query_handler *handler;
842 struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
843 .wdata = NULL, .rdata = &value,
844 .wlen = 0, .rlen = 1};
845
846 /*
847 * Query the EC to find out which _Qxx method we need to evaluate.
848 * Note that successful completion of the query causes the ACPI_EC_SCI
849 * bit to be cleared (and thus clearing the interrupt source).
850 */
851 result = acpi_ec_transaction(ec, &t);
852 if (result)
853 return result;
854 if (data)
855 *data = value;
856 if (!value)
857 return -ENODATA;
858
859 mutex_lock(&ec->mutex);
860 list_for_each_entry(handler, &ec->list, node) {
861 if (value == handler->query_bit) {
862 /* have custom handler for this bit */
863 handler = acpi_ec_get_query_handler(handler);
864 pr_debug("##### Query(0x%02x) scheduled #####\n",
865 handler->query_bit);
866 status = acpi_os_execute((handler->func) ?
867 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
868 acpi_ec_run, handler);
869 if (ACPI_FAILURE(status))
870 result = -EBUSY;
871 break;
872 }
873 }
874 mutex_unlock(&ec->mutex);
875 return result;
876 }
877
878 static void acpi_ec_gpe_poller(struct work_struct *work)
879 {
880 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
881
882 acpi_ec_query(ec, NULL);
883 }
884
885 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
886 u32 gpe_number, void *data)
887 {
888 unsigned long flags;
889 struct acpi_ec *ec = data;
890
891 spin_lock_irqsave(&ec->lock, flags);
892 advance_transaction(ec);
893 spin_unlock_irqrestore(&ec->lock, flags);
894 return ACPI_INTERRUPT_HANDLED;
895 }
896
897 /* --------------------------------------------------------------------------
898 * Address Space Management
899 * -------------------------------------------------------------------------- */
900
901 static acpi_status
902 acpi_ec_space_handler(u32 function, acpi_physical_address address,
903 u32 bits, u64 *value64,
904 void *handler_context, void *region_context)
905 {
906 struct acpi_ec *ec = handler_context;
907 int result = 0, i, bytes = bits / 8;
908 u8 *value = (u8 *)value64;
909
910 if ((address > 0xFF) || !value || !handler_context)
911 return AE_BAD_PARAMETER;
912
913 if (function != ACPI_READ && function != ACPI_WRITE)
914 return AE_BAD_PARAMETER;
915
916 if (EC_FLAGS_MSI || bits > 8)
917 acpi_ec_burst_enable(ec);
918
919 for (i = 0; i < bytes; ++i, ++address, ++value)
920 result = (function == ACPI_READ) ?
921 acpi_ec_read(ec, address, value) :
922 acpi_ec_write(ec, address, *value);
923
924 if (EC_FLAGS_MSI || bits > 8)
925 acpi_ec_burst_disable(ec);
926
927 switch (result) {
928 case -EINVAL:
929 return AE_BAD_PARAMETER;
930 case -ENODEV:
931 return AE_NOT_FOUND;
932 case -ETIME:
933 return AE_TIME;
934 default:
935 return AE_OK;
936 }
937 }
938
939 /* --------------------------------------------------------------------------
940 * Driver Interface
941 * -------------------------------------------------------------------------- */
942
943 static acpi_status
944 ec_parse_io_ports(struct acpi_resource *resource, void *context);
945
946 static struct acpi_ec *make_acpi_ec(void)
947 {
948 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
949
950 if (!ec)
951 return NULL;
952 ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
953 mutex_init(&ec->mutex);
954 init_waitqueue_head(&ec->wait);
955 INIT_LIST_HEAD(&ec->list);
956 spin_lock_init(&ec->lock);
957 INIT_WORK(&ec->work, acpi_ec_gpe_poller);
958 return ec;
959 }
960
961 static acpi_status
962 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
963 void *context, void **return_value)
964 {
965 char node_name[5];
966 struct acpi_buffer buffer = { sizeof(node_name), node_name };
967 struct acpi_ec *ec = context;
968 int value = 0;
969 acpi_status status;
970
971 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
972
973 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
974 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
975 return AE_OK;
976 }
977
978 static acpi_status
979 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
980 {
981 acpi_status status;
982 unsigned long long tmp = 0;
983 struct acpi_ec *ec = context;
984
985 /* clear addr values, ec_parse_io_ports depend on it */
986 ec->command_addr = ec->data_addr = 0;
987
988 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
989 ec_parse_io_ports, ec);
990 if (ACPI_FAILURE(status))
991 return status;
992
993 /* Get GPE bit assignment (EC events). */
994 /* TODO: Add support for _GPE returning a package */
995 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
996 if (ACPI_FAILURE(status))
997 return status;
998 ec->gpe = tmp;
999 /* Use the global lock for all EC transactions? */
1000 tmp = 0;
1001 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1002 ec->global_lock = tmp;
1003 ec->handle = handle;
1004 return AE_CTRL_TERMINATE;
1005 }
1006
1007 static int ec_install_handlers(struct acpi_ec *ec)
1008 {
1009 acpi_status status;
1010
1011 if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1012 return 0;
1013 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1014 ACPI_GPE_EDGE_TRIGGERED,
1015 &acpi_ec_gpe_handler, ec);
1016 if (ACPI_FAILURE(status))
1017 return -ENODEV;
1018
1019 acpi_ec_start(ec, false);
1020 status = acpi_install_address_space_handler(ec->handle,
1021 ACPI_ADR_SPACE_EC,
1022 &acpi_ec_space_handler,
1023 NULL, ec);
1024 if (ACPI_FAILURE(status)) {
1025 if (status == AE_NOT_FOUND) {
1026 /*
1027 * Maybe OS fails in evaluating the _REG object.
1028 * The AE_NOT_FOUND error will be ignored and OS
1029 * continue to initialize EC.
1030 */
1031 pr_err("Fail in evaluating the _REG object"
1032 " of EC device. Broken bios is suspected.\n");
1033 } else {
1034 acpi_ec_stop(ec, false);
1035 acpi_remove_gpe_handler(NULL, ec->gpe,
1036 &acpi_ec_gpe_handler);
1037 return -ENODEV;
1038 }
1039 }
1040
1041 set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1042 return 0;
1043 }
1044
1045 static void ec_remove_handlers(struct acpi_ec *ec)
1046 {
1047 if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1048 return;
1049 acpi_ec_stop(ec, false);
1050 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1051 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1052 pr_err("failed to remove space handler\n");
1053 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1054 &acpi_ec_gpe_handler)))
1055 pr_err("failed to remove gpe handler\n");
1056 clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1057 }
1058
1059 static int acpi_ec_add(struct acpi_device *device)
1060 {
1061 struct acpi_ec *ec = NULL;
1062 int ret;
1063
1064 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1065 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1066
1067 /* Check for boot EC */
1068 if (boot_ec &&
1069 (boot_ec->handle == device->handle ||
1070 boot_ec->handle == ACPI_ROOT_OBJECT)) {
1071 ec = boot_ec;
1072 boot_ec = NULL;
1073 } else {
1074 ec = make_acpi_ec();
1075 if (!ec)
1076 return -ENOMEM;
1077 }
1078 if (ec_parse_device(device->handle, 0, ec, NULL) !=
1079 AE_CTRL_TERMINATE) {
1080 kfree(ec);
1081 return -EINVAL;
1082 }
1083
1084 /* Find and register all query methods */
1085 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1086 acpi_ec_register_query_methods, NULL, ec, NULL);
1087
1088 if (!first_ec)
1089 first_ec = ec;
1090 device->driver_data = ec;
1091
1092 ret = !!request_region(ec->data_addr, 1, "EC data");
1093 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1094 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1095 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1096
1097 pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
1098 ec->gpe, ec->command_addr, ec->data_addr);
1099
1100 ret = ec_install_handlers(ec);
1101
1102 /* EC is fully operational, allow queries */
1103 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1104
1105 /* Clear stale _Q events if hardware might require that */
1106 if (EC_FLAGS_CLEAR_ON_RESUME)
1107 acpi_ec_clear(ec);
1108 return ret;
1109 }
1110
1111 static int acpi_ec_remove(struct acpi_device *device)
1112 {
1113 struct acpi_ec *ec;
1114 struct acpi_ec_query_handler *handler, *tmp;
1115
1116 if (!device)
1117 return -EINVAL;
1118
1119 ec = acpi_driver_data(device);
1120 ec_remove_handlers(ec);
1121 mutex_lock(&ec->mutex);
1122 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1123 list_del(&handler->node);
1124 kfree(handler);
1125 }
1126 mutex_unlock(&ec->mutex);
1127 release_region(ec->data_addr, 1);
1128 release_region(ec->command_addr, 1);
1129 device->driver_data = NULL;
1130 if (ec == first_ec)
1131 first_ec = NULL;
1132 kfree(ec);
1133 return 0;
1134 }
1135
1136 static acpi_status
1137 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1138 {
1139 struct acpi_ec *ec = context;
1140
1141 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1142 return AE_OK;
1143
1144 /*
1145 * The first address region returned is the data port, and
1146 * the second address region returned is the status/command
1147 * port.
1148 */
1149 if (ec->data_addr == 0)
1150 ec->data_addr = resource->data.io.minimum;
1151 else if (ec->command_addr == 0)
1152 ec->command_addr = resource->data.io.minimum;
1153 else
1154 return AE_CTRL_TERMINATE;
1155
1156 return AE_OK;
1157 }
1158
1159 int __init acpi_boot_ec_enable(void)
1160 {
1161 if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1162 return 0;
1163 if (!ec_install_handlers(boot_ec)) {
1164 first_ec = boot_ec;
1165 return 0;
1166 }
1167 return -EFAULT;
1168 }
1169
1170 static const struct acpi_device_id ec_device_ids[] = {
1171 {"PNP0C09", 0},
1172 {"", 0},
1173 };
1174
1175 /* Some BIOS do not survive early DSDT scan, skip it */
1176 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1177 {
1178 EC_FLAGS_SKIP_DSDT_SCAN = 1;
1179 return 0;
1180 }
1181
1182 /* ASUStek often supplies us with broken ECDT, validate it */
1183 static int ec_validate_ecdt(const struct dmi_system_id *id)
1184 {
1185 EC_FLAGS_VALIDATE_ECDT = 1;
1186 return 0;
1187 }
1188
1189 /* MSI EC needs special treatment, enable it */
1190 static int ec_flag_msi(const struct dmi_system_id *id)
1191 {
1192 pr_debug("Detected MSI hardware, enabling workarounds.\n");
1193 EC_FLAGS_MSI = 1;
1194 EC_FLAGS_VALIDATE_ECDT = 1;
1195 return 0;
1196 }
1197
1198 /*
1199 * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1200 * the GPE storm threshold back to 20
1201 */
1202 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1203 {
1204 pr_debug("Setting the EC GPE storm threshold to 20\n");
1205 ec_storm_threshold = 20;
1206 return 0;
1207 }
1208
1209 /*
1210 * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1211 * which case, we complete the QR_EC without issuing it to the firmware.
1212 * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1213 */
1214 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1215 {
1216 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1217 EC_FLAGS_QUERY_HANDSHAKE = 1;
1218 return 0;
1219 }
1220
1221 /*
1222 * On some hardware it is necessary to clear events accumulated by the EC during
1223 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1224 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1225 *
1226 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1227 *
1228 * Ideally, the EC should also be instructed NOT to accumulate events during
1229 * sleep (which Windows seems to do somehow), but the interface to control this
1230 * behaviour is not known at this time.
1231 *
1232 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1233 * however it is very likely that other Samsung models are affected.
1234 *
1235 * On systems which don't accumulate _Q events during sleep, this extra check
1236 * should be harmless.
1237 */
1238 static int ec_clear_on_resume(const struct dmi_system_id *id)
1239 {
1240 pr_debug("Detected system needing EC poll on resume.\n");
1241 EC_FLAGS_CLEAR_ON_RESUME = 1;
1242 return 0;
1243 }
1244
1245 static struct dmi_system_id ec_dmi_table[] __initdata = {
1246 {
1247 ec_skip_dsdt_scan, "Compal JFL92", {
1248 DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1249 DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1250 {
1251 ec_flag_msi, "MSI hardware", {
1252 DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1253 {
1254 ec_flag_msi, "MSI hardware", {
1255 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1256 {
1257 ec_flag_msi, "MSI hardware", {
1258 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1259 {
1260 ec_flag_msi, "MSI hardware", {
1261 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1262 {
1263 ec_flag_msi, "Quanta hardware", {
1264 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1265 DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1266 {
1267 ec_flag_msi, "Quanta hardware", {
1268 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1269 DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1270 {
1271 ec_flag_msi, "Clevo W350etq", {
1272 DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1273 DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1274 {
1275 ec_validate_ecdt, "ASUS hardware", {
1276 DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1277 {
1278 ec_validate_ecdt, "ASUS hardware", {
1279 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1280 {
1281 ec_enlarge_storm_threshold, "CLEVO hardware", {
1282 DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1283 DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1284 {
1285 ec_skip_dsdt_scan, "HP Folio 13", {
1286 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1287 DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1288 {
1289 ec_validate_ecdt, "ASUS hardware", {
1290 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1291 DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1292 {
1293 ec_clear_on_resume, "Samsung hardware", {
1294 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1295 {
1296 ec_flag_query_handshake, "Acer hardware", {
1297 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1298 {},
1299 };
1300
1301 int __init acpi_ec_ecdt_probe(void)
1302 {
1303 acpi_status status;
1304 struct acpi_ec *saved_ec = NULL;
1305 struct acpi_table_ecdt *ecdt_ptr;
1306
1307 boot_ec = make_acpi_ec();
1308 if (!boot_ec)
1309 return -ENOMEM;
1310 /*
1311 * Generate a boot ec context
1312 */
1313 dmi_check_system(ec_dmi_table);
1314 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1315 (struct acpi_table_header **)&ecdt_ptr);
1316 if (ACPI_SUCCESS(status)) {
1317 pr_info("EC description table is found, configuring boot EC\n");
1318 boot_ec->command_addr = ecdt_ptr->control.address;
1319 boot_ec->data_addr = ecdt_ptr->data.address;
1320 boot_ec->gpe = ecdt_ptr->gpe;
1321 boot_ec->handle = ACPI_ROOT_OBJECT;
1322 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1323 &boot_ec->handle);
1324 /* Don't trust ECDT, which comes from ASUSTek */
1325 if (!EC_FLAGS_VALIDATE_ECDT)
1326 goto install;
1327 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1328 if (!saved_ec)
1329 return -ENOMEM;
1330 /* fall through */
1331 }
1332
1333 if (EC_FLAGS_SKIP_DSDT_SCAN) {
1334 kfree(saved_ec);
1335 return -ENODEV;
1336 }
1337
1338 /* This workaround is needed only on some broken machines,
1339 * which require early EC, but fail to provide ECDT */
1340 pr_debug("Look up EC in DSDT\n");
1341 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1342 boot_ec, NULL);
1343 /* Check that acpi_get_devices actually find something */
1344 if (ACPI_FAILURE(status) || !boot_ec->handle)
1345 goto error;
1346 if (saved_ec) {
1347 /* try to find good ECDT from ASUSTek */
1348 if (saved_ec->command_addr != boot_ec->command_addr ||
1349 saved_ec->data_addr != boot_ec->data_addr ||
1350 saved_ec->gpe != boot_ec->gpe ||
1351 saved_ec->handle != boot_ec->handle)
1352 pr_info("ASUSTek keeps feeding us with broken "
1353 "ECDT tables, which are very hard to workaround. "
1354 "Trying to use DSDT EC info instead. Please send "
1355 "output of acpidump to linux-acpi@vger.kernel.org\n");
1356 kfree(saved_ec);
1357 saved_ec = NULL;
1358 } else {
1359 /* We really need to limit this workaround, the only ASUS,
1360 * which needs it, has fake EC._INI method, so use it as flag.
1361 * Keep boot_ec struct as it will be needed soon.
1362 */
1363 if (!dmi_name_in_vendors("ASUS") ||
1364 !acpi_has_method(boot_ec->handle, "_INI"))
1365 return -ENODEV;
1366 }
1367 install:
1368 if (!ec_install_handlers(boot_ec)) {
1369 first_ec = boot_ec;
1370 return 0;
1371 }
1372 error:
1373 kfree(boot_ec);
1374 kfree(saved_ec);
1375 boot_ec = NULL;
1376 return -ENODEV;
1377 }
1378
1379 static struct acpi_driver acpi_ec_driver = {
1380 .name = "ec",
1381 .class = ACPI_EC_CLASS,
1382 .ids = ec_device_ids,
1383 .ops = {
1384 .add = acpi_ec_add,
1385 .remove = acpi_ec_remove,
1386 },
1387 };
1388
1389 int __init acpi_ec_init(void)
1390 {
1391 int result = 0;
1392
1393 /* Now register the driver for the EC */
1394 result = acpi_bus_register_driver(&acpi_ec_driver);
1395 if (result < 0)
1396 return -ENODEV;
1397
1398 return result;
1399 }
1400
1401 /* EC driver currently not unloadable */
1402 #if 0
1403 static void __exit acpi_ec_exit(void)
1404 {
1405
1406 acpi_bus_unregister_driver(&acpi_ec_driver);
1407 }
1408 #endif /* 0 */
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