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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/interrupt.h>
38#include <linux/list.h>
39#include <linux/spinlock.h>
40#include <linux/slab.h>
41#include <asm/io.h>
42#include <acpi/acpi_bus.h>
43#include <acpi/acpi_drivers.h>
44#include <linux/dmi.h>
45
46#include "internal.h"
47
48#define ACPI_EC_CLASS "embedded_controller"
49#define ACPI_EC_DEVICE_NAME "Embedded Controller"
50#define ACPI_EC_FILE_INFO "info"
51
52#undef PREFIX
53#define PREFIX "ACPI: EC: "
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_BURST 0x10 /* burst mode */
59#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
60
61/* EC commands */
62enum ec_command {
63 ACPI_EC_COMMAND_READ = 0x80,
64 ACPI_EC_COMMAND_WRITE = 0x81,
65 ACPI_EC_BURST_ENABLE = 0x82,
66 ACPI_EC_BURST_DISABLE = 0x83,
67 ACPI_EC_COMMAND_QUERY = 0x84,
68};
69
70#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
71#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
72#define ACPI_EC_MSI_UDELAY 550 /* Wait 550us for MSI EC */
73
74#define ACPI_EC_STORM_THRESHOLD 8 /* number of false interrupts
75 per one transaction */
76
77enum {
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/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
86static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
87module_param(ec_delay, uint, 0644);
88MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
89
90/* If we find an EC via the ECDT, we need to keep a ptr to its context */
91/* External interfaces use first EC only, so remember */
92typedef int (*acpi_ec_query_func) (void *data);
93
94struct acpi_ec_query_handler {
95 struct list_head node;
96 acpi_ec_query_func func;
97 acpi_handle handle;
98 void *data;
99 u8 query_bit;
100};
101
102struct transaction {
103 const u8 *wdata;
104 u8 *rdata;
105 unsigned short irq_count;
106 u8 command;
107 u8 wi;
108 u8 ri;
109 u8 wlen;
110 u8 rlen;
111 bool done;
112};
113
114struct acpi_ec *boot_ec, *first_ec;
115EXPORT_SYMBOL(first_ec);
116
117static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
118static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
119static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
120
121/* --------------------------------------------------------------------------
122 Transaction Management
123 -------------------------------------------------------------------------- */
124
125static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
126{
127 u8 x = inb(ec->command_addr);
128 pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
129 return x;
130}
131
132static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
133{
134 u8 x = inb(ec->data_addr);
135 pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
136 return x;
137}
138
139static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
140{
141 pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
142 outb(command, ec->command_addr);
143}
144
145static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
146{
147 pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
148 outb(data, ec->data_addr);
149}
150
151static int ec_transaction_done(struct acpi_ec *ec)
152{
153 unsigned long flags;
154 int ret = 0;
155 spin_lock_irqsave(&ec->curr_lock, flags);
156 if (!ec->curr || ec->curr->done)
157 ret = 1;
158 spin_unlock_irqrestore(&ec->curr_lock, flags);
159 return ret;
160}
161
162static void start_transaction(struct acpi_ec *ec)
163{
164 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
165 ec->curr->done = false;
166 acpi_ec_write_cmd(ec, ec->curr->command);
167}
168
169static void advance_transaction(struct acpi_ec *ec, u8 status)
170{
171 unsigned long flags;
172 spin_lock_irqsave(&ec->curr_lock, flags);
173 if (!ec->curr)
174 goto unlock;
175 if (ec->curr->wlen > ec->curr->wi) {
176 if ((status & ACPI_EC_FLAG_IBF) == 0)
177 acpi_ec_write_data(ec,
178 ec->curr->wdata[ec->curr->wi++]);
179 else
180 goto err;
181 } else if (ec->curr->rlen > ec->curr->ri) {
182 if ((status & ACPI_EC_FLAG_OBF) == 1) {
183 ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
184 if (ec->curr->rlen == ec->curr->ri)
185 ec->curr->done = true;
186 } else
187 goto err;
188 } else if (ec->curr->wlen == ec->curr->wi &&
189 (status & ACPI_EC_FLAG_IBF) == 0)
190 ec->curr->done = true;
191 goto unlock;
192err:
193 /* false interrupt, state didn't change */
194 if (in_interrupt())
195 ++ec->curr->irq_count;
196unlock:
197 spin_unlock_irqrestore(&ec->curr_lock, flags);
198}
199
200static int acpi_ec_sync_query(struct acpi_ec *ec);
201
202static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
203{
204 if (state & ACPI_EC_FLAG_SCI) {
205 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
206 return acpi_ec_sync_query(ec);
207 }
208 return 0;
209}
210
211static int ec_poll(struct acpi_ec *ec)
212{
213 unsigned long flags;
214 int repeat = 2; /* number of command restarts */
215 while (repeat--) {
216 unsigned long delay = jiffies +
217 msecs_to_jiffies(ec_delay);
218 do {
219 /* don't sleep with disabled interrupts */
220 if (EC_FLAGS_MSI || irqs_disabled()) {
221 udelay(ACPI_EC_MSI_UDELAY);
222 if (ec_transaction_done(ec))
223 return 0;
224 } else {
225 if (wait_event_timeout(ec->wait,
226 ec_transaction_done(ec),
227 msecs_to_jiffies(1)))
228 return 0;
229 }
230 advance_transaction(ec, acpi_ec_read_status(ec));
231 } while (time_before(jiffies, delay));
232 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
233 break;
234 pr_debug(PREFIX "controller reset, restart transaction\n");
235 spin_lock_irqsave(&ec->curr_lock, flags);
236 start_transaction(ec);
237 spin_unlock_irqrestore(&ec->curr_lock, flags);
238 }
239 return -ETIME;
240}
241
242static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
243 struct transaction *t)
244{
245 unsigned long tmp;
246 int ret = 0;
247 if (EC_FLAGS_MSI)
248 udelay(ACPI_EC_MSI_UDELAY);
249 /* start transaction */
250 spin_lock_irqsave(&ec->curr_lock, tmp);
251 /* following two actions should be kept atomic */
252 ec->curr = t;
253 start_transaction(ec);
254 if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
255 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
256 spin_unlock_irqrestore(&ec->curr_lock, tmp);
257 ret = ec_poll(ec);
258 spin_lock_irqsave(&ec->curr_lock, tmp);
259 ec->curr = NULL;
260 spin_unlock_irqrestore(&ec->curr_lock, tmp);
261 return ret;
262}
263
264static int ec_check_ibf0(struct acpi_ec *ec)
265{
266 u8 status = acpi_ec_read_status(ec);
267 return (status & ACPI_EC_FLAG_IBF) == 0;
268}
269
270static int ec_wait_ibf0(struct acpi_ec *ec)
271{
272 unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
273 /* interrupt wait manually if GPE mode is not active */
274 while (time_before(jiffies, delay))
275 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
276 msecs_to_jiffies(1)))
277 return 0;
278 return -ETIME;
279}
280
281static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
282{
283 int status;
284 u32 glk;
285 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
286 return -EINVAL;
287 if (t->rdata)
288 memset(t->rdata, 0, t->rlen);
289 mutex_lock(&ec->lock);
290 if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
291 status = -EINVAL;
292 goto unlock;
293 }
294 if (ec->global_lock) {
295 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
296 if (ACPI_FAILURE(status)) {
297 status = -ENODEV;
298 goto unlock;
299 }
300 }
301 if (ec_wait_ibf0(ec)) {
302 pr_err(PREFIX "input buffer is not empty, "
303 "aborting transaction\n");
304 status = -ETIME;
305 goto end;
306 }
307 pr_debug(PREFIX "transaction start\n");
308 /* disable GPE during transaction if storm is detected */
309 if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
310 /* It has to be disabled, so that it doesn't trigger. */
311 acpi_disable_gpe(NULL, ec->gpe);
312 }
313
314 status = acpi_ec_transaction_unlocked(ec, t);
315
316 /* check if we received SCI during transaction */
317 ec_check_sci_sync(ec, acpi_ec_read_status(ec));
318 if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
319 msleep(1);
320 /* It is safe to enable the GPE outside of the transaction. */
321 acpi_enable_gpe(NULL, ec->gpe);
322 } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
323 pr_info(PREFIX "GPE storm detected, "
324 "transactions will use polling mode\n");
325 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
326 }
327 pr_debug(PREFIX "transaction end\n");
328end:
329 if (ec->global_lock)
330 acpi_release_global_lock(glk);
331unlock:
332 mutex_unlock(&ec->lock);
333 return status;
334}
335
336static int acpi_ec_burst_enable(struct acpi_ec *ec)
337{
338 u8 d;
339 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
340 .wdata = NULL, .rdata = &d,
341 .wlen = 0, .rlen = 1};
342
343 return acpi_ec_transaction(ec, &t);
344}
345
346static int acpi_ec_burst_disable(struct acpi_ec *ec)
347{
348 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
349 .wdata = NULL, .rdata = NULL,
350 .wlen = 0, .rlen = 0};
351
352 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
353 acpi_ec_transaction(ec, &t) : 0;
354}
355
356static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
357{
358 int result;
359 u8 d;
360 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
361 .wdata = &address, .rdata = &d,
362 .wlen = 1, .rlen = 1};
363
364 result = acpi_ec_transaction(ec, &t);
365 *data = d;
366 return result;
367}
368
369static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
370{
371 u8 wdata[2] = { address, data };
372 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
373 .wdata = wdata, .rdata = NULL,
374 .wlen = 2, .rlen = 0};
375
376 return acpi_ec_transaction(ec, &t);
377}
378
379/*
380 * Externally callable EC access functions. For now, assume 1 EC only
381 */
382int ec_burst_enable(void)
383{
384 if (!first_ec)
385 return -ENODEV;
386 return acpi_ec_burst_enable(first_ec);
387}
388
389EXPORT_SYMBOL(ec_burst_enable);
390
391int ec_burst_disable(void)
392{
393 if (!first_ec)
394 return -ENODEV;
395 return acpi_ec_burst_disable(first_ec);
396}
397
398EXPORT_SYMBOL(ec_burst_disable);
399
400int ec_read(u8 addr, u8 * val)
401{
402 int err;
403 u8 temp_data;
404
405 if (!first_ec)
406 return -ENODEV;
407
408 err = acpi_ec_read(first_ec, addr, &temp_data);
409
410 if (!err) {
411 *val = temp_data;
412 return 0;
413 } else
414 return err;
415}
416
417EXPORT_SYMBOL(ec_read);
418
419int ec_write(u8 addr, u8 val)
420{
421 int err;
422
423 if (!first_ec)
424 return -ENODEV;
425
426 err = acpi_ec_write(first_ec, addr, val);
427
428 return err;
429}
430
431EXPORT_SYMBOL(ec_write);
432
433int ec_transaction(u8 command,
434 const u8 * wdata, unsigned wdata_len,
435 u8 * rdata, unsigned rdata_len)
436{
437 struct transaction t = {.command = command,
438 .wdata = wdata, .rdata = rdata,
439 .wlen = wdata_len, .rlen = rdata_len};
440 if (!first_ec)
441 return -ENODEV;
442
443 return acpi_ec_transaction(first_ec, &t);
444}
445
446EXPORT_SYMBOL(ec_transaction);
447
448void acpi_ec_block_transactions(void)
449{
450 struct acpi_ec *ec = first_ec;
451
452 if (!ec)
453 return;
454
455 mutex_lock(&ec->lock);
456 /* Prevent transactions from being carried out */
457 set_bit(EC_FLAGS_BLOCKED, &ec->flags);
458 mutex_unlock(&ec->lock);
459}
460
461void acpi_ec_unblock_transactions(void)
462{
463 struct acpi_ec *ec = first_ec;
464
465 if (!ec)
466 return;
467
468 mutex_lock(&ec->lock);
469 /* Allow transactions to be carried out again */
470 clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
471 mutex_unlock(&ec->lock);
472}
473
474void acpi_ec_unblock_transactions_early(void)
475{
476 /*
477 * Allow transactions to happen again (this function is called from
478 * atomic context during wakeup, so we don't need to acquire the mutex).
479 */
480 if (first_ec)
481 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
482}
483
484static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
485{
486 int result;
487 u8 d;
488 struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
489 .wdata = NULL, .rdata = &d,
490 .wlen = 0, .rlen = 1};
491 if (!ec || !data)
492 return -EINVAL;
493 /*
494 * Query the EC to find out which _Qxx method we need to evaluate.
495 * Note that successful completion of the query causes the ACPI_EC_SCI
496 * bit to be cleared (and thus clearing the interrupt source).
497 */
498 result = acpi_ec_transaction_unlocked(ec, &t);
499 if (result)
500 return result;
501 if (!d)
502 return -ENODATA;
503 *data = d;
504 return 0;
505}
506
507/* --------------------------------------------------------------------------
508 Event Management
509 -------------------------------------------------------------------------- */
510int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
511 acpi_handle handle, acpi_ec_query_func func,
512 void *data)
513{
514 struct acpi_ec_query_handler *handler =
515 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
516 if (!handler)
517 return -ENOMEM;
518
519 handler->query_bit = query_bit;
520 handler->handle = handle;
521 handler->func = func;
522 handler->data = data;
523 mutex_lock(&ec->lock);
524 list_add(&handler->node, &ec->list);
525 mutex_unlock(&ec->lock);
526 return 0;
527}
528
529EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
530
531void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
532{
533 struct acpi_ec_query_handler *handler, *tmp;
534 mutex_lock(&ec->lock);
535 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
536 if (query_bit == handler->query_bit) {
537 list_del(&handler->node);
538 kfree(handler);
539 }
540 }
541 mutex_unlock(&ec->lock);
542}
543
544EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
545
546static void acpi_ec_run(void *cxt)
547{
548 struct acpi_ec_query_handler *handler = cxt;
549 if (!handler)
550 return;
551 pr_debug(PREFIX "start query execution\n");
552 if (handler->func)
553 handler->func(handler->data);
554 else if (handler->handle)
555 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
556 pr_debug(PREFIX "stop query execution\n");
557 kfree(handler);
558}
559
560static int acpi_ec_sync_query(struct acpi_ec *ec)
561{
562 u8 value = 0;
563 int status;
564 struct acpi_ec_query_handler *handler, *copy;
565 if ((status = acpi_ec_query_unlocked(ec, &value)))
566 return status;
567 list_for_each_entry(handler, &ec->list, node) {
568 if (value == handler->query_bit) {
569 /* have custom handler for this bit */
570 copy = kmalloc(sizeof(*handler), GFP_KERNEL);
571 if (!copy)
572 return -ENOMEM;
573 memcpy(copy, handler, sizeof(*copy));
574 pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
575 return acpi_os_execute((copy->func) ?
576 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
577 acpi_ec_run, copy);
578 }
579 }
580 return 0;
581}
582
583static void acpi_ec_gpe_query(void *ec_cxt)
584{
585 struct acpi_ec *ec = ec_cxt;
586 if (!ec)
587 return;
588 mutex_lock(&ec->lock);
589 acpi_ec_sync_query(ec);
590 mutex_unlock(&ec->lock);
591}
592
593static int ec_check_sci(struct acpi_ec *ec, u8 state)
594{
595 if (state & ACPI_EC_FLAG_SCI) {
596 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
597 pr_debug(PREFIX "push gpe query to the queue\n");
598 return acpi_os_execute(OSL_NOTIFY_HANDLER,
599 acpi_ec_gpe_query, ec);
600 }
601 }
602 return 0;
603}
604
605static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
606 u32 gpe_number, void *data)
607{
608 struct acpi_ec *ec = data;
609
610 pr_debug(PREFIX "~~~> interrupt\n");
611
612 advance_transaction(ec, acpi_ec_read_status(ec));
613 if (ec_transaction_done(ec) &&
614 (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
615 wake_up(&ec->wait);
616 ec_check_sci(ec, acpi_ec_read_status(ec));
617 }
618 return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
619}
620
621/* --------------------------------------------------------------------------
622 Address Space Management
623 -------------------------------------------------------------------------- */
624
625static acpi_status
626acpi_ec_space_handler(u32 function, acpi_physical_address address,
627 u32 bits, u64 *value64,
628 void *handler_context, void *region_context)
629{
630 struct acpi_ec *ec = handler_context;
631 int result = 0, i, bytes = bits / 8;
632 u8 *value = (u8 *)value64;
633
634 if ((address > 0xFF) || !value || !handler_context)
635 return AE_BAD_PARAMETER;
636
637 if (function != ACPI_READ && function != ACPI_WRITE)
638 return AE_BAD_PARAMETER;
639
640 if (EC_FLAGS_MSI || bits > 8)
641 acpi_ec_burst_enable(ec);
642
643 for (i = 0; i < bytes; ++i, ++address, ++value)
644 result = (function == ACPI_READ) ?
645 acpi_ec_read(ec, address, value) :
646 acpi_ec_write(ec, address, *value);
647
648 if (EC_FLAGS_MSI || bits > 8)
649 acpi_ec_burst_disable(ec);
650
651 switch (result) {
652 case -EINVAL:
653 return AE_BAD_PARAMETER;
654 break;
655 case -ENODEV:
656 return AE_NOT_FOUND;
657 break;
658 case -ETIME:
659 return AE_TIME;
660 break;
661 default:
662 return AE_OK;
663 }
664}
665
666/* --------------------------------------------------------------------------
667 Driver Interface
668 -------------------------------------------------------------------------- */
669static acpi_status
670ec_parse_io_ports(struct acpi_resource *resource, void *context);
671
672static struct acpi_ec *make_acpi_ec(void)
673{
674 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
675 if (!ec)
676 return NULL;
677 ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
678 mutex_init(&ec->lock);
679 init_waitqueue_head(&ec->wait);
680 INIT_LIST_HEAD(&ec->list);
681 spin_lock_init(&ec->curr_lock);
682 return ec;
683}
684
685static acpi_status
686acpi_ec_register_query_methods(acpi_handle handle, u32 level,
687 void *context, void **return_value)
688{
689 char node_name[5];
690 struct acpi_buffer buffer = { sizeof(node_name), node_name };
691 struct acpi_ec *ec = context;
692 int value = 0;
693 acpi_status status;
694
695 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
696
697 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
698 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
699 }
700 return AE_OK;
701}
702
703static acpi_status
704ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
705{
706 acpi_status status;
707 unsigned long long tmp = 0;
708
709 struct acpi_ec *ec = context;
710
711 /* clear addr values, ec_parse_io_ports depend on it */
712 ec->command_addr = ec->data_addr = 0;
713
714 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
715 ec_parse_io_ports, ec);
716 if (ACPI_FAILURE(status))
717 return status;
718
719 /* Get GPE bit assignment (EC events). */
720 /* TODO: Add support for _GPE returning a package */
721 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
722 if (ACPI_FAILURE(status))
723 return status;
724 ec->gpe = tmp;
725 /* Use the global lock for all EC transactions? */
726 tmp = 0;
727 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
728 ec->global_lock = tmp;
729 ec->handle = handle;
730 return AE_CTRL_TERMINATE;
731}
732
733static int ec_install_handlers(struct acpi_ec *ec)
734{
735 acpi_status status;
736 if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
737 return 0;
738 status = acpi_install_gpe_handler(NULL, ec->gpe,
739 ACPI_GPE_EDGE_TRIGGERED,
740 &acpi_ec_gpe_handler, ec);
741 if (ACPI_FAILURE(status))
742 return -ENODEV;
743
744 acpi_enable_gpe(NULL, ec->gpe);
745 status = acpi_install_address_space_handler(ec->handle,
746 ACPI_ADR_SPACE_EC,
747 &acpi_ec_space_handler,
748 NULL, ec);
749 if (ACPI_FAILURE(status)) {
750 if (status == AE_NOT_FOUND) {
751 /*
752 * Maybe OS fails in evaluating the _REG object.
753 * The AE_NOT_FOUND error will be ignored and OS
754 * continue to initialize EC.
755 */
756 printk(KERN_ERR "Fail in evaluating the _REG object"
757 " of EC device. Broken bios is suspected.\n");
758 } else {
759 acpi_remove_gpe_handler(NULL, ec->gpe,
760 &acpi_ec_gpe_handler);
761 acpi_disable_gpe(NULL, ec->gpe);
762 return -ENODEV;
763 }
764 }
765
766 set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
767 return 0;
768}
769
770static void ec_remove_handlers(struct acpi_ec *ec)
771{
772 acpi_disable_gpe(NULL, ec->gpe);
773 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
774 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
775 pr_err(PREFIX "failed to remove space handler\n");
776 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
777 &acpi_ec_gpe_handler)))
778 pr_err(PREFIX "failed to remove gpe handler\n");
779 clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
780}
781
782static int acpi_ec_add(struct acpi_device *device)
783{
784 struct acpi_ec *ec = NULL;
785 int ret;
786
787 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
788 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
789
790 /* Check for boot EC */
791 if (boot_ec &&
792 (boot_ec->handle == device->handle ||
793 boot_ec->handle == ACPI_ROOT_OBJECT)) {
794 ec = boot_ec;
795 boot_ec = NULL;
796 } else {
797 ec = make_acpi_ec();
798 if (!ec)
799 return -ENOMEM;
800 }
801 if (ec_parse_device(device->handle, 0, ec, NULL) !=
802 AE_CTRL_TERMINATE) {
803 kfree(ec);
804 return -EINVAL;
805 }
806
807 /* Find and register all query methods */
808 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
809 acpi_ec_register_query_methods, NULL, ec, NULL);
810
811 if (!first_ec)
812 first_ec = ec;
813 device->driver_data = ec;
814
815 WARN(!request_region(ec->data_addr, 1, "EC data"),
816 "Could not request EC data io port 0x%lx", ec->data_addr);
817 WARN(!request_region(ec->command_addr, 1, "EC cmd"),
818 "Could not request EC cmd io port 0x%lx", ec->command_addr);
819
820 pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
821 ec->gpe, ec->command_addr, ec->data_addr);
822
823 ret = ec_install_handlers(ec);
824
825 /* EC is fully operational, allow queries */
826 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
827 return ret;
828}
829
830static int acpi_ec_remove(struct acpi_device *device, int type)
831{
832 struct acpi_ec *ec;
833 struct acpi_ec_query_handler *handler, *tmp;
834
835 if (!device)
836 return -EINVAL;
837
838 ec = acpi_driver_data(device);
839 ec_remove_handlers(ec);
840 mutex_lock(&ec->lock);
841 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
842 list_del(&handler->node);
843 kfree(handler);
844 }
845 mutex_unlock(&ec->lock);
846 release_region(ec->data_addr, 1);
847 release_region(ec->command_addr, 1);
848 device->driver_data = NULL;
849 if (ec == first_ec)
850 first_ec = NULL;
851 kfree(ec);
852 return 0;
853}
854
855static acpi_status
856ec_parse_io_ports(struct acpi_resource *resource, void *context)
857{
858 struct acpi_ec *ec = context;
859
860 if (resource->type != ACPI_RESOURCE_TYPE_IO)
861 return AE_OK;
862
863 /*
864 * The first address region returned is the data port, and
865 * the second address region returned is the status/command
866 * port.
867 */
868 if (ec->data_addr == 0)
869 ec->data_addr = resource->data.io.minimum;
870 else if (ec->command_addr == 0)
871 ec->command_addr = resource->data.io.minimum;
872 else
873 return AE_CTRL_TERMINATE;
874
875 return AE_OK;
876}
877
878int __init acpi_boot_ec_enable(void)
879{
880 if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
881 return 0;
882 if (!ec_install_handlers(boot_ec)) {
883 first_ec = boot_ec;
884 return 0;
885 }
886 return -EFAULT;
887}
888
889static const struct acpi_device_id ec_device_ids[] = {
890 {"PNP0C09", 0},
891 {"", 0},
892};
893
894/* Some BIOS do not survive early DSDT scan, skip it */
895static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
896{
897 EC_FLAGS_SKIP_DSDT_SCAN = 1;
898 return 0;
899}
900
901/* ASUStek often supplies us with broken ECDT, validate it */
902static int ec_validate_ecdt(const struct dmi_system_id *id)
903{
904 EC_FLAGS_VALIDATE_ECDT = 1;
905 return 0;
906}
907
908/* MSI EC needs special treatment, enable it */
909static int ec_flag_msi(const struct dmi_system_id *id)
910{
911 printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
912 EC_FLAGS_MSI = 1;
913 EC_FLAGS_VALIDATE_ECDT = 1;
914 return 0;
915}
916
917static struct dmi_system_id __initdata ec_dmi_table[] = {
918 {
919 ec_skip_dsdt_scan, "Compal JFL92", {
920 DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
921 DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
922 {
923 ec_flag_msi, "MSI hardware", {
924 DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
925 {
926 ec_flag_msi, "MSI hardware", {
927 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
928 {
929 ec_flag_msi, "MSI hardware", {
930 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
931 {
932 ec_flag_msi, "MSI hardware", {
933 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
934 {
935 ec_flag_msi, "Quanta hardware", {
936 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
937 DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
938 {
939 ec_flag_msi, "Quanta hardware", {
940 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
941 DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
942 {
943 ec_validate_ecdt, "ASUS hardware", {
944 DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
945 {
946 ec_validate_ecdt, "ASUS hardware", {
947 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
948 {},
949};
950
951
952int __init acpi_ec_ecdt_probe(void)
953{
954 acpi_status status;
955 struct acpi_ec *saved_ec = NULL;
956 struct acpi_table_ecdt *ecdt_ptr;
957
958 boot_ec = make_acpi_ec();
959 if (!boot_ec)
960 return -ENOMEM;
961 /*
962 * Generate a boot ec context
963 */
964 dmi_check_system(ec_dmi_table);
965 status = acpi_get_table(ACPI_SIG_ECDT, 1,
966 (struct acpi_table_header **)&ecdt_ptr);
967 if (ACPI_SUCCESS(status)) {
968 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
969 boot_ec->command_addr = ecdt_ptr->control.address;
970 boot_ec->data_addr = ecdt_ptr->data.address;
971 boot_ec->gpe = ecdt_ptr->gpe;
972 boot_ec->handle = ACPI_ROOT_OBJECT;
973 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
974 /* Don't trust ECDT, which comes from ASUSTek */
975 if (!EC_FLAGS_VALIDATE_ECDT)
976 goto install;
977 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
978 if (!saved_ec)
979 return -ENOMEM;
980 /* fall through */
981 }
982
983 if (EC_FLAGS_SKIP_DSDT_SCAN)
984 return -ENODEV;
985
986 /* This workaround is needed only on some broken machines,
987 * which require early EC, but fail to provide ECDT */
988 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
989 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
990 boot_ec, NULL);
991 /* Check that acpi_get_devices actually find something */
992 if (ACPI_FAILURE(status) || !boot_ec->handle)
993 goto error;
994 if (saved_ec) {
995 /* try to find good ECDT from ASUSTek */
996 if (saved_ec->command_addr != boot_ec->command_addr ||
997 saved_ec->data_addr != boot_ec->data_addr ||
998 saved_ec->gpe != boot_ec->gpe ||
999 saved_ec->handle != boot_ec->handle)
1000 pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1001 "ECDT tables, which are very hard to workaround. "
1002 "Trying to use DSDT EC info instead. Please send "
1003 "output of acpidump to linux-acpi@vger.kernel.org\n");
1004 kfree(saved_ec);
1005 saved_ec = NULL;
1006 } else {
1007 /* We really need to limit this workaround, the only ASUS,
1008 * which needs it, has fake EC._INI method, so use it as flag.
1009 * Keep boot_ec struct as it will be needed soon.
1010 */
1011 acpi_handle dummy;
1012 if (!dmi_name_in_vendors("ASUS") ||
1013 ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1014 &dummy)))
1015 return -ENODEV;
1016 }
1017install:
1018 if (!ec_install_handlers(boot_ec)) {
1019 first_ec = boot_ec;
1020 return 0;
1021 }
1022error:
1023 kfree(boot_ec);
1024 boot_ec = NULL;
1025 return -ENODEV;
1026}
1027
1028static struct acpi_driver acpi_ec_driver = {
1029 .name = "ec",
1030 .class = ACPI_EC_CLASS,
1031 .ids = ec_device_ids,
1032 .ops = {
1033 .add = acpi_ec_add,
1034 .remove = acpi_ec_remove,
1035 },
1036};
1037
1038int __init acpi_ec_init(void)
1039{
1040 int result = 0;
1041
1042 /* Now register the driver for the EC */
1043 result = acpi_bus_register_driver(&acpi_ec_driver);
1044 if (result < 0)
1045 return -ENODEV;
1046
1047 return result;
1048}
1049
1050/* EC driver currently not unloadable */
1051#if 0
1052static void __exit acpi_ec_exit(void)
1053{
1054
1055 acpi_bus_unregister_driver(&acpi_ec_driver);
1056 return;
1057}
1058#endif /* 0 */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ec.c - ACPI Embedded Controller Driver (v3)
4 *
5 * Copyright (C) 2001-2015 Intel Corporation
6 * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
7 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
8 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
9 * 2004 Luming Yu <luming.yu@intel.com>
10 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
11 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
12 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
13 */
14
15/* Uncomment next line to get verbose printout */
16/* #define DEBUG */
17#define pr_fmt(fmt) "ACPI: EC: " fmt
18
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/types.h>
23#include <linux/delay.h>
24#include <linux/interrupt.h>
25#include <linux/list.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/suspend.h>
29#include <linux/acpi.h>
30#include <linux/dmi.h>
31#include <asm/io.h>
32
33#include "internal.h"
34
35#define ACPI_EC_CLASS "embedded_controller"
36#define ACPI_EC_DEVICE_NAME "Embedded Controller"
37
38/* EC status register */
39#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
40#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
41#define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
42#define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
43#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
44
45/*
46 * The SCI_EVT clearing timing is not defined by the ACPI specification.
47 * This leads to lots of practical timing issues for the host EC driver.
48 * The following variations are defined (from the target EC firmware's
49 * perspective):
50 * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
51 * target can clear SCI_EVT at any time so long as the host can see
52 * the indication by reading the status register (EC_SC). So the
53 * host should re-check SCI_EVT after the first time the SCI_EVT
54 * indication is seen, which is the same time the query request
55 * (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
56 * at any later time could indicate another event. Normally such
57 * kind of EC firmware has implemented an event queue and will
58 * return 0x00 to indicate "no outstanding event".
59 * QUERY: After seeing the query request (QR_EC) written to the command
60 * register (EC_CMD) by the host and having prepared the responding
61 * event value in the data register (EC_DATA), the target can safely
62 * clear SCI_EVT because the target can confirm that the current
63 * event is being handled by the host. The host then should check
64 * SCI_EVT right after reading the event response from the data
65 * register (EC_DATA).
66 * EVENT: After seeing the event response read from the data register
67 * (EC_DATA) by the host, the target can clear SCI_EVT. As the
68 * target requires time to notice the change in the data register
69 * (EC_DATA), the host may be required to wait additional guarding
70 * time before checking the SCI_EVT again. Such guarding may not be
71 * necessary if the host is notified via another IRQ.
72 */
73#define ACPI_EC_EVT_TIMING_STATUS 0x00
74#define ACPI_EC_EVT_TIMING_QUERY 0x01
75#define ACPI_EC_EVT_TIMING_EVENT 0x02
76
77/* EC commands */
78enum ec_command {
79 ACPI_EC_COMMAND_READ = 0x80,
80 ACPI_EC_COMMAND_WRITE = 0x81,
81 ACPI_EC_BURST_ENABLE = 0x82,
82 ACPI_EC_BURST_DISABLE = 0x83,
83 ACPI_EC_COMMAND_QUERY = 0x84,
84};
85
86#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
87#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
88#define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
89#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
90 * when trying to clear the EC */
91#define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
92
93enum {
94 EC_FLAGS_QUERY_ENABLED, /* Query is enabled */
95 EC_FLAGS_QUERY_PENDING, /* Query is pending */
96 EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */
97 EC_FLAGS_EVENT_HANDLER_INSTALLED, /* Event handler installed */
98 EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */
99 EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
100 EC_FLAGS_STARTED, /* Driver is started */
101 EC_FLAGS_STOPPED, /* Driver is stopped */
102 EC_FLAGS_EVENTS_MASKED, /* Events masked */
103};
104
105#define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
106#define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
107
108/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
109static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
110module_param(ec_delay, uint, 0644);
111MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
112
113static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
114module_param(ec_max_queries, uint, 0644);
115MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
116
117static bool ec_busy_polling __read_mostly;
118module_param(ec_busy_polling, bool, 0644);
119MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
120
121static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
122module_param(ec_polling_guard, uint, 0644);
123MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
124
125static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
126
127/*
128 * If the number of false interrupts per one transaction exceeds
129 * this threshold, will think there is a GPE storm happened and
130 * will disable the GPE for normal transaction.
131 */
132static unsigned int ec_storm_threshold __read_mostly = 8;
133module_param(ec_storm_threshold, uint, 0644);
134MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
135
136static bool ec_freeze_events __read_mostly = false;
137module_param(ec_freeze_events, bool, 0644);
138MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
139
140static bool ec_no_wakeup __read_mostly;
141module_param(ec_no_wakeup, bool, 0644);
142MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
143
144struct acpi_ec_query_handler {
145 struct list_head node;
146 acpi_ec_query_func func;
147 acpi_handle handle;
148 void *data;
149 u8 query_bit;
150 struct kref kref;
151};
152
153struct transaction {
154 const u8 *wdata;
155 u8 *rdata;
156 unsigned short irq_count;
157 u8 command;
158 u8 wi;
159 u8 ri;
160 u8 wlen;
161 u8 rlen;
162 u8 flags;
163};
164
165struct acpi_ec_query {
166 struct transaction transaction;
167 struct work_struct work;
168 struct acpi_ec_query_handler *handler;
169};
170
171static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
172static void advance_transaction(struct acpi_ec *ec, bool interrupt);
173static void acpi_ec_event_handler(struct work_struct *work);
174static void acpi_ec_event_processor(struct work_struct *work);
175
176struct acpi_ec *first_ec;
177EXPORT_SYMBOL(first_ec);
178
179static struct acpi_ec *boot_ec;
180static bool boot_ec_is_ecdt = false;
181static struct workqueue_struct *ec_wq;
182static struct workqueue_struct *ec_query_wq;
183
184static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
185static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
186static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
187static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
188
189/* --------------------------------------------------------------------------
190 * Logging/Debugging
191 * -------------------------------------------------------------------------- */
192
193/*
194 * Splitters used by the developers to track the boundary of the EC
195 * handling processes.
196 */
197#ifdef DEBUG
198#define EC_DBG_SEP " "
199#define EC_DBG_DRV "+++++"
200#define EC_DBG_STM "====="
201#define EC_DBG_REQ "*****"
202#define EC_DBG_EVT "#####"
203#else
204#define EC_DBG_SEP ""
205#define EC_DBG_DRV
206#define EC_DBG_STM
207#define EC_DBG_REQ
208#define EC_DBG_EVT
209#endif
210
211#define ec_log_raw(fmt, ...) \
212 pr_info(fmt "\n", ##__VA_ARGS__)
213#define ec_dbg_raw(fmt, ...) \
214 pr_debug(fmt "\n", ##__VA_ARGS__)
215#define ec_log(filter, fmt, ...) \
216 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
217#define ec_dbg(filter, fmt, ...) \
218 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
219
220#define ec_log_drv(fmt, ...) \
221 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
222#define ec_dbg_drv(fmt, ...) \
223 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
224#define ec_dbg_stm(fmt, ...) \
225 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
226#define ec_dbg_req(fmt, ...) \
227 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
228#define ec_dbg_evt(fmt, ...) \
229 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
230#define ec_dbg_ref(ec, fmt, ...) \
231 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
232
233/* --------------------------------------------------------------------------
234 * Device Flags
235 * -------------------------------------------------------------------------- */
236
237static bool acpi_ec_started(struct acpi_ec *ec)
238{
239 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
240 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
241}
242
243static bool acpi_ec_event_enabled(struct acpi_ec *ec)
244{
245 /*
246 * There is an OSPM early stage logic. During the early stages
247 * (boot/resume), OSPMs shouldn't enable the event handling, only
248 * the EC transactions are allowed to be performed.
249 */
250 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
251 return false;
252 /*
253 * However, disabling the event handling is experimental for late
254 * stage (suspend), and is controlled by the boot parameter of
255 * "ec_freeze_events":
256 * 1. true: The EC event handling is disabled before entering
257 * the noirq stage.
258 * 2. false: The EC event handling is automatically disabled as
259 * soon as the EC driver is stopped.
260 */
261 if (ec_freeze_events)
262 return acpi_ec_started(ec);
263 else
264 return test_bit(EC_FLAGS_STARTED, &ec->flags);
265}
266
267static bool acpi_ec_flushed(struct acpi_ec *ec)
268{
269 return ec->reference_count == 1;
270}
271
272/* --------------------------------------------------------------------------
273 * EC Registers
274 * -------------------------------------------------------------------------- */
275
276static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
277{
278 u8 x = inb(ec->command_addr);
279
280 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
281 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
282 x,
283 !!(x & ACPI_EC_FLAG_SCI),
284 !!(x & ACPI_EC_FLAG_BURST),
285 !!(x & ACPI_EC_FLAG_CMD),
286 !!(x & ACPI_EC_FLAG_IBF),
287 !!(x & ACPI_EC_FLAG_OBF));
288 return x;
289}
290
291static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
292{
293 u8 x = inb(ec->data_addr);
294
295 ec->timestamp = jiffies;
296 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
297 return x;
298}
299
300static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
301{
302 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
303 outb(command, ec->command_addr);
304 ec->timestamp = jiffies;
305}
306
307static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
308{
309 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
310 outb(data, ec->data_addr);
311 ec->timestamp = jiffies;
312}
313
314#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
315static const char *acpi_ec_cmd_string(u8 cmd)
316{
317 switch (cmd) {
318 case 0x80:
319 return "RD_EC";
320 case 0x81:
321 return "WR_EC";
322 case 0x82:
323 return "BE_EC";
324 case 0x83:
325 return "BD_EC";
326 case 0x84:
327 return "QR_EC";
328 }
329 return "UNKNOWN";
330}
331#else
332#define acpi_ec_cmd_string(cmd) "UNDEF"
333#endif
334
335/* --------------------------------------------------------------------------
336 * GPE Registers
337 * -------------------------------------------------------------------------- */
338
339static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
340{
341 acpi_event_status gpe_status = 0;
342
343 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
344 return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
345}
346
347static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
348{
349 if (open)
350 acpi_enable_gpe(NULL, ec->gpe);
351 else {
352 BUG_ON(ec->reference_count < 1);
353 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
354 }
355 if (acpi_ec_gpe_status_set(ec)) {
356 /*
357 * On some platforms, EN=1 writes cannot trigger GPE. So
358 * software need to manually trigger a pseudo GPE event on
359 * EN=1 writes.
360 */
361 ec_dbg_raw("Polling quirk");
362 advance_transaction(ec, false);
363 }
364}
365
366static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
367{
368 if (close)
369 acpi_disable_gpe(NULL, ec->gpe);
370 else {
371 BUG_ON(ec->reference_count < 1);
372 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
373 }
374}
375
376/* --------------------------------------------------------------------------
377 * Transaction Management
378 * -------------------------------------------------------------------------- */
379
380static void acpi_ec_submit_request(struct acpi_ec *ec)
381{
382 ec->reference_count++;
383 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
384 ec->gpe >= 0 && ec->reference_count == 1)
385 acpi_ec_enable_gpe(ec, true);
386}
387
388static void acpi_ec_complete_request(struct acpi_ec *ec)
389{
390 bool flushed = false;
391
392 ec->reference_count--;
393 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
394 ec->gpe >= 0 && ec->reference_count == 0)
395 acpi_ec_disable_gpe(ec, true);
396 flushed = acpi_ec_flushed(ec);
397 if (flushed)
398 wake_up(&ec->wait);
399}
400
401static void acpi_ec_mask_events(struct acpi_ec *ec)
402{
403 if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
404 if (ec->gpe >= 0)
405 acpi_ec_disable_gpe(ec, false);
406 else
407 disable_irq_nosync(ec->irq);
408
409 ec_dbg_drv("Polling enabled");
410 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
411 }
412}
413
414static void acpi_ec_unmask_events(struct acpi_ec *ec)
415{
416 if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
417 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
418 if (ec->gpe >= 0)
419 acpi_ec_enable_gpe(ec, false);
420 else
421 enable_irq(ec->irq);
422
423 ec_dbg_drv("Polling disabled");
424 }
425}
426
427/*
428 * acpi_ec_submit_flushable_request() - Increase the reference count unless
429 * the flush operation is not in
430 * progress
431 * @ec: the EC device
432 *
433 * This function must be used before taking a new action that should hold
434 * the reference count. If this function returns false, then the action
435 * must be discarded or it will prevent the flush operation from being
436 * completed.
437 */
438static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
439{
440 if (!acpi_ec_started(ec))
441 return false;
442 acpi_ec_submit_request(ec);
443 return true;
444}
445
446static void acpi_ec_submit_query(struct acpi_ec *ec)
447{
448 acpi_ec_mask_events(ec);
449 if (!acpi_ec_event_enabled(ec))
450 return;
451 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
452 ec_dbg_evt("Command(%s) submitted/blocked",
453 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
454 ec->nr_pending_queries++;
455 queue_work(ec_wq, &ec->work);
456 }
457}
458
459static void acpi_ec_complete_query(struct acpi_ec *ec)
460{
461 if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
462 ec_dbg_evt("Command(%s) unblocked",
463 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
464 acpi_ec_unmask_events(ec);
465}
466
467static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
468{
469 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
470 ec_log_drv("event unblocked");
471 /*
472 * Unconditionally invoke this once after enabling the event
473 * handling mechanism to detect the pending events.
474 */
475 advance_transaction(ec, false);
476}
477
478static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
479{
480 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
481 ec_log_drv("event blocked");
482}
483
484/*
485 * Process _Q events that might have accumulated in the EC.
486 * Run with locked ec mutex.
487 */
488static void acpi_ec_clear(struct acpi_ec *ec)
489{
490 int i, status;
491 u8 value = 0;
492
493 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
494 status = acpi_ec_query(ec, &value);
495 if (status || !value)
496 break;
497 }
498 if (unlikely(i == ACPI_EC_CLEAR_MAX))
499 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
500 else
501 pr_info("%d stale EC events cleared\n", i);
502}
503
504static void acpi_ec_enable_event(struct acpi_ec *ec)
505{
506 unsigned long flags;
507
508 spin_lock_irqsave(&ec->lock, flags);
509 if (acpi_ec_started(ec))
510 __acpi_ec_enable_event(ec);
511 spin_unlock_irqrestore(&ec->lock, flags);
512
513 /* Drain additional events if hardware requires that */
514 if (EC_FLAGS_CLEAR_ON_RESUME)
515 acpi_ec_clear(ec);
516}
517
518#ifdef CONFIG_PM_SLEEP
519static void __acpi_ec_flush_work(void)
520{
521 drain_workqueue(ec_wq); /* flush ec->work */
522 flush_workqueue(ec_query_wq); /* flush queries */
523}
524
525static void acpi_ec_disable_event(struct acpi_ec *ec)
526{
527 unsigned long flags;
528
529 spin_lock_irqsave(&ec->lock, flags);
530 __acpi_ec_disable_event(ec);
531 spin_unlock_irqrestore(&ec->lock, flags);
532
533 /*
534 * When ec_freeze_events is true, we need to flush events in
535 * the proper position before entering the noirq stage.
536 */
537 __acpi_ec_flush_work();
538}
539
540void acpi_ec_flush_work(void)
541{
542 /* Without ec_wq there is nothing to flush. */
543 if (!ec_wq)
544 return;
545
546 __acpi_ec_flush_work();
547}
548#endif /* CONFIG_PM_SLEEP */
549
550static bool acpi_ec_guard_event(struct acpi_ec *ec)
551{
552 bool guarded = true;
553 unsigned long flags;
554
555 spin_lock_irqsave(&ec->lock, flags);
556 /*
557 * If firmware SCI_EVT clearing timing is "event", we actually
558 * don't know when the SCI_EVT will be cleared by firmware after
559 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
560 * acceptable period.
561 *
562 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
563 * flagged, which means SCI_EVT check has just been performed.
564 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
565 * guarding should have already been performed (via
566 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
567 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
568 * ACPI_EC_COMMAND_POLL state immediately.
569 */
570 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
571 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
572 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
573 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
574 guarded = false;
575 spin_unlock_irqrestore(&ec->lock, flags);
576 return guarded;
577}
578
579static int ec_transaction_polled(struct acpi_ec *ec)
580{
581 unsigned long flags;
582 int ret = 0;
583
584 spin_lock_irqsave(&ec->lock, flags);
585 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
586 ret = 1;
587 spin_unlock_irqrestore(&ec->lock, flags);
588 return ret;
589}
590
591static int ec_transaction_completed(struct acpi_ec *ec)
592{
593 unsigned long flags;
594 int ret = 0;
595
596 spin_lock_irqsave(&ec->lock, flags);
597 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
598 ret = 1;
599 spin_unlock_irqrestore(&ec->lock, flags);
600 return ret;
601}
602
603static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
604{
605 ec->curr->flags |= flag;
606 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
607 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
608 flag == ACPI_EC_COMMAND_POLL)
609 acpi_ec_complete_query(ec);
610 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
611 flag == ACPI_EC_COMMAND_COMPLETE)
612 acpi_ec_complete_query(ec);
613 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
614 flag == ACPI_EC_COMMAND_COMPLETE)
615 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
616 }
617}
618
619static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
620{
621 if (t->irq_count < ec_storm_threshold)
622 ++t->irq_count;
623
624 /* Trigger if the threshold is 0 too. */
625 if (t->irq_count == ec_storm_threshold)
626 acpi_ec_mask_events(ec);
627}
628
629static void advance_transaction(struct acpi_ec *ec, bool interrupt)
630{
631 struct transaction *t = ec->curr;
632 bool wakeup = false;
633 u8 status;
634
635 ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
636
637 /*
638 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
639 * changes to always trigger a GPE interrupt.
640 *
641 * GPE STS is a W1C register, which means:
642 *
643 * 1. Software can clear it without worrying about clearing the other
644 * GPEs' STS bits when the hardware sets them in parallel.
645 *
646 * 2. As long as software can ensure only clearing it when it is set,
647 * hardware won't set it in parallel.
648 */
649 if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
650 acpi_clear_gpe(NULL, ec->gpe);
651
652 status = acpi_ec_read_status(ec);
653
654 /*
655 * Another IRQ or a guarded polling mode advancement is detected,
656 * the next QR_EC submission is then allowed.
657 */
658 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
659 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
660 (!ec->nr_pending_queries ||
661 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
662 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
663 acpi_ec_complete_query(ec);
664 }
665 if (!t)
666 goto out;
667 }
668
669 if (t->flags & ACPI_EC_COMMAND_POLL) {
670 if (t->wlen > t->wi) {
671 if (!(status & ACPI_EC_FLAG_IBF))
672 acpi_ec_write_data(ec, t->wdata[t->wi++]);
673 else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
674 acpi_ec_spurious_interrupt(ec, t);
675 } else if (t->rlen > t->ri) {
676 if (status & ACPI_EC_FLAG_OBF) {
677 t->rdata[t->ri++] = acpi_ec_read_data(ec);
678 if (t->rlen == t->ri) {
679 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
680 wakeup = true;
681 if (t->command == ACPI_EC_COMMAND_QUERY)
682 ec_dbg_evt("Command(%s) completed by hardware",
683 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
684 }
685 } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
686 acpi_ec_spurious_interrupt(ec, t);
687 }
688 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
689 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
690 wakeup = true;
691 }
692 } else if (!(status & ACPI_EC_FLAG_IBF)) {
693 acpi_ec_write_cmd(ec, t->command);
694 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
695 }
696
697out:
698 if (status & ACPI_EC_FLAG_SCI)
699 acpi_ec_submit_query(ec);
700
701 if (wakeup && interrupt)
702 wake_up(&ec->wait);
703}
704
705static void start_transaction(struct acpi_ec *ec)
706{
707 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
708 ec->curr->flags = 0;
709}
710
711static int ec_guard(struct acpi_ec *ec)
712{
713 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
714 unsigned long timeout = ec->timestamp + guard;
715
716 /* Ensure guarding period before polling EC status */
717 do {
718 if (ec->busy_polling) {
719 /* Perform busy polling */
720 if (ec_transaction_completed(ec))
721 return 0;
722 udelay(jiffies_to_usecs(guard));
723 } else {
724 /*
725 * Perform wait polling
726 * 1. Wait the transaction to be completed by the
727 * GPE handler after the transaction enters
728 * ACPI_EC_COMMAND_POLL state.
729 * 2. A special guarding logic is also required
730 * for event clearing mode "event" before the
731 * transaction enters ACPI_EC_COMMAND_POLL
732 * state.
733 */
734 if (!ec_transaction_polled(ec) &&
735 !acpi_ec_guard_event(ec))
736 break;
737 if (wait_event_timeout(ec->wait,
738 ec_transaction_completed(ec),
739 guard))
740 return 0;
741 }
742 } while (time_before(jiffies, timeout));
743 return -ETIME;
744}
745
746static int ec_poll(struct acpi_ec *ec)
747{
748 unsigned long flags;
749 int repeat = 5; /* number of command restarts */
750
751 while (repeat--) {
752 unsigned long delay = jiffies +
753 msecs_to_jiffies(ec_delay);
754 do {
755 if (!ec_guard(ec))
756 return 0;
757 spin_lock_irqsave(&ec->lock, flags);
758 advance_transaction(ec, false);
759 spin_unlock_irqrestore(&ec->lock, flags);
760 } while (time_before(jiffies, delay));
761 pr_debug("controller reset, restart transaction\n");
762 spin_lock_irqsave(&ec->lock, flags);
763 start_transaction(ec);
764 spin_unlock_irqrestore(&ec->lock, flags);
765 }
766 return -ETIME;
767}
768
769static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
770 struct transaction *t)
771{
772 unsigned long tmp;
773 int ret = 0;
774
775 /* start transaction */
776 spin_lock_irqsave(&ec->lock, tmp);
777 /* Enable GPE for command processing (IBF=0/OBF=1) */
778 if (!acpi_ec_submit_flushable_request(ec)) {
779 ret = -EINVAL;
780 goto unlock;
781 }
782 ec_dbg_ref(ec, "Increase command");
783 /* following two actions should be kept atomic */
784 ec->curr = t;
785 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
786 start_transaction(ec);
787 spin_unlock_irqrestore(&ec->lock, tmp);
788
789 ret = ec_poll(ec);
790
791 spin_lock_irqsave(&ec->lock, tmp);
792 if (t->irq_count == ec_storm_threshold)
793 acpi_ec_unmask_events(ec);
794 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
795 ec->curr = NULL;
796 /* Disable GPE for command processing (IBF=0/OBF=1) */
797 acpi_ec_complete_request(ec);
798 ec_dbg_ref(ec, "Decrease command");
799unlock:
800 spin_unlock_irqrestore(&ec->lock, tmp);
801 return ret;
802}
803
804static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
805{
806 int status;
807 u32 glk;
808
809 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
810 return -EINVAL;
811 if (t->rdata)
812 memset(t->rdata, 0, t->rlen);
813
814 mutex_lock(&ec->mutex);
815 if (ec->global_lock) {
816 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
817 if (ACPI_FAILURE(status)) {
818 status = -ENODEV;
819 goto unlock;
820 }
821 }
822
823 status = acpi_ec_transaction_unlocked(ec, t);
824
825 if (ec->global_lock)
826 acpi_release_global_lock(glk);
827unlock:
828 mutex_unlock(&ec->mutex);
829 return status;
830}
831
832static int acpi_ec_burst_enable(struct acpi_ec *ec)
833{
834 u8 d;
835 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
836 .wdata = NULL, .rdata = &d,
837 .wlen = 0, .rlen = 1};
838
839 return acpi_ec_transaction(ec, &t);
840}
841
842static int acpi_ec_burst_disable(struct acpi_ec *ec)
843{
844 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
845 .wdata = NULL, .rdata = NULL,
846 .wlen = 0, .rlen = 0};
847
848 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
849 acpi_ec_transaction(ec, &t) : 0;
850}
851
852static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
853{
854 int result;
855 u8 d;
856 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
857 .wdata = &address, .rdata = &d,
858 .wlen = 1, .rlen = 1};
859
860 result = acpi_ec_transaction(ec, &t);
861 *data = d;
862 return result;
863}
864
865static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
866{
867 u8 wdata[2] = { address, data };
868 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
869 .wdata = wdata, .rdata = NULL,
870 .wlen = 2, .rlen = 0};
871
872 return acpi_ec_transaction(ec, &t);
873}
874
875int ec_read(u8 addr, u8 *val)
876{
877 int err;
878 u8 temp_data;
879
880 if (!first_ec)
881 return -ENODEV;
882
883 err = acpi_ec_read(first_ec, addr, &temp_data);
884
885 if (!err) {
886 *val = temp_data;
887 return 0;
888 }
889 return err;
890}
891EXPORT_SYMBOL(ec_read);
892
893int ec_write(u8 addr, u8 val)
894{
895 int err;
896
897 if (!first_ec)
898 return -ENODEV;
899
900 err = acpi_ec_write(first_ec, addr, val);
901
902 return err;
903}
904EXPORT_SYMBOL(ec_write);
905
906int ec_transaction(u8 command,
907 const u8 *wdata, unsigned wdata_len,
908 u8 *rdata, unsigned rdata_len)
909{
910 struct transaction t = {.command = command,
911 .wdata = wdata, .rdata = rdata,
912 .wlen = wdata_len, .rlen = rdata_len};
913
914 if (!first_ec)
915 return -ENODEV;
916
917 return acpi_ec_transaction(first_ec, &t);
918}
919EXPORT_SYMBOL(ec_transaction);
920
921/* Get the handle to the EC device */
922acpi_handle ec_get_handle(void)
923{
924 if (!first_ec)
925 return NULL;
926 return first_ec->handle;
927}
928EXPORT_SYMBOL(ec_get_handle);
929
930static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
931{
932 unsigned long flags;
933
934 spin_lock_irqsave(&ec->lock, flags);
935 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
936 ec_dbg_drv("Starting EC");
937 /* Enable GPE for event processing (SCI_EVT=1) */
938 if (!resuming) {
939 acpi_ec_submit_request(ec);
940 ec_dbg_ref(ec, "Increase driver");
941 }
942 ec_log_drv("EC started");
943 }
944 spin_unlock_irqrestore(&ec->lock, flags);
945}
946
947static bool acpi_ec_stopped(struct acpi_ec *ec)
948{
949 unsigned long flags;
950 bool flushed;
951
952 spin_lock_irqsave(&ec->lock, flags);
953 flushed = acpi_ec_flushed(ec);
954 spin_unlock_irqrestore(&ec->lock, flags);
955 return flushed;
956}
957
958static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
959{
960 unsigned long flags;
961
962 spin_lock_irqsave(&ec->lock, flags);
963 if (acpi_ec_started(ec)) {
964 ec_dbg_drv("Stopping EC");
965 set_bit(EC_FLAGS_STOPPED, &ec->flags);
966 spin_unlock_irqrestore(&ec->lock, flags);
967 wait_event(ec->wait, acpi_ec_stopped(ec));
968 spin_lock_irqsave(&ec->lock, flags);
969 /* Disable GPE for event processing (SCI_EVT=1) */
970 if (!suspending) {
971 acpi_ec_complete_request(ec);
972 ec_dbg_ref(ec, "Decrease driver");
973 } else if (!ec_freeze_events)
974 __acpi_ec_disable_event(ec);
975 clear_bit(EC_FLAGS_STARTED, &ec->flags);
976 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
977 ec_log_drv("EC stopped");
978 }
979 spin_unlock_irqrestore(&ec->lock, flags);
980}
981
982static void acpi_ec_enter_noirq(struct acpi_ec *ec)
983{
984 unsigned long flags;
985
986 spin_lock_irqsave(&ec->lock, flags);
987 ec->busy_polling = true;
988 ec->polling_guard = 0;
989 ec_log_drv("interrupt blocked");
990 spin_unlock_irqrestore(&ec->lock, flags);
991}
992
993static void acpi_ec_leave_noirq(struct acpi_ec *ec)
994{
995 unsigned long flags;
996
997 spin_lock_irqsave(&ec->lock, flags);
998 ec->busy_polling = ec_busy_polling;
999 ec->polling_guard = ec_polling_guard;
1000 ec_log_drv("interrupt unblocked");
1001 spin_unlock_irqrestore(&ec->lock, flags);
1002}
1003
1004void acpi_ec_block_transactions(void)
1005{
1006 struct acpi_ec *ec = first_ec;
1007
1008 if (!ec)
1009 return;
1010
1011 mutex_lock(&ec->mutex);
1012 /* Prevent transactions from being carried out */
1013 acpi_ec_stop(ec, true);
1014 mutex_unlock(&ec->mutex);
1015}
1016
1017void acpi_ec_unblock_transactions(void)
1018{
1019 /*
1020 * Allow transactions to happen again (this function is called from
1021 * atomic context during wakeup, so we don't need to acquire the mutex).
1022 */
1023 if (first_ec)
1024 acpi_ec_start(first_ec, true);
1025}
1026
1027/* --------------------------------------------------------------------------
1028 Event Management
1029 -------------------------------------------------------------------------- */
1030static struct acpi_ec_query_handler *
1031acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1032{
1033 struct acpi_ec_query_handler *handler;
1034
1035 mutex_lock(&ec->mutex);
1036 list_for_each_entry(handler, &ec->list, node) {
1037 if (value == handler->query_bit) {
1038 kref_get(&handler->kref);
1039 mutex_unlock(&ec->mutex);
1040 return handler;
1041 }
1042 }
1043 mutex_unlock(&ec->mutex);
1044 return NULL;
1045}
1046
1047static void acpi_ec_query_handler_release(struct kref *kref)
1048{
1049 struct acpi_ec_query_handler *handler =
1050 container_of(kref, struct acpi_ec_query_handler, kref);
1051
1052 kfree(handler);
1053}
1054
1055static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1056{
1057 kref_put(&handler->kref, acpi_ec_query_handler_release);
1058}
1059
1060int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1061 acpi_handle handle, acpi_ec_query_func func,
1062 void *data)
1063{
1064 struct acpi_ec_query_handler *handler =
1065 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1066
1067 if (!handler)
1068 return -ENOMEM;
1069
1070 handler->query_bit = query_bit;
1071 handler->handle = handle;
1072 handler->func = func;
1073 handler->data = data;
1074 mutex_lock(&ec->mutex);
1075 kref_init(&handler->kref);
1076 list_add(&handler->node, &ec->list);
1077 mutex_unlock(&ec->mutex);
1078 return 0;
1079}
1080EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1081
1082static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1083 bool remove_all, u8 query_bit)
1084{
1085 struct acpi_ec_query_handler *handler, *tmp;
1086 LIST_HEAD(free_list);
1087
1088 mutex_lock(&ec->mutex);
1089 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1090 if (remove_all || query_bit == handler->query_bit) {
1091 list_del_init(&handler->node);
1092 list_add(&handler->node, &free_list);
1093 }
1094 }
1095 mutex_unlock(&ec->mutex);
1096 list_for_each_entry_safe(handler, tmp, &free_list, node)
1097 acpi_ec_put_query_handler(handler);
1098}
1099
1100void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1101{
1102 acpi_ec_remove_query_handlers(ec, false, query_bit);
1103}
1104EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1105
1106static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1107{
1108 struct acpi_ec_query *q;
1109 struct transaction *t;
1110
1111 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1112 if (!q)
1113 return NULL;
1114 INIT_WORK(&q->work, acpi_ec_event_processor);
1115 t = &q->transaction;
1116 t->command = ACPI_EC_COMMAND_QUERY;
1117 t->rdata = pval;
1118 t->rlen = 1;
1119 return q;
1120}
1121
1122static void acpi_ec_delete_query(struct acpi_ec_query *q)
1123{
1124 if (q) {
1125 if (q->handler)
1126 acpi_ec_put_query_handler(q->handler);
1127 kfree(q);
1128 }
1129}
1130
1131static void acpi_ec_event_processor(struct work_struct *work)
1132{
1133 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1134 struct acpi_ec_query_handler *handler = q->handler;
1135
1136 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1137 if (handler->func)
1138 handler->func(handler->data);
1139 else if (handler->handle)
1140 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1141 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1142 acpi_ec_delete_query(q);
1143}
1144
1145static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1146{
1147 u8 value = 0;
1148 int result;
1149 struct acpi_ec_query *q;
1150
1151 q = acpi_ec_create_query(&value);
1152 if (!q)
1153 return -ENOMEM;
1154
1155 /*
1156 * Query the EC to find out which _Qxx method we need to evaluate.
1157 * Note that successful completion of the query causes the ACPI_EC_SCI
1158 * bit to be cleared (and thus clearing the interrupt source).
1159 */
1160 result = acpi_ec_transaction(ec, &q->transaction);
1161 if (!value)
1162 result = -ENODATA;
1163 if (result)
1164 goto err_exit;
1165
1166 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1167 if (!q->handler) {
1168 result = -ENODATA;
1169 goto err_exit;
1170 }
1171
1172 /*
1173 * It is reported that _Qxx are evaluated in a parallel way on
1174 * Windows:
1175 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1176 *
1177 * Put this log entry before schedule_work() in order to make
1178 * it appearing before any other log entries occurred during the
1179 * work queue execution.
1180 */
1181 ec_dbg_evt("Query(0x%02x) scheduled", value);
1182 if (!queue_work(ec_query_wq, &q->work)) {
1183 ec_dbg_evt("Query(0x%02x) overlapped", value);
1184 result = -EBUSY;
1185 }
1186
1187err_exit:
1188 if (result)
1189 acpi_ec_delete_query(q);
1190 if (data)
1191 *data = value;
1192 return result;
1193}
1194
1195static void acpi_ec_check_event(struct acpi_ec *ec)
1196{
1197 unsigned long flags;
1198
1199 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1200 if (ec_guard(ec)) {
1201 spin_lock_irqsave(&ec->lock, flags);
1202 /*
1203 * Take care of the SCI_EVT unless no one else is
1204 * taking care of it.
1205 */
1206 if (!ec->curr)
1207 advance_transaction(ec, false);
1208 spin_unlock_irqrestore(&ec->lock, flags);
1209 }
1210 }
1211}
1212
1213static void acpi_ec_event_handler(struct work_struct *work)
1214{
1215 unsigned long flags;
1216 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1217
1218 ec_dbg_evt("Event started");
1219
1220 spin_lock_irqsave(&ec->lock, flags);
1221 while (ec->nr_pending_queries) {
1222 spin_unlock_irqrestore(&ec->lock, flags);
1223 (void)acpi_ec_query(ec, NULL);
1224 spin_lock_irqsave(&ec->lock, flags);
1225 ec->nr_pending_queries--;
1226 /*
1227 * Before exit, make sure that this work item can be
1228 * scheduled again. There might be QR_EC failures, leaving
1229 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1230 * item from being scheduled again.
1231 */
1232 if (!ec->nr_pending_queries) {
1233 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1234 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1235 acpi_ec_complete_query(ec);
1236 }
1237 }
1238 spin_unlock_irqrestore(&ec->lock, flags);
1239
1240 ec_dbg_evt("Event stopped");
1241
1242 acpi_ec_check_event(ec);
1243}
1244
1245static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1246{
1247 unsigned long flags;
1248
1249 spin_lock_irqsave(&ec->lock, flags);
1250 advance_transaction(ec, true);
1251 spin_unlock_irqrestore(&ec->lock, flags);
1252}
1253
1254static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1255 u32 gpe_number, void *data)
1256{
1257 acpi_ec_handle_interrupt(data);
1258 return ACPI_INTERRUPT_HANDLED;
1259}
1260
1261static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1262{
1263 acpi_ec_handle_interrupt(data);
1264 return IRQ_HANDLED;
1265}
1266
1267/* --------------------------------------------------------------------------
1268 * Address Space Management
1269 * -------------------------------------------------------------------------- */
1270
1271static acpi_status
1272acpi_ec_space_handler(u32 function, acpi_physical_address address,
1273 u32 bits, u64 *value64,
1274 void *handler_context, void *region_context)
1275{
1276 struct acpi_ec *ec = handler_context;
1277 int result = 0, i, bytes = bits / 8;
1278 u8 *value = (u8 *)value64;
1279
1280 if ((address > 0xFF) || !value || !handler_context)
1281 return AE_BAD_PARAMETER;
1282
1283 if (function != ACPI_READ && function != ACPI_WRITE)
1284 return AE_BAD_PARAMETER;
1285
1286 if (ec->busy_polling || bits > 8)
1287 acpi_ec_burst_enable(ec);
1288
1289 for (i = 0; i < bytes; ++i, ++address, ++value)
1290 result = (function == ACPI_READ) ?
1291 acpi_ec_read(ec, address, value) :
1292 acpi_ec_write(ec, address, *value);
1293
1294 if (ec->busy_polling || bits > 8)
1295 acpi_ec_burst_disable(ec);
1296
1297 switch (result) {
1298 case -EINVAL:
1299 return AE_BAD_PARAMETER;
1300 case -ENODEV:
1301 return AE_NOT_FOUND;
1302 case -ETIME:
1303 return AE_TIME;
1304 default:
1305 return AE_OK;
1306 }
1307}
1308
1309/* --------------------------------------------------------------------------
1310 * Driver Interface
1311 * -------------------------------------------------------------------------- */
1312
1313static acpi_status
1314ec_parse_io_ports(struct acpi_resource *resource, void *context);
1315
1316static void acpi_ec_free(struct acpi_ec *ec)
1317{
1318 if (first_ec == ec)
1319 first_ec = NULL;
1320 if (boot_ec == ec)
1321 boot_ec = NULL;
1322 kfree(ec);
1323}
1324
1325static struct acpi_ec *acpi_ec_alloc(void)
1326{
1327 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1328
1329 if (!ec)
1330 return NULL;
1331 mutex_init(&ec->mutex);
1332 init_waitqueue_head(&ec->wait);
1333 INIT_LIST_HEAD(&ec->list);
1334 spin_lock_init(&ec->lock);
1335 INIT_WORK(&ec->work, acpi_ec_event_handler);
1336 ec->timestamp = jiffies;
1337 ec->busy_polling = true;
1338 ec->polling_guard = 0;
1339 ec->gpe = -1;
1340 ec->irq = -1;
1341 return ec;
1342}
1343
1344static acpi_status
1345acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1346 void *context, void **return_value)
1347{
1348 char node_name[5];
1349 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1350 struct acpi_ec *ec = context;
1351 int value = 0;
1352 acpi_status status;
1353
1354 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1355
1356 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1357 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1358 return AE_OK;
1359}
1360
1361static acpi_status
1362ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1363{
1364 acpi_status status;
1365 unsigned long long tmp = 0;
1366 struct acpi_ec *ec = context;
1367
1368 /* clear addr values, ec_parse_io_ports depend on it */
1369 ec->command_addr = ec->data_addr = 0;
1370
1371 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1372 ec_parse_io_ports, ec);
1373 if (ACPI_FAILURE(status))
1374 return status;
1375 if (ec->data_addr == 0 || ec->command_addr == 0)
1376 return AE_OK;
1377
1378 if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1379 /*
1380 * Always inherit the GPE number setting from the ECDT
1381 * EC.
1382 */
1383 ec->gpe = boot_ec->gpe;
1384 } else {
1385 /* Get GPE bit assignment (EC events). */
1386 /* TODO: Add support for _GPE returning a package */
1387 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1388 if (ACPI_SUCCESS(status))
1389 ec->gpe = tmp;
1390
1391 /*
1392 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1393 * platforms which use GpioInt instead of GPE.
1394 */
1395 }
1396 /* Use the global lock for all EC transactions? */
1397 tmp = 0;
1398 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1399 ec->global_lock = tmp;
1400 ec->handle = handle;
1401 return AE_CTRL_TERMINATE;
1402}
1403
1404static bool install_gpe_event_handler(struct acpi_ec *ec)
1405{
1406 acpi_status status;
1407
1408 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1409 ACPI_GPE_EDGE_TRIGGERED,
1410 &acpi_ec_gpe_handler, ec);
1411 if (ACPI_FAILURE(status))
1412 return false;
1413
1414 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1415 acpi_ec_enable_gpe(ec, true);
1416
1417 return true;
1418}
1419
1420static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1421{
1422 return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1423 "ACPI EC", ec) >= 0;
1424}
1425
1426/**
1427 * ec_install_handlers - Install service callbacks and register query methods.
1428 * @ec: Target EC.
1429 * @device: ACPI device object corresponding to @ec.
1430 *
1431 * Install a handler for the EC address space type unless it has been installed
1432 * already. If @device is not NULL, also look for EC query methods in the
1433 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1434 * handler for the EC, if possible.
1435 *
1436 * Return:
1437 * -ENODEV if the address space handler cannot be installed, which means
1438 * "unable to handle transactions",
1439 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1440 * or 0 (success) otherwise.
1441 */
1442static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1443{
1444 acpi_status status;
1445
1446 acpi_ec_start(ec, false);
1447
1448 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1449 acpi_ec_enter_noirq(ec);
1450 status = acpi_install_address_space_handler(ec->handle,
1451 ACPI_ADR_SPACE_EC,
1452 &acpi_ec_space_handler,
1453 NULL, ec);
1454 if (ACPI_FAILURE(status)) {
1455 acpi_ec_stop(ec, false);
1456 return -ENODEV;
1457 }
1458 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1459 }
1460
1461 if (!device)
1462 return 0;
1463
1464 if (ec->gpe < 0) {
1465 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1466 int irq = acpi_dev_gpio_irq_get(device, 0);
1467 /*
1468 * Bail out right away for deferred probing or complete the
1469 * initialization regardless of any other errors.
1470 */
1471 if (irq == -EPROBE_DEFER)
1472 return -EPROBE_DEFER;
1473 else if (irq >= 0)
1474 ec->irq = irq;
1475 }
1476
1477 if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1478 /* Find and register all query methods */
1479 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1480 acpi_ec_register_query_methods,
1481 NULL, ec, NULL);
1482 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1483 }
1484 if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1485 bool ready = false;
1486
1487 if (ec->gpe >= 0)
1488 ready = install_gpe_event_handler(ec);
1489 else if (ec->irq >= 0)
1490 ready = install_gpio_irq_event_handler(ec);
1491
1492 if (ready) {
1493 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1494 acpi_ec_leave_noirq(ec);
1495 }
1496 /*
1497 * Failures to install an event handler are not fatal, because
1498 * the EC can be polled for events.
1499 */
1500 }
1501 /* EC is fully operational, allow queries */
1502 acpi_ec_enable_event(ec);
1503
1504 return 0;
1505}
1506
1507static void ec_remove_handlers(struct acpi_ec *ec)
1508{
1509 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1510 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1511 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1512 pr_err("failed to remove space handler\n");
1513 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1514 }
1515
1516 /*
1517 * Stops handling the EC transactions after removing the operation
1518 * region handler. This is required because _REG(DISCONNECT)
1519 * invoked during the removal can result in new EC transactions.
1520 *
1521 * Flushes the EC requests and thus disables the GPE before
1522 * removing the GPE handler. This is required by the current ACPICA
1523 * GPE core. ACPICA GPE core will automatically disable a GPE when
1524 * it is indicated but there is no way to handle it. So the drivers
1525 * must disable the GPEs prior to removing the GPE handlers.
1526 */
1527 acpi_ec_stop(ec, false);
1528
1529 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1530 if (ec->gpe >= 0 &&
1531 ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1532 &acpi_ec_gpe_handler)))
1533 pr_err("failed to remove gpe handler\n");
1534
1535 if (ec->irq >= 0)
1536 free_irq(ec->irq, ec);
1537
1538 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1539 }
1540 if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1541 acpi_ec_remove_query_handlers(ec, true, 0);
1542 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1543 }
1544}
1545
1546static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1547{
1548 int ret;
1549
1550 ret = ec_install_handlers(ec, device);
1551 if (ret)
1552 return ret;
1553
1554 /* First EC capable of handling transactions */
1555 if (!first_ec)
1556 first_ec = ec;
1557
1558 pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1559 ec->data_addr);
1560
1561 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1562 if (ec->gpe >= 0)
1563 pr_info("GPE=0x%x\n", ec->gpe);
1564 else
1565 pr_info("IRQ=%d\n", ec->irq);
1566 }
1567
1568 return ret;
1569}
1570
1571static int acpi_ec_add(struct acpi_device *device)
1572{
1573 struct acpi_ec *ec;
1574 int ret;
1575
1576 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1577 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1578
1579 if (boot_ec && (boot_ec->handle == device->handle ||
1580 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1581 /* Fast path: this device corresponds to the boot EC. */
1582 ec = boot_ec;
1583 } else {
1584 acpi_status status;
1585
1586 ec = acpi_ec_alloc();
1587 if (!ec)
1588 return -ENOMEM;
1589
1590 status = ec_parse_device(device->handle, 0, ec, NULL);
1591 if (status != AE_CTRL_TERMINATE) {
1592 ret = -EINVAL;
1593 goto err;
1594 }
1595
1596 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1597 ec->data_addr == boot_ec->data_addr &&
1598 !EC_FLAGS_TRUST_DSDT_GPE) {
1599 /*
1600 * Trust PNP0C09 namespace location rather than
1601 * ECDT ID. But trust ECDT GPE rather than _GPE
1602 * because of ASUS quirks, so do not change
1603 * boot_ec->gpe to ec->gpe.
1604 */
1605 boot_ec->handle = ec->handle;
1606 acpi_handle_debug(ec->handle, "duplicated.\n");
1607 acpi_ec_free(ec);
1608 ec = boot_ec;
1609 }
1610 }
1611
1612 ret = acpi_ec_setup(ec, device);
1613 if (ret)
1614 goto err;
1615
1616 if (ec == boot_ec)
1617 acpi_handle_info(boot_ec->handle,
1618 "Boot %s EC initialization complete\n",
1619 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1620
1621 acpi_handle_info(ec->handle,
1622 "EC: Used to handle transactions and events\n");
1623
1624 device->driver_data = ec;
1625
1626 ret = !!request_region(ec->data_addr, 1, "EC data");
1627 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1628 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1629 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1630
1631 /* Reprobe devices depending on the EC */
1632 acpi_dev_clear_dependencies(device);
1633
1634 acpi_handle_debug(ec->handle, "enumerated.\n");
1635 return 0;
1636
1637err:
1638 if (ec != boot_ec)
1639 acpi_ec_free(ec);
1640
1641 return ret;
1642}
1643
1644static int acpi_ec_remove(struct acpi_device *device)
1645{
1646 struct acpi_ec *ec;
1647
1648 if (!device)
1649 return -EINVAL;
1650
1651 ec = acpi_driver_data(device);
1652 release_region(ec->data_addr, 1);
1653 release_region(ec->command_addr, 1);
1654 device->driver_data = NULL;
1655 if (ec != boot_ec) {
1656 ec_remove_handlers(ec);
1657 acpi_ec_free(ec);
1658 }
1659 return 0;
1660}
1661
1662static acpi_status
1663ec_parse_io_ports(struct acpi_resource *resource, void *context)
1664{
1665 struct acpi_ec *ec = context;
1666
1667 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1668 return AE_OK;
1669
1670 /*
1671 * The first address region returned is the data port, and
1672 * the second address region returned is the status/command
1673 * port.
1674 */
1675 if (ec->data_addr == 0)
1676 ec->data_addr = resource->data.io.minimum;
1677 else if (ec->command_addr == 0)
1678 ec->command_addr = resource->data.io.minimum;
1679 else
1680 return AE_CTRL_TERMINATE;
1681
1682 return AE_OK;
1683}
1684
1685static const struct acpi_device_id ec_device_ids[] = {
1686 {"PNP0C09", 0},
1687 {ACPI_ECDT_HID, 0},
1688 {"", 0},
1689};
1690
1691/*
1692 * This function is not Windows-compatible as Windows never enumerates the
1693 * namespace EC before the main ACPI device enumeration process. It is
1694 * retained for historical reason and will be deprecated in the future.
1695 */
1696void __init acpi_ec_dsdt_probe(void)
1697{
1698 struct acpi_ec *ec;
1699 acpi_status status;
1700 int ret;
1701
1702 /*
1703 * If a platform has ECDT, there is no need to proceed as the
1704 * following probe is not a part of the ACPI device enumeration,
1705 * executing _STA is not safe, and thus this probe may risk of
1706 * picking up an invalid EC device.
1707 */
1708 if (boot_ec)
1709 return;
1710
1711 ec = acpi_ec_alloc();
1712 if (!ec)
1713 return;
1714
1715 /*
1716 * At this point, the namespace is initialized, so start to find
1717 * the namespace objects.
1718 */
1719 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1720 if (ACPI_FAILURE(status) || !ec->handle) {
1721 acpi_ec_free(ec);
1722 return;
1723 }
1724
1725 /*
1726 * When the DSDT EC is available, always re-configure boot EC to
1727 * have _REG evaluated. _REG can only be evaluated after the
1728 * namespace initialization.
1729 * At this point, the GPE is not fully initialized, so do not to
1730 * handle the events.
1731 */
1732 ret = acpi_ec_setup(ec, NULL);
1733 if (ret) {
1734 acpi_ec_free(ec);
1735 return;
1736 }
1737
1738 boot_ec = ec;
1739
1740 acpi_handle_info(ec->handle,
1741 "Boot DSDT EC used to handle transactions\n");
1742}
1743
1744/*
1745 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1746 *
1747 * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1748 * found a matching object in the namespace.
1749 *
1750 * Next, in case the DSDT EC is not functioning, it is still necessary to
1751 * provide a functional ECDT EC to handle events, so add an extra device object
1752 * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1753 *
1754 * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1755 * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1756 */
1757static void __init acpi_ec_ecdt_start(void)
1758{
1759 struct acpi_table_ecdt *ecdt_ptr;
1760 acpi_handle handle;
1761 acpi_status status;
1762
1763 /* Bail out if a matching EC has been found in the namespace. */
1764 if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1765 return;
1766
1767 /* Look up the object pointed to from the ECDT in the namespace. */
1768 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1769 (struct acpi_table_header **)&ecdt_ptr);
1770 if (ACPI_FAILURE(status))
1771 return;
1772
1773 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1774 if (ACPI_SUCCESS(status)) {
1775 boot_ec->handle = handle;
1776
1777 /* Add a special ACPI device object to represent the boot EC. */
1778 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1779 }
1780
1781 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1782}
1783
1784/*
1785 * On some hardware it is necessary to clear events accumulated by the EC during
1786 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1787 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1788 *
1789 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1790 *
1791 * Ideally, the EC should also be instructed NOT to accumulate events during
1792 * sleep (which Windows seems to do somehow), but the interface to control this
1793 * behaviour is not known at this time.
1794 *
1795 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1796 * however it is very likely that other Samsung models are affected.
1797 *
1798 * On systems which don't accumulate _Q events during sleep, this extra check
1799 * should be harmless.
1800 */
1801static int ec_clear_on_resume(const struct dmi_system_id *id)
1802{
1803 pr_debug("Detected system needing EC poll on resume.\n");
1804 EC_FLAGS_CLEAR_ON_RESUME = 1;
1805 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1806 return 0;
1807}
1808
1809/*
1810 * Some ECDTs contain wrong register addresses.
1811 * MSI MS-171F
1812 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1813 */
1814static int ec_correct_ecdt(const struct dmi_system_id *id)
1815{
1816 pr_debug("Detected system needing ECDT address correction.\n");
1817 EC_FLAGS_CORRECT_ECDT = 1;
1818 return 0;
1819}
1820
1821/*
1822 * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1823 * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1824 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1825 */
1826static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1827{
1828 pr_debug("Detected system needing DSDT GPE setting.\n");
1829 EC_FLAGS_TRUST_DSDT_GPE = 1;
1830 return 0;
1831}
1832
1833/*
1834 * Some DSDTs contain wrong GPE setting.
1835 * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1836 * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1837 */
1838static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1839{
1840 pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1841 EC_FLAGS_IGNORE_DSDT_GPE = 1;
1842 return 0;
1843}
1844
1845static const struct dmi_system_id ec_dmi_table[] __initconst = {
1846 {
1847 ec_correct_ecdt, "MSI MS-171F", {
1848 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1849 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1850 {
1851 ec_honor_ecdt_gpe, "ASUS FX502VD", {
1852 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1853 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1854 {
1855 ec_honor_ecdt_gpe, "ASUS FX502VE", {
1856 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1857 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1858 {
1859 ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1860 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1861 DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1862 {
1863 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BA", {
1864 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1865 DMI_MATCH(DMI_PRODUCT_NAME, "X505BA"),}, NULL},
1866 {
1867 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BP", {
1868 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1869 DMI_MATCH(DMI_PRODUCT_NAME, "X505BP"),}, NULL},
1870 {
1871 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BA", {
1872 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1873 DMI_MATCH(DMI_PRODUCT_NAME, "X542BA"),}, NULL},
1874 {
1875 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BP", {
1876 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1877 DMI_MATCH(DMI_PRODUCT_NAME, "X542BP"),}, NULL},
1878 {
1879 ec_honor_ecdt_gpe, "ASUS X550VXK", {
1880 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1881 DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1882 {
1883 ec_honor_ecdt_gpe, "ASUS X580VD", {
1884 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1885 DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1886 {
1887 /* https://bugzilla.kernel.org/show_bug.cgi?id=209989 */
1888 ec_honor_dsdt_gpe, "HP Pavilion Gaming Laptop 15-cx0xxx", {
1889 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1890 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),}, NULL},
1891 {
1892 ec_clear_on_resume, "Samsung hardware", {
1893 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1894 {},
1895};
1896
1897void __init acpi_ec_ecdt_probe(void)
1898{
1899 struct acpi_table_ecdt *ecdt_ptr;
1900 struct acpi_ec *ec;
1901 acpi_status status;
1902 int ret;
1903
1904 /* Generate a boot ec context. */
1905 dmi_check_system(ec_dmi_table);
1906 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1907 (struct acpi_table_header **)&ecdt_ptr);
1908 if (ACPI_FAILURE(status))
1909 return;
1910
1911 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1912 /*
1913 * Asus X50GL:
1914 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1915 */
1916 goto out;
1917 }
1918
1919 ec = acpi_ec_alloc();
1920 if (!ec)
1921 goto out;
1922
1923 if (EC_FLAGS_CORRECT_ECDT) {
1924 ec->command_addr = ecdt_ptr->data.address;
1925 ec->data_addr = ecdt_ptr->control.address;
1926 } else {
1927 ec->command_addr = ecdt_ptr->control.address;
1928 ec->data_addr = ecdt_ptr->data.address;
1929 }
1930
1931 /*
1932 * Ignore the GPE value on Reduced Hardware platforms.
1933 * Some products have this set to an erroneous value.
1934 */
1935 if (!acpi_gbl_reduced_hardware)
1936 ec->gpe = ecdt_ptr->gpe;
1937
1938 ec->handle = ACPI_ROOT_OBJECT;
1939
1940 /*
1941 * At this point, the namespace is not initialized, so do not find
1942 * the namespace objects, or handle the events.
1943 */
1944 ret = acpi_ec_setup(ec, NULL);
1945 if (ret) {
1946 acpi_ec_free(ec);
1947 goto out;
1948 }
1949
1950 boot_ec = ec;
1951 boot_ec_is_ecdt = true;
1952
1953 pr_info("Boot ECDT EC used to handle transactions\n");
1954
1955out:
1956 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1957}
1958
1959#ifdef CONFIG_PM_SLEEP
1960static int acpi_ec_suspend(struct device *dev)
1961{
1962 struct acpi_ec *ec =
1963 acpi_driver_data(to_acpi_device(dev));
1964
1965 if (!pm_suspend_no_platform() && ec_freeze_events)
1966 acpi_ec_disable_event(ec);
1967 return 0;
1968}
1969
1970static int acpi_ec_suspend_noirq(struct device *dev)
1971{
1972 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1973
1974 /*
1975 * The SCI handler doesn't run at this point, so the GPE can be
1976 * masked at the low level without side effects.
1977 */
1978 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1979 ec->gpe >= 0 && ec->reference_count >= 1)
1980 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1981
1982 acpi_ec_enter_noirq(ec);
1983
1984 return 0;
1985}
1986
1987static int acpi_ec_resume_noirq(struct device *dev)
1988{
1989 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1990
1991 acpi_ec_leave_noirq(ec);
1992
1993 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1994 ec->gpe >= 0 && ec->reference_count >= 1)
1995 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1996
1997 return 0;
1998}
1999
2000static int acpi_ec_resume(struct device *dev)
2001{
2002 struct acpi_ec *ec =
2003 acpi_driver_data(to_acpi_device(dev));
2004
2005 acpi_ec_enable_event(ec);
2006 return 0;
2007}
2008
2009void acpi_ec_mark_gpe_for_wake(void)
2010{
2011 if (first_ec && !ec_no_wakeup)
2012 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2013}
2014EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2015
2016void acpi_ec_set_gpe_wake_mask(u8 action)
2017{
2018 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2019 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2020}
2021
2022bool acpi_ec_dispatch_gpe(void)
2023{
2024 u32 ret;
2025
2026 if (!first_ec)
2027 return acpi_any_gpe_status_set(U32_MAX);
2028
2029 /*
2030 * Report wakeup if the status bit is set for any enabled GPE other
2031 * than the EC one.
2032 */
2033 if (acpi_any_gpe_status_set(first_ec->gpe))
2034 return true;
2035
2036 /*
2037 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2038 * to allow the caller to process events properly after that.
2039 */
2040 ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2041 if (ret == ACPI_INTERRUPT_HANDLED)
2042 pm_pr_dbg("ACPI EC GPE dispatched\n");
2043
2044 /* Flush the event and query workqueues. */
2045 acpi_ec_flush_work();
2046
2047 return false;
2048}
2049#endif /* CONFIG_PM_SLEEP */
2050
2051static const struct dev_pm_ops acpi_ec_pm = {
2052 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2053 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2054};
2055
2056static int param_set_event_clearing(const char *val,
2057 const struct kernel_param *kp)
2058{
2059 int result = 0;
2060
2061 if (!strncmp(val, "status", sizeof("status") - 1)) {
2062 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2063 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2064 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2065 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2066 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2067 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2068 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2069 pr_info("Assuming SCI_EVT clearing on event reads\n");
2070 } else
2071 result = -EINVAL;
2072 return result;
2073}
2074
2075static int param_get_event_clearing(char *buffer,
2076 const struct kernel_param *kp)
2077{
2078 switch (ec_event_clearing) {
2079 case ACPI_EC_EVT_TIMING_STATUS:
2080 return sprintf(buffer, "status\n");
2081 case ACPI_EC_EVT_TIMING_QUERY:
2082 return sprintf(buffer, "query\n");
2083 case ACPI_EC_EVT_TIMING_EVENT:
2084 return sprintf(buffer, "event\n");
2085 default:
2086 return sprintf(buffer, "invalid\n");
2087 }
2088 return 0;
2089}
2090
2091module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2092 NULL, 0644);
2093MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2094
2095static struct acpi_driver acpi_ec_driver = {
2096 .name = "ec",
2097 .class = ACPI_EC_CLASS,
2098 .ids = ec_device_ids,
2099 .ops = {
2100 .add = acpi_ec_add,
2101 .remove = acpi_ec_remove,
2102 },
2103 .drv.pm = &acpi_ec_pm,
2104};
2105
2106static void acpi_ec_destroy_workqueues(void)
2107{
2108 if (ec_wq) {
2109 destroy_workqueue(ec_wq);
2110 ec_wq = NULL;
2111 }
2112 if (ec_query_wq) {
2113 destroy_workqueue(ec_query_wq);
2114 ec_query_wq = NULL;
2115 }
2116}
2117
2118static int acpi_ec_init_workqueues(void)
2119{
2120 if (!ec_wq)
2121 ec_wq = alloc_ordered_workqueue("kec", 0);
2122
2123 if (!ec_query_wq)
2124 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2125
2126 if (!ec_wq || !ec_query_wq) {
2127 acpi_ec_destroy_workqueues();
2128 return -ENODEV;
2129 }
2130 return 0;
2131}
2132
2133static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2134 {
2135 .ident = "Thinkpad X1 Carbon 6th",
2136 .matches = {
2137 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2138 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2139 },
2140 },
2141 {
2142 .ident = "ThinkPad X1 Carbon 6th",
2143 .matches = {
2144 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2145 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2146 },
2147 },
2148 {
2149 .ident = "ThinkPad X1 Yoga 3rd",
2150 .matches = {
2151 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2152 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2153 },
2154 },
2155 { },
2156};
2157
2158void __init acpi_ec_init(void)
2159{
2160 int result;
2161
2162 result = acpi_ec_init_workqueues();
2163 if (result)
2164 return;
2165
2166 /*
2167 * Disable EC wakeup on following systems to prevent periodic
2168 * wakeup from EC GPE.
2169 */
2170 if (dmi_check_system(acpi_ec_no_wakeup)) {
2171 ec_no_wakeup = true;
2172 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2173 }
2174
2175 /* Driver must be registered after acpi_ec_init_workqueues(). */
2176 acpi_bus_register_driver(&acpi_ec_driver);
2177
2178 acpi_ec_ecdt_start();
2179}
2180
2181/* EC driver currently not unloadable */
2182#if 0
2183static void __exit acpi_ec_exit(void)
2184{
2185
2186 acpi_bus_unregister_driver(&acpi_ec_driver);
2187 acpi_ec_destroy_workqueues();
2188}
2189#endif /* 0 */