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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_EVENT_HANDLER_INSTALLED, /* Event handler installed */
96 EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */
97 EC_FLAGS_EC_REG_CALLED, /* OpReg ACPI _REG method called */
98 EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
99 EC_FLAGS_STARTED, /* Driver is started */
100 EC_FLAGS_STOPPED, /* Driver is stopped */
101 EC_FLAGS_EVENTS_MASKED, /* Events masked */
102};
103
104#define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
105#define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
106
107/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
108static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
109module_param(ec_delay, uint, 0644);
110MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
111
112static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
113module_param(ec_max_queries, uint, 0644);
114MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
115
116static bool ec_busy_polling __read_mostly;
117module_param(ec_busy_polling, bool, 0644);
118MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
119
120static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
121module_param(ec_polling_guard, uint, 0644);
122MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
123
124static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
125
126/*
127 * If the number of false interrupts per one transaction exceeds
128 * this threshold, will think there is a GPE storm happened and
129 * will disable the GPE for normal transaction.
130 */
131static unsigned int ec_storm_threshold __read_mostly = 8;
132module_param(ec_storm_threshold, uint, 0644);
133MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
134
135static bool ec_freeze_events __read_mostly;
136module_param(ec_freeze_events, bool, 0644);
137MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
138
139static bool ec_no_wakeup __read_mostly;
140module_param(ec_no_wakeup, bool, 0644);
141MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
142
143struct acpi_ec_query_handler {
144 struct list_head node;
145 acpi_ec_query_func func;
146 acpi_handle handle;
147 void *data;
148 u8 query_bit;
149 struct kref kref;
150};
151
152struct transaction {
153 const u8 *wdata;
154 u8 *rdata;
155 unsigned short irq_count;
156 u8 command;
157 u8 wi;
158 u8 ri;
159 u8 wlen;
160 u8 rlen;
161 u8 flags;
162};
163
164struct acpi_ec_query {
165 struct transaction transaction;
166 struct work_struct work;
167 struct acpi_ec_query_handler *handler;
168 struct acpi_ec *ec;
169};
170
171static int acpi_ec_submit_query(struct acpi_ec *ec);
172static void advance_transaction(struct acpi_ec *ec, bool interrupt);
173static void acpi_ec_event_handler(struct work_struct *work);
174
175struct acpi_ec *first_ec;
176EXPORT_SYMBOL(first_ec);
177
178static struct acpi_ec *boot_ec;
179static bool boot_ec_is_ecdt;
180static struct workqueue_struct *ec_wq;
181static struct workqueue_struct *ec_query_wq;
182
183static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
184static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
185static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
186
187/* --------------------------------------------------------------------------
188 * Logging/Debugging
189 * -------------------------------------------------------------------------- */
190
191/*
192 * Splitters used by the developers to track the boundary of the EC
193 * handling processes.
194 */
195#ifdef DEBUG
196#define EC_DBG_SEP " "
197#define EC_DBG_DRV "+++++"
198#define EC_DBG_STM "====="
199#define EC_DBG_REQ "*****"
200#define EC_DBG_EVT "#####"
201#else
202#define EC_DBG_SEP ""
203#define EC_DBG_DRV
204#define EC_DBG_STM
205#define EC_DBG_REQ
206#define EC_DBG_EVT
207#endif
208
209#define ec_log_raw(fmt, ...) \
210 pr_info(fmt "\n", ##__VA_ARGS__)
211#define ec_dbg_raw(fmt, ...) \
212 pr_debug(fmt "\n", ##__VA_ARGS__)
213#define ec_log(filter, fmt, ...) \
214 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
215#define ec_dbg(filter, fmt, ...) \
216 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
217
218#define ec_log_drv(fmt, ...) \
219 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
220#define ec_dbg_drv(fmt, ...) \
221 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
222#define ec_dbg_stm(fmt, ...) \
223 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
224#define ec_dbg_req(fmt, ...) \
225 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
226#define ec_dbg_evt(fmt, ...) \
227 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
228#define ec_dbg_ref(ec, fmt, ...) \
229 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
230
231/* --------------------------------------------------------------------------
232 * Device Flags
233 * -------------------------------------------------------------------------- */
234
235static bool acpi_ec_started(struct acpi_ec *ec)
236{
237 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
238 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
239}
240
241static bool acpi_ec_event_enabled(struct acpi_ec *ec)
242{
243 /*
244 * There is an OSPM early stage logic. During the early stages
245 * (boot/resume), OSPMs shouldn't enable the event handling, only
246 * the EC transactions are allowed to be performed.
247 */
248 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
249 return false;
250 /*
251 * However, disabling the event handling is experimental for late
252 * stage (suspend), and is controlled by the boot parameter of
253 * "ec_freeze_events":
254 * 1. true: The EC event handling is disabled before entering
255 * the noirq stage.
256 * 2. false: The EC event handling is automatically disabled as
257 * soon as the EC driver is stopped.
258 */
259 if (ec_freeze_events)
260 return acpi_ec_started(ec);
261 else
262 return test_bit(EC_FLAGS_STARTED, &ec->flags);
263}
264
265static bool acpi_ec_flushed(struct acpi_ec *ec)
266{
267 return ec->reference_count == 1;
268}
269
270/* --------------------------------------------------------------------------
271 * EC Registers
272 * -------------------------------------------------------------------------- */
273
274static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
275{
276 u8 x = inb(ec->command_addr);
277
278 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
279 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
280 x,
281 !!(x & ACPI_EC_FLAG_SCI),
282 !!(x & ACPI_EC_FLAG_BURST),
283 !!(x & ACPI_EC_FLAG_CMD),
284 !!(x & ACPI_EC_FLAG_IBF),
285 !!(x & ACPI_EC_FLAG_OBF));
286 return x;
287}
288
289static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
290{
291 u8 x = inb(ec->data_addr);
292
293 ec->timestamp = jiffies;
294 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
295 return x;
296}
297
298static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
299{
300 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
301 outb(command, ec->command_addr);
302 ec->timestamp = jiffies;
303}
304
305static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
306{
307 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
308 outb(data, ec->data_addr);
309 ec->timestamp = jiffies;
310}
311
312#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
313static const char *acpi_ec_cmd_string(u8 cmd)
314{
315 switch (cmd) {
316 case 0x80:
317 return "RD_EC";
318 case 0x81:
319 return "WR_EC";
320 case 0x82:
321 return "BE_EC";
322 case 0x83:
323 return "BD_EC";
324 case 0x84:
325 return "QR_EC";
326 }
327 return "UNKNOWN";
328}
329#else
330#define acpi_ec_cmd_string(cmd) "UNDEF"
331#endif
332
333/* --------------------------------------------------------------------------
334 * GPE Registers
335 * -------------------------------------------------------------------------- */
336
337static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
338{
339 acpi_event_status gpe_status = 0;
340
341 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
342 return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
343}
344
345static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
346{
347 if (open)
348 acpi_enable_gpe(NULL, ec->gpe);
349 else {
350 BUG_ON(ec->reference_count < 1);
351 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
352 }
353 if (acpi_ec_gpe_status_set(ec)) {
354 /*
355 * On some platforms, EN=1 writes cannot trigger GPE. So
356 * software need to manually trigger a pseudo GPE event on
357 * EN=1 writes.
358 */
359 ec_dbg_raw("Polling quirk");
360 advance_transaction(ec, false);
361 }
362}
363
364static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
365{
366 if (close)
367 acpi_disable_gpe(NULL, ec->gpe);
368 else {
369 BUG_ON(ec->reference_count < 1);
370 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
371 }
372}
373
374/* --------------------------------------------------------------------------
375 * Transaction Management
376 * -------------------------------------------------------------------------- */
377
378static void acpi_ec_submit_request(struct acpi_ec *ec)
379{
380 ec->reference_count++;
381 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
382 ec->gpe >= 0 && ec->reference_count == 1)
383 acpi_ec_enable_gpe(ec, true);
384}
385
386static void acpi_ec_complete_request(struct acpi_ec *ec)
387{
388 bool flushed = false;
389
390 ec->reference_count--;
391 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
392 ec->gpe >= 0 && ec->reference_count == 0)
393 acpi_ec_disable_gpe(ec, true);
394 flushed = acpi_ec_flushed(ec);
395 if (flushed)
396 wake_up(&ec->wait);
397}
398
399static void acpi_ec_mask_events(struct acpi_ec *ec)
400{
401 if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
402 if (ec->gpe >= 0)
403 acpi_ec_disable_gpe(ec, false);
404 else
405 disable_irq_nosync(ec->irq);
406
407 ec_dbg_drv("Polling enabled");
408 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
409 }
410}
411
412static void acpi_ec_unmask_events(struct acpi_ec *ec)
413{
414 if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
415 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
416 if (ec->gpe >= 0)
417 acpi_ec_enable_gpe(ec, false);
418 else
419 enable_irq(ec->irq);
420
421 ec_dbg_drv("Polling disabled");
422 }
423}
424
425/*
426 * acpi_ec_submit_flushable_request() - Increase the reference count unless
427 * the flush operation is not in
428 * progress
429 * @ec: the EC device
430 *
431 * This function must be used before taking a new action that should hold
432 * the reference count. If this function returns false, then the action
433 * must be discarded or it will prevent the flush operation from being
434 * completed.
435 */
436static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
437{
438 if (!acpi_ec_started(ec))
439 return false;
440 acpi_ec_submit_request(ec);
441 return true;
442}
443
444static void acpi_ec_submit_event(struct acpi_ec *ec)
445{
446 /*
447 * It is safe to mask the events here, because acpi_ec_close_event()
448 * will run at least once after this.
449 */
450 acpi_ec_mask_events(ec);
451 if (!acpi_ec_event_enabled(ec))
452 return;
453
454 if (ec->event_state != EC_EVENT_READY)
455 return;
456
457 ec_dbg_evt("Command(%s) submitted/blocked",
458 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
459
460 ec->event_state = EC_EVENT_IN_PROGRESS;
461 /*
462 * If events_to_process is greater than 0 at this point, the while ()
463 * loop in acpi_ec_event_handler() is still running and incrementing
464 * events_to_process will cause it to invoke acpi_ec_submit_query() once
465 * more, so it is not necessary to queue up the event work to start the
466 * same loop again.
467 */
468 if (ec->events_to_process++ > 0)
469 return;
470
471 ec->events_in_progress++;
472 queue_work(ec_wq, &ec->work);
473}
474
475static void acpi_ec_complete_event(struct acpi_ec *ec)
476{
477 if (ec->event_state == EC_EVENT_IN_PROGRESS)
478 ec->event_state = EC_EVENT_COMPLETE;
479}
480
481static void acpi_ec_close_event(struct acpi_ec *ec)
482{
483 if (ec->event_state != EC_EVENT_READY)
484 ec_dbg_evt("Command(%s) unblocked",
485 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
486
487 ec->event_state = EC_EVENT_READY;
488 acpi_ec_unmask_events(ec);
489}
490
491static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
492{
493 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
494 ec_log_drv("event unblocked");
495 /*
496 * Unconditionally invoke this once after enabling the event
497 * handling mechanism to detect the pending events.
498 */
499 advance_transaction(ec, false);
500}
501
502static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
503{
504 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
505 ec_log_drv("event blocked");
506}
507
508/*
509 * Process _Q events that might have accumulated in the EC.
510 * Run with locked ec mutex.
511 */
512static void acpi_ec_clear(struct acpi_ec *ec)
513{
514 int i;
515
516 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
517 if (acpi_ec_submit_query(ec))
518 break;
519 }
520 if (unlikely(i == ACPI_EC_CLEAR_MAX))
521 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
522 else
523 pr_info("%d stale EC events cleared\n", i);
524}
525
526static void acpi_ec_enable_event(struct acpi_ec *ec)
527{
528 unsigned long flags;
529
530 spin_lock_irqsave(&ec->lock, flags);
531 if (acpi_ec_started(ec))
532 __acpi_ec_enable_event(ec);
533 spin_unlock_irqrestore(&ec->lock, flags);
534
535 /* Drain additional events if hardware requires that */
536 if (EC_FLAGS_CLEAR_ON_RESUME)
537 acpi_ec_clear(ec);
538}
539
540#ifdef CONFIG_PM_SLEEP
541static void __acpi_ec_flush_work(void)
542{
543 flush_workqueue(ec_wq); /* flush ec->work */
544 flush_workqueue(ec_query_wq); /* flush queries */
545}
546
547static void acpi_ec_disable_event(struct acpi_ec *ec)
548{
549 unsigned long flags;
550
551 spin_lock_irqsave(&ec->lock, flags);
552 __acpi_ec_disable_event(ec);
553 spin_unlock_irqrestore(&ec->lock, flags);
554
555 /*
556 * When ec_freeze_events is true, we need to flush events in
557 * the proper position before entering the noirq stage.
558 */
559 __acpi_ec_flush_work();
560}
561
562void acpi_ec_flush_work(void)
563{
564 /* Without ec_wq there is nothing to flush. */
565 if (!ec_wq)
566 return;
567
568 __acpi_ec_flush_work();
569}
570#endif /* CONFIG_PM_SLEEP */
571
572static bool acpi_ec_guard_event(struct acpi_ec *ec)
573{
574 unsigned long flags;
575 bool guarded;
576
577 spin_lock_irqsave(&ec->lock, flags);
578 /*
579 * If firmware SCI_EVT clearing timing is "event", we actually
580 * don't know when the SCI_EVT will be cleared by firmware after
581 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
582 * acceptable period.
583 *
584 * The guarding period is applicable if the event state is not
585 * EC_EVENT_READY, but otherwise if the current transaction is of the
586 * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
587 * and it should not be applied to let the transaction transition into
588 * the ACPI_EC_COMMAND_POLL state immediately.
589 */
590 guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
591 ec->event_state != EC_EVENT_READY &&
592 (!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
593 spin_unlock_irqrestore(&ec->lock, flags);
594 return guarded;
595}
596
597static int ec_transaction_polled(struct acpi_ec *ec)
598{
599 unsigned long flags;
600 int ret = 0;
601
602 spin_lock_irqsave(&ec->lock, flags);
603 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
604 ret = 1;
605 spin_unlock_irqrestore(&ec->lock, flags);
606 return ret;
607}
608
609static int ec_transaction_completed(struct acpi_ec *ec)
610{
611 unsigned long flags;
612 int ret = 0;
613
614 spin_lock_irqsave(&ec->lock, flags);
615 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
616 ret = 1;
617 spin_unlock_irqrestore(&ec->lock, flags);
618 return ret;
619}
620
621static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
622{
623 ec->curr->flags |= flag;
624
625 if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
626 return;
627
628 switch (ec_event_clearing) {
629 case ACPI_EC_EVT_TIMING_STATUS:
630 if (flag == ACPI_EC_COMMAND_POLL)
631 acpi_ec_close_event(ec);
632
633 return;
634
635 case ACPI_EC_EVT_TIMING_QUERY:
636 if (flag == ACPI_EC_COMMAND_COMPLETE)
637 acpi_ec_close_event(ec);
638
639 return;
640
641 case ACPI_EC_EVT_TIMING_EVENT:
642 if (flag == ACPI_EC_COMMAND_COMPLETE)
643 acpi_ec_complete_event(ec);
644 }
645}
646
647static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
648{
649 if (t->irq_count < ec_storm_threshold)
650 ++t->irq_count;
651
652 /* Trigger if the threshold is 0 too. */
653 if (t->irq_count == ec_storm_threshold)
654 acpi_ec_mask_events(ec);
655}
656
657static void advance_transaction(struct acpi_ec *ec, bool interrupt)
658{
659 struct transaction *t = ec->curr;
660 bool wakeup = false;
661 u8 status;
662
663 ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
664
665 status = acpi_ec_read_status(ec);
666
667 /*
668 * Another IRQ or a guarded polling mode advancement is detected,
669 * the next QR_EC submission is then allowed.
670 */
671 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
672 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
673 ec->event_state == EC_EVENT_COMPLETE)
674 acpi_ec_close_event(ec);
675
676 if (!t)
677 goto out;
678 }
679
680 if (t->flags & ACPI_EC_COMMAND_POLL) {
681 if (t->wlen > t->wi) {
682 if (!(status & ACPI_EC_FLAG_IBF))
683 acpi_ec_write_data(ec, t->wdata[t->wi++]);
684 else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
685 acpi_ec_spurious_interrupt(ec, t);
686 } else if (t->rlen > t->ri) {
687 if (status & ACPI_EC_FLAG_OBF) {
688 t->rdata[t->ri++] = acpi_ec_read_data(ec);
689 if (t->rlen == t->ri) {
690 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
691 wakeup = true;
692 if (t->command == ACPI_EC_COMMAND_QUERY)
693 ec_dbg_evt("Command(%s) completed by hardware",
694 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
695 }
696 } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
697 acpi_ec_spurious_interrupt(ec, t);
698 }
699 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
700 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
701 wakeup = true;
702 }
703 } else if (!(status & ACPI_EC_FLAG_IBF)) {
704 acpi_ec_write_cmd(ec, t->command);
705 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
706 }
707
708out:
709 if (status & ACPI_EC_FLAG_SCI)
710 acpi_ec_submit_event(ec);
711
712 if (wakeup && interrupt)
713 wake_up(&ec->wait);
714}
715
716static void start_transaction(struct acpi_ec *ec)
717{
718 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
719 ec->curr->flags = 0;
720}
721
722static int ec_guard(struct acpi_ec *ec)
723{
724 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
725 unsigned long timeout = ec->timestamp + guard;
726
727 /* Ensure guarding period before polling EC status */
728 do {
729 if (ec->busy_polling) {
730 /* Perform busy polling */
731 if (ec_transaction_completed(ec))
732 return 0;
733 udelay(jiffies_to_usecs(guard));
734 } else {
735 /*
736 * Perform wait polling
737 * 1. Wait the transaction to be completed by the
738 * GPE handler after the transaction enters
739 * ACPI_EC_COMMAND_POLL state.
740 * 2. A special guarding logic is also required
741 * for event clearing mode "event" before the
742 * transaction enters ACPI_EC_COMMAND_POLL
743 * state.
744 */
745 if (!ec_transaction_polled(ec) &&
746 !acpi_ec_guard_event(ec))
747 break;
748 if (wait_event_timeout(ec->wait,
749 ec_transaction_completed(ec),
750 guard))
751 return 0;
752 }
753 } while (time_before(jiffies, timeout));
754 return -ETIME;
755}
756
757static int ec_poll(struct acpi_ec *ec)
758{
759 unsigned long flags;
760 int repeat = 5; /* number of command restarts */
761
762 while (repeat--) {
763 unsigned long delay = jiffies +
764 msecs_to_jiffies(ec_delay);
765 do {
766 if (!ec_guard(ec))
767 return 0;
768 spin_lock_irqsave(&ec->lock, flags);
769 advance_transaction(ec, false);
770 spin_unlock_irqrestore(&ec->lock, flags);
771 } while (time_before(jiffies, delay));
772 pr_debug("controller reset, restart transaction\n");
773 spin_lock_irqsave(&ec->lock, flags);
774 start_transaction(ec);
775 spin_unlock_irqrestore(&ec->lock, flags);
776 }
777 return -ETIME;
778}
779
780static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
781 struct transaction *t)
782{
783 unsigned long tmp;
784 int ret = 0;
785
786 /* start transaction */
787 spin_lock_irqsave(&ec->lock, tmp);
788 /* Enable GPE for command processing (IBF=0/OBF=1) */
789 if (!acpi_ec_submit_flushable_request(ec)) {
790 ret = -EINVAL;
791 goto unlock;
792 }
793 ec_dbg_ref(ec, "Increase command");
794 /* following two actions should be kept atomic */
795 ec->curr = t;
796 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
797 start_transaction(ec);
798 spin_unlock_irqrestore(&ec->lock, tmp);
799
800 ret = ec_poll(ec);
801
802 spin_lock_irqsave(&ec->lock, tmp);
803 if (t->irq_count == ec_storm_threshold)
804 acpi_ec_unmask_events(ec);
805 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
806 ec->curr = NULL;
807 /* Disable GPE for command processing (IBF=0/OBF=1) */
808 acpi_ec_complete_request(ec);
809 ec_dbg_ref(ec, "Decrease command");
810unlock:
811 spin_unlock_irqrestore(&ec->lock, tmp);
812 return ret;
813}
814
815static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
816{
817 int status;
818 u32 glk;
819
820 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
821 return -EINVAL;
822 if (t->rdata)
823 memset(t->rdata, 0, t->rlen);
824
825 mutex_lock(&ec->mutex);
826 if (ec->global_lock) {
827 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
828 if (ACPI_FAILURE(status)) {
829 status = -ENODEV;
830 goto unlock;
831 }
832 }
833
834 status = acpi_ec_transaction_unlocked(ec, t);
835
836 if (ec->global_lock)
837 acpi_release_global_lock(glk);
838unlock:
839 mutex_unlock(&ec->mutex);
840 return status;
841}
842
843static int acpi_ec_burst_enable(struct acpi_ec *ec)
844{
845 u8 d;
846 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
847 .wdata = NULL, .rdata = &d,
848 .wlen = 0, .rlen = 1};
849
850 return acpi_ec_transaction(ec, &t);
851}
852
853static int acpi_ec_burst_disable(struct acpi_ec *ec)
854{
855 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
856 .wdata = NULL, .rdata = NULL,
857 .wlen = 0, .rlen = 0};
858
859 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
860 acpi_ec_transaction(ec, &t) : 0;
861}
862
863static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
864{
865 int result;
866 u8 d;
867 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
868 .wdata = &address, .rdata = &d,
869 .wlen = 1, .rlen = 1};
870
871 result = acpi_ec_transaction(ec, &t);
872 *data = d;
873 return result;
874}
875
876static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
877{
878 u8 wdata[2] = { address, data };
879 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
880 .wdata = wdata, .rdata = NULL,
881 .wlen = 2, .rlen = 0};
882
883 return acpi_ec_transaction(ec, &t);
884}
885
886int ec_read(u8 addr, u8 *val)
887{
888 int err;
889 u8 temp_data;
890
891 if (!first_ec)
892 return -ENODEV;
893
894 err = acpi_ec_read(first_ec, addr, &temp_data);
895
896 if (!err) {
897 *val = temp_data;
898 return 0;
899 }
900 return err;
901}
902EXPORT_SYMBOL(ec_read);
903
904int ec_write(u8 addr, u8 val)
905{
906 if (!first_ec)
907 return -ENODEV;
908
909 return acpi_ec_write(first_ec, addr, val);
910}
911EXPORT_SYMBOL(ec_write);
912
913int ec_transaction(u8 command,
914 const u8 *wdata, unsigned wdata_len,
915 u8 *rdata, unsigned rdata_len)
916{
917 struct transaction t = {.command = command,
918 .wdata = wdata, .rdata = rdata,
919 .wlen = wdata_len, .rlen = rdata_len};
920
921 if (!first_ec)
922 return -ENODEV;
923
924 return acpi_ec_transaction(first_ec, &t);
925}
926EXPORT_SYMBOL(ec_transaction);
927
928/* Get the handle to the EC device */
929acpi_handle ec_get_handle(void)
930{
931 if (!first_ec)
932 return NULL;
933 return first_ec->handle;
934}
935EXPORT_SYMBOL(ec_get_handle);
936
937static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
938{
939 unsigned long flags;
940
941 spin_lock_irqsave(&ec->lock, flags);
942 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
943 ec_dbg_drv("Starting EC");
944 /* Enable GPE for event processing (SCI_EVT=1) */
945 if (!resuming) {
946 acpi_ec_submit_request(ec);
947 ec_dbg_ref(ec, "Increase driver");
948 }
949 ec_log_drv("EC started");
950 }
951 spin_unlock_irqrestore(&ec->lock, flags);
952}
953
954static bool acpi_ec_stopped(struct acpi_ec *ec)
955{
956 unsigned long flags;
957 bool flushed;
958
959 spin_lock_irqsave(&ec->lock, flags);
960 flushed = acpi_ec_flushed(ec);
961 spin_unlock_irqrestore(&ec->lock, flags);
962 return flushed;
963}
964
965static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
966{
967 unsigned long flags;
968
969 spin_lock_irqsave(&ec->lock, flags);
970 if (acpi_ec_started(ec)) {
971 ec_dbg_drv("Stopping EC");
972 set_bit(EC_FLAGS_STOPPED, &ec->flags);
973 spin_unlock_irqrestore(&ec->lock, flags);
974 wait_event(ec->wait, acpi_ec_stopped(ec));
975 spin_lock_irqsave(&ec->lock, flags);
976 /* Disable GPE for event processing (SCI_EVT=1) */
977 if (!suspending) {
978 acpi_ec_complete_request(ec);
979 ec_dbg_ref(ec, "Decrease driver");
980 } else if (!ec_freeze_events)
981 __acpi_ec_disable_event(ec);
982 clear_bit(EC_FLAGS_STARTED, &ec->flags);
983 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
984 ec_log_drv("EC stopped");
985 }
986 spin_unlock_irqrestore(&ec->lock, flags);
987}
988
989static void acpi_ec_enter_noirq(struct acpi_ec *ec)
990{
991 unsigned long flags;
992
993 spin_lock_irqsave(&ec->lock, flags);
994 ec->busy_polling = true;
995 ec->polling_guard = 0;
996 ec_log_drv("interrupt blocked");
997 spin_unlock_irqrestore(&ec->lock, flags);
998}
999
1000static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1001{
1002 unsigned long flags;
1003
1004 spin_lock_irqsave(&ec->lock, flags);
1005 ec->busy_polling = ec_busy_polling;
1006 ec->polling_guard = ec_polling_guard;
1007 ec_log_drv("interrupt unblocked");
1008 spin_unlock_irqrestore(&ec->lock, flags);
1009}
1010
1011void acpi_ec_block_transactions(void)
1012{
1013 struct acpi_ec *ec = first_ec;
1014
1015 if (!ec)
1016 return;
1017
1018 mutex_lock(&ec->mutex);
1019 /* Prevent transactions from being carried out */
1020 acpi_ec_stop(ec, true);
1021 mutex_unlock(&ec->mutex);
1022}
1023
1024void acpi_ec_unblock_transactions(void)
1025{
1026 /*
1027 * Allow transactions to happen again (this function is called from
1028 * atomic context during wakeup, so we don't need to acquire the mutex).
1029 */
1030 if (first_ec)
1031 acpi_ec_start(first_ec, true);
1032}
1033
1034/* --------------------------------------------------------------------------
1035 Event Management
1036 -------------------------------------------------------------------------- */
1037static struct acpi_ec_query_handler *
1038acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1039{
1040 struct acpi_ec_query_handler *handler;
1041
1042 mutex_lock(&ec->mutex);
1043 list_for_each_entry(handler, &ec->list, node) {
1044 if (value == handler->query_bit) {
1045 kref_get(&handler->kref);
1046 mutex_unlock(&ec->mutex);
1047 return handler;
1048 }
1049 }
1050 mutex_unlock(&ec->mutex);
1051 return NULL;
1052}
1053
1054static void acpi_ec_query_handler_release(struct kref *kref)
1055{
1056 struct acpi_ec_query_handler *handler =
1057 container_of(kref, struct acpi_ec_query_handler, kref);
1058
1059 kfree(handler);
1060}
1061
1062static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1063{
1064 kref_put(&handler->kref, acpi_ec_query_handler_release);
1065}
1066
1067int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1068 acpi_handle handle, acpi_ec_query_func func,
1069 void *data)
1070{
1071 struct acpi_ec_query_handler *handler;
1072
1073 if (!handle && !func)
1074 return -EINVAL;
1075
1076 handler = kzalloc(sizeof(*handler), GFP_KERNEL);
1077 if (!handler)
1078 return -ENOMEM;
1079
1080 handler->query_bit = query_bit;
1081 handler->handle = handle;
1082 handler->func = func;
1083 handler->data = data;
1084 mutex_lock(&ec->mutex);
1085 kref_init(&handler->kref);
1086 list_add(&handler->node, &ec->list);
1087 mutex_unlock(&ec->mutex);
1088
1089 return 0;
1090}
1091EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1092
1093static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1094 bool remove_all, u8 query_bit)
1095{
1096 struct acpi_ec_query_handler *handler, *tmp;
1097 LIST_HEAD(free_list);
1098
1099 mutex_lock(&ec->mutex);
1100 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1101 /*
1102 * When remove_all is false, only remove custom query handlers
1103 * which have handler->func set. This is done to preserve query
1104 * handlers discovered thru ACPI, as they should continue handling
1105 * EC queries.
1106 */
1107 if (remove_all || (handler->func && handler->query_bit == query_bit)) {
1108 list_del_init(&handler->node);
1109 list_add(&handler->node, &free_list);
1110
1111 }
1112 }
1113 mutex_unlock(&ec->mutex);
1114 list_for_each_entry_safe(handler, tmp, &free_list, node)
1115 acpi_ec_put_query_handler(handler);
1116}
1117
1118void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1119{
1120 acpi_ec_remove_query_handlers(ec, false, query_bit);
1121 flush_workqueue(ec_query_wq);
1122}
1123EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1124
1125static void acpi_ec_event_processor(struct work_struct *work)
1126{
1127 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1128 struct acpi_ec_query_handler *handler = q->handler;
1129 struct acpi_ec *ec = q->ec;
1130
1131 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1132
1133 if (handler->func)
1134 handler->func(handler->data);
1135 else if (handler->handle)
1136 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1137
1138 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1139
1140 spin_lock_irq(&ec->lock);
1141 ec->queries_in_progress--;
1142 spin_unlock_irq(&ec->lock);
1143
1144 acpi_ec_put_query_handler(handler);
1145 kfree(q);
1146}
1147
1148static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1149{
1150 struct acpi_ec_query *q;
1151 struct transaction *t;
1152
1153 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1154 if (!q)
1155 return NULL;
1156
1157 INIT_WORK(&q->work, acpi_ec_event_processor);
1158 t = &q->transaction;
1159 t->command = ACPI_EC_COMMAND_QUERY;
1160 t->rdata = pval;
1161 t->rlen = 1;
1162 q->ec = ec;
1163 return q;
1164}
1165
1166static int acpi_ec_submit_query(struct acpi_ec *ec)
1167{
1168 struct acpi_ec_query *q;
1169 u8 value = 0;
1170 int result;
1171
1172 q = acpi_ec_create_query(ec, &value);
1173 if (!q)
1174 return -ENOMEM;
1175
1176 /*
1177 * Query the EC to find out which _Qxx method we need to evaluate.
1178 * Note that successful completion of the query causes the ACPI_EC_SCI
1179 * bit to be cleared (and thus clearing the interrupt source).
1180 */
1181 result = acpi_ec_transaction(ec, &q->transaction);
1182 if (result)
1183 goto err_exit;
1184
1185 if (!value) {
1186 result = -ENODATA;
1187 goto err_exit;
1188 }
1189
1190 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1191 if (!q->handler) {
1192 result = -ENODATA;
1193 goto err_exit;
1194 }
1195
1196 /*
1197 * It is reported that _Qxx are evaluated in a parallel way on Windows:
1198 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1199 *
1200 * Put this log entry before queue_work() to make it appear in the log
1201 * before any other messages emitted during workqueue handling.
1202 */
1203 ec_dbg_evt("Query(0x%02x) scheduled", value);
1204
1205 spin_lock_irq(&ec->lock);
1206
1207 ec->queries_in_progress++;
1208 queue_work(ec_query_wq, &q->work);
1209
1210 spin_unlock_irq(&ec->lock);
1211
1212 return 0;
1213
1214err_exit:
1215 kfree(q);
1216
1217 return result;
1218}
1219
1220static void acpi_ec_event_handler(struct work_struct *work)
1221{
1222 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1223
1224 ec_dbg_evt("Event started");
1225
1226 spin_lock_irq(&ec->lock);
1227
1228 while (ec->events_to_process) {
1229 spin_unlock_irq(&ec->lock);
1230
1231 acpi_ec_submit_query(ec);
1232
1233 spin_lock_irq(&ec->lock);
1234
1235 ec->events_to_process--;
1236 }
1237
1238 /*
1239 * Before exit, make sure that the it will be possible to queue up the
1240 * event handling work again regardless of whether or not the query
1241 * queued up above is processed successfully.
1242 */
1243 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1244 bool guard_timeout;
1245
1246 acpi_ec_complete_event(ec);
1247
1248 ec_dbg_evt("Event stopped");
1249
1250 spin_unlock_irq(&ec->lock);
1251
1252 guard_timeout = !!ec_guard(ec);
1253
1254 spin_lock_irq(&ec->lock);
1255
1256 /* Take care of SCI_EVT unless someone else is doing that. */
1257 if (guard_timeout && !ec->curr)
1258 advance_transaction(ec, false);
1259 } else {
1260 acpi_ec_close_event(ec);
1261
1262 ec_dbg_evt("Event stopped");
1263 }
1264
1265 ec->events_in_progress--;
1266
1267 spin_unlock_irq(&ec->lock);
1268}
1269
1270static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)
1271{
1272 /*
1273 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
1274 * changes to always trigger a GPE interrupt.
1275 *
1276 * GPE STS is a W1C register, which means:
1277 *
1278 * 1. Software can clear it without worrying about clearing the other
1279 * GPEs' STS bits when the hardware sets them in parallel.
1280 *
1281 * 2. As long as software can ensure only clearing it when it is set,
1282 * hardware won't set it in parallel.
1283 */
1284 if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
1285 acpi_clear_gpe(NULL, ec->gpe);
1286
1287 advance_transaction(ec, true);
1288}
1289
1290static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1291{
1292 unsigned long flags;
1293
1294 spin_lock_irqsave(&ec->lock, flags);
1295
1296 clear_gpe_and_advance_transaction(ec, true);
1297
1298 spin_unlock_irqrestore(&ec->lock, flags);
1299}
1300
1301static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1302 u32 gpe_number, void *data)
1303{
1304 acpi_ec_handle_interrupt(data);
1305 return ACPI_INTERRUPT_HANDLED;
1306}
1307
1308static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1309{
1310 acpi_ec_handle_interrupt(data);
1311 return IRQ_HANDLED;
1312}
1313
1314/* --------------------------------------------------------------------------
1315 * Address Space Management
1316 * -------------------------------------------------------------------------- */
1317
1318static acpi_status
1319acpi_ec_space_handler(u32 function, acpi_physical_address address,
1320 u32 bits, u64 *value64,
1321 void *handler_context, void *region_context)
1322{
1323 struct acpi_ec *ec = handler_context;
1324 int result = 0, i, bytes = bits / 8;
1325 u8 *value = (u8 *)value64;
1326
1327 if ((address > 0xFF) || !value || !handler_context)
1328 return AE_BAD_PARAMETER;
1329
1330 if (function != ACPI_READ && function != ACPI_WRITE)
1331 return AE_BAD_PARAMETER;
1332
1333 if (ec->busy_polling || bits > 8)
1334 acpi_ec_burst_enable(ec);
1335
1336 for (i = 0; i < bytes; ++i, ++address, ++value)
1337 result = (function == ACPI_READ) ?
1338 acpi_ec_read(ec, address, value) :
1339 acpi_ec_write(ec, address, *value);
1340
1341 if (ec->busy_polling || bits > 8)
1342 acpi_ec_burst_disable(ec);
1343
1344 switch (result) {
1345 case -EINVAL:
1346 return AE_BAD_PARAMETER;
1347 case -ENODEV:
1348 return AE_NOT_FOUND;
1349 case -ETIME:
1350 return AE_TIME;
1351 default:
1352 return AE_OK;
1353 }
1354}
1355
1356/* --------------------------------------------------------------------------
1357 * Driver Interface
1358 * -------------------------------------------------------------------------- */
1359
1360static acpi_status
1361ec_parse_io_ports(struct acpi_resource *resource, void *context);
1362
1363static void acpi_ec_free(struct acpi_ec *ec)
1364{
1365 if (first_ec == ec)
1366 first_ec = NULL;
1367 if (boot_ec == ec)
1368 boot_ec = NULL;
1369 kfree(ec);
1370}
1371
1372static struct acpi_ec *acpi_ec_alloc(void)
1373{
1374 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1375
1376 if (!ec)
1377 return NULL;
1378 mutex_init(&ec->mutex);
1379 init_waitqueue_head(&ec->wait);
1380 INIT_LIST_HEAD(&ec->list);
1381 spin_lock_init(&ec->lock);
1382 INIT_WORK(&ec->work, acpi_ec_event_handler);
1383 ec->timestamp = jiffies;
1384 ec->busy_polling = true;
1385 ec->polling_guard = 0;
1386 ec->gpe = -1;
1387 ec->irq = -1;
1388 return ec;
1389}
1390
1391static acpi_status
1392acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1393 void *context, void **return_value)
1394{
1395 char node_name[5];
1396 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1397 struct acpi_ec *ec = context;
1398 int value = 0;
1399 acpi_status status;
1400
1401 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1402
1403 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1404 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1405 return AE_OK;
1406}
1407
1408static acpi_status
1409ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1410{
1411 acpi_status status;
1412 unsigned long long tmp = 0;
1413 struct acpi_ec *ec = context;
1414
1415 /* clear addr values, ec_parse_io_ports depend on it */
1416 ec->command_addr = ec->data_addr = 0;
1417
1418 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1419 ec_parse_io_ports, ec);
1420 if (ACPI_FAILURE(status))
1421 return status;
1422 if (ec->data_addr == 0 || ec->command_addr == 0)
1423 return AE_OK;
1424
1425 /* Get GPE bit assignment (EC events). */
1426 /* TODO: Add support for _GPE returning a package */
1427 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1428 if (ACPI_SUCCESS(status))
1429 ec->gpe = tmp;
1430 /*
1431 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1432 * platforms which use GpioInt instead of GPE.
1433 */
1434
1435 /* Use the global lock for all EC transactions? */
1436 tmp = 0;
1437 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1438 ec->global_lock = tmp;
1439 ec->handle = handle;
1440 return AE_CTRL_TERMINATE;
1441}
1442
1443static bool install_gpe_event_handler(struct acpi_ec *ec)
1444{
1445 acpi_status status;
1446
1447 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1448 ACPI_GPE_EDGE_TRIGGERED,
1449 &acpi_ec_gpe_handler, ec);
1450 if (ACPI_FAILURE(status))
1451 return false;
1452
1453 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1454 acpi_ec_enable_gpe(ec, true);
1455
1456 return true;
1457}
1458
1459static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1460{
1461 return request_threaded_irq(ec->irq, NULL, acpi_ec_irq_handler,
1462 IRQF_SHARED | IRQF_ONESHOT, "ACPI EC", ec) >= 0;
1463}
1464
1465/**
1466 * ec_install_handlers - Install service callbacks and register query methods.
1467 * @ec: Target EC.
1468 * @device: ACPI device object corresponding to @ec.
1469 * @call_reg: If _REG should be called to notify OpRegion availability
1470 *
1471 * Install a handler for the EC address space type unless it has been installed
1472 * already. If @device is not NULL, also look for EC query methods in the
1473 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1474 * handler for the EC, if possible.
1475 *
1476 * Return:
1477 * -ENODEV if the address space handler cannot be installed, which means
1478 * "unable to handle transactions",
1479 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1480 * or 0 (success) otherwise.
1481 */
1482static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1483 bool call_reg)
1484{
1485 acpi_status status;
1486
1487 acpi_ec_start(ec, false);
1488
1489 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1490 acpi_ec_enter_noirq(ec);
1491 status = acpi_install_address_space_handler_no_reg(ec->handle,
1492 ACPI_ADR_SPACE_EC,
1493 &acpi_ec_space_handler,
1494 NULL, ec);
1495 if (ACPI_FAILURE(status)) {
1496 acpi_ec_stop(ec, false);
1497 return -ENODEV;
1498 }
1499 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1500 ec->address_space_handler_holder = ec->handle;
1501 }
1502
1503 if (call_reg && !test_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags)) {
1504 acpi_execute_reg_methods(ec->handle, ACPI_ADR_SPACE_EC);
1505 set_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags);
1506 }
1507
1508 if (!device)
1509 return 0;
1510
1511 if (ec->gpe < 0) {
1512 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1513 int irq = acpi_dev_gpio_irq_get(device, 0);
1514 /*
1515 * Bail out right away for deferred probing or complete the
1516 * initialization regardless of any other errors.
1517 */
1518 if (irq == -EPROBE_DEFER)
1519 return -EPROBE_DEFER;
1520 else if (irq >= 0)
1521 ec->irq = irq;
1522 }
1523
1524 if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1525 /* Find and register all query methods */
1526 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1527 acpi_ec_register_query_methods,
1528 NULL, ec, NULL);
1529 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1530 }
1531 if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1532 bool ready = false;
1533
1534 if (ec->gpe >= 0)
1535 ready = install_gpe_event_handler(ec);
1536 else if (ec->irq >= 0)
1537 ready = install_gpio_irq_event_handler(ec);
1538
1539 if (ready) {
1540 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1541 acpi_ec_leave_noirq(ec);
1542 }
1543 /*
1544 * Failures to install an event handler are not fatal, because
1545 * the EC can be polled for events.
1546 */
1547 }
1548 /* EC is fully operational, allow queries */
1549 acpi_ec_enable_event(ec);
1550
1551 return 0;
1552}
1553
1554static void ec_remove_handlers(struct acpi_ec *ec)
1555{
1556 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1557 if (ACPI_FAILURE(acpi_remove_address_space_handler(
1558 ec->address_space_handler_holder,
1559 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1560 pr_err("failed to remove space handler\n");
1561 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1562 }
1563
1564 /*
1565 * Stops handling the EC transactions after removing the operation
1566 * region handler. This is required because _REG(DISCONNECT)
1567 * invoked during the removal can result in new EC transactions.
1568 *
1569 * Flushes the EC requests and thus disables the GPE before
1570 * removing the GPE handler. This is required by the current ACPICA
1571 * GPE core. ACPICA GPE core will automatically disable a GPE when
1572 * it is indicated but there is no way to handle it. So the drivers
1573 * must disable the GPEs prior to removing the GPE handlers.
1574 */
1575 acpi_ec_stop(ec, false);
1576
1577 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1578 if (ec->gpe >= 0 &&
1579 ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1580 &acpi_ec_gpe_handler)))
1581 pr_err("failed to remove gpe handler\n");
1582
1583 if (ec->irq >= 0)
1584 free_irq(ec->irq, ec);
1585
1586 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1587 }
1588 if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1589 acpi_ec_remove_query_handlers(ec, true, 0);
1590 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1591 }
1592}
1593
1594static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device, bool call_reg)
1595{
1596 int ret;
1597
1598 ret = ec_install_handlers(ec, device, call_reg);
1599 if (ret)
1600 return ret;
1601
1602 /* First EC capable of handling transactions */
1603 if (!first_ec)
1604 first_ec = ec;
1605
1606 pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1607 ec->data_addr);
1608
1609 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1610 if (ec->gpe >= 0)
1611 pr_info("GPE=0x%x\n", ec->gpe);
1612 else
1613 pr_info("IRQ=%d\n", ec->irq);
1614 }
1615
1616 return ret;
1617}
1618
1619static int acpi_ec_add(struct acpi_device *device)
1620{
1621 struct acpi_ec *ec;
1622 int ret;
1623
1624 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1625 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1626
1627 if (boot_ec && (boot_ec->handle == device->handle ||
1628 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1629 /* Fast path: this device corresponds to the boot EC. */
1630 ec = boot_ec;
1631 } else {
1632 acpi_status status;
1633
1634 ec = acpi_ec_alloc();
1635 if (!ec)
1636 return -ENOMEM;
1637
1638 status = ec_parse_device(device->handle, 0, ec, NULL);
1639 if (status != AE_CTRL_TERMINATE) {
1640 ret = -EINVAL;
1641 goto err;
1642 }
1643
1644 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1645 ec->data_addr == boot_ec->data_addr) {
1646 /*
1647 * Trust PNP0C09 namespace location rather than ECDT ID.
1648 * But trust ECDT GPE rather than _GPE because of ASUS
1649 * quirks. So do not change boot_ec->gpe to ec->gpe,
1650 * except when the TRUST_DSDT_GPE quirk is set.
1651 */
1652 boot_ec->handle = ec->handle;
1653
1654 if (EC_FLAGS_TRUST_DSDT_GPE)
1655 boot_ec->gpe = ec->gpe;
1656
1657 acpi_handle_debug(ec->handle, "duplicated.\n");
1658 acpi_ec_free(ec);
1659 ec = boot_ec;
1660 }
1661 }
1662
1663 ret = acpi_ec_setup(ec, device, true);
1664 if (ret)
1665 goto err;
1666
1667 if (ec == boot_ec)
1668 acpi_handle_info(boot_ec->handle,
1669 "Boot %s EC initialization complete\n",
1670 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1671
1672 acpi_handle_info(ec->handle,
1673 "EC: Used to handle transactions and events\n");
1674
1675 device->driver_data = ec;
1676
1677 ret = !!request_region(ec->data_addr, 1, "EC data");
1678 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1679 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1680 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1681
1682 /* Reprobe devices depending on the EC */
1683 acpi_dev_clear_dependencies(device);
1684
1685 acpi_handle_debug(ec->handle, "enumerated.\n");
1686 return 0;
1687
1688err:
1689 if (ec != boot_ec)
1690 acpi_ec_free(ec);
1691
1692 return ret;
1693}
1694
1695static void acpi_ec_remove(struct acpi_device *device)
1696{
1697 struct acpi_ec *ec;
1698
1699 if (!device)
1700 return;
1701
1702 ec = acpi_driver_data(device);
1703 release_region(ec->data_addr, 1);
1704 release_region(ec->command_addr, 1);
1705 device->driver_data = NULL;
1706 if (ec != boot_ec) {
1707 ec_remove_handlers(ec);
1708 acpi_ec_free(ec);
1709 }
1710}
1711
1712static acpi_status
1713ec_parse_io_ports(struct acpi_resource *resource, void *context)
1714{
1715 struct acpi_ec *ec = context;
1716
1717 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1718 return AE_OK;
1719
1720 /*
1721 * The first address region returned is the data port, and
1722 * the second address region returned is the status/command
1723 * port.
1724 */
1725 if (ec->data_addr == 0)
1726 ec->data_addr = resource->data.io.minimum;
1727 else if (ec->command_addr == 0)
1728 ec->command_addr = resource->data.io.minimum;
1729 else
1730 return AE_CTRL_TERMINATE;
1731
1732 return AE_OK;
1733}
1734
1735static const struct acpi_device_id ec_device_ids[] = {
1736 {"PNP0C09", 0},
1737 {ACPI_ECDT_HID, 0},
1738 {"", 0},
1739};
1740
1741/*
1742 * This function is not Windows-compatible as Windows never enumerates the
1743 * namespace EC before the main ACPI device enumeration process. It is
1744 * retained for historical reason and will be deprecated in the future.
1745 */
1746void __init acpi_ec_dsdt_probe(void)
1747{
1748 struct acpi_ec *ec;
1749 acpi_status status;
1750 int ret;
1751
1752 /*
1753 * If a platform has ECDT, there is no need to proceed as the
1754 * following probe is not a part of the ACPI device enumeration,
1755 * executing _STA is not safe, and thus this probe may risk of
1756 * picking up an invalid EC device.
1757 */
1758 if (boot_ec)
1759 return;
1760
1761 ec = acpi_ec_alloc();
1762 if (!ec)
1763 return;
1764
1765 /*
1766 * At this point, the namespace is initialized, so start to find
1767 * the namespace objects.
1768 */
1769 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1770 if (ACPI_FAILURE(status) || !ec->handle) {
1771 acpi_ec_free(ec);
1772 return;
1773 }
1774
1775 /*
1776 * When the DSDT EC is available, always re-configure boot EC to
1777 * have _REG evaluated. _REG can only be evaluated after the
1778 * namespace initialization.
1779 * At this point, the GPE is not fully initialized, so do not to
1780 * handle the events.
1781 */
1782 ret = acpi_ec_setup(ec, NULL, true);
1783 if (ret) {
1784 acpi_ec_free(ec);
1785 return;
1786 }
1787
1788 boot_ec = ec;
1789
1790 acpi_handle_info(ec->handle,
1791 "Boot DSDT EC used to handle transactions\n");
1792}
1793
1794/*
1795 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1796 *
1797 * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1798 * found a matching object in the namespace.
1799 *
1800 * Next, in case the DSDT EC is not functioning, it is still necessary to
1801 * provide a functional ECDT EC to handle events, so add an extra device object
1802 * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1803 *
1804 * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1805 * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1806 */
1807static void __init acpi_ec_ecdt_start(void)
1808{
1809 struct acpi_table_ecdt *ecdt_ptr;
1810 acpi_handle handle;
1811 acpi_status status;
1812
1813 /* Bail out if a matching EC has been found in the namespace. */
1814 if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1815 return;
1816
1817 /* Look up the object pointed to from the ECDT in the namespace. */
1818 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1819 (struct acpi_table_header **)&ecdt_ptr);
1820 if (ACPI_FAILURE(status))
1821 return;
1822
1823 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1824 if (ACPI_SUCCESS(status)) {
1825 boot_ec->handle = handle;
1826
1827 /* Add a special ACPI device object to represent the boot EC. */
1828 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1829 }
1830
1831 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1832}
1833
1834/*
1835 * On some hardware it is necessary to clear events accumulated by the EC during
1836 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1837 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1838 *
1839 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1840 *
1841 * Ideally, the EC should also be instructed NOT to accumulate events during
1842 * sleep (which Windows seems to do somehow), but the interface to control this
1843 * behaviour is not known at this time.
1844 *
1845 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1846 * however it is very likely that other Samsung models are affected.
1847 *
1848 * On systems which don't accumulate _Q events during sleep, this extra check
1849 * should be harmless.
1850 */
1851static int ec_clear_on_resume(const struct dmi_system_id *id)
1852{
1853 pr_debug("Detected system needing EC poll on resume.\n");
1854 EC_FLAGS_CLEAR_ON_RESUME = 1;
1855 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1856 return 0;
1857}
1858
1859/*
1860 * Some ECDTs contain wrong register addresses.
1861 * MSI MS-171F
1862 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1863 */
1864static int ec_correct_ecdt(const struct dmi_system_id *id)
1865{
1866 pr_debug("Detected system needing ECDT address correction.\n");
1867 EC_FLAGS_CORRECT_ECDT = 1;
1868 return 0;
1869}
1870
1871/*
1872 * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1873 * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1874 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1875 */
1876static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1877{
1878 pr_debug("Detected system needing DSDT GPE setting.\n");
1879 EC_FLAGS_TRUST_DSDT_GPE = 1;
1880 return 0;
1881}
1882
1883static const struct dmi_system_id ec_dmi_table[] __initconst = {
1884 {
1885 /*
1886 * MSI MS-171F
1887 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1888 */
1889 .callback = ec_correct_ecdt,
1890 .matches = {
1891 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1892 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),
1893 },
1894 },
1895 {
1896 /*
1897 * HP Pavilion Gaming Laptop 15-cx0xxx
1898 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1899 */
1900 .callback = ec_honor_dsdt_gpe,
1901 .matches = {
1902 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1903 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),
1904 },
1905 },
1906 {
1907 /*
1908 * HP Pavilion Gaming Laptop 15-cx0041ur
1909 */
1910 .callback = ec_honor_dsdt_gpe,
1911 .matches = {
1912 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1913 DMI_MATCH(DMI_PRODUCT_NAME, "HP 15-cx0041ur"),
1914 },
1915 },
1916 {
1917 /*
1918 * HP Pavilion Gaming Laptop 15-dk1xxx
1919 * https://github.com/systemd/systemd/issues/28942
1920 */
1921 .callback = ec_honor_dsdt_gpe,
1922 .matches = {
1923 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1924 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-dk1xxx"),
1925 },
1926 },
1927 {
1928 /*
1929 * HP 250 G7 Notebook PC
1930 */
1931 .callback = ec_honor_dsdt_gpe,
1932 .matches = {
1933 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1934 DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"),
1935 },
1936 },
1937 {
1938 /*
1939 * Samsung hardware
1940 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1941 */
1942 .callback = ec_clear_on_resume,
1943 .matches = {
1944 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
1945 },
1946 },
1947 {}
1948};
1949
1950void __init acpi_ec_ecdt_probe(void)
1951{
1952 struct acpi_table_ecdt *ecdt_ptr;
1953 struct acpi_ec *ec;
1954 acpi_status status;
1955 int ret;
1956
1957 /* Generate a boot ec context. */
1958 dmi_check_system(ec_dmi_table);
1959 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1960 (struct acpi_table_header **)&ecdt_ptr);
1961 if (ACPI_FAILURE(status))
1962 return;
1963
1964 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1965 /*
1966 * Asus X50GL:
1967 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1968 */
1969 goto out;
1970 }
1971
1972 ec = acpi_ec_alloc();
1973 if (!ec)
1974 goto out;
1975
1976 if (EC_FLAGS_CORRECT_ECDT) {
1977 ec->command_addr = ecdt_ptr->data.address;
1978 ec->data_addr = ecdt_ptr->control.address;
1979 } else {
1980 ec->command_addr = ecdt_ptr->control.address;
1981 ec->data_addr = ecdt_ptr->data.address;
1982 }
1983
1984 /*
1985 * Ignore the GPE value on Reduced Hardware platforms.
1986 * Some products have this set to an erroneous value.
1987 */
1988 if (!acpi_gbl_reduced_hardware)
1989 ec->gpe = ecdt_ptr->gpe;
1990
1991 ec->handle = ACPI_ROOT_OBJECT;
1992
1993 /*
1994 * At this point, the namespace is not initialized, so do not find
1995 * the namespace objects, or handle the events.
1996 */
1997 ret = acpi_ec_setup(ec, NULL, false);
1998 if (ret) {
1999 acpi_ec_free(ec);
2000 goto out;
2001 }
2002
2003 boot_ec = ec;
2004 boot_ec_is_ecdt = true;
2005
2006 pr_info("Boot ECDT EC used to handle transactions\n");
2007
2008out:
2009 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
2010}
2011
2012#ifdef CONFIG_PM_SLEEP
2013static int acpi_ec_suspend(struct device *dev)
2014{
2015 struct acpi_ec *ec =
2016 acpi_driver_data(to_acpi_device(dev));
2017
2018 if (!pm_suspend_no_platform() && ec_freeze_events)
2019 acpi_ec_disable_event(ec);
2020 return 0;
2021}
2022
2023static int acpi_ec_suspend_noirq(struct device *dev)
2024{
2025 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2026
2027 /*
2028 * The SCI handler doesn't run at this point, so the GPE can be
2029 * masked at the low level without side effects.
2030 */
2031 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2032 ec->gpe >= 0 && ec->reference_count >= 1)
2033 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2034
2035 acpi_ec_enter_noirq(ec);
2036
2037 return 0;
2038}
2039
2040static int acpi_ec_resume_noirq(struct device *dev)
2041{
2042 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2043
2044 acpi_ec_leave_noirq(ec);
2045
2046 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2047 ec->gpe >= 0 && ec->reference_count >= 1)
2048 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2049
2050 return 0;
2051}
2052
2053static int acpi_ec_resume(struct device *dev)
2054{
2055 struct acpi_ec *ec =
2056 acpi_driver_data(to_acpi_device(dev));
2057
2058 acpi_ec_enable_event(ec);
2059 return 0;
2060}
2061
2062void acpi_ec_mark_gpe_for_wake(void)
2063{
2064 if (first_ec && !ec_no_wakeup)
2065 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2066}
2067EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2068
2069void acpi_ec_set_gpe_wake_mask(u8 action)
2070{
2071 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2072 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2073}
2074
2075static bool acpi_ec_work_in_progress(struct acpi_ec *ec)
2076{
2077 return ec->events_in_progress + ec->queries_in_progress > 0;
2078}
2079
2080bool acpi_ec_dispatch_gpe(void)
2081{
2082 bool work_in_progress = false;
2083
2084 if (!first_ec)
2085 return acpi_any_gpe_status_set(U32_MAX);
2086
2087 /*
2088 * Report wakeup if the status bit is set for any enabled GPE other
2089 * than the EC one.
2090 */
2091 if (acpi_any_gpe_status_set(first_ec->gpe))
2092 return true;
2093
2094 /*
2095 * Cancel the SCI wakeup and process all pending events in case there
2096 * are any wakeup ones in there.
2097 *
2098 * Note that if any non-EC GPEs are active at this point, the SCI will
2099 * retrigger after the rearming in acpi_s2idle_wake(), so no events
2100 * should be missed by canceling the wakeup here.
2101 */
2102 pm_system_cancel_wakeup();
2103
2104 /*
2105 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2106 * to allow the caller to process events properly after that.
2107 */
2108 spin_lock_irq(&first_ec->lock);
2109
2110 if (acpi_ec_gpe_status_set(first_ec)) {
2111 pm_pr_dbg("ACPI EC GPE status set\n");
2112
2113 clear_gpe_and_advance_transaction(first_ec, false);
2114 work_in_progress = acpi_ec_work_in_progress(first_ec);
2115 }
2116
2117 spin_unlock_irq(&first_ec->lock);
2118
2119 if (!work_in_progress)
2120 return false;
2121
2122 pm_pr_dbg("ACPI EC GPE dispatched\n");
2123
2124 /* Drain EC work. */
2125 do {
2126 acpi_ec_flush_work();
2127
2128 pm_pr_dbg("ACPI EC work flushed\n");
2129
2130 spin_lock_irq(&first_ec->lock);
2131
2132 work_in_progress = acpi_ec_work_in_progress(first_ec);
2133
2134 spin_unlock_irq(&first_ec->lock);
2135 } while (work_in_progress && !pm_wakeup_pending());
2136
2137 return false;
2138}
2139#endif /* CONFIG_PM_SLEEP */
2140
2141static const struct dev_pm_ops acpi_ec_pm = {
2142 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2143 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2144};
2145
2146static int param_set_event_clearing(const char *val,
2147 const struct kernel_param *kp)
2148{
2149 int result = 0;
2150
2151 if (!strncmp(val, "status", sizeof("status") - 1)) {
2152 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2153 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2154 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2155 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2156 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2157 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2158 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2159 pr_info("Assuming SCI_EVT clearing on event reads\n");
2160 } else
2161 result = -EINVAL;
2162 return result;
2163}
2164
2165static int param_get_event_clearing(char *buffer,
2166 const struct kernel_param *kp)
2167{
2168 switch (ec_event_clearing) {
2169 case ACPI_EC_EVT_TIMING_STATUS:
2170 return sprintf(buffer, "status\n");
2171 case ACPI_EC_EVT_TIMING_QUERY:
2172 return sprintf(buffer, "query\n");
2173 case ACPI_EC_EVT_TIMING_EVENT:
2174 return sprintf(buffer, "event\n");
2175 default:
2176 return sprintf(buffer, "invalid\n");
2177 }
2178 return 0;
2179}
2180
2181module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2182 NULL, 0644);
2183MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2184
2185static struct acpi_driver acpi_ec_driver = {
2186 .name = "ec",
2187 .class = ACPI_EC_CLASS,
2188 .ids = ec_device_ids,
2189 .ops = {
2190 .add = acpi_ec_add,
2191 .remove = acpi_ec_remove,
2192 },
2193 .drv.pm = &acpi_ec_pm,
2194};
2195
2196static void acpi_ec_destroy_workqueues(void)
2197{
2198 if (ec_wq) {
2199 destroy_workqueue(ec_wq);
2200 ec_wq = NULL;
2201 }
2202 if (ec_query_wq) {
2203 destroy_workqueue(ec_query_wq);
2204 ec_query_wq = NULL;
2205 }
2206}
2207
2208static int acpi_ec_init_workqueues(void)
2209{
2210 if (!ec_wq)
2211 ec_wq = alloc_ordered_workqueue("kec", 0);
2212
2213 if (!ec_query_wq)
2214 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2215
2216 if (!ec_wq || !ec_query_wq) {
2217 acpi_ec_destroy_workqueues();
2218 return -ENODEV;
2219 }
2220 return 0;
2221}
2222
2223static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2224 {
2225 .matches = {
2226 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2227 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2228 },
2229 },
2230 {
2231 .matches = {
2232 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2233 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2234 },
2235 },
2236 {
2237 .matches = {
2238 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2239 DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2240 },
2241 },
2242 { },
2243};
2244
2245void __init acpi_ec_init(void)
2246{
2247 int result;
2248
2249 result = acpi_ec_init_workqueues();
2250 if (result)
2251 return;
2252
2253 /*
2254 * Disable EC wakeup on following systems to prevent periodic
2255 * wakeup from EC GPE.
2256 */
2257 if (dmi_check_system(acpi_ec_no_wakeup)) {
2258 ec_no_wakeup = true;
2259 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2260 }
2261
2262 /* Driver must be registered after acpi_ec_init_workqueues(). */
2263 acpi_bus_register_driver(&acpi_ec_driver);
2264
2265 acpi_ec_ecdt_start();
2266}
2267
2268/* EC driver currently not unloadable */
2269#if 0
2270static void __exit acpi_ec_exit(void)
2271{
2272
2273 acpi_bus_unregister_driver(&acpi_ec_driver);
2274 acpi_ec_destroy_workqueues();
2275}
2276#endif /* 0 */