Merge remote-tracking branch 'vfio/next'
[deliverable/linux.git] / drivers / acpi / ec.c
1 /*
2 * ec.c - ACPI Embedded Controller Driver (v3)
3 *
4 * Copyright (C) 2001-2015 Intel Corporation
5 * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
6 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
7 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
8 * 2004 Luming Yu <luming.yu@intel.com>
9 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
10 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
11 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
12 *
13 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or (at
18 * your option) any later version.
19 *
20 * This program is distributed in the hope that it will be useful, but
21 * WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 * General Public License for more details.
24 *
25 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26 */
27
28 /* Uncomment next line to get verbose printout */
29 /* #define DEBUG */
30 #define pr_fmt(fmt) "ACPI : EC: " fmt
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 <linux/acpi.h>
42 #include <linux/dmi.h>
43 #include <asm/io.h>
44
45 #include "internal.h"
46
47 #define ACPI_EC_CLASS "embedded_controller"
48 #define ACPI_EC_DEVICE_NAME "Embedded Controller"
49 #define ACPI_EC_FILE_INFO "info"
50
51 /* EC status register */
52 #define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
53 #define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
54 #define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
55 #define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
56 #define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
57
58 /*
59 * The SCI_EVT clearing timing is not defined by the ACPI specification.
60 * This leads to lots of practical timing issues for the host EC driver.
61 * The following variations are defined (from the target EC firmware's
62 * perspective):
63 * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
64 * target can clear SCI_EVT at any time so long as the host can see
65 * the indication by reading the status register (EC_SC). So the
66 * host should re-check SCI_EVT after the first time the SCI_EVT
67 * indication is seen, which is the same time the query request
68 * (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
69 * at any later time could indicate another event. Normally such
70 * kind of EC firmware has implemented an event queue and will
71 * return 0x00 to indicate "no outstanding event".
72 * QUERY: After seeing the query request (QR_EC) written to the command
73 * register (EC_CMD) by the host and having prepared the responding
74 * event value in the data register (EC_DATA), the target can safely
75 * clear SCI_EVT because the target can confirm that the current
76 * event is being handled by the host. The host then should check
77 * SCI_EVT right after reading the event response from the data
78 * register (EC_DATA).
79 * EVENT: After seeing the event response read from the data register
80 * (EC_DATA) by the host, the target can clear SCI_EVT. As the
81 * target requires time to notice the change in the data register
82 * (EC_DATA), the host may be required to wait additional guarding
83 * time before checking the SCI_EVT again. Such guarding may not be
84 * necessary if the host is notified via another IRQ.
85 */
86 #define ACPI_EC_EVT_TIMING_STATUS 0x00
87 #define ACPI_EC_EVT_TIMING_QUERY 0x01
88 #define ACPI_EC_EVT_TIMING_EVENT 0x02
89
90 /* EC commands */
91 enum ec_command {
92 ACPI_EC_COMMAND_READ = 0x80,
93 ACPI_EC_COMMAND_WRITE = 0x81,
94 ACPI_EC_BURST_ENABLE = 0x82,
95 ACPI_EC_BURST_DISABLE = 0x83,
96 ACPI_EC_COMMAND_QUERY = 0x84,
97 };
98
99 #define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
100 #define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
101 #define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
102 #define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
103 * when trying to clear the EC */
104 #define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
105
106 enum {
107 EC_FLAGS_QUERY_ENABLED, /* Query is enabled */
108 EC_FLAGS_QUERY_PENDING, /* Query is pending */
109 EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */
110 EC_FLAGS_GPE_HANDLER_INSTALLED, /* GPE handler installed */
111 EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */
112 EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */
113 EC_FLAGS_STARTED, /* Driver is started */
114 EC_FLAGS_STOPPED, /* Driver is stopped */
115 EC_FLAGS_COMMAND_STORM, /* GPE storms occurred to the
116 * current command processing */
117 };
118
119 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
120 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
121
122 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
123 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
124 module_param(ec_delay, uint, 0644);
125 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
126
127 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
128 module_param(ec_max_queries, uint, 0644);
129 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
130
131 static bool ec_busy_polling __read_mostly;
132 module_param(ec_busy_polling, bool, 0644);
133 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
134
135 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
136 module_param(ec_polling_guard, uint, 0644);
137 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
138
139 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
140
141 /*
142 * If the number of false interrupts per one transaction exceeds
143 * this threshold, will think there is a GPE storm happened and
144 * will disable the GPE for normal transaction.
145 */
146 static unsigned int ec_storm_threshold __read_mostly = 8;
147 module_param(ec_storm_threshold, uint, 0644);
148 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
149
150 static bool ec_freeze_events __read_mostly = true;
151 module_param(ec_freeze_events, bool, 0644);
152 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
153
154 struct acpi_ec_query_handler {
155 struct list_head node;
156 acpi_ec_query_func func;
157 acpi_handle handle;
158 void *data;
159 u8 query_bit;
160 struct kref kref;
161 };
162
163 struct transaction {
164 const u8 *wdata;
165 u8 *rdata;
166 unsigned short irq_count;
167 u8 command;
168 u8 wi;
169 u8 ri;
170 u8 wlen;
171 u8 rlen;
172 u8 flags;
173 };
174
175 struct acpi_ec_query {
176 struct transaction transaction;
177 struct work_struct work;
178 struct acpi_ec_query_handler *handler;
179 };
180
181 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
182 static void advance_transaction(struct acpi_ec *ec);
183 static void acpi_ec_event_handler(struct work_struct *work);
184 static void acpi_ec_event_processor(struct work_struct *work);
185
186 struct acpi_ec *boot_ec, *first_ec;
187 EXPORT_SYMBOL(first_ec);
188 static bool boot_ec_is_ecdt = false;
189 static struct workqueue_struct *ec_query_wq;
190
191 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
192 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
193 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
194
195 /* --------------------------------------------------------------------------
196 * Logging/Debugging
197 * -------------------------------------------------------------------------- */
198
199 /*
200 * Splitters used by the developers to track the boundary of the EC
201 * handling processes.
202 */
203 #ifdef DEBUG
204 #define EC_DBG_SEP " "
205 #define EC_DBG_DRV "+++++"
206 #define EC_DBG_STM "====="
207 #define EC_DBG_REQ "*****"
208 #define EC_DBG_EVT "#####"
209 #else
210 #define EC_DBG_SEP ""
211 #define EC_DBG_DRV
212 #define EC_DBG_STM
213 #define EC_DBG_REQ
214 #define EC_DBG_EVT
215 #endif
216
217 #define ec_log_raw(fmt, ...) \
218 pr_info(fmt "\n", ##__VA_ARGS__)
219 #define ec_dbg_raw(fmt, ...) \
220 pr_debug(fmt "\n", ##__VA_ARGS__)
221 #define ec_log(filter, fmt, ...) \
222 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
223 #define ec_dbg(filter, fmt, ...) \
224 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
225
226 #define ec_log_drv(fmt, ...) \
227 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
228 #define ec_dbg_drv(fmt, ...) \
229 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
230 #define ec_dbg_stm(fmt, ...) \
231 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
232 #define ec_dbg_req(fmt, ...) \
233 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
234 #define ec_dbg_evt(fmt, ...) \
235 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
236 #define ec_dbg_ref(ec, fmt, ...) \
237 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
238
239 /* --------------------------------------------------------------------------
240 * Device Flags
241 * -------------------------------------------------------------------------- */
242
243 static bool acpi_ec_started(struct acpi_ec *ec)
244 {
245 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
246 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
247 }
248
249 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
250 {
251 /*
252 * There is an OSPM early stage logic. During the early stages
253 * (boot/resume), OSPMs shouldn't enable the event handling, only
254 * the EC transactions are allowed to be performed.
255 */
256 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
257 return false;
258 /*
259 * However, disabling the event handling is experimental for late
260 * stage (suspend), and is controlled by the boot parameter of
261 * "ec_freeze_events":
262 * 1. true: The EC event handling is disabled before entering
263 * the noirq stage.
264 * 2. false: The EC event handling is automatically disabled as
265 * soon as the EC driver is stopped.
266 */
267 if (ec_freeze_events)
268 return acpi_ec_started(ec);
269 else
270 return test_bit(EC_FLAGS_STARTED, &ec->flags);
271 }
272
273 static bool acpi_ec_flushed(struct acpi_ec *ec)
274 {
275 return ec->reference_count == 1;
276 }
277
278 /* --------------------------------------------------------------------------
279 * EC Registers
280 * -------------------------------------------------------------------------- */
281
282 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
283 {
284 u8 x = inb(ec->command_addr);
285
286 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
287 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
288 x,
289 !!(x & ACPI_EC_FLAG_SCI),
290 !!(x & ACPI_EC_FLAG_BURST),
291 !!(x & ACPI_EC_FLAG_CMD),
292 !!(x & ACPI_EC_FLAG_IBF),
293 !!(x & ACPI_EC_FLAG_OBF));
294 return x;
295 }
296
297 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
298 {
299 u8 x = inb(ec->data_addr);
300
301 ec->timestamp = jiffies;
302 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
303 return x;
304 }
305
306 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
307 {
308 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
309 outb(command, ec->command_addr);
310 ec->timestamp = jiffies;
311 }
312
313 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
314 {
315 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
316 outb(data, ec->data_addr);
317 ec->timestamp = jiffies;
318 }
319
320 #ifdef DEBUG
321 static const char *acpi_ec_cmd_string(u8 cmd)
322 {
323 switch (cmd) {
324 case 0x80:
325 return "RD_EC";
326 case 0x81:
327 return "WR_EC";
328 case 0x82:
329 return "BE_EC";
330 case 0x83:
331 return "BD_EC";
332 case 0x84:
333 return "QR_EC";
334 }
335 return "UNKNOWN";
336 }
337 #else
338 #define acpi_ec_cmd_string(cmd) "UNDEF"
339 #endif
340
341 /* --------------------------------------------------------------------------
342 * GPE Registers
343 * -------------------------------------------------------------------------- */
344
345 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
346 {
347 acpi_event_status gpe_status = 0;
348
349 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
350 return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
351 }
352
353 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
354 {
355 if (open)
356 acpi_enable_gpe(NULL, ec->gpe);
357 else {
358 BUG_ON(ec->reference_count < 1);
359 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
360 }
361 if (acpi_ec_is_gpe_raised(ec)) {
362 /*
363 * On some platforms, EN=1 writes cannot trigger GPE. So
364 * software need to manually trigger a pseudo GPE event on
365 * EN=1 writes.
366 */
367 ec_dbg_raw("Polling quirk");
368 advance_transaction(ec);
369 }
370 }
371
372 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
373 {
374 if (close)
375 acpi_disable_gpe(NULL, ec->gpe);
376 else {
377 BUG_ON(ec->reference_count < 1);
378 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
379 }
380 }
381
382 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
383 {
384 /*
385 * GPE STS is a W1C register, which means:
386 * 1. Software can clear it without worrying about clearing other
387 * GPEs' STS bits when the hardware sets them in parallel.
388 * 2. As long as software can ensure only clearing it when it is
389 * set, hardware won't set it in parallel.
390 * So software can clear GPE in any contexts.
391 * Warning: do not move the check into advance_transaction() as the
392 * EC commands will be sent without GPE raised.
393 */
394 if (!acpi_ec_is_gpe_raised(ec))
395 return;
396 acpi_clear_gpe(NULL, ec->gpe);
397 }
398
399 /* --------------------------------------------------------------------------
400 * Transaction Management
401 * -------------------------------------------------------------------------- */
402
403 static void acpi_ec_submit_request(struct acpi_ec *ec)
404 {
405 ec->reference_count++;
406 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
407 ec->reference_count == 1)
408 acpi_ec_enable_gpe(ec, true);
409 }
410
411 static void acpi_ec_complete_request(struct acpi_ec *ec)
412 {
413 bool flushed = false;
414
415 ec->reference_count--;
416 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
417 ec->reference_count == 0)
418 acpi_ec_disable_gpe(ec, true);
419 flushed = acpi_ec_flushed(ec);
420 if (flushed)
421 wake_up(&ec->wait);
422 }
423
424 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
425 {
426 if (!test_bit(flag, &ec->flags)) {
427 acpi_ec_disable_gpe(ec, false);
428 ec_dbg_drv("Polling enabled");
429 set_bit(flag, &ec->flags);
430 }
431 }
432
433 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
434 {
435 if (test_bit(flag, &ec->flags)) {
436 clear_bit(flag, &ec->flags);
437 acpi_ec_enable_gpe(ec, false);
438 ec_dbg_drv("Polling disabled");
439 }
440 }
441
442 /*
443 * acpi_ec_submit_flushable_request() - Increase the reference count unless
444 * the flush operation is not in
445 * progress
446 * @ec: the EC device
447 *
448 * This function must be used before taking a new action that should hold
449 * the reference count. If this function returns false, then the action
450 * must be discarded or it will prevent the flush operation from being
451 * completed.
452 */
453 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
454 {
455 if (!acpi_ec_started(ec))
456 return false;
457 acpi_ec_submit_request(ec);
458 return true;
459 }
460
461 static void acpi_ec_submit_query(struct acpi_ec *ec)
462 {
463 if (acpi_ec_event_enabled(ec) &&
464 !test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
465 ec_dbg_evt("Command(%s) submitted/blocked",
466 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
467 ec->nr_pending_queries++;
468 schedule_work(&ec->work);
469 }
470 }
471
472 static void acpi_ec_complete_query(struct acpi_ec *ec)
473 {
474 if (test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
475 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
476 ec_dbg_evt("Command(%s) unblocked",
477 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
478 }
479 }
480
481 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
482 {
483 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
484 ec_log_drv("event unblocked");
485 if (!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
486 advance_transaction(ec);
487 }
488
489 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
490 {
491 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
492 ec_log_drv("event blocked");
493 }
494
495 /*
496 * Process _Q events that might have accumulated in the EC.
497 * Run with locked ec mutex.
498 */
499 static void acpi_ec_clear(struct acpi_ec *ec)
500 {
501 int i, status;
502 u8 value = 0;
503
504 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
505 status = acpi_ec_query(ec, &value);
506 if (status || !value)
507 break;
508 }
509 if (unlikely(i == ACPI_EC_CLEAR_MAX))
510 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
511 else
512 pr_info("%d stale EC events cleared\n", i);
513 }
514
515 static void acpi_ec_enable_event(struct acpi_ec *ec)
516 {
517 unsigned long flags;
518
519 spin_lock_irqsave(&ec->lock, flags);
520 if (acpi_ec_started(ec))
521 __acpi_ec_enable_event(ec);
522 spin_unlock_irqrestore(&ec->lock, flags);
523
524 /* Drain additional events if hardware requires that */
525 if (EC_FLAGS_CLEAR_ON_RESUME)
526 acpi_ec_clear(ec);
527 }
528
529 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
530 {
531 bool flushed;
532 unsigned long flags;
533
534 spin_lock_irqsave(&ec->lock, flags);
535 flushed = !ec->nr_pending_queries;
536 spin_unlock_irqrestore(&ec->lock, flags);
537 return flushed;
538 }
539
540 static void __acpi_ec_flush_event(struct acpi_ec *ec)
541 {
542 /*
543 * When ec_freeze_events is true, we need to flush events in
544 * the proper position before entering the noirq stage.
545 */
546 wait_event(ec->wait, acpi_ec_query_flushed(ec));
547 if (ec_query_wq)
548 flush_workqueue(ec_query_wq);
549 }
550
551 static void acpi_ec_disable_event(struct acpi_ec *ec)
552 {
553 unsigned long flags;
554
555 spin_lock_irqsave(&ec->lock, flags);
556 __acpi_ec_disable_event(ec);
557 spin_unlock_irqrestore(&ec->lock, flags);
558 __acpi_ec_flush_event(ec);
559 }
560
561 static bool acpi_ec_guard_event(struct acpi_ec *ec)
562 {
563 bool guarded = true;
564 unsigned long flags;
565
566 spin_lock_irqsave(&ec->lock, flags);
567 /*
568 * If firmware SCI_EVT clearing timing is "event", we actually
569 * don't know when the SCI_EVT will be cleared by firmware after
570 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
571 * acceptable period.
572 *
573 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
574 * flagged, which means SCI_EVT check has just been performed.
575 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
576 * guarding should have already been performed (via
577 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
578 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
579 * ACPI_EC_COMMAND_POLL state immediately.
580 */
581 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
582 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
583 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
584 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
585 guarded = false;
586 spin_unlock_irqrestore(&ec->lock, flags);
587 return guarded;
588 }
589
590 static int ec_transaction_polled(struct acpi_ec *ec)
591 {
592 unsigned long flags;
593 int ret = 0;
594
595 spin_lock_irqsave(&ec->lock, flags);
596 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
597 ret = 1;
598 spin_unlock_irqrestore(&ec->lock, flags);
599 return ret;
600 }
601
602 static int ec_transaction_completed(struct acpi_ec *ec)
603 {
604 unsigned long flags;
605 int ret = 0;
606
607 spin_lock_irqsave(&ec->lock, flags);
608 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
609 ret = 1;
610 spin_unlock_irqrestore(&ec->lock, flags);
611 return ret;
612 }
613
614 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
615 {
616 ec->curr->flags |= flag;
617 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
618 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
619 flag == ACPI_EC_COMMAND_POLL)
620 acpi_ec_complete_query(ec);
621 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
622 flag == ACPI_EC_COMMAND_COMPLETE)
623 acpi_ec_complete_query(ec);
624 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
625 flag == ACPI_EC_COMMAND_COMPLETE)
626 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
627 }
628 }
629
630 static void advance_transaction(struct acpi_ec *ec)
631 {
632 struct transaction *t;
633 u8 status;
634 bool wakeup = false;
635
636 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
637 smp_processor_id());
638 /*
639 * By always clearing STS before handling all indications, we can
640 * ensure a hardware STS 0->1 change after this clearing can always
641 * trigger a GPE interrupt.
642 */
643 acpi_ec_clear_gpe(ec);
644 status = acpi_ec_read_status(ec);
645 t = ec->curr;
646 /*
647 * Another IRQ or a guarded polling mode advancement is detected,
648 * the next QR_EC submission is then allowed.
649 */
650 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
651 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
652 (!ec->nr_pending_queries ||
653 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
654 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
655 acpi_ec_complete_query(ec);
656 }
657 }
658 if (!t)
659 goto err;
660 if (t->flags & ACPI_EC_COMMAND_POLL) {
661 if (t->wlen > t->wi) {
662 if ((status & ACPI_EC_FLAG_IBF) == 0)
663 acpi_ec_write_data(ec, t->wdata[t->wi++]);
664 else
665 goto err;
666 } else if (t->rlen > t->ri) {
667 if ((status & ACPI_EC_FLAG_OBF) == 1) {
668 t->rdata[t->ri++] = acpi_ec_read_data(ec);
669 if (t->rlen == t->ri) {
670 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
671 if (t->command == ACPI_EC_COMMAND_QUERY)
672 ec_dbg_evt("Command(%s) completed by hardware",
673 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
674 wakeup = true;
675 }
676 } else
677 goto err;
678 } else if (t->wlen == t->wi &&
679 (status & ACPI_EC_FLAG_IBF) == 0) {
680 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
681 wakeup = true;
682 }
683 goto out;
684 } else {
685 if (EC_FLAGS_QUERY_HANDSHAKE &&
686 !(status & ACPI_EC_FLAG_SCI) &&
687 (t->command == ACPI_EC_COMMAND_QUERY)) {
688 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
689 t->rdata[t->ri++] = 0x00;
690 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
691 ec_dbg_evt("Command(%s) completed by software",
692 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
693 wakeup = true;
694 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
695 acpi_ec_write_cmd(ec, t->command);
696 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
697 } else
698 goto err;
699 goto out;
700 }
701 err:
702 /*
703 * If SCI bit is set, then don't think it's a false IRQ
704 * otherwise will take a not handled IRQ as a false one.
705 */
706 if (!(status & ACPI_EC_FLAG_SCI)) {
707 if (in_interrupt() && t) {
708 if (t->irq_count < ec_storm_threshold)
709 ++t->irq_count;
710 /* Allow triggering on 0 threshold */
711 if (t->irq_count == ec_storm_threshold)
712 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
713 }
714 }
715 out:
716 if (status & ACPI_EC_FLAG_SCI)
717 acpi_ec_submit_query(ec);
718 if (wakeup && in_interrupt())
719 wake_up(&ec->wait);
720 }
721
722 static void start_transaction(struct acpi_ec *ec)
723 {
724 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
725 ec->curr->flags = 0;
726 }
727
728 static int ec_guard(struct acpi_ec *ec)
729 {
730 unsigned long guard = usecs_to_jiffies(ec_polling_guard);
731 unsigned long timeout = ec->timestamp + guard;
732
733 /* Ensure guarding period before polling EC status */
734 do {
735 if (ec_busy_polling) {
736 /* Perform busy polling */
737 if (ec_transaction_completed(ec))
738 return 0;
739 udelay(jiffies_to_usecs(guard));
740 } else {
741 /*
742 * Perform wait polling
743 * 1. Wait the transaction to be completed by the
744 * GPE handler after the transaction enters
745 * ACPI_EC_COMMAND_POLL state.
746 * 2. A special guarding logic is also required
747 * for event clearing mode "event" before the
748 * transaction enters ACPI_EC_COMMAND_POLL
749 * state.
750 */
751 if (!ec_transaction_polled(ec) &&
752 !acpi_ec_guard_event(ec))
753 break;
754 if (wait_event_timeout(ec->wait,
755 ec_transaction_completed(ec),
756 guard))
757 return 0;
758 }
759 } while (time_before(jiffies, timeout));
760 return -ETIME;
761 }
762
763 static int ec_poll(struct acpi_ec *ec)
764 {
765 unsigned long flags;
766 int repeat = 5; /* number of command restarts */
767
768 while (repeat--) {
769 unsigned long delay = jiffies +
770 msecs_to_jiffies(ec_delay);
771 do {
772 if (!ec_guard(ec))
773 return 0;
774 spin_lock_irqsave(&ec->lock, flags);
775 advance_transaction(ec);
776 spin_unlock_irqrestore(&ec->lock, flags);
777 } while (time_before(jiffies, delay));
778 pr_debug("controller reset, restart transaction\n");
779 spin_lock_irqsave(&ec->lock, flags);
780 start_transaction(ec);
781 spin_unlock_irqrestore(&ec->lock, flags);
782 }
783 return -ETIME;
784 }
785
786 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
787 struct transaction *t)
788 {
789 unsigned long tmp;
790 int ret = 0;
791
792 /* start transaction */
793 spin_lock_irqsave(&ec->lock, tmp);
794 /* Enable GPE for command processing (IBF=0/OBF=1) */
795 if (!acpi_ec_submit_flushable_request(ec)) {
796 ret = -EINVAL;
797 goto unlock;
798 }
799 ec_dbg_ref(ec, "Increase command");
800 /* following two actions should be kept atomic */
801 ec->curr = t;
802 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
803 start_transaction(ec);
804 spin_unlock_irqrestore(&ec->lock, tmp);
805
806 ret = ec_poll(ec);
807
808 spin_lock_irqsave(&ec->lock, tmp);
809 if (t->irq_count == ec_storm_threshold)
810 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
811 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
812 ec->curr = NULL;
813 /* Disable GPE for command processing (IBF=0/OBF=1) */
814 acpi_ec_complete_request(ec);
815 ec_dbg_ref(ec, "Decrease command");
816 unlock:
817 spin_unlock_irqrestore(&ec->lock, tmp);
818 return ret;
819 }
820
821 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
822 {
823 int status;
824 u32 glk;
825
826 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
827 return -EINVAL;
828 if (t->rdata)
829 memset(t->rdata, 0, t->rlen);
830
831 mutex_lock(&ec->mutex);
832 if (ec->global_lock) {
833 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
834 if (ACPI_FAILURE(status)) {
835 status = -ENODEV;
836 goto unlock;
837 }
838 }
839
840 status = acpi_ec_transaction_unlocked(ec, t);
841
842 if (ec->global_lock)
843 acpi_release_global_lock(glk);
844 unlock:
845 mutex_unlock(&ec->mutex);
846 return status;
847 }
848
849 static int acpi_ec_burst_enable(struct acpi_ec *ec)
850 {
851 u8 d;
852 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
853 .wdata = NULL, .rdata = &d,
854 .wlen = 0, .rlen = 1};
855
856 return acpi_ec_transaction(ec, &t);
857 }
858
859 static int acpi_ec_burst_disable(struct acpi_ec *ec)
860 {
861 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
862 .wdata = NULL, .rdata = NULL,
863 .wlen = 0, .rlen = 0};
864
865 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
866 acpi_ec_transaction(ec, &t) : 0;
867 }
868
869 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
870 {
871 int result;
872 u8 d;
873 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
874 .wdata = &address, .rdata = &d,
875 .wlen = 1, .rlen = 1};
876
877 result = acpi_ec_transaction(ec, &t);
878 *data = d;
879 return result;
880 }
881
882 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
883 {
884 u8 wdata[2] = { address, data };
885 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
886 .wdata = wdata, .rdata = NULL,
887 .wlen = 2, .rlen = 0};
888
889 return acpi_ec_transaction(ec, &t);
890 }
891
892 int ec_read(u8 addr, u8 *val)
893 {
894 int err;
895 u8 temp_data;
896
897 if (!first_ec)
898 return -ENODEV;
899
900 err = acpi_ec_read(first_ec, addr, &temp_data);
901
902 if (!err) {
903 *val = temp_data;
904 return 0;
905 }
906 return err;
907 }
908 EXPORT_SYMBOL(ec_read);
909
910 int ec_write(u8 addr, u8 val)
911 {
912 int err;
913
914 if (!first_ec)
915 return -ENODEV;
916
917 err = acpi_ec_write(first_ec, addr, val);
918
919 return err;
920 }
921 EXPORT_SYMBOL(ec_write);
922
923 int ec_transaction(u8 command,
924 const u8 *wdata, unsigned wdata_len,
925 u8 *rdata, unsigned rdata_len)
926 {
927 struct transaction t = {.command = command,
928 .wdata = wdata, .rdata = rdata,
929 .wlen = wdata_len, .rlen = rdata_len};
930
931 if (!first_ec)
932 return -ENODEV;
933
934 return acpi_ec_transaction(first_ec, &t);
935 }
936 EXPORT_SYMBOL(ec_transaction);
937
938 /* Get the handle to the EC device */
939 acpi_handle ec_get_handle(void)
940 {
941 if (!first_ec)
942 return NULL;
943 return first_ec->handle;
944 }
945 EXPORT_SYMBOL(ec_get_handle);
946
947 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
948 {
949 unsigned long flags;
950
951 spin_lock_irqsave(&ec->lock, flags);
952 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
953 ec_dbg_drv("Starting EC");
954 /* Enable GPE for event processing (SCI_EVT=1) */
955 if (!resuming) {
956 acpi_ec_submit_request(ec);
957 ec_dbg_ref(ec, "Increase driver");
958 }
959 ec_log_drv("EC started");
960 }
961 spin_unlock_irqrestore(&ec->lock, flags);
962 }
963
964 static bool acpi_ec_stopped(struct acpi_ec *ec)
965 {
966 unsigned long flags;
967 bool flushed;
968
969 spin_lock_irqsave(&ec->lock, flags);
970 flushed = acpi_ec_flushed(ec);
971 spin_unlock_irqrestore(&ec->lock, flags);
972 return flushed;
973 }
974
975 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
976 {
977 unsigned long flags;
978
979 spin_lock_irqsave(&ec->lock, flags);
980 if (acpi_ec_started(ec)) {
981 ec_dbg_drv("Stopping EC");
982 set_bit(EC_FLAGS_STOPPED, &ec->flags);
983 spin_unlock_irqrestore(&ec->lock, flags);
984 wait_event(ec->wait, acpi_ec_stopped(ec));
985 spin_lock_irqsave(&ec->lock, flags);
986 /* Disable GPE for event processing (SCI_EVT=1) */
987 if (!suspending) {
988 acpi_ec_complete_request(ec);
989 ec_dbg_ref(ec, "Decrease driver");
990 } else if (!ec_freeze_events)
991 __acpi_ec_disable_event(ec);
992 clear_bit(EC_FLAGS_STARTED, &ec->flags);
993 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
994 ec_log_drv("EC stopped");
995 }
996 spin_unlock_irqrestore(&ec->lock, flags);
997 }
998
999 void acpi_ec_block_transactions(void)
1000 {
1001 struct acpi_ec *ec = first_ec;
1002
1003 if (!ec)
1004 return;
1005
1006 mutex_lock(&ec->mutex);
1007 /* Prevent transactions from being carried out */
1008 acpi_ec_stop(ec, true);
1009 mutex_unlock(&ec->mutex);
1010 }
1011
1012 void acpi_ec_unblock_transactions(void)
1013 {
1014 /*
1015 * Allow transactions to happen again (this function is called from
1016 * atomic context during wakeup, so we don't need to acquire the mutex).
1017 */
1018 if (first_ec)
1019 acpi_ec_start(first_ec, true);
1020 }
1021
1022 /* --------------------------------------------------------------------------
1023 Event Management
1024 -------------------------------------------------------------------------- */
1025 static struct acpi_ec_query_handler *
1026 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1027 {
1028 if (handler)
1029 kref_get(&handler->kref);
1030 return handler;
1031 }
1032
1033 static struct acpi_ec_query_handler *
1034 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1035 {
1036 struct acpi_ec_query_handler *handler;
1037 bool found = false;
1038
1039 mutex_lock(&ec->mutex);
1040 list_for_each_entry(handler, &ec->list, node) {
1041 if (value == handler->query_bit) {
1042 found = true;
1043 break;
1044 }
1045 }
1046 mutex_unlock(&ec->mutex);
1047 return found ? acpi_ec_get_query_handler(handler) : NULL;
1048 }
1049
1050 static void acpi_ec_query_handler_release(struct kref *kref)
1051 {
1052 struct acpi_ec_query_handler *handler =
1053 container_of(kref, struct acpi_ec_query_handler, kref);
1054
1055 kfree(handler);
1056 }
1057
1058 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1059 {
1060 kref_put(&handler->kref, acpi_ec_query_handler_release);
1061 }
1062
1063 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1064 acpi_handle handle, acpi_ec_query_func func,
1065 void *data)
1066 {
1067 struct acpi_ec_query_handler *handler =
1068 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1069
1070 if (!handler)
1071 return -ENOMEM;
1072
1073 handler->query_bit = query_bit;
1074 handler->handle = handle;
1075 handler->func = func;
1076 handler->data = data;
1077 mutex_lock(&ec->mutex);
1078 kref_init(&handler->kref);
1079 list_add(&handler->node, &ec->list);
1080 mutex_unlock(&ec->mutex);
1081 return 0;
1082 }
1083 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1084
1085 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1086 bool remove_all, u8 query_bit)
1087 {
1088 struct acpi_ec_query_handler *handler, *tmp;
1089 LIST_HEAD(free_list);
1090
1091 mutex_lock(&ec->mutex);
1092 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1093 if (remove_all || query_bit == handler->query_bit) {
1094 list_del_init(&handler->node);
1095 list_add(&handler->node, &free_list);
1096 }
1097 }
1098 mutex_unlock(&ec->mutex);
1099 list_for_each_entry_safe(handler, tmp, &free_list, node)
1100 acpi_ec_put_query_handler(handler);
1101 }
1102
1103 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1104 {
1105 acpi_ec_remove_query_handlers(ec, false, query_bit);
1106 }
1107 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1108
1109 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1110 {
1111 struct acpi_ec_query *q;
1112 struct transaction *t;
1113
1114 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1115 if (!q)
1116 return NULL;
1117 INIT_WORK(&q->work, acpi_ec_event_processor);
1118 t = &q->transaction;
1119 t->command = ACPI_EC_COMMAND_QUERY;
1120 t->rdata = pval;
1121 t->rlen = 1;
1122 return q;
1123 }
1124
1125 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1126 {
1127 if (q) {
1128 if (q->handler)
1129 acpi_ec_put_query_handler(q->handler);
1130 kfree(q);
1131 }
1132 }
1133
1134 static void acpi_ec_event_processor(struct work_struct *work)
1135 {
1136 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1137 struct acpi_ec_query_handler *handler = q->handler;
1138
1139 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1140 if (handler->func)
1141 handler->func(handler->data);
1142 else if (handler->handle)
1143 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1144 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1145 acpi_ec_delete_query(q);
1146 }
1147
1148 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1149 {
1150 u8 value = 0;
1151 int result;
1152 struct acpi_ec_query *q;
1153
1154 q = acpi_ec_create_query(&value);
1155 if (!q)
1156 return -ENOMEM;
1157
1158 /*
1159 * Query the EC to find out which _Qxx method we need to evaluate.
1160 * Note that successful completion of the query causes the ACPI_EC_SCI
1161 * bit to be cleared (and thus clearing the interrupt source).
1162 */
1163 result = acpi_ec_transaction(ec, &q->transaction);
1164 if (!value)
1165 result = -ENODATA;
1166 if (result)
1167 goto err_exit;
1168
1169 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1170 if (!q->handler) {
1171 result = -ENODATA;
1172 goto err_exit;
1173 }
1174
1175 /*
1176 * It is reported that _Qxx are evaluated in a parallel way on
1177 * Windows:
1178 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1179 *
1180 * Put this log entry before schedule_work() in order to make
1181 * it appearing before any other log entries occurred during the
1182 * work queue execution.
1183 */
1184 ec_dbg_evt("Query(0x%02x) scheduled", value);
1185 if (!queue_work(ec_query_wq, &q->work)) {
1186 ec_dbg_evt("Query(0x%02x) overlapped", value);
1187 result = -EBUSY;
1188 }
1189
1190 err_exit:
1191 if (result)
1192 acpi_ec_delete_query(q);
1193 if (data)
1194 *data = value;
1195 return result;
1196 }
1197
1198 static void acpi_ec_check_event(struct acpi_ec *ec)
1199 {
1200 unsigned long flags;
1201
1202 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1203 if (ec_guard(ec)) {
1204 spin_lock_irqsave(&ec->lock, flags);
1205 /*
1206 * Take care of the SCI_EVT unless no one else is
1207 * taking care of it.
1208 */
1209 if (!ec->curr)
1210 advance_transaction(ec);
1211 spin_unlock_irqrestore(&ec->lock, flags);
1212 }
1213 }
1214 }
1215
1216 static void acpi_ec_event_handler(struct work_struct *work)
1217 {
1218 unsigned long flags;
1219 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1220
1221 ec_dbg_evt("Event started");
1222
1223 spin_lock_irqsave(&ec->lock, flags);
1224 while (ec->nr_pending_queries) {
1225 spin_unlock_irqrestore(&ec->lock, flags);
1226 (void)acpi_ec_query(ec, NULL);
1227 spin_lock_irqsave(&ec->lock, flags);
1228 ec->nr_pending_queries--;
1229 /*
1230 * Before exit, make sure that this work item can be
1231 * scheduled again. There might be QR_EC failures, leaving
1232 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1233 * item from being scheduled again.
1234 */
1235 if (!ec->nr_pending_queries) {
1236 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1237 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1238 acpi_ec_complete_query(ec);
1239 }
1240 }
1241 spin_unlock_irqrestore(&ec->lock, flags);
1242
1243 ec_dbg_evt("Event stopped");
1244
1245 acpi_ec_check_event(ec);
1246 }
1247
1248 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1249 u32 gpe_number, void *data)
1250 {
1251 unsigned long flags;
1252 struct acpi_ec *ec = data;
1253
1254 spin_lock_irqsave(&ec->lock, flags);
1255 advance_transaction(ec);
1256 spin_unlock_irqrestore(&ec->lock, flags);
1257 return ACPI_INTERRUPT_HANDLED;
1258 }
1259
1260 /* --------------------------------------------------------------------------
1261 * Address Space Management
1262 * -------------------------------------------------------------------------- */
1263
1264 static acpi_status
1265 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1266 u32 bits, u64 *value64,
1267 void *handler_context, void *region_context)
1268 {
1269 struct acpi_ec *ec = handler_context;
1270 int result = 0, i, bytes = bits / 8;
1271 u8 *value = (u8 *)value64;
1272
1273 if ((address > 0xFF) || !value || !handler_context)
1274 return AE_BAD_PARAMETER;
1275
1276 if (function != ACPI_READ && function != ACPI_WRITE)
1277 return AE_BAD_PARAMETER;
1278
1279 if (ec_busy_polling || bits > 8)
1280 acpi_ec_burst_enable(ec);
1281
1282 for (i = 0; i < bytes; ++i, ++address, ++value)
1283 result = (function == ACPI_READ) ?
1284 acpi_ec_read(ec, address, value) :
1285 acpi_ec_write(ec, address, *value);
1286
1287 if (ec_busy_polling || bits > 8)
1288 acpi_ec_burst_disable(ec);
1289
1290 switch (result) {
1291 case -EINVAL:
1292 return AE_BAD_PARAMETER;
1293 case -ENODEV:
1294 return AE_NOT_FOUND;
1295 case -ETIME:
1296 return AE_TIME;
1297 default:
1298 return AE_OK;
1299 }
1300 }
1301
1302 /* --------------------------------------------------------------------------
1303 * Driver Interface
1304 * -------------------------------------------------------------------------- */
1305
1306 static acpi_status
1307 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1308
1309 static void acpi_ec_free(struct acpi_ec *ec)
1310 {
1311 if (first_ec == ec)
1312 first_ec = NULL;
1313 if (boot_ec == ec)
1314 boot_ec = NULL;
1315 kfree(ec);
1316 }
1317
1318 static struct acpi_ec *acpi_ec_alloc(void)
1319 {
1320 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1321
1322 if (!ec)
1323 return NULL;
1324 mutex_init(&ec->mutex);
1325 init_waitqueue_head(&ec->wait);
1326 INIT_LIST_HEAD(&ec->list);
1327 spin_lock_init(&ec->lock);
1328 INIT_WORK(&ec->work, acpi_ec_event_handler);
1329 ec->timestamp = jiffies;
1330 return ec;
1331 }
1332
1333 static acpi_status
1334 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1335 void *context, void **return_value)
1336 {
1337 char node_name[5];
1338 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1339 struct acpi_ec *ec = context;
1340 int value = 0;
1341 acpi_status status;
1342
1343 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1344
1345 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1346 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1347 return AE_OK;
1348 }
1349
1350 static acpi_status
1351 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1352 {
1353 acpi_status status;
1354 unsigned long long tmp = 0;
1355 struct acpi_ec *ec = context;
1356
1357 /* clear addr values, ec_parse_io_ports depend on it */
1358 ec->command_addr = ec->data_addr = 0;
1359
1360 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1361 ec_parse_io_ports, ec);
1362 if (ACPI_FAILURE(status))
1363 return status;
1364
1365 /* Get GPE bit assignment (EC events). */
1366 /* TODO: Add support for _GPE returning a package */
1367 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1368 if (ACPI_FAILURE(status))
1369 return status;
1370 ec->gpe = tmp;
1371 /* Use the global lock for all EC transactions? */
1372 tmp = 0;
1373 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1374 ec->global_lock = tmp;
1375 ec->handle = handle;
1376 return AE_CTRL_TERMINATE;
1377 }
1378
1379 /*
1380 * Note: This function returns an error code only when the address space
1381 * handler is not installed, which means "not able to handle
1382 * transactions".
1383 */
1384 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1385 {
1386 acpi_status status;
1387
1388 acpi_ec_start(ec, false);
1389
1390 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1391 status = acpi_install_address_space_handler(ec->handle,
1392 ACPI_ADR_SPACE_EC,
1393 &acpi_ec_space_handler,
1394 NULL, ec);
1395 if (ACPI_FAILURE(status)) {
1396 if (status == AE_NOT_FOUND) {
1397 /*
1398 * Maybe OS fails in evaluating the _REG
1399 * object. The AE_NOT_FOUND error will be
1400 * ignored and OS * continue to initialize
1401 * EC.
1402 */
1403 pr_err("Fail in evaluating the _REG object"
1404 " of EC device. Broken bios is suspected.\n");
1405 } else {
1406 acpi_ec_stop(ec, false);
1407 return -ENODEV;
1408 }
1409 }
1410 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1411 }
1412
1413 if (!handle_events)
1414 return 0;
1415
1416 if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1417 /* Find and register all query methods */
1418 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1419 acpi_ec_register_query_methods,
1420 NULL, ec, NULL);
1421 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1422 }
1423 if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1424 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1425 ACPI_GPE_EDGE_TRIGGERED,
1426 &acpi_ec_gpe_handler, ec);
1427 /* This is not fatal as we can poll EC events */
1428 if (ACPI_SUCCESS(status)) {
1429 set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1430 if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1431 ec->reference_count >= 1)
1432 acpi_ec_enable_gpe(ec, true);
1433
1434 /* EC is fully operational, allow queries */
1435 acpi_ec_enable_event(ec);
1436 }
1437 }
1438
1439 return 0;
1440 }
1441
1442 static void ec_remove_handlers(struct acpi_ec *ec)
1443 {
1444 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1445 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1446 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1447 pr_err("failed to remove space handler\n");
1448 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1449 }
1450
1451 /*
1452 * Stops handling the EC transactions after removing the operation
1453 * region handler. This is required because _REG(DISCONNECT)
1454 * invoked during the removal can result in new EC transactions.
1455 *
1456 * Flushes the EC requests and thus disables the GPE before
1457 * removing the GPE handler. This is required by the current ACPICA
1458 * GPE core. ACPICA GPE core will automatically disable a GPE when
1459 * it is indicated but there is no way to handle it. So the drivers
1460 * must disable the GPEs prior to removing the GPE handlers.
1461 */
1462 acpi_ec_stop(ec, false);
1463
1464 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1465 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1466 &acpi_ec_gpe_handler)))
1467 pr_err("failed to remove gpe handler\n");
1468 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1469 }
1470 if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1471 acpi_ec_remove_query_handlers(ec, true, 0);
1472 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1473 }
1474 }
1475
1476 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1477 {
1478 int ret;
1479
1480 ret = ec_install_handlers(ec, handle_events);
1481 if (ret)
1482 return ret;
1483
1484 /* First EC capable of handling transactions */
1485 if (!first_ec) {
1486 first_ec = ec;
1487 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1488 }
1489
1490 acpi_handle_info(ec->handle,
1491 "GPE=0x%lx, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1492 ec->gpe, ec->command_addr, ec->data_addr);
1493 return ret;
1494 }
1495
1496 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1497 bool handle_events, bool is_ecdt)
1498 {
1499 int ret;
1500
1501 /*
1502 * Changing the ACPI handle results in a re-configuration of the
1503 * boot EC. And if it happens after the namespace initialization,
1504 * it causes _REG evaluations.
1505 */
1506 if (boot_ec && boot_ec->handle != handle)
1507 ec_remove_handlers(boot_ec);
1508
1509 /* Unset old boot EC */
1510 if (boot_ec != ec)
1511 acpi_ec_free(boot_ec);
1512
1513 /*
1514 * ECDT device creation is split into acpi_ec_ecdt_probe() and
1515 * acpi_ec_ecdt_start(). This function takes care of completing the
1516 * ECDT parsing logic as the handle update should be performed
1517 * between the installation/uninstallation of the handlers.
1518 */
1519 if (ec->handle != handle)
1520 ec->handle = handle;
1521
1522 ret = acpi_ec_setup(ec, handle_events);
1523 if (ret)
1524 return ret;
1525
1526 /* Set new boot EC */
1527 if (!boot_ec) {
1528 boot_ec = ec;
1529 boot_ec_is_ecdt = is_ecdt;
1530 }
1531
1532 acpi_handle_info(boot_ec->handle,
1533 "Used as boot %s EC to handle transactions%s\n",
1534 is_ecdt ? "ECDT" : "DSDT",
1535 handle_events ? " and events" : "");
1536 return ret;
1537 }
1538
1539 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1540 {
1541 struct acpi_table_ecdt *ecdt_ptr;
1542 acpi_status status;
1543 acpi_handle handle;
1544
1545 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1546 (struct acpi_table_header **)&ecdt_ptr);
1547 if (ACPI_FAILURE(status))
1548 return false;
1549
1550 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1551 if (ACPI_FAILURE(status))
1552 return false;
1553
1554 *phandle = handle;
1555 return true;
1556 }
1557
1558 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1559 {
1560 if (!boot_ec)
1561 return false;
1562 if (ec->handle == boot_ec->handle &&
1563 ec->gpe == boot_ec->gpe &&
1564 ec->command_addr == boot_ec->command_addr &&
1565 ec->data_addr == boot_ec->data_addr)
1566 return true;
1567 return false;
1568 }
1569
1570 static int acpi_ec_add(struct acpi_device *device)
1571 {
1572 struct acpi_ec *ec = NULL;
1573 int ret;
1574
1575 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1576 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1577
1578 ec = acpi_ec_alloc();
1579 if (!ec)
1580 return -ENOMEM;
1581 if (ec_parse_device(device->handle, 0, ec, NULL) !=
1582 AE_CTRL_TERMINATE) {
1583 ret = -EINVAL;
1584 goto err_alloc;
1585 }
1586
1587 if (acpi_is_boot_ec(ec)) {
1588 boot_ec_is_ecdt = false;
1589 acpi_handle_debug(ec->handle, "duplicated.\n");
1590 acpi_ec_free(ec);
1591 ec = boot_ec;
1592 ret = acpi_config_boot_ec(ec, ec->handle, true, false);
1593 } else
1594 ret = acpi_ec_setup(ec, true);
1595 if (ret)
1596 goto err_query;
1597
1598 device->driver_data = ec;
1599
1600 ret = !!request_region(ec->data_addr, 1, "EC data");
1601 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1602 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1603 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1604
1605 /* Reprobe devices depending on the EC */
1606 acpi_walk_dep_device_list(ec->handle);
1607 acpi_handle_debug(ec->handle, "enumerated.\n");
1608 return 0;
1609
1610 err_query:
1611 if (ec != boot_ec)
1612 acpi_ec_remove_query_handlers(ec, true, 0);
1613 err_alloc:
1614 if (ec != boot_ec)
1615 acpi_ec_free(ec);
1616 return ret;
1617 }
1618
1619 static int acpi_ec_remove(struct acpi_device *device)
1620 {
1621 struct acpi_ec *ec;
1622
1623 if (!device)
1624 return -EINVAL;
1625
1626 ec = acpi_driver_data(device);
1627 release_region(ec->data_addr, 1);
1628 release_region(ec->command_addr, 1);
1629 device->driver_data = NULL;
1630 if (ec != boot_ec) {
1631 ec_remove_handlers(ec);
1632 acpi_ec_free(ec);
1633 }
1634 return 0;
1635 }
1636
1637 static acpi_status
1638 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1639 {
1640 struct acpi_ec *ec = context;
1641
1642 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1643 return AE_OK;
1644
1645 /*
1646 * The first address region returned is the data port, and
1647 * the second address region returned is the status/command
1648 * port.
1649 */
1650 if (ec->data_addr == 0)
1651 ec->data_addr = resource->data.io.minimum;
1652 else if (ec->command_addr == 0)
1653 ec->command_addr = resource->data.io.minimum;
1654 else
1655 return AE_CTRL_TERMINATE;
1656
1657 return AE_OK;
1658 }
1659
1660 static const struct acpi_device_id ec_device_ids[] = {
1661 {"PNP0C09", 0},
1662 {"", 0},
1663 };
1664
1665 int __init acpi_ec_dsdt_probe(void)
1666 {
1667 acpi_status status;
1668 struct acpi_ec *ec;
1669 int ret;
1670
1671 ec = acpi_ec_alloc();
1672 if (!ec)
1673 return -ENOMEM;
1674 /*
1675 * At this point, the namespace is initialized, so start to find
1676 * the namespace objects.
1677 */
1678 status = acpi_get_devices(ec_device_ids[0].id,
1679 ec_parse_device, ec, NULL);
1680 if (ACPI_FAILURE(status) || !ec->handle) {
1681 ret = -ENODEV;
1682 goto error;
1683 }
1684 /*
1685 * When the DSDT EC is available, always re-configure boot EC to
1686 * have _REG evaluated. _REG can only be evaluated after the
1687 * namespace initialization.
1688 * At this point, the GPE is not fully initialized, so do not to
1689 * handle the events.
1690 */
1691 ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1692 error:
1693 if (ret)
1694 acpi_ec_free(ec);
1695 return ret;
1696 }
1697
1698 /*
1699 * If the DSDT EC is not functioning, we still need to prepare a fully
1700 * functioning ECDT EC first in order to handle the events.
1701 * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1702 */
1703 int __init acpi_ec_ecdt_start(void)
1704 {
1705 acpi_handle handle;
1706
1707 if (!boot_ec)
1708 return -ENODEV;
1709 /*
1710 * The DSDT EC should have already been started in
1711 * acpi_ec_add().
1712 */
1713 if (!boot_ec_is_ecdt)
1714 return -ENODEV;
1715
1716 /*
1717 * At this point, the namespace and the GPE is initialized, so
1718 * start to find the namespace objects and handle the events.
1719 */
1720 if (!acpi_ec_ecdt_get_handle(&handle))
1721 return -ENODEV;
1722 return acpi_config_boot_ec(boot_ec, handle, true, true);
1723 }
1724
1725 #if 0
1726 /*
1727 * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1728 * set, for which case, we complete the QR_EC without issuing it to the
1729 * firmware.
1730 * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1731 * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1732 */
1733 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1734 {
1735 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1736 EC_FLAGS_QUERY_HANDSHAKE = 1;
1737 return 0;
1738 }
1739 #endif
1740
1741 /*
1742 * On some hardware it is necessary to clear events accumulated by the EC during
1743 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1744 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1745 *
1746 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1747 *
1748 * Ideally, the EC should also be instructed NOT to accumulate events during
1749 * sleep (which Windows seems to do somehow), but the interface to control this
1750 * behaviour is not known at this time.
1751 *
1752 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1753 * however it is very likely that other Samsung models are affected.
1754 *
1755 * On systems which don't accumulate _Q events during sleep, this extra check
1756 * should be harmless.
1757 */
1758 static int ec_clear_on_resume(const struct dmi_system_id *id)
1759 {
1760 pr_debug("Detected system needing EC poll on resume.\n");
1761 EC_FLAGS_CLEAR_ON_RESUME = 1;
1762 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1763 return 0;
1764 }
1765
1766 /*
1767 * Some ECDTs contain wrong register addresses.
1768 * MSI MS-171F
1769 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1770 */
1771 static int ec_correct_ecdt(const struct dmi_system_id *id)
1772 {
1773 pr_debug("Detected system needing ECDT address correction.\n");
1774 EC_FLAGS_CORRECT_ECDT = 1;
1775 return 0;
1776 }
1777
1778 static struct dmi_system_id ec_dmi_table[] __initdata = {
1779 {
1780 ec_correct_ecdt, "MSI MS-171F", {
1781 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1782 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1783 {
1784 ec_clear_on_resume, "Samsung hardware", {
1785 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1786 {},
1787 };
1788
1789 int __init acpi_ec_ecdt_probe(void)
1790 {
1791 int ret;
1792 acpi_status status;
1793 struct acpi_table_ecdt *ecdt_ptr;
1794 struct acpi_ec *ec;
1795
1796 ec = acpi_ec_alloc();
1797 if (!ec)
1798 return -ENOMEM;
1799 /*
1800 * Generate a boot ec context
1801 */
1802 dmi_check_system(ec_dmi_table);
1803 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1804 (struct acpi_table_header **)&ecdt_ptr);
1805 if (ACPI_FAILURE(status)) {
1806 ret = -ENODEV;
1807 goto error;
1808 }
1809
1810 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1811 /*
1812 * Asus X50GL:
1813 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1814 */
1815 ret = -ENODEV;
1816 goto error;
1817 }
1818
1819 if (EC_FLAGS_CORRECT_ECDT) {
1820 ec->command_addr = ecdt_ptr->data.address;
1821 ec->data_addr = ecdt_ptr->control.address;
1822 } else {
1823 ec->command_addr = ecdt_ptr->control.address;
1824 ec->data_addr = ecdt_ptr->data.address;
1825 }
1826 ec->gpe = ecdt_ptr->gpe;
1827
1828 /*
1829 * At this point, the namespace is not initialized, so do not find
1830 * the namespace objects, or handle the events.
1831 */
1832 ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1833 error:
1834 if (ret)
1835 acpi_ec_free(ec);
1836 return ret;
1837 }
1838
1839 #ifdef CONFIG_PM_SLEEP
1840 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1841 {
1842 unsigned long flags;
1843
1844 if (ec == first_ec) {
1845 spin_lock_irqsave(&ec->lock, flags);
1846 ec->saved_busy_polling = ec_busy_polling;
1847 ec->saved_polling_guard = ec_polling_guard;
1848 ec_busy_polling = true;
1849 ec_polling_guard = 0;
1850 ec_log_drv("interrupt blocked");
1851 spin_unlock_irqrestore(&ec->lock, flags);
1852 }
1853 }
1854
1855 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1856 {
1857 unsigned long flags;
1858
1859 if (ec == first_ec) {
1860 spin_lock_irqsave(&ec->lock, flags);
1861 ec_busy_polling = ec->saved_busy_polling;
1862 ec_polling_guard = ec->saved_polling_guard;
1863 ec_log_drv("interrupt unblocked");
1864 spin_unlock_irqrestore(&ec->lock, flags);
1865 }
1866 }
1867
1868 static int acpi_ec_suspend_noirq(struct device *dev)
1869 {
1870 struct acpi_ec *ec =
1871 acpi_driver_data(to_acpi_device(dev));
1872
1873 acpi_ec_enter_noirq(ec);
1874 return 0;
1875 }
1876
1877 static int acpi_ec_resume_noirq(struct device *dev)
1878 {
1879 struct acpi_ec *ec =
1880 acpi_driver_data(to_acpi_device(dev));
1881
1882 acpi_ec_leave_noirq(ec);
1883 return 0;
1884 }
1885
1886 static int acpi_ec_suspend(struct device *dev)
1887 {
1888 struct acpi_ec *ec =
1889 acpi_driver_data(to_acpi_device(dev));
1890
1891 if (ec_freeze_events)
1892 acpi_ec_disable_event(ec);
1893 return 0;
1894 }
1895
1896 static int acpi_ec_resume(struct device *dev)
1897 {
1898 struct acpi_ec *ec =
1899 acpi_driver_data(to_acpi_device(dev));
1900
1901 acpi_ec_enable_event(ec);
1902 return 0;
1903 }
1904 #endif
1905
1906 static const struct dev_pm_ops acpi_ec_pm = {
1907 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1908 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1909 };
1910
1911 static int param_set_event_clearing(const char *val, struct kernel_param *kp)
1912 {
1913 int result = 0;
1914
1915 if (!strncmp(val, "status", sizeof("status") - 1)) {
1916 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1917 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1918 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1919 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1920 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1921 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1922 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1923 pr_info("Assuming SCI_EVT clearing on event reads\n");
1924 } else
1925 result = -EINVAL;
1926 return result;
1927 }
1928
1929 static int param_get_event_clearing(char *buffer, struct kernel_param *kp)
1930 {
1931 switch (ec_event_clearing) {
1932 case ACPI_EC_EVT_TIMING_STATUS:
1933 return sprintf(buffer, "status");
1934 case ACPI_EC_EVT_TIMING_QUERY:
1935 return sprintf(buffer, "query");
1936 case ACPI_EC_EVT_TIMING_EVENT:
1937 return sprintf(buffer, "event");
1938 default:
1939 return sprintf(buffer, "invalid");
1940 }
1941 return 0;
1942 }
1943
1944 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
1945 NULL, 0644);
1946 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
1947
1948 static struct acpi_driver acpi_ec_driver = {
1949 .name = "ec",
1950 .class = ACPI_EC_CLASS,
1951 .ids = ec_device_ids,
1952 .ops = {
1953 .add = acpi_ec_add,
1954 .remove = acpi_ec_remove,
1955 },
1956 .drv.pm = &acpi_ec_pm,
1957 };
1958
1959 static inline int acpi_ec_query_init(void)
1960 {
1961 if (!ec_query_wq) {
1962 ec_query_wq = alloc_workqueue("kec_query", 0,
1963 ec_max_queries);
1964 if (!ec_query_wq)
1965 return -ENODEV;
1966 }
1967 return 0;
1968 }
1969
1970 static inline void acpi_ec_query_exit(void)
1971 {
1972 if (ec_query_wq) {
1973 destroy_workqueue(ec_query_wq);
1974 ec_query_wq = NULL;
1975 }
1976 }
1977
1978 int __init acpi_ec_init(void)
1979 {
1980 int result;
1981
1982 /* register workqueue for _Qxx evaluations */
1983 result = acpi_ec_query_init();
1984 if (result)
1985 goto err_exit;
1986 /* Now register the driver for the EC */
1987 result = acpi_bus_register_driver(&acpi_ec_driver);
1988 if (result)
1989 goto err_exit;
1990
1991 err_exit:
1992 if (result)
1993 acpi_ec_query_exit();
1994 return result;
1995 }
1996
1997 /* EC driver currently not unloadable */
1998 #if 0
1999 static void __exit acpi_ec_exit(void)
2000 {
2001
2002 acpi_bus_unregister_driver(&acpi_ec_driver);
2003 acpi_ec_query_exit();
2004 }
2005 #endif /* 0 */
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