Merge tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu...
[sfrench/cifs-2.6.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_GPE_MASKED,            /* GPE masked */
116 };
117
118 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
119 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
120
121 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
122 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
123 module_param(ec_delay, uint, 0644);
124 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
125
126 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
127 module_param(ec_max_queries, uint, 0644);
128 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
129
130 static bool ec_busy_polling __read_mostly;
131 module_param(ec_busy_polling, bool, 0644);
132 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
133
134 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
135 module_param(ec_polling_guard, uint, 0644);
136 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
137
138 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
139
140 /*
141  * If the number of false interrupts per one transaction exceeds
142  * this threshold, will think there is a GPE storm happened and
143  * will disable the GPE for normal transaction.
144  */
145 static unsigned int ec_storm_threshold  __read_mostly = 8;
146 module_param(ec_storm_threshold, uint, 0644);
147 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
148
149 static bool ec_freeze_events __read_mostly = false;
150 module_param(ec_freeze_events, bool, 0644);
151 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
152
153 static bool ec_no_wakeup __read_mostly;
154 module_param(ec_no_wakeup, bool, 0644);
155 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
156
157 struct acpi_ec_query_handler {
158         struct list_head node;
159         acpi_ec_query_func func;
160         acpi_handle handle;
161         void *data;
162         u8 query_bit;
163         struct kref kref;
164 };
165
166 struct transaction {
167         const u8 *wdata;
168         u8 *rdata;
169         unsigned short irq_count;
170         u8 command;
171         u8 wi;
172         u8 ri;
173         u8 wlen;
174         u8 rlen;
175         u8 flags;
176 };
177
178 struct acpi_ec_query {
179         struct transaction transaction;
180         struct work_struct work;
181         struct acpi_ec_query_handler *handler;
182 };
183
184 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
185 static void advance_transaction(struct acpi_ec *ec);
186 static void acpi_ec_event_handler(struct work_struct *work);
187 static void acpi_ec_event_processor(struct work_struct *work);
188
189 struct acpi_ec *boot_ec, *first_ec;
190 EXPORT_SYMBOL(first_ec);
191 static bool boot_ec_is_ecdt = false;
192 static struct workqueue_struct *ec_query_wq;
193
194 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
195 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
196 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
197
198 /* --------------------------------------------------------------------------
199  *                           Logging/Debugging
200  * -------------------------------------------------------------------------- */
201
202 /*
203  * Splitters used by the developers to track the boundary of the EC
204  * handling processes.
205  */
206 #ifdef DEBUG
207 #define EC_DBG_SEP      " "
208 #define EC_DBG_DRV      "+++++"
209 #define EC_DBG_STM      "====="
210 #define EC_DBG_REQ      "*****"
211 #define EC_DBG_EVT      "#####"
212 #else
213 #define EC_DBG_SEP      ""
214 #define EC_DBG_DRV
215 #define EC_DBG_STM
216 #define EC_DBG_REQ
217 #define EC_DBG_EVT
218 #endif
219
220 #define ec_log_raw(fmt, ...) \
221         pr_info(fmt "\n", ##__VA_ARGS__)
222 #define ec_dbg_raw(fmt, ...) \
223         pr_debug(fmt "\n", ##__VA_ARGS__)
224 #define ec_log(filter, fmt, ...) \
225         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
226 #define ec_dbg(filter, fmt, ...) \
227         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
228
229 #define ec_log_drv(fmt, ...) \
230         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
231 #define ec_dbg_drv(fmt, ...) \
232         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
233 #define ec_dbg_stm(fmt, ...) \
234         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
235 #define ec_dbg_req(fmt, ...) \
236         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
237 #define ec_dbg_evt(fmt, ...) \
238         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
239 #define ec_dbg_ref(ec, fmt, ...) \
240         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
241
242 /* --------------------------------------------------------------------------
243  *                           Device Flags
244  * -------------------------------------------------------------------------- */
245
246 static bool acpi_ec_started(struct acpi_ec *ec)
247 {
248         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
249                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
250 }
251
252 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
253 {
254         /*
255          * There is an OSPM early stage logic. During the early stages
256          * (boot/resume), OSPMs shouldn't enable the event handling, only
257          * the EC transactions are allowed to be performed.
258          */
259         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
260                 return false;
261         /*
262          * However, disabling the event handling is experimental for late
263          * stage (suspend), and is controlled by the boot parameter of
264          * "ec_freeze_events":
265          * 1. true:  The EC event handling is disabled before entering
266          *           the noirq stage.
267          * 2. false: The EC event handling is automatically disabled as
268          *           soon as the EC driver is stopped.
269          */
270         if (ec_freeze_events)
271                 return acpi_ec_started(ec);
272         else
273                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
274 }
275
276 static bool acpi_ec_flushed(struct acpi_ec *ec)
277 {
278         return ec->reference_count == 1;
279 }
280
281 /* --------------------------------------------------------------------------
282  *                           EC Registers
283  * -------------------------------------------------------------------------- */
284
285 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
286 {
287         u8 x = inb(ec->command_addr);
288
289         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
290                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
291                    x,
292                    !!(x & ACPI_EC_FLAG_SCI),
293                    !!(x & ACPI_EC_FLAG_BURST),
294                    !!(x & ACPI_EC_FLAG_CMD),
295                    !!(x & ACPI_EC_FLAG_IBF),
296                    !!(x & ACPI_EC_FLAG_OBF));
297         return x;
298 }
299
300 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
301 {
302         u8 x = inb(ec->data_addr);
303
304         ec->timestamp = jiffies;
305         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
306         return x;
307 }
308
309 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
310 {
311         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
312         outb(command, ec->command_addr);
313         ec->timestamp = jiffies;
314 }
315
316 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
317 {
318         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
319         outb(data, ec->data_addr);
320         ec->timestamp = jiffies;
321 }
322
323 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
324 static const char *acpi_ec_cmd_string(u8 cmd)
325 {
326         switch (cmd) {
327         case 0x80:
328                 return "RD_EC";
329         case 0x81:
330                 return "WR_EC";
331         case 0x82:
332                 return "BE_EC";
333         case 0x83:
334                 return "BD_EC";
335         case 0x84:
336                 return "QR_EC";
337         }
338         return "UNKNOWN";
339 }
340 #else
341 #define acpi_ec_cmd_string(cmd)         "UNDEF"
342 #endif
343
344 /* --------------------------------------------------------------------------
345  *                           GPE Registers
346  * -------------------------------------------------------------------------- */
347
348 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
349 {
350         acpi_event_status gpe_status = 0;
351
352         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
353         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
354 }
355
356 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
357 {
358         if (open)
359                 acpi_enable_gpe(NULL, ec->gpe);
360         else {
361                 BUG_ON(ec->reference_count < 1);
362                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
363         }
364         if (acpi_ec_is_gpe_raised(ec)) {
365                 /*
366                  * On some platforms, EN=1 writes cannot trigger GPE. So
367                  * software need to manually trigger a pseudo GPE event on
368                  * EN=1 writes.
369                  */
370                 ec_dbg_raw("Polling quirk");
371                 advance_transaction(ec);
372         }
373 }
374
375 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
376 {
377         if (close)
378                 acpi_disable_gpe(NULL, ec->gpe);
379         else {
380                 BUG_ON(ec->reference_count < 1);
381                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
382         }
383 }
384
385 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
386 {
387         /*
388          * GPE STS is a W1C register, which means:
389          * 1. Software can clear it without worrying about clearing other
390          *    GPEs' STS bits when the hardware sets them in parallel.
391          * 2. As long as software can ensure only clearing it when it is
392          *    set, hardware won't set it in parallel.
393          * So software can clear GPE in any contexts.
394          * Warning: do not move the check into advance_transaction() as the
395          * EC commands will be sent without GPE raised.
396          */
397         if (!acpi_ec_is_gpe_raised(ec))
398                 return;
399         acpi_clear_gpe(NULL, ec->gpe);
400 }
401
402 /* --------------------------------------------------------------------------
403  *                           Transaction Management
404  * -------------------------------------------------------------------------- */
405
406 static void acpi_ec_submit_request(struct acpi_ec *ec)
407 {
408         ec->reference_count++;
409         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
410             ec->reference_count == 1)
411                 acpi_ec_enable_gpe(ec, true);
412 }
413
414 static void acpi_ec_complete_request(struct acpi_ec *ec)
415 {
416         bool flushed = false;
417
418         ec->reference_count--;
419         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
420             ec->reference_count == 0)
421                 acpi_ec_disable_gpe(ec, true);
422         flushed = acpi_ec_flushed(ec);
423         if (flushed)
424                 wake_up(&ec->wait);
425 }
426
427 static void acpi_ec_mask_gpe(struct acpi_ec *ec)
428 {
429         if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
430                 acpi_ec_disable_gpe(ec, false);
431                 ec_dbg_drv("Polling enabled");
432                 set_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
433         }
434 }
435
436 static void acpi_ec_unmask_gpe(struct acpi_ec *ec)
437 {
438         if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
439                 clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
440                 acpi_ec_enable_gpe(ec, false);
441                 ec_dbg_drv("Polling disabled");
442         }
443 }
444
445 /*
446  * acpi_ec_submit_flushable_request() - Increase the reference count unless
447  *                                      the flush operation is not in
448  *                                      progress
449  * @ec: the EC device
450  *
451  * This function must be used before taking a new action that should hold
452  * the reference count.  If this function returns false, then the action
453  * must be discarded or it will prevent the flush operation from being
454  * completed.
455  */
456 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
457 {
458         if (!acpi_ec_started(ec))
459                 return false;
460         acpi_ec_submit_request(ec);
461         return true;
462 }
463
464 static void acpi_ec_submit_query(struct acpi_ec *ec)
465 {
466         acpi_ec_mask_gpe(ec);
467         if (!acpi_ec_event_enabled(ec))
468                 return;
469         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
470                 ec_dbg_evt("Command(%s) submitted/blocked",
471                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
472                 ec->nr_pending_queries++;
473                 schedule_work(&ec->work);
474         }
475 }
476
477 static void acpi_ec_complete_query(struct acpi_ec *ec)
478 {
479         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
480                 ec_dbg_evt("Command(%s) unblocked",
481                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
482         acpi_ec_unmask_gpe(ec);
483 }
484
485 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
486 {
487         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
488                 ec_log_drv("event unblocked");
489         /*
490          * Unconditionally invoke this once after enabling the event
491          * handling mechanism to detect the pending events.
492          */
493         advance_transaction(ec);
494 }
495
496 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
497 {
498         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
499                 ec_log_drv("event blocked");
500 }
501
502 static void acpi_ec_enable_event(struct acpi_ec *ec)
503 {
504         unsigned long flags;
505
506         spin_lock_irqsave(&ec->lock, flags);
507         if (acpi_ec_started(ec))
508                 __acpi_ec_enable_event(ec);
509         spin_unlock_irqrestore(&ec->lock, flags);
510 }
511
512 #ifdef CONFIG_PM_SLEEP
513 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
514 {
515         bool flushed;
516         unsigned long flags;
517
518         spin_lock_irqsave(&ec->lock, flags);
519         flushed = !ec->nr_pending_queries;
520         spin_unlock_irqrestore(&ec->lock, flags);
521         return flushed;
522 }
523
524 static void __acpi_ec_flush_event(struct acpi_ec *ec)
525 {
526         /*
527          * When ec_freeze_events is true, we need to flush events in
528          * the proper position before entering the noirq stage.
529          */
530         wait_event(ec->wait, acpi_ec_query_flushed(ec));
531         if (ec_query_wq)
532                 flush_workqueue(ec_query_wq);
533 }
534
535 static void acpi_ec_disable_event(struct acpi_ec *ec)
536 {
537         unsigned long flags;
538
539         spin_lock_irqsave(&ec->lock, flags);
540         __acpi_ec_disable_event(ec);
541         spin_unlock_irqrestore(&ec->lock, flags);
542         __acpi_ec_flush_event(ec);
543 }
544
545 void acpi_ec_flush_work(void)
546 {
547         if (first_ec)
548                 __acpi_ec_flush_event(first_ec);
549
550         flush_scheduled_work();
551 }
552 #endif /* CONFIG_PM_SLEEP */
553
554 static bool acpi_ec_guard_event(struct acpi_ec *ec)
555 {
556         bool guarded = true;
557         unsigned long flags;
558
559         spin_lock_irqsave(&ec->lock, flags);
560         /*
561          * If firmware SCI_EVT clearing timing is "event", we actually
562          * don't know when the SCI_EVT will be cleared by firmware after
563          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
564          * acceptable period.
565          *
566          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
567          * flagged, which means SCI_EVT check has just been performed.
568          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
569          * guarding should have already been performed (via
570          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
571          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
572          * ACPI_EC_COMMAND_POLL state immediately.
573          */
574         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
575             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
576             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
577             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
578                 guarded = false;
579         spin_unlock_irqrestore(&ec->lock, flags);
580         return guarded;
581 }
582
583 static int ec_transaction_polled(struct acpi_ec *ec)
584 {
585         unsigned long flags;
586         int ret = 0;
587
588         spin_lock_irqsave(&ec->lock, flags);
589         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
590                 ret = 1;
591         spin_unlock_irqrestore(&ec->lock, flags);
592         return ret;
593 }
594
595 static int ec_transaction_completed(struct acpi_ec *ec)
596 {
597         unsigned long flags;
598         int ret = 0;
599
600         spin_lock_irqsave(&ec->lock, flags);
601         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
602                 ret = 1;
603         spin_unlock_irqrestore(&ec->lock, flags);
604         return ret;
605 }
606
607 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
608 {
609         ec->curr->flags |= flag;
610         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
611                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
612                     flag == ACPI_EC_COMMAND_POLL)
613                         acpi_ec_complete_query(ec);
614                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
615                     flag == ACPI_EC_COMMAND_COMPLETE)
616                         acpi_ec_complete_query(ec);
617                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
618                     flag == ACPI_EC_COMMAND_COMPLETE)
619                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
620         }
621 }
622
623 static void advance_transaction(struct acpi_ec *ec)
624 {
625         struct transaction *t;
626         u8 status;
627         bool wakeup = false;
628
629         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
630                    smp_processor_id());
631         /*
632          * By always clearing STS before handling all indications, we can
633          * ensure a hardware STS 0->1 change after this clearing can always
634          * trigger a GPE interrupt.
635          */
636         acpi_ec_clear_gpe(ec);
637         status = acpi_ec_read_status(ec);
638         t = ec->curr;
639         /*
640          * Another IRQ or a guarded polling mode advancement is detected,
641          * the next QR_EC submission is then allowed.
642          */
643         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
644                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
645                     (!ec->nr_pending_queries ||
646                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
647                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
648                         acpi_ec_complete_query(ec);
649                 }
650         }
651         if (!t)
652                 goto err;
653         if (t->flags & ACPI_EC_COMMAND_POLL) {
654                 if (t->wlen > t->wi) {
655                         if ((status & ACPI_EC_FLAG_IBF) == 0)
656                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
657                         else
658                                 goto err;
659                 } else if (t->rlen > t->ri) {
660                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
661                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
662                                 if (t->rlen == t->ri) {
663                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
664                                         if (t->command == ACPI_EC_COMMAND_QUERY)
665                                                 ec_dbg_evt("Command(%s) completed by hardware",
666                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
667                                         wakeup = true;
668                                 }
669                         } else
670                                 goto err;
671                 } else if (t->wlen == t->wi &&
672                            (status & ACPI_EC_FLAG_IBF) == 0) {
673                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
674                         wakeup = true;
675                 }
676                 goto out;
677         } else {
678                 if (EC_FLAGS_QUERY_HANDSHAKE &&
679                     !(status & ACPI_EC_FLAG_SCI) &&
680                     (t->command == ACPI_EC_COMMAND_QUERY)) {
681                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
682                         t->rdata[t->ri++] = 0x00;
683                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
684                         ec_dbg_evt("Command(%s) completed by software",
685                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
686                         wakeup = true;
687                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
688                         acpi_ec_write_cmd(ec, t->command);
689                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
690                 } else
691                         goto err;
692                 goto out;
693         }
694 err:
695         /*
696          * If SCI bit is set, then don't think it's a false IRQ
697          * otherwise will take a not handled IRQ as a false one.
698          */
699         if (!(status & ACPI_EC_FLAG_SCI)) {
700                 if (in_interrupt() && t) {
701                         if (t->irq_count < ec_storm_threshold)
702                                 ++t->irq_count;
703                         /* Allow triggering on 0 threshold */
704                         if (t->irq_count == ec_storm_threshold)
705                                 acpi_ec_mask_gpe(ec);
706                 }
707         }
708 out:
709         if (status & ACPI_EC_FLAG_SCI)
710                 acpi_ec_submit_query(ec);
711         if (wakeup && in_interrupt())
712                 wake_up(&ec->wait);
713 }
714
715 static void start_transaction(struct acpi_ec *ec)
716 {
717         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
718         ec->curr->flags = 0;
719 }
720
721 static int ec_guard(struct acpi_ec *ec)
722 {
723         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
724         unsigned long timeout = ec->timestamp + guard;
725
726         /* Ensure guarding period before polling EC status */
727         do {
728                 if (ec->busy_polling) {
729                         /* Perform busy polling */
730                         if (ec_transaction_completed(ec))
731                                 return 0;
732                         udelay(jiffies_to_usecs(guard));
733                 } else {
734                         /*
735                          * Perform wait polling
736                          * 1. Wait the transaction to be completed by the
737                          *    GPE handler after the transaction enters
738                          *    ACPI_EC_COMMAND_POLL state.
739                          * 2. A special guarding logic is also required
740                          *    for event clearing mode "event" before the
741                          *    transaction enters ACPI_EC_COMMAND_POLL
742                          *    state.
743                          */
744                         if (!ec_transaction_polled(ec) &&
745                             !acpi_ec_guard_event(ec))
746                                 break;
747                         if (wait_event_timeout(ec->wait,
748                                                ec_transaction_completed(ec),
749                                                guard))
750                                 return 0;
751                 }
752         } while (time_before(jiffies, timeout));
753         return -ETIME;
754 }
755
756 static int ec_poll(struct acpi_ec *ec)
757 {
758         unsigned long flags;
759         int repeat = 5; /* number of command restarts */
760
761         while (repeat--) {
762                 unsigned long delay = jiffies +
763                         msecs_to_jiffies(ec_delay);
764                 do {
765                         if (!ec_guard(ec))
766                                 return 0;
767                         spin_lock_irqsave(&ec->lock, flags);
768                         advance_transaction(ec);
769                         spin_unlock_irqrestore(&ec->lock, flags);
770                 } while (time_before(jiffies, delay));
771                 pr_debug("controller reset, restart transaction\n");
772                 spin_lock_irqsave(&ec->lock, flags);
773                 start_transaction(ec);
774                 spin_unlock_irqrestore(&ec->lock, flags);
775         }
776         return -ETIME;
777 }
778
779 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
780                                         struct transaction *t)
781 {
782         unsigned long tmp;
783         int ret = 0;
784
785         /* start transaction */
786         spin_lock_irqsave(&ec->lock, tmp);
787         /* Enable GPE for command processing (IBF=0/OBF=1) */
788         if (!acpi_ec_submit_flushable_request(ec)) {
789                 ret = -EINVAL;
790                 goto unlock;
791         }
792         ec_dbg_ref(ec, "Increase command");
793         /* following two actions should be kept atomic */
794         ec->curr = t;
795         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
796         start_transaction(ec);
797         spin_unlock_irqrestore(&ec->lock, tmp);
798
799         ret = ec_poll(ec);
800
801         spin_lock_irqsave(&ec->lock, tmp);
802         if (t->irq_count == ec_storm_threshold)
803                 acpi_ec_unmask_gpe(ec);
804         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
805         ec->curr = NULL;
806         /* Disable GPE for command processing (IBF=0/OBF=1) */
807         acpi_ec_complete_request(ec);
808         ec_dbg_ref(ec, "Decrease command");
809 unlock:
810         spin_unlock_irqrestore(&ec->lock, tmp);
811         return ret;
812 }
813
814 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
815 {
816         int status;
817         u32 glk;
818
819         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
820                 return -EINVAL;
821         if (t->rdata)
822                 memset(t->rdata, 0, t->rlen);
823
824         mutex_lock(&ec->mutex);
825         if (ec->global_lock) {
826                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
827                 if (ACPI_FAILURE(status)) {
828                         status = -ENODEV;
829                         goto unlock;
830                 }
831         }
832
833         status = acpi_ec_transaction_unlocked(ec, t);
834
835         if (ec->global_lock)
836                 acpi_release_global_lock(glk);
837 unlock:
838         mutex_unlock(&ec->mutex);
839         return status;
840 }
841
842 static int acpi_ec_burst_enable(struct acpi_ec *ec)
843 {
844         u8 d;
845         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
846                                 .wdata = NULL, .rdata = &d,
847                                 .wlen = 0, .rlen = 1};
848
849         return acpi_ec_transaction(ec, &t);
850 }
851
852 static int acpi_ec_burst_disable(struct acpi_ec *ec)
853 {
854         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
855                                 .wdata = NULL, .rdata = NULL,
856                                 .wlen = 0, .rlen = 0};
857
858         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
859                                 acpi_ec_transaction(ec, &t) : 0;
860 }
861
862 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
863 {
864         int result;
865         u8 d;
866         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
867                                 .wdata = &address, .rdata = &d,
868                                 .wlen = 1, .rlen = 1};
869
870         result = acpi_ec_transaction(ec, &t);
871         *data = d;
872         return result;
873 }
874
875 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
876 {
877         u8 wdata[2] = { address, data };
878         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
879                                 .wdata = wdata, .rdata = NULL,
880                                 .wlen = 2, .rlen = 0};
881
882         return acpi_ec_transaction(ec, &t);
883 }
884
885 int ec_read(u8 addr, u8 *val)
886 {
887         int err;
888         u8 temp_data;
889
890         if (!first_ec)
891                 return -ENODEV;
892
893         err = acpi_ec_read(first_ec, addr, &temp_data);
894
895         if (!err) {
896                 *val = temp_data;
897                 return 0;
898         }
899         return err;
900 }
901 EXPORT_SYMBOL(ec_read);
902
903 int ec_write(u8 addr, u8 val)
904 {
905         int err;
906
907         if (!first_ec)
908                 return -ENODEV;
909
910         err = acpi_ec_write(first_ec, addr, val);
911
912         return err;
913 }
914 EXPORT_SYMBOL(ec_write);
915
916 int ec_transaction(u8 command,
917                    const u8 *wdata, unsigned wdata_len,
918                    u8 *rdata, unsigned rdata_len)
919 {
920         struct transaction t = {.command = command,
921                                 .wdata = wdata, .rdata = rdata,
922                                 .wlen = wdata_len, .rlen = rdata_len};
923
924         if (!first_ec)
925                 return -ENODEV;
926
927         return acpi_ec_transaction(first_ec, &t);
928 }
929 EXPORT_SYMBOL(ec_transaction);
930
931 /* Get the handle to the EC device */
932 acpi_handle ec_get_handle(void)
933 {
934         if (!first_ec)
935                 return NULL;
936         return first_ec->handle;
937 }
938 EXPORT_SYMBOL(ec_get_handle);
939
940 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
941 {
942         unsigned long flags;
943
944         spin_lock_irqsave(&ec->lock, flags);
945         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
946                 ec_dbg_drv("Starting EC");
947                 /* Enable GPE for event processing (SCI_EVT=1) */
948                 if (!resuming) {
949                         acpi_ec_submit_request(ec);
950                         ec_dbg_ref(ec, "Increase driver");
951                 }
952                 ec_log_drv("EC started");
953         }
954         spin_unlock_irqrestore(&ec->lock, flags);
955 }
956
957 static bool acpi_ec_stopped(struct acpi_ec *ec)
958 {
959         unsigned long flags;
960         bool flushed;
961
962         spin_lock_irqsave(&ec->lock, flags);
963         flushed = acpi_ec_flushed(ec);
964         spin_unlock_irqrestore(&ec->lock, flags);
965         return flushed;
966 }
967
968 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
969 {
970         unsigned long flags;
971
972         spin_lock_irqsave(&ec->lock, flags);
973         if (acpi_ec_started(ec)) {
974                 ec_dbg_drv("Stopping EC");
975                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
976                 spin_unlock_irqrestore(&ec->lock, flags);
977                 wait_event(ec->wait, acpi_ec_stopped(ec));
978                 spin_lock_irqsave(&ec->lock, flags);
979                 /* Disable GPE for event processing (SCI_EVT=1) */
980                 if (!suspending) {
981                         acpi_ec_complete_request(ec);
982                         ec_dbg_ref(ec, "Decrease driver");
983                 } else if (!ec_freeze_events)
984                         __acpi_ec_disable_event(ec);
985                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
986                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
987                 ec_log_drv("EC stopped");
988         }
989         spin_unlock_irqrestore(&ec->lock, flags);
990 }
991
992 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
993 {
994         unsigned long flags;
995
996         spin_lock_irqsave(&ec->lock, flags);
997         ec->busy_polling = true;
998         ec->polling_guard = 0;
999         ec_log_drv("interrupt blocked");
1000         spin_unlock_irqrestore(&ec->lock, flags);
1001 }
1002
1003 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1004 {
1005         unsigned long flags;
1006
1007         spin_lock_irqsave(&ec->lock, flags);
1008         ec->busy_polling = ec_busy_polling;
1009         ec->polling_guard = ec_polling_guard;
1010         ec_log_drv("interrupt unblocked");
1011         spin_unlock_irqrestore(&ec->lock, flags);
1012 }
1013
1014 void acpi_ec_block_transactions(void)
1015 {
1016         struct acpi_ec *ec = first_ec;
1017
1018         if (!ec)
1019                 return;
1020
1021         mutex_lock(&ec->mutex);
1022         /* Prevent transactions from being carried out */
1023         acpi_ec_stop(ec, true);
1024         mutex_unlock(&ec->mutex);
1025 }
1026
1027 void acpi_ec_unblock_transactions(void)
1028 {
1029         /*
1030          * Allow transactions to happen again (this function is called from
1031          * atomic context during wakeup, so we don't need to acquire the mutex).
1032          */
1033         if (first_ec)
1034                 acpi_ec_start(first_ec, true);
1035 }
1036
1037 /* --------------------------------------------------------------------------
1038                                 Event Management
1039    -------------------------------------------------------------------------- */
1040 static struct acpi_ec_query_handler *
1041 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1042 {
1043         if (handler)
1044                 kref_get(&handler->kref);
1045         return handler;
1046 }
1047
1048 static struct acpi_ec_query_handler *
1049 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1050 {
1051         struct acpi_ec_query_handler *handler;
1052         bool found = false;
1053
1054         mutex_lock(&ec->mutex);
1055         list_for_each_entry(handler, &ec->list, node) {
1056                 if (value == handler->query_bit) {
1057                         found = true;
1058                         break;
1059                 }
1060         }
1061         mutex_unlock(&ec->mutex);
1062         return found ? acpi_ec_get_query_handler(handler) : NULL;
1063 }
1064
1065 static void acpi_ec_query_handler_release(struct kref *kref)
1066 {
1067         struct acpi_ec_query_handler *handler =
1068                 container_of(kref, struct acpi_ec_query_handler, kref);
1069
1070         kfree(handler);
1071 }
1072
1073 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1074 {
1075         kref_put(&handler->kref, acpi_ec_query_handler_release);
1076 }
1077
1078 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1079                               acpi_handle handle, acpi_ec_query_func func,
1080                               void *data)
1081 {
1082         struct acpi_ec_query_handler *handler =
1083             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1084
1085         if (!handler)
1086                 return -ENOMEM;
1087
1088         handler->query_bit = query_bit;
1089         handler->handle = handle;
1090         handler->func = func;
1091         handler->data = data;
1092         mutex_lock(&ec->mutex);
1093         kref_init(&handler->kref);
1094         list_add(&handler->node, &ec->list);
1095         mutex_unlock(&ec->mutex);
1096         return 0;
1097 }
1098 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1099
1100 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1101                                           bool remove_all, u8 query_bit)
1102 {
1103         struct acpi_ec_query_handler *handler, *tmp;
1104         LIST_HEAD(free_list);
1105
1106         mutex_lock(&ec->mutex);
1107         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1108                 if (remove_all || query_bit == handler->query_bit) {
1109                         list_del_init(&handler->node);
1110                         list_add(&handler->node, &free_list);
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
1118 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1119 {
1120         acpi_ec_remove_query_handlers(ec, false, query_bit);
1121 }
1122 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1123
1124 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1125 {
1126         struct acpi_ec_query *q;
1127         struct transaction *t;
1128
1129         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1130         if (!q)
1131                 return NULL;
1132         INIT_WORK(&q->work, acpi_ec_event_processor);
1133         t = &q->transaction;
1134         t->command = ACPI_EC_COMMAND_QUERY;
1135         t->rdata = pval;
1136         t->rlen = 1;
1137         return q;
1138 }
1139
1140 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1141 {
1142         if (q) {
1143                 if (q->handler)
1144                         acpi_ec_put_query_handler(q->handler);
1145                 kfree(q);
1146         }
1147 }
1148
1149 static void acpi_ec_event_processor(struct work_struct *work)
1150 {
1151         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1152         struct acpi_ec_query_handler *handler = q->handler;
1153
1154         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1155         if (handler->func)
1156                 handler->func(handler->data);
1157         else if (handler->handle)
1158                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1159         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1160         acpi_ec_delete_query(q);
1161 }
1162
1163 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1164 {
1165         u8 value = 0;
1166         int result;
1167         struct acpi_ec_query *q;
1168
1169         q = acpi_ec_create_query(&value);
1170         if (!q)
1171                 return -ENOMEM;
1172
1173         /*
1174          * Query the EC to find out which _Qxx method we need to evaluate.
1175          * Note that successful completion of the query causes the ACPI_EC_SCI
1176          * bit to be cleared (and thus clearing the interrupt source).
1177          */
1178         result = acpi_ec_transaction(ec, &q->transaction);
1179         if (!value)
1180                 result = -ENODATA;
1181         if (result)
1182                 goto err_exit;
1183
1184         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1185         if (!q->handler) {
1186                 result = -ENODATA;
1187                 goto err_exit;
1188         }
1189
1190         /*
1191          * It is reported that _Qxx are evaluated in a parallel way on
1192          * Windows:
1193          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1194          *
1195          * Put this log entry before schedule_work() in order to make
1196          * it appearing before any other log entries occurred during the
1197          * work queue execution.
1198          */
1199         ec_dbg_evt("Query(0x%02x) scheduled", value);
1200         if (!queue_work(ec_query_wq, &q->work)) {
1201                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1202                 result = -EBUSY;
1203         }
1204
1205 err_exit:
1206         if (result)
1207                 acpi_ec_delete_query(q);
1208         if (data)
1209                 *data = value;
1210         return result;
1211 }
1212
1213 static void acpi_ec_check_event(struct acpi_ec *ec)
1214 {
1215         unsigned long flags;
1216
1217         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1218                 if (ec_guard(ec)) {
1219                         spin_lock_irqsave(&ec->lock, flags);
1220                         /*
1221                          * Take care of the SCI_EVT unless no one else is
1222                          * taking care of it.
1223                          */
1224                         if (!ec->curr)
1225                                 advance_transaction(ec);
1226                         spin_unlock_irqrestore(&ec->lock, flags);
1227                 }
1228         }
1229 }
1230
1231 static void acpi_ec_event_handler(struct work_struct *work)
1232 {
1233         unsigned long flags;
1234         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1235
1236         ec_dbg_evt("Event started");
1237
1238         spin_lock_irqsave(&ec->lock, flags);
1239         while (ec->nr_pending_queries) {
1240                 spin_unlock_irqrestore(&ec->lock, flags);
1241                 (void)acpi_ec_query(ec, NULL);
1242                 spin_lock_irqsave(&ec->lock, flags);
1243                 ec->nr_pending_queries--;
1244                 /*
1245                  * Before exit, make sure that this work item can be
1246                  * scheduled again. There might be QR_EC failures, leaving
1247                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1248                  * item from being scheduled again.
1249                  */
1250                 if (!ec->nr_pending_queries) {
1251                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1252                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1253                                 acpi_ec_complete_query(ec);
1254                 }
1255         }
1256         spin_unlock_irqrestore(&ec->lock, flags);
1257
1258         ec_dbg_evt("Event stopped");
1259
1260         acpi_ec_check_event(ec);
1261 }
1262
1263 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1264         u32 gpe_number, void *data)
1265 {
1266         unsigned long flags;
1267         struct acpi_ec *ec = data;
1268
1269         spin_lock_irqsave(&ec->lock, flags);
1270         advance_transaction(ec);
1271         spin_unlock_irqrestore(&ec->lock, flags);
1272         return ACPI_INTERRUPT_HANDLED;
1273 }
1274
1275 /* --------------------------------------------------------------------------
1276  *                           Address Space Management
1277  * -------------------------------------------------------------------------- */
1278
1279 static acpi_status
1280 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1281                       u32 bits, u64 *value64,
1282                       void *handler_context, void *region_context)
1283 {
1284         struct acpi_ec *ec = handler_context;
1285         int result = 0, i, bytes = bits / 8;
1286         u8 *value = (u8 *)value64;
1287
1288         if ((address > 0xFF) || !value || !handler_context)
1289                 return AE_BAD_PARAMETER;
1290
1291         if (function != ACPI_READ && function != ACPI_WRITE)
1292                 return AE_BAD_PARAMETER;
1293
1294         if (ec->busy_polling || bits > 8)
1295                 acpi_ec_burst_enable(ec);
1296
1297         for (i = 0; i < bytes; ++i, ++address, ++value)
1298                 result = (function == ACPI_READ) ?
1299                         acpi_ec_read(ec, address, value) :
1300                         acpi_ec_write(ec, address, *value);
1301
1302         if (ec->busy_polling || bits > 8)
1303                 acpi_ec_burst_disable(ec);
1304
1305         switch (result) {
1306         case -EINVAL:
1307                 return AE_BAD_PARAMETER;
1308         case -ENODEV:
1309                 return AE_NOT_FOUND;
1310         case -ETIME:
1311                 return AE_TIME;
1312         default:
1313                 return AE_OK;
1314         }
1315 }
1316
1317 /* --------------------------------------------------------------------------
1318  *                             Driver Interface
1319  * -------------------------------------------------------------------------- */
1320
1321 static acpi_status
1322 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1323
1324 static void acpi_ec_free(struct acpi_ec *ec)
1325 {
1326         if (first_ec == ec)
1327                 first_ec = NULL;
1328         if (boot_ec == ec)
1329                 boot_ec = NULL;
1330         kfree(ec);
1331 }
1332
1333 static struct acpi_ec *acpi_ec_alloc(void)
1334 {
1335         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1336
1337         if (!ec)
1338                 return NULL;
1339         mutex_init(&ec->mutex);
1340         init_waitqueue_head(&ec->wait);
1341         INIT_LIST_HEAD(&ec->list);
1342         spin_lock_init(&ec->lock);
1343         INIT_WORK(&ec->work, acpi_ec_event_handler);
1344         ec->timestamp = jiffies;
1345         ec->busy_polling = true;
1346         ec->polling_guard = 0;
1347         return ec;
1348 }
1349
1350 static acpi_status
1351 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1352                                void *context, void **return_value)
1353 {
1354         char node_name[5];
1355         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1356         struct acpi_ec *ec = context;
1357         int value = 0;
1358         acpi_status status;
1359
1360         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1361
1362         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1363                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1364         return AE_OK;
1365 }
1366
1367 static acpi_status
1368 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1369 {
1370         acpi_status status;
1371         unsigned long long tmp = 0;
1372         struct acpi_ec *ec = context;
1373
1374         /* clear addr values, ec_parse_io_ports depend on it */
1375         ec->command_addr = ec->data_addr = 0;
1376
1377         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1378                                      ec_parse_io_ports, ec);
1379         if (ACPI_FAILURE(status))
1380                 return status;
1381         if (ec->data_addr == 0 || ec->command_addr == 0)
1382                 return AE_OK;
1383
1384         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1385                 /*
1386                  * Always inherit the GPE number setting from the ECDT
1387                  * EC.
1388                  */
1389                 ec->gpe = boot_ec->gpe;
1390         } else {
1391                 /* Get GPE bit assignment (EC events). */
1392                 /* TODO: Add support for _GPE returning a package */
1393                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1394                 if (ACPI_FAILURE(status))
1395                         return status;
1396                 ec->gpe = tmp;
1397         }
1398         /* Use the global lock for all EC transactions? */
1399         tmp = 0;
1400         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1401         ec->global_lock = tmp;
1402         ec->handle = handle;
1403         return AE_CTRL_TERMINATE;
1404 }
1405
1406 /*
1407  * Note: This function returns an error code only when the address space
1408  *       handler is not installed, which means "not able to handle
1409  *       transactions".
1410  */
1411 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1412 {
1413         acpi_status status;
1414
1415         acpi_ec_start(ec, false);
1416
1417         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1418                 acpi_ec_enter_noirq(ec);
1419                 status = acpi_install_address_space_handler(ec->handle,
1420                                                             ACPI_ADR_SPACE_EC,
1421                                                             &acpi_ec_space_handler,
1422                                                             NULL, ec);
1423                 if (ACPI_FAILURE(status)) {
1424                         if (status == AE_NOT_FOUND) {
1425                                 /*
1426                                  * Maybe OS fails in evaluating the _REG
1427                                  * object. The AE_NOT_FOUND error will be
1428                                  * ignored and OS * continue to initialize
1429                                  * EC.
1430                                  */
1431                                 pr_err("Fail in evaluating the _REG object"
1432                                         " of EC device. Broken bios is suspected.\n");
1433                         } else {
1434                                 acpi_ec_stop(ec, false);
1435                                 return -ENODEV;
1436                         }
1437                 }
1438                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1439         }
1440
1441         if (!handle_events)
1442                 return 0;
1443
1444         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1445                 /* Find and register all query methods */
1446                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1447                                     acpi_ec_register_query_methods,
1448                                     NULL, ec, NULL);
1449                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1450         }
1451         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1452                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1453                                           ACPI_GPE_EDGE_TRIGGERED,
1454                                           &acpi_ec_gpe_handler, ec);
1455                 /* This is not fatal as we can poll EC events */
1456                 if (ACPI_SUCCESS(status)) {
1457                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1458                         acpi_ec_leave_noirq(ec);
1459                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1460                             ec->reference_count >= 1)
1461                                 acpi_ec_enable_gpe(ec, true);
1462                 }
1463         }
1464         /* EC is fully operational, allow queries */
1465         acpi_ec_enable_event(ec);
1466
1467         return 0;
1468 }
1469
1470 static void ec_remove_handlers(struct acpi_ec *ec)
1471 {
1472         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1473                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1474                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1475                         pr_err("failed to remove space handler\n");
1476                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1477         }
1478
1479         /*
1480          * Stops handling the EC transactions after removing the operation
1481          * region handler. This is required because _REG(DISCONNECT)
1482          * invoked during the removal can result in new EC transactions.
1483          *
1484          * Flushes the EC requests and thus disables the GPE before
1485          * removing the GPE handler. This is required by the current ACPICA
1486          * GPE core. ACPICA GPE core will automatically disable a GPE when
1487          * it is indicated but there is no way to handle it. So the drivers
1488          * must disable the GPEs prior to removing the GPE handlers.
1489          */
1490         acpi_ec_stop(ec, false);
1491
1492         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1493                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1494                                         &acpi_ec_gpe_handler)))
1495                         pr_err("failed to remove gpe handler\n");
1496                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1497         }
1498         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1499                 acpi_ec_remove_query_handlers(ec, true, 0);
1500                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1501         }
1502 }
1503
1504 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1505 {
1506         int ret;
1507
1508         ret = ec_install_handlers(ec, handle_events);
1509         if (ret)
1510                 return ret;
1511
1512         /* First EC capable of handling transactions */
1513         if (!first_ec) {
1514                 first_ec = ec;
1515                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1516         }
1517
1518         acpi_handle_info(ec->handle,
1519                          "GPE=0x%lx, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1520                          ec->gpe, ec->command_addr, ec->data_addr);
1521         return ret;
1522 }
1523
1524 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1525                                bool handle_events, bool is_ecdt)
1526 {
1527         int ret;
1528
1529         /*
1530          * Changing the ACPI handle results in a re-configuration of the
1531          * boot EC. And if it happens after the namespace initialization,
1532          * it causes _REG evaluations.
1533          */
1534         if (boot_ec && boot_ec->handle != handle)
1535                 ec_remove_handlers(boot_ec);
1536
1537         /* Unset old boot EC */
1538         if (boot_ec != ec)
1539                 acpi_ec_free(boot_ec);
1540
1541         /*
1542          * ECDT device creation is split into acpi_ec_ecdt_probe() and
1543          * acpi_ec_ecdt_start(). This function takes care of completing the
1544          * ECDT parsing logic as the handle update should be performed
1545          * between the installation/uninstallation of the handlers.
1546          */
1547         if (ec->handle != handle)
1548                 ec->handle = handle;
1549
1550         ret = acpi_ec_setup(ec, handle_events);
1551         if (ret)
1552                 return ret;
1553
1554         /* Set new boot EC */
1555         if (!boot_ec) {
1556                 boot_ec = ec;
1557                 boot_ec_is_ecdt = is_ecdt;
1558         }
1559
1560         acpi_handle_info(boot_ec->handle,
1561                          "Used as boot %s EC to handle transactions%s\n",
1562                          is_ecdt ? "ECDT" : "DSDT",
1563                          handle_events ? " and events" : "");
1564         return ret;
1565 }
1566
1567 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1568 {
1569         struct acpi_table_ecdt *ecdt_ptr;
1570         acpi_status status;
1571         acpi_handle handle;
1572
1573         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1574                                 (struct acpi_table_header **)&ecdt_ptr);
1575         if (ACPI_FAILURE(status))
1576                 return false;
1577
1578         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1579         if (ACPI_FAILURE(status))
1580                 return false;
1581
1582         *phandle = handle;
1583         return true;
1584 }
1585
1586 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1587 {
1588         if (!boot_ec)
1589                 return false;
1590         if (ec->command_addr == boot_ec->command_addr &&
1591             ec->data_addr == boot_ec->data_addr)
1592                 return true;
1593         return false;
1594 }
1595
1596 static int acpi_ec_add(struct acpi_device *device)
1597 {
1598         struct acpi_ec *ec = NULL;
1599         int ret;
1600
1601         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1602         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1603
1604         ec = acpi_ec_alloc();
1605         if (!ec)
1606                 return -ENOMEM;
1607         if (ec_parse_device(device->handle, 0, ec, NULL) !=
1608                 AE_CTRL_TERMINATE) {
1609                         ret = -EINVAL;
1610                         goto err_alloc;
1611         }
1612
1613         if (acpi_is_boot_ec(ec)) {
1614                 boot_ec_is_ecdt = false;
1615                 /*
1616                  * Trust PNP0C09 namespace location rather than ECDT ID.
1617                  *
1618                  * But trust ECDT GPE rather than _GPE because of ASUS quirks,
1619                  * so do not change boot_ec->gpe to ec->gpe.
1620                  */
1621                 boot_ec->handle = ec->handle;
1622                 acpi_handle_debug(ec->handle, "duplicated.\n");
1623                 acpi_ec_free(ec);
1624                 ec = boot_ec;
1625                 ret = acpi_config_boot_ec(ec, ec->handle, true, false);
1626         } else
1627                 ret = acpi_ec_setup(ec, true);
1628         if (ret)
1629                 goto err_query;
1630
1631         device->driver_data = ec;
1632
1633         ret = !!request_region(ec->data_addr, 1, "EC data");
1634         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1635         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1636         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1637
1638         /* Reprobe devices depending on the EC */
1639         acpi_walk_dep_device_list(ec->handle);
1640         acpi_handle_debug(ec->handle, "enumerated.\n");
1641         return 0;
1642
1643 err_query:
1644         if (ec != boot_ec)
1645                 acpi_ec_remove_query_handlers(ec, true, 0);
1646 err_alloc:
1647         if (ec != boot_ec)
1648                 acpi_ec_free(ec);
1649         return ret;
1650 }
1651
1652 static int acpi_ec_remove(struct acpi_device *device)
1653 {
1654         struct acpi_ec *ec;
1655
1656         if (!device)
1657                 return -EINVAL;
1658
1659         ec = acpi_driver_data(device);
1660         release_region(ec->data_addr, 1);
1661         release_region(ec->command_addr, 1);
1662         device->driver_data = NULL;
1663         if (ec != boot_ec) {
1664                 ec_remove_handlers(ec);
1665                 acpi_ec_free(ec);
1666         }
1667         return 0;
1668 }
1669
1670 static acpi_status
1671 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1672 {
1673         struct acpi_ec *ec = context;
1674
1675         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1676                 return AE_OK;
1677
1678         /*
1679          * The first address region returned is the data port, and
1680          * the second address region returned is the status/command
1681          * port.
1682          */
1683         if (ec->data_addr == 0)
1684                 ec->data_addr = resource->data.io.minimum;
1685         else if (ec->command_addr == 0)
1686                 ec->command_addr = resource->data.io.minimum;
1687         else
1688                 return AE_CTRL_TERMINATE;
1689
1690         return AE_OK;
1691 }
1692
1693 static const struct acpi_device_id ec_device_ids[] = {
1694         {"PNP0C09", 0},
1695         {"", 0},
1696 };
1697
1698 /*
1699  * This function is not Windows-compatible as Windows never enumerates the
1700  * namespace EC before the main ACPI device enumeration process. It is
1701  * retained for historical reason and will be deprecated in the future.
1702  */
1703 int __init acpi_ec_dsdt_probe(void)
1704 {
1705         acpi_status status;
1706         struct acpi_ec *ec;
1707         int ret;
1708
1709         /*
1710          * If a platform has ECDT, there is no need to proceed as the
1711          * following probe is not a part of the ACPI device enumeration,
1712          * executing _STA is not safe, and thus this probe may risk of
1713          * picking up an invalid EC device.
1714          */
1715         if (boot_ec)
1716                 return -ENODEV;
1717
1718         ec = acpi_ec_alloc();
1719         if (!ec)
1720                 return -ENOMEM;
1721         /*
1722          * At this point, the namespace is initialized, so start to find
1723          * the namespace objects.
1724          */
1725         status = acpi_get_devices(ec_device_ids[0].id,
1726                                   ec_parse_device, ec, NULL);
1727         if (ACPI_FAILURE(status) || !ec->handle) {
1728                 ret = -ENODEV;
1729                 goto error;
1730         }
1731         /*
1732          * When the DSDT EC is available, always re-configure boot EC to
1733          * have _REG evaluated. _REG can only be evaluated after the
1734          * namespace initialization.
1735          * At this point, the GPE is not fully initialized, so do not to
1736          * handle the events.
1737          */
1738         ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1739 error:
1740         if (ret)
1741                 acpi_ec_free(ec);
1742         return ret;
1743 }
1744
1745 /*
1746  * If the DSDT EC is not functioning, we still need to prepare a fully
1747  * functioning ECDT EC first in order to handle the events.
1748  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1749  */
1750 static int __init acpi_ec_ecdt_start(void)
1751 {
1752         acpi_handle handle;
1753
1754         if (!boot_ec)
1755                 return -ENODEV;
1756         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1757         if (!boot_ec_is_ecdt)
1758                 return -ENODEV;
1759
1760         /*
1761          * At this point, the namespace and the GPE is initialized, so
1762          * start to find the namespace objects and handle the events.
1763          *
1764          * Note: ec->handle can be valid if this function is called after
1765          * acpi_ec_add(), hence the fast path.
1766          */
1767         if (boot_ec->handle != ACPI_ROOT_OBJECT)
1768                 handle = boot_ec->handle;
1769         else if (!acpi_ec_ecdt_get_handle(&handle))
1770                 return -ENODEV;
1771         return acpi_config_boot_ec(boot_ec, handle, true, true);
1772 }
1773
1774 #if 0
1775 /*
1776  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1777  * set, for which case, we complete the QR_EC without issuing it to the
1778  * firmware.
1779  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1780  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1781  */
1782 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1783 {
1784         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1785         EC_FLAGS_QUERY_HANDSHAKE = 1;
1786         return 0;
1787 }
1788 #endif
1789
1790 /*
1791  * Some ECDTs contain wrong register addresses.
1792  * MSI MS-171F
1793  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1794  */
1795 static int ec_correct_ecdt(const struct dmi_system_id *id)
1796 {
1797         pr_debug("Detected system needing ECDT address correction.\n");
1798         EC_FLAGS_CORRECT_ECDT = 1;
1799         return 0;
1800 }
1801
1802 /*
1803  * Some DSDTs contain wrong GPE setting.
1804  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1805  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1806  */
1807 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1808 {
1809         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1810         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1811         return 0;
1812 }
1813
1814 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1815         {
1816         ec_correct_ecdt, "MSI MS-171F", {
1817         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1818         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1819         {
1820         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1821         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1822         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1823         {
1824         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1825         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1826         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1827         {
1828         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1829         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1830         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1831         {
1832         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1833         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1834         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1835         {
1836         ec_honor_ecdt_gpe, "ASUS X580VD", {
1837         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1838         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1839         {},
1840 };
1841
1842 int __init acpi_ec_ecdt_probe(void)
1843 {
1844         int ret;
1845         acpi_status status;
1846         struct acpi_table_ecdt *ecdt_ptr;
1847         struct acpi_ec *ec;
1848
1849         ec = acpi_ec_alloc();
1850         if (!ec)
1851                 return -ENOMEM;
1852         /*
1853          * Generate a boot ec context
1854          */
1855         dmi_check_system(ec_dmi_table);
1856         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1857                                 (struct acpi_table_header **)&ecdt_ptr);
1858         if (ACPI_FAILURE(status)) {
1859                 ret = -ENODEV;
1860                 goto error;
1861         }
1862
1863         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1864                 /*
1865                  * Asus X50GL:
1866                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1867                  */
1868                 ret = -ENODEV;
1869                 goto error;
1870         }
1871
1872         if (EC_FLAGS_CORRECT_ECDT) {
1873                 ec->command_addr = ecdt_ptr->data.address;
1874                 ec->data_addr = ecdt_ptr->control.address;
1875         } else {
1876                 ec->command_addr = ecdt_ptr->control.address;
1877                 ec->data_addr = ecdt_ptr->data.address;
1878         }
1879         ec->gpe = ecdt_ptr->gpe;
1880
1881         /*
1882          * At this point, the namespace is not initialized, so do not find
1883          * the namespace objects, or handle the events.
1884          */
1885         ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1886 error:
1887         if (ret)
1888                 acpi_ec_free(ec);
1889         return ret;
1890 }
1891
1892 #ifdef CONFIG_PM_SLEEP
1893 static int acpi_ec_suspend(struct device *dev)
1894 {
1895         struct acpi_ec *ec =
1896                 acpi_driver_data(to_acpi_device(dev));
1897
1898         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1899                 acpi_ec_disable_event(ec);
1900         return 0;
1901 }
1902
1903 static int acpi_ec_suspend_noirq(struct device *dev)
1904 {
1905         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1906
1907         /*
1908          * The SCI handler doesn't run at this point, so the GPE can be
1909          * masked at the low level without side effects.
1910          */
1911         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1912             ec->reference_count >= 1)
1913                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1914
1915         return 0;
1916 }
1917
1918 static int acpi_ec_resume_noirq(struct device *dev)
1919 {
1920         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1921
1922         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1923             ec->reference_count >= 1)
1924                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1925
1926         return 0;
1927 }
1928
1929 static int acpi_ec_resume(struct device *dev)
1930 {
1931         struct acpi_ec *ec =
1932                 acpi_driver_data(to_acpi_device(dev));
1933
1934         acpi_ec_enable_event(ec);
1935         return 0;
1936 }
1937 #endif
1938
1939 static const struct dev_pm_ops acpi_ec_pm = {
1940         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1941         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1942 };
1943
1944 static int param_set_event_clearing(const char *val,
1945                                     const struct kernel_param *kp)
1946 {
1947         int result = 0;
1948
1949         if (!strncmp(val, "status", sizeof("status") - 1)) {
1950                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1951                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1952         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1953                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1954                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1955         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1956                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1957                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1958         } else
1959                 result = -EINVAL;
1960         return result;
1961 }
1962
1963 static int param_get_event_clearing(char *buffer,
1964                                     const struct kernel_param *kp)
1965 {
1966         switch (ec_event_clearing) {
1967         case ACPI_EC_EVT_TIMING_STATUS:
1968                 return sprintf(buffer, "status");
1969         case ACPI_EC_EVT_TIMING_QUERY:
1970                 return sprintf(buffer, "query");
1971         case ACPI_EC_EVT_TIMING_EVENT:
1972                 return sprintf(buffer, "event");
1973         default:
1974                 return sprintf(buffer, "invalid");
1975         }
1976         return 0;
1977 }
1978
1979 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
1980                   NULL, 0644);
1981 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
1982
1983 static struct acpi_driver acpi_ec_driver = {
1984         .name = "ec",
1985         .class = ACPI_EC_CLASS,
1986         .ids = ec_device_ids,
1987         .ops = {
1988                 .add = acpi_ec_add,
1989                 .remove = acpi_ec_remove,
1990                 },
1991         .drv.pm = &acpi_ec_pm,
1992 };
1993
1994 static inline int acpi_ec_query_init(void)
1995 {
1996         if (!ec_query_wq) {
1997                 ec_query_wq = alloc_workqueue("kec_query", 0,
1998                                               ec_max_queries);
1999                 if (!ec_query_wq)
2000                         return -ENODEV;
2001         }
2002         return 0;
2003 }
2004
2005 static inline void acpi_ec_query_exit(void)
2006 {
2007         if (ec_query_wq) {
2008                 destroy_workqueue(ec_query_wq);
2009                 ec_query_wq = NULL;
2010         }
2011 }
2012
2013 int __init acpi_ec_init(void)
2014 {
2015         int result;
2016         int ecdt_fail, dsdt_fail;
2017
2018         /* register workqueue for _Qxx evaluations */
2019         result = acpi_ec_query_init();
2020         if (result)
2021                 return result;
2022
2023         /* Drivers must be started after acpi_ec_query_init() */
2024         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2025         ecdt_fail = acpi_ec_ecdt_start();
2026         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2027 }
2028
2029 /* EC driver currently not unloadable */
2030 #if 0
2031 static void __exit acpi_ec_exit(void)
2032 {
2033
2034         acpi_bus_unregister_driver(&acpi_ec_driver);
2035         acpi_ec_query_exit();
2036 }
2037 #endif  /* 0 */