treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / drivers / acpi / ec.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  ec.c - ACPI Embedded Controller Driver (v3)
4  *
5  *  Copyright (C) 2001-2015 Intel Corporation
6  *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
7  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
8  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
9  *            2004       Luming Yu <luming.yu@intel.com>
10  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
11  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
12  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
13  */
14
15 /* Uncomment next line to get verbose printout */
16 /* #define DEBUG */
17 #define pr_fmt(fmt) "ACPI: EC: " fmt
18
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/types.h>
23 #include <linux/delay.h>
24 #include <linux/interrupt.h>
25 #include <linux/list.h>
26 #include <linux/spinlock.h>
27 #include <linux/slab.h>
28 #include <linux/acpi.h>
29 #include <linux/dmi.h>
30 #include <asm/io.h>
31
32 #include "internal.h"
33
34 #define ACPI_EC_CLASS                   "embedded_controller"
35 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
36 #define ACPI_EC_FILE_INFO               "info"
37
38 /* EC status register */
39 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
40 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
41 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
42 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
43 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
44
45 /*
46  * The SCI_EVT clearing timing is not defined by the ACPI specification.
47  * This leads to lots of practical timing issues for the host EC driver.
48  * The following variations are defined (from the target EC firmware's
49  * perspective):
50  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
51  *         target can clear SCI_EVT at any time so long as the host can see
52  *         the indication by reading the status register (EC_SC). So the
53  *         host should re-check SCI_EVT after the first time the SCI_EVT
54  *         indication is seen, which is the same time the query request
55  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
56  *         at any later time could indicate another event. Normally such
57  *         kind of EC firmware has implemented an event queue and will
58  *         return 0x00 to indicate "no outstanding event".
59  * QUERY: After seeing the query request (QR_EC) written to the command
60  *        register (EC_CMD) by the host and having prepared the responding
61  *        event value in the data register (EC_DATA), the target can safely
62  *        clear SCI_EVT because the target can confirm that the current
63  *        event is being handled by the host. The host then should check
64  *        SCI_EVT right after reading the event response from the data
65  *        register (EC_DATA).
66  * EVENT: After seeing the event response read from the data register
67  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
68  *        target requires time to notice the change in the data register
69  *        (EC_DATA), the host may be required to wait additional guarding
70  *        time before checking the SCI_EVT again. Such guarding may not be
71  *        necessary if the host is notified via another IRQ.
72  */
73 #define ACPI_EC_EVT_TIMING_STATUS       0x00
74 #define ACPI_EC_EVT_TIMING_QUERY        0x01
75 #define ACPI_EC_EVT_TIMING_EVENT        0x02
76
77 /* EC commands */
78 enum ec_command {
79         ACPI_EC_COMMAND_READ = 0x80,
80         ACPI_EC_COMMAND_WRITE = 0x81,
81         ACPI_EC_BURST_ENABLE = 0x82,
82         ACPI_EC_BURST_DISABLE = 0x83,
83         ACPI_EC_COMMAND_QUERY = 0x84,
84 };
85
86 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
87 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
88 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
89 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
90                                          * when trying to clear the EC */
91 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
92
93 enum {
94         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
95         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
96         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
97         EC_FLAGS_GPE_HANDLER_INSTALLED, /* GPE handler installed */
98         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
99         EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */
100         EC_FLAGS_STARTED,               /* Driver is started */
101         EC_FLAGS_STOPPED,               /* Driver is stopped */
102         EC_FLAGS_GPE_MASKED,            /* GPE masked */
103 };
104
105 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
106 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
107
108 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
109 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
110 module_param(ec_delay, uint, 0644);
111 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
112
113 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
114 module_param(ec_max_queries, uint, 0644);
115 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
116
117 static bool ec_busy_polling __read_mostly;
118 module_param(ec_busy_polling, bool, 0644);
119 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
120
121 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
122 module_param(ec_polling_guard, uint, 0644);
123 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
124
125 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
126
127 /*
128  * If the number of false interrupts per one transaction exceeds
129  * this threshold, will think there is a GPE storm happened and
130  * will disable the GPE for normal transaction.
131  */
132 static unsigned int ec_storm_threshold  __read_mostly = 8;
133 module_param(ec_storm_threshold, uint, 0644);
134 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
135
136 static bool ec_freeze_events __read_mostly = false;
137 module_param(ec_freeze_events, bool, 0644);
138 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
139
140 static bool ec_no_wakeup __read_mostly;
141 module_param(ec_no_wakeup, bool, 0644);
142 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
143
144 struct acpi_ec_query_handler {
145         struct list_head node;
146         acpi_ec_query_func func;
147         acpi_handle handle;
148         void *data;
149         u8 query_bit;
150         struct kref kref;
151 };
152
153 struct transaction {
154         const u8 *wdata;
155         u8 *rdata;
156         unsigned short irq_count;
157         u8 command;
158         u8 wi;
159         u8 ri;
160         u8 wlen;
161         u8 rlen;
162         u8 flags;
163 };
164
165 struct acpi_ec_query {
166         struct transaction transaction;
167         struct work_struct work;
168         struct acpi_ec_query_handler *handler;
169 };
170
171 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
172 static void advance_transaction(struct acpi_ec *ec);
173 static void acpi_ec_event_handler(struct work_struct *work);
174 static void acpi_ec_event_processor(struct work_struct *work);
175
176 struct acpi_ec *first_ec;
177 EXPORT_SYMBOL(first_ec);
178
179 static struct acpi_ec *boot_ec;
180 static bool boot_ec_is_ecdt = false;
181 static struct workqueue_struct *ec_query_wq;
182
183 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
184 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
185 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
186 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
187
188 /* --------------------------------------------------------------------------
189  *                           Logging/Debugging
190  * -------------------------------------------------------------------------- */
191
192 /*
193  * Splitters used by the developers to track the boundary of the EC
194  * handling processes.
195  */
196 #ifdef DEBUG
197 #define EC_DBG_SEP      " "
198 #define EC_DBG_DRV      "+++++"
199 #define EC_DBG_STM      "====="
200 #define EC_DBG_REQ      "*****"
201 #define EC_DBG_EVT      "#####"
202 #else
203 #define EC_DBG_SEP      ""
204 #define EC_DBG_DRV
205 #define EC_DBG_STM
206 #define EC_DBG_REQ
207 #define EC_DBG_EVT
208 #endif
209
210 #define ec_log_raw(fmt, ...) \
211         pr_info(fmt "\n", ##__VA_ARGS__)
212 #define ec_dbg_raw(fmt, ...) \
213         pr_debug(fmt "\n", ##__VA_ARGS__)
214 #define ec_log(filter, fmt, ...) \
215         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
216 #define ec_dbg(filter, fmt, ...) \
217         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
218
219 #define ec_log_drv(fmt, ...) \
220         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
221 #define ec_dbg_drv(fmt, ...) \
222         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
223 #define ec_dbg_stm(fmt, ...) \
224         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
225 #define ec_dbg_req(fmt, ...) \
226         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
227 #define ec_dbg_evt(fmt, ...) \
228         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
229 #define ec_dbg_ref(ec, fmt, ...) \
230         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
231
232 /* --------------------------------------------------------------------------
233  *                           Device Flags
234  * -------------------------------------------------------------------------- */
235
236 static bool acpi_ec_started(struct acpi_ec *ec)
237 {
238         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
239                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
240 }
241
242 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
243 {
244         /*
245          * There is an OSPM early stage logic. During the early stages
246          * (boot/resume), OSPMs shouldn't enable the event handling, only
247          * the EC transactions are allowed to be performed.
248          */
249         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
250                 return false;
251         /*
252          * However, disabling the event handling is experimental for late
253          * stage (suspend), and is controlled by the boot parameter of
254          * "ec_freeze_events":
255          * 1. true:  The EC event handling is disabled before entering
256          *           the noirq stage.
257          * 2. false: The EC event handling is automatically disabled as
258          *           soon as the EC driver is stopped.
259          */
260         if (ec_freeze_events)
261                 return acpi_ec_started(ec);
262         else
263                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
264 }
265
266 static bool acpi_ec_flushed(struct acpi_ec *ec)
267 {
268         return ec->reference_count == 1;
269 }
270
271 /* --------------------------------------------------------------------------
272  *                           EC Registers
273  * -------------------------------------------------------------------------- */
274
275 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
276 {
277         u8 x = inb(ec->command_addr);
278
279         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
280                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
281                    x,
282                    !!(x & ACPI_EC_FLAG_SCI),
283                    !!(x & ACPI_EC_FLAG_BURST),
284                    !!(x & ACPI_EC_FLAG_CMD),
285                    !!(x & ACPI_EC_FLAG_IBF),
286                    !!(x & ACPI_EC_FLAG_OBF));
287         return x;
288 }
289
290 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
291 {
292         u8 x = inb(ec->data_addr);
293
294         ec->timestamp = jiffies;
295         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
296         return x;
297 }
298
299 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
300 {
301         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
302         outb(command, ec->command_addr);
303         ec->timestamp = jiffies;
304 }
305
306 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
307 {
308         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
309         outb(data, ec->data_addr);
310         ec->timestamp = jiffies;
311 }
312
313 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
314 static const char *acpi_ec_cmd_string(u8 cmd)
315 {
316         switch (cmd) {
317         case 0x80:
318                 return "RD_EC";
319         case 0x81:
320                 return "WR_EC";
321         case 0x82:
322                 return "BE_EC";
323         case 0x83:
324                 return "BD_EC";
325         case 0x84:
326                 return "QR_EC";
327         }
328         return "UNKNOWN";
329 }
330 #else
331 #define acpi_ec_cmd_string(cmd)         "UNDEF"
332 #endif
333
334 /* --------------------------------------------------------------------------
335  *                           GPE Registers
336  * -------------------------------------------------------------------------- */
337
338 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
339 {
340         acpi_event_status gpe_status = 0;
341
342         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
343         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
344 }
345
346 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
347 {
348         if (open)
349                 acpi_enable_gpe(NULL, ec->gpe);
350         else {
351                 BUG_ON(ec->reference_count < 1);
352                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
353         }
354         if (acpi_ec_is_gpe_raised(ec)) {
355                 /*
356                  * On some platforms, EN=1 writes cannot trigger GPE. So
357                  * software need to manually trigger a pseudo GPE event on
358                  * EN=1 writes.
359                  */
360                 ec_dbg_raw("Polling quirk");
361                 advance_transaction(ec);
362         }
363 }
364
365 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
366 {
367         if (close)
368                 acpi_disable_gpe(NULL, ec->gpe);
369         else {
370                 BUG_ON(ec->reference_count < 1);
371                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
372         }
373 }
374
375 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
376 {
377         /*
378          * GPE STS is a W1C register, which means:
379          * 1. Software can clear it without worrying about clearing other
380          *    GPEs' STS bits when the hardware sets them in parallel.
381          * 2. As long as software can ensure only clearing it when it is
382          *    set, hardware won't set it in parallel.
383          * So software can clear GPE in any contexts.
384          * Warning: do not move the check into advance_transaction() as the
385          * EC commands will be sent without GPE raised.
386          */
387         if (!acpi_ec_is_gpe_raised(ec))
388                 return;
389         acpi_clear_gpe(NULL, ec->gpe);
390 }
391
392 /* --------------------------------------------------------------------------
393  *                           Transaction Management
394  * -------------------------------------------------------------------------- */
395
396 static void acpi_ec_submit_request(struct acpi_ec *ec)
397 {
398         ec->reference_count++;
399         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
400             ec->reference_count == 1)
401                 acpi_ec_enable_gpe(ec, true);
402 }
403
404 static void acpi_ec_complete_request(struct acpi_ec *ec)
405 {
406         bool flushed = false;
407
408         ec->reference_count--;
409         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
410             ec->reference_count == 0)
411                 acpi_ec_disable_gpe(ec, true);
412         flushed = acpi_ec_flushed(ec);
413         if (flushed)
414                 wake_up(&ec->wait);
415 }
416
417 static void acpi_ec_mask_gpe(struct acpi_ec *ec)
418 {
419         if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
420                 acpi_ec_disable_gpe(ec, false);
421                 ec_dbg_drv("Polling enabled");
422                 set_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
423         }
424 }
425
426 static void acpi_ec_unmask_gpe(struct acpi_ec *ec)
427 {
428         if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
429                 clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
430                 acpi_ec_enable_gpe(ec, false);
431                 ec_dbg_drv("Polling disabled");
432         }
433 }
434
435 /*
436  * acpi_ec_submit_flushable_request() - Increase the reference count unless
437  *                                      the flush operation is not in
438  *                                      progress
439  * @ec: the EC device
440  *
441  * This function must be used before taking a new action that should hold
442  * the reference count.  If this function returns false, then the action
443  * must be discarded or it will prevent the flush operation from being
444  * completed.
445  */
446 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
447 {
448         if (!acpi_ec_started(ec))
449                 return false;
450         acpi_ec_submit_request(ec);
451         return true;
452 }
453
454 static void acpi_ec_submit_query(struct acpi_ec *ec)
455 {
456         acpi_ec_mask_gpe(ec);
457         if (!acpi_ec_event_enabled(ec))
458                 return;
459         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
460                 ec_dbg_evt("Command(%s) submitted/blocked",
461                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
462                 ec->nr_pending_queries++;
463                 schedule_work(&ec->work);
464         }
465 }
466
467 static void acpi_ec_complete_query(struct acpi_ec *ec)
468 {
469         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
470                 ec_dbg_evt("Command(%s) unblocked",
471                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
472         acpi_ec_unmask_gpe(ec);
473 }
474
475 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
476 {
477         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
478                 ec_log_drv("event unblocked");
479         /*
480          * Unconditionally invoke this once after enabling the event
481          * handling mechanism to detect the pending events.
482          */
483         advance_transaction(ec);
484 }
485
486 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
487 {
488         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
489                 ec_log_drv("event blocked");
490 }
491
492 /*
493  * Process _Q events that might have accumulated in the EC.
494  * Run with locked ec mutex.
495  */
496 static void acpi_ec_clear(struct acpi_ec *ec)
497 {
498         int i, status;
499         u8 value = 0;
500
501         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
502                 status = acpi_ec_query(ec, &value);
503                 if (status || !value)
504                         break;
505         }
506         if (unlikely(i == ACPI_EC_CLEAR_MAX))
507                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
508         else
509                 pr_info("%d stale EC events cleared\n", i);
510 }
511
512 static void acpi_ec_enable_event(struct acpi_ec *ec)
513 {
514         unsigned long flags;
515
516         spin_lock_irqsave(&ec->lock, flags);
517         if (acpi_ec_started(ec))
518                 __acpi_ec_enable_event(ec);
519         spin_unlock_irqrestore(&ec->lock, flags);
520
521         /* Drain additional events if hardware requires that */
522         if (EC_FLAGS_CLEAR_ON_RESUME)
523                 acpi_ec_clear(ec);
524 }
525
526 #ifdef CONFIG_PM_SLEEP
527 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
528 {
529         bool flushed;
530         unsigned long flags;
531
532         spin_lock_irqsave(&ec->lock, flags);
533         flushed = !ec->nr_pending_queries;
534         spin_unlock_irqrestore(&ec->lock, flags);
535         return flushed;
536 }
537
538 static void __acpi_ec_flush_event(struct acpi_ec *ec)
539 {
540         /*
541          * When ec_freeze_events is true, we need to flush events in
542          * the proper position before entering the noirq stage.
543          */
544         wait_event(ec->wait, acpi_ec_query_flushed(ec));
545         if (ec_query_wq)
546                 flush_workqueue(ec_query_wq);
547 }
548
549 static void acpi_ec_disable_event(struct acpi_ec *ec)
550 {
551         unsigned long flags;
552
553         spin_lock_irqsave(&ec->lock, flags);
554         __acpi_ec_disable_event(ec);
555         spin_unlock_irqrestore(&ec->lock, flags);
556         __acpi_ec_flush_event(ec);
557 }
558
559 void acpi_ec_flush_work(void)
560 {
561         if (first_ec)
562                 __acpi_ec_flush_event(first_ec);
563
564         flush_scheduled_work();
565 }
566 #endif /* CONFIG_PM_SLEEP */
567
568 static bool acpi_ec_guard_event(struct acpi_ec *ec)
569 {
570         bool guarded = true;
571         unsigned long flags;
572
573         spin_lock_irqsave(&ec->lock, flags);
574         /*
575          * If firmware SCI_EVT clearing timing is "event", we actually
576          * don't know when the SCI_EVT will be cleared by firmware after
577          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
578          * acceptable period.
579          *
580          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
581          * flagged, which means SCI_EVT check has just been performed.
582          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
583          * guarding should have already been performed (via
584          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
585          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
586          * ACPI_EC_COMMAND_POLL state immediately.
587          */
588         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
589             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
590             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
591             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
592                 guarded = false;
593         spin_unlock_irqrestore(&ec->lock, flags);
594         return guarded;
595 }
596
597 static int ec_transaction_polled(struct acpi_ec *ec)
598 {
599         unsigned long flags;
600         int ret = 0;
601
602         spin_lock_irqsave(&ec->lock, flags);
603         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
604                 ret = 1;
605         spin_unlock_irqrestore(&ec->lock, flags);
606         return ret;
607 }
608
609 static int ec_transaction_completed(struct acpi_ec *ec)
610 {
611         unsigned long flags;
612         int ret = 0;
613
614         spin_lock_irqsave(&ec->lock, flags);
615         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
616                 ret = 1;
617         spin_unlock_irqrestore(&ec->lock, flags);
618         return ret;
619 }
620
621 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
622 {
623         ec->curr->flags |= flag;
624         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
625                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
626                     flag == ACPI_EC_COMMAND_POLL)
627                         acpi_ec_complete_query(ec);
628                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
629                     flag == ACPI_EC_COMMAND_COMPLETE)
630                         acpi_ec_complete_query(ec);
631                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
632                     flag == ACPI_EC_COMMAND_COMPLETE)
633                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
634         }
635 }
636
637 static void advance_transaction(struct acpi_ec *ec)
638 {
639         struct transaction *t;
640         u8 status;
641         bool wakeup = false;
642
643         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
644                    smp_processor_id());
645         /*
646          * By always clearing STS before handling all indications, we can
647          * ensure a hardware STS 0->1 change after this clearing can always
648          * trigger a GPE interrupt.
649          */
650         acpi_ec_clear_gpe(ec);
651         status = acpi_ec_read_status(ec);
652         t = ec->curr;
653         /*
654          * Another IRQ or a guarded polling mode advancement is detected,
655          * the next QR_EC submission is then allowed.
656          */
657         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
658                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
659                     (!ec->nr_pending_queries ||
660                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
661                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
662                         acpi_ec_complete_query(ec);
663                 }
664         }
665         if (!t)
666                 goto err;
667         if (t->flags & ACPI_EC_COMMAND_POLL) {
668                 if (t->wlen > t->wi) {
669                         if ((status & ACPI_EC_FLAG_IBF) == 0)
670                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
671                         else
672                                 goto err;
673                 } else if (t->rlen > t->ri) {
674                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
675                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
676                                 if (t->rlen == t->ri) {
677                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
678                                         if (t->command == ACPI_EC_COMMAND_QUERY)
679                                                 ec_dbg_evt("Command(%s) completed by hardware",
680                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
681                                         wakeup = true;
682                                 }
683                         } else
684                                 goto err;
685                 } else if (t->wlen == t->wi &&
686                            (status & ACPI_EC_FLAG_IBF) == 0) {
687                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
688                         wakeup = true;
689                 }
690                 goto out;
691         } else {
692                 if (EC_FLAGS_QUERY_HANDSHAKE &&
693                     !(status & ACPI_EC_FLAG_SCI) &&
694                     (t->command == ACPI_EC_COMMAND_QUERY)) {
695                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
696                         t->rdata[t->ri++] = 0x00;
697                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
698                         ec_dbg_evt("Command(%s) completed by software",
699                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
700                         wakeup = true;
701                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
702                         acpi_ec_write_cmd(ec, t->command);
703                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
704                 } else
705                         goto err;
706                 goto out;
707         }
708 err:
709         /*
710          * If SCI bit is set, then don't think it's a false IRQ
711          * otherwise will take a not handled IRQ as a false one.
712          */
713         if (!(status & ACPI_EC_FLAG_SCI)) {
714                 if (in_interrupt() && t) {
715                         if (t->irq_count < ec_storm_threshold)
716                                 ++t->irq_count;
717                         /* Allow triggering on 0 threshold */
718                         if (t->irq_count == ec_storm_threshold)
719                                 acpi_ec_mask_gpe(ec);
720                 }
721         }
722 out:
723         if (status & ACPI_EC_FLAG_SCI)
724                 acpi_ec_submit_query(ec);
725         if (wakeup && in_interrupt())
726                 wake_up(&ec->wait);
727 }
728
729 static void start_transaction(struct acpi_ec *ec)
730 {
731         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
732         ec->curr->flags = 0;
733 }
734
735 static int ec_guard(struct acpi_ec *ec)
736 {
737         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
738         unsigned long timeout = ec->timestamp + guard;
739
740         /* Ensure guarding period before polling EC status */
741         do {
742                 if (ec->busy_polling) {
743                         /* Perform busy polling */
744                         if (ec_transaction_completed(ec))
745                                 return 0;
746                         udelay(jiffies_to_usecs(guard));
747                 } else {
748                         /*
749                          * Perform wait polling
750                          * 1. Wait the transaction to be completed by the
751                          *    GPE handler after the transaction enters
752                          *    ACPI_EC_COMMAND_POLL state.
753                          * 2. A special guarding logic is also required
754                          *    for event clearing mode "event" before the
755                          *    transaction enters ACPI_EC_COMMAND_POLL
756                          *    state.
757                          */
758                         if (!ec_transaction_polled(ec) &&
759                             !acpi_ec_guard_event(ec))
760                                 break;
761                         if (wait_event_timeout(ec->wait,
762                                                ec_transaction_completed(ec),
763                                                guard))
764                                 return 0;
765                 }
766         } while (time_before(jiffies, timeout));
767         return -ETIME;
768 }
769
770 static int ec_poll(struct acpi_ec *ec)
771 {
772         unsigned long flags;
773         int repeat = 5; /* number of command restarts */
774
775         while (repeat--) {
776                 unsigned long delay = jiffies +
777                         msecs_to_jiffies(ec_delay);
778                 do {
779                         if (!ec_guard(ec))
780                                 return 0;
781                         spin_lock_irqsave(&ec->lock, flags);
782                         advance_transaction(ec);
783                         spin_unlock_irqrestore(&ec->lock, flags);
784                 } while (time_before(jiffies, delay));
785                 pr_debug("controller reset, restart transaction\n");
786                 spin_lock_irqsave(&ec->lock, flags);
787                 start_transaction(ec);
788                 spin_unlock_irqrestore(&ec->lock, flags);
789         }
790         return -ETIME;
791 }
792
793 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
794                                         struct transaction *t)
795 {
796         unsigned long tmp;
797         int ret = 0;
798
799         /* start transaction */
800         spin_lock_irqsave(&ec->lock, tmp);
801         /* Enable GPE for command processing (IBF=0/OBF=1) */
802         if (!acpi_ec_submit_flushable_request(ec)) {
803                 ret = -EINVAL;
804                 goto unlock;
805         }
806         ec_dbg_ref(ec, "Increase command");
807         /* following two actions should be kept atomic */
808         ec->curr = t;
809         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
810         start_transaction(ec);
811         spin_unlock_irqrestore(&ec->lock, tmp);
812
813         ret = ec_poll(ec);
814
815         spin_lock_irqsave(&ec->lock, tmp);
816         if (t->irq_count == ec_storm_threshold)
817                 acpi_ec_unmask_gpe(ec);
818         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
819         ec->curr = NULL;
820         /* Disable GPE for command processing (IBF=0/OBF=1) */
821         acpi_ec_complete_request(ec);
822         ec_dbg_ref(ec, "Decrease command");
823 unlock:
824         spin_unlock_irqrestore(&ec->lock, tmp);
825         return ret;
826 }
827
828 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
829 {
830         int status;
831         u32 glk;
832
833         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
834                 return -EINVAL;
835         if (t->rdata)
836                 memset(t->rdata, 0, t->rlen);
837
838         mutex_lock(&ec->mutex);
839         if (ec->global_lock) {
840                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
841                 if (ACPI_FAILURE(status)) {
842                         status = -ENODEV;
843                         goto unlock;
844                 }
845         }
846
847         status = acpi_ec_transaction_unlocked(ec, t);
848
849         if (ec->global_lock)
850                 acpi_release_global_lock(glk);
851 unlock:
852         mutex_unlock(&ec->mutex);
853         return status;
854 }
855
856 static int acpi_ec_burst_enable(struct acpi_ec *ec)
857 {
858         u8 d;
859         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
860                                 .wdata = NULL, .rdata = &d,
861                                 .wlen = 0, .rlen = 1};
862
863         return acpi_ec_transaction(ec, &t);
864 }
865
866 static int acpi_ec_burst_disable(struct acpi_ec *ec)
867 {
868         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
869                                 .wdata = NULL, .rdata = NULL,
870                                 .wlen = 0, .rlen = 0};
871
872         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
873                                 acpi_ec_transaction(ec, &t) : 0;
874 }
875
876 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
877 {
878         int result;
879         u8 d;
880         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
881                                 .wdata = &address, .rdata = &d,
882                                 .wlen = 1, .rlen = 1};
883
884         result = acpi_ec_transaction(ec, &t);
885         *data = d;
886         return result;
887 }
888
889 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
890 {
891         u8 wdata[2] = { address, data };
892         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
893                                 .wdata = wdata, .rdata = NULL,
894                                 .wlen = 2, .rlen = 0};
895
896         return acpi_ec_transaction(ec, &t);
897 }
898
899 int ec_read(u8 addr, u8 *val)
900 {
901         int err;
902         u8 temp_data;
903
904         if (!first_ec)
905                 return -ENODEV;
906
907         err = acpi_ec_read(first_ec, addr, &temp_data);
908
909         if (!err) {
910                 *val = temp_data;
911                 return 0;
912         }
913         return err;
914 }
915 EXPORT_SYMBOL(ec_read);
916
917 int ec_write(u8 addr, u8 val)
918 {
919         int err;
920
921         if (!first_ec)
922                 return -ENODEV;
923
924         err = acpi_ec_write(first_ec, addr, val);
925
926         return err;
927 }
928 EXPORT_SYMBOL(ec_write);
929
930 int ec_transaction(u8 command,
931                    const u8 *wdata, unsigned wdata_len,
932                    u8 *rdata, unsigned rdata_len)
933 {
934         struct transaction t = {.command = command,
935                                 .wdata = wdata, .rdata = rdata,
936                                 .wlen = wdata_len, .rlen = rdata_len};
937
938         if (!first_ec)
939                 return -ENODEV;
940
941         return acpi_ec_transaction(first_ec, &t);
942 }
943 EXPORT_SYMBOL(ec_transaction);
944
945 /* Get the handle to the EC device */
946 acpi_handle ec_get_handle(void)
947 {
948         if (!first_ec)
949                 return NULL;
950         return first_ec->handle;
951 }
952 EXPORT_SYMBOL(ec_get_handle);
953
954 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
955 {
956         unsigned long flags;
957
958         spin_lock_irqsave(&ec->lock, flags);
959         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
960                 ec_dbg_drv("Starting EC");
961                 /* Enable GPE for event processing (SCI_EVT=1) */
962                 if (!resuming) {
963                         acpi_ec_submit_request(ec);
964                         ec_dbg_ref(ec, "Increase driver");
965                 }
966                 ec_log_drv("EC started");
967         }
968         spin_unlock_irqrestore(&ec->lock, flags);
969 }
970
971 static bool acpi_ec_stopped(struct acpi_ec *ec)
972 {
973         unsigned long flags;
974         bool flushed;
975
976         spin_lock_irqsave(&ec->lock, flags);
977         flushed = acpi_ec_flushed(ec);
978         spin_unlock_irqrestore(&ec->lock, flags);
979         return flushed;
980 }
981
982 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
983 {
984         unsigned long flags;
985
986         spin_lock_irqsave(&ec->lock, flags);
987         if (acpi_ec_started(ec)) {
988                 ec_dbg_drv("Stopping EC");
989                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
990                 spin_unlock_irqrestore(&ec->lock, flags);
991                 wait_event(ec->wait, acpi_ec_stopped(ec));
992                 spin_lock_irqsave(&ec->lock, flags);
993                 /* Disable GPE for event processing (SCI_EVT=1) */
994                 if (!suspending) {
995                         acpi_ec_complete_request(ec);
996                         ec_dbg_ref(ec, "Decrease driver");
997                 } else if (!ec_freeze_events)
998                         __acpi_ec_disable_event(ec);
999                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
1000                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
1001                 ec_log_drv("EC stopped");
1002         }
1003         spin_unlock_irqrestore(&ec->lock, flags);
1004 }
1005
1006 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1007 {
1008         unsigned long flags;
1009
1010         spin_lock_irqsave(&ec->lock, flags);
1011         ec->busy_polling = true;
1012         ec->polling_guard = 0;
1013         ec_log_drv("interrupt blocked");
1014         spin_unlock_irqrestore(&ec->lock, flags);
1015 }
1016
1017 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1018 {
1019         unsigned long flags;
1020
1021         spin_lock_irqsave(&ec->lock, flags);
1022         ec->busy_polling = ec_busy_polling;
1023         ec->polling_guard = ec_polling_guard;
1024         ec_log_drv("interrupt unblocked");
1025         spin_unlock_irqrestore(&ec->lock, flags);
1026 }
1027
1028 void acpi_ec_block_transactions(void)
1029 {
1030         struct acpi_ec *ec = first_ec;
1031
1032         if (!ec)
1033                 return;
1034
1035         mutex_lock(&ec->mutex);
1036         /* Prevent transactions from being carried out */
1037         acpi_ec_stop(ec, true);
1038         mutex_unlock(&ec->mutex);
1039 }
1040
1041 void acpi_ec_unblock_transactions(void)
1042 {
1043         /*
1044          * Allow transactions to happen again (this function is called from
1045          * atomic context during wakeup, so we don't need to acquire the mutex).
1046          */
1047         if (first_ec)
1048                 acpi_ec_start(first_ec, true);
1049 }
1050
1051 void acpi_ec_mark_gpe_for_wake(void)
1052 {
1053         if (first_ec && !ec_no_wakeup)
1054                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1055 }
1056
1057 void acpi_ec_set_gpe_wake_mask(u8 action)
1058 {
1059         if (first_ec && !ec_no_wakeup)
1060                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1061 }
1062
1063 void acpi_ec_dispatch_gpe(void)
1064 {
1065         if (first_ec)
1066                 acpi_dispatch_gpe(NULL, first_ec->gpe);
1067 }
1068
1069 /* --------------------------------------------------------------------------
1070                                 Event Management
1071    -------------------------------------------------------------------------- */
1072 static struct acpi_ec_query_handler *
1073 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1074 {
1075         if (handler)
1076                 kref_get(&handler->kref);
1077         return handler;
1078 }
1079
1080 static struct acpi_ec_query_handler *
1081 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1082 {
1083         struct acpi_ec_query_handler *handler;
1084         bool found = false;
1085
1086         mutex_lock(&ec->mutex);
1087         list_for_each_entry(handler, &ec->list, node) {
1088                 if (value == handler->query_bit) {
1089                         found = true;
1090                         break;
1091                 }
1092         }
1093         mutex_unlock(&ec->mutex);
1094         return found ? acpi_ec_get_query_handler(handler) : NULL;
1095 }
1096
1097 static void acpi_ec_query_handler_release(struct kref *kref)
1098 {
1099         struct acpi_ec_query_handler *handler =
1100                 container_of(kref, struct acpi_ec_query_handler, kref);
1101
1102         kfree(handler);
1103 }
1104
1105 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1106 {
1107         kref_put(&handler->kref, acpi_ec_query_handler_release);
1108 }
1109
1110 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1111                               acpi_handle handle, acpi_ec_query_func func,
1112                               void *data)
1113 {
1114         struct acpi_ec_query_handler *handler =
1115             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1116
1117         if (!handler)
1118                 return -ENOMEM;
1119
1120         handler->query_bit = query_bit;
1121         handler->handle = handle;
1122         handler->func = func;
1123         handler->data = data;
1124         mutex_lock(&ec->mutex);
1125         kref_init(&handler->kref);
1126         list_add(&handler->node, &ec->list);
1127         mutex_unlock(&ec->mutex);
1128         return 0;
1129 }
1130 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1131
1132 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1133                                           bool remove_all, u8 query_bit)
1134 {
1135         struct acpi_ec_query_handler *handler, *tmp;
1136         LIST_HEAD(free_list);
1137
1138         mutex_lock(&ec->mutex);
1139         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1140                 if (remove_all || query_bit == handler->query_bit) {
1141                         list_del_init(&handler->node);
1142                         list_add(&handler->node, &free_list);
1143                 }
1144         }
1145         mutex_unlock(&ec->mutex);
1146         list_for_each_entry_safe(handler, tmp, &free_list, node)
1147                 acpi_ec_put_query_handler(handler);
1148 }
1149
1150 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1151 {
1152         acpi_ec_remove_query_handlers(ec, false, query_bit);
1153 }
1154 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1155
1156 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1157 {
1158         struct acpi_ec_query *q;
1159         struct transaction *t;
1160
1161         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1162         if (!q)
1163                 return NULL;
1164         INIT_WORK(&q->work, acpi_ec_event_processor);
1165         t = &q->transaction;
1166         t->command = ACPI_EC_COMMAND_QUERY;
1167         t->rdata = pval;
1168         t->rlen = 1;
1169         return q;
1170 }
1171
1172 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1173 {
1174         if (q) {
1175                 if (q->handler)
1176                         acpi_ec_put_query_handler(q->handler);
1177                 kfree(q);
1178         }
1179 }
1180
1181 static void acpi_ec_event_processor(struct work_struct *work)
1182 {
1183         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1184         struct acpi_ec_query_handler *handler = q->handler;
1185
1186         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1187         if (handler->func)
1188                 handler->func(handler->data);
1189         else if (handler->handle)
1190                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1191         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1192         acpi_ec_delete_query(q);
1193 }
1194
1195 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1196 {
1197         u8 value = 0;
1198         int result;
1199         struct acpi_ec_query *q;
1200
1201         q = acpi_ec_create_query(&value);
1202         if (!q)
1203                 return -ENOMEM;
1204
1205         /*
1206          * Query the EC to find out which _Qxx method we need to evaluate.
1207          * Note that successful completion of the query causes the ACPI_EC_SCI
1208          * bit to be cleared (and thus clearing the interrupt source).
1209          */
1210         result = acpi_ec_transaction(ec, &q->transaction);
1211         if (!value)
1212                 result = -ENODATA;
1213         if (result)
1214                 goto err_exit;
1215
1216         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1217         if (!q->handler) {
1218                 result = -ENODATA;
1219                 goto err_exit;
1220         }
1221
1222         /*
1223          * It is reported that _Qxx are evaluated in a parallel way on
1224          * Windows:
1225          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1226          *
1227          * Put this log entry before schedule_work() in order to make
1228          * it appearing before any other log entries occurred during the
1229          * work queue execution.
1230          */
1231         ec_dbg_evt("Query(0x%02x) scheduled", value);
1232         if (!queue_work(ec_query_wq, &q->work)) {
1233                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1234                 result = -EBUSY;
1235         }
1236
1237 err_exit:
1238         if (result)
1239                 acpi_ec_delete_query(q);
1240         if (data)
1241                 *data = value;
1242         return result;
1243 }
1244
1245 static void acpi_ec_check_event(struct acpi_ec *ec)
1246 {
1247         unsigned long flags;
1248
1249         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1250                 if (ec_guard(ec)) {
1251                         spin_lock_irqsave(&ec->lock, flags);
1252                         /*
1253                          * Take care of the SCI_EVT unless no one else is
1254                          * taking care of it.
1255                          */
1256                         if (!ec->curr)
1257                                 advance_transaction(ec);
1258                         spin_unlock_irqrestore(&ec->lock, flags);
1259                 }
1260         }
1261 }
1262
1263 static void acpi_ec_event_handler(struct work_struct *work)
1264 {
1265         unsigned long flags;
1266         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1267
1268         ec_dbg_evt("Event started");
1269
1270         spin_lock_irqsave(&ec->lock, flags);
1271         while (ec->nr_pending_queries) {
1272                 spin_unlock_irqrestore(&ec->lock, flags);
1273                 (void)acpi_ec_query(ec, NULL);
1274                 spin_lock_irqsave(&ec->lock, flags);
1275                 ec->nr_pending_queries--;
1276                 /*
1277                  * Before exit, make sure that this work item can be
1278                  * scheduled again. There might be QR_EC failures, leaving
1279                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1280                  * item from being scheduled again.
1281                  */
1282                 if (!ec->nr_pending_queries) {
1283                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1284                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1285                                 acpi_ec_complete_query(ec);
1286                 }
1287         }
1288         spin_unlock_irqrestore(&ec->lock, flags);
1289
1290         ec_dbg_evt("Event stopped");
1291
1292         acpi_ec_check_event(ec);
1293 }
1294
1295 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1296         u32 gpe_number, void *data)
1297 {
1298         unsigned long flags;
1299         struct acpi_ec *ec = data;
1300
1301         spin_lock_irqsave(&ec->lock, flags);
1302         advance_transaction(ec);
1303         spin_unlock_irqrestore(&ec->lock, flags);
1304         return ACPI_INTERRUPT_HANDLED;
1305 }
1306
1307 /* --------------------------------------------------------------------------
1308  *                           Address Space Management
1309  * -------------------------------------------------------------------------- */
1310
1311 static acpi_status
1312 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1313                       u32 bits, u64 *value64,
1314                       void *handler_context, void *region_context)
1315 {
1316         struct acpi_ec *ec = handler_context;
1317         int result = 0, i, bytes = bits / 8;
1318         u8 *value = (u8 *)value64;
1319
1320         if ((address > 0xFF) || !value || !handler_context)
1321                 return AE_BAD_PARAMETER;
1322
1323         if (function != ACPI_READ && function != ACPI_WRITE)
1324                 return AE_BAD_PARAMETER;
1325
1326         if (ec->busy_polling || bits > 8)
1327                 acpi_ec_burst_enable(ec);
1328
1329         for (i = 0; i < bytes; ++i, ++address, ++value)
1330                 result = (function == ACPI_READ) ?
1331                         acpi_ec_read(ec, address, value) :
1332                         acpi_ec_write(ec, address, *value);
1333
1334         if (ec->busy_polling || bits > 8)
1335                 acpi_ec_burst_disable(ec);
1336
1337         switch (result) {
1338         case -EINVAL:
1339                 return AE_BAD_PARAMETER;
1340         case -ENODEV:
1341                 return AE_NOT_FOUND;
1342         case -ETIME:
1343                 return AE_TIME;
1344         default:
1345                 return AE_OK;
1346         }
1347 }
1348
1349 /* --------------------------------------------------------------------------
1350  *                             Driver Interface
1351  * -------------------------------------------------------------------------- */
1352
1353 static acpi_status
1354 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1355
1356 static void acpi_ec_free(struct acpi_ec *ec)
1357 {
1358         if (first_ec == ec)
1359                 first_ec = NULL;
1360         if (boot_ec == ec)
1361                 boot_ec = NULL;
1362         kfree(ec);
1363 }
1364
1365 static struct acpi_ec *acpi_ec_alloc(void)
1366 {
1367         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1368
1369         if (!ec)
1370                 return NULL;
1371         mutex_init(&ec->mutex);
1372         init_waitqueue_head(&ec->wait);
1373         INIT_LIST_HEAD(&ec->list);
1374         spin_lock_init(&ec->lock);
1375         INIT_WORK(&ec->work, acpi_ec_event_handler);
1376         ec->timestamp = jiffies;
1377         ec->busy_polling = true;
1378         ec->polling_guard = 0;
1379         return ec;
1380 }
1381
1382 static acpi_status
1383 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1384                                void *context, void **return_value)
1385 {
1386         char node_name[5];
1387         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1388         struct acpi_ec *ec = context;
1389         int value = 0;
1390         acpi_status status;
1391
1392         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1393
1394         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1395                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1396         return AE_OK;
1397 }
1398
1399 static acpi_status
1400 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1401 {
1402         acpi_status status;
1403         unsigned long long tmp = 0;
1404         struct acpi_ec *ec = context;
1405
1406         /* clear addr values, ec_parse_io_ports depend on it */
1407         ec->command_addr = ec->data_addr = 0;
1408
1409         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1410                                      ec_parse_io_ports, ec);
1411         if (ACPI_FAILURE(status))
1412                 return status;
1413         if (ec->data_addr == 0 || ec->command_addr == 0)
1414                 return AE_OK;
1415
1416         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1417                 /*
1418                  * Always inherit the GPE number setting from the ECDT
1419                  * EC.
1420                  */
1421                 ec->gpe = boot_ec->gpe;
1422         } else {
1423                 /* Get GPE bit assignment (EC events). */
1424                 /* TODO: Add support for _GPE returning a package */
1425                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1426                 if (ACPI_FAILURE(status))
1427                         return status;
1428                 ec->gpe = tmp;
1429         }
1430         /* Use the global lock for all EC transactions? */
1431         tmp = 0;
1432         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1433         ec->global_lock = tmp;
1434         ec->handle = handle;
1435         return AE_CTRL_TERMINATE;
1436 }
1437
1438 /*
1439  * Note: This function returns an error code only when the address space
1440  *       handler is not installed, which means "not able to handle
1441  *       transactions".
1442  */
1443 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1444 {
1445         acpi_status status;
1446
1447         acpi_ec_start(ec, false);
1448
1449         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1450                 acpi_ec_enter_noirq(ec);
1451                 status = acpi_install_address_space_handler(ec->handle,
1452                                                             ACPI_ADR_SPACE_EC,
1453                                                             &acpi_ec_space_handler,
1454                                                             NULL, ec);
1455                 if (ACPI_FAILURE(status)) {
1456                         if (status == AE_NOT_FOUND) {
1457                                 /*
1458                                  * Maybe OS fails in evaluating the _REG
1459                                  * object. The AE_NOT_FOUND error will be
1460                                  * ignored and OS * continue to initialize
1461                                  * EC.
1462                                  */
1463                                 pr_err("Fail in evaluating the _REG object"
1464                                         " of EC device. Broken bios is suspected.\n");
1465                         } else {
1466                                 acpi_ec_stop(ec, false);
1467                                 return -ENODEV;
1468                         }
1469                 }
1470                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1471         }
1472
1473         if (!handle_events)
1474                 return 0;
1475
1476         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1477                 /* Find and register all query methods */
1478                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1479                                     acpi_ec_register_query_methods,
1480                                     NULL, ec, NULL);
1481                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1482         }
1483         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1484                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1485                                           ACPI_GPE_EDGE_TRIGGERED,
1486                                           &acpi_ec_gpe_handler, ec);
1487                 /* This is not fatal as we can poll EC events */
1488                 if (ACPI_SUCCESS(status)) {
1489                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1490                         acpi_ec_leave_noirq(ec);
1491                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1492                             ec->reference_count >= 1)
1493                                 acpi_ec_enable_gpe(ec, true);
1494                 }
1495         }
1496         /* EC is fully operational, allow queries */
1497         acpi_ec_enable_event(ec);
1498
1499         return 0;
1500 }
1501
1502 static void ec_remove_handlers(struct acpi_ec *ec)
1503 {
1504         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1505                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1506                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1507                         pr_err("failed to remove space handler\n");
1508                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1509         }
1510
1511         /*
1512          * Stops handling the EC transactions after removing the operation
1513          * region handler. This is required because _REG(DISCONNECT)
1514          * invoked during the removal can result in new EC transactions.
1515          *
1516          * Flushes the EC requests and thus disables the GPE before
1517          * removing the GPE handler. This is required by the current ACPICA
1518          * GPE core. ACPICA GPE core will automatically disable a GPE when
1519          * it is indicated but there is no way to handle it. So the drivers
1520          * must disable the GPEs prior to removing the GPE handlers.
1521          */
1522         acpi_ec_stop(ec, false);
1523
1524         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1525                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1526                                         &acpi_ec_gpe_handler)))
1527                         pr_err("failed to remove gpe handler\n");
1528                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1529         }
1530         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1531                 acpi_ec_remove_query_handlers(ec, true, 0);
1532                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1533         }
1534 }
1535
1536 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1537 {
1538         int ret;
1539
1540         ret = ec_install_handlers(ec, handle_events);
1541         if (ret)
1542                 return ret;
1543
1544         /* First EC capable of handling transactions */
1545         if (!first_ec) {
1546                 first_ec = ec;
1547                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1548         }
1549
1550         acpi_handle_info(ec->handle,
1551                          "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1552                          ec->gpe, ec->command_addr, ec->data_addr);
1553         return ret;
1554 }
1555
1556 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1557 {
1558         struct acpi_table_ecdt *ecdt_ptr;
1559         acpi_status status;
1560         acpi_handle handle;
1561
1562         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1563                                 (struct acpi_table_header **)&ecdt_ptr);
1564         if (ACPI_FAILURE(status))
1565                 return false;
1566
1567         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1568         if (ACPI_FAILURE(status))
1569                 return false;
1570
1571         *phandle = handle;
1572         return true;
1573 }
1574
1575 static int acpi_ec_add(struct acpi_device *device)
1576 {
1577         struct acpi_ec *ec = NULL;
1578         bool dep_update = true;
1579         acpi_status status;
1580         int ret;
1581
1582         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1583         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1584
1585         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1586                 boot_ec_is_ecdt = true;
1587                 ec = boot_ec;
1588                 dep_update = false;
1589         } else {
1590                 ec = acpi_ec_alloc();
1591                 if (!ec)
1592                         return -ENOMEM;
1593
1594                 status = ec_parse_device(device->handle, 0, ec, NULL);
1595                 if (status != AE_CTRL_TERMINATE) {
1596                         ret = -EINVAL;
1597                         goto err_alloc;
1598                 }
1599
1600                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1601                     ec->data_addr == boot_ec->data_addr) {
1602                         boot_ec_is_ecdt = false;
1603                         /*
1604                          * Trust PNP0C09 namespace location rather than
1605                          * ECDT ID. But trust ECDT GPE rather than _GPE
1606                          * because of ASUS quirks, so do not change
1607                          * boot_ec->gpe to ec->gpe.
1608                          */
1609                         boot_ec->handle = ec->handle;
1610                         acpi_handle_debug(ec->handle, "duplicated.\n");
1611                         acpi_ec_free(ec);
1612                         ec = boot_ec;
1613                 }
1614         }
1615
1616         ret = acpi_ec_setup(ec, true);
1617         if (ret)
1618                 goto err_query;
1619
1620         if (ec == boot_ec)
1621                 acpi_handle_info(boot_ec->handle,
1622                                  "Boot %s EC used to handle transactions and events\n",
1623                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1624
1625         device->driver_data = ec;
1626
1627         ret = !!request_region(ec->data_addr, 1, "EC data");
1628         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1629         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1630         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1631
1632         if (dep_update) {
1633                 /* Reprobe devices depending on the EC */
1634                 acpi_walk_dep_device_list(ec->handle);
1635         }
1636         acpi_handle_debug(ec->handle, "enumerated.\n");
1637         return 0;
1638
1639 err_query:
1640         if (ec != boot_ec)
1641                 acpi_ec_remove_query_handlers(ec, true, 0);
1642 err_alloc:
1643         if (ec != boot_ec)
1644                 acpi_ec_free(ec);
1645         return ret;
1646 }
1647
1648 static int acpi_ec_remove(struct acpi_device *device)
1649 {
1650         struct acpi_ec *ec;
1651
1652         if (!device)
1653                 return -EINVAL;
1654
1655         ec = acpi_driver_data(device);
1656         release_region(ec->data_addr, 1);
1657         release_region(ec->command_addr, 1);
1658         device->driver_data = NULL;
1659         if (ec != boot_ec) {
1660                 ec_remove_handlers(ec);
1661                 acpi_ec_free(ec);
1662         }
1663         return 0;
1664 }
1665
1666 static acpi_status
1667 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1668 {
1669         struct acpi_ec *ec = context;
1670
1671         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1672                 return AE_OK;
1673
1674         /*
1675          * The first address region returned is the data port, and
1676          * the second address region returned is the status/command
1677          * port.
1678          */
1679         if (ec->data_addr == 0)
1680                 ec->data_addr = resource->data.io.minimum;
1681         else if (ec->command_addr == 0)
1682                 ec->command_addr = resource->data.io.minimum;
1683         else
1684                 return AE_CTRL_TERMINATE;
1685
1686         return AE_OK;
1687 }
1688
1689 static const struct acpi_device_id ec_device_ids[] = {
1690         {"PNP0C09", 0},
1691         {ACPI_ECDT_HID, 0},
1692         {"", 0},
1693 };
1694
1695 /*
1696  * This function is not Windows-compatible as Windows never enumerates the
1697  * namespace EC before the main ACPI device enumeration process. It is
1698  * retained for historical reason and will be deprecated in the future.
1699  */
1700 void __init acpi_ec_dsdt_probe(void)
1701 {
1702         struct acpi_ec *ec;
1703         acpi_status status;
1704         int ret;
1705
1706         /*
1707          * If a platform has ECDT, there is no need to proceed as the
1708          * following probe is not a part of the ACPI device enumeration,
1709          * executing _STA is not safe, and thus this probe may risk of
1710          * picking up an invalid EC device.
1711          */
1712         if (boot_ec)
1713                 return;
1714
1715         ec = acpi_ec_alloc();
1716         if (!ec)
1717                 return;
1718
1719         /*
1720          * At this point, the namespace is initialized, so start to find
1721          * the namespace objects.
1722          */
1723         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1724         if (ACPI_FAILURE(status) || !ec->handle) {
1725                 acpi_ec_free(ec);
1726                 return;
1727         }
1728
1729         /*
1730          * When the DSDT EC is available, always re-configure boot EC to
1731          * have _REG evaluated. _REG can only be evaluated after the
1732          * namespace initialization.
1733          * At this point, the GPE is not fully initialized, so do not to
1734          * handle the events.
1735          */
1736         ret = acpi_ec_setup(ec, false);
1737         if (ret) {
1738                 acpi_ec_free(ec);
1739                 return;
1740         }
1741
1742         boot_ec = ec;
1743
1744         acpi_handle_info(ec->handle,
1745                          "Boot DSDT EC used to handle transactions\n");
1746 }
1747
1748 /*
1749  * If the DSDT EC is not functioning, we still need to prepare a fully
1750  * functioning ECDT EC first in order to handle the events.
1751  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1752  */
1753 static int __init acpi_ec_ecdt_start(void)
1754 {
1755         acpi_handle handle;
1756
1757         if (!boot_ec)
1758                 return -ENODEV;
1759         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1760         if (!boot_ec_is_ecdt)
1761                 return -ENODEV;
1762
1763         /*
1764          * At this point, the namespace and the GPE is initialized, so
1765          * start to find the namespace objects and handle the events.
1766          *
1767          * Note: ec->handle can be valid if this function is called after
1768          * acpi_ec_add(), hence the fast path.
1769          */
1770         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1771                 if (!acpi_ec_ecdt_get_handle(&handle))
1772                         return -ENODEV;
1773                 boot_ec->handle = handle;
1774         }
1775
1776         /* Register to ACPI bus with PM ops attached */
1777         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1778 }
1779
1780 #if 0
1781 /*
1782  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1783  * set, for which case, we complete the QR_EC without issuing it to the
1784  * firmware.
1785  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1786  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1787  */
1788 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1789 {
1790         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1791         EC_FLAGS_QUERY_HANDSHAKE = 1;
1792         return 0;
1793 }
1794 #endif
1795
1796 /*
1797  * On some hardware it is necessary to clear events accumulated by the EC during
1798  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1799  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1800  *
1801  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1802  *
1803  * Ideally, the EC should also be instructed NOT to accumulate events during
1804  * sleep (which Windows seems to do somehow), but the interface to control this
1805  * behaviour is not known at this time.
1806  *
1807  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1808  * however it is very likely that other Samsung models are affected.
1809  *
1810  * On systems which don't accumulate _Q events during sleep, this extra check
1811  * should be harmless.
1812  */
1813 static int ec_clear_on_resume(const struct dmi_system_id *id)
1814 {
1815         pr_debug("Detected system needing EC poll on resume.\n");
1816         EC_FLAGS_CLEAR_ON_RESUME = 1;
1817         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1818         return 0;
1819 }
1820
1821 /*
1822  * Some ECDTs contain wrong register addresses.
1823  * MSI MS-171F
1824  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1825  */
1826 static int ec_correct_ecdt(const struct dmi_system_id *id)
1827 {
1828         pr_debug("Detected system needing ECDT address correction.\n");
1829         EC_FLAGS_CORRECT_ECDT = 1;
1830         return 0;
1831 }
1832
1833 /*
1834  * Some DSDTs contain wrong GPE setting.
1835  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1836  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1837  */
1838 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1839 {
1840         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1841         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1842         return 0;
1843 }
1844
1845 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1846         {
1847         ec_correct_ecdt, "MSI MS-171F", {
1848         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1849         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1850         {
1851         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1852         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1853         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1854         {
1855         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1856         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1857         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1858         {
1859         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1860         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1861         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1862         {
1863         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1864         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1865         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1866         {
1867         ec_honor_ecdt_gpe, "ASUS X580VD", {
1868         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1869         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1870         {
1871         ec_clear_on_resume, "Samsung hardware", {
1872         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1873         {},
1874 };
1875
1876 void __init acpi_ec_ecdt_probe(void)
1877 {
1878         struct acpi_table_ecdt *ecdt_ptr;
1879         struct acpi_ec *ec;
1880         acpi_status status;
1881         int ret;
1882
1883         /* Generate a boot ec context. */
1884         dmi_check_system(ec_dmi_table);
1885         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1886                                 (struct acpi_table_header **)&ecdt_ptr);
1887         if (ACPI_FAILURE(status))
1888                 return;
1889
1890         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1891                 /*
1892                  * Asus X50GL:
1893                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1894                  */
1895                 return;
1896         }
1897
1898         ec = acpi_ec_alloc();
1899         if (!ec)
1900                 return;
1901
1902         if (EC_FLAGS_CORRECT_ECDT) {
1903                 ec->command_addr = ecdt_ptr->data.address;
1904                 ec->data_addr = ecdt_ptr->control.address;
1905         } else {
1906                 ec->command_addr = ecdt_ptr->control.address;
1907                 ec->data_addr = ecdt_ptr->data.address;
1908         }
1909         ec->gpe = ecdt_ptr->gpe;
1910         ec->handle = ACPI_ROOT_OBJECT;
1911
1912         /*
1913          * At this point, the namespace is not initialized, so do not find
1914          * the namespace objects, or handle the events.
1915          */
1916         ret = acpi_ec_setup(ec, false);
1917         if (ret) {
1918                 acpi_ec_free(ec);
1919                 return;
1920         }
1921
1922         boot_ec = ec;
1923         boot_ec_is_ecdt = true;
1924
1925         pr_info("Boot ECDT EC used to handle transactions\n");
1926 }
1927
1928 #ifdef CONFIG_PM_SLEEP
1929 static int acpi_ec_suspend(struct device *dev)
1930 {
1931         struct acpi_ec *ec =
1932                 acpi_driver_data(to_acpi_device(dev));
1933
1934         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1935                 acpi_ec_disable_event(ec);
1936         return 0;
1937 }
1938
1939 static int acpi_ec_suspend_noirq(struct device *dev)
1940 {
1941         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1942
1943         /*
1944          * The SCI handler doesn't run at this point, so the GPE can be
1945          * masked at the low level without side effects.
1946          */
1947         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1948             ec->reference_count >= 1)
1949                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1950
1951         if (acpi_sleep_no_ec_events())
1952                 acpi_ec_enter_noirq(ec);
1953
1954         return 0;
1955 }
1956
1957 static int acpi_ec_resume_noirq(struct device *dev)
1958 {
1959         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1960
1961         if (acpi_sleep_no_ec_events())
1962                 acpi_ec_leave_noirq(ec);
1963
1964         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1965             ec->reference_count >= 1)
1966                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1967
1968         return 0;
1969 }
1970
1971 static int acpi_ec_resume(struct device *dev)
1972 {
1973         struct acpi_ec *ec =
1974                 acpi_driver_data(to_acpi_device(dev));
1975
1976         acpi_ec_enable_event(ec);
1977         return 0;
1978 }
1979 #endif
1980
1981 static const struct dev_pm_ops acpi_ec_pm = {
1982         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1983         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1984 };
1985
1986 static int param_set_event_clearing(const char *val,
1987                                     const struct kernel_param *kp)
1988 {
1989         int result = 0;
1990
1991         if (!strncmp(val, "status", sizeof("status") - 1)) {
1992                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1993                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1994         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1995                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1996                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1997         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1998                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1999                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2000         } else
2001                 result = -EINVAL;
2002         return result;
2003 }
2004
2005 static int param_get_event_clearing(char *buffer,
2006                                     const struct kernel_param *kp)
2007 {
2008         switch (ec_event_clearing) {
2009         case ACPI_EC_EVT_TIMING_STATUS:
2010                 return sprintf(buffer, "status");
2011         case ACPI_EC_EVT_TIMING_QUERY:
2012                 return sprintf(buffer, "query");
2013         case ACPI_EC_EVT_TIMING_EVENT:
2014                 return sprintf(buffer, "event");
2015         default:
2016                 return sprintf(buffer, "invalid");
2017         }
2018         return 0;
2019 }
2020
2021 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2022                   NULL, 0644);
2023 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2024
2025 static struct acpi_driver acpi_ec_driver = {
2026         .name = "ec",
2027         .class = ACPI_EC_CLASS,
2028         .ids = ec_device_ids,
2029         .ops = {
2030                 .add = acpi_ec_add,
2031                 .remove = acpi_ec_remove,
2032                 },
2033         .drv.pm = &acpi_ec_pm,
2034 };
2035
2036 static inline int acpi_ec_query_init(void)
2037 {
2038         if (!ec_query_wq) {
2039                 ec_query_wq = alloc_workqueue("kec_query", 0,
2040                                               ec_max_queries);
2041                 if (!ec_query_wq)
2042                         return -ENODEV;
2043         }
2044         return 0;
2045 }
2046
2047 static inline void acpi_ec_query_exit(void)
2048 {
2049         if (ec_query_wq) {
2050                 destroy_workqueue(ec_query_wq);
2051                 ec_query_wq = NULL;
2052         }
2053 }
2054
2055 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2056         {
2057                 .ident = "Thinkpad X1 Carbon 6th",
2058                 .matches = {
2059                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2060                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2061                 },
2062         },
2063         {
2064                 .ident = "ThinkPad X1 Carbon 6th",
2065                 .matches = {
2066                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2067                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2068                 },
2069         },
2070         {
2071                 .ident = "ThinkPad X1 Yoga 3rd",
2072                 .matches = {
2073                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2074                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2075                 },
2076         },
2077         { },
2078 };
2079
2080 int __init acpi_ec_init(void)
2081 {
2082         int result;
2083         int ecdt_fail, dsdt_fail;
2084
2085         /* register workqueue for _Qxx evaluations */
2086         result = acpi_ec_query_init();
2087         if (result)
2088                 return result;
2089
2090         /*
2091          * Disable EC wakeup on following systems to prevent periodic
2092          * wakeup from EC GPE.
2093          */
2094         if (dmi_check_system(acpi_ec_no_wakeup)) {
2095                 ec_no_wakeup = true;
2096                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2097         }
2098
2099         /* Drivers must be started after acpi_ec_query_init() */
2100         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2101         /*
2102          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2103          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2104          * settings but invalid DSDT settings.
2105          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2106          */
2107         ecdt_fail = acpi_ec_ecdt_start();
2108         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2109 }
2110
2111 /* EC driver currently not unloadable */
2112 #if 0
2113 static void __exit acpi_ec_exit(void)
2114 {
2115
2116         acpi_bus_unregister_driver(&acpi_ec_driver);
2117         acpi_ec_query_exit();
2118 }
2119 #endif  /* 0 */