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