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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ec.c - ACPI Embedded Controller Driver (v3)
4 *
5 * Copyright (C) 2001-2015 Intel Corporation
6 * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
7 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
8 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
9 * 2004 Luming Yu <luming.yu@intel.com>
10 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
11 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
12 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
13 */
14
15/* Uncomment next line to get verbose printout */
16/* #define DEBUG */
17#define pr_fmt(fmt) "ACPI: EC: " fmt
18
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/types.h>
23#include <linux/delay.h>
24#include <linux/interrupt.h>
25#include <linux/list.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/suspend.h>
29#include <linux/acpi.h>
30#include <linux/dmi.h>
31#include <asm/io.h>
32
33#include "internal.h"
34
35#define ACPI_EC_CLASS "embedded_controller"
36#define ACPI_EC_DEVICE_NAME "Embedded Controller"
37
38/* EC status register */
39#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
40#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
41#define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
42#define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
43#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
44
45/*
46 * The SCI_EVT clearing timing is not defined by the ACPI specification.
47 * This leads to lots of practical timing issues for the host EC driver.
48 * The following variations are defined (from the target EC firmware's
49 * perspective):
50 * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
51 * target can clear SCI_EVT at any time so long as the host can see
52 * the indication by reading the status register (EC_SC). So the
53 * host should re-check SCI_EVT after the first time the SCI_EVT
54 * indication is seen, which is the same time the query request
55 * (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
56 * at any later time could indicate another event. Normally such
57 * kind of EC firmware has implemented an event queue and will
58 * return 0x00 to indicate "no outstanding event".
59 * QUERY: After seeing the query request (QR_EC) written to the command
60 * register (EC_CMD) by the host and having prepared the responding
61 * event value in the data register (EC_DATA), the target can safely
62 * clear SCI_EVT because the target can confirm that the current
63 * event is being handled by the host. The host then should check
64 * SCI_EVT right after reading the event response from the data
65 * register (EC_DATA).
66 * EVENT: After seeing the event response read from the data register
67 * (EC_DATA) by the host, the target can clear SCI_EVT. As the
68 * target requires time to notice the change in the data register
69 * (EC_DATA), the host may be required to wait additional guarding
70 * time before checking the SCI_EVT again. Such guarding may not be
71 * necessary if the host is notified via another IRQ.
72 */
73#define ACPI_EC_EVT_TIMING_STATUS 0x00
74#define ACPI_EC_EVT_TIMING_QUERY 0x01
75#define ACPI_EC_EVT_TIMING_EVENT 0x02
76
77/* EC commands */
78enum ec_command {
79 ACPI_EC_COMMAND_READ = 0x80,
80 ACPI_EC_COMMAND_WRITE = 0x81,
81 ACPI_EC_BURST_ENABLE = 0x82,
82 ACPI_EC_BURST_DISABLE = 0x83,
83 ACPI_EC_COMMAND_QUERY = 0x84,
84};
85
86#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
87#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
88#define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
89#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
90 * when trying to clear the EC */
91#define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
92
93enum {
94 EC_FLAGS_QUERY_ENABLED, /* Query is enabled */
95 EC_FLAGS_QUERY_PENDING, /* Query is pending */
96 EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */
97 EC_FLAGS_EVENT_HANDLER_INSTALLED, /* Event handler installed */
98 EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */
99 EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
100 EC_FLAGS_STARTED, /* Driver is started */
101 EC_FLAGS_STOPPED, /* Driver is stopped */
102 EC_FLAGS_EVENTS_MASKED, /* Events 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 */
109static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
110module_param(ec_delay, uint, 0644);
111MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
112
113static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
114module_param(ec_max_queries, uint, 0644);
115MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
116
117static bool ec_busy_polling __read_mostly;
118module_param(ec_busy_polling, bool, 0644);
119MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
120
121static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
122module_param(ec_polling_guard, uint, 0644);
123MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
124
125static 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 */
132static unsigned int ec_storm_threshold __read_mostly = 8;
133module_param(ec_storm_threshold, uint, 0644);
134MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
135
136static bool ec_freeze_events __read_mostly = false;
137module_param(ec_freeze_events, bool, 0644);
138MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
139
140static bool ec_no_wakeup __read_mostly;
141module_param(ec_no_wakeup, bool, 0644);
142MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
143
144struct 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
153struct 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
165struct acpi_ec_query {
166 struct transaction transaction;
167 struct work_struct work;
168 struct acpi_ec_query_handler *handler;
169};
170
171static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
172static void advance_transaction(struct acpi_ec *ec);
173static void acpi_ec_event_handler(struct work_struct *work);
174static void acpi_ec_event_processor(struct work_struct *work);
175
176struct acpi_ec *first_ec;
177EXPORT_SYMBOL(first_ec);
178
179static struct acpi_ec *boot_ec;
180static bool boot_ec_is_ecdt = false;
181static struct workqueue_struct *ec_wq;
182static struct workqueue_struct *ec_query_wq;
183
184static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
185static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
186static 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
236static 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
242static 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
266static bool acpi_ec_flushed(struct acpi_ec *ec)
267{
268 return ec->reference_count == 1;
269}
270
271/* --------------------------------------------------------------------------
272 * EC Registers
273 * -------------------------------------------------------------------------- */
274
275static 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
290static 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
299static 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
306static 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)
314static 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
338static 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
346static 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
365static 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
375static 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
396static void acpi_ec_submit_request(struct acpi_ec *ec)
397{
398 ec->reference_count++;
399 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
400 ec->gpe >= 0 && ec->reference_count == 1)
401 acpi_ec_enable_gpe(ec, true);
402}
403
404static 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_EVENT_HANDLER_INSTALLED, &ec->flags) &&
410 ec->gpe >= 0 && 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
417static void acpi_ec_mask_events(struct acpi_ec *ec)
418{
419 if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
420 if (ec->gpe >= 0)
421 acpi_ec_disable_gpe(ec, false);
422 else
423 disable_irq_nosync(ec->irq);
424
425 ec_dbg_drv("Polling enabled");
426 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
427 }
428}
429
430static void acpi_ec_unmask_events(struct acpi_ec *ec)
431{
432 if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
433 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
434 if (ec->gpe >= 0)
435 acpi_ec_enable_gpe(ec, false);
436 else
437 enable_irq(ec->irq);
438
439 ec_dbg_drv("Polling disabled");
440 }
441}
442
443/*
444 * acpi_ec_submit_flushable_request() - Increase the reference count unless
445 * the flush operation is not in
446 * progress
447 * @ec: the EC device
448 *
449 * This function must be used before taking a new action that should hold
450 * the reference count. If this function returns false, then the action
451 * must be discarded or it will prevent the flush operation from being
452 * completed.
453 */
454static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
455{
456 if (!acpi_ec_started(ec))
457 return false;
458 acpi_ec_submit_request(ec);
459 return true;
460}
461
462static void acpi_ec_submit_query(struct acpi_ec *ec)
463{
464 acpi_ec_mask_events(ec);
465 if (!acpi_ec_event_enabled(ec))
466 return;
467 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
468 ec_dbg_evt("Command(%s) submitted/blocked",
469 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
470 ec->nr_pending_queries++;
471 queue_work(ec_wq, &ec->work);
472 }
473}
474
475static void acpi_ec_complete_query(struct acpi_ec *ec)
476{
477 if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
478 ec_dbg_evt("Command(%s) unblocked",
479 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
480 acpi_ec_unmask_events(ec);
481}
482
483static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
484{
485 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
486 ec_log_drv("event unblocked");
487 /*
488 * Unconditionally invoke this once after enabling the event
489 * handling mechanism to detect the pending events.
490 */
491 advance_transaction(ec);
492}
493
494static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
495{
496 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
497 ec_log_drv("event blocked");
498}
499
500/*
501 * Process _Q events that might have accumulated in the EC.
502 * Run with locked ec mutex.
503 */
504static void acpi_ec_clear(struct acpi_ec *ec)
505{
506 int i, status;
507 u8 value = 0;
508
509 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
510 status = acpi_ec_query(ec, &value);
511 if (status || !value)
512 break;
513 }
514 if (unlikely(i == ACPI_EC_CLEAR_MAX))
515 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
516 else
517 pr_info("%d stale EC events cleared\n", i);
518}
519
520static void acpi_ec_enable_event(struct acpi_ec *ec)
521{
522 unsigned long flags;
523
524 spin_lock_irqsave(&ec->lock, flags);
525 if (acpi_ec_started(ec))
526 __acpi_ec_enable_event(ec);
527 spin_unlock_irqrestore(&ec->lock, flags);
528
529 /* Drain additional events if hardware requires that */
530 if (EC_FLAGS_CLEAR_ON_RESUME)
531 acpi_ec_clear(ec);
532}
533
534#ifdef CONFIG_PM_SLEEP
535static void __acpi_ec_flush_work(void)
536{
537 drain_workqueue(ec_wq); /* flush ec->work */
538 flush_workqueue(ec_query_wq); /* flush queries */
539}
540
541static void acpi_ec_disable_event(struct acpi_ec *ec)
542{
543 unsigned long flags;
544
545 spin_lock_irqsave(&ec->lock, flags);
546 __acpi_ec_disable_event(ec);
547 spin_unlock_irqrestore(&ec->lock, flags);
548
549 /*
550 * When ec_freeze_events is true, we need to flush events in
551 * the proper position before entering the noirq stage.
552 */
553 __acpi_ec_flush_work();
554}
555
556void acpi_ec_flush_work(void)
557{
558 /* Without ec_wq there is nothing to flush. */
559 if (!ec_wq)
560 return;
561
562 __acpi_ec_flush_work();
563}
564#endif /* CONFIG_PM_SLEEP */
565
566static bool acpi_ec_guard_event(struct acpi_ec *ec)
567{
568 bool guarded = true;
569 unsigned long flags;
570
571 spin_lock_irqsave(&ec->lock, flags);
572 /*
573 * If firmware SCI_EVT clearing timing is "event", we actually
574 * don't know when the SCI_EVT will be cleared by firmware after
575 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
576 * acceptable period.
577 *
578 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
579 * flagged, which means SCI_EVT check has just been performed.
580 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
581 * guarding should have already been performed (via
582 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
583 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
584 * ACPI_EC_COMMAND_POLL state immediately.
585 */
586 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
587 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
588 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
589 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
590 guarded = false;
591 spin_unlock_irqrestore(&ec->lock, flags);
592 return guarded;
593}
594
595static int ec_transaction_polled(struct acpi_ec *ec)
596{
597 unsigned long flags;
598 int ret = 0;
599
600 spin_lock_irqsave(&ec->lock, flags);
601 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
602 ret = 1;
603 spin_unlock_irqrestore(&ec->lock, flags);
604 return ret;
605}
606
607static int ec_transaction_completed(struct acpi_ec *ec)
608{
609 unsigned long flags;
610 int ret = 0;
611
612 spin_lock_irqsave(&ec->lock, flags);
613 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
614 ret = 1;
615 spin_unlock_irqrestore(&ec->lock, flags);
616 return ret;
617}
618
619static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
620{
621 ec->curr->flags |= flag;
622 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
623 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
624 flag == ACPI_EC_COMMAND_POLL)
625 acpi_ec_complete_query(ec);
626 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
627 flag == ACPI_EC_COMMAND_COMPLETE)
628 acpi_ec_complete_query(ec);
629 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
630 flag == ACPI_EC_COMMAND_COMPLETE)
631 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
632 }
633}
634
635static void advance_transaction(struct acpi_ec *ec)
636{
637 struct transaction *t;
638 u8 status;
639 bool wakeup = false;
640
641 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
642 smp_processor_id());
643 /*
644 * By always clearing STS before handling all indications, we can
645 * ensure a hardware STS 0->1 change after this clearing can always
646 * trigger a GPE interrupt.
647 */
648 if (ec->gpe >= 0)
649 acpi_ec_clear_gpe(ec);
650
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 if (!(status & ACPI_EC_FLAG_IBF)) {
692 acpi_ec_write_cmd(ec, t->command);
693 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
694 goto out;
695 }
696err:
697 /*
698 * If SCI bit is set, then don't think it's a false IRQ
699 * otherwise will take a not handled IRQ as a false one.
700 */
701 if (!(status & ACPI_EC_FLAG_SCI)) {
702 if (in_interrupt() && t) {
703 if (t->irq_count < ec_storm_threshold)
704 ++t->irq_count;
705 /* Allow triggering on 0 threshold */
706 if (t->irq_count == ec_storm_threshold)
707 acpi_ec_mask_events(ec);
708 }
709 }
710out:
711 if (status & ACPI_EC_FLAG_SCI)
712 acpi_ec_submit_query(ec);
713 if (wakeup && in_interrupt())
714 wake_up(&ec->wait);
715}
716
717static void start_transaction(struct acpi_ec *ec)
718{
719 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
720 ec->curr->flags = 0;
721}
722
723static int ec_guard(struct acpi_ec *ec)
724{
725 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
726 unsigned long timeout = ec->timestamp + guard;
727
728 /* Ensure guarding period before polling EC status */
729 do {
730 if (ec->busy_polling) {
731 /* Perform busy polling */
732 if (ec_transaction_completed(ec))
733 return 0;
734 udelay(jiffies_to_usecs(guard));
735 } else {
736 /*
737 * Perform wait polling
738 * 1. Wait the transaction to be completed by the
739 * GPE handler after the transaction enters
740 * ACPI_EC_COMMAND_POLL state.
741 * 2. A special guarding logic is also required
742 * for event clearing mode "event" before the
743 * transaction enters ACPI_EC_COMMAND_POLL
744 * state.
745 */
746 if (!ec_transaction_polled(ec) &&
747 !acpi_ec_guard_event(ec))
748 break;
749 if (wait_event_timeout(ec->wait,
750 ec_transaction_completed(ec),
751 guard))
752 return 0;
753 }
754 } while (time_before(jiffies, timeout));
755 return -ETIME;
756}
757
758static int ec_poll(struct acpi_ec *ec)
759{
760 unsigned long flags;
761 int repeat = 5; /* number of command restarts */
762
763 while (repeat--) {
764 unsigned long delay = jiffies +
765 msecs_to_jiffies(ec_delay);
766 do {
767 if (!ec_guard(ec))
768 return 0;
769 spin_lock_irqsave(&ec->lock, flags);
770 advance_transaction(ec);
771 spin_unlock_irqrestore(&ec->lock, flags);
772 } while (time_before(jiffies, delay));
773 pr_debug("controller reset, restart transaction\n");
774 spin_lock_irqsave(&ec->lock, flags);
775 start_transaction(ec);
776 spin_unlock_irqrestore(&ec->lock, flags);
777 }
778 return -ETIME;
779}
780
781static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
782 struct transaction *t)
783{
784 unsigned long tmp;
785 int ret = 0;
786
787 /* start transaction */
788 spin_lock_irqsave(&ec->lock, tmp);
789 /* Enable GPE for command processing (IBF=0/OBF=1) */
790 if (!acpi_ec_submit_flushable_request(ec)) {
791 ret = -EINVAL;
792 goto unlock;
793 }
794 ec_dbg_ref(ec, "Increase command");
795 /* following two actions should be kept atomic */
796 ec->curr = t;
797 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
798 start_transaction(ec);
799 spin_unlock_irqrestore(&ec->lock, tmp);
800
801 ret = ec_poll(ec);
802
803 spin_lock_irqsave(&ec->lock, tmp);
804 if (t->irq_count == ec_storm_threshold)
805 acpi_ec_unmask_events(ec);
806 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
807 ec->curr = NULL;
808 /* Disable GPE for command processing (IBF=0/OBF=1) */
809 acpi_ec_complete_request(ec);
810 ec_dbg_ref(ec, "Decrease command");
811unlock:
812 spin_unlock_irqrestore(&ec->lock, tmp);
813 return ret;
814}
815
816static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
817{
818 int status;
819 u32 glk;
820
821 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
822 return -EINVAL;
823 if (t->rdata)
824 memset(t->rdata, 0, t->rlen);
825
826 mutex_lock(&ec->mutex);
827 if (ec->global_lock) {
828 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
829 if (ACPI_FAILURE(status)) {
830 status = -ENODEV;
831 goto unlock;
832 }
833 }
834
835 status = acpi_ec_transaction_unlocked(ec, t);
836
837 if (ec->global_lock)
838 acpi_release_global_lock(glk);
839unlock:
840 mutex_unlock(&ec->mutex);
841 return status;
842}
843
844static int acpi_ec_burst_enable(struct acpi_ec *ec)
845{
846 u8 d;
847 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
848 .wdata = NULL, .rdata = &d,
849 .wlen = 0, .rlen = 1};
850
851 return acpi_ec_transaction(ec, &t);
852}
853
854static int acpi_ec_burst_disable(struct acpi_ec *ec)
855{
856 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
857 .wdata = NULL, .rdata = NULL,
858 .wlen = 0, .rlen = 0};
859
860 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
861 acpi_ec_transaction(ec, &t) : 0;
862}
863
864static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
865{
866 int result;
867 u8 d;
868 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
869 .wdata = &address, .rdata = &d,
870 .wlen = 1, .rlen = 1};
871
872 result = acpi_ec_transaction(ec, &t);
873 *data = d;
874 return result;
875}
876
877static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
878{
879 u8 wdata[2] = { address, data };
880 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
881 .wdata = wdata, .rdata = NULL,
882 .wlen = 2, .rlen = 0};
883
884 return acpi_ec_transaction(ec, &t);
885}
886
887int ec_read(u8 addr, u8 *val)
888{
889 int err;
890 u8 temp_data;
891
892 if (!first_ec)
893 return -ENODEV;
894
895 err = acpi_ec_read(first_ec, addr, &temp_data);
896
897 if (!err) {
898 *val = temp_data;
899 return 0;
900 }
901 return err;
902}
903EXPORT_SYMBOL(ec_read);
904
905int ec_write(u8 addr, u8 val)
906{
907 int err;
908
909 if (!first_ec)
910 return -ENODEV;
911
912 err = acpi_ec_write(first_ec, addr, val);
913
914 return err;
915}
916EXPORT_SYMBOL(ec_write);
917
918int ec_transaction(u8 command,
919 const u8 *wdata, unsigned wdata_len,
920 u8 *rdata, unsigned rdata_len)
921{
922 struct transaction t = {.command = command,
923 .wdata = wdata, .rdata = rdata,
924 .wlen = wdata_len, .rlen = rdata_len};
925
926 if (!first_ec)
927 return -ENODEV;
928
929 return acpi_ec_transaction(first_ec, &t);
930}
931EXPORT_SYMBOL(ec_transaction);
932
933/* Get the handle to the EC device */
934acpi_handle ec_get_handle(void)
935{
936 if (!first_ec)
937 return NULL;
938 return first_ec->handle;
939}
940EXPORT_SYMBOL(ec_get_handle);
941
942static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
943{
944 unsigned long flags;
945
946 spin_lock_irqsave(&ec->lock, flags);
947 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
948 ec_dbg_drv("Starting EC");
949 /* Enable GPE for event processing (SCI_EVT=1) */
950 if (!resuming) {
951 acpi_ec_submit_request(ec);
952 ec_dbg_ref(ec, "Increase driver");
953 }
954 ec_log_drv("EC started");
955 }
956 spin_unlock_irqrestore(&ec->lock, flags);
957}
958
959static bool acpi_ec_stopped(struct acpi_ec *ec)
960{
961 unsigned long flags;
962 bool flushed;
963
964 spin_lock_irqsave(&ec->lock, flags);
965 flushed = acpi_ec_flushed(ec);
966 spin_unlock_irqrestore(&ec->lock, flags);
967 return flushed;
968}
969
970static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
971{
972 unsigned long flags;
973
974 spin_lock_irqsave(&ec->lock, flags);
975 if (acpi_ec_started(ec)) {
976 ec_dbg_drv("Stopping EC");
977 set_bit(EC_FLAGS_STOPPED, &ec->flags);
978 spin_unlock_irqrestore(&ec->lock, flags);
979 wait_event(ec->wait, acpi_ec_stopped(ec));
980 spin_lock_irqsave(&ec->lock, flags);
981 /* Disable GPE for event processing (SCI_EVT=1) */
982 if (!suspending) {
983 acpi_ec_complete_request(ec);
984 ec_dbg_ref(ec, "Decrease driver");
985 } else if (!ec_freeze_events)
986 __acpi_ec_disable_event(ec);
987 clear_bit(EC_FLAGS_STARTED, &ec->flags);
988 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
989 ec_log_drv("EC stopped");
990 }
991 spin_unlock_irqrestore(&ec->lock, flags);
992}
993
994static void acpi_ec_enter_noirq(struct acpi_ec *ec)
995{
996 unsigned long flags;
997
998 spin_lock_irqsave(&ec->lock, flags);
999 ec->busy_polling = true;
1000 ec->polling_guard = 0;
1001 ec_log_drv("interrupt blocked");
1002 spin_unlock_irqrestore(&ec->lock, flags);
1003}
1004
1005static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1006{
1007 unsigned long flags;
1008
1009 spin_lock_irqsave(&ec->lock, flags);
1010 ec->busy_polling = ec_busy_polling;
1011 ec->polling_guard = ec_polling_guard;
1012 ec_log_drv("interrupt unblocked");
1013 spin_unlock_irqrestore(&ec->lock, flags);
1014}
1015
1016void acpi_ec_block_transactions(void)
1017{
1018 struct acpi_ec *ec = first_ec;
1019
1020 if (!ec)
1021 return;
1022
1023 mutex_lock(&ec->mutex);
1024 /* Prevent transactions from being carried out */
1025 acpi_ec_stop(ec, true);
1026 mutex_unlock(&ec->mutex);
1027}
1028
1029void acpi_ec_unblock_transactions(void)
1030{
1031 /*
1032 * Allow transactions to happen again (this function is called from
1033 * atomic context during wakeup, so we don't need to acquire the mutex).
1034 */
1035 if (first_ec)
1036 acpi_ec_start(first_ec, true);
1037}
1038
1039/* --------------------------------------------------------------------------
1040 Event Management
1041 -------------------------------------------------------------------------- */
1042static struct acpi_ec_query_handler *
1043acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1044{
1045 struct acpi_ec_query_handler *handler;
1046
1047 mutex_lock(&ec->mutex);
1048 list_for_each_entry(handler, &ec->list, node) {
1049 if (value == handler->query_bit) {
1050 kref_get(&handler->kref);
1051 mutex_unlock(&ec->mutex);
1052 return handler;
1053 }
1054 }
1055 mutex_unlock(&ec->mutex);
1056 return NULL;
1057}
1058
1059static void acpi_ec_query_handler_release(struct kref *kref)
1060{
1061 struct acpi_ec_query_handler *handler =
1062 container_of(kref, struct acpi_ec_query_handler, kref);
1063
1064 kfree(handler);
1065}
1066
1067static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1068{
1069 kref_put(&handler->kref, acpi_ec_query_handler_release);
1070}
1071
1072int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1073 acpi_handle handle, acpi_ec_query_func func,
1074 void *data)
1075{
1076 struct acpi_ec_query_handler *handler =
1077 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1078
1079 if (!handler)
1080 return -ENOMEM;
1081
1082 handler->query_bit = query_bit;
1083 handler->handle = handle;
1084 handler->func = func;
1085 handler->data = data;
1086 mutex_lock(&ec->mutex);
1087 kref_init(&handler->kref);
1088 list_add(&handler->node, &ec->list);
1089 mutex_unlock(&ec->mutex);
1090 return 0;
1091}
1092EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1093
1094static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1095 bool remove_all, u8 query_bit)
1096{
1097 struct acpi_ec_query_handler *handler, *tmp;
1098 LIST_HEAD(free_list);
1099
1100 mutex_lock(&ec->mutex);
1101 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1102 if (remove_all || query_bit == handler->query_bit) {
1103 list_del_init(&handler->node);
1104 list_add(&handler->node, &free_list);
1105 }
1106 }
1107 mutex_unlock(&ec->mutex);
1108 list_for_each_entry_safe(handler, tmp, &free_list, node)
1109 acpi_ec_put_query_handler(handler);
1110}
1111
1112void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1113{
1114 acpi_ec_remove_query_handlers(ec, false, query_bit);
1115}
1116EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1117
1118static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1119{
1120 struct acpi_ec_query *q;
1121 struct transaction *t;
1122
1123 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1124 if (!q)
1125 return NULL;
1126 INIT_WORK(&q->work, acpi_ec_event_processor);
1127 t = &q->transaction;
1128 t->command = ACPI_EC_COMMAND_QUERY;
1129 t->rdata = pval;
1130 t->rlen = 1;
1131 return q;
1132}
1133
1134static void acpi_ec_delete_query(struct acpi_ec_query *q)
1135{
1136 if (q) {
1137 if (q->handler)
1138 acpi_ec_put_query_handler(q->handler);
1139 kfree(q);
1140 }
1141}
1142
1143static void acpi_ec_event_processor(struct work_struct *work)
1144{
1145 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1146 struct acpi_ec_query_handler *handler = q->handler;
1147
1148 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1149 if (handler->func)
1150 handler->func(handler->data);
1151 else if (handler->handle)
1152 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1153 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1154 acpi_ec_delete_query(q);
1155}
1156
1157static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1158{
1159 u8 value = 0;
1160 int result;
1161 struct acpi_ec_query *q;
1162
1163 q = acpi_ec_create_query(&value);
1164 if (!q)
1165 return -ENOMEM;
1166
1167 /*
1168 * Query the EC to find out which _Qxx method we need to evaluate.
1169 * Note that successful completion of the query causes the ACPI_EC_SCI
1170 * bit to be cleared (and thus clearing the interrupt source).
1171 */
1172 result = acpi_ec_transaction(ec, &q->transaction);
1173 if (!value)
1174 result = -ENODATA;
1175 if (result)
1176 goto err_exit;
1177
1178 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1179 if (!q->handler) {
1180 result = -ENODATA;
1181 goto err_exit;
1182 }
1183
1184 /*
1185 * It is reported that _Qxx are evaluated in a parallel way on
1186 * Windows:
1187 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1188 *
1189 * Put this log entry before schedule_work() in order to make
1190 * it appearing before any other log entries occurred during the
1191 * work queue execution.
1192 */
1193 ec_dbg_evt("Query(0x%02x) scheduled", value);
1194 if (!queue_work(ec_query_wq, &q->work)) {
1195 ec_dbg_evt("Query(0x%02x) overlapped", value);
1196 result = -EBUSY;
1197 }
1198
1199err_exit:
1200 if (result)
1201 acpi_ec_delete_query(q);
1202 if (data)
1203 *data = value;
1204 return result;
1205}
1206
1207static void acpi_ec_check_event(struct acpi_ec *ec)
1208{
1209 unsigned long flags;
1210
1211 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1212 if (ec_guard(ec)) {
1213 spin_lock_irqsave(&ec->lock, flags);
1214 /*
1215 * Take care of the SCI_EVT unless no one else is
1216 * taking care of it.
1217 */
1218 if (!ec->curr)
1219 advance_transaction(ec);
1220 spin_unlock_irqrestore(&ec->lock, flags);
1221 }
1222 }
1223}
1224
1225static void acpi_ec_event_handler(struct work_struct *work)
1226{
1227 unsigned long flags;
1228 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1229
1230 ec_dbg_evt("Event started");
1231
1232 spin_lock_irqsave(&ec->lock, flags);
1233 while (ec->nr_pending_queries) {
1234 spin_unlock_irqrestore(&ec->lock, flags);
1235 (void)acpi_ec_query(ec, NULL);
1236 spin_lock_irqsave(&ec->lock, flags);
1237 ec->nr_pending_queries--;
1238 /*
1239 * Before exit, make sure that this work item can be
1240 * scheduled again. There might be QR_EC failures, leaving
1241 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1242 * item from being scheduled again.
1243 */
1244 if (!ec->nr_pending_queries) {
1245 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1246 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1247 acpi_ec_complete_query(ec);
1248 }
1249 }
1250 spin_unlock_irqrestore(&ec->lock, flags);
1251
1252 ec_dbg_evt("Event stopped");
1253
1254 acpi_ec_check_event(ec);
1255}
1256
1257static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1258{
1259 unsigned long flags;
1260
1261 spin_lock_irqsave(&ec->lock, flags);
1262 advance_transaction(ec);
1263 spin_unlock_irqrestore(&ec->lock, flags);
1264}
1265
1266static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1267 u32 gpe_number, void *data)
1268{
1269 acpi_ec_handle_interrupt(data);
1270 return ACPI_INTERRUPT_HANDLED;
1271}
1272
1273static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1274{
1275 acpi_ec_handle_interrupt(data);
1276 return IRQ_HANDLED;
1277}
1278
1279/* --------------------------------------------------------------------------
1280 * Address Space Management
1281 * -------------------------------------------------------------------------- */
1282
1283static acpi_status
1284acpi_ec_space_handler(u32 function, acpi_physical_address address,
1285 u32 bits, u64 *value64,
1286 void *handler_context, void *region_context)
1287{
1288 struct acpi_ec *ec = handler_context;
1289 int result = 0, i, bytes = bits / 8;
1290 u8 *value = (u8 *)value64;
1291
1292 if ((address > 0xFF) || !value || !handler_context)
1293 return AE_BAD_PARAMETER;
1294
1295 if (function != ACPI_READ && function != ACPI_WRITE)
1296 return AE_BAD_PARAMETER;
1297
1298 if (ec->busy_polling || bits > 8)
1299 acpi_ec_burst_enable(ec);
1300
1301 for (i = 0; i < bytes; ++i, ++address, ++value)
1302 result = (function == ACPI_READ) ?
1303 acpi_ec_read(ec, address, value) :
1304 acpi_ec_write(ec, address, *value);
1305
1306 if (ec->busy_polling || bits > 8)
1307 acpi_ec_burst_disable(ec);
1308
1309 switch (result) {
1310 case -EINVAL:
1311 return AE_BAD_PARAMETER;
1312 case -ENODEV:
1313 return AE_NOT_FOUND;
1314 case -ETIME:
1315 return AE_TIME;
1316 default:
1317 return AE_OK;
1318 }
1319}
1320
1321/* --------------------------------------------------------------------------
1322 * Driver Interface
1323 * -------------------------------------------------------------------------- */
1324
1325static acpi_status
1326ec_parse_io_ports(struct acpi_resource *resource, void *context);
1327
1328static void acpi_ec_free(struct acpi_ec *ec)
1329{
1330 if (first_ec == ec)
1331 first_ec = NULL;
1332 if (boot_ec == ec)
1333 boot_ec = NULL;
1334 kfree(ec);
1335}
1336
1337static struct acpi_ec *acpi_ec_alloc(void)
1338{
1339 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1340
1341 if (!ec)
1342 return NULL;
1343 mutex_init(&ec->mutex);
1344 init_waitqueue_head(&ec->wait);
1345 INIT_LIST_HEAD(&ec->list);
1346 spin_lock_init(&ec->lock);
1347 INIT_WORK(&ec->work, acpi_ec_event_handler);
1348 ec->timestamp = jiffies;
1349 ec->busy_polling = true;
1350 ec->polling_guard = 0;
1351 ec->gpe = -1;
1352 ec->irq = -1;
1353 return ec;
1354}
1355
1356static acpi_status
1357acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1358 void *context, void **return_value)
1359{
1360 char node_name[5];
1361 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1362 struct acpi_ec *ec = context;
1363 int value = 0;
1364 acpi_status status;
1365
1366 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1367
1368 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1369 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1370 return AE_OK;
1371}
1372
1373static acpi_status
1374ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1375{
1376 acpi_status status;
1377 unsigned long long tmp = 0;
1378 struct acpi_ec *ec = context;
1379
1380 /* clear addr values, ec_parse_io_ports depend on it */
1381 ec->command_addr = ec->data_addr = 0;
1382
1383 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1384 ec_parse_io_ports, ec);
1385 if (ACPI_FAILURE(status))
1386 return status;
1387 if (ec->data_addr == 0 || ec->command_addr == 0)
1388 return AE_OK;
1389
1390 if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1391 /*
1392 * Always inherit the GPE number setting from the ECDT
1393 * EC.
1394 */
1395 ec->gpe = boot_ec->gpe;
1396 } else {
1397 /* Get GPE bit assignment (EC events). */
1398 /* TODO: Add support for _GPE returning a package */
1399 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1400 if (ACPI_SUCCESS(status))
1401 ec->gpe = tmp;
1402
1403 /*
1404 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1405 * platforms which use GpioInt instead of GPE.
1406 */
1407 }
1408 /* Use the global lock for all EC transactions? */
1409 tmp = 0;
1410 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1411 ec->global_lock = tmp;
1412 ec->handle = handle;
1413 return AE_CTRL_TERMINATE;
1414}
1415
1416static bool install_gpe_event_handler(struct acpi_ec *ec)
1417{
1418 acpi_status status;
1419
1420 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1421 ACPI_GPE_EDGE_TRIGGERED,
1422 &acpi_ec_gpe_handler, ec);
1423 if (ACPI_FAILURE(status))
1424 return false;
1425
1426 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1427 acpi_ec_enable_gpe(ec, true);
1428
1429 return true;
1430}
1431
1432static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1433{
1434 return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1435 "ACPI EC", ec) >= 0;
1436}
1437
1438/**
1439 * ec_install_handlers - Install service callbacks and register query methods.
1440 * @ec: Target EC.
1441 * @device: ACPI device object corresponding to @ec.
1442 *
1443 * Install a handler for the EC address space type unless it has been installed
1444 * already. If @device is not NULL, also look for EC query methods in the
1445 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1446 * handler for the EC, if possible.
1447 *
1448 * Return:
1449 * -ENODEV if the address space handler cannot be installed, which means
1450 * "unable to handle transactions",
1451 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1452 * or 0 (success) otherwise.
1453 */
1454static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1455{
1456 acpi_status status;
1457
1458 acpi_ec_start(ec, false);
1459
1460 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1461 acpi_ec_enter_noirq(ec);
1462 status = acpi_install_address_space_handler(ec->handle,
1463 ACPI_ADR_SPACE_EC,
1464 &acpi_ec_space_handler,
1465 NULL, ec);
1466 if (ACPI_FAILURE(status)) {
1467 acpi_ec_stop(ec, false);
1468 return -ENODEV;
1469 }
1470 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1471 }
1472
1473 if (!device)
1474 return 0;
1475
1476 if (ec->gpe < 0) {
1477 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1478 int irq = acpi_dev_gpio_irq_get(device, 0);
1479 /*
1480 * Bail out right away for deferred probing or complete the
1481 * initialization regardless of any other errors.
1482 */
1483 if (irq == -EPROBE_DEFER)
1484 return -EPROBE_DEFER;
1485 else if (irq >= 0)
1486 ec->irq = irq;
1487 }
1488
1489 if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1490 /* Find and register all query methods */
1491 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1492 acpi_ec_register_query_methods,
1493 NULL, ec, NULL);
1494 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1495 }
1496 if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1497 bool ready = false;
1498
1499 if (ec->gpe >= 0)
1500 ready = install_gpe_event_handler(ec);
1501 else if (ec->irq >= 0)
1502 ready = install_gpio_irq_event_handler(ec);
1503
1504 if (ready) {
1505 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1506 acpi_ec_leave_noirq(ec);
1507 }
1508 /*
1509 * Failures to install an event handler are not fatal, because
1510 * the EC can be polled for events.
1511 */
1512 }
1513 /* EC is fully operational, allow queries */
1514 acpi_ec_enable_event(ec);
1515
1516 return 0;
1517}
1518
1519static void ec_remove_handlers(struct acpi_ec *ec)
1520{
1521 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1522 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1523 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1524 pr_err("failed to remove space handler\n");
1525 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1526 }
1527
1528 /*
1529 * Stops handling the EC transactions after removing the operation
1530 * region handler. This is required because _REG(DISCONNECT)
1531 * invoked during the removal can result in new EC transactions.
1532 *
1533 * Flushes the EC requests and thus disables the GPE before
1534 * removing the GPE handler. This is required by the current ACPICA
1535 * GPE core. ACPICA GPE core will automatically disable a GPE when
1536 * it is indicated but there is no way to handle it. So the drivers
1537 * must disable the GPEs prior to removing the GPE handlers.
1538 */
1539 acpi_ec_stop(ec, false);
1540
1541 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1542 if (ec->gpe >= 0 &&
1543 ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1544 &acpi_ec_gpe_handler)))
1545 pr_err("failed to remove gpe handler\n");
1546
1547 if (ec->irq >= 0)
1548 free_irq(ec->irq, ec);
1549
1550 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1551 }
1552 if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1553 acpi_ec_remove_query_handlers(ec, true, 0);
1554 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1555 }
1556}
1557
1558static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1559{
1560 int ret;
1561
1562 ret = ec_install_handlers(ec, device);
1563 if (ret)
1564 return ret;
1565
1566 /* First EC capable of handling transactions */
1567 if (!first_ec)
1568 first_ec = ec;
1569
1570 pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1571 ec->data_addr);
1572
1573 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1574 if (ec->gpe >= 0)
1575 pr_info("GPE=0x%x\n", ec->gpe);
1576 else
1577 pr_info("IRQ=%d\n", ec->irq);
1578 }
1579
1580 return ret;
1581}
1582
1583static int acpi_ec_add(struct acpi_device *device)
1584{
1585 struct acpi_ec *ec;
1586 int ret;
1587
1588 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1589 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1590
1591 if (boot_ec && (boot_ec->handle == device->handle ||
1592 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1593 /* Fast path: this device corresponds to the boot EC. */
1594 ec = boot_ec;
1595 } else {
1596 acpi_status status;
1597
1598 ec = acpi_ec_alloc();
1599 if (!ec)
1600 return -ENOMEM;
1601
1602 status = ec_parse_device(device->handle, 0, ec, NULL);
1603 if (status != AE_CTRL_TERMINATE) {
1604 ret = -EINVAL;
1605 goto err;
1606 }
1607
1608 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1609 ec->data_addr == boot_ec->data_addr) {
1610 /*
1611 * Trust PNP0C09 namespace location rather than
1612 * ECDT ID. But trust ECDT GPE rather than _GPE
1613 * because of ASUS quirks, so do not change
1614 * boot_ec->gpe to ec->gpe.
1615 */
1616 boot_ec->handle = ec->handle;
1617 acpi_handle_debug(ec->handle, "duplicated.\n");
1618 acpi_ec_free(ec);
1619 ec = boot_ec;
1620 }
1621 }
1622
1623 ret = acpi_ec_setup(ec, device);
1624 if (ret)
1625 goto err;
1626
1627 if (ec == boot_ec)
1628 acpi_handle_info(boot_ec->handle,
1629 "Boot %s EC initialization complete\n",
1630 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1631
1632 acpi_handle_info(ec->handle,
1633 "EC: Used to handle transactions and events\n");
1634
1635 device->driver_data = ec;
1636
1637 ret = !!request_region(ec->data_addr, 1, "EC data");
1638 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1639 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1640 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1641
1642 /* Reprobe devices depending on the EC */
1643 acpi_walk_dep_device_list(ec->handle);
1644
1645 acpi_handle_debug(ec->handle, "enumerated.\n");
1646 return 0;
1647
1648err:
1649 if (ec != boot_ec)
1650 acpi_ec_free(ec);
1651
1652 return ret;
1653}
1654
1655static int acpi_ec_remove(struct acpi_device *device)
1656{
1657 struct acpi_ec *ec;
1658
1659 if (!device)
1660 return -EINVAL;
1661
1662 ec = acpi_driver_data(device);
1663 release_region(ec->data_addr, 1);
1664 release_region(ec->command_addr, 1);
1665 device->driver_data = NULL;
1666 if (ec != boot_ec) {
1667 ec_remove_handlers(ec);
1668 acpi_ec_free(ec);
1669 }
1670 return 0;
1671}
1672
1673static acpi_status
1674ec_parse_io_ports(struct acpi_resource *resource, void *context)
1675{
1676 struct acpi_ec *ec = context;
1677
1678 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1679 return AE_OK;
1680
1681 /*
1682 * The first address region returned is the data port, and
1683 * the second address region returned is the status/command
1684 * port.
1685 */
1686 if (ec->data_addr == 0)
1687 ec->data_addr = resource->data.io.minimum;
1688 else if (ec->command_addr == 0)
1689 ec->command_addr = resource->data.io.minimum;
1690 else
1691 return AE_CTRL_TERMINATE;
1692
1693 return AE_OK;
1694}
1695
1696static const struct acpi_device_id ec_device_ids[] = {
1697 {"PNP0C09", 0},
1698 {ACPI_ECDT_HID, 0},
1699 {"", 0},
1700};
1701
1702/*
1703 * This function is not Windows-compatible as Windows never enumerates the
1704 * namespace EC before the main ACPI device enumeration process. It is
1705 * retained for historical reason and will be deprecated in the future.
1706 */
1707void __init acpi_ec_dsdt_probe(void)
1708{
1709 struct acpi_ec *ec;
1710 acpi_status status;
1711 int ret;
1712
1713 /*
1714 * If a platform has ECDT, there is no need to proceed as the
1715 * following probe is not a part of the ACPI device enumeration,
1716 * executing _STA is not safe, and thus this probe may risk of
1717 * picking up an invalid EC device.
1718 */
1719 if (boot_ec)
1720 return;
1721
1722 ec = acpi_ec_alloc();
1723 if (!ec)
1724 return;
1725
1726 /*
1727 * At this point, the namespace is initialized, so start to find
1728 * the namespace objects.
1729 */
1730 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1731 if (ACPI_FAILURE(status) || !ec->handle) {
1732 acpi_ec_free(ec);
1733 return;
1734 }
1735
1736 /*
1737 * When the DSDT EC is available, always re-configure boot EC to
1738 * have _REG evaluated. _REG can only be evaluated after the
1739 * namespace initialization.
1740 * At this point, the GPE is not fully initialized, so do not to
1741 * handle the events.
1742 */
1743 ret = acpi_ec_setup(ec, NULL);
1744 if (ret) {
1745 acpi_ec_free(ec);
1746 return;
1747 }
1748
1749 boot_ec = ec;
1750
1751 acpi_handle_info(ec->handle,
1752 "Boot DSDT EC used to handle transactions\n");
1753}
1754
1755/*
1756 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1757 *
1758 * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1759 * found a matching object in the namespace.
1760 *
1761 * Next, in case the DSDT EC is not functioning, it is still necessary to
1762 * provide a functional ECDT EC to handle events, so add an extra device object
1763 * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1764 *
1765 * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1766 * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1767 */
1768static void __init acpi_ec_ecdt_start(void)
1769{
1770 struct acpi_table_ecdt *ecdt_ptr;
1771 acpi_handle handle;
1772 acpi_status status;
1773
1774 /* Bail out if a matching EC has been found in the namespace. */
1775 if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1776 return;
1777
1778 /* Look up the object pointed to from the ECDT in the namespace. */
1779 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1780 (struct acpi_table_header **)&ecdt_ptr);
1781 if (ACPI_FAILURE(status))
1782 return;
1783
1784 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1785 if (ACPI_SUCCESS(status)) {
1786 boot_ec->handle = handle;
1787
1788 /* Add a special ACPI device object to represent the boot EC. */
1789 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1790 }
1791
1792 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1793}
1794
1795/*
1796 * On some hardware it is necessary to clear events accumulated by the EC during
1797 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1798 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1799 *
1800 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1801 *
1802 * Ideally, the EC should also be instructed NOT to accumulate events during
1803 * sleep (which Windows seems to do somehow), but the interface to control this
1804 * behaviour is not known at this time.
1805 *
1806 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1807 * however it is very likely that other Samsung models are affected.
1808 *
1809 * On systems which don't accumulate _Q events during sleep, this extra check
1810 * should be harmless.
1811 */
1812static int ec_clear_on_resume(const struct dmi_system_id *id)
1813{
1814 pr_debug("Detected system needing EC poll on resume.\n");
1815 EC_FLAGS_CLEAR_ON_RESUME = 1;
1816 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1817 return 0;
1818}
1819
1820/*
1821 * Some ECDTs contain wrong register addresses.
1822 * MSI MS-171F
1823 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1824 */
1825static int ec_correct_ecdt(const struct dmi_system_id *id)
1826{
1827 pr_debug("Detected system needing ECDT address correction.\n");
1828 EC_FLAGS_CORRECT_ECDT = 1;
1829 return 0;
1830}
1831
1832/*
1833 * Some DSDTs contain wrong GPE setting.
1834 * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1835 * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1836 */
1837static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1838{
1839 pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1840 EC_FLAGS_IGNORE_DSDT_GPE = 1;
1841 return 0;
1842}
1843
1844static const struct dmi_system_id ec_dmi_table[] __initconst = {
1845 {
1846 ec_correct_ecdt, "MSI MS-171F", {
1847 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1848 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1849 {
1850 ec_honor_ecdt_gpe, "ASUS FX502VD", {
1851 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1852 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1853 {
1854 ec_honor_ecdt_gpe, "ASUS FX502VE", {
1855 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1856 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1857 {
1858 ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1859 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1860 DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1861 {
1862 ec_honor_ecdt_gpe, "ASUS X550VXK", {
1863 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1864 DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1865 {
1866 ec_honor_ecdt_gpe, "ASUS X580VD", {
1867 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1868 DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1869 {
1870 ec_clear_on_resume, "Samsung hardware", {
1871 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1872 {},
1873};
1874
1875void __init acpi_ec_ecdt_probe(void)
1876{
1877 struct acpi_table_ecdt *ecdt_ptr;
1878 struct acpi_ec *ec;
1879 acpi_status status;
1880 int ret;
1881
1882 /* Generate a boot ec context. */
1883 dmi_check_system(ec_dmi_table);
1884 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1885 (struct acpi_table_header **)&ecdt_ptr);
1886 if (ACPI_FAILURE(status))
1887 return;
1888
1889 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1890 /*
1891 * Asus X50GL:
1892 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1893 */
1894 goto out;
1895 }
1896
1897 ec = acpi_ec_alloc();
1898 if (!ec)
1899 goto out;
1900
1901 if (EC_FLAGS_CORRECT_ECDT) {
1902 ec->command_addr = ecdt_ptr->data.address;
1903 ec->data_addr = ecdt_ptr->control.address;
1904 } else {
1905 ec->command_addr = ecdt_ptr->control.address;
1906 ec->data_addr = ecdt_ptr->data.address;
1907 }
1908
1909 /*
1910 * Ignore the GPE value on Reduced Hardware platforms.
1911 * Some products have this set to an erroneous value.
1912 */
1913 if (!acpi_gbl_reduced_hardware)
1914 ec->gpe = ecdt_ptr->gpe;
1915
1916 ec->handle = ACPI_ROOT_OBJECT;
1917
1918 /*
1919 * At this point, the namespace is not initialized, so do not find
1920 * the namespace objects, or handle the events.
1921 */
1922 ret = acpi_ec_setup(ec, NULL);
1923 if (ret) {
1924 acpi_ec_free(ec);
1925 goto out;
1926 }
1927
1928 boot_ec = ec;
1929 boot_ec_is_ecdt = true;
1930
1931 pr_info("Boot ECDT EC used to handle transactions\n");
1932
1933out:
1934 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1935}
1936
1937#ifdef CONFIG_PM_SLEEP
1938static int acpi_ec_suspend(struct device *dev)
1939{
1940 struct acpi_ec *ec =
1941 acpi_driver_data(to_acpi_device(dev));
1942
1943 if (!pm_suspend_no_platform() && ec_freeze_events)
1944 acpi_ec_disable_event(ec);
1945 return 0;
1946}
1947
1948static int acpi_ec_suspend_noirq(struct device *dev)
1949{
1950 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1951
1952 /*
1953 * The SCI handler doesn't run at this point, so the GPE can be
1954 * masked at the low level without side effects.
1955 */
1956 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1957 ec->gpe >= 0 && ec->reference_count >= 1)
1958 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1959
1960 acpi_ec_enter_noirq(ec);
1961
1962 return 0;
1963}
1964
1965static int acpi_ec_resume_noirq(struct device *dev)
1966{
1967 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1968
1969 acpi_ec_leave_noirq(ec);
1970
1971 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1972 ec->gpe >= 0 && ec->reference_count >= 1)
1973 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1974
1975 return 0;
1976}
1977
1978static int acpi_ec_resume(struct device *dev)
1979{
1980 struct acpi_ec *ec =
1981 acpi_driver_data(to_acpi_device(dev));
1982
1983 acpi_ec_enable_event(ec);
1984 return 0;
1985}
1986
1987void acpi_ec_mark_gpe_for_wake(void)
1988{
1989 if (first_ec && !ec_no_wakeup)
1990 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1991}
1992EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
1993
1994void acpi_ec_set_gpe_wake_mask(u8 action)
1995{
1996 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
1997 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1998}
1999
2000bool acpi_ec_dispatch_gpe(void)
2001{
2002 u32 ret;
2003
2004 if (!first_ec)
2005 return acpi_any_gpe_status_set(U32_MAX);
2006
2007 /*
2008 * Report wakeup if the status bit is set for any enabled GPE other
2009 * than the EC one.
2010 */
2011 if (acpi_any_gpe_status_set(first_ec->gpe))
2012 return true;
2013
2014 if (ec_no_wakeup)
2015 return false;
2016
2017 /*
2018 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2019 * to allow the caller to process events properly after that.
2020 */
2021 ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2022 if (ret == ACPI_INTERRUPT_HANDLED) {
2023 pm_pr_dbg("ACPI EC GPE dispatched\n");
2024
2025 /* Flush the event and query workqueues. */
2026 acpi_ec_flush_work();
2027 }
2028
2029 return false;
2030}
2031#endif /* CONFIG_PM_SLEEP */
2032
2033static const struct dev_pm_ops acpi_ec_pm = {
2034 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2035 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2036};
2037
2038static int param_set_event_clearing(const char *val,
2039 const struct kernel_param *kp)
2040{
2041 int result = 0;
2042
2043 if (!strncmp(val, "status", sizeof("status") - 1)) {
2044 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2045 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2046 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2047 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2048 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2049 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2050 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2051 pr_info("Assuming SCI_EVT clearing on event reads\n");
2052 } else
2053 result = -EINVAL;
2054 return result;
2055}
2056
2057static int param_get_event_clearing(char *buffer,
2058 const struct kernel_param *kp)
2059{
2060 switch (ec_event_clearing) {
2061 case ACPI_EC_EVT_TIMING_STATUS:
2062 return sprintf(buffer, "status\n");
2063 case ACPI_EC_EVT_TIMING_QUERY:
2064 return sprintf(buffer, "query\n");
2065 case ACPI_EC_EVT_TIMING_EVENT:
2066 return sprintf(buffer, "event\n");
2067 default:
2068 return sprintf(buffer, "invalid\n");
2069 }
2070 return 0;
2071}
2072
2073module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2074 NULL, 0644);
2075MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2076
2077static struct acpi_driver acpi_ec_driver = {
2078 .name = "ec",
2079 .class = ACPI_EC_CLASS,
2080 .ids = ec_device_ids,
2081 .ops = {
2082 .add = acpi_ec_add,
2083 .remove = acpi_ec_remove,
2084 },
2085 .drv.pm = &acpi_ec_pm,
2086};
2087
2088static void acpi_ec_destroy_workqueues(void)
2089{
2090 if (ec_wq) {
2091 destroy_workqueue(ec_wq);
2092 ec_wq = NULL;
2093 }
2094 if (ec_query_wq) {
2095 destroy_workqueue(ec_query_wq);
2096 ec_query_wq = NULL;
2097 }
2098}
2099
2100static int acpi_ec_init_workqueues(void)
2101{
2102 if (!ec_wq)
2103 ec_wq = alloc_ordered_workqueue("kec", 0);
2104
2105 if (!ec_query_wq)
2106 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2107
2108 if (!ec_wq || !ec_query_wq) {
2109 acpi_ec_destroy_workqueues();
2110 return -ENODEV;
2111 }
2112 return 0;
2113}
2114
2115static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2116 {
2117 .ident = "Thinkpad X1 Carbon 6th",
2118 .matches = {
2119 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2120 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2121 },
2122 },
2123 {
2124 .ident = "ThinkPad X1 Carbon 6th",
2125 .matches = {
2126 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2127 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2128 },
2129 },
2130 {
2131 .ident = "ThinkPad X1 Yoga 3rd",
2132 .matches = {
2133 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2134 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2135 },
2136 },
2137 { },
2138};
2139
2140void __init acpi_ec_init(void)
2141{
2142 int result;
2143
2144 result = acpi_ec_init_workqueues();
2145 if (result)
2146 return;
2147
2148 /*
2149 * Disable EC wakeup on following systems to prevent periodic
2150 * wakeup from EC GPE.
2151 */
2152 if (dmi_check_system(acpi_ec_no_wakeup)) {
2153 ec_no_wakeup = true;
2154 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2155 }
2156
2157 /* Driver must be registered after acpi_ec_init_workqueues(). */
2158 acpi_bus_register_driver(&acpi_ec_driver);
2159
2160 acpi_ec_ecdt_start();
2161}
2162
2163/* EC driver currently not unloadable */
2164#if 0
2165static void __exit acpi_ec_exit(void)
2166{
2167
2168 acpi_bus_unregister_driver(&acpi_ec_driver);
2169 acpi_ec_destroy_workqueues();
2170}
2171#endif /* 0 */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ec.c - ACPI Embedded Controller Driver (v3)
4 *
5 * Copyright (C) 2001-2015 Intel Corporation
6 * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
7 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
8 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
9 * 2004 Luming Yu <luming.yu@intel.com>
10 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
11 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
12 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
13 */
14
15/* Uncomment next line to get verbose printout */
16/* #define DEBUG */
17#define pr_fmt(fmt) "ACPI: EC: " fmt
18
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/types.h>
23#include <linux/delay.h>
24#include <linux/interrupt.h>
25#include <linux/list.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/suspend.h>
29#include <linux/acpi.h>
30#include <linux/dmi.h>
31#include <asm/io.h>
32
33#include "internal.h"
34
35#define ACPI_EC_CLASS "embedded_controller"
36#define ACPI_EC_DEVICE_NAME "Embedded Controller"
37#define ACPI_EC_FILE_INFO "info"
38
39/* EC status register */
40#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
41#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
42#define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
43#define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
44#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
45
46/*
47 * The SCI_EVT clearing timing is not defined by the ACPI specification.
48 * This leads to lots of practical timing issues for the host EC driver.
49 * The following variations are defined (from the target EC firmware's
50 * perspective):
51 * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
52 * target can clear SCI_EVT at any time so long as the host can see
53 * the indication by reading the status register (EC_SC). So the
54 * host should re-check SCI_EVT after the first time the SCI_EVT
55 * indication is seen, which is the same time the query request
56 * (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
57 * at any later time could indicate another event. Normally such
58 * kind of EC firmware has implemented an event queue and will
59 * return 0x00 to indicate "no outstanding event".
60 * QUERY: After seeing the query request (QR_EC) written to the command
61 * register (EC_CMD) by the host and having prepared the responding
62 * event value in the data register (EC_DATA), the target can safely
63 * clear SCI_EVT because the target can confirm that the current
64 * event is being handled by the host. The host then should check
65 * SCI_EVT right after reading the event response from the data
66 * register (EC_DATA).
67 * EVENT: After seeing the event response read from the data register
68 * (EC_DATA) by the host, the target can clear SCI_EVT. As the
69 * target requires time to notice the change in the data register
70 * (EC_DATA), the host may be required to wait additional guarding
71 * time before checking the SCI_EVT again. Such guarding may not be
72 * necessary if the host is notified via another IRQ.
73 */
74#define ACPI_EC_EVT_TIMING_STATUS 0x00
75#define ACPI_EC_EVT_TIMING_QUERY 0x01
76#define ACPI_EC_EVT_TIMING_EVENT 0x02
77
78/* EC commands */
79enum ec_command {
80 ACPI_EC_COMMAND_READ = 0x80,
81 ACPI_EC_COMMAND_WRITE = 0x81,
82 ACPI_EC_BURST_ENABLE = 0x82,
83 ACPI_EC_BURST_DISABLE = 0x83,
84 ACPI_EC_COMMAND_QUERY = 0x84,
85};
86
87#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
88#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
89#define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
90#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
91 * when trying to clear the EC */
92#define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
93
94enum {
95 EC_FLAGS_QUERY_ENABLED, /* Query is enabled */
96 EC_FLAGS_QUERY_PENDING, /* Query is pending */
97 EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */
98 EC_FLAGS_GPE_HANDLER_INSTALLED, /* GPE handler installed */
99 EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */
100 EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */
101 EC_FLAGS_STARTED, /* Driver is started */
102 EC_FLAGS_STOPPED, /* Driver is stopped */
103 EC_FLAGS_GPE_MASKED, /* GPE masked */
104};
105
106#define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
107#define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
108
109/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
110static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
111module_param(ec_delay, uint, 0644);
112MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
113
114static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
115module_param(ec_max_queries, uint, 0644);
116MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
117
118static bool ec_busy_polling __read_mostly;
119module_param(ec_busy_polling, bool, 0644);
120MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
121
122static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
123module_param(ec_polling_guard, uint, 0644);
124MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
125
126static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
127
128/*
129 * If the number of false interrupts per one transaction exceeds
130 * this threshold, will think there is a GPE storm happened and
131 * will disable the GPE for normal transaction.
132 */
133static unsigned int ec_storm_threshold __read_mostly = 8;
134module_param(ec_storm_threshold, uint, 0644);
135MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
136
137static bool ec_freeze_events __read_mostly = false;
138module_param(ec_freeze_events, bool, 0644);
139MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
140
141static bool ec_no_wakeup __read_mostly;
142module_param(ec_no_wakeup, bool, 0644);
143MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
144
145struct acpi_ec_query_handler {
146 struct list_head node;
147 acpi_ec_query_func func;
148 acpi_handle handle;
149 void *data;
150 u8 query_bit;
151 struct kref kref;
152};
153
154struct transaction {
155 const u8 *wdata;
156 u8 *rdata;
157 unsigned short irq_count;
158 u8 command;
159 u8 wi;
160 u8 ri;
161 u8 wlen;
162 u8 rlen;
163 u8 flags;
164};
165
166struct acpi_ec_query {
167 struct transaction transaction;
168 struct work_struct work;
169 struct acpi_ec_query_handler *handler;
170};
171
172static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
173static void advance_transaction(struct acpi_ec *ec);
174static void acpi_ec_event_handler(struct work_struct *work);
175static void acpi_ec_event_processor(struct work_struct *work);
176
177struct acpi_ec *first_ec;
178EXPORT_SYMBOL(first_ec);
179
180static struct acpi_ec *boot_ec;
181static bool boot_ec_is_ecdt = false;
182static struct workqueue_struct *ec_query_wq;
183
184static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
185static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
186static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
187static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
188
189/* --------------------------------------------------------------------------
190 * Logging/Debugging
191 * -------------------------------------------------------------------------- */
192
193/*
194 * Splitters used by the developers to track the boundary of the EC
195 * handling processes.
196 */
197#ifdef DEBUG
198#define EC_DBG_SEP " "
199#define EC_DBG_DRV "+++++"
200#define EC_DBG_STM "====="
201#define EC_DBG_REQ "*****"
202#define EC_DBG_EVT "#####"
203#else
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#endif
210
211#define ec_log_raw(fmt, ...) \
212 pr_info(fmt "\n", ##__VA_ARGS__)
213#define ec_dbg_raw(fmt, ...) \
214 pr_debug(fmt "\n", ##__VA_ARGS__)
215#define ec_log(filter, fmt, ...) \
216 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
217#define ec_dbg(filter, fmt, ...) \
218 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
219
220#define ec_log_drv(fmt, ...) \
221 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
222#define ec_dbg_drv(fmt, ...) \
223 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
224#define ec_dbg_stm(fmt, ...) \
225 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
226#define ec_dbg_req(fmt, ...) \
227 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
228#define ec_dbg_evt(fmt, ...) \
229 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
230#define ec_dbg_ref(ec, fmt, ...) \
231 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
232
233/* --------------------------------------------------------------------------
234 * Device Flags
235 * -------------------------------------------------------------------------- */
236
237static bool acpi_ec_started(struct acpi_ec *ec)
238{
239 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
240 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
241}
242
243static bool acpi_ec_event_enabled(struct acpi_ec *ec)
244{
245 /*
246 * There is an OSPM early stage logic. During the early stages
247 * (boot/resume), OSPMs shouldn't enable the event handling, only
248 * the EC transactions are allowed to be performed.
249 */
250 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
251 return false;
252 /*
253 * However, disabling the event handling is experimental for late
254 * stage (suspend), and is controlled by the boot parameter of
255 * "ec_freeze_events":
256 * 1. true: The EC event handling is disabled before entering
257 * the noirq stage.
258 * 2. false: The EC event handling is automatically disabled as
259 * soon as the EC driver is stopped.
260 */
261 if (ec_freeze_events)
262 return acpi_ec_started(ec);
263 else
264 return test_bit(EC_FLAGS_STARTED, &ec->flags);
265}
266
267static bool acpi_ec_flushed(struct acpi_ec *ec)
268{
269 return ec->reference_count == 1;
270}
271
272/* --------------------------------------------------------------------------
273 * EC Registers
274 * -------------------------------------------------------------------------- */
275
276static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
277{
278 u8 x = inb(ec->command_addr);
279
280 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
281 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
282 x,
283 !!(x & ACPI_EC_FLAG_SCI),
284 !!(x & ACPI_EC_FLAG_BURST),
285 !!(x & ACPI_EC_FLAG_CMD),
286 !!(x & ACPI_EC_FLAG_IBF),
287 !!(x & ACPI_EC_FLAG_OBF));
288 return x;
289}
290
291static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
292{
293 u8 x = inb(ec->data_addr);
294
295 ec->timestamp = jiffies;
296 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
297 return x;
298}
299
300static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
301{
302 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
303 outb(command, ec->command_addr);
304 ec->timestamp = jiffies;
305}
306
307static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
308{
309 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
310 outb(data, ec->data_addr);
311 ec->timestamp = jiffies;
312}
313
314#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
315static const char *acpi_ec_cmd_string(u8 cmd)
316{
317 switch (cmd) {
318 case 0x80:
319 return "RD_EC";
320 case 0x81:
321 return "WR_EC";
322 case 0x82:
323 return "BE_EC";
324 case 0x83:
325 return "BD_EC";
326 case 0x84:
327 return "QR_EC";
328 }
329 return "UNKNOWN";
330}
331#else
332#define acpi_ec_cmd_string(cmd) "UNDEF"
333#endif
334
335/* --------------------------------------------------------------------------
336 * GPE Registers
337 * -------------------------------------------------------------------------- */
338
339static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
340{
341 acpi_event_status gpe_status = 0;
342
343 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
344 return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
345}
346
347static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
348{
349 if (open)
350 acpi_enable_gpe(NULL, ec->gpe);
351 else {
352 BUG_ON(ec->reference_count < 1);
353 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
354 }
355 if (acpi_ec_is_gpe_raised(ec)) {
356 /*
357 * On some platforms, EN=1 writes cannot trigger GPE. So
358 * software need to manually trigger a pseudo GPE event on
359 * EN=1 writes.
360 */
361 ec_dbg_raw("Polling quirk");
362 advance_transaction(ec);
363 }
364}
365
366static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
367{
368 if (close)
369 acpi_disable_gpe(NULL, ec->gpe);
370 else {
371 BUG_ON(ec->reference_count < 1);
372 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
373 }
374}
375
376static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
377{
378 /*
379 * GPE STS is a W1C register, which means:
380 * 1. Software can clear it without worrying about clearing other
381 * GPEs' STS bits when the hardware sets them in parallel.
382 * 2. As long as software can ensure only clearing it when it is
383 * set, hardware won't set it in parallel.
384 * So software can clear GPE in any contexts.
385 * Warning: do not move the check into advance_transaction() as the
386 * EC commands will be sent without GPE raised.
387 */
388 if (!acpi_ec_is_gpe_raised(ec))
389 return;
390 acpi_clear_gpe(NULL, ec->gpe);
391}
392
393/* --------------------------------------------------------------------------
394 * Transaction Management
395 * -------------------------------------------------------------------------- */
396
397static void acpi_ec_submit_request(struct acpi_ec *ec)
398{
399 ec->reference_count++;
400 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
401 ec->reference_count == 1)
402 acpi_ec_enable_gpe(ec, true);
403}
404
405static void acpi_ec_complete_request(struct acpi_ec *ec)
406{
407 bool flushed = false;
408
409 ec->reference_count--;
410 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
411 ec->reference_count == 0)
412 acpi_ec_disable_gpe(ec, true);
413 flushed = acpi_ec_flushed(ec);
414 if (flushed)
415 wake_up(&ec->wait);
416}
417
418static void acpi_ec_mask_gpe(struct acpi_ec *ec)
419{
420 if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
421 acpi_ec_disable_gpe(ec, false);
422 ec_dbg_drv("Polling enabled");
423 set_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
424 }
425}
426
427static void acpi_ec_unmask_gpe(struct acpi_ec *ec)
428{
429 if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
430 clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
431 acpi_ec_enable_gpe(ec, false);
432 ec_dbg_drv("Polling disabled");
433 }
434}
435
436/*
437 * acpi_ec_submit_flushable_request() - Increase the reference count unless
438 * the flush operation is not in
439 * progress
440 * @ec: the EC device
441 *
442 * This function must be used before taking a new action that should hold
443 * the reference count. If this function returns false, then the action
444 * must be discarded or it will prevent the flush operation from being
445 * completed.
446 */
447static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
448{
449 if (!acpi_ec_started(ec))
450 return false;
451 acpi_ec_submit_request(ec);
452 return true;
453}
454
455static void acpi_ec_submit_query(struct acpi_ec *ec)
456{
457 acpi_ec_mask_gpe(ec);
458 if (!acpi_ec_event_enabled(ec))
459 return;
460 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
461 ec_dbg_evt("Command(%s) submitted/blocked",
462 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
463 ec->nr_pending_queries++;
464 schedule_work(&ec->work);
465 }
466}
467
468static void acpi_ec_complete_query(struct acpi_ec *ec)
469{
470 if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
471 ec_dbg_evt("Command(%s) unblocked",
472 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
473 acpi_ec_unmask_gpe(ec);
474}
475
476static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
477{
478 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
479 ec_log_drv("event unblocked");
480 /*
481 * Unconditionally invoke this once after enabling the event
482 * handling mechanism to detect the pending events.
483 */
484 advance_transaction(ec);
485}
486
487static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
488{
489 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
490 ec_log_drv("event blocked");
491}
492
493/*
494 * Process _Q events that might have accumulated in the EC.
495 * Run with locked ec mutex.
496 */
497static void acpi_ec_clear(struct acpi_ec *ec)
498{
499 int i, status;
500 u8 value = 0;
501
502 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
503 status = acpi_ec_query(ec, &value);
504 if (status || !value)
505 break;
506 }
507 if (unlikely(i == ACPI_EC_CLEAR_MAX))
508 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
509 else
510 pr_info("%d stale EC events cleared\n", i);
511}
512
513static void acpi_ec_enable_event(struct acpi_ec *ec)
514{
515 unsigned long flags;
516
517 spin_lock_irqsave(&ec->lock, flags);
518 if (acpi_ec_started(ec))
519 __acpi_ec_enable_event(ec);
520 spin_unlock_irqrestore(&ec->lock, flags);
521
522 /* Drain additional events if hardware requires that */
523 if (EC_FLAGS_CLEAR_ON_RESUME)
524 acpi_ec_clear(ec);
525}
526
527#ifdef CONFIG_PM_SLEEP
528static bool acpi_ec_query_flushed(struct acpi_ec *ec)
529{
530 bool flushed;
531 unsigned long flags;
532
533 spin_lock_irqsave(&ec->lock, flags);
534 flushed = !ec->nr_pending_queries;
535 spin_unlock_irqrestore(&ec->lock, flags);
536 return flushed;
537}
538
539static void __acpi_ec_flush_event(struct acpi_ec *ec)
540{
541 /*
542 * When ec_freeze_events is true, we need to flush events in
543 * the proper position before entering the noirq stage.
544 */
545 wait_event(ec->wait, acpi_ec_query_flushed(ec));
546 if (ec_query_wq)
547 flush_workqueue(ec_query_wq);
548}
549
550static void acpi_ec_disable_event(struct acpi_ec *ec)
551{
552 unsigned long flags;
553
554 spin_lock_irqsave(&ec->lock, flags);
555 __acpi_ec_disable_event(ec);
556 spin_unlock_irqrestore(&ec->lock, flags);
557 __acpi_ec_flush_event(ec);
558}
559
560void acpi_ec_flush_work(void)
561{
562 if (first_ec)
563 __acpi_ec_flush_event(first_ec);
564
565 flush_scheduled_work();
566}
567#endif /* CONFIG_PM_SLEEP */
568
569static bool acpi_ec_guard_event(struct acpi_ec *ec)
570{
571 bool guarded = true;
572 unsigned long flags;
573
574 spin_lock_irqsave(&ec->lock, flags);
575 /*
576 * If firmware SCI_EVT clearing timing is "event", we actually
577 * don't know when the SCI_EVT will be cleared by firmware after
578 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
579 * acceptable period.
580 *
581 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
582 * flagged, which means SCI_EVT check has just been performed.
583 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
584 * guarding should have already been performed (via
585 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
586 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
587 * ACPI_EC_COMMAND_POLL state immediately.
588 */
589 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
590 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
591 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
592 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
593 guarded = false;
594 spin_unlock_irqrestore(&ec->lock, flags);
595 return guarded;
596}
597
598static int ec_transaction_polled(struct acpi_ec *ec)
599{
600 unsigned long flags;
601 int ret = 0;
602
603 spin_lock_irqsave(&ec->lock, flags);
604 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
605 ret = 1;
606 spin_unlock_irqrestore(&ec->lock, flags);
607 return ret;
608}
609
610static int ec_transaction_completed(struct acpi_ec *ec)
611{
612 unsigned long flags;
613 int ret = 0;
614
615 spin_lock_irqsave(&ec->lock, flags);
616 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
617 ret = 1;
618 spin_unlock_irqrestore(&ec->lock, flags);
619 return ret;
620}
621
622static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
623{
624 ec->curr->flags |= flag;
625 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
626 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
627 flag == ACPI_EC_COMMAND_POLL)
628 acpi_ec_complete_query(ec);
629 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
630 flag == ACPI_EC_COMMAND_COMPLETE)
631 acpi_ec_complete_query(ec);
632 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
633 flag == ACPI_EC_COMMAND_COMPLETE)
634 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
635 }
636}
637
638static void advance_transaction(struct acpi_ec *ec)
639{
640 struct transaction *t;
641 u8 status;
642 bool wakeup = false;
643
644 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
645 smp_processor_id());
646 /*
647 * By always clearing STS before handling all indications, we can
648 * ensure a hardware STS 0->1 change after this clearing can always
649 * trigger a GPE interrupt.
650 */
651 acpi_ec_clear_gpe(ec);
652 status = acpi_ec_read_status(ec);
653 t = ec->curr;
654 /*
655 * Another IRQ or a guarded polling mode advancement is detected,
656 * the next QR_EC submission is then allowed.
657 */
658 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
659 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
660 (!ec->nr_pending_queries ||
661 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
662 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
663 acpi_ec_complete_query(ec);
664 }
665 }
666 if (!t)
667 goto err;
668 if (t->flags & ACPI_EC_COMMAND_POLL) {
669 if (t->wlen > t->wi) {
670 if ((status & ACPI_EC_FLAG_IBF) == 0)
671 acpi_ec_write_data(ec, t->wdata[t->wi++]);
672 else
673 goto err;
674 } else if (t->rlen > t->ri) {
675 if ((status & ACPI_EC_FLAG_OBF) == 1) {
676 t->rdata[t->ri++] = acpi_ec_read_data(ec);
677 if (t->rlen == t->ri) {
678 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
679 if (t->command == ACPI_EC_COMMAND_QUERY)
680 ec_dbg_evt("Command(%s) completed by hardware",
681 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
682 wakeup = true;
683 }
684 } else
685 goto err;
686 } else if (t->wlen == t->wi &&
687 (status & ACPI_EC_FLAG_IBF) == 0) {
688 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
689 wakeup = true;
690 }
691 goto out;
692 } else {
693 if (EC_FLAGS_QUERY_HANDSHAKE &&
694 !(status & ACPI_EC_FLAG_SCI) &&
695 (t->command == ACPI_EC_COMMAND_QUERY)) {
696 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
697 t->rdata[t->ri++] = 0x00;
698 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
699 ec_dbg_evt("Command(%s) completed by software",
700 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
701 wakeup = true;
702 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
703 acpi_ec_write_cmd(ec, t->command);
704 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
705 } else
706 goto err;
707 goto out;
708 }
709err:
710 /*
711 * If SCI bit is set, then don't think it's a false IRQ
712 * otherwise will take a not handled IRQ as a false one.
713 */
714 if (!(status & ACPI_EC_FLAG_SCI)) {
715 if (in_interrupt() && t) {
716 if (t->irq_count < ec_storm_threshold)
717 ++t->irq_count;
718 /* Allow triggering on 0 threshold */
719 if (t->irq_count == ec_storm_threshold)
720 acpi_ec_mask_gpe(ec);
721 }
722 }
723out:
724 if (status & ACPI_EC_FLAG_SCI)
725 acpi_ec_submit_query(ec);
726 if (wakeup && in_interrupt())
727 wake_up(&ec->wait);
728}
729
730static void start_transaction(struct acpi_ec *ec)
731{
732 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
733 ec->curr->flags = 0;
734}
735
736static int ec_guard(struct acpi_ec *ec)
737{
738 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
739 unsigned long timeout = ec->timestamp + guard;
740
741 /* Ensure guarding period before polling EC status */
742 do {
743 if (ec->busy_polling) {
744 /* Perform busy polling */
745 if (ec_transaction_completed(ec))
746 return 0;
747 udelay(jiffies_to_usecs(guard));
748 } else {
749 /*
750 * Perform wait polling
751 * 1. Wait the transaction to be completed by the
752 * GPE handler after the transaction enters
753 * ACPI_EC_COMMAND_POLL state.
754 * 2. A special guarding logic is also required
755 * for event clearing mode "event" before the
756 * transaction enters ACPI_EC_COMMAND_POLL
757 * state.
758 */
759 if (!ec_transaction_polled(ec) &&
760 !acpi_ec_guard_event(ec))
761 break;
762 if (wait_event_timeout(ec->wait,
763 ec_transaction_completed(ec),
764 guard))
765 return 0;
766 }
767 } while (time_before(jiffies, timeout));
768 return -ETIME;
769}
770
771static int ec_poll(struct acpi_ec *ec)
772{
773 unsigned long flags;
774 int repeat = 5; /* number of command restarts */
775
776 while (repeat--) {
777 unsigned long delay = jiffies +
778 msecs_to_jiffies(ec_delay);
779 do {
780 if (!ec_guard(ec))
781 return 0;
782 spin_lock_irqsave(&ec->lock, flags);
783 advance_transaction(ec);
784 spin_unlock_irqrestore(&ec->lock, flags);
785 } while (time_before(jiffies, delay));
786 pr_debug("controller reset, restart transaction\n");
787 spin_lock_irqsave(&ec->lock, flags);
788 start_transaction(ec);
789 spin_unlock_irqrestore(&ec->lock, flags);
790 }
791 return -ETIME;
792}
793
794static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
795 struct transaction *t)
796{
797 unsigned long tmp;
798 int ret = 0;
799
800 /* start transaction */
801 spin_lock_irqsave(&ec->lock, tmp);
802 /* Enable GPE for command processing (IBF=0/OBF=1) */
803 if (!acpi_ec_submit_flushable_request(ec)) {
804 ret = -EINVAL;
805 goto unlock;
806 }
807 ec_dbg_ref(ec, "Increase command");
808 /* following two actions should be kept atomic */
809 ec->curr = t;
810 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
811 start_transaction(ec);
812 spin_unlock_irqrestore(&ec->lock, tmp);
813
814 ret = ec_poll(ec);
815
816 spin_lock_irqsave(&ec->lock, tmp);
817 if (t->irq_count == ec_storm_threshold)
818 acpi_ec_unmask_gpe(ec);
819 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
820 ec->curr = NULL;
821 /* Disable GPE for command processing (IBF=0/OBF=1) */
822 acpi_ec_complete_request(ec);
823 ec_dbg_ref(ec, "Decrease command");
824unlock:
825 spin_unlock_irqrestore(&ec->lock, tmp);
826 return ret;
827}
828
829static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
830{
831 int status;
832 u32 glk;
833
834 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
835 return -EINVAL;
836 if (t->rdata)
837 memset(t->rdata, 0, t->rlen);
838
839 mutex_lock(&ec->mutex);
840 if (ec->global_lock) {
841 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
842 if (ACPI_FAILURE(status)) {
843 status = -ENODEV;
844 goto unlock;
845 }
846 }
847
848 status = acpi_ec_transaction_unlocked(ec, t);
849
850 if (ec->global_lock)
851 acpi_release_global_lock(glk);
852unlock:
853 mutex_unlock(&ec->mutex);
854 return status;
855}
856
857static int acpi_ec_burst_enable(struct acpi_ec *ec)
858{
859 u8 d;
860 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
861 .wdata = NULL, .rdata = &d,
862 .wlen = 0, .rlen = 1};
863
864 return acpi_ec_transaction(ec, &t);
865}
866
867static int acpi_ec_burst_disable(struct acpi_ec *ec)
868{
869 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
870 .wdata = NULL, .rdata = NULL,
871 .wlen = 0, .rlen = 0};
872
873 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
874 acpi_ec_transaction(ec, &t) : 0;
875}
876
877static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
878{
879 int result;
880 u8 d;
881 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
882 .wdata = &address, .rdata = &d,
883 .wlen = 1, .rlen = 1};
884
885 result = acpi_ec_transaction(ec, &t);
886 *data = d;
887 return result;
888}
889
890static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
891{
892 u8 wdata[2] = { address, data };
893 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
894 .wdata = wdata, .rdata = NULL,
895 .wlen = 2, .rlen = 0};
896
897 return acpi_ec_transaction(ec, &t);
898}
899
900int ec_read(u8 addr, u8 *val)
901{
902 int err;
903 u8 temp_data;
904
905 if (!first_ec)
906 return -ENODEV;
907
908 err = acpi_ec_read(first_ec, addr, &temp_data);
909
910 if (!err) {
911 *val = temp_data;
912 return 0;
913 }
914 return err;
915}
916EXPORT_SYMBOL(ec_read);
917
918int ec_write(u8 addr, u8 val)
919{
920 int err;
921
922 if (!first_ec)
923 return -ENODEV;
924
925 err = acpi_ec_write(first_ec, addr, val);
926
927 return err;
928}
929EXPORT_SYMBOL(ec_write);
930
931int ec_transaction(u8 command,
932 const u8 *wdata, unsigned wdata_len,
933 u8 *rdata, unsigned rdata_len)
934{
935 struct transaction t = {.command = command,
936 .wdata = wdata, .rdata = rdata,
937 .wlen = wdata_len, .rlen = rdata_len};
938
939 if (!first_ec)
940 return -ENODEV;
941
942 return acpi_ec_transaction(first_ec, &t);
943}
944EXPORT_SYMBOL(ec_transaction);
945
946/* Get the handle to the EC device */
947acpi_handle ec_get_handle(void)
948{
949 if (!first_ec)
950 return NULL;
951 return first_ec->handle;
952}
953EXPORT_SYMBOL(ec_get_handle);
954
955static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
956{
957 unsigned long flags;
958
959 spin_lock_irqsave(&ec->lock, flags);
960 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
961 ec_dbg_drv("Starting EC");
962 /* Enable GPE for event processing (SCI_EVT=1) */
963 if (!resuming) {
964 acpi_ec_submit_request(ec);
965 ec_dbg_ref(ec, "Increase driver");
966 }
967 ec_log_drv("EC started");
968 }
969 spin_unlock_irqrestore(&ec->lock, flags);
970}
971
972static bool acpi_ec_stopped(struct acpi_ec *ec)
973{
974 unsigned long flags;
975 bool flushed;
976
977 spin_lock_irqsave(&ec->lock, flags);
978 flushed = acpi_ec_flushed(ec);
979 spin_unlock_irqrestore(&ec->lock, flags);
980 return flushed;
981}
982
983static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
984{
985 unsigned long flags;
986
987 spin_lock_irqsave(&ec->lock, flags);
988 if (acpi_ec_started(ec)) {
989 ec_dbg_drv("Stopping EC");
990 set_bit(EC_FLAGS_STOPPED, &ec->flags);
991 spin_unlock_irqrestore(&ec->lock, flags);
992 wait_event(ec->wait, acpi_ec_stopped(ec));
993 spin_lock_irqsave(&ec->lock, flags);
994 /* Disable GPE for event processing (SCI_EVT=1) */
995 if (!suspending) {
996 acpi_ec_complete_request(ec);
997 ec_dbg_ref(ec, "Decrease driver");
998 } else if (!ec_freeze_events)
999 __acpi_ec_disable_event(ec);
1000 clear_bit(EC_FLAGS_STARTED, &ec->flags);
1001 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
1002 ec_log_drv("EC stopped");
1003 }
1004 spin_unlock_irqrestore(&ec->lock, flags);
1005}
1006
1007static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1008{
1009 unsigned long flags;
1010
1011 spin_lock_irqsave(&ec->lock, flags);
1012 ec->busy_polling = true;
1013 ec->polling_guard = 0;
1014 ec_log_drv("interrupt blocked");
1015 spin_unlock_irqrestore(&ec->lock, flags);
1016}
1017
1018static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1019{
1020 unsigned long flags;
1021
1022 spin_lock_irqsave(&ec->lock, flags);
1023 ec->busy_polling = ec_busy_polling;
1024 ec->polling_guard = ec_polling_guard;
1025 ec_log_drv("interrupt unblocked");
1026 spin_unlock_irqrestore(&ec->lock, flags);
1027}
1028
1029void acpi_ec_block_transactions(void)
1030{
1031 struct acpi_ec *ec = first_ec;
1032
1033 if (!ec)
1034 return;
1035
1036 mutex_lock(&ec->mutex);
1037 /* Prevent transactions from being carried out */
1038 acpi_ec_stop(ec, true);
1039 mutex_unlock(&ec->mutex);
1040}
1041
1042void acpi_ec_unblock_transactions(void)
1043{
1044 /*
1045 * Allow transactions to happen again (this function is called from
1046 * atomic context during wakeup, so we don't need to acquire the mutex).
1047 */
1048 if (first_ec)
1049 acpi_ec_start(first_ec, true);
1050}
1051
1052/* --------------------------------------------------------------------------
1053 Event Management
1054 -------------------------------------------------------------------------- */
1055static struct acpi_ec_query_handler *
1056acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1057{
1058 if (handler)
1059 kref_get(&handler->kref);
1060 return handler;
1061}
1062
1063static struct acpi_ec_query_handler *
1064acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1065{
1066 struct acpi_ec_query_handler *handler;
1067 bool found = false;
1068
1069 mutex_lock(&ec->mutex);
1070 list_for_each_entry(handler, &ec->list, node) {
1071 if (value == handler->query_bit) {
1072 found = true;
1073 break;
1074 }
1075 }
1076 mutex_unlock(&ec->mutex);
1077 return found ? acpi_ec_get_query_handler(handler) : NULL;
1078}
1079
1080static void acpi_ec_query_handler_release(struct kref *kref)
1081{
1082 struct acpi_ec_query_handler *handler =
1083 container_of(kref, struct acpi_ec_query_handler, kref);
1084
1085 kfree(handler);
1086}
1087
1088static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1089{
1090 kref_put(&handler->kref, acpi_ec_query_handler_release);
1091}
1092
1093int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1094 acpi_handle handle, acpi_ec_query_func func,
1095 void *data)
1096{
1097 struct acpi_ec_query_handler *handler =
1098 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1099
1100 if (!handler)
1101 return -ENOMEM;
1102
1103 handler->query_bit = query_bit;
1104 handler->handle = handle;
1105 handler->func = func;
1106 handler->data = data;
1107 mutex_lock(&ec->mutex);
1108 kref_init(&handler->kref);
1109 list_add(&handler->node, &ec->list);
1110 mutex_unlock(&ec->mutex);
1111 return 0;
1112}
1113EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1114
1115static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1116 bool remove_all, u8 query_bit)
1117{
1118 struct acpi_ec_query_handler *handler, *tmp;
1119 LIST_HEAD(free_list);
1120
1121 mutex_lock(&ec->mutex);
1122 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1123 if (remove_all || query_bit == handler->query_bit) {
1124 list_del_init(&handler->node);
1125 list_add(&handler->node, &free_list);
1126 }
1127 }
1128 mutex_unlock(&ec->mutex);
1129 list_for_each_entry_safe(handler, tmp, &free_list, node)
1130 acpi_ec_put_query_handler(handler);
1131}
1132
1133void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1134{
1135 acpi_ec_remove_query_handlers(ec, false, query_bit);
1136}
1137EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1138
1139static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1140{
1141 struct acpi_ec_query *q;
1142 struct transaction *t;
1143
1144 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1145 if (!q)
1146 return NULL;
1147 INIT_WORK(&q->work, acpi_ec_event_processor);
1148 t = &q->transaction;
1149 t->command = ACPI_EC_COMMAND_QUERY;
1150 t->rdata = pval;
1151 t->rlen = 1;
1152 return q;
1153}
1154
1155static void acpi_ec_delete_query(struct acpi_ec_query *q)
1156{
1157 if (q) {
1158 if (q->handler)
1159 acpi_ec_put_query_handler(q->handler);
1160 kfree(q);
1161 }
1162}
1163
1164static void acpi_ec_event_processor(struct work_struct *work)
1165{
1166 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1167 struct acpi_ec_query_handler *handler = q->handler;
1168
1169 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1170 if (handler->func)
1171 handler->func(handler->data);
1172 else if (handler->handle)
1173 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1174 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1175 acpi_ec_delete_query(q);
1176}
1177
1178static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1179{
1180 u8 value = 0;
1181 int result;
1182 struct acpi_ec_query *q;
1183
1184 q = acpi_ec_create_query(&value);
1185 if (!q)
1186 return -ENOMEM;
1187
1188 /*
1189 * Query the EC to find out which _Qxx method we need to evaluate.
1190 * Note that successful completion of the query causes the ACPI_EC_SCI
1191 * bit to be cleared (and thus clearing the interrupt source).
1192 */
1193 result = acpi_ec_transaction(ec, &q->transaction);
1194 if (!value)
1195 result = -ENODATA;
1196 if (result)
1197 goto err_exit;
1198
1199 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1200 if (!q->handler) {
1201 result = -ENODATA;
1202 goto err_exit;
1203 }
1204
1205 /*
1206 * It is reported that _Qxx are evaluated in a parallel way on
1207 * Windows:
1208 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1209 *
1210 * Put this log entry before schedule_work() in order to make
1211 * it appearing before any other log entries occurred during the
1212 * work queue execution.
1213 */
1214 ec_dbg_evt("Query(0x%02x) scheduled", value);
1215 if (!queue_work(ec_query_wq, &q->work)) {
1216 ec_dbg_evt("Query(0x%02x) overlapped", value);
1217 result = -EBUSY;
1218 }
1219
1220err_exit:
1221 if (result)
1222 acpi_ec_delete_query(q);
1223 if (data)
1224 *data = value;
1225 return result;
1226}
1227
1228static void acpi_ec_check_event(struct acpi_ec *ec)
1229{
1230 unsigned long flags;
1231
1232 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1233 if (ec_guard(ec)) {
1234 spin_lock_irqsave(&ec->lock, flags);
1235 /*
1236 * Take care of the SCI_EVT unless no one else is
1237 * taking care of it.
1238 */
1239 if (!ec->curr)
1240 advance_transaction(ec);
1241 spin_unlock_irqrestore(&ec->lock, flags);
1242 }
1243 }
1244}
1245
1246static void acpi_ec_event_handler(struct work_struct *work)
1247{
1248 unsigned long flags;
1249 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1250
1251 ec_dbg_evt("Event started");
1252
1253 spin_lock_irqsave(&ec->lock, flags);
1254 while (ec->nr_pending_queries) {
1255 spin_unlock_irqrestore(&ec->lock, flags);
1256 (void)acpi_ec_query(ec, NULL);
1257 spin_lock_irqsave(&ec->lock, flags);
1258 ec->nr_pending_queries--;
1259 /*
1260 * Before exit, make sure that this work item can be
1261 * scheduled again. There might be QR_EC failures, leaving
1262 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1263 * item from being scheduled again.
1264 */
1265 if (!ec->nr_pending_queries) {
1266 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1267 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1268 acpi_ec_complete_query(ec);
1269 }
1270 }
1271 spin_unlock_irqrestore(&ec->lock, flags);
1272
1273 ec_dbg_evt("Event stopped");
1274
1275 acpi_ec_check_event(ec);
1276}
1277
1278static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1279 u32 gpe_number, void *data)
1280{
1281 unsigned long flags;
1282 struct acpi_ec *ec = data;
1283
1284 spin_lock_irqsave(&ec->lock, flags);
1285 advance_transaction(ec);
1286 spin_unlock_irqrestore(&ec->lock, flags);
1287 return ACPI_INTERRUPT_HANDLED;
1288}
1289
1290/* --------------------------------------------------------------------------
1291 * Address Space Management
1292 * -------------------------------------------------------------------------- */
1293
1294static acpi_status
1295acpi_ec_space_handler(u32 function, acpi_physical_address address,
1296 u32 bits, u64 *value64,
1297 void *handler_context, void *region_context)
1298{
1299 struct acpi_ec *ec = handler_context;
1300 int result = 0, i, bytes = bits / 8;
1301 u8 *value = (u8 *)value64;
1302
1303 if ((address > 0xFF) || !value || !handler_context)
1304 return AE_BAD_PARAMETER;
1305
1306 if (function != ACPI_READ && function != ACPI_WRITE)
1307 return AE_BAD_PARAMETER;
1308
1309 if (ec->busy_polling || bits > 8)
1310 acpi_ec_burst_enable(ec);
1311
1312 for (i = 0; i < bytes; ++i, ++address, ++value)
1313 result = (function == ACPI_READ) ?
1314 acpi_ec_read(ec, address, value) :
1315 acpi_ec_write(ec, address, *value);
1316
1317 if (ec->busy_polling || bits > 8)
1318 acpi_ec_burst_disable(ec);
1319
1320 switch (result) {
1321 case -EINVAL:
1322 return AE_BAD_PARAMETER;
1323 case -ENODEV:
1324 return AE_NOT_FOUND;
1325 case -ETIME:
1326 return AE_TIME;
1327 default:
1328 return AE_OK;
1329 }
1330}
1331
1332/* --------------------------------------------------------------------------
1333 * Driver Interface
1334 * -------------------------------------------------------------------------- */
1335
1336static acpi_status
1337ec_parse_io_ports(struct acpi_resource *resource, void *context);
1338
1339static void acpi_ec_free(struct acpi_ec *ec)
1340{
1341 if (first_ec == ec)
1342 first_ec = NULL;
1343 if (boot_ec == ec)
1344 boot_ec = NULL;
1345 kfree(ec);
1346}
1347
1348static struct acpi_ec *acpi_ec_alloc(void)
1349{
1350 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1351
1352 if (!ec)
1353 return NULL;
1354 mutex_init(&ec->mutex);
1355 init_waitqueue_head(&ec->wait);
1356 INIT_LIST_HEAD(&ec->list);
1357 spin_lock_init(&ec->lock);
1358 INIT_WORK(&ec->work, acpi_ec_event_handler);
1359 ec->timestamp = jiffies;
1360 ec->busy_polling = true;
1361 ec->polling_guard = 0;
1362 return ec;
1363}
1364
1365static acpi_status
1366acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1367 void *context, void **return_value)
1368{
1369 char node_name[5];
1370 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1371 struct acpi_ec *ec = context;
1372 int value = 0;
1373 acpi_status status;
1374
1375 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1376
1377 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1378 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1379 return AE_OK;
1380}
1381
1382static acpi_status
1383ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1384{
1385 acpi_status status;
1386 unsigned long long tmp = 0;
1387 struct acpi_ec *ec = context;
1388
1389 /* clear addr values, ec_parse_io_ports depend on it */
1390 ec->command_addr = ec->data_addr = 0;
1391
1392 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1393 ec_parse_io_ports, ec);
1394 if (ACPI_FAILURE(status))
1395 return status;
1396 if (ec->data_addr == 0 || ec->command_addr == 0)
1397 return AE_OK;
1398
1399 if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1400 /*
1401 * Always inherit the GPE number setting from the ECDT
1402 * EC.
1403 */
1404 ec->gpe = boot_ec->gpe;
1405 } else {
1406 /* Get GPE bit assignment (EC events). */
1407 /* TODO: Add support for _GPE returning a package */
1408 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1409 if (ACPI_FAILURE(status))
1410 return status;
1411 ec->gpe = tmp;
1412 }
1413 /* Use the global lock for all EC transactions? */
1414 tmp = 0;
1415 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1416 ec->global_lock = tmp;
1417 ec->handle = handle;
1418 return AE_CTRL_TERMINATE;
1419}
1420
1421/*
1422 * Note: This function returns an error code only when the address space
1423 * handler is not installed, which means "not able to handle
1424 * transactions".
1425 */
1426static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1427{
1428 acpi_status status;
1429
1430 acpi_ec_start(ec, false);
1431
1432 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1433 acpi_ec_enter_noirq(ec);
1434 status = acpi_install_address_space_handler(ec->handle,
1435 ACPI_ADR_SPACE_EC,
1436 &acpi_ec_space_handler,
1437 NULL, ec);
1438 if (ACPI_FAILURE(status)) {
1439 if (status == AE_NOT_FOUND) {
1440 /*
1441 * Maybe OS fails in evaluating the _REG
1442 * object. The AE_NOT_FOUND error will be
1443 * ignored and OS * continue to initialize
1444 * EC.
1445 */
1446 pr_err("Fail in evaluating the _REG object"
1447 " of EC device. Broken bios is suspected.\n");
1448 } else {
1449 acpi_ec_stop(ec, false);
1450 return -ENODEV;
1451 }
1452 }
1453 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1454 }
1455
1456 if (!handle_events)
1457 return 0;
1458
1459 if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1460 /* Find and register all query methods */
1461 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1462 acpi_ec_register_query_methods,
1463 NULL, ec, NULL);
1464 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1465 }
1466 if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1467 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1468 ACPI_GPE_EDGE_TRIGGERED,
1469 &acpi_ec_gpe_handler, ec);
1470 /* This is not fatal as we can poll EC events */
1471 if (ACPI_SUCCESS(status)) {
1472 set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1473 acpi_ec_leave_noirq(ec);
1474 if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1475 ec->reference_count >= 1)
1476 acpi_ec_enable_gpe(ec, true);
1477 }
1478 }
1479 /* EC is fully operational, allow queries */
1480 acpi_ec_enable_event(ec);
1481
1482 return 0;
1483}
1484
1485static void ec_remove_handlers(struct acpi_ec *ec)
1486{
1487 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1488 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1489 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1490 pr_err("failed to remove space handler\n");
1491 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1492 }
1493
1494 /*
1495 * Stops handling the EC transactions after removing the operation
1496 * region handler. This is required because _REG(DISCONNECT)
1497 * invoked during the removal can result in new EC transactions.
1498 *
1499 * Flushes the EC requests and thus disables the GPE before
1500 * removing the GPE handler. This is required by the current ACPICA
1501 * GPE core. ACPICA GPE core will automatically disable a GPE when
1502 * it is indicated but there is no way to handle it. So the drivers
1503 * must disable the GPEs prior to removing the GPE handlers.
1504 */
1505 acpi_ec_stop(ec, false);
1506
1507 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1508 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1509 &acpi_ec_gpe_handler)))
1510 pr_err("failed to remove gpe handler\n");
1511 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1512 }
1513 if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1514 acpi_ec_remove_query_handlers(ec, true, 0);
1515 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1516 }
1517}
1518
1519static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1520{
1521 int ret;
1522
1523 ret = ec_install_handlers(ec, handle_events);
1524 if (ret)
1525 return ret;
1526
1527 /* First EC capable of handling transactions */
1528 if (!first_ec) {
1529 first_ec = ec;
1530 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1531 }
1532
1533 acpi_handle_info(ec->handle,
1534 "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1535 ec->gpe, ec->command_addr, ec->data_addr);
1536 return ret;
1537}
1538
1539static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1540{
1541 struct acpi_table_ecdt *ecdt_ptr;
1542 acpi_status status;
1543 acpi_handle handle;
1544
1545 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1546 (struct acpi_table_header **)&ecdt_ptr);
1547 if (ACPI_FAILURE(status))
1548 return false;
1549
1550 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1551 if (ACPI_FAILURE(status))
1552 return false;
1553
1554 *phandle = handle;
1555 return true;
1556}
1557
1558static int acpi_ec_add(struct acpi_device *device)
1559{
1560 struct acpi_ec *ec = NULL;
1561 bool dep_update = true;
1562 acpi_status status;
1563 int ret;
1564
1565 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1566 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1567
1568 if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1569 boot_ec_is_ecdt = true;
1570 ec = boot_ec;
1571 dep_update = false;
1572 } else {
1573 ec = acpi_ec_alloc();
1574 if (!ec)
1575 return -ENOMEM;
1576
1577 status = ec_parse_device(device->handle, 0, ec, NULL);
1578 if (status != AE_CTRL_TERMINATE) {
1579 ret = -EINVAL;
1580 goto err_alloc;
1581 }
1582
1583 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1584 ec->data_addr == boot_ec->data_addr) {
1585 boot_ec_is_ecdt = false;
1586 /*
1587 * Trust PNP0C09 namespace location rather than
1588 * ECDT ID. But trust ECDT GPE rather than _GPE
1589 * because of ASUS quirks, so do not change
1590 * boot_ec->gpe to ec->gpe.
1591 */
1592 boot_ec->handle = ec->handle;
1593 acpi_handle_debug(ec->handle, "duplicated.\n");
1594 acpi_ec_free(ec);
1595 ec = boot_ec;
1596 }
1597 }
1598
1599 ret = acpi_ec_setup(ec, true);
1600 if (ret)
1601 goto err_query;
1602
1603 if (ec == boot_ec)
1604 acpi_handle_info(boot_ec->handle,
1605 "Boot %s EC used to handle transactions and events\n",
1606 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1607
1608 device->driver_data = ec;
1609
1610 ret = !!request_region(ec->data_addr, 1, "EC data");
1611 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1612 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1613 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1614
1615 if (dep_update) {
1616 /* Reprobe devices depending on the EC */
1617 acpi_walk_dep_device_list(ec->handle);
1618 }
1619 acpi_handle_debug(ec->handle, "enumerated.\n");
1620 return 0;
1621
1622err_query:
1623 if (ec != boot_ec)
1624 acpi_ec_remove_query_handlers(ec, true, 0);
1625err_alloc:
1626 if (ec != boot_ec)
1627 acpi_ec_free(ec);
1628 return ret;
1629}
1630
1631static int acpi_ec_remove(struct acpi_device *device)
1632{
1633 struct acpi_ec *ec;
1634
1635 if (!device)
1636 return -EINVAL;
1637
1638 ec = acpi_driver_data(device);
1639 release_region(ec->data_addr, 1);
1640 release_region(ec->command_addr, 1);
1641 device->driver_data = NULL;
1642 if (ec != boot_ec) {
1643 ec_remove_handlers(ec);
1644 acpi_ec_free(ec);
1645 }
1646 return 0;
1647}
1648
1649static acpi_status
1650ec_parse_io_ports(struct acpi_resource *resource, void *context)
1651{
1652 struct acpi_ec *ec = context;
1653
1654 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1655 return AE_OK;
1656
1657 /*
1658 * The first address region returned is the data port, and
1659 * the second address region returned is the status/command
1660 * port.
1661 */
1662 if (ec->data_addr == 0)
1663 ec->data_addr = resource->data.io.minimum;
1664 else if (ec->command_addr == 0)
1665 ec->command_addr = resource->data.io.minimum;
1666 else
1667 return AE_CTRL_TERMINATE;
1668
1669 return AE_OK;
1670}
1671
1672static const struct acpi_device_id ec_device_ids[] = {
1673 {"PNP0C09", 0},
1674 {ACPI_ECDT_HID, 0},
1675 {"", 0},
1676};
1677
1678/*
1679 * This function is not Windows-compatible as Windows never enumerates the
1680 * namespace EC before the main ACPI device enumeration process. It is
1681 * retained for historical reason and will be deprecated in the future.
1682 */
1683void __init acpi_ec_dsdt_probe(void)
1684{
1685 struct acpi_ec *ec;
1686 acpi_status status;
1687 int ret;
1688
1689 /*
1690 * If a platform has ECDT, there is no need to proceed as the
1691 * following probe is not a part of the ACPI device enumeration,
1692 * executing _STA is not safe, and thus this probe may risk of
1693 * picking up an invalid EC device.
1694 */
1695 if (boot_ec)
1696 return;
1697
1698 ec = acpi_ec_alloc();
1699 if (!ec)
1700 return;
1701
1702 /*
1703 * At this point, the namespace is initialized, so start to find
1704 * the namespace objects.
1705 */
1706 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1707 if (ACPI_FAILURE(status) || !ec->handle) {
1708 acpi_ec_free(ec);
1709 return;
1710 }
1711
1712 /*
1713 * When the DSDT EC is available, always re-configure boot EC to
1714 * have _REG evaluated. _REG can only be evaluated after the
1715 * namespace initialization.
1716 * At this point, the GPE is not fully initialized, so do not to
1717 * handle the events.
1718 */
1719 ret = acpi_ec_setup(ec, false);
1720 if (ret) {
1721 acpi_ec_free(ec);
1722 return;
1723 }
1724
1725 boot_ec = ec;
1726
1727 acpi_handle_info(ec->handle,
1728 "Boot DSDT EC used to handle transactions\n");
1729}
1730
1731/*
1732 * If the DSDT EC is not functioning, we still need to prepare a fully
1733 * functioning ECDT EC first in order to handle the events.
1734 * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1735 */
1736static int __init acpi_ec_ecdt_start(void)
1737{
1738 acpi_handle handle;
1739
1740 if (!boot_ec)
1741 return -ENODEV;
1742 /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1743 if (!boot_ec_is_ecdt)
1744 return -ENODEV;
1745
1746 /*
1747 * At this point, the namespace and the GPE is initialized, so
1748 * start to find the namespace objects and handle the events.
1749 *
1750 * Note: ec->handle can be valid if this function is called after
1751 * acpi_ec_add(), hence the fast path.
1752 */
1753 if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1754 if (!acpi_ec_ecdt_get_handle(&handle))
1755 return -ENODEV;
1756 boot_ec->handle = handle;
1757 }
1758
1759 /* Register to ACPI bus with PM ops attached */
1760 return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1761}
1762
1763#if 0
1764/*
1765 * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1766 * set, for which case, we complete the QR_EC without issuing it to the
1767 * firmware.
1768 * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1769 * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1770 */
1771static int ec_flag_query_handshake(const struct dmi_system_id *id)
1772{
1773 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1774 EC_FLAGS_QUERY_HANDSHAKE = 1;
1775 return 0;
1776}
1777#endif
1778
1779/*
1780 * On some hardware it is necessary to clear events accumulated by the EC during
1781 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1782 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1783 *
1784 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1785 *
1786 * Ideally, the EC should also be instructed NOT to accumulate events during
1787 * sleep (which Windows seems to do somehow), but the interface to control this
1788 * behaviour is not known at this time.
1789 *
1790 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1791 * however it is very likely that other Samsung models are affected.
1792 *
1793 * On systems which don't accumulate _Q events during sleep, this extra check
1794 * should be harmless.
1795 */
1796static int ec_clear_on_resume(const struct dmi_system_id *id)
1797{
1798 pr_debug("Detected system needing EC poll on resume.\n");
1799 EC_FLAGS_CLEAR_ON_RESUME = 1;
1800 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1801 return 0;
1802}
1803
1804/*
1805 * Some ECDTs contain wrong register addresses.
1806 * MSI MS-171F
1807 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1808 */
1809static int ec_correct_ecdt(const struct dmi_system_id *id)
1810{
1811 pr_debug("Detected system needing ECDT address correction.\n");
1812 EC_FLAGS_CORRECT_ECDT = 1;
1813 return 0;
1814}
1815
1816/*
1817 * Some DSDTs contain wrong GPE setting.
1818 * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1819 * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1820 */
1821static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1822{
1823 pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1824 EC_FLAGS_IGNORE_DSDT_GPE = 1;
1825 return 0;
1826}
1827
1828static const struct dmi_system_id ec_dmi_table[] __initconst = {
1829 {
1830 ec_correct_ecdt, "MSI MS-171F", {
1831 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1832 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1833 {
1834 ec_honor_ecdt_gpe, "ASUS FX502VD", {
1835 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1836 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1837 {
1838 ec_honor_ecdt_gpe, "ASUS FX502VE", {
1839 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1840 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1841 {
1842 ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1843 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1844 DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1845 {
1846 ec_honor_ecdt_gpe, "ASUS X550VXK", {
1847 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1848 DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1849 {
1850 ec_honor_ecdt_gpe, "ASUS X580VD", {
1851 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1852 DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1853 {
1854 ec_clear_on_resume, "Samsung hardware", {
1855 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1856 {},
1857};
1858
1859void __init acpi_ec_ecdt_probe(void)
1860{
1861 struct acpi_table_ecdt *ecdt_ptr;
1862 struct acpi_ec *ec;
1863 acpi_status status;
1864 int ret;
1865
1866 /* Generate a boot ec context. */
1867 dmi_check_system(ec_dmi_table);
1868 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1869 (struct acpi_table_header **)&ecdt_ptr);
1870 if (ACPI_FAILURE(status))
1871 return;
1872
1873 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1874 /*
1875 * Asus X50GL:
1876 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1877 */
1878 return;
1879 }
1880
1881 ec = acpi_ec_alloc();
1882 if (!ec)
1883 return;
1884
1885 if (EC_FLAGS_CORRECT_ECDT) {
1886 ec->command_addr = ecdt_ptr->data.address;
1887 ec->data_addr = ecdt_ptr->control.address;
1888 } else {
1889 ec->command_addr = ecdt_ptr->control.address;
1890 ec->data_addr = ecdt_ptr->data.address;
1891 }
1892 ec->gpe = ecdt_ptr->gpe;
1893 ec->handle = ACPI_ROOT_OBJECT;
1894
1895 /*
1896 * At this point, the namespace is not initialized, so do not find
1897 * the namespace objects, or handle the events.
1898 */
1899 ret = acpi_ec_setup(ec, false);
1900 if (ret) {
1901 acpi_ec_free(ec);
1902 return;
1903 }
1904
1905 boot_ec = ec;
1906 boot_ec_is_ecdt = true;
1907
1908 pr_info("Boot ECDT EC used to handle transactions\n");
1909}
1910
1911#ifdef CONFIG_PM_SLEEP
1912static int acpi_ec_suspend(struct device *dev)
1913{
1914 struct acpi_ec *ec =
1915 acpi_driver_data(to_acpi_device(dev));
1916
1917 if (!pm_suspend_no_platform() && ec_freeze_events)
1918 acpi_ec_disable_event(ec);
1919 return 0;
1920}
1921
1922static int acpi_ec_suspend_noirq(struct device *dev)
1923{
1924 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1925
1926 /*
1927 * The SCI handler doesn't run at this point, so the GPE can be
1928 * masked at the low level without side effects.
1929 */
1930 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1931 ec->reference_count >= 1)
1932 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1933
1934 acpi_ec_enter_noirq(ec);
1935
1936 return 0;
1937}
1938
1939static int acpi_ec_resume_noirq(struct device *dev)
1940{
1941 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1942
1943 acpi_ec_leave_noirq(ec);
1944
1945 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1946 ec->reference_count >= 1)
1947 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1948
1949 return 0;
1950}
1951
1952static int acpi_ec_resume(struct device *dev)
1953{
1954 struct acpi_ec *ec =
1955 acpi_driver_data(to_acpi_device(dev));
1956
1957 acpi_ec_enable_event(ec);
1958 return 0;
1959}
1960
1961void acpi_ec_mark_gpe_for_wake(void)
1962{
1963 if (first_ec && !ec_no_wakeup)
1964 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1965}
1966EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
1967
1968void acpi_ec_set_gpe_wake_mask(u8 action)
1969{
1970 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
1971 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1972}
1973
1974bool acpi_ec_dispatch_gpe(void)
1975{
1976 u32 ret;
1977
1978 if (!first_ec)
1979 return false;
1980
1981 ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
1982 if (ret == ACPI_INTERRUPT_HANDLED) {
1983 pm_pr_dbg("EC GPE dispatched\n");
1984 return true;
1985 }
1986 return false;
1987}
1988#endif /* CONFIG_PM_SLEEP */
1989
1990static const struct dev_pm_ops acpi_ec_pm = {
1991 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1992 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1993};
1994
1995static int param_set_event_clearing(const char *val,
1996 const struct kernel_param *kp)
1997{
1998 int result = 0;
1999
2000 if (!strncmp(val, "status", sizeof("status") - 1)) {
2001 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2002 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2003 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2004 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2005 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2006 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2007 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2008 pr_info("Assuming SCI_EVT clearing on event reads\n");
2009 } else
2010 result = -EINVAL;
2011 return result;
2012}
2013
2014static int param_get_event_clearing(char *buffer,
2015 const struct kernel_param *kp)
2016{
2017 switch (ec_event_clearing) {
2018 case ACPI_EC_EVT_TIMING_STATUS:
2019 return sprintf(buffer, "status");
2020 case ACPI_EC_EVT_TIMING_QUERY:
2021 return sprintf(buffer, "query");
2022 case ACPI_EC_EVT_TIMING_EVENT:
2023 return sprintf(buffer, "event");
2024 default:
2025 return sprintf(buffer, "invalid");
2026 }
2027 return 0;
2028}
2029
2030module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2031 NULL, 0644);
2032MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2033
2034static struct acpi_driver acpi_ec_driver = {
2035 .name = "ec",
2036 .class = ACPI_EC_CLASS,
2037 .ids = ec_device_ids,
2038 .ops = {
2039 .add = acpi_ec_add,
2040 .remove = acpi_ec_remove,
2041 },
2042 .drv.pm = &acpi_ec_pm,
2043};
2044
2045static inline int acpi_ec_query_init(void)
2046{
2047 if (!ec_query_wq) {
2048 ec_query_wq = alloc_workqueue("kec_query", 0,
2049 ec_max_queries);
2050 if (!ec_query_wq)
2051 return -ENODEV;
2052 }
2053 return 0;
2054}
2055
2056static inline void acpi_ec_query_exit(void)
2057{
2058 if (ec_query_wq) {
2059 destroy_workqueue(ec_query_wq);
2060 ec_query_wq = NULL;
2061 }
2062}
2063
2064static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2065 {
2066 .ident = "Thinkpad X1 Carbon 6th",
2067 .matches = {
2068 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2069 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2070 },
2071 },
2072 {
2073 .ident = "ThinkPad X1 Carbon 6th",
2074 .matches = {
2075 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2076 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2077 },
2078 },
2079 {
2080 .ident = "ThinkPad X1 Yoga 3rd",
2081 .matches = {
2082 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2083 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2084 },
2085 },
2086 { },
2087};
2088
2089int __init acpi_ec_init(void)
2090{
2091 int result;
2092 int ecdt_fail, dsdt_fail;
2093
2094 /* register workqueue for _Qxx evaluations */
2095 result = acpi_ec_query_init();
2096 if (result)
2097 return result;
2098
2099 /*
2100 * Disable EC wakeup on following systems to prevent periodic
2101 * wakeup from EC GPE.
2102 */
2103 if (dmi_check_system(acpi_ec_no_wakeup)) {
2104 ec_no_wakeup = true;
2105 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2106 }
2107
2108 /* Drivers must be started after acpi_ec_query_init() */
2109 dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2110 /*
2111 * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2112 * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2113 * settings but invalid DSDT settings.
2114 * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2115 */
2116 ecdt_fail = acpi_ec_ecdt_start();
2117 return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2118}
2119
2120/* EC driver currently not unloadable */
2121#if 0
2122static void __exit acpi_ec_exit(void)
2123{
2124
2125 acpi_bus_unregister_driver(&acpi_ec_driver);
2126 acpi_ec_query_exit();
2127}
2128#endif /* 0 */