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[thirdparty/linux.git] / drivers / acpi / ec.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ec.c - ACPI Embedded Controller Driver (v3)
4 *
5 * Copyright (C) 2001-2015 Intel Corporation
6 * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
7 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
8 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
9 * 2004 Luming Yu <luming.yu@intel.com>
10 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
11 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
12 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
13 */
14
15 /* Uncomment next line to get verbose printout */
16 /* #define DEBUG */
17 #define pr_fmt(fmt) "ACPI: EC: " fmt
18
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/types.h>
23 #include <linux/delay.h>
24 #include <linux/interrupt.h>
25 #include <linux/list.h>
26 #include <linux/spinlock.h>
27 #include <linux/slab.h>
28 #include <linux/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 */
78 enum ec_command {
79 ACPI_EC_COMMAND_READ = 0x80,
80 ACPI_EC_COMMAND_WRITE = 0x81,
81 ACPI_EC_BURST_ENABLE = 0x82,
82 ACPI_EC_BURST_DISABLE = 0x83,
83 ACPI_EC_COMMAND_QUERY = 0x84,
84 };
85
86 #define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
87 #define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
88 #define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
89 #define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
90 * when trying to clear the EC */
91 #define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
92
93 enum {
94 EC_FLAGS_QUERY_ENABLED, /* Query is enabled */
95 EC_FLAGS_EVENT_HANDLER_INSTALLED, /* Event handler installed */
96 EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */
97 EC_FLAGS_EC_REG_CALLED, /* OpReg ACPI _REG method called */
98 EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
99 EC_FLAGS_STARTED, /* Driver is started */
100 EC_FLAGS_STOPPED, /* Driver is stopped */
101 EC_FLAGS_EVENTS_MASKED, /* Events masked */
102 };
103
104 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
105 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
106
107 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
108 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
109 module_param(ec_delay, uint, 0644);
110 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
111
112 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
113 module_param(ec_max_queries, uint, 0644);
114 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
115
116 static bool ec_busy_polling __read_mostly;
117 module_param(ec_busy_polling, bool, 0644);
118 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
119
120 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
121 module_param(ec_polling_guard, uint, 0644);
122 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
123
124 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
125
126 /*
127 * If the number of false interrupts per one transaction exceeds
128 * this threshold, will think there is a GPE storm happened and
129 * will disable the GPE for normal transaction.
130 */
131 static unsigned int ec_storm_threshold __read_mostly = 8;
132 module_param(ec_storm_threshold, uint, 0644);
133 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
134
135 static bool ec_freeze_events __read_mostly;
136 module_param(ec_freeze_events, bool, 0644);
137 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
138
139 static bool ec_no_wakeup __read_mostly;
140 module_param(ec_no_wakeup, bool, 0644);
141 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
142
143 struct acpi_ec_query_handler {
144 struct list_head node;
145 acpi_ec_query_func func;
146 acpi_handle handle;
147 void *data;
148 u8 query_bit;
149 struct kref kref;
150 };
151
152 struct transaction {
153 const u8 *wdata;
154 u8 *rdata;
155 unsigned short irq_count;
156 u8 command;
157 u8 wi;
158 u8 ri;
159 u8 wlen;
160 u8 rlen;
161 u8 flags;
162 };
163
164 struct acpi_ec_query {
165 struct transaction transaction;
166 struct work_struct work;
167 struct acpi_ec_query_handler *handler;
168 struct acpi_ec *ec;
169 };
170
171 static int acpi_ec_submit_query(struct acpi_ec *ec);
172 static void advance_transaction(struct acpi_ec *ec, bool interrupt);
173 static void acpi_ec_event_handler(struct work_struct *work);
174
175 struct acpi_ec *first_ec;
176 EXPORT_SYMBOL(first_ec);
177
178 static struct acpi_ec *boot_ec;
179 static bool boot_ec_is_ecdt;
180 static struct workqueue_struct *ec_wq;
181 static struct workqueue_struct *ec_query_wq;
182
183 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
184 static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
185 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
186
187 /* --------------------------------------------------------------------------
188 * Logging/Debugging
189 * -------------------------------------------------------------------------- */
190
191 /*
192 * Splitters used by the developers to track the boundary of the EC
193 * handling processes.
194 */
195 #ifdef DEBUG
196 #define EC_DBG_SEP " "
197 #define EC_DBG_DRV "+++++"
198 #define EC_DBG_STM "====="
199 #define EC_DBG_REQ "*****"
200 #define EC_DBG_EVT "#####"
201 #else
202 #define EC_DBG_SEP ""
203 #define EC_DBG_DRV
204 #define EC_DBG_STM
205 #define EC_DBG_REQ
206 #define EC_DBG_EVT
207 #endif
208
209 #define ec_log_raw(fmt, ...) \
210 pr_info(fmt "\n", ##__VA_ARGS__)
211 #define ec_dbg_raw(fmt, ...) \
212 pr_debug(fmt "\n", ##__VA_ARGS__)
213 #define ec_log(filter, fmt, ...) \
214 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
215 #define ec_dbg(filter, fmt, ...) \
216 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
217
218 #define ec_log_drv(fmt, ...) \
219 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
220 #define ec_dbg_drv(fmt, ...) \
221 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
222 #define ec_dbg_stm(fmt, ...) \
223 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
224 #define ec_dbg_req(fmt, ...) \
225 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
226 #define ec_dbg_evt(fmt, ...) \
227 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
228 #define ec_dbg_ref(ec, fmt, ...) \
229 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
230
231 /* --------------------------------------------------------------------------
232 * Device Flags
233 * -------------------------------------------------------------------------- */
234
235 static bool acpi_ec_started(struct acpi_ec *ec)
236 {
237 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
238 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
239 }
240
241 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
242 {
243 /*
244 * There is an OSPM early stage logic. During the early stages
245 * (boot/resume), OSPMs shouldn't enable the event handling, only
246 * the EC transactions are allowed to be performed.
247 */
248 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
249 return false;
250 /*
251 * However, disabling the event handling is experimental for late
252 * stage (suspend), and is controlled by the boot parameter of
253 * "ec_freeze_events":
254 * 1. true: The EC event handling is disabled before entering
255 * the noirq stage.
256 * 2. false: The EC event handling is automatically disabled as
257 * soon as the EC driver is stopped.
258 */
259 if (ec_freeze_events)
260 return acpi_ec_started(ec);
261 else
262 return test_bit(EC_FLAGS_STARTED, &ec->flags);
263 }
264
265 static bool acpi_ec_flushed(struct acpi_ec *ec)
266 {
267 return ec->reference_count == 1;
268 }
269
270 /* --------------------------------------------------------------------------
271 * EC Registers
272 * -------------------------------------------------------------------------- */
273
274 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
275 {
276 u8 x = inb(ec->command_addr);
277
278 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
279 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
280 x,
281 !!(x & ACPI_EC_FLAG_SCI),
282 !!(x & ACPI_EC_FLAG_BURST),
283 !!(x & ACPI_EC_FLAG_CMD),
284 !!(x & ACPI_EC_FLAG_IBF),
285 !!(x & ACPI_EC_FLAG_OBF));
286 return x;
287 }
288
289 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
290 {
291 u8 x = inb(ec->data_addr);
292
293 ec->timestamp = jiffies;
294 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
295 return x;
296 }
297
298 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
299 {
300 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
301 outb(command, ec->command_addr);
302 ec->timestamp = jiffies;
303 }
304
305 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
306 {
307 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
308 outb(data, ec->data_addr);
309 ec->timestamp = jiffies;
310 }
311
312 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
313 static const char *acpi_ec_cmd_string(u8 cmd)
314 {
315 switch (cmd) {
316 case 0x80:
317 return "RD_EC";
318 case 0x81:
319 return "WR_EC";
320 case 0x82:
321 return "BE_EC";
322 case 0x83:
323 return "BD_EC";
324 case 0x84:
325 return "QR_EC";
326 }
327 return "UNKNOWN";
328 }
329 #else
330 #define acpi_ec_cmd_string(cmd) "UNDEF"
331 #endif
332
333 /* --------------------------------------------------------------------------
334 * GPE Registers
335 * -------------------------------------------------------------------------- */
336
337 static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
338 {
339 acpi_event_status gpe_status = 0;
340
341 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
342 return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
343 }
344
345 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
346 {
347 if (open)
348 acpi_enable_gpe(NULL, ec->gpe);
349 else {
350 BUG_ON(ec->reference_count < 1);
351 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
352 }
353 if (acpi_ec_gpe_status_set(ec)) {
354 /*
355 * On some platforms, EN=1 writes cannot trigger GPE. So
356 * software need to manually trigger a pseudo GPE event on
357 * EN=1 writes.
358 */
359 ec_dbg_raw("Polling quirk");
360 advance_transaction(ec, false);
361 }
362 }
363
364 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
365 {
366 if (close)
367 acpi_disable_gpe(NULL, ec->gpe);
368 else {
369 BUG_ON(ec->reference_count < 1);
370 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
371 }
372 }
373
374 /* --------------------------------------------------------------------------
375 * Transaction Management
376 * -------------------------------------------------------------------------- */
377
378 static void acpi_ec_submit_request(struct acpi_ec *ec)
379 {
380 ec->reference_count++;
381 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
382 ec->gpe >= 0 && ec->reference_count == 1)
383 acpi_ec_enable_gpe(ec, true);
384 }
385
386 static void acpi_ec_complete_request(struct acpi_ec *ec)
387 {
388 bool flushed = false;
389
390 ec->reference_count--;
391 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
392 ec->gpe >= 0 && ec->reference_count == 0)
393 acpi_ec_disable_gpe(ec, true);
394 flushed = acpi_ec_flushed(ec);
395 if (flushed)
396 wake_up(&ec->wait);
397 }
398
399 static void acpi_ec_mask_events(struct acpi_ec *ec)
400 {
401 if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
402 if (ec->gpe >= 0)
403 acpi_ec_disable_gpe(ec, false);
404 else
405 disable_irq_nosync(ec->irq);
406
407 ec_dbg_drv("Polling enabled");
408 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
409 }
410 }
411
412 static void acpi_ec_unmask_events(struct acpi_ec *ec)
413 {
414 if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
415 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
416 if (ec->gpe >= 0)
417 acpi_ec_enable_gpe(ec, false);
418 else
419 enable_irq(ec->irq);
420
421 ec_dbg_drv("Polling disabled");
422 }
423 }
424
425 /*
426 * acpi_ec_submit_flushable_request() - Increase the reference count unless
427 * the flush operation is not in
428 * progress
429 * @ec: the EC device
430 *
431 * This function must be used before taking a new action that should hold
432 * the reference count. If this function returns false, then the action
433 * must be discarded or it will prevent the flush operation from being
434 * completed.
435 */
436 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
437 {
438 if (!acpi_ec_started(ec))
439 return false;
440 acpi_ec_submit_request(ec);
441 return true;
442 }
443
444 static void acpi_ec_submit_event(struct acpi_ec *ec)
445 {
446 /*
447 * It is safe to mask the events here, because acpi_ec_close_event()
448 * will run at least once after this.
449 */
450 acpi_ec_mask_events(ec);
451 if (!acpi_ec_event_enabled(ec))
452 return;
453
454 if (ec->event_state != EC_EVENT_READY)
455 return;
456
457 ec_dbg_evt("Command(%s) submitted/blocked",
458 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
459
460 ec->event_state = EC_EVENT_IN_PROGRESS;
461 /*
462 * If events_to_process is greater than 0 at this point, the while ()
463 * loop in acpi_ec_event_handler() is still running and incrementing
464 * events_to_process will cause it to invoke acpi_ec_submit_query() once
465 * more, so it is not necessary to queue up the event work to start the
466 * same loop again.
467 */
468 if (ec->events_to_process++ > 0)
469 return;
470
471 ec->events_in_progress++;
472 queue_work(ec_wq, &ec->work);
473 }
474
475 static void acpi_ec_complete_event(struct acpi_ec *ec)
476 {
477 if (ec->event_state == EC_EVENT_IN_PROGRESS)
478 ec->event_state = EC_EVENT_COMPLETE;
479 }
480
481 static void acpi_ec_close_event(struct acpi_ec *ec)
482 {
483 if (ec->event_state != EC_EVENT_READY)
484 ec_dbg_evt("Command(%s) unblocked",
485 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
486
487 ec->event_state = EC_EVENT_READY;
488 acpi_ec_unmask_events(ec);
489 }
490
491 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
492 {
493 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
494 ec_log_drv("event unblocked");
495 /*
496 * Unconditionally invoke this once after enabling the event
497 * handling mechanism to detect the pending events.
498 */
499 advance_transaction(ec, false);
500 }
501
502 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
503 {
504 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
505 ec_log_drv("event blocked");
506 }
507
508 /*
509 * Process _Q events that might have accumulated in the EC.
510 * Run with locked ec mutex.
511 */
512 static void acpi_ec_clear(struct acpi_ec *ec)
513 {
514 int i;
515
516 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
517 if (acpi_ec_submit_query(ec))
518 break;
519 }
520 if (unlikely(i == ACPI_EC_CLEAR_MAX))
521 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
522 else
523 pr_info("%d stale EC events cleared\n", i);
524 }
525
526 static void acpi_ec_enable_event(struct acpi_ec *ec)
527 {
528 spin_lock(&ec->lock);
529 if (acpi_ec_started(ec))
530 __acpi_ec_enable_event(ec);
531 spin_unlock(&ec->lock);
532
533 /* Drain additional events if hardware requires that */
534 if (EC_FLAGS_CLEAR_ON_RESUME)
535 acpi_ec_clear(ec);
536 }
537
538 #ifdef CONFIG_PM_SLEEP
539 static void __acpi_ec_flush_work(void)
540 {
541 flush_workqueue(ec_wq); /* flush ec->work */
542 flush_workqueue(ec_query_wq); /* flush queries */
543 }
544
545 static void acpi_ec_disable_event(struct acpi_ec *ec)
546 {
547 spin_lock(&ec->lock);
548 __acpi_ec_disable_event(ec);
549 spin_unlock(&ec->lock);
550
551 /*
552 * When ec_freeze_events is true, we need to flush events in
553 * the proper position before entering the noirq stage.
554 */
555 __acpi_ec_flush_work();
556 }
557
558 void acpi_ec_flush_work(void)
559 {
560 /* Without ec_wq there is nothing to flush. */
561 if (!ec_wq)
562 return;
563
564 __acpi_ec_flush_work();
565 }
566 #endif /* CONFIG_PM_SLEEP */
567
568 static bool acpi_ec_guard_event(struct acpi_ec *ec)
569 {
570 bool guarded;
571
572 spin_lock(&ec->lock);
573 /*
574 * If firmware SCI_EVT clearing timing is "event", we actually
575 * don't know when the SCI_EVT will be cleared by firmware after
576 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
577 * acceptable period.
578 *
579 * The guarding period is applicable if the event state is not
580 * EC_EVENT_READY, but otherwise if the current transaction is of the
581 * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
582 * and it should not be applied to let the transaction transition into
583 * the ACPI_EC_COMMAND_POLL state immediately.
584 */
585 guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
586 ec->event_state != EC_EVENT_READY &&
587 (!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
588 spin_unlock(&ec->lock);
589 return guarded;
590 }
591
592 static int ec_transaction_polled(struct acpi_ec *ec)
593 {
594 int ret = 0;
595
596 spin_lock(&ec->lock);
597 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
598 ret = 1;
599 spin_unlock(&ec->lock);
600 return ret;
601 }
602
603 static int ec_transaction_completed(struct acpi_ec *ec)
604 {
605 int ret = 0;
606
607 spin_lock(&ec->lock);
608 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
609 ret = 1;
610 spin_unlock(&ec->lock);
611 return ret;
612 }
613
614 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
615 {
616 ec->curr->flags |= flag;
617
618 if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
619 return;
620
621 switch (ec_event_clearing) {
622 case ACPI_EC_EVT_TIMING_STATUS:
623 if (flag == ACPI_EC_COMMAND_POLL)
624 acpi_ec_close_event(ec);
625
626 return;
627
628 case ACPI_EC_EVT_TIMING_QUERY:
629 if (flag == ACPI_EC_COMMAND_COMPLETE)
630 acpi_ec_close_event(ec);
631
632 return;
633
634 case ACPI_EC_EVT_TIMING_EVENT:
635 if (flag == ACPI_EC_COMMAND_COMPLETE)
636 acpi_ec_complete_event(ec);
637 }
638 }
639
640 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
641 {
642 if (t->irq_count < ec_storm_threshold)
643 ++t->irq_count;
644
645 /* Trigger if the threshold is 0 too. */
646 if (t->irq_count == ec_storm_threshold)
647 acpi_ec_mask_events(ec);
648 }
649
650 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
651 {
652 struct transaction *t = ec->curr;
653 bool wakeup = false;
654 u8 status;
655
656 ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
657
658 status = acpi_ec_read_status(ec);
659
660 /*
661 * Another IRQ or a guarded polling mode advancement is detected,
662 * the next QR_EC submission is then allowed.
663 */
664 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
665 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
666 ec->event_state == EC_EVENT_COMPLETE)
667 acpi_ec_close_event(ec);
668
669 if (!t)
670 goto out;
671 }
672
673 if (t->flags & ACPI_EC_COMMAND_POLL) {
674 if (t->wlen > t->wi) {
675 if (!(status & ACPI_EC_FLAG_IBF))
676 acpi_ec_write_data(ec, t->wdata[t->wi++]);
677 else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
678 acpi_ec_spurious_interrupt(ec, t);
679 } else if (t->rlen > t->ri) {
680 if (status & ACPI_EC_FLAG_OBF) {
681 t->rdata[t->ri++] = acpi_ec_read_data(ec);
682 if (t->rlen == t->ri) {
683 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
684 wakeup = true;
685 if (t->command == ACPI_EC_COMMAND_QUERY)
686 ec_dbg_evt("Command(%s) completed by hardware",
687 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
688 }
689 } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
690 acpi_ec_spurious_interrupt(ec, t);
691 }
692 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
693 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
694 wakeup = true;
695 }
696 } else if (!(status & ACPI_EC_FLAG_IBF)) {
697 acpi_ec_write_cmd(ec, t->command);
698 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
699 }
700
701 out:
702 if (status & ACPI_EC_FLAG_SCI)
703 acpi_ec_submit_event(ec);
704
705 if (wakeup && interrupt)
706 wake_up(&ec->wait);
707 }
708
709 static void start_transaction(struct acpi_ec *ec)
710 {
711 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
712 ec->curr->flags = 0;
713 }
714
715 static int ec_guard(struct acpi_ec *ec)
716 {
717 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
718 unsigned long timeout = ec->timestamp + guard;
719
720 /* Ensure guarding period before polling EC status */
721 do {
722 if (ec->busy_polling) {
723 /* Perform busy polling */
724 if (ec_transaction_completed(ec))
725 return 0;
726 udelay(jiffies_to_usecs(guard));
727 } else {
728 /*
729 * Perform wait polling
730 * 1. Wait the transaction to be completed by the
731 * GPE handler after the transaction enters
732 * ACPI_EC_COMMAND_POLL state.
733 * 2. A special guarding logic is also required
734 * for event clearing mode "event" before the
735 * transaction enters ACPI_EC_COMMAND_POLL
736 * state.
737 */
738 if (!ec_transaction_polled(ec) &&
739 !acpi_ec_guard_event(ec))
740 break;
741 if (wait_event_timeout(ec->wait,
742 ec_transaction_completed(ec),
743 guard))
744 return 0;
745 }
746 } while (time_before(jiffies, timeout));
747 return -ETIME;
748 }
749
750 static int ec_poll(struct acpi_ec *ec)
751 {
752 int repeat = 5; /* number of command restarts */
753
754 while (repeat--) {
755 unsigned long delay = jiffies +
756 msecs_to_jiffies(ec_delay);
757 do {
758 if (!ec_guard(ec))
759 return 0;
760 spin_lock(&ec->lock);
761 advance_transaction(ec, false);
762 spin_unlock(&ec->lock);
763 } while (time_before(jiffies, delay));
764 pr_debug("controller reset, restart transaction\n");
765 spin_lock(&ec->lock);
766 start_transaction(ec);
767 spin_unlock(&ec->lock);
768 }
769 return -ETIME;
770 }
771
772 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
773 struct transaction *t)
774 {
775 int ret = 0;
776
777 /* start transaction */
778 spin_lock(&ec->lock);
779 /* Enable GPE for command processing (IBF=0/OBF=1) */
780 if (!acpi_ec_submit_flushable_request(ec)) {
781 ret = -EINVAL;
782 goto unlock;
783 }
784 ec_dbg_ref(ec, "Increase command");
785 /* following two actions should be kept atomic */
786 ec->curr = t;
787 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
788 start_transaction(ec);
789 spin_unlock(&ec->lock);
790
791 ret = ec_poll(ec);
792
793 spin_lock(&ec->lock);
794 if (t->irq_count == ec_storm_threshold)
795 acpi_ec_unmask_events(ec);
796 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
797 ec->curr = NULL;
798 /* Disable GPE for command processing (IBF=0/OBF=1) */
799 acpi_ec_complete_request(ec);
800 ec_dbg_ref(ec, "Decrease command");
801 unlock:
802 spin_unlock(&ec->lock);
803 return ret;
804 }
805
806 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
807 {
808 int status;
809 u32 glk;
810
811 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
812 return -EINVAL;
813 if (t->rdata)
814 memset(t->rdata, 0, t->rlen);
815
816 mutex_lock(&ec->mutex);
817 if (ec->global_lock) {
818 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
819 if (ACPI_FAILURE(status)) {
820 status = -ENODEV;
821 goto unlock;
822 }
823 }
824
825 status = acpi_ec_transaction_unlocked(ec, t);
826
827 if (ec->global_lock)
828 acpi_release_global_lock(glk);
829 unlock:
830 mutex_unlock(&ec->mutex);
831 return status;
832 }
833
834 static int acpi_ec_burst_enable(struct acpi_ec *ec)
835 {
836 u8 d;
837 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
838 .wdata = NULL, .rdata = &d,
839 .wlen = 0, .rlen = 1};
840
841 return acpi_ec_transaction(ec, &t);
842 }
843
844 static int acpi_ec_burst_disable(struct acpi_ec *ec)
845 {
846 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
847 .wdata = NULL, .rdata = NULL,
848 .wlen = 0, .rlen = 0};
849
850 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
851 acpi_ec_transaction(ec, &t) : 0;
852 }
853
854 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
855 {
856 int result;
857 u8 d;
858 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
859 .wdata = &address, .rdata = &d,
860 .wlen = 1, .rlen = 1};
861
862 result = acpi_ec_transaction(ec, &t);
863 *data = d;
864 return result;
865 }
866
867 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
868 {
869 u8 wdata[2] = { address, data };
870 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
871 .wdata = wdata, .rdata = NULL,
872 .wlen = 2, .rlen = 0};
873
874 return acpi_ec_transaction(ec, &t);
875 }
876
877 int ec_read(u8 addr, u8 *val)
878 {
879 int err;
880 u8 temp_data;
881
882 if (!first_ec)
883 return -ENODEV;
884
885 err = acpi_ec_read(first_ec, addr, &temp_data);
886
887 if (!err) {
888 *val = temp_data;
889 return 0;
890 }
891 return err;
892 }
893 EXPORT_SYMBOL(ec_read);
894
895 int ec_write(u8 addr, u8 val)
896 {
897 if (!first_ec)
898 return -ENODEV;
899
900 return acpi_ec_write(first_ec, addr, val);
901 }
902 EXPORT_SYMBOL(ec_write);
903
904 int ec_transaction(u8 command,
905 const u8 *wdata, unsigned wdata_len,
906 u8 *rdata, unsigned rdata_len)
907 {
908 struct transaction t = {.command = command,
909 .wdata = wdata, .rdata = rdata,
910 .wlen = wdata_len, .rlen = rdata_len};
911
912 if (!first_ec)
913 return -ENODEV;
914
915 return acpi_ec_transaction(first_ec, &t);
916 }
917 EXPORT_SYMBOL(ec_transaction);
918
919 /* Get the handle to the EC device */
920 acpi_handle ec_get_handle(void)
921 {
922 if (!first_ec)
923 return NULL;
924 return first_ec->handle;
925 }
926 EXPORT_SYMBOL(ec_get_handle);
927
928 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
929 {
930 spin_lock(&ec->lock);
931 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
932 ec_dbg_drv("Starting EC");
933 /* Enable GPE for event processing (SCI_EVT=1) */
934 if (!resuming) {
935 acpi_ec_submit_request(ec);
936 ec_dbg_ref(ec, "Increase driver");
937 }
938 ec_log_drv("EC started");
939 }
940 spin_unlock(&ec->lock);
941 }
942
943 static bool acpi_ec_stopped(struct acpi_ec *ec)
944 {
945 bool flushed;
946
947 spin_lock(&ec->lock);
948 flushed = acpi_ec_flushed(ec);
949 spin_unlock(&ec->lock);
950 return flushed;
951 }
952
953 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
954 {
955 spin_lock(&ec->lock);
956 if (acpi_ec_started(ec)) {
957 ec_dbg_drv("Stopping EC");
958 set_bit(EC_FLAGS_STOPPED, &ec->flags);
959 spin_unlock(&ec->lock);
960 wait_event(ec->wait, acpi_ec_stopped(ec));
961 spin_lock(&ec->lock);
962 /* Disable GPE for event processing (SCI_EVT=1) */
963 if (!suspending) {
964 acpi_ec_complete_request(ec);
965 ec_dbg_ref(ec, "Decrease driver");
966 } else if (!ec_freeze_events)
967 __acpi_ec_disable_event(ec);
968 clear_bit(EC_FLAGS_STARTED, &ec->flags);
969 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
970 ec_log_drv("EC stopped");
971 }
972 spin_unlock(&ec->lock);
973 }
974
975 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
976 {
977 spin_lock(&ec->lock);
978 ec->busy_polling = true;
979 ec->polling_guard = 0;
980 ec_log_drv("interrupt blocked");
981 spin_unlock(&ec->lock);
982 }
983
984 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
985 {
986 spin_lock(&ec->lock);
987 ec->busy_polling = ec_busy_polling;
988 ec->polling_guard = ec_polling_guard;
989 ec_log_drv("interrupt unblocked");
990 spin_unlock(&ec->lock);
991 }
992
993 void acpi_ec_block_transactions(void)
994 {
995 struct acpi_ec *ec = first_ec;
996
997 if (!ec)
998 return;
999
1000 mutex_lock(&ec->mutex);
1001 /* Prevent transactions from being carried out */
1002 acpi_ec_stop(ec, true);
1003 mutex_unlock(&ec->mutex);
1004 }
1005
1006 void acpi_ec_unblock_transactions(void)
1007 {
1008 /*
1009 * Allow transactions to happen again (this function is called from
1010 * atomic context during wakeup, so we don't need to acquire the mutex).
1011 */
1012 if (first_ec)
1013 acpi_ec_start(first_ec, true);
1014 }
1015
1016 /* --------------------------------------------------------------------------
1017 Event Management
1018 -------------------------------------------------------------------------- */
1019 static struct acpi_ec_query_handler *
1020 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1021 {
1022 struct acpi_ec_query_handler *handler;
1023
1024 mutex_lock(&ec->mutex);
1025 list_for_each_entry(handler, &ec->list, node) {
1026 if (value == handler->query_bit) {
1027 kref_get(&handler->kref);
1028 mutex_unlock(&ec->mutex);
1029 return handler;
1030 }
1031 }
1032 mutex_unlock(&ec->mutex);
1033 return NULL;
1034 }
1035
1036 static void acpi_ec_query_handler_release(struct kref *kref)
1037 {
1038 struct acpi_ec_query_handler *handler =
1039 container_of(kref, struct acpi_ec_query_handler, kref);
1040
1041 kfree(handler);
1042 }
1043
1044 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1045 {
1046 kref_put(&handler->kref, acpi_ec_query_handler_release);
1047 }
1048
1049 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1050 acpi_handle handle, acpi_ec_query_func func,
1051 void *data)
1052 {
1053 struct acpi_ec_query_handler *handler;
1054
1055 if (!handle && !func)
1056 return -EINVAL;
1057
1058 handler = kzalloc(sizeof(*handler), GFP_KERNEL);
1059 if (!handler)
1060 return -ENOMEM;
1061
1062 handler->query_bit = query_bit;
1063 handler->handle = handle;
1064 handler->func = func;
1065 handler->data = data;
1066 mutex_lock(&ec->mutex);
1067 kref_init(&handler->kref);
1068 list_add(&handler->node, &ec->list);
1069 mutex_unlock(&ec->mutex);
1070
1071 return 0;
1072 }
1073 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1074
1075 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1076 bool remove_all, u8 query_bit)
1077 {
1078 struct acpi_ec_query_handler *handler, *tmp;
1079 LIST_HEAD(free_list);
1080
1081 mutex_lock(&ec->mutex);
1082 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1083 /*
1084 * When remove_all is false, only remove custom query handlers
1085 * which have handler->func set. This is done to preserve query
1086 * handlers discovered thru ACPI, as they should continue handling
1087 * EC queries.
1088 */
1089 if (remove_all || (handler->func && handler->query_bit == query_bit)) {
1090 list_del_init(&handler->node);
1091 list_add(&handler->node, &free_list);
1092
1093 }
1094 }
1095 mutex_unlock(&ec->mutex);
1096 list_for_each_entry_safe(handler, tmp, &free_list, node)
1097 acpi_ec_put_query_handler(handler);
1098 }
1099
1100 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1101 {
1102 acpi_ec_remove_query_handlers(ec, false, query_bit);
1103 flush_workqueue(ec_query_wq);
1104 }
1105 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1106
1107 static void acpi_ec_event_processor(struct work_struct *work)
1108 {
1109 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1110 struct acpi_ec_query_handler *handler = q->handler;
1111 struct acpi_ec *ec = q->ec;
1112
1113 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1114
1115 if (handler->func)
1116 handler->func(handler->data);
1117 else if (handler->handle)
1118 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1119
1120 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1121
1122 spin_lock(&ec->lock);
1123 ec->queries_in_progress--;
1124 spin_unlock(&ec->lock);
1125
1126 acpi_ec_put_query_handler(handler);
1127 kfree(q);
1128 }
1129
1130 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1131 {
1132 struct acpi_ec_query *q;
1133 struct transaction *t;
1134
1135 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1136 if (!q)
1137 return NULL;
1138
1139 INIT_WORK(&q->work, acpi_ec_event_processor);
1140 t = &q->transaction;
1141 t->command = ACPI_EC_COMMAND_QUERY;
1142 t->rdata = pval;
1143 t->rlen = 1;
1144 q->ec = ec;
1145 return q;
1146 }
1147
1148 static int acpi_ec_submit_query(struct acpi_ec *ec)
1149 {
1150 struct acpi_ec_query *q;
1151 u8 value = 0;
1152 int result;
1153
1154 q = acpi_ec_create_query(ec, &value);
1155 if (!q)
1156 return -ENOMEM;
1157
1158 /*
1159 * Query the EC to find out which _Qxx method we need to evaluate.
1160 * Note that successful completion of the query causes the ACPI_EC_SCI
1161 * bit to be cleared (and thus clearing the interrupt source).
1162 */
1163 result = acpi_ec_transaction(ec, &q->transaction);
1164 if (result)
1165 goto err_exit;
1166
1167 if (!value) {
1168 result = -ENODATA;
1169 goto err_exit;
1170 }
1171
1172 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1173 if (!q->handler) {
1174 result = -ENODATA;
1175 goto err_exit;
1176 }
1177
1178 /*
1179 * It is reported that _Qxx are evaluated in a parallel way on Windows:
1180 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1181 *
1182 * Put this log entry before queue_work() to make it appear in the log
1183 * before any other messages emitted during workqueue handling.
1184 */
1185 ec_dbg_evt("Query(0x%02x) scheduled", value);
1186
1187 spin_lock(&ec->lock);
1188
1189 ec->queries_in_progress++;
1190 queue_work(ec_query_wq, &q->work);
1191
1192 spin_unlock(&ec->lock);
1193
1194 return 0;
1195
1196 err_exit:
1197 kfree(q);
1198
1199 return result;
1200 }
1201
1202 static void acpi_ec_event_handler(struct work_struct *work)
1203 {
1204 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1205
1206 ec_dbg_evt("Event started");
1207
1208 spin_lock(&ec->lock);
1209
1210 while (ec->events_to_process) {
1211 spin_unlock(&ec->lock);
1212
1213 acpi_ec_submit_query(ec);
1214
1215 spin_lock(&ec->lock);
1216
1217 ec->events_to_process--;
1218 }
1219
1220 /*
1221 * Before exit, make sure that the it will be possible to queue up the
1222 * event handling work again regardless of whether or not the query
1223 * queued up above is processed successfully.
1224 */
1225 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1226 bool guard_timeout;
1227
1228 acpi_ec_complete_event(ec);
1229
1230 ec_dbg_evt("Event stopped");
1231
1232 spin_unlock(&ec->lock);
1233
1234 guard_timeout = !!ec_guard(ec);
1235
1236 spin_lock(&ec->lock);
1237
1238 /* Take care of SCI_EVT unless someone else is doing that. */
1239 if (guard_timeout && !ec->curr)
1240 advance_transaction(ec, false);
1241 } else {
1242 acpi_ec_close_event(ec);
1243
1244 ec_dbg_evt("Event stopped");
1245 }
1246
1247 ec->events_in_progress--;
1248
1249 spin_unlock(&ec->lock);
1250 }
1251
1252 static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)
1253 {
1254 /*
1255 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
1256 * changes to always trigger a GPE interrupt.
1257 *
1258 * GPE STS is a W1C register, which means:
1259 *
1260 * 1. Software can clear it without worrying about clearing the other
1261 * GPEs' STS bits when the hardware sets them in parallel.
1262 *
1263 * 2. As long as software can ensure only clearing it when it is set,
1264 * hardware won't set it in parallel.
1265 */
1266 if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
1267 acpi_clear_gpe(NULL, ec->gpe);
1268
1269 advance_transaction(ec, true);
1270 }
1271
1272 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1273 {
1274 spin_lock(&ec->lock);
1275
1276 clear_gpe_and_advance_transaction(ec, true);
1277
1278 spin_unlock(&ec->lock);
1279 }
1280
1281 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1282 u32 gpe_number, void *data)
1283 {
1284 acpi_ec_handle_interrupt(data);
1285 return ACPI_INTERRUPT_HANDLED;
1286 }
1287
1288 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1289 {
1290 acpi_ec_handle_interrupt(data);
1291 return IRQ_HANDLED;
1292 }
1293
1294 /* --------------------------------------------------------------------------
1295 * Address Space Management
1296 * -------------------------------------------------------------------------- */
1297
1298 static acpi_status
1299 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1300 u32 bits, u64 *value64,
1301 void *handler_context, void *region_context)
1302 {
1303 struct acpi_ec *ec = handler_context;
1304 int result = 0, i, bytes = bits / 8;
1305 u8 *value = (u8 *)value64;
1306
1307 if ((address > 0xFF) || !value || !handler_context)
1308 return AE_BAD_PARAMETER;
1309
1310 if (function != ACPI_READ && function != ACPI_WRITE)
1311 return AE_BAD_PARAMETER;
1312
1313 if (ec->busy_polling || bits > 8)
1314 acpi_ec_burst_enable(ec);
1315
1316 for (i = 0; i < bytes; ++i, ++address, ++value)
1317 result = (function == ACPI_READ) ?
1318 acpi_ec_read(ec, address, value) :
1319 acpi_ec_write(ec, address, *value);
1320
1321 if (ec->busy_polling || bits > 8)
1322 acpi_ec_burst_disable(ec);
1323
1324 switch (result) {
1325 case -EINVAL:
1326 return AE_BAD_PARAMETER;
1327 case -ENODEV:
1328 return AE_NOT_FOUND;
1329 case -ETIME:
1330 return AE_TIME;
1331 default:
1332 return AE_OK;
1333 }
1334 }
1335
1336 /* --------------------------------------------------------------------------
1337 * Driver Interface
1338 * -------------------------------------------------------------------------- */
1339
1340 static acpi_status
1341 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1342
1343 static void acpi_ec_free(struct acpi_ec *ec)
1344 {
1345 if (first_ec == ec)
1346 first_ec = NULL;
1347 if (boot_ec == ec)
1348 boot_ec = NULL;
1349 kfree(ec);
1350 }
1351
1352 static struct acpi_ec *acpi_ec_alloc(void)
1353 {
1354 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1355
1356 if (!ec)
1357 return NULL;
1358 mutex_init(&ec->mutex);
1359 init_waitqueue_head(&ec->wait);
1360 INIT_LIST_HEAD(&ec->list);
1361 spin_lock_init(&ec->lock);
1362 INIT_WORK(&ec->work, acpi_ec_event_handler);
1363 ec->timestamp = jiffies;
1364 ec->busy_polling = true;
1365 ec->polling_guard = 0;
1366 ec->gpe = -1;
1367 ec->irq = -1;
1368 return ec;
1369 }
1370
1371 static acpi_status
1372 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1373 void *context, void **return_value)
1374 {
1375 char node_name[5];
1376 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1377 struct acpi_ec *ec = context;
1378 int value = 0;
1379 acpi_status status;
1380
1381 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1382
1383 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1384 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1385 return AE_OK;
1386 }
1387
1388 static acpi_status
1389 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1390 {
1391 acpi_status status;
1392 unsigned long long tmp = 0;
1393 struct acpi_ec *ec = context;
1394
1395 /* clear addr values, ec_parse_io_ports depend on it */
1396 ec->command_addr = ec->data_addr = 0;
1397
1398 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1399 ec_parse_io_ports, ec);
1400 if (ACPI_FAILURE(status))
1401 return status;
1402 if (ec->data_addr == 0 || ec->command_addr == 0)
1403 return AE_OK;
1404
1405 /* Get GPE bit assignment (EC events). */
1406 /* TODO: Add support for _GPE returning a package */
1407 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1408 if (ACPI_SUCCESS(status))
1409 ec->gpe = tmp;
1410 /*
1411 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1412 * platforms which use GpioInt instead of GPE.
1413 */
1414
1415 /* Use the global lock for all EC transactions? */
1416 tmp = 0;
1417 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1418 ec->global_lock = tmp;
1419 ec->handle = handle;
1420 return AE_CTRL_TERMINATE;
1421 }
1422
1423 static bool install_gpe_event_handler(struct acpi_ec *ec)
1424 {
1425 acpi_status status;
1426
1427 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1428 ACPI_GPE_EDGE_TRIGGERED,
1429 &acpi_ec_gpe_handler, ec);
1430 if (ACPI_FAILURE(status))
1431 return false;
1432
1433 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1434 acpi_ec_enable_gpe(ec, true);
1435
1436 return true;
1437 }
1438
1439 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1440 {
1441 return request_threaded_irq(ec->irq, NULL, acpi_ec_irq_handler,
1442 IRQF_SHARED | IRQF_ONESHOT, "ACPI EC", ec) >= 0;
1443 }
1444
1445 /**
1446 * ec_install_handlers - Install service callbacks and register query methods.
1447 * @ec: Target EC.
1448 * @device: ACPI device object corresponding to @ec.
1449 * @call_reg: If _REG should be called to notify OpRegion availability
1450 *
1451 * Install a handler for the EC address space type unless it has been installed
1452 * already. If @device is not NULL, also look for EC query methods in the
1453 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1454 * handler for the EC, if possible.
1455 *
1456 * Return:
1457 * -ENODEV if the address space handler cannot be installed, which means
1458 * "unable to handle transactions",
1459 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1460 * or 0 (success) otherwise.
1461 */
1462 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1463 bool call_reg)
1464 {
1465 acpi_status status;
1466
1467 acpi_ec_start(ec, false);
1468
1469 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1470 acpi_ec_enter_noirq(ec);
1471 status = acpi_install_address_space_handler_no_reg(ec->handle,
1472 ACPI_ADR_SPACE_EC,
1473 &acpi_ec_space_handler,
1474 NULL, ec);
1475 if (ACPI_FAILURE(status)) {
1476 acpi_ec_stop(ec, false);
1477 return -ENODEV;
1478 }
1479 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1480 ec->address_space_handler_holder = ec->handle;
1481 }
1482
1483 if (call_reg && !test_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags)) {
1484 acpi_execute_reg_methods(ec->handle, ACPI_ADR_SPACE_EC);
1485 set_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags);
1486 }
1487
1488 if (!device)
1489 return 0;
1490
1491 if (ec->gpe < 0) {
1492 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1493 int irq = acpi_dev_gpio_irq_get(device, 0);
1494 /*
1495 * Bail out right away for deferred probing or complete the
1496 * initialization regardless of any other errors.
1497 */
1498 if (irq == -EPROBE_DEFER)
1499 return -EPROBE_DEFER;
1500 else if (irq >= 0)
1501 ec->irq = irq;
1502 }
1503
1504 if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1505 /* Find and register all query methods */
1506 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1507 acpi_ec_register_query_methods,
1508 NULL, ec, NULL);
1509 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1510 }
1511 if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1512 bool ready = false;
1513
1514 if (ec->gpe >= 0)
1515 ready = install_gpe_event_handler(ec);
1516 else if (ec->irq >= 0)
1517 ready = install_gpio_irq_event_handler(ec);
1518
1519 if (ready) {
1520 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1521 acpi_ec_leave_noirq(ec);
1522 }
1523 /*
1524 * Failures to install an event handler are not fatal, because
1525 * the EC can be polled for events.
1526 */
1527 }
1528 /* EC is fully operational, allow queries */
1529 acpi_ec_enable_event(ec);
1530
1531 return 0;
1532 }
1533
1534 static void ec_remove_handlers(struct acpi_ec *ec)
1535 {
1536 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1537 if (ACPI_FAILURE(acpi_remove_address_space_handler(
1538 ec->address_space_handler_holder,
1539 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1540 pr_err("failed to remove space handler\n");
1541 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1542 }
1543
1544 /*
1545 * Stops handling the EC transactions after removing the operation
1546 * region handler. This is required because _REG(DISCONNECT)
1547 * invoked during the removal can result in new EC transactions.
1548 *
1549 * Flushes the EC requests and thus disables the GPE before
1550 * removing the GPE handler. This is required by the current ACPICA
1551 * GPE core. ACPICA GPE core will automatically disable a GPE when
1552 * it is indicated but there is no way to handle it. So the drivers
1553 * must disable the GPEs prior to removing the GPE handlers.
1554 */
1555 acpi_ec_stop(ec, false);
1556
1557 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1558 if (ec->gpe >= 0 &&
1559 ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1560 &acpi_ec_gpe_handler)))
1561 pr_err("failed to remove gpe handler\n");
1562
1563 if (ec->irq >= 0)
1564 free_irq(ec->irq, ec);
1565
1566 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1567 }
1568 if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1569 acpi_ec_remove_query_handlers(ec, true, 0);
1570 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1571 }
1572 }
1573
1574 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device, bool call_reg)
1575 {
1576 int ret;
1577
1578 ret = ec_install_handlers(ec, device, call_reg);
1579 if (ret)
1580 return ret;
1581
1582 /* First EC capable of handling transactions */
1583 if (!first_ec)
1584 first_ec = ec;
1585
1586 pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1587 ec->data_addr);
1588
1589 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1590 if (ec->gpe >= 0)
1591 pr_info("GPE=0x%x\n", ec->gpe);
1592 else
1593 pr_info("IRQ=%d\n", ec->irq);
1594 }
1595
1596 return ret;
1597 }
1598
1599 static int acpi_ec_add(struct acpi_device *device)
1600 {
1601 struct acpi_ec *ec;
1602 int ret;
1603
1604 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1605 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1606
1607 if (boot_ec && (boot_ec->handle == device->handle ||
1608 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1609 /* Fast path: this device corresponds to the boot EC. */
1610 ec = boot_ec;
1611 } else {
1612 acpi_status status;
1613
1614 ec = acpi_ec_alloc();
1615 if (!ec)
1616 return -ENOMEM;
1617
1618 status = ec_parse_device(device->handle, 0, ec, NULL);
1619 if (status != AE_CTRL_TERMINATE) {
1620 ret = -EINVAL;
1621 goto err;
1622 }
1623
1624 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1625 ec->data_addr == boot_ec->data_addr) {
1626 /*
1627 * Trust PNP0C09 namespace location rather than ECDT ID.
1628 * But trust ECDT GPE rather than _GPE because of ASUS
1629 * quirks. So do not change boot_ec->gpe to ec->gpe,
1630 * except when the TRUST_DSDT_GPE quirk is set.
1631 */
1632 boot_ec->handle = ec->handle;
1633
1634 if (EC_FLAGS_TRUST_DSDT_GPE)
1635 boot_ec->gpe = ec->gpe;
1636
1637 acpi_handle_debug(ec->handle, "duplicated.\n");
1638 acpi_ec_free(ec);
1639 ec = boot_ec;
1640 }
1641 }
1642
1643 ret = acpi_ec_setup(ec, device, true);
1644 if (ret)
1645 goto err;
1646
1647 if (ec == boot_ec)
1648 acpi_handle_info(boot_ec->handle,
1649 "Boot %s EC initialization complete\n",
1650 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1651
1652 acpi_handle_info(ec->handle,
1653 "EC: Used to handle transactions and events\n");
1654
1655 device->driver_data = ec;
1656
1657 ret = !!request_region(ec->data_addr, 1, "EC data");
1658 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1659 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1660 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1661
1662 /* Reprobe devices depending on the EC */
1663 acpi_dev_clear_dependencies(device);
1664
1665 acpi_handle_debug(ec->handle, "enumerated.\n");
1666 return 0;
1667
1668 err:
1669 if (ec != boot_ec)
1670 acpi_ec_free(ec);
1671
1672 return ret;
1673 }
1674
1675 static void acpi_ec_remove(struct acpi_device *device)
1676 {
1677 struct acpi_ec *ec;
1678
1679 if (!device)
1680 return;
1681
1682 ec = acpi_driver_data(device);
1683 release_region(ec->data_addr, 1);
1684 release_region(ec->command_addr, 1);
1685 device->driver_data = NULL;
1686 if (ec != boot_ec) {
1687 ec_remove_handlers(ec);
1688 acpi_ec_free(ec);
1689 }
1690 }
1691
1692 static acpi_status
1693 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1694 {
1695 struct acpi_ec *ec = context;
1696
1697 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1698 return AE_OK;
1699
1700 /*
1701 * The first address region returned is the data port, and
1702 * the second address region returned is the status/command
1703 * port.
1704 */
1705 if (ec->data_addr == 0)
1706 ec->data_addr = resource->data.io.minimum;
1707 else if (ec->command_addr == 0)
1708 ec->command_addr = resource->data.io.minimum;
1709 else
1710 return AE_CTRL_TERMINATE;
1711
1712 return AE_OK;
1713 }
1714
1715 static const struct acpi_device_id ec_device_ids[] = {
1716 {"PNP0C09", 0},
1717 {ACPI_ECDT_HID, 0},
1718 {"", 0},
1719 };
1720
1721 /*
1722 * This function is not Windows-compatible as Windows never enumerates the
1723 * namespace EC before the main ACPI device enumeration process. It is
1724 * retained for historical reason and will be deprecated in the future.
1725 */
1726 void __init acpi_ec_dsdt_probe(void)
1727 {
1728 struct acpi_ec *ec;
1729 acpi_status status;
1730 int ret;
1731
1732 /*
1733 * If a platform has ECDT, there is no need to proceed as the
1734 * following probe is not a part of the ACPI device enumeration,
1735 * executing _STA is not safe, and thus this probe may risk of
1736 * picking up an invalid EC device.
1737 */
1738 if (boot_ec)
1739 return;
1740
1741 ec = acpi_ec_alloc();
1742 if (!ec)
1743 return;
1744
1745 /*
1746 * At this point, the namespace is initialized, so start to find
1747 * the namespace objects.
1748 */
1749 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1750 if (ACPI_FAILURE(status) || !ec->handle) {
1751 acpi_ec_free(ec);
1752 return;
1753 }
1754
1755 /*
1756 * When the DSDT EC is available, always re-configure boot EC to
1757 * have _REG evaluated. _REG can only be evaluated after the
1758 * namespace initialization.
1759 * At this point, the GPE is not fully initialized, so do not to
1760 * handle the events.
1761 */
1762 ret = acpi_ec_setup(ec, NULL, true);
1763 if (ret) {
1764 acpi_ec_free(ec);
1765 return;
1766 }
1767
1768 boot_ec = ec;
1769
1770 acpi_handle_info(ec->handle,
1771 "Boot DSDT EC used to handle transactions\n");
1772 }
1773
1774 /*
1775 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1776 *
1777 * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1778 * found a matching object in the namespace.
1779 *
1780 * Next, in case the DSDT EC is not functioning, it is still necessary to
1781 * provide a functional ECDT EC to handle events, so add an extra device object
1782 * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1783 *
1784 * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1785 * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1786 */
1787 static void __init acpi_ec_ecdt_start(void)
1788 {
1789 struct acpi_table_ecdt *ecdt_ptr;
1790 acpi_handle handle;
1791 acpi_status status;
1792
1793 /* Bail out if a matching EC has been found in the namespace. */
1794 if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1795 return;
1796
1797 /* Look up the object pointed to from the ECDT in the namespace. */
1798 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1799 (struct acpi_table_header **)&ecdt_ptr);
1800 if (ACPI_FAILURE(status))
1801 return;
1802
1803 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1804 if (ACPI_SUCCESS(status)) {
1805 boot_ec->handle = handle;
1806
1807 /* Add a special ACPI device object to represent the boot EC. */
1808 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1809 }
1810
1811 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1812 }
1813
1814 /*
1815 * On some hardware it is necessary to clear events accumulated by the EC during
1816 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1817 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1818 *
1819 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1820 *
1821 * Ideally, the EC should also be instructed NOT to accumulate events during
1822 * sleep (which Windows seems to do somehow), but the interface to control this
1823 * behaviour is not known at this time.
1824 *
1825 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1826 * however it is very likely that other Samsung models are affected.
1827 *
1828 * On systems which don't accumulate _Q events during sleep, this extra check
1829 * should be harmless.
1830 */
1831 static int ec_clear_on_resume(const struct dmi_system_id *id)
1832 {
1833 pr_debug("Detected system needing EC poll on resume.\n");
1834 EC_FLAGS_CLEAR_ON_RESUME = 1;
1835 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1836 return 0;
1837 }
1838
1839 /*
1840 * Some ECDTs contain wrong register addresses.
1841 * MSI MS-171F
1842 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1843 */
1844 static int ec_correct_ecdt(const struct dmi_system_id *id)
1845 {
1846 pr_debug("Detected system needing ECDT address correction.\n");
1847 EC_FLAGS_CORRECT_ECDT = 1;
1848 return 0;
1849 }
1850
1851 /*
1852 * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1853 * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1854 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1855 */
1856 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1857 {
1858 pr_debug("Detected system needing DSDT GPE setting.\n");
1859 EC_FLAGS_TRUST_DSDT_GPE = 1;
1860 return 0;
1861 }
1862
1863 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1864 {
1865 /*
1866 * MSI MS-171F
1867 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1868 */
1869 .callback = ec_correct_ecdt,
1870 .matches = {
1871 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1872 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),
1873 },
1874 },
1875 {
1876 /*
1877 * HP Pavilion Gaming Laptop 15-cx0xxx
1878 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1879 */
1880 .callback = ec_honor_dsdt_gpe,
1881 .matches = {
1882 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1883 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),
1884 },
1885 },
1886 {
1887 /*
1888 * HP Pavilion Gaming Laptop 15-cx0041ur
1889 */
1890 .callback = ec_honor_dsdt_gpe,
1891 .matches = {
1892 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1893 DMI_MATCH(DMI_PRODUCT_NAME, "HP 15-cx0041ur"),
1894 },
1895 },
1896 {
1897 /*
1898 * HP Pavilion Gaming Laptop 15-dk1xxx
1899 * https://github.com/systemd/systemd/issues/28942
1900 */
1901 .callback = ec_honor_dsdt_gpe,
1902 .matches = {
1903 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1904 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-dk1xxx"),
1905 },
1906 },
1907 {
1908 /*
1909 * HP 250 G7 Notebook PC
1910 */
1911 .callback = ec_honor_dsdt_gpe,
1912 .matches = {
1913 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1914 DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"),
1915 },
1916 },
1917 {
1918 /*
1919 * Samsung hardware
1920 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1921 */
1922 .callback = ec_clear_on_resume,
1923 .matches = {
1924 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
1925 },
1926 },
1927 {}
1928 };
1929
1930 void __init acpi_ec_ecdt_probe(void)
1931 {
1932 struct acpi_table_ecdt *ecdt_ptr;
1933 struct acpi_ec *ec;
1934 acpi_status status;
1935 int ret;
1936
1937 /* Generate a boot ec context. */
1938 dmi_check_system(ec_dmi_table);
1939 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1940 (struct acpi_table_header **)&ecdt_ptr);
1941 if (ACPI_FAILURE(status))
1942 return;
1943
1944 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1945 /*
1946 * Asus X50GL:
1947 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1948 */
1949 goto out;
1950 }
1951
1952 ec = acpi_ec_alloc();
1953 if (!ec)
1954 goto out;
1955
1956 if (EC_FLAGS_CORRECT_ECDT) {
1957 ec->command_addr = ecdt_ptr->data.address;
1958 ec->data_addr = ecdt_ptr->control.address;
1959 } else {
1960 ec->command_addr = ecdt_ptr->control.address;
1961 ec->data_addr = ecdt_ptr->data.address;
1962 }
1963
1964 /*
1965 * Ignore the GPE value on Reduced Hardware platforms.
1966 * Some products have this set to an erroneous value.
1967 */
1968 if (!acpi_gbl_reduced_hardware)
1969 ec->gpe = ecdt_ptr->gpe;
1970
1971 ec->handle = ACPI_ROOT_OBJECT;
1972
1973 /*
1974 * At this point, the namespace is not initialized, so do not find
1975 * the namespace objects, or handle the events.
1976 */
1977 ret = acpi_ec_setup(ec, NULL, false);
1978 if (ret) {
1979 acpi_ec_free(ec);
1980 goto out;
1981 }
1982
1983 boot_ec = ec;
1984 boot_ec_is_ecdt = true;
1985
1986 pr_info("Boot ECDT EC used to handle transactions\n");
1987
1988 out:
1989 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1990 }
1991
1992 #ifdef CONFIG_PM_SLEEP
1993 static int acpi_ec_suspend(struct device *dev)
1994 {
1995 struct acpi_ec *ec =
1996 acpi_driver_data(to_acpi_device(dev));
1997
1998 if (!pm_suspend_no_platform() && ec_freeze_events)
1999 acpi_ec_disable_event(ec);
2000 return 0;
2001 }
2002
2003 static int acpi_ec_suspend_noirq(struct device *dev)
2004 {
2005 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2006
2007 /*
2008 * The SCI handler doesn't run at this point, so the GPE can be
2009 * masked at the low level without side effects.
2010 */
2011 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2012 ec->gpe >= 0 && ec->reference_count >= 1)
2013 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2014
2015 acpi_ec_enter_noirq(ec);
2016
2017 return 0;
2018 }
2019
2020 static int acpi_ec_resume_noirq(struct device *dev)
2021 {
2022 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2023
2024 acpi_ec_leave_noirq(ec);
2025
2026 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2027 ec->gpe >= 0 && ec->reference_count >= 1)
2028 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2029
2030 return 0;
2031 }
2032
2033 static int acpi_ec_resume(struct device *dev)
2034 {
2035 struct acpi_ec *ec =
2036 acpi_driver_data(to_acpi_device(dev));
2037
2038 acpi_ec_enable_event(ec);
2039 return 0;
2040 }
2041
2042 void acpi_ec_mark_gpe_for_wake(void)
2043 {
2044 if (first_ec && !ec_no_wakeup)
2045 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2046 }
2047 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2048
2049 void acpi_ec_set_gpe_wake_mask(u8 action)
2050 {
2051 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2052 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2053 }
2054
2055 static bool acpi_ec_work_in_progress(struct acpi_ec *ec)
2056 {
2057 return ec->events_in_progress + ec->queries_in_progress > 0;
2058 }
2059
2060 bool acpi_ec_dispatch_gpe(void)
2061 {
2062 bool work_in_progress = false;
2063
2064 if (!first_ec)
2065 return acpi_any_gpe_status_set(U32_MAX);
2066
2067 /*
2068 * Report wakeup if the status bit is set for any enabled GPE other
2069 * than the EC one.
2070 */
2071 if (acpi_any_gpe_status_set(first_ec->gpe))
2072 return true;
2073
2074 /*
2075 * Cancel the SCI wakeup and process all pending events in case there
2076 * are any wakeup ones in there.
2077 *
2078 * Note that if any non-EC GPEs are active at this point, the SCI will
2079 * retrigger after the rearming in acpi_s2idle_wake(), so no events
2080 * should be missed by canceling the wakeup here.
2081 */
2082 pm_system_cancel_wakeup();
2083
2084 /*
2085 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2086 * to allow the caller to process events properly after that.
2087 */
2088 spin_lock(&first_ec->lock);
2089
2090 if (acpi_ec_gpe_status_set(first_ec)) {
2091 pm_pr_dbg("ACPI EC GPE status set\n");
2092
2093 clear_gpe_and_advance_transaction(first_ec, false);
2094 work_in_progress = acpi_ec_work_in_progress(first_ec);
2095 }
2096
2097 spin_unlock(&first_ec->lock);
2098
2099 if (!work_in_progress)
2100 return false;
2101
2102 pm_pr_dbg("ACPI EC GPE dispatched\n");
2103
2104 /* Drain EC work. */
2105 do {
2106 acpi_ec_flush_work();
2107
2108 pm_pr_dbg("ACPI EC work flushed\n");
2109
2110 spin_lock(&first_ec->lock);
2111
2112 work_in_progress = acpi_ec_work_in_progress(first_ec);
2113
2114 spin_unlock(&first_ec->lock);
2115 } while (work_in_progress && !pm_wakeup_pending());
2116
2117 return false;
2118 }
2119 #endif /* CONFIG_PM_SLEEP */
2120
2121 static const struct dev_pm_ops acpi_ec_pm = {
2122 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2123 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2124 };
2125
2126 static int param_set_event_clearing(const char *val,
2127 const struct kernel_param *kp)
2128 {
2129 int result = 0;
2130
2131 if (!strncmp(val, "status", sizeof("status") - 1)) {
2132 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2133 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2134 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2135 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2136 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2137 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2138 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2139 pr_info("Assuming SCI_EVT clearing on event reads\n");
2140 } else
2141 result = -EINVAL;
2142 return result;
2143 }
2144
2145 static int param_get_event_clearing(char *buffer,
2146 const struct kernel_param *kp)
2147 {
2148 switch (ec_event_clearing) {
2149 case ACPI_EC_EVT_TIMING_STATUS:
2150 return sprintf(buffer, "status\n");
2151 case ACPI_EC_EVT_TIMING_QUERY:
2152 return sprintf(buffer, "query\n");
2153 case ACPI_EC_EVT_TIMING_EVENT:
2154 return sprintf(buffer, "event\n");
2155 default:
2156 return sprintf(buffer, "invalid\n");
2157 }
2158 return 0;
2159 }
2160
2161 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2162 NULL, 0644);
2163 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2164
2165 static struct acpi_driver acpi_ec_driver = {
2166 .name = "ec",
2167 .class = ACPI_EC_CLASS,
2168 .ids = ec_device_ids,
2169 .ops = {
2170 .add = acpi_ec_add,
2171 .remove = acpi_ec_remove,
2172 },
2173 .drv.pm = &acpi_ec_pm,
2174 };
2175
2176 static void acpi_ec_destroy_workqueues(void)
2177 {
2178 if (ec_wq) {
2179 destroy_workqueue(ec_wq);
2180 ec_wq = NULL;
2181 }
2182 if (ec_query_wq) {
2183 destroy_workqueue(ec_query_wq);
2184 ec_query_wq = NULL;
2185 }
2186 }
2187
2188 static int acpi_ec_init_workqueues(void)
2189 {
2190 if (!ec_wq)
2191 ec_wq = alloc_ordered_workqueue("kec", 0);
2192
2193 if (!ec_query_wq)
2194 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2195
2196 if (!ec_wq || !ec_query_wq) {
2197 acpi_ec_destroy_workqueues();
2198 return -ENODEV;
2199 }
2200 return 0;
2201 }
2202
2203 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2204 {
2205 .matches = {
2206 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2207 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2208 },
2209 },
2210 {
2211 .matches = {
2212 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2213 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2214 },
2215 },
2216 {
2217 .matches = {
2218 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2219 DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2220 },
2221 },
2222 { },
2223 };
2224
2225 void __init acpi_ec_init(void)
2226 {
2227 int result;
2228
2229 result = acpi_ec_init_workqueues();
2230 if (result)
2231 return;
2232
2233 /*
2234 * Disable EC wakeup on following systems to prevent periodic
2235 * wakeup from EC GPE.
2236 */
2237 if (dmi_check_system(acpi_ec_no_wakeup)) {
2238 ec_no_wakeup = true;
2239 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2240 }
2241
2242 /* Driver must be registered after acpi_ec_init_workqueues(). */
2243 acpi_bus_register_driver(&acpi_ec_driver);
2244
2245 acpi_ec_ecdt_start();
2246 }
2247
2248 /* EC driver currently not unloadable */
2249 #if 0
2250 static void __exit acpi_ec_exit(void)
2251 {
2252
2253 acpi_bus_unregister_driver(&acpi_ec_driver);
2254 acpi_ec_destroy_workqueues();
2255 }
2256 #endif /* 0 */
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