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_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 */
109 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
110 module_param(ec_delay, uint, 0644);
111 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
112
113 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
114 module_param(ec_max_queries, uint, 0644);
115 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
116
117 static bool ec_busy_polling __read_mostly;
118 module_param(ec_busy_polling, bool, 0644);
119 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
120
121 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
122 module_param(ec_polling_guard, uint, 0644);
123 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
124
125 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
126
127 /*
128 * If the number of false interrupts per one transaction exceeds
129 * this threshold, will think there is a GPE storm happened and
130 * will disable the GPE for normal transaction.
131 */
132 static unsigned int ec_storm_threshold __read_mostly = 8;
133 module_param(ec_storm_threshold, uint, 0644);
134 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
135
136 static bool ec_freeze_events __read_mostly = false;
137 module_param(ec_freeze_events, bool, 0644);
138 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
139
140 static bool ec_no_wakeup __read_mostly;
141 module_param(ec_no_wakeup, bool, 0644);
142 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
143
144 struct acpi_ec_query_handler {
145 struct list_head node;
146 acpi_ec_query_func func;
147 acpi_handle handle;
148 void *data;
149 u8 query_bit;
150 struct kref kref;
151 };
152
153 struct transaction {
154 const u8 *wdata;
155 u8 *rdata;
156 unsigned short irq_count;
157 u8 command;
158 u8 wi;
159 u8 ri;
160 u8 wlen;
161 u8 rlen;
162 u8 flags;
163 };
164
165 struct acpi_ec_query {
166 struct transaction transaction;
167 struct work_struct work;
168 struct acpi_ec_query_handler *handler;
169 struct acpi_ec *ec;
170 };
171
172 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
173 static void advance_transaction(struct acpi_ec *ec);
174 static void acpi_ec_event_handler(struct work_struct *work);
175 static void acpi_ec_event_processor(struct work_struct *work);
176
177 struct acpi_ec *first_ec;
178 EXPORT_SYMBOL(first_ec);
179
180 static struct acpi_ec *boot_ec;
181 static bool boot_ec_is_ecdt = false;
182 static struct workqueue_struct *ec_wq;
183 static struct workqueue_struct *ec_query_wq;
184
185 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
186 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
187 static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
188 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
189
190 /* --------------------------------------------------------------------------
191 * Logging/Debugging
192 * -------------------------------------------------------------------------- */
193
194 /*
195 * Splitters used by the developers to track the boundary of the EC
196 * handling processes.
197 */
198 #ifdef DEBUG
199 #define EC_DBG_SEP " "
200 #define EC_DBG_DRV "+++++"
201 #define EC_DBG_STM "====="
202 #define EC_DBG_REQ "*****"
203 #define EC_DBG_EVT "#####"
204 #else
205 #define EC_DBG_SEP ""
206 #define EC_DBG_DRV
207 #define EC_DBG_STM
208 #define EC_DBG_REQ
209 #define EC_DBG_EVT
210 #endif
211
212 #define ec_log_raw(fmt, ...) \
213 pr_info(fmt "\n", ##__VA_ARGS__)
214 #define ec_dbg_raw(fmt, ...) \
215 pr_debug(fmt "\n", ##__VA_ARGS__)
216 #define ec_log(filter, fmt, ...) \
217 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
218 #define ec_dbg(filter, fmt, ...) \
219 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
220
221 #define ec_log_drv(fmt, ...) \
222 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
223 #define ec_dbg_drv(fmt, ...) \
224 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
225 #define ec_dbg_stm(fmt, ...) \
226 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
227 #define ec_dbg_req(fmt, ...) \
228 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
229 #define ec_dbg_evt(fmt, ...) \
230 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
231 #define ec_dbg_ref(ec, fmt, ...) \
232 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
233
234 /* --------------------------------------------------------------------------
235 * Device Flags
236 * -------------------------------------------------------------------------- */
237
acpi_ec_started(struct acpi_ec * ec)238 static bool acpi_ec_started(struct acpi_ec *ec)
239 {
240 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
241 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
242 }
243
acpi_ec_event_enabled(struct acpi_ec * ec)244 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
245 {
246 /*
247 * There is an OSPM early stage logic. During the early stages
248 * (boot/resume), OSPMs shouldn't enable the event handling, only
249 * the EC transactions are allowed to be performed.
250 */
251 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
252 return false;
253 /*
254 * However, disabling the event handling is experimental for late
255 * stage (suspend), and is controlled by the boot parameter of
256 * "ec_freeze_events":
257 * 1. true: The EC event handling is disabled before entering
258 * the noirq stage.
259 * 2. false: The EC event handling is automatically disabled as
260 * soon as the EC driver is stopped.
261 */
262 if (ec_freeze_events)
263 return acpi_ec_started(ec);
264 else
265 return test_bit(EC_FLAGS_STARTED, &ec->flags);
266 }
267
acpi_ec_flushed(struct acpi_ec * ec)268 static bool acpi_ec_flushed(struct acpi_ec *ec)
269 {
270 return ec->reference_count == 1;
271 }
272
273 /* --------------------------------------------------------------------------
274 * EC Registers
275 * -------------------------------------------------------------------------- */
276
acpi_ec_read_status(struct acpi_ec * ec)277 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
278 {
279 u8 x = inb(ec->command_addr);
280
281 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
282 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
283 x,
284 !!(x & ACPI_EC_FLAG_SCI),
285 !!(x & ACPI_EC_FLAG_BURST),
286 !!(x & ACPI_EC_FLAG_CMD),
287 !!(x & ACPI_EC_FLAG_IBF),
288 !!(x & ACPI_EC_FLAG_OBF));
289 return x;
290 }
291
acpi_ec_read_data(struct acpi_ec * ec)292 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
293 {
294 u8 x = inb(ec->data_addr);
295
296 ec->timestamp = jiffies;
297 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
298 return x;
299 }
300
acpi_ec_write_cmd(struct acpi_ec * ec,u8 command)301 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
302 {
303 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
304 outb(command, ec->command_addr);
305 ec->timestamp = jiffies;
306 }
307
acpi_ec_write_data(struct acpi_ec * ec,u8 data)308 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
309 {
310 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
311 outb(data, ec->data_addr);
312 ec->timestamp = jiffies;
313 }
314
315 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
acpi_ec_cmd_string(u8 cmd)316 static const char *acpi_ec_cmd_string(u8 cmd)
317 {
318 switch (cmd) {
319 case 0x80:
320 return "RD_EC";
321 case 0x81:
322 return "WR_EC";
323 case 0x82:
324 return "BE_EC";
325 case 0x83:
326 return "BD_EC";
327 case 0x84:
328 return "QR_EC";
329 }
330 return "UNKNOWN";
331 }
332 #else
333 #define acpi_ec_cmd_string(cmd) "UNDEF"
334 #endif
335
336 /* --------------------------------------------------------------------------
337 * GPE Registers
338 * -------------------------------------------------------------------------- */
339
acpi_ec_is_gpe_raised(struct acpi_ec * ec)340 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
341 {
342 acpi_event_status gpe_status = 0;
343
344 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
345 return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
346 }
347
acpi_ec_enable_gpe(struct acpi_ec * ec,bool open)348 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
349 {
350 if (open)
351 acpi_enable_gpe(NULL, ec->gpe);
352 else {
353 BUG_ON(ec->reference_count < 1);
354 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
355 }
356 if (acpi_ec_is_gpe_raised(ec)) {
357 /*
358 * On some platforms, EN=1 writes cannot trigger GPE. So
359 * software need to manually trigger a pseudo GPE event on
360 * EN=1 writes.
361 */
362 ec_dbg_raw("Polling quirk");
363 advance_transaction(ec);
364 }
365 }
366
acpi_ec_disable_gpe(struct acpi_ec * ec,bool close)367 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
368 {
369 if (close)
370 acpi_disable_gpe(NULL, ec->gpe);
371 else {
372 BUG_ON(ec->reference_count < 1);
373 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
374 }
375 }
376
acpi_ec_clear_gpe(struct acpi_ec * ec)377 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
378 {
379 /*
380 * GPE STS is a W1C register, which means:
381 * 1. Software can clear it without worrying about clearing other
382 * GPEs' STS bits when the hardware sets them in parallel.
383 * 2. As long as software can ensure only clearing it when it is
384 * set, hardware won't set it in parallel.
385 * So software can clear GPE in any contexts.
386 * Warning: do not move the check into advance_transaction() as the
387 * EC commands will be sent without GPE raised.
388 */
389 if (!acpi_ec_is_gpe_raised(ec))
390 return;
391 acpi_clear_gpe(NULL, ec->gpe);
392 }
393
394 /* --------------------------------------------------------------------------
395 * Transaction Management
396 * -------------------------------------------------------------------------- */
397
acpi_ec_submit_request(struct acpi_ec * ec)398 static void acpi_ec_submit_request(struct acpi_ec *ec)
399 {
400 ec->reference_count++;
401 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
402 ec->gpe >= 0 && ec->reference_count == 1)
403 acpi_ec_enable_gpe(ec, true);
404 }
405
acpi_ec_complete_request(struct acpi_ec * ec)406 static void acpi_ec_complete_request(struct acpi_ec *ec)
407 {
408 bool flushed = false;
409
410 ec->reference_count--;
411 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
412 ec->gpe >= 0 && ec->reference_count == 0)
413 acpi_ec_disable_gpe(ec, true);
414 flushed = acpi_ec_flushed(ec);
415 if (flushed)
416 wake_up(&ec->wait);
417 }
418
acpi_ec_mask_events(struct acpi_ec * ec)419 static void acpi_ec_mask_events(struct acpi_ec *ec)
420 {
421 if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
422 if (ec->gpe >= 0)
423 acpi_ec_disable_gpe(ec, false);
424 else
425 disable_irq_nosync(ec->irq);
426
427 ec_dbg_drv("Polling enabled");
428 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
429 }
430 }
431
acpi_ec_unmask_events(struct acpi_ec * ec)432 static void acpi_ec_unmask_events(struct acpi_ec *ec)
433 {
434 if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
435 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
436 if (ec->gpe >= 0)
437 acpi_ec_enable_gpe(ec, false);
438 else
439 enable_irq(ec->irq);
440
441 ec_dbg_drv("Polling disabled");
442 }
443 }
444
445 /*
446 * acpi_ec_submit_flushable_request() - Increase the reference count unless
447 * the flush operation is not in
448 * progress
449 * @ec: the EC device
450 *
451 * This function must be used before taking a new action that should hold
452 * the reference count. If this function returns false, then the action
453 * must be discarded or it will prevent the flush operation from being
454 * completed.
455 */
acpi_ec_submit_flushable_request(struct acpi_ec * ec)456 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
457 {
458 if (!acpi_ec_started(ec))
459 return false;
460 acpi_ec_submit_request(ec);
461 return true;
462 }
463
acpi_ec_submit_query(struct acpi_ec * ec)464 static void acpi_ec_submit_query(struct acpi_ec *ec)
465 {
466 acpi_ec_mask_events(ec);
467 if (!acpi_ec_event_enabled(ec))
468 return;
469 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
470 ec_dbg_evt("Command(%s) submitted/blocked",
471 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
472 ec->nr_pending_queries++;
473 ec->events_in_progress++;
474 queue_work(ec_wq, &ec->work);
475 }
476 }
477
acpi_ec_complete_query(struct acpi_ec * ec)478 static void acpi_ec_complete_query(struct acpi_ec *ec)
479 {
480 if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
481 ec_dbg_evt("Command(%s) unblocked",
482 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
483 acpi_ec_unmask_events(ec);
484 }
485
__acpi_ec_enable_event(struct acpi_ec * ec)486 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
487 {
488 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
489 ec_log_drv("event unblocked");
490 /*
491 * Unconditionally invoke this once after enabling the event
492 * handling mechanism to detect the pending events.
493 */
494 advance_transaction(ec);
495 }
496
__acpi_ec_disable_event(struct acpi_ec * ec)497 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
498 {
499 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
500 ec_log_drv("event blocked");
501 }
502
503 /*
504 * Process _Q events that might have accumulated in the EC.
505 * Run with locked ec mutex.
506 */
acpi_ec_clear(struct acpi_ec * ec)507 static void acpi_ec_clear(struct acpi_ec *ec)
508 {
509 int i, status;
510 u8 value = 0;
511
512 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
513 status = acpi_ec_query(ec, &value);
514 if (status || !value)
515 break;
516 }
517 if (unlikely(i == ACPI_EC_CLEAR_MAX))
518 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
519 else
520 pr_info("%d stale EC events cleared\n", i);
521 }
522
acpi_ec_enable_event(struct acpi_ec * ec)523 static void acpi_ec_enable_event(struct acpi_ec *ec)
524 {
525 unsigned long flags;
526
527 spin_lock_irqsave(&ec->lock, flags);
528 if (acpi_ec_started(ec))
529 __acpi_ec_enable_event(ec);
530 spin_unlock_irqrestore(&ec->lock, flags);
531
532 /* Drain additional events if hardware requires that */
533 if (EC_FLAGS_CLEAR_ON_RESUME)
534 acpi_ec_clear(ec);
535 }
536
537 #ifdef CONFIG_PM_SLEEP
__acpi_ec_flush_work(void)538 static void __acpi_ec_flush_work(void)
539 {
540 flush_workqueue(ec_wq); /* flush ec->work */
541 flush_workqueue(ec_query_wq); /* flush queries */
542 }
543
acpi_ec_disable_event(struct acpi_ec * ec)544 static void acpi_ec_disable_event(struct acpi_ec *ec)
545 {
546 unsigned long flags;
547
548 spin_lock_irqsave(&ec->lock, flags);
549 __acpi_ec_disable_event(ec);
550 spin_unlock_irqrestore(&ec->lock, flags);
551
552 /*
553 * When ec_freeze_events is true, we need to flush events in
554 * the proper position before entering the noirq stage.
555 */
556 __acpi_ec_flush_work();
557 }
558
acpi_ec_flush_work(void)559 void acpi_ec_flush_work(void)
560 {
561 /* Without ec_wq there is nothing to flush. */
562 if (!ec_wq)
563 return;
564
565 __acpi_ec_flush_work();
566 }
567 #endif /* CONFIG_PM_SLEEP */
568
acpi_ec_guard_event(struct acpi_ec * ec)569 static 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
ec_transaction_polled(struct acpi_ec * ec)598 static 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
ec_transaction_completed(struct acpi_ec * ec)610 static 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
ec_transaction_transition(struct acpi_ec * ec,unsigned long flag)622 static 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
advance_transaction(struct acpi_ec * ec)638 static 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 if (ec->gpe >= 0)
652 acpi_ec_clear_gpe(ec);
653
654 status = acpi_ec_read_status(ec);
655 t = ec->curr;
656 /*
657 * Another IRQ or a guarded polling mode advancement is detected,
658 * the next QR_EC submission is then allowed.
659 */
660 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
661 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
662 (!ec->nr_pending_queries ||
663 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
664 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
665 acpi_ec_complete_query(ec);
666 }
667 }
668 if (!t)
669 goto err;
670 if (t->flags & ACPI_EC_COMMAND_POLL) {
671 if (t->wlen > t->wi) {
672 if ((status & ACPI_EC_FLAG_IBF) == 0)
673 acpi_ec_write_data(ec, t->wdata[t->wi++]);
674 else
675 goto err;
676 } else if (t->rlen > t->ri) {
677 if ((status & ACPI_EC_FLAG_OBF) == 1) {
678 t->rdata[t->ri++] = acpi_ec_read_data(ec);
679 if (t->rlen == t->ri) {
680 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
681 if (t->command == ACPI_EC_COMMAND_QUERY)
682 ec_dbg_evt("Command(%s) completed by hardware",
683 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
684 wakeup = true;
685 }
686 } else
687 goto err;
688 } else if (t->wlen == t->wi &&
689 (status & ACPI_EC_FLAG_IBF) == 0) {
690 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
691 wakeup = true;
692 }
693 goto out;
694 } else if (!(status & ACPI_EC_FLAG_IBF)) {
695 acpi_ec_write_cmd(ec, t->command);
696 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
697 goto out;
698 }
699 err:
700 /*
701 * If SCI bit is set, then don't think it's a false IRQ
702 * otherwise will take a not handled IRQ as a false one.
703 */
704 if (!(status & ACPI_EC_FLAG_SCI)) {
705 if (in_interrupt() && t) {
706 if (t->irq_count < ec_storm_threshold)
707 ++t->irq_count;
708 /* Allow triggering on 0 threshold */
709 if (t->irq_count == ec_storm_threshold)
710 acpi_ec_mask_events(ec);
711 }
712 }
713 out:
714 if (status & ACPI_EC_FLAG_SCI)
715 acpi_ec_submit_query(ec);
716 if (wakeup && in_interrupt())
717 wake_up(&ec->wait);
718 }
719
start_transaction(struct acpi_ec * ec)720 static void start_transaction(struct acpi_ec *ec)
721 {
722 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
723 ec->curr->flags = 0;
724 }
725
ec_guard(struct acpi_ec * ec)726 static int ec_guard(struct acpi_ec *ec)
727 {
728 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
729 unsigned long timeout = ec->timestamp + guard;
730
731 /* Ensure guarding period before polling EC status */
732 do {
733 if (ec->busy_polling) {
734 /* Perform busy polling */
735 if (ec_transaction_completed(ec))
736 return 0;
737 udelay(jiffies_to_usecs(guard));
738 } else {
739 /*
740 * Perform wait polling
741 * 1. Wait the transaction to be completed by the
742 * GPE handler after the transaction enters
743 * ACPI_EC_COMMAND_POLL state.
744 * 2. A special guarding logic is also required
745 * for event clearing mode "event" before the
746 * transaction enters ACPI_EC_COMMAND_POLL
747 * state.
748 */
749 if (!ec_transaction_polled(ec) &&
750 !acpi_ec_guard_event(ec))
751 break;
752 if (wait_event_timeout(ec->wait,
753 ec_transaction_completed(ec),
754 guard))
755 return 0;
756 }
757 } while (time_before(jiffies, timeout));
758 return -ETIME;
759 }
760
ec_poll(struct acpi_ec * ec)761 static int ec_poll(struct acpi_ec *ec)
762 {
763 unsigned long flags;
764 int repeat = 5; /* number of command restarts */
765
766 while (repeat--) {
767 unsigned long delay = jiffies +
768 msecs_to_jiffies(ec_delay);
769 do {
770 if (!ec_guard(ec))
771 return 0;
772 spin_lock_irqsave(&ec->lock, flags);
773 advance_transaction(ec);
774 spin_unlock_irqrestore(&ec->lock, flags);
775 } while (time_before(jiffies, delay));
776 pr_debug("controller reset, restart transaction\n");
777 spin_lock_irqsave(&ec->lock, flags);
778 start_transaction(ec);
779 spin_unlock_irqrestore(&ec->lock, flags);
780 }
781 return -ETIME;
782 }
783
acpi_ec_transaction_unlocked(struct acpi_ec * ec,struct transaction * t)784 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
785 struct transaction *t)
786 {
787 unsigned long tmp;
788 int ret = 0;
789
790 /* start transaction */
791 spin_lock_irqsave(&ec->lock, tmp);
792 /* Enable GPE for command processing (IBF=0/OBF=1) */
793 if (!acpi_ec_submit_flushable_request(ec)) {
794 ret = -EINVAL;
795 goto unlock;
796 }
797 ec_dbg_ref(ec, "Increase command");
798 /* following two actions should be kept atomic */
799 ec->curr = t;
800 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
801 start_transaction(ec);
802 spin_unlock_irqrestore(&ec->lock, tmp);
803
804 ret = ec_poll(ec);
805
806 spin_lock_irqsave(&ec->lock, tmp);
807 if (t->irq_count == ec_storm_threshold)
808 acpi_ec_unmask_events(ec);
809 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
810 ec->curr = NULL;
811 /* Disable GPE for command processing (IBF=0/OBF=1) */
812 acpi_ec_complete_request(ec);
813 ec_dbg_ref(ec, "Decrease command");
814 unlock:
815 spin_unlock_irqrestore(&ec->lock, tmp);
816 return ret;
817 }
818
acpi_ec_transaction(struct acpi_ec * ec,struct transaction * t)819 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
820 {
821 int status;
822 u32 glk;
823
824 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
825 return -EINVAL;
826 if (t->rdata)
827 memset(t->rdata, 0, t->rlen);
828
829 mutex_lock(&ec->mutex);
830 if (ec->global_lock) {
831 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
832 if (ACPI_FAILURE(status)) {
833 status = -ENODEV;
834 goto unlock;
835 }
836 }
837
838 status = acpi_ec_transaction_unlocked(ec, t);
839
840 if (ec->global_lock)
841 acpi_release_global_lock(glk);
842 unlock:
843 mutex_unlock(&ec->mutex);
844 return status;
845 }
846
acpi_ec_burst_enable(struct acpi_ec * ec)847 static int acpi_ec_burst_enable(struct acpi_ec *ec)
848 {
849 u8 d;
850 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
851 .wdata = NULL, .rdata = &d,
852 .wlen = 0, .rlen = 1};
853
854 return acpi_ec_transaction(ec, &t);
855 }
856
acpi_ec_burst_disable(struct acpi_ec * ec)857 static int acpi_ec_burst_disable(struct acpi_ec *ec)
858 {
859 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
860 .wdata = NULL, .rdata = NULL,
861 .wlen = 0, .rlen = 0};
862
863 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
864 acpi_ec_transaction(ec, &t) : 0;
865 }
866
acpi_ec_read(struct acpi_ec * ec,u8 address,u8 * data)867 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
868 {
869 int result;
870 u8 d;
871 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
872 .wdata = &address, .rdata = &d,
873 .wlen = 1, .rlen = 1};
874
875 result = acpi_ec_transaction(ec, &t);
876 *data = d;
877 return result;
878 }
879
acpi_ec_write(struct acpi_ec * ec,u8 address,u8 data)880 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
881 {
882 u8 wdata[2] = { address, data };
883 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
884 .wdata = wdata, .rdata = NULL,
885 .wlen = 2, .rlen = 0};
886
887 return acpi_ec_transaction(ec, &t);
888 }
889
ec_read(u8 addr,u8 * val)890 int ec_read(u8 addr, u8 *val)
891 {
892 int err;
893 u8 temp_data;
894
895 if (!first_ec)
896 return -ENODEV;
897
898 err = acpi_ec_read(first_ec, addr, &temp_data);
899
900 if (!err) {
901 *val = temp_data;
902 return 0;
903 }
904 return err;
905 }
906 EXPORT_SYMBOL(ec_read);
907
ec_write(u8 addr,u8 val)908 int ec_write(u8 addr, u8 val)
909 {
910 int err;
911
912 if (!first_ec)
913 return -ENODEV;
914
915 err = acpi_ec_write(first_ec, addr, val);
916
917 return err;
918 }
919 EXPORT_SYMBOL(ec_write);
920
ec_transaction(u8 command,const u8 * wdata,unsigned wdata_len,u8 * rdata,unsigned rdata_len)921 int ec_transaction(u8 command,
922 const u8 *wdata, unsigned wdata_len,
923 u8 *rdata, unsigned rdata_len)
924 {
925 struct transaction t = {.command = command,
926 .wdata = wdata, .rdata = rdata,
927 .wlen = wdata_len, .rlen = rdata_len};
928
929 if (!first_ec)
930 return -ENODEV;
931
932 return acpi_ec_transaction(first_ec, &t);
933 }
934 EXPORT_SYMBOL(ec_transaction);
935
936 /* Get the handle to the EC device */
ec_get_handle(void)937 acpi_handle ec_get_handle(void)
938 {
939 if (!first_ec)
940 return NULL;
941 return first_ec->handle;
942 }
943 EXPORT_SYMBOL(ec_get_handle);
944
acpi_ec_start(struct acpi_ec * ec,bool resuming)945 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
946 {
947 unsigned long flags;
948
949 spin_lock_irqsave(&ec->lock, flags);
950 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
951 ec_dbg_drv("Starting EC");
952 /* Enable GPE for event processing (SCI_EVT=1) */
953 if (!resuming) {
954 acpi_ec_submit_request(ec);
955 ec_dbg_ref(ec, "Increase driver");
956 }
957 ec_log_drv("EC started");
958 }
959 spin_unlock_irqrestore(&ec->lock, flags);
960 }
961
acpi_ec_stopped(struct acpi_ec * ec)962 static bool acpi_ec_stopped(struct acpi_ec *ec)
963 {
964 unsigned long flags;
965 bool flushed;
966
967 spin_lock_irqsave(&ec->lock, flags);
968 flushed = acpi_ec_flushed(ec);
969 spin_unlock_irqrestore(&ec->lock, flags);
970 return flushed;
971 }
972
acpi_ec_stop(struct acpi_ec * ec,bool suspending)973 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
974 {
975 unsigned long flags;
976
977 spin_lock_irqsave(&ec->lock, flags);
978 if (acpi_ec_started(ec)) {
979 ec_dbg_drv("Stopping EC");
980 set_bit(EC_FLAGS_STOPPED, &ec->flags);
981 spin_unlock_irqrestore(&ec->lock, flags);
982 wait_event(ec->wait, acpi_ec_stopped(ec));
983 spin_lock_irqsave(&ec->lock, flags);
984 /* Disable GPE for event processing (SCI_EVT=1) */
985 if (!suspending) {
986 acpi_ec_complete_request(ec);
987 ec_dbg_ref(ec, "Decrease driver");
988 } else if (!ec_freeze_events)
989 __acpi_ec_disable_event(ec);
990 clear_bit(EC_FLAGS_STARTED, &ec->flags);
991 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
992 ec_log_drv("EC stopped");
993 }
994 spin_unlock_irqrestore(&ec->lock, flags);
995 }
996
acpi_ec_enter_noirq(struct acpi_ec * ec)997 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
998 {
999 unsigned long flags;
1000
1001 spin_lock_irqsave(&ec->lock, flags);
1002 ec->busy_polling = true;
1003 ec->polling_guard = 0;
1004 ec_log_drv("interrupt blocked");
1005 spin_unlock_irqrestore(&ec->lock, flags);
1006 }
1007
acpi_ec_leave_noirq(struct acpi_ec * ec)1008 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1009 {
1010 unsigned long flags;
1011
1012 spin_lock_irqsave(&ec->lock, flags);
1013 ec->busy_polling = ec_busy_polling;
1014 ec->polling_guard = ec_polling_guard;
1015 ec_log_drv("interrupt unblocked");
1016 spin_unlock_irqrestore(&ec->lock, flags);
1017 }
1018
acpi_ec_block_transactions(void)1019 void acpi_ec_block_transactions(void)
1020 {
1021 struct acpi_ec *ec = first_ec;
1022
1023 if (!ec)
1024 return;
1025
1026 mutex_lock(&ec->mutex);
1027 /* Prevent transactions from being carried out */
1028 acpi_ec_stop(ec, true);
1029 mutex_unlock(&ec->mutex);
1030 }
1031
acpi_ec_unblock_transactions(void)1032 void acpi_ec_unblock_transactions(void)
1033 {
1034 /*
1035 * Allow transactions to happen again (this function is called from
1036 * atomic context during wakeup, so we don't need to acquire the mutex).
1037 */
1038 if (first_ec)
1039 acpi_ec_start(first_ec, true);
1040 }
1041
1042 /* --------------------------------------------------------------------------
1043 Event Management
1044 -------------------------------------------------------------------------- */
1045 static struct acpi_ec_query_handler *
acpi_ec_get_query_handler_by_value(struct acpi_ec * ec,u8 value)1046 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1047 {
1048 struct acpi_ec_query_handler *handler;
1049
1050 mutex_lock(&ec->mutex);
1051 list_for_each_entry(handler, &ec->list, node) {
1052 if (value == handler->query_bit) {
1053 kref_get(&handler->kref);
1054 mutex_unlock(&ec->mutex);
1055 return handler;
1056 }
1057 }
1058 mutex_unlock(&ec->mutex);
1059 return NULL;
1060 }
1061
acpi_ec_query_handler_release(struct kref * kref)1062 static void acpi_ec_query_handler_release(struct kref *kref)
1063 {
1064 struct acpi_ec_query_handler *handler =
1065 container_of(kref, struct acpi_ec_query_handler, kref);
1066
1067 kfree(handler);
1068 }
1069
acpi_ec_put_query_handler(struct acpi_ec_query_handler * handler)1070 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1071 {
1072 kref_put(&handler->kref, acpi_ec_query_handler_release);
1073 }
1074
acpi_ec_add_query_handler(struct acpi_ec * ec,u8 query_bit,acpi_handle handle,acpi_ec_query_func func,void * data)1075 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1076 acpi_handle handle, acpi_ec_query_func func,
1077 void *data)
1078 {
1079 struct acpi_ec_query_handler *handler =
1080 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1081
1082 if (!handler)
1083 return -ENOMEM;
1084
1085 handler->query_bit = query_bit;
1086 handler->handle = handle;
1087 handler->func = func;
1088 handler->data = data;
1089 mutex_lock(&ec->mutex);
1090 kref_init(&handler->kref);
1091 list_add(&handler->node, &ec->list);
1092 mutex_unlock(&ec->mutex);
1093 return 0;
1094 }
1095 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1096
acpi_ec_remove_query_handlers(struct acpi_ec * ec,bool remove_all,u8 query_bit)1097 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1098 bool remove_all, u8 query_bit)
1099 {
1100 struct acpi_ec_query_handler *handler, *tmp;
1101 LIST_HEAD(free_list);
1102
1103 mutex_lock(&ec->mutex);
1104 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1105 if (remove_all || query_bit == handler->query_bit) {
1106 list_del_init(&handler->node);
1107 list_add(&handler->node, &free_list);
1108 }
1109 }
1110 mutex_unlock(&ec->mutex);
1111 list_for_each_entry_safe(handler, tmp, &free_list, node)
1112 acpi_ec_put_query_handler(handler);
1113 }
1114
acpi_ec_remove_query_handler(struct acpi_ec * ec,u8 query_bit)1115 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1116 {
1117 acpi_ec_remove_query_handlers(ec, false, query_bit);
1118 }
1119 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1120
acpi_ec_create_query(struct acpi_ec * ec,u8 * pval)1121 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1122 {
1123 struct acpi_ec_query *q;
1124 struct transaction *t;
1125
1126 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1127 if (!q)
1128 return NULL;
1129
1130 INIT_WORK(&q->work, acpi_ec_event_processor);
1131 t = &q->transaction;
1132 t->command = ACPI_EC_COMMAND_QUERY;
1133 t->rdata = pval;
1134 t->rlen = 1;
1135 q->ec = ec;
1136 return q;
1137 }
1138
acpi_ec_delete_query(struct acpi_ec_query * q)1139 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1140 {
1141 if (q) {
1142 if (q->handler)
1143 acpi_ec_put_query_handler(q->handler);
1144 kfree(q);
1145 }
1146 }
1147
acpi_ec_event_processor(struct work_struct * work)1148 static void acpi_ec_event_processor(struct work_struct *work)
1149 {
1150 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1151 struct acpi_ec_query_handler *handler = q->handler;
1152 struct acpi_ec *ec = q->ec;
1153
1154 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1155
1156 if (handler->func)
1157 handler->func(handler->data);
1158 else if (handler->handle)
1159 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1160
1161 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1162
1163 spin_lock_irq(&ec->lock);
1164 ec->queries_in_progress--;
1165 spin_unlock_irq(&ec->lock);
1166
1167 acpi_ec_delete_query(q);
1168 }
1169
acpi_ec_query(struct acpi_ec * ec,u8 * data)1170 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1171 {
1172 u8 value = 0;
1173 int result;
1174 struct acpi_ec_query *q;
1175
1176 q = acpi_ec_create_query(ec, &value);
1177 if (!q)
1178 return -ENOMEM;
1179
1180 /*
1181 * Query the EC to find out which _Qxx method we need to evaluate.
1182 * Note that successful completion of the query causes the ACPI_EC_SCI
1183 * bit to be cleared (and thus clearing the interrupt source).
1184 */
1185 result = acpi_ec_transaction(ec, &q->transaction);
1186 if (!value)
1187 result = -ENODATA;
1188 if (result)
1189 goto err_exit;
1190
1191 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1192 if (!q->handler) {
1193 result = -ENODATA;
1194 goto err_exit;
1195 }
1196
1197 /*
1198 * It is reported that _Qxx are evaluated in a parallel way on Windows:
1199 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1200 *
1201 * Put this log entry before queue_work() to make it appear in the log
1202 * before any other messages emitted during workqueue handling.
1203 */
1204 ec_dbg_evt("Query(0x%02x) scheduled", value);
1205
1206 spin_lock_irq(&ec->lock);
1207
1208 ec->queries_in_progress++;
1209 queue_work(ec_query_wq, &q->work);
1210
1211 spin_unlock_irq(&ec->lock);
1212
1213 err_exit:
1214 if (result)
1215 acpi_ec_delete_query(q);
1216 if (data)
1217 *data = value;
1218 return result;
1219 }
1220
acpi_ec_check_event(struct acpi_ec * ec)1221 static void acpi_ec_check_event(struct acpi_ec *ec)
1222 {
1223 unsigned long flags;
1224
1225 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1226 if (ec_guard(ec)) {
1227 spin_lock_irqsave(&ec->lock, flags);
1228 /*
1229 * Take care of the SCI_EVT unless no one else is
1230 * taking care of it.
1231 */
1232 if (!ec->curr)
1233 advance_transaction(ec);
1234 spin_unlock_irqrestore(&ec->lock, flags);
1235 }
1236 }
1237 }
1238
acpi_ec_event_handler(struct work_struct * work)1239 static void acpi_ec_event_handler(struct work_struct *work)
1240 {
1241 unsigned long flags;
1242 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1243
1244 ec_dbg_evt("Event started");
1245
1246 spin_lock_irqsave(&ec->lock, flags);
1247 while (ec->nr_pending_queries) {
1248 spin_unlock_irqrestore(&ec->lock, flags);
1249 (void)acpi_ec_query(ec, NULL);
1250 spin_lock_irqsave(&ec->lock, flags);
1251 ec->nr_pending_queries--;
1252 /*
1253 * Before exit, make sure that this work item can be
1254 * scheduled again. There might be QR_EC failures, leaving
1255 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1256 * item from being scheduled again.
1257 */
1258 if (!ec->nr_pending_queries) {
1259 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1260 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1261 acpi_ec_complete_query(ec);
1262 }
1263 }
1264 spin_unlock_irqrestore(&ec->lock, flags);
1265
1266 ec_dbg_evt("Event stopped");
1267
1268 acpi_ec_check_event(ec);
1269
1270 spin_lock_irqsave(&ec->lock, flags);
1271 ec->events_in_progress--;
1272 spin_unlock_irqrestore(&ec->lock, flags);
1273 }
1274
acpi_ec_handle_interrupt(struct acpi_ec * ec)1275 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1276 {
1277 unsigned long flags;
1278
1279 spin_lock_irqsave(&ec->lock, flags);
1280 advance_transaction(ec);
1281 spin_unlock_irqrestore(&ec->lock, flags);
1282 }
1283
acpi_ec_gpe_handler(acpi_handle gpe_device,u32 gpe_number,void * data)1284 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1285 u32 gpe_number, void *data)
1286 {
1287 acpi_ec_handle_interrupt(data);
1288 return ACPI_INTERRUPT_HANDLED;
1289 }
1290
acpi_ec_irq_handler(int irq,void * data)1291 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1292 {
1293 acpi_ec_handle_interrupt(data);
1294 return IRQ_HANDLED;
1295 }
1296
1297 /* --------------------------------------------------------------------------
1298 * Address Space Management
1299 * -------------------------------------------------------------------------- */
1300
1301 static acpi_status
acpi_ec_space_handler(u32 function,acpi_physical_address address,u32 bits,u64 * value64,void * handler_context,void * region_context)1302 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1303 u32 bits, u64 *value64,
1304 void *handler_context, void *region_context)
1305 {
1306 struct acpi_ec *ec = handler_context;
1307 int result = 0, i, bytes = bits / 8;
1308 u8 *value = (u8 *)value64;
1309
1310 if ((address > 0xFF) || !value || !handler_context)
1311 return AE_BAD_PARAMETER;
1312
1313 if (function != ACPI_READ && function != ACPI_WRITE)
1314 return AE_BAD_PARAMETER;
1315
1316 if (ec->busy_polling || bits > 8)
1317 acpi_ec_burst_enable(ec);
1318
1319 for (i = 0; i < bytes; ++i, ++address, ++value)
1320 result = (function == ACPI_READ) ?
1321 acpi_ec_read(ec, address, value) :
1322 acpi_ec_write(ec, address, *value);
1323
1324 if (ec->busy_polling || bits > 8)
1325 acpi_ec_burst_disable(ec);
1326
1327 switch (result) {
1328 case -EINVAL:
1329 return AE_BAD_PARAMETER;
1330 case -ENODEV:
1331 return AE_NOT_FOUND;
1332 case -ETIME:
1333 return AE_TIME;
1334 default:
1335 return AE_OK;
1336 }
1337 }
1338
1339 /* --------------------------------------------------------------------------
1340 * Driver Interface
1341 * -------------------------------------------------------------------------- */
1342
1343 static acpi_status
1344 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1345
acpi_ec_free(struct acpi_ec * ec)1346 static void acpi_ec_free(struct acpi_ec *ec)
1347 {
1348 if (first_ec == ec)
1349 first_ec = NULL;
1350 if (boot_ec == ec)
1351 boot_ec = NULL;
1352 kfree(ec);
1353 }
1354
acpi_ec_alloc(void)1355 static struct acpi_ec *acpi_ec_alloc(void)
1356 {
1357 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1358
1359 if (!ec)
1360 return NULL;
1361 mutex_init(&ec->mutex);
1362 init_waitqueue_head(&ec->wait);
1363 INIT_LIST_HEAD(&ec->list);
1364 spin_lock_init(&ec->lock);
1365 INIT_WORK(&ec->work, acpi_ec_event_handler);
1366 ec->timestamp = jiffies;
1367 ec->busy_polling = true;
1368 ec->polling_guard = 0;
1369 ec->gpe = -1;
1370 ec->irq = -1;
1371 return ec;
1372 }
1373
1374 static acpi_status
acpi_ec_register_query_methods(acpi_handle handle,u32 level,void * context,void ** return_value)1375 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1376 void *context, void **return_value)
1377 {
1378 char node_name[5];
1379 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1380 struct acpi_ec *ec = context;
1381 int value = 0;
1382 acpi_status status;
1383
1384 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1385
1386 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1387 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1388 return AE_OK;
1389 }
1390
1391 static acpi_status
ec_parse_device(acpi_handle handle,u32 Level,void * context,void ** retval)1392 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1393 {
1394 acpi_status status;
1395 unsigned long long tmp = 0;
1396 struct acpi_ec *ec = context;
1397
1398 /* clear addr values, ec_parse_io_ports depend on it */
1399 ec->command_addr = ec->data_addr = 0;
1400
1401 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1402 ec_parse_io_ports, ec);
1403 if (ACPI_FAILURE(status))
1404 return status;
1405 if (ec->data_addr == 0 || ec->command_addr == 0)
1406 return AE_OK;
1407
1408 if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1409 /*
1410 * Always inherit the GPE number setting from the ECDT
1411 * EC.
1412 */
1413 ec->gpe = boot_ec->gpe;
1414 } else {
1415 /* Get GPE bit assignment (EC events). */
1416 /* TODO: Add support for _GPE returning a package */
1417 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1418 if (ACPI_SUCCESS(status))
1419 ec->gpe = tmp;
1420
1421 /*
1422 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1423 * platforms which use GpioInt instead of GPE.
1424 */
1425 }
1426 /* Use the global lock for all EC transactions? */
1427 tmp = 0;
1428 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1429 ec->global_lock = tmp;
1430 ec->handle = handle;
1431 return AE_CTRL_TERMINATE;
1432 }
1433
install_gpe_event_handler(struct acpi_ec * ec)1434 static bool install_gpe_event_handler(struct acpi_ec *ec)
1435 {
1436 acpi_status status;
1437
1438 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1439 ACPI_GPE_EDGE_TRIGGERED,
1440 &acpi_ec_gpe_handler, ec);
1441 if (ACPI_FAILURE(status))
1442 return false;
1443
1444 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1445 acpi_ec_enable_gpe(ec, true);
1446
1447 return true;
1448 }
1449
install_gpio_irq_event_handler(struct acpi_ec * ec)1450 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1451 {
1452 return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1453 "ACPI EC", ec) >= 0;
1454 }
1455
1456 /**
1457 * ec_install_handlers - Install service callbacks and register query methods.
1458 * @ec: Target EC.
1459 * @device: ACPI device object corresponding to @ec.
1460 *
1461 * Install a handler for the EC address space type unless it has been installed
1462 * already. If @device is not NULL, also look for EC query methods in the
1463 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1464 * handler for the EC, if possible.
1465 *
1466 * Return:
1467 * -ENODEV if the address space handler cannot be installed, which means
1468 * "unable to handle transactions",
1469 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1470 * or 0 (success) otherwise.
1471 */
ec_install_handlers(struct acpi_ec * ec,struct acpi_device * device)1472 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1473 {
1474 acpi_status status;
1475
1476 acpi_ec_start(ec, false);
1477
1478 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1479 acpi_ec_enter_noirq(ec);
1480 status = acpi_install_address_space_handler(ec->handle,
1481 ACPI_ADR_SPACE_EC,
1482 &acpi_ec_space_handler,
1483 NULL, ec);
1484 if (ACPI_FAILURE(status)) {
1485 acpi_ec_stop(ec, false);
1486 return -ENODEV;
1487 }
1488 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1489 }
1490
1491 if (!device)
1492 return 0;
1493
1494 if (ec->gpe < 0) {
1495 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1496 int irq = acpi_dev_gpio_irq_get(device, 0);
1497 /*
1498 * Bail out right away for deferred probing or complete the
1499 * initialization regardless of any other errors.
1500 */
1501 if (irq == -EPROBE_DEFER)
1502 return -EPROBE_DEFER;
1503 else if (irq >= 0)
1504 ec->irq = irq;
1505 }
1506
1507 if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1508 /* Find and register all query methods */
1509 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1510 acpi_ec_register_query_methods,
1511 NULL, ec, NULL);
1512 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1513 }
1514 if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1515 bool ready = false;
1516
1517 if (ec->gpe >= 0)
1518 ready = install_gpe_event_handler(ec);
1519 else if (ec->irq >= 0)
1520 ready = install_gpio_irq_event_handler(ec);
1521
1522 if (ready) {
1523 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1524 acpi_ec_leave_noirq(ec);
1525 }
1526 /*
1527 * Failures to install an event handler are not fatal, because
1528 * the EC can be polled for events.
1529 */
1530 }
1531 /* EC is fully operational, allow queries */
1532 acpi_ec_enable_event(ec);
1533
1534 return 0;
1535 }
1536
ec_remove_handlers(struct acpi_ec * ec)1537 static void ec_remove_handlers(struct acpi_ec *ec)
1538 {
1539 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1540 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1541 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1542 pr_err("failed to remove space handler\n");
1543 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1544 }
1545
1546 /*
1547 * Stops handling the EC transactions after removing the operation
1548 * region handler. This is required because _REG(DISCONNECT)
1549 * invoked during the removal can result in new EC transactions.
1550 *
1551 * Flushes the EC requests and thus disables the GPE before
1552 * removing the GPE handler. This is required by the current ACPICA
1553 * GPE core. ACPICA GPE core will automatically disable a GPE when
1554 * it is indicated but there is no way to handle it. So the drivers
1555 * must disable the GPEs prior to removing the GPE handlers.
1556 */
1557 acpi_ec_stop(ec, false);
1558
1559 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1560 if (ec->gpe >= 0 &&
1561 ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1562 &acpi_ec_gpe_handler)))
1563 pr_err("failed to remove gpe handler\n");
1564
1565 if (ec->irq >= 0)
1566 free_irq(ec->irq, ec);
1567
1568 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1569 }
1570 if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1571 acpi_ec_remove_query_handlers(ec, true, 0);
1572 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1573 }
1574 }
1575
acpi_ec_setup(struct acpi_ec * ec,struct acpi_device * device)1576 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1577 {
1578 int ret;
1579
1580 ret = ec_install_handlers(ec, device);
1581 if (ret)
1582 return ret;
1583
1584 /* First EC capable of handling transactions */
1585 if (!first_ec)
1586 first_ec = ec;
1587
1588 pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1589 ec->data_addr);
1590
1591 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1592 if (ec->gpe >= 0)
1593 pr_info("GPE=0x%x\n", ec->gpe);
1594 else
1595 pr_info("IRQ=%d\n", ec->irq);
1596 }
1597
1598 return ret;
1599 }
1600
acpi_ec_add(struct acpi_device * device)1601 static int acpi_ec_add(struct acpi_device *device)
1602 {
1603 struct acpi_ec *ec;
1604 int ret;
1605
1606 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1607 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1608
1609 if (boot_ec && (boot_ec->handle == device->handle ||
1610 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1611 /* Fast path: this device corresponds to the boot EC. */
1612 ec = boot_ec;
1613 } else {
1614 acpi_status status;
1615
1616 ec = acpi_ec_alloc();
1617 if (!ec)
1618 return -ENOMEM;
1619
1620 status = ec_parse_device(device->handle, 0, ec, NULL);
1621 if (status != AE_CTRL_TERMINATE) {
1622 ret = -EINVAL;
1623 goto err;
1624 }
1625
1626 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1627 ec->data_addr == boot_ec->data_addr &&
1628 !EC_FLAGS_TRUST_DSDT_GPE) {
1629 /*
1630 * Trust PNP0C09 namespace location rather than
1631 * ECDT ID. But trust ECDT GPE rather than _GPE
1632 * because of ASUS quirks, so do not change
1633 * boot_ec->gpe to ec->gpe.
1634 */
1635 boot_ec->handle = ec->handle;
1636 acpi_handle_debug(ec->handle, "duplicated.\n");
1637 acpi_ec_free(ec);
1638 ec = boot_ec;
1639 }
1640 }
1641
1642 ret = acpi_ec_setup(ec, device);
1643 if (ret)
1644 goto err;
1645
1646 if (ec == boot_ec)
1647 acpi_handle_info(boot_ec->handle,
1648 "Boot %s EC initialization complete\n",
1649 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1650
1651 acpi_handle_info(ec->handle,
1652 "EC: Used to handle transactions and events\n");
1653
1654 device->driver_data = ec;
1655
1656 ret = !!request_region(ec->data_addr, 1, "EC data");
1657 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1658 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1659 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1660
1661 /* Reprobe devices depending on the EC */
1662 acpi_walk_dep_device_list(ec->handle);
1663
1664 acpi_handle_debug(ec->handle, "enumerated.\n");
1665 return 0;
1666
1667 err:
1668 if (ec != boot_ec)
1669 acpi_ec_free(ec);
1670
1671 return ret;
1672 }
1673
acpi_ec_remove(struct acpi_device * device)1674 static int acpi_ec_remove(struct acpi_device *device)
1675 {
1676 struct acpi_ec *ec;
1677
1678 if (!device)
1679 return -EINVAL;
1680
1681 ec = acpi_driver_data(device);
1682 release_region(ec->data_addr, 1);
1683 release_region(ec->command_addr, 1);
1684 device->driver_data = NULL;
1685 if (ec != boot_ec) {
1686 ec_remove_handlers(ec);
1687 acpi_ec_free(ec);
1688 }
1689 return 0;
1690 }
1691
1692 static acpi_status
ec_parse_io_ports(struct acpi_resource * resource,void * context)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 */
acpi_ec_dsdt_probe(void)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);
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 */
acpi_ec_ecdt_start(void)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 */
ec_clear_on_resume(const struct dmi_system_id * id)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 */
ec_correct_ecdt(const struct dmi_system_id * id)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 */
ec_honor_dsdt_gpe(const struct dmi_system_id * id)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 /*
1864 * Some DSDTs contain wrong GPE setting.
1865 * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1866 * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1867 */
ec_honor_ecdt_gpe(const struct dmi_system_id * id)1868 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1869 {
1870 pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1871 EC_FLAGS_IGNORE_DSDT_GPE = 1;
1872 return 0;
1873 }
1874
1875 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1876 {
1877 ec_correct_ecdt, "MSI MS-171F", {
1878 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1879 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1880 {
1881 ec_honor_ecdt_gpe, "ASUS FX502VD", {
1882 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1883 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1884 {
1885 ec_honor_ecdt_gpe, "ASUS FX502VE", {
1886 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1887 DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1888 {
1889 ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1890 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1891 DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1892 {
1893 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BA", {
1894 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1895 DMI_MATCH(DMI_PRODUCT_NAME, "X505BA"),}, NULL},
1896 {
1897 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BP", {
1898 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1899 DMI_MATCH(DMI_PRODUCT_NAME, "X505BP"),}, NULL},
1900 {
1901 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BA", {
1902 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1903 DMI_MATCH(DMI_PRODUCT_NAME, "X542BA"),}, NULL},
1904 {
1905 ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BP", {
1906 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1907 DMI_MATCH(DMI_PRODUCT_NAME, "X542BP"),}, NULL},
1908 {
1909 ec_honor_ecdt_gpe, "ASUS X550VXK", {
1910 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1911 DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1912 {
1913 ec_honor_ecdt_gpe, "ASUS X580VD", {
1914 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1915 DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1916 {
1917 /* https://bugzilla.kernel.org/show_bug.cgi?id=209989 */
1918 ec_honor_dsdt_gpe, "HP Pavilion Gaming Laptop 15-cx0xxx", {
1919 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1920 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),}, NULL},
1921 {
1922 ec_clear_on_resume, "Samsung hardware", {
1923 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1924 {},
1925 };
1926
acpi_ec_ecdt_probe(void)1927 void __init acpi_ec_ecdt_probe(void)
1928 {
1929 struct acpi_table_ecdt *ecdt_ptr;
1930 struct acpi_ec *ec;
1931 acpi_status status;
1932 int ret;
1933
1934 /* Generate a boot ec context. */
1935 dmi_check_system(ec_dmi_table);
1936 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1937 (struct acpi_table_header **)&ecdt_ptr);
1938 if (ACPI_FAILURE(status))
1939 return;
1940
1941 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1942 /*
1943 * Asus X50GL:
1944 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1945 */
1946 goto out;
1947 }
1948
1949 ec = acpi_ec_alloc();
1950 if (!ec)
1951 goto out;
1952
1953 if (EC_FLAGS_CORRECT_ECDT) {
1954 ec->command_addr = ecdt_ptr->data.address;
1955 ec->data_addr = ecdt_ptr->control.address;
1956 } else {
1957 ec->command_addr = ecdt_ptr->control.address;
1958 ec->data_addr = ecdt_ptr->data.address;
1959 }
1960
1961 /*
1962 * Ignore the GPE value on Reduced Hardware platforms.
1963 * Some products have this set to an erroneous value.
1964 */
1965 if (!acpi_gbl_reduced_hardware)
1966 ec->gpe = ecdt_ptr->gpe;
1967
1968 ec->handle = ACPI_ROOT_OBJECT;
1969
1970 /*
1971 * At this point, the namespace is not initialized, so do not find
1972 * the namespace objects, or handle the events.
1973 */
1974 ret = acpi_ec_setup(ec, NULL);
1975 if (ret) {
1976 acpi_ec_free(ec);
1977 goto out;
1978 }
1979
1980 boot_ec = ec;
1981 boot_ec_is_ecdt = true;
1982
1983 pr_info("Boot ECDT EC used to handle transactions\n");
1984
1985 out:
1986 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1987 }
1988
1989 #ifdef CONFIG_PM_SLEEP
acpi_ec_suspend(struct device * dev)1990 static int acpi_ec_suspend(struct device *dev)
1991 {
1992 struct acpi_ec *ec =
1993 acpi_driver_data(to_acpi_device(dev));
1994
1995 if (!pm_suspend_no_platform() && ec_freeze_events)
1996 acpi_ec_disable_event(ec);
1997 return 0;
1998 }
1999
acpi_ec_suspend_noirq(struct device * dev)2000 static int acpi_ec_suspend_noirq(struct device *dev)
2001 {
2002 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2003
2004 /*
2005 * The SCI handler doesn't run at this point, so the GPE can be
2006 * masked at the low level without side effects.
2007 */
2008 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2009 ec->gpe >= 0 && ec->reference_count >= 1)
2010 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2011
2012 acpi_ec_enter_noirq(ec);
2013
2014 return 0;
2015 }
2016
acpi_ec_resume_noirq(struct device * dev)2017 static int acpi_ec_resume_noirq(struct device *dev)
2018 {
2019 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2020
2021 acpi_ec_leave_noirq(ec);
2022
2023 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2024 ec->gpe >= 0 && ec->reference_count >= 1)
2025 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2026
2027 return 0;
2028 }
2029
acpi_ec_resume(struct device * dev)2030 static int acpi_ec_resume(struct device *dev)
2031 {
2032 struct acpi_ec *ec =
2033 acpi_driver_data(to_acpi_device(dev));
2034
2035 acpi_ec_enable_event(ec);
2036 return 0;
2037 }
2038
acpi_ec_mark_gpe_for_wake(void)2039 void acpi_ec_mark_gpe_for_wake(void)
2040 {
2041 if (first_ec && !ec_no_wakeup)
2042 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2043 }
2044 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2045
acpi_ec_set_gpe_wake_mask(u8 action)2046 void acpi_ec_set_gpe_wake_mask(u8 action)
2047 {
2048 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2049 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2050 }
2051
acpi_ec_dispatch_gpe(void)2052 bool acpi_ec_dispatch_gpe(void)
2053 {
2054 bool work_in_progress;
2055 u32 ret;
2056
2057 if (!first_ec)
2058 return acpi_any_gpe_status_set(U32_MAX);
2059
2060 /*
2061 * Report wakeup if the status bit is set for any enabled GPE other
2062 * than the EC one.
2063 */
2064 if (acpi_any_gpe_status_set(first_ec->gpe))
2065 return true;
2066
2067 /*
2068 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2069 * to allow the caller to process events properly after that.
2070 */
2071 ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2072 if (ret == ACPI_INTERRUPT_HANDLED)
2073 pm_pr_dbg("ACPI EC GPE dispatched\n");
2074
2075 /* Drain EC work. */
2076 do {
2077 acpi_ec_flush_work();
2078
2079 pm_pr_dbg("ACPI EC work flushed\n");
2080
2081 spin_lock_irq(&first_ec->lock);
2082
2083 work_in_progress = first_ec->events_in_progress +
2084 first_ec->queries_in_progress > 0;
2085
2086 spin_unlock_irq(&first_ec->lock);
2087 } while (work_in_progress && !pm_wakeup_pending());
2088
2089 return false;
2090 }
2091 #endif /* CONFIG_PM_SLEEP */
2092
2093 static const struct dev_pm_ops acpi_ec_pm = {
2094 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2095 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2096 };
2097
param_set_event_clearing(const char * val,const struct kernel_param * kp)2098 static int param_set_event_clearing(const char *val,
2099 const struct kernel_param *kp)
2100 {
2101 int result = 0;
2102
2103 if (!strncmp(val, "status", sizeof("status") - 1)) {
2104 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2105 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2106 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2107 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2108 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2109 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2110 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2111 pr_info("Assuming SCI_EVT clearing on event reads\n");
2112 } else
2113 result = -EINVAL;
2114 return result;
2115 }
2116
param_get_event_clearing(char * buffer,const struct kernel_param * kp)2117 static int param_get_event_clearing(char *buffer,
2118 const struct kernel_param *kp)
2119 {
2120 switch (ec_event_clearing) {
2121 case ACPI_EC_EVT_TIMING_STATUS:
2122 return sprintf(buffer, "status\n");
2123 case ACPI_EC_EVT_TIMING_QUERY:
2124 return sprintf(buffer, "query\n");
2125 case ACPI_EC_EVT_TIMING_EVENT:
2126 return sprintf(buffer, "event\n");
2127 default:
2128 return sprintf(buffer, "invalid\n");
2129 }
2130 return 0;
2131 }
2132
2133 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2134 NULL, 0644);
2135 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2136
2137 static struct acpi_driver acpi_ec_driver = {
2138 .name = "ec",
2139 .class = ACPI_EC_CLASS,
2140 .ids = ec_device_ids,
2141 .ops = {
2142 .add = acpi_ec_add,
2143 .remove = acpi_ec_remove,
2144 },
2145 .drv.pm = &acpi_ec_pm,
2146 };
2147
acpi_ec_destroy_workqueues(void)2148 static void acpi_ec_destroy_workqueues(void)
2149 {
2150 if (ec_wq) {
2151 destroy_workqueue(ec_wq);
2152 ec_wq = NULL;
2153 }
2154 if (ec_query_wq) {
2155 destroy_workqueue(ec_query_wq);
2156 ec_query_wq = NULL;
2157 }
2158 }
2159
acpi_ec_init_workqueues(void)2160 static int acpi_ec_init_workqueues(void)
2161 {
2162 if (!ec_wq)
2163 ec_wq = alloc_ordered_workqueue("kec", 0);
2164
2165 if (!ec_query_wq)
2166 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2167
2168 if (!ec_wq || !ec_query_wq) {
2169 acpi_ec_destroy_workqueues();
2170 return -ENODEV;
2171 }
2172 return 0;
2173 }
2174
2175 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2176 {
2177 .ident = "Thinkpad X1 Carbon 6th",
2178 .matches = {
2179 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2180 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2181 },
2182 },
2183 {
2184 .ident = "ThinkPad X1 Carbon 6th",
2185 .matches = {
2186 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2187 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2188 },
2189 },
2190 {
2191 .ident = "ThinkPad X1 Yoga 3rd",
2192 .matches = {
2193 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2194 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2195 },
2196 },
2197 { },
2198 };
2199
acpi_ec_init(void)2200 void __init acpi_ec_init(void)
2201 {
2202 int result;
2203
2204 result = acpi_ec_init_workqueues();
2205 if (result)
2206 return;
2207
2208 /*
2209 * Disable EC wakeup on following systems to prevent periodic
2210 * wakeup from EC GPE.
2211 */
2212 if (dmi_check_system(acpi_ec_no_wakeup)) {
2213 ec_no_wakeup = true;
2214 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2215 }
2216
2217 /* Driver must be registered after acpi_ec_init_workqueues(). */
2218 acpi_bus_register_driver(&acpi_ec_driver);
2219
2220 acpi_ec_ecdt_start();
2221 }
2222
2223 /* EC driver currently not unloadable */
2224 #if 0
2225 static void __exit acpi_ec_exit(void)
2226 {
2227
2228 acpi_bus_unregister_driver(&acpi_ec_driver);
2229 acpi_ec_destroy_workqueues();
2230 }
2231 #endif /* 0 */
2232