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
acpi_ec_started(struct acpi_ec * ec)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
acpi_ec_event_enabled(struct acpi_ec * ec)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
acpi_ec_flushed(struct acpi_ec * ec)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
acpi_ec_read_status(struct acpi_ec * ec)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
acpi_ec_read_data(struct acpi_ec * ec)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
acpi_ec_write_cmd(struct acpi_ec * ec,u8 command)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
acpi_ec_write_data(struct acpi_ec * ec,u8 data)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)
acpi_ec_cmd_string(u8 cmd)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
acpi_ec_gpe_status_set(struct acpi_ec * ec)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
acpi_ec_enable_gpe(struct acpi_ec * ec,bool open)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
acpi_ec_disable_gpe(struct acpi_ec * ec,bool close)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
acpi_ec_submit_request(struct acpi_ec * ec)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
acpi_ec_complete_request(struct acpi_ec * ec)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
acpi_ec_mask_events(struct acpi_ec * ec)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
acpi_ec_unmask_events(struct acpi_ec * ec)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 */
acpi_ec_submit_flushable_request(struct acpi_ec * ec)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
acpi_ec_submit_event(struct acpi_ec * ec)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
acpi_ec_complete_event(struct acpi_ec * ec)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
acpi_ec_close_event(struct acpi_ec * ec)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
__acpi_ec_enable_event(struct acpi_ec * ec)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
__acpi_ec_disable_event(struct acpi_ec * ec)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 */
acpi_ec_clear(struct acpi_ec * ec)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
acpi_ec_enable_event(struct acpi_ec * ec)526 static void acpi_ec_enable_event(struct acpi_ec *ec)
527 {
528 unsigned long flags;
529
530 spin_lock_irqsave(&ec->lock, flags);
531 if (acpi_ec_started(ec))
532 __acpi_ec_enable_event(ec);
533 spin_unlock_irqrestore(&ec->lock, flags);
534
535 /* Drain additional events if hardware requires that */
536 if (EC_FLAGS_CLEAR_ON_RESUME)
537 acpi_ec_clear(ec);
538 }
539
540 #ifdef CONFIG_PM_SLEEP
__acpi_ec_flush_work(void)541 static void __acpi_ec_flush_work(void)
542 {
543 flush_workqueue(ec_wq); /* flush ec->work */
544 flush_workqueue(ec_query_wq); /* flush queries */
545 }
546
acpi_ec_disable_event(struct acpi_ec * ec)547 static void acpi_ec_disable_event(struct acpi_ec *ec)
548 {
549 unsigned long flags;
550
551 spin_lock_irqsave(&ec->lock, flags);
552 __acpi_ec_disable_event(ec);
553 spin_unlock_irqrestore(&ec->lock, flags);
554
555 /*
556 * When ec_freeze_events is true, we need to flush events in
557 * the proper position before entering the noirq stage.
558 */
559 __acpi_ec_flush_work();
560 }
561
acpi_ec_flush_work(void)562 void acpi_ec_flush_work(void)
563 {
564 /* Without ec_wq there is nothing to flush. */
565 if (!ec_wq)
566 return;
567
568 __acpi_ec_flush_work();
569 }
570 #endif /* CONFIG_PM_SLEEP */
571
acpi_ec_guard_event(struct acpi_ec * ec)572 static bool acpi_ec_guard_event(struct acpi_ec *ec)
573 {
574 unsigned long flags;
575 bool guarded;
576
577 spin_lock_irqsave(&ec->lock, flags);
578 /*
579 * If firmware SCI_EVT clearing timing is "event", we actually
580 * don't know when the SCI_EVT will be cleared by firmware after
581 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
582 * acceptable period.
583 *
584 * The guarding period is applicable if the event state is not
585 * EC_EVENT_READY, but otherwise if the current transaction is of the
586 * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
587 * and it should not be applied to let the transaction transition into
588 * the ACPI_EC_COMMAND_POLL state immediately.
589 */
590 guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
591 ec->event_state != EC_EVENT_READY &&
592 (!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
593 spin_unlock_irqrestore(&ec->lock, flags);
594 return guarded;
595 }
596
ec_transaction_polled(struct acpi_ec * ec)597 static int ec_transaction_polled(struct acpi_ec *ec)
598 {
599 unsigned long flags;
600 int ret = 0;
601
602 spin_lock_irqsave(&ec->lock, flags);
603 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
604 ret = 1;
605 spin_unlock_irqrestore(&ec->lock, flags);
606 return ret;
607 }
608
ec_transaction_completed(struct acpi_ec * ec)609 static int ec_transaction_completed(struct acpi_ec *ec)
610 {
611 unsigned long flags;
612 int ret = 0;
613
614 spin_lock_irqsave(&ec->lock, flags);
615 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
616 ret = 1;
617 spin_unlock_irqrestore(&ec->lock, flags);
618 return ret;
619 }
620
ec_transaction_transition(struct acpi_ec * ec,unsigned long flag)621 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
622 {
623 ec->curr->flags |= flag;
624
625 if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
626 return;
627
628 switch (ec_event_clearing) {
629 case ACPI_EC_EVT_TIMING_STATUS:
630 if (flag == ACPI_EC_COMMAND_POLL)
631 acpi_ec_close_event(ec);
632
633 return;
634
635 case ACPI_EC_EVT_TIMING_QUERY:
636 if (flag == ACPI_EC_COMMAND_COMPLETE)
637 acpi_ec_close_event(ec);
638
639 return;
640
641 case ACPI_EC_EVT_TIMING_EVENT:
642 if (flag == ACPI_EC_COMMAND_COMPLETE)
643 acpi_ec_complete_event(ec);
644 }
645 }
646
acpi_ec_spurious_interrupt(struct acpi_ec * ec,struct transaction * t)647 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
648 {
649 if (t->irq_count < ec_storm_threshold)
650 ++t->irq_count;
651
652 /* Trigger if the threshold is 0 too. */
653 if (t->irq_count == ec_storm_threshold)
654 acpi_ec_mask_events(ec);
655 }
656
advance_transaction(struct acpi_ec * ec,bool interrupt)657 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
658 {
659 struct transaction *t = ec->curr;
660 bool wakeup = false;
661 u8 status;
662
663 ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
664
665 status = acpi_ec_read_status(ec);
666
667 /*
668 * Another IRQ or a guarded polling mode advancement is detected,
669 * the next QR_EC submission is then allowed.
670 */
671 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
672 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
673 ec->event_state == EC_EVENT_COMPLETE)
674 acpi_ec_close_event(ec);
675
676 if (!t)
677 goto out;
678 }
679
680 if (t->flags & ACPI_EC_COMMAND_POLL) {
681 if (t->wlen > t->wi) {
682 if (!(status & ACPI_EC_FLAG_IBF))
683 acpi_ec_write_data(ec, t->wdata[t->wi++]);
684 else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
685 acpi_ec_spurious_interrupt(ec, t);
686 } else if (t->rlen > t->ri) {
687 if (status & ACPI_EC_FLAG_OBF) {
688 t->rdata[t->ri++] = acpi_ec_read_data(ec);
689 if (t->rlen == t->ri) {
690 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
691 wakeup = true;
692 if (t->command == ACPI_EC_COMMAND_QUERY)
693 ec_dbg_evt("Command(%s) completed by hardware",
694 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
695 }
696 } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
697 acpi_ec_spurious_interrupt(ec, t);
698 }
699 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
700 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
701 wakeup = true;
702 }
703 } else if (!(status & ACPI_EC_FLAG_IBF)) {
704 acpi_ec_write_cmd(ec, t->command);
705 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
706 }
707
708 out:
709 if (status & ACPI_EC_FLAG_SCI)
710 acpi_ec_submit_event(ec);
711
712 if (wakeup && interrupt)
713 wake_up(&ec->wait);
714 }
715
start_transaction(struct acpi_ec * ec)716 static void start_transaction(struct acpi_ec *ec)
717 {
718 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
719 ec->curr->flags = 0;
720 }
721
ec_guard(struct acpi_ec * ec)722 static int ec_guard(struct acpi_ec *ec)
723 {
724 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
725 unsigned long timeout = ec->timestamp + guard;
726
727 /* Ensure guarding period before polling EC status */
728 do {
729 if (ec->busy_polling) {
730 /* Perform busy polling */
731 if (ec_transaction_completed(ec))
732 return 0;
733 udelay(jiffies_to_usecs(guard));
734 } else {
735 /*
736 * Perform wait polling
737 * 1. Wait the transaction to be completed by the
738 * GPE handler after the transaction enters
739 * ACPI_EC_COMMAND_POLL state.
740 * 2. A special guarding logic is also required
741 * for event clearing mode "event" before the
742 * transaction enters ACPI_EC_COMMAND_POLL
743 * state.
744 */
745 if (!ec_transaction_polled(ec) &&
746 !acpi_ec_guard_event(ec))
747 break;
748 if (wait_event_timeout(ec->wait,
749 ec_transaction_completed(ec),
750 guard))
751 return 0;
752 }
753 } while (time_before(jiffies, timeout));
754 return -ETIME;
755 }
756
ec_poll(struct acpi_ec * ec)757 static int ec_poll(struct acpi_ec *ec)
758 {
759 unsigned long flags;
760 int repeat = 5; /* number of command restarts */
761
762 while (repeat--) {
763 unsigned long delay = jiffies +
764 msecs_to_jiffies(ec_delay);
765 do {
766 if (!ec_guard(ec))
767 return 0;
768 spin_lock_irqsave(&ec->lock, flags);
769 advance_transaction(ec, false);
770 spin_unlock_irqrestore(&ec->lock, flags);
771 } while (time_before(jiffies, delay));
772 pr_debug("controller reset, restart transaction\n");
773 spin_lock_irqsave(&ec->lock, flags);
774 start_transaction(ec);
775 spin_unlock_irqrestore(&ec->lock, flags);
776 }
777 return -ETIME;
778 }
779
acpi_ec_transaction_unlocked(struct acpi_ec * ec,struct transaction * t)780 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
781 struct transaction *t)
782 {
783 unsigned long tmp;
784 int ret = 0;
785
786 /* start transaction */
787 spin_lock_irqsave(&ec->lock, tmp);
788 /* Enable GPE for command processing (IBF=0/OBF=1) */
789 if (!acpi_ec_submit_flushable_request(ec)) {
790 ret = -EINVAL;
791 goto unlock;
792 }
793 ec_dbg_ref(ec, "Increase command");
794 /* following two actions should be kept atomic */
795 ec->curr = t;
796 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
797 start_transaction(ec);
798 spin_unlock_irqrestore(&ec->lock, tmp);
799
800 ret = ec_poll(ec);
801
802 spin_lock_irqsave(&ec->lock, tmp);
803 if (t->irq_count == ec_storm_threshold)
804 acpi_ec_unmask_events(ec);
805 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
806 ec->curr = NULL;
807 /* Disable GPE for command processing (IBF=0/OBF=1) */
808 acpi_ec_complete_request(ec);
809 ec_dbg_ref(ec, "Decrease command");
810 unlock:
811 spin_unlock_irqrestore(&ec->lock, tmp);
812 return ret;
813 }
814
acpi_ec_transaction(struct acpi_ec * ec,struct transaction * t)815 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
816 {
817 int status;
818 u32 glk;
819
820 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
821 return -EINVAL;
822 if (t->rdata)
823 memset(t->rdata, 0, t->rlen);
824
825 mutex_lock(&ec->mutex);
826 if (ec->global_lock) {
827 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
828 if (ACPI_FAILURE(status)) {
829 status = -ENODEV;
830 goto unlock;
831 }
832 }
833
834 status = acpi_ec_transaction_unlocked(ec, t);
835
836 if (ec->global_lock)
837 acpi_release_global_lock(glk);
838 unlock:
839 mutex_unlock(&ec->mutex);
840 return status;
841 }
842
acpi_ec_burst_enable(struct acpi_ec * ec)843 static int acpi_ec_burst_enable(struct acpi_ec *ec)
844 {
845 u8 d;
846 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
847 .wdata = NULL, .rdata = &d,
848 .wlen = 0, .rlen = 1};
849
850 return acpi_ec_transaction(ec, &t);
851 }
852
acpi_ec_burst_disable(struct acpi_ec * ec)853 static int acpi_ec_burst_disable(struct acpi_ec *ec)
854 {
855 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
856 .wdata = NULL, .rdata = NULL,
857 .wlen = 0, .rlen = 0};
858
859 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
860 acpi_ec_transaction(ec, &t) : 0;
861 }
862
acpi_ec_read(struct acpi_ec * ec,u8 address,u8 * data)863 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
864 {
865 int result;
866 u8 d;
867 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
868 .wdata = &address, .rdata = &d,
869 .wlen = 1, .rlen = 1};
870
871 result = acpi_ec_transaction(ec, &t);
872 *data = d;
873 return result;
874 }
875
acpi_ec_write(struct acpi_ec * ec,u8 address,u8 data)876 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
877 {
878 u8 wdata[2] = { address, data };
879 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
880 .wdata = wdata, .rdata = NULL,
881 .wlen = 2, .rlen = 0};
882
883 return acpi_ec_transaction(ec, &t);
884 }
885
ec_read(u8 addr,u8 * val)886 int ec_read(u8 addr, u8 *val)
887 {
888 int err;
889 u8 temp_data;
890
891 if (!first_ec)
892 return -ENODEV;
893
894 err = acpi_ec_read(first_ec, addr, &temp_data);
895
896 if (!err) {
897 *val = temp_data;
898 return 0;
899 }
900 return err;
901 }
902 EXPORT_SYMBOL(ec_read);
903
ec_write(u8 addr,u8 val)904 int ec_write(u8 addr, u8 val)
905 {
906 if (!first_ec)
907 return -ENODEV;
908
909 return acpi_ec_write(first_ec, addr, val);
910 }
911 EXPORT_SYMBOL(ec_write);
912
ec_transaction(u8 command,const u8 * wdata,unsigned wdata_len,u8 * rdata,unsigned rdata_len)913 int ec_transaction(u8 command,
914 const u8 *wdata, unsigned wdata_len,
915 u8 *rdata, unsigned rdata_len)
916 {
917 struct transaction t = {.command = command,
918 .wdata = wdata, .rdata = rdata,
919 .wlen = wdata_len, .rlen = rdata_len};
920
921 if (!first_ec)
922 return -ENODEV;
923
924 return acpi_ec_transaction(first_ec, &t);
925 }
926 EXPORT_SYMBOL(ec_transaction);
927
928 /* Get the handle to the EC device */
ec_get_handle(void)929 acpi_handle ec_get_handle(void)
930 {
931 if (!first_ec)
932 return NULL;
933 return first_ec->handle;
934 }
935 EXPORT_SYMBOL(ec_get_handle);
936
acpi_ec_start(struct acpi_ec * ec,bool resuming)937 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
938 {
939 unsigned long flags;
940
941 spin_lock_irqsave(&ec->lock, flags);
942 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
943 ec_dbg_drv("Starting EC");
944 /* Enable GPE for event processing (SCI_EVT=1) */
945 if (!resuming) {
946 acpi_ec_submit_request(ec);
947 ec_dbg_ref(ec, "Increase driver");
948 }
949 ec_log_drv("EC started");
950 }
951 spin_unlock_irqrestore(&ec->lock, flags);
952 }
953
acpi_ec_stopped(struct acpi_ec * ec)954 static bool acpi_ec_stopped(struct acpi_ec *ec)
955 {
956 unsigned long flags;
957 bool flushed;
958
959 spin_lock_irqsave(&ec->lock, flags);
960 flushed = acpi_ec_flushed(ec);
961 spin_unlock_irqrestore(&ec->lock, flags);
962 return flushed;
963 }
964
acpi_ec_stop(struct acpi_ec * ec,bool suspending)965 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
966 {
967 unsigned long flags;
968
969 spin_lock_irqsave(&ec->lock, flags);
970 if (acpi_ec_started(ec)) {
971 ec_dbg_drv("Stopping EC");
972 set_bit(EC_FLAGS_STOPPED, &ec->flags);
973 spin_unlock_irqrestore(&ec->lock, flags);
974 wait_event(ec->wait, acpi_ec_stopped(ec));
975 spin_lock_irqsave(&ec->lock, flags);
976 /* Disable GPE for event processing (SCI_EVT=1) */
977 if (!suspending) {
978 acpi_ec_complete_request(ec);
979 ec_dbg_ref(ec, "Decrease driver");
980 } else if (!ec_freeze_events)
981 __acpi_ec_disable_event(ec);
982 clear_bit(EC_FLAGS_STARTED, &ec->flags);
983 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
984 ec_log_drv("EC stopped");
985 }
986 spin_unlock_irqrestore(&ec->lock, flags);
987 }
988
acpi_ec_enter_noirq(struct acpi_ec * ec)989 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
990 {
991 unsigned long flags;
992
993 spin_lock_irqsave(&ec->lock, flags);
994 ec->busy_polling = true;
995 ec->polling_guard = 0;
996 ec_log_drv("interrupt blocked");
997 spin_unlock_irqrestore(&ec->lock, flags);
998 }
999
acpi_ec_leave_noirq(struct acpi_ec * ec)1000 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1001 {
1002 unsigned long flags;
1003
1004 spin_lock_irqsave(&ec->lock, flags);
1005 ec->busy_polling = ec_busy_polling;
1006 ec->polling_guard = ec_polling_guard;
1007 ec_log_drv("interrupt unblocked");
1008 spin_unlock_irqrestore(&ec->lock, flags);
1009 }
1010
acpi_ec_block_transactions(void)1011 void acpi_ec_block_transactions(void)
1012 {
1013 struct acpi_ec *ec = first_ec;
1014
1015 if (!ec)
1016 return;
1017
1018 mutex_lock(&ec->mutex);
1019 /* Prevent transactions from being carried out */
1020 acpi_ec_stop(ec, true);
1021 mutex_unlock(&ec->mutex);
1022 }
1023
acpi_ec_unblock_transactions(void)1024 void acpi_ec_unblock_transactions(void)
1025 {
1026 /*
1027 * Allow transactions to happen again (this function is called from
1028 * atomic context during wakeup, so we don't need to acquire the mutex).
1029 */
1030 if (first_ec)
1031 acpi_ec_start(first_ec, true);
1032 }
1033
1034 /* --------------------------------------------------------------------------
1035 Event Management
1036 -------------------------------------------------------------------------- */
1037 static struct acpi_ec_query_handler *
acpi_ec_get_query_handler_by_value(struct acpi_ec * ec,u8 value)1038 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1039 {
1040 struct acpi_ec_query_handler *handler;
1041
1042 mutex_lock(&ec->mutex);
1043 list_for_each_entry(handler, &ec->list, node) {
1044 if (value == handler->query_bit) {
1045 kref_get(&handler->kref);
1046 mutex_unlock(&ec->mutex);
1047 return handler;
1048 }
1049 }
1050 mutex_unlock(&ec->mutex);
1051 return NULL;
1052 }
1053
acpi_ec_query_handler_release(struct kref * kref)1054 static void acpi_ec_query_handler_release(struct kref *kref)
1055 {
1056 struct acpi_ec_query_handler *handler =
1057 container_of(kref, struct acpi_ec_query_handler, kref);
1058
1059 kfree(handler);
1060 }
1061
acpi_ec_put_query_handler(struct acpi_ec_query_handler * handler)1062 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1063 {
1064 kref_put(&handler->kref, acpi_ec_query_handler_release);
1065 }
1066
acpi_ec_add_query_handler(struct acpi_ec * ec,u8 query_bit,acpi_handle handle,acpi_ec_query_func func,void * data)1067 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1068 acpi_handle handle, acpi_ec_query_func func,
1069 void *data)
1070 {
1071 struct acpi_ec_query_handler *handler;
1072
1073 if (!handle && !func)
1074 return -EINVAL;
1075
1076 handler = kzalloc(sizeof(*handler), GFP_KERNEL);
1077 if (!handler)
1078 return -ENOMEM;
1079
1080 handler->query_bit = query_bit;
1081 handler->handle = handle;
1082 handler->func = func;
1083 handler->data = data;
1084 mutex_lock(&ec->mutex);
1085 kref_init(&handler->kref);
1086 list_add(&handler->node, &ec->list);
1087 mutex_unlock(&ec->mutex);
1088
1089 return 0;
1090 }
1091 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1092
acpi_ec_remove_query_handlers(struct acpi_ec * ec,bool remove_all,u8 query_bit)1093 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1094 bool remove_all, u8 query_bit)
1095 {
1096 struct acpi_ec_query_handler *handler, *tmp;
1097 LIST_HEAD(free_list);
1098
1099 mutex_lock(&ec->mutex);
1100 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1101 /*
1102 * When remove_all is false, only remove custom query handlers
1103 * which have handler->func set. This is done to preserve query
1104 * handlers discovered thru ACPI, as they should continue handling
1105 * EC queries.
1106 */
1107 if (remove_all || (handler->func && handler->query_bit == query_bit)) {
1108 list_del_init(&handler->node);
1109 list_add(&handler->node, &free_list);
1110
1111 }
1112 }
1113 mutex_unlock(&ec->mutex);
1114 list_for_each_entry_safe(handler, tmp, &free_list, node)
1115 acpi_ec_put_query_handler(handler);
1116 }
1117
acpi_ec_remove_query_handler(struct acpi_ec * ec,u8 query_bit)1118 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1119 {
1120 acpi_ec_remove_query_handlers(ec, false, query_bit);
1121 flush_workqueue(ec_query_wq);
1122 }
1123 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1124
acpi_ec_event_processor(struct work_struct * work)1125 static void acpi_ec_event_processor(struct work_struct *work)
1126 {
1127 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1128 struct acpi_ec_query_handler *handler = q->handler;
1129 struct acpi_ec *ec = q->ec;
1130
1131 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1132
1133 if (handler->func)
1134 handler->func(handler->data);
1135 else if (handler->handle)
1136 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1137
1138 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1139
1140 spin_lock_irq(&ec->lock);
1141 ec->queries_in_progress--;
1142 spin_unlock_irq(&ec->lock);
1143
1144 acpi_ec_put_query_handler(handler);
1145 kfree(q);
1146 }
1147
acpi_ec_create_query(struct acpi_ec * ec,u8 * pval)1148 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1149 {
1150 struct acpi_ec_query *q;
1151 struct transaction *t;
1152
1153 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1154 if (!q)
1155 return NULL;
1156
1157 INIT_WORK(&q->work, acpi_ec_event_processor);
1158 t = &q->transaction;
1159 t->command = ACPI_EC_COMMAND_QUERY;
1160 t->rdata = pval;
1161 t->rlen = 1;
1162 q->ec = ec;
1163 return q;
1164 }
1165
acpi_ec_submit_query(struct acpi_ec * ec)1166 static int acpi_ec_submit_query(struct acpi_ec *ec)
1167 {
1168 struct acpi_ec_query *q;
1169 u8 value = 0;
1170 int result;
1171
1172 q = acpi_ec_create_query(ec, &value);
1173 if (!q)
1174 return -ENOMEM;
1175
1176 /*
1177 * Query the EC to find out which _Qxx method we need to evaluate.
1178 * Note that successful completion of the query causes the ACPI_EC_SCI
1179 * bit to be cleared (and thus clearing the interrupt source).
1180 */
1181 result = acpi_ec_transaction(ec, &q->transaction);
1182 if (result)
1183 goto err_exit;
1184
1185 if (!value) {
1186 result = -ENODATA;
1187 goto err_exit;
1188 }
1189
1190 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1191 if (!q->handler) {
1192 result = -ENODATA;
1193 goto err_exit;
1194 }
1195
1196 /*
1197 * It is reported that _Qxx are evaluated in a parallel way on Windows:
1198 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1199 *
1200 * Put this log entry before queue_work() to make it appear in the log
1201 * before any other messages emitted during workqueue handling.
1202 */
1203 ec_dbg_evt("Query(0x%02x) scheduled", value);
1204
1205 spin_lock_irq(&ec->lock);
1206
1207 ec->queries_in_progress++;
1208 queue_work(ec_query_wq, &q->work);
1209
1210 spin_unlock_irq(&ec->lock);
1211
1212 return 0;
1213
1214 err_exit:
1215 kfree(q);
1216
1217 return result;
1218 }
1219
acpi_ec_event_handler(struct work_struct * work)1220 static void acpi_ec_event_handler(struct work_struct *work)
1221 {
1222 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1223
1224 ec_dbg_evt("Event started");
1225
1226 spin_lock_irq(&ec->lock);
1227
1228 while (ec->events_to_process) {
1229 spin_unlock_irq(&ec->lock);
1230
1231 acpi_ec_submit_query(ec);
1232
1233 spin_lock_irq(&ec->lock);
1234
1235 ec->events_to_process--;
1236 }
1237
1238 /*
1239 * Before exit, make sure that the it will be possible to queue up the
1240 * event handling work again regardless of whether or not the query
1241 * queued up above is processed successfully.
1242 */
1243 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1244 bool guard_timeout;
1245
1246 acpi_ec_complete_event(ec);
1247
1248 ec_dbg_evt("Event stopped");
1249
1250 spin_unlock_irq(&ec->lock);
1251
1252 guard_timeout = !!ec_guard(ec);
1253
1254 spin_lock_irq(&ec->lock);
1255
1256 /* Take care of SCI_EVT unless someone else is doing that. */
1257 if (guard_timeout && !ec->curr)
1258 advance_transaction(ec, false);
1259 } else {
1260 acpi_ec_close_event(ec);
1261
1262 ec_dbg_evt("Event stopped");
1263 }
1264
1265 ec->events_in_progress--;
1266
1267 spin_unlock_irq(&ec->lock);
1268 }
1269
clear_gpe_and_advance_transaction(struct acpi_ec * ec,bool interrupt)1270 static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)
1271 {
1272 /*
1273 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
1274 * changes to always trigger a GPE interrupt.
1275 *
1276 * GPE STS is a W1C register, which means:
1277 *
1278 * 1. Software can clear it without worrying about clearing the other
1279 * GPEs' STS bits when the hardware sets them in parallel.
1280 *
1281 * 2. As long as software can ensure only clearing it when it is set,
1282 * hardware won't set it in parallel.
1283 */
1284 if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
1285 acpi_clear_gpe(NULL, ec->gpe);
1286
1287 advance_transaction(ec, true);
1288 }
1289
acpi_ec_handle_interrupt(struct acpi_ec * ec)1290 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1291 {
1292 unsigned long flags;
1293
1294 spin_lock_irqsave(&ec->lock, flags);
1295
1296 clear_gpe_and_advance_transaction(ec, true);
1297
1298 spin_unlock_irqrestore(&ec->lock, flags);
1299 }
1300
acpi_ec_gpe_handler(acpi_handle gpe_device,u32 gpe_number,void * data)1301 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1302 u32 gpe_number, void *data)
1303 {
1304 acpi_ec_handle_interrupt(data);
1305 return ACPI_INTERRUPT_HANDLED;
1306 }
1307
acpi_ec_irq_handler(int irq,void * data)1308 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1309 {
1310 acpi_ec_handle_interrupt(data);
1311 return IRQ_HANDLED;
1312 }
1313
1314 /* --------------------------------------------------------------------------
1315 * Address Space Management
1316 * -------------------------------------------------------------------------- */
1317
1318 static acpi_status
acpi_ec_space_handler(u32 function,acpi_physical_address address,u32 bits,u64 * value64,void * handler_context,void * region_context)1319 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1320 u32 bits, u64 *value64,
1321 void *handler_context, void *region_context)
1322 {
1323 struct acpi_ec *ec = handler_context;
1324 int result = 0, i, bytes = bits / 8;
1325 u8 *value = (u8 *)value64;
1326
1327 if ((address > 0xFF) || !value || !handler_context)
1328 return AE_BAD_PARAMETER;
1329
1330 if (function != ACPI_READ && function != ACPI_WRITE)
1331 return AE_BAD_PARAMETER;
1332
1333 if (ec->busy_polling || bits > 8)
1334 acpi_ec_burst_enable(ec);
1335
1336 for (i = 0; i < bytes; ++i, ++address, ++value) {
1337 result = (function == ACPI_READ) ?
1338 acpi_ec_read(ec, address, value) :
1339 acpi_ec_write(ec, address, *value);
1340 if (result < 0)
1341 break;
1342 }
1343
1344 if (ec->busy_polling || bits > 8)
1345 acpi_ec_burst_disable(ec);
1346
1347 switch (result) {
1348 case -EINVAL:
1349 return AE_BAD_PARAMETER;
1350 case -ENODEV:
1351 return AE_NOT_FOUND;
1352 case -ETIME:
1353 return AE_TIME;
1354 case 0:
1355 return AE_OK;
1356 default:
1357 return AE_ERROR;
1358 }
1359 }
1360
1361 /* --------------------------------------------------------------------------
1362 * Driver Interface
1363 * -------------------------------------------------------------------------- */
1364
1365 static acpi_status
1366 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1367
acpi_ec_free(struct acpi_ec * ec)1368 static void acpi_ec_free(struct acpi_ec *ec)
1369 {
1370 if (first_ec == ec)
1371 first_ec = NULL;
1372 if (boot_ec == ec)
1373 boot_ec = NULL;
1374 kfree(ec);
1375 }
1376
acpi_ec_alloc(void)1377 static struct acpi_ec *acpi_ec_alloc(void)
1378 {
1379 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1380
1381 if (!ec)
1382 return NULL;
1383 mutex_init(&ec->mutex);
1384 init_waitqueue_head(&ec->wait);
1385 INIT_LIST_HEAD(&ec->list);
1386 spin_lock_init(&ec->lock);
1387 INIT_WORK(&ec->work, acpi_ec_event_handler);
1388 ec->timestamp = jiffies;
1389 ec->busy_polling = true;
1390 ec->polling_guard = 0;
1391 ec->gpe = -1;
1392 ec->irq = -1;
1393 return ec;
1394 }
1395
1396 static acpi_status
acpi_ec_register_query_methods(acpi_handle handle,u32 level,void * context,void ** return_value)1397 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1398 void *context, void **return_value)
1399 {
1400 char node_name[5];
1401 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1402 struct acpi_ec *ec = context;
1403 int value = 0;
1404 acpi_status status;
1405
1406 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1407
1408 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1409 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1410 return AE_OK;
1411 }
1412
1413 static acpi_status
ec_parse_device(acpi_handle handle,u32 Level,void * context,void ** retval)1414 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1415 {
1416 acpi_status status;
1417 unsigned long long tmp = 0;
1418 struct acpi_ec *ec = context;
1419
1420 /* clear addr values, ec_parse_io_ports depend on it */
1421 ec->command_addr = ec->data_addr = 0;
1422
1423 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1424 ec_parse_io_ports, ec);
1425 if (ACPI_FAILURE(status))
1426 return status;
1427 if (ec->data_addr == 0 || ec->command_addr == 0)
1428 return AE_OK;
1429
1430 /* Get GPE bit assignment (EC events). */
1431 /* TODO: Add support for _GPE returning a package */
1432 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1433 if (ACPI_SUCCESS(status))
1434 ec->gpe = tmp;
1435 /*
1436 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1437 * platforms which use GpioInt instead of GPE.
1438 */
1439
1440 /* Use the global lock for all EC transactions? */
1441 tmp = 0;
1442 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1443 ec->global_lock = tmp;
1444 ec->handle = handle;
1445 return AE_CTRL_TERMINATE;
1446 }
1447
install_gpe_event_handler(struct acpi_ec * ec)1448 static bool install_gpe_event_handler(struct acpi_ec *ec)
1449 {
1450 acpi_status status;
1451
1452 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1453 ACPI_GPE_EDGE_TRIGGERED,
1454 &acpi_ec_gpe_handler, ec);
1455 if (ACPI_FAILURE(status))
1456 return false;
1457
1458 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1459 acpi_ec_enable_gpe(ec, true);
1460
1461 return true;
1462 }
1463
install_gpio_irq_event_handler(struct acpi_ec * ec)1464 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1465 {
1466 return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1467 "ACPI EC", ec) >= 0;
1468 }
1469
1470 /**
1471 * ec_install_handlers - Install service callbacks and register query methods.
1472 * @ec: Target EC.
1473 * @device: ACPI device object corresponding to @ec.
1474 * @call_reg: If _REG should be called to notify OpRegion availability
1475 *
1476 * Install a handler for the EC address space type unless it has been installed
1477 * already. If @device is not NULL, also look for EC query methods in the
1478 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1479 * handler for the EC, if possible.
1480 *
1481 * Return:
1482 * -ENODEV if the address space handler cannot be installed, which means
1483 * "unable to handle transactions",
1484 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1485 * or 0 (success) otherwise.
1486 */
ec_install_handlers(struct acpi_ec * ec,struct acpi_device * device,bool call_reg)1487 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1488 bool call_reg)
1489 {
1490 acpi_status status;
1491
1492 acpi_ec_start(ec, false);
1493
1494 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1495 acpi_handle scope_handle = ec == first_ec ? ACPI_ROOT_OBJECT : ec->handle;
1496
1497 acpi_ec_enter_noirq(ec);
1498 status = acpi_install_address_space_handler_no_reg(scope_handle,
1499 ACPI_ADR_SPACE_EC,
1500 &acpi_ec_space_handler,
1501 NULL, ec);
1502 if (ACPI_FAILURE(status)) {
1503 acpi_ec_stop(ec, false);
1504 return -ENODEV;
1505 }
1506 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1507 }
1508
1509 if (call_reg && !test_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags)) {
1510 acpi_execute_reg_methods(ec->handle, ACPI_UINT32_MAX, ACPI_ADR_SPACE_EC);
1511 set_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags);
1512 }
1513
1514 if (!device)
1515 return 0;
1516
1517 if (ec->gpe < 0) {
1518 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1519 int irq = acpi_dev_gpio_irq_get(device, 0);
1520 /*
1521 * Bail out right away for deferred probing or complete the
1522 * initialization regardless of any other errors.
1523 */
1524 if (irq == -EPROBE_DEFER)
1525 return -EPROBE_DEFER;
1526 else if (irq >= 0)
1527 ec->irq = irq;
1528 }
1529
1530 if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1531 /* Find and register all query methods */
1532 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1533 acpi_ec_register_query_methods,
1534 NULL, ec, NULL);
1535 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1536 }
1537 if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1538 bool ready = false;
1539
1540 if (ec->gpe >= 0)
1541 ready = install_gpe_event_handler(ec);
1542 else if (ec->irq >= 0)
1543 ready = install_gpio_irq_event_handler(ec);
1544
1545 if (ready) {
1546 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1547 acpi_ec_leave_noirq(ec);
1548 }
1549 /*
1550 * Failures to install an event handler are not fatal, because
1551 * the EC can be polled for events.
1552 */
1553 }
1554 /* EC is fully operational, allow queries */
1555 acpi_ec_enable_event(ec);
1556
1557 return 0;
1558 }
1559
ec_remove_handlers(struct acpi_ec * ec)1560 static void ec_remove_handlers(struct acpi_ec *ec)
1561 {
1562 acpi_handle scope_handle = ec == first_ec ? ACPI_ROOT_OBJECT : ec->handle;
1563
1564 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1565 if (ACPI_FAILURE(acpi_remove_address_space_handler(
1566 scope_handle,
1567 ACPI_ADR_SPACE_EC,
1568 &acpi_ec_space_handler)))
1569 pr_err("failed to remove space handler\n");
1570 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1571 }
1572
1573 /*
1574 * Stops handling the EC transactions after removing the operation
1575 * region handler. This is required because _REG(DISCONNECT)
1576 * invoked during the removal can result in new EC transactions.
1577 *
1578 * Flushes the EC requests and thus disables the GPE before
1579 * removing the GPE handler. This is required by the current ACPICA
1580 * GPE core. ACPICA GPE core will automatically disable a GPE when
1581 * it is indicated but there is no way to handle it. So the drivers
1582 * must disable the GPEs prior to removing the GPE handlers.
1583 */
1584 acpi_ec_stop(ec, false);
1585
1586 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1587 if (ec->gpe >= 0 &&
1588 ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1589 &acpi_ec_gpe_handler)))
1590 pr_err("failed to remove gpe handler\n");
1591
1592 if (ec->irq >= 0)
1593 free_irq(ec->irq, ec);
1594
1595 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1596 }
1597 if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1598 acpi_ec_remove_query_handlers(ec, true, 0);
1599 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1600 }
1601 }
1602
acpi_ec_setup(struct acpi_ec * ec,struct acpi_device * device,bool call_reg)1603 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device, bool call_reg)
1604 {
1605 int ret;
1606
1607 /* First EC capable of handling transactions */
1608 if (!first_ec)
1609 first_ec = ec;
1610
1611 ret = ec_install_handlers(ec, device, call_reg);
1612 if (ret) {
1613 if (ec == first_ec)
1614 first_ec = NULL;
1615
1616 return ret;
1617 }
1618
1619 pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1620 ec->data_addr);
1621
1622 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1623 if (ec->gpe >= 0)
1624 pr_info("GPE=0x%x\n", ec->gpe);
1625 else
1626 pr_info("IRQ=%d\n", ec->irq);
1627 }
1628
1629 return ret;
1630 }
1631
acpi_ec_add(struct acpi_device * device)1632 static int acpi_ec_add(struct acpi_device *device)
1633 {
1634 struct acpi_ec *ec;
1635 int ret;
1636
1637 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1638 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1639
1640 if (boot_ec && (boot_ec->handle == device->handle ||
1641 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1642 /* Fast path: this device corresponds to the boot EC. */
1643 ec = boot_ec;
1644 } else {
1645 acpi_status status;
1646
1647 ec = acpi_ec_alloc();
1648 if (!ec)
1649 return -ENOMEM;
1650
1651 status = ec_parse_device(device->handle, 0, ec, NULL);
1652 if (status != AE_CTRL_TERMINATE) {
1653 ret = -EINVAL;
1654 goto err;
1655 }
1656
1657 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1658 ec->data_addr == boot_ec->data_addr) {
1659 /*
1660 * Trust PNP0C09 namespace location rather than ECDT ID.
1661 * But trust ECDT GPE rather than _GPE because of ASUS
1662 * quirks. So do not change boot_ec->gpe to ec->gpe,
1663 * except when the TRUST_DSDT_GPE quirk is set.
1664 */
1665 boot_ec->handle = ec->handle;
1666
1667 if (EC_FLAGS_TRUST_DSDT_GPE)
1668 boot_ec->gpe = ec->gpe;
1669
1670 acpi_handle_debug(ec->handle, "duplicated.\n");
1671 acpi_ec_free(ec);
1672 ec = boot_ec;
1673 }
1674 }
1675
1676 ret = acpi_ec_setup(ec, device, true);
1677 if (ret)
1678 goto err;
1679
1680 if (ec == boot_ec)
1681 acpi_handle_info(boot_ec->handle,
1682 "Boot %s EC initialization complete\n",
1683 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1684
1685 acpi_handle_info(ec->handle,
1686 "EC: Used to handle transactions and events\n");
1687
1688 device->driver_data = ec;
1689
1690 ret = !!request_region(ec->data_addr, 1, "EC data");
1691 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1692 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1693 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1694
1695 /* Reprobe devices depending on the EC */
1696 acpi_dev_clear_dependencies(device);
1697
1698 acpi_handle_debug(ec->handle, "enumerated.\n");
1699 return 0;
1700
1701 err:
1702 if (ec != boot_ec)
1703 acpi_ec_free(ec);
1704
1705 return ret;
1706 }
1707
acpi_ec_remove(struct acpi_device * device)1708 static void acpi_ec_remove(struct acpi_device *device)
1709 {
1710 struct acpi_ec *ec;
1711
1712 if (!device)
1713 return;
1714
1715 ec = acpi_driver_data(device);
1716 release_region(ec->data_addr, 1);
1717 release_region(ec->command_addr, 1);
1718 device->driver_data = NULL;
1719 if (ec != boot_ec) {
1720 ec_remove_handlers(ec);
1721 acpi_ec_free(ec);
1722 }
1723 }
1724
acpi_ec_register_opregions(struct acpi_device * adev)1725 void acpi_ec_register_opregions(struct acpi_device *adev)
1726 {
1727 if (first_ec && first_ec->handle != adev->handle)
1728 acpi_execute_reg_methods(adev->handle, 1, ACPI_ADR_SPACE_EC);
1729 }
1730
1731 static acpi_status
ec_parse_io_ports(struct acpi_resource * resource,void * context)1732 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1733 {
1734 struct acpi_ec *ec = context;
1735
1736 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1737 return AE_OK;
1738
1739 /*
1740 * The first address region returned is the data port, and
1741 * the second address region returned is the status/command
1742 * port.
1743 */
1744 if (ec->data_addr == 0)
1745 ec->data_addr = resource->data.io.minimum;
1746 else if (ec->command_addr == 0)
1747 ec->command_addr = resource->data.io.minimum;
1748 else
1749 return AE_CTRL_TERMINATE;
1750
1751 return AE_OK;
1752 }
1753
1754 static const struct acpi_device_id ec_device_ids[] = {
1755 {"PNP0C09", 0},
1756 {ACPI_ECDT_HID, 0},
1757 {"", 0},
1758 };
1759
1760 /*
1761 * This function is not Windows-compatible as Windows never enumerates the
1762 * namespace EC before the main ACPI device enumeration process. It is
1763 * retained for historical reason and will be deprecated in the future.
1764 */
acpi_ec_dsdt_probe(void)1765 void __init acpi_ec_dsdt_probe(void)
1766 {
1767 struct acpi_ec *ec;
1768 acpi_status status;
1769 int ret;
1770
1771 /*
1772 * If a platform has ECDT, there is no need to proceed as the
1773 * following probe is not a part of the ACPI device enumeration,
1774 * executing _STA is not safe, and thus this probe may risk of
1775 * picking up an invalid EC device.
1776 */
1777 if (boot_ec)
1778 return;
1779
1780 ec = acpi_ec_alloc();
1781 if (!ec)
1782 return;
1783
1784 /*
1785 * At this point, the namespace is initialized, so start to find
1786 * the namespace objects.
1787 */
1788 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1789 if (ACPI_FAILURE(status) || !ec->handle) {
1790 acpi_ec_free(ec);
1791 return;
1792 }
1793
1794 /*
1795 * When the DSDT EC is available, always re-configure boot EC to
1796 * have _REG evaluated. _REG can only be evaluated after the
1797 * namespace initialization.
1798 * At this point, the GPE is not fully initialized, so do not to
1799 * handle the events.
1800 */
1801 ret = acpi_ec_setup(ec, NULL, true);
1802 if (ret) {
1803 acpi_ec_free(ec);
1804 return;
1805 }
1806
1807 boot_ec = ec;
1808
1809 acpi_handle_info(ec->handle,
1810 "Boot DSDT EC used to handle transactions\n");
1811 }
1812
1813 /*
1814 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1815 *
1816 * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1817 * found a matching object in the namespace.
1818 *
1819 * Next, in case the DSDT EC is not functioning, it is still necessary to
1820 * provide a functional ECDT EC to handle events, so add an extra device object
1821 * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1822 *
1823 * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1824 * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1825 */
acpi_ec_ecdt_start(void)1826 static void __init acpi_ec_ecdt_start(void)
1827 {
1828 struct acpi_table_ecdt *ecdt_ptr;
1829 acpi_handle handle;
1830 acpi_status status;
1831
1832 /* Bail out if a matching EC has been found in the namespace. */
1833 if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1834 return;
1835
1836 /* Look up the object pointed to from the ECDT in the namespace. */
1837 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1838 (struct acpi_table_header **)&ecdt_ptr);
1839 if (ACPI_FAILURE(status))
1840 return;
1841
1842 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1843 if (ACPI_SUCCESS(status)) {
1844 boot_ec->handle = handle;
1845
1846 /* Add a special ACPI device object to represent the boot EC. */
1847 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1848 }
1849
1850 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1851 }
1852
1853 /*
1854 * On some hardware it is necessary to clear events accumulated by the EC during
1855 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1856 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1857 *
1858 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1859 *
1860 * Ideally, the EC should also be instructed NOT to accumulate events during
1861 * sleep (which Windows seems to do somehow), but the interface to control this
1862 * behaviour is not known at this time.
1863 *
1864 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1865 * however it is very likely that other Samsung models are affected.
1866 *
1867 * On systems which don't accumulate _Q events during sleep, this extra check
1868 * should be harmless.
1869 */
ec_clear_on_resume(const struct dmi_system_id * id)1870 static int ec_clear_on_resume(const struct dmi_system_id *id)
1871 {
1872 pr_debug("Detected system needing EC poll on resume.\n");
1873 EC_FLAGS_CLEAR_ON_RESUME = 1;
1874 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1875 return 0;
1876 }
1877
1878 /*
1879 * Some ECDTs contain wrong register addresses.
1880 * MSI MS-171F
1881 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1882 */
ec_correct_ecdt(const struct dmi_system_id * id)1883 static int ec_correct_ecdt(const struct dmi_system_id *id)
1884 {
1885 pr_debug("Detected system needing ECDT address correction.\n");
1886 EC_FLAGS_CORRECT_ECDT = 1;
1887 return 0;
1888 }
1889
1890 /*
1891 * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1892 * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1893 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1894 */
ec_honor_dsdt_gpe(const struct dmi_system_id * id)1895 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1896 {
1897 pr_debug("Detected system needing DSDT GPE setting.\n");
1898 EC_FLAGS_TRUST_DSDT_GPE = 1;
1899 return 0;
1900 }
1901
1902 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1903 {
1904 /*
1905 * MSI MS-171F
1906 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1907 */
1908 .callback = ec_correct_ecdt,
1909 .matches = {
1910 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1911 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),
1912 },
1913 },
1914 {
1915 /*
1916 * HP Pavilion Gaming Laptop 15-cx0xxx
1917 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1918 */
1919 .callback = ec_honor_dsdt_gpe,
1920 .matches = {
1921 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1922 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),
1923 },
1924 },
1925 {
1926 /*
1927 * HP Pavilion Gaming Laptop 15-cx0041ur
1928 */
1929 .callback = ec_honor_dsdt_gpe,
1930 .matches = {
1931 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1932 DMI_MATCH(DMI_PRODUCT_NAME, "HP 15-cx0041ur"),
1933 },
1934 },
1935 {
1936 /*
1937 * HP Pavilion Gaming Laptop 15-dk1xxx
1938 * https://github.com/systemd/systemd/issues/28942
1939 */
1940 .callback = ec_honor_dsdt_gpe,
1941 .matches = {
1942 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1943 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-dk1xxx"),
1944 },
1945 },
1946 {
1947 /*
1948 * HP 250 G7 Notebook PC
1949 */
1950 .callback = ec_honor_dsdt_gpe,
1951 .matches = {
1952 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1953 DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"),
1954 },
1955 },
1956 {
1957 /*
1958 * Samsung hardware
1959 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1960 */
1961 .callback = ec_clear_on_resume,
1962 .matches = {
1963 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
1964 },
1965 },
1966 {}
1967 };
1968
acpi_ec_ecdt_probe(void)1969 void __init acpi_ec_ecdt_probe(void)
1970 {
1971 struct acpi_table_ecdt *ecdt_ptr;
1972 struct acpi_ec *ec;
1973 acpi_status status;
1974 int ret;
1975
1976 /* Generate a boot ec context. */
1977 dmi_check_system(ec_dmi_table);
1978 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1979 (struct acpi_table_header **)&ecdt_ptr);
1980 if (ACPI_FAILURE(status))
1981 return;
1982
1983 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1984 /*
1985 * Asus X50GL:
1986 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1987 */
1988 goto out;
1989 }
1990
1991 ec = acpi_ec_alloc();
1992 if (!ec)
1993 goto out;
1994
1995 if (EC_FLAGS_CORRECT_ECDT) {
1996 ec->command_addr = ecdt_ptr->data.address;
1997 ec->data_addr = ecdt_ptr->control.address;
1998 } else {
1999 ec->command_addr = ecdt_ptr->control.address;
2000 ec->data_addr = ecdt_ptr->data.address;
2001 }
2002
2003 /*
2004 * Ignore the GPE value on Reduced Hardware platforms.
2005 * Some products have this set to an erroneous value.
2006 */
2007 if (!acpi_gbl_reduced_hardware)
2008 ec->gpe = ecdt_ptr->gpe;
2009
2010 ec->handle = ACPI_ROOT_OBJECT;
2011
2012 /*
2013 * At this point, the namespace is not initialized, so do not find
2014 * the namespace objects, or handle the events.
2015 */
2016 ret = acpi_ec_setup(ec, NULL, false);
2017 if (ret) {
2018 acpi_ec_free(ec);
2019 goto out;
2020 }
2021
2022 boot_ec = ec;
2023 boot_ec_is_ecdt = true;
2024
2025 pr_info("Boot ECDT EC used to handle transactions\n");
2026
2027 out:
2028 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
2029 }
2030
2031 #ifdef CONFIG_PM_SLEEP
acpi_ec_suspend(struct device * dev)2032 static int acpi_ec_suspend(struct device *dev)
2033 {
2034 struct acpi_ec *ec =
2035 acpi_driver_data(to_acpi_device(dev));
2036
2037 if (!pm_suspend_no_platform() && ec_freeze_events)
2038 acpi_ec_disable_event(ec);
2039 return 0;
2040 }
2041
acpi_ec_suspend_noirq(struct device * dev)2042 static int acpi_ec_suspend_noirq(struct device *dev)
2043 {
2044 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2045
2046 /*
2047 * The SCI handler doesn't run at this point, so the GPE can be
2048 * masked at the low level without side effects.
2049 */
2050 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2051 ec->gpe >= 0 && ec->reference_count >= 1)
2052 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2053
2054 acpi_ec_enter_noirq(ec);
2055
2056 return 0;
2057 }
2058
acpi_ec_resume_noirq(struct device * dev)2059 static int acpi_ec_resume_noirq(struct device *dev)
2060 {
2061 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2062
2063 acpi_ec_leave_noirq(ec);
2064
2065 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2066 ec->gpe >= 0 && ec->reference_count >= 1)
2067 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2068
2069 return 0;
2070 }
2071
acpi_ec_resume(struct device * dev)2072 static int acpi_ec_resume(struct device *dev)
2073 {
2074 struct acpi_ec *ec =
2075 acpi_driver_data(to_acpi_device(dev));
2076
2077 acpi_ec_enable_event(ec);
2078 return 0;
2079 }
2080
acpi_ec_mark_gpe_for_wake(void)2081 void acpi_ec_mark_gpe_for_wake(void)
2082 {
2083 if (first_ec && !ec_no_wakeup)
2084 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2085 }
2086 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2087
acpi_ec_set_gpe_wake_mask(u8 action)2088 void acpi_ec_set_gpe_wake_mask(u8 action)
2089 {
2090 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2091 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2092 }
2093
acpi_ec_work_in_progress(struct acpi_ec * ec)2094 static bool acpi_ec_work_in_progress(struct acpi_ec *ec)
2095 {
2096 return ec->events_in_progress + ec->queries_in_progress > 0;
2097 }
2098
acpi_ec_dispatch_gpe(void)2099 bool acpi_ec_dispatch_gpe(void)
2100 {
2101 bool work_in_progress = false;
2102
2103 if (!first_ec)
2104 return acpi_any_gpe_status_set(U32_MAX);
2105
2106 /*
2107 * Report wakeup if the status bit is set for any enabled GPE other
2108 * than the EC one.
2109 */
2110 if (acpi_any_gpe_status_set(first_ec->gpe))
2111 return true;
2112
2113 /*
2114 * Cancel the SCI wakeup and process all pending events in case there
2115 * are any wakeup ones in there.
2116 *
2117 * Note that if any non-EC GPEs are active at this point, the SCI will
2118 * retrigger after the rearming in acpi_s2idle_wake(), so no events
2119 * should be missed by canceling the wakeup here.
2120 */
2121 pm_system_cancel_wakeup();
2122
2123 /*
2124 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2125 * to allow the caller to process events properly after that.
2126 */
2127 spin_lock_irq(&first_ec->lock);
2128
2129 if (acpi_ec_gpe_status_set(first_ec)) {
2130 pm_pr_dbg("ACPI EC GPE status set\n");
2131
2132 clear_gpe_and_advance_transaction(first_ec, false);
2133 work_in_progress = acpi_ec_work_in_progress(first_ec);
2134 }
2135
2136 spin_unlock_irq(&first_ec->lock);
2137
2138 if (!work_in_progress)
2139 return false;
2140
2141 pm_pr_dbg("ACPI EC GPE dispatched\n");
2142
2143 /* Drain EC work. */
2144 do {
2145 acpi_ec_flush_work();
2146
2147 pm_pr_dbg("ACPI EC work flushed\n");
2148
2149 spin_lock_irq(&first_ec->lock);
2150
2151 work_in_progress = acpi_ec_work_in_progress(first_ec);
2152
2153 spin_unlock_irq(&first_ec->lock);
2154 } while (work_in_progress && !pm_wakeup_pending());
2155
2156 return false;
2157 }
2158 #endif /* CONFIG_PM_SLEEP */
2159
2160 static const struct dev_pm_ops acpi_ec_pm = {
2161 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2162 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2163 };
2164
param_set_event_clearing(const char * val,const struct kernel_param * kp)2165 static int param_set_event_clearing(const char *val,
2166 const struct kernel_param *kp)
2167 {
2168 int result = 0;
2169
2170 if (!strncmp(val, "status", sizeof("status") - 1)) {
2171 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2172 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2173 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2174 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2175 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2176 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2177 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2178 pr_info("Assuming SCI_EVT clearing on event reads\n");
2179 } else
2180 result = -EINVAL;
2181 return result;
2182 }
2183
param_get_event_clearing(char * buffer,const struct kernel_param * kp)2184 static int param_get_event_clearing(char *buffer,
2185 const struct kernel_param *kp)
2186 {
2187 switch (ec_event_clearing) {
2188 case ACPI_EC_EVT_TIMING_STATUS:
2189 return sprintf(buffer, "status\n");
2190 case ACPI_EC_EVT_TIMING_QUERY:
2191 return sprintf(buffer, "query\n");
2192 case ACPI_EC_EVT_TIMING_EVENT:
2193 return sprintf(buffer, "event\n");
2194 default:
2195 return sprintf(buffer, "invalid\n");
2196 }
2197 return 0;
2198 }
2199
2200 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2201 NULL, 0644);
2202 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2203
2204 static struct acpi_driver acpi_ec_driver = {
2205 .name = "ec",
2206 .class = ACPI_EC_CLASS,
2207 .ids = ec_device_ids,
2208 .ops = {
2209 .add = acpi_ec_add,
2210 .remove = acpi_ec_remove,
2211 },
2212 .drv.pm = &acpi_ec_pm,
2213 };
2214
acpi_ec_destroy_workqueues(void)2215 static void acpi_ec_destroy_workqueues(void)
2216 {
2217 if (ec_wq) {
2218 destroy_workqueue(ec_wq);
2219 ec_wq = NULL;
2220 }
2221 if (ec_query_wq) {
2222 destroy_workqueue(ec_query_wq);
2223 ec_query_wq = NULL;
2224 }
2225 }
2226
acpi_ec_init_workqueues(void)2227 static int acpi_ec_init_workqueues(void)
2228 {
2229 if (!ec_wq)
2230 ec_wq = alloc_ordered_workqueue("kec", 0);
2231
2232 if (!ec_query_wq)
2233 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2234
2235 if (!ec_wq || !ec_query_wq) {
2236 acpi_ec_destroy_workqueues();
2237 return -ENODEV;
2238 }
2239 return 0;
2240 }
2241
2242 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2243 {
2244 .matches = {
2245 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2246 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2247 },
2248 },
2249 {
2250 .matches = {
2251 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2252 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2253 },
2254 },
2255 {
2256 .matches = {
2257 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2258 DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2259 },
2260 },
2261 { },
2262 };
2263
acpi_ec_init(void)2264 void __init acpi_ec_init(void)
2265 {
2266 int result;
2267
2268 result = acpi_ec_init_workqueues();
2269 if (result)
2270 return;
2271
2272 /*
2273 * Disable EC wakeup on following systems to prevent periodic
2274 * wakeup from EC GPE.
2275 */
2276 if (dmi_check_system(acpi_ec_no_wakeup)) {
2277 ec_no_wakeup = true;
2278 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2279 }
2280
2281 /* Driver must be registered after acpi_ec_init_workqueues(). */
2282 acpi_bus_register_driver(&acpi_ec_driver);
2283
2284 acpi_ec_ecdt_start();
2285 }
2286
2287 /* EC driver currently not unloadable */
2288 #if 0
2289 static void __exit acpi_ec_exit(void)
2290 {
2291
2292 acpi_bus_unregister_driver(&acpi_ec_driver);
2293 acpi_ec_destroy_workqueues();
2294 }
2295 #endif /* 0 */
2296