1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * ec.c - ACPI Embedded Controller Driver (v3)
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>
15 /* Uncomment next line to get verbose printout */
17 #define pr_fmt(fmt) "ACPI: EC: " fmt
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>
35 #define ACPI_EC_CLASS "embedded_controller"
36 #define ACPI_EC_DEVICE_NAME "Embedded Controller"
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 */
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
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
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.
73 #define ACPI_EC_EVT_TIMING_STATUS 0x00
74 #define ACPI_EC_EVT_TIMING_QUERY 0x01
75 #define ACPI_EC_EVT_TIMING_EVENT 0x02
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,
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 */
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 */
104 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
105 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
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");
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");
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");
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");
124 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
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.
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");
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");
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");
143 struct acpi_ec_query_handler {
144 struct list_head node;
145 acpi_ec_query_func func;
155 unsigned short irq_count;
164 struct acpi_ec_query {
165 struct transaction transaction;
166 struct work_struct work;
167 struct acpi_ec_query_handler *handler;
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);
175 struct acpi_ec *first_ec;
176 EXPORT_SYMBOL(first_ec);
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;
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 */
187 /* --------------------------------------------------------------------------
189 * -------------------------------------------------------------------------- */
192 * Splitters used by the developers to track the boundary of the EC
193 * handling processes.
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 "#####"
202 #define EC_DBG_SEP ""
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__)
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__)
231 /* --------------------------------------------------------------------------
233 * -------------------------------------------------------------------------- */
235 static bool acpi_ec_started(struct acpi_ec *ec)
237 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
238 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
241 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
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.
248 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
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
256 * 2. false: The EC event handling is automatically disabled as
257 * soon as the EC driver is stopped.
259 if (ec_freeze_events)
260 return acpi_ec_started(ec);
262 return test_bit(EC_FLAGS_STARTED, &ec->flags);
265 static bool acpi_ec_flushed(struct acpi_ec *ec)
267 return ec->reference_count == 1;
270 /* --------------------------------------------------------------------------
272 * -------------------------------------------------------------------------- */
274 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
276 u8 x = inb(ec->command_addr);
278 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
279 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
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));
289 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
291 u8 x = inb(ec->data_addr);
293 ec->timestamp = jiffies;
294 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
298 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
300 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
301 outb(command, ec->command_addr);
302 ec->timestamp = jiffies;
305 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
307 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
308 outb(data, ec->data_addr);
309 ec->timestamp = jiffies;
312 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
313 static const char *acpi_ec_cmd_string(u8 cmd)
330 #define acpi_ec_cmd_string(cmd) "UNDEF"
333 /* --------------------------------------------------------------------------
335 * -------------------------------------------------------------------------- */
337 static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
339 acpi_event_status gpe_status = 0;
341 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
342 return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
345 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
348 acpi_enable_gpe(NULL, ec->gpe);
350 BUG_ON(ec->reference_count < 1);
351 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
353 if (acpi_ec_gpe_status_set(ec)) {
355 * On some platforms, EN=1 writes cannot trigger GPE. So
356 * software need to manually trigger a pseudo GPE event on
359 ec_dbg_raw("Polling quirk");
360 advance_transaction(ec, false);
364 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
367 acpi_disable_gpe(NULL, ec->gpe);
369 BUG_ON(ec->reference_count < 1);
370 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
374 /* --------------------------------------------------------------------------
375 * Transaction Management
376 * -------------------------------------------------------------------------- */
378 static void acpi_ec_submit_request(struct acpi_ec *ec)
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);
386 static void acpi_ec_complete_request(struct acpi_ec *ec)
388 bool flushed = false;
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);
399 static void acpi_ec_mask_events(struct acpi_ec *ec)
401 if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
403 acpi_ec_disable_gpe(ec, false);
405 disable_irq_nosync(ec->irq);
407 ec_dbg_drv("Polling enabled");
408 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
412 static void acpi_ec_unmask_events(struct acpi_ec *ec)
414 if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
415 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
417 acpi_ec_enable_gpe(ec, false);
421 ec_dbg_drv("Polling disabled");
426 * acpi_ec_submit_flushable_request() - Increase the reference count unless
427 * the flush operation is not in
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
436 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
438 if (!acpi_ec_started(ec))
440 acpi_ec_submit_request(ec);
444 static void acpi_ec_submit_event(struct acpi_ec *ec)
447 * It is safe to mask the events here, because acpi_ec_close_event()
448 * will run at least once after this.
450 acpi_ec_mask_events(ec);
451 if (!acpi_ec_event_enabled(ec))
454 if (ec->event_state != EC_EVENT_READY)
457 ec_dbg_evt("Command(%s) submitted/blocked",
458 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
460 ec->event_state = EC_EVENT_IN_PROGRESS;
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
468 if (ec->events_to_process++ > 0)
471 ec->events_in_progress++;
472 queue_work(ec_wq, &ec->work);
475 static void acpi_ec_complete_event(struct acpi_ec *ec)
477 if (ec->event_state == EC_EVENT_IN_PROGRESS)
478 ec->event_state = EC_EVENT_COMPLETE;
481 static void acpi_ec_close_event(struct acpi_ec *ec)
483 if (ec->event_state != EC_EVENT_READY)
484 ec_dbg_evt("Command(%s) unblocked",
485 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
487 ec->event_state = EC_EVENT_READY;
488 acpi_ec_unmask_events(ec);
491 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
493 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
494 ec_log_drv("event unblocked");
496 * Unconditionally invoke this once after enabling the event
497 * handling mechanism to detect the pending events.
499 advance_transaction(ec, false);
502 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
504 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
505 ec_log_drv("event blocked");
509 * Process _Q events that might have accumulated in the EC.
510 * Run with locked ec mutex.
512 static void acpi_ec_clear(struct acpi_ec *ec)
516 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
517 if (acpi_ec_submit_query(ec))
520 if (unlikely(i == ACPI_EC_CLEAR_MAX))
521 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
523 pr_info("%d stale EC events cleared\n", i);
526 static void acpi_ec_enable_event(struct acpi_ec *ec)
528 spin_lock(&ec->lock);
529 if (acpi_ec_started(ec))
530 __acpi_ec_enable_event(ec);
531 spin_unlock(&ec->lock);
533 /* Drain additional events if hardware requires that */
534 if (EC_FLAGS_CLEAR_ON_RESUME)
538 #ifdef CONFIG_PM_SLEEP
539 static void __acpi_ec_flush_work(void)
541 flush_workqueue(ec_wq); /* flush ec->work */
542 flush_workqueue(ec_query_wq); /* flush queries */
545 static void acpi_ec_disable_event(struct acpi_ec *ec)
547 spin_lock(&ec->lock);
548 __acpi_ec_disable_event(ec);
549 spin_unlock(&ec->lock);
552 * When ec_freeze_events is true, we need to flush events in
553 * the proper position before entering the noirq stage.
555 __acpi_ec_flush_work();
558 void acpi_ec_flush_work(void)
560 /* Without ec_wq there is nothing to flush. */
564 __acpi_ec_flush_work();
566 #endif /* CONFIG_PM_SLEEP */
568 static bool acpi_ec_guard_event(struct acpi_ec *ec)
572 spin_lock(&ec->lock);
574 * If firmware SCI_EVT clearing timing is "event", we actually
575 * don't know when the SCI_EVT will be cleared by firmware after
576 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
579 * The guarding period is applicable if the event state is not
580 * EC_EVENT_READY, but otherwise if the current transaction is of the
581 * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
582 * and it should not be applied to let the transaction transition into
583 * the ACPI_EC_COMMAND_POLL state immediately.
585 guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
586 ec->event_state != EC_EVENT_READY &&
587 (!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
588 spin_unlock(&ec->lock);
592 static int ec_transaction_polled(struct acpi_ec *ec)
596 spin_lock(&ec->lock);
597 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
599 spin_unlock(&ec->lock);
603 static int ec_transaction_completed(struct acpi_ec *ec)
607 spin_lock(&ec->lock);
608 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
610 spin_unlock(&ec->lock);
614 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
616 ec->curr->flags |= flag;
618 if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
621 switch (ec_event_clearing) {
622 case ACPI_EC_EVT_TIMING_STATUS:
623 if (flag == ACPI_EC_COMMAND_POLL)
624 acpi_ec_close_event(ec);
628 case ACPI_EC_EVT_TIMING_QUERY:
629 if (flag == ACPI_EC_COMMAND_COMPLETE)
630 acpi_ec_close_event(ec);
634 case ACPI_EC_EVT_TIMING_EVENT:
635 if (flag == ACPI_EC_COMMAND_COMPLETE)
636 acpi_ec_complete_event(ec);
640 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
642 if (t->irq_count < ec_storm_threshold)
645 /* Trigger if the threshold is 0 too. */
646 if (t->irq_count == ec_storm_threshold)
647 acpi_ec_mask_events(ec);
650 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
652 struct transaction *t = ec->curr;
656 ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
658 status = acpi_ec_read_status(ec);
661 * Another IRQ or a guarded polling mode advancement is detected,
662 * the next QR_EC submission is then allowed.
664 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
665 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
666 ec->event_state == EC_EVENT_COMPLETE)
667 acpi_ec_close_event(ec);
673 if (t->flags & ACPI_EC_COMMAND_POLL) {
674 if (t->wlen > t->wi) {
675 if (!(status & ACPI_EC_FLAG_IBF))
676 acpi_ec_write_data(ec, t->wdata[t->wi++]);
677 else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
678 acpi_ec_spurious_interrupt(ec, t);
679 } else if (t->rlen > t->ri) {
680 if (status & ACPI_EC_FLAG_OBF) {
681 t->rdata[t->ri++] = acpi_ec_read_data(ec);
682 if (t->rlen == t->ri) {
683 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
685 if (t->command == ACPI_EC_COMMAND_QUERY)
686 ec_dbg_evt("Command(%s) completed by hardware",
687 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
689 } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
690 acpi_ec_spurious_interrupt(ec, t);
692 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
693 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
696 } else if (!(status & ACPI_EC_FLAG_IBF)) {
697 acpi_ec_write_cmd(ec, t->command);
698 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
702 if (status & ACPI_EC_FLAG_SCI)
703 acpi_ec_submit_event(ec);
705 if (wakeup && interrupt)
709 static void start_transaction(struct acpi_ec *ec)
711 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
715 static int ec_guard(struct acpi_ec *ec)
717 unsigned long guard = usecs_to_jiffies(ec->polling_guard);
718 unsigned long timeout = ec->timestamp + guard;
720 /* Ensure guarding period before polling EC status */
722 if (ec->busy_polling) {
723 /* Perform busy polling */
724 if (ec_transaction_completed(ec))
726 udelay(jiffies_to_usecs(guard));
729 * Perform wait polling
730 * 1. Wait the transaction to be completed by the
731 * GPE handler after the transaction enters
732 * ACPI_EC_COMMAND_POLL state.
733 * 2. A special guarding logic is also required
734 * for event clearing mode "event" before the
735 * transaction enters ACPI_EC_COMMAND_POLL
738 if (!ec_transaction_polled(ec) &&
739 !acpi_ec_guard_event(ec))
741 if (wait_event_timeout(ec->wait,
742 ec_transaction_completed(ec),
746 } while (time_before(jiffies, timeout));
750 static int ec_poll(struct acpi_ec *ec)
752 int repeat = 5; /* number of command restarts */
755 unsigned long delay = jiffies +
756 msecs_to_jiffies(ec_delay);
760 spin_lock(&ec->lock);
761 advance_transaction(ec, false);
762 spin_unlock(&ec->lock);
763 } while (time_before(jiffies, delay));
764 pr_debug("controller reset, restart transaction\n");
765 spin_lock(&ec->lock);
766 start_transaction(ec);
767 spin_unlock(&ec->lock);
772 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
773 struct transaction *t)
777 /* start transaction */
778 spin_lock(&ec->lock);
779 /* Enable GPE for command processing (IBF=0/OBF=1) */
780 if (!acpi_ec_submit_flushable_request(ec)) {
784 ec_dbg_ref(ec, "Increase command");
785 /* following two actions should be kept atomic */
787 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
788 start_transaction(ec);
789 spin_unlock(&ec->lock);
793 spin_lock(&ec->lock);
794 if (t->irq_count == ec_storm_threshold)
795 acpi_ec_unmask_events(ec);
796 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
798 /* Disable GPE for command processing (IBF=0/OBF=1) */
799 acpi_ec_complete_request(ec);
800 ec_dbg_ref(ec, "Decrease command");
802 spin_unlock(&ec->lock);
806 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
811 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
814 memset(t->rdata, 0, t->rlen);
816 mutex_lock(&ec->mutex);
817 if (ec->global_lock) {
818 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
819 if (ACPI_FAILURE(status)) {
825 status = acpi_ec_transaction_unlocked(ec, t);
828 acpi_release_global_lock(glk);
830 mutex_unlock(&ec->mutex);
834 static int acpi_ec_burst_enable(struct acpi_ec *ec)
837 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
838 .wdata = NULL, .rdata = &d,
839 .wlen = 0, .rlen = 1};
841 return acpi_ec_transaction(ec, &t);
844 static int acpi_ec_burst_disable(struct acpi_ec *ec)
846 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
847 .wdata = NULL, .rdata = NULL,
848 .wlen = 0, .rlen = 0};
850 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
851 acpi_ec_transaction(ec, &t) : 0;
854 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
858 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
859 .wdata = &address, .rdata = &d,
860 .wlen = 1, .rlen = 1};
862 result = acpi_ec_transaction(ec, &t);
867 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
869 u8 wdata[2] = { address, data };
870 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
871 .wdata = wdata, .rdata = NULL,
872 .wlen = 2, .rlen = 0};
874 return acpi_ec_transaction(ec, &t);
877 int ec_read(u8 addr, u8 *val)
885 err = acpi_ec_read(first_ec, addr, &temp_data);
893 EXPORT_SYMBOL(ec_read);
895 int ec_write(u8 addr, u8 val)
900 return acpi_ec_write(first_ec, addr, val);
902 EXPORT_SYMBOL(ec_write);
904 int ec_transaction(u8 command,
905 const u8 *wdata, unsigned wdata_len,
906 u8 *rdata, unsigned rdata_len)
908 struct transaction t = {.command = command,
909 .wdata = wdata, .rdata = rdata,
910 .wlen = wdata_len, .rlen = rdata_len};
915 return acpi_ec_transaction(first_ec, &t);
917 EXPORT_SYMBOL(ec_transaction);
919 /* Get the handle to the EC device */
920 acpi_handle ec_get_handle(void)
924 return first_ec->handle;
926 EXPORT_SYMBOL(ec_get_handle);
928 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
930 spin_lock(&ec->lock);
931 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
932 ec_dbg_drv("Starting EC");
933 /* Enable GPE for event processing (SCI_EVT=1) */
935 acpi_ec_submit_request(ec);
936 ec_dbg_ref(ec, "Increase driver");
938 ec_log_drv("EC started");
940 spin_unlock(&ec->lock);
943 static bool acpi_ec_stopped(struct acpi_ec *ec)
947 spin_lock(&ec->lock);
948 flushed = acpi_ec_flushed(ec);
949 spin_unlock(&ec->lock);
953 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
955 spin_lock(&ec->lock);
956 if (acpi_ec_started(ec)) {
957 ec_dbg_drv("Stopping EC");
958 set_bit(EC_FLAGS_STOPPED, &ec->flags);
959 spin_unlock(&ec->lock);
960 wait_event(ec->wait, acpi_ec_stopped(ec));
961 spin_lock(&ec->lock);
962 /* Disable GPE for event processing (SCI_EVT=1) */
964 acpi_ec_complete_request(ec);
965 ec_dbg_ref(ec, "Decrease driver");
966 } else if (!ec_freeze_events)
967 __acpi_ec_disable_event(ec);
968 clear_bit(EC_FLAGS_STARTED, &ec->flags);
969 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
970 ec_log_drv("EC stopped");
972 spin_unlock(&ec->lock);
975 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
977 spin_lock(&ec->lock);
978 ec->busy_polling = true;
979 ec->polling_guard = 0;
980 ec_log_drv("interrupt blocked");
981 spin_unlock(&ec->lock);
984 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
986 spin_lock(&ec->lock);
987 ec->busy_polling = ec_busy_polling;
988 ec->polling_guard = ec_polling_guard;
989 ec_log_drv("interrupt unblocked");
990 spin_unlock(&ec->lock);
993 void acpi_ec_block_transactions(void)
995 struct acpi_ec *ec = first_ec;
1000 mutex_lock(&ec->mutex);
1001 /* Prevent transactions from being carried out */
1002 acpi_ec_stop(ec, true);
1003 mutex_unlock(&ec->mutex);
1006 void acpi_ec_unblock_transactions(void)
1009 * Allow transactions to happen again (this function is called from
1010 * atomic context during wakeup, so we don't need to acquire the mutex).
1013 acpi_ec_start(first_ec, true);
1016 /* --------------------------------------------------------------------------
1018 -------------------------------------------------------------------------- */
1019 static struct acpi_ec_query_handler *
1020 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1022 struct acpi_ec_query_handler *handler;
1024 mutex_lock(&ec->mutex);
1025 list_for_each_entry(handler, &ec->list, node) {
1026 if (value == handler->query_bit) {
1027 kref_get(&handler->kref);
1028 mutex_unlock(&ec->mutex);
1032 mutex_unlock(&ec->mutex);
1036 static void acpi_ec_query_handler_release(struct kref *kref)
1038 struct acpi_ec_query_handler *handler =
1039 container_of(kref, struct acpi_ec_query_handler, kref);
1044 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1046 kref_put(&handler->kref, acpi_ec_query_handler_release);
1049 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1050 acpi_handle handle, acpi_ec_query_func func,
1053 struct acpi_ec_query_handler *handler;
1055 if (!handle && !func)
1058 handler = kzalloc(sizeof(*handler), GFP_KERNEL);
1062 handler->query_bit = query_bit;
1063 handler->handle = handle;
1064 handler->func = func;
1065 handler->data = data;
1066 mutex_lock(&ec->mutex);
1067 kref_init(&handler->kref);
1068 list_add(&handler->node, &ec->list);
1069 mutex_unlock(&ec->mutex);
1073 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1075 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1076 bool remove_all, u8 query_bit)
1078 struct acpi_ec_query_handler *handler, *tmp;
1079 LIST_HEAD(free_list);
1081 mutex_lock(&ec->mutex);
1082 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1084 * When remove_all is false, only remove custom query handlers
1085 * which have handler->func set. This is done to preserve query
1086 * handlers discovered thru ACPI, as they should continue handling
1089 if (remove_all || (handler->func && handler->query_bit == query_bit)) {
1090 list_del_init(&handler->node);
1091 list_add(&handler->node, &free_list);
1095 mutex_unlock(&ec->mutex);
1096 list_for_each_entry_safe(handler, tmp, &free_list, node)
1097 acpi_ec_put_query_handler(handler);
1100 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1102 acpi_ec_remove_query_handlers(ec, false, query_bit);
1103 flush_workqueue(ec_query_wq);
1105 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1107 static void acpi_ec_event_processor(struct work_struct *work)
1109 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1110 struct acpi_ec_query_handler *handler = q->handler;
1111 struct acpi_ec *ec = q->ec;
1113 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1116 handler->func(handler->data);
1117 else if (handler->handle)
1118 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1120 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1122 spin_lock(&ec->lock);
1123 ec->queries_in_progress--;
1124 spin_unlock(&ec->lock);
1126 acpi_ec_put_query_handler(handler);
1130 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1132 struct acpi_ec_query *q;
1133 struct transaction *t;
1135 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1139 INIT_WORK(&q->work, acpi_ec_event_processor);
1140 t = &q->transaction;
1141 t->command = ACPI_EC_COMMAND_QUERY;
1148 static int acpi_ec_submit_query(struct acpi_ec *ec)
1150 struct acpi_ec_query *q;
1154 q = acpi_ec_create_query(ec, &value);
1159 * Query the EC to find out which _Qxx method we need to evaluate.
1160 * Note that successful completion of the query causes the ACPI_EC_SCI
1161 * bit to be cleared (and thus clearing the interrupt source).
1163 result = acpi_ec_transaction(ec, &q->transaction);
1172 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1179 * It is reported that _Qxx are evaluated in a parallel way on Windows:
1180 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1182 * Put this log entry before queue_work() to make it appear in the log
1183 * before any other messages emitted during workqueue handling.
1185 ec_dbg_evt("Query(0x%02x) scheduled", value);
1187 spin_lock(&ec->lock);
1189 ec->queries_in_progress++;
1190 queue_work(ec_query_wq, &q->work);
1192 spin_unlock(&ec->lock);
1202 static void acpi_ec_event_handler(struct work_struct *work)
1204 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1206 ec_dbg_evt("Event started");
1208 spin_lock(&ec->lock);
1210 while (ec->events_to_process) {
1211 spin_unlock(&ec->lock);
1213 acpi_ec_submit_query(ec);
1215 spin_lock(&ec->lock);
1217 ec->events_to_process--;
1221 * Before exit, make sure that the it will be possible to queue up the
1222 * event handling work again regardless of whether or not the query
1223 * queued up above is processed successfully.
1225 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1228 acpi_ec_complete_event(ec);
1230 ec_dbg_evt("Event stopped");
1232 spin_unlock(&ec->lock);
1234 guard_timeout = !!ec_guard(ec);
1236 spin_lock(&ec->lock);
1238 /* Take care of SCI_EVT unless someone else is doing that. */
1239 if (guard_timeout && !ec->curr)
1240 advance_transaction(ec, false);
1242 acpi_ec_close_event(ec);
1244 ec_dbg_evt("Event stopped");
1247 ec->events_in_progress--;
1249 spin_unlock(&ec->lock);
1252 static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)
1255 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
1256 * changes to always trigger a GPE interrupt.
1258 * GPE STS is a W1C register, which means:
1260 * 1. Software can clear it without worrying about clearing the other
1261 * GPEs' STS bits when the hardware sets them in parallel.
1263 * 2. As long as software can ensure only clearing it when it is set,
1264 * hardware won't set it in parallel.
1266 if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
1267 acpi_clear_gpe(NULL, ec->gpe);
1269 advance_transaction(ec, true);
1272 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1274 spin_lock(&ec->lock);
1276 clear_gpe_and_advance_transaction(ec, true);
1278 spin_unlock(&ec->lock);
1281 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1282 u32 gpe_number, void *data)
1284 acpi_ec_handle_interrupt(data);
1285 return ACPI_INTERRUPT_HANDLED;
1288 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1290 acpi_ec_handle_interrupt(data);
1294 /* --------------------------------------------------------------------------
1295 * Address Space Management
1296 * -------------------------------------------------------------------------- */
1299 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1300 u32 bits, u64 *value64,
1301 void *handler_context, void *region_context)
1303 struct acpi_ec *ec = handler_context;
1304 int result = 0, i, bytes = bits / 8;
1305 u8 *value = (u8 *)value64;
1307 if ((address > 0xFF) || !value || !handler_context)
1308 return AE_BAD_PARAMETER;
1310 if (function != ACPI_READ && function != ACPI_WRITE)
1311 return AE_BAD_PARAMETER;
1313 if (ec->busy_polling || bits > 8)
1314 acpi_ec_burst_enable(ec);
1316 for (i = 0; i < bytes; ++i, ++address, ++value)
1317 result = (function == ACPI_READ) ?
1318 acpi_ec_read(ec, address, value) :
1319 acpi_ec_write(ec, address, *value);
1321 if (ec->busy_polling || bits > 8)
1322 acpi_ec_burst_disable(ec);
1326 return AE_BAD_PARAMETER;
1328 return AE_NOT_FOUND;
1336 /* --------------------------------------------------------------------------
1338 * -------------------------------------------------------------------------- */
1341 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1343 static void acpi_ec_free(struct acpi_ec *ec)
1352 static struct acpi_ec *acpi_ec_alloc(void)
1354 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1358 mutex_init(&ec->mutex);
1359 init_waitqueue_head(&ec->wait);
1360 INIT_LIST_HEAD(&ec->list);
1361 spin_lock_init(&ec->lock);
1362 INIT_WORK(&ec->work, acpi_ec_event_handler);
1363 ec->timestamp = jiffies;
1364 ec->busy_polling = true;
1365 ec->polling_guard = 0;
1372 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1373 void *context, void **return_value)
1376 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1377 struct acpi_ec *ec = context;
1381 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1383 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1384 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1389 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1392 unsigned long long tmp = 0;
1393 struct acpi_ec *ec = context;
1395 /* clear addr values, ec_parse_io_ports depend on it */
1396 ec->command_addr = ec->data_addr = 0;
1398 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1399 ec_parse_io_ports, ec);
1400 if (ACPI_FAILURE(status))
1402 if (ec->data_addr == 0 || ec->command_addr == 0)
1405 /* Get GPE bit assignment (EC events). */
1406 /* TODO: Add support for _GPE returning a package */
1407 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1408 if (ACPI_SUCCESS(status))
1411 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1412 * platforms which use GpioInt instead of GPE.
1415 /* Use the global lock for all EC transactions? */
1417 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1418 ec->global_lock = tmp;
1419 ec->handle = handle;
1420 return AE_CTRL_TERMINATE;
1423 static bool install_gpe_event_handler(struct acpi_ec *ec)
1427 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1428 ACPI_GPE_EDGE_TRIGGERED,
1429 &acpi_ec_gpe_handler, ec);
1430 if (ACPI_FAILURE(status))
1433 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1434 acpi_ec_enable_gpe(ec, true);
1439 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1441 return request_threaded_irq(ec->irq, NULL, acpi_ec_irq_handler,
1442 IRQF_SHARED | IRQF_ONESHOT, "ACPI EC", ec) >= 0;
1446 * ec_install_handlers - Install service callbacks and register query methods.
1448 * @device: ACPI device object corresponding to @ec.
1449 * @call_reg: If _REG should be called to notify OpRegion availability
1451 * Install a handler for the EC address space type unless it has been installed
1452 * already. If @device is not NULL, also look for EC query methods in the
1453 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1454 * handler for the EC, if possible.
1457 * -ENODEV if the address space handler cannot be installed, which means
1458 * "unable to handle transactions",
1459 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1460 * or 0 (success) otherwise.
1462 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1467 acpi_ec_start(ec, false);
1469 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1470 acpi_ec_enter_noirq(ec);
1471 status = acpi_install_address_space_handler_no_reg(ec->handle,
1473 &acpi_ec_space_handler,
1475 if (ACPI_FAILURE(status)) {
1476 acpi_ec_stop(ec, false);
1479 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1480 ec->address_space_handler_holder = ec->handle;
1483 if (call_reg && !test_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags)) {
1484 acpi_execute_reg_methods(ec->handle, ACPI_ADR_SPACE_EC);
1485 set_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags);
1492 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1493 int irq = acpi_dev_gpio_irq_get(device, 0);
1495 * Bail out right away for deferred probing or complete the
1496 * initialization regardless of any other errors.
1498 if (irq == -EPROBE_DEFER)
1499 return -EPROBE_DEFER;
1504 if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1505 /* Find and register all query methods */
1506 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1507 acpi_ec_register_query_methods,
1509 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1511 if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1515 ready = install_gpe_event_handler(ec);
1516 else if (ec->irq >= 0)
1517 ready = install_gpio_irq_event_handler(ec);
1520 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1521 acpi_ec_leave_noirq(ec);
1524 * Failures to install an event handler are not fatal, because
1525 * the EC can be polled for events.
1528 /* EC is fully operational, allow queries */
1529 acpi_ec_enable_event(ec);
1534 static void ec_remove_handlers(struct acpi_ec *ec)
1536 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1537 if (ACPI_FAILURE(acpi_remove_address_space_handler(
1538 ec->address_space_handler_holder,
1539 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1540 pr_err("failed to remove space handler\n");
1541 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1545 * Stops handling the EC transactions after removing the operation
1546 * region handler. This is required because _REG(DISCONNECT)
1547 * invoked during the removal can result in new EC transactions.
1549 * Flushes the EC requests and thus disables the GPE before
1550 * removing the GPE handler. This is required by the current ACPICA
1551 * GPE core. ACPICA GPE core will automatically disable a GPE when
1552 * it is indicated but there is no way to handle it. So the drivers
1553 * must disable the GPEs prior to removing the GPE handlers.
1555 acpi_ec_stop(ec, false);
1557 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1559 ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1560 &acpi_ec_gpe_handler)))
1561 pr_err("failed to remove gpe handler\n");
1564 free_irq(ec->irq, ec);
1566 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1568 if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1569 acpi_ec_remove_query_handlers(ec, true, 0);
1570 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1574 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device, bool call_reg)
1578 ret = ec_install_handlers(ec, device, call_reg);
1582 /* First EC capable of handling transactions */
1586 pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1589 if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1591 pr_info("GPE=0x%x\n", ec->gpe);
1593 pr_info("IRQ=%d\n", ec->irq);
1599 static int acpi_ec_add(struct acpi_device *device)
1604 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1605 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1607 if (boot_ec && (boot_ec->handle == device->handle ||
1608 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1609 /* Fast path: this device corresponds to the boot EC. */
1614 ec = acpi_ec_alloc();
1618 status = ec_parse_device(device->handle, 0, ec, NULL);
1619 if (status != AE_CTRL_TERMINATE) {
1624 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1625 ec->data_addr == boot_ec->data_addr) {
1627 * Trust PNP0C09 namespace location rather than ECDT ID.
1628 * But trust ECDT GPE rather than _GPE because of ASUS
1629 * quirks. So do not change boot_ec->gpe to ec->gpe,
1630 * except when the TRUST_DSDT_GPE quirk is set.
1632 boot_ec->handle = ec->handle;
1634 if (EC_FLAGS_TRUST_DSDT_GPE)
1635 boot_ec->gpe = ec->gpe;
1637 acpi_handle_debug(ec->handle, "duplicated.\n");
1643 ret = acpi_ec_setup(ec, device, true);
1648 acpi_handle_info(boot_ec->handle,
1649 "Boot %s EC initialization complete\n",
1650 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1652 acpi_handle_info(ec->handle,
1653 "EC: Used to handle transactions and events\n");
1655 device->driver_data = ec;
1657 ret = !!request_region(ec->data_addr, 1, "EC data");
1658 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1659 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1660 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1662 /* Reprobe devices depending on the EC */
1663 acpi_dev_clear_dependencies(device);
1665 acpi_handle_debug(ec->handle, "enumerated.\n");
1675 static void acpi_ec_remove(struct acpi_device *device)
1682 ec = acpi_driver_data(device);
1683 release_region(ec->data_addr, 1);
1684 release_region(ec->command_addr, 1);
1685 device->driver_data = NULL;
1686 if (ec != boot_ec) {
1687 ec_remove_handlers(ec);
1693 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1695 struct acpi_ec *ec = context;
1697 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1701 * The first address region returned is the data port, and
1702 * the second address region returned is the status/command
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;
1710 return AE_CTRL_TERMINATE;
1715 static const struct acpi_device_id ec_device_ids[] = {
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.
1726 void __init acpi_ec_dsdt_probe(void)
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.
1741 ec = acpi_ec_alloc();
1746 * At this point, the namespace is initialized, so start to find
1747 * the namespace objects.
1749 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1750 if (ACPI_FAILURE(status) || !ec->handle) {
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.
1762 ret = acpi_ec_setup(ec, NULL, true);
1770 acpi_handle_info(ec->handle,
1771 "Boot DSDT EC used to handle transactions\n");
1775 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
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.
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).
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).
1787 static void __init acpi_ec_ecdt_start(void)
1789 struct acpi_table_ecdt *ecdt_ptr;
1793 /* Bail out if a matching EC has been found in the namespace. */
1794 if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
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))
1803 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1804 if (ACPI_SUCCESS(status)) {
1805 boot_ec->handle = handle;
1807 /* Add a special ACPI device object to represent the boot EC. */
1808 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1811 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
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)
1819 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
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.
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.
1828 * On systems which don't accumulate _Q events during sleep, this extra check
1829 * should be harmless.
1831 static int ec_clear_on_resume(const struct dmi_system_id *id)
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;
1840 * Some ECDTs contain wrong register addresses.
1842 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1844 static int ec_correct_ecdt(const struct dmi_system_id *id)
1846 pr_debug("Detected system needing ECDT address correction.\n");
1847 EC_FLAGS_CORRECT_ECDT = 1;
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
1856 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1858 pr_debug("Detected system needing DSDT GPE setting.\n");
1859 EC_FLAGS_TRUST_DSDT_GPE = 1;
1863 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1867 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1869 .callback = ec_correct_ecdt,
1871 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1872 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),
1877 * HP Pavilion Gaming Laptop 15-cx0xxx
1878 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1880 .callback = ec_honor_dsdt_gpe,
1882 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1883 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),
1888 * HP Pavilion Gaming Laptop 15-cx0041ur
1890 .callback = ec_honor_dsdt_gpe,
1892 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1893 DMI_MATCH(DMI_PRODUCT_NAME, "HP 15-cx0041ur"),
1898 * HP Pavilion Gaming Laptop 15-dk1xxx
1899 * https://github.com/systemd/systemd/issues/28942
1901 .callback = ec_honor_dsdt_gpe,
1903 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1904 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-dk1xxx"),
1909 * HP 250 G7 Notebook PC
1911 .callback = ec_honor_dsdt_gpe,
1913 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1914 DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"),
1920 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1922 .callback = ec_clear_on_resume,
1924 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
1930 void __init acpi_ec_ecdt_probe(void)
1932 struct acpi_table_ecdt *ecdt_ptr;
1937 /* Generate a boot ec context. */
1938 dmi_check_system(ec_dmi_table);
1939 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1940 (struct acpi_table_header **)&ecdt_ptr);
1941 if (ACPI_FAILURE(status))
1944 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1947 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1952 ec = acpi_ec_alloc();
1956 if (EC_FLAGS_CORRECT_ECDT) {
1957 ec->command_addr = ecdt_ptr->data.address;
1958 ec->data_addr = ecdt_ptr->control.address;
1960 ec->command_addr = ecdt_ptr->control.address;
1961 ec->data_addr = ecdt_ptr->data.address;
1965 * Ignore the GPE value on Reduced Hardware platforms.
1966 * Some products have this set to an erroneous value.
1968 if (!acpi_gbl_reduced_hardware)
1969 ec->gpe = ecdt_ptr->gpe;
1971 ec->handle = ACPI_ROOT_OBJECT;
1974 * At this point, the namespace is not initialized, so do not find
1975 * the namespace objects, or handle the events.
1977 ret = acpi_ec_setup(ec, NULL, false);
1984 boot_ec_is_ecdt = true;
1986 pr_info("Boot ECDT EC used to handle transactions\n");
1989 acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1992 #ifdef CONFIG_PM_SLEEP
1993 static int acpi_ec_suspend(struct device *dev)
1995 struct acpi_ec *ec =
1996 acpi_driver_data(to_acpi_device(dev));
1998 if (!pm_suspend_no_platform() && ec_freeze_events)
1999 acpi_ec_disable_event(ec);
2003 static int acpi_ec_suspend_noirq(struct device *dev)
2005 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2008 * The SCI handler doesn't run at this point, so the GPE can be
2009 * masked at the low level without side effects.
2011 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2012 ec->gpe >= 0 && ec->reference_count >= 1)
2013 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2015 acpi_ec_enter_noirq(ec);
2020 static int acpi_ec_resume_noirq(struct device *dev)
2022 struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2024 acpi_ec_leave_noirq(ec);
2026 if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2027 ec->gpe >= 0 && ec->reference_count >= 1)
2028 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2033 static int acpi_ec_resume(struct device *dev)
2035 struct acpi_ec *ec =
2036 acpi_driver_data(to_acpi_device(dev));
2038 acpi_ec_enable_event(ec);
2042 void acpi_ec_mark_gpe_for_wake(void)
2044 if (first_ec && !ec_no_wakeup)
2045 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2047 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2049 void acpi_ec_set_gpe_wake_mask(u8 action)
2051 if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2052 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2055 static bool acpi_ec_work_in_progress(struct acpi_ec *ec)
2057 return ec->events_in_progress + ec->queries_in_progress > 0;
2060 bool acpi_ec_dispatch_gpe(void)
2062 bool work_in_progress = false;
2065 return acpi_any_gpe_status_set(U32_MAX);
2068 * Report wakeup if the status bit is set for any enabled GPE other
2071 if (acpi_any_gpe_status_set(first_ec->gpe))
2075 * Cancel the SCI wakeup and process all pending events in case there
2076 * are any wakeup ones in there.
2078 * Note that if any non-EC GPEs are active at this point, the SCI will
2079 * retrigger after the rearming in acpi_s2idle_wake(), so no events
2080 * should be missed by canceling the wakeup here.
2082 pm_system_cancel_wakeup();
2085 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2086 * to allow the caller to process events properly after that.
2088 spin_lock(&first_ec->lock);
2090 if (acpi_ec_gpe_status_set(first_ec)) {
2091 pm_pr_dbg("ACPI EC GPE status set\n");
2093 clear_gpe_and_advance_transaction(first_ec, false);
2094 work_in_progress = acpi_ec_work_in_progress(first_ec);
2097 spin_unlock(&first_ec->lock);
2099 if (!work_in_progress)
2102 pm_pr_dbg("ACPI EC GPE dispatched\n");
2104 /* Drain EC work. */
2106 acpi_ec_flush_work();
2108 pm_pr_dbg("ACPI EC work flushed\n");
2110 spin_lock(&first_ec->lock);
2112 work_in_progress = acpi_ec_work_in_progress(first_ec);
2114 spin_unlock(&first_ec->lock);
2115 } while (work_in_progress && !pm_wakeup_pending());
2119 #endif /* CONFIG_PM_SLEEP */
2121 static const struct dev_pm_ops acpi_ec_pm = {
2122 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2123 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2126 static int param_set_event_clearing(const char *val,
2127 const struct kernel_param *kp)
2131 if (!strncmp(val, "status", sizeof("status") - 1)) {
2132 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2133 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2134 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2135 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2136 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2137 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2138 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2139 pr_info("Assuming SCI_EVT clearing on event reads\n");
2145 static int param_get_event_clearing(char *buffer,
2146 const struct kernel_param *kp)
2148 switch (ec_event_clearing) {
2149 case ACPI_EC_EVT_TIMING_STATUS:
2150 return sprintf(buffer, "status\n");
2151 case ACPI_EC_EVT_TIMING_QUERY:
2152 return sprintf(buffer, "query\n");
2153 case ACPI_EC_EVT_TIMING_EVENT:
2154 return sprintf(buffer, "event\n");
2156 return sprintf(buffer, "invalid\n");
2161 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2163 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2165 static struct acpi_driver acpi_ec_driver = {
2167 .class = ACPI_EC_CLASS,
2168 .ids = ec_device_ids,
2171 .remove = acpi_ec_remove,
2173 .drv.pm = &acpi_ec_pm,
2176 static void acpi_ec_destroy_workqueues(void)
2179 destroy_workqueue(ec_wq);
2183 destroy_workqueue(ec_query_wq);
2188 static int acpi_ec_init_workqueues(void)
2191 ec_wq = alloc_ordered_workqueue("kec", 0);
2194 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2196 if (!ec_wq || !ec_query_wq) {
2197 acpi_ec_destroy_workqueues();
2203 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2206 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2207 DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2212 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2213 DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2218 DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2219 DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2225 void __init acpi_ec_init(void)
2229 result = acpi_ec_init_workqueues();
2234 * Disable EC wakeup on following systems to prevent periodic
2235 * wakeup from EC GPE.
2237 if (dmi_check_system(acpi_ec_no_wakeup)) {
2238 ec_no_wakeup = true;
2239 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2242 /* Driver must be registered after acpi_ec_init_workqueues(). */
2243 acpi_bus_register_driver(&acpi_ec_driver);
2245 acpi_ec_ecdt_start();
2248 /* EC driver currently not unloadable */
2250 static void __exit acpi_ec_exit(void)
2253 acpi_bus_unregister_driver(&acpi_ec_driver);
2254 acpi_ec_destroy_workqueues();