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block: Minor blk_account_io_start usage cleanup
[deliverable/linux.git] / drivers / acpi / ec.c
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1/*
2 * ec.c - ACPI Embedded Controller Driver (v3)
3 *
4 * Copyright (C) 2001-2015 Intel Corporation
5 * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
6 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
7 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
8 * 2004 Luming Yu <luming.yu@intel.com>
9 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
10 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
11 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
12 *
13 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or (at
18 * your option) any later version.
19 *
20 * This program is distributed in the hope that it will be useful, but
21 * WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 * General Public License for more details.
24 *
25 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26 */
27
28/* Uncomment next line to get verbose printout */
29/* #define DEBUG */
30#define pr_fmt(fmt) "ACPI : EC: " fmt
31
32#include <linux/kernel.h>
33#include <linux/module.h>
34#include <linux/init.h>
35#include <linux/types.h>
36#include <linux/delay.h>
37#include <linux/interrupt.h>
38#include <linux/list.h>
39#include <linux/spinlock.h>
40#include <linux/slab.h>
41#include <linux/acpi.h>
42#include <linux/dmi.h>
43#include <asm/io.h>
44
45#include "internal.h"
46
47#define ACPI_EC_CLASS "embedded_controller"
48#define ACPI_EC_DEVICE_NAME "Embedded Controller"
49#define ACPI_EC_FILE_INFO "info"
50
51/* EC status register */
52#define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
53#define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
54#define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
55#define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
56#define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
57
58/*
59 * The SCI_EVT clearing timing is not defined by the ACPI specification.
60 * This leads to lots of practical timing issues for the host EC driver.
61 * The following variations are defined (from the target EC firmware's
62 * perspective):
63 * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
64 * target can clear SCI_EVT at any time so long as the host can see
65 * the indication by reading the status register (EC_SC). So the
66 * host should re-check SCI_EVT after the first time the SCI_EVT
67 * indication is seen, which is the same time the query request
68 * (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
69 * at any later time could indicate another event. Normally such
70 * kind of EC firmware has implemented an event queue and will
71 * return 0x00 to indicate "no outstanding event".
72 * QUERY: After seeing the query request (QR_EC) written to the command
73 * register (EC_CMD) by the host and having prepared the responding
74 * event value in the data register (EC_DATA), the target can safely
75 * clear SCI_EVT because the target can confirm that the current
76 * event is being handled by the host. The host then should check
77 * SCI_EVT right after reading the event response from the data
78 * register (EC_DATA).
79 * EVENT: After seeing the event response read from the data register
80 * (EC_DATA) by the host, the target can clear SCI_EVT. As the
81 * target requires time to notice the change in the data register
82 * (EC_DATA), the host may be required to wait additional guarding
83 * time before checking the SCI_EVT again. Such guarding may not be
84 * necessary if the host is notified via another IRQ.
85 */
86#define ACPI_EC_EVT_TIMING_STATUS 0x00
87#define ACPI_EC_EVT_TIMING_QUERY 0x01
88#define ACPI_EC_EVT_TIMING_EVENT 0x02
89
90/* EC commands */
91enum ec_command {
92 ACPI_EC_COMMAND_READ = 0x80,
93 ACPI_EC_COMMAND_WRITE = 0x81,
94 ACPI_EC_BURST_ENABLE = 0x82,
95 ACPI_EC_BURST_DISABLE = 0x83,
96 ACPI_EC_COMMAND_QUERY = 0x84,
97};
98
99#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
100#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
101#define ACPI_EC_UDELAY_POLL 550 /* Wait 1ms for EC transaction polling */
102#define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
103 * when trying to clear the EC */
104
105enum {
106 EC_FLAGS_QUERY_PENDING, /* Query is pending */
107 EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */
108 EC_FLAGS_HANDLERS_INSTALLED, /* Handlers for GPE and
109 * OpReg are installed */
110 EC_FLAGS_STARTED, /* Driver is started */
111 EC_FLAGS_STOPPED, /* Driver is stopped */
112 EC_FLAGS_COMMAND_STORM, /* GPE storms occurred to the
113 * current command processing */
114};
115
116#define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
117#define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
118
119/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
120static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
121module_param(ec_delay, uint, 0644);
122MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
123
124static bool ec_busy_polling __read_mostly;
125module_param(ec_busy_polling, bool, 0644);
126MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
127
128static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
129module_param(ec_polling_guard, uint, 0644);
130MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
131
132static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
133
134/*
135 * If the number of false interrupts per one transaction exceeds
136 * this threshold, will think there is a GPE storm happened and
137 * will disable the GPE for normal transaction.
138 */
139static unsigned int ec_storm_threshold __read_mostly = 8;
140module_param(ec_storm_threshold, uint, 0644);
141MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
142
143struct 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
152struct 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
164struct acpi_ec_query {
165 struct transaction transaction;
166 struct work_struct work;
167 struct acpi_ec_query_handler *handler;
168};
169
170static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
171static void advance_transaction(struct acpi_ec *ec);
172static void acpi_ec_event_handler(struct work_struct *work);
173static void acpi_ec_event_processor(struct work_struct *work);
174
175struct acpi_ec *boot_ec, *first_ec;
176EXPORT_SYMBOL(first_ec);
177
178static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
179static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
180static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
181static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
182
183/* --------------------------------------------------------------------------
184 * Logging/Debugging
185 * -------------------------------------------------------------------------- */
186
187/*
188 * Splitters used by the developers to track the boundary of the EC
189 * handling processes.
190 */
191#ifdef DEBUG
192#define EC_DBG_SEP " "
193#define EC_DBG_DRV "+++++"
194#define EC_DBG_STM "====="
195#define EC_DBG_REQ "*****"
196#define EC_DBG_EVT "#####"
197#else
198#define EC_DBG_SEP ""
199#define EC_DBG_DRV
200#define EC_DBG_STM
201#define EC_DBG_REQ
202#define EC_DBG_EVT
203#endif
204
205#define ec_log_raw(fmt, ...) \
206 pr_info(fmt "\n", ##__VA_ARGS__)
207#define ec_dbg_raw(fmt, ...) \
208 pr_debug(fmt "\n", ##__VA_ARGS__)
209#define ec_log(filter, fmt, ...) \
210 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
211#define ec_dbg(filter, fmt, ...) \
212 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
213
214#define ec_log_drv(fmt, ...) \
215 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
216#define ec_dbg_drv(fmt, ...) \
217 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
218#define ec_dbg_stm(fmt, ...) \
219 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
220#define ec_dbg_req(fmt, ...) \
221 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
222#define ec_dbg_evt(fmt, ...) \
223 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
224#define ec_dbg_ref(ec, fmt, ...) \
225 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
226
227/* --------------------------------------------------------------------------
228 * Device Flags
229 * -------------------------------------------------------------------------- */
230
231static bool acpi_ec_started(struct acpi_ec *ec)
232{
233 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
234 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
235}
236
237static bool acpi_ec_flushed(struct acpi_ec *ec)
238{
239 return ec->reference_count == 1;
240}
241
242/* --------------------------------------------------------------------------
243 * EC Registers
244 * -------------------------------------------------------------------------- */
245
246static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
247{
248 u8 x = inb(ec->command_addr);
249
250 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
251 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
252 x,
253 !!(x & ACPI_EC_FLAG_SCI),
254 !!(x & ACPI_EC_FLAG_BURST),
255 !!(x & ACPI_EC_FLAG_CMD),
256 !!(x & ACPI_EC_FLAG_IBF),
257 !!(x & ACPI_EC_FLAG_OBF));
258 return x;
259}
260
261static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
262{
263 u8 x = inb(ec->data_addr);
264
265 ec->timestamp = jiffies;
266 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
267 return x;
268}
269
270static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
271{
272 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
273 outb(command, ec->command_addr);
274 ec->timestamp = jiffies;
275}
276
277static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
278{
279 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
280 outb(data, ec->data_addr);
281 ec->timestamp = jiffies;
282}
283
284#ifdef DEBUG
285static const char *acpi_ec_cmd_string(u8 cmd)
286{
287 switch (cmd) {
288 case 0x80:
289 return "RD_EC";
290 case 0x81:
291 return "WR_EC";
292 case 0x82:
293 return "BE_EC";
294 case 0x83:
295 return "BD_EC";
296 case 0x84:
297 return "QR_EC";
298 }
299 return "UNKNOWN";
300}
301#else
302#define acpi_ec_cmd_string(cmd) "UNDEF"
303#endif
304
305/* --------------------------------------------------------------------------
306 * GPE Registers
307 * -------------------------------------------------------------------------- */
308
309static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
310{
311 acpi_event_status gpe_status = 0;
312
313 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
314 return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
315}
316
317static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
318{
319 if (open)
320 acpi_enable_gpe(NULL, ec->gpe);
321 else {
322 BUG_ON(ec->reference_count < 1);
323 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
324 }
325 if (acpi_ec_is_gpe_raised(ec)) {
326 /*
327 * On some platforms, EN=1 writes cannot trigger GPE. So
328 * software need to manually trigger a pseudo GPE event on
329 * EN=1 writes.
330 */
331 ec_dbg_raw("Polling quirk");
332 advance_transaction(ec);
333 }
334}
335
336static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
337{
338 if (close)
339 acpi_disable_gpe(NULL, ec->gpe);
340 else {
341 BUG_ON(ec->reference_count < 1);
342 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
343 }
344}
345
346static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
347{
348 /*
349 * GPE STS is a W1C register, which means:
350 * 1. Software can clear it without worrying about clearing other
351 * GPEs' STS bits when the hardware sets them in parallel.
352 * 2. As long as software can ensure only clearing it when it is
353 * set, hardware won't set it in parallel.
354 * So software can clear GPE in any contexts.
355 * Warning: do not move the check into advance_transaction() as the
356 * EC commands will be sent without GPE raised.
357 */
358 if (!acpi_ec_is_gpe_raised(ec))
359 return;
360 acpi_clear_gpe(NULL, ec->gpe);
361}
362
363/* --------------------------------------------------------------------------
364 * Transaction Management
365 * -------------------------------------------------------------------------- */
366
367static void acpi_ec_submit_request(struct acpi_ec *ec)
368{
369 ec->reference_count++;
370 if (ec->reference_count == 1)
371 acpi_ec_enable_gpe(ec, true);
372}
373
374static void acpi_ec_complete_request(struct acpi_ec *ec)
375{
376 bool flushed = false;
377
378 ec->reference_count--;
379 if (ec->reference_count == 0)
380 acpi_ec_disable_gpe(ec, true);
381 flushed = acpi_ec_flushed(ec);
382 if (flushed)
383 wake_up(&ec->wait);
384}
385
386static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
387{
388 if (!test_bit(flag, &ec->flags)) {
389 acpi_ec_disable_gpe(ec, false);
390 ec_dbg_drv("Polling enabled");
391 set_bit(flag, &ec->flags);
392 }
393}
394
395static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
396{
397 if (test_bit(flag, &ec->flags)) {
398 clear_bit(flag, &ec->flags);
399 acpi_ec_enable_gpe(ec, false);
400 ec_dbg_drv("Polling disabled");
401 }
402}
403
404/*
405 * acpi_ec_submit_flushable_request() - Increase the reference count unless
406 * the flush operation is not in
407 * progress
408 * @ec: the EC device
409 *
410 * This function must be used before taking a new action that should hold
411 * the reference count. If this function returns false, then the action
412 * must be discarded or it will prevent the flush operation from being
413 * completed.
414 */
415static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
416{
417 if (!acpi_ec_started(ec))
418 return false;
419 acpi_ec_submit_request(ec);
420 return true;
421}
422
423static void acpi_ec_submit_query(struct acpi_ec *ec)
424{
425 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
426 ec_dbg_evt("Command(%s) submitted/blocked",
427 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
428 ec->nr_pending_queries++;
429 schedule_work(&ec->work);
430 }
431}
432
433static void acpi_ec_complete_query(struct acpi_ec *ec)
434{
435 if (test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
436 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
437 ec_dbg_evt("Command(%s) unblocked",
438 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
439 }
440}
441
442static bool acpi_ec_guard_event(struct acpi_ec *ec)
443{
444 bool guarded = true;
445 unsigned long flags;
446
447 spin_lock_irqsave(&ec->lock, flags);
448 /*
449 * If firmware SCI_EVT clearing timing is "event", we actually
450 * don't know when the SCI_EVT will be cleared by firmware after
451 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
452 * acceptable period.
453 *
454 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
455 * flagged, which means SCI_EVT check has just been performed.
456 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
457 * guarding should have already been performed (via
458 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
459 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
460 * ACPI_EC_COMMAND_POLL state immediately.
461 */
462 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
463 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
464 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
465 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
466 guarded = false;
467 spin_unlock_irqrestore(&ec->lock, flags);
468 return guarded;
469}
470
471static int ec_transaction_polled(struct acpi_ec *ec)
472{
473 unsigned long flags;
474 int ret = 0;
475
476 spin_lock_irqsave(&ec->lock, flags);
477 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
478 ret = 1;
479 spin_unlock_irqrestore(&ec->lock, flags);
480 return ret;
481}
482
483static int ec_transaction_completed(struct acpi_ec *ec)
484{
485 unsigned long flags;
486 int ret = 0;
487
488 spin_lock_irqsave(&ec->lock, flags);
489 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
490 ret = 1;
491 spin_unlock_irqrestore(&ec->lock, flags);
492 return ret;
493}
494
495static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
496{
497 ec->curr->flags |= flag;
498 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
499 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
500 flag == ACPI_EC_COMMAND_POLL)
501 acpi_ec_complete_query(ec);
502 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
503 flag == ACPI_EC_COMMAND_COMPLETE)
504 acpi_ec_complete_query(ec);
505 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
506 flag == ACPI_EC_COMMAND_COMPLETE)
507 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
508 }
509}
510
511static void advance_transaction(struct acpi_ec *ec)
512{
513 struct transaction *t;
514 u8 status;
515 bool wakeup = false;
516
517 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
518 smp_processor_id());
519 /*
520 * By always clearing STS before handling all indications, we can
521 * ensure a hardware STS 0->1 change after this clearing can always
522 * trigger a GPE interrupt.
523 */
524 acpi_ec_clear_gpe(ec);
525 status = acpi_ec_read_status(ec);
526 t = ec->curr;
527 /*
528 * Another IRQ or a guarded polling mode advancement is detected,
529 * the next QR_EC submission is then allowed.
530 */
531 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
532 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
533 (!ec->nr_pending_queries ||
534 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
535 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
536 acpi_ec_complete_query(ec);
537 }
538 }
539 if (!t)
540 goto err;
541 if (t->flags & ACPI_EC_COMMAND_POLL) {
542 if (t->wlen > t->wi) {
543 if ((status & ACPI_EC_FLAG_IBF) == 0)
544 acpi_ec_write_data(ec, t->wdata[t->wi++]);
545 else
546 goto err;
547 } else if (t->rlen > t->ri) {
548 if ((status & ACPI_EC_FLAG_OBF) == 1) {
549 t->rdata[t->ri++] = acpi_ec_read_data(ec);
550 if (t->rlen == t->ri) {
551 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
552 if (t->command == ACPI_EC_COMMAND_QUERY)
553 ec_dbg_evt("Command(%s) completed by hardware",
554 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
555 wakeup = true;
556 }
557 } else
558 goto err;
559 } else if (t->wlen == t->wi &&
560 (status & ACPI_EC_FLAG_IBF) == 0) {
561 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
562 wakeup = true;
563 }
564 goto out;
565 } else {
566 if (EC_FLAGS_QUERY_HANDSHAKE &&
567 !(status & ACPI_EC_FLAG_SCI) &&
568 (t->command == ACPI_EC_COMMAND_QUERY)) {
569 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
570 t->rdata[t->ri++] = 0x00;
571 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
572 ec_dbg_evt("Command(%s) completed by software",
573 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
574 wakeup = true;
575 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
576 acpi_ec_write_cmd(ec, t->command);
577 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
578 } else
579 goto err;
580 goto out;
581 }
582err:
583 /*
584 * If SCI bit is set, then don't think it's a false IRQ
585 * otherwise will take a not handled IRQ as a false one.
586 */
587 if (!(status & ACPI_EC_FLAG_SCI)) {
588 if (in_interrupt() && t) {
589 if (t->irq_count < ec_storm_threshold)
590 ++t->irq_count;
591 /* Allow triggering on 0 threshold */
592 if (t->irq_count == ec_storm_threshold)
593 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
594 }
595 }
596out:
597 if (status & ACPI_EC_FLAG_SCI)
598 acpi_ec_submit_query(ec);
599 if (wakeup && in_interrupt())
600 wake_up(&ec->wait);
601}
602
603static void start_transaction(struct acpi_ec *ec)
604{
605 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
606 ec->curr->flags = 0;
607}
608
609static int ec_guard(struct acpi_ec *ec)
610{
611 unsigned long guard = usecs_to_jiffies(ec_polling_guard);
612 unsigned long timeout = ec->timestamp + guard;
613
614 /* Ensure guarding period before polling EC status */
615 do {
616 if (ec_busy_polling) {
617 /* Perform busy polling */
618 if (ec_transaction_completed(ec))
619 return 0;
620 udelay(jiffies_to_usecs(guard));
621 } else {
622 /*
623 * Perform wait polling
624 * 1. Wait the transaction to be completed by the
625 * GPE handler after the transaction enters
626 * ACPI_EC_COMMAND_POLL state.
627 * 2. A special guarding logic is also required
628 * for event clearing mode "event" before the
629 * transaction enters ACPI_EC_COMMAND_POLL
630 * state.
631 */
632 if (!ec_transaction_polled(ec) &&
633 !acpi_ec_guard_event(ec))
634 break;
635 if (wait_event_timeout(ec->wait,
636 ec_transaction_completed(ec),
637 guard))
638 return 0;
639 }
640 } while (time_before(jiffies, timeout));
641 return -ETIME;
642}
643
644static int ec_poll(struct acpi_ec *ec)
645{
646 unsigned long flags;
647 int repeat = 5; /* number of command restarts */
648
649 while (repeat--) {
650 unsigned long delay = jiffies +
651 msecs_to_jiffies(ec_delay);
652 do {
653 if (!ec_guard(ec))
654 return 0;
655 spin_lock_irqsave(&ec->lock, flags);
656 advance_transaction(ec);
657 spin_unlock_irqrestore(&ec->lock, flags);
658 } while (time_before(jiffies, delay));
659 pr_debug("controller reset, restart transaction\n");
660 spin_lock_irqsave(&ec->lock, flags);
661 start_transaction(ec);
662 spin_unlock_irqrestore(&ec->lock, flags);
663 }
664 return -ETIME;
665}
666
667static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
668 struct transaction *t)
669{
670 unsigned long tmp;
671 int ret = 0;
672
673 /* start transaction */
674 spin_lock_irqsave(&ec->lock, tmp);
675 /* Enable GPE for command processing (IBF=0/OBF=1) */
676 if (!acpi_ec_submit_flushable_request(ec)) {
677 ret = -EINVAL;
678 goto unlock;
679 }
680 ec_dbg_ref(ec, "Increase command");
681 /* following two actions should be kept atomic */
682 ec->curr = t;
683 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
684 start_transaction(ec);
685 spin_unlock_irqrestore(&ec->lock, tmp);
686
687 ret = ec_poll(ec);
688
689 spin_lock_irqsave(&ec->lock, tmp);
690 if (t->irq_count == ec_storm_threshold)
691 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
692 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
693 ec->curr = NULL;
694 /* Disable GPE for command processing (IBF=0/OBF=1) */
695 acpi_ec_complete_request(ec);
696 ec_dbg_ref(ec, "Decrease command");
697unlock:
698 spin_unlock_irqrestore(&ec->lock, tmp);
699 return ret;
700}
701
702static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
703{
704 int status;
705 u32 glk;
706
707 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
708 return -EINVAL;
709 if (t->rdata)
710 memset(t->rdata, 0, t->rlen);
711
712 mutex_lock(&ec->mutex);
713 if (ec->global_lock) {
714 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
715 if (ACPI_FAILURE(status)) {
716 status = -ENODEV;
717 goto unlock;
718 }
719 }
720
721 status = acpi_ec_transaction_unlocked(ec, t);
722
723 if (ec->global_lock)
724 acpi_release_global_lock(glk);
725unlock:
726 mutex_unlock(&ec->mutex);
727 return status;
728}
729
730static int acpi_ec_burst_enable(struct acpi_ec *ec)
731{
732 u8 d;
733 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
734 .wdata = NULL, .rdata = &d,
735 .wlen = 0, .rlen = 1};
736
737 return acpi_ec_transaction(ec, &t);
738}
739
740static int acpi_ec_burst_disable(struct acpi_ec *ec)
741{
742 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
743 .wdata = NULL, .rdata = NULL,
744 .wlen = 0, .rlen = 0};
745
746 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
747 acpi_ec_transaction(ec, &t) : 0;
748}
749
750static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
751{
752 int result;
753 u8 d;
754 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
755 .wdata = &address, .rdata = &d,
756 .wlen = 1, .rlen = 1};
757
758 result = acpi_ec_transaction(ec, &t);
759 *data = d;
760 return result;
761}
762
763static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
764{
765 u8 wdata[2] = { address, data };
766 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
767 .wdata = wdata, .rdata = NULL,
768 .wlen = 2, .rlen = 0};
769
770 return acpi_ec_transaction(ec, &t);
771}
772
773int ec_read(u8 addr, u8 *val)
774{
775 int err;
776 u8 temp_data;
777
778 if (!first_ec)
779 return -ENODEV;
780
781 err = acpi_ec_read(first_ec, addr, &temp_data);
782
783 if (!err) {
784 *val = temp_data;
785 return 0;
786 }
787 return err;
788}
789EXPORT_SYMBOL(ec_read);
790
791int ec_write(u8 addr, u8 val)
792{
793 int err;
794
795 if (!first_ec)
796 return -ENODEV;
797
798 err = acpi_ec_write(first_ec, addr, val);
799
800 return err;
801}
802EXPORT_SYMBOL(ec_write);
803
804int ec_transaction(u8 command,
805 const u8 *wdata, unsigned wdata_len,
806 u8 *rdata, unsigned rdata_len)
807{
808 struct transaction t = {.command = command,
809 .wdata = wdata, .rdata = rdata,
810 .wlen = wdata_len, .rlen = rdata_len};
811
812 if (!first_ec)
813 return -ENODEV;
814
815 return acpi_ec_transaction(first_ec, &t);
816}
817EXPORT_SYMBOL(ec_transaction);
818
819/* Get the handle to the EC device */
820acpi_handle ec_get_handle(void)
821{
822 if (!first_ec)
823 return NULL;
824 return first_ec->handle;
825}
826EXPORT_SYMBOL(ec_get_handle);
827
828/*
829 * Process _Q events that might have accumulated in the EC.
830 * Run with locked ec mutex.
831 */
832static void acpi_ec_clear(struct acpi_ec *ec)
833{
834 int i, status;
835 u8 value = 0;
836
837 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
838 status = acpi_ec_query(ec, &value);
839 if (status || !value)
840 break;
841 }
842
843 if (unlikely(i == ACPI_EC_CLEAR_MAX))
844 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
845 else
846 pr_info("%d stale EC events cleared\n", i);
847}
848
849static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
850{
851 unsigned long flags;
852
853 spin_lock_irqsave(&ec->lock, flags);
854 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
855 ec_dbg_drv("Starting EC");
856 /* Enable GPE for event processing (SCI_EVT=1) */
857 if (!resuming) {
858 acpi_ec_submit_request(ec);
859 ec_dbg_ref(ec, "Increase driver");
860 }
861 ec_log_drv("EC started");
862 }
863 spin_unlock_irqrestore(&ec->lock, flags);
864}
865
866static bool acpi_ec_stopped(struct acpi_ec *ec)
867{
868 unsigned long flags;
869 bool flushed;
870
871 spin_lock_irqsave(&ec->lock, flags);
872 flushed = acpi_ec_flushed(ec);
873 spin_unlock_irqrestore(&ec->lock, flags);
874 return flushed;
875}
876
877static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
878{
879 unsigned long flags;
880
881 spin_lock_irqsave(&ec->lock, flags);
882 if (acpi_ec_started(ec)) {
883 ec_dbg_drv("Stopping EC");
884 set_bit(EC_FLAGS_STOPPED, &ec->flags);
885 spin_unlock_irqrestore(&ec->lock, flags);
886 wait_event(ec->wait, acpi_ec_stopped(ec));
887 spin_lock_irqsave(&ec->lock, flags);
888 /* Disable GPE for event processing (SCI_EVT=1) */
889 if (!suspending) {
890 acpi_ec_complete_request(ec);
891 ec_dbg_ref(ec, "Decrease driver");
892 }
893 clear_bit(EC_FLAGS_STARTED, &ec->flags);
894 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
895 ec_log_drv("EC stopped");
896 }
897 spin_unlock_irqrestore(&ec->lock, flags);
898}
899
900void acpi_ec_block_transactions(void)
901{
902 struct acpi_ec *ec = first_ec;
903
904 if (!ec)
905 return;
906
907 mutex_lock(&ec->mutex);
908 /* Prevent transactions from being carried out */
909 acpi_ec_stop(ec, true);
910 mutex_unlock(&ec->mutex);
911}
912
913void acpi_ec_unblock_transactions(void)
914{
915 struct acpi_ec *ec = first_ec;
916
917 if (!ec)
918 return;
919
920 /* Allow transactions to be carried out again */
921 acpi_ec_start(ec, true);
922
923 if (EC_FLAGS_CLEAR_ON_RESUME)
924 acpi_ec_clear(ec);
925}
926
927void acpi_ec_unblock_transactions_early(void)
928{
929 /*
930 * Allow transactions to happen again (this function is called from
931 * atomic context during wakeup, so we don't need to acquire the mutex).
932 */
933 if (first_ec)
934 acpi_ec_start(first_ec, true);
935}
936
937/* --------------------------------------------------------------------------
938 Event Management
939 -------------------------------------------------------------------------- */
940static struct acpi_ec_query_handler *
941acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
942{
943 if (handler)
944 kref_get(&handler->kref);
945 return handler;
946}
947
948static struct acpi_ec_query_handler *
949acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
950{
951 struct acpi_ec_query_handler *handler;
952 bool found = false;
953
954 mutex_lock(&ec->mutex);
955 list_for_each_entry(handler, &ec->list, node) {
956 if (value == handler->query_bit) {
957 found = true;
958 break;
959 }
960 }
961 mutex_unlock(&ec->mutex);
962 return found ? acpi_ec_get_query_handler(handler) : NULL;
963}
964
965static void acpi_ec_query_handler_release(struct kref *kref)
966{
967 struct acpi_ec_query_handler *handler =
968 container_of(kref, struct acpi_ec_query_handler, kref);
969
970 kfree(handler);
971}
972
973static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
974{
975 kref_put(&handler->kref, acpi_ec_query_handler_release);
976}
977
978int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
979 acpi_handle handle, acpi_ec_query_func func,
980 void *data)
981{
982 struct acpi_ec_query_handler *handler =
983 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
984
985 if (!handler)
986 return -ENOMEM;
987
988 handler->query_bit = query_bit;
989 handler->handle = handle;
990 handler->func = func;
991 handler->data = data;
992 mutex_lock(&ec->mutex);
993 kref_init(&handler->kref);
994 list_add(&handler->node, &ec->list);
995 mutex_unlock(&ec->mutex);
996 return 0;
997}
998EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
999
1000static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1001 bool remove_all, u8 query_bit)
1002{
1003 struct acpi_ec_query_handler *handler, *tmp;
1004 LIST_HEAD(free_list);
1005
1006 mutex_lock(&ec->mutex);
1007 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1008 if (remove_all || query_bit == handler->query_bit) {
1009 list_del_init(&handler->node);
1010 list_add(&handler->node, &free_list);
1011 }
1012 }
1013 mutex_unlock(&ec->mutex);
1014 list_for_each_entry_safe(handler, tmp, &free_list, node)
1015 acpi_ec_put_query_handler(handler);
1016}
1017
1018void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1019{
1020 acpi_ec_remove_query_handlers(ec, false, query_bit);
1021}
1022EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1023
1024static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1025{
1026 struct acpi_ec_query *q;
1027 struct transaction *t;
1028
1029 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1030 if (!q)
1031 return NULL;
1032 INIT_WORK(&q->work, acpi_ec_event_processor);
1033 t = &q->transaction;
1034 t->command = ACPI_EC_COMMAND_QUERY;
1035 t->rdata = pval;
1036 t->rlen = 1;
1037 return q;
1038}
1039
1040static void acpi_ec_delete_query(struct acpi_ec_query *q)
1041{
1042 if (q) {
1043 if (q->handler)
1044 acpi_ec_put_query_handler(q->handler);
1045 kfree(q);
1046 }
1047}
1048
1049static void acpi_ec_event_processor(struct work_struct *work)
1050{
1051 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1052 struct acpi_ec_query_handler *handler = q->handler;
1053
1054 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1055 if (handler->func)
1056 handler->func(handler->data);
1057 else if (handler->handle)
1058 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1059 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1060 acpi_ec_delete_query(q);
1061}
1062
1063static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1064{
1065 u8 value = 0;
1066 int result;
1067 struct acpi_ec_query *q;
1068
1069 q = acpi_ec_create_query(&value);
1070 if (!q)
1071 return -ENOMEM;
1072
1073 /*
1074 * Query the EC to find out which _Qxx method we need to evaluate.
1075 * Note that successful completion of the query causes the ACPI_EC_SCI
1076 * bit to be cleared (and thus clearing the interrupt source).
1077 */
1078 result = acpi_ec_transaction(ec, &q->transaction);
1079 if (!value)
1080 result = -ENODATA;
1081 if (result)
1082 goto err_exit;
1083
1084 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1085 if (!q->handler) {
1086 result = -ENODATA;
1087 goto err_exit;
1088 }
1089
1090 /*
1091 * It is reported that _Qxx are evaluated in a parallel way on
1092 * Windows:
1093 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1094 *
1095 * Put this log entry before schedule_work() in order to make
1096 * it appearing before any other log entries occurred during the
1097 * work queue execution.
1098 */
1099 ec_dbg_evt("Query(0x%02x) scheduled", value);
1100 if (!schedule_work(&q->work)) {
1101 ec_dbg_evt("Query(0x%02x) overlapped", value);
1102 result = -EBUSY;
1103 }
1104
1105err_exit:
1106 if (result)
1107 acpi_ec_delete_query(q);
1108 if (data)
1109 *data = value;
1110 return result;
1111}
1112
1113static void acpi_ec_check_event(struct acpi_ec *ec)
1114{
1115 unsigned long flags;
1116
1117 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1118 if (ec_guard(ec)) {
1119 spin_lock_irqsave(&ec->lock, flags);
1120 /*
1121 * Take care of the SCI_EVT unless no one else is
1122 * taking care of it.
1123 */
1124 if (!ec->curr)
1125 advance_transaction(ec);
1126 spin_unlock_irqrestore(&ec->lock, flags);
1127 }
1128 }
1129}
1130
1131static void acpi_ec_event_handler(struct work_struct *work)
1132{
1133 unsigned long flags;
1134 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1135
1136 ec_dbg_evt("Event started");
1137
1138 spin_lock_irqsave(&ec->lock, flags);
1139 while (ec->nr_pending_queries) {
1140 spin_unlock_irqrestore(&ec->lock, flags);
1141 (void)acpi_ec_query(ec, NULL);
1142 spin_lock_irqsave(&ec->lock, flags);
1143 ec->nr_pending_queries--;
1144 /*
1145 * Before exit, make sure that this work item can be
1146 * scheduled again. There might be QR_EC failures, leaving
1147 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1148 * item from being scheduled again.
1149 */
1150 if (!ec->nr_pending_queries) {
1151 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1152 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1153 acpi_ec_complete_query(ec);
1154 }
1155 }
1156 spin_unlock_irqrestore(&ec->lock, flags);
1157
1158 ec_dbg_evt("Event stopped");
1159
1160 acpi_ec_check_event(ec);
1161}
1162
1163static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1164 u32 gpe_number, void *data)
1165{
1166 unsigned long flags;
1167 struct acpi_ec *ec = data;
1168
1169 spin_lock_irqsave(&ec->lock, flags);
1170 advance_transaction(ec);
1171 spin_unlock_irqrestore(&ec->lock, flags);
1172 return ACPI_INTERRUPT_HANDLED;
1173}
1174
1175/* --------------------------------------------------------------------------
1176 * Address Space Management
1177 * -------------------------------------------------------------------------- */
1178
1179static acpi_status
1180acpi_ec_space_handler(u32 function, acpi_physical_address address,
1181 u32 bits, u64 *value64,
1182 void *handler_context, void *region_context)
1183{
1184 struct acpi_ec *ec = handler_context;
1185 int result = 0, i, bytes = bits / 8;
1186 u8 *value = (u8 *)value64;
1187
1188 if ((address > 0xFF) || !value || !handler_context)
1189 return AE_BAD_PARAMETER;
1190
1191 if (function != ACPI_READ && function != ACPI_WRITE)
1192 return AE_BAD_PARAMETER;
1193
1194 if (ec_busy_polling || bits > 8)
1195 acpi_ec_burst_enable(ec);
1196
1197 for (i = 0; i < bytes; ++i, ++address, ++value)
1198 result = (function == ACPI_READ) ?
1199 acpi_ec_read(ec, address, value) :
1200 acpi_ec_write(ec, address, *value);
1201
1202 if (ec_busy_polling || bits > 8)
1203 acpi_ec_burst_disable(ec);
1204
1205 switch (result) {
1206 case -EINVAL:
1207 return AE_BAD_PARAMETER;
1208 case -ENODEV:
1209 return AE_NOT_FOUND;
1210 case -ETIME:
1211 return AE_TIME;
1212 default:
1213 return AE_OK;
1214 }
1215}
1216
1217/* --------------------------------------------------------------------------
1218 * Driver Interface
1219 * -------------------------------------------------------------------------- */
1220
1221static acpi_status
1222ec_parse_io_ports(struct acpi_resource *resource, void *context);
1223
1224static struct acpi_ec *make_acpi_ec(void)
1225{
1226 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1227
1228 if (!ec)
1229 return NULL;
1230 ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
1231 mutex_init(&ec->mutex);
1232 init_waitqueue_head(&ec->wait);
1233 INIT_LIST_HEAD(&ec->list);
1234 spin_lock_init(&ec->lock);
1235 INIT_WORK(&ec->work, acpi_ec_event_handler);
1236 ec->timestamp = jiffies;
1237 return ec;
1238}
1239
1240static acpi_status
1241acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1242 void *context, void **return_value)
1243{
1244 char node_name[5];
1245 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1246 struct acpi_ec *ec = context;
1247 int value = 0;
1248 acpi_status status;
1249
1250 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1251
1252 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1253 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1254 return AE_OK;
1255}
1256
1257static acpi_status
1258ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1259{
1260 acpi_status status;
1261 unsigned long long tmp = 0;
1262 struct acpi_ec *ec = context;
1263
1264 /* clear addr values, ec_parse_io_ports depend on it */
1265 ec->command_addr = ec->data_addr = 0;
1266
1267 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1268 ec_parse_io_ports, ec);
1269 if (ACPI_FAILURE(status))
1270 return status;
1271
1272 /* Get GPE bit assignment (EC events). */
1273 /* TODO: Add support for _GPE returning a package */
1274 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1275 if (ACPI_FAILURE(status))
1276 return status;
1277 ec->gpe = tmp;
1278 /* Use the global lock for all EC transactions? */
1279 tmp = 0;
1280 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1281 ec->global_lock = tmp;
1282 ec->handle = handle;
1283 return AE_CTRL_TERMINATE;
1284}
1285
1286static int ec_install_handlers(struct acpi_ec *ec)
1287{
1288 acpi_status status;
1289
1290 if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1291 return 0;
1292 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1293 ACPI_GPE_EDGE_TRIGGERED,
1294 &acpi_ec_gpe_handler, ec);
1295 if (ACPI_FAILURE(status))
1296 return -ENODEV;
1297
1298 acpi_ec_start(ec, false);
1299 status = acpi_install_address_space_handler(ec->handle,
1300 ACPI_ADR_SPACE_EC,
1301 &acpi_ec_space_handler,
1302 NULL, ec);
1303 if (ACPI_FAILURE(status)) {
1304 if (status == AE_NOT_FOUND) {
1305 /*
1306 * Maybe OS fails in evaluating the _REG object.
1307 * The AE_NOT_FOUND error will be ignored and OS
1308 * continue to initialize EC.
1309 */
1310 pr_err("Fail in evaluating the _REG object"
1311 " of EC device. Broken bios is suspected.\n");
1312 } else {
1313 acpi_ec_stop(ec, false);
1314 acpi_remove_gpe_handler(NULL, ec->gpe,
1315 &acpi_ec_gpe_handler);
1316 return -ENODEV;
1317 }
1318 }
1319
1320 set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1321 return 0;
1322}
1323
1324static void ec_remove_handlers(struct acpi_ec *ec)
1325{
1326 if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1327 return;
1328 acpi_ec_stop(ec, false);
1329 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1330 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1331 pr_err("failed to remove space handler\n");
1332 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1333 &acpi_ec_gpe_handler)))
1334 pr_err("failed to remove gpe handler\n");
1335 clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1336}
1337
1338static int acpi_ec_add(struct acpi_device *device)
1339{
1340 struct acpi_ec *ec = NULL;
1341 int ret;
1342
1343 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1344 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1345
1346 /* Check for boot EC */
1347 if (boot_ec &&
1348 (boot_ec->handle == device->handle ||
1349 boot_ec->handle == ACPI_ROOT_OBJECT)) {
1350 ec = boot_ec;
1351 boot_ec = NULL;
1352 } else {
1353 ec = make_acpi_ec();
1354 if (!ec)
1355 return -ENOMEM;
1356 }
1357 if (ec_parse_device(device->handle, 0, ec, NULL) !=
1358 AE_CTRL_TERMINATE) {
1359 kfree(ec);
1360 return -EINVAL;
1361 }
1362
1363 /* Find and register all query methods */
1364 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1365 acpi_ec_register_query_methods, NULL, ec, NULL);
1366
1367 if (!first_ec)
1368 first_ec = ec;
1369 device->driver_data = ec;
1370
1371 ret = !!request_region(ec->data_addr, 1, "EC data");
1372 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1373 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1374 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1375
1376 pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
1377 ec->gpe, ec->command_addr, ec->data_addr);
1378
1379 ret = ec_install_handlers(ec);
1380
1381 /* Reprobe devices depending on the EC */
1382 acpi_walk_dep_device_list(ec->handle);
1383
1384 /* EC is fully operational, allow queries */
1385 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1386
1387 /* Clear stale _Q events if hardware might require that */
1388 if (EC_FLAGS_CLEAR_ON_RESUME)
1389 acpi_ec_clear(ec);
1390 return ret;
1391}
1392
1393static int acpi_ec_remove(struct acpi_device *device)
1394{
1395 struct acpi_ec *ec;
1396
1397 if (!device)
1398 return -EINVAL;
1399
1400 ec = acpi_driver_data(device);
1401 ec_remove_handlers(ec);
1402 acpi_ec_remove_query_handlers(ec, true, 0);
1403 release_region(ec->data_addr, 1);
1404 release_region(ec->command_addr, 1);
1405 device->driver_data = NULL;
1406 if (ec == first_ec)
1407 first_ec = NULL;
1408 kfree(ec);
1409 return 0;
1410}
1411
1412static acpi_status
1413ec_parse_io_ports(struct acpi_resource *resource, void *context)
1414{
1415 struct acpi_ec *ec = context;
1416
1417 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1418 return AE_OK;
1419
1420 /*
1421 * The first address region returned is the data port, and
1422 * the second address region returned is the status/command
1423 * port.
1424 */
1425 if (ec->data_addr == 0)
1426 ec->data_addr = resource->data.io.minimum;
1427 else if (ec->command_addr == 0)
1428 ec->command_addr = resource->data.io.minimum;
1429 else
1430 return AE_CTRL_TERMINATE;
1431
1432 return AE_OK;
1433}
1434
1435int __init acpi_boot_ec_enable(void)
1436{
1437 if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1438 return 0;
1439 if (!ec_install_handlers(boot_ec)) {
1440 first_ec = boot_ec;
1441 return 0;
1442 }
1443 return -EFAULT;
1444}
1445
1446static const struct acpi_device_id ec_device_ids[] = {
1447 {"PNP0C09", 0},
1448 {"", 0},
1449};
1450
1451/* Some BIOS do not survive early DSDT scan, skip it */
1452static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1453{
1454 EC_FLAGS_SKIP_DSDT_SCAN = 1;
1455 return 0;
1456}
1457
1458/* ASUStek often supplies us with broken ECDT, validate it */
1459static int ec_validate_ecdt(const struct dmi_system_id *id)
1460{
1461 EC_FLAGS_VALIDATE_ECDT = 1;
1462 return 0;
1463}
1464
1465#if 0
1466/*
1467 * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1468 * set, for which case, we complete the QR_EC without issuing it to the
1469 * firmware.
1470 * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1471 * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1472 */
1473static int ec_flag_query_handshake(const struct dmi_system_id *id)
1474{
1475 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1476 EC_FLAGS_QUERY_HANDSHAKE = 1;
1477 return 0;
1478}
1479#endif
1480
1481/*
1482 * On some hardware it is necessary to clear events accumulated by the EC during
1483 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1484 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1485 *
1486 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1487 *
1488 * Ideally, the EC should also be instructed NOT to accumulate events during
1489 * sleep (which Windows seems to do somehow), but the interface to control this
1490 * behaviour is not known at this time.
1491 *
1492 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1493 * however it is very likely that other Samsung models are affected.
1494 *
1495 * On systems which don't accumulate _Q events during sleep, this extra check
1496 * should be harmless.
1497 */
1498static int ec_clear_on_resume(const struct dmi_system_id *id)
1499{
1500 pr_debug("Detected system needing EC poll on resume.\n");
1501 EC_FLAGS_CLEAR_ON_RESUME = 1;
1502 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1503 return 0;
1504}
1505
1506static struct dmi_system_id ec_dmi_table[] __initdata = {
1507 {
1508 ec_skip_dsdt_scan, "Compal JFL92", {
1509 DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1510 DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1511 {
1512 ec_validate_ecdt, "MSI MS-171F", {
1513 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1514 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1515 {
1516 ec_validate_ecdt, "ASUS hardware", {
1517 DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1518 {
1519 ec_validate_ecdt, "ASUS hardware", {
1520 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1521 {
1522 ec_skip_dsdt_scan, "HP Folio 13", {
1523 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1524 DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1525 {
1526 ec_validate_ecdt, "ASUS hardware", {
1527 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1528 DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1529 {
1530 ec_clear_on_resume, "Samsung hardware", {
1531 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1532 {},
1533};
1534
1535int __init acpi_ec_ecdt_probe(void)
1536{
1537 acpi_status status;
1538 struct acpi_ec *saved_ec = NULL;
1539 struct acpi_table_ecdt *ecdt_ptr;
1540
1541 boot_ec = make_acpi_ec();
1542 if (!boot_ec)
1543 return -ENOMEM;
1544 /*
1545 * Generate a boot ec context
1546 */
1547 dmi_check_system(ec_dmi_table);
1548 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1549 (struct acpi_table_header **)&ecdt_ptr);
1550 if (ACPI_SUCCESS(status)) {
1551 pr_info("EC description table is found, configuring boot EC\n");
1552 boot_ec->command_addr = ecdt_ptr->control.address;
1553 boot_ec->data_addr = ecdt_ptr->data.address;
1554 boot_ec->gpe = ecdt_ptr->gpe;
1555 boot_ec->handle = ACPI_ROOT_OBJECT;
1556 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1557 &boot_ec->handle);
1558 /* Don't trust ECDT, which comes from ASUSTek */
1559 if (!EC_FLAGS_VALIDATE_ECDT)
1560 goto install;
1561 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1562 if (!saved_ec)
1563 return -ENOMEM;
1564 /* fall through */
1565 }
1566
1567 if (EC_FLAGS_SKIP_DSDT_SCAN) {
1568 kfree(saved_ec);
1569 return -ENODEV;
1570 }
1571
1572 /* This workaround is needed only on some broken machines,
1573 * which require early EC, but fail to provide ECDT */
1574 pr_debug("Look up EC in DSDT\n");
1575 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1576 boot_ec, NULL);
1577 /* Check that acpi_get_devices actually find something */
1578 if (ACPI_FAILURE(status) || !boot_ec->handle)
1579 goto error;
1580 if (saved_ec) {
1581 /* try to find good ECDT from ASUSTek */
1582 if (saved_ec->command_addr != boot_ec->command_addr ||
1583 saved_ec->data_addr != boot_ec->data_addr ||
1584 saved_ec->gpe != boot_ec->gpe ||
1585 saved_ec->handle != boot_ec->handle)
1586 pr_info("ASUSTek keeps feeding us with broken "
1587 "ECDT tables, which are very hard to workaround. "
1588 "Trying to use DSDT EC info instead. Please send "
1589 "output of acpidump to linux-acpi@vger.kernel.org\n");
1590 kfree(saved_ec);
1591 saved_ec = NULL;
1592 } else {
1593 /* We really need to limit this workaround, the only ASUS,
1594 * which needs it, has fake EC._INI method, so use it as flag.
1595 * Keep boot_ec struct as it will be needed soon.
1596 */
1597 if (!dmi_name_in_vendors("ASUS") ||
1598 !acpi_has_method(boot_ec->handle, "_INI"))
1599 return -ENODEV;
1600 }
1601install:
1602 if (!ec_install_handlers(boot_ec)) {
1603 first_ec = boot_ec;
1604 return 0;
1605 }
1606error:
1607 kfree(boot_ec);
1608 kfree(saved_ec);
1609 boot_ec = NULL;
1610 return -ENODEV;
1611}
1612
1613static int param_set_event_clearing(const char *val, struct kernel_param *kp)
1614{
1615 int result = 0;
1616
1617 if (!strncmp(val, "status", sizeof("status") - 1)) {
1618 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1619 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1620 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1621 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1622 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1623 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1624 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1625 pr_info("Assuming SCI_EVT clearing on event reads\n");
1626 } else
1627 result = -EINVAL;
1628 return result;
1629}
1630
1631static int param_get_event_clearing(char *buffer, struct kernel_param *kp)
1632{
1633 switch (ec_event_clearing) {
1634 case ACPI_EC_EVT_TIMING_STATUS:
1635 return sprintf(buffer, "status");
1636 case ACPI_EC_EVT_TIMING_QUERY:
1637 return sprintf(buffer, "query");
1638 case ACPI_EC_EVT_TIMING_EVENT:
1639 return sprintf(buffer, "event");
1640 default:
1641 return sprintf(buffer, "invalid");
1642 }
1643 return 0;
1644}
1645
1646module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
1647 NULL, 0644);
1648MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
1649
1650static struct acpi_driver acpi_ec_driver = {
1651 .name = "ec",
1652 .class = ACPI_EC_CLASS,
1653 .ids = ec_device_ids,
1654 .ops = {
1655 .add = acpi_ec_add,
1656 .remove = acpi_ec_remove,
1657 },
1658};
1659
1660int __init acpi_ec_init(void)
1661{
1662 int result = 0;
1663
1664 /* Now register the driver for the EC */
1665 result = acpi_bus_register_driver(&acpi_ec_driver);
1666 if (result < 0)
1667 return -ENODEV;
1668
1669 return result;
1670}
1671
1672/* EC driver currently not unloadable */
1673#if 0
1674static void __exit acpi_ec_exit(void)
1675{
1676
1677 acpi_bus_unregister_driver(&acpi_ec_driver);
1678}
1679#endif /* 0 */
Linux kernel - Deliverables
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