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 */
91 enum 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 #define ACPI_EC_MAX_QUERIES 16 /* Maximum number of parallel queries */
105
106 enum {
107 EC_FLAGS_QUERY_PENDING, /* Query is pending */
108 EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */
109 EC_FLAGS_HANDLERS_INSTALLED, /* Handlers for GPE and
110 * OpReg are installed */
111 EC_FLAGS_STARTED, /* Driver is started */
112 EC_FLAGS_STOPPED, /* Driver is stopped */
113 EC_FLAGS_COMMAND_STORM, /* GPE storms occurred to the
114 * current command processing */
115 };
116
117 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
118 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
119
120 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
121 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
122 module_param(ec_delay, uint, 0644);
123 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
124
125 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
126 module_param(ec_max_queries, uint, 0644);
127 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
128
129 static bool ec_busy_polling __read_mostly;
130 module_param(ec_busy_polling, bool, 0644);
131 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
132
133 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
134 module_param(ec_polling_guard, uint, 0644);
135 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
136
137 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
138
139 /*
140 * If the number of false interrupts per one transaction exceeds
141 * this threshold, will think there is a GPE storm happened and
142 * will disable the GPE for normal transaction.
143 */
144 static unsigned int ec_storm_threshold __read_mostly = 8;
145 module_param(ec_storm_threshold, uint, 0644);
146 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
147
148 struct acpi_ec_query_handler {
149 struct list_head node;
150 acpi_ec_query_func func;
151 acpi_handle handle;
152 void *data;
153 u8 query_bit;
154 struct kref kref;
155 };
156
157 struct transaction {
158 const u8 *wdata;
159 u8 *rdata;
160 unsigned short irq_count;
161 u8 command;
162 u8 wi;
163 u8 ri;
164 u8 wlen;
165 u8 rlen;
166 u8 flags;
167 };
168
169 struct acpi_ec_query {
170 struct transaction transaction;
171 struct work_struct work;
172 struct acpi_ec_query_handler *handler;
173 };
174
175 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
176 static void advance_transaction(struct acpi_ec *ec);
177 static void acpi_ec_event_handler(struct work_struct *work);
178 static void acpi_ec_event_processor(struct work_struct *work);
179
180 struct acpi_ec *boot_ec, *first_ec;
181 EXPORT_SYMBOL(first_ec);
182 static struct workqueue_struct *ec_query_wq;
183
184 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
185 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
186 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
187 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
188
189 /* --------------------------------------------------------------------------
190 * Logging/Debugging
191 * -------------------------------------------------------------------------- */
192
193 /*
194 * Splitters used by the developers to track the boundary of the EC
195 * handling processes.
196 */
197 #ifdef DEBUG
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 #else
204 #define EC_DBG_SEP ""
205 #define EC_DBG_DRV
206 #define EC_DBG_STM
207 #define EC_DBG_REQ
208 #define EC_DBG_EVT
209 #endif
210
211 #define ec_log_raw(fmt, ...) \
212 pr_info(fmt "\n", ##__VA_ARGS__)
213 #define ec_dbg_raw(fmt, ...) \
214 pr_debug(fmt "\n", ##__VA_ARGS__)
215 #define ec_log(filter, fmt, ...) \
216 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
217 #define ec_dbg(filter, fmt, ...) \
218 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
219
220 #define ec_log_drv(fmt, ...) \
221 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
222 #define ec_dbg_drv(fmt, ...) \
223 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
224 #define ec_dbg_stm(fmt, ...) \
225 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
226 #define ec_dbg_req(fmt, ...) \
227 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
228 #define ec_dbg_evt(fmt, ...) \
229 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
230 #define ec_dbg_ref(ec, fmt, ...) \
231 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
232
233 /* --------------------------------------------------------------------------
234 * Device Flags
235 * -------------------------------------------------------------------------- */
236
acpi_ec_started(struct acpi_ec * ec)237 static bool acpi_ec_started(struct acpi_ec *ec)
238 {
239 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
240 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
241 }
242
acpi_ec_flushed(struct acpi_ec * ec)243 static bool acpi_ec_flushed(struct acpi_ec *ec)
244 {
245 return ec->reference_count == 1;
246 }
247
248 /* --------------------------------------------------------------------------
249 * EC Registers
250 * -------------------------------------------------------------------------- */
251
acpi_ec_read_status(struct acpi_ec * ec)252 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
253 {
254 u8 x = inb(ec->command_addr);
255
256 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
257 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
258 x,
259 !!(x & ACPI_EC_FLAG_SCI),
260 !!(x & ACPI_EC_FLAG_BURST),
261 !!(x & ACPI_EC_FLAG_CMD),
262 !!(x & ACPI_EC_FLAG_IBF),
263 !!(x & ACPI_EC_FLAG_OBF));
264 return x;
265 }
266
acpi_ec_read_data(struct acpi_ec * ec)267 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
268 {
269 u8 x = inb(ec->data_addr);
270
271 ec->timestamp = jiffies;
272 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
273 return x;
274 }
275
acpi_ec_write_cmd(struct acpi_ec * ec,u8 command)276 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
277 {
278 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
279 outb(command, ec->command_addr);
280 ec->timestamp = jiffies;
281 }
282
acpi_ec_write_data(struct acpi_ec * ec,u8 data)283 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
284 {
285 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
286 outb(data, ec->data_addr);
287 ec->timestamp = jiffies;
288 }
289
290 #ifdef DEBUG
acpi_ec_cmd_string(u8 cmd)291 static const char *acpi_ec_cmd_string(u8 cmd)
292 {
293 switch (cmd) {
294 case 0x80:
295 return "RD_EC";
296 case 0x81:
297 return "WR_EC";
298 case 0x82:
299 return "BE_EC";
300 case 0x83:
301 return "BD_EC";
302 case 0x84:
303 return "QR_EC";
304 }
305 return "UNKNOWN";
306 }
307 #else
308 #define acpi_ec_cmd_string(cmd) "UNDEF"
309 #endif
310
311 /* --------------------------------------------------------------------------
312 * GPE Registers
313 * -------------------------------------------------------------------------- */
314
acpi_ec_is_gpe_raised(struct acpi_ec * ec)315 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
316 {
317 acpi_event_status gpe_status = 0;
318
319 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
320 return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
321 }
322
acpi_ec_enable_gpe(struct acpi_ec * ec,bool open)323 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
324 {
325 if (open)
326 acpi_enable_gpe(NULL, ec->gpe);
327 else {
328 BUG_ON(ec->reference_count < 1);
329 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
330 }
331 if (acpi_ec_is_gpe_raised(ec)) {
332 /*
333 * On some platforms, EN=1 writes cannot trigger GPE. So
334 * software need to manually trigger a pseudo GPE event on
335 * EN=1 writes.
336 */
337 ec_dbg_raw("Polling quirk");
338 advance_transaction(ec);
339 }
340 }
341
acpi_ec_disable_gpe(struct acpi_ec * ec,bool close)342 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
343 {
344 if (close)
345 acpi_disable_gpe(NULL, ec->gpe);
346 else {
347 BUG_ON(ec->reference_count < 1);
348 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
349 }
350 }
351
acpi_ec_clear_gpe(struct acpi_ec * ec)352 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
353 {
354 /*
355 * GPE STS is a W1C register, which means:
356 * 1. Software can clear it without worrying about clearing other
357 * GPEs' STS bits when the hardware sets them in parallel.
358 * 2. As long as software can ensure only clearing it when it is
359 * set, hardware won't set it in parallel.
360 * So software can clear GPE in any contexts.
361 * Warning: do not move the check into advance_transaction() as the
362 * EC commands will be sent without GPE raised.
363 */
364 if (!acpi_ec_is_gpe_raised(ec))
365 return;
366 acpi_clear_gpe(NULL, ec->gpe);
367 }
368
369 /* --------------------------------------------------------------------------
370 * Transaction Management
371 * -------------------------------------------------------------------------- */
372
acpi_ec_submit_request(struct acpi_ec * ec)373 static void acpi_ec_submit_request(struct acpi_ec *ec)
374 {
375 ec->reference_count++;
376 if (ec->reference_count == 1)
377 acpi_ec_enable_gpe(ec, true);
378 }
379
acpi_ec_complete_request(struct acpi_ec * ec)380 static void acpi_ec_complete_request(struct acpi_ec *ec)
381 {
382 bool flushed = false;
383
384 ec->reference_count--;
385 if (ec->reference_count == 0)
386 acpi_ec_disable_gpe(ec, true);
387 flushed = acpi_ec_flushed(ec);
388 if (flushed)
389 wake_up(&ec->wait);
390 }
391
acpi_ec_set_storm(struct acpi_ec * ec,u8 flag)392 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
393 {
394 if (!test_bit(flag, &ec->flags)) {
395 acpi_ec_disable_gpe(ec, false);
396 ec_dbg_drv("Polling enabled");
397 set_bit(flag, &ec->flags);
398 }
399 }
400
acpi_ec_clear_storm(struct acpi_ec * ec,u8 flag)401 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
402 {
403 if (test_bit(flag, &ec->flags)) {
404 clear_bit(flag, &ec->flags);
405 acpi_ec_enable_gpe(ec, false);
406 ec_dbg_drv("Polling disabled");
407 }
408 }
409
410 /*
411 * acpi_ec_submit_flushable_request() - Increase the reference count unless
412 * the flush operation is not in
413 * progress
414 * @ec: the EC device
415 *
416 * This function must be used before taking a new action that should hold
417 * the reference count. If this function returns false, then the action
418 * must be discarded or it will prevent the flush operation from being
419 * completed.
420 */
acpi_ec_submit_flushable_request(struct acpi_ec * ec)421 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
422 {
423 if (!acpi_ec_started(ec))
424 return false;
425 acpi_ec_submit_request(ec);
426 return true;
427 }
428
acpi_ec_submit_query(struct acpi_ec * ec)429 static void acpi_ec_submit_query(struct acpi_ec *ec)
430 {
431 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
432 ec_dbg_evt("Command(%s) submitted/blocked",
433 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
434 ec->nr_pending_queries++;
435 schedule_work(&ec->work);
436 }
437 }
438
acpi_ec_complete_query(struct acpi_ec * ec)439 static void acpi_ec_complete_query(struct acpi_ec *ec)
440 {
441 if (test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
442 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
443 ec_dbg_evt("Command(%s) unblocked",
444 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
445 }
446 }
447
acpi_ec_guard_event(struct acpi_ec * ec)448 static bool acpi_ec_guard_event(struct acpi_ec *ec)
449 {
450 bool guarded = true;
451 unsigned long flags;
452
453 spin_lock_irqsave(&ec->lock, flags);
454 /*
455 * If firmware SCI_EVT clearing timing is "event", we actually
456 * don't know when the SCI_EVT will be cleared by firmware after
457 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
458 * acceptable period.
459 *
460 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
461 * flagged, which means SCI_EVT check has just been performed.
462 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
463 * guarding should have already been performed (via
464 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
465 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
466 * ACPI_EC_COMMAND_POLL state immediately.
467 */
468 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
469 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
470 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
471 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
472 guarded = false;
473 spin_unlock_irqrestore(&ec->lock, flags);
474 return guarded;
475 }
476
ec_transaction_polled(struct acpi_ec * ec)477 static int ec_transaction_polled(struct acpi_ec *ec)
478 {
479 unsigned long flags;
480 int ret = 0;
481
482 spin_lock_irqsave(&ec->lock, flags);
483 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
484 ret = 1;
485 spin_unlock_irqrestore(&ec->lock, flags);
486 return ret;
487 }
488
ec_transaction_completed(struct acpi_ec * ec)489 static int ec_transaction_completed(struct acpi_ec *ec)
490 {
491 unsigned long flags;
492 int ret = 0;
493
494 spin_lock_irqsave(&ec->lock, flags);
495 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
496 ret = 1;
497 spin_unlock_irqrestore(&ec->lock, flags);
498 return ret;
499 }
500
ec_transaction_transition(struct acpi_ec * ec,unsigned long flag)501 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
502 {
503 ec->curr->flags |= flag;
504 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
505 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
506 flag == ACPI_EC_COMMAND_POLL)
507 acpi_ec_complete_query(ec);
508 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
509 flag == ACPI_EC_COMMAND_COMPLETE)
510 acpi_ec_complete_query(ec);
511 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
512 flag == ACPI_EC_COMMAND_COMPLETE)
513 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
514 }
515 }
516
advance_transaction(struct acpi_ec * ec)517 static void advance_transaction(struct acpi_ec *ec)
518 {
519 struct transaction *t;
520 u8 status;
521 bool wakeup = false;
522
523 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
524 smp_processor_id());
525 /*
526 * By always clearing STS before handling all indications, we can
527 * ensure a hardware STS 0->1 change after this clearing can always
528 * trigger a GPE interrupt.
529 */
530 acpi_ec_clear_gpe(ec);
531 status = acpi_ec_read_status(ec);
532 t = ec->curr;
533 /*
534 * Another IRQ or a guarded polling mode advancement is detected,
535 * the next QR_EC submission is then allowed.
536 */
537 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
538 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
539 (!ec->nr_pending_queries ||
540 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
541 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
542 acpi_ec_complete_query(ec);
543 }
544 }
545 if (!t)
546 goto err;
547 if (t->flags & ACPI_EC_COMMAND_POLL) {
548 if (t->wlen > t->wi) {
549 if ((status & ACPI_EC_FLAG_IBF) == 0)
550 acpi_ec_write_data(ec, t->wdata[t->wi++]);
551 else
552 goto err;
553 } else if (t->rlen > t->ri) {
554 if ((status & ACPI_EC_FLAG_OBF) == 1) {
555 t->rdata[t->ri++] = acpi_ec_read_data(ec);
556 if (t->rlen == t->ri) {
557 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
558 if (t->command == ACPI_EC_COMMAND_QUERY)
559 ec_dbg_evt("Command(%s) completed by hardware",
560 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
561 wakeup = true;
562 }
563 } else
564 goto err;
565 } else if (t->wlen == t->wi &&
566 (status & ACPI_EC_FLAG_IBF) == 0) {
567 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
568 wakeup = true;
569 }
570 goto out;
571 } else {
572 if (EC_FLAGS_QUERY_HANDSHAKE &&
573 !(status & ACPI_EC_FLAG_SCI) &&
574 (t->command == ACPI_EC_COMMAND_QUERY)) {
575 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
576 t->rdata[t->ri++] = 0x00;
577 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
578 ec_dbg_evt("Command(%s) completed by software",
579 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
580 wakeup = true;
581 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
582 acpi_ec_write_cmd(ec, t->command);
583 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
584 } else
585 goto err;
586 goto out;
587 }
588 err:
589 /*
590 * If SCI bit is set, then don't think it's a false IRQ
591 * otherwise will take a not handled IRQ as a false one.
592 */
593 if (!(status & ACPI_EC_FLAG_SCI)) {
594 if (in_interrupt() && t) {
595 if (t->irq_count < ec_storm_threshold)
596 ++t->irq_count;
597 /* Allow triggering on 0 threshold */
598 if (t->irq_count == ec_storm_threshold)
599 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
600 }
601 }
602 out:
603 if (status & ACPI_EC_FLAG_SCI)
604 acpi_ec_submit_query(ec);
605 if (wakeup && in_interrupt())
606 wake_up(&ec->wait);
607 }
608
start_transaction(struct acpi_ec * ec)609 static void start_transaction(struct acpi_ec *ec)
610 {
611 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
612 ec->curr->flags = 0;
613 }
614
ec_guard(struct acpi_ec * ec)615 static int ec_guard(struct acpi_ec *ec)
616 {
617 unsigned long guard = usecs_to_jiffies(ec_polling_guard);
618 unsigned long timeout = ec->timestamp + guard;
619
620 /* Ensure guarding period before polling EC status */
621 do {
622 if (ec_busy_polling) {
623 /* Perform busy polling */
624 if (ec_transaction_completed(ec))
625 return 0;
626 udelay(jiffies_to_usecs(guard));
627 } else {
628 /*
629 * Perform wait polling
630 * 1. Wait the transaction to be completed by the
631 * GPE handler after the transaction enters
632 * ACPI_EC_COMMAND_POLL state.
633 * 2. A special guarding logic is also required
634 * for event clearing mode "event" before the
635 * transaction enters ACPI_EC_COMMAND_POLL
636 * state.
637 */
638 if (!ec_transaction_polled(ec) &&
639 !acpi_ec_guard_event(ec))
640 break;
641 if (wait_event_timeout(ec->wait,
642 ec_transaction_completed(ec),
643 guard))
644 return 0;
645 }
646 } while (time_before(jiffies, timeout));
647 return -ETIME;
648 }
649
ec_poll(struct acpi_ec * ec)650 static int ec_poll(struct acpi_ec *ec)
651 {
652 unsigned long flags;
653 int repeat = 5; /* number of command restarts */
654
655 while (repeat--) {
656 unsigned long delay = jiffies +
657 msecs_to_jiffies(ec_delay);
658 do {
659 if (!ec_guard(ec))
660 return 0;
661 spin_lock_irqsave(&ec->lock, flags);
662 advance_transaction(ec);
663 spin_unlock_irqrestore(&ec->lock, flags);
664 } while (time_before(jiffies, delay));
665 pr_debug("controller reset, restart transaction\n");
666 spin_lock_irqsave(&ec->lock, flags);
667 start_transaction(ec);
668 spin_unlock_irqrestore(&ec->lock, flags);
669 }
670 return -ETIME;
671 }
672
acpi_ec_transaction_unlocked(struct acpi_ec * ec,struct transaction * t)673 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
674 struct transaction *t)
675 {
676 unsigned long tmp;
677 int ret = 0;
678
679 /* start transaction */
680 spin_lock_irqsave(&ec->lock, tmp);
681 /* Enable GPE for command processing (IBF=0/OBF=1) */
682 if (!acpi_ec_submit_flushable_request(ec)) {
683 ret = -EINVAL;
684 goto unlock;
685 }
686 ec_dbg_ref(ec, "Increase command");
687 /* following two actions should be kept atomic */
688 ec->curr = t;
689 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
690 start_transaction(ec);
691 spin_unlock_irqrestore(&ec->lock, tmp);
692
693 ret = ec_poll(ec);
694
695 spin_lock_irqsave(&ec->lock, tmp);
696 if (t->irq_count == ec_storm_threshold)
697 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
698 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
699 ec->curr = NULL;
700 /* Disable GPE for command processing (IBF=0/OBF=1) */
701 acpi_ec_complete_request(ec);
702 ec_dbg_ref(ec, "Decrease command");
703 unlock:
704 spin_unlock_irqrestore(&ec->lock, tmp);
705 return ret;
706 }
707
acpi_ec_transaction(struct acpi_ec * ec,struct transaction * t)708 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
709 {
710 int status;
711 u32 glk;
712
713 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
714 return -EINVAL;
715 if (t->rdata)
716 memset(t->rdata, 0, t->rlen);
717
718 mutex_lock(&ec->mutex);
719 if (ec->global_lock) {
720 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
721 if (ACPI_FAILURE(status)) {
722 status = -ENODEV;
723 goto unlock;
724 }
725 }
726
727 status = acpi_ec_transaction_unlocked(ec, t);
728
729 if (ec->global_lock)
730 acpi_release_global_lock(glk);
731 unlock:
732 mutex_unlock(&ec->mutex);
733 return status;
734 }
735
acpi_ec_burst_enable(struct acpi_ec * ec)736 static int acpi_ec_burst_enable(struct acpi_ec *ec)
737 {
738 u8 d;
739 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
740 .wdata = NULL, .rdata = &d,
741 .wlen = 0, .rlen = 1};
742
743 return acpi_ec_transaction(ec, &t);
744 }
745
acpi_ec_burst_disable(struct acpi_ec * ec)746 static int acpi_ec_burst_disable(struct acpi_ec *ec)
747 {
748 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
749 .wdata = NULL, .rdata = NULL,
750 .wlen = 0, .rlen = 0};
751
752 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
753 acpi_ec_transaction(ec, &t) : 0;
754 }
755
acpi_ec_read(struct acpi_ec * ec,u8 address,u8 * data)756 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
757 {
758 int result;
759 u8 d;
760 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
761 .wdata = &address, .rdata = &d,
762 .wlen = 1, .rlen = 1};
763
764 result = acpi_ec_transaction(ec, &t);
765 *data = d;
766 return result;
767 }
768
acpi_ec_write(struct acpi_ec * ec,u8 address,u8 data)769 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
770 {
771 u8 wdata[2] = { address, data };
772 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
773 .wdata = wdata, .rdata = NULL,
774 .wlen = 2, .rlen = 0};
775
776 return acpi_ec_transaction(ec, &t);
777 }
778
ec_read(u8 addr,u8 * val)779 int ec_read(u8 addr, u8 *val)
780 {
781 int err;
782 u8 temp_data;
783
784 if (!first_ec)
785 return -ENODEV;
786
787 err = acpi_ec_read(first_ec, addr, &temp_data);
788
789 if (!err) {
790 *val = temp_data;
791 return 0;
792 }
793 return err;
794 }
795 EXPORT_SYMBOL(ec_read);
796
ec_write(u8 addr,u8 val)797 int ec_write(u8 addr, u8 val)
798 {
799 int err;
800
801 if (!first_ec)
802 return -ENODEV;
803
804 err = acpi_ec_write(first_ec, addr, val);
805
806 return err;
807 }
808 EXPORT_SYMBOL(ec_write);
809
ec_transaction(u8 command,const u8 * wdata,unsigned wdata_len,u8 * rdata,unsigned rdata_len)810 int ec_transaction(u8 command,
811 const u8 *wdata, unsigned wdata_len,
812 u8 *rdata, unsigned rdata_len)
813 {
814 struct transaction t = {.command = command,
815 .wdata = wdata, .rdata = rdata,
816 .wlen = wdata_len, .rlen = rdata_len};
817
818 if (!first_ec)
819 return -ENODEV;
820
821 return acpi_ec_transaction(first_ec, &t);
822 }
823 EXPORT_SYMBOL(ec_transaction);
824
825 /* Get the handle to the EC device */
ec_get_handle(void)826 acpi_handle ec_get_handle(void)
827 {
828 if (!first_ec)
829 return NULL;
830 return first_ec->handle;
831 }
832 EXPORT_SYMBOL(ec_get_handle);
833
834 /*
835 * Process _Q events that might have accumulated in the EC.
836 * Run with locked ec mutex.
837 */
acpi_ec_clear(struct acpi_ec * ec)838 static void acpi_ec_clear(struct acpi_ec *ec)
839 {
840 int i, status;
841 u8 value = 0;
842
843 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
844 status = acpi_ec_query(ec, &value);
845 if (status || !value)
846 break;
847 }
848
849 if (unlikely(i == ACPI_EC_CLEAR_MAX))
850 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
851 else
852 pr_info("%d stale EC events cleared\n", i);
853 }
854
acpi_ec_start(struct acpi_ec * ec,bool resuming)855 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
856 {
857 unsigned long flags;
858
859 spin_lock_irqsave(&ec->lock, flags);
860 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
861 ec_dbg_drv("Starting EC");
862 /* Enable GPE for event processing (SCI_EVT=1) */
863 if (!resuming) {
864 acpi_ec_submit_request(ec);
865 ec_dbg_ref(ec, "Increase driver");
866 }
867 ec_log_drv("EC started");
868 }
869 spin_unlock_irqrestore(&ec->lock, flags);
870 }
871
acpi_ec_stopped(struct acpi_ec * ec)872 static bool acpi_ec_stopped(struct acpi_ec *ec)
873 {
874 unsigned long flags;
875 bool flushed;
876
877 spin_lock_irqsave(&ec->lock, flags);
878 flushed = acpi_ec_flushed(ec);
879 spin_unlock_irqrestore(&ec->lock, flags);
880 return flushed;
881 }
882
acpi_ec_stop(struct acpi_ec * ec,bool suspending)883 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
884 {
885 unsigned long flags;
886
887 spin_lock_irqsave(&ec->lock, flags);
888 if (acpi_ec_started(ec)) {
889 ec_dbg_drv("Stopping EC");
890 set_bit(EC_FLAGS_STOPPED, &ec->flags);
891 spin_unlock_irqrestore(&ec->lock, flags);
892 wait_event(ec->wait, acpi_ec_stopped(ec));
893 spin_lock_irqsave(&ec->lock, flags);
894 /* Disable GPE for event processing (SCI_EVT=1) */
895 if (!suspending) {
896 acpi_ec_complete_request(ec);
897 ec_dbg_ref(ec, "Decrease driver");
898 }
899 clear_bit(EC_FLAGS_STARTED, &ec->flags);
900 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
901 ec_log_drv("EC stopped");
902 }
903 spin_unlock_irqrestore(&ec->lock, flags);
904 }
905
acpi_ec_block_transactions(void)906 void acpi_ec_block_transactions(void)
907 {
908 struct acpi_ec *ec = first_ec;
909
910 if (!ec)
911 return;
912
913 mutex_lock(&ec->mutex);
914 /* Prevent transactions from being carried out */
915 acpi_ec_stop(ec, true);
916 mutex_unlock(&ec->mutex);
917 }
918
acpi_ec_unblock_transactions(void)919 void acpi_ec_unblock_transactions(void)
920 {
921 struct acpi_ec *ec = first_ec;
922
923 if (!ec)
924 return;
925
926 /* Allow transactions to be carried out again */
927 acpi_ec_start(ec, true);
928
929 if (EC_FLAGS_CLEAR_ON_RESUME)
930 acpi_ec_clear(ec);
931 }
932
acpi_ec_unblock_transactions_early(void)933 void acpi_ec_unblock_transactions_early(void)
934 {
935 /*
936 * Allow transactions to happen again (this function is called from
937 * atomic context during wakeup, so we don't need to acquire the mutex).
938 */
939 if (first_ec)
940 acpi_ec_start(first_ec, true);
941 }
942
943 /* --------------------------------------------------------------------------
944 Event Management
945 -------------------------------------------------------------------------- */
946 static struct acpi_ec_query_handler *
acpi_ec_get_query_handler_by_value(struct acpi_ec * ec,u8 value)947 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
948 {
949 struct acpi_ec_query_handler *handler;
950
951 mutex_lock(&ec->mutex);
952 list_for_each_entry(handler, &ec->list, node) {
953 if (value == handler->query_bit) {
954 kref_get(&handler->kref);
955 mutex_unlock(&ec->mutex);
956 return handler;
957 }
958 }
959 mutex_unlock(&ec->mutex);
960 return NULL;
961 }
962
acpi_ec_query_handler_release(struct kref * kref)963 static void acpi_ec_query_handler_release(struct kref *kref)
964 {
965 struct acpi_ec_query_handler *handler =
966 container_of(kref, struct acpi_ec_query_handler, kref);
967
968 kfree(handler);
969 }
970
acpi_ec_put_query_handler(struct acpi_ec_query_handler * handler)971 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
972 {
973 kref_put(&handler->kref, acpi_ec_query_handler_release);
974 }
975
acpi_ec_add_query_handler(struct acpi_ec * ec,u8 query_bit,acpi_handle handle,acpi_ec_query_func func,void * data)976 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
977 acpi_handle handle, acpi_ec_query_func func,
978 void *data)
979 {
980 struct acpi_ec_query_handler *handler =
981 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
982
983 if (!handler)
984 return -ENOMEM;
985
986 handler->query_bit = query_bit;
987 handler->handle = handle;
988 handler->func = func;
989 handler->data = data;
990 mutex_lock(&ec->mutex);
991 kref_init(&handler->kref);
992 list_add(&handler->node, &ec->list);
993 mutex_unlock(&ec->mutex);
994 return 0;
995 }
996 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
997
acpi_ec_remove_query_handlers(struct acpi_ec * ec,bool remove_all,u8 query_bit)998 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
999 bool remove_all, u8 query_bit)
1000 {
1001 struct acpi_ec_query_handler *handler, *tmp;
1002 LIST_HEAD(free_list);
1003
1004 mutex_lock(&ec->mutex);
1005 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1006 if (remove_all || query_bit == handler->query_bit) {
1007 list_del_init(&handler->node);
1008 list_add(&handler->node, &free_list);
1009 }
1010 }
1011 mutex_unlock(&ec->mutex);
1012 list_for_each_entry_safe(handler, tmp, &free_list, node)
1013 acpi_ec_put_query_handler(handler);
1014 }
1015
acpi_ec_remove_query_handler(struct acpi_ec * ec,u8 query_bit)1016 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1017 {
1018 acpi_ec_remove_query_handlers(ec, false, query_bit);
1019 }
1020 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1021
acpi_ec_create_query(u8 * pval)1022 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1023 {
1024 struct acpi_ec_query *q;
1025 struct transaction *t;
1026
1027 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1028 if (!q)
1029 return NULL;
1030 INIT_WORK(&q->work, acpi_ec_event_processor);
1031 t = &q->transaction;
1032 t->command = ACPI_EC_COMMAND_QUERY;
1033 t->rdata = pval;
1034 t->rlen = 1;
1035 return q;
1036 }
1037
acpi_ec_delete_query(struct acpi_ec_query * q)1038 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1039 {
1040 if (q) {
1041 if (q->handler)
1042 acpi_ec_put_query_handler(q->handler);
1043 kfree(q);
1044 }
1045 }
1046
acpi_ec_event_processor(struct work_struct * work)1047 static void acpi_ec_event_processor(struct work_struct *work)
1048 {
1049 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1050 struct acpi_ec_query_handler *handler = q->handler;
1051
1052 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1053 if (handler->func)
1054 handler->func(handler->data);
1055 else if (handler->handle)
1056 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1057 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1058 acpi_ec_delete_query(q);
1059 }
1060
acpi_ec_query(struct acpi_ec * ec,u8 * data)1061 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1062 {
1063 u8 value = 0;
1064 int result;
1065 struct acpi_ec_query *q;
1066
1067 q = acpi_ec_create_query(&value);
1068 if (!q)
1069 return -ENOMEM;
1070
1071 /*
1072 * Query the EC to find out which _Qxx method we need to evaluate.
1073 * Note that successful completion of the query causes the ACPI_EC_SCI
1074 * bit to be cleared (and thus clearing the interrupt source).
1075 */
1076 result = acpi_ec_transaction(ec, &q->transaction);
1077 if (!value)
1078 result = -ENODATA;
1079 if (result)
1080 goto err_exit;
1081
1082 q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1083 if (!q->handler) {
1084 result = -ENODATA;
1085 goto err_exit;
1086 }
1087
1088 /*
1089 * It is reported that _Qxx are evaluated in a parallel way on
1090 * Windows:
1091 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1092 *
1093 * Put this log entry before schedule_work() in order to make
1094 * it appearing before any other log entries occurred during the
1095 * work queue execution.
1096 */
1097 ec_dbg_evt("Query(0x%02x) scheduled", value);
1098 if (!queue_work(ec_query_wq, &q->work)) {
1099 ec_dbg_evt("Query(0x%02x) overlapped", value);
1100 result = -EBUSY;
1101 }
1102
1103 err_exit:
1104 if (result)
1105 acpi_ec_delete_query(q);
1106 if (data)
1107 *data = value;
1108 return result;
1109 }
1110
acpi_ec_check_event(struct acpi_ec * ec)1111 static void acpi_ec_check_event(struct acpi_ec *ec)
1112 {
1113 unsigned long flags;
1114
1115 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1116 if (ec_guard(ec)) {
1117 spin_lock_irqsave(&ec->lock, flags);
1118 /*
1119 * Take care of the SCI_EVT unless no one else is
1120 * taking care of it.
1121 */
1122 if (!ec->curr)
1123 advance_transaction(ec);
1124 spin_unlock_irqrestore(&ec->lock, flags);
1125 }
1126 }
1127 }
1128
acpi_ec_event_handler(struct work_struct * work)1129 static void acpi_ec_event_handler(struct work_struct *work)
1130 {
1131 unsigned long flags;
1132 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1133
1134 ec_dbg_evt("Event started");
1135
1136 spin_lock_irqsave(&ec->lock, flags);
1137 while (ec->nr_pending_queries) {
1138 spin_unlock_irqrestore(&ec->lock, flags);
1139 (void)acpi_ec_query(ec, NULL);
1140 spin_lock_irqsave(&ec->lock, flags);
1141 ec->nr_pending_queries--;
1142 /*
1143 * Before exit, make sure that this work item can be
1144 * scheduled again. There might be QR_EC failures, leaving
1145 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1146 * item from being scheduled again.
1147 */
1148 if (!ec->nr_pending_queries) {
1149 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1150 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1151 acpi_ec_complete_query(ec);
1152 }
1153 }
1154 spin_unlock_irqrestore(&ec->lock, flags);
1155
1156 ec_dbg_evt("Event stopped");
1157
1158 acpi_ec_check_event(ec);
1159 }
1160
acpi_ec_gpe_handler(acpi_handle gpe_device,u32 gpe_number,void * data)1161 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1162 u32 gpe_number, void *data)
1163 {
1164 unsigned long flags;
1165 struct acpi_ec *ec = data;
1166
1167 spin_lock_irqsave(&ec->lock, flags);
1168 advance_transaction(ec);
1169 spin_unlock_irqrestore(&ec->lock, flags);
1170 return ACPI_INTERRUPT_HANDLED;
1171 }
1172
1173 /* --------------------------------------------------------------------------
1174 * Address Space Management
1175 * -------------------------------------------------------------------------- */
1176
1177 static acpi_status
acpi_ec_space_handler(u32 function,acpi_physical_address address,u32 bits,u64 * value64,void * handler_context,void * region_context)1178 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1179 u32 bits, u64 *value64,
1180 void *handler_context, void *region_context)
1181 {
1182 struct acpi_ec *ec = handler_context;
1183 int result = 0, i, bytes = bits / 8;
1184 u8 *value = (u8 *)value64;
1185
1186 if ((address > 0xFF) || !value || !handler_context)
1187 return AE_BAD_PARAMETER;
1188
1189 if (function != ACPI_READ && function != ACPI_WRITE)
1190 return AE_BAD_PARAMETER;
1191
1192 if (ec_busy_polling || bits > 8)
1193 acpi_ec_burst_enable(ec);
1194
1195 for (i = 0; i < bytes; ++i, ++address, ++value)
1196 result = (function == ACPI_READ) ?
1197 acpi_ec_read(ec, address, value) :
1198 acpi_ec_write(ec, address, *value);
1199
1200 if (ec_busy_polling || bits > 8)
1201 acpi_ec_burst_disable(ec);
1202
1203 switch (result) {
1204 case -EINVAL:
1205 return AE_BAD_PARAMETER;
1206 case -ENODEV:
1207 return AE_NOT_FOUND;
1208 case -ETIME:
1209 return AE_TIME;
1210 default:
1211 return AE_OK;
1212 }
1213 }
1214
1215 /* --------------------------------------------------------------------------
1216 * Driver Interface
1217 * -------------------------------------------------------------------------- */
1218
1219 static acpi_status
1220 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1221
make_acpi_ec(void)1222 static struct acpi_ec *make_acpi_ec(void)
1223 {
1224 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1225
1226 if (!ec)
1227 return NULL;
1228 ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
1229 mutex_init(&ec->mutex);
1230 init_waitqueue_head(&ec->wait);
1231 INIT_LIST_HEAD(&ec->list);
1232 spin_lock_init(&ec->lock);
1233 INIT_WORK(&ec->work, acpi_ec_event_handler);
1234 ec->timestamp = jiffies;
1235 return ec;
1236 }
1237
1238 static acpi_status
acpi_ec_register_query_methods(acpi_handle handle,u32 level,void * context,void ** return_value)1239 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1240 void *context, void **return_value)
1241 {
1242 char node_name[5];
1243 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1244 struct acpi_ec *ec = context;
1245 int value = 0;
1246 acpi_status status;
1247
1248 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1249
1250 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1251 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1252 return AE_OK;
1253 }
1254
1255 static acpi_status
ec_parse_device(acpi_handle handle,u32 Level,void * context,void ** retval)1256 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1257 {
1258 acpi_status status;
1259 unsigned long long tmp = 0;
1260 struct acpi_ec *ec = context;
1261
1262 /* clear addr values, ec_parse_io_ports depend on it */
1263 ec->command_addr = ec->data_addr = 0;
1264
1265 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1266 ec_parse_io_ports, ec);
1267 if (ACPI_FAILURE(status))
1268 return status;
1269
1270 /* Get GPE bit assignment (EC events). */
1271 /* TODO: Add support for _GPE returning a package */
1272 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1273 if (ACPI_FAILURE(status))
1274 return status;
1275 ec->gpe = tmp;
1276 /* Use the global lock for all EC transactions? */
1277 tmp = 0;
1278 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1279 ec->global_lock = tmp;
1280 ec->handle = handle;
1281 return AE_CTRL_TERMINATE;
1282 }
1283
ec_install_handlers(struct acpi_ec * ec)1284 static int ec_install_handlers(struct acpi_ec *ec)
1285 {
1286 acpi_status status;
1287
1288 if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1289 return 0;
1290 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1291 ACPI_GPE_EDGE_TRIGGERED,
1292 &acpi_ec_gpe_handler, ec);
1293 if (ACPI_FAILURE(status))
1294 return -ENODEV;
1295
1296 acpi_ec_start(ec, false);
1297 status = acpi_install_address_space_handler(ec->handle,
1298 ACPI_ADR_SPACE_EC,
1299 &acpi_ec_space_handler,
1300 NULL, ec);
1301 if (ACPI_FAILURE(status)) {
1302 if (status == AE_NOT_FOUND) {
1303 /*
1304 * Maybe OS fails in evaluating the _REG object.
1305 * The AE_NOT_FOUND error will be ignored and OS
1306 * continue to initialize EC.
1307 */
1308 pr_err("Fail in evaluating the _REG object"
1309 " of EC device. Broken bios is suspected.\n");
1310 } else {
1311 acpi_ec_stop(ec, false);
1312 acpi_remove_gpe_handler(NULL, ec->gpe,
1313 &acpi_ec_gpe_handler);
1314 return -ENODEV;
1315 }
1316 }
1317
1318 set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1319 return 0;
1320 }
1321
ec_remove_handlers(struct acpi_ec * ec)1322 static void ec_remove_handlers(struct acpi_ec *ec)
1323 {
1324 if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1325 return;
1326 acpi_ec_stop(ec, false);
1327 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1328 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1329 pr_err("failed to remove space handler\n");
1330 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1331 &acpi_ec_gpe_handler)))
1332 pr_err("failed to remove gpe handler\n");
1333 clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1334 }
1335
acpi_ec_add(struct acpi_device * device)1336 static int acpi_ec_add(struct acpi_device *device)
1337 {
1338 struct acpi_ec *ec = NULL;
1339 int ret;
1340
1341 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1342 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1343
1344 /* Check for boot EC */
1345 if (boot_ec &&
1346 (boot_ec->handle == device->handle ||
1347 boot_ec->handle == ACPI_ROOT_OBJECT)) {
1348 ec = boot_ec;
1349 boot_ec = NULL;
1350 } else {
1351 ec = make_acpi_ec();
1352 if (!ec)
1353 return -ENOMEM;
1354 }
1355 if (ec_parse_device(device->handle, 0, ec, NULL) !=
1356 AE_CTRL_TERMINATE) {
1357 kfree(ec);
1358 return -EINVAL;
1359 }
1360
1361 /* Find and register all query methods */
1362 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1363 acpi_ec_register_query_methods, NULL, ec, NULL);
1364
1365 if (!first_ec)
1366 first_ec = ec;
1367 device->driver_data = ec;
1368
1369 ret = !!request_region(ec->data_addr, 1, "EC data");
1370 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1371 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1372 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1373
1374 pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
1375 ec->gpe, ec->command_addr, ec->data_addr);
1376
1377 ret = ec_install_handlers(ec);
1378
1379 /* Reprobe devices depending on the EC */
1380 acpi_walk_dep_device_list(ec->handle);
1381
1382 /* EC is fully operational, allow queries */
1383 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1384
1385 /* Clear stale _Q events if hardware might require that */
1386 if (EC_FLAGS_CLEAR_ON_RESUME)
1387 acpi_ec_clear(ec);
1388 return ret;
1389 }
1390
acpi_ec_remove(struct acpi_device * device)1391 static int acpi_ec_remove(struct acpi_device *device)
1392 {
1393 struct acpi_ec *ec;
1394
1395 if (!device)
1396 return -EINVAL;
1397
1398 ec = acpi_driver_data(device);
1399 ec_remove_handlers(ec);
1400 acpi_ec_remove_query_handlers(ec, true, 0);
1401 release_region(ec->data_addr, 1);
1402 release_region(ec->command_addr, 1);
1403 device->driver_data = NULL;
1404 if (ec == first_ec)
1405 first_ec = NULL;
1406 kfree(ec);
1407 return 0;
1408 }
1409
1410 static acpi_status
ec_parse_io_ports(struct acpi_resource * resource,void * context)1411 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1412 {
1413 struct acpi_ec *ec = context;
1414
1415 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1416 return AE_OK;
1417
1418 /*
1419 * The first address region returned is the data port, and
1420 * the second address region returned is the status/command
1421 * port.
1422 */
1423 if (ec->data_addr == 0)
1424 ec->data_addr = resource->data.io.minimum;
1425 else if (ec->command_addr == 0)
1426 ec->command_addr = resource->data.io.minimum;
1427 else
1428 return AE_CTRL_TERMINATE;
1429
1430 return AE_OK;
1431 }
1432
acpi_boot_ec_enable(void)1433 int __init acpi_boot_ec_enable(void)
1434 {
1435 if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1436 return 0;
1437 if (!ec_install_handlers(boot_ec)) {
1438 first_ec = boot_ec;
1439 return 0;
1440 }
1441 return -EFAULT;
1442 }
1443
1444 static const struct acpi_device_id ec_device_ids[] = {
1445 {"PNP0C09", 0},
1446 {"", 0},
1447 };
1448
1449 /* Some BIOS do not survive early DSDT scan, skip it */
ec_skip_dsdt_scan(const struct dmi_system_id * id)1450 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1451 {
1452 EC_FLAGS_SKIP_DSDT_SCAN = 1;
1453 return 0;
1454 }
1455
1456 /* ASUStek often supplies us with broken ECDT, validate it */
ec_validate_ecdt(const struct dmi_system_id * id)1457 static int ec_validate_ecdt(const struct dmi_system_id *id)
1458 {
1459 EC_FLAGS_VALIDATE_ECDT = 1;
1460 return 0;
1461 }
1462
1463 #if 0
1464 /*
1465 * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1466 * set, for which case, we complete the QR_EC without issuing it to the
1467 * firmware.
1468 * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1469 * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1470 */
1471 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1472 {
1473 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1474 EC_FLAGS_QUERY_HANDSHAKE = 1;
1475 return 0;
1476 }
1477 #endif
1478
1479 /*
1480 * On some hardware it is necessary to clear events accumulated by the EC during
1481 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1482 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1483 *
1484 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1485 *
1486 * Ideally, the EC should also be instructed NOT to accumulate events during
1487 * sleep (which Windows seems to do somehow), but the interface to control this
1488 * behaviour is not known at this time.
1489 *
1490 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1491 * however it is very likely that other Samsung models are affected.
1492 *
1493 * On systems which don't accumulate _Q events during sleep, this extra check
1494 * should be harmless.
1495 */
ec_clear_on_resume(const struct dmi_system_id * id)1496 static int ec_clear_on_resume(const struct dmi_system_id *id)
1497 {
1498 pr_debug("Detected system needing EC poll on resume.\n");
1499 EC_FLAGS_CLEAR_ON_RESUME = 1;
1500 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1501 return 0;
1502 }
1503
1504 static struct dmi_system_id ec_dmi_table[] __initdata = {
1505 {
1506 ec_skip_dsdt_scan, "Compal JFL92", {
1507 DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1508 DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1509 {
1510 ec_validate_ecdt, "MSI MS-171F", {
1511 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1512 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1513 {
1514 ec_validate_ecdt, "ASUS hardware", {
1515 DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1516 {
1517 ec_validate_ecdt, "ASUS hardware", {
1518 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1519 {
1520 ec_skip_dsdt_scan, "HP Folio 13", {
1521 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1522 DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1523 {
1524 ec_validate_ecdt, "ASUS hardware", {
1525 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1526 DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1527 {
1528 ec_clear_on_resume, "Samsung hardware", {
1529 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1530 {},
1531 };
1532
acpi_ec_ecdt_probe(void)1533 int __init acpi_ec_ecdt_probe(void)
1534 {
1535 acpi_status status;
1536 struct acpi_ec *saved_ec = NULL;
1537 struct acpi_table_ecdt *ecdt_ptr;
1538
1539 boot_ec = make_acpi_ec();
1540 if (!boot_ec)
1541 return -ENOMEM;
1542 /*
1543 * Generate a boot ec context
1544 */
1545 dmi_check_system(ec_dmi_table);
1546 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1547 (struct acpi_table_header **)&ecdt_ptr);
1548 if (ACPI_SUCCESS(status)) {
1549 pr_info("EC description table is found, configuring boot EC\n");
1550 boot_ec->command_addr = ecdt_ptr->control.address;
1551 boot_ec->data_addr = ecdt_ptr->data.address;
1552 boot_ec->gpe = ecdt_ptr->gpe;
1553 boot_ec->handle = ACPI_ROOT_OBJECT;
1554 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1555 &boot_ec->handle);
1556 /* Don't trust ECDT, which comes from ASUSTek */
1557 if (!EC_FLAGS_VALIDATE_ECDT)
1558 goto install;
1559 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1560 if (!saved_ec)
1561 return -ENOMEM;
1562 /* fall through */
1563 }
1564
1565 if (EC_FLAGS_SKIP_DSDT_SCAN) {
1566 kfree(saved_ec);
1567 return -ENODEV;
1568 }
1569
1570 /* This workaround is needed only on some broken machines,
1571 * which require early EC, but fail to provide ECDT */
1572 pr_debug("Look up EC in DSDT\n");
1573 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1574 boot_ec, NULL);
1575 /* Check that acpi_get_devices actually find something */
1576 if (ACPI_FAILURE(status) || !boot_ec->handle)
1577 goto error;
1578 if (saved_ec) {
1579 /* try to find good ECDT from ASUSTek */
1580 if (saved_ec->command_addr != boot_ec->command_addr ||
1581 saved_ec->data_addr != boot_ec->data_addr ||
1582 saved_ec->gpe != boot_ec->gpe ||
1583 saved_ec->handle != boot_ec->handle)
1584 pr_info("ASUSTek keeps feeding us with broken "
1585 "ECDT tables, which are very hard to workaround. "
1586 "Trying to use DSDT EC info instead. Please send "
1587 "output of acpidump to linux-acpi@vger.kernel.org\n");
1588 kfree(saved_ec);
1589 saved_ec = NULL;
1590 } else {
1591 /* We really need to limit this workaround, the only ASUS,
1592 * which needs it, has fake EC._INI method, so use it as flag.
1593 * Keep boot_ec struct as it will be needed soon.
1594 */
1595 if (!dmi_name_in_vendors("ASUS") ||
1596 !acpi_has_method(boot_ec->handle, "_INI"))
1597 return -ENODEV;
1598 }
1599 install:
1600 if (!ec_install_handlers(boot_ec)) {
1601 first_ec = boot_ec;
1602 return 0;
1603 }
1604 error:
1605 kfree(boot_ec);
1606 kfree(saved_ec);
1607 boot_ec = NULL;
1608 return -ENODEV;
1609 }
1610
param_set_event_clearing(const char * val,struct kernel_param * kp)1611 static int param_set_event_clearing(const char *val, struct kernel_param *kp)
1612 {
1613 int result = 0;
1614
1615 if (!strncmp(val, "status", sizeof("status") - 1)) {
1616 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1617 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1618 } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1619 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1620 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1621 } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1622 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1623 pr_info("Assuming SCI_EVT clearing on event reads\n");
1624 } else
1625 result = -EINVAL;
1626 return result;
1627 }
1628
param_get_event_clearing(char * buffer,struct kernel_param * kp)1629 static int param_get_event_clearing(char *buffer, struct kernel_param *kp)
1630 {
1631 switch (ec_event_clearing) {
1632 case ACPI_EC_EVT_TIMING_STATUS:
1633 return sprintf(buffer, "status");
1634 case ACPI_EC_EVT_TIMING_QUERY:
1635 return sprintf(buffer, "query");
1636 case ACPI_EC_EVT_TIMING_EVENT:
1637 return sprintf(buffer, "event");
1638 default:
1639 return sprintf(buffer, "invalid");
1640 }
1641 return 0;
1642 }
1643
1644 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
1645 NULL, 0644);
1646 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
1647
1648 static struct acpi_driver acpi_ec_driver = {
1649 .name = "ec",
1650 .class = ACPI_EC_CLASS,
1651 .ids = ec_device_ids,
1652 .ops = {
1653 .add = acpi_ec_add,
1654 .remove = acpi_ec_remove,
1655 },
1656 };
1657
acpi_ec_query_init(void)1658 static inline int acpi_ec_query_init(void)
1659 {
1660 if (!ec_query_wq) {
1661 ec_query_wq = alloc_workqueue("kec_query", 0,
1662 ec_max_queries);
1663 if (!ec_query_wq)
1664 return -ENODEV;
1665 }
1666 return 0;
1667 }
1668
acpi_ec_query_exit(void)1669 static inline void acpi_ec_query_exit(void)
1670 {
1671 if (ec_query_wq) {
1672 destroy_workqueue(ec_query_wq);
1673 ec_query_wq = NULL;
1674 }
1675 }
1676
acpi_ec_init(void)1677 int __init acpi_ec_init(void)
1678 {
1679 int result;
1680
1681 /* register workqueue for _Qxx evaluations */
1682 result = acpi_ec_query_init();
1683 if (result)
1684 goto err_exit;
1685 /* Now register the driver for the EC */
1686 result = acpi_bus_register_driver(&acpi_ec_driver);
1687 if (result)
1688 goto err_exit;
1689
1690 err_exit:
1691 if (result)
1692 acpi_ec_query_exit();
1693 return result;
1694 }
1695
1696 /* EC driver currently not unloadable */
1697 #if 0
1698 static void __exit acpi_ec_exit(void)
1699 {
1700
1701 acpi_bus_unregister_driver(&acpi_ec_driver);
1702 acpi_ec_query_exit();
1703 }
1704 #endif /* 0 */
1705