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_ENABLED, /* Query is enabled */ 108 EC_FLAGS_QUERY_PENDING, /* Query is pending */ 109 EC_FLAGS_QUERY_GUARDING, /* Guard for SCI_EVT check */ 110 EC_FLAGS_GPE_HANDLER_INSTALLED, /* GPE handler installed */ 111 EC_FLAGS_EC_HANDLER_INSTALLED, /* OpReg handler installed */ 112 EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */ 113 EC_FLAGS_STARTED, /* Driver is started */ 114 EC_FLAGS_STOPPED, /* Driver is stopped */ 115 EC_FLAGS_COMMAND_STORM, /* GPE storms occurred to the 116 * current command processing */ 117 }; 118 119 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */ 120 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */ 121 122 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */ 123 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY; 124 module_param(ec_delay, uint, 0644); 125 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes"); 126 127 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES; 128 module_param(ec_max_queries, uint, 0644); 129 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations"); 130 131 static bool ec_busy_polling __read_mostly; 132 module_param(ec_busy_polling, bool, 0644); 133 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction"); 134 135 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL; 136 module_param(ec_polling_guard, uint, 0644); 137 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes"); 138 139 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY; 140 141 /* 142 * If the number of false interrupts per one transaction exceeds 143 * this threshold, will think there is a GPE storm happened and 144 * will disable the GPE for normal transaction. 145 */ 146 static unsigned int ec_storm_threshold __read_mostly = 8; 147 module_param(ec_storm_threshold, uint, 0644); 148 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm"); 149 150 static bool ec_freeze_events __read_mostly = true; 151 module_param(ec_freeze_events, bool, 0644); 152 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume"); 153 154 struct acpi_ec_query_handler { 155 struct list_head node; 156 acpi_ec_query_func func; 157 acpi_handle handle; 158 void *data; 159 u8 query_bit; 160 struct kref kref; 161 }; 162 163 struct transaction { 164 const u8 *wdata; 165 u8 *rdata; 166 unsigned short irq_count; 167 u8 command; 168 u8 wi; 169 u8 ri; 170 u8 wlen; 171 u8 rlen; 172 u8 flags; 173 }; 174 175 struct acpi_ec_query { 176 struct transaction transaction; 177 struct work_struct work; 178 struct acpi_ec_query_handler *handler; 179 }; 180 181 static int acpi_ec_query(struct acpi_ec *ec, u8 *data); 182 static void advance_transaction(struct acpi_ec *ec); 183 static void acpi_ec_event_handler(struct work_struct *work); 184 static void acpi_ec_event_processor(struct work_struct *work); 185 186 struct acpi_ec *boot_ec, *first_ec; 187 EXPORT_SYMBOL(first_ec); 188 static bool boot_ec_is_ecdt = false; 189 static struct workqueue_struct *ec_query_wq; 190 191 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */ 192 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */ 193 194 /* -------------------------------------------------------------------------- 195 * Logging/Debugging 196 * -------------------------------------------------------------------------- */ 197 198 /* 199 * Splitters used by the developers to track the boundary of the EC 200 * handling processes. 201 */ 202 #ifdef DEBUG 203 #define EC_DBG_SEP " " 204 #define EC_DBG_DRV "+++++" 205 #define EC_DBG_STM "=====" 206 #define EC_DBG_REQ "*****" 207 #define EC_DBG_EVT "#####" 208 #else 209 #define EC_DBG_SEP "" 210 #define EC_DBG_DRV 211 #define EC_DBG_STM 212 #define EC_DBG_REQ 213 #define EC_DBG_EVT 214 #endif 215 216 #define ec_log_raw(fmt, ...) \ 217 pr_info(fmt "\n", ##__VA_ARGS__) 218 #define ec_dbg_raw(fmt, ...) \ 219 pr_debug(fmt "\n", ##__VA_ARGS__) 220 #define ec_log(filter, fmt, ...) \ 221 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__) 222 #define ec_dbg(filter, fmt, ...) \ 223 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__) 224 225 #define ec_log_drv(fmt, ...) \ 226 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__) 227 #define ec_dbg_drv(fmt, ...) \ 228 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__) 229 #define ec_dbg_stm(fmt, ...) \ 230 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__) 231 #define ec_dbg_req(fmt, ...) \ 232 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__) 233 #define ec_dbg_evt(fmt, ...) \ 234 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__) 235 #define ec_dbg_ref(ec, fmt, ...) \ 236 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__) 237 238 /* -------------------------------------------------------------------------- 239 * Device Flags 240 * -------------------------------------------------------------------------- */ 241 242 static bool acpi_ec_started(struct acpi_ec *ec) 243 { 244 return test_bit(EC_FLAGS_STARTED, &ec->flags) && 245 !test_bit(EC_FLAGS_STOPPED, &ec->flags); 246 } 247 248 static bool acpi_ec_event_enabled(struct acpi_ec *ec) 249 { 250 /* 251 * There is an OSPM early stage logic. During the early stages 252 * (boot/resume), OSPMs shouldn't enable the event handling, only 253 * the EC transactions are allowed to be performed. 254 */ 255 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) 256 return false; 257 /* 258 * However, disabling the event handling is experimental for late 259 * stage (suspend), and is controlled by the boot parameter of 260 * "ec_freeze_events": 261 * 1. true: The EC event handling is disabled before entering 262 * the noirq stage. 263 * 2. false: The EC event handling is automatically disabled as 264 * soon as the EC driver is stopped. 265 */ 266 if (ec_freeze_events) 267 return acpi_ec_started(ec); 268 else 269 return test_bit(EC_FLAGS_STARTED, &ec->flags); 270 } 271 272 static bool acpi_ec_flushed(struct acpi_ec *ec) 273 { 274 return ec->reference_count == 1; 275 } 276 277 /* -------------------------------------------------------------------------- 278 * EC Registers 279 * -------------------------------------------------------------------------- */ 280 281 static inline u8 acpi_ec_read_status(struct acpi_ec *ec) 282 { 283 u8 x = inb(ec->command_addr); 284 285 ec_dbg_raw("EC_SC(R) = 0x%2.2x " 286 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d", 287 x, 288 !!(x & ACPI_EC_FLAG_SCI), 289 !!(x & ACPI_EC_FLAG_BURST), 290 !!(x & ACPI_EC_FLAG_CMD), 291 !!(x & ACPI_EC_FLAG_IBF), 292 !!(x & ACPI_EC_FLAG_OBF)); 293 return x; 294 } 295 296 static inline u8 acpi_ec_read_data(struct acpi_ec *ec) 297 { 298 u8 x = inb(ec->data_addr); 299 300 ec->timestamp = jiffies; 301 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x); 302 return x; 303 } 304 305 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command) 306 { 307 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command); 308 outb(command, ec->command_addr); 309 ec->timestamp = jiffies; 310 } 311 312 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data) 313 { 314 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data); 315 outb(data, ec->data_addr); 316 ec->timestamp = jiffies; 317 } 318 319 #ifdef DEBUG 320 static const char *acpi_ec_cmd_string(u8 cmd) 321 { 322 switch (cmd) { 323 case 0x80: 324 return "RD_EC"; 325 case 0x81: 326 return "WR_EC"; 327 case 0x82: 328 return "BE_EC"; 329 case 0x83: 330 return "BD_EC"; 331 case 0x84: 332 return "QR_EC"; 333 } 334 return "UNKNOWN"; 335 } 336 #else 337 #define acpi_ec_cmd_string(cmd) "UNDEF" 338 #endif 339 340 /* -------------------------------------------------------------------------- 341 * GPE Registers 342 * -------------------------------------------------------------------------- */ 343 344 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec) 345 { 346 acpi_event_status gpe_status = 0; 347 348 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status); 349 return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false; 350 } 351 352 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open) 353 { 354 if (open) 355 acpi_enable_gpe(NULL, ec->gpe); 356 else { 357 BUG_ON(ec->reference_count < 1); 358 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE); 359 } 360 if (acpi_ec_is_gpe_raised(ec)) { 361 /* 362 * On some platforms, EN=1 writes cannot trigger GPE. So 363 * software need to manually trigger a pseudo GPE event on 364 * EN=1 writes. 365 */ 366 ec_dbg_raw("Polling quirk"); 367 advance_transaction(ec); 368 } 369 } 370 371 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close) 372 { 373 if (close) 374 acpi_disable_gpe(NULL, ec->gpe); 375 else { 376 BUG_ON(ec->reference_count < 1); 377 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE); 378 } 379 } 380 381 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec) 382 { 383 /* 384 * GPE STS is a W1C register, which means: 385 * 1. Software can clear it without worrying about clearing other 386 * GPEs' STS bits when the hardware sets them in parallel. 387 * 2. As long as software can ensure only clearing it when it is 388 * set, hardware won't set it in parallel. 389 * So software can clear GPE in any contexts. 390 * Warning: do not move the check into advance_transaction() as the 391 * EC commands will be sent without GPE raised. 392 */ 393 if (!acpi_ec_is_gpe_raised(ec)) 394 return; 395 acpi_clear_gpe(NULL, ec->gpe); 396 } 397 398 /* -------------------------------------------------------------------------- 399 * Transaction Management 400 * -------------------------------------------------------------------------- */ 401 402 static void acpi_ec_submit_request(struct acpi_ec *ec) 403 { 404 ec->reference_count++; 405 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) && 406 ec->reference_count == 1) 407 acpi_ec_enable_gpe(ec, true); 408 } 409 410 static void acpi_ec_complete_request(struct acpi_ec *ec) 411 { 412 bool flushed = false; 413 414 ec->reference_count--; 415 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) && 416 ec->reference_count == 0) 417 acpi_ec_disable_gpe(ec, true); 418 flushed = acpi_ec_flushed(ec); 419 if (flushed) 420 wake_up(&ec->wait); 421 } 422 423 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag) 424 { 425 if (!test_bit(flag, &ec->flags)) { 426 acpi_ec_disable_gpe(ec, false); 427 ec_dbg_drv("Polling enabled"); 428 set_bit(flag, &ec->flags); 429 } 430 } 431 432 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag) 433 { 434 if (test_bit(flag, &ec->flags)) { 435 clear_bit(flag, &ec->flags); 436 acpi_ec_enable_gpe(ec, false); 437 ec_dbg_drv("Polling disabled"); 438 } 439 } 440 441 /* 442 * acpi_ec_submit_flushable_request() - Increase the reference count unless 443 * the flush operation is not in 444 * progress 445 * @ec: the EC device 446 * 447 * This function must be used before taking a new action that should hold 448 * the reference count. If this function returns false, then the action 449 * must be discarded or it will prevent the flush operation from being 450 * completed. 451 */ 452 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec) 453 { 454 if (!acpi_ec_started(ec)) 455 return false; 456 acpi_ec_submit_request(ec); 457 return true; 458 } 459 460 static void acpi_ec_submit_query(struct acpi_ec *ec) 461 { 462 if (acpi_ec_event_enabled(ec) && 463 !test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { 464 ec_dbg_evt("Command(%s) submitted/blocked", 465 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 466 ec->nr_pending_queries++; 467 schedule_work(&ec->work); 468 } 469 } 470 471 static void acpi_ec_complete_query(struct acpi_ec *ec) 472 { 473 if (test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { 474 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); 475 ec_dbg_evt("Command(%s) unblocked", 476 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 477 } 478 } 479 480 static inline void __acpi_ec_enable_event(struct acpi_ec *ec) 481 { 482 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) 483 ec_log_drv("event unblocked"); 484 if (!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) 485 advance_transaction(ec); 486 } 487 488 static inline void __acpi_ec_disable_event(struct acpi_ec *ec) 489 { 490 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) 491 ec_log_drv("event blocked"); 492 } 493 494 static void acpi_ec_enable_event(struct acpi_ec *ec) 495 { 496 unsigned long flags; 497 498 spin_lock_irqsave(&ec->lock, flags); 499 if (acpi_ec_started(ec)) 500 __acpi_ec_enable_event(ec); 501 spin_unlock_irqrestore(&ec->lock, flags); 502 } 503 504 #ifdef CONFIG_PM_SLEEP 505 static bool acpi_ec_query_flushed(struct acpi_ec *ec) 506 { 507 bool flushed; 508 unsigned long flags; 509 510 spin_lock_irqsave(&ec->lock, flags); 511 flushed = !ec->nr_pending_queries; 512 spin_unlock_irqrestore(&ec->lock, flags); 513 return flushed; 514 } 515 516 static void __acpi_ec_flush_event(struct acpi_ec *ec) 517 { 518 /* 519 * When ec_freeze_events is true, we need to flush events in 520 * the proper position before entering the noirq stage. 521 */ 522 wait_event(ec->wait, acpi_ec_query_flushed(ec)); 523 if (ec_query_wq) 524 flush_workqueue(ec_query_wq); 525 } 526 527 static void acpi_ec_disable_event(struct acpi_ec *ec) 528 { 529 unsigned long flags; 530 531 spin_lock_irqsave(&ec->lock, flags); 532 __acpi_ec_disable_event(ec); 533 spin_unlock_irqrestore(&ec->lock, flags); 534 __acpi_ec_flush_event(ec); 535 } 536 #endif /* CONFIG_PM_SLEEP */ 537 538 static bool acpi_ec_guard_event(struct acpi_ec *ec) 539 { 540 bool guarded = true; 541 unsigned long flags; 542 543 spin_lock_irqsave(&ec->lock, flags); 544 /* 545 * If firmware SCI_EVT clearing timing is "event", we actually 546 * don't know when the SCI_EVT will be cleared by firmware after 547 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an 548 * acceptable period. 549 * 550 * The guarding period begins when EC_FLAGS_QUERY_PENDING is 551 * flagged, which means SCI_EVT check has just been performed. 552 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the 553 * guarding should have already been performed (via 554 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the 555 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into 556 * ACPI_EC_COMMAND_POLL state immediately. 557 */ 558 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || 559 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY || 560 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) || 561 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY)) 562 guarded = false; 563 spin_unlock_irqrestore(&ec->lock, flags); 564 return guarded; 565 } 566 567 static int ec_transaction_polled(struct acpi_ec *ec) 568 { 569 unsigned long flags; 570 int ret = 0; 571 572 spin_lock_irqsave(&ec->lock, flags); 573 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL)) 574 ret = 1; 575 spin_unlock_irqrestore(&ec->lock, flags); 576 return ret; 577 } 578 579 static int ec_transaction_completed(struct acpi_ec *ec) 580 { 581 unsigned long flags; 582 int ret = 0; 583 584 spin_lock_irqsave(&ec->lock, flags); 585 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE)) 586 ret = 1; 587 spin_unlock_irqrestore(&ec->lock, flags); 588 return ret; 589 } 590 591 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag) 592 { 593 ec->curr->flags |= flag; 594 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) { 595 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS && 596 flag == ACPI_EC_COMMAND_POLL) 597 acpi_ec_complete_query(ec); 598 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY && 599 flag == ACPI_EC_COMMAND_COMPLETE) 600 acpi_ec_complete_query(ec); 601 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && 602 flag == ACPI_EC_COMMAND_COMPLETE) 603 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); 604 } 605 } 606 607 static void advance_transaction(struct acpi_ec *ec) 608 { 609 struct transaction *t; 610 u8 status; 611 bool wakeup = false; 612 613 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK", 614 smp_processor_id()); 615 /* 616 * By always clearing STS before handling all indications, we can 617 * ensure a hardware STS 0->1 change after this clearing can always 618 * trigger a GPE interrupt. 619 */ 620 acpi_ec_clear_gpe(ec); 621 status = acpi_ec_read_status(ec); 622 t = ec->curr; 623 /* 624 * Another IRQ or a guarded polling mode advancement is detected, 625 * the next QR_EC submission is then allowed. 626 */ 627 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) { 628 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && 629 (!ec->nr_pending_queries || 630 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) { 631 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); 632 acpi_ec_complete_query(ec); 633 } 634 } 635 if (!t) 636 goto err; 637 if (t->flags & ACPI_EC_COMMAND_POLL) { 638 if (t->wlen > t->wi) { 639 if ((status & ACPI_EC_FLAG_IBF) == 0) 640 acpi_ec_write_data(ec, t->wdata[t->wi++]); 641 else 642 goto err; 643 } else if (t->rlen > t->ri) { 644 if ((status & ACPI_EC_FLAG_OBF) == 1) { 645 t->rdata[t->ri++] = acpi_ec_read_data(ec); 646 if (t->rlen == t->ri) { 647 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 648 if (t->command == ACPI_EC_COMMAND_QUERY) 649 ec_dbg_evt("Command(%s) completed by hardware", 650 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 651 wakeup = true; 652 } 653 } else 654 goto err; 655 } else if (t->wlen == t->wi && 656 (status & ACPI_EC_FLAG_IBF) == 0) { 657 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 658 wakeup = true; 659 } 660 goto out; 661 } else { 662 if (EC_FLAGS_QUERY_HANDSHAKE && 663 !(status & ACPI_EC_FLAG_SCI) && 664 (t->command == ACPI_EC_COMMAND_QUERY)) { 665 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); 666 t->rdata[t->ri++] = 0x00; 667 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 668 ec_dbg_evt("Command(%s) completed by software", 669 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 670 wakeup = true; 671 } else if ((status & ACPI_EC_FLAG_IBF) == 0) { 672 acpi_ec_write_cmd(ec, t->command); 673 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); 674 } else 675 goto err; 676 goto out; 677 } 678 err: 679 /* 680 * If SCI bit is set, then don't think it's a false IRQ 681 * otherwise will take a not handled IRQ as a false one. 682 */ 683 if (!(status & ACPI_EC_FLAG_SCI)) { 684 if (in_interrupt() && t) { 685 if (t->irq_count < ec_storm_threshold) 686 ++t->irq_count; 687 /* Allow triggering on 0 threshold */ 688 if (t->irq_count == ec_storm_threshold) 689 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM); 690 } 691 } 692 out: 693 if (status & ACPI_EC_FLAG_SCI) 694 acpi_ec_submit_query(ec); 695 if (wakeup && in_interrupt()) 696 wake_up(&ec->wait); 697 } 698 699 static void start_transaction(struct acpi_ec *ec) 700 { 701 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0; 702 ec->curr->flags = 0; 703 } 704 705 static int ec_guard(struct acpi_ec *ec) 706 { 707 unsigned long guard = usecs_to_jiffies(ec->polling_guard); 708 unsigned long timeout = ec->timestamp + guard; 709 710 /* Ensure guarding period before polling EC status */ 711 do { 712 if (ec->busy_polling) { 713 /* Perform busy polling */ 714 if (ec_transaction_completed(ec)) 715 return 0; 716 udelay(jiffies_to_usecs(guard)); 717 } else { 718 /* 719 * Perform wait polling 720 * 1. Wait the transaction to be completed by the 721 * GPE handler after the transaction enters 722 * ACPI_EC_COMMAND_POLL state. 723 * 2. A special guarding logic is also required 724 * for event clearing mode "event" before the 725 * transaction enters ACPI_EC_COMMAND_POLL 726 * state. 727 */ 728 if (!ec_transaction_polled(ec) && 729 !acpi_ec_guard_event(ec)) 730 break; 731 if (wait_event_timeout(ec->wait, 732 ec_transaction_completed(ec), 733 guard)) 734 return 0; 735 } 736 } while (time_before(jiffies, timeout)); 737 return -ETIME; 738 } 739 740 static int ec_poll(struct acpi_ec *ec) 741 { 742 unsigned long flags; 743 int repeat = 5; /* number of command restarts */ 744 745 while (repeat--) { 746 unsigned long delay = jiffies + 747 msecs_to_jiffies(ec_delay); 748 do { 749 if (!ec_guard(ec)) 750 return 0; 751 spin_lock_irqsave(&ec->lock, flags); 752 advance_transaction(ec); 753 spin_unlock_irqrestore(&ec->lock, flags); 754 } while (time_before(jiffies, delay)); 755 pr_debug("controller reset, restart transaction\n"); 756 spin_lock_irqsave(&ec->lock, flags); 757 start_transaction(ec); 758 spin_unlock_irqrestore(&ec->lock, flags); 759 } 760 return -ETIME; 761 } 762 763 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, 764 struct transaction *t) 765 { 766 unsigned long tmp; 767 int ret = 0; 768 769 /* start transaction */ 770 spin_lock_irqsave(&ec->lock, tmp); 771 /* Enable GPE for command processing (IBF=0/OBF=1) */ 772 if (!acpi_ec_submit_flushable_request(ec)) { 773 ret = -EINVAL; 774 goto unlock; 775 } 776 ec_dbg_ref(ec, "Increase command"); 777 /* following two actions should be kept atomic */ 778 ec->curr = t; 779 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command)); 780 start_transaction(ec); 781 spin_unlock_irqrestore(&ec->lock, tmp); 782 783 ret = ec_poll(ec); 784 785 spin_lock_irqsave(&ec->lock, tmp); 786 if (t->irq_count == ec_storm_threshold) 787 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM); 788 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command)); 789 ec->curr = NULL; 790 /* Disable GPE for command processing (IBF=0/OBF=1) */ 791 acpi_ec_complete_request(ec); 792 ec_dbg_ref(ec, "Decrease command"); 793 unlock: 794 spin_unlock_irqrestore(&ec->lock, tmp); 795 return ret; 796 } 797 798 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) 799 { 800 int status; 801 u32 glk; 802 803 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata)) 804 return -EINVAL; 805 if (t->rdata) 806 memset(t->rdata, 0, t->rlen); 807 808 mutex_lock(&ec->mutex); 809 if (ec->global_lock) { 810 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk); 811 if (ACPI_FAILURE(status)) { 812 status = -ENODEV; 813 goto unlock; 814 } 815 } 816 817 status = acpi_ec_transaction_unlocked(ec, t); 818 819 if (ec->global_lock) 820 acpi_release_global_lock(glk); 821 unlock: 822 mutex_unlock(&ec->mutex); 823 return status; 824 } 825 826 static int acpi_ec_burst_enable(struct acpi_ec *ec) 827 { 828 u8 d; 829 struct transaction t = {.command = ACPI_EC_BURST_ENABLE, 830 .wdata = NULL, .rdata = &d, 831 .wlen = 0, .rlen = 1}; 832 833 return acpi_ec_transaction(ec, &t); 834 } 835 836 static int acpi_ec_burst_disable(struct acpi_ec *ec) 837 { 838 struct transaction t = {.command = ACPI_EC_BURST_DISABLE, 839 .wdata = NULL, .rdata = NULL, 840 .wlen = 0, .rlen = 0}; 841 842 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ? 843 acpi_ec_transaction(ec, &t) : 0; 844 } 845 846 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data) 847 { 848 int result; 849 u8 d; 850 struct transaction t = {.command = ACPI_EC_COMMAND_READ, 851 .wdata = &address, .rdata = &d, 852 .wlen = 1, .rlen = 1}; 853 854 result = acpi_ec_transaction(ec, &t); 855 *data = d; 856 return result; 857 } 858 859 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data) 860 { 861 u8 wdata[2] = { address, data }; 862 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE, 863 .wdata = wdata, .rdata = NULL, 864 .wlen = 2, .rlen = 0}; 865 866 return acpi_ec_transaction(ec, &t); 867 } 868 869 int ec_read(u8 addr, u8 *val) 870 { 871 int err; 872 u8 temp_data; 873 874 if (!first_ec) 875 return -ENODEV; 876 877 err = acpi_ec_read(first_ec, addr, &temp_data); 878 879 if (!err) { 880 *val = temp_data; 881 return 0; 882 } 883 return err; 884 } 885 EXPORT_SYMBOL(ec_read); 886 887 int ec_write(u8 addr, u8 val) 888 { 889 int err; 890 891 if (!first_ec) 892 return -ENODEV; 893 894 err = acpi_ec_write(first_ec, addr, val); 895 896 return err; 897 } 898 EXPORT_SYMBOL(ec_write); 899 900 int ec_transaction(u8 command, 901 const u8 *wdata, unsigned wdata_len, 902 u8 *rdata, unsigned rdata_len) 903 { 904 struct transaction t = {.command = command, 905 .wdata = wdata, .rdata = rdata, 906 .wlen = wdata_len, .rlen = rdata_len}; 907 908 if (!first_ec) 909 return -ENODEV; 910 911 return acpi_ec_transaction(first_ec, &t); 912 } 913 EXPORT_SYMBOL(ec_transaction); 914 915 /* Get the handle to the EC device */ 916 acpi_handle ec_get_handle(void) 917 { 918 if (!first_ec) 919 return NULL; 920 return first_ec->handle; 921 } 922 EXPORT_SYMBOL(ec_get_handle); 923 924 static void acpi_ec_start(struct acpi_ec *ec, bool resuming) 925 { 926 unsigned long flags; 927 928 spin_lock_irqsave(&ec->lock, flags); 929 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) { 930 ec_dbg_drv("Starting EC"); 931 /* Enable GPE for event processing (SCI_EVT=1) */ 932 if (!resuming) { 933 acpi_ec_submit_request(ec); 934 ec_dbg_ref(ec, "Increase driver"); 935 } 936 ec_log_drv("EC started"); 937 } 938 spin_unlock_irqrestore(&ec->lock, flags); 939 } 940 941 static bool acpi_ec_stopped(struct acpi_ec *ec) 942 { 943 unsigned long flags; 944 bool flushed; 945 946 spin_lock_irqsave(&ec->lock, flags); 947 flushed = acpi_ec_flushed(ec); 948 spin_unlock_irqrestore(&ec->lock, flags); 949 return flushed; 950 } 951 952 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) 953 { 954 unsigned long flags; 955 956 spin_lock_irqsave(&ec->lock, flags); 957 if (acpi_ec_started(ec)) { 958 ec_dbg_drv("Stopping EC"); 959 set_bit(EC_FLAGS_STOPPED, &ec->flags); 960 spin_unlock_irqrestore(&ec->lock, flags); 961 wait_event(ec->wait, acpi_ec_stopped(ec)); 962 spin_lock_irqsave(&ec->lock, flags); 963 /* Disable GPE for event processing (SCI_EVT=1) */ 964 if (!suspending) { 965 acpi_ec_complete_request(ec); 966 ec_dbg_ref(ec, "Decrease driver"); 967 } else if (!ec_freeze_events) 968 __acpi_ec_disable_event(ec); 969 clear_bit(EC_FLAGS_STARTED, &ec->flags); 970 clear_bit(EC_FLAGS_STOPPED, &ec->flags); 971 ec_log_drv("EC stopped"); 972 } 973 spin_unlock_irqrestore(&ec->lock, flags); 974 } 975 976 static void acpi_ec_enter_noirq(struct acpi_ec *ec) 977 { 978 unsigned long flags; 979 980 spin_lock_irqsave(&ec->lock, flags); 981 ec->busy_polling = true; 982 ec->polling_guard = 0; 983 ec_log_drv("interrupt blocked"); 984 spin_unlock_irqrestore(&ec->lock, flags); 985 } 986 987 static void acpi_ec_leave_noirq(struct acpi_ec *ec) 988 { 989 unsigned long flags; 990 991 spin_lock_irqsave(&ec->lock, flags); 992 ec->busy_polling = ec_busy_polling; 993 ec->polling_guard = ec_polling_guard; 994 ec_log_drv("interrupt unblocked"); 995 spin_unlock_irqrestore(&ec->lock, flags); 996 } 997 998 void acpi_ec_block_transactions(void) 999 { 1000 struct acpi_ec *ec = first_ec; 1001 1002 if (!ec) 1003 return; 1004 1005 mutex_lock(&ec->mutex); 1006 /* Prevent transactions from being carried out */ 1007 acpi_ec_stop(ec, true); 1008 mutex_unlock(&ec->mutex); 1009 } 1010 1011 void acpi_ec_unblock_transactions(void) 1012 { 1013 /* 1014 * Allow transactions to happen again (this function is called from 1015 * atomic context during wakeup, so we don't need to acquire the mutex). 1016 */ 1017 if (first_ec) 1018 acpi_ec_start(first_ec, true); 1019 } 1020 1021 /* -------------------------------------------------------------------------- 1022 Event Management 1023 -------------------------------------------------------------------------- */ 1024 static struct acpi_ec_query_handler * 1025 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler) 1026 { 1027 if (handler) 1028 kref_get(&handler->kref); 1029 return handler; 1030 } 1031 1032 static struct acpi_ec_query_handler * 1033 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value) 1034 { 1035 struct acpi_ec_query_handler *handler; 1036 bool found = false; 1037 1038 mutex_lock(&ec->mutex); 1039 list_for_each_entry(handler, &ec->list, node) { 1040 if (value == handler->query_bit) { 1041 found = true; 1042 break; 1043 } 1044 } 1045 mutex_unlock(&ec->mutex); 1046 return found ? acpi_ec_get_query_handler(handler) : NULL; 1047 } 1048 1049 static void acpi_ec_query_handler_release(struct kref *kref) 1050 { 1051 struct acpi_ec_query_handler *handler = 1052 container_of(kref, struct acpi_ec_query_handler, kref); 1053 1054 kfree(handler); 1055 } 1056 1057 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler) 1058 { 1059 kref_put(&handler->kref, acpi_ec_query_handler_release); 1060 } 1061 1062 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, 1063 acpi_handle handle, acpi_ec_query_func func, 1064 void *data) 1065 { 1066 struct acpi_ec_query_handler *handler = 1067 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL); 1068 1069 if (!handler) 1070 return -ENOMEM; 1071 1072 handler->query_bit = query_bit; 1073 handler->handle = handle; 1074 handler->func = func; 1075 handler->data = data; 1076 mutex_lock(&ec->mutex); 1077 kref_init(&handler->kref); 1078 list_add(&handler->node, &ec->list); 1079 mutex_unlock(&ec->mutex); 1080 return 0; 1081 } 1082 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler); 1083 1084 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec, 1085 bool remove_all, u8 query_bit) 1086 { 1087 struct acpi_ec_query_handler *handler, *tmp; 1088 LIST_HEAD(free_list); 1089 1090 mutex_lock(&ec->mutex); 1091 list_for_each_entry_safe(handler, tmp, &ec->list, node) { 1092 if (remove_all || query_bit == handler->query_bit) { 1093 list_del_init(&handler->node); 1094 list_add(&handler->node, &free_list); 1095 } 1096 } 1097 mutex_unlock(&ec->mutex); 1098 list_for_each_entry_safe(handler, tmp, &free_list, node) 1099 acpi_ec_put_query_handler(handler); 1100 } 1101 1102 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) 1103 { 1104 acpi_ec_remove_query_handlers(ec, false, query_bit); 1105 } 1106 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler); 1107 1108 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval) 1109 { 1110 struct acpi_ec_query *q; 1111 struct transaction *t; 1112 1113 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL); 1114 if (!q) 1115 return NULL; 1116 INIT_WORK(&q->work, acpi_ec_event_processor); 1117 t = &q->transaction; 1118 t->command = ACPI_EC_COMMAND_QUERY; 1119 t->rdata = pval; 1120 t->rlen = 1; 1121 return q; 1122 } 1123 1124 static void acpi_ec_delete_query(struct acpi_ec_query *q) 1125 { 1126 if (q) { 1127 if (q->handler) 1128 acpi_ec_put_query_handler(q->handler); 1129 kfree(q); 1130 } 1131 } 1132 1133 static void acpi_ec_event_processor(struct work_struct *work) 1134 { 1135 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work); 1136 struct acpi_ec_query_handler *handler = q->handler; 1137 1138 ec_dbg_evt("Query(0x%02x) started", handler->query_bit); 1139 if (handler->func) 1140 handler->func(handler->data); 1141 else if (handler->handle) 1142 acpi_evaluate_object(handler->handle, NULL, NULL, NULL); 1143 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit); 1144 acpi_ec_delete_query(q); 1145 } 1146 1147 static int acpi_ec_query(struct acpi_ec *ec, u8 *data) 1148 { 1149 u8 value = 0; 1150 int result; 1151 struct acpi_ec_query *q; 1152 1153 q = acpi_ec_create_query(&value); 1154 if (!q) 1155 return -ENOMEM; 1156 1157 /* 1158 * Query the EC to find out which _Qxx method we need to evaluate. 1159 * Note that successful completion of the query causes the ACPI_EC_SCI 1160 * bit to be cleared (and thus clearing the interrupt source). 1161 */ 1162 result = acpi_ec_transaction(ec, &q->transaction); 1163 if (!value) 1164 result = -ENODATA; 1165 if (result) 1166 goto err_exit; 1167 1168 q->handler = acpi_ec_get_query_handler_by_value(ec, value); 1169 if (!q->handler) { 1170 result = -ENODATA; 1171 goto err_exit; 1172 } 1173 1174 /* 1175 * It is reported that _Qxx are evaluated in a parallel way on 1176 * Windows: 1177 * https://bugzilla.kernel.org/show_bug.cgi?id=94411 1178 * 1179 * Put this log entry before schedule_work() in order to make 1180 * it appearing before any other log entries occurred during the 1181 * work queue execution. 1182 */ 1183 ec_dbg_evt("Query(0x%02x) scheduled", value); 1184 if (!queue_work(ec_query_wq, &q->work)) { 1185 ec_dbg_evt("Query(0x%02x) overlapped", value); 1186 result = -EBUSY; 1187 } 1188 1189 err_exit: 1190 if (result) 1191 acpi_ec_delete_query(q); 1192 if (data) 1193 *data = value; 1194 return result; 1195 } 1196 1197 static void acpi_ec_check_event(struct acpi_ec *ec) 1198 { 1199 unsigned long flags; 1200 1201 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) { 1202 if (ec_guard(ec)) { 1203 spin_lock_irqsave(&ec->lock, flags); 1204 /* 1205 * Take care of the SCI_EVT unless no one else is 1206 * taking care of it. 1207 */ 1208 if (!ec->curr) 1209 advance_transaction(ec); 1210 spin_unlock_irqrestore(&ec->lock, flags); 1211 } 1212 } 1213 } 1214 1215 static void acpi_ec_event_handler(struct work_struct *work) 1216 { 1217 unsigned long flags; 1218 struct acpi_ec *ec = container_of(work, struct acpi_ec, work); 1219 1220 ec_dbg_evt("Event started"); 1221 1222 spin_lock_irqsave(&ec->lock, flags); 1223 while (ec->nr_pending_queries) { 1224 spin_unlock_irqrestore(&ec->lock, flags); 1225 (void)acpi_ec_query(ec, NULL); 1226 spin_lock_irqsave(&ec->lock, flags); 1227 ec->nr_pending_queries--; 1228 /* 1229 * Before exit, make sure that this work item can be 1230 * scheduled again. There might be QR_EC failures, leaving 1231 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work 1232 * item from being scheduled again. 1233 */ 1234 if (!ec->nr_pending_queries) { 1235 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || 1236 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY) 1237 acpi_ec_complete_query(ec); 1238 } 1239 } 1240 spin_unlock_irqrestore(&ec->lock, flags); 1241 1242 ec_dbg_evt("Event stopped"); 1243 1244 acpi_ec_check_event(ec); 1245 } 1246 1247 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device, 1248 u32 gpe_number, void *data) 1249 { 1250 unsigned long flags; 1251 struct acpi_ec *ec = data; 1252 1253 spin_lock_irqsave(&ec->lock, flags); 1254 advance_transaction(ec); 1255 spin_unlock_irqrestore(&ec->lock, flags); 1256 return ACPI_INTERRUPT_HANDLED; 1257 } 1258 1259 /* -------------------------------------------------------------------------- 1260 * Address Space Management 1261 * -------------------------------------------------------------------------- */ 1262 1263 static acpi_status 1264 acpi_ec_space_handler(u32 function, acpi_physical_address address, 1265 u32 bits, u64 *value64, 1266 void *handler_context, void *region_context) 1267 { 1268 struct acpi_ec *ec = handler_context; 1269 int result = 0, i, bytes = bits / 8; 1270 u8 *value = (u8 *)value64; 1271 1272 if ((address > 0xFF) || !value || !handler_context) 1273 return AE_BAD_PARAMETER; 1274 1275 if (function != ACPI_READ && function != ACPI_WRITE) 1276 return AE_BAD_PARAMETER; 1277 1278 if (ec->busy_polling || bits > 8) 1279 acpi_ec_burst_enable(ec); 1280 1281 for (i = 0; i < bytes; ++i, ++address, ++value) 1282 result = (function == ACPI_READ) ? 1283 acpi_ec_read(ec, address, value) : 1284 acpi_ec_write(ec, address, *value); 1285 1286 if (ec->busy_polling || bits > 8) 1287 acpi_ec_burst_disable(ec); 1288 1289 switch (result) { 1290 case -EINVAL: 1291 return AE_BAD_PARAMETER; 1292 case -ENODEV: 1293 return AE_NOT_FOUND; 1294 case -ETIME: 1295 return AE_TIME; 1296 default: 1297 return AE_OK; 1298 } 1299 } 1300 1301 /* -------------------------------------------------------------------------- 1302 * Driver Interface 1303 * -------------------------------------------------------------------------- */ 1304 1305 static acpi_status 1306 ec_parse_io_ports(struct acpi_resource *resource, void *context); 1307 1308 static void acpi_ec_free(struct acpi_ec *ec) 1309 { 1310 if (first_ec == ec) 1311 first_ec = NULL; 1312 if (boot_ec == ec) 1313 boot_ec = NULL; 1314 kfree(ec); 1315 } 1316 1317 static struct acpi_ec *acpi_ec_alloc(void) 1318 { 1319 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL); 1320 1321 if (!ec) 1322 return NULL; 1323 mutex_init(&ec->mutex); 1324 init_waitqueue_head(&ec->wait); 1325 INIT_LIST_HEAD(&ec->list); 1326 spin_lock_init(&ec->lock); 1327 INIT_WORK(&ec->work, acpi_ec_event_handler); 1328 ec->timestamp = jiffies; 1329 ec->busy_polling = true; 1330 ec->polling_guard = 0; 1331 return ec; 1332 } 1333 1334 static acpi_status 1335 acpi_ec_register_query_methods(acpi_handle handle, u32 level, 1336 void *context, void **return_value) 1337 { 1338 char node_name[5]; 1339 struct acpi_buffer buffer = { sizeof(node_name), node_name }; 1340 struct acpi_ec *ec = context; 1341 int value = 0; 1342 acpi_status status; 1343 1344 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); 1345 1346 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) 1347 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL); 1348 return AE_OK; 1349 } 1350 1351 static acpi_status 1352 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval) 1353 { 1354 acpi_status status; 1355 unsigned long long tmp = 0; 1356 struct acpi_ec *ec = context; 1357 1358 /* clear addr values, ec_parse_io_ports depend on it */ 1359 ec->command_addr = ec->data_addr = 0; 1360 1361 status = acpi_walk_resources(handle, METHOD_NAME__CRS, 1362 ec_parse_io_ports, ec); 1363 if (ACPI_FAILURE(status)) 1364 return status; 1365 1366 /* Get GPE bit assignment (EC events). */ 1367 /* TODO: Add support for _GPE returning a package */ 1368 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp); 1369 if (ACPI_FAILURE(status)) 1370 return status; 1371 ec->gpe = tmp; 1372 /* Use the global lock for all EC transactions? */ 1373 tmp = 0; 1374 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp); 1375 ec->global_lock = tmp; 1376 ec->handle = handle; 1377 return AE_CTRL_TERMINATE; 1378 } 1379 1380 /* 1381 * Note: This function returns an error code only when the address space 1382 * handler is not installed, which means "not able to handle 1383 * transactions". 1384 */ 1385 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events) 1386 { 1387 acpi_status status; 1388 1389 acpi_ec_start(ec, false); 1390 1391 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { 1392 acpi_ec_enter_noirq(ec); 1393 status = acpi_install_address_space_handler(ec->handle, 1394 ACPI_ADR_SPACE_EC, 1395 &acpi_ec_space_handler, 1396 NULL, ec); 1397 if (ACPI_FAILURE(status)) { 1398 if (status == AE_NOT_FOUND) { 1399 /* 1400 * Maybe OS fails in evaluating the _REG 1401 * object. The AE_NOT_FOUND error will be 1402 * ignored and OS * continue to initialize 1403 * EC. 1404 */ 1405 pr_err("Fail in evaluating the _REG object" 1406 " of EC device. Broken bios is suspected.\n"); 1407 } else { 1408 acpi_ec_stop(ec, false); 1409 return -ENODEV; 1410 } 1411 } 1412 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags); 1413 } 1414 1415 if (!handle_events) 1416 return 0; 1417 1418 if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) { 1419 /* Find and register all query methods */ 1420 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1, 1421 acpi_ec_register_query_methods, 1422 NULL, ec, NULL); 1423 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags); 1424 } 1425 if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) { 1426 status = acpi_install_gpe_raw_handler(NULL, ec->gpe, 1427 ACPI_GPE_EDGE_TRIGGERED, 1428 &acpi_ec_gpe_handler, ec); 1429 /* This is not fatal as we can poll EC events */ 1430 if (ACPI_SUCCESS(status)) { 1431 set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags); 1432 acpi_ec_leave_noirq(ec); 1433 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && 1434 ec->reference_count >= 1) 1435 acpi_ec_enable_gpe(ec, true); 1436 1437 /* EC is fully operational, allow queries */ 1438 acpi_ec_enable_event(ec); 1439 } 1440 } 1441 1442 return 0; 1443 } 1444 1445 static void ec_remove_handlers(struct acpi_ec *ec) 1446 { 1447 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { 1448 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle, 1449 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler))) 1450 pr_err("failed to remove space handler\n"); 1451 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags); 1452 } 1453 1454 /* 1455 * Stops handling the EC transactions after removing the operation 1456 * region handler. This is required because _REG(DISCONNECT) 1457 * invoked during the removal can result in new EC transactions. 1458 * 1459 * Flushes the EC requests and thus disables the GPE before 1460 * removing the GPE handler. This is required by the current ACPICA 1461 * GPE core. ACPICA GPE core will automatically disable a GPE when 1462 * it is indicated but there is no way to handle it. So the drivers 1463 * must disable the GPEs prior to removing the GPE handlers. 1464 */ 1465 acpi_ec_stop(ec, false); 1466 1467 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) { 1468 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe, 1469 &acpi_ec_gpe_handler))) 1470 pr_err("failed to remove gpe handler\n"); 1471 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags); 1472 } 1473 if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) { 1474 acpi_ec_remove_query_handlers(ec, true, 0); 1475 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags); 1476 } 1477 } 1478 1479 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events) 1480 { 1481 int ret; 1482 1483 ret = ec_install_handlers(ec, handle_events); 1484 if (ret) 1485 return ret; 1486 1487 /* First EC capable of handling transactions */ 1488 if (!first_ec) { 1489 first_ec = ec; 1490 acpi_handle_info(first_ec->handle, "Used as first EC\n"); 1491 } 1492 1493 acpi_handle_info(ec->handle, 1494 "GPE=0x%lx, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", 1495 ec->gpe, ec->command_addr, ec->data_addr); 1496 return ret; 1497 } 1498 1499 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle, 1500 bool handle_events, bool is_ecdt) 1501 { 1502 int ret; 1503 1504 /* 1505 * Changing the ACPI handle results in a re-configuration of the 1506 * boot EC. And if it happens after the namespace initialization, 1507 * it causes _REG evaluations. 1508 */ 1509 if (boot_ec && boot_ec->handle != handle) 1510 ec_remove_handlers(boot_ec); 1511 1512 /* Unset old boot EC */ 1513 if (boot_ec != ec) 1514 acpi_ec_free(boot_ec); 1515 1516 /* 1517 * ECDT device creation is split into acpi_ec_ecdt_probe() and 1518 * acpi_ec_ecdt_start(). This function takes care of completing the 1519 * ECDT parsing logic as the handle update should be performed 1520 * between the installation/uninstallation of the handlers. 1521 */ 1522 if (ec->handle != handle) 1523 ec->handle = handle; 1524 1525 ret = acpi_ec_setup(ec, handle_events); 1526 if (ret) 1527 return ret; 1528 1529 /* Set new boot EC */ 1530 if (!boot_ec) { 1531 boot_ec = ec; 1532 boot_ec_is_ecdt = is_ecdt; 1533 } 1534 1535 acpi_handle_info(boot_ec->handle, 1536 "Used as boot %s EC to handle transactions%s\n", 1537 is_ecdt ? "ECDT" : "DSDT", 1538 handle_events ? " and events" : ""); 1539 return ret; 1540 } 1541 1542 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle) 1543 { 1544 struct acpi_table_ecdt *ecdt_ptr; 1545 acpi_status status; 1546 acpi_handle handle; 1547 1548 status = acpi_get_table(ACPI_SIG_ECDT, 1, 1549 (struct acpi_table_header **)&ecdt_ptr); 1550 if (ACPI_FAILURE(status)) 1551 return false; 1552 1553 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle); 1554 if (ACPI_FAILURE(status)) 1555 return false; 1556 1557 *phandle = handle; 1558 return true; 1559 } 1560 1561 static bool acpi_is_boot_ec(struct acpi_ec *ec) 1562 { 1563 if (!boot_ec) 1564 return false; 1565 if (ec->handle == boot_ec->handle && 1566 ec->gpe == boot_ec->gpe && 1567 ec->command_addr == boot_ec->command_addr && 1568 ec->data_addr == boot_ec->data_addr) 1569 return true; 1570 return false; 1571 } 1572 1573 static int acpi_ec_add(struct acpi_device *device) 1574 { 1575 struct acpi_ec *ec = NULL; 1576 int ret; 1577 1578 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME); 1579 strcpy(acpi_device_class(device), ACPI_EC_CLASS); 1580 1581 ec = acpi_ec_alloc(); 1582 if (!ec) 1583 return -ENOMEM; 1584 if (ec_parse_device(device->handle, 0, ec, NULL) != 1585 AE_CTRL_TERMINATE) { 1586 ret = -EINVAL; 1587 goto err_alloc; 1588 } 1589 1590 if (acpi_is_boot_ec(ec)) { 1591 boot_ec_is_ecdt = false; 1592 acpi_handle_debug(ec->handle, "duplicated.\n"); 1593 acpi_ec_free(ec); 1594 ec = boot_ec; 1595 ret = acpi_config_boot_ec(ec, ec->handle, true, false); 1596 } else 1597 ret = acpi_ec_setup(ec, true); 1598 if (ret) 1599 goto err_query; 1600 1601 device->driver_data = ec; 1602 1603 ret = !!request_region(ec->data_addr, 1, "EC data"); 1604 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr); 1605 ret = !!request_region(ec->command_addr, 1, "EC cmd"); 1606 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr); 1607 1608 /* Reprobe devices depending on the EC */ 1609 acpi_walk_dep_device_list(ec->handle); 1610 acpi_handle_debug(ec->handle, "enumerated.\n"); 1611 return 0; 1612 1613 err_query: 1614 if (ec != boot_ec) 1615 acpi_ec_remove_query_handlers(ec, true, 0); 1616 err_alloc: 1617 if (ec != boot_ec) 1618 acpi_ec_free(ec); 1619 return ret; 1620 } 1621 1622 static int acpi_ec_remove(struct acpi_device *device) 1623 { 1624 struct acpi_ec *ec; 1625 1626 if (!device) 1627 return -EINVAL; 1628 1629 ec = acpi_driver_data(device); 1630 release_region(ec->data_addr, 1); 1631 release_region(ec->command_addr, 1); 1632 device->driver_data = NULL; 1633 if (ec != boot_ec) { 1634 ec_remove_handlers(ec); 1635 acpi_ec_free(ec); 1636 } 1637 return 0; 1638 } 1639 1640 static acpi_status 1641 ec_parse_io_ports(struct acpi_resource *resource, void *context) 1642 { 1643 struct acpi_ec *ec = context; 1644 1645 if (resource->type != ACPI_RESOURCE_TYPE_IO) 1646 return AE_OK; 1647 1648 /* 1649 * The first address region returned is the data port, and 1650 * the second address region returned is the status/command 1651 * port. 1652 */ 1653 if (ec->data_addr == 0) 1654 ec->data_addr = resource->data.io.minimum; 1655 else if (ec->command_addr == 0) 1656 ec->command_addr = resource->data.io.minimum; 1657 else 1658 return AE_CTRL_TERMINATE; 1659 1660 return AE_OK; 1661 } 1662 1663 static const struct acpi_device_id ec_device_ids[] = { 1664 {"PNP0C09", 0}, 1665 {"", 0}, 1666 }; 1667 1668 int __init acpi_ec_dsdt_probe(void) 1669 { 1670 acpi_status status; 1671 struct acpi_ec *ec; 1672 int ret; 1673 1674 ec = acpi_ec_alloc(); 1675 if (!ec) 1676 return -ENOMEM; 1677 /* 1678 * At this point, the namespace is initialized, so start to find 1679 * the namespace objects. 1680 */ 1681 status = acpi_get_devices(ec_device_ids[0].id, 1682 ec_parse_device, ec, NULL); 1683 if (ACPI_FAILURE(status) || !ec->handle) { 1684 ret = -ENODEV; 1685 goto error; 1686 } 1687 /* 1688 * When the DSDT EC is available, always re-configure boot EC to 1689 * have _REG evaluated. _REG can only be evaluated after the 1690 * namespace initialization. 1691 * At this point, the GPE is not fully initialized, so do not to 1692 * handle the events. 1693 */ 1694 ret = acpi_config_boot_ec(ec, ec->handle, false, false); 1695 error: 1696 if (ret) 1697 acpi_ec_free(ec); 1698 return ret; 1699 } 1700 1701 /* 1702 * If the DSDT EC is not functioning, we still need to prepare a fully 1703 * functioning ECDT EC first in order to handle the events. 1704 * https://bugzilla.kernel.org/show_bug.cgi?id=115021 1705 */ 1706 int __init acpi_ec_ecdt_start(void) 1707 { 1708 acpi_handle handle; 1709 1710 if (!boot_ec) 1711 return -ENODEV; 1712 /* 1713 * The DSDT EC should have already been started in 1714 * acpi_ec_add(). 1715 */ 1716 if (!boot_ec_is_ecdt) 1717 return -ENODEV; 1718 1719 /* 1720 * At this point, the namespace and the GPE is initialized, so 1721 * start to find the namespace objects and handle the events. 1722 */ 1723 if (!acpi_ec_ecdt_get_handle(&handle)) 1724 return -ENODEV; 1725 return acpi_config_boot_ec(boot_ec, handle, true, true); 1726 } 1727 1728 #if 0 1729 /* 1730 * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not 1731 * set, for which case, we complete the QR_EC without issuing it to the 1732 * firmware. 1733 * https://bugzilla.kernel.org/show_bug.cgi?id=82611 1734 * https://bugzilla.kernel.org/show_bug.cgi?id=97381 1735 */ 1736 static int ec_flag_query_handshake(const struct dmi_system_id *id) 1737 { 1738 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n"); 1739 EC_FLAGS_QUERY_HANDSHAKE = 1; 1740 return 0; 1741 } 1742 #endif 1743 1744 /* 1745 * Some ECDTs contain wrong register addresses. 1746 * MSI MS-171F 1747 * https://bugzilla.kernel.org/show_bug.cgi?id=12461 1748 */ 1749 static int ec_correct_ecdt(const struct dmi_system_id *id) 1750 { 1751 pr_debug("Detected system needing ECDT address correction.\n"); 1752 EC_FLAGS_CORRECT_ECDT = 1; 1753 return 0; 1754 } 1755 1756 static struct dmi_system_id ec_dmi_table[] __initdata = { 1757 { 1758 ec_correct_ecdt, "MSI MS-171F", { 1759 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"), 1760 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL}, 1761 {}, 1762 }; 1763 1764 int __init acpi_ec_ecdt_probe(void) 1765 { 1766 int ret; 1767 acpi_status status; 1768 struct acpi_table_ecdt *ecdt_ptr; 1769 struct acpi_ec *ec; 1770 1771 ec = acpi_ec_alloc(); 1772 if (!ec) 1773 return -ENOMEM; 1774 /* 1775 * Generate a boot ec context 1776 */ 1777 dmi_check_system(ec_dmi_table); 1778 status = acpi_get_table(ACPI_SIG_ECDT, 1, 1779 (struct acpi_table_header **)&ecdt_ptr); 1780 if (ACPI_FAILURE(status)) { 1781 ret = -ENODEV; 1782 goto error; 1783 } 1784 1785 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) { 1786 /* 1787 * Asus X50GL: 1788 * https://bugzilla.kernel.org/show_bug.cgi?id=11880 1789 */ 1790 ret = -ENODEV; 1791 goto error; 1792 } 1793 1794 if (EC_FLAGS_CORRECT_ECDT) { 1795 ec->command_addr = ecdt_ptr->data.address; 1796 ec->data_addr = ecdt_ptr->control.address; 1797 } else { 1798 ec->command_addr = ecdt_ptr->control.address; 1799 ec->data_addr = ecdt_ptr->data.address; 1800 } 1801 ec->gpe = ecdt_ptr->gpe; 1802 1803 /* 1804 * At this point, the namespace is not initialized, so do not find 1805 * the namespace objects, or handle the events. 1806 */ 1807 ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true); 1808 error: 1809 if (ret) 1810 acpi_ec_free(ec); 1811 return ret; 1812 } 1813 1814 #ifdef CONFIG_PM_SLEEP 1815 static int acpi_ec_suspend_noirq(struct device *dev) 1816 { 1817 struct acpi_ec *ec = 1818 acpi_driver_data(to_acpi_device(dev)); 1819 1820 acpi_ec_enter_noirq(ec); 1821 return 0; 1822 } 1823 1824 static int acpi_ec_resume_noirq(struct device *dev) 1825 { 1826 struct acpi_ec *ec = 1827 acpi_driver_data(to_acpi_device(dev)); 1828 1829 acpi_ec_leave_noirq(ec); 1830 return 0; 1831 } 1832 1833 static int acpi_ec_suspend(struct device *dev) 1834 { 1835 struct acpi_ec *ec = 1836 acpi_driver_data(to_acpi_device(dev)); 1837 1838 if (ec_freeze_events) 1839 acpi_ec_disable_event(ec); 1840 return 0; 1841 } 1842 1843 static int acpi_ec_resume(struct device *dev) 1844 { 1845 struct acpi_ec *ec = 1846 acpi_driver_data(to_acpi_device(dev)); 1847 1848 acpi_ec_enable_event(ec); 1849 return 0; 1850 } 1851 #endif 1852 1853 static const struct dev_pm_ops acpi_ec_pm = { 1854 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq) 1855 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume) 1856 }; 1857 1858 static int param_set_event_clearing(const char *val, struct kernel_param *kp) 1859 { 1860 int result = 0; 1861 1862 if (!strncmp(val, "status", sizeof("status") - 1)) { 1863 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS; 1864 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n"); 1865 } else if (!strncmp(val, "query", sizeof("query") - 1)) { 1866 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY; 1867 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n"); 1868 } else if (!strncmp(val, "event", sizeof("event") - 1)) { 1869 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT; 1870 pr_info("Assuming SCI_EVT clearing on event reads\n"); 1871 } else 1872 result = -EINVAL; 1873 return result; 1874 } 1875 1876 static int param_get_event_clearing(char *buffer, struct kernel_param *kp) 1877 { 1878 switch (ec_event_clearing) { 1879 case ACPI_EC_EVT_TIMING_STATUS: 1880 return sprintf(buffer, "status"); 1881 case ACPI_EC_EVT_TIMING_QUERY: 1882 return sprintf(buffer, "query"); 1883 case ACPI_EC_EVT_TIMING_EVENT: 1884 return sprintf(buffer, "event"); 1885 default: 1886 return sprintf(buffer, "invalid"); 1887 } 1888 return 0; 1889 } 1890 1891 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing, 1892 NULL, 0644); 1893 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing"); 1894 1895 static struct acpi_driver acpi_ec_driver = { 1896 .name = "ec", 1897 .class = ACPI_EC_CLASS, 1898 .ids = ec_device_ids, 1899 .ops = { 1900 .add = acpi_ec_add, 1901 .remove = acpi_ec_remove, 1902 }, 1903 .drv.pm = &acpi_ec_pm, 1904 }; 1905 1906 static inline int acpi_ec_query_init(void) 1907 { 1908 if (!ec_query_wq) { 1909 ec_query_wq = alloc_workqueue("kec_query", 0, 1910 ec_max_queries); 1911 if (!ec_query_wq) 1912 return -ENODEV; 1913 } 1914 return 0; 1915 } 1916 1917 static inline void acpi_ec_query_exit(void) 1918 { 1919 if (ec_query_wq) { 1920 destroy_workqueue(ec_query_wq); 1921 ec_query_wq = NULL; 1922 } 1923 } 1924 1925 int __init acpi_ec_init(void) 1926 { 1927 int result; 1928 1929 /* register workqueue for _Qxx evaluations */ 1930 result = acpi_ec_query_init(); 1931 if (result) 1932 goto err_exit; 1933 /* Now register the driver for the EC */ 1934 result = acpi_bus_register_driver(&acpi_ec_driver); 1935 if (result) 1936 goto err_exit; 1937 1938 err_exit: 1939 if (result) 1940 acpi_ec_query_exit(); 1941 return result; 1942 } 1943 1944 /* EC driver currently not unloadable */ 1945 #if 0 1946 static void __exit acpi_ec_exit(void) 1947 { 1948 1949 acpi_bus_unregister_driver(&acpi_ec_driver); 1950 acpi_ec_query_exit(); 1951 } 1952 #endif /* 0 */ 1953