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_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */ 192 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */ 193 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */ 194 195 /* -------------------------------------------------------------------------- 196 * Logging/Debugging 197 * -------------------------------------------------------------------------- */ 198 199 /* 200 * Splitters used by the developers to track the boundary of the EC 201 * handling processes. 202 */ 203 #ifdef DEBUG 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 #else 210 #define EC_DBG_SEP "" 211 #define EC_DBG_DRV 212 #define EC_DBG_STM 213 #define EC_DBG_REQ 214 #define EC_DBG_EVT 215 #endif 216 217 #define ec_log_raw(fmt, ...) \ 218 pr_info(fmt "\n", ##__VA_ARGS__) 219 #define ec_dbg_raw(fmt, ...) \ 220 pr_debug(fmt "\n", ##__VA_ARGS__) 221 #define ec_log(filter, fmt, ...) \ 222 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__) 223 #define ec_dbg(filter, fmt, ...) \ 224 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__) 225 226 #define ec_log_drv(fmt, ...) \ 227 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__) 228 #define ec_dbg_drv(fmt, ...) \ 229 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__) 230 #define ec_dbg_stm(fmt, ...) \ 231 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__) 232 #define ec_dbg_req(fmt, ...) \ 233 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__) 234 #define ec_dbg_evt(fmt, ...) \ 235 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__) 236 #define ec_dbg_ref(ec, fmt, ...) \ 237 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__) 238 239 /* -------------------------------------------------------------------------- 240 * Device Flags 241 * -------------------------------------------------------------------------- */ 242 243 static bool acpi_ec_started(struct acpi_ec *ec) 244 { 245 return test_bit(EC_FLAGS_STARTED, &ec->flags) && 246 !test_bit(EC_FLAGS_STOPPED, &ec->flags); 247 } 248 249 static bool acpi_ec_event_enabled(struct acpi_ec *ec) 250 { 251 /* 252 * There is an OSPM early stage logic. During the early stages 253 * (boot/resume), OSPMs shouldn't enable the event handling, only 254 * the EC transactions are allowed to be performed. 255 */ 256 if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) 257 return false; 258 /* 259 * However, disabling the event handling is experimental for late 260 * stage (suspend), and is controlled by the boot parameter of 261 * "ec_freeze_events": 262 * 1. true: The EC event handling is disabled before entering 263 * the noirq stage. 264 * 2. false: The EC event handling is automatically disabled as 265 * soon as the EC driver is stopped. 266 */ 267 if (ec_freeze_events) 268 return acpi_ec_started(ec); 269 else 270 return test_bit(EC_FLAGS_STARTED, &ec->flags); 271 } 272 273 static bool acpi_ec_flushed(struct acpi_ec *ec) 274 { 275 return ec->reference_count == 1; 276 } 277 278 /* -------------------------------------------------------------------------- 279 * EC Registers 280 * -------------------------------------------------------------------------- */ 281 282 static inline u8 acpi_ec_read_status(struct acpi_ec *ec) 283 { 284 u8 x = inb(ec->command_addr); 285 286 ec_dbg_raw("EC_SC(R) = 0x%2.2x " 287 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d", 288 x, 289 !!(x & ACPI_EC_FLAG_SCI), 290 !!(x & ACPI_EC_FLAG_BURST), 291 !!(x & ACPI_EC_FLAG_CMD), 292 !!(x & ACPI_EC_FLAG_IBF), 293 !!(x & ACPI_EC_FLAG_OBF)); 294 return x; 295 } 296 297 static inline u8 acpi_ec_read_data(struct acpi_ec *ec) 298 { 299 u8 x = inb(ec->data_addr); 300 301 ec->timestamp = jiffies; 302 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x); 303 return x; 304 } 305 306 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command) 307 { 308 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command); 309 outb(command, ec->command_addr); 310 ec->timestamp = jiffies; 311 } 312 313 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data) 314 { 315 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data); 316 outb(data, ec->data_addr); 317 ec->timestamp = jiffies; 318 } 319 320 #ifdef DEBUG 321 static const char *acpi_ec_cmd_string(u8 cmd) 322 { 323 switch (cmd) { 324 case 0x80: 325 return "RD_EC"; 326 case 0x81: 327 return "WR_EC"; 328 case 0x82: 329 return "BE_EC"; 330 case 0x83: 331 return "BD_EC"; 332 case 0x84: 333 return "QR_EC"; 334 } 335 return "UNKNOWN"; 336 } 337 #else 338 #define acpi_ec_cmd_string(cmd) "UNDEF" 339 #endif 340 341 /* -------------------------------------------------------------------------- 342 * GPE Registers 343 * -------------------------------------------------------------------------- */ 344 345 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec) 346 { 347 acpi_event_status gpe_status = 0; 348 349 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status); 350 return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false; 351 } 352 353 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open) 354 { 355 if (open) 356 acpi_enable_gpe(NULL, ec->gpe); 357 else { 358 BUG_ON(ec->reference_count < 1); 359 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE); 360 } 361 if (acpi_ec_is_gpe_raised(ec)) { 362 /* 363 * On some platforms, EN=1 writes cannot trigger GPE. So 364 * software need to manually trigger a pseudo GPE event on 365 * EN=1 writes. 366 */ 367 ec_dbg_raw("Polling quirk"); 368 advance_transaction(ec); 369 } 370 } 371 372 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close) 373 { 374 if (close) 375 acpi_disable_gpe(NULL, ec->gpe); 376 else { 377 BUG_ON(ec->reference_count < 1); 378 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE); 379 } 380 } 381 382 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec) 383 { 384 /* 385 * GPE STS is a W1C register, which means: 386 * 1. Software can clear it without worrying about clearing other 387 * GPEs' STS bits when the hardware sets them in parallel. 388 * 2. As long as software can ensure only clearing it when it is 389 * set, hardware won't set it in parallel. 390 * So software can clear GPE in any contexts. 391 * Warning: do not move the check into advance_transaction() as the 392 * EC commands will be sent without GPE raised. 393 */ 394 if (!acpi_ec_is_gpe_raised(ec)) 395 return; 396 acpi_clear_gpe(NULL, ec->gpe); 397 } 398 399 /* -------------------------------------------------------------------------- 400 * Transaction Management 401 * -------------------------------------------------------------------------- */ 402 403 static void acpi_ec_submit_request(struct acpi_ec *ec) 404 { 405 ec->reference_count++; 406 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) && 407 ec->reference_count == 1) 408 acpi_ec_enable_gpe(ec, true); 409 } 410 411 static void acpi_ec_complete_request(struct acpi_ec *ec) 412 { 413 bool flushed = false; 414 415 ec->reference_count--; 416 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) && 417 ec->reference_count == 0) 418 acpi_ec_disable_gpe(ec, true); 419 flushed = acpi_ec_flushed(ec); 420 if (flushed) 421 wake_up(&ec->wait); 422 } 423 424 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag) 425 { 426 if (!test_bit(flag, &ec->flags)) { 427 acpi_ec_disable_gpe(ec, false); 428 ec_dbg_drv("Polling enabled"); 429 set_bit(flag, &ec->flags); 430 } 431 } 432 433 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag) 434 { 435 if (test_bit(flag, &ec->flags)) { 436 clear_bit(flag, &ec->flags); 437 acpi_ec_enable_gpe(ec, false); 438 ec_dbg_drv("Polling disabled"); 439 } 440 } 441 442 /* 443 * acpi_ec_submit_flushable_request() - Increase the reference count unless 444 * the flush operation is not in 445 * progress 446 * @ec: the EC device 447 * 448 * This function must be used before taking a new action that should hold 449 * the reference count. If this function returns false, then the action 450 * must be discarded or it will prevent the flush operation from being 451 * completed. 452 */ 453 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec) 454 { 455 if (!acpi_ec_started(ec)) 456 return false; 457 acpi_ec_submit_request(ec); 458 return true; 459 } 460 461 static void acpi_ec_submit_query(struct acpi_ec *ec) 462 { 463 if (acpi_ec_event_enabled(ec) && 464 !test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { 465 ec_dbg_evt("Command(%s) submitted/blocked", 466 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 467 ec->nr_pending_queries++; 468 schedule_work(&ec->work); 469 } 470 } 471 472 static void acpi_ec_complete_query(struct acpi_ec *ec) 473 { 474 if (test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { 475 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); 476 ec_dbg_evt("Command(%s) unblocked", 477 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 478 } 479 } 480 481 static inline void __acpi_ec_enable_event(struct acpi_ec *ec) 482 { 483 if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) 484 ec_log_drv("event unblocked"); 485 if (!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) 486 advance_transaction(ec); 487 } 488 489 static inline void __acpi_ec_disable_event(struct acpi_ec *ec) 490 { 491 if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags)) 492 ec_log_drv("event blocked"); 493 } 494 495 /* 496 * Process _Q events that might have accumulated in the EC. 497 * Run with locked ec mutex. 498 */ 499 static void acpi_ec_clear(struct acpi_ec *ec) 500 { 501 int i, status; 502 u8 value = 0; 503 504 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) { 505 status = acpi_ec_query(ec, &value); 506 if (status || !value) 507 break; 508 } 509 if (unlikely(i == ACPI_EC_CLEAR_MAX)) 510 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i); 511 else 512 pr_info("%d stale EC events cleared\n", i); 513 } 514 515 static void acpi_ec_enable_event(struct acpi_ec *ec) 516 { 517 unsigned long flags; 518 519 spin_lock_irqsave(&ec->lock, flags); 520 if (acpi_ec_started(ec)) 521 __acpi_ec_enable_event(ec); 522 spin_unlock_irqrestore(&ec->lock, flags); 523 524 /* Drain additional events if hardware requires that */ 525 if (EC_FLAGS_CLEAR_ON_RESUME) 526 acpi_ec_clear(ec); 527 } 528 529 #ifdef CONFIG_PM_SLEEP 530 static bool acpi_ec_query_flushed(struct acpi_ec *ec) 531 { 532 bool flushed; 533 unsigned long flags; 534 535 spin_lock_irqsave(&ec->lock, flags); 536 flushed = !ec->nr_pending_queries; 537 spin_unlock_irqrestore(&ec->lock, flags); 538 return flushed; 539 } 540 541 static void __acpi_ec_flush_event(struct acpi_ec *ec) 542 { 543 /* 544 * When ec_freeze_events is true, we need to flush events in 545 * the proper position before entering the noirq stage. 546 */ 547 wait_event(ec->wait, acpi_ec_query_flushed(ec)); 548 if (ec_query_wq) 549 flush_workqueue(ec_query_wq); 550 } 551 552 static void acpi_ec_disable_event(struct acpi_ec *ec) 553 { 554 unsigned long flags; 555 556 spin_lock_irqsave(&ec->lock, flags); 557 __acpi_ec_disable_event(ec); 558 spin_unlock_irqrestore(&ec->lock, flags); 559 __acpi_ec_flush_event(ec); 560 } 561 #endif /* CONFIG_PM_SLEEP */ 562 563 static bool acpi_ec_guard_event(struct acpi_ec *ec) 564 { 565 bool guarded = true; 566 unsigned long flags; 567 568 spin_lock_irqsave(&ec->lock, flags); 569 /* 570 * If firmware SCI_EVT clearing timing is "event", we actually 571 * don't know when the SCI_EVT will be cleared by firmware after 572 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an 573 * acceptable period. 574 * 575 * The guarding period begins when EC_FLAGS_QUERY_PENDING is 576 * flagged, which means SCI_EVT check has just been performed. 577 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the 578 * guarding should have already been performed (via 579 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the 580 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into 581 * ACPI_EC_COMMAND_POLL state immediately. 582 */ 583 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || 584 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY || 585 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) || 586 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY)) 587 guarded = false; 588 spin_unlock_irqrestore(&ec->lock, flags); 589 return guarded; 590 } 591 592 static int ec_transaction_polled(struct acpi_ec *ec) 593 { 594 unsigned long flags; 595 int ret = 0; 596 597 spin_lock_irqsave(&ec->lock, flags); 598 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL)) 599 ret = 1; 600 spin_unlock_irqrestore(&ec->lock, flags); 601 return ret; 602 } 603 604 static int ec_transaction_completed(struct acpi_ec *ec) 605 { 606 unsigned long flags; 607 int ret = 0; 608 609 spin_lock_irqsave(&ec->lock, flags); 610 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE)) 611 ret = 1; 612 spin_unlock_irqrestore(&ec->lock, flags); 613 return ret; 614 } 615 616 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag) 617 { 618 ec->curr->flags |= flag; 619 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) { 620 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS && 621 flag == ACPI_EC_COMMAND_POLL) 622 acpi_ec_complete_query(ec); 623 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY && 624 flag == ACPI_EC_COMMAND_COMPLETE) 625 acpi_ec_complete_query(ec); 626 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && 627 flag == ACPI_EC_COMMAND_COMPLETE) 628 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); 629 } 630 } 631 632 static void advance_transaction(struct acpi_ec *ec) 633 { 634 struct transaction *t; 635 u8 status; 636 bool wakeup = false; 637 638 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK", 639 smp_processor_id()); 640 /* 641 * By always clearing STS before handling all indications, we can 642 * ensure a hardware STS 0->1 change after this clearing can always 643 * trigger a GPE interrupt. 644 */ 645 acpi_ec_clear_gpe(ec); 646 status = acpi_ec_read_status(ec); 647 t = ec->curr; 648 /* 649 * Another IRQ or a guarded polling mode advancement is detected, 650 * the next QR_EC submission is then allowed. 651 */ 652 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) { 653 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && 654 (!ec->nr_pending_queries || 655 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) { 656 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); 657 acpi_ec_complete_query(ec); 658 } 659 } 660 if (!t) 661 goto err; 662 if (t->flags & ACPI_EC_COMMAND_POLL) { 663 if (t->wlen > t->wi) { 664 if ((status & ACPI_EC_FLAG_IBF) == 0) 665 acpi_ec_write_data(ec, t->wdata[t->wi++]); 666 else 667 goto err; 668 } else if (t->rlen > t->ri) { 669 if ((status & ACPI_EC_FLAG_OBF) == 1) { 670 t->rdata[t->ri++] = acpi_ec_read_data(ec); 671 if (t->rlen == t->ri) { 672 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 673 if (t->command == ACPI_EC_COMMAND_QUERY) 674 ec_dbg_evt("Command(%s) completed by hardware", 675 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 676 wakeup = true; 677 } 678 } else 679 goto err; 680 } else if (t->wlen == t->wi && 681 (status & ACPI_EC_FLAG_IBF) == 0) { 682 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 683 wakeup = true; 684 } 685 goto out; 686 } else { 687 if (EC_FLAGS_QUERY_HANDSHAKE && 688 !(status & ACPI_EC_FLAG_SCI) && 689 (t->command == ACPI_EC_COMMAND_QUERY)) { 690 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); 691 t->rdata[t->ri++] = 0x00; 692 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 693 ec_dbg_evt("Command(%s) completed by software", 694 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 695 wakeup = true; 696 } else if ((status & ACPI_EC_FLAG_IBF) == 0) { 697 acpi_ec_write_cmd(ec, t->command); 698 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); 699 } else 700 goto err; 701 goto out; 702 } 703 err: 704 /* 705 * If SCI bit is set, then don't think it's a false IRQ 706 * otherwise will take a not handled IRQ as a false one. 707 */ 708 if (!(status & ACPI_EC_FLAG_SCI)) { 709 if (in_interrupt() && t) { 710 if (t->irq_count < ec_storm_threshold) 711 ++t->irq_count; 712 /* Allow triggering on 0 threshold */ 713 if (t->irq_count == ec_storm_threshold) 714 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM); 715 } 716 } 717 out: 718 if (status & ACPI_EC_FLAG_SCI) 719 acpi_ec_submit_query(ec); 720 if (wakeup && in_interrupt()) 721 wake_up(&ec->wait); 722 } 723 724 static void start_transaction(struct acpi_ec *ec) 725 { 726 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0; 727 ec->curr->flags = 0; 728 } 729 730 static int ec_guard(struct acpi_ec *ec) 731 { 732 unsigned long guard = usecs_to_jiffies(ec_polling_guard); 733 unsigned long timeout = ec->timestamp + guard; 734 735 /* Ensure guarding period before polling EC status */ 736 do { 737 if (ec_busy_polling) { 738 /* Perform busy polling */ 739 if (ec_transaction_completed(ec)) 740 return 0; 741 udelay(jiffies_to_usecs(guard)); 742 } else { 743 /* 744 * Perform wait polling 745 * 1. Wait the transaction to be completed by the 746 * GPE handler after the transaction enters 747 * ACPI_EC_COMMAND_POLL state. 748 * 2. A special guarding logic is also required 749 * for event clearing mode "event" before the 750 * transaction enters ACPI_EC_COMMAND_POLL 751 * state. 752 */ 753 if (!ec_transaction_polled(ec) && 754 !acpi_ec_guard_event(ec)) 755 break; 756 if (wait_event_timeout(ec->wait, 757 ec_transaction_completed(ec), 758 guard)) 759 return 0; 760 } 761 } while (time_before(jiffies, timeout)); 762 return -ETIME; 763 } 764 765 static int ec_poll(struct acpi_ec *ec) 766 { 767 unsigned long flags; 768 int repeat = 5; /* number of command restarts */ 769 770 while (repeat--) { 771 unsigned long delay = jiffies + 772 msecs_to_jiffies(ec_delay); 773 do { 774 if (!ec_guard(ec)) 775 return 0; 776 spin_lock_irqsave(&ec->lock, flags); 777 advance_transaction(ec); 778 spin_unlock_irqrestore(&ec->lock, flags); 779 } while (time_before(jiffies, delay)); 780 pr_debug("controller reset, restart transaction\n"); 781 spin_lock_irqsave(&ec->lock, flags); 782 start_transaction(ec); 783 spin_unlock_irqrestore(&ec->lock, flags); 784 } 785 return -ETIME; 786 } 787 788 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, 789 struct transaction *t) 790 { 791 unsigned long tmp; 792 int ret = 0; 793 794 /* start transaction */ 795 spin_lock_irqsave(&ec->lock, tmp); 796 /* Enable GPE for command processing (IBF=0/OBF=1) */ 797 if (!acpi_ec_submit_flushable_request(ec)) { 798 ret = -EINVAL; 799 goto unlock; 800 } 801 ec_dbg_ref(ec, "Increase command"); 802 /* following two actions should be kept atomic */ 803 ec->curr = t; 804 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command)); 805 start_transaction(ec); 806 spin_unlock_irqrestore(&ec->lock, tmp); 807 808 ret = ec_poll(ec); 809 810 spin_lock_irqsave(&ec->lock, tmp); 811 if (t->irq_count == ec_storm_threshold) 812 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM); 813 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command)); 814 ec->curr = NULL; 815 /* Disable GPE for command processing (IBF=0/OBF=1) */ 816 acpi_ec_complete_request(ec); 817 ec_dbg_ref(ec, "Decrease command"); 818 unlock: 819 spin_unlock_irqrestore(&ec->lock, tmp); 820 return ret; 821 } 822 823 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) 824 { 825 int status; 826 u32 glk; 827 828 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata)) 829 return -EINVAL; 830 if (t->rdata) 831 memset(t->rdata, 0, t->rlen); 832 833 mutex_lock(&ec->mutex); 834 if (ec->global_lock) { 835 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk); 836 if (ACPI_FAILURE(status)) { 837 status = -ENODEV; 838 goto unlock; 839 } 840 } 841 842 status = acpi_ec_transaction_unlocked(ec, t); 843 844 if (ec->global_lock) 845 acpi_release_global_lock(glk); 846 unlock: 847 mutex_unlock(&ec->mutex); 848 return status; 849 } 850 851 static int acpi_ec_burst_enable(struct acpi_ec *ec) 852 { 853 u8 d; 854 struct transaction t = {.command = ACPI_EC_BURST_ENABLE, 855 .wdata = NULL, .rdata = &d, 856 .wlen = 0, .rlen = 1}; 857 858 return acpi_ec_transaction(ec, &t); 859 } 860 861 static int acpi_ec_burst_disable(struct acpi_ec *ec) 862 { 863 struct transaction t = {.command = ACPI_EC_BURST_DISABLE, 864 .wdata = NULL, .rdata = NULL, 865 .wlen = 0, .rlen = 0}; 866 867 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ? 868 acpi_ec_transaction(ec, &t) : 0; 869 } 870 871 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data) 872 { 873 int result; 874 u8 d; 875 struct transaction t = {.command = ACPI_EC_COMMAND_READ, 876 .wdata = &address, .rdata = &d, 877 .wlen = 1, .rlen = 1}; 878 879 result = acpi_ec_transaction(ec, &t); 880 *data = d; 881 return result; 882 } 883 884 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data) 885 { 886 u8 wdata[2] = { address, data }; 887 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE, 888 .wdata = wdata, .rdata = NULL, 889 .wlen = 2, .rlen = 0}; 890 891 return acpi_ec_transaction(ec, &t); 892 } 893 894 int ec_read(u8 addr, u8 *val) 895 { 896 int err; 897 u8 temp_data; 898 899 if (!first_ec) 900 return -ENODEV; 901 902 err = acpi_ec_read(first_ec, addr, &temp_data); 903 904 if (!err) { 905 *val = temp_data; 906 return 0; 907 } 908 return err; 909 } 910 EXPORT_SYMBOL(ec_read); 911 912 int ec_write(u8 addr, u8 val) 913 { 914 int err; 915 916 if (!first_ec) 917 return -ENODEV; 918 919 err = acpi_ec_write(first_ec, addr, val); 920 921 return err; 922 } 923 EXPORT_SYMBOL(ec_write); 924 925 int ec_transaction(u8 command, 926 const u8 *wdata, unsigned wdata_len, 927 u8 *rdata, unsigned rdata_len) 928 { 929 struct transaction t = {.command = command, 930 .wdata = wdata, .rdata = rdata, 931 .wlen = wdata_len, .rlen = rdata_len}; 932 933 if (!first_ec) 934 return -ENODEV; 935 936 return acpi_ec_transaction(first_ec, &t); 937 } 938 EXPORT_SYMBOL(ec_transaction); 939 940 /* Get the handle to the EC device */ 941 acpi_handle ec_get_handle(void) 942 { 943 if (!first_ec) 944 return NULL; 945 return first_ec->handle; 946 } 947 EXPORT_SYMBOL(ec_get_handle); 948 949 static void acpi_ec_start(struct acpi_ec *ec, bool resuming) 950 { 951 unsigned long flags; 952 953 spin_lock_irqsave(&ec->lock, flags); 954 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) { 955 ec_dbg_drv("Starting EC"); 956 /* Enable GPE for event processing (SCI_EVT=1) */ 957 if (!resuming) { 958 acpi_ec_submit_request(ec); 959 ec_dbg_ref(ec, "Increase driver"); 960 } 961 ec_log_drv("EC started"); 962 } 963 spin_unlock_irqrestore(&ec->lock, flags); 964 } 965 966 static bool acpi_ec_stopped(struct acpi_ec *ec) 967 { 968 unsigned long flags; 969 bool flushed; 970 971 spin_lock_irqsave(&ec->lock, flags); 972 flushed = acpi_ec_flushed(ec); 973 spin_unlock_irqrestore(&ec->lock, flags); 974 return flushed; 975 } 976 977 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) 978 { 979 unsigned long flags; 980 981 spin_lock_irqsave(&ec->lock, flags); 982 if (acpi_ec_started(ec)) { 983 ec_dbg_drv("Stopping EC"); 984 set_bit(EC_FLAGS_STOPPED, &ec->flags); 985 spin_unlock_irqrestore(&ec->lock, flags); 986 wait_event(ec->wait, acpi_ec_stopped(ec)); 987 spin_lock_irqsave(&ec->lock, flags); 988 /* Disable GPE for event processing (SCI_EVT=1) */ 989 if (!suspending) { 990 acpi_ec_complete_request(ec); 991 ec_dbg_ref(ec, "Decrease driver"); 992 } else if (!ec_freeze_events) 993 __acpi_ec_disable_event(ec); 994 clear_bit(EC_FLAGS_STARTED, &ec->flags); 995 clear_bit(EC_FLAGS_STOPPED, &ec->flags); 996 ec_log_drv("EC stopped"); 997 } 998 spin_unlock_irqrestore(&ec->lock, flags); 999 } 1000 1001 void acpi_ec_block_transactions(void) 1002 { 1003 struct acpi_ec *ec = first_ec; 1004 1005 if (!ec) 1006 return; 1007 1008 mutex_lock(&ec->mutex); 1009 /* Prevent transactions from being carried out */ 1010 acpi_ec_stop(ec, true); 1011 mutex_unlock(&ec->mutex); 1012 } 1013 1014 void acpi_ec_unblock_transactions(void) 1015 { 1016 /* 1017 * Allow transactions to happen again (this function is called from 1018 * atomic context during wakeup, so we don't need to acquire the mutex). 1019 */ 1020 if (first_ec) 1021 acpi_ec_start(first_ec, true); 1022 } 1023 1024 /* -------------------------------------------------------------------------- 1025 Event Management 1026 -------------------------------------------------------------------------- */ 1027 static struct acpi_ec_query_handler * 1028 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler) 1029 { 1030 if (handler) 1031 kref_get(&handler->kref); 1032 return handler; 1033 } 1034 1035 static struct acpi_ec_query_handler * 1036 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value) 1037 { 1038 struct acpi_ec_query_handler *handler; 1039 bool found = false; 1040 1041 mutex_lock(&ec->mutex); 1042 list_for_each_entry(handler, &ec->list, node) { 1043 if (value == handler->query_bit) { 1044 found = true; 1045 break; 1046 } 1047 } 1048 mutex_unlock(&ec->mutex); 1049 return found ? acpi_ec_get_query_handler(handler) : NULL; 1050 } 1051 1052 static void acpi_ec_query_handler_release(struct kref *kref) 1053 { 1054 struct acpi_ec_query_handler *handler = 1055 container_of(kref, struct acpi_ec_query_handler, kref); 1056 1057 kfree(handler); 1058 } 1059 1060 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler) 1061 { 1062 kref_put(&handler->kref, acpi_ec_query_handler_release); 1063 } 1064 1065 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, 1066 acpi_handle handle, acpi_ec_query_func func, 1067 void *data) 1068 { 1069 struct acpi_ec_query_handler *handler = 1070 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL); 1071 1072 if (!handler) 1073 return -ENOMEM; 1074 1075 handler->query_bit = query_bit; 1076 handler->handle = handle; 1077 handler->func = func; 1078 handler->data = data; 1079 mutex_lock(&ec->mutex); 1080 kref_init(&handler->kref); 1081 list_add(&handler->node, &ec->list); 1082 mutex_unlock(&ec->mutex); 1083 return 0; 1084 } 1085 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler); 1086 1087 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec, 1088 bool remove_all, u8 query_bit) 1089 { 1090 struct acpi_ec_query_handler *handler, *tmp; 1091 LIST_HEAD(free_list); 1092 1093 mutex_lock(&ec->mutex); 1094 list_for_each_entry_safe(handler, tmp, &ec->list, node) { 1095 if (remove_all || query_bit == handler->query_bit) { 1096 list_del_init(&handler->node); 1097 list_add(&handler->node, &free_list); 1098 } 1099 } 1100 mutex_unlock(&ec->mutex); 1101 list_for_each_entry_safe(handler, tmp, &free_list, node) 1102 acpi_ec_put_query_handler(handler); 1103 } 1104 1105 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) 1106 { 1107 acpi_ec_remove_query_handlers(ec, false, query_bit); 1108 } 1109 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler); 1110 1111 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval) 1112 { 1113 struct acpi_ec_query *q; 1114 struct transaction *t; 1115 1116 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL); 1117 if (!q) 1118 return NULL; 1119 INIT_WORK(&q->work, acpi_ec_event_processor); 1120 t = &q->transaction; 1121 t->command = ACPI_EC_COMMAND_QUERY; 1122 t->rdata = pval; 1123 t->rlen = 1; 1124 return q; 1125 } 1126 1127 static void acpi_ec_delete_query(struct acpi_ec_query *q) 1128 { 1129 if (q) { 1130 if (q->handler) 1131 acpi_ec_put_query_handler(q->handler); 1132 kfree(q); 1133 } 1134 } 1135 1136 static void acpi_ec_event_processor(struct work_struct *work) 1137 { 1138 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work); 1139 struct acpi_ec_query_handler *handler = q->handler; 1140 1141 ec_dbg_evt("Query(0x%02x) started", handler->query_bit); 1142 if (handler->func) 1143 handler->func(handler->data); 1144 else if (handler->handle) 1145 acpi_evaluate_object(handler->handle, NULL, NULL, NULL); 1146 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit); 1147 acpi_ec_delete_query(q); 1148 } 1149 1150 static int acpi_ec_query(struct acpi_ec *ec, u8 *data) 1151 { 1152 u8 value = 0; 1153 int result; 1154 struct acpi_ec_query *q; 1155 1156 q = acpi_ec_create_query(&value); 1157 if (!q) 1158 return -ENOMEM; 1159 1160 /* 1161 * Query the EC to find out which _Qxx method we need to evaluate. 1162 * Note that successful completion of the query causes the ACPI_EC_SCI 1163 * bit to be cleared (and thus clearing the interrupt source). 1164 */ 1165 result = acpi_ec_transaction(ec, &q->transaction); 1166 if (!value) 1167 result = -ENODATA; 1168 if (result) 1169 goto err_exit; 1170 1171 q->handler = acpi_ec_get_query_handler_by_value(ec, value); 1172 if (!q->handler) { 1173 result = -ENODATA; 1174 goto err_exit; 1175 } 1176 1177 /* 1178 * It is reported that _Qxx are evaluated in a parallel way on 1179 * Windows: 1180 * https://bugzilla.kernel.org/show_bug.cgi?id=94411 1181 * 1182 * Put this log entry before schedule_work() in order to make 1183 * it appearing before any other log entries occurred during the 1184 * work queue execution. 1185 */ 1186 ec_dbg_evt("Query(0x%02x) scheduled", value); 1187 if (!queue_work(ec_query_wq, &q->work)) { 1188 ec_dbg_evt("Query(0x%02x) overlapped", value); 1189 result = -EBUSY; 1190 } 1191 1192 err_exit: 1193 if (result) 1194 acpi_ec_delete_query(q); 1195 if (data) 1196 *data = value; 1197 return result; 1198 } 1199 1200 static void acpi_ec_check_event(struct acpi_ec *ec) 1201 { 1202 unsigned long flags; 1203 1204 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) { 1205 if (ec_guard(ec)) { 1206 spin_lock_irqsave(&ec->lock, flags); 1207 /* 1208 * Take care of the SCI_EVT unless no one else is 1209 * taking care of it. 1210 */ 1211 if (!ec->curr) 1212 advance_transaction(ec); 1213 spin_unlock_irqrestore(&ec->lock, flags); 1214 } 1215 } 1216 } 1217 1218 static void acpi_ec_event_handler(struct work_struct *work) 1219 { 1220 unsigned long flags; 1221 struct acpi_ec *ec = container_of(work, struct acpi_ec, work); 1222 1223 ec_dbg_evt("Event started"); 1224 1225 spin_lock_irqsave(&ec->lock, flags); 1226 while (ec->nr_pending_queries) { 1227 spin_unlock_irqrestore(&ec->lock, flags); 1228 (void)acpi_ec_query(ec, NULL); 1229 spin_lock_irqsave(&ec->lock, flags); 1230 ec->nr_pending_queries--; 1231 /* 1232 * Before exit, make sure that this work item can be 1233 * scheduled again. There might be QR_EC failures, leaving 1234 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work 1235 * item from being scheduled again. 1236 */ 1237 if (!ec->nr_pending_queries) { 1238 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || 1239 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY) 1240 acpi_ec_complete_query(ec); 1241 } 1242 } 1243 spin_unlock_irqrestore(&ec->lock, flags); 1244 1245 ec_dbg_evt("Event stopped"); 1246 1247 acpi_ec_check_event(ec); 1248 } 1249 1250 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device, 1251 u32 gpe_number, void *data) 1252 { 1253 unsigned long flags; 1254 struct acpi_ec *ec = data; 1255 1256 spin_lock_irqsave(&ec->lock, flags); 1257 advance_transaction(ec); 1258 spin_unlock_irqrestore(&ec->lock, flags); 1259 return ACPI_INTERRUPT_HANDLED; 1260 } 1261 1262 /* -------------------------------------------------------------------------- 1263 * Address Space Management 1264 * -------------------------------------------------------------------------- */ 1265 1266 static acpi_status 1267 acpi_ec_space_handler(u32 function, acpi_physical_address address, 1268 u32 bits, u64 *value64, 1269 void *handler_context, void *region_context) 1270 { 1271 struct acpi_ec *ec = handler_context; 1272 int result = 0, i, bytes = bits / 8; 1273 u8 *value = (u8 *)value64; 1274 1275 if ((address > 0xFF) || !value || !handler_context) 1276 return AE_BAD_PARAMETER; 1277 1278 if (function != ACPI_READ && function != ACPI_WRITE) 1279 return AE_BAD_PARAMETER; 1280 1281 if (ec_busy_polling || bits > 8) 1282 acpi_ec_burst_enable(ec); 1283 1284 for (i = 0; i < bytes; ++i, ++address, ++value) 1285 result = (function == ACPI_READ) ? 1286 acpi_ec_read(ec, address, value) : 1287 acpi_ec_write(ec, address, *value); 1288 1289 if (ec_busy_polling || bits > 8) 1290 acpi_ec_burst_disable(ec); 1291 1292 switch (result) { 1293 case -EINVAL: 1294 return AE_BAD_PARAMETER; 1295 case -ENODEV: 1296 return AE_NOT_FOUND; 1297 case -ETIME: 1298 return AE_TIME; 1299 default: 1300 return AE_OK; 1301 } 1302 } 1303 1304 /* -------------------------------------------------------------------------- 1305 * Driver Interface 1306 * -------------------------------------------------------------------------- */ 1307 1308 static acpi_status 1309 ec_parse_io_ports(struct acpi_resource *resource, void *context); 1310 1311 static void acpi_ec_free(struct acpi_ec *ec) 1312 { 1313 if (first_ec == ec) 1314 first_ec = NULL; 1315 if (boot_ec == ec) 1316 boot_ec = NULL; 1317 kfree(ec); 1318 } 1319 1320 static struct acpi_ec *acpi_ec_alloc(void) 1321 { 1322 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL); 1323 1324 if (!ec) 1325 return NULL; 1326 mutex_init(&ec->mutex); 1327 init_waitqueue_head(&ec->wait); 1328 INIT_LIST_HEAD(&ec->list); 1329 spin_lock_init(&ec->lock); 1330 INIT_WORK(&ec->work, acpi_ec_event_handler); 1331 ec->timestamp = jiffies; 1332 return ec; 1333 } 1334 1335 static acpi_status 1336 acpi_ec_register_query_methods(acpi_handle handle, u32 level, 1337 void *context, void **return_value) 1338 { 1339 char node_name[5]; 1340 struct acpi_buffer buffer = { sizeof(node_name), node_name }; 1341 struct acpi_ec *ec = context; 1342 int value = 0; 1343 acpi_status status; 1344 1345 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); 1346 1347 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) 1348 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL); 1349 return AE_OK; 1350 } 1351 1352 static acpi_status 1353 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval) 1354 { 1355 acpi_status status; 1356 unsigned long long tmp = 0; 1357 struct acpi_ec *ec = context; 1358 1359 /* clear addr values, ec_parse_io_ports depend on it */ 1360 ec->command_addr = ec->data_addr = 0; 1361 1362 status = acpi_walk_resources(handle, METHOD_NAME__CRS, 1363 ec_parse_io_ports, ec); 1364 if (ACPI_FAILURE(status)) 1365 return status; 1366 1367 /* Get GPE bit assignment (EC events). */ 1368 /* TODO: Add support for _GPE returning a package */ 1369 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp); 1370 if (ACPI_FAILURE(status)) 1371 return status; 1372 ec->gpe = tmp; 1373 /* Use the global lock for all EC transactions? */ 1374 tmp = 0; 1375 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp); 1376 ec->global_lock = tmp; 1377 ec->handle = handle; 1378 return AE_CTRL_TERMINATE; 1379 } 1380 1381 /* 1382 * Note: This function returns an error code only when the address space 1383 * handler is not installed, which means "not able to handle 1384 * transactions". 1385 */ 1386 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events) 1387 { 1388 acpi_status status; 1389 1390 acpi_ec_start(ec, false); 1391 1392 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { 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 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && 1433 ec->reference_count >= 1) 1434 acpi_ec_enable_gpe(ec, true); 1435 1436 /* EC is fully operational, allow queries */ 1437 acpi_ec_enable_event(ec); 1438 } 1439 } 1440 1441 return 0; 1442 } 1443 1444 static void ec_remove_handlers(struct acpi_ec *ec) 1445 { 1446 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { 1447 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle, 1448 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler))) 1449 pr_err("failed to remove space handler\n"); 1450 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags); 1451 } 1452 1453 /* 1454 * Stops handling the EC transactions after removing the operation 1455 * region handler. This is required because _REG(DISCONNECT) 1456 * invoked during the removal can result in new EC transactions. 1457 * 1458 * Flushes the EC requests and thus disables the GPE before 1459 * removing the GPE handler. This is required by the current ACPICA 1460 * GPE core. ACPICA GPE core will automatically disable a GPE when 1461 * it is indicated but there is no way to handle it. So the drivers 1462 * must disable the GPEs prior to removing the GPE handlers. 1463 */ 1464 acpi_ec_stop(ec, false); 1465 1466 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) { 1467 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe, 1468 &acpi_ec_gpe_handler))) 1469 pr_err("failed to remove gpe handler\n"); 1470 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags); 1471 } 1472 if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) { 1473 acpi_ec_remove_query_handlers(ec, true, 0); 1474 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags); 1475 } 1476 } 1477 1478 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events) 1479 { 1480 int ret; 1481 1482 ret = ec_install_handlers(ec, handle_events); 1483 if (ret) 1484 return ret; 1485 1486 /* First EC capable of handling transactions */ 1487 if (!first_ec) { 1488 first_ec = ec; 1489 acpi_handle_info(first_ec->handle, "Used as first EC\n"); 1490 } 1491 1492 acpi_handle_info(ec->handle, 1493 "GPE=0x%lx, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", 1494 ec->gpe, ec->command_addr, ec->data_addr); 1495 return ret; 1496 } 1497 1498 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle, 1499 bool handle_events, bool is_ecdt) 1500 { 1501 int ret; 1502 1503 /* 1504 * Changing the ACPI handle results in a re-configuration of the 1505 * boot EC. And if it happens after the namespace initialization, 1506 * it causes _REG evaluations. 1507 */ 1508 if (boot_ec && boot_ec->handle != handle) 1509 ec_remove_handlers(boot_ec); 1510 1511 /* Unset old boot EC */ 1512 if (boot_ec != ec) 1513 acpi_ec_free(boot_ec); 1514 1515 /* 1516 * ECDT device creation is split into acpi_ec_ecdt_probe() and 1517 * acpi_ec_ecdt_start(). This function takes care of completing the 1518 * ECDT parsing logic as the handle update should be performed 1519 * between the installation/uninstallation of the handlers. 1520 */ 1521 if (ec->handle != handle) 1522 ec->handle = handle; 1523 1524 ret = acpi_ec_setup(ec, handle_events); 1525 if (ret) 1526 return ret; 1527 1528 /* Set new boot EC */ 1529 if (!boot_ec) { 1530 boot_ec = ec; 1531 boot_ec_is_ecdt = is_ecdt; 1532 } 1533 1534 acpi_handle_info(boot_ec->handle, 1535 "Used as boot %s EC to handle transactions%s\n", 1536 is_ecdt ? "ECDT" : "DSDT", 1537 handle_events ? " and events" : ""); 1538 return ret; 1539 } 1540 1541 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle) 1542 { 1543 struct acpi_table_ecdt *ecdt_ptr; 1544 acpi_status status; 1545 acpi_handle handle; 1546 1547 status = acpi_get_table(ACPI_SIG_ECDT, 1, 1548 (struct acpi_table_header **)&ecdt_ptr); 1549 if (ACPI_FAILURE(status)) 1550 return false; 1551 1552 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle); 1553 if (ACPI_FAILURE(status)) 1554 return false; 1555 1556 *phandle = handle; 1557 return true; 1558 } 1559 1560 static bool acpi_is_boot_ec(struct acpi_ec *ec) 1561 { 1562 if (!boot_ec) 1563 return false; 1564 if (ec->handle == boot_ec->handle && 1565 ec->gpe == boot_ec->gpe && 1566 ec->command_addr == boot_ec->command_addr && 1567 ec->data_addr == boot_ec->data_addr) 1568 return true; 1569 return false; 1570 } 1571 1572 static int acpi_ec_add(struct acpi_device *device) 1573 { 1574 struct acpi_ec *ec = NULL; 1575 int ret; 1576 1577 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME); 1578 strcpy(acpi_device_class(device), ACPI_EC_CLASS); 1579 1580 ec = acpi_ec_alloc(); 1581 if (!ec) 1582 return -ENOMEM; 1583 if (ec_parse_device(device->handle, 0, ec, NULL) != 1584 AE_CTRL_TERMINATE) { 1585 ret = -EINVAL; 1586 goto err_alloc; 1587 } 1588 1589 if (acpi_is_boot_ec(ec)) { 1590 boot_ec_is_ecdt = false; 1591 acpi_handle_debug(ec->handle, "duplicated.\n"); 1592 acpi_ec_free(ec); 1593 ec = boot_ec; 1594 ret = acpi_config_boot_ec(ec, ec->handle, true, false); 1595 } else 1596 ret = acpi_ec_setup(ec, true); 1597 if (ret) 1598 goto err_query; 1599 1600 device->driver_data = ec; 1601 1602 ret = !!request_region(ec->data_addr, 1, "EC data"); 1603 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr); 1604 ret = !!request_region(ec->command_addr, 1, "EC cmd"); 1605 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr); 1606 1607 /* Reprobe devices depending on the EC */ 1608 acpi_walk_dep_device_list(ec->handle); 1609 acpi_handle_debug(ec->handle, "enumerated.\n"); 1610 return 0; 1611 1612 err_query: 1613 if (ec != boot_ec) 1614 acpi_ec_remove_query_handlers(ec, true, 0); 1615 err_alloc: 1616 if (ec != boot_ec) 1617 acpi_ec_free(ec); 1618 return ret; 1619 } 1620 1621 static int acpi_ec_remove(struct acpi_device *device) 1622 { 1623 struct acpi_ec *ec; 1624 1625 if (!device) 1626 return -EINVAL; 1627 1628 ec = acpi_driver_data(device); 1629 release_region(ec->data_addr, 1); 1630 release_region(ec->command_addr, 1); 1631 device->driver_data = NULL; 1632 if (ec != boot_ec) { 1633 ec_remove_handlers(ec); 1634 acpi_ec_free(ec); 1635 } 1636 return 0; 1637 } 1638 1639 static acpi_status 1640 ec_parse_io_ports(struct acpi_resource *resource, void *context) 1641 { 1642 struct acpi_ec *ec = context; 1643 1644 if (resource->type != ACPI_RESOURCE_TYPE_IO) 1645 return AE_OK; 1646 1647 /* 1648 * The first address region returned is the data port, and 1649 * the second address region returned is the status/command 1650 * port. 1651 */ 1652 if (ec->data_addr == 0) 1653 ec->data_addr = resource->data.io.minimum; 1654 else if (ec->command_addr == 0) 1655 ec->command_addr = resource->data.io.minimum; 1656 else 1657 return AE_CTRL_TERMINATE; 1658 1659 return AE_OK; 1660 } 1661 1662 static const struct acpi_device_id ec_device_ids[] = { 1663 {"PNP0C09", 0}, 1664 {"", 0}, 1665 }; 1666 1667 int __init acpi_ec_dsdt_probe(void) 1668 { 1669 acpi_status status; 1670 struct acpi_ec *ec; 1671 int ret; 1672 1673 ec = acpi_ec_alloc(); 1674 if (!ec) 1675 return -ENOMEM; 1676 /* 1677 * At this point, the namespace is initialized, so start to find 1678 * the namespace objects. 1679 */ 1680 status = acpi_get_devices(ec_device_ids[0].id, 1681 ec_parse_device, ec, NULL); 1682 if (ACPI_FAILURE(status) || !ec->handle) { 1683 ret = -ENODEV; 1684 goto error; 1685 } 1686 /* 1687 * When the DSDT EC is available, always re-configure boot EC to 1688 * have _REG evaluated. _REG can only be evaluated after the 1689 * namespace initialization. 1690 * At this point, the GPE is not fully initialized, so do not to 1691 * handle the events. 1692 */ 1693 ret = acpi_config_boot_ec(ec, ec->handle, false, false); 1694 error: 1695 if (ret) 1696 acpi_ec_free(ec); 1697 return ret; 1698 } 1699 1700 /* 1701 * If the DSDT EC is not functioning, we still need to prepare a fully 1702 * functioning ECDT EC first in order to handle the events. 1703 * https://bugzilla.kernel.org/show_bug.cgi?id=115021 1704 */ 1705 int __init acpi_ec_ecdt_start(void) 1706 { 1707 acpi_handle handle; 1708 1709 if (!boot_ec) 1710 return -ENODEV; 1711 /* 1712 * The DSDT EC should have already been started in 1713 * acpi_ec_add(). 1714 */ 1715 if (!boot_ec_is_ecdt) 1716 return -ENODEV; 1717 1718 /* 1719 * At this point, the namespace and the GPE is initialized, so 1720 * start to find the namespace objects and handle the events. 1721 */ 1722 if (!acpi_ec_ecdt_get_handle(&handle)) 1723 return -ENODEV; 1724 return acpi_config_boot_ec(boot_ec, handle, true, true); 1725 } 1726 1727 #if 0 1728 /* 1729 * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not 1730 * set, for which case, we complete the QR_EC without issuing it to the 1731 * firmware. 1732 * https://bugzilla.kernel.org/show_bug.cgi?id=82611 1733 * https://bugzilla.kernel.org/show_bug.cgi?id=97381 1734 */ 1735 static int ec_flag_query_handshake(const struct dmi_system_id *id) 1736 { 1737 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n"); 1738 EC_FLAGS_QUERY_HANDSHAKE = 1; 1739 return 0; 1740 } 1741 #endif 1742 1743 /* 1744 * On some hardware it is necessary to clear events accumulated by the EC during 1745 * sleep. These ECs stop reporting GPEs until they are manually polled, if too 1746 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks) 1747 * 1748 * https://bugzilla.kernel.org/show_bug.cgi?id=44161 1749 * 1750 * Ideally, the EC should also be instructed NOT to accumulate events during 1751 * sleep (which Windows seems to do somehow), but the interface to control this 1752 * behaviour is not known at this time. 1753 * 1754 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx, 1755 * however it is very likely that other Samsung models are affected. 1756 * 1757 * On systems which don't accumulate _Q events during sleep, this extra check 1758 * should be harmless. 1759 */ 1760 static int ec_clear_on_resume(const struct dmi_system_id *id) 1761 { 1762 pr_debug("Detected system needing EC poll on resume.\n"); 1763 EC_FLAGS_CLEAR_ON_RESUME = 1; 1764 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS; 1765 return 0; 1766 } 1767 1768 /* 1769 * Some ECDTs contain wrong register addresses. 1770 * MSI MS-171F 1771 * https://bugzilla.kernel.org/show_bug.cgi?id=12461 1772 */ 1773 static int ec_correct_ecdt(const struct dmi_system_id *id) 1774 { 1775 pr_debug("Detected system needing ECDT address correction.\n"); 1776 EC_FLAGS_CORRECT_ECDT = 1; 1777 return 0; 1778 } 1779 1780 static struct dmi_system_id ec_dmi_table[] __initdata = { 1781 { 1782 ec_correct_ecdt, "MSI MS-171F", { 1783 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"), 1784 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL}, 1785 { 1786 ec_clear_on_resume, "Samsung hardware", { 1787 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL}, 1788 {}, 1789 }; 1790 1791 int __init acpi_ec_ecdt_probe(void) 1792 { 1793 int ret; 1794 acpi_status status; 1795 struct acpi_table_ecdt *ecdt_ptr; 1796 struct acpi_ec *ec; 1797 1798 ec = acpi_ec_alloc(); 1799 if (!ec) 1800 return -ENOMEM; 1801 /* 1802 * Generate a boot ec context 1803 */ 1804 dmi_check_system(ec_dmi_table); 1805 status = acpi_get_table(ACPI_SIG_ECDT, 1, 1806 (struct acpi_table_header **)&ecdt_ptr); 1807 if (ACPI_FAILURE(status)) { 1808 ret = -ENODEV; 1809 goto error; 1810 } 1811 1812 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) { 1813 /* 1814 * Asus X50GL: 1815 * https://bugzilla.kernel.org/show_bug.cgi?id=11880 1816 */ 1817 ret = -ENODEV; 1818 goto error; 1819 } 1820 1821 if (EC_FLAGS_CORRECT_ECDT) { 1822 ec->command_addr = ecdt_ptr->data.address; 1823 ec->data_addr = ecdt_ptr->control.address; 1824 } else { 1825 ec->command_addr = ecdt_ptr->control.address; 1826 ec->data_addr = ecdt_ptr->data.address; 1827 } 1828 ec->gpe = ecdt_ptr->gpe; 1829 1830 /* 1831 * At this point, the namespace is not initialized, so do not find 1832 * the namespace objects, or handle the events. 1833 */ 1834 ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true); 1835 error: 1836 if (ret) 1837 acpi_ec_free(ec); 1838 return ret; 1839 } 1840 1841 #ifdef CONFIG_PM_SLEEP 1842 static void acpi_ec_enter_noirq(struct acpi_ec *ec) 1843 { 1844 unsigned long flags; 1845 1846 if (ec == first_ec) { 1847 spin_lock_irqsave(&ec->lock, flags); 1848 ec->saved_busy_polling = ec_busy_polling; 1849 ec->saved_polling_guard = ec_polling_guard; 1850 ec_busy_polling = true; 1851 ec_polling_guard = 0; 1852 ec_log_drv("interrupt blocked"); 1853 spin_unlock_irqrestore(&ec->lock, flags); 1854 } 1855 } 1856 1857 static void acpi_ec_leave_noirq(struct acpi_ec *ec) 1858 { 1859 unsigned long flags; 1860 1861 if (ec == first_ec) { 1862 spin_lock_irqsave(&ec->lock, flags); 1863 ec_busy_polling = ec->saved_busy_polling; 1864 ec_polling_guard = ec->saved_polling_guard; 1865 ec_log_drv("interrupt unblocked"); 1866 spin_unlock_irqrestore(&ec->lock, flags); 1867 } 1868 } 1869 1870 static int acpi_ec_suspend_noirq(struct device *dev) 1871 { 1872 struct acpi_ec *ec = 1873 acpi_driver_data(to_acpi_device(dev)); 1874 1875 acpi_ec_enter_noirq(ec); 1876 return 0; 1877 } 1878 1879 static int acpi_ec_resume_noirq(struct device *dev) 1880 { 1881 struct acpi_ec *ec = 1882 acpi_driver_data(to_acpi_device(dev)); 1883 1884 acpi_ec_leave_noirq(ec); 1885 return 0; 1886 } 1887 1888 static int acpi_ec_suspend(struct device *dev) 1889 { 1890 struct acpi_ec *ec = 1891 acpi_driver_data(to_acpi_device(dev)); 1892 1893 if (ec_freeze_events) 1894 acpi_ec_disable_event(ec); 1895 return 0; 1896 } 1897 1898 static int acpi_ec_resume(struct device *dev) 1899 { 1900 struct acpi_ec *ec = 1901 acpi_driver_data(to_acpi_device(dev)); 1902 1903 acpi_ec_enable_event(ec); 1904 return 0; 1905 } 1906 #endif 1907 1908 static const struct dev_pm_ops acpi_ec_pm = { 1909 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq) 1910 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume) 1911 }; 1912 1913 static int param_set_event_clearing(const char *val, struct kernel_param *kp) 1914 { 1915 int result = 0; 1916 1917 if (!strncmp(val, "status", sizeof("status") - 1)) { 1918 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS; 1919 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n"); 1920 } else if (!strncmp(val, "query", sizeof("query") - 1)) { 1921 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY; 1922 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n"); 1923 } else if (!strncmp(val, "event", sizeof("event") - 1)) { 1924 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT; 1925 pr_info("Assuming SCI_EVT clearing on event reads\n"); 1926 } else 1927 result = -EINVAL; 1928 return result; 1929 } 1930 1931 static int param_get_event_clearing(char *buffer, struct kernel_param *kp) 1932 { 1933 switch (ec_event_clearing) { 1934 case ACPI_EC_EVT_TIMING_STATUS: 1935 return sprintf(buffer, "status"); 1936 case ACPI_EC_EVT_TIMING_QUERY: 1937 return sprintf(buffer, "query"); 1938 case ACPI_EC_EVT_TIMING_EVENT: 1939 return sprintf(buffer, "event"); 1940 default: 1941 return sprintf(buffer, "invalid"); 1942 } 1943 return 0; 1944 } 1945 1946 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing, 1947 NULL, 0644); 1948 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing"); 1949 1950 static struct acpi_driver acpi_ec_driver = { 1951 .name = "ec", 1952 .class = ACPI_EC_CLASS, 1953 .ids = ec_device_ids, 1954 .ops = { 1955 .add = acpi_ec_add, 1956 .remove = acpi_ec_remove, 1957 }, 1958 .drv.pm = &acpi_ec_pm, 1959 }; 1960 1961 static inline int acpi_ec_query_init(void) 1962 { 1963 if (!ec_query_wq) { 1964 ec_query_wq = alloc_workqueue("kec_query", 0, 1965 ec_max_queries); 1966 if (!ec_query_wq) 1967 return -ENODEV; 1968 } 1969 return 0; 1970 } 1971 1972 static inline void acpi_ec_query_exit(void) 1973 { 1974 if (ec_query_wq) { 1975 destroy_workqueue(ec_query_wq); 1976 ec_query_wq = NULL; 1977 } 1978 } 1979 1980 int __init acpi_ec_init(void) 1981 { 1982 int result; 1983 1984 /* register workqueue for _Qxx evaluations */ 1985 result = acpi_ec_query_init(); 1986 if (result) 1987 goto err_exit; 1988 /* Now register the driver for the EC */ 1989 result = acpi_bus_register_driver(&acpi_ec_driver); 1990 if (result) 1991 goto err_exit; 1992 1993 err_exit: 1994 if (result) 1995 acpi_ec_query_exit(); 1996 return result; 1997 } 1998 1999 /* EC driver currently not unloadable */ 2000 #if 0 2001 static void __exit acpi_ec_exit(void) 2002 { 2003 2004 acpi_bus_unregister_driver(&acpi_ec_driver); 2005 acpi_ec_query_exit(); 2006 } 2007 #endif /* 0 */ 2008