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 static bool acpi_ec_query_flushed(struct acpi_ec *ec) 530 { 531 bool flushed; 532 unsigned long flags; 533 534 spin_lock_irqsave(&ec->lock, flags); 535 flushed = !ec->nr_pending_queries; 536 spin_unlock_irqrestore(&ec->lock, flags); 537 return flushed; 538 } 539 540 static void __acpi_ec_flush_event(struct acpi_ec *ec) 541 { 542 /* 543 * When ec_freeze_events is true, we need to flush events in 544 * the proper position before entering the noirq stage. 545 */ 546 wait_event(ec->wait, acpi_ec_query_flushed(ec)); 547 if (ec_query_wq) 548 flush_workqueue(ec_query_wq); 549 } 550 551 static void acpi_ec_disable_event(struct acpi_ec *ec) 552 { 553 unsigned long flags; 554 555 spin_lock_irqsave(&ec->lock, flags); 556 __acpi_ec_disable_event(ec); 557 spin_unlock_irqrestore(&ec->lock, flags); 558 __acpi_ec_flush_event(ec); 559 } 560 561 static bool acpi_ec_guard_event(struct acpi_ec *ec) 562 { 563 bool guarded = true; 564 unsigned long flags; 565 566 spin_lock_irqsave(&ec->lock, flags); 567 /* 568 * If firmware SCI_EVT clearing timing is "event", we actually 569 * don't know when the SCI_EVT will be cleared by firmware after 570 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an 571 * acceptable period. 572 * 573 * The guarding period begins when EC_FLAGS_QUERY_PENDING is 574 * flagged, which means SCI_EVT check has just been performed. 575 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the 576 * guarding should have already been performed (via 577 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the 578 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into 579 * ACPI_EC_COMMAND_POLL state immediately. 580 */ 581 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || 582 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY || 583 !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) || 584 (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY)) 585 guarded = false; 586 spin_unlock_irqrestore(&ec->lock, flags); 587 return guarded; 588 } 589 590 static int ec_transaction_polled(struct acpi_ec *ec) 591 { 592 unsigned long flags; 593 int ret = 0; 594 595 spin_lock_irqsave(&ec->lock, flags); 596 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL)) 597 ret = 1; 598 spin_unlock_irqrestore(&ec->lock, flags); 599 return ret; 600 } 601 602 static int ec_transaction_completed(struct acpi_ec *ec) 603 { 604 unsigned long flags; 605 int ret = 0; 606 607 spin_lock_irqsave(&ec->lock, flags); 608 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE)) 609 ret = 1; 610 spin_unlock_irqrestore(&ec->lock, flags); 611 return ret; 612 } 613 614 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag) 615 { 616 ec->curr->flags |= flag; 617 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) { 618 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS && 619 flag == ACPI_EC_COMMAND_POLL) 620 acpi_ec_complete_query(ec); 621 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY && 622 flag == ACPI_EC_COMMAND_COMPLETE) 623 acpi_ec_complete_query(ec); 624 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && 625 flag == ACPI_EC_COMMAND_COMPLETE) 626 set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); 627 } 628 } 629 630 static void advance_transaction(struct acpi_ec *ec) 631 { 632 struct transaction *t; 633 u8 status; 634 bool wakeup = false; 635 636 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK", 637 smp_processor_id()); 638 /* 639 * By always clearing STS before handling all indications, we can 640 * ensure a hardware STS 0->1 change after this clearing can always 641 * trigger a GPE interrupt. 642 */ 643 acpi_ec_clear_gpe(ec); 644 status = acpi_ec_read_status(ec); 645 t = ec->curr; 646 /* 647 * Another IRQ or a guarded polling mode advancement is detected, 648 * the next QR_EC submission is then allowed. 649 */ 650 if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) { 651 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && 652 (!ec->nr_pending_queries || 653 test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) { 654 clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); 655 acpi_ec_complete_query(ec); 656 } 657 } 658 if (!t) 659 goto err; 660 if (t->flags & ACPI_EC_COMMAND_POLL) { 661 if (t->wlen > t->wi) { 662 if ((status & ACPI_EC_FLAG_IBF) == 0) 663 acpi_ec_write_data(ec, t->wdata[t->wi++]); 664 else 665 goto err; 666 } else if (t->rlen > t->ri) { 667 if ((status & ACPI_EC_FLAG_OBF) == 1) { 668 t->rdata[t->ri++] = acpi_ec_read_data(ec); 669 if (t->rlen == t->ri) { 670 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 671 if (t->command == ACPI_EC_COMMAND_QUERY) 672 ec_dbg_evt("Command(%s) completed by hardware", 673 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 674 wakeup = true; 675 } 676 } else 677 goto err; 678 } else if (t->wlen == t->wi && 679 (status & ACPI_EC_FLAG_IBF) == 0) { 680 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 681 wakeup = true; 682 } 683 goto out; 684 } else { 685 if (EC_FLAGS_QUERY_HANDSHAKE && 686 !(status & ACPI_EC_FLAG_SCI) && 687 (t->command == ACPI_EC_COMMAND_QUERY)) { 688 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); 689 t->rdata[t->ri++] = 0x00; 690 ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); 691 ec_dbg_evt("Command(%s) completed by software", 692 acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); 693 wakeup = true; 694 } else if ((status & ACPI_EC_FLAG_IBF) == 0) { 695 acpi_ec_write_cmd(ec, t->command); 696 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); 697 } else 698 goto err; 699 goto out; 700 } 701 err: 702 /* 703 * If SCI bit is set, then don't think it's a false IRQ 704 * otherwise will take a not handled IRQ as a false one. 705 */ 706 if (!(status & ACPI_EC_FLAG_SCI)) { 707 if (in_interrupt() && t) { 708 if (t->irq_count < ec_storm_threshold) 709 ++t->irq_count; 710 /* Allow triggering on 0 threshold */ 711 if (t->irq_count == ec_storm_threshold) 712 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM); 713 } 714 } 715 out: 716 if (status & ACPI_EC_FLAG_SCI) 717 acpi_ec_submit_query(ec); 718 if (wakeup && in_interrupt()) 719 wake_up(&ec->wait); 720 } 721 722 static void start_transaction(struct acpi_ec *ec) 723 { 724 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0; 725 ec->curr->flags = 0; 726 } 727 728 static int ec_guard(struct acpi_ec *ec) 729 { 730 unsigned long guard = usecs_to_jiffies(ec_polling_guard); 731 unsigned long timeout = ec->timestamp + guard; 732 733 /* Ensure guarding period before polling EC status */ 734 do { 735 if (ec_busy_polling) { 736 /* Perform busy polling */ 737 if (ec_transaction_completed(ec)) 738 return 0; 739 udelay(jiffies_to_usecs(guard)); 740 } else { 741 /* 742 * Perform wait polling 743 * 1. Wait the transaction to be completed by the 744 * GPE handler after the transaction enters 745 * ACPI_EC_COMMAND_POLL state. 746 * 2. A special guarding logic is also required 747 * for event clearing mode "event" before the 748 * transaction enters ACPI_EC_COMMAND_POLL 749 * state. 750 */ 751 if (!ec_transaction_polled(ec) && 752 !acpi_ec_guard_event(ec)) 753 break; 754 if (wait_event_timeout(ec->wait, 755 ec_transaction_completed(ec), 756 guard)) 757 return 0; 758 } 759 } while (time_before(jiffies, timeout)); 760 return -ETIME; 761 } 762 763 static int ec_poll(struct acpi_ec *ec) 764 { 765 unsigned long flags; 766 int repeat = 5; /* number of command restarts */ 767 768 while (repeat--) { 769 unsigned long delay = jiffies + 770 msecs_to_jiffies(ec_delay); 771 do { 772 if (!ec_guard(ec)) 773 return 0; 774 spin_lock_irqsave(&ec->lock, flags); 775 advance_transaction(ec); 776 spin_unlock_irqrestore(&ec->lock, flags); 777 } while (time_before(jiffies, delay)); 778 pr_debug("controller reset, restart transaction\n"); 779 spin_lock_irqsave(&ec->lock, flags); 780 start_transaction(ec); 781 spin_unlock_irqrestore(&ec->lock, flags); 782 } 783 return -ETIME; 784 } 785 786 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, 787 struct transaction *t) 788 { 789 unsigned long tmp; 790 int ret = 0; 791 792 /* start transaction */ 793 spin_lock_irqsave(&ec->lock, tmp); 794 /* Enable GPE for command processing (IBF=0/OBF=1) */ 795 if (!acpi_ec_submit_flushable_request(ec)) { 796 ret = -EINVAL; 797 goto unlock; 798 } 799 ec_dbg_ref(ec, "Increase command"); 800 /* following two actions should be kept atomic */ 801 ec->curr = t; 802 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command)); 803 start_transaction(ec); 804 spin_unlock_irqrestore(&ec->lock, tmp); 805 806 ret = ec_poll(ec); 807 808 spin_lock_irqsave(&ec->lock, tmp); 809 if (t->irq_count == ec_storm_threshold) 810 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM); 811 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command)); 812 ec->curr = NULL; 813 /* Disable GPE for command processing (IBF=0/OBF=1) */ 814 acpi_ec_complete_request(ec); 815 ec_dbg_ref(ec, "Decrease command"); 816 unlock: 817 spin_unlock_irqrestore(&ec->lock, tmp); 818 return ret; 819 } 820 821 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) 822 { 823 int status; 824 u32 glk; 825 826 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata)) 827 return -EINVAL; 828 if (t->rdata) 829 memset(t->rdata, 0, t->rlen); 830 831 mutex_lock(&ec->mutex); 832 if (ec->global_lock) { 833 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk); 834 if (ACPI_FAILURE(status)) { 835 status = -ENODEV; 836 goto unlock; 837 } 838 } 839 840 status = acpi_ec_transaction_unlocked(ec, t); 841 842 if (ec->global_lock) 843 acpi_release_global_lock(glk); 844 unlock: 845 mutex_unlock(&ec->mutex); 846 return status; 847 } 848 849 static int acpi_ec_burst_enable(struct acpi_ec *ec) 850 { 851 u8 d; 852 struct transaction t = {.command = ACPI_EC_BURST_ENABLE, 853 .wdata = NULL, .rdata = &d, 854 .wlen = 0, .rlen = 1}; 855 856 return acpi_ec_transaction(ec, &t); 857 } 858 859 static int acpi_ec_burst_disable(struct acpi_ec *ec) 860 { 861 struct transaction t = {.command = ACPI_EC_BURST_DISABLE, 862 .wdata = NULL, .rdata = NULL, 863 .wlen = 0, .rlen = 0}; 864 865 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ? 866 acpi_ec_transaction(ec, &t) : 0; 867 } 868 869 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data) 870 { 871 int result; 872 u8 d; 873 struct transaction t = {.command = ACPI_EC_COMMAND_READ, 874 .wdata = &address, .rdata = &d, 875 .wlen = 1, .rlen = 1}; 876 877 result = acpi_ec_transaction(ec, &t); 878 *data = d; 879 return result; 880 } 881 882 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data) 883 { 884 u8 wdata[2] = { address, data }; 885 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE, 886 .wdata = wdata, .rdata = NULL, 887 .wlen = 2, .rlen = 0}; 888 889 return acpi_ec_transaction(ec, &t); 890 } 891 892 int ec_read(u8 addr, u8 *val) 893 { 894 int err; 895 u8 temp_data; 896 897 if (!first_ec) 898 return -ENODEV; 899 900 err = acpi_ec_read(first_ec, addr, &temp_data); 901 902 if (!err) { 903 *val = temp_data; 904 return 0; 905 } 906 return err; 907 } 908 EXPORT_SYMBOL(ec_read); 909 910 int ec_write(u8 addr, u8 val) 911 { 912 int err; 913 914 if (!first_ec) 915 return -ENODEV; 916 917 err = acpi_ec_write(first_ec, addr, val); 918 919 return err; 920 } 921 EXPORT_SYMBOL(ec_write); 922 923 int ec_transaction(u8 command, 924 const u8 *wdata, unsigned wdata_len, 925 u8 *rdata, unsigned rdata_len) 926 { 927 struct transaction t = {.command = command, 928 .wdata = wdata, .rdata = rdata, 929 .wlen = wdata_len, .rlen = rdata_len}; 930 931 if (!first_ec) 932 return -ENODEV; 933 934 return acpi_ec_transaction(first_ec, &t); 935 } 936 EXPORT_SYMBOL(ec_transaction); 937 938 /* Get the handle to the EC device */ 939 acpi_handle ec_get_handle(void) 940 { 941 if (!first_ec) 942 return NULL; 943 return first_ec->handle; 944 } 945 EXPORT_SYMBOL(ec_get_handle); 946 947 static void acpi_ec_start(struct acpi_ec *ec, bool resuming) 948 { 949 unsigned long flags; 950 951 spin_lock_irqsave(&ec->lock, flags); 952 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) { 953 ec_dbg_drv("Starting EC"); 954 /* Enable GPE for event processing (SCI_EVT=1) */ 955 if (!resuming) { 956 acpi_ec_submit_request(ec); 957 ec_dbg_ref(ec, "Increase driver"); 958 } 959 ec_log_drv("EC started"); 960 } 961 spin_unlock_irqrestore(&ec->lock, flags); 962 } 963 964 static bool acpi_ec_stopped(struct acpi_ec *ec) 965 { 966 unsigned long flags; 967 bool flushed; 968 969 spin_lock_irqsave(&ec->lock, flags); 970 flushed = acpi_ec_flushed(ec); 971 spin_unlock_irqrestore(&ec->lock, flags); 972 return flushed; 973 } 974 975 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) 976 { 977 unsigned long flags; 978 979 spin_lock_irqsave(&ec->lock, flags); 980 if (acpi_ec_started(ec)) { 981 ec_dbg_drv("Stopping EC"); 982 set_bit(EC_FLAGS_STOPPED, &ec->flags); 983 spin_unlock_irqrestore(&ec->lock, flags); 984 wait_event(ec->wait, acpi_ec_stopped(ec)); 985 spin_lock_irqsave(&ec->lock, flags); 986 /* Disable GPE for event processing (SCI_EVT=1) */ 987 if (!suspending) { 988 acpi_ec_complete_request(ec); 989 ec_dbg_ref(ec, "Decrease driver"); 990 } else if (!ec_freeze_events) 991 __acpi_ec_disable_event(ec); 992 clear_bit(EC_FLAGS_STARTED, &ec->flags); 993 clear_bit(EC_FLAGS_STOPPED, &ec->flags); 994 ec_log_drv("EC stopped"); 995 } 996 spin_unlock_irqrestore(&ec->lock, flags); 997 } 998 999 void acpi_ec_block_transactions(void) 1000 { 1001 struct acpi_ec *ec = first_ec; 1002 1003 if (!ec) 1004 return; 1005 1006 mutex_lock(&ec->mutex); 1007 /* Prevent transactions from being carried out */ 1008 acpi_ec_stop(ec, true); 1009 mutex_unlock(&ec->mutex); 1010 } 1011 1012 void acpi_ec_unblock_transactions(void) 1013 { 1014 /* 1015 * Allow transactions to happen again (this function is called from 1016 * atomic context during wakeup, so we don't need to acquire the mutex). 1017 */ 1018 if (first_ec) 1019 acpi_ec_start(first_ec, true); 1020 } 1021 1022 /* -------------------------------------------------------------------------- 1023 Event Management 1024 -------------------------------------------------------------------------- */ 1025 static struct acpi_ec_query_handler * 1026 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler) 1027 { 1028 if (handler) 1029 kref_get(&handler->kref); 1030 return handler; 1031 } 1032 1033 static struct acpi_ec_query_handler * 1034 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value) 1035 { 1036 struct acpi_ec_query_handler *handler; 1037 bool found = false; 1038 1039 mutex_lock(&ec->mutex); 1040 list_for_each_entry(handler, &ec->list, node) { 1041 if (value == handler->query_bit) { 1042 found = true; 1043 break; 1044 } 1045 } 1046 mutex_unlock(&ec->mutex); 1047 return found ? acpi_ec_get_query_handler(handler) : NULL; 1048 } 1049 1050 static void acpi_ec_query_handler_release(struct kref *kref) 1051 { 1052 struct acpi_ec_query_handler *handler = 1053 container_of(kref, struct acpi_ec_query_handler, kref); 1054 1055 kfree(handler); 1056 } 1057 1058 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler) 1059 { 1060 kref_put(&handler->kref, acpi_ec_query_handler_release); 1061 } 1062 1063 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, 1064 acpi_handle handle, acpi_ec_query_func func, 1065 void *data) 1066 { 1067 struct acpi_ec_query_handler *handler = 1068 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL); 1069 1070 if (!handler) 1071 return -ENOMEM; 1072 1073 handler->query_bit = query_bit; 1074 handler->handle = handle; 1075 handler->func = func; 1076 handler->data = data; 1077 mutex_lock(&ec->mutex); 1078 kref_init(&handler->kref); 1079 list_add(&handler->node, &ec->list); 1080 mutex_unlock(&ec->mutex); 1081 return 0; 1082 } 1083 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler); 1084 1085 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec, 1086 bool remove_all, u8 query_bit) 1087 { 1088 struct acpi_ec_query_handler *handler, *tmp; 1089 LIST_HEAD(free_list); 1090 1091 mutex_lock(&ec->mutex); 1092 list_for_each_entry_safe(handler, tmp, &ec->list, node) { 1093 if (remove_all || query_bit == handler->query_bit) { 1094 list_del_init(&handler->node); 1095 list_add(&handler->node, &free_list); 1096 } 1097 } 1098 mutex_unlock(&ec->mutex); 1099 list_for_each_entry_safe(handler, tmp, &free_list, node) 1100 acpi_ec_put_query_handler(handler); 1101 } 1102 1103 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) 1104 { 1105 acpi_ec_remove_query_handlers(ec, false, query_bit); 1106 } 1107 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler); 1108 1109 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval) 1110 { 1111 struct acpi_ec_query *q; 1112 struct transaction *t; 1113 1114 q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL); 1115 if (!q) 1116 return NULL; 1117 INIT_WORK(&q->work, acpi_ec_event_processor); 1118 t = &q->transaction; 1119 t->command = ACPI_EC_COMMAND_QUERY; 1120 t->rdata = pval; 1121 t->rlen = 1; 1122 return q; 1123 } 1124 1125 static void acpi_ec_delete_query(struct acpi_ec_query *q) 1126 { 1127 if (q) { 1128 if (q->handler) 1129 acpi_ec_put_query_handler(q->handler); 1130 kfree(q); 1131 } 1132 } 1133 1134 static void acpi_ec_event_processor(struct work_struct *work) 1135 { 1136 struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work); 1137 struct acpi_ec_query_handler *handler = q->handler; 1138 1139 ec_dbg_evt("Query(0x%02x) started", handler->query_bit); 1140 if (handler->func) 1141 handler->func(handler->data); 1142 else if (handler->handle) 1143 acpi_evaluate_object(handler->handle, NULL, NULL, NULL); 1144 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit); 1145 acpi_ec_delete_query(q); 1146 } 1147 1148 static int acpi_ec_query(struct acpi_ec *ec, u8 *data) 1149 { 1150 u8 value = 0; 1151 int result; 1152 struct acpi_ec_query *q; 1153 1154 q = acpi_ec_create_query(&value); 1155 if (!q) 1156 return -ENOMEM; 1157 1158 /* 1159 * Query the EC to find out which _Qxx method we need to evaluate. 1160 * Note that successful completion of the query causes the ACPI_EC_SCI 1161 * bit to be cleared (and thus clearing the interrupt source). 1162 */ 1163 result = acpi_ec_transaction(ec, &q->transaction); 1164 if (!value) 1165 result = -ENODATA; 1166 if (result) 1167 goto err_exit; 1168 1169 q->handler = acpi_ec_get_query_handler_by_value(ec, value); 1170 if (!q->handler) { 1171 result = -ENODATA; 1172 goto err_exit; 1173 } 1174 1175 /* 1176 * It is reported that _Qxx are evaluated in a parallel way on 1177 * Windows: 1178 * https://bugzilla.kernel.org/show_bug.cgi?id=94411 1179 * 1180 * Put this log entry before schedule_work() in order to make 1181 * it appearing before any other log entries occurred during the 1182 * work queue execution. 1183 */ 1184 ec_dbg_evt("Query(0x%02x) scheduled", value); 1185 if (!queue_work(ec_query_wq, &q->work)) { 1186 ec_dbg_evt("Query(0x%02x) overlapped", value); 1187 result = -EBUSY; 1188 } 1189 1190 err_exit: 1191 if (result) 1192 acpi_ec_delete_query(q); 1193 if (data) 1194 *data = value; 1195 return result; 1196 } 1197 1198 static void acpi_ec_check_event(struct acpi_ec *ec) 1199 { 1200 unsigned long flags; 1201 1202 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) { 1203 if (ec_guard(ec)) { 1204 spin_lock_irqsave(&ec->lock, flags); 1205 /* 1206 * Take care of the SCI_EVT unless no one else is 1207 * taking care of it. 1208 */ 1209 if (!ec->curr) 1210 advance_transaction(ec); 1211 spin_unlock_irqrestore(&ec->lock, flags); 1212 } 1213 } 1214 } 1215 1216 static void acpi_ec_event_handler(struct work_struct *work) 1217 { 1218 unsigned long flags; 1219 struct acpi_ec *ec = container_of(work, struct acpi_ec, work); 1220 1221 ec_dbg_evt("Event started"); 1222 1223 spin_lock_irqsave(&ec->lock, flags); 1224 while (ec->nr_pending_queries) { 1225 spin_unlock_irqrestore(&ec->lock, flags); 1226 (void)acpi_ec_query(ec, NULL); 1227 spin_lock_irqsave(&ec->lock, flags); 1228 ec->nr_pending_queries--; 1229 /* 1230 * Before exit, make sure that this work item can be 1231 * scheduled again. There might be QR_EC failures, leaving 1232 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work 1233 * item from being scheduled again. 1234 */ 1235 if (!ec->nr_pending_queries) { 1236 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS || 1237 ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY) 1238 acpi_ec_complete_query(ec); 1239 } 1240 } 1241 spin_unlock_irqrestore(&ec->lock, flags); 1242 1243 ec_dbg_evt("Event stopped"); 1244 1245 acpi_ec_check_event(ec); 1246 } 1247 1248 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device, 1249 u32 gpe_number, void *data) 1250 { 1251 unsigned long flags; 1252 struct acpi_ec *ec = data; 1253 1254 spin_lock_irqsave(&ec->lock, flags); 1255 advance_transaction(ec); 1256 spin_unlock_irqrestore(&ec->lock, flags); 1257 return ACPI_INTERRUPT_HANDLED; 1258 } 1259 1260 /* -------------------------------------------------------------------------- 1261 * Address Space Management 1262 * -------------------------------------------------------------------------- */ 1263 1264 static acpi_status 1265 acpi_ec_space_handler(u32 function, acpi_physical_address address, 1266 u32 bits, u64 *value64, 1267 void *handler_context, void *region_context) 1268 { 1269 struct acpi_ec *ec = handler_context; 1270 int result = 0, i, bytes = bits / 8; 1271 u8 *value = (u8 *)value64; 1272 1273 if ((address > 0xFF) || !value || !handler_context) 1274 return AE_BAD_PARAMETER; 1275 1276 if (function != ACPI_READ && function != ACPI_WRITE) 1277 return AE_BAD_PARAMETER; 1278 1279 if (ec_busy_polling || bits > 8) 1280 acpi_ec_burst_enable(ec); 1281 1282 for (i = 0; i < bytes; ++i, ++address, ++value) 1283 result = (function == ACPI_READ) ? 1284 acpi_ec_read(ec, address, value) : 1285 acpi_ec_write(ec, address, *value); 1286 1287 if (ec_busy_polling || bits > 8) 1288 acpi_ec_burst_disable(ec); 1289 1290 switch (result) { 1291 case -EINVAL: 1292 return AE_BAD_PARAMETER; 1293 case -ENODEV: 1294 return AE_NOT_FOUND; 1295 case -ETIME: 1296 return AE_TIME; 1297 default: 1298 return AE_OK; 1299 } 1300 } 1301 1302 /* -------------------------------------------------------------------------- 1303 * Driver Interface 1304 * -------------------------------------------------------------------------- */ 1305 1306 static acpi_status 1307 ec_parse_io_ports(struct acpi_resource *resource, void *context); 1308 1309 static void acpi_ec_free(struct acpi_ec *ec) 1310 { 1311 if (first_ec == ec) 1312 first_ec = NULL; 1313 if (boot_ec == ec) 1314 boot_ec = NULL; 1315 kfree(ec); 1316 } 1317 1318 static struct acpi_ec *acpi_ec_alloc(void) 1319 { 1320 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL); 1321 1322 if (!ec) 1323 return NULL; 1324 mutex_init(&ec->mutex); 1325 init_waitqueue_head(&ec->wait); 1326 INIT_LIST_HEAD(&ec->list); 1327 spin_lock_init(&ec->lock); 1328 INIT_WORK(&ec->work, acpi_ec_event_handler); 1329 ec->timestamp = jiffies; 1330 return ec; 1331 } 1332 1333 static acpi_status 1334 acpi_ec_register_query_methods(acpi_handle handle, u32 level, 1335 void *context, void **return_value) 1336 { 1337 char node_name[5]; 1338 struct acpi_buffer buffer = { sizeof(node_name), node_name }; 1339 struct acpi_ec *ec = context; 1340 int value = 0; 1341 acpi_status status; 1342 1343 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); 1344 1345 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) 1346 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL); 1347 return AE_OK; 1348 } 1349 1350 static acpi_status 1351 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval) 1352 { 1353 acpi_status status; 1354 unsigned long long tmp = 0; 1355 struct acpi_ec *ec = context; 1356 1357 /* clear addr values, ec_parse_io_ports depend on it */ 1358 ec->command_addr = ec->data_addr = 0; 1359 1360 status = acpi_walk_resources(handle, METHOD_NAME__CRS, 1361 ec_parse_io_ports, ec); 1362 if (ACPI_FAILURE(status)) 1363 return status; 1364 1365 /* Get GPE bit assignment (EC events). */ 1366 /* TODO: Add support for _GPE returning a package */ 1367 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp); 1368 if (ACPI_FAILURE(status)) 1369 return status; 1370 ec->gpe = tmp; 1371 /* Use the global lock for all EC transactions? */ 1372 tmp = 0; 1373 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp); 1374 ec->global_lock = tmp; 1375 ec->handle = handle; 1376 return AE_CTRL_TERMINATE; 1377 } 1378 1379 /* 1380 * Note: This function returns an error code only when the address space 1381 * handler is not installed, which means "not able to handle 1382 * transactions". 1383 */ 1384 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events) 1385 { 1386 acpi_status status; 1387 1388 acpi_ec_start(ec, false); 1389 1390 if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { 1391 status = acpi_install_address_space_handler(ec->handle, 1392 ACPI_ADR_SPACE_EC, 1393 &acpi_ec_space_handler, 1394 NULL, ec); 1395 if (ACPI_FAILURE(status)) { 1396 if (status == AE_NOT_FOUND) { 1397 /* 1398 * Maybe OS fails in evaluating the _REG 1399 * object. The AE_NOT_FOUND error will be 1400 * ignored and OS * continue to initialize 1401 * EC. 1402 */ 1403 pr_err("Fail in evaluating the _REG object" 1404 " of EC device. Broken bios is suspected.\n"); 1405 } else { 1406 acpi_ec_stop(ec, false); 1407 return -ENODEV; 1408 } 1409 } 1410 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags); 1411 } 1412 1413 if (!handle_events) 1414 return 0; 1415 1416 if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) { 1417 /* Find and register all query methods */ 1418 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1, 1419 acpi_ec_register_query_methods, 1420 NULL, ec, NULL); 1421 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags); 1422 } 1423 if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) { 1424 status = acpi_install_gpe_raw_handler(NULL, ec->gpe, 1425 ACPI_GPE_EDGE_TRIGGERED, 1426 &acpi_ec_gpe_handler, ec); 1427 /* This is not fatal as we can poll EC events */ 1428 if (ACPI_SUCCESS(status)) { 1429 set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags); 1430 if (test_bit(EC_FLAGS_STARTED, &ec->flags) && 1431 ec->reference_count >= 1) 1432 acpi_ec_enable_gpe(ec, true); 1433 1434 /* EC is fully operational, allow queries */ 1435 acpi_ec_enable_event(ec); 1436 } 1437 } 1438 1439 return 0; 1440 } 1441 1442 static void ec_remove_handlers(struct acpi_ec *ec) 1443 { 1444 if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) { 1445 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle, 1446 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler))) 1447 pr_err("failed to remove space handler\n"); 1448 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags); 1449 } 1450 1451 /* 1452 * Stops handling the EC transactions after removing the operation 1453 * region handler. This is required because _REG(DISCONNECT) 1454 * invoked during the removal can result in new EC transactions. 1455 * 1456 * Flushes the EC requests and thus disables the GPE before 1457 * removing the GPE handler. This is required by the current ACPICA 1458 * GPE core. ACPICA GPE core will automatically disable a GPE when 1459 * it is indicated but there is no way to handle it. So the drivers 1460 * must disable the GPEs prior to removing the GPE handlers. 1461 */ 1462 acpi_ec_stop(ec, false); 1463 1464 if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) { 1465 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe, 1466 &acpi_ec_gpe_handler))) 1467 pr_err("failed to remove gpe handler\n"); 1468 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags); 1469 } 1470 if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) { 1471 acpi_ec_remove_query_handlers(ec, true, 0); 1472 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags); 1473 } 1474 } 1475 1476 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events) 1477 { 1478 int ret; 1479 1480 ret = ec_install_handlers(ec, handle_events); 1481 if (ret) 1482 return ret; 1483 1484 /* First EC capable of handling transactions */ 1485 if (!first_ec) { 1486 first_ec = ec; 1487 acpi_handle_info(first_ec->handle, "Used as first EC\n"); 1488 } 1489 1490 acpi_handle_info(ec->handle, 1491 "GPE=0x%lx, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", 1492 ec->gpe, ec->command_addr, ec->data_addr); 1493 return ret; 1494 } 1495 1496 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle, 1497 bool handle_events, bool is_ecdt) 1498 { 1499 int ret; 1500 1501 /* 1502 * Changing the ACPI handle results in a re-configuration of the 1503 * boot EC. And if it happens after the namespace initialization, 1504 * it causes _REG evaluations. 1505 */ 1506 if (boot_ec && boot_ec->handle != handle) 1507 ec_remove_handlers(boot_ec); 1508 1509 /* Unset old boot EC */ 1510 if (boot_ec != ec) 1511 acpi_ec_free(boot_ec); 1512 1513 /* 1514 * ECDT device creation is split into acpi_ec_ecdt_probe() and 1515 * acpi_ec_ecdt_start(). This function takes care of completing the 1516 * ECDT parsing logic as the handle update should be performed 1517 * between the installation/uninstallation of the handlers. 1518 */ 1519 if (ec->handle != handle) 1520 ec->handle = handle; 1521 1522 ret = acpi_ec_setup(ec, handle_events); 1523 if (ret) 1524 return ret; 1525 1526 /* Set new boot EC */ 1527 if (!boot_ec) { 1528 boot_ec = ec; 1529 boot_ec_is_ecdt = is_ecdt; 1530 } 1531 1532 acpi_handle_info(boot_ec->handle, 1533 "Used as boot %s EC to handle transactions%s\n", 1534 is_ecdt ? "ECDT" : "DSDT", 1535 handle_events ? " and events" : ""); 1536 return ret; 1537 } 1538 1539 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle) 1540 { 1541 struct acpi_table_ecdt *ecdt_ptr; 1542 acpi_status status; 1543 acpi_handle handle; 1544 1545 status = acpi_get_table(ACPI_SIG_ECDT, 1, 1546 (struct acpi_table_header **)&ecdt_ptr); 1547 if (ACPI_FAILURE(status)) 1548 return false; 1549 1550 status = acpi_get_handle(NULL, ecdt_ptr->id, &handle); 1551 if (ACPI_FAILURE(status)) 1552 return false; 1553 1554 *phandle = handle; 1555 return true; 1556 } 1557 1558 static bool acpi_is_boot_ec(struct acpi_ec *ec) 1559 { 1560 if (!boot_ec) 1561 return false; 1562 if (ec->handle == boot_ec->handle && 1563 ec->gpe == boot_ec->gpe && 1564 ec->command_addr == boot_ec->command_addr && 1565 ec->data_addr == boot_ec->data_addr) 1566 return true; 1567 return false; 1568 } 1569 1570 static int acpi_ec_add(struct acpi_device *device) 1571 { 1572 struct acpi_ec *ec = NULL; 1573 int ret; 1574 1575 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME); 1576 strcpy(acpi_device_class(device), ACPI_EC_CLASS); 1577 1578 ec = acpi_ec_alloc(); 1579 if (!ec) 1580 return -ENOMEM; 1581 if (ec_parse_device(device->handle, 0, ec, NULL) != 1582 AE_CTRL_TERMINATE) { 1583 ret = -EINVAL; 1584 goto err_alloc; 1585 } 1586 1587 if (acpi_is_boot_ec(ec)) { 1588 boot_ec_is_ecdt = false; 1589 acpi_handle_debug(ec->handle, "duplicated.\n"); 1590 acpi_ec_free(ec); 1591 ec = boot_ec; 1592 ret = acpi_config_boot_ec(ec, ec->handle, true, false); 1593 } else 1594 ret = acpi_ec_setup(ec, true); 1595 if (ret) 1596 goto err_query; 1597 1598 device->driver_data = ec; 1599 1600 ret = !!request_region(ec->data_addr, 1, "EC data"); 1601 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr); 1602 ret = !!request_region(ec->command_addr, 1, "EC cmd"); 1603 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr); 1604 1605 /* Reprobe devices depending on the EC */ 1606 acpi_walk_dep_device_list(ec->handle); 1607 acpi_handle_debug(ec->handle, "enumerated.\n"); 1608 return 0; 1609 1610 err_query: 1611 if (ec != boot_ec) 1612 acpi_ec_remove_query_handlers(ec, true, 0); 1613 err_alloc: 1614 if (ec != boot_ec) 1615 acpi_ec_free(ec); 1616 return ret; 1617 } 1618 1619 static int acpi_ec_remove(struct acpi_device *device) 1620 { 1621 struct acpi_ec *ec; 1622 1623 if (!device) 1624 return -EINVAL; 1625 1626 ec = acpi_driver_data(device); 1627 release_region(ec->data_addr, 1); 1628 release_region(ec->command_addr, 1); 1629 device->driver_data = NULL; 1630 if (ec != boot_ec) { 1631 ec_remove_handlers(ec); 1632 acpi_ec_free(ec); 1633 } 1634 return 0; 1635 } 1636 1637 static acpi_status 1638 ec_parse_io_ports(struct acpi_resource *resource, void *context) 1639 { 1640 struct acpi_ec *ec = context; 1641 1642 if (resource->type != ACPI_RESOURCE_TYPE_IO) 1643 return AE_OK; 1644 1645 /* 1646 * The first address region returned is the data port, and 1647 * the second address region returned is the status/command 1648 * port. 1649 */ 1650 if (ec->data_addr == 0) 1651 ec->data_addr = resource->data.io.minimum; 1652 else if (ec->command_addr == 0) 1653 ec->command_addr = resource->data.io.minimum; 1654 else 1655 return AE_CTRL_TERMINATE; 1656 1657 return AE_OK; 1658 } 1659 1660 static const struct acpi_device_id ec_device_ids[] = { 1661 {"PNP0C09", 0}, 1662 {"", 0}, 1663 }; 1664 1665 int __init acpi_ec_dsdt_probe(void) 1666 { 1667 acpi_status status; 1668 struct acpi_ec *ec; 1669 int ret; 1670 1671 ec = acpi_ec_alloc(); 1672 if (!ec) 1673 return -ENOMEM; 1674 /* 1675 * At this point, the namespace is initialized, so start to find 1676 * the namespace objects. 1677 */ 1678 status = acpi_get_devices(ec_device_ids[0].id, 1679 ec_parse_device, ec, NULL); 1680 if (ACPI_FAILURE(status) || !ec->handle) { 1681 ret = -ENODEV; 1682 goto error; 1683 } 1684 /* 1685 * When the DSDT EC is available, always re-configure boot EC to 1686 * have _REG evaluated. _REG can only be evaluated after the 1687 * namespace initialization. 1688 * At this point, the GPE is not fully initialized, so do not to 1689 * handle the events. 1690 */ 1691 ret = acpi_config_boot_ec(ec, ec->handle, false, false); 1692 error: 1693 if (ret) 1694 acpi_ec_free(ec); 1695 return ret; 1696 } 1697 1698 /* 1699 * If the DSDT EC is not functioning, we still need to prepare a fully 1700 * functioning ECDT EC first in order to handle the events. 1701 * https://bugzilla.kernel.org/show_bug.cgi?id=115021 1702 */ 1703 int __init acpi_ec_ecdt_start(void) 1704 { 1705 acpi_handle handle; 1706 1707 if (!boot_ec) 1708 return -ENODEV; 1709 /* 1710 * The DSDT EC should have already been started in 1711 * acpi_ec_add(). 1712 */ 1713 if (!boot_ec_is_ecdt) 1714 return -ENODEV; 1715 1716 /* 1717 * At this point, the namespace and the GPE is initialized, so 1718 * start to find the namespace objects and handle the events. 1719 */ 1720 if (!acpi_ec_ecdt_get_handle(&handle)) 1721 return -ENODEV; 1722 return acpi_config_boot_ec(boot_ec, handle, true, true); 1723 } 1724 1725 #if 0 1726 /* 1727 * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not 1728 * set, for which case, we complete the QR_EC without issuing it to the 1729 * firmware. 1730 * https://bugzilla.kernel.org/show_bug.cgi?id=82611 1731 * https://bugzilla.kernel.org/show_bug.cgi?id=97381 1732 */ 1733 static int ec_flag_query_handshake(const struct dmi_system_id *id) 1734 { 1735 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n"); 1736 EC_FLAGS_QUERY_HANDSHAKE = 1; 1737 return 0; 1738 } 1739 #endif 1740 1741 /* 1742 * On some hardware it is necessary to clear events accumulated by the EC during 1743 * sleep. These ECs stop reporting GPEs until they are manually polled, if too 1744 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks) 1745 * 1746 * https://bugzilla.kernel.org/show_bug.cgi?id=44161 1747 * 1748 * Ideally, the EC should also be instructed NOT to accumulate events during 1749 * sleep (which Windows seems to do somehow), but the interface to control this 1750 * behaviour is not known at this time. 1751 * 1752 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx, 1753 * however it is very likely that other Samsung models are affected. 1754 * 1755 * On systems which don't accumulate _Q events during sleep, this extra check 1756 * should be harmless. 1757 */ 1758 static int ec_clear_on_resume(const struct dmi_system_id *id) 1759 { 1760 pr_debug("Detected system needing EC poll on resume.\n"); 1761 EC_FLAGS_CLEAR_ON_RESUME = 1; 1762 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS; 1763 return 0; 1764 } 1765 1766 /* 1767 * Some ECDTs contain wrong register addresses. 1768 * MSI MS-171F 1769 * https://bugzilla.kernel.org/show_bug.cgi?id=12461 1770 */ 1771 static int ec_correct_ecdt(const struct dmi_system_id *id) 1772 { 1773 pr_debug("Detected system needing ECDT address correction.\n"); 1774 EC_FLAGS_CORRECT_ECDT = 1; 1775 return 0; 1776 } 1777 1778 static struct dmi_system_id ec_dmi_table[] __initdata = { 1779 { 1780 ec_correct_ecdt, "MSI MS-171F", { 1781 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"), 1782 DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL}, 1783 { 1784 ec_clear_on_resume, "Samsung hardware", { 1785 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL}, 1786 {}, 1787 }; 1788 1789 int __init acpi_ec_ecdt_probe(void) 1790 { 1791 int ret; 1792 acpi_status status; 1793 struct acpi_table_ecdt *ecdt_ptr; 1794 struct acpi_ec *ec; 1795 1796 ec = acpi_ec_alloc(); 1797 if (!ec) 1798 return -ENOMEM; 1799 /* 1800 * Generate a boot ec context 1801 */ 1802 dmi_check_system(ec_dmi_table); 1803 status = acpi_get_table(ACPI_SIG_ECDT, 1, 1804 (struct acpi_table_header **)&ecdt_ptr); 1805 if (ACPI_FAILURE(status)) { 1806 ret = -ENODEV; 1807 goto error; 1808 } 1809 1810 if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) { 1811 /* 1812 * Asus X50GL: 1813 * https://bugzilla.kernel.org/show_bug.cgi?id=11880 1814 */ 1815 ret = -ENODEV; 1816 goto error; 1817 } 1818 1819 if (EC_FLAGS_CORRECT_ECDT) { 1820 ec->command_addr = ecdt_ptr->data.address; 1821 ec->data_addr = ecdt_ptr->control.address; 1822 } else { 1823 ec->command_addr = ecdt_ptr->control.address; 1824 ec->data_addr = ecdt_ptr->data.address; 1825 } 1826 ec->gpe = ecdt_ptr->gpe; 1827 1828 /* 1829 * At this point, the namespace is not initialized, so do not find 1830 * the namespace objects, or handle the events. 1831 */ 1832 ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true); 1833 error: 1834 if (ret) 1835 acpi_ec_free(ec); 1836 return ret; 1837 } 1838 1839 #ifdef CONFIG_PM_SLEEP 1840 static void acpi_ec_enter_noirq(struct acpi_ec *ec) 1841 { 1842 unsigned long flags; 1843 1844 if (ec == first_ec) { 1845 spin_lock_irqsave(&ec->lock, flags); 1846 ec->saved_busy_polling = ec_busy_polling; 1847 ec->saved_polling_guard = ec_polling_guard; 1848 ec_busy_polling = true; 1849 ec_polling_guard = 0; 1850 ec_log_drv("interrupt blocked"); 1851 spin_unlock_irqrestore(&ec->lock, flags); 1852 } 1853 } 1854 1855 static void acpi_ec_leave_noirq(struct acpi_ec *ec) 1856 { 1857 unsigned long flags; 1858 1859 if (ec == first_ec) { 1860 spin_lock_irqsave(&ec->lock, flags); 1861 ec_busy_polling = ec->saved_busy_polling; 1862 ec_polling_guard = ec->saved_polling_guard; 1863 ec_log_drv("interrupt unblocked"); 1864 spin_unlock_irqrestore(&ec->lock, flags); 1865 } 1866 } 1867 1868 static int acpi_ec_suspend_noirq(struct device *dev) 1869 { 1870 struct acpi_ec *ec = 1871 acpi_driver_data(to_acpi_device(dev)); 1872 1873 acpi_ec_enter_noirq(ec); 1874 return 0; 1875 } 1876 1877 static int acpi_ec_resume_noirq(struct device *dev) 1878 { 1879 struct acpi_ec *ec = 1880 acpi_driver_data(to_acpi_device(dev)); 1881 1882 acpi_ec_leave_noirq(ec); 1883 return 0; 1884 } 1885 1886 static int acpi_ec_suspend(struct device *dev) 1887 { 1888 struct acpi_ec *ec = 1889 acpi_driver_data(to_acpi_device(dev)); 1890 1891 if (ec_freeze_events) 1892 acpi_ec_disable_event(ec); 1893 return 0; 1894 } 1895 1896 static int acpi_ec_resume(struct device *dev) 1897 { 1898 struct acpi_ec *ec = 1899 acpi_driver_data(to_acpi_device(dev)); 1900 1901 acpi_ec_enable_event(ec); 1902 return 0; 1903 } 1904 #endif 1905 1906 static const struct dev_pm_ops acpi_ec_pm = { 1907 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq) 1908 SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume) 1909 }; 1910 1911 static int param_set_event_clearing(const char *val, struct kernel_param *kp) 1912 { 1913 int result = 0; 1914 1915 if (!strncmp(val, "status", sizeof("status") - 1)) { 1916 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS; 1917 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n"); 1918 } else if (!strncmp(val, "query", sizeof("query") - 1)) { 1919 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY; 1920 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n"); 1921 } else if (!strncmp(val, "event", sizeof("event") - 1)) { 1922 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT; 1923 pr_info("Assuming SCI_EVT clearing on event reads\n"); 1924 } else 1925 result = -EINVAL; 1926 return result; 1927 } 1928 1929 static int param_get_event_clearing(char *buffer, struct kernel_param *kp) 1930 { 1931 switch (ec_event_clearing) { 1932 case ACPI_EC_EVT_TIMING_STATUS: 1933 return sprintf(buffer, "status"); 1934 case ACPI_EC_EVT_TIMING_QUERY: 1935 return sprintf(buffer, "query"); 1936 case ACPI_EC_EVT_TIMING_EVENT: 1937 return sprintf(buffer, "event"); 1938 default: 1939 return sprintf(buffer, "invalid"); 1940 } 1941 return 0; 1942 } 1943 1944 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing, 1945 NULL, 0644); 1946 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing"); 1947 1948 static struct acpi_driver acpi_ec_driver = { 1949 .name = "ec", 1950 .class = ACPI_EC_CLASS, 1951 .ids = ec_device_ids, 1952 .ops = { 1953 .add = acpi_ec_add, 1954 .remove = acpi_ec_remove, 1955 }, 1956 .drv.pm = &acpi_ec_pm, 1957 }; 1958 1959 static inline int acpi_ec_query_init(void) 1960 { 1961 if (!ec_query_wq) { 1962 ec_query_wq = alloc_workqueue("kec_query", 0, 1963 ec_max_queries); 1964 if (!ec_query_wq) 1965 return -ENODEV; 1966 } 1967 return 0; 1968 } 1969 1970 static inline void acpi_ec_query_exit(void) 1971 { 1972 if (ec_query_wq) { 1973 destroy_workqueue(ec_query_wq); 1974 ec_query_wq = NULL; 1975 } 1976 } 1977 1978 int __init acpi_ec_init(void) 1979 { 1980 int result; 1981 1982 /* register workqueue for _Qxx evaluations */ 1983 result = acpi_ec_query_init(); 1984 if (result) 1985 goto err_exit; 1986 /* Now register the driver for the EC */ 1987 result = acpi_bus_register_driver(&acpi_ec_driver); 1988 if (result) 1989 goto err_exit; 1990 1991 err_exit: 1992 if (result) 1993 acpi_ec_query_exit(); 1994 return result; 1995 } 1996 1997 /* EC driver currently not unloadable */ 1998 #if 0 1999 static void __exit acpi_ec_exit(void) 2000 { 2001 2002 acpi_bus_unregister_driver(&acpi_ec_driver); 2003 acpi_ec_query_exit(); 2004 } 2005 #endif /* 0 */ 2006