drivers/acpi/ec.c

   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_GPE_MASKED,            /* GPE masked */
 116 };
 117
 118 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 119 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 120
 121 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 122 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 123 module_param(ec_delay, uint, 0644);
 124 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 125
 126 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 127 module_param(ec_max_queries, uint, 0644);
 128 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 129
 130 static bool ec_busy_polling __read_mostly;
 131 module_param(ec_busy_polling, bool, 0644);
 132 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 133
 134 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 135 module_param(ec_polling_guard, uint, 0644);
 136 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 137
 138 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 139
 140 /*
 141  * If the number of false interrupts per one transaction exceeds
 142  * this threshold, will think there is a GPE storm happened and
 143  * will disable the GPE for normal transaction.
 144  */
 145 static unsigned int ec_storm_threshold  __read_mostly = 8;
 146 module_param(ec_storm_threshold, uint, 0644);
 147 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 148
 149 static bool ec_freeze_events __read_mostly = false;
 150 module_param(ec_freeze_events, bool, 0644);
 151 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 152
 153 static bool ec_no_wakeup __read_mostly;
 154 module_param(ec_no_wakeup, bool, 0644);
 155 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 156
 157 struct acpi_ec_query_handler {
 158         struct list_head node;
 159         acpi_ec_query_func func;
 160         acpi_handle handle;
 161         void *data;
 162         u8 query_bit;
 163         struct kref kref;
 164 };
 165
 166 struct transaction {
 167         const u8 *wdata;
 168         u8 *rdata;
 169         unsigned short irq_count;
 170         u8 command;
 171         u8 wi;
 172         u8 ri;
 173         u8 wlen;
 174         u8 rlen;
 175         u8 flags;
 176 };
 177
 178 struct acpi_ec_query {
 179         struct transaction transaction;
 180         struct work_struct work;
 181         struct acpi_ec_query_handler *handler;
 182 };
 183
 184 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 185 static void advance_transaction(struct acpi_ec *ec);
 186 static void acpi_ec_event_handler(struct work_struct *work);
 187 static void acpi_ec_event_processor(struct work_struct *work);
 188
 189 struct acpi_ec *boot_ec, *first_ec;
 190 EXPORT_SYMBOL(first_ec);
 191 static bool boot_ec_is_ecdt = false;
 192 static struct workqueue_struct *ec_query_wq;
 193
 194 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 195 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 196 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 197
 198 /* --------------------------------------------------------------------------
 199  *                           Logging/Debugging
 200  * -------------------------------------------------------------------------- */
 201
 202 /*
 203  * Splitters used by the developers to track the boundary of the EC
 204  * handling processes.
 205  */
 206 #ifdef DEBUG
 207 #define EC_DBG_SEP      " "
 208 #define EC_DBG_DRV      "+++++"
 209 #define EC_DBG_STM      "====="
 210 #define EC_DBG_REQ      "*****"
 211 #define EC_DBG_EVT      "#####"
 212 #else
 213 #define EC_DBG_SEP      ""
 214 #define EC_DBG_DRV
 215 #define EC_DBG_STM
 216 #define EC_DBG_REQ
 217 #define EC_DBG_EVT
 218 #endif
 219
 220 #define ec_log_raw(fmt, ...) \
 221         pr_info(fmt "\n", ##__VA_ARGS__)
 222 #define ec_dbg_raw(fmt, ...) \
 223         pr_debug(fmt "\n", ##__VA_ARGS__)
 224 #define ec_log(filter, fmt, ...) \
 225         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 226 #define ec_dbg(filter, fmt, ...) \
 227         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 228
 229 #define ec_log_drv(fmt, ...) \
 230         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 231 #define ec_dbg_drv(fmt, ...) \
 232         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 233 #define ec_dbg_stm(fmt, ...) \
 234         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 235 #define ec_dbg_req(fmt, ...) \
 236         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 237 #define ec_dbg_evt(fmt, ...) \
 238         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 239 #define ec_dbg_ref(ec, fmt, ...) \
 240         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 241
 242 /* --------------------------------------------------------------------------
 243  *                           Device Flags
 244  * -------------------------------------------------------------------------- */
 245
 246 static bool acpi_ec_started(struct acpi_ec *ec)
 247 {
 248         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 249                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 250 }
 251
 252 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 253 {
 254         /*
 255          * There is an OSPM early stage logic. During the early stages
 256          * (boot/resume), OSPMs shouldn't enable the event handling, only
 257          * the EC transactions are allowed to be performed.
 258          */
 259         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 260                 return false;
 261         /*
 262          * However, disabling the event handling is experimental for late
 263          * stage (suspend), and is controlled by the boot parameter of
 264          * "ec_freeze_events":
 265          * 1. true:  The EC event handling is disabled before entering
 266          *           the noirq stage.
 267          * 2. false: The EC event handling is automatically disabled as
 268          *           soon as the EC driver is stopped.
 269          */
 270         if (ec_freeze_events)
 271                 return acpi_ec_started(ec);
 272         else
 273                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 274 }
 275
 276 static bool acpi_ec_flushed(struct acpi_ec *ec)
 277 {
 278         return ec->reference_count == 1;
 279 }
 280
 281 /* --------------------------------------------------------------------------
 282  *                           EC Registers
 283  * -------------------------------------------------------------------------- */
 284
 285 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 286 {
 287         u8 x = inb(ec->command_addr);
 288
 289         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 290                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 291                    x,
 292                    !!(x & ACPI_EC_FLAG_SCI),
 293                    !!(x & ACPI_EC_FLAG_BURST),
 294                    !!(x & ACPI_EC_FLAG_CMD),
 295                    !!(x & ACPI_EC_FLAG_IBF),
 296                    !!(x & ACPI_EC_FLAG_OBF));
 297         return x;
 298 }
 299
 300 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 301 {
 302         u8 x = inb(ec->data_addr);
 303
 304         ec->timestamp = jiffies;
 305         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 306         return x;
 307 }
 308
 309 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 310 {
 311         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 312         outb(command, ec->command_addr);
 313         ec->timestamp = jiffies;
 314 }
 315
 316 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 317 {
 318         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 319         outb(data, ec->data_addr);
 320         ec->timestamp = jiffies;
 321 }
 322
 323 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 324 static const char *acpi_ec_cmd_string(u8 cmd)
 325 {
 326         switch (cmd) {
 327         case 0x80:
 328                 return "RD_EC";
 329         case 0x81:
 330                 return "WR_EC";
 331         case 0x82:
 332                 return "BE_EC";
 333         case 0x83:
 334                 return "BD_EC";
 335         case 0x84:
 336                 return "QR_EC";
 337         }
 338         return "UNKNOWN";
 339 }
 340 #else
 341 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 342 #endif
 343
 344 /* --------------------------------------------------------------------------
 345  *                           GPE Registers
 346  * -------------------------------------------------------------------------- */
 347
 348 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 349 {
 350         acpi_event_status gpe_status = 0;
 351
 352         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 353         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 354 }
 355
 356 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 357 {
 358         if (open)
 359                 acpi_enable_gpe(NULL, ec->gpe);
 360         else {
 361                 BUG_ON(ec->reference_count < 1);
 362                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 363         }
 364         if (acpi_ec_is_gpe_raised(ec)) {
 365                 /*
 366                  * On some platforms, EN=1 writes cannot trigger GPE. So
 367                  * software need to manually trigger a pseudo GPE event on
 368                  * EN=1 writes.
 369                  */
 370                 ec_dbg_raw("Polling quirk");
 371                 advance_transaction(ec);
 372         }
 373 }
 374
 375 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 376 {
 377         if (close)
 378                 acpi_disable_gpe(NULL, ec->gpe);
 379         else {
 380                 BUG_ON(ec->reference_count < 1);
 381                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 382         }
 383 }
 384
 385 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 386 {
 387         /*
 388          * GPE STS is a W1C register, which means:
 389          * 1. Software can clear it without worrying about clearing other
 390          *    GPEs' STS bits when the hardware sets them in parallel.
 391          * 2. As long as software can ensure only clearing it when it is
 392          *    set, hardware won't set it in parallel.
 393          * So software can clear GPE in any contexts.
 394          * Warning: do not move the check into advance_transaction() as the
 395          * EC commands will be sent without GPE raised.
 396          */
 397         if (!acpi_ec_is_gpe_raised(ec))
 398                 return;
 399         acpi_clear_gpe(NULL, ec->gpe);
 400 }
 401
 402 /* --------------------------------------------------------------------------
 403  *                           Transaction Management
 404  * -------------------------------------------------------------------------- */
 405
 406 static void acpi_ec_submit_request(struct acpi_ec *ec)
 407 {
 408         ec->reference_count++;
 409         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 410             ec->reference_count == 1)
 411                 acpi_ec_enable_gpe(ec, true);
 412 }
 413
 414 static void acpi_ec_complete_request(struct acpi_ec *ec)
 415 {
 416         bool flushed = false;
 417
 418         ec->reference_count--;
 419         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 420             ec->reference_count == 0)
 421                 acpi_ec_disable_gpe(ec, true);
 422         flushed = acpi_ec_flushed(ec);
 423         if (flushed)
 424                 wake_up(&ec->wait);
 425 }
 426
 427 static void acpi_ec_mask_gpe(struct acpi_ec *ec)
 428 {
 429         if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 430                 acpi_ec_disable_gpe(ec, false);
 431                 ec_dbg_drv("Polling enabled");
 432                 set_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 433         }
 434 }
 435
 436 static void acpi_ec_unmask_gpe(struct acpi_ec *ec)
 437 {
 438         if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 439                 clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 440                 acpi_ec_enable_gpe(ec, false);
 441                 ec_dbg_drv("Polling disabled");
 442         }
 443 }
 444
 445 /*
 446  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 447  *                                      the flush operation is not in
 448  *                                      progress
 449  * @ec: the EC device
 450  *
 451  * This function must be used before taking a new action that should hold
 452  * the reference count.  If this function returns false, then the action
 453  * must be discarded or it will prevent the flush operation from being
 454  * completed.
 455  */
 456 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 457 {
 458         if (!acpi_ec_started(ec))
 459                 return false;
 460         acpi_ec_submit_request(ec);
 461         return true;
 462 }
 463
 464 static void acpi_ec_submit_query(struct acpi_ec *ec)
 465 {
 466         acpi_ec_mask_gpe(ec);
 467         if (!acpi_ec_event_enabled(ec))
 468                 return;
 469         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 470                 ec_dbg_evt("Command(%s) submitted/blocked",
 471                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 472                 ec->nr_pending_queries++;
 473                 schedule_work(&ec->work);
 474         }
 475 }
 476
 477 static void acpi_ec_complete_query(struct acpi_ec *ec)
 478 {
 479         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 480                 ec_dbg_evt("Command(%s) unblocked",
 481                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 482         acpi_ec_unmask_gpe(ec);
 483 }
 484
 485 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 486 {
 487         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 488                 ec_log_drv("event unblocked");
 489         if (!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 490                 advance_transaction(ec);
 491 }
 492
 493 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 494 {
 495         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 496                 ec_log_drv("event blocked");
 497 }
 498
 499 static void acpi_ec_enable_event(struct acpi_ec *ec)
 500 {
 501         unsigned long flags;
 502
 503         spin_lock_irqsave(&ec->lock, flags);
 504         if (acpi_ec_started(ec))
 505                 __acpi_ec_enable_event(ec);
 506         spin_unlock_irqrestore(&ec->lock, flags);
 507 }
 508
 509 #ifdef CONFIG_PM_SLEEP
 510 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
 511 {
 512         bool flushed;
 513         unsigned long flags;
 514
 515         spin_lock_irqsave(&ec->lock, flags);
 516         flushed = !ec->nr_pending_queries;
 517         spin_unlock_irqrestore(&ec->lock, flags);
 518         return flushed;
 519 }
 520
 521 static void __acpi_ec_flush_event(struct acpi_ec *ec)
 522 {
 523         /*
 524          * When ec_freeze_events is true, we need to flush events in
 525          * the proper position before entering the noirq stage.
 526          */
 527         wait_event(ec->wait, acpi_ec_query_flushed(ec));
 528         if (ec_query_wq)
 529                 flush_workqueue(ec_query_wq);
 530 }
 531
 532 static void acpi_ec_disable_event(struct acpi_ec *ec)
 533 {
 534         unsigned long flags;
 535
 536         spin_lock_irqsave(&ec->lock, flags);
 537         __acpi_ec_disable_event(ec);
 538         spin_unlock_irqrestore(&ec->lock, flags);
 539         __acpi_ec_flush_event(ec);
 540 }
 541
 542 void acpi_ec_flush_work(void)
 543 {
 544         if (first_ec)
 545                 __acpi_ec_flush_event(first_ec);
 546
 547         flush_scheduled_work();
 548 }
 549 #endif /* CONFIG_PM_SLEEP */
 550
 551 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 552 {
 553         bool guarded = true;
 554         unsigned long flags;
 555
 556         spin_lock_irqsave(&ec->lock, flags);
 557         /*
 558          * If firmware SCI_EVT clearing timing is "event", we actually
 559          * don't know when the SCI_EVT will be cleared by firmware after
 560          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 561          * acceptable period.
 562          *
 563          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 564          * flagged, which means SCI_EVT check has just been performed.
 565          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 566          * guarding should have already been performed (via
 567          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 568          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 569          * ACPI_EC_COMMAND_POLL state immediately.
 570          */
 571         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 572             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 573             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 574             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 575                 guarded = false;
 576         spin_unlock_irqrestore(&ec->lock, flags);
 577         return guarded;
 578 }
 579
 580 static int ec_transaction_polled(struct acpi_ec *ec)
 581 {
 582         unsigned long flags;
 583         int ret = 0;
 584
 585         spin_lock_irqsave(&ec->lock, flags);
 586         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 587                 ret = 1;
 588         spin_unlock_irqrestore(&ec->lock, flags);
 589         return ret;
 590 }
 591
 592 static int ec_transaction_completed(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_COMPLETE))
 599                 ret = 1;
 600         spin_unlock_irqrestore(&ec->lock, flags);
 601         return ret;
 602 }
 603
 604 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 605 {
 606         ec->curr->flags |= flag;
 607         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 608                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 609                     flag == ACPI_EC_COMMAND_POLL)
 610                         acpi_ec_complete_query(ec);
 611                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 612                     flag == ACPI_EC_COMMAND_COMPLETE)
 613                         acpi_ec_complete_query(ec);
 614                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 615                     flag == ACPI_EC_COMMAND_COMPLETE)
 616                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 617         }
 618 }
 619
 620 static void advance_transaction(struct acpi_ec *ec)
 621 {
 622         struct transaction *t;
 623         u8 status;
 624         bool wakeup = false;
 625
 626         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 627                    smp_processor_id());
 628         /*
 629          * By always clearing STS before handling all indications, we can
 630          * ensure a hardware STS 0->1 change after this clearing can always
 631          * trigger a GPE interrupt.
 632          */
 633         acpi_ec_clear_gpe(ec);
 634         status = acpi_ec_read_status(ec);
 635         t = ec->curr;
 636         /*
 637          * Another IRQ or a guarded polling mode advancement is detected,
 638          * the next QR_EC submission is then allowed.
 639          */
 640         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 641                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 642                     (!ec->nr_pending_queries ||
 643                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 644                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 645                         acpi_ec_complete_query(ec);
 646                 }
 647         }
 648         if (!t)
 649                 goto err;
 650         if (t->flags & ACPI_EC_COMMAND_POLL) {
 651                 if (t->wlen > t->wi) {
 652                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 653                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 654                         else
 655                                 goto err;
 656                 } else if (t->rlen > t->ri) {
 657                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 658                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 659                                 if (t->rlen == t->ri) {
 660                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 661                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 662                                                 ec_dbg_evt("Command(%s) completed by hardware",
 663                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 664                                         wakeup = true;
 665                                 }
 666                         } else
 667                                 goto err;
 668                 } else if (t->wlen == t->wi &&
 669                            (status & ACPI_EC_FLAG_IBF) == 0) {
 670                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 671                         wakeup = true;
 672                 }
 673                 goto out;
 674         } else {
 675                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 676                     !(status & ACPI_EC_FLAG_SCI) &&
 677                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 678                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 679                         t->rdata[t->ri++] = 0x00;
 680                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 681                         ec_dbg_evt("Command(%s) completed by software",
 682                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 683                         wakeup = true;
 684                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 685                         acpi_ec_write_cmd(ec, t->command);
 686                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 687                 } else
 688                         goto err;
 689                 goto out;
 690         }
 691 err:
 692         /*
 693          * If SCI bit is set, then don't think it's a false IRQ
 694          * otherwise will take a not handled IRQ as a false one.
 695          */
 696         if (!(status & ACPI_EC_FLAG_SCI)) {
 697                 if (in_interrupt() && t) {
 698                         if (t->irq_count < ec_storm_threshold)
 699                                 ++t->irq_count;
 700                         /* Allow triggering on 0 threshold */
 701                         if (t->irq_count == ec_storm_threshold)
 702                                 acpi_ec_mask_gpe(ec);
 703                 }
 704         }
 705 out:
 706         if (status & ACPI_EC_FLAG_SCI)
 707                 acpi_ec_submit_query(ec);
 708         if (wakeup && in_interrupt())
 709                 wake_up(&ec->wait);
 710 }
 711
 712 static void start_transaction(struct acpi_ec *ec)
 713 {
 714         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 715         ec->curr->flags = 0;
 716 }
 717
 718 static int ec_guard(struct acpi_ec *ec)
 719 {
 720         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 721         unsigned long timeout = ec->timestamp + guard;
 722
 723         /* Ensure guarding period before polling EC status */
 724         do {
 725                 if (ec->busy_polling) {
 726                         /* Perform busy polling */
 727                         if (ec_transaction_completed(ec))
 728                                 return 0;
 729                         udelay(jiffies_to_usecs(guard));
 730                 } else {
 731                         /*
 732                          * Perform wait polling
 733                          * 1. Wait the transaction to be completed by the
 734                          *    GPE handler after the transaction enters
 735                          *    ACPI_EC_COMMAND_POLL state.
 736                          * 2. A special guarding logic is also required
 737                          *    for event clearing mode "event" before the
 738                          *    transaction enters ACPI_EC_COMMAND_POLL
 739                          *    state.
 740                          */
 741                         if (!ec_transaction_polled(ec) &&
 742                             !acpi_ec_guard_event(ec))
 743                                 break;
 744                         if (wait_event_timeout(ec->wait,
 745                                                ec_transaction_completed(ec),
 746                                                guard))
 747                                 return 0;
 748                 }
 749         } while (time_before(jiffies, timeout));
 750         return -ETIME;
 751 }
 752
 753 static int ec_poll(struct acpi_ec *ec)
 754 {
 755         unsigned long flags;
 756         int repeat = 5; /* number of command restarts */
 757
 758         while (repeat--) {
 759                 unsigned long delay = jiffies +
 760                         msecs_to_jiffies(ec_delay);
 761                 do {
 762                         if (!ec_guard(ec))
 763                                 return 0;
 764                         spin_lock_irqsave(&ec->lock, flags);
 765                         advance_transaction(ec);
 766                         spin_unlock_irqrestore(&ec->lock, flags);
 767                 } while (time_before(jiffies, delay));
 768                 pr_debug("controller reset, restart transaction\n");
 769                 spin_lock_irqsave(&ec->lock, flags);
 770                 start_transaction(ec);
 771                 spin_unlock_irqrestore(&ec->lock, flags);
 772         }
 773         return -ETIME;
 774 }
 775
 776 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 777                                         struct transaction *t)
 778 {
 779         unsigned long tmp;
 780         int ret = 0;
 781
 782         /* start transaction */
 783         spin_lock_irqsave(&ec->lock, tmp);
 784         /* Enable GPE for command processing (IBF=0/OBF=1) */
 785         if (!acpi_ec_submit_flushable_request(ec)) {
 786                 ret = -EINVAL;
 787                 goto unlock;
 788         }
 789         ec_dbg_ref(ec, "Increase command");
 790         /* following two actions should be kept atomic */
 791         ec->curr = t;
 792         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 793         start_transaction(ec);
 794         spin_unlock_irqrestore(&ec->lock, tmp);
 795
 796         ret = ec_poll(ec);
 797
 798         spin_lock_irqsave(&ec->lock, tmp);
 799         if (t->irq_count == ec_storm_threshold)
 800                 acpi_ec_unmask_gpe(ec);
 801         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 802         ec->curr = NULL;
 803         /* Disable GPE for command processing (IBF=0/OBF=1) */
 804         acpi_ec_complete_request(ec);
 805         ec_dbg_ref(ec, "Decrease command");
 806 unlock:
 807         spin_unlock_irqrestore(&ec->lock, tmp);
 808         return ret;
 809 }
 810
 811 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 812 {
 813         int status;
 814         u32 glk;
 815
 816         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 817                 return -EINVAL;
 818         if (t->rdata)
 819                 memset(t->rdata, 0, t->rlen);
 820
 821         mutex_lock(&ec->mutex);
 822         if (ec->global_lock) {
 823                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 824                 if (ACPI_FAILURE(status)) {
 825                         status = -ENODEV;
 826                         goto unlock;
 827                 }
 828         }
 829
 830         status = acpi_ec_transaction_unlocked(ec, t);
 831
 832         if (ec->global_lock)
 833                 acpi_release_global_lock(glk);
 834 unlock:
 835         mutex_unlock(&ec->mutex);
 836         return status;
 837 }
 838
 839 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 840 {
 841         u8 d;
 842         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 843                                 .wdata = NULL, .rdata = &d,
 844                                 .wlen = 0, .rlen = 1};
 845
 846         return acpi_ec_transaction(ec, &t);
 847 }
 848
 849 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 850 {
 851         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 852                                 .wdata = NULL, .rdata = NULL,
 853                                 .wlen = 0, .rlen = 0};
 854
 855         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 856                                 acpi_ec_transaction(ec, &t) : 0;
 857 }
 858
 859 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 860 {
 861         int result;
 862         u8 d;
 863         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 864                                 .wdata = &address, .rdata = &d,
 865                                 .wlen = 1, .rlen = 1};
 866
 867         result = acpi_ec_transaction(ec, &t);
 868         *data = d;
 869         return result;
 870 }
 871
 872 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 873 {
 874         u8 wdata[2] = { address, data };
 875         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 876                                 .wdata = wdata, .rdata = NULL,
 877                                 .wlen = 2, .rlen = 0};
 878
 879         return acpi_ec_transaction(ec, &t);
 880 }
 881
 882 int ec_read(u8 addr, u8 *val)
 883 {
 884         int err;
 885         u8 temp_data;
 886
 887         if (!first_ec)
 888                 return -ENODEV;
 889
 890         err = acpi_ec_read(first_ec, addr, &temp_data);
 891
 892         if (!err) {
 893                 *val = temp_data;
 894                 return 0;
 895         }
 896         return err;
 897 }
 898 EXPORT_SYMBOL(ec_read);
 899
 900 int ec_write(u8 addr, u8 val)
 901 {
 902         int err;
 903
 904         if (!first_ec)
 905                 return -ENODEV;
 906
 907         err = acpi_ec_write(first_ec, addr, val);
 908
 909         return err;
 910 }
 911 EXPORT_SYMBOL(ec_write);
 912
 913 int ec_transaction(u8 command,
 914                    const u8 *wdata, unsigned wdata_len,
 915                    u8 *rdata, unsigned rdata_len)
 916 {
 917         struct transaction t = {.command = command,
 918                                 .wdata = wdata, .rdata = rdata,
 919                                 .wlen = wdata_len, .rlen = rdata_len};
 920
 921         if (!first_ec)
 922                 return -ENODEV;
 923
 924         return acpi_ec_transaction(first_ec, &t);
 925 }
 926 EXPORT_SYMBOL(ec_transaction);
 927
 928 /* Get the handle to the EC device */
 929 acpi_handle ec_get_handle(void)
 930 {
 931         if (!first_ec)
 932                 return NULL;
 933         return first_ec->handle;
 934 }
 935 EXPORT_SYMBOL(ec_get_handle);
 936
 937 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 938 {
 939         unsigned long flags;
 940
 941         spin_lock_irqsave(&ec->lock, flags);
 942         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 943                 ec_dbg_drv("Starting EC");
 944                 /* Enable GPE for event processing (SCI_EVT=1) */
 945                 if (!resuming) {
 946                         acpi_ec_submit_request(ec);
 947                         ec_dbg_ref(ec, "Increase driver");
 948                 }
 949                 ec_log_drv("EC started");
 950         }
 951         spin_unlock_irqrestore(&ec->lock, flags);
 952 }
 953
 954 static bool acpi_ec_stopped(struct acpi_ec *ec)
 955 {
 956         unsigned long flags;
 957         bool flushed;
 958
 959         spin_lock_irqsave(&ec->lock, flags);
 960         flushed = acpi_ec_flushed(ec);
 961         spin_unlock_irqrestore(&ec->lock, flags);
 962         return flushed;
 963 }
 964
 965 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 966 {
 967         unsigned long flags;
 968
 969         spin_lock_irqsave(&ec->lock, flags);
 970         if (acpi_ec_started(ec)) {
 971                 ec_dbg_drv("Stopping EC");
 972                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 973                 spin_unlock_irqrestore(&ec->lock, flags);
 974                 wait_event(ec->wait, acpi_ec_stopped(ec));
 975                 spin_lock_irqsave(&ec->lock, flags);
 976                 /* Disable GPE for event processing (SCI_EVT=1) */
 977                 if (!suspending) {
 978                         acpi_ec_complete_request(ec);
 979                         ec_dbg_ref(ec, "Decrease driver");
 980                 } else if (!ec_freeze_events)
 981                         __acpi_ec_disable_event(ec);
 982                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 983                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 984                 ec_log_drv("EC stopped");
 985         }
 986         spin_unlock_irqrestore(&ec->lock, flags);
 987 }
 988
 989 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 990 {
 991         unsigned long flags;
 992
 993         spin_lock_irqsave(&ec->lock, flags);
 994         ec->busy_polling = true;
 995         ec->polling_guard = 0;
 996         ec_log_drv("interrupt blocked");
 997         spin_unlock_irqrestore(&ec->lock, flags);
 998 }
 999
1000 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1001 {
1002         unsigned long flags;
1003
1004         spin_lock_irqsave(&ec->lock, flags);
1005         ec->busy_polling = ec_busy_polling;
1006         ec->polling_guard = ec_polling_guard;
1007         ec_log_drv("interrupt unblocked");
1008         spin_unlock_irqrestore(&ec->lock, flags);
1009 }
1010
1011 void acpi_ec_block_transactions(void)
1012 {
1013         struct acpi_ec *ec = first_ec;
1014
1015         if (!ec)
1016                 return;
1017
1018         mutex_lock(&ec->mutex);
1019         /* Prevent transactions from being carried out */
1020         acpi_ec_stop(ec, true);
1021         mutex_unlock(&ec->mutex);
1022 }
1023
1024 void acpi_ec_unblock_transactions(void)
1025 {
1026         /*
1027          * Allow transactions to happen again (this function is called from
1028          * atomic context during wakeup, so we don't need to acquire the mutex).
1029          */
1030         if (first_ec)
1031                 acpi_ec_start(first_ec, true);
1032 }
1033
1034 /* --------------------------------------------------------------------------
1035                                 Event Management
1036    -------------------------------------------------------------------------- */
1037 static struct acpi_ec_query_handler *
1038 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1039 {
1040         if (handler)
1041                 kref_get(&handler->kref);
1042         return handler;
1043 }
1044
1045 static struct acpi_ec_query_handler *
1046 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1047 {
1048         struct acpi_ec_query_handler *handler;
1049         bool found = false;
1050
1051         mutex_lock(&ec->mutex);
1052         list_for_each_entry(handler, &ec->list, node) {
1053                 if (value == handler->query_bit) {
1054                         found = true;
1055                         break;
1056                 }
1057         }
1058         mutex_unlock(&ec->mutex);
1059         return found ? acpi_ec_get_query_handler(handler) : NULL;
1060 }
1061
1062 static void acpi_ec_query_handler_release(struct kref *kref)
1063 {
1064         struct acpi_ec_query_handler *handler =
1065                 container_of(kref, struct acpi_ec_query_handler, kref);
1066
1067         kfree(handler);
1068 }
1069
1070 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1071 {
1072         kref_put(&handler->kref, acpi_ec_query_handler_release);
1073 }
1074
1075 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1076                               acpi_handle handle, acpi_ec_query_func func,
1077                               void *data)
1078 {
1079         struct acpi_ec_query_handler *handler =
1080             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1081
1082         if (!handler)
1083                 return -ENOMEM;
1084
1085         handler->query_bit = query_bit;
1086         handler->handle = handle;
1087         handler->func = func;
1088         handler->data = data;
1089         mutex_lock(&ec->mutex);
1090         kref_init(&handler->kref);
1091         list_add(&handler->node, &ec->list);
1092         mutex_unlock(&ec->mutex);
1093         return 0;
1094 }
1095 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1096
1097 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1098                                           bool remove_all, u8 query_bit)
1099 {
1100         struct acpi_ec_query_handler *handler, *tmp;
1101         LIST_HEAD(free_list);
1102
1103         mutex_lock(&ec->mutex);
1104         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1105                 if (remove_all || query_bit == handler->query_bit) {
1106                         list_del_init(&handler->node);
1107                         list_add(&handler->node, &free_list);
1108                 }
1109         }
1110         mutex_unlock(&ec->mutex);
1111         list_for_each_entry_safe(handler, tmp, &free_list, node)
1112                 acpi_ec_put_query_handler(handler);
1113 }
1114
1115 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1116 {
1117         acpi_ec_remove_query_handlers(ec, false, query_bit);
1118 }
1119 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1120
1121 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1122 {
1123         struct acpi_ec_query *q;
1124         struct transaction *t;
1125
1126         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1127         if (!q)
1128                 return NULL;
1129         INIT_WORK(&q->work, acpi_ec_event_processor);
1130         t = &q->transaction;
1131         t->command = ACPI_EC_COMMAND_QUERY;
1132         t->rdata = pval;
1133         t->rlen = 1;
1134         return q;
1135 }
1136
1137 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1138 {
1139         if (q) {
1140                 if (q->handler)
1141                         acpi_ec_put_query_handler(q->handler);
1142                 kfree(q);
1143         }
1144 }
1145
1146 static void acpi_ec_event_processor(struct work_struct *work)
1147 {
1148         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1149         struct acpi_ec_query_handler *handler = q->handler;
1150
1151         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1152         if (handler->func)
1153                 handler->func(handler->data);
1154         else if (handler->handle)
1155                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1156         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1157         acpi_ec_delete_query(q);
1158 }
1159
1160 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1161 {
1162         u8 value = 0;
1163         int result;
1164         struct acpi_ec_query *q;
1165
1166         q = acpi_ec_create_query(&value);
1167         if (!q)
1168                 return -ENOMEM;
1169
1170         /*
1171          * Query the EC to find out which _Qxx method we need to evaluate.
1172          * Note that successful completion of the query causes the ACPI_EC_SCI
1173          * bit to be cleared (and thus clearing the interrupt source).
1174          */
1175         result = acpi_ec_transaction(ec, &q->transaction);
1176         if (!value)
1177                 result = -ENODATA;
1178         if (result)
1179                 goto err_exit;
1180
1181         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1182         if (!q->handler) {
1183                 result = -ENODATA;
1184                 goto err_exit;
1185         }
1186
1187         /*
1188          * It is reported that _Qxx are evaluated in a parallel way on
1189          * Windows:
1190          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1191          *
1192          * Put this log entry before schedule_work() in order to make
1193          * it appearing before any other log entries occurred during the
1194          * work queue execution.
1195          */
1196         ec_dbg_evt("Query(0x%02x) scheduled", value);
1197         if (!queue_work(ec_query_wq, &q->work)) {
1198                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1199                 result = -EBUSY;
1200         }
1201
1202 err_exit:
1203         if (result)
1204                 acpi_ec_delete_query(q);
1205         if (data)
1206                 *data = value;
1207         return result;
1208 }
1209
1210 static void acpi_ec_check_event(struct acpi_ec *ec)
1211 {
1212         unsigned long flags;
1213
1214         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1215                 if (ec_guard(ec)) {
1216                         spin_lock_irqsave(&ec->lock, flags);
1217                         /*
1218                          * Take care of the SCI_EVT unless no one else is
1219                          * taking care of it.
1220                          */
1221                         if (!ec->curr)
1222                                 advance_transaction(ec);
1223                         spin_unlock_irqrestore(&ec->lock, flags);
1224                 }
1225         }
1226 }
1227
1228 static void acpi_ec_event_handler(struct work_struct *work)
1229 {
1230         unsigned long flags;
1231         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1232
1233         ec_dbg_evt("Event started");
1234
1235         spin_lock_irqsave(&ec->lock, flags);
1236         while (ec->nr_pending_queries) {
1237                 spin_unlock_irqrestore(&ec->lock, flags);
1238                 (void)acpi_ec_query(ec, NULL);
1239                 spin_lock_irqsave(&ec->lock, flags);
1240                 ec->nr_pending_queries--;
1241                 /*
1242                  * Before exit, make sure that this work item can be
1243                  * scheduled again. There might be QR_EC failures, leaving
1244                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1245                  * item from being scheduled again.
1246                  */
1247                 if (!ec->nr_pending_queries) {
1248                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1249                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1250                                 acpi_ec_complete_query(ec);
1251                 }
1252         }
1253         spin_unlock_irqrestore(&ec->lock, flags);
1254
1255         ec_dbg_evt("Event stopped");
1256
1257         acpi_ec_check_event(ec);
1258 }
1259
1260 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1261         u32 gpe_number, void *data)
1262 {
1263         unsigned long flags;
1264         struct acpi_ec *ec = data;
1265
1266         spin_lock_irqsave(&ec->lock, flags);
1267         advance_transaction(ec);
1268         spin_unlock_irqrestore(&ec->lock, flags);
1269         return ACPI_INTERRUPT_HANDLED;
1270 }
1271
1272 /* --------------------------------------------------------------------------
1273  *                           Address Space Management
1274  * -------------------------------------------------------------------------- */
1275
1276 static acpi_status
1277 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1278                       u32 bits, u64 *value64,
1279                       void *handler_context, void *region_context)
1280 {
1281         struct acpi_ec *ec = handler_context;
1282         int result = 0, i, bytes = bits / 8;
1283         u8 *value = (u8 *)value64;
1284
1285         if ((address > 0xFF) || !value || !handler_context)
1286                 return AE_BAD_PARAMETER;
1287
1288         if (function != ACPI_READ && function != ACPI_WRITE)
1289                 return AE_BAD_PARAMETER;
1290
1291         if (ec->busy_polling || bits > 8)
1292                 acpi_ec_burst_enable(ec);
1293
1294         for (i = 0; i < bytes; ++i, ++address, ++value)
1295                 result = (function == ACPI_READ) ?
1296                         acpi_ec_read(ec, address, value) :
1297                         acpi_ec_write(ec, address, *value);
1298
1299         if (ec->busy_polling || bits > 8)
1300                 acpi_ec_burst_disable(ec);
1301
1302         switch (result) {
1303         case -EINVAL:
1304                 return AE_BAD_PARAMETER;
1305         case -ENODEV:
1306                 return AE_NOT_FOUND;
1307         case -ETIME:
1308                 return AE_TIME;
1309         default:
1310                 return AE_OK;
1311         }
1312 }
1313
1314 /* --------------------------------------------------------------------------
1315  *                             Driver Interface
1316  * -------------------------------------------------------------------------- */
1317
1318 static acpi_status
1319 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1320
1321 static void acpi_ec_free(struct acpi_ec *ec)
1322 {
1323         if (first_ec == ec)
1324                 first_ec = NULL;
1325         if (boot_ec == ec)
1326                 boot_ec = NULL;
1327         kfree(ec);
1328 }
1329
1330 static struct acpi_ec *acpi_ec_alloc(void)
1331 {
1332         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1333
1334         if (!ec)
1335                 return NULL;
1336         mutex_init(&ec->mutex);
1337         init_waitqueue_head(&ec->wait);
1338         INIT_LIST_HEAD(&ec->list);
1339         spin_lock_init(&ec->lock);
1340         INIT_WORK(&ec->work, acpi_ec_event_handler);
1341         ec->timestamp = jiffies;
1342         ec->busy_polling = true;
1343         ec->polling_guard = 0;
1344         return ec;
1345 }
1346
1347 static acpi_status
1348 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1349                                void *context, void **return_value)
1350 {
1351         char node_name[5];
1352         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1353         struct acpi_ec *ec = context;
1354         int value = 0;
1355         acpi_status status;
1356
1357         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1358
1359         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1360                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1361         return AE_OK;
1362 }
1363
1364 static acpi_status
1365 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1366 {
1367         acpi_status status;
1368         unsigned long long tmp = 0;
1369         struct acpi_ec *ec = context;
1370
1371         /* clear addr values, ec_parse_io_ports depend on it */
1372         ec->command_addr = ec->data_addr = 0;
1373
1374         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1375                                      ec_parse_io_ports, ec);
1376         if (ACPI_FAILURE(status))
1377                 return status;
1378         if (ec->data_addr == 0 || ec->command_addr == 0)
1379                 return AE_OK;
1380
1381         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1382                 /*
1383                  * Always inherit the GPE number setting from the ECDT
1384                  * EC.
1385                  */
1386                 ec->gpe = boot_ec->gpe;
1387         } else {
1388                 /* Get GPE bit assignment (EC events). */
1389                 /* TODO: Add support for _GPE returning a package */
1390                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1391                 if (ACPI_FAILURE(status))
1392                         return status;
1393                 ec->gpe = tmp;
1394         }
1395         /* Use the global lock for all EC transactions? */
1396         tmp = 0;
1397         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1398         ec->global_lock = tmp;
1399         ec->handle = handle;
1400         return AE_CTRL_TERMINATE;
1401 }
1402
1403 /*
1404  * Note: This function returns an error code only when the address space
1405  *       handler is not installed, which means "not able to handle
1406  *       transactions".
1407  */
1408 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1409 {
1410         acpi_status status;
1411
1412         acpi_ec_start(ec, false);
1413
1414         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1415                 acpi_ec_enter_noirq(ec);
1416                 status = acpi_install_address_space_handler(ec->handle,
1417                                                             ACPI_ADR_SPACE_EC,
1418                                                             &acpi_ec_space_handler,
1419                                                             NULL, ec);
1420                 if (ACPI_FAILURE(status)) {
1421                         if (status == AE_NOT_FOUND) {
1422                                 /*
1423                                  * Maybe OS fails in evaluating the _REG
1424                                  * object. The AE_NOT_FOUND error will be
1425                                  * ignored and OS * continue to initialize
1426                                  * EC.
1427                                  */
1428                                 pr_err("Fail in evaluating the _REG object"
1429                                         " of EC device. Broken bios is suspected.\n");
1430                         } else {
1431                                 acpi_ec_stop(ec, false);
1432                                 return -ENODEV;
1433                         }
1434                 }
1435                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1436         }
1437
1438         if (!handle_events)
1439                 return 0;
1440
1441         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1442                 /* Find and register all query methods */
1443                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1444                                     acpi_ec_register_query_methods,
1445                                     NULL, ec, NULL);
1446                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1447         }
1448         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1449                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1450                                           ACPI_GPE_EDGE_TRIGGERED,
1451                                           &acpi_ec_gpe_handler, ec);
1452                 /* This is not fatal as we can poll EC events */
1453                 if (ACPI_SUCCESS(status)) {
1454                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1455                         acpi_ec_leave_noirq(ec);
1456                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1457                             ec->reference_count >= 1)
1458                                 acpi_ec_enable_gpe(ec, true);
1459
1460                         /* EC is fully operational, allow queries */
1461                         acpi_ec_enable_event(ec);
1462                 }
1463         }
1464
1465         return 0;
1466 }
1467
1468 static void ec_remove_handlers(struct acpi_ec *ec)
1469 {
1470         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1471                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1472                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1473                         pr_err("failed to remove space handler\n");
1474                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1475         }
1476
1477         /*
1478          * Stops handling the EC transactions after removing the operation
1479          * region handler. This is required because _REG(DISCONNECT)
1480          * invoked during the removal can result in new EC transactions.
1481          *
1482          * Flushes the EC requests and thus disables the GPE before
1483          * removing the GPE handler. This is required by the current ACPICA
1484          * GPE core. ACPICA GPE core will automatically disable a GPE when
1485          * it is indicated but there is no way to handle it. So the drivers
1486          * must disable the GPEs prior to removing the GPE handlers.
1487          */
1488         acpi_ec_stop(ec, false);
1489
1490         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1491                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1492                                         &acpi_ec_gpe_handler)))
1493                         pr_err("failed to remove gpe handler\n");
1494                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1495         }
1496         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1497                 acpi_ec_remove_query_handlers(ec, true, 0);
1498                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1499         }
1500 }
1501
1502 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1503 {
1504         int ret;
1505
1506         ret = ec_install_handlers(ec, handle_events);
1507         if (ret)
1508                 return ret;
1509
1510         /* First EC capable of handling transactions */
1511         if (!first_ec) {
1512                 first_ec = ec;
1513                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1514         }
1515
1516         acpi_handle_info(ec->handle,
1517                          "GPE=0x%lx, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1518                          ec->gpe, ec->command_addr, ec->data_addr);
1519         return ret;
1520 }
1521
1522 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1523                                bool handle_events, bool is_ecdt)
1524 {
1525         int ret;
1526
1527         /*
1528          * Changing the ACPI handle results in a re-configuration of the
1529          * boot EC. And if it happens after the namespace initialization,
1530          * it causes _REG evaluations.
1531          */
1532         if (boot_ec && boot_ec->handle != handle)
1533                 ec_remove_handlers(boot_ec);
1534
1535         /* Unset old boot EC */
1536         if (boot_ec != ec)
1537                 acpi_ec_free(boot_ec);
1538
1539         /*
1540          * ECDT device creation is split into acpi_ec_ecdt_probe() and
1541          * acpi_ec_ecdt_start(). This function takes care of completing the
1542          * ECDT parsing logic as the handle update should be performed
1543          * between the installation/uninstallation of the handlers.
1544          */
1545         if (ec->handle != handle)
1546                 ec->handle = handle;
1547
1548         ret = acpi_ec_setup(ec, handle_events);
1549         if (ret)
1550                 return ret;
1551
1552         /* Set new boot EC */
1553         if (!boot_ec) {
1554                 boot_ec = ec;
1555                 boot_ec_is_ecdt = is_ecdt;
1556         }
1557
1558         acpi_handle_info(boot_ec->handle,
1559                          "Used as boot %s EC to handle transactions%s\n",
1560                          is_ecdt ? "ECDT" : "DSDT",
1561                          handle_events ? " and events" : "");
1562         return ret;
1563 }
1564
1565 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1566 {
1567         struct acpi_table_ecdt *ecdt_ptr;
1568         acpi_status status;
1569         acpi_handle handle;
1570
1571         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1572                                 (struct acpi_table_header **)&ecdt_ptr);
1573         if (ACPI_FAILURE(status))
1574                 return false;
1575
1576         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1577         if (ACPI_FAILURE(status))
1578                 return false;
1579
1580         *phandle = handle;
1581         return true;
1582 }
1583
1584 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1585 {
1586         if (!boot_ec)
1587                 return false;
1588         if (ec->command_addr == boot_ec->command_addr &&
1589             ec->data_addr == boot_ec->data_addr)
1590                 return true;
1591         return false;
1592 }
1593
1594 static int acpi_ec_add(struct acpi_device *device)
1595 {
1596         struct acpi_ec *ec = NULL;
1597         int ret;
1598
1599         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1600         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1601
1602         ec = acpi_ec_alloc();
1603         if (!ec)
1604                 return -ENOMEM;
1605         if (ec_parse_device(device->handle, 0, ec, NULL) !=
1606                 AE_CTRL_TERMINATE) {
1607                         ret = -EINVAL;
1608                         goto err_alloc;
1609         }
1610
1611         if (acpi_is_boot_ec(ec)) {
1612                 boot_ec_is_ecdt = false;
1613                 /*
1614                  * Trust PNP0C09 namespace location rather than ECDT ID.
1615                  *
1616                  * But trust ECDT GPE rather than _GPE because of ASUS quirks,
1617                  * so do not change boot_ec->gpe to ec->gpe.
1618                  */
1619                 boot_ec->handle = ec->handle;
1620                 acpi_handle_debug(ec->handle, "duplicated.\n");
1621                 acpi_ec_free(ec);
1622                 ec = boot_ec;
1623                 ret = acpi_config_boot_ec(ec, ec->handle, true, false);
1624         } else
1625                 ret = acpi_ec_setup(ec, true);
1626         if (ret)
1627                 goto err_query;
1628
1629         device->driver_data = ec;
1630
1631         ret = !!request_region(ec->data_addr, 1, "EC data");
1632         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1633         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1634         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1635
1636         /* Reprobe devices depending on the EC */
1637         acpi_walk_dep_device_list(ec->handle);
1638         acpi_handle_debug(ec->handle, "enumerated.\n");
1639         return 0;
1640
1641 err_query:
1642         if (ec != boot_ec)
1643                 acpi_ec_remove_query_handlers(ec, true, 0);
1644 err_alloc:
1645         if (ec != boot_ec)
1646                 acpi_ec_free(ec);
1647         return ret;
1648 }
1649
1650 static int acpi_ec_remove(struct acpi_device *device)
1651 {
1652         struct acpi_ec *ec;
1653
1654         if (!device)
1655                 return -EINVAL;
1656
1657         ec = acpi_driver_data(device);
1658         release_region(ec->data_addr, 1);
1659         release_region(ec->command_addr, 1);
1660         device->driver_data = NULL;
1661         if (ec != boot_ec) {
1662                 ec_remove_handlers(ec);
1663                 acpi_ec_free(ec);
1664         }
1665         return 0;
1666 }
1667
1668 static acpi_status
1669 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1670 {
1671         struct acpi_ec *ec = context;
1672
1673         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1674                 return AE_OK;
1675
1676         /*
1677          * The first address region returned is the data port, and
1678          * the second address region returned is the status/command
1679          * port.
1680          */
1681         if (ec->data_addr == 0)
1682                 ec->data_addr = resource->data.io.minimum;
1683         else if (ec->command_addr == 0)
1684                 ec->command_addr = resource->data.io.minimum;
1685         else
1686                 return AE_CTRL_TERMINATE;
1687
1688         return AE_OK;
1689 }
1690
1691 static const struct acpi_device_id ec_device_ids[] = {
1692         {"PNP0C09", 0},
1693         {"", 0},
1694 };
1695
1696 /*
1697  * This function is not Windows-compatible as Windows never enumerates the
1698  * namespace EC before the main ACPI device enumeration process. It is
1699  * retained for historical reason and will be deprecated in the future.
1700  */
1701 int __init acpi_ec_dsdt_probe(void)
1702 {
1703         acpi_status status;
1704         struct acpi_ec *ec;
1705         int ret;
1706
1707         /*
1708          * If a platform has ECDT, there is no need to proceed as the
1709          * following probe is not a part of the ACPI device enumeration,
1710          * executing _STA is not safe, and thus this probe may risk of
1711          * picking up an invalid EC device.
1712          */
1713         if (boot_ec)
1714                 return -ENODEV;
1715
1716         ec = acpi_ec_alloc();
1717         if (!ec)
1718                 return -ENOMEM;
1719         /*
1720          * At this point, the namespace is initialized, so start to find
1721          * the namespace objects.
1722          */
1723         status = acpi_get_devices(ec_device_ids[0].id,
1724                                   ec_parse_device, ec, NULL);
1725         if (ACPI_FAILURE(status) || !ec->handle) {
1726                 ret = -ENODEV;
1727                 goto error;
1728         }
1729         /*
1730          * When the DSDT EC is available, always re-configure boot EC to
1731          * have _REG evaluated. _REG can only be evaluated after the
1732          * namespace initialization.
1733          * At this point, the GPE is not fully initialized, so do not to
1734          * handle the events.
1735          */
1736         ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1737 error:
1738         if (ret)
1739                 acpi_ec_free(ec);
1740         return ret;
1741 }
1742
1743 /*
1744  * If the DSDT EC is not functioning, we still need to prepare a fully
1745  * functioning ECDT EC first in order to handle the events.
1746  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1747  */
1748 static int __init acpi_ec_ecdt_start(void)
1749 {
1750         acpi_handle handle;
1751
1752         if (!boot_ec)
1753                 return -ENODEV;
1754         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1755         if (!boot_ec_is_ecdt)
1756                 return -ENODEV;
1757
1758         /*
1759          * At this point, the namespace and the GPE is initialized, so
1760          * start to find the namespace objects and handle the events.
1761          *
1762          * Note: ec->handle can be valid if this function is called after
1763          * acpi_ec_add(), hence the fast path.
1764          */
1765         if (boot_ec->handle != ACPI_ROOT_OBJECT)
1766                 handle = boot_ec->handle;
1767         else if (!acpi_ec_ecdt_get_handle(&handle))
1768                 return -ENODEV;
1769         return acpi_config_boot_ec(boot_ec, handle, true, true);
1770 }
1771
1772 #if 0
1773 /*
1774  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1775  * set, for which case, we complete the QR_EC without issuing it to the
1776  * firmware.
1777  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1778  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1779  */
1780 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1781 {
1782         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1783         EC_FLAGS_QUERY_HANDSHAKE = 1;
1784         return 0;
1785 }
1786 #endif
1787
1788 /*
1789  * Some ECDTs contain wrong register addresses.
1790  * MSI MS-171F
1791  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1792  */
1793 static int ec_correct_ecdt(const struct dmi_system_id *id)
1794 {
1795         pr_debug("Detected system needing ECDT address correction.\n");
1796         EC_FLAGS_CORRECT_ECDT = 1;
1797         return 0;
1798 }
1799
1800 /*
1801  * Some DSDTs contain wrong GPE setting.
1802  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1803  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1804  */
1805 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1806 {
1807         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1808         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1809         return 0;
1810 }
1811
1812 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1813         {
1814         ec_correct_ecdt, "MSI MS-171F", {
1815         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1816         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1817         {
1818         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1819         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1820         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1821         {
1822         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1823         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1824         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1825         {
1826         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1827         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1828         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1829         {
1830         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1831         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1832         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1833         {
1834         ec_honor_ecdt_gpe, "ASUS X580VD", {
1835         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1836         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1837         {},
1838 };
1839
1840 int __init acpi_ec_ecdt_probe(void)
1841 {
1842         int ret;
1843         acpi_status status;
1844         struct acpi_table_ecdt *ecdt_ptr;
1845         struct acpi_ec *ec;
1846
1847         ec = acpi_ec_alloc();
1848         if (!ec)
1849                 return -ENOMEM;
1850         /*
1851          * Generate a boot ec context
1852          */
1853         dmi_check_system(ec_dmi_table);
1854         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1855                                 (struct acpi_table_header **)&ecdt_ptr);
1856         if (ACPI_FAILURE(status)) {
1857                 ret = -ENODEV;
1858                 goto error;
1859         }
1860
1861         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1862                 /*
1863                  * Asus X50GL:
1864                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1865                  */
1866                 ret = -ENODEV;
1867                 goto error;
1868         }
1869
1870         if (EC_FLAGS_CORRECT_ECDT) {
1871                 ec->command_addr = ecdt_ptr->data.address;
1872                 ec->data_addr = ecdt_ptr->control.address;
1873         } else {
1874                 ec->command_addr = ecdt_ptr->control.address;
1875                 ec->data_addr = ecdt_ptr->data.address;
1876         }
1877         ec->gpe = ecdt_ptr->gpe;
1878
1879         /*
1880          * At this point, the namespace is not initialized, so do not find
1881          * the namespace objects, or handle the events.
1882          */
1883         ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1884 error:
1885         if (ret)
1886                 acpi_ec_free(ec);
1887         return ret;
1888 }
1889
1890 #ifdef CONFIG_PM_SLEEP
1891 static int acpi_ec_suspend(struct device *dev)
1892 {
1893         struct acpi_ec *ec =
1894                 acpi_driver_data(to_acpi_device(dev));
1895
1896         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1897                 acpi_ec_disable_event(ec);
1898         return 0;
1899 }
1900
1901 static int acpi_ec_suspend_noirq(struct device *dev)
1902 {
1903         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1904
1905         /*
1906          * The SCI handler doesn't run at this point, so the GPE can be
1907          * masked at the low level without side effects.
1908          */
1909         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1910             ec->reference_count >= 1)
1911                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1912
1913         return 0;
1914 }
1915
1916 static int acpi_ec_resume_noirq(struct device *dev)
1917 {
1918         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1919
1920         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1921             ec->reference_count >= 1)
1922                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1923
1924         return 0;
1925 }
1926
1927 static int acpi_ec_resume(struct device *dev)
1928 {
1929         struct acpi_ec *ec =
1930                 acpi_driver_data(to_acpi_device(dev));
1931
1932         acpi_ec_enable_event(ec);
1933         return 0;
1934 }
1935 #endif
1936
1937 static const struct dev_pm_ops acpi_ec_pm = {
1938         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1939         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1940 };
1941
1942 static int param_set_event_clearing(const char *val, struct kernel_param *kp)
1943 {
1944         int result = 0;
1945
1946         if (!strncmp(val, "status", sizeof("status") - 1)) {
1947                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1948                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1949         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1950                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1951                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1952         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1953                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1954                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1955         } else
1956                 result = -EINVAL;
1957         return result;
1958 }
1959
1960 static int param_get_event_clearing(char *buffer, struct kernel_param *kp)
1961 {
1962         switch (ec_event_clearing) {
1963         case ACPI_EC_EVT_TIMING_STATUS:
1964                 return sprintf(buffer, "status");
1965         case ACPI_EC_EVT_TIMING_QUERY:
1966                 return sprintf(buffer, "query");
1967         case ACPI_EC_EVT_TIMING_EVENT:
1968                 return sprintf(buffer, "event");
1969         default:
1970                 return sprintf(buffer, "invalid");
1971         }
1972         return 0;
1973 }
1974
1975 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
1976                   NULL, 0644);
1977 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
1978
1979 static struct acpi_driver acpi_ec_driver = {
1980         .name = "ec",
1981         .class = ACPI_EC_CLASS,
1982         .ids = ec_device_ids,
1983         .ops = {
1984                 .add = acpi_ec_add,
1985                 .remove = acpi_ec_remove,
1986                 },
1987         .drv.pm = &acpi_ec_pm,
1988 };
1989
1990 static inline int acpi_ec_query_init(void)
1991 {
1992         if (!ec_query_wq) {
1993                 ec_query_wq = alloc_workqueue("kec_query", 0,
1994                                               ec_max_queries);
1995                 if (!ec_query_wq)
1996                         return -ENODEV;
1997         }
1998         return 0;
1999 }
2000
2001 static inline void acpi_ec_query_exit(void)
2002 {
2003         if (ec_query_wq) {
2004                 destroy_workqueue(ec_query_wq);
2005                 ec_query_wq = NULL;
2006         }
2007 }
2008
2009 int __init acpi_ec_init(void)
2010 {
2011         int result;
2012         int ecdt_fail, dsdt_fail;
2013
2014         /* register workqueue for _Qxx evaluations */
2015         result = acpi_ec_query_init();
2016         if (result)
2017                 return result;
2018
2019         /* Drivers must be started after acpi_ec_query_init() */
2020         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2021         ecdt_fail = acpi_ec_ecdt_start();
2022         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2023 }
2024
2025 /* EC driver currently not unloadable */
2026 #if 0
2027 static void __exit acpi_ec_exit(void)
2028 {
2029
2030         acpi_bus_unregister_driver(&acpi_ec_driver);
2031         acpi_ec_query_exit();
2032 }
2033 #endif  /* 0 */