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         /*
 490          * Unconditionally invoke this once after enabling the event
 491          * handling mechanism to detect the pending events.
 492          */
 493         advance_transaction(ec);
 494 }
 495
 496 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 497 {
 498         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 499                 ec_log_drv("event blocked");
 500 }
 501
 502 static void acpi_ec_enable_event(struct acpi_ec *ec)
 503 {
 504         unsigned long flags;
 505
 506         spin_lock_irqsave(&ec->lock, flags);
 507         if (acpi_ec_started(ec))
 508                 __acpi_ec_enable_event(ec);
 509         spin_unlock_irqrestore(&ec->lock, flags);
 510 }
 511
 512 #ifdef CONFIG_PM_SLEEP
 513 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
 514 {
 515         bool flushed;
 516         unsigned long flags;
 517
 518         spin_lock_irqsave(&ec->lock, flags);
 519         flushed = !ec->nr_pending_queries;
 520         spin_unlock_irqrestore(&ec->lock, flags);
 521         return flushed;
 522 }
 523
 524 static void __acpi_ec_flush_event(struct acpi_ec *ec)
 525 {
 526         /*
 527          * When ec_freeze_events is true, we need to flush events in
 528          * the proper position before entering the noirq stage.
 529          */
 530         wait_event(ec->wait, acpi_ec_query_flushed(ec));
 531         if (ec_query_wq)
 532                 flush_workqueue(ec_query_wq);
 533 }
 534
 535 static void acpi_ec_disable_event(struct acpi_ec *ec)
 536 {
 537         unsigned long flags;
 538
 539         spin_lock_irqsave(&ec->lock, flags);
 540         __acpi_ec_disable_event(ec);
 541         spin_unlock_irqrestore(&ec->lock, flags);
 542         __acpi_ec_flush_event(ec);
 543 }
 544
 545 void acpi_ec_flush_work(void)
 546 {
 547         if (first_ec)
 548                 __acpi_ec_flush_event(first_ec);
 549
 550         flush_scheduled_work();
 551 }
 552 #endif /* CONFIG_PM_SLEEP */
 553
 554 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 555 {
 556         bool guarded = true;
 557         unsigned long flags;
 558
 559         spin_lock_irqsave(&ec->lock, flags);
 560         /*
 561          * If firmware SCI_EVT clearing timing is "event", we actually
 562          * don't know when the SCI_EVT will be cleared by firmware after
 563          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 564          * acceptable period.
 565          *
 566          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 567          * flagged, which means SCI_EVT check has just been performed.
 568          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 569          * guarding should have already been performed (via
 570          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 571          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 572          * ACPI_EC_COMMAND_POLL state immediately.
 573          */
 574         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 575             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 576             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 577             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 578                 guarded = false;
 579         spin_unlock_irqrestore(&ec->lock, flags);
 580         return guarded;
 581 }
 582
 583 static int ec_transaction_polled(struct acpi_ec *ec)
 584 {
 585         unsigned long flags;
 586         int ret = 0;
 587
 588         spin_lock_irqsave(&ec->lock, flags);
 589         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 590                 ret = 1;
 591         spin_unlock_irqrestore(&ec->lock, flags);
 592         return ret;
 593 }
 594
 595 static int ec_transaction_completed(struct acpi_ec *ec)
 596 {
 597         unsigned long flags;
 598         int ret = 0;
 599
 600         spin_lock_irqsave(&ec->lock, flags);
 601         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 602                 ret = 1;
 603         spin_unlock_irqrestore(&ec->lock, flags);
 604         return ret;
 605 }
 606
 607 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 608 {
 609         ec->curr->flags |= flag;
 610         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 611                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 612                     flag == ACPI_EC_COMMAND_POLL)
 613                         acpi_ec_complete_query(ec);
 614                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 615                     flag == ACPI_EC_COMMAND_COMPLETE)
 616                         acpi_ec_complete_query(ec);
 617                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 618                     flag == ACPI_EC_COMMAND_COMPLETE)
 619                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 620         }
 621 }
 622
 623 static void advance_transaction(struct acpi_ec *ec)
 624 {
 625         struct transaction *t;
 626         u8 status;
 627         bool wakeup = false;
 628
 629         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 630                    smp_processor_id());
 631         /*
 632          * By always clearing STS before handling all indications, we can
 633          * ensure a hardware STS 0->1 change after this clearing can always
 634          * trigger a GPE interrupt.
 635          */
 636         acpi_ec_clear_gpe(ec);
 637         status = acpi_ec_read_status(ec);
 638         t = ec->curr;
 639         /*
 640          * Another IRQ or a guarded polling mode advancement is detected,
 641          * the next QR_EC submission is then allowed.
 642          */
 643         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 644                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 645                     (!ec->nr_pending_queries ||
 646                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 647                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 648                         acpi_ec_complete_query(ec);
 649                 }
 650         }
 651         if (!t)
 652                 goto err;
 653         if (t->flags & ACPI_EC_COMMAND_POLL) {
 654                 if (t->wlen > t->wi) {
 655                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 656                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 657                         else
 658                                 goto err;
 659                 } else if (t->rlen > t->ri) {
 660                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 661                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 662                                 if (t->rlen == t->ri) {
 663                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 664                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 665                                                 ec_dbg_evt("Command(%s) completed by hardware",
 666                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 667                                         wakeup = true;
 668                                 }
 669                         } else
 670                                 goto err;
 671                 } else if (t->wlen == t->wi &&
 672                            (status & ACPI_EC_FLAG_IBF) == 0) {
 673                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 674                         wakeup = true;
 675                 }
 676                 goto out;
 677         } else {
 678                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 679                     !(status & ACPI_EC_FLAG_SCI) &&
 680                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 681                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 682                         t->rdata[t->ri++] = 0x00;
 683                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 684                         ec_dbg_evt("Command(%s) completed by software",
 685                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 686                         wakeup = true;
 687                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 688                         acpi_ec_write_cmd(ec, t->command);
 689                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 690                 } else
 691                         goto err;
 692                 goto out;
 693         }
 694 err:
 695         /*
 696          * If SCI bit is set, then don't think it's a false IRQ
 697          * otherwise will take a not handled IRQ as a false one.
 698          */
 699         if (!(status & ACPI_EC_FLAG_SCI)) {
 700                 if (in_interrupt() && t) {
 701                         if (t->irq_count < ec_storm_threshold)
 702                                 ++t->irq_count;
 703                         /* Allow triggering on 0 threshold */
 704                         if (t->irq_count == ec_storm_threshold)
 705                                 acpi_ec_mask_gpe(ec);
 706                 }
 707         }
 708 out:
 709         if (status & ACPI_EC_FLAG_SCI)
 710                 acpi_ec_submit_query(ec);
 711         if (wakeup && in_interrupt())
 712                 wake_up(&ec->wait);
 713 }
 714
 715 static void start_transaction(struct acpi_ec *ec)
 716 {
 717         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 718         ec->curr->flags = 0;
 719 }
 720
 721 static int ec_guard(struct acpi_ec *ec)
 722 {
 723         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 724         unsigned long timeout = ec->timestamp + guard;
 725
 726         /* Ensure guarding period before polling EC status */
 727         do {
 728                 if (ec->busy_polling) {
 729                         /* Perform busy polling */
 730                         if (ec_transaction_completed(ec))
 731                                 return 0;
 732                         udelay(jiffies_to_usecs(guard));
 733                 } else {
 734                         /*
 735                          * Perform wait polling
 736                          * 1. Wait the transaction to be completed by the
 737                          *    GPE handler after the transaction enters
 738                          *    ACPI_EC_COMMAND_POLL state.
 739                          * 2. A special guarding logic is also required
 740                          *    for event clearing mode "event" before the
 741                          *    transaction enters ACPI_EC_COMMAND_POLL
 742                          *    state.
 743                          */
 744                         if (!ec_transaction_polled(ec) &&
 745                             !acpi_ec_guard_event(ec))
 746                                 break;
 747                         if (wait_event_timeout(ec->wait,
 748                                                ec_transaction_completed(ec),
 749                                                guard))
 750                                 return 0;
 751                 }
 752         } while (time_before(jiffies, timeout));
 753         return -ETIME;
 754 }
 755
 756 static int ec_poll(struct acpi_ec *ec)
 757 {
 758         unsigned long flags;
 759         int repeat = 5; /* number of command restarts */
 760
 761         while (repeat--) {
 762                 unsigned long delay = jiffies +
 763                         msecs_to_jiffies(ec_delay);
 764                 do {
 765                         if (!ec_guard(ec))
 766                                 return 0;
 767                         spin_lock_irqsave(&ec->lock, flags);
 768                         advance_transaction(ec);
 769                         spin_unlock_irqrestore(&ec->lock, flags);
 770                 } while (time_before(jiffies, delay));
 771                 pr_debug("controller reset, restart transaction\n");
 772                 spin_lock_irqsave(&ec->lock, flags);
 773                 start_transaction(ec);
 774                 spin_unlock_irqrestore(&ec->lock, flags);
 775         }
 776         return -ETIME;
 777 }
 778
 779 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 780                                         struct transaction *t)
 781 {
 782         unsigned long tmp;
 783         int ret = 0;
 784
 785         /* start transaction */
 786         spin_lock_irqsave(&ec->lock, tmp);
 787         /* Enable GPE for command processing (IBF=0/OBF=1) */
 788         if (!acpi_ec_submit_flushable_request(ec)) {
 789                 ret = -EINVAL;
 790                 goto unlock;
 791         }
 792         ec_dbg_ref(ec, "Increase command");
 793         /* following two actions should be kept atomic */
 794         ec->curr = t;
 795         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 796         start_transaction(ec);
 797         spin_unlock_irqrestore(&ec->lock, tmp);
 798
 799         ret = ec_poll(ec);
 800
 801         spin_lock_irqsave(&ec->lock, tmp);
 802         if (t->irq_count == ec_storm_threshold)
 803                 acpi_ec_unmask_gpe(ec);
 804         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 805         ec->curr = NULL;
 806         /* Disable GPE for command processing (IBF=0/OBF=1) */
 807         acpi_ec_complete_request(ec);
 808         ec_dbg_ref(ec, "Decrease command");
 809 unlock:
 810         spin_unlock_irqrestore(&ec->lock, tmp);
 811         return ret;
 812 }
 813
 814 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 815 {
 816         int status;
 817         u32 glk;
 818
 819         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 820                 return -EINVAL;
 821         if (t->rdata)
 822                 memset(t->rdata, 0, t->rlen);
 823
 824         mutex_lock(&ec->mutex);
 825         if (ec->global_lock) {
 826                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 827                 if (ACPI_FAILURE(status)) {
 828                         status = -ENODEV;
 829                         goto unlock;
 830                 }
 831         }
 832
 833         status = acpi_ec_transaction_unlocked(ec, t);
 834
 835         if (ec->global_lock)
 836                 acpi_release_global_lock(glk);
 837 unlock:
 838         mutex_unlock(&ec->mutex);
 839         return status;
 840 }
 841
 842 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 843 {
 844         u8 d;
 845         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 846                                 .wdata = NULL, .rdata = &d,
 847                                 .wlen = 0, .rlen = 1};
 848
 849         return acpi_ec_transaction(ec, &t);
 850 }
 851
 852 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 853 {
 854         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 855                                 .wdata = NULL, .rdata = NULL,
 856                                 .wlen = 0, .rlen = 0};
 857
 858         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 859                                 acpi_ec_transaction(ec, &t) : 0;
 860 }
 861
 862 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 863 {
 864         int result;
 865         u8 d;
 866         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 867                                 .wdata = &address, .rdata = &d,
 868                                 .wlen = 1, .rlen = 1};
 869
 870         result = acpi_ec_transaction(ec, &t);
 871         *data = d;
 872         return result;
 873 }
 874
 875 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 876 {
 877         u8 wdata[2] = { address, data };
 878         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 879                                 .wdata = wdata, .rdata = NULL,
 880                                 .wlen = 2, .rlen = 0};
 881
 882         return acpi_ec_transaction(ec, &t);
 883 }
 884
 885 int ec_read(u8 addr, u8 *val)
 886 {
 887         int err;
 888         u8 temp_data;
 889
 890         if (!first_ec)
 891                 return -ENODEV;
 892
 893         err = acpi_ec_read(first_ec, addr, &temp_data);
 894
 895         if (!err) {
 896                 *val = temp_data;
 897                 return 0;
 898         }
 899         return err;
 900 }
 901 EXPORT_SYMBOL(ec_read);
 902
 903 int ec_write(u8 addr, u8 val)
 904 {
 905         int err;
 906
 907         if (!first_ec)
 908                 return -ENODEV;
 909
 910         err = acpi_ec_write(first_ec, addr, val);
 911
 912         return err;
 913 }
 914 EXPORT_SYMBOL(ec_write);
 915
 916 int ec_transaction(u8 command,
 917                    const u8 *wdata, unsigned wdata_len,
 918                    u8 *rdata, unsigned rdata_len)
 919 {
 920         struct transaction t = {.command = command,
 921                                 .wdata = wdata, .rdata = rdata,
 922                                 .wlen = wdata_len, .rlen = rdata_len};
 923
 924         if (!first_ec)
 925                 return -ENODEV;
 926
 927         return acpi_ec_transaction(first_ec, &t);
 928 }
 929 EXPORT_SYMBOL(ec_transaction);
 930
 931 /* Get the handle to the EC device */
 932 acpi_handle ec_get_handle(void)
 933 {
 934         if (!first_ec)
 935                 return NULL;
 936         return first_ec->handle;
 937 }
 938 EXPORT_SYMBOL(ec_get_handle);
 939
 940 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 941 {
 942         unsigned long flags;
 943
 944         spin_lock_irqsave(&ec->lock, flags);
 945         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 946                 ec_dbg_drv("Starting EC");
 947                 /* Enable GPE for event processing (SCI_EVT=1) */
 948                 if (!resuming) {
 949                         acpi_ec_submit_request(ec);
 950                         ec_dbg_ref(ec, "Increase driver");
 951                 }
 952                 ec_log_drv("EC started");
 953         }
 954         spin_unlock_irqrestore(&ec->lock, flags);
 955 }
 956
 957 static bool acpi_ec_stopped(struct acpi_ec *ec)
 958 {
 959         unsigned long flags;
 960         bool flushed;
 961
 962         spin_lock_irqsave(&ec->lock, flags);
 963         flushed = acpi_ec_flushed(ec);
 964         spin_unlock_irqrestore(&ec->lock, flags);
 965         return flushed;
 966 }
 967
 968 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 969 {
 970         unsigned long flags;
 971
 972         spin_lock_irqsave(&ec->lock, flags);
 973         if (acpi_ec_started(ec)) {
 974                 ec_dbg_drv("Stopping EC");
 975                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 976                 spin_unlock_irqrestore(&ec->lock, flags);
 977                 wait_event(ec->wait, acpi_ec_stopped(ec));
 978                 spin_lock_irqsave(&ec->lock, flags);
 979                 /* Disable GPE for event processing (SCI_EVT=1) */
 980                 if (!suspending) {
 981                         acpi_ec_complete_request(ec);
 982                         ec_dbg_ref(ec, "Decrease driver");
 983                 } else if (!ec_freeze_events)
 984                         __acpi_ec_disable_event(ec);
 985                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 986                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 987                 ec_log_drv("EC stopped");
 988         }
 989         spin_unlock_irqrestore(&ec->lock, flags);
 990 }
 991
 992 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 993 {
 994         unsigned long flags;
 995
 996         spin_lock_irqsave(&ec->lock, flags);
 997         ec->busy_polling = true;
 998         ec->polling_guard = 0;
 999         ec_log_drv("interrupt blocked");
1000         spin_unlock_irqrestore(&ec->lock, flags);
1001 }
1002
1003 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1004 {
1005         unsigned long flags;
1006
1007         spin_lock_irqsave(&ec->lock, flags);
1008         ec->busy_polling = ec_busy_polling;
1009         ec->polling_guard = ec_polling_guard;
1010         ec_log_drv("interrupt unblocked");
1011         spin_unlock_irqrestore(&ec->lock, flags);
1012 }
1013
1014 void acpi_ec_block_transactions(void)
1015 {
1016         struct acpi_ec *ec = first_ec;
1017
1018         if (!ec)
1019                 return;
1020
1021         mutex_lock(&ec->mutex);
1022         /* Prevent transactions from being carried out */
1023         acpi_ec_stop(ec, true);
1024         mutex_unlock(&ec->mutex);
1025 }
1026
1027 void acpi_ec_unblock_transactions(void)
1028 {
1029         /*
1030          * Allow transactions to happen again (this function is called from
1031          * atomic context during wakeup, so we don't need to acquire the mutex).
1032          */
1033         if (first_ec)
1034                 acpi_ec_start(first_ec, true);
1035 }
1036
1037 void acpi_ec_dispatch_gpe(void)
1038 {
1039         if (first_ec)
1040                 acpi_dispatch_gpe(NULL, first_ec->gpe);
1041 }
1042
1043 /* --------------------------------------------------------------------------
1044                                 Event Management
1045    -------------------------------------------------------------------------- */
1046 static struct acpi_ec_query_handler *
1047 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1048 {
1049         if (handler)
1050                 kref_get(&handler->kref);
1051         return handler;
1052 }
1053
1054 static struct acpi_ec_query_handler *
1055 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1056 {
1057         struct acpi_ec_query_handler *handler;
1058         bool found = false;
1059
1060         mutex_lock(&ec->mutex);
1061         list_for_each_entry(handler, &ec->list, node) {
1062                 if (value == handler->query_bit) {
1063                         found = true;
1064                         break;
1065                 }
1066         }
1067         mutex_unlock(&ec->mutex);
1068         return found ? acpi_ec_get_query_handler(handler) : NULL;
1069 }
1070
1071 static void acpi_ec_query_handler_release(struct kref *kref)
1072 {
1073         struct acpi_ec_query_handler *handler =
1074                 container_of(kref, struct acpi_ec_query_handler, kref);
1075
1076         kfree(handler);
1077 }
1078
1079 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1080 {
1081         kref_put(&handler->kref, acpi_ec_query_handler_release);
1082 }
1083
1084 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1085                               acpi_handle handle, acpi_ec_query_func func,
1086                               void *data)
1087 {
1088         struct acpi_ec_query_handler *handler =
1089             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1090
1091         if (!handler)
1092                 return -ENOMEM;
1093
1094         handler->query_bit = query_bit;
1095         handler->handle = handle;
1096         handler->func = func;
1097         handler->data = data;
1098         mutex_lock(&ec->mutex);
1099         kref_init(&handler->kref);
1100         list_add(&handler->node, &ec->list);
1101         mutex_unlock(&ec->mutex);
1102         return 0;
1103 }
1104 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1105
1106 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1107                                           bool remove_all, u8 query_bit)
1108 {
1109         struct acpi_ec_query_handler *handler, *tmp;
1110         LIST_HEAD(free_list);
1111
1112         mutex_lock(&ec->mutex);
1113         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1114                 if (remove_all || query_bit == handler->query_bit) {
1115                         list_del_init(&handler->node);
1116                         list_add(&handler->node, &free_list);
1117                 }
1118         }
1119         mutex_unlock(&ec->mutex);
1120         list_for_each_entry_safe(handler, tmp, &free_list, node)
1121                 acpi_ec_put_query_handler(handler);
1122 }
1123
1124 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1125 {
1126         acpi_ec_remove_query_handlers(ec, false, query_bit);
1127 }
1128 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1129
1130 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1131 {
1132         struct acpi_ec_query *q;
1133         struct transaction *t;
1134
1135         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1136         if (!q)
1137                 return NULL;
1138         INIT_WORK(&q->work, acpi_ec_event_processor);
1139         t = &q->transaction;
1140         t->command = ACPI_EC_COMMAND_QUERY;
1141         t->rdata = pval;
1142         t->rlen = 1;
1143         return q;
1144 }
1145
1146 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1147 {
1148         if (q) {
1149                 if (q->handler)
1150                         acpi_ec_put_query_handler(q->handler);
1151                 kfree(q);
1152         }
1153 }
1154
1155 static void acpi_ec_event_processor(struct work_struct *work)
1156 {
1157         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1158         struct acpi_ec_query_handler *handler = q->handler;
1159
1160         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1161         if (handler->func)
1162                 handler->func(handler->data);
1163         else if (handler->handle)
1164                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1165         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1166         acpi_ec_delete_query(q);
1167 }
1168
1169 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1170 {
1171         u8 value = 0;
1172         int result;
1173         struct acpi_ec_query *q;
1174
1175         q = acpi_ec_create_query(&value);
1176         if (!q)
1177                 return -ENOMEM;
1178
1179         /*
1180          * Query the EC to find out which _Qxx method we need to evaluate.
1181          * Note that successful completion of the query causes the ACPI_EC_SCI
1182          * bit to be cleared (and thus clearing the interrupt source).
1183          */
1184         result = acpi_ec_transaction(ec, &q->transaction);
1185         if (!value)
1186                 result = -ENODATA;
1187         if (result)
1188                 goto err_exit;
1189
1190         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1191         if (!q->handler) {
1192                 result = -ENODATA;
1193                 goto err_exit;
1194         }
1195
1196         /*
1197          * It is reported that _Qxx are evaluated in a parallel way on
1198          * Windows:
1199          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1200          *
1201          * Put this log entry before schedule_work() in order to make
1202          * it appearing before any other log entries occurred during the
1203          * work queue execution.
1204          */
1205         ec_dbg_evt("Query(0x%02x) scheduled", value);
1206         if (!queue_work(ec_query_wq, &q->work)) {
1207                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1208                 result = -EBUSY;
1209         }
1210
1211 err_exit:
1212         if (result)
1213                 acpi_ec_delete_query(q);
1214         if (data)
1215                 *data = value;
1216         return result;
1217 }
1218
1219 static void acpi_ec_check_event(struct acpi_ec *ec)
1220 {
1221         unsigned long flags;
1222
1223         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1224                 if (ec_guard(ec)) {
1225                         spin_lock_irqsave(&ec->lock, flags);
1226                         /*
1227                          * Take care of the SCI_EVT unless no one else is
1228                          * taking care of it.
1229                          */
1230                         if (!ec->curr)
1231                                 advance_transaction(ec);
1232                         spin_unlock_irqrestore(&ec->lock, flags);
1233                 }
1234         }
1235 }
1236
1237 static void acpi_ec_event_handler(struct work_struct *work)
1238 {
1239         unsigned long flags;
1240         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1241
1242         ec_dbg_evt("Event started");
1243
1244         spin_lock_irqsave(&ec->lock, flags);
1245         while (ec->nr_pending_queries) {
1246                 spin_unlock_irqrestore(&ec->lock, flags);
1247                 (void)acpi_ec_query(ec, NULL);
1248                 spin_lock_irqsave(&ec->lock, flags);
1249                 ec->nr_pending_queries--;
1250                 /*
1251                  * Before exit, make sure that this work item can be
1252                  * scheduled again. There might be QR_EC failures, leaving
1253                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1254                  * item from being scheduled again.
1255                  */
1256                 if (!ec->nr_pending_queries) {
1257                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1258                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1259                                 acpi_ec_complete_query(ec);
1260                 }
1261         }
1262         spin_unlock_irqrestore(&ec->lock, flags);
1263
1264         ec_dbg_evt("Event stopped");
1265
1266         acpi_ec_check_event(ec);
1267 }
1268
1269 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1270         u32 gpe_number, void *data)
1271 {
1272         unsigned long flags;
1273         struct acpi_ec *ec = data;
1274
1275         spin_lock_irqsave(&ec->lock, flags);
1276         advance_transaction(ec);
1277         spin_unlock_irqrestore(&ec->lock, flags);
1278         return ACPI_INTERRUPT_HANDLED;
1279 }
1280
1281 /* --------------------------------------------------------------------------
1282  *                           Address Space Management
1283  * -------------------------------------------------------------------------- */
1284
1285 static acpi_status
1286 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1287                       u32 bits, u64 *value64,
1288                       void *handler_context, void *region_context)
1289 {
1290         struct acpi_ec *ec = handler_context;
1291         int result = 0, i, bytes = bits / 8;
1292         u8 *value = (u8 *)value64;
1293
1294         if ((address > 0xFF) || !value || !handler_context)
1295                 return AE_BAD_PARAMETER;
1296
1297         if (function != ACPI_READ && function != ACPI_WRITE)
1298                 return AE_BAD_PARAMETER;
1299
1300         if (ec->busy_polling || bits > 8)
1301                 acpi_ec_burst_enable(ec);
1302
1303         for (i = 0; i < bytes; ++i, ++address, ++value)
1304                 result = (function == ACPI_READ) ?
1305                         acpi_ec_read(ec, address, value) :
1306                         acpi_ec_write(ec, address, *value);
1307
1308         if (ec->busy_polling || bits > 8)
1309                 acpi_ec_burst_disable(ec);
1310
1311         switch (result) {
1312         case -EINVAL:
1313                 return AE_BAD_PARAMETER;
1314         case -ENODEV:
1315                 return AE_NOT_FOUND;
1316         case -ETIME:
1317                 return AE_TIME;
1318         default:
1319                 return AE_OK;
1320         }
1321 }
1322
1323 /* --------------------------------------------------------------------------
1324  *                             Driver Interface
1325  * -------------------------------------------------------------------------- */
1326
1327 static acpi_status
1328 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1329
1330 static void acpi_ec_free(struct acpi_ec *ec)
1331 {
1332         if (first_ec == ec)
1333                 first_ec = NULL;
1334         if (boot_ec == ec)
1335                 boot_ec = NULL;
1336         kfree(ec);
1337 }
1338
1339 static struct acpi_ec *acpi_ec_alloc(void)
1340 {
1341         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1342
1343         if (!ec)
1344                 return NULL;
1345         mutex_init(&ec->mutex);
1346         init_waitqueue_head(&ec->wait);
1347         INIT_LIST_HEAD(&ec->list);
1348         spin_lock_init(&ec->lock);
1349         INIT_WORK(&ec->work, acpi_ec_event_handler);
1350         ec->timestamp = jiffies;
1351         ec->busy_polling = true;
1352         ec->polling_guard = 0;
1353         return ec;
1354 }
1355
1356 static acpi_status
1357 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1358                                void *context, void **return_value)
1359 {
1360         char node_name[5];
1361         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1362         struct acpi_ec *ec = context;
1363         int value = 0;
1364         acpi_status status;
1365
1366         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1367
1368         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1369                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1370         return AE_OK;
1371 }
1372
1373 static acpi_status
1374 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1375 {
1376         acpi_status status;
1377         unsigned long long tmp = 0;
1378         struct acpi_ec *ec = context;
1379
1380         /* clear addr values, ec_parse_io_ports depend on it */
1381         ec->command_addr = ec->data_addr = 0;
1382
1383         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1384                                      ec_parse_io_ports, ec);
1385         if (ACPI_FAILURE(status))
1386                 return status;
1387         if (ec->data_addr == 0 || ec->command_addr == 0)
1388                 return AE_OK;
1389
1390         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1391                 /*
1392                  * Always inherit the GPE number setting from the ECDT
1393                  * EC.
1394                  */
1395                 ec->gpe = boot_ec->gpe;
1396         } else {
1397                 /* Get GPE bit assignment (EC events). */
1398                 /* TODO: Add support for _GPE returning a package */
1399                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1400                 if (ACPI_FAILURE(status))
1401                         return status;
1402                 ec->gpe = tmp;
1403         }
1404         /* Use the global lock for all EC transactions? */
1405         tmp = 0;
1406         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1407         ec->global_lock = tmp;
1408         ec->handle = handle;
1409         return AE_CTRL_TERMINATE;
1410 }
1411
1412 /*
1413  * Note: This function returns an error code only when the address space
1414  *       handler is not installed, which means "not able to handle
1415  *       transactions".
1416  */
1417 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1418 {
1419         acpi_status status;
1420
1421         acpi_ec_start(ec, false);
1422
1423         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1424                 acpi_ec_enter_noirq(ec);
1425                 status = acpi_install_address_space_handler(ec->handle,
1426                                                             ACPI_ADR_SPACE_EC,
1427                                                             &acpi_ec_space_handler,
1428                                                             NULL, ec);
1429                 if (ACPI_FAILURE(status)) {
1430                         if (status == AE_NOT_FOUND) {
1431                                 /*
1432                                  * Maybe OS fails in evaluating the _REG
1433                                  * object. The AE_NOT_FOUND error will be
1434                                  * ignored and OS * continue to initialize
1435                                  * EC.
1436                                  */
1437                                 pr_err("Fail in evaluating the _REG object"
1438                                         " of EC device. Broken bios is suspected.\n");
1439                         } else {
1440                                 acpi_ec_stop(ec, false);
1441                                 return -ENODEV;
1442                         }
1443                 }
1444                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1445         }
1446
1447         if (!handle_events)
1448                 return 0;
1449
1450         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1451                 /* Find and register all query methods */
1452                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1453                                     acpi_ec_register_query_methods,
1454                                     NULL, ec, NULL);
1455                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1456         }
1457         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1458                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1459                                           ACPI_GPE_EDGE_TRIGGERED,
1460                                           &acpi_ec_gpe_handler, ec);
1461                 /* This is not fatal as we can poll EC events */
1462                 if (ACPI_SUCCESS(status)) {
1463                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1464                         acpi_ec_leave_noirq(ec);
1465                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1466                             ec->reference_count >= 1)
1467                                 acpi_ec_enable_gpe(ec, true);
1468                 }
1469         }
1470         /* EC is fully operational, allow queries */
1471         acpi_ec_enable_event(ec);
1472
1473         return 0;
1474 }
1475
1476 static void ec_remove_handlers(struct acpi_ec *ec)
1477 {
1478         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1479                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1480                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1481                         pr_err("failed to remove space handler\n");
1482                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1483         }
1484
1485         /*
1486          * Stops handling the EC transactions after removing the operation
1487          * region handler. This is required because _REG(DISCONNECT)
1488          * invoked during the removal can result in new EC transactions.
1489          *
1490          * Flushes the EC requests and thus disables the GPE before
1491          * removing the GPE handler. This is required by the current ACPICA
1492          * GPE core. ACPICA GPE core will automatically disable a GPE when
1493          * it is indicated but there is no way to handle it. So the drivers
1494          * must disable the GPEs prior to removing the GPE handlers.
1495          */
1496         acpi_ec_stop(ec, false);
1497
1498         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1499                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1500                                         &acpi_ec_gpe_handler)))
1501                         pr_err("failed to remove gpe handler\n");
1502                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1503         }
1504         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1505                 acpi_ec_remove_query_handlers(ec, true, 0);
1506                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1507         }
1508 }
1509
1510 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1511 {
1512         int ret;
1513
1514         ret = ec_install_handlers(ec, handle_events);
1515         if (ret)
1516                 return ret;
1517
1518         /* First EC capable of handling transactions */
1519         if (!first_ec) {
1520                 first_ec = ec;
1521                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1522         }
1523
1524         acpi_handle_info(ec->handle,
1525                          "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1526                          ec->gpe, ec->command_addr, ec->data_addr);
1527         return ret;
1528 }
1529
1530 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1531                                bool handle_events, bool is_ecdt)
1532 {
1533         int ret;
1534
1535         /*
1536          * Changing the ACPI handle results in a re-configuration of the
1537          * boot EC. And if it happens after the namespace initialization,
1538          * it causes _REG evaluations.
1539          */
1540         if (boot_ec && boot_ec->handle != handle)
1541                 ec_remove_handlers(boot_ec);
1542
1543         /* Unset old boot EC */
1544         if (boot_ec != ec)
1545                 acpi_ec_free(boot_ec);
1546
1547         /*
1548          * ECDT device creation is split into acpi_ec_ecdt_probe() and
1549          * acpi_ec_ecdt_start(). This function takes care of completing the
1550          * ECDT parsing logic as the handle update should be performed
1551          * between the installation/uninstallation of the handlers.
1552          */
1553         if (ec->handle != handle)
1554                 ec->handle = handle;
1555
1556         ret = acpi_ec_setup(ec, handle_events);
1557         if (ret)
1558                 return ret;
1559
1560         /* Set new boot EC */
1561         if (!boot_ec) {
1562                 boot_ec = ec;
1563                 boot_ec_is_ecdt = is_ecdt;
1564         }
1565
1566         acpi_handle_info(boot_ec->handle,
1567                          "Used as boot %s EC to handle transactions%s\n",
1568                          is_ecdt ? "ECDT" : "DSDT",
1569                          handle_events ? " and events" : "");
1570         return ret;
1571 }
1572
1573 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1574 {
1575         struct acpi_table_ecdt *ecdt_ptr;
1576         acpi_status status;
1577         acpi_handle handle;
1578
1579         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1580                                 (struct acpi_table_header **)&ecdt_ptr);
1581         if (ACPI_FAILURE(status))
1582                 return false;
1583
1584         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1585         if (ACPI_FAILURE(status))
1586                 return false;
1587
1588         *phandle = handle;
1589         return true;
1590 }
1591
1592 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1593 {
1594         if (!boot_ec)
1595                 return false;
1596         if (ec->command_addr == boot_ec->command_addr &&
1597             ec->data_addr == boot_ec->data_addr)
1598                 return true;
1599         return false;
1600 }
1601
1602 static int acpi_ec_add(struct acpi_device *device)
1603 {
1604         struct acpi_ec *ec = NULL;
1605         int ret;
1606         bool is_ecdt = false;
1607         acpi_status status;
1608
1609         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1610         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1611
1612         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1613                 is_ecdt = true;
1614                 ec = boot_ec;
1615         } else {
1616                 ec = acpi_ec_alloc();
1617                 if (!ec)
1618                         return -ENOMEM;
1619                 status = ec_parse_device(device->handle, 0, ec, NULL);
1620                 if (status != AE_CTRL_TERMINATE) {
1621                         ret = -EINVAL;
1622                         goto err_alloc;
1623                 }
1624         }
1625
1626         if (acpi_is_boot_ec(ec)) {
1627                 boot_ec_is_ecdt = is_ecdt;
1628                 if (!is_ecdt) {
1629                         /*
1630                          * Trust PNP0C09 namespace location rather than
1631                          * ECDT ID. But trust ECDT GPE rather than _GPE
1632                          * because of ASUS quirks, so do not change
1633                          * boot_ec->gpe to ec->gpe.
1634                          */
1635                         boot_ec->handle = ec->handle;
1636                         acpi_handle_debug(ec->handle, "duplicated.\n");
1637                         acpi_ec_free(ec);
1638                         ec = boot_ec;
1639                 }
1640                 ret = acpi_config_boot_ec(ec, ec->handle, true, is_ecdt);
1641         } else
1642                 ret = acpi_ec_setup(ec, true);
1643         if (ret)
1644                 goto err_query;
1645
1646         device->driver_data = ec;
1647
1648         ret = !!request_region(ec->data_addr, 1, "EC data");
1649         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1650         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1651         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1652
1653         if (!is_ecdt) {
1654                 /* Reprobe devices depending on the EC */
1655                 acpi_walk_dep_device_list(ec->handle);
1656         }
1657         acpi_handle_debug(ec->handle, "enumerated.\n");
1658         return 0;
1659
1660 err_query:
1661         if (ec != boot_ec)
1662                 acpi_ec_remove_query_handlers(ec, true, 0);
1663 err_alloc:
1664         if (ec != boot_ec)
1665                 acpi_ec_free(ec);
1666         return ret;
1667 }
1668
1669 static int acpi_ec_remove(struct acpi_device *device)
1670 {
1671         struct acpi_ec *ec;
1672
1673         if (!device)
1674                 return -EINVAL;
1675
1676         ec = acpi_driver_data(device);
1677         release_region(ec->data_addr, 1);
1678         release_region(ec->command_addr, 1);
1679         device->driver_data = NULL;
1680         if (ec != boot_ec) {
1681                 ec_remove_handlers(ec);
1682                 acpi_ec_free(ec);
1683         }
1684         return 0;
1685 }
1686
1687 static acpi_status
1688 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1689 {
1690         struct acpi_ec *ec = context;
1691
1692         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1693                 return AE_OK;
1694
1695         /*
1696          * The first address region returned is the data port, and
1697          * the second address region returned is the status/command
1698          * port.
1699          */
1700         if (ec->data_addr == 0)
1701                 ec->data_addr = resource->data.io.minimum;
1702         else if (ec->command_addr == 0)
1703                 ec->command_addr = resource->data.io.minimum;
1704         else
1705                 return AE_CTRL_TERMINATE;
1706
1707         return AE_OK;
1708 }
1709
1710 static const struct acpi_device_id ec_device_ids[] = {
1711         {"PNP0C09", 0},
1712         {ACPI_ECDT_HID, 0},
1713         {"", 0},
1714 };
1715
1716 /*
1717  * This function is not Windows-compatible as Windows never enumerates the
1718  * namespace EC before the main ACPI device enumeration process. It is
1719  * retained for historical reason and will be deprecated in the future.
1720  */
1721 int __init acpi_ec_dsdt_probe(void)
1722 {
1723         acpi_status status;
1724         struct acpi_ec *ec;
1725         int ret;
1726
1727         /*
1728          * If a platform has ECDT, there is no need to proceed as the
1729          * following probe is not a part of the ACPI device enumeration,
1730          * executing _STA is not safe, and thus this probe may risk of
1731          * picking up an invalid EC device.
1732          */
1733         if (boot_ec)
1734                 return -ENODEV;
1735
1736         ec = acpi_ec_alloc();
1737         if (!ec)
1738                 return -ENOMEM;
1739         /*
1740          * At this point, the namespace is initialized, so start to find
1741          * the namespace objects.
1742          */
1743         status = acpi_get_devices(ec_device_ids[0].id,
1744                                   ec_parse_device, ec, NULL);
1745         if (ACPI_FAILURE(status) || !ec->handle) {
1746                 ret = -ENODEV;
1747                 goto error;
1748         }
1749         /*
1750          * When the DSDT EC is available, always re-configure boot EC to
1751          * have _REG evaluated. _REG can only be evaluated after the
1752          * namespace initialization.
1753          * At this point, the GPE is not fully initialized, so do not to
1754          * handle the events.
1755          */
1756         ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1757 error:
1758         if (ret)
1759                 acpi_ec_free(ec);
1760         return ret;
1761 }
1762
1763 /*
1764  * If the DSDT EC is not functioning, we still need to prepare a fully
1765  * functioning ECDT EC first in order to handle the events.
1766  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1767  */
1768 static int __init acpi_ec_ecdt_start(void)
1769 {
1770         acpi_handle handle;
1771
1772         if (!boot_ec)
1773                 return -ENODEV;
1774         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1775         if (!boot_ec_is_ecdt)
1776                 return -ENODEV;
1777
1778         /*
1779          * At this point, the namespace and the GPE is initialized, so
1780          * start to find the namespace objects and handle the events.
1781          *
1782          * Note: ec->handle can be valid if this function is called after
1783          * acpi_ec_add(), hence the fast path.
1784          */
1785         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1786                 if (!acpi_ec_ecdt_get_handle(&handle))
1787                         return -ENODEV;
1788                 boot_ec->handle = handle;
1789         }
1790
1791         /* Register to ACPI bus with PM ops attached */
1792         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1793 }
1794
1795 #if 0
1796 /*
1797  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1798  * set, for which case, we complete the QR_EC without issuing it to the
1799  * firmware.
1800  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1801  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1802  */
1803 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1804 {
1805         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1806         EC_FLAGS_QUERY_HANDSHAKE = 1;
1807         return 0;
1808 }
1809 #endif
1810
1811 /*
1812  * Some ECDTs contain wrong register addresses.
1813  * MSI MS-171F
1814  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1815  */
1816 static int ec_correct_ecdt(const struct dmi_system_id *id)
1817 {
1818         pr_debug("Detected system needing ECDT address correction.\n");
1819         EC_FLAGS_CORRECT_ECDT = 1;
1820         return 0;
1821 }
1822
1823 /*
1824  * Some DSDTs contain wrong GPE setting.
1825  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1826  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1827  */
1828 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1829 {
1830         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1831         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1832         return 0;
1833 }
1834
1835 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1836         {
1837         ec_correct_ecdt, "MSI MS-171F", {
1838         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1839         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1840         {
1841         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1842         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1843         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1844         {
1845         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1846         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1847         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1848         {
1849         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1850         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1851         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1852         {
1853         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1854         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1855         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1856         {
1857         ec_honor_ecdt_gpe, "ASUS X580VD", {
1858         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1859         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1860         {},
1861 };
1862
1863 int __init acpi_ec_ecdt_probe(void)
1864 {
1865         int ret;
1866         acpi_status status;
1867         struct acpi_table_ecdt *ecdt_ptr;
1868         struct acpi_ec *ec;
1869
1870         ec = acpi_ec_alloc();
1871         if (!ec)
1872                 return -ENOMEM;
1873         /*
1874          * Generate a boot ec context
1875          */
1876         dmi_check_system(ec_dmi_table);
1877         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1878                                 (struct acpi_table_header **)&ecdt_ptr);
1879         if (ACPI_FAILURE(status)) {
1880                 ret = -ENODEV;
1881                 goto error;
1882         }
1883
1884         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1885                 /*
1886                  * Asus X50GL:
1887                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1888                  */
1889                 ret = -ENODEV;
1890                 goto error;
1891         }
1892
1893         if (EC_FLAGS_CORRECT_ECDT) {
1894                 ec->command_addr = ecdt_ptr->data.address;
1895                 ec->data_addr = ecdt_ptr->control.address;
1896         } else {
1897                 ec->command_addr = ecdt_ptr->control.address;
1898                 ec->data_addr = ecdt_ptr->data.address;
1899         }
1900         ec->gpe = ecdt_ptr->gpe;
1901
1902         /*
1903          * At this point, the namespace is not initialized, so do not find
1904          * the namespace objects, or handle the events.
1905          */
1906         ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1907 error:
1908         if (ret)
1909                 acpi_ec_free(ec);
1910         return ret;
1911 }
1912
1913 #ifdef CONFIG_PM_SLEEP
1914 static int acpi_ec_suspend(struct device *dev)
1915 {
1916         struct acpi_ec *ec =
1917                 acpi_driver_data(to_acpi_device(dev));
1918
1919         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1920                 acpi_ec_disable_event(ec);
1921         return 0;
1922 }
1923
1924 static int acpi_ec_suspend_noirq(struct device *dev)
1925 {
1926         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1927
1928         /*
1929          * The SCI handler doesn't run at this point, so the GPE can be
1930          * masked at the low level without side effects.
1931          */
1932         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1933             ec->reference_count >= 1)
1934                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1935
1936         if (acpi_sleep_no_ec_events())
1937                 acpi_ec_enter_noirq(ec);
1938
1939         return 0;
1940 }
1941
1942 static int acpi_ec_resume_noirq(struct device *dev)
1943 {
1944         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1945
1946         if (acpi_sleep_no_ec_events())
1947                 acpi_ec_leave_noirq(ec);
1948
1949         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1950             ec->reference_count >= 1)
1951                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1952
1953         return 0;
1954 }
1955
1956 static int acpi_ec_resume(struct device *dev)
1957 {
1958         struct acpi_ec *ec =
1959                 acpi_driver_data(to_acpi_device(dev));
1960
1961         acpi_ec_enable_event(ec);
1962         return 0;
1963 }
1964 #endif
1965
1966 static const struct dev_pm_ops acpi_ec_pm = {
1967         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1968         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1969 };
1970
1971 static int param_set_event_clearing(const char *val,
1972                                     const struct kernel_param *kp)
1973 {
1974         int result = 0;
1975
1976         if (!strncmp(val, "status", sizeof("status") - 1)) {
1977                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1978                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1979         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1980                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1981                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1982         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1983                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1984                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1985         } else
1986                 result = -EINVAL;
1987         return result;
1988 }
1989
1990 static int param_get_event_clearing(char *buffer,
1991                                     const struct kernel_param *kp)
1992 {
1993         switch (ec_event_clearing) {
1994         case ACPI_EC_EVT_TIMING_STATUS:
1995                 return sprintf(buffer, "status");
1996         case ACPI_EC_EVT_TIMING_QUERY:
1997                 return sprintf(buffer, "query");
1998         case ACPI_EC_EVT_TIMING_EVENT:
1999                 return sprintf(buffer, "event");
2000         default:
2001                 return sprintf(buffer, "invalid");
2002         }
2003         return 0;
2004 }
2005
2006 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2007                   NULL, 0644);
2008 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2009
2010 static struct acpi_driver acpi_ec_driver = {
2011         .name = "ec",
2012         .class = ACPI_EC_CLASS,
2013         .ids = ec_device_ids,
2014         .ops = {
2015                 .add = acpi_ec_add,
2016                 .remove = acpi_ec_remove,
2017                 },
2018         .drv.pm = &acpi_ec_pm,
2019 };
2020
2021 static inline int acpi_ec_query_init(void)
2022 {
2023         if (!ec_query_wq) {
2024                 ec_query_wq = alloc_workqueue("kec_query", 0,
2025                                               ec_max_queries);
2026                 if (!ec_query_wq)
2027                         return -ENODEV;
2028         }
2029         return 0;
2030 }
2031
2032 static inline void acpi_ec_query_exit(void)
2033 {
2034         if (ec_query_wq) {
2035                 destroy_workqueue(ec_query_wq);
2036                 ec_query_wq = NULL;
2037         }
2038 }
2039
2040 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2041         {
2042                 .ident = "Thinkpad X1 Carbon 6th",
2043                 .matches = {
2044                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2045                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2046                 },
2047         },
2048         { },
2049 };
2050
2051 int __init acpi_ec_init(void)
2052 {
2053         int result;
2054         int ecdt_fail, dsdt_fail;
2055
2056         /* register workqueue for _Qxx evaluations */
2057         result = acpi_ec_query_init();
2058         if (result)
2059                 return result;
2060
2061         /*
2062          * Disable EC wakeup on following systems to prevent periodic
2063          * wakeup from EC GPE.
2064          */
2065         if (dmi_check_system(acpi_ec_no_wakeup)) {
2066                 ec_no_wakeup = true;
2067                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2068         }
2069
2070         /* Drivers must be started after acpi_ec_query_init() */
2071         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2072         /*
2073          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2074          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2075          * settings but invalid DSDT settings.
2076          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2077          */
2078         ecdt_fail = acpi_ec_ecdt_start();
2079         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2080 }
2081
2082 /* EC driver currently not unloadable */
2083 #if 0
2084 static void __exit acpi_ec_exit(void)
2085 {
2086
2087         acpi_bus_unregister_driver(&acpi_ec_driver);
2088         acpi_ec_query_exit();
2089 }
2090 #endif  /* 0 */