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_mark_gpe_for_wake(void)
1038 {
1039         if (first_ec && !ec_no_wakeup)
1040                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1041 }
1042
1043 void acpi_ec_set_gpe_wake_mask(u8 action)
1044 {
1045         if (first_ec && !ec_no_wakeup)
1046                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1047 }
1048
1049 void acpi_ec_dispatch_gpe(void)
1050 {
1051         if (first_ec)
1052                 acpi_dispatch_gpe(NULL, first_ec->gpe);
1053 }
1054
1055 /* --------------------------------------------------------------------------
1056                                 Event Management
1057    -------------------------------------------------------------------------- */
1058 static struct acpi_ec_query_handler *
1059 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1060 {
1061         if (handler)
1062                 kref_get(&handler->kref);
1063         return handler;
1064 }
1065
1066 static struct acpi_ec_query_handler *
1067 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1068 {
1069         struct acpi_ec_query_handler *handler;
1070         bool found = false;
1071
1072         mutex_lock(&ec->mutex);
1073         list_for_each_entry(handler, &ec->list, node) {
1074                 if (value == handler->query_bit) {
1075                         found = true;
1076                         break;
1077                 }
1078         }
1079         mutex_unlock(&ec->mutex);
1080         return found ? acpi_ec_get_query_handler(handler) : NULL;
1081 }
1082
1083 static void acpi_ec_query_handler_release(struct kref *kref)
1084 {
1085         struct acpi_ec_query_handler *handler =
1086                 container_of(kref, struct acpi_ec_query_handler, kref);
1087
1088         kfree(handler);
1089 }
1090
1091 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1092 {
1093         kref_put(&handler->kref, acpi_ec_query_handler_release);
1094 }
1095
1096 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1097                               acpi_handle handle, acpi_ec_query_func func,
1098                               void *data)
1099 {
1100         struct acpi_ec_query_handler *handler =
1101             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1102
1103         if (!handler)
1104                 return -ENOMEM;
1105
1106         handler->query_bit = query_bit;
1107         handler->handle = handle;
1108         handler->func = func;
1109         handler->data = data;
1110         mutex_lock(&ec->mutex);
1111         kref_init(&handler->kref);
1112         list_add(&handler->node, &ec->list);
1113         mutex_unlock(&ec->mutex);
1114         return 0;
1115 }
1116 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1117
1118 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1119                                           bool remove_all, u8 query_bit)
1120 {
1121         struct acpi_ec_query_handler *handler, *tmp;
1122         LIST_HEAD(free_list);
1123
1124         mutex_lock(&ec->mutex);
1125         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1126                 if (remove_all || query_bit == handler->query_bit) {
1127                         list_del_init(&handler->node);
1128                         list_add(&handler->node, &free_list);
1129                 }
1130         }
1131         mutex_unlock(&ec->mutex);
1132         list_for_each_entry_safe(handler, tmp, &free_list, node)
1133                 acpi_ec_put_query_handler(handler);
1134 }
1135
1136 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1137 {
1138         acpi_ec_remove_query_handlers(ec, false, query_bit);
1139 }
1140 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1141
1142 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1143 {
1144         struct acpi_ec_query *q;
1145         struct transaction *t;
1146
1147         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1148         if (!q)
1149                 return NULL;
1150         INIT_WORK(&q->work, acpi_ec_event_processor);
1151         t = &q->transaction;
1152         t->command = ACPI_EC_COMMAND_QUERY;
1153         t->rdata = pval;
1154         t->rlen = 1;
1155         return q;
1156 }
1157
1158 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1159 {
1160         if (q) {
1161                 if (q->handler)
1162                         acpi_ec_put_query_handler(q->handler);
1163                 kfree(q);
1164         }
1165 }
1166
1167 static void acpi_ec_event_processor(struct work_struct *work)
1168 {
1169         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1170         struct acpi_ec_query_handler *handler = q->handler;
1171
1172         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1173         if (handler->func)
1174                 handler->func(handler->data);
1175         else if (handler->handle)
1176                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1177         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1178         acpi_ec_delete_query(q);
1179 }
1180
1181 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1182 {
1183         u8 value = 0;
1184         int result;
1185         struct acpi_ec_query *q;
1186
1187         q = acpi_ec_create_query(&value);
1188         if (!q)
1189                 return -ENOMEM;
1190
1191         /*
1192          * Query the EC to find out which _Qxx method we need to evaluate.
1193          * Note that successful completion of the query causes the ACPI_EC_SCI
1194          * bit to be cleared (and thus clearing the interrupt source).
1195          */
1196         result = acpi_ec_transaction(ec, &q->transaction);
1197         if (!value)
1198                 result = -ENODATA;
1199         if (result)
1200                 goto err_exit;
1201
1202         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1203         if (!q->handler) {
1204                 result = -ENODATA;
1205                 goto err_exit;
1206         }
1207
1208         /*
1209          * It is reported that _Qxx are evaluated in a parallel way on
1210          * Windows:
1211          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1212          *
1213          * Put this log entry before schedule_work() in order to make
1214          * it appearing before any other log entries occurred during the
1215          * work queue execution.
1216          */
1217         ec_dbg_evt("Query(0x%02x) scheduled", value);
1218         if (!queue_work(ec_query_wq, &q->work)) {
1219                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1220                 result = -EBUSY;
1221         }
1222
1223 err_exit:
1224         if (result)
1225                 acpi_ec_delete_query(q);
1226         if (data)
1227                 *data = value;
1228         return result;
1229 }
1230
1231 static void acpi_ec_check_event(struct acpi_ec *ec)
1232 {
1233         unsigned long flags;
1234
1235         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1236                 if (ec_guard(ec)) {
1237                         spin_lock_irqsave(&ec->lock, flags);
1238                         /*
1239                          * Take care of the SCI_EVT unless no one else is
1240                          * taking care of it.
1241                          */
1242                         if (!ec->curr)
1243                                 advance_transaction(ec);
1244                         spin_unlock_irqrestore(&ec->lock, flags);
1245                 }
1246         }
1247 }
1248
1249 static void acpi_ec_event_handler(struct work_struct *work)
1250 {
1251         unsigned long flags;
1252         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1253
1254         ec_dbg_evt("Event started");
1255
1256         spin_lock_irqsave(&ec->lock, flags);
1257         while (ec->nr_pending_queries) {
1258                 spin_unlock_irqrestore(&ec->lock, flags);
1259                 (void)acpi_ec_query(ec, NULL);
1260                 spin_lock_irqsave(&ec->lock, flags);
1261                 ec->nr_pending_queries--;
1262                 /*
1263                  * Before exit, make sure that this work item can be
1264                  * scheduled again. There might be QR_EC failures, leaving
1265                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1266                  * item from being scheduled again.
1267                  */
1268                 if (!ec->nr_pending_queries) {
1269                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1270                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1271                                 acpi_ec_complete_query(ec);
1272                 }
1273         }
1274         spin_unlock_irqrestore(&ec->lock, flags);
1275
1276         ec_dbg_evt("Event stopped");
1277
1278         acpi_ec_check_event(ec);
1279 }
1280
1281 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1282         u32 gpe_number, void *data)
1283 {
1284         unsigned long flags;
1285         struct acpi_ec *ec = data;
1286
1287         spin_lock_irqsave(&ec->lock, flags);
1288         advance_transaction(ec);
1289         spin_unlock_irqrestore(&ec->lock, flags);
1290         return ACPI_INTERRUPT_HANDLED;
1291 }
1292
1293 /* --------------------------------------------------------------------------
1294  *                           Address Space Management
1295  * -------------------------------------------------------------------------- */
1296
1297 static acpi_status
1298 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1299                       u32 bits, u64 *value64,
1300                       void *handler_context, void *region_context)
1301 {
1302         struct acpi_ec *ec = handler_context;
1303         int result = 0, i, bytes = bits / 8;
1304         u8 *value = (u8 *)value64;
1305
1306         if ((address > 0xFF) || !value || !handler_context)
1307                 return AE_BAD_PARAMETER;
1308
1309         if (function != ACPI_READ && function != ACPI_WRITE)
1310                 return AE_BAD_PARAMETER;
1311
1312         if (ec->busy_polling || bits > 8)
1313                 acpi_ec_burst_enable(ec);
1314
1315         for (i = 0; i < bytes; ++i, ++address, ++value)
1316                 result = (function == ACPI_READ) ?
1317                         acpi_ec_read(ec, address, value) :
1318                         acpi_ec_write(ec, address, *value);
1319
1320         if (ec->busy_polling || bits > 8)
1321                 acpi_ec_burst_disable(ec);
1322
1323         switch (result) {
1324         case -EINVAL:
1325                 return AE_BAD_PARAMETER;
1326         case -ENODEV:
1327                 return AE_NOT_FOUND;
1328         case -ETIME:
1329                 return AE_TIME;
1330         default:
1331                 return AE_OK;
1332         }
1333 }
1334
1335 /* --------------------------------------------------------------------------
1336  *                             Driver Interface
1337  * -------------------------------------------------------------------------- */
1338
1339 static acpi_status
1340 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1341
1342 static void acpi_ec_free(struct acpi_ec *ec)
1343 {
1344         if (first_ec == ec)
1345                 first_ec = NULL;
1346         if (boot_ec == ec)
1347                 boot_ec = NULL;
1348         kfree(ec);
1349 }
1350
1351 static struct acpi_ec *acpi_ec_alloc(void)
1352 {
1353         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1354
1355         if (!ec)
1356                 return NULL;
1357         mutex_init(&ec->mutex);
1358         init_waitqueue_head(&ec->wait);
1359         INIT_LIST_HEAD(&ec->list);
1360         spin_lock_init(&ec->lock);
1361         INIT_WORK(&ec->work, acpi_ec_event_handler);
1362         ec->timestamp = jiffies;
1363         ec->busy_polling = true;
1364         ec->polling_guard = 0;
1365         return ec;
1366 }
1367
1368 static acpi_status
1369 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1370                                void *context, void **return_value)
1371 {
1372         char node_name[5];
1373         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1374         struct acpi_ec *ec = context;
1375         int value = 0;
1376         acpi_status status;
1377
1378         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1379
1380         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1381                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1382         return AE_OK;
1383 }
1384
1385 static acpi_status
1386 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1387 {
1388         acpi_status status;
1389         unsigned long long tmp = 0;
1390         struct acpi_ec *ec = context;
1391
1392         /* clear addr values, ec_parse_io_ports depend on it */
1393         ec->command_addr = ec->data_addr = 0;
1394
1395         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1396                                      ec_parse_io_ports, ec);
1397         if (ACPI_FAILURE(status))
1398                 return status;
1399         if (ec->data_addr == 0 || ec->command_addr == 0)
1400                 return AE_OK;
1401
1402         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1403                 /*
1404                  * Always inherit the GPE number setting from the ECDT
1405                  * EC.
1406                  */
1407                 ec->gpe = boot_ec->gpe;
1408         } else {
1409                 /* Get GPE bit assignment (EC events). */
1410                 /* TODO: Add support for _GPE returning a package */
1411                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1412                 if (ACPI_FAILURE(status))
1413                         return status;
1414                 ec->gpe = tmp;
1415         }
1416         /* Use the global lock for all EC transactions? */
1417         tmp = 0;
1418         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1419         ec->global_lock = tmp;
1420         ec->handle = handle;
1421         return AE_CTRL_TERMINATE;
1422 }
1423
1424 /*
1425  * Note: This function returns an error code only when the address space
1426  *       handler is not installed, which means "not able to handle
1427  *       transactions".
1428  */
1429 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1430 {
1431         acpi_status status;
1432
1433         acpi_ec_start(ec, false);
1434
1435         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1436                 acpi_ec_enter_noirq(ec);
1437                 status = acpi_install_address_space_handler(ec->handle,
1438                                                             ACPI_ADR_SPACE_EC,
1439                                                             &acpi_ec_space_handler,
1440                                                             NULL, ec);
1441                 if (ACPI_FAILURE(status)) {
1442                         if (status == AE_NOT_FOUND) {
1443                                 /*
1444                                  * Maybe OS fails in evaluating the _REG
1445                                  * object. The AE_NOT_FOUND error will be
1446                                  * ignored and OS * continue to initialize
1447                                  * EC.
1448                                  */
1449                                 pr_err("Fail in evaluating the _REG object"
1450                                         " of EC device. Broken bios is suspected.\n");
1451                         } else {
1452                                 acpi_ec_stop(ec, false);
1453                                 return -ENODEV;
1454                         }
1455                 }
1456                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1457         }
1458
1459         if (!handle_events)
1460                 return 0;
1461
1462         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1463                 /* Find and register all query methods */
1464                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1465                                     acpi_ec_register_query_methods,
1466                                     NULL, ec, NULL);
1467                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1468         }
1469         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1470                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1471                                           ACPI_GPE_EDGE_TRIGGERED,
1472                                           &acpi_ec_gpe_handler, ec);
1473                 /* This is not fatal as we can poll EC events */
1474                 if (ACPI_SUCCESS(status)) {
1475                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1476                         acpi_ec_leave_noirq(ec);
1477                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1478                             ec->reference_count >= 1)
1479                                 acpi_ec_enable_gpe(ec, true);
1480                 }
1481         }
1482         /* EC is fully operational, allow queries */
1483         acpi_ec_enable_event(ec);
1484
1485         return 0;
1486 }
1487
1488 static void ec_remove_handlers(struct acpi_ec *ec)
1489 {
1490         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1491                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1492                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1493                         pr_err("failed to remove space handler\n");
1494                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1495         }
1496
1497         /*
1498          * Stops handling the EC transactions after removing the operation
1499          * region handler. This is required because _REG(DISCONNECT)
1500          * invoked during the removal can result in new EC transactions.
1501          *
1502          * Flushes the EC requests and thus disables the GPE before
1503          * removing the GPE handler. This is required by the current ACPICA
1504          * GPE core. ACPICA GPE core will automatically disable a GPE when
1505          * it is indicated but there is no way to handle it. So the drivers
1506          * must disable the GPEs prior to removing the GPE handlers.
1507          */
1508         acpi_ec_stop(ec, false);
1509
1510         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1511                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1512                                         &acpi_ec_gpe_handler)))
1513                         pr_err("failed to remove gpe handler\n");
1514                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1515         }
1516         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1517                 acpi_ec_remove_query_handlers(ec, true, 0);
1518                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1519         }
1520 }
1521
1522 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1523 {
1524         int ret;
1525
1526         ret = ec_install_handlers(ec, handle_events);
1527         if (ret)
1528                 return ret;
1529
1530         /* First EC capable of handling transactions */
1531         if (!first_ec) {
1532                 first_ec = ec;
1533                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1534         }
1535
1536         acpi_handle_info(ec->handle,
1537                          "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1538                          ec->gpe, ec->command_addr, ec->data_addr);
1539         return ret;
1540 }
1541
1542 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1543                                bool handle_events, bool is_ecdt)
1544 {
1545         int ret;
1546
1547         /*
1548          * Changing the ACPI handle results in a re-configuration of the
1549          * boot EC. And if it happens after the namespace initialization,
1550          * it causes _REG evaluations.
1551          */
1552         if (boot_ec && boot_ec->handle != handle)
1553                 ec_remove_handlers(boot_ec);
1554
1555         /* Unset old boot EC */
1556         if (boot_ec != ec)
1557                 acpi_ec_free(boot_ec);
1558
1559         /*
1560          * ECDT device creation is split into acpi_ec_ecdt_probe() and
1561          * acpi_ec_ecdt_start(). This function takes care of completing the
1562          * ECDT parsing logic as the handle update should be performed
1563          * between the installation/uninstallation of the handlers.
1564          */
1565         if (ec->handle != handle)
1566                 ec->handle = handle;
1567
1568         ret = acpi_ec_setup(ec, handle_events);
1569         if (ret)
1570                 return ret;
1571
1572         /* Set new boot EC */
1573         if (!boot_ec) {
1574                 boot_ec = ec;
1575                 boot_ec_is_ecdt = is_ecdt;
1576         }
1577
1578         acpi_handle_info(boot_ec->handle,
1579                          "Used as boot %s EC to handle transactions%s\n",
1580                          is_ecdt ? "ECDT" : "DSDT",
1581                          handle_events ? " and events" : "");
1582         return ret;
1583 }
1584
1585 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1586 {
1587         struct acpi_table_ecdt *ecdt_ptr;
1588         acpi_status status;
1589         acpi_handle handle;
1590
1591         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1592                                 (struct acpi_table_header **)&ecdt_ptr);
1593         if (ACPI_FAILURE(status))
1594                 return false;
1595
1596         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1597         if (ACPI_FAILURE(status))
1598                 return false;
1599
1600         *phandle = handle;
1601         return true;
1602 }
1603
1604 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1605 {
1606         if (!boot_ec)
1607                 return false;
1608         if (ec->command_addr == boot_ec->command_addr &&
1609             ec->data_addr == boot_ec->data_addr)
1610                 return true;
1611         return false;
1612 }
1613
1614 static int acpi_ec_add(struct acpi_device *device)
1615 {
1616         struct acpi_ec *ec = NULL;
1617         int ret;
1618         bool is_ecdt = false;
1619         acpi_status status;
1620
1621         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1622         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1623
1624         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1625                 is_ecdt = true;
1626                 ec = boot_ec;
1627         } else {
1628                 ec = acpi_ec_alloc();
1629                 if (!ec)
1630                         return -ENOMEM;
1631                 status = ec_parse_device(device->handle, 0, ec, NULL);
1632                 if (status != AE_CTRL_TERMINATE) {
1633                         ret = -EINVAL;
1634                         goto err_alloc;
1635                 }
1636         }
1637
1638         if (acpi_is_boot_ec(ec)) {
1639                 boot_ec_is_ecdt = is_ecdt;
1640                 if (!is_ecdt) {
1641                         /*
1642                          * Trust PNP0C09 namespace location rather than
1643                          * ECDT ID. But trust ECDT GPE rather than _GPE
1644                          * because of ASUS quirks, so do not change
1645                          * boot_ec->gpe to ec->gpe.
1646                          */
1647                         boot_ec->handle = ec->handle;
1648                         acpi_handle_debug(ec->handle, "duplicated.\n");
1649                         acpi_ec_free(ec);
1650                         ec = boot_ec;
1651                 }
1652                 ret = acpi_config_boot_ec(ec, ec->handle, true, is_ecdt);
1653         } else
1654                 ret = acpi_ec_setup(ec, true);
1655         if (ret)
1656                 goto err_query;
1657
1658         device->driver_data = ec;
1659
1660         ret = !!request_region(ec->data_addr, 1, "EC data");
1661         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1662         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1663         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1664
1665         if (!is_ecdt) {
1666                 /* Reprobe devices depending on the EC */
1667                 acpi_walk_dep_device_list(ec->handle);
1668         }
1669         acpi_handle_debug(ec->handle, "enumerated.\n");
1670         return 0;
1671
1672 err_query:
1673         if (ec != boot_ec)
1674                 acpi_ec_remove_query_handlers(ec, true, 0);
1675 err_alloc:
1676         if (ec != boot_ec)
1677                 acpi_ec_free(ec);
1678         return ret;
1679 }
1680
1681 static int acpi_ec_remove(struct acpi_device *device)
1682 {
1683         struct acpi_ec *ec;
1684
1685         if (!device)
1686                 return -EINVAL;
1687
1688         ec = acpi_driver_data(device);
1689         release_region(ec->data_addr, 1);
1690         release_region(ec->command_addr, 1);
1691         device->driver_data = NULL;
1692         if (ec != boot_ec) {
1693                 ec_remove_handlers(ec);
1694                 acpi_ec_free(ec);
1695         }
1696         return 0;
1697 }
1698
1699 static acpi_status
1700 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1701 {
1702         struct acpi_ec *ec = context;
1703
1704         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1705                 return AE_OK;
1706
1707         /*
1708          * The first address region returned is the data port, and
1709          * the second address region returned is the status/command
1710          * port.
1711          */
1712         if (ec->data_addr == 0)
1713                 ec->data_addr = resource->data.io.minimum;
1714         else if (ec->command_addr == 0)
1715                 ec->command_addr = resource->data.io.minimum;
1716         else
1717                 return AE_CTRL_TERMINATE;
1718
1719         return AE_OK;
1720 }
1721
1722 static const struct acpi_device_id ec_device_ids[] = {
1723         {"PNP0C09", 0},
1724         {ACPI_ECDT_HID, 0},
1725         {"", 0},
1726 };
1727
1728 /*
1729  * This function is not Windows-compatible as Windows never enumerates the
1730  * namespace EC before the main ACPI device enumeration process. It is
1731  * retained for historical reason and will be deprecated in the future.
1732  */
1733 int __init acpi_ec_dsdt_probe(void)
1734 {
1735         acpi_status status;
1736         struct acpi_ec *ec;
1737         int ret;
1738
1739         /*
1740          * If a platform has ECDT, there is no need to proceed as the
1741          * following probe is not a part of the ACPI device enumeration,
1742          * executing _STA is not safe, and thus this probe may risk of
1743          * picking up an invalid EC device.
1744          */
1745         if (boot_ec)
1746                 return -ENODEV;
1747
1748         ec = acpi_ec_alloc();
1749         if (!ec)
1750                 return -ENOMEM;
1751         /*
1752          * At this point, the namespace is initialized, so start to find
1753          * the namespace objects.
1754          */
1755         status = acpi_get_devices(ec_device_ids[0].id,
1756                                   ec_parse_device, ec, NULL);
1757         if (ACPI_FAILURE(status) || !ec->handle) {
1758                 ret = -ENODEV;
1759                 goto error;
1760         }
1761         /*
1762          * When the DSDT EC is available, always re-configure boot EC to
1763          * have _REG evaluated. _REG can only be evaluated after the
1764          * namespace initialization.
1765          * At this point, the GPE is not fully initialized, so do not to
1766          * handle the events.
1767          */
1768         ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1769 error:
1770         if (ret)
1771                 acpi_ec_free(ec);
1772         return ret;
1773 }
1774
1775 /*
1776  * If the DSDT EC is not functioning, we still need to prepare a fully
1777  * functioning ECDT EC first in order to handle the events.
1778  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1779  */
1780 static int __init acpi_ec_ecdt_start(void)
1781 {
1782         acpi_handle handle;
1783
1784         if (!boot_ec)
1785                 return -ENODEV;
1786         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1787         if (!boot_ec_is_ecdt)
1788                 return -ENODEV;
1789
1790         /*
1791          * At this point, the namespace and the GPE is initialized, so
1792          * start to find the namespace objects and handle the events.
1793          *
1794          * Note: ec->handle can be valid if this function is called after
1795          * acpi_ec_add(), hence the fast path.
1796          */
1797         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1798                 if (!acpi_ec_ecdt_get_handle(&handle))
1799                         return -ENODEV;
1800                 boot_ec->handle = handle;
1801         }
1802
1803         /* Register to ACPI bus with PM ops attached */
1804         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1805 }
1806
1807 #if 0
1808 /*
1809  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1810  * set, for which case, we complete the QR_EC without issuing it to the
1811  * firmware.
1812  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1813  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1814  */
1815 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1816 {
1817         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1818         EC_FLAGS_QUERY_HANDSHAKE = 1;
1819         return 0;
1820 }
1821 #endif
1822
1823 /*
1824  * Some ECDTs contain wrong register addresses.
1825  * MSI MS-171F
1826  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1827  */
1828 static int ec_correct_ecdt(const struct dmi_system_id *id)
1829 {
1830         pr_debug("Detected system needing ECDT address correction.\n");
1831         EC_FLAGS_CORRECT_ECDT = 1;
1832         return 0;
1833 }
1834
1835 /*
1836  * Some DSDTs contain wrong GPE setting.
1837  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1838  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1839  */
1840 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1841 {
1842         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1843         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1844         return 0;
1845 }
1846
1847 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1848         {
1849         ec_correct_ecdt, "MSI MS-171F", {
1850         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1851         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1852         {
1853         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1854         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1855         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1856         {
1857         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1858         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1859         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1860         {
1861         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1862         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1863         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1864         {
1865         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1866         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1867         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1868         {
1869         ec_honor_ecdt_gpe, "ASUS X580VD", {
1870         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1871         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1872         {},
1873 };
1874
1875 int __init acpi_ec_ecdt_probe(void)
1876 {
1877         int ret;
1878         acpi_status status;
1879         struct acpi_table_ecdt *ecdt_ptr;
1880         struct acpi_ec *ec;
1881
1882         ec = acpi_ec_alloc();
1883         if (!ec)
1884                 return -ENOMEM;
1885         /*
1886          * Generate a boot ec context
1887          */
1888         dmi_check_system(ec_dmi_table);
1889         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1890                                 (struct acpi_table_header **)&ecdt_ptr);
1891         if (ACPI_FAILURE(status)) {
1892                 ret = -ENODEV;
1893                 goto error;
1894         }
1895
1896         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1897                 /*
1898                  * Asus X50GL:
1899                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1900                  */
1901                 ret = -ENODEV;
1902                 goto error;
1903         }
1904
1905         if (EC_FLAGS_CORRECT_ECDT) {
1906                 ec->command_addr = ecdt_ptr->data.address;
1907                 ec->data_addr = ecdt_ptr->control.address;
1908         } else {
1909                 ec->command_addr = ecdt_ptr->control.address;
1910                 ec->data_addr = ecdt_ptr->data.address;
1911         }
1912         ec->gpe = ecdt_ptr->gpe;
1913
1914         /*
1915          * At this point, the namespace is not initialized, so do not find
1916          * the namespace objects, or handle the events.
1917          */
1918         ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1919 error:
1920         if (ret)
1921                 acpi_ec_free(ec);
1922         return ret;
1923 }
1924
1925 #ifdef CONFIG_PM_SLEEP
1926 static int acpi_ec_suspend(struct device *dev)
1927 {
1928         struct acpi_ec *ec =
1929                 acpi_driver_data(to_acpi_device(dev));
1930
1931         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1932                 acpi_ec_disable_event(ec);
1933         return 0;
1934 }
1935
1936 static int acpi_ec_suspend_noirq(struct device *dev)
1937 {
1938         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1939
1940         /*
1941          * The SCI handler doesn't run at this point, so the GPE can be
1942          * masked at the low level without side effects.
1943          */
1944         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1945             ec->reference_count >= 1)
1946                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1947
1948         if (acpi_sleep_no_ec_events())
1949                 acpi_ec_enter_noirq(ec);
1950
1951         return 0;
1952 }
1953
1954 static int acpi_ec_resume_noirq(struct device *dev)
1955 {
1956         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1957
1958         if (acpi_sleep_no_ec_events())
1959                 acpi_ec_leave_noirq(ec);
1960
1961         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1962             ec->reference_count >= 1)
1963                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1964
1965         return 0;
1966 }
1967
1968 static int acpi_ec_resume(struct device *dev)
1969 {
1970         struct acpi_ec *ec =
1971                 acpi_driver_data(to_acpi_device(dev));
1972
1973         acpi_ec_enable_event(ec);
1974         return 0;
1975 }
1976 #endif
1977
1978 static const struct dev_pm_ops acpi_ec_pm = {
1979         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1980         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1981 };
1982
1983 static int param_set_event_clearing(const char *val,
1984                                     const struct kernel_param *kp)
1985 {
1986         int result = 0;
1987
1988         if (!strncmp(val, "status", sizeof("status") - 1)) {
1989                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1990                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1991         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1992                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1993                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1994         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1995                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1996                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1997         } else
1998                 result = -EINVAL;
1999         return result;
2000 }
2001
2002 static int param_get_event_clearing(char *buffer,
2003                                     const struct kernel_param *kp)
2004 {
2005         switch (ec_event_clearing) {
2006         case ACPI_EC_EVT_TIMING_STATUS:
2007                 return sprintf(buffer, "status");
2008         case ACPI_EC_EVT_TIMING_QUERY:
2009                 return sprintf(buffer, "query");
2010         case ACPI_EC_EVT_TIMING_EVENT:
2011                 return sprintf(buffer, "event");
2012         default:
2013                 return sprintf(buffer, "invalid");
2014         }
2015         return 0;
2016 }
2017
2018 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2019                   NULL, 0644);
2020 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2021
2022 static struct acpi_driver acpi_ec_driver = {
2023         .name = "ec",
2024         .class = ACPI_EC_CLASS,
2025         .ids = ec_device_ids,
2026         .ops = {
2027                 .add = acpi_ec_add,
2028                 .remove = acpi_ec_remove,
2029                 },
2030         .drv.pm = &acpi_ec_pm,
2031 };
2032
2033 static inline int acpi_ec_query_init(void)
2034 {
2035         if (!ec_query_wq) {
2036                 ec_query_wq = alloc_workqueue("kec_query", 0,
2037                                               ec_max_queries);
2038                 if (!ec_query_wq)
2039                         return -ENODEV;
2040         }
2041         return 0;
2042 }
2043
2044 static inline void acpi_ec_query_exit(void)
2045 {
2046         if (ec_query_wq) {
2047                 destroy_workqueue(ec_query_wq);
2048                 ec_query_wq = NULL;
2049         }
2050 }
2051
2052 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2053         {
2054                 .ident = "Thinkpad X1 Carbon 6th",
2055                 .matches = {
2056                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2057                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2058                 },
2059         },
2060         {
2061                 .ident = "ThinkPad X1 Carbon 6th",
2062                 .matches = {
2063                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2064                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2065                 },
2066         },
2067         {
2068                 .ident = "ThinkPad X1 Yoga 3rd",
2069                 .matches = {
2070                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2071                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2072                 },
2073         },
2074         { },
2075 };
2076
2077 int __init acpi_ec_init(void)
2078 {
2079         int result;
2080         int ecdt_fail, dsdt_fail;
2081
2082         /* register workqueue for _Qxx evaluations */
2083         result = acpi_ec_query_init();
2084         if (result)
2085                 return result;
2086
2087         /*
2088          * Disable EC wakeup on following systems to prevent periodic
2089          * wakeup from EC GPE.
2090          */
2091         if (dmi_check_system(acpi_ec_no_wakeup)) {
2092                 ec_no_wakeup = true;
2093                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2094         }
2095
2096         /* Drivers must be started after acpi_ec_query_init() */
2097         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2098         /*
2099          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2100          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2101          * settings but invalid DSDT settings.
2102          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2103          */
2104         ecdt_fail = acpi_ec_ecdt_start();
2105         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2106 }
2107
2108 /* EC driver currently not unloadable */
2109 #if 0
2110 static void __exit acpi_ec_exit(void)
2111 {
2112
2113         acpi_bus_unregister_driver(&acpi_ec_driver);
2114         acpi_ec_query_exit();
2115 }
2116 #endif  /* 0 */