linux/drivers/acpi/ec.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  ec.c - ACPI Embedded Controller Driver (v3)
   4 *
   5 *  Copyright (C) 2001-2015 Intel Corporation
   6 *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
   7 *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   8 *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   9 *            2004       Luming Yu <luming.yu@intel.com>
  10 *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  11 *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  12 *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  13 */
  14
  15/* Uncomment next line to get verbose printout */
  16/* #define DEBUG */
  17#define pr_fmt(fmt) "ACPI: EC: " fmt
  18
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/init.h>
  22#include <linux/types.h>
  23#include <linux/delay.h>
  24#include <linux/interrupt.h>
  25#include <linux/list.h>
  26#include <linux/spinlock.h>
  27#include <linux/slab.h>
  28#include <linux/suspend.h>
  29#include <linux/acpi.h>
  30#include <linux/dmi.h>
  31#include <asm/io.h>
  32
  33#include "internal.h"
  34
  35#define ACPI_EC_CLASS                   "embedded_controller"
  36#define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  37
  38/* EC status register */
  39#define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  40#define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  41#define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  42#define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  43#define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  44
  45/*
  46 * The SCI_EVT clearing timing is not defined by the ACPI specification.
  47 * This leads to lots of practical timing issues for the host EC driver.
  48 * The following variations are defined (from the target EC firmware's
  49 * perspective):
  50 * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  51 *         target can clear SCI_EVT at any time so long as the host can see
  52 *         the indication by reading the status register (EC_SC). So the
  53 *         host should re-check SCI_EVT after the first time the SCI_EVT
  54 *         indication is seen, which is the same time the query request
  55 *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  56 *         at any later time could indicate another event. Normally such
  57 *         kind of EC firmware has implemented an event queue and will
  58 *         return 0x00 to indicate "no outstanding event".
  59 * QUERY: After seeing the query request (QR_EC) written to the command
  60 *        register (EC_CMD) by the host and having prepared the responding
  61 *        event value in the data register (EC_DATA), the target can safely
  62 *        clear SCI_EVT because the target can confirm that the current
  63 *        event is being handled by the host. The host then should check
  64 *        SCI_EVT right after reading the event response from the data
  65 *        register (EC_DATA).
  66 * EVENT: After seeing the event response read from the data register
  67 *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  68 *        target requires time to notice the change in the data register
  69 *        (EC_DATA), the host may be required to wait additional guarding
  70 *        time before checking the SCI_EVT again. Such guarding may not be
  71 *        necessary if the host is notified via another IRQ.
  72 */
  73#define ACPI_EC_EVT_TIMING_STATUS       0x00
  74#define ACPI_EC_EVT_TIMING_QUERY        0x01
  75#define ACPI_EC_EVT_TIMING_EVENT        0x02
  76
  77/* EC commands */
  78enum ec_command {
  79        ACPI_EC_COMMAND_READ = 0x80,
  80        ACPI_EC_COMMAND_WRITE = 0x81,
  81        ACPI_EC_BURST_ENABLE = 0x82,
  82        ACPI_EC_BURST_DISABLE = 0x83,
  83        ACPI_EC_COMMAND_QUERY = 0x84,
  84};
  85
  86#define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  87#define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  88#define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
  89#define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  90                                         * when trying to clear the EC */
  91#define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
  92
  93enum {
  94        EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
  95        EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  96        EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
  97        EC_FLAGS_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  98        EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
  99        EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
 100        EC_FLAGS_STARTED,               /* Driver is started */
 101        EC_FLAGS_STOPPED,               /* Driver is stopped */
 102        EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 103};
 104
 105#define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 106#define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 107
 108/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 109static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 110module_param(ec_delay, uint, 0644);
 111MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 112
 113static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 114module_param(ec_max_queries, uint, 0644);
 115MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 116
 117static bool ec_busy_polling __read_mostly;
 118module_param(ec_busy_polling, bool, 0644);
 119MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 120
 121static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 122module_param(ec_polling_guard, uint, 0644);
 123MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 124
 125static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 126
 127/*
 128 * If the number of false interrupts per one transaction exceeds
 129 * this threshold, will think there is a GPE storm happened and
 130 * will disable the GPE for normal transaction.
 131 */
 132static unsigned int ec_storm_threshold  __read_mostly = 8;
 133module_param(ec_storm_threshold, uint, 0644);
 134MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 135
 136static bool ec_freeze_events __read_mostly = false;
 137module_param(ec_freeze_events, bool, 0644);
 138MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 139
 140static bool ec_no_wakeup __read_mostly;
 141module_param(ec_no_wakeup, bool, 0644);
 142MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 143
 144struct acpi_ec_query_handler {
 145        struct list_head node;
 146        acpi_ec_query_func func;
 147        acpi_handle handle;
 148        void *data;
 149        u8 query_bit;
 150        struct kref kref;
 151};
 152
 153struct transaction {
 154        const u8 *wdata;
 155        u8 *rdata;
 156        unsigned short irq_count;
 157        u8 command;
 158        u8 wi;
 159        u8 ri;
 160        u8 wlen;
 161        u8 rlen;
 162        u8 flags;
 163};
 164
 165struct acpi_ec_query {
 166        struct transaction transaction;
 167        struct work_struct work;
 168        struct acpi_ec_query_handler *handler;
 169};
 170
 171static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 172static void advance_transaction(struct acpi_ec *ec, bool interrupt);
 173static void acpi_ec_event_handler(struct work_struct *work);
 174static void acpi_ec_event_processor(struct work_struct *work);
 175
 176struct acpi_ec *first_ec;
 177EXPORT_SYMBOL(first_ec);
 178
 179static struct acpi_ec *boot_ec;
 180static bool boot_ec_is_ecdt = false;
 181static struct workqueue_struct *ec_wq;
 182static struct workqueue_struct *ec_query_wq;
 183
 184static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 185static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 186static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
 187static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 188
 189/* --------------------------------------------------------------------------
 190 *                           Logging/Debugging
 191 * -------------------------------------------------------------------------- */
 192
 193/*
 194 * Splitters used by the developers to track the boundary of the EC
 195 * handling processes.
 196 */
 197#ifdef DEBUG
 198#define EC_DBG_SEP      " "
 199#define EC_DBG_DRV      "+++++"
 200#define EC_DBG_STM      "====="
 201#define EC_DBG_REQ      "*****"
 202#define EC_DBG_EVT      "#####"
 203#else
 204#define EC_DBG_SEP      ""
 205#define EC_DBG_DRV
 206#define EC_DBG_STM
 207#define EC_DBG_REQ
 208#define EC_DBG_EVT
 209#endif
 210
 211#define ec_log_raw(fmt, ...) \
 212        pr_info(fmt "\n", ##__VA_ARGS__)
 213#define ec_dbg_raw(fmt, ...) \
 214        pr_debug(fmt "\n", ##__VA_ARGS__)
 215#define ec_log(filter, fmt, ...) \
 216        ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 217#define ec_dbg(filter, fmt, ...) \
 218        ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 219
 220#define ec_log_drv(fmt, ...) \
 221        ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 222#define ec_dbg_drv(fmt, ...) \
 223        ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 224#define ec_dbg_stm(fmt, ...) \
 225        ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 226#define ec_dbg_req(fmt, ...) \
 227        ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 228#define ec_dbg_evt(fmt, ...) \
 229        ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 230#define ec_dbg_ref(ec, fmt, ...) \
 231        ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 232
 233/* --------------------------------------------------------------------------
 234 *                           Device Flags
 235 * -------------------------------------------------------------------------- */
 236
 237static bool acpi_ec_started(struct acpi_ec *ec)
 238{
 239        return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 240               !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 241}
 242
 243static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 244{
 245        /*
 246         * There is an OSPM early stage logic. During the early stages
 247         * (boot/resume), OSPMs shouldn't enable the event handling, only
 248         * the EC transactions are allowed to be performed.
 249         */
 250        if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 251                return false;
 252        /*
 253         * However, disabling the event handling is experimental for late
 254         * stage (suspend), and is controlled by the boot parameter of
 255         * "ec_freeze_events":
 256         * 1. true:  The EC event handling is disabled before entering
 257         *           the noirq stage.
 258         * 2. false: The EC event handling is automatically disabled as
 259         *           soon as the EC driver is stopped.
 260         */
 261        if (ec_freeze_events)
 262                return acpi_ec_started(ec);
 263        else
 264                return test_bit(EC_FLAGS_STARTED, &ec->flags);
 265}
 266
 267static bool acpi_ec_flushed(struct acpi_ec *ec)
 268{
 269        return ec->reference_count == 1;
 270}
 271
 272/* --------------------------------------------------------------------------
 273 *                           EC Registers
 274 * -------------------------------------------------------------------------- */
 275
 276static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 277{
 278        u8 x = inb(ec->command_addr);
 279
 280        ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 281                   "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 282                   x,
 283                   !!(x & ACPI_EC_FLAG_SCI),
 284                   !!(x & ACPI_EC_FLAG_BURST),
 285                   !!(x & ACPI_EC_FLAG_CMD),
 286                   !!(x & ACPI_EC_FLAG_IBF),
 287                   !!(x & ACPI_EC_FLAG_OBF));
 288        return x;
 289}
 290
 291static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 292{
 293        u8 x = inb(ec->data_addr);
 294
 295        ec->timestamp = jiffies;
 296        ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 297        return x;
 298}
 299
 300static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 301{
 302        ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 303        outb(command, ec->command_addr);
 304        ec->timestamp = jiffies;
 305}
 306
 307static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 308{
 309        ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 310        outb(data, ec->data_addr);
 311        ec->timestamp = jiffies;
 312}
 313
 314#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 315static const char *acpi_ec_cmd_string(u8 cmd)
 316{
 317        switch (cmd) {
 318        case 0x80:
 319                return "RD_EC";
 320        case 0x81:
 321                return "WR_EC";
 322        case 0x82:
 323                return "BE_EC";
 324        case 0x83:
 325                return "BD_EC";
 326        case 0x84:
 327                return "QR_EC";
 328        }
 329        return "UNKNOWN";
 330}
 331#else
 332#define acpi_ec_cmd_string(cmd)         "UNDEF"
 333#endif
 334
 335/* --------------------------------------------------------------------------
 336 *                           GPE Registers
 337 * -------------------------------------------------------------------------- */
 338
 339static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
 340{
 341        acpi_event_status gpe_status = 0;
 342
 343        (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 344        return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
 345}
 346
 347static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 348{
 349        if (open)
 350                acpi_enable_gpe(NULL, ec->gpe);
 351        else {
 352                BUG_ON(ec->reference_count < 1);
 353                acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 354        }
 355        if (acpi_ec_gpe_status_set(ec)) {
 356                /*
 357                 * On some platforms, EN=1 writes cannot trigger GPE. So
 358                 * software need to manually trigger a pseudo GPE event on
 359                 * EN=1 writes.
 360                 */
 361                ec_dbg_raw("Polling quirk");
 362                advance_transaction(ec, false);
 363        }
 364}
 365
 366static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 367{
 368        if (close)
 369                acpi_disable_gpe(NULL, ec->gpe);
 370        else {
 371                BUG_ON(ec->reference_count < 1);
 372                acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 373        }
 374}
 375
 376/* --------------------------------------------------------------------------
 377 *                           Transaction Management
 378 * -------------------------------------------------------------------------- */
 379
 380static void acpi_ec_submit_request(struct acpi_ec *ec)
 381{
 382        ec->reference_count++;
 383        if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 384            ec->gpe >= 0 && ec->reference_count == 1)
 385                acpi_ec_enable_gpe(ec, true);
 386}
 387
 388static void acpi_ec_complete_request(struct acpi_ec *ec)
 389{
 390        bool flushed = false;
 391
 392        ec->reference_count--;
 393        if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 394            ec->gpe >= 0 && ec->reference_count == 0)
 395                acpi_ec_disable_gpe(ec, true);
 396        flushed = acpi_ec_flushed(ec);
 397        if (flushed)
 398                wake_up(&ec->wait);
 399}
 400
 401static void acpi_ec_mask_events(struct acpi_ec *ec)
 402{
 403        if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 404                if (ec->gpe >= 0)
 405                        acpi_ec_disable_gpe(ec, false);
 406                else
 407                        disable_irq_nosync(ec->irq);
 408
 409                ec_dbg_drv("Polling enabled");
 410                set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 411        }
 412}
 413
 414static void acpi_ec_unmask_events(struct acpi_ec *ec)
 415{
 416        if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 417                clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 418                if (ec->gpe >= 0)
 419                        acpi_ec_enable_gpe(ec, false);
 420                else
 421                        enable_irq(ec->irq);
 422
 423                ec_dbg_drv("Polling disabled");
 424        }
 425}
 426
 427/*
 428 * acpi_ec_submit_flushable_request() - Increase the reference count unless
 429 *                                      the flush operation is not in
 430 *                                      progress
 431 * @ec: the EC device
 432 *
 433 * This function must be used before taking a new action that should hold
 434 * the reference count.  If this function returns false, then the action
 435 * must be discarded or it will prevent the flush operation from being
 436 * completed.
 437 */
 438static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 439{
 440        if (!acpi_ec_started(ec))
 441                return false;
 442        acpi_ec_submit_request(ec);
 443        return true;
 444}
 445
 446static void acpi_ec_submit_query(struct acpi_ec *ec)
 447{
 448        acpi_ec_mask_events(ec);
 449        if (!acpi_ec_event_enabled(ec))
 450                return;
 451        if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 452                ec_dbg_evt("Command(%s) submitted/blocked",
 453                           acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 454                ec->nr_pending_queries++;
 455                queue_work(ec_wq, &ec->work);
 456        }
 457}
 458
 459static void acpi_ec_complete_query(struct acpi_ec *ec)
 460{
 461        if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 462                ec_dbg_evt("Command(%s) unblocked",
 463                           acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 464        acpi_ec_unmask_events(ec);
 465}
 466
 467static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 468{
 469        if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 470                ec_log_drv("event unblocked");
 471        /*
 472         * Unconditionally invoke this once after enabling the event
 473         * handling mechanism to detect the pending events.
 474         */
 475        advance_transaction(ec, false);
 476}
 477
 478static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 479{
 480        if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 481                ec_log_drv("event blocked");
 482}
 483
 484/*
 485 * Process _Q events that might have accumulated in the EC.
 486 * Run with locked ec mutex.
 487 */
 488static void acpi_ec_clear(struct acpi_ec *ec)
 489{
 490        int i, status;
 491        u8 value = 0;
 492
 493        for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 494                status = acpi_ec_query(ec, &value);
 495                if (status || !value)
 496                        break;
 497        }
 498        if (unlikely(i == ACPI_EC_CLEAR_MAX))
 499                pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 500        else
 501                pr_info("%d stale EC events cleared\n", i);
 502}
 503
 504static void acpi_ec_enable_event(struct acpi_ec *ec)
 505{
 506        unsigned long flags;
 507
 508        spin_lock_irqsave(&ec->lock, flags);
 509        if (acpi_ec_started(ec))
 510                __acpi_ec_enable_event(ec);
 511        spin_unlock_irqrestore(&ec->lock, flags);
 512
 513        /* Drain additional events if hardware requires that */
 514        if (EC_FLAGS_CLEAR_ON_RESUME)
 515                acpi_ec_clear(ec);
 516}
 517
 518#ifdef CONFIG_PM_SLEEP
 519static void __acpi_ec_flush_work(void)
 520{
 521        drain_workqueue(ec_wq); /* flush ec->work */
 522        flush_workqueue(ec_query_wq); /* flush queries */
 523}
 524
 525static void acpi_ec_disable_event(struct acpi_ec *ec)
 526{
 527        unsigned long flags;
 528
 529        spin_lock_irqsave(&ec->lock, flags);
 530        __acpi_ec_disable_event(ec);
 531        spin_unlock_irqrestore(&ec->lock, flags);
 532
 533        /*
 534         * When ec_freeze_events is true, we need to flush events in
 535         * the proper position before entering the noirq stage.
 536         */
 537        __acpi_ec_flush_work();
 538}
 539
 540void acpi_ec_flush_work(void)
 541{
 542        /* Without ec_wq there is nothing to flush. */
 543        if (!ec_wq)
 544                return;
 545
 546        __acpi_ec_flush_work();
 547}
 548#endif /* CONFIG_PM_SLEEP */
 549
 550static bool acpi_ec_guard_event(struct acpi_ec *ec)
 551{
 552        bool guarded = true;
 553        unsigned long flags;
 554
 555        spin_lock_irqsave(&ec->lock, flags);
 556        /*
 557         * If firmware SCI_EVT clearing timing is "event", we actually
 558         * don't know when the SCI_EVT will be cleared by firmware after
 559         * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 560         * acceptable period.
 561         *
 562         * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 563         * flagged, which means SCI_EVT check has just been performed.
 564         * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 565         * guarding should have already been performed (via
 566         * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 567         * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 568         * ACPI_EC_COMMAND_POLL state immediately.
 569         */
 570        if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 571            ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 572            !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 573            (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 574                guarded = false;
 575        spin_unlock_irqrestore(&ec->lock, flags);
 576        return guarded;
 577}
 578
 579static int ec_transaction_polled(struct acpi_ec *ec)
 580{
 581        unsigned long flags;
 582        int ret = 0;
 583
 584        spin_lock_irqsave(&ec->lock, flags);
 585        if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 586                ret = 1;
 587        spin_unlock_irqrestore(&ec->lock, flags);
 588        return ret;
 589}
 590
 591static int ec_transaction_completed(struct acpi_ec *ec)
 592{
 593        unsigned long flags;
 594        int ret = 0;
 595
 596        spin_lock_irqsave(&ec->lock, flags);
 597        if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 598                ret = 1;
 599        spin_unlock_irqrestore(&ec->lock, flags);
 600        return ret;
 601}
 602
 603static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 604{
 605        ec->curr->flags |= flag;
 606        if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 607                if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 608                    flag == ACPI_EC_COMMAND_POLL)
 609                        acpi_ec_complete_query(ec);
 610                if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 611                    flag == ACPI_EC_COMMAND_COMPLETE)
 612                        acpi_ec_complete_query(ec);
 613                if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 614                    flag == ACPI_EC_COMMAND_COMPLETE)
 615                        set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 616        }
 617}
 618
 619static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
 620{
 621        if (t->irq_count < ec_storm_threshold)
 622                ++t->irq_count;
 623
 624        /* Trigger if the threshold is 0 too. */
 625        if (t->irq_count == ec_storm_threshold)
 626                acpi_ec_mask_events(ec);
 627}
 628
 629static void advance_transaction(struct acpi_ec *ec, bool interrupt)
 630{
 631        struct transaction *t = ec->curr;
 632        bool wakeup = false;
 633        u8 status;
 634
 635        ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
 636
 637        /*
 638         * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
 639         * changes to always trigger a GPE interrupt.
 640         *
 641         * GPE STS is a W1C register, which means:
 642         *
 643         * 1. Software can clear it without worrying about clearing the other
 644         *    GPEs' STS bits when the hardware sets them in parallel.
 645         *
 646         * 2. As long as software can ensure only clearing it when it is set,
 647         *    hardware won't set it in parallel.
 648         */
 649        if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
 650                acpi_clear_gpe(NULL, ec->gpe);
 651
 652        status = acpi_ec_read_status(ec);
 653
 654        /*
 655         * Another IRQ or a guarded polling mode advancement is detected,
 656         * the next QR_EC submission is then allowed.
 657         */
 658        if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 659                if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 660                    (!ec->nr_pending_queries ||
 661                     test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 662                        clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 663                        acpi_ec_complete_query(ec);
 664                }
 665                if (!t)
 666                        goto out;
 667        }
 668
 669        if (t->flags & ACPI_EC_COMMAND_POLL) {
 670                if (t->wlen > t->wi) {
 671                        if (!(status & ACPI_EC_FLAG_IBF))
 672                                acpi_ec_write_data(ec, t->wdata[t->wi++]);
 673                        else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
 674                                acpi_ec_spurious_interrupt(ec, t);
 675                } else if (t->rlen > t->ri) {
 676                        if (status & ACPI_EC_FLAG_OBF) {
 677                                t->rdata[t->ri++] = acpi_ec_read_data(ec);
 678                                if (t->rlen == t->ri) {
 679                                        ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 680                                        wakeup = true;
 681                                        if (t->command == ACPI_EC_COMMAND_QUERY)
 682                                                ec_dbg_evt("Command(%s) completed by hardware",
 683                                                           acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 684                                }
 685                        } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
 686                                acpi_ec_spurious_interrupt(ec, t);
 687                        }
 688                } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
 689                        ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 690                        wakeup = true;
 691                }
 692        } else if (!(status & ACPI_EC_FLAG_IBF)) {
 693                acpi_ec_write_cmd(ec, t->command);
 694                ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 695        }
 696
 697out:
 698        if (status & ACPI_EC_FLAG_SCI)
 699                acpi_ec_submit_query(ec);
 700
 701        if (wakeup && interrupt)
 702                wake_up(&ec->wait);
 703}
 704
 705static void start_transaction(struct acpi_ec *ec)
 706{
 707        ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 708        ec->curr->flags = 0;
 709}
 710
 711static int ec_guard(struct acpi_ec *ec)
 712{
 713        unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 714        unsigned long timeout = ec->timestamp + guard;
 715
 716        /* Ensure guarding period before polling EC status */
 717        do {
 718                if (ec->busy_polling) {
 719                        /* Perform busy polling */
 720                        if (ec_transaction_completed(ec))
 721                                return 0;
 722                        udelay(jiffies_to_usecs(guard));
 723                } else {
 724                        /*
 725                         * Perform wait polling
 726                         * 1. Wait the transaction to be completed by the
 727                         *    GPE handler after the transaction enters
 728                         *    ACPI_EC_COMMAND_POLL state.
 729                         * 2. A special guarding logic is also required
 730                         *    for event clearing mode "event" before the
 731                         *    transaction enters ACPI_EC_COMMAND_POLL
 732                         *    state.
 733                         */
 734                        if (!ec_transaction_polled(ec) &&
 735                            !acpi_ec_guard_event(ec))
 736                                break;
 737                        if (wait_event_timeout(ec->wait,
 738                                               ec_transaction_completed(ec),
 739                                               guard))
 740                                return 0;
 741                }
 742        } while (time_before(jiffies, timeout));
 743        return -ETIME;
 744}
 745
 746static int ec_poll(struct acpi_ec *ec)
 747{
 748        unsigned long flags;
 749        int repeat = 5; /* number of command restarts */
 750
 751        while (repeat--) {
 752                unsigned long delay = jiffies +
 753                        msecs_to_jiffies(ec_delay);
 754                do {
 755                        if (!ec_guard(ec))
 756                                return 0;
 757                        spin_lock_irqsave(&ec->lock, flags);
 758                        advance_transaction(ec, false);
 759                        spin_unlock_irqrestore(&ec->lock, flags);
 760                } while (time_before(jiffies, delay));
 761                pr_debug("controller reset, restart transaction\n");
 762                spin_lock_irqsave(&ec->lock, flags);
 763                start_transaction(ec);
 764                spin_unlock_irqrestore(&ec->lock, flags);
 765        }
 766        return -ETIME;
 767}
 768
 769static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 770                                        struct transaction *t)
 771{
 772        unsigned long tmp;
 773        int ret = 0;
 774
 775        /* start transaction */
 776        spin_lock_irqsave(&ec->lock, tmp);
 777        /* Enable GPE for command processing (IBF=0/OBF=1) */
 778        if (!acpi_ec_submit_flushable_request(ec)) {
 779                ret = -EINVAL;
 780                goto unlock;
 781        }
 782        ec_dbg_ref(ec, "Increase command");
 783        /* following two actions should be kept atomic */
 784        ec->curr = t;
 785        ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 786        start_transaction(ec);
 787        spin_unlock_irqrestore(&ec->lock, tmp);
 788
 789        ret = ec_poll(ec);
 790
 791        spin_lock_irqsave(&ec->lock, tmp);
 792        if (t->irq_count == ec_storm_threshold)
 793                acpi_ec_unmask_events(ec);
 794        ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 795        ec->curr = NULL;
 796        /* Disable GPE for command processing (IBF=0/OBF=1) */
 797        acpi_ec_complete_request(ec);
 798        ec_dbg_ref(ec, "Decrease command");
 799unlock:
 800        spin_unlock_irqrestore(&ec->lock, tmp);
 801        return ret;
 802}
 803
 804static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 805{
 806        int status;
 807        u32 glk;
 808
 809        if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 810                return -EINVAL;
 811        if (t->rdata)
 812                memset(t->rdata, 0, t->rlen);
 813
 814        mutex_lock(&ec->mutex);
 815        if (ec->global_lock) {
 816                status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 817                if (ACPI_FAILURE(status)) {
 818                        status = -ENODEV;
 819                        goto unlock;
 820                }
 821        }
 822
 823        status = acpi_ec_transaction_unlocked(ec, t);
 824
 825        if (ec->global_lock)
 826                acpi_release_global_lock(glk);
 827unlock:
 828        mutex_unlock(&ec->mutex);
 829        return status;
 830}
 831
 832static int acpi_ec_burst_enable(struct acpi_ec *ec)
 833{
 834        u8 d;
 835        struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 836                                .wdata = NULL, .rdata = &d,
 837                                .wlen = 0, .rlen = 1};
 838
 839        return acpi_ec_transaction(ec, &t);
 840}
 841
 842static int acpi_ec_burst_disable(struct acpi_ec *ec)
 843{
 844        struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 845                                .wdata = NULL, .rdata = NULL,
 846                                .wlen = 0, .rlen = 0};
 847
 848        return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 849                                acpi_ec_transaction(ec, &t) : 0;
 850}
 851
 852static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 853{
 854        int result;
 855        u8 d;
 856        struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 857                                .wdata = &address, .rdata = &d,
 858                                .wlen = 1, .rlen = 1};
 859
 860        result = acpi_ec_transaction(ec, &t);
 861        *data = d;
 862        return result;
 863}
 864
 865static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 866{
 867        u8 wdata[2] = { address, data };
 868        struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 869                                .wdata = wdata, .rdata = NULL,
 870                                .wlen = 2, .rlen = 0};
 871
 872        return acpi_ec_transaction(ec, &t);
 873}
 874
 875int ec_read(u8 addr, u8 *val)
 876{
 877        int err;
 878        u8 temp_data;
 879
 880        if (!first_ec)
 881                return -ENODEV;
 882
 883        err = acpi_ec_read(first_ec, addr, &temp_data);
 884
 885        if (!err) {
 886                *val = temp_data;
 887                return 0;
 888        }
 889        return err;
 890}
 891EXPORT_SYMBOL(ec_read);
 892
 893int ec_write(u8 addr, u8 val)
 894{
 895        int err;
 896
 897        if (!first_ec)
 898                return -ENODEV;
 899
 900        err = acpi_ec_write(first_ec, addr, val);
 901
 902        return err;
 903}
 904EXPORT_SYMBOL(ec_write);
 905
 906int ec_transaction(u8 command,
 907                   const u8 *wdata, unsigned wdata_len,
 908                   u8 *rdata, unsigned rdata_len)
 909{
 910        struct transaction t = {.command = command,
 911                                .wdata = wdata, .rdata = rdata,
 912                                .wlen = wdata_len, .rlen = rdata_len};
 913
 914        if (!first_ec)
 915                return -ENODEV;
 916
 917        return acpi_ec_transaction(first_ec, &t);
 918}
 919EXPORT_SYMBOL(ec_transaction);
 920
 921/* Get the handle to the EC device */
 922acpi_handle ec_get_handle(void)
 923{
 924        if (!first_ec)
 925                return NULL;
 926        return first_ec->handle;
 927}
 928EXPORT_SYMBOL(ec_get_handle);
 929
 930static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 931{
 932        unsigned long flags;
 933
 934        spin_lock_irqsave(&ec->lock, flags);
 935        if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 936                ec_dbg_drv("Starting EC");
 937                /* Enable GPE for event processing (SCI_EVT=1) */
 938                if (!resuming) {
 939                        acpi_ec_submit_request(ec);
 940                        ec_dbg_ref(ec, "Increase driver");
 941                }
 942                ec_log_drv("EC started");
 943        }
 944        spin_unlock_irqrestore(&ec->lock, flags);
 945}
 946
 947static bool acpi_ec_stopped(struct acpi_ec *ec)
 948{
 949        unsigned long flags;
 950        bool flushed;
 951
 952        spin_lock_irqsave(&ec->lock, flags);
 953        flushed = acpi_ec_flushed(ec);
 954        spin_unlock_irqrestore(&ec->lock, flags);
 955        return flushed;
 956}
 957
 958static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 959{
 960        unsigned long flags;
 961
 962        spin_lock_irqsave(&ec->lock, flags);
 963        if (acpi_ec_started(ec)) {
 964                ec_dbg_drv("Stopping EC");
 965                set_bit(EC_FLAGS_STOPPED, &ec->flags);
 966                spin_unlock_irqrestore(&ec->lock, flags);
 967                wait_event(ec->wait, acpi_ec_stopped(ec));
 968                spin_lock_irqsave(&ec->lock, flags);
 969                /* Disable GPE for event processing (SCI_EVT=1) */
 970                if (!suspending) {
 971                        acpi_ec_complete_request(ec);
 972                        ec_dbg_ref(ec, "Decrease driver");
 973                } else if (!ec_freeze_events)
 974                        __acpi_ec_disable_event(ec);
 975                clear_bit(EC_FLAGS_STARTED, &ec->flags);
 976                clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 977                ec_log_drv("EC stopped");
 978        }
 979        spin_unlock_irqrestore(&ec->lock, flags);
 980}
 981
 982static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 983{
 984        unsigned long flags;
 985
 986        spin_lock_irqsave(&ec->lock, flags);
 987        ec->busy_polling = true;
 988        ec->polling_guard = 0;
 989        ec_log_drv("interrupt blocked");
 990        spin_unlock_irqrestore(&ec->lock, flags);
 991}
 992
 993static void acpi_ec_leave_noirq(struct acpi_ec *ec)
 994{
 995        unsigned long flags;
 996
 997        spin_lock_irqsave(&ec->lock, flags);
 998        ec->busy_polling = ec_busy_polling;
 999        ec->polling_guard = ec_polling_guard;
1000        ec_log_drv("interrupt unblocked");
1001        spin_unlock_irqrestore(&ec->lock, flags);
1002}
1003
1004void acpi_ec_block_transactions(void)
1005{
1006        struct acpi_ec *ec = first_ec;
1007
1008        if (!ec)
1009                return;
1010
1011        mutex_lock(&ec->mutex);
1012        /* Prevent transactions from being carried out */
1013        acpi_ec_stop(ec, true);
1014        mutex_unlock(&ec->mutex);
1015}
1016
1017void acpi_ec_unblock_transactions(void)
1018{
1019        /*
1020         * Allow transactions to happen again (this function is called from
1021         * atomic context during wakeup, so we don't need to acquire the mutex).
1022         */
1023        if (first_ec)
1024                acpi_ec_start(first_ec, true);
1025}
1026
1027/* --------------------------------------------------------------------------
1028                                Event Management
1029   -------------------------------------------------------------------------- */
1030static struct acpi_ec_query_handler *
1031acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1032{
1033        struct acpi_ec_query_handler *handler;
1034
1035        mutex_lock(&ec->mutex);
1036        list_for_each_entry(handler, &ec->list, node) {
1037                if (value == handler->query_bit) {
1038                        kref_get(&handler->kref);
1039                        mutex_unlock(&ec->mutex);
1040                        return handler;
1041                }
1042        }
1043        mutex_unlock(&ec->mutex);
1044        return NULL;
1045}
1046
1047static void acpi_ec_query_handler_release(struct kref *kref)
1048{
1049        struct acpi_ec_query_handler *handler =
1050                container_of(kref, struct acpi_ec_query_handler, kref);
1051
1052        kfree(handler);
1053}
1054
1055static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1056{
1057        kref_put(&handler->kref, acpi_ec_query_handler_release);
1058}
1059
1060int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1061                              acpi_handle handle, acpi_ec_query_func func,
1062                              void *data)
1063{
1064        struct acpi_ec_query_handler *handler =
1065            kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1066
1067        if (!handler)
1068                return -ENOMEM;
1069
1070        handler->query_bit = query_bit;
1071        handler->handle = handle;
1072        handler->func = func;
1073        handler->data = data;
1074        mutex_lock(&ec->mutex);
1075        kref_init(&handler->kref);
1076        list_add(&handler->node, &ec->list);
1077        mutex_unlock(&ec->mutex);
1078        return 0;
1079}
1080EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1081
1082static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1083                                          bool remove_all, u8 query_bit)
1084{
1085        struct acpi_ec_query_handler *handler, *tmp;
1086        LIST_HEAD(free_list);
1087
1088        mutex_lock(&ec->mutex);
1089        list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1090                if (remove_all || query_bit == handler->query_bit) {
1091                        list_del_init(&handler->node);
1092                        list_add(&handler->node, &free_list);
1093                }
1094        }
1095        mutex_unlock(&ec->mutex);
1096        list_for_each_entry_safe(handler, tmp, &free_list, node)
1097                acpi_ec_put_query_handler(handler);
1098}
1099
1100void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1101{
1102        acpi_ec_remove_query_handlers(ec, false, query_bit);
1103}
1104EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1105
1106static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1107{
1108        struct acpi_ec_query *q;
1109        struct transaction *t;
1110
1111        q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1112        if (!q)
1113                return NULL;
1114        INIT_WORK(&q->work, acpi_ec_event_processor);
1115        t = &q->transaction;
1116        t->command = ACPI_EC_COMMAND_QUERY;
1117        t->rdata = pval;
1118        t->rlen = 1;
1119        return q;
1120}
1121
1122static void acpi_ec_delete_query(struct acpi_ec_query *q)
1123{
1124        if (q) {
1125                if (q->handler)
1126                        acpi_ec_put_query_handler(q->handler);
1127                kfree(q);
1128        }
1129}
1130
1131static void acpi_ec_event_processor(struct work_struct *work)
1132{
1133        struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1134        struct acpi_ec_query_handler *handler = q->handler;
1135
1136        ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1137        if (handler->func)
1138                handler->func(handler->data);
1139        else if (handler->handle)
1140                acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1141        ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1142        acpi_ec_delete_query(q);
1143}
1144
1145static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1146{
1147        u8 value = 0;
1148        int result;
1149        struct acpi_ec_query *q;
1150
1151        q = acpi_ec_create_query(&value);
1152        if (!q)
1153                return -ENOMEM;
1154
1155        /*
1156         * Query the EC to find out which _Qxx method we need to evaluate.
1157         * Note that successful completion of the query causes the ACPI_EC_SCI
1158         * bit to be cleared (and thus clearing the interrupt source).
1159         */
1160        result = acpi_ec_transaction(ec, &q->transaction);
1161        if (!value)
1162                result = -ENODATA;
1163        if (result)
1164                goto err_exit;
1165
1166        q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1167        if (!q->handler) {
1168                result = -ENODATA;
1169                goto err_exit;
1170        }
1171
1172        /*
1173         * It is reported that _Qxx are evaluated in a parallel way on
1174         * Windows:
1175         * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1176         *
1177         * Put this log entry before schedule_work() in order to make
1178         * it appearing before any other log entries occurred during the
1179         * work queue execution.
1180         */
1181        ec_dbg_evt("Query(0x%02x) scheduled", value);
1182        if (!queue_work(ec_query_wq, &q->work)) {
1183                ec_dbg_evt("Query(0x%02x) overlapped", value);
1184                result = -EBUSY;
1185        }
1186
1187err_exit:
1188        if (result)
1189                acpi_ec_delete_query(q);
1190        if (data)
1191                *data = value;
1192        return result;
1193}
1194
1195static void acpi_ec_check_event(struct acpi_ec *ec)
1196{
1197        unsigned long flags;
1198
1199        if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1200                if (ec_guard(ec)) {
1201                        spin_lock_irqsave(&ec->lock, flags);
1202                        /*
1203                         * Take care of the SCI_EVT unless no one else is
1204                         * taking care of it.
1205                         */
1206                        if (!ec->curr)
1207                                advance_transaction(ec, false);
1208                        spin_unlock_irqrestore(&ec->lock, flags);
1209                }
1210        }
1211}
1212
1213static void acpi_ec_event_handler(struct work_struct *work)
1214{
1215        unsigned long flags;
1216        struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1217
1218        ec_dbg_evt("Event started");
1219
1220        spin_lock_irqsave(&ec->lock, flags);
1221        while (ec->nr_pending_queries) {
1222                spin_unlock_irqrestore(&ec->lock, flags);
1223                (void)acpi_ec_query(ec, NULL);
1224                spin_lock_irqsave(&ec->lock, flags);
1225                ec->nr_pending_queries--;
1226                /*
1227                 * Before exit, make sure that this work item can be
1228                 * scheduled again. There might be QR_EC failures, leaving
1229                 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1230                 * item from being scheduled again.
1231                 */
1232                if (!ec->nr_pending_queries) {
1233                        if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1234                            ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1235                                acpi_ec_complete_query(ec);
1236                }
1237        }
1238        spin_unlock_irqrestore(&ec->lock, flags);
1239
1240        ec_dbg_evt("Event stopped");
1241
1242        acpi_ec_check_event(ec);
1243}
1244
1245static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1246{
1247        unsigned long flags;
1248
1249        spin_lock_irqsave(&ec->lock, flags);
1250        advance_transaction(ec, true);
1251        spin_unlock_irqrestore(&ec->lock, flags);
1252}
1253
1254static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1255                               u32 gpe_number, void *data)
1256{
1257        acpi_ec_handle_interrupt(data);
1258        return ACPI_INTERRUPT_HANDLED;
1259}
1260
1261static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1262{
1263        acpi_ec_handle_interrupt(data);
1264        return IRQ_HANDLED;
1265}
1266
1267/* --------------------------------------------------------------------------
1268 *                           Address Space Management
1269 * -------------------------------------------------------------------------- */
1270
1271static acpi_status
1272acpi_ec_space_handler(u32 function, acpi_physical_address address,
1273                      u32 bits, u64 *value64,
1274                      void *handler_context, void *region_context)
1275{
1276        struct acpi_ec *ec = handler_context;
1277        int result = 0, i, bytes = bits / 8;
1278        u8 *value = (u8 *)value64;
1279
1280        if ((address > 0xFF) || !value || !handler_context)
1281                return AE_BAD_PARAMETER;
1282
1283        if (function != ACPI_READ && function != ACPI_WRITE)
1284                return AE_BAD_PARAMETER;
1285
1286        if (ec->busy_polling || bits > 8)
1287                acpi_ec_burst_enable(ec);
1288
1289        for (i = 0; i < bytes; ++i, ++address, ++value)
1290                result = (function == ACPI_READ) ?
1291                        acpi_ec_read(ec, address, value) :
1292                        acpi_ec_write(ec, address, *value);
1293
1294        if (ec->busy_polling || bits > 8)
1295                acpi_ec_burst_disable(ec);
1296
1297        switch (result) {
1298        case -EINVAL:
1299                return AE_BAD_PARAMETER;
1300        case -ENODEV:
1301                return AE_NOT_FOUND;
1302        case -ETIME:
1303                return AE_TIME;
1304        default:
1305                return AE_OK;
1306        }
1307}
1308
1309/* --------------------------------------------------------------------------
1310 *                             Driver Interface
1311 * -------------------------------------------------------------------------- */
1312
1313static acpi_status
1314ec_parse_io_ports(struct acpi_resource *resource, void *context);
1315
1316static void acpi_ec_free(struct acpi_ec *ec)
1317{
1318        if (first_ec == ec)
1319                first_ec = NULL;
1320        if (boot_ec == ec)
1321                boot_ec = NULL;
1322        kfree(ec);
1323}
1324
1325static struct acpi_ec *acpi_ec_alloc(void)
1326{
1327        struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1328
1329        if (!ec)
1330                return NULL;
1331        mutex_init(&ec->mutex);
1332        init_waitqueue_head(&ec->wait);
1333        INIT_LIST_HEAD(&ec->list);
1334        spin_lock_init(&ec->lock);
1335        INIT_WORK(&ec->work, acpi_ec_event_handler);
1336        ec->timestamp = jiffies;
1337        ec->busy_polling = true;
1338        ec->polling_guard = 0;
1339        ec->gpe = -1;
1340        ec->irq = -1;
1341        return ec;
1342}
1343
1344static acpi_status
1345acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1346                               void *context, void **return_value)
1347{
1348        char node_name[5];
1349        struct acpi_buffer buffer = { sizeof(node_name), node_name };
1350        struct acpi_ec *ec = context;
1351        int value = 0;
1352        acpi_status status;
1353
1354        status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1355
1356        if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1357                acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1358        return AE_OK;
1359}
1360
1361static acpi_status
1362ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1363{
1364        acpi_status status;
1365        unsigned long long tmp = 0;
1366        struct acpi_ec *ec = context;
1367
1368        /* clear addr values, ec_parse_io_ports depend on it */
1369        ec->command_addr = ec->data_addr = 0;
1370
1371        status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1372                                     ec_parse_io_ports, ec);
1373        if (ACPI_FAILURE(status))
1374                return status;
1375        if (ec->data_addr == 0 || ec->command_addr == 0)
1376                return AE_OK;
1377
1378        if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1379                /*
1380                 * Always inherit the GPE number setting from the ECDT
1381                 * EC.
1382                 */
1383                ec->gpe = boot_ec->gpe;
1384        } else {
1385                /* Get GPE bit assignment (EC events). */
1386                /* TODO: Add support for _GPE returning a package */
1387                status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1388                if (ACPI_SUCCESS(status))
1389                        ec->gpe = tmp;
1390
1391                /*
1392                 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1393                 * platforms which use GpioInt instead of GPE.
1394                 */
1395        }
1396        /* Use the global lock for all EC transactions? */
1397        tmp = 0;
1398        acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1399        ec->global_lock = tmp;
1400        ec->handle = handle;
1401        return AE_CTRL_TERMINATE;
1402}
1403
1404static bool install_gpe_event_handler(struct acpi_ec *ec)
1405{
1406        acpi_status status;
1407
1408        status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1409                                              ACPI_GPE_EDGE_TRIGGERED,
1410                                              &acpi_ec_gpe_handler, ec);
1411        if (ACPI_FAILURE(status))
1412                return false;
1413
1414        if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1415                acpi_ec_enable_gpe(ec, true);
1416
1417        return true;
1418}
1419
1420static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1421{
1422        return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1423                           "ACPI EC", ec) >= 0;
1424}
1425
1426/**
1427 * ec_install_handlers - Install service callbacks and register query methods.
1428 * @ec: Target EC.
1429 * @device: ACPI device object corresponding to @ec.
1430 *
1431 * Install a handler for the EC address space type unless it has been installed
1432 * already.  If @device is not NULL, also look for EC query methods in the
1433 * namespace and register them, and install an event (either GPE or GPIO IRQ)
1434 * handler for the EC, if possible.
1435 *
1436 * Return:
1437 * -ENODEV if the address space handler cannot be installed, which means
1438 *  "unable to handle transactions",
1439 * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1440 * or 0 (success) otherwise.
1441 */
1442static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1443{
1444        acpi_status status;
1445
1446        acpi_ec_start(ec, false);
1447
1448        if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1449                acpi_ec_enter_noirq(ec);
1450                status = acpi_install_address_space_handler(ec->handle,
1451                                                            ACPI_ADR_SPACE_EC,
1452                                                            &acpi_ec_space_handler,
1453                                                            NULL, ec);
1454                if (ACPI_FAILURE(status)) {
1455                        acpi_ec_stop(ec, false);
1456                        return -ENODEV;
1457                }
1458                set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1459        }
1460
1461        if (!device)
1462                return 0;
1463
1464        if (ec->gpe < 0) {
1465                /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1466                int irq = acpi_dev_gpio_irq_get(device, 0);
1467                /*
1468                 * Bail out right away for deferred probing or complete the
1469                 * initialization regardless of any other errors.
1470                 */
1471                if (irq == -EPROBE_DEFER)
1472                        return -EPROBE_DEFER;
1473                else if (irq >= 0)
1474                        ec->irq = irq;
1475        }
1476
1477        if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1478                /* Find and register all query methods */
1479                acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1480                                    acpi_ec_register_query_methods,
1481                                    NULL, ec, NULL);
1482                set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1483        }
1484        if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1485                bool ready = false;
1486
1487                if (ec->gpe >= 0)
1488                        ready = install_gpe_event_handler(ec);
1489                else if (ec->irq >= 0)
1490                        ready = install_gpio_irq_event_handler(ec);
1491
1492                if (ready) {
1493                        set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1494                        acpi_ec_leave_noirq(ec);
1495                }
1496                /*
1497                 * Failures to install an event handler are not fatal, because
1498                 * the EC can be polled for events.
1499                 */
1500        }
1501        /* EC is fully operational, allow queries */
1502        acpi_ec_enable_event(ec);
1503
1504        return 0;
1505}
1506
1507static void ec_remove_handlers(struct acpi_ec *ec)
1508{
1509        if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1510                if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1511                                        ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1512                        pr_err("failed to remove space handler\n");
1513                clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1514        }
1515
1516        /*
1517         * Stops handling the EC transactions after removing the operation
1518         * region handler. This is required because _REG(DISCONNECT)
1519         * invoked during the removal can result in new EC transactions.
1520         *
1521         * Flushes the EC requests and thus disables the GPE before
1522         * removing the GPE handler. This is required by the current ACPICA
1523         * GPE core. ACPICA GPE core will automatically disable a GPE when
1524         * it is indicated but there is no way to handle it. So the drivers
1525         * must disable the GPEs prior to removing the GPE handlers.
1526         */
1527        acpi_ec_stop(ec, false);
1528
1529        if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1530                if (ec->gpe >= 0 &&
1531                    ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1532                                 &acpi_ec_gpe_handler)))
1533                        pr_err("failed to remove gpe handler\n");
1534
1535                if (ec->irq >= 0)
1536                        free_irq(ec->irq, ec);
1537
1538                clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1539        }
1540        if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1541                acpi_ec_remove_query_handlers(ec, true, 0);
1542                clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1543        }
1544}
1545
1546static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1547{
1548        int ret;
1549
1550        ret = ec_install_handlers(ec, device);
1551        if (ret)
1552                return ret;
1553
1554        /* First EC capable of handling transactions */
1555        if (!first_ec)
1556                first_ec = ec;
1557
1558        pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1559                ec->data_addr);
1560
1561        if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1562                if (ec->gpe >= 0)
1563                        pr_info("GPE=0x%x\n", ec->gpe);
1564                else
1565                        pr_info("IRQ=%d\n", ec->irq);
1566        }
1567
1568        return ret;
1569}
1570
1571static int acpi_ec_add(struct acpi_device *device)
1572{
1573        struct acpi_ec *ec;
1574        int ret;
1575
1576        strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1577        strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1578
1579        if (boot_ec && (boot_ec->handle == device->handle ||
1580            !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1581                /* Fast path: this device corresponds to the boot EC. */
1582                ec = boot_ec;
1583        } else {
1584                acpi_status status;
1585
1586                ec = acpi_ec_alloc();
1587                if (!ec)
1588                        return -ENOMEM;
1589
1590                status = ec_parse_device(device->handle, 0, ec, NULL);
1591                if (status != AE_CTRL_TERMINATE) {
1592                        ret = -EINVAL;
1593                        goto err;
1594                }
1595
1596                if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1597                    ec->data_addr == boot_ec->data_addr &&
1598                    !EC_FLAGS_TRUST_DSDT_GPE) {
1599                        /*
1600                         * Trust PNP0C09 namespace location rather than
1601                         * ECDT ID. But trust ECDT GPE rather than _GPE
1602                         * because of ASUS quirks, so do not change
1603                         * boot_ec->gpe to ec->gpe.
1604                         */
1605                        boot_ec->handle = ec->handle;
1606                        acpi_handle_debug(ec->handle, "duplicated.\n");
1607                        acpi_ec_free(ec);
1608                        ec = boot_ec;
1609                }
1610        }
1611
1612        ret = acpi_ec_setup(ec, device);
1613        if (ret)
1614                goto err;
1615
1616        if (ec == boot_ec)
1617                acpi_handle_info(boot_ec->handle,
1618                                 "Boot %s EC initialization complete\n",
1619                                 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1620
1621        acpi_handle_info(ec->handle,
1622                         "EC: Used to handle transactions and events\n");
1623
1624        device->driver_data = ec;
1625
1626        ret = !!request_region(ec->data_addr, 1, "EC data");
1627        WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1628        ret = !!request_region(ec->command_addr, 1, "EC cmd");
1629        WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1630
1631        /* Reprobe devices depending on the EC */
1632        acpi_walk_dep_device_list(ec->handle);
1633
1634        acpi_handle_debug(ec->handle, "enumerated.\n");
1635        return 0;
1636
1637err:
1638        if (ec != boot_ec)
1639                acpi_ec_free(ec);
1640
1641        return ret;
1642}
1643
1644static int acpi_ec_remove(struct acpi_device *device)
1645{
1646        struct acpi_ec *ec;
1647
1648        if (!device)
1649                return -EINVAL;
1650
1651        ec = acpi_driver_data(device);
1652        release_region(ec->data_addr, 1);
1653        release_region(ec->command_addr, 1);
1654        device->driver_data = NULL;
1655        if (ec != boot_ec) {
1656                ec_remove_handlers(ec);
1657                acpi_ec_free(ec);
1658        }
1659        return 0;
1660}
1661
1662static acpi_status
1663ec_parse_io_ports(struct acpi_resource *resource, void *context)
1664{
1665        struct acpi_ec *ec = context;
1666
1667        if (resource->type != ACPI_RESOURCE_TYPE_IO)
1668                return AE_OK;
1669
1670        /*
1671         * The first address region returned is the data port, and
1672         * the second address region returned is the status/command
1673         * port.
1674         */
1675        if (ec->data_addr == 0)
1676                ec->data_addr = resource->data.io.minimum;
1677        else if (ec->command_addr == 0)
1678                ec->command_addr = resource->data.io.minimum;
1679        else
1680                return AE_CTRL_TERMINATE;
1681
1682        return AE_OK;
1683}
1684
1685static const struct acpi_device_id ec_device_ids[] = {
1686        {"PNP0C09", 0},
1687        {ACPI_ECDT_HID, 0},
1688        {"", 0},
1689};
1690
1691/*
1692 * This function is not Windows-compatible as Windows never enumerates the
1693 * namespace EC before the main ACPI device enumeration process. It is
1694 * retained for historical reason and will be deprecated in the future.
1695 */
1696void __init acpi_ec_dsdt_probe(void)
1697{
1698        struct acpi_ec *ec;
1699        acpi_status status;
1700        int ret;
1701
1702        /*
1703         * If a platform has ECDT, there is no need to proceed as the
1704         * following probe is not a part of the ACPI device enumeration,
1705         * executing _STA is not safe, and thus this probe may risk of
1706         * picking up an invalid EC device.
1707         */
1708        if (boot_ec)
1709                return;
1710
1711        ec = acpi_ec_alloc();
1712        if (!ec)
1713                return;
1714
1715        /*
1716         * At this point, the namespace is initialized, so start to find
1717         * the namespace objects.
1718         */
1719        status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1720        if (ACPI_FAILURE(status) || !ec->handle) {
1721                acpi_ec_free(ec);
1722                return;
1723        }
1724
1725        /*
1726         * When the DSDT EC is available, always re-configure boot EC to
1727         * have _REG evaluated. _REG can only be evaluated after the
1728         * namespace initialization.
1729         * At this point, the GPE is not fully initialized, so do not to
1730         * handle the events.
1731         */
1732        ret = acpi_ec_setup(ec, NULL);
1733        if (ret) {
1734                acpi_ec_free(ec);
1735                return;
1736        }
1737
1738        boot_ec = ec;
1739
1740        acpi_handle_info(ec->handle,
1741                         "Boot DSDT EC used to handle transactions\n");
1742}
1743
1744/*
1745 * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1746 *
1747 * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1748 * found a matching object in the namespace.
1749 *
1750 * Next, in case the DSDT EC is not functioning, it is still necessary to
1751 * provide a functional ECDT EC to handle events, so add an extra device object
1752 * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1753 *
1754 * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1755 * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1756 */
1757static void __init acpi_ec_ecdt_start(void)
1758{
1759        struct acpi_table_ecdt *ecdt_ptr;
1760        acpi_handle handle;
1761        acpi_status status;
1762
1763        /* Bail out if a matching EC has been found in the namespace. */
1764        if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1765                return;
1766
1767        /* Look up the object pointed to from the ECDT in the namespace. */
1768        status = acpi_get_table(ACPI_SIG_ECDT, 1,
1769                                (struct acpi_table_header **)&ecdt_ptr);
1770        if (ACPI_FAILURE(status))
1771                return;
1772
1773        status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1774        if (ACPI_SUCCESS(status)) {
1775                boot_ec->handle = handle;
1776
1777                /* Add a special ACPI device object to represent the boot EC. */
1778                acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1779        }
1780
1781        acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1782}
1783
1784/*
1785 * On some hardware it is necessary to clear events accumulated by the EC during
1786 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1787 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1788 *
1789 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1790 *
1791 * Ideally, the EC should also be instructed NOT to accumulate events during
1792 * sleep (which Windows seems to do somehow), but the interface to control this
1793 * behaviour is not known at this time.
1794 *
1795 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1796 * however it is very likely that other Samsung models are affected.
1797 *
1798 * On systems which don't accumulate _Q events during sleep, this extra check
1799 * should be harmless.
1800 */
1801static int ec_clear_on_resume(const struct dmi_system_id *id)
1802{
1803        pr_debug("Detected system needing EC poll on resume.\n");
1804        EC_FLAGS_CLEAR_ON_RESUME = 1;
1805        ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1806        return 0;
1807}
1808
1809/*
1810 * Some ECDTs contain wrong register addresses.
1811 * MSI MS-171F
1812 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1813 */
1814static int ec_correct_ecdt(const struct dmi_system_id *id)
1815{
1816        pr_debug("Detected system needing ECDT address correction.\n");
1817        EC_FLAGS_CORRECT_ECDT = 1;
1818        return 0;
1819}
1820
1821/*
1822 * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1823 * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1824 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1825 */
1826static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1827{
1828        pr_debug("Detected system needing DSDT GPE setting.\n");
1829        EC_FLAGS_TRUST_DSDT_GPE = 1;
1830        return 0;
1831}
1832
1833/*
1834 * Some DSDTs contain wrong GPE setting.
1835 * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1836 * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1837 */
1838static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1839{
1840        pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1841        EC_FLAGS_IGNORE_DSDT_GPE = 1;
1842        return 0;
1843}
1844
1845static const struct dmi_system_id ec_dmi_table[] __initconst = {
1846        {
1847        ec_correct_ecdt, "MSI MS-171F", {
1848        DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1849        DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1850        {
1851        ec_honor_ecdt_gpe, "ASUS FX502VD", {
1852        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1853        DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1854        {
1855        ec_honor_ecdt_gpe, "ASUS FX502VE", {
1856        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1857        DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1858        {
1859        ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1860        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1861        DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1862        {
1863        ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BA", {
1864        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1865        DMI_MATCH(DMI_PRODUCT_NAME, "X505BA"),}, NULL},
1866        {
1867        ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BP", {
1868        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1869        DMI_MATCH(DMI_PRODUCT_NAME, "X505BP"),}, NULL},
1870        {
1871        ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BA", {
1872        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1873        DMI_MATCH(DMI_PRODUCT_NAME, "X542BA"),}, NULL},
1874        {
1875        ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BP", {
1876        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1877        DMI_MATCH(DMI_PRODUCT_NAME, "X542BP"),}, NULL},
1878        {
1879        ec_honor_ecdt_gpe, "ASUS X550VXK", {
1880        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1881        DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1882        {
1883        ec_honor_ecdt_gpe, "ASUS X580VD", {
1884        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1885        DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1886        {
1887        /* https://bugzilla.kernel.org/show_bug.cgi?id=209989 */
1888        ec_honor_dsdt_gpe, "HP Pavilion Gaming Laptop 15-cx0xxx", {
1889        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1890        DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),}, NULL},
1891        {
1892        ec_clear_on_resume, "Samsung hardware", {
1893        DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1894        {},
1895};
1896
1897void __init acpi_ec_ecdt_probe(void)
1898{
1899        struct acpi_table_ecdt *ecdt_ptr;
1900        struct acpi_ec *ec;
1901        acpi_status status;
1902        int ret;
1903
1904        /* Generate a boot ec context. */
1905        dmi_check_system(ec_dmi_table);
1906        status = acpi_get_table(ACPI_SIG_ECDT, 1,
1907                                (struct acpi_table_header **)&ecdt_ptr);
1908        if (ACPI_FAILURE(status))
1909                return;
1910
1911        if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1912                /*
1913                 * Asus X50GL:
1914                 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1915                 */
1916                goto out;
1917        }
1918
1919        ec = acpi_ec_alloc();
1920        if (!ec)
1921                goto out;
1922
1923        if (EC_FLAGS_CORRECT_ECDT) {
1924                ec->command_addr = ecdt_ptr->data.address;
1925                ec->data_addr = ecdt_ptr->control.address;
1926        } else {
1927                ec->command_addr = ecdt_ptr->control.address;
1928                ec->data_addr = ecdt_ptr->data.address;
1929        }
1930
1931        /*
1932         * Ignore the GPE value on Reduced Hardware platforms.
1933         * Some products have this set to an erroneous value.
1934         */
1935        if (!acpi_gbl_reduced_hardware)
1936                ec->gpe = ecdt_ptr->gpe;
1937
1938        ec->handle = ACPI_ROOT_OBJECT;
1939
1940        /*
1941         * At this point, the namespace is not initialized, so do not find
1942         * the namespace objects, or handle the events.
1943         */
1944        ret = acpi_ec_setup(ec, NULL);
1945        if (ret) {
1946                acpi_ec_free(ec);
1947                goto out;
1948        }
1949
1950        boot_ec = ec;
1951        boot_ec_is_ecdt = true;
1952
1953        pr_info("Boot ECDT EC used to handle transactions\n");
1954
1955out:
1956        acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1957}
1958
1959#ifdef CONFIG_PM_SLEEP
1960static int acpi_ec_suspend(struct device *dev)
1961{
1962        struct acpi_ec *ec =
1963                acpi_driver_data(to_acpi_device(dev));
1964
1965        if (!pm_suspend_no_platform() && ec_freeze_events)
1966                acpi_ec_disable_event(ec);
1967        return 0;
1968}
1969
1970static int acpi_ec_suspend_noirq(struct device *dev)
1971{
1972        struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1973
1974        /*
1975         * The SCI handler doesn't run at this point, so the GPE can be
1976         * masked at the low level without side effects.
1977         */
1978        if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1979            ec->gpe >= 0 && ec->reference_count >= 1)
1980                acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1981
1982        acpi_ec_enter_noirq(ec);
1983
1984        return 0;
1985}
1986
1987static int acpi_ec_resume_noirq(struct device *dev)
1988{
1989        struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1990
1991        acpi_ec_leave_noirq(ec);
1992
1993        if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1994            ec->gpe >= 0 && ec->reference_count >= 1)
1995                acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1996
1997        return 0;
1998}
1999
2000static int acpi_ec_resume(struct device *dev)
2001{
2002        struct acpi_ec *ec =
2003                acpi_driver_data(to_acpi_device(dev));
2004
2005        acpi_ec_enable_event(ec);
2006        return 0;
2007}
2008
2009void acpi_ec_mark_gpe_for_wake(void)
2010{
2011        if (first_ec && !ec_no_wakeup)
2012                acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2013}
2014EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2015
2016void acpi_ec_set_gpe_wake_mask(u8 action)
2017{
2018        if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2019                acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2020}
2021
2022bool acpi_ec_dispatch_gpe(void)
2023{
2024        u32 ret;
2025
2026        if (!first_ec)
2027                return acpi_any_gpe_status_set(U32_MAX);
2028
2029        /*
2030         * Report wakeup if the status bit is set for any enabled GPE other
2031         * than the EC one.
2032         */
2033        if (acpi_any_gpe_status_set(first_ec->gpe))
2034                return true;
2035
2036        /*
2037         * Dispatch the EC GPE in-band, but do not report wakeup in any case
2038         * to allow the caller to process events properly after that.
2039         */
2040        ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2041        if (ret == ACPI_INTERRUPT_HANDLED)
2042                pm_pr_dbg("ACPI EC GPE dispatched\n");
2043
2044        /* Flush the event and query workqueues. */
2045        acpi_ec_flush_work();
2046
2047        return false;
2048}
2049#endif /* CONFIG_PM_SLEEP */
2050
2051static const struct dev_pm_ops acpi_ec_pm = {
2052        SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2053        SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2054};
2055
2056static int param_set_event_clearing(const char *val,
2057                                    const struct kernel_param *kp)
2058{
2059        int result = 0;
2060
2061        if (!strncmp(val, "status", sizeof("status") - 1)) {
2062                ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2063                pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2064        } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2065                ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2066                pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2067        } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2068                ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2069                pr_info("Assuming SCI_EVT clearing on event reads\n");
2070        } else
2071                result = -EINVAL;
2072        return result;
2073}
2074
2075static int param_get_event_clearing(char *buffer,
2076                                    const struct kernel_param *kp)
2077{
2078        switch (ec_event_clearing) {
2079        case ACPI_EC_EVT_TIMING_STATUS:
2080                return sprintf(buffer, "status\n");
2081        case ACPI_EC_EVT_TIMING_QUERY:
2082                return sprintf(buffer, "query\n");
2083        case ACPI_EC_EVT_TIMING_EVENT:
2084                return sprintf(buffer, "event\n");
2085        default:
2086                return sprintf(buffer, "invalid\n");
2087        }
2088        return 0;
2089}
2090
2091module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2092                  NULL, 0644);
2093MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2094
2095static struct acpi_driver acpi_ec_driver = {
2096        .name = "ec",
2097        .class = ACPI_EC_CLASS,
2098        .ids = ec_device_ids,
2099        .ops = {
2100                .add = acpi_ec_add,
2101                .remove = acpi_ec_remove,
2102                },
2103        .drv.pm = &acpi_ec_pm,
2104};
2105
2106static void acpi_ec_destroy_workqueues(void)
2107{
2108        if (ec_wq) {
2109                destroy_workqueue(ec_wq);
2110                ec_wq = NULL;
2111        }
2112        if (ec_query_wq) {
2113                destroy_workqueue(ec_query_wq);
2114                ec_query_wq = NULL;
2115        }
2116}
2117
2118static int acpi_ec_init_workqueues(void)
2119{
2120        if (!ec_wq)
2121                ec_wq = alloc_ordered_workqueue("kec", 0);
2122
2123        if (!ec_query_wq)
2124                ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2125
2126        if (!ec_wq || !ec_query_wq) {
2127                acpi_ec_destroy_workqueues();
2128                return -ENODEV;
2129        }
2130        return 0;
2131}
2132
2133static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2134        {
2135                .ident = "Thinkpad X1 Carbon 6th",
2136                .matches = {
2137                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2138                        DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2139                },
2140        },
2141        {
2142                .ident = "ThinkPad X1 Carbon 6th",
2143                .matches = {
2144                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2145                        DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2146                },
2147        },
2148        {
2149                .ident = "ThinkPad X1 Yoga 3rd",
2150                .matches = {
2151                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2152                        DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2153                },
2154        },
2155        { },
2156};
2157
2158void __init acpi_ec_init(void)
2159{
2160        int result;
2161
2162        result = acpi_ec_init_workqueues();
2163        if (result)
2164                return;
2165
2166        /*
2167         * Disable EC wakeup on following systems to prevent periodic
2168         * wakeup from EC GPE.
2169         */
2170        if (dmi_check_system(acpi_ec_no_wakeup)) {
2171                ec_no_wakeup = true;
2172                pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2173        }
2174
2175        /* Driver must be registered after acpi_ec_init_workqueues(). */
2176        acpi_bus_register_driver(&acpi_ec_driver);
2177
2178        acpi_ec_ecdt_start();
2179}
2180
2181/* EC driver currently not unloadable */
2182#if 0
2183static void __exit acpi_ec_exit(void)
2184{
2185
2186        acpi_bus_unregister_driver(&acpi_ec_driver);
2187        acpi_ec_destroy_workqueues();
2188}
2189#endif  /* 0 */
2190