drivers/acpi/ec.c

   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 #define ACPI_EC_FILE_INFO               "info"
  38
  39 /* EC status register */
  40 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  41 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  42 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  43 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  44 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  45
  46 /*
  47  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  48  * This leads to lots of practical timing issues for the host EC driver.
  49  * The following variations are defined (from the target EC firmware's
  50  * perspective):
  51  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  52  *         target can clear SCI_EVT at any time so long as the host can see
  53  *         the indication by reading the status register (EC_SC). So the
  54  *         host should re-check SCI_EVT after the first time the SCI_EVT
  55  *         indication is seen, which is the same time the query request
  56  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  57  *         at any later time could indicate another event. Normally such
  58  *         kind of EC firmware has implemented an event queue and will
  59  *         return 0x00 to indicate "no outstanding event".
  60  * QUERY: After seeing the query request (QR_EC) written to the command
  61  *        register (EC_CMD) by the host and having prepared the responding
  62  *        event value in the data register (EC_DATA), the target can safely
  63  *        clear SCI_EVT because the target can confirm that the current
  64  *        event is being handled by the host. The host then should check
  65  *        SCI_EVT right after reading the event response from the data
  66  *        register (EC_DATA).
  67  * EVENT: After seeing the event response read from the data register
  68  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  69  *        target requires time to notice the change in the data register
  70  *        (EC_DATA), the host may be required to wait additional guarding
  71  *        time before checking the SCI_EVT again. Such guarding may not be
  72  *        necessary if the host is notified via another IRQ.
  73  */
  74 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  75 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  76 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  77
  78 /* EC commands */
  79 enum ec_command {
  80         ACPI_EC_COMMAND_READ = 0x80,
  81         ACPI_EC_COMMAND_WRITE = 0x81,
  82         ACPI_EC_BURST_ENABLE = 0x82,
  83         ACPI_EC_BURST_DISABLE = 0x83,
  84         ACPI_EC_COMMAND_QUERY = 0x84,
  85 };
  86
  87 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  88 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  89 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
  90 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  91                                          * when trying to clear the EC */
  92 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
  93
  94 enum {
  95         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
  96         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  97         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
  98         EC_FLAGS_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  99         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
 100         EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
 101         EC_FLAGS_STARTED,               /* Driver is started */
 102         EC_FLAGS_STOPPED,               /* Driver is stopped */
 103         EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 104 };
 105
 106 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 107 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 108
 109 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 110 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 111 module_param(ec_delay, uint, 0644);
 112 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 113
 114 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 115 module_param(ec_max_queries, uint, 0644);
 116 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 117
 118 static bool ec_busy_polling __read_mostly;
 119 module_param(ec_busy_polling, bool, 0644);
 120 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 121
 122 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 123 module_param(ec_polling_guard, uint, 0644);
 124 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 125
 126 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 127
 128 /*
 129  * If the number of false interrupts per one transaction exceeds
 130  * this threshold, will think there is a GPE storm happened and
 131  * will disable the GPE for normal transaction.
 132  */
 133 static unsigned int ec_storm_threshold  __read_mostly = 8;
 134 module_param(ec_storm_threshold, uint, 0644);
 135 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 136
 137 static bool ec_freeze_events __read_mostly = false;
 138 module_param(ec_freeze_events, bool, 0644);
 139 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 140
 141 static bool ec_no_wakeup __read_mostly;
 142 module_param(ec_no_wakeup, bool, 0644);
 143 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 144
 145 struct acpi_ec_query_handler {
 146         struct list_head node;
 147         acpi_ec_query_func func;
 148         acpi_handle handle;
 149         void *data;
 150         u8 query_bit;
 151         struct kref kref;
 152 };
 153
 154 struct transaction {
 155         const u8 *wdata;
 156         u8 *rdata;
 157         unsigned short irq_count;
 158         u8 command;
 159         u8 wi;
 160         u8 ri;
 161         u8 wlen;
 162         u8 rlen;
 163         u8 flags;
 164 };
 165
 166 struct acpi_ec_query {
 167         struct transaction transaction;
 168         struct work_struct work;
 169         struct acpi_ec_query_handler *handler;
 170 };
 171
 172 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 173 static void advance_transaction(struct acpi_ec *ec);
 174 static void acpi_ec_event_handler(struct work_struct *work);
 175 static void acpi_ec_event_processor(struct work_struct *work);
 176
 177 struct acpi_ec *first_ec;
 178 EXPORT_SYMBOL(first_ec);
 179
 180 static struct acpi_ec *boot_ec;
 181 static bool boot_ec_is_ecdt = false;
 182 static struct workqueue_struct *ec_wq;
 183 static struct workqueue_struct *ec_query_wq;
 184
 185 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 186 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 187 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 188 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 189
 190 /* --------------------------------------------------------------------------
 191  *                           Logging/Debugging
 192  * -------------------------------------------------------------------------- */
 193
 194 /*
 195  * Splitters used by the developers to track the boundary of the EC
 196  * handling processes.
 197  */
 198 #ifdef DEBUG
 199 #define EC_DBG_SEP      " "
 200 #define EC_DBG_DRV      "+++++"
 201 #define EC_DBG_STM      "====="
 202 #define EC_DBG_REQ      "*****"
 203 #define EC_DBG_EVT      "#####"
 204 #else
 205 #define EC_DBG_SEP      ""
 206 #define EC_DBG_DRV
 207 #define EC_DBG_STM
 208 #define EC_DBG_REQ
 209 #define EC_DBG_EVT
 210 #endif
 211
 212 #define ec_log_raw(fmt, ...) \
 213         pr_info(fmt "\n", ##__VA_ARGS__)
 214 #define ec_dbg_raw(fmt, ...) \
 215         pr_debug(fmt "\n", ##__VA_ARGS__)
 216 #define ec_log(filter, fmt, ...) \
 217         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 218 #define ec_dbg(filter, fmt, ...) \
 219         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 220
 221 #define ec_log_drv(fmt, ...) \
 222         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 223 #define ec_dbg_drv(fmt, ...) \
 224         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 225 #define ec_dbg_stm(fmt, ...) \
 226         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 227 #define ec_dbg_req(fmt, ...) \
 228         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 229 #define ec_dbg_evt(fmt, ...) \
 230         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 231 #define ec_dbg_ref(ec, fmt, ...) \
 232         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 233
 234 /* --------------------------------------------------------------------------
 235  *                           Device Flags
 236  * -------------------------------------------------------------------------- */
 237
 238 static bool acpi_ec_started(struct acpi_ec *ec)
 239 {
 240         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 241                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 242 }
 243
 244 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 245 {
 246         /*
 247          * There is an OSPM early stage logic. During the early stages
 248          * (boot/resume), OSPMs shouldn't enable the event handling, only
 249          * the EC transactions are allowed to be performed.
 250          */
 251         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 252                 return false;
 253         /*
 254          * However, disabling the event handling is experimental for late
 255          * stage (suspend), and is controlled by the boot parameter of
 256          * "ec_freeze_events":
 257          * 1. true:  The EC event handling is disabled before entering
 258          *           the noirq stage.
 259          * 2. false: The EC event handling is automatically disabled as
 260          *           soon as the EC driver is stopped.
 261          */
 262         if (ec_freeze_events)
 263                 return acpi_ec_started(ec);
 264         else
 265                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 266 }
 267
 268 static bool acpi_ec_flushed(struct acpi_ec *ec)
 269 {
 270         return ec->reference_count == 1;
 271 }
 272
 273 /* --------------------------------------------------------------------------
 274  *                           EC Registers
 275  * -------------------------------------------------------------------------- */
 276
 277 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 278 {
 279         u8 x = inb(ec->command_addr);
 280
 281         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 282                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 283                    x,
 284                    !!(x & ACPI_EC_FLAG_SCI),
 285                    !!(x & ACPI_EC_FLAG_BURST),
 286                    !!(x & ACPI_EC_FLAG_CMD),
 287                    !!(x & ACPI_EC_FLAG_IBF),
 288                    !!(x & ACPI_EC_FLAG_OBF));
 289         return x;
 290 }
 291
 292 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 293 {
 294         u8 x = inb(ec->data_addr);
 295
 296         ec->timestamp = jiffies;
 297         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 298         return x;
 299 }
 300
 301 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 302 {
 303         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 304         outb(command, ec->command_addr);
 305         ec->timestamp = jiffies;
 306 }
 307
 308 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 309 {
 310         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 311         outb(data, ec->data_addr);
 312         ec->timestamp = jiffies;
 313 }
 314
 315 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 316 static const char *acpi_ec_cmd_string(u8 cmd)
 317 {
 318         switch (cmd) {
 319         case 0x80:
 320                 return "RD_EC";
 321         case 0x81:
 322                 return "WR_EC";
 323         case 0x82:
 324                 return "BE_EC";
 325         case 0x83:
 326                 return "BD_EC";
 327         case 0x84:
 328                 return "QR_EC";
 329         }
 330         return "UNKNOWN";
 331 }
 332 #else
 333 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 334 #endif
 335
 336 /* --------------------------------------------------------------------------
 337  *                           GPE Registers
 338  * -------------------------------------------------------------------------- */
 339
 340 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 341 {
 342         acpi_event_status gpe_status = 0;
 343
 344         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 345         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 346 }
 347
 348 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 349 {
 350         if (open)
 351                 acpi_enable_gpe(NULL, ec->gpe);
 352         else {
 353                 BUG_ON(ec->reference_count < 1);
 354                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 355         }
 356         if (acpi_ec_is_gpe_raised(ec)) {
 357                 /*
 358                  * On some platforms, EN=1 writes cannot trigger GPE. So
 359                  * software need to manually trigger a pseudo GPE event on
 360                  * EN=1 writes.
 361                  */
 362                 ec_dbg_raw("Polling quirk");
 363                 advance_transaction(ec);
 364         }
 365 }
 366
 367 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 368 {
 369         if (close)
 370                 acpi_disable_gpe(NULL, ec->gpe);
 371         else {
 372                 BUG_ON(ec->reference_count < 1);
 373                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 374         }
 375 }
 376
 377 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 378 {
 379         /*
 380          * GPE STS is a W1C register, which means:
 381          * 1. Software can clear it without worrying about clearing other
 382          *    GPEs' STS bits when the hardware sets them in parallel.
 383          * 2. As long as software can ensure only clearing it when it is
 384          *    set, hardware won't set it in parallel.
 385          * So software can clear GPE in any contexts.
 386          * Warning: do not move the check into advance_transaction() as the
 387          * EC commands will be sent without GPE raised.
 388          */
 389         if (!acpi_ec_is_gpe_raised(ec))
 390                 return;
 391         acpi_clear_gpe(NULL, ec->gpe);
 392 }
 393
 394 /* --------------------------------------------------------------------------
 395  *                           Transaction Management
 396  * -------------------------------------------------------------------------- */
 397
 398 static void acpi_ec_submit_request(struct acpi_ec *ec)
 399 {
 400         ec->reference_count++;
 401         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 402             ec->gpe >= 0 && ec->reference_count == 1)
 403                 acpi_ec_enable_gpe(ec, true);
 404 }
 405
 406 static void acpi_ec_complete_request(struct acpi_ec *ec)
 407 {
 408         bool flushed = false;
 409
 410         ec->reference_count--;
 411         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 412             ec->gpe >= 0 && ec->reference_count == 0)
 413                 acpi_ec_disable_gpe(ec, true);
 414         flushed = acpi_ec_flushed(ec);
 415         if (flushed)
 416                 wake_up(&ec->wait);
 417 }
 418
 419 static void acpi_ec_mask_events(struct acpi_ec *ec)
 420 {
 421         if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 422                 if (ec->gpe >= 0)
 423                         acpi_ec_disable_gpe(ec, false);
 424                 else
 425                         disable_irq_nosync(ec->irq);
 426
 427                 ec_dbg_drv("Polling enabled");
 428                 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 429         }
 430 }
 431
 432 static void acpi_ec_unmask_events(struct acpi_ec *ec)
 433 {
 434         if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 435                 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 436                 if (ec->gpe >= 0)
 437                         acpi_ec_enable_gpe(ec, false);
 438                 else
 439                         enable_irq(ec->irq);
 440
 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_events(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                 queue_work(ec_wq, &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_events(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 /*
 503  * Process _Q events that might have accumulated in the EC.
 504  * Run with locked ec mutex.
 505  */
 506 static void acpi_ec_clear(struct acpi_ec *ec)
 507 {
 508         int i, status;
 509         u8 value = 0;
 510
 511         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 512                 status = acpi_ec_query(ec, &value);
 513                 if (status || !value)
 514                         break;
 515         }
 516         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 517                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 518         else
 519                 pr_info("%d stale EC events cleared\n", i);
 520 }
 521
 522 static void acpi_ec_enable_event(struct acpi_ec *ec)
 523 {
 524         unsigned long flags;
 525
 526         spin_lock_irqsave(&ec->lock, flags);
 527         if (acpi_ec_started(ec))
 528                 __acpi_ec_enable_event(ec);
 529         spin_unlock_irqrestore(&ec->lock, flags);
 530
 531         /* Drain additional events if hardware requires that */
 532         if (EC_FLAGS_CLEAR_ON_RESUME)
 533                 acpi_ec_clear(ec);
 534 }
 535
 536 #ifdef CONFIG_PM_SLEEP
 537 static void __acpi_ec_flush_work(void)
 538 {
 539         drain_workqueue(ec_wq); /* flush ec->work */
 540         flush_workqueue(ec_query_wq); /* flush queries */
 541 }
 542
 543 static void acpi_ec_disable_event(struct acpi_ec *ec)
 544 {
 545         unsigned long flags;
 546
 547         spin_lock_irqsave(&ec->lock, flags);
 548         __acpi_ec_disable_event(ec);
 549         spin_unlock_irqrestore(&ec->lock, flags);
 550
 551         /*
 552          * When ec_freeze_events is true, we need to flush events in
 553          * the proper position before entering the noirq stage.
 554          */
 555         __acpi_ec_flush_work();
 556 }
 557
 558 void acpi_ec_flush_work(void)
 559 {
 560         /* Without ec_wq there is nothing to flush. */
 561         if (!ec_wq)
 562                 return;
 563
 564         __acpi_ec_flush_work();
 565 }
 566 #endif /* CONFIG_PM_SLEEP */
 567
 568 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 569 {
 570         bool guarded = true;
 571         unsigned long flags;
 572
 573         spin_lock_irqsave(&ec->lock, flags);
 574         /*
 575          * If firmware SCI_EVT clearing timing is "event", we actually
 576          * don't know when the SCI_EVT will be cleared by firmware after
 577          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 578          * acceptable period.
 579          *
 580          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 581          * flagged, which means SCI_EVT check has just been performed.
 582          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 583          * guarding should have already been performed (via
 584          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 585          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 586          * ACPI_EC_COMMAND_POLL state immediately.
 587          */
 588         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 589             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 590             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 591             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 592                 guarded = false;
 593         spin_unlock_irqrestore(&ec->lock, flags);
 594         return guarded;
 595 }
 596
 597 static int ec_transaction_polled(struct acpi_ec *ec)
 598 {
 599         unsigned long flags;
 600         int ret = 0;
 601
 602         spin_lock_irqsave(&ec->lock, flags);
 603         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 604                 ret = 1;
 605         spin_unlock_irqrestore(&ec->lock, flags);
 606         return ret;
 607 }
 608
 609 static int ec_transaction_completed(struct acpi_ec *ec)
 610 {
 611         unsigned long flags;
 612         int ret = 0;
 613
 614         spin_lock_irqsave(&ec->lock, flags);
 615         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 616                 ret = 1;
 617         spin_unlock_irqrestore(&ec->lock, flags);
 618         return ret;
 619 }
 620
 621 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 622 {
 623         ec->curr->flags |= flag;
 624         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 625                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 626                     flag == ACPI_EC_COMMAND_POLL)
 627                         acpi_ec_complete_query(ec);
 628                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 629                     flag == ACPI_EC_COMMAND_COMPLETE)
 630                         acpi_ec_complete_query(ec);
 631                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 632                     flag == ACPI_EC_COMMAND_COMPLETE)
 633                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 634         }
 635 }
 636
 637 static void advance_transaction(struct acpi_ec *ec)
 638 {
 639         struct transaction *t;
 640         u8 status;
 641         bool wakeup = false;
 642
 643         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 644                    smp_processor_id());
 645         /*
 646          * By always clearing STS before handling all indications, we can
 647          * ensure a hardware STS 0->1 change after this clearing can always
 648          * trigger a GPE interrupt.
 649          */
 650         if (ec->gpe >= 0)
 651                 acpi_ec_clear_gpe(ec);
 652
 653         status = acpi_ec_read_status(ec);
 654         t = ec->curr;
 655         /*
 656          * Another IRQ or a guarded polling mode advancement is detected,
 657          * the next QR_EC submission is then allowed.
 658          */
 659         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 660                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 661                     (!ec->nr_pending_queries ||
 662                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 663                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 664                         acpi_ec_complete_query(ec);
 665                 }
 666         }
 667         if (!t)
 668                 goto err;
 669         if (t->flags & ACPI_EC_COMMAND_POLL) {
 670                 if (t->wlen > t->wi) {
 671                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 672                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 673                         else
 674                                 goto err;
 675                 } else if (t->rlen > t->ri) {
 676                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 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                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 681                                                 ec_dbg_evt("Command(%s) completed by hardware",
 682                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 683                                         wakeup = true;
 684                                 }
 685                         } else
 686                                 goto err;
 687                 } else if (t->wlen == t->wi &&
 688                            (status & ACPI_EC_FLAG_IBF) == 0) {
 689                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 690                         wakeup = true;
 691                 }
 692                 goto out;
 693         } else {
 694                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 695                     !(status & ACPI_EC_FLAG_SCI) &&
 696                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 697                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 698                         t->rdata[t->ri++] = 0x00;
 699                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 700                         ec_dbg_evt("Command(%s) completed by software",
 701                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 702                         wakeup = true;
 703                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 704                         acpi_ec_write_cmd(ec, t->command);
 705                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 706                 } else
 707                         goto err;
 708                 goto out;
 709         }
 710 err:
 711         /*
 712          * If SCI bit is set, then don't think it's a false IRQ
 713          * otherwise will take a not handled IRQ as a false one.
 714          */
 715         if (!(status & ACPI_EC_FLAG_SCI)) {
 716                 if (in_interrupt() && t) {
 717                         if (t->irq_count < ec_storm_threshold)
 718                                 ++t->irq_count;
 719                         /* Allow triggering on 0 threshold */
 720                         if (t->irq_count == ec_storm_threshold)
 721                                 acpi_ec_mask_events(ec);
 722                 }
 723         }
 724 out:
 725         if (status & ACPI_EC_FLAG_SCI)
 726                 acpi_ec_submit_query(ec);
 727         if (wakeup && in_interrupt())
 728                 wake_up(&ec->wait);
 729 }
 730
 731 static void start_transaction(struct acpi_ec *ec)
 732 {
 733         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 734         ec->curr->flags = 0;
 735 }
 736
 737 static int ec_guard(struct acpi_ec *ec)
 738 {
 739         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 740         unsigned long timeout = ec->timestamp + guard;
 741
 742         /* Ensure guarding period before polling EC status */
 743         do {
 744                 if (ec->busy_polling) {
 745                         /* Perform busy polling */
 746                         if (ec_transaction_completed(ec))
 747                                 return 0;
 748                         udelay(jiffies_to_usecs(guard));
 749                 } else {
 750                         /*
 751                          * Perform wait polling
 752                          * 1. Wait the transaction to be completed by the
 753                          *    GPE handler after the transaction enters
 754                          *    ACPI_EC_COMMAND_POLL state.
 755                          * 2. A special guarding logic is also required
 756                          *    for event clearing mode "event" before the
 757                          *    transaction enters ACPI_EC_COMMAND_POLL
 758                          *    state.
 759                          */
 760                         if (!ec_transaction_polled(ec) &&
 761                             !acpi_ec_guard_event(ec))
 762                                 break;
 763                         if (wait_event_timeout(ec->wait,
 764                                                ec_transaction_completed(ec),
 765                                                guard))
 766                                 return 0;
 767                 }
 768         } while (time_before(jiffies, timeout));
 769         return -ETIME;
 770 }
 771
 772 static int ec_poll(struct acpi_ec *ec)
 773 {
 774         unsigned long flags;
 775         int repeat = 5; /* number of command restarts */
 776
 777         while (repeat--) {
 778                 unsigned long delay = jiffies +
 779                         msecs_to_jiffies(ec_delay);
 780                 do {
 781                         if (!ec_guard(ec))
 782                                 return 0;
 783                         spin_lock_irqsave(&ec->lock, flags);
 784                         advance_transaction(ec);
 785                         spin_unlock_irqrestore(&ec->lock, flags);
 786                 } while (time_before(jiffies, delay));
 787                 pr_debug("controller reset, restart transaction\n");
 788                 spin_lock_irqsave(&ec->lock, flags);
 789                 start_transaction(ec);
 790                 spin_unlock_irqrestore(&ec->lock, flags);
 791         }
 792         return -ETIME;
 793 }
 794
 795 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 796                                         struct transaction *t)
 797 {
 798         unsigned long tmp;
 799         int ret = 0;
 800
 801         /* start transaction */
 802         spin_lock_irqsave(&ec->lock, tmp);
 803         /* Enable GPE for command processing (IBF=0/OBF=1) */
 804         if (!acpi_ec_submit_flushable_request(ec)) {
 805                 ret = -EINVAL;
 806                 goto unlock;
 807         }
 808         ec_dbg_ref(ec, "Increase command");
 809         /* following two actions should be kept atomic */
 810         ec->curr = t;
 811         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 812         start_transaction(ec);
 813         spin_unlock_irqrestore(&ec->lock, tmp);
 814
 815         ret = ec_poll(ec);
 816
 817         spin_lock_irqsave(&ec->lock, tmp);
 818         if (t->irq_count == ec_storm_threshold)
 819                 acpi_ec_unmask_events(ec);
 820         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 821         ec->curr = NULL;
 822         /* Disable GPE for command processing (IBF=0/OBF=1) */
 823         acpi_ec_complete_request(ec);
 824         ec_dbg_ref(ec, "Decrease command");
 825 unlock:
 826         spin_unlock_irqrestore(&ec->lock, tmp);
 827         return ret;
 828 }
 829
 830 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 831 {
 832         int status;
 833         u32 glk;
 834
 835         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 836                 return -EINVAL;
 837         if (t->rdata)
 838                 memset(t->rdata, 0, t->rlen);
 839
 840         mutex_lock(&ec->mutex);
 841         if (ec->global_lock) {
 842                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 843                 if (ACPI_FAILURE(status)) {
 844                         status = -ENODEV;
 845                         goto unlock;
 846                 }
 847         }
 848
 849         status = acpi_ec_transaction_unlocked(ec, t);
 850
 851         if (ec->global_lock)
 852                 acpi_release_global_lock(glk);
 853 unlock:
 854         mutex_unlock(&ec->mutex);
 855         return status;
 856 }
 857
 858 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 859 {
 860         u8 d;
 861         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 862                                 .wdata = NULL, .rdata = &d,
 863                                 .wlen = 0, .rlen = 1};
 864
 865         return acpi_ec_transaction(ec, &t);
 866 }
 867
 868 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 869 {
 870         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 871                                 .wdata = NULL, .rdata = NULL,
 872                                 .wlen = 0, .rlen = 0};
 873
 874         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 875                                 acpi_ec_transaction(ec, &t) : 0;
 876 }
 877
 878 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 879 {
 880         int result;
 881         u8 d;
 882         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 883                                 .wdata = &address, .rdata = &d,
 884                                 .wlen = 1, .rlen = 1};
 885
 886         result = acpi_ec_transaction(ec, &t);
 887         *data = d;
 888         return result;
 889 }
 890
 891 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 892 {
 893         u8 wdata[2] = { address, data };
 894         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 895                                 .wdata = wdata, .rdata = NULL,
 896                                 .wlen = 2, .rlen = 0};
 897
 898         return acpi_ec_transaction(ec, &t);
 899 }
 900
 901 int ec_read(u8 addr, u8 *val)
 902 {
 903         int err;
 904         u8 temp_data;
 905
 906         if (!first_ec)
 907                 return -ENODEV;
 908
 909         err = acpi_ec_read(first_ec, addr, &temp_data);
 910
 911         if (!err) {
 912                 *val = temp_data;
 913                 return 0;
 914         }
 915         return err;
 916 }
 917 EXPORT_SYMBOL(ec_read);
 918
 919 int ec_write(u8 addr, u8 val)
 920 {
 921         int err;
 922
 923         if (!first_ec)
 924                 return -ENODEV;
 925
 926         err = acpi_ec_write(first_ec, addr, val);
 927
 928         return err;
 929 }
 930 EXPORT_SYMBOL(ec_write);
 931
 932 int ec_transaction(u8 command,
 933                    const u8 *wdata, unsigned wdata_len,
 934                    u8 *rdata, unsigned rdata_len)
 935 {
 936         struct transaction t = {.command = command,
 937                                 .wdata = wdata, .rdata = rdata,
 938                                 .wlen = wdata_len, .rlen = rdata_len};
 939
 940         if (!first_ec)
 941                 return -ENODEV;
 942
 943         return acpi_ec_transaction(first_ec, &t);
 944 }
 945 EXPORT_SYMBOL(ec_transaction);
 946
 947 /* Get the handle to the EC device */
 948 acpi_handle ec_get_handle(void)
 949 {
 950         if (!first_ec)
 951                 return NULL;
 952         return first_ec->handle;
 953 }
 954 EXPORT_SYMBOL(ec_get_handle);
 955
 956 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 957 {
 958         unsigned long flags;
 959
 960         spin_lock_irqsave(&ec->lock, flags);
 961         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 962                 ec_dbg_drv("Starting EC");
 963                 /* Enable GPE for event processing (SCI_EVT=1) */
 964                 if (!resuming) {
 965                         acpi_ec_submit_request(ec);
 966                         ec_dbg_ref(ec, "Increase driver");
 967                 }
 968                 ec_log_drv("EC started");
 969         }
 970         spin_unlock_irqrestore(&ec->lock, flags);
 971 }
 972
 973 static bool acpi_ec_stopped(struct acpi_ec *ec)
 974 {
 975         unsigned long flags;
 976         bool flushed;
 977
 978         spin_lock_irqsave(&ec->lock, flags);
 979         flushed = acpi_ec_flushed(ec);
 980         spin_unlock_irqrestore(&ec->lock, flags);
 981         return flushed;
 982 }
 983
 984 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 985 {
 986         unsigned long flags;
 987
 988         spin_lock_irqsave(&ec->lock, flags);
 989         if (acpi_ec_started(ec)) {
 990                 ec_dbg_drv("Stopping EC");
 991                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 992                 spin_unlock_irqrestore(&ec->lock, flags);
 993                 wait_event(ec->wait, acpi_ec_stopped(ec));
 994                 spin_lock_irqsave(&ec->lock, flags);
 995                 /* Disable GPE for event processing (SCI_EVT=1) */
 996                 if (!suspending) {
 997                         acpi_ec_complete_request(ec);
 998                         ec_dbg_ref(ec, "Decrease driver");
 999                 } else if (!ec_freeze_events)
1000                         __acpi_ec_disable_event(ec);
1001                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
1002                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
1003                 ec_log_drv("EC stopped");
1004         }
1005         spin_unlock_irqrestore(&ec->lock, flags);
1006 }
1007
1008 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1009 {
1010         unsigned long flags;
1011
1012         spin_lock_irqsave(&ec->lock, flags);
1013         ec->busy_polling = true;
1014         ec->polling_guard = 0;
1015         ec_log_drv("interrupt blocked");
1016         spin_unlock_irqrestore(&ec->lock, flags);
1017 }
1018
1019 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1020 {
1021         unsigned long flags;
1022
1023         spin_lock_irqsave(&ec->lock, flags);
1024         ec->busy_polling = ec_busy_polling;
1025         ec->polling_guard = ec_polling_guard;
1026         ec_log_drv("interrupt unblocked");
1027         spin_unlock_irqrestore(&ec->lock, flags);
1028 }
1029
1030 void acpi_ec_block_transactions(void)
1031 {
1032         struct acpi_ec *ec = first_ec;
1033
1034         if (!ec)
1035                 return;
1036
1037         mutex_lock(&ec->mutex);
1038         /* Prevent transactions from being carried out */
1039         acpi_ec_stop(ec, true);
1040         mutex_unlock(&ec->mutex);
1041 }
1042
1043 void acpi_ec_unblock_transactions(void)
1044 {
1045         /*
1046          * Allow transactions to happen again (this function is called from
1047          * atomic context during wakeup, so we don't need to acquire the mutex).
1048          */
1049         if (first_ec)
1050                 acpi_ec_start(first_ec, true);
1051 }
1052
1053 /* --------------------------------------------------------------------------
1054                                 Event Management
1055    -------------------------------------------------------------------------- */
1056 static struct acpi_ec_query_handler *
1057 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1058 {
1059         struct acpi_ec_query_handler *handler;
1060
1061         mutex_lock(&ec->mutex);
1062         list_for_each_entry(handler, &ec->list, node) {
1063                 if (value == handler->query_bit) {
1064                         kref_get(&handler->kref);
1065                         mutex_unlock(&ec->mutex);
1066                         return handler;
1067                 }
1068         }
1069         mutex_unlock(&ec->mutex);
1070         return NULL;
1071 }
1072
1073 static void acpi_ec_query_handler_release(struct kref *kref)
1074 {
1075         struct acpi_ec_query_handler *handler =
1076                 container_of(kref, struct acpi_ec_query_handler, kref);
1077
1078         kfree(handler);
1079 }
1080
1081 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1082 {
1083         kref_put(&handler->kref, acpi_ec_query_handler_release);
1084 }
1085
1086 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1087                               acpi_handle handle, acpi_ec_query_func func,
1088                               void *data)
1089 {
1090         struct acpi_ec_query_handler *handler =
1091             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1092
1093         if (!handler)
1094                 return -ENOMEM;
1095
1096         handler->query_bit = query_bit;
1097         handler->handle = handle;
1098         handler->func = func;
1099         handler->data = data;
1100         mutex_lock(&ec->mutex);
1101         kref_init(&handler->kref);
1102         list_add(&handler->node, &ec->list);
1103         mutex_unlock(&ec->mutex);
1104         return 0;
1105 }
1106 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1107
1108 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1109                                           bool remove_all, u8 query_bit)
1110 {
1111         struct acpi_ec_query_handler *handler, *tmp;
1112         LIST_HEAD(free_list);
1113
1114         mutex_lock(&ec->mutex);
1115         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1116                 if (remove_all || query_bit == handler->query_bit) {
1117                         list_del_init(&handler->node);
1118                         list_add(&handler->node, &free_list);
1119                 }
1120         }
1121         mutex_unlock(&ec->mutex);
1122         list_for_each_entry_safe(handler, tmp, &free_list, node)
1123                 acpi_ec_put_query_handler(handler);
1124 }
1125
1126 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1127 {
1128         acpi_ec_remove_query_handlers(ec, false, query_bit);
1129 }
1130 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1131
1132 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1133 {
1134         struct acpi_ec_query *q;
1135         struct transaction *t;
1136
1137         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1138         if (!q)
1139                 return NULL;
1140         INIT_WORK(&q->work, acpi_ec_event_processor);
1141         t = &q->transaction;
1142         t->command = ACPI_EC_COMMAND_QUERY;
1143         t->rdata = pval;
1144         t->rlen = 1;
1145         return q;
1146 }
1147
1148 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1149 {
1150         if (q) {
1151                 if (q->handler)
1152                         acpi_ec_put_query_handler(q->handler);
1153                 kfree(q);
1154         }
1155 }
1156
1157 static void acpi_ec_event_processor(struct work_struct *work)
1158 {
1159         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1160         struct acpi_ec_query_handler *handler = q->handler;
1161
1162         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1163         if (handler->func)
1164                 handler->func(handler->data);
1165         else if (handler->handle)
1166                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1167         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1168         acpi_ec_delete_query(q);
1169 }
1170
1171 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1172 {
1173         u8 value = 0;
1174         int result;
1175         struct acpi_ec_query *q;
1176
1177         q = acpi_ec_create_query(&value);
1178         if (!q)
1179                 return -ENOMEM;
1180
1181         /*
1182          * Query the EC to find out which _Qxx method we need to evaluate.
1183          * Note that successful completion of the query causes the ACPI_EC_SCI
1184          * bit to be cleared (and thus clearing the interrupt source).
1185          */
1186         result = acpi_ec_transaction(ec, &q->transaction);
1187         if (!value)
1188                 result = -ENODATA;
1189         if (result)
1190                 goto err_exit;
1191
1192         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1193         if (!q->handler) {
1194                 result = -ENODATA;
1195                 goto err_exit;
1196         }
1197
1198         /*
1199          * It is reported that _Qxx are evaluated in a parallel way on
1200          * Windows:
1201          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1202          *
1203          * Put this log entry before schedule_work() in order to make
1204          * it appearing before any other log entries occurred during the
1205          * work queue execution.
1206          */
1207         ec_dbg_evt("Query(0x%02x) scheduled", value);
1208         if (!queue_work(ec_query_wq, &q->work)) {
1209                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1210                 result = -EBUSY;
1211         }
1212
1213 err_exit:
1214         if (result)
1215                 acpi_ec_delete_query(q);
1216         if (data)
1217                 *data = value;
1218         return result;
1219 }
1220
1221 static void acpi_ec_check_event(struct acpi_ec *ec)
1222 {
1223         unsigned long flags;
1224
1225         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1226                 if (ec_guard(ec)) {
1227                         spin_lock_irqsave(&ec->lock, flags);
1228                         /*
1229                          * Take care of the SCI_EVT unless no one else is
1230                          * taking care of it.
1231                          */
1232                         if (!ec->curr)
1233                                 advance_transaction(ec);
1234                         spin_unlock_irqrestore(&ec->lock, flags);
1235                 }
1236         }
1237 }
1238
1239 static void acpi_ec_event_handler(struct work_struct *work)
1240 {
1241         unsigned long flags;
1242         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1243
1244         ec_dbg_evt("Event started");
1245
1246         spin_lock_irqsave(&ec->lock, flags);
1247         while (ec->nr_pending_queries) {
1248                 spin_unlock_irqrestore(&ec->lock, flags);
1249                 (void)acpi_ec_query(ec, NULL);
1250                 spin_lock_irqsave(&ec->lock, flags);
1251                 ec->nr_pending_queries--;
1252                 /*
1253                  * Before exit, make sure that this work item can be
1254                  * scheduled again. There might be QR_EC failures, leaving
1255                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1256                  * item from being scheduled again.
1257                  */
1258                 if (!ec->nr_pending_queries) {
1259                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1260                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1261                                 acpi_ec_complete_query(ec);
1262                 }
1263         }
1264         spin_unlock_irqrestore(&ec->lock, flags);
1265
1266         ec_dbg_evt("Event stopped");
1267
1268         acpi_ec_check_event(ec);
1269 }
1270
1271 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1272 {
1273         unsigned long flags;
1274
1275         spin_lock_irqsave(&ec->lock, flags);
1276         advance_transaction(ec);
1277         spin_unlock_irqrestore(&ec->lock, flags);
1278 }
1279
1280 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1281                                u32 gpe_number, void *data)
1282 {
1283         acpi_ec_handle_interrupt(data);
1284         return ACPI_INTERRUPT_HANDLED;
1285 }
1286
1287 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1288 {
1289         acpi_ec_handle_interrupt(data);
1290         return IRQ_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         ec->gpe = -1;
1366         ec->irq = -1;
1367         return ec;
1368 }
1369
1370 static acpi_status
1371 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1372                                void *context, void **return_value)
1373 {
1374         char node_name[5];
1375         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1376         struct acpi_ec *ec = context;
1377         int value = 0;
1378         acpi_status status;
1379
1380         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1381
1382         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1383                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1384         return AE_OK;
1385 }
1386
1387 static acpi_status
1388 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1389 {
1390         acpi_status status;
1391         unsigned long long tmp = 0;
1392         struct acpi_ec *ec = context;
1393
1394         /* clear addr values, ec_parse_io_ports depend on it */
1395         ec->command_addr = ec->data_addr = 0;
1396
1397         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1398                                      ec_parse_io_ports, ec);
1399         if (ACPI_FAILURE(status))
1400                 return status;
1401         if (ec->data_addr == 0 || ec->command_addr == 0)
1402                 return AE_OK;
1403
1404         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1405                 /*
1406                  * Always inherit the GPE number setting from the ECDT
1407                  * EC.
1408                  */
1409                 ec->gpe = boot_ec->gpe;
1410         } else {
1411                 /* Get GPE bit assignment (EC events). */
1412                 /* TODO: Add support for _GPE returning a package */
1413                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1414                 if (ACPI_SUCCESS(status))
1415                         ec->gpe = tmp;
1416
1417                 /*
1418                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1419                  * platforms which use GpioInt instead of GPE.
1420                  */
1421         }
1422         /* Use the global lock for all EC transactions? */
1423         tmp = 0;
1424         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1425         ec->global_lock = tmp;
1426         ec->handle = handle;
1427         return AE_CTRL_TERMINATE;
1428 }
1429
1430 static bool install_gpe_event_handler(struct acpi_ec *ec)
1431 {
1432         acpi_status status;
1433
1434         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1435                                               ACPI_GPE_EDGE_TRIGGERED,
1436                                               &acpi_ec_gpe_handler, ec);
1437         if (ACPI_FAILURE(status))
1438                 return false;
1439
1440         if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1441                 acpi_ec_enable_gpe(ec, true);
1442
1443         return true;
1444 }
1445
1446 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1447 {
1448         return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1449                            "ACPI EC", ec) >= 0;
1450 }
1451
1452 /**
1453  * ec_install_handlers - Install service callbacks and register query methods.
1454  * @ec: Target EC.
1455  * @device: ACPI device object corresponding to @ec.
1456  *
1457  * Install a handler for the EC address space type unless it has been installed
1458  * already.  If @device is not NULL, also look for EC query methods in the
1459  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1460  * handler for the EC, if possible.
1461  *
1462  * Return:
1463  * -ENODEV if the address space handler cannot be installed, which means
1464  *  "unable to handle transactions",
1465  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1466  * or 0 (success) otherwise.
1467  */
1468 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1469 {
1470         acpi_status status;
1471
1472         acpi_ec_start(ec, false);
1473
1474         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1475                 acpi_ec_enter_noirq(ec);
1476                 status = acpi_install_address_space_handler(ec->handle,
1477                                                             ACPI_ADR_SPACE_EC,
1478                                                             &acpi_ec_space_handler,
1479                                                             NULL, ec);
1480                 if (ACPI_FAILURE(status)) {
1481                         acpi_ec_stop(ec, false);
1482                         return -ENODEV;
1483                 }
1484                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1485         }
1486
1487         if (!device)
1488                 return 0;
1489
1490         if (ec->gpe < 0) {
1491                 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1492                 int irq = acpi_dev_gpio_irq_get(device, 0);
1493                 /*
1494                  * Bail out right away for deferred probing or complete the
1495                  * initialization regardless of any other errors.
1496                  */
1497                 if (irq == -EPROBE_DEFER)
1498                         return -EPROBE_DEFER;
1499                 else if (irq >= 0)
1500                         ec->irq = irq;
1501         }
1502
1503         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1504                 /* Find and register all query methods */
1505                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1506                                     acpi_ec_register_query_methods,
1507                                     NULL, ec, NULL);
1508                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1509         }
1510         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1511                 bool ready = false;
1512
1513                 if (ec->gpe >= 0)
1514                         ready = install_gpe_event_handler(ec);
1515                 else if (ec->irq >= 0)
1516                         ready = install_gpio_irq_event_handler(ec);
1517
1518                 if (ready) {
1519                         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1520                         acpi_ec_leave_noirq(ec);
1521                 }
1522                 /*
1523                  * Failures to install an event handler are not fatal, because
1524                  * the EC can be polled for events.
1525                  */
1526         }
1527         /* EC is fully operational, allow queries */
1528         acpi_ec_enable_event(ec);
1529
1530         return 0;
1531 }
1532
1533 static void ec_remove_handlers(struct acpi_ec *ec)
1534 {
1535         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1536                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1537                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1538                         pr_err("failed to remove space handler\n");
1539                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1540         }
1541
1542         /*
1543          * Stops handling the EC transactions after removing the operation
1544          * region handler. This is required because _REG(DISCONNECT)
1545          * invoked during the removal can result in new EC transactions.
1546          *
1547          * Flushes the EC requests and thus disables the GPE before
1548          * removing the GPE handler. This is required by the current ACPICA
1549          * GPE core. ACPICA GPE core will automatically disable a GPE when
1550          * it is indicated but there is no way to handle it. So the drivers
1551          * must disable the GPEs prior to removing the GPE handlers.
1552          */
1553         acpi_ec_stop(ec, false);
1554
1555         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1556                 if (ec->gpe >= 0 &&
1557                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1558                                  &acpi_ec_gpe_handler)))
1559                         pr_err("failed to remove gpe handler\n");
1560
1561                 if (ec->irq >= 0)
1562                         free_irq(ec->irq, ec);
1563
1564                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1565         }
1566         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1567                 acpi_ec_remove_query_handlers(ec, true, 0);
1568                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1569         }
1570 }
1571
1572 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1573 {
1574         int ret;
1575
1576         ret = ec_install_handlers(ec, device);
1577         if (ret)
1578                 return ret;
1579
1580         /* First EC capable of handling transactions */
1581         if (!first_ec)
1582                 first_ec = ec;
1583
1584         pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1585                 ec->data_addr);
1586
1587         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1588                 if (ec->gpe >= 0)
1589                         pr_info("GPE=0x%x\n", ec->gpe);
1590                 else
1591                         pr_info("IRQ=%d\n", ec->irq);
1592         }
1593
1594         return ret;
1595 }
1596
1597 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1598 {
1599         struct acpi_table_ecdt *ecdt_ptr;
1600         acpi_status status;
1601         acpi_handle handle;
1602
1603         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1604                                 (struct acpi_table_header **)&ecdt_ptr);
1605         if (ACPI_FAILURE(status))
1606                 return false;
1607
1608         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1609         if (ACPI_FAILURE(status))
1610                 return false;
1611
1612         *phandle = handle;
1613         return true;
1614 }
1615
1616 static int acpi_ec_add(struct acpi_device *device)
1617 {
1618         struct acpi_ec *ec;
1619         int ret;
1620
1621         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1622         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1623
1624         if ((boot_ec && boot_ec->handle == device->handle) ||
1625             !strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1626                 /* Fast path: this device corresponds to the boot EC. */
1627                 ec = boot_ec;
1628         } else {
1629                 acpi_status status;
1630
1631                 ec = acpi_ec_alloc();
1632                 if (!ec)
1633                         return -ENOMEM;
1634
1635                 status = ec_parse_device(device->handle, 0, ec, NULL);
1636                 if (status != AE_CTRL_TERMINATE) {
1637                         ret = -EINVAL;
1638                         goto err;
1639                 }
1640
1641                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1642                     ec->data_addr == boot_ec->data_addr) {
1643                         boot_ec_is_ecdt = false;
1644                         /*
1645                          * Trust PNP0C09 namespace location rather than
1646                          * ECDT ID. But trust ECDT GPE rather than _GPE
1647                          * because of ASUS quirks, so do not change
1648                          * boot_ec->gpe to ec->gpe.
1649                          */
1650                         boot_ec->handle = ec->handle;
1651                         acpi_handle_debug(ec->handle, "duplicated.\n");
1652                         acpi_ec_free(ec);
1653                         ec = boot_ec;
1654                 }
1655         }
1656
1657         ret = acpi_ec_setup(ec, device);
1658         if (ret)
1659                 goto err;
1660
1661         if (ec == boot_ec)
1662                 acpi_handle_info(boot_ec->handle,
1663                                  "Boot %s EC used to handle transactions and events\n",
1664                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1665
1666         device->driver_data = ec;
1667
1668         ret = !!request_region(ec->data_addr, 1, "EC data");
1669         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1670         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1671         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1672
1673         /* Reprobe devices depending on the EC */
1674         acpi_walk_dep_device_list(ec->handle);
1675
1676         acpi_handle_debug(ec->handle, "enumerated.\n");
1677         return 0;
1678
1679 err:
1680         if (ec != boot_ec)
1681                 acpi_ec_free(ec);
1682
1683         return ret;
1684 }
1685
1686 static int acpi_ec_remove(struct acpi_device *device)
1687 {
1688         struct acpi_ec *ec;
1689
1690         if (!device)
1691                 return -EINVAL;
1692
1693         ec = acpi_driver_data(device);
1694         release_region(ec->data_addr, 1);
1695         release_region(ec->command_addr, 1);
1696         device->driver_data = NULL;
1697         if (ec != boot_ec) {
1698                 ec_remove_handlers(ec);
1699                 acpi_ec_free(ec);
1700         }
1701         return 0;
1702 }
1703
1704 static acpi_status
1705 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1706 {
1707         struct acpi_ec *ec = context;
1708
1709         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1710                 return AE_OK;
1711
1712         /*
1713          * The first address region returned is the data port, and
1714          * the second address region returned is the status/command
1715          * port.
1716          */
1717         if (ec->data_addr == 0)
1718                 ec->data_addr = resource->data.io.minimum;
1719         else if (ec->command_addr == 0)
1720                 ec->command_addr = resource->data.io.minimum;
1721         else
1722                 return AE_CTRL_TERMINATE;
1723
1724         return AE_OK;
1725 }
1726
1727 static const struct acpi_device_id ec_device_ids[] = {
1728         {"PNP0C09", 0},
1729         {ACPI_ECDT_HID, 0},
1730         {"", 0},
1731 };
1732
1733 /*
1734  * This function is not Windows-compatible as Windows never enumerates the
1735  * namespace EC before the main ACPI device enumeration process. It is
1736  * retained for historical reason and will be deprecated in the future.
1737  */
1738 void __init acpi_ec_dsdt_probe(void)
1739 {
1740         struct acpi_ec *ec;
1741         acpi_status status;
1742         int ret;
1743
1744         /*
1745          * If a platform has ECDT, there is no need to proceed as the
1746          * following probe is not a part of the ACPI device enumeration,
1747          * executing _STA is not safe, and thus this probe may risk of
1748          * picking up an invalid EC device.
1749          */
1750         if (boot_ec)
1751                 return;
1752
1753         ec = acpi_ec_alloc();
1754         if (!ec)
1755                 return;
1756
1757         /*
1758          * At this point, the namespace is initialized, so start to find
1759          * the namespace objects.
1760          */
1761         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1762         if (ACPI_FAILURE(status) || !ec->handle) {
1763                 acpi_ec_free(ec);
1764                 return;
1765         }
1766
1767         /*
1768          * When the DSDT EC is available, always re-configure boot EC to
1769          * have _REG evaluated. _REG can only be evaluated after the
1770          * namespace initialization.
1771          * At this point, the GPE is not fully initialized, so do not to
1772          * handle the events.
1773          */
1774         ret = acpi_ec_setup(ec, NULL);
1775         if (ret) {
1776                 acpi_ec_free(ec);
1777                 return;
1778         }
1779
1780         boot_ec = ec;
1781
1782         acpi_handle_info(ec->handle,
1783                          "Boot DSDT EC used to handle transactions\n");
1784 }
1785
1786 /*
1787  * If the DSDT EC is not functioning, we still need to prepare a fully
1788  * functioning ECDT EC first in order to handle the events.
1789  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1790  */
1791 static int __init acpi_ec_ecdt_start(void)
1792 {
1793         acpi_handle handle;
1794
1795         if (!boot_ec)
1796                 return -ENODEV;
1797         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1798         if (!boot_ec_is_ecdt)
1799                 return -ENODEV;
1800
1801         /*
1802          * At this point, the namespace and the GPE is initialized, so
1803          * start to find the namespace objects and handle the events.
1804          *
1805          * Note: ec->handle can be valid if this function is called after
1806          * acpi_ec_add(), hence the fast path.
1807          */
1808         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1809                 if (!acpi_ec_ecdt_get_handle(&handle))
1810                         return -ENODEV;
1811                 boot_ec->handle = handle;
1812         }
1813
1814         /* Register to ACPI bus with PM ops attached */
1815         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1816 }
1817
1818 #if 0
1819 /*
1820  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1821  * set, for which case, we complete the QR_EC without issuing it to the
1822  * firmware.
1823  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1824  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1825  */
1826 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1827 {
1828         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1829         EC_FLAGS_QUERY_HANDSHAKE = 1;
1830         return 0;
1831 }
1832 #endif
1833
1834 /*
1835  * On some hardware it is necessary to clear events accumulated by the EC during
1836  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1837  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1838  *
1839  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1840  *
1841  * Ideally, the EC should also be instructed NOT to accumulate events during
1842  * sleep (which Windows seems to do somehow), but the interface to control this
1843  * behaviour is not known at this time.
1844  *
1845  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1846  * however it is very likely that other Samsung models are affected.
1847  *
1848  * On systems which don't accumulate _Q events during sleep, this extra check
1849  * should be harmless.
1850  */
1851 static int ec_clear_on_resume(const struct dmi_system_id *id)
1852 {
1853         pr_debug("Detected system needing EC poll on resume.\n");
1854         EC_FLAGS_CLEAR_ON_RESUME = 1;
1855         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1856         return 0;
1857 }
1858
1859 /*
1860  * Some ECDTs contain wrong register addresses.
1861  * MSI MS-171F
1862  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1863  */
1864 static int ec_correct_ecdt(const struct dmi_system_id *id)
1865 {
1866         pr_debug("Detected system needing ECDT address correction.\n");
1867         EC_FLAGS_CORRECT_ECDT = 1;
1868         return 0;
1869 }
1870
1871 /*
1872  * Some DSDTs contain wrong GPE setting.
1873  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1874  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1875  */
1876 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1877 {
1878         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1879         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1880         return 0;
1881 }
1882
1883 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1884         {
1885         ec_correct_ecdt, "MSI MS-171F", {
1886         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1887         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1888         {
1889         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1890         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1891         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1892         {
1893         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1894         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1895         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1896         {
1897         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1898         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1899         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1900         {
1901         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1902         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1903         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1904         {
1905         ec_honor_ecdt_gpe, "ASUS X580VD", {
1906         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1907         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1908         {
1909         ec_clear_on_resume, "Samsung hardware", {
1910         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1911         {},
1912 };
1913
1914 void __init acpi_ec_ecdt_probe(void)
1915 {
1916         struct acpi_table_ecdt *ecdt_ptr;
1917         struct acpi_ec *ec;
1918         acpi_status status;
1919         int ret;
1920
1921         /* Generate a boot ec context. */
1922         dmi_check_system(ec_dmi_table);
1923         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1924                                 (struct acpi_table_header **)&ecdt_ptr);
1925         if (ACPI_FAILURE(status))
1926                 return;
1927
1928         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1929                 /*
1930                  * Asus X50GL:
1931                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1932                  */
1933                 return;
1934         }
1935
1936         ec = acpi_ec_alloc();
1937         if (!ec)
1938                 return;
1939
1940         if (EC_FLAGS_CORRECT_ECDT) {
1941                 ec->command_addr = ecdt_ptr->data.address;
1942                 ec->data_addr = ecdt_ptr->control.address;
1943         } else {
1944                 ec->command_addr = ecdt_ptr->control.address;
1945                 ec->data_addr = ecdt_ptr->data.address;
1946         }
1947
1948         /*
1949          * Ignore the GPE value on Reduced Hardware platforms.
1950          * Some products have this set to an erroneous value.
1951          */
1952         if (!acpi_gbl_reduced_hardware)
1953                 ec->gpe = ecdt_ptr->gpe;
1954
1955         ec->handle = ACPI_ROOT_OBJECT;
1956
1957         /*
1958          * At this point, the namespace is not initialized, so do not find
1959          * the namespace objects, or handle the events.
1960          */
1961         ret = acpi_ec_setup(ec, NULL);
1962         if (ret) {
1963                 acpi_ec_free(ec);
1964                 return;
1965         }
1966
1967         boot_ec = ec;
1968         boot_ec_is_ecdt = true;
1969
1970         pr_info("Boot ECDT EC used to handle transactions\n");
1971 }
1972
1973 #ifdef CONFIG_PM_SLEEP
1974 static int acpi_ec_suspend(struct device *dev)
1975 {
1976         struct acpi_ec *ec =
1977                 acpi_driver_data(to_acpi_device(dev));
1978
1979         if (!pm_suspend_no_platform() && ec_freeze_events)
1980                 acpi_ec_disable_event(ec);
1981         return 0;
1982 }
1983
1984 static int acpi_ec_suspend_noirq(struct device *dev)
1985 {
1986         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1987
1988         /*
1989          * The SCI handler doesn't run at this point, so the GPE can be
1990          * masked at the low level without side effects.
1991          */
1992         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1993             ec->gpe >= 0 && ec->reference_count >= 1)
1994                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1995
1996         acpi_ec_enter_noirq(ec);
1997
1998         return 0;
1999 }
2000
2001 static int acpi_ec_resume_noirq(struct device *dev)
2002 {
2003         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2004
2005         acpi_ec_leave_noirq(ec);
2006
2007         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2008             ec->gpe >= 0 && ec->reference_count >= 1)
2009                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2010
2011         return 0;
2012 }
2013
2014 static int acpi_ec_resume(struct device *dev)
2015 {
2016         struct acpi_ec *ec =
2017                 acpi_driver_data(to_acpi_device(dev));
2018
2019         acpi_ec_enable_event(ec);
2020         return 0;
2021 }
2022
2023 void acpi_ec_mark_gpe_for_wake(void)
2024 {
2025         if (first_ec && !ec_no_wakeup)
2026                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2027 }
2028 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2029
2030 void acpi_ec_set_gpe_wake_mask(u8 action)
2031 {
2032         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2033                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2034 }
2035
2036 bool acpi_ec_dispatch_gpe(void)
2037 {
2038         u32 ret;
2039
2040         if (!first_ec)
2041                 return false;
2042
2043         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2044         if (ret == ACPI_INTERRUPT_HANDLED) {
2045                 pm_pr_dbg("EC GPE dispatched\n");
2046                 return true;
2047         }
2048         return false;
2049 }
2050 #endif /* CONFIG_PM_SLEEP */
2051
2052 static const struct dev_pm_ops acpi_ec_pm = {
2053         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2054         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2055 };
2056
2057 static int param_set_event_clearing(const char *val,
2058                                     const struct kernel_param *kp)
2059 {
2060         int result = 0;
2061
2062         if (!strncmp(val, "status", sizeof("status") - 1)) {
2063                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2064                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2065         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2066                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2067                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2068         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2069                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2070                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2071         } else
2072                 result = -EINVAL;
2073         return result;
2074 }
2075
2076 static int param_get_event_clearing(char *buffer,
2077                                     const struct kernel_param *kp)
2078 {
2079         switch (ec_event_clearing) {
2080         case ACPI_EC_EVT_TIMING_STATUS:
2081                 return sprintf(buffer, "status");
2082         case ACPI_EC_EVT_TIMING_QUERY:
2083                 return sprintf(buffer, "query");
2084         case ACPI_EC_EVT_TIMING_EVENT:
2085                 return sprintf(buffer, "event");
2086         default:
2087                 return sprintf(buffer, "invalid");
2088         }
2089         return 0;
2090 }
2091
2092 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2093                   NULL, 0644);
2094 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2095
2096 static struct acpi_driver acpi_ec_driver = {
2097         .name = "ec",
2098         .class = ACPI_EC_CLASS,
2099         .ids = ec_device_ids,
2100         .ops = {
2101                 .add = acpi_ec_add,
2102                 .remove = acpi_ec_remove,
2103                 },
2104         .drv.pm = &acpi_ec_pm,
2105 };
2106
2107 static void acpi_ec_destroy_workqueues(void)
2108 {
2109         if (ec_wq) {
2110                 destroy_workqueue(ec_wq);
2111                 ec_wq = NULL;
2112         }
2113         if (ec_query_wq) {
2114                 destroy_workqueue(ec_query_wq);
2115                 ec_query_wq = NULL;
2116         }
2117 }
2118
2119 static int acpi_ec_init_workqueues(void)
2120 {
2121         if (!ec_wq)
2122                 ec_wq = alloc_ordered_workqueue("kec", 0);
2123
2124         if (!ec_query_wq)
2125                 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2126
2127         if (!ec_wq || !ec_query_wq) {
2128                 acpi_ec_destroy_workqueues();
2129                 return -ENODEV;
2130         }
2131         return 0;
2132 }
2133
2134 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2135         {
2136                 .ident = "Thinkpad X1 Carbon 6th",
2137                 .matches = {
2138                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2139                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2140                 },
2141         },
2142         {
2143                 .ident = "ThinkPad X1 Carbon 6th",
2144                 .matches = {
2145                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2146                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2147                 },
2148         },
2149         {
2150                 .ident = "ThinkPad X1 Yoga 3rd",
2151                 .matches = {
2152                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2153                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2154                 },
2155         },
2156         { },
2157 };
2158
2159 int __init acpi_ec_init(void)
2160 {
2161         int result;
2162         int ecdt_fail, dsdt_fail;
2163
2164         result = acpi_ec_init_workqueues();
2165         if (result)
2166                 return result;
2167
2168         /*
2169          * Disable EC wakeup on following systems to prevent periodic
2170          * wakeup from EC GPE.
2171          */
2172         if (dmi_check_system(acpi_ec_no_wakeup)) {
2173                 ec_no_wakeup = true;
2174                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2175         }
2176
2177         /* Drivers must be started after acpi_ec_query_init() */
2178         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2179         /*
2180          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2181          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2182          * settings but invalid DSDT settings.
2183          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2184          */
2185         ecdt_fail = acpi_ec_ecdt_start();
2186         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2187 }
2188
2189 /* EC driver currently not unloadable */
2190 #if 0
2191 static void __exit acpi_ec_exit(void)
2192 {
2193
2194         acpi_bus_unregister_driver(&acpi_ec_driver);
2195         acpi_ec_destroy_workqueues();
2196 }
2197 #endif  /* 0 */