drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v3)
   3  *
   4  *  Copyright (C) 2001-2015 Intel Corporation
   5  *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
   6  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   7  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8  *            2004       Luming Yu <luming.yu@intel.com>
   9  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  10  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  11  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  12  *
  13  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or (at
  18  *  your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful, but
  21  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23  *  General Public License for more details.
  24  *
  25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  26  */
  27
  28 /* Uncomment next line to get verbose printout */
  29 /* #define DEBUG */
  30 #define pr_fmt(fmt) "ACPI: EC: " fmt
  31
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/types.h>
  36 #include <linux/delay.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/list.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/slab.h>
  41 #include <linux/acpi.h>
  42 #include <linux/dmi.h>
  43 #include <asm/io.h>
  44
  45 #include "internal.h"
  46
  47 #define ACPI_EC_CLASS                   "embedded_controller"
  48 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  49 #define ACPI_EC_FILE_INFO               "info"
  50
  51 /* EC status register */
  52 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  53 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  54 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  55 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  56 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  57
  58 /*
  59  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  60  * This leads to lots of practical timing issues for the host EC driver.
  61  * The following variations are defined (from the target EC firmware's
  62  * perspective):
  63  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  64  *         target can clear SCI_EVT at any time so long as the host can see
  65  *         the indication by reading the status register (EC_SC). So the
  66  *         host should re-check SCI_EVT after the first time the SCI_EVT
  67  *         indication is seen, which is the same time the query request
  68  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  69  *         at any later time could indicate another event. Normally such
  70  *         kind of EC firmware has implemented an event queue and will
  71  *         return 0x00 to indicate "no outstanding event".
  72  * QUERY: After seeing the query request (QR_EC) written to the command
  73  *        register (EC_CMD) by the host and having prepared the responding
  74  *        event value in the data register (EC_DATA), the target can safely
  75  *        clear SCI_EVT because the target can confirm that the current
  76  *        event is being handled by the host. The host then should check
  77  *        SCI_EVT right after reading the event response from the data
  78  *        register (EC_DATA).
  79  * EVENT: After seeing the event response read from the data register
  80  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  81  *        target requires time to notice the change in the data register
  82  *        (EC_DATA), the host may be required to wait additional guarding
  83  *        time before checking the SCI_EVT again. Such guarding may not be
  84  *        necessary if the host is notified via another IRQ.
  85  */
  86 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  87 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  88 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  89
  90 /* EC commands */
  91 enum ec_command {
  92         ACPI_EC_COMMAND_READ = 0x80,
  93         ACPI_EC_COMMAND_WRITE = 0x81,
  94         ACPI_EC_BURST_ENABLE = 0x82,
  95         ACPI_EC_BURST_DISABLE = 0x83,
  96         ACPI_EC_COMMAND_QUERY = 0x84,
  97 };
  98
  99 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
 100 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
 101 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
 102 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
 103                                          * when trying to clear the EC */
 104 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
 105
 106 enum {
 107         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
 108         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
 109         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
 110         EC_FLAGS_GPE_HANDLER_INSTALLED, /* GPE handler installed */
 111         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
 112         EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */
 113         EC_FLAGS_STARTED,               /* Driver is started */
 114         EC_FLAGS_STOPPED,               /* Driver is stopped */
 115         EC_FLAGS_GPE_MASKED,            /* GPE masked */
 116 };
 117
 118 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 119 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 120
 121 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 122 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 123 module_param(ec_delay, uint, 0644);
 124 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 125
 126 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 127 module_param(ec_max_queries, uint, 0644);
 128 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 129
 130 static bool ec_busy_polling __read_mostly;
 131 module_param(ec_busy_polling, bool, 0644);
 132 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 133
 134 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 135 module_param(ec_polling_guard, uint, 0644);
 136 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 137
 138 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 139
 140 /*
 141  * If the number of false interrupts per one transaction exceeds
 142  * this threshold, will think there is a GPE storm happened and
 143  * will disable the GPE for normal transaction.
 144  */
 145 static unsigned int ec_storm_threshold  __read_mostly = 8;
 146 module_param(ec_storm_threshold, uint, 0644);
 147 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 148
 149 static bool ec_freeze_events __read_mostly = false;
 150 module_param(ec_freeze_events, bool, 0644);
 151 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 152
 153 static bool ec_no_wakeup __read_mostly;
 154 module_param(ec_no_wakeup, bool, 0644);
 155 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 156
 157 struct acpi_ec_query_handler {
 158         struct list_head node;
 159         acpi_ec_query_func func;
 160         acpi_handle handle;
 161         void *data;
 162         u8 query_bit;
 163         struct kref kref;
 164 };
 165
 166 struct transaction {
 167         const u8 *wdata;
 168         u8 *rdata;
 169         unsigned short irq_count;
 170         u8 command;
 171         u8 wi;
 172         u8 ri;
 173         u8 wlen;
 174         u8 rlen;
 175         u8 flags;
 176 };
 177
 178 struct acpi_ec_query {
 179         struct transaction transaction;
 180         struct work_struct work;
 181         struct acpi_ec_query_handler *handler;
 182 };
 183
 184 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 185 static void advance_transaction(struct acpi_ec *ec);
 186 static void acpi_ec_event_handler(struct work_struct *work);
 187 static void acpi_ec_event_processor(struct work_struct *work);
 188
 189 struct acpi_ec *boot_ec, *first_ec;
 190 EXPORT_SYMBOL(first_ec);
 191 static bool boot_ec_is_ecdt = false;
 192 static struct workqueue_struct *ec_query_wq;
 193
 194 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 195 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 196 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 197 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 198
 199 /* --------------------------------------------------------------------------
 200  *                           Logging/Debugging
 201  * -------------------------------------------------------------------------- */
 202
 203 /*
 204  * Splitters used by the developers to track the boundary of the EC
 205  * handling processes.
 206  */
 207 #ifdef DEBUG
 208 #define EC_DBG_SEP      " "
 209 #define EC_DBG_DRV      "+++++"
 210 #define EC_DBG_STM      "====="
 211 #define EC_DBG_REQ      "*****"
 212 #define EC_DBG_EVT      "#####"
 213 #else
 214 #define EC_DBG_SEP      ""
 215 #define EC_DBG_DRV
 216 #define EC_DBG_STM
 217 #define EC_DBG_REQ
 218 #define EC_DBG_EVT
 219 #endif
 220
 221 #define ec_log_raw(fmt, ...) \
 222         pr_info(fmt "\n", ##__VA_ARGS__)
 223 #define ec_dbg_raw(fmt, ...) \
 224         pr_debug(fmt "\n", ##__VA_ARGS__)
 225 #define ec_log(filter, fmt, ...) \
 226         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 227 #define ec_dbg(filter, fmt, ...) \
 228         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 229
 230 #define ec_log_drv(fmt, ...) \
 231         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 232 #define ec_dbg_drv(fmt, ...) \
 233         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 234 #define ec_dbg_stm(fmt, ...) \
 235         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 236 #define ec_dbg_req(fmt, ...) \
 237         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 238 #define ec_dbg_evt(fmt, ...) \
 239         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 240 #define ec_dbg_ref(ec, fmt, ...) \
 241         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 242
 243 /* --------------------------------------------------------------------------
 244  *                           Device Flags
 245  * -------------------------------------------------------------------------- */
 246
 247 static bool acpi_ec_started(struct acpi_ec *ec)
 248 {
 249         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 250                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 251 }
 252
 253 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 254 {
 255         /*
 256          * There is an OSPM early stage logic. During the early stages
 257          * (boot/resume), OSPMs shouldn't enable the event handling, only
 258          * the EC transactions are allowed to be performed.
 259          */
 260         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 261                 return false;
 262         /*
 263          * However, disabling the event handling is experimental for late
 264          * stage (suspend), and is controlled by the boot parameter of
 265          * "ec_freeze_events":
 266          * 1. true:  The EC event handling is disabled before entering
 267          *           the noirq stage.
 268          * 2. false: The EC event handling is automatically disabled as
 269          *           soon as the EC driver is stopped.
 270          */
 271         if (ec_freeze_events)
 272                 return acpi_ec_started(ec);
 273         else
 274                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 275 }
 276
 277 static bool acpi_ec_flushed(struct acpi_ec *ec)
 278 {
 279         return ec->reference_count == 1;
 280 }
 281
 282 /* --------------------------------------------------------------------------
 283  *                           EC Registers
 284  * -------------------------------------------------------------------------- */
 285
 286 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 287 {
 288         u8 x = inb(ec->command_addr);
 289
 290         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 291                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 292                    x,
 293                    !!(x & ACPI_EC_FLAG_SCI),
 294                    !!(x & ACPI_EC_FLAG_BURST),
 295                    !!(x & ACPI_EC_FLAG_CMD),
 296                    !!(x & ACPI_EC_FLAG_IBF),
 297                    !!(x & ACPI_EC_FLAG_OBF));
 298         return x;
 299 }
 300
 301 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 302 {
 303         u8 x = inb(ec->data_addr);
 304
 305         ec->timestamp = jiffies;
 306         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 307         return x;
 308 }
 309
 310 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 311 {
 312         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 313         outb(command, ec->command_addr);
 314         ec->timestamp = jiffies;
 315 }
 316
 317 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 318 {
 319         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 320         outb(data, ec->data_addr);
 321         ec->timestamp = jiffies;
 322 }
 323
 324 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 325 static const char *acpi_ec_cmd_string(u8 cmd)
 326 {
 327         switch (cmd) {
 328         case 0x80:
 329                 return "RD_EC";
 330         case 0x81:
 331                 return "WR_EC";
 332         case 0x82:
 333                 return "BE_EC";
 334         case 0x83:
 335                 return "BD_EC";
 336         case 0x84:
 337                 return "QR_EC";
 338         }
 339         return "UNKNOWN";
 340 }
 341 #else
 342 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 343 #endif
 344
 345 /* --------------------------------------------------------------------------
 346  *                           GPE Registers
 347  * -------------------------------------------------------------------------- */
 348
 349 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 350 {
 351         acpi_event_status gpe_status = 0;
 352
 353         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 354         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 355 }
 356
 357 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 358 {
 359         if (open)
 360                 acpi_enable_gpe(NULL, ec->gpe);
 361         else {
 362                 BUG_ON(ec->reference_count < 1);
 363                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 364         }
 365         if (acpi_ec_is_gpe_raised(ec)) {
 366                 /*
 367                  * On some platforms, EN=1 writes cannot trigger GPE. So
 368                  * software need to manually trigger a pseudo GPE event on
 369                  * EN=1 writes.
 370                  */
 371                 ec_dbg_raw("Polling quirk");
 372                 advance_transaction(ec);
 373         }
 374 }
 375
 376 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 377 {
 378         if (close)
 379                 acpi_disable_gpe(NULL, ec->gpe);
 380         else {
 381                 BUG_ON(ec->reference_count < 1);
 382                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 383         }
 384 }
 385
 386 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 387 {
 388         /*
 389          * GPE STS is a W1C register, which means:
 390          * 1. Software can clear it without worrying about clearing other
 391          *    GPEs' STS bits when the hardware sets them in parallel.
 392          * 2. As long as software can ensure only clearing it when it is
 393          *    set, hardware won't set it in parallel.
 394          * So software can clear GPE in any contexts.
 395          * Warning: do not move the check into advance_transaction() as the
 396          * EC commands will be sent without GPE raised.
 397          */
 398         if (!acpi_ec_is_gpe_raised(ec))
 399                 return;
 400         acpi_clear_gpe(NULL, ec->gpe);
 401 }
 402
 403 /* --------------------------------------------------------------------------
 404  *                           Transaction Management
 405  * -------------------------------------------------------------------------- */
 406
 407 static void acpi_ec_submit_request(struct acpi_ec *ec)
 408 {
 409         ec->reference_count++;
 410         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 411             ec->reference_count == 1)
 412                 acpi_ec_enable_gpe(ec, true);
 413 }
 414
 415 static void acpi_ec_complete_request(struct acpi_ec *ec)
 416 {
 417         bool flushed = false;
 418
 419         ec->reference_count--;
 420         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 421             ec->reference_count == 0)
 422                 acpi_ec_disable_gpe(ec, true);
 423         flushed = acpi_ec_flushed(ec);
 424         if (flushed)
 425                 wake_up(&ec->wait);
 426 }
 427
 428 static void acpi_ec_mask_gpe(struct acpi_ec *ec)
 429 {
 430         if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 431                 acpi_ec_disable_gpe(ec, false);
 432                 ec_dbg_drv("Polling enabled");
 433                 set_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 434         }
 435 }
 436
 437 static void acpi_ec_unmask_gpe(struct acpi_ec *ec)
 438 {
 439         if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 440                 clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 441                 acpi_ec_enable_gpe(ec, false);
 442                 ec_dbg_drv("Polling disabled");
 443         }
 444 }
 445
 446 /*
 447  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 448  *                                      the flush operation is not in
 449  *                                      progress
 450  * @ec: the EC device
 451  *
 452  * This function must be used before taking a new action that should hold
 453  * the reference count.  If this function returns false, then the action
 454  * must be discarded or it will prevent the flush operation from being
 455  * completed.
 456  */
 457 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 458 {
 459         if (!acpi_ec_started(ec))
 460                 return false;
 461         acpi_ec_submit_request(ec);
 462         return true;
 463 }
 464
 465 static void acpi_ec_submit_query(struct acpi_ec *ec)
 466 {
 467         acpi_ec_mask_gpe(ec);
 468         if (!acpi_ec_event_enabled(ec))
 469                 return;
 470         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 471                 ec_dbg_evt("Command(%s) submitted/blocked",
 472                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 473                 ec->nr_pending_queries++;
 474                 schedule_work(&ec->work);
 475         }
 476 }
 477
 478 static void acpi_ec_complete_query(struct acpi_ec *ec)
 479 {
 480         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 481                 ec_dbg_evt("Command(%s) unblocked",
 482                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 483         acpi_ec_unmask_gpe(ec);
 484 }
 485
 486 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 487 {
 488         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 489                 ec_log_drv("event unblocked");
 490         /*
 491          * Unconditionally invoke this once after enabling the event
 492          * handling mechanism to detect the pending events.
 493          */
 494         advance_transaction(ec);
 495 }
 496
 497 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 498 {
 499         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 500                 ec_log_drv("event blocked");
 501 }
 502
 503 /*
 504  * Process _Q events that might have accumulated in the EC.
 505  * Run with locked ec mutex.
 506  */
 507 static void acpi_ec_clear(struct acpi_ec *ec)
 508 {
 509         int i, status;
 510         u8 value = 0;
 511
 512         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 513                 status = acpi_ec_query(ec, &value);
 514                 if (status || !value)
 515                         break;
 516         }
 517         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 518                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 519         else
 520                 pr_info("%d stale EC events cleared\n", i);
 521 }
 522
 523 static void acpi_ec_enable_event(struct acpi_ec *ec)
 524 {
 525         unsigned long flags;
 526
 527         spin_lock_irqsave(&ec->lock, flags);
 528         if (acpi_ec_started(ec))
 529                 __acpi_ec_enable_event(ec);
 530         spin_unlock_irqrestore(&ec->lock, flags);
 531
 532         /* Drain additional events if hardware requires that */
 533         if (EC_FLAGS_CLEAR_ON_RESUME)
 534                 acpi_ec_clear(ec);
 535 }
 536
 537 #ifdef CONFIG_PM_SLEEP
 538 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
 539 {
 540         bool flushed;
 541         unsigned long flags;
 542
 543         spin_lock_irqsave(&ec->lock, flags);
 544         flushed = !ec->nr_pending_queries;
 545         spin_unlock_irqrestore(&ec->lock, flags);
 546         return flushed;
 547 }
 548
 549 static void __acpi_ec_flush_event(struct acpi_ec *ec)
 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         wait_event(ec->wait, acpi_ec_query_flushed(ec));
 556         if (ec_query_wq)
 557                 flush_workqueue(ec_query_wq);
 558 }
 559
 560 static void acpi_ec_disable_event(struct acpi_ec *ec)
 561 {
 562         unsigned long flags;
 563
 564         spin_lock_irqsave(&ec->lock, flags);
 565         __acpi_ec_disable_event(ec);
 566         spin_unlock_irqrestore(&ec->lock, flags);
 567         __acpi_ec_flush_event(ec);
 568 }
 569
 570 void acpi_ec_flush_work(void)
 571 {
 572         if (first_ec)
 573                 __acpi_ec_flush_event(first_ec);
 574
 575         flush_scheduled_work();
 576 }
 577 #endif /* CONFIG_PM_SLEEP */
 578
 579 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 580 {
 581         bool guarded = true;
 582         unsigned long flags;
 583
 584         spin_lock_irqsave(&ec->lock, flags);
 585         /*
 586          * If firmware SCI_EVT clearing timing is "event", we actually
 587          * don't know when the SCI_EVT will be cleared by firmware after
 588          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 589          * acceptable period.
 590          *
 591          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 592          * flagged, which means SCI_EVT check has just been performed.
 593          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 594          * guarding should have already been performed (via
 595          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 596          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 597          * ACPI_EC_COMMAND_POLL state immediately.
 598          */
 599         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 600             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 601             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 602             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 603                 guarded = false;
 604         spin_unlock_irqrestore(&ec->lock, flags);
 605         return guarded;
 606 }
 607
 608 static int ec_transaction_polled(struct acpi_ec *ec)
 609 {
 610         unsigned long flags;
 611         int ret = 0;
 612
 613         spin_lock_irqsave(&ec->lock, flags);
 614         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 615                 ret = 1;
 616         spin_unlock_irqrestore(&ec->lock, flags);
 617         return ret;
 618 }
 619
 620 static int ec_transaction_completed(struct acpi_ec *ec)
 621 {
 622         unsigned long flags;
 623         int ret = 0;
 624
 625         spin_lock_irqsave(&ec->lock, flags);
 626         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 627                 ret = 1;
 628         spin_unlock_irqrestore(&ec->lock, flags);
 629         return ret;
 630 }
 631
 632 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 633 {
 634         ec->curr->flags |= flag;
 635         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 636                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 637                     flag == ACPI_EC_COMMAND_POLL)
 638                         acpi_ec_complete_query(ec);
 639                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 640                     flag == ACPI_EC_COMMAND_COMPLETE)
 641                         acpi_ec_complete_query(ec);
 642                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 643                     flag == ACPI_EC_COMMAND_COMPLETE)
 644                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 645         }
 646 }
 647
 648 static void advance_transaction(struct acpi_ec *ec)
 649 {
 650         struct transaction *t;
 651         u8 status;
 652         bool wakeup = false;
 653
 654         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 655                    smp_processor_id());
 656         /*
 657          * By always clearing STS before handling all indications, we can
 658          * ensure a hardware STS 0->1 change after this clearing can always
 659          * trigger a GPE interrupt.
 660          */
 661         acpi_ec_clear_gpe(ec);
 662         status = acpi_ec_read_status(ec);
 663         t = ec->curr;
 664         /*
 665          * Another IRQ or a guarded polling mode advancement is detected,
 666          * the next QR_EC submission is then allowed.
 667          */
 668         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 669                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 670                     (!ec->nr_pending_queries ||
 671                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 672                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 673                         acpi_ec_complete_query(ec);
 674                 }
 675         }
 676         if (!t)
 677                 goto err;
 678         if (t->flags & ACPI_EC_COMMAND_POLL) {
 679                 if (t->wlen > t->wi) {
 680                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 681                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 682                         else
 683                                 goto err;
 684                 } else if (t->rlen > t->ri) {
 685                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 686                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 687                                 if (t->rlen == t->ri) {
 688                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 689                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 690                                                 ec_dbg_evt("Command(%s) completed by hardware",
 691                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 692                                         wakeup = true;
 693                                 }
 694                         } else
 695                                 goto err;
 696                 } else if (t->wlen == t->wi &&
 697                            (status & ACPI_EC_FLAG_IBF) == 0) {
 698                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 699                         wakeup = true;
 700                 }
 701                 goto out;
 702         } else {
 703                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 704                     !(status & ACPI_EC_FLAG_SCI) &&
 705                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 706                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 707                         t->rdata[t->ri++] = 0x00;
 708                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 709                         ec_dbg_evt("Command(%s) completed by software",
 710                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 711                         wakeup = true;
 712                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 713                         acpi_ec_write_cmd(ec, t->command);
 714                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 715                 } else
 716                         goto err;
 717                 goto out;
 718         }
 719 err:
 720         /*
 721          * If SCI bit is set, then don't think it's a false IRQ
 722          * otherwise will take a not handled IRQ as a false one.
 723          */
 724         if (!(status & ACPI_EC_FLAG_SCI)) {
 725                 if (in_interrupt() && t) {
 726                         if (t->irq_count < ec_storm_threshold)
 727                                 ++t->irq_count;
 728                         /* Allow triggering on 0 threshold */
 729                         if (t->irq_count == ec_storm_threshold)
 730                                 acpi_ec_mask_gpe(ec);
 731                 }
 732         }
 733 out:
 734         if (status & ACPI_EC_FLAG_SCI)
 735                 acpi_ec_submit_query(ec);
 736         if (wakeup && in_interrupt())
 737                 wake_up(&ec->wait);
 738 }
 739
 740 static void start_transaction(struct acpi_ec *ec)
 741 {
 742         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 743         ec->curr->flags = 0;
 744 }
 745
 746 static int ec_guard(struct acpi_ec *ec)
 747 {
 748         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 749         unsigned long timeout = ec->timestamp + guard;
 750
 751         /* Ensure guarding period before polling EC status */
 752         do {
 753                 if (ec->busy_polling) {
 754                         /* Perform busy polling */
 755                         if (ec_transaction_completed(ec))
 756                                 return 0;
 757                         udelay(jiffies_to_usecs(guard));
 758                 } else {
 759                         /*
 760                          * Perform wait polling
 761                          * 1. Wait the transaction to be completed by the
 762                          *    GPE handler after the transaction enters
 763                          *    ACPI_EC_COMMAND_POLL state.
 764                          * 2. A special guarding logic is also required
 765                          *    for event clearing mode "event" before the
 766                          *    transaction enters ACPI_EC_COMMAND_POLL
 767                          *    state.
 768                          */
 769                         if (!ec_transaction_polled(ec) &&
 770                             !acpi_ec_guard_event(ec))
 771                                 break;
 772                         if (wait_event_timeout(ec->wait,
 773                                                ec_transaction_completed(ec),
 774                                                guard))
 775                                 return 0;
 776                 }
 777         } while (time_before(jiffies, timeout));
 778         return -ETIME;
 779 }
 780
 781 static int ec_poll(struct acpi_ec *ec)
 782 {
 783         unsigned long flags;
 784         int repeat = 5; /* number of command restarts */
 785
 786         while (repeat--) {
 787                 unsigned long delay = jiffies +
 788                         msecs_to_jiffies(ec_delay);
 789                 do {
 790                         if (!ec_guard(ec))
 791                                 return 0;
 792                         spin_lock_irqsave(&ec->lock, flags);
 793                         advance_transaction(ec);
 794                         spin_unlock_irqrestore(&ec->lock, flags);
 795                 } while (time_before(jiffies, delay));
 796                 pr_debug("controller reset, restart transaction\n");
 797                 spin_lock_irqsave(&ec->lock, flags);
 798                 start_transaction(ec);
 799                 spin_unlock_irqrestore(&ec->lock, flags);
 800         }
 801         return -ETIME;
 802 }
 803
 804 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 805                                         struct transaction *t)
 806 {
 807         unsigned long tmp;
 808         int ret = 0;
 809
 810         /* start transaction */
 811         spin_lock_irqsave(&ec->lock, tmp);
 812         /* Enable GPE for command processing (IBF=0/OBF=1) */
 813         if (!acpi_ec_submit_flushable_request(ec)) {
 814                 ret = -EINVAL;
 815                 goto unlock;
 816         }
 817         ec_dbg_ref(ec, "Increase command");
 818         /* following two actions should be kept atomic */
 819         ec->curr = t;
 820         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 821         start_transaction(ec);
 822         spin_unlock_irqrestore(&ec->lock, tmp);
 823
 824         ret = ec_poll(ec);
 825
 826         spin_lock_irqsave(&ec->lock, tmp);
 827         if (t->irq_count == ec_storm_threshold)
 828                 acpi_ec_unmask_gpe(ec);
 829         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 830         ec->curr = NULL;
 831         /* Disable GPE for command processing (IBF=0/OBF=1) */
 832         acpi_ec_complete_request(ec);
 833         ec_dbg_ref(ec, "Decrease command");
 834 unlock:
 835         spin_unlock_irqrestore(&ec->lock, tmp);
 836         return ret;
 837 }
 838
 839 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 840 {
 841         int status;
 842         u32 glk;
 843
 844         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 845                 return -EINVAL;
 846         if (t->rdata)
 847                 memset(t->rdata, 0, t->rlen);
 848
 849         mutex_lock(&ec->mutex);
 850         if (ec->global_lock) {
 851                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 852                 if (ACPI_FAILURE(status)) {
 853                         status = -ENODEV;
 854                         goto unlock;
 855                 }
 856         }
 857
 858         status = acpi_ec_transaction_unlocked(ec, t);
 859
 860         if (ec->global_lock)
 861                 acpi_release_global_lock(glk);
 862 unlock:
 863         mutex_unlock(&ec->mutex);
 864         return status;
 865 }
 866
 867 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 868 {
 869         u8 d;
 870         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 871                                 .wdata = NULL, .rdata = &d,
 872                                 .wlen = 0, .rlen = 1};
 873
 874         return acpi_ec_transaction(ec, &t);
 875 }
 876
 877 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 878 {
 879         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 880                                 .wdata = NULL, .rdata = NULL,
 881                                 .wlen = 0, .rlen = 0};
 882
 883         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 884                                 acpi_ec_transaction(ec, &t) : 0;
 885 }
 886
 887 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 888 {
 889         int result;
 890         u8 d;
 891         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 892                                 .wdata = &address, .rdata = &d,
 893                                 .wlen = 1, .rlen = 1};
 894
 895         result = acpi_ec_transaction(ec, &t);
 896         *data = d;
 897         return result;
 898 }
 899
 900 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 901 {
 902         u8 wdata[2] = { address, data };
 903         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 904                                 .wdata = wdata, .rdata = NULL,
 905                                 .wlen = 2, .rlen = 0};
 906
 907         return acpi_ec_transaction(ec, &t);
 908 }
 909
 910 int ec_read(u8 addr, u8 *val)
 911 {
 912         int err;
 913         u8 temp_data;
 914
 915         if (!first_ec)
 916                 return -ENODEV;
 917
 918         err = acpi_ec_read(first_ec, addr, &temp_data);
 919
 920         if (!err) {
 921                 *val = temp_data;
 922                 return 0;
 923         }
 924         return err;
 925 }
 926 EXPORT_SYMBOL(ec_read);
 927
 928 int ec_write(u8 addr, u8 val)
 929 {
 930         int err;
 931
 932         if (!first_ec)
 933                 return -ENODEV;
 934
 935         err = acpi_ec_write(first_ec, addr, val);
 936
 937         return err;
 938 }
 939 EXPORT_SYMBOL(ec_write);
 940
 941 int ec_transaction(u8 command,
 942                    const u8 *wdata, unsigned wdata_len,
 943                    u8 *rdata, unsigned rdata_len)
 944 {
 945         struct transaction t = {.command = command,
 946                                 .wdata = wdata, .rdata = rdata,
 947                                 .wlen = wdata_len, .rlen = rdata_len};
 948
 949         if (!first_ec)
 950                 return -ENODEV;
 951
 952         return acpi_ec_transaction(first_ec, &t);
 953 }
 954 EXPORT_SYMBOL(ec_transaction);
 955
 956 /* Get the handle to the EC device */
 957 acpi_handle ec_get_handle(void)
 958 {
 959         if (!first_ec)
 960                 return NULL;
 961         return first_ec->handle;
 962 }
 963 EXPORT_SYMBOL(ec_get_handle);
 964
 965 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 966 {
 967         unsigned long flags;
 968
 969         spin_lock_irqsave(&ec->lock, flags);
 970         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 971                 ec_dbg_drv("Starting EC");
 972                 /* Enable GPE for event processing (SCI_EVT=1) */
 973                 if (!resuming) {
 974                         acpi_ec_submit_request(ec);
 975                         ec_dbg_ref(ec, "Increase driver");
 976                 }
 977                 ec_log_drv("EC started");
 978         }
 979         spin_unlock_irqrestore(&ec->lock, flags);
 980 }
 981
 982 static bool acpi_ec_stopped(struct acpi_ec *ec)
 983 {
 984         unsigned long flags;
 985         bool flushed;
 986
 987         spin_lock_irqsave(&ec->lock, flags);
 988         flushed = acpi_ec_flushed(ec);
 989         spin_unlock_irqrestore(&ec->lock, flags);
 990         return flushed;
 991 }
 992
 993 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 994 {
 995         unsigned long flags;
 996
 997         spin_lock_irqsave(&ec->lock, flags);
 998         if (acpi_ec_started(ec)) {
 999                 ec_dbg_drv("Stopping EC");
1000                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
1001                 spin_unlock_irqrestore(&ec->lock, flags);
1002                 wait_event(ec->wait, acpi_ec_stopped(ec));
1003                 spin_lock_irqsave(&ec->lock, flags);
1004                 /* Disable GPE for event processing (SCI_EVT=1) */
1005                 if (!suspending) {
1006                         acpi_ec_complete_request(ec);
1007                         ec_dbg_ref(ec, "Decrease driver");
1008                 } else if (!ec_freeze_events)
1009                         __acpi_ec_disable_event(ec);
1010                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
1011                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
1012                 ec_log_drv("EC stopped");
1013         }
1014         spin_unlock_irqrestore(&ec->lock, flags);
1015 }
1016
1017 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1018 {
1019         unsigned long flags;
1020
1021         spin_lock_irqsave(&ec->lock, flags);
1022         ec->busy_polling = true;
1023         ec->polling_guard = 0;
1024         ec_log_drv("interrupt blocked");
1025         spin_unlock_irqrestore(&ec->lock, flags);
1026 }
1027
1028 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1029 {
1030         unsigned long flags;
1031
1032         spin_lock_irqsave(&ec->lock, flags);
1033         ec->busy_polling = ec_busy_polling;
1034         ec->polling_guard = ec_polling_guard;
1035         ec_log_drv("interrupt unblocked");
1036         spin_unlock_irqrestore(&ec->lock, flags);
1037 }
1038
1039 void acpi_ec_block_transactions(void)
1040 {
1041         struct acpi_ec *ec = first_ec;
1042
1043         if (!ec)
1044                 return;
1045
1046         mutex_lock(&ec->mutex);
1047         /* Prevent transactions from being carried out */
1048         acpi_ec_stop(ec, true);
1049         mutex_unlock(&ec->mutex);
1050 }
1051
1052 void acpi_ec_unblock_transactions(void)
1053 {
1054         /*
1055          * Allow transactions to happen again (this function is called from
1056          * atomic context during wakeup, so we don't need to acquire the mutex).
1057          */
1058         if (first_ec)
1059                 acpi_ec_start(first_ec, true);
1060 }
1061
1062 /* --------------------------------------------------------------------------
1063                                 Event Management
1064    -------------------------------------------------------------------------- */
1065 static struct acpi_ec_query_handler *
1066 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1067 {
1068         struct acpi_ec_query_handler *handler;
1069
1070         mutex_lock(&ec->mutex);
1071         list_for_each_entry(handler, &ec->list, node) {
1072                 if (value == handler->query_bit) {
1073                         kref_get(&handler->kref);
1074                         mutex_unlock(&ec->mutex);
1075                         return handler;
1076                 }
1077         }
1078         mutex_unlock(&ec->mutex);
1079         return NULL;
1080 }
1081
1082 static void acpi_ec_query_handler_release(struct kref *kref)
1083 {
1084         struct acpi_ec_query_handler *handler =
1085                 container_of(kref, struct acpi_ec_query_handler, kref);
1086
1087         kfree(handler);
1088 }
1089
1090 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1091 {
1092         kref_put(&handler->kref, acpi_ec_query_handler_release);
1093 }
1094
1095 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1096                               acpi_handle handle, acpi_ec_query_func func,
1097                               void *data)
1098 {
1099         struct acpi_ec_query_handler *handler =
1100             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1101
1102         if (!handler)
1103                 return -ENOMEM;
1104
1105         handler->query_bit = query_bit;
1106         handler->handle = handle;
1107         handler->func = func;
1108         handler->data = data;
1109         mutex_lock(&ec->mutex);
1110         kref_init(&handler->kref);
1111         list_add(&handler->node, &ec->list);
1112         mutex_unlock(&ec->mutex);
1113         return 0;
1114 }
1115 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1116
1117 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1118                                           bool remove_all, u8 query_bit)
1119 {
1120         struct acpi_ec_query_handler *handler, *tmp;
1121         LIST_HEAD(free_list);
1122
1123         mutex_lock(&ec->mutex);
1124         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1125                 if (remove_all || query_bit == handler->query_bit) {
1126                         list_del_init(&handler->node);
1127                         list_add(&handler->node, &free_list);
1128                 }
1129         }
1130         mutex_unlock(&ec->mutex);
1131         list_for_each_entry_safe(handler, tmp, &free_list, node)
1132                 acpi_ec_put_query_handler(handler);
1133 }
1134
1135 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1136 {
1137         acpi_ec_remove_query_handlers(ec, false, query_bit);
1138 }
1139 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1140
1141 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1142 {
1143         struct acpi_ec_query *q;
1144         struct transaction *t;
1145
1146         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1147         if (!q)
1148                 return NULL;
1149         INIT_WORK(&q->work, acpi_ec_event_processor);
1150         t = &q->transaction;
1151         t->command = ACPI_EC_COMMAND_QUERY;
1152         t->rdata = pval;
1153         t->rlen = 1;
1154         return q;
1155 }
1156
1157 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1158 {
1159         if (q) {
1160                 if (q->handler)
1161                         acpi_ec_put_query_handler(q->handler);
1162                 kfree(q);
1163         }
1164 }
1165
1166 static void acpi_ec_event_processor(struct work_struct *work)
1167 {
1168         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1169         struct acpi_ec_query_handler *handler = q->handler;
1170
1171         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1172         if (handler->func)
1173                 handler->func(handler->data);
1174         else if (handler->handle)
1175                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1176         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1177         acpi_ec_delete_query(q);
1178 }
1179
1180 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1181 {
1182         u8 value = 0;
1183         int result;
1184         struct acpi_ec_query *q;
1185
1186         q = acpi_ec_create_query(&value);
1187         if (!q)
1188                 return -ENOMEM;
1189
1190         /*
1191          * Query the EC to find out which _Qxx method we need to evaluate.
1192          * Note that successful completion of the query causes the ACPI_EC_SCI
1193          * bit to be cleared (and thus clearing the interrupt source).
1194          */
1195         result = acpi_ec_transaction(ec, &q->transaction);
1196         if (!value)
1197                 result = -ENODATA;
1198         if (result)
1199                 goto err_exit;
1200
1201         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1202         if (!q->handler) {
1203                 result = -ENODATA;
1204                 goto err_exit;
1205         }
1206
1207         /*
1208          * It is reported that _Qxx are evaluated in a parallel way on
1209          * Windows:
1210          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1211          *
1212          * Put this log entry before schedule_work() in order to make
1213          * it appearing before any other log entries occurred during the
1214          * work queue execution.
1215          */
1216         ec_dbg_evt("Query(0x%02x) scheduled", value);
1217         if (!queue_work(ec_query_wq, &q->work)) {
1218                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1219                 result = -EBUSY;
1220         }
1221
1222 err_exit:
1223         if (result)
1224                 acpi_ec_delete_query(q);
1225         if (data)
1226                 *data = value;
1227         return result;
1228 }
1229
1230 static void acpi_ec_check_event(struct acpi_ec *ec)
1231 {
1232         unsigned long flags;
1233
1234         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1235                 if (ec_guard(ec)) {
1236                         spin_lock_irqsave(&ec->lock, flags);
1237                         /*
1238                          * Take care of the SCI_EVT unless no one else is
1239                          * taking care of it.
1240                          */
1241                         if (!ec->curr)
1242                                 advance_transaction(ec);
1243                         spin_unlock_irqrestore(&ec->lock, flags);
1244                 }
1245         }
1246 }
1247
1248 static void acpi_ec_event_handler(struct work_struct *work)
1249 {
1250         unsigned long flags;
1251         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1252
1253         ec_dbg_evt("Event started");
1254
1255         spin_lock_irqsave(&ec->lock, flags);
1256         while (ec->nr_pending_queries) {
1257                 spin_unlock_irqrestore(&ec->lock, flags);
1258                 (void)acpi_ec_query(ec, NULL);
1259                 spin_lock_irqsave(&ec->lock, flags);
1260                 ec->nr_pending_queries--;
1261                 /*
1262                  * Before exit, make sure that this work item can be
1263                  * scheduled again. There might be QR_EC failures, leaving
1264                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1265                  * item from being scheduled again.
1266                  */
1267                 if (!ec->nr_pending_queries) {
1268                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1269                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1270                                 acpi_ec_complete_query(ec);
1271                 }
1272         }
1273         spin_unlock_irqrestore(&ec->lock, flags);
1274
1275         ec_dbg_evt("Event stopped");
1276
1277         acpi_ec_check_event(ec);
1278 }
1279
1280 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1281         u32 gpe_number, void *data)
1282 {
1283         unsigned long flags;
1284         struct acpi_ec *ec = data;
1285
1286         spin_lock_irqsave(&ec->lock, flags);
1287         advance_transaction(ec);
1288         spin_unlock_irqrestore(&ec->lock, flags);
1289         return ACPI_INTERRUPT_HANDLED;
1290 }
1291
1292 /* --------------------------------------------------------------------------
1293  *                           Address Space Management
1294  * -------------------------------------------------------------------------- */
1295
1296 static acpi_status
1297 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1298                       u32 bits, u64 *value64,
1299                       void *handler_context, void *region_context)
1300 {
1301         struct acpi_ec *ec = handler_context;
1302         int result = 0, i, bytes = bits / 8;
1303         u8 *value = (u8 *)value64;
1304
1305         if ((address > 0xFF) || !value || !handler_context)
1306                 return AE_BAD_PARAMETER;
1307
1308         if (function != ACPI_READ && function != ACPI_WRITE)
1309                 return AE_BAD_PARAMETER;
1310
1311         if (ec->busy_polling || bits > 8)
1312                 acpi_ec_burst_enable(ec);
1313
1314         for (i = 0; i < bytes; ++i, ++address, ++value)
1315                 result = (function == ACPI_READ) ?
1316                         acpi_ec_read(ec, address, value) :
1317                         acpi_ec_write(ec, address, *value);
1318
1319         if (ec->busy_polling || bits > 8)
1320                 acpi_ec_burst_disable(ec);
1321
1322         switch (result) {
1323         case -EINVAL:
1324                 return AE_BAD_PARAMETER;
1325         case -ENODEV:
1326                 return AE_NOT_FOUND;
1327         case -ETIME:
1328                 return AE_TIME;
1329         default:
1330                 return AE_OK;
1331         }
1332 }
1333
1334 /* --------------------------------------------------------------------------
1335  *                             Driver Interface
1336  * -------------------------------------------------------------------------- */
1337
1338 static acpi_status
1339 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1340
1341 static void acpi_ec_free(struct acpi_ec *ec)
1342 {
1343         if (first_ec == ec)
1344                 first_ec = NULL;
1345         if (boot_ec == ec)
1346                 boot_ec = NULL;
1347         kfree(ec);
1348 }
1349
1350 static struct acpi_ec *acpi_ec_alloc(void)
1351 {
1352         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1353
1354         if (!ec)
1355                 return NULL;
1356         mutex_init(&ec->mutex);
1357         init_waitqueue_head(&ec->wait);
1358         INIT_LIST_HEAD(&ec->list);
1359         spin_lock_init(&ec->lock);
1360         INIT_WORK(&ec->work, acpi_ec_event_handler);
1361         ec->timestamp = jiffies;
1362         ec->busy_polling = true;
1363         ec->polling_guard = 0;
1364         return ec;
1365 }
1366
1367 static acpi_status
1368 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1369                                void *context, void **return_value)
1370 {
1371         char node_name[5];
1372         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1373         struct acpi_ec *ec = context;
1374         int value = 0;
1375         acpi_status status;
1376
1377         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1378
1379         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1380                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1381         return AE_OK;
1382 }
1383
1384 static acpi_status
1385 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1386 {
1387         acpi_status status;
1388         unsigned long long tmp = 0;
1389         struct acpi_ec *ec = context;
1390
1391         /* clear addr values, ec_parse_io_ports depend on it */
1392         ec->command_addr = ec->data_addr = 0;
1393
1394         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1395                                      ec_parse_io_ports, ec);
1396         if (ACPI_FAILURE(status))
1397                 return status;
1398         if (ec->data_addr == 0 || ec->command_addr == 0)
1399                 return AE_OK;
1400
1401         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1402                 /*
1403                  * Always inherit the GPE number setting from the ECDT
1404                  * EC.
1405                  */
1406                 ec->gpe = boot_ec->gpe;
1407         } else {
1408                 /* Get GPE bit assignment (EC events). */
1409                 /* TODO: Add support for _GPE returning a package */
1410                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1411                 if (ACPI_FAILURE(status))
1412                         return status;
1413                 ec->gpe = tmp;
1414         }
1415         /* Use the global lock for all EC transactions? */
1416         tmp = 0;
1417         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1418         ec->global_lock = tmp;
1419         ec->handle = handle;
1420         return AE_CTRL_TERMINATE;
1421 }
1422
1423 /*
1424  * Note: This function returns an error code only when the address space
1425  *       handler is not installed, which means "not able to handle
1426  *       transactions".
1427  */
1428 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1429 {
1430         acpi_status status;
1431
1432         acpi_ec_start(ec, false);
1433
1434         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1435                 acpi_ec_enter_noirq(ec);
1436                 status = acpi_install_address_space_handler(ec->handle,
1437                                                             ACPI_ADR_SPACE_EC,
1438                                                             &acpi_ec_space_handler,
1439                                                             NULL, ec);
1440                 if (ACPI_FAILURE(status)) {
1441                         if (status == AE_NOT_FOUND) {
1442                                 /*
1443                                  * Maybe OS fails in evaluating the _REG
1444                                  * object. The AE_NOT_FOUND error will be
1445                                  * ignored and OS * continue to initialize
1446                                  * EC.
1447                                  */
1448                                 pr_err("Fail in evaluating the _REG object"
1449                                         " of EC device. Broken bios is suspected.\n");
1450                         } else {
1451                                 acpi_ec_stop(ec, false);
1452                                 return -ENODEV;
1453                         }
1454                 }
1455                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1456         }
1457
1458         if (!handle_events)
1459                 return 0;
1460
1461         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1462                 /* Find and register all query methods */
1463                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1464                                     acpi_ec_register_query_methods,
1465                                     NULL, ec, NULL);
1466                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1467         }
1468         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1469                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1470                                           ACPI_GPE_EDGE_TRIGGERED,
1471                                           &acpi_ec_gpe_handler, ec);
1472                 /* This is not fatal as we can poll EC events */
1473                 if (ACPI_SUCCESS(status)) {
1474                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1475                         acpi_ec_leave_noirq(ec);
1476                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1477                             ec->reference_count >= 1)
1478                                 acpi_ec_enable_gpe(ec, true);
1479                 }
1480         }
1481         /* EC is fully operational, allow queries */
1482         acpi_ec_enable_event(ec);
1483
1484         return 0;
1485 }
1486
1487 static void ec_remove_handlers(struct acpi_ec *ec)
1488 {
1489         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1490                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1491                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1492                         pr_err("failed to remove space handler\n");
1493                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1494         }
1495
1496         /*
1497          * Stops handling the EC transactions after removing the operation
1498          * region handler. This is required because _REG(DISCONNECT)
1499          * invoked during the removal can result in new EC transactions.
1500          *
1501          * Flushes the EC requests and thus disables the GPE before
1502          * removing the GPE handler. This is required by the current ACPICA
1503          * GPE core. ACPICA GPE core will automatically disable a GPE when
1504          * it is indicated but there is no way to handle it. So the drivers
1505          * must disable the GPEs prior to removing the GPE handlers.
1506          */
1507         acpi_ec_stop(ec, false);
1508
1509         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1510                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1511                                         &acpi_ec_gpe_handler)))
1512                         pr_err("failed to remove gpe handler\n");
1513                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1514         }
1515         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1516                 acpi_ec_remove_query_handlers(ec, true, 0);
1517                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1518         }
1519 }
1520
1521 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1522 {
1523         int ret;
1524
1525         ret = ec_install_handlers(ec, handle_events);
1526         if (ret)
1527                 return ret;
1528
1529         /* First EC capable of handling transactions */
1530         if (!first_ec) {
1531                 first_ec = ec;
1532                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1533         }
1534
1535         acpi_handle_info(ec->handle,
1536                          "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1537                          ec->gpe, ec->command_addr, ec->data_addr);
1538         return ret;
1539 }
1540
1541 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1542                                bool handle_events, bool is_ecdt)
1543 {
1544         int ret;
1545
1546         /*
1547          * Changing the ACPI handle results in a re-configuration of the
1548          * boot EC. And if it happens after the namespace initialization,
1549          * it causes _REG evaluations.
1550          */
1551         if (boot_ec && boot_ec->handle != handle)
1552                 ec_remove_handlers(boot_ec);
1553
1554         /* Unset old boot EC */
1555         if (boot_ec != ec)
1556                 acpi_ec_free(boot_ec);
1557
1558         /*
1559          * ECDT device creation is split into acpi_ec_ecdt_probe() and
1560          * acpi_ec_ecdt_start(). This function takes care of completing the
1561          * ECDT parsing logic as the handle update should be performed
1562          * between the installation/uninstallation of the handlers.
1563          */
1564         if (ec->handle != handle)
1565                 ec->handle = handle;
1566
1567         ret = acpi_ec_setup(ec, handle_events);
1568         if (ret)
1569                 return ret;
1570
1571         /* Set new boot EC */
1572         if (!boot_ec) {
1573                 boot_ec = ec;
1574                 boot_ec_is_ecdt = is_ecdt;
1575         }
1576
1577         acpi_handle_info(boot_ec->handle,
1578                          "Used as boot %s EC to handle transactions%s\n",
1579                          is_ecdt ? "ECDT" : "DSDT",
1580                          handle_events ? " and events" : "");
1581         return ret;
1582 }
1583
1584 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1585 {
1586         struct acpi_table_ecdt *ecdt_ptr;
1587         acpi_status status;
1588         acpi_handle handle;
1589
1590         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1591                                 (struct acpi_table_header **)&ecdt_ptr);
1592         if (ACPI_FAILURE(status))
1593                 return false;
1594
1595         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1596         if (ACPI_FAILURE(status))
1597                 return false;
1598
1599         *phandle = handle;
1600         return true;
1601 }
1602
1603 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1604 {
1605         if (!boot_ec)
1606                 return false;
1607         if (ec->command_addr == boot_ec->command_addr &&
1608             ec->data_addr == boot_ec->data_addr)
1609                 return true;
1610         return false;
1611 }
1612
1613 static int acpi_ec_add(struct acpi_device *device)
1614 {
1615         struct acpi_ec *ec = NULL;
1616         int ret;
1617         bool is_ecdt = false;
1618         acpi_status status;
1619
1620         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1621         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1622
1623         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1624                 is_ecdt = true;
1625                 ec = boot_ec;
1626         } else {
1627                 ec = acpi_ec_alloc();
1628                 if (!ec)
1629                         return -ENOMEM;
1630                 status = ec_parse_device(device->handle, 0, ec, NULL);
1631                 if (status != AE_CTRL_TERMINATE) {
1632                         ret = -EINVAL;
1633                         goto err_alloc;
1634                 }
1635         }
1636
1637         if (acpi_is_boot_ec(ec)) {
1638                 boot_ec_is_ecdt = is_ecdt;
1639                 if (!is_ecdt) {
1640                         /*
1641                          * Trust PNP0C09 namespace location rather than
1642                          * ECDT ID. But trust ECDT GPE rather than _GPE
1643                          * because of ASUS quirks, so do not change
1644                          * boot_ec->gpe to ec->gpe.
1645                          */
1646                         boot_ec->handle = ec->handle;
1647                         acpi_handle_debug(ec->handle, "duplicated.\n");
1648                         acpi_ec_free(ec);
1649                         ec = boot_ec;
1650                 }
1651                 ret = acpi_config_boot_ec(ec, ec->handle, true, is_ecdt);
1652         } else
1653                 ret = acpi_ec_setup(ec, true);
1654         if (ret)
1655                 goto err_query;
1656
1657         device->driver_data = ec;
1658
1659         ret = !!request_region(ec->data_addr, 1, "EC data");
1660         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1661         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1662         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1663
1664         if (!is_ecdt) {
1665                 /* Reprobe devices depending on the EC */
1666                 acpi_walk_dep_device_list(ec->handle);
1667         }
1668         acpi_handle_debug(ec->handle, "enumerated.\n");
1669         return 0;
1670
1671 err_query:
1672         if (ec != boot_ec)
1673                 acpi_ec_remove_query_handlers(ec, true, 0);
1674 err_alloc:
1675         if (ec != boot_ec)
1676                 acpi_ec_free(ec);
1677         return ret;
1678 }
1679
1680 static int acpi_ec_remove(struct acpi_device *device)
1681 {
1682         struct acpi_ec *ec;
1683
1684         if (!device)
1685                 return -EINVAL;
1686
1687         ec = acpi_driver_data(device);
1688         release_region(ec->data_addr, 1);
1689         release_region(ec->command_addr, 1);
1690         device->driver_data = NULL;
1691         if (ec != boot_ec) {
1692                 ec_remove_handlers(ec);
1693                 acpi_ec_free(ec);
1694         }
1695         return 0;
1696 }
1697
1698 static acpi_status
1699 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1700 {
1701         struct acpi_ec *ec = context;
1702
1703         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1704                 return AE_OK;
1705
1706         /*
1707          * The first address region returned is the data port, and
1708          * the second address region returned is the status/command
1709          * port.
1710          */
1711         if (ec->data_addr == 0)
1712                 ec->data_addr = resource->data.io.minimum;
1713         else if (ec->command_addr == 0)
1714                 ec->command_addr = resource->data.io.minimum;
1715         else
1716                 return AE_CTRL_TERMINATE;
1717
1718         return AE_OK;
1719 }
1720
1721 static const struct acpi_device_id ec_device_ids[] = {
1722         {"PNP0C09", 0},
1723         {ACPI_ECDT_HID, 0},
1724         {"", 0},
1725 };
1726
1727 /*
1728  * This function is not Windows-compatible as Windows never enumerates the
1729  * namespace EC before the main ACPI device enumeration process. It is
1730  * retained for historical reason and will be deprecated in the future.
1731  */
1732 int __init acpi_ec_dsdt_probe(void)
1733 {
1734         acpi_status status;
1735         struct acpi_ec *ec;
1736         int ret;
1737
1738         /*
1739          * If a platform has ECDT, there is no need to proceed as the
1740          * following probe is not a part of the ACPI device enumeration,
1741          * executing _STA is not safe, and thus this probe may risk of
1742          * picking up an invalid EC device.
1743          */
1744         if (boot_ec)
1745                 return -ENODEV;
1746
1747         ec = acpi_ec_alloc();
1748         if (!ec)
1749                 return -ENOMEM;
1750         /*
1751          * At this point, the namespace is initialized, so start to find
1752          * the namespace objects.
1753          */
1754         status = acpi_get_devices(ec_device_ids[0].id,
1755                                   ec_parse_device, ec, NULL);
1756         if (ACPI_FAILURE(status) || !ec->handle) {
1757                 ret = -ENODEV;
1758                 goto error;
1759         }
1760         /*
1761          * When the DSDT EC is available, always re-configure boot EC to
1762          * have _REG evaluated. _REG can only be evaluated after the
1763          * namespace initialization.
1764          * At this point, the GPE is not fully initialized, so do not to
1765          * handle the events.
1766          */
1767         ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1768 error:
1769         if (ret)
1770                 acpi_ec_free(ec);
1771         return ret;
1772 }
1773
1774 /*
1775  * If the DSDT EC is not functioning, we still need to prepare a fully
1776  * functioning ECDT EC first in order to handle the events.
1777  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1778  */
1779 static int __init acpi_ec_ecdt_start(void)
1780 {
1781         acpi_handle handle;
1782
1783         if (!boot_ec)
1784                 return -ENODEV;
1785         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1786         if (!boot_ec_is_ecdt)
1787                 return -ENODEV;
1788
1789         /*
1790          * At this point, the namespace and the GPE is initialized, so
1791          * start to find the namespace objects and handle the events.
1792          *
1793          * Note: ec->handle can be valid if this function is called after
1794          * acpi_ec_add(), hence the fast path.
1795          */
1796         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1797                 if (!acpi_ec_ecdt_get_handle(&handle))
1798                         return -ENODEV;
1799                 boot_ec->handle = handle;
1800         }
1801
1802         /* Register to ACPI bus with PM ops attached */
1803         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1804 }
1805
1806 #if 0
1807 /*
1808  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1809  * set, for which case, we complete the QR_EC without issuing it to the
1810  * firmware.
1811  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1812  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1813  */
1814 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1815 {
1816         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1817         EC_FLAGS_QUERY_HANDSHAKE = 1;
1818         return 0;
1819 }
1820 #endif
1821
1822 /*
1823  * On some hardware it is necessary to clear events accumulated by the EC during
1824  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1825  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1826  *
1827  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1828  *
1829  * Ideally, the EC should also be instructed NOT to accumulate events during
1830  * sleep (which Windows seems to do somehow), but the interface to control this
1831  * behaviour is not known at this time.
1832  *
1833  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1834  * however it is very likely that other Samsung models are affected.
1835  *
1836  * On systems which don't accumulate _Q events during sleep, this extra check
1837  * should be harmless.
1838  */
1839 static int ec_clear_on_resume(const struct dmi_system_id *id)
1840 {
1841         pr_debug("Detected system needing EC poll on resume.\n");
1842         EC_FLAGS_CLEAR_ON_RESUME = 1;
1843         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1844         return 0;
1845 }
1846
1847 /*
1848  * Some ECDTs contain wrong register addresses.
1849  * MSI MS-171F
1850  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1851  */
1852 static int ec_correct_ecdt(const struct dmi_system_id *id)
1853 {
1854         pr_debug("Detected system needing ECDT address correction.\n");
1855         EC_FLAGS_CORRECT_ECDT = 1;
1856         return 0;
1857 }
1858
1859 /*
1860  * Some DSDTs contain wrong GPE setting.
1861  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1862  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1863  */
1864 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1865 {
1866         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1867         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1868         return 0;
1869 }
1870
1871 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1872         {
1873         ec_correct_ecdt, "MSI MS-171F", {
1874         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1875         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1876         {
1877         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1878         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1879         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1880         {
1881         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1882         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1883         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1884         {
1885         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1886         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1887         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1888         {
1889         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BA", {
1890         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1891         DMI_MATCH(DMI_PRODUCT_NAME, "X505BA"),}, NULL},
1892         {
1893         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BP", {
1894         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1895         DMI_MATCH(DMI_PRODUCT_NAME, "X505BP"),}, NULL},
1896         {
1897         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BA", {
1898         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1899         DMI_MATCH(DMI_PRODUCT_NAME, "X542BA"),}, NULL},
1900         {
1901         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BP", {
1902         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1903         DMI_MATCH(DMI_PRODUCT_NAME, "X542BP"),}, NULL},
1904         {
1905         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1906         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1907         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1908         {
1909         ec_honor_ecdt_gpe, "ASUS X580VD", {
1910         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1911         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1912         {
1913         ec_clear_on_resume, "Samsung hardware", {
1914         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1915         {},
1916 };
1917
1918 int __init acpi_ec_ecdt_probe(void)
1919 {
1920         int ret;
1921         acpi_status status;
1922         struct acpi_table_ecdt *ecdt_ptr;
1923         struct acpi_ec *ec;
1924
1925         ec = acpi_ec_alloc();
1926         if (!ec)
1927                 return -ENOMEM;
1928         /*
1929          * Generate a boot ec context
1930          */
1931         dmi_check_system(ec_dmi_table);
1932         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1933                                 (struct acpi_table_header **)&ecdt_ptr);
1934         if (ACPI_FAILURE(status)) {
1935                 ret = -ENODEV;
1936                 goto error;
1937         }
1938
1939         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1940                 /*
1941                  * Asus X50GL:
1942                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1943                  */
1944                 ret = -ENODEV;
1945                 goto error;
1946         }
1947
1948         if (EC_FLAGS_CORRECT_ECDT) {
1949                 ec->command_addr = ecdt_ptr->data.address;
1950                 ec->data_addr = ecdt_ptr->control.address;
1951         } else {
1952                 ec->command_addr = ecdt_ptr->control.address;
1953                 ec->data_addr = ecdt_ptr->data.address;
1954         }
1955         ec->gpe = ecdt_ptr->gpe;
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_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1962 error:
1963         if (ret)
1964                 acpi_ec_free(ec);
1965         return ret;
1966 }
1967
1968 #ifdef CONFIG_PM_SLEEP
1969 static int acpi_ec_suspend(struct device *dev)
1970 {
1971         struct acpi_ec *ec =
1972                 acpi_driver_data(to_acpi_device(dev));
1973
1974         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1975                 acpi_ec_disable_event(ec);
1976         return 0;
1977 }
1978
1979 static int acpi_ec_suspend_noirq(struct device *dev)
1980 {
1981         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1982
1983         /*
1984          * The SCI handler doesn't run at this point, so the GPE can be
1985          * masked at the low level without side effects.
1986          */
1987         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1988             ec->reference_count >= 1)
1989                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1990
1991         if (acpi_sleep_no_ec_events())
1992                 acpi_ec_enter_noirq(ec);
1993
1994         return 0;
1995 }
1996
1997 static int acpi_ec_resume_noirq(struct device *dev)
1998 {
1999         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2000
2001         if (acpi_sleep_no_ec_events())
2002                 acpi_ec_leave_noirq(ec);
2003
2004         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2005             ec->reference_count >= 1)
2006                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2007
2008         return 0;
2009 }
2010
2011 static int acpi_ec_resume(struct device *dev)
2012 {
2013         struct acpi_ec *ec =
2014                 acpi_driver_data(to_acpi_device(dev));
2015
2016         acpi_ec_enable_event(ec);
2017         return 0;
2018 }
2019 #endif
2020
2021 static const struct dev_pm_ops acpi_ec_pm = {
2022         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2023         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2024 };
2025
2026 static int param_set_event_clearing(const char *val, struct kernel_param *kp)
2027 {
2028         int result = 0;
2029
2030         if (!strncmp(val, "status", sizeof("status") - 1)) {
2031                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2032                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2033         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2034                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2035                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2036         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2037                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2038                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2039         } else
2040                 result = -EINVAL;
2041         return result;
2042 }
2043
2044 static int param_get_event_clearing(char *buffer, struct kernel_param *kp)
2045 {
2046         switch (ec_event_clearing) {
2047         case ACPI_EC_EVT_TIMING_STATUS:
2048                 return sprintf(buffer, "status");
2049         case ACPI_EC_EVT_TIMING_QUERY:
2050                 return sprintf(buffer, "query");
2051         case ACPI_EC_EVT_TIMING_EVENT:
2052                 return sprintf(buffer, "event");
2053         default:
2054                 return sprintf(buffer, "invalid");
2055         }
2056         return 0;
2057 }
2058
2059 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2060                   NULL, 0644);
2061 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2062
2063 static struct acpi_driver acpi_ec_driver = {
2064         .name = "ec",
2065         .class = ACPI_EC_CLASS,
2066         .ids = ec_device_ids,
2067         .ops = {
2068                 .add = acpi_ec_add,
2069                 .remove = acpi_ec_remove,
2070                 },
2071         .drv.pm = &acpi_ec_pm,
2072 };
2073
2074 static inline int acpi_ec_query_init(void)
2075 {
2076         if (!ec_query_wq) {
2077                 ec_query_wq = alloc_workqueue("kec_query", 0,
2078                                               ec_max_queries);
2079                 if (!ec_query_wq)
2080                         return -ENODEV;
2081         }
2082         return 0;
2083 }
2084
2085 static inline void acpi_ec_query_exit(void)
2086 {
2087         if (ec_query_wq) {
2088                 destroy_workqueue(ec_query_wq);
2089                 ec_query_wq = NULL;
2090         }
2091 }
2092
2093 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2094         {
2095                 .ident = "Thinkpad X1 Carbon 6th",
2096                 .matches = {
2097                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2098                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2099                 },
2100         },
2101         { },
2102 };
2103
2104 int __init acpi_ec_init(void)
2105 {
2106         int result;
2107         int ecdt_fail, dsdt_fail;
2108
2109         /* register workqueue for _Qxx evaluations */
2110         result = acpi_ec_query_init();
2111         if (result)
2112                 return result;
2113
2114         /*
2115          * Disable EC wakeup on following systems to prevent periodic
2116          * wakeup from EC GPE.
2117          */
2118         if (dmi_check_system(acpi_ec_no_wakeup)) {
2119                 ec_no_wakeup = true;
2120                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2121         }
2122
2123         /* Drivers must be started after acpi_ec_query_init() */
2124         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2125         /*
2126          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2127          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2128          * settings but invalid DSDT settings.
2129          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2130          */
2131         ecdt_fail = acpi_ec_ecdt_start();
2132         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2133 }
2134
2135 /* EC driver currently not unloadable */
2136 #if 0
2137 static void __exit acpi_ec_exit(void)
2138 {
2139
2140         acpi_bus_unregister_driver(&acpi_ec_driver);
2141         acpi_ec_query_exit();
2142 }
2143 #endif  /* 0 */