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_GPE_HANDLER_INSTALLED, /* GPE handler installed */
  99         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
 100         EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */
 101         EC_FLAGS_STARTED,               /* Driver is started */
 102         EC_FLAGS_STOPPED,               /* Driver is stopped */
 103         EC_FLAGS_GPE_MASKED,            /* GPE 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_query_wq;
 183
 184 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 185 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 186 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 187 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 188
 189 /* --------------------------------------------------------------------------
 190  *                           Logging/Debugging
 191  * -------------------------------------------------------------------------- */
 192
 193 /*
 194  * Splitters used by the developers to track the boundary of the EC
 195  * handling processes.
 196  */
 197 #ifdef DEBUG
 198 #define EC_DBG_SEP      " "
 199 #define EC_DBG_DRV      "+++++"
 200 #define EC_DBG_STM      "====="
 201 #define EC_DBG_REQ      "*****"
 202 #define EC_DBG_EVT      "#####"
 203 #else
 204 #define EC_DBG_SEP      ""
 205 #define EC_DBG_DRV
 206 #define EC_DBG_STM
 207 #define EC_DBG_REQ
 208 #define EC_DBG_EVT
 209 #endif
 210
 211 #define ec_log_raw(fmt, ...) \
 212         pr_info(fmt "\n", ##__VA_ARGS__)
 213 #define ec_dbg_raw(fmt, ...) \
 214         pr_debug(fmt "\n", ##__VA_ARGS__)
 215 #define ec_log(filter, fmt, ...) \
 216         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 217 #define ec_dbg(filter, fmt, ...) \
 218         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 219
 220 #define ec_log_drv(fmt, ...) \
 221         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 222 #define ec_dbg_drv(fmt, ...) \
 223         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 224 #define ec_dbg_stm(fmt, ...) \
 225         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 226 #define ec_dbg_req(fmt, ...) \
 227         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 228 #define ec_dbg_evt(fmt, ...) \
 229         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 230 #define ec_dbg_ref(ec, fmt, ...) \
 231         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 232
 233 /* --------------------------------------------------------------------------
 234  *                           Device Flags
 235  * -------------------------------------------------------------------------- */
 236
 237 static bool acpi_ec_started(struct acpi_ec *ec)
 238 {
 239         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 240                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 241 }
 242
 243 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 244 {
 245         /*
 246          * There is an OSPM early stage logic. During the early stages
 247          * (boot/resume), OSPMs shouldn't enable the event handling, only
 248          * the EC transactions are allowed to be performed.
 249          */
 250         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 251                 return false;
 252         /*
 253          * However, disabling the event handling is experimental for late
 254          * stage (suspend), and is controlled by the boot parameter of
 255          * "ec_freeze_events":
 256          * 1. true:  The EC event handling is disabled before entering
 257          *           the noirq stage.
 258          * 2. false: The EC event handling is automatically disabled as
 259          *           soon as the EC driver is stopped.
 260          */
 261         if (ec_freeze_events)
 262                 return acpi_ec_started(ec);
 263         else
 264                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 265 }
 266
 267 static bool acpi_ec_flushed(struct acpi_ec *ec)
 268 {
 269         return ec->reference_count == 1;
 270 }
 271
 272 /* --------------------------------------------------------------------------
 273  *                           EC Registers
 274  * -------------------------------------------------------------------------- */
 275
 276 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 277 {
 278         u8 x = inb(ec->command_addr);
 279
 280         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 281                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 282                    x,
 283                    !!(x & ACPI_EC_FLAG_SCI),
 284                    !!(x & ACPI_EC_FLAG_BURST),
 285                    !!(x & ACPI_EC_FLAG_CMD),
 286                    !!(x & ACPI_EC_FLAG_IBF),
 287                    !!(x & ACPI_EC_FLAG_OBF));
 288         return x;
 289 }
 290
 291 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 292 {
 293         u8 x = inb(ec->data_addr);
 294
 295         ec->timestamp = jiffies;
 296         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 297         return x;
 298 }
 299
 300 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 301 {
 302         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 303         outb(command, ec->command_addr);
 304         ec->timestamp = jiffies;
 305 }
 306
 307 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 308 {
 309         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 310         outb(data, ec->data_addr);
 311         ec->timestamp = jiffies;
 312 }
 313
 314 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 315 static const char *acpi_ec_cmd_string(u8 cmd)
 316 {
 317         switch (cmd) {
 318         case 0x80:
 319                 return "RD_EC";
 320         case 0x81:
 321                 return "WR_EC";
 322         case 0x82:
 323                 return "BE_EC";
 324         case 0x83:
 325                 return "BD_EC";
 326         case 0x84:
 327                 return "QR_EC";
 328         }
 329         return "UNKNOWN";
 330 }
 331 #else
 332 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 333 #endif
 334
 335 /* --------------------------------------------------------------------------
 336  *                           GPE Registers
 337  * -------------------------------------------------------------------------- */
 338
 339 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 340 {
 341         acpi_event_status gpe_status = 0;
 342
 343         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 344         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 345 }
 346
 347 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 348 {
 349         if (open)
 350                 acpi_enable_gpe(NULL, ec->gpe);
 351         else {
 352                 BUG_ON(ec->reference_count < 1);
 353                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 354         }
 355         if (acpi_ec_is_gpe_raised(ec)) {
 356                 /*
 357                  * On some platforms, EN=1 writes cannot trigger GPE. So
 358                  * software need to manually trigger a pseudo GPE event on
 359                  * EN=1 writes.
 360                  */
 361                 ec_dbg_raw("Polling quirk");
 362                 advance_transaction(ec);
 363         }
 364 }
 365
 366 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 367 {
 368         if (close)
 369                 acpi_disable_gpe(NULL, ec->gpe);
 370         else {
 371                 BUG_ON(ec->reference_count < 1);
 372                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 373         }
 374 }
 375
 376 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 377 {
 378         /*
 379          * GPE STS is a W1C register, which means:
 380          * 1. Software can clear it without worrying about clearing other
 381          *    GPEs' STS bits when the hardware sets them in parallel.
 382          * 2. As long as software can ensure only clearing it when it is
 383          *    set, hardware won't set it in parallel.
 384          * So software can clear GPE in any contexts.
 385          * Warning: do not move the check into advance_transaction() as the
 386          * EC commands will be sent without GPE raised.
 387          */
 388         if (!acpi_ec_is_gpe_raised(ec))
 389                 return;
 390         acpi_clear_gpe(NULL, ec->gpe);
 391 }
 392
 393 /* --------------------------------------------------------------------------
 394  *                           Transaction Management
 395  * -------------------------------------------------------------------------- */
 396
 397 static void acpi_ec_submit_request(struct acpi_ec *ec)
 398 {
 399         ec->reference_count++;
 400         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 401             ec->reference_count == 1)
 402                 acpi_ec_enable_gpe(ec, true);
 403 }
 404
 405 static void acpi_ec_complete_request(struct acpi_ec *ec)
 406 {
 407         bool flushed = false;
 408
 409         ec->reference_count--;
 410         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 411             ec->reference_count == 0)
 412                 acpi_ec_disable_gpe(ec, true);
 413         flushed = acpi_ec_flushed(ec);
 414         if (flushed)
 415                 wake_up(&ec->wait);
 416 }
 417
 418 static void acpi_ec_mask_gpe(struct acpi_ec *ec)
 419 {
 420         if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 421                 acpi_ec_disable_gpe(ec, false);
 422                 ec_dbg_drv("Polling enabled");
 423                 set_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 424         }
 425 }
 426
 427 static void acpi_ec_unmask_gpe(struct acpi_ec *ec)
 428 {
 429         if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 430                 clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 431                 acpi_ec_enable_gpe(ec, false);
 432                 ec_dbg_drv("Polling disabled");
 433         }
 434 }
 435
 436 /*
 437  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 438  *                                      the flush operation is not in
 439  *                                      progress
 440  * @ec: the EC device
 441  *
 442  * This function must be used before taking a new action that should hold
 443  * the reference count.  If this function returns false, then the action
 444  * must be discarded or it will prevent the flush operation from being
 445  * completed.
 446  */
 447 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 448 {
 449         if (!acpi_ec_started(ec))
 450                 return false;
 451         acpi_ec_submit_request(ec);
 452         return true;
 453 }
 454
 455 static void acpi_ec_submit_query(struct acpi_ec *ec)
 456 {
 457         acpi_ec_mask_gpe(ec);
 458         if (!acpi_ec_event_enabled(ec))
 459                 return;
 460         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 461                 ec_dbg_evt("Command(%s) submitted/blocked",
 462                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 463                 ec->nr_pending_queries++;
 464                 schedule_work(&ec->work);
 465         }
 466 }
 467
 468 static void acpi_ec_complete_query(struct acpi_ec *ec)
 469 {
 470         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 471                 ec_dbg_evt("Command(%s) unblocked",
 472                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 473         acpi_ec_unmask_gpe(ec);
 474 }
 475
 476 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 477 {
 478         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 479                 ec_log_drv("event unblocked");
 480         /*
 481          * Unconditionally invoke this once after enabling the event
 482          * handling mechanism to detect the pending events.
 483          */
 484         advance_transaction(ec);
 485 }
 486
 487 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 488 {
 489         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 490                 ec_log_drv("event blocked");
 491 }
 492
 493 /*
 494  * Process _Q events that might have accumulated in the EC.
 495  * Run with locked ec mutex.
 496  */
 497 static void acpi_ec_clear(struct acpi_ec *ec)
 498 {
 499         int i, status;
 500         u8 value = 0;
 501
 502         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 503                 status = acpi_ec_query(ec, &value);
 504                 if (status || !value)
 505                         break;
 506         }
 507         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 508                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 509         else
 510                 pr_info("%d stale EC events cleared\n", i);
 511 }
 512
 513 static void acpi_ec_enable_event(struct acpi_ec *ec)
 514 {
 515         unsigned long flags;
 516
 517         spin_lock_irqsave(&ec->lock, flags);
 518         if (acpi_ec_started(ec))
 519                 __acpi_ec_enable_event(ec);
 520         spin_unlock_irqrestore(&ec->lock, flags);
 521
 522         /* Drain additional events if hardware requires that */
 523         if (EC_FLAGS_CLEAR_ON_RESUME)
 524                 acpi_ec_clear(ec);
 525 }
 526
 527 #ifdef CONFIG_PM_SLEEP
 528 static void __acpi_ec_flush_work(void)
 529 {
 530         flush_scheduled_work(); /* flush ec->work */
 531         flush_workqueue(ec_query_wq); /* flush queries */
 532 }
 533
 534 static void acpi_ec_disable_event(struct acpi_ec *ec)
 535 {
 536         unsigned long flags;
 537
 538         spin_lock_irqsave(&ec->lock, flags);
 539         __acpi_ec_disable_event(ec);
 540         spin_unlock_irqrestore(&ec->lock, flags);
 541
 542         /*
 543          * When ec_freeze_events is true, we need to flush events in
 544          * the proper position before entering the noirq stage.
 545          */
 546         __acpi_ec_flush_work();
 547 }
 548
 549 void acpi_ec_flush_work(void)
 550 {
 551         /* Without ec_query_wq there is nothing to flush. */
 552         if (!ec_query_wq)
 553                 return;
 554
 555         __acpi_ec_flush_work();
 556 }
 557 #endif /* CONFIG_PM_SLEEP */
 558
 559 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 560 {
 561         bool guarded = true;
 562         unsigned long flags;
 563
 564         spin_lock_irqsave(&ec->lock, flags);
 565         /*
 566          * If firmware SCI_EVT clearing timing is "event", we actually
 567          * don't know when the SCI_EVT will be cleared by firmware after
 568          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 569          * acceptable period.
 570          *
 571          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 572          * flagged, which means SCI_EVT check has just been performed.
 573          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 574          * guarding should have already been performed (via
 575          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 576          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 577          * ACPI_EC_COMMAND_POLL state immediately.
 578          */
 579         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 580             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 581             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 582             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 583                 guarded = false;
 584         spin_unlock_irqrestore(&ec->lock, flags);
 585         return guarded;
 586 }
 587
 588 static int ec_transaction_polled(struct acpi_ec *ec)
 589 {
 590         unsigned long flags;
 591         int ret = 0;
 592
 593         spin_lock_irqsave(&ec->lock, flags);
 594         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 595                 ret = 1;
 596         spin_unlock_irqrestore(&ec->lock, flags);
 597         return ret;
 598 }
 599
 600 static int ec_transaction_completed(struct acpi_ec *ec)
 601 {
 602         unsigned long flags;
 603         int ret = 0;
 604
 605         spin_lock_irqsave(&ec->lock, flags);
 606         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 607                 ret = 1;
 608         spin_unlock_irqrestore(&ec->lock, flags);
 609         return ret;
 610 }
 611
 612 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 613 {
 614         ec->curr->flags |= flag;
 615         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 616                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 617                     flag == ACPI_EC_COMMAND_POLL)
 618                         acpi_ec_complete_query(ec);
 619                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 620                     flag == ACPI_EC_COMMAND_COMPLETE)
 621                         acpi_ec_complete_query(ec);
 622                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 623                     flag == ACPI_EC_COMMAND_COMPLETE)
 624                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 625         }
 626 }
 627
 628 static void advance_transaction(struct acpi_ec *ec)
 629 {
 630         struct transaction *t;
 631         u8 status;
 632         bool wakeup = false;
 633
 634         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 635                    smp_processor_id());
 636         /*
 637          * By always clearing STS before handling all indications, we can
 638          * ensure a hardware STS 0->1 change after this clearing can always
 639          * trigger a GPE interrupt.
 640          */
 641         acpi_ec_clear_gpe(ec);
 642         status = acpi_ec_read_status(ec);
 643         t = ec->curr;
 644         /*
 645          * Another IRQ or a guarded polling mode advancement is detected,
 646          * the next QR_EC submission is then allowed.
 647          */
 648         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 649                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 650                     (!ec->nr_pending_queries ||
 651                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 652                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 653                         acpi_ec_complete_query(ec);
 654                 }
 655         }
 656         if (!t)
 657                 goto err;
 658         if (t->flags & ACPI_EC_COMMAND_POLL) {
 659                 if (t->wlen > t->wi) {
 660                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 661                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 662                         else
 663                                 goto err;
 664                 } else if (t->rlen > t->ri) {
 665                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 666                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 667                                 if (t->rlen == t->ri) {
 668                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 669                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 670                                                 ec_dbg_evt("Command(%s) completed by hardware",
 671                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 672                                         wakeup = true;
 673                                 }
 674                         } else
 675                                 goto err;
 676                 } else if (t->wlen == t->wi &&
 677                            (status & ACPI_EC_FLAG_IBF) == 0) {
 678                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 679                         wakeup = true;
 680                 }
 681                 goto out;
 682         } else {
 683                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 684                     !(status & ACPI_EC_FLAG_SCI) &&
 685                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 686                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 687                         t->rdata[t->ri++] = 0x00;
 688                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 689                         ec_dbg_evt("Command(%s) completed by software",
 690                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 691                         wakeup = true;
 692                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 693                         acpi_ec_write_cmd(ec, t->command);
 694                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 695                 } else
 696                         goto err;
 697                 goto out;
 698         }
 699 err:
 700         /*
 701          * If SCI bit is set, then don't think it's a false IRQ
 702          * otherwise will take a not handled IRQ as a false one.
 703          */
 704         if (!(status & ACPI_EC_FLAG_SCI)) {
 705                 if (in_interrupt() && t) {
 706                         if (t->irq_count < ec_storm_threshold)
 707                                 ++t->irq_count;
 708                         /* Allow triggering on 0 threshold */
 709                         if (t->irq_count == ec_storm_threshold)
 710                                 acpi_ec_mask_gpe(ec);
 711                 }
 712         }
 713 out:
 714         if (status & ACPI_EC_FLAG_SCI)
 715                 acpi_ec_submit_query(ec);
 716         if (wakeup && in_interrupt())
 717                 wake_up(&ec->wait);
 718 }
 719
 720 static void start_transaction(struct acpi_ec *ec)
 721 {
 722         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 723         ec->curr->flags = 0;
 724 }
 725
 726 static int ec_guard(struct acpi_ec *ec)
 727 {
 728         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 729         unsigned long timeout = ec->timestamp + guard;
 730
 731         /* Ensure guarding period before polling EC status */
 732         do {
 733                 if (ec->busy_polling) {
 734                         /* Perform busy polling */
 735                         if (ec_transaction_completed(ec))
 736                                 return 0;
 737                         udelay(jiffies_to_usecs(guard));
 738                 } else {
 739                         /*
 740                          * Perform wait polling
 741                          * 1. Wait the transaction to be completed by the
 742                          *    GPE handler after the transaction enters
 743                          *    ACPI_EC_COMMAND_POLL state.
 744                          * 2. A special guarding logic is also required
 745                          *    for event clearing mode "event" before the
 746                          *    transaction enters ACPI_EC_COMMAND_POLL
 747                          *    state.
 748                          */
 749                         if (!ec_transaction_polled(ec) &&
 750                             !acpi_ec_guard_event(ec))
 751                                 break;
 752                         if (wait_event_timeout(ec->wait,
 753                                                ec_transaction_completed(ec),
 754                                                guard))
 755                                 return 0;
 756                 }
 757         } while (time_before(jiffies, timeout));
 758         return -ETIME;
 759 }
 760
 761 static int ec_poll(struct acpi_ec *ec)
 762 {
 763         unsigned long flags;
 764         int repeat = 5; /* number of command restarts */
 765
 766         while (repeat--) {
 767                 unsigned long delay = jiffies +
 768                         msecs_to_jiffies(ec_delay);
 769                 do {
 770                         if (!ec_guard(ec))
 771                                 return 0;
 772                         spin_lock_irqsave(&ec->lock, flags);
 773                         advance_transaction(ec);
 774                         spin_unlock_irqrestore(&ec->lock, flags);
 775                 } while (time_before(jiffies, delay));
 776                 pr_debug("controller reset, restart transaction\n");
 777                 spin_lock_irqsave(&ec->lock, flags);
 778                 start_transaction(ec);
 779                 spin_unlock_irqrestore(&ec->lock, flags);
 780         }
 781         return -ETIME;
 782 }
 783
 784 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 785                                         struct transaction *t)
 786 {
 787         unsigned long tmp;
 788         int ret = 0;
 789
 790         /* start transaction */
 791         spin_lock_irqsave(&ec->lock, tmp);
 792         /* Enable GPE for command processing (IBF=0/OBF=1) */
 793         if (!acpi_ec_submit_flushable_request(ec)) {
 794                 ret = -EINVAL;
 795                 goto unlock;
 796         }
 797         ec_dbg_ref(ec, "Increase command");
 798         /* following two actions should be kept atomic */
 799         ec->curr = t;
 800         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 801         start_transaction(ec);
 802         spin_unlock_irqrestore(&ec->lock, tmp);
 803
 804         ret = ec_poll(ec);
 805
 806         spin_lock_irqsave(&ec->lock, tmp);
 807         if (t->irq_count == ec_storm_threshold)
 808                 acpi_ec_unmask_gpe(ec);
 809         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 810         ec->curr = NULL;
 811         /* Disable GPE for command processing (IBF=0/OBF=1) */
 812         acpi_ec_complete_request(ec);
 813         ec_dbg_ref(ec, "Decrease command");
 814 unlock:
 815         spin_unlock_irqrestore(&ec->lock, tmp);
 816         return ret;
 817 }
 818
 819 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 820 {
 821         int status;
 822         u32 glk;
 823
 824         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 825                 return -EINVAL;
 826         if (t->rdata)
 827                 memset(t->rdata, 0, t->rlen);
 828
 829         mutex_lock(&ec->mutex);
 830         if (ec->global_lock) {
 831                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 832                 if (ACPI_FAILURE(status)) {
 833                         status = -ENODEV;
 834                         goto unlock;
 835                 }
 836         }
 837
 838         status = acpi_ec_transaction_unlocked(ec, t);
 839
 840         if (ec->global_lock)
 841                 acpi_release_global_lock(glk);
 842 unlock:
 843         mutex_unlock(&ec->mutex);
 844         return status;
 845 }
 846
 847 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 848 {
 849         u8 d;
 850         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 851                                 .wdata = NULL, .rdata = &d,
 852                                 .wlen = 0, .rlen = 1};
 853
 854         return acpi_ec_transaction(ec, &t);
 855 }
 856
 857 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 858 {
 859         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 860                                 .wdata = NULL, .rdata = NULL,
 861                                 .wlen = 0, .rlen = 0};
 862
 863         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 864                                 acpi_ec_transaction(ec, &t) : 0;
 865 }
 866
 867 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 868 {
 869         int result;
 870         u8 d;
 871         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 872                                 .wdata = &address, .rdata = &d,
 873                                 .wlen = 1, .rlen = 1};
 874
 875         result = acpi_ec_transaction(ec, &t);
 876         *data = d;
 877         return result;
 878 }
 879
 880 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 881 {
 882         u8 wdata[2] = { address, data };
 883         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 884                                 .wdata = wdata, .rdata = NULL,
 885                                 .wlen = 2, .rlen = 0};
 886
 887         return acpi_ec_transaction(ec, &t);
 888 }
 889
 890 int ec_read(u8 addr, u8 *val)
 891 {
 892         int err;
 893         u8 temp_data;
 894
 895         if (!first_ec)
 896                 return -ENODEV;
 897
 898         err = acpi_ec_read(first_ec, addr, &temp_data);
 899
 900         if (!err) {
 901                 *val = temp_data;
 902                 return 0;
 903         }
 904         return err;
 905 }
 906 EXPORT_SYMBOL(ec_read);
 907
 908 int ec_write(u8 addr, u8 val)
 909 {
 910         int err;
 911
 912         if (!first_ec)
 913                 return -ENODEV;
 914
 915         err = acpi_ec_write(first_ec, addr, val);
 916
 917         return err;
 918 }
 919 EXPORT_SYMBOL(ec_write);
 920
 921 int ec_transaction(u8 command,
 922                    const u8 *wdata, unsigned wdata_len,
 923                    u8 *rdata, unsigned rdata_len)
 924 {
 925         struct transaction t = {.command = command,
 926                                 .wdata = wdata, .rdata = rdata,
 927                                 .wlen = wdata_len, .rlen = rdata_len};
 928
 929         if (!first_ec)
 930                 return -ENODEV;
 931
 932         return acpi_ec_transaction(first_ec, &t);
 933 }
 934 EXPORT_SYMBOL(ec_transaction);
 935
 936 /* Get the handle to the EC device */
 937 acpi_handle ec_get_handle(void)
 938 {
 939         if (!first_ec)
 940                 return NULL;
 941         return first_ec->handle;
 942 }
 943 EXPORT_SYMBOL(ec_get_handle);
 944
 945 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 946 {
 947         unsigned long flags;
 948
 949         spin_lock_irqsave(&ec->lock, flags);
 950         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 951                 ec_dbg_drv("Starting EC");
 952                 /* Enable GPE for event processing (SCI_EVT=1) */
 953                 if (!resuming) {
 954                         acpi_ec_submit_request(ec);
 955                         ec_dbg_ref(ec, "Increase driver");
 956                 }
 957                 ec_log_drv("EC started");
 958         }
 959         spin_unlock_irqrestore(&ec->lock, flags);
 960 }
 961
 962 static bool acpi_ec_stopped(struct acpi_ec *ec)
 963 {
 964         unsigned long flags;
 965         bool flushed;
 966
 967         spin_lock_irqsave(&ec->lock, flags);
 968         flushed = acpi_ec_flushed(ec);
 969         spin_unlock_irqrestore(&ec->lock, flags);
 970         return flushed;
 971 }
 972
 973 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 974 {
 975         unsigned long flags;
 976
 977         spin_lock_irqsave(&ec->lock, flags);
 978         if (acpi_ec_started(ec)) {
 979                 ec_dbg_drv("Stopping EC");
 980                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 981                 spin_unlock_irqrestore(&ec->lock, flags);
 982                 wait_event(ec->wait, acpi_ec_stopped(ec));
 983                 spin_lock_irqsave(&ec->lock, flags);
 984                 /* Disable GPE for event processing (SCI_EVT=1) */
 985                 if (!suspending) {
 986                         acpi_ec_complete_request(ec);
 987                         ec_dbg_ref(ec, "Decrease driver");
 988                 } else if (!ec_freeze_events)
 989                         __acpi_ec_disable_event(ec);
 990                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 991                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 992                 ec_log_drv("EC stopped");
 993         }
 994         spin_unlock_irqrestore(&ec->lock, flags);
 995 }
 996
 997 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 998 {
 999         unsigned long flags;
1000
1001         spin_lock_irqsave(&ec->lock, flags);
1002         ec->busy_polling = true;
1003         ec->polling_guard = 0;
1004         ec_log_drv("interrupt blocked");
1005         spin_unlock_irqrestore(&ec->lock, flags);
1006 }
1007
1008 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1009 {
1010         unsigned long flags;
1011
1012         spin_lock_irqsave(&ec->lock, flags);
1013         ec->busy_polling = ec_busy_polling;
1014         ec->polling_guard = ec_polling_guard;
1015         ec_log_drv("interrupt unblocked");
1016         spin_unlock_irqrestore(&ec->lock, flags);
1017 }
1018
1019 void acpi_ec_block_transactions(void)
1020 {
1021         struct acpi_ec *ec = first_ec;
1022
1023         if (!ec)
1024                 return;
1025
1026         mutex_lock(&ec->mutex);
1027         /* Prevent transactions from being carried out */
1028         acpi_ec_stop(ec, true);
1029         mutex_unlock(&ec->mutex);
1030 }
1031
1032 void acpi_ec_unblock_transactions(void)
1033 {
1034         /*
1035          * Allow transactions to happen again (this function is called from
1036          * atomic context during wakeup, so we don't need to acquire the mutex).
1037          */
1038         if (first_ec)
1039                 acpi_ec_start(first_ec, true);
1040 }
1041
1042 /* --------------------------------------------------------------------------
1043                                 Event Management
1044    -------------------------------------------------------------------------- */
1045 static struct acpi_ec_query_handler *
1046 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1047 {
1048         if (handler)
1049                 kref_get(&handler->kref);
1050         return handler;
1051 }
1052
1053 static struct acpi_ec_query_handler *
1054 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1055 {
1056         struct acpi_ec_query_handler *handler;
1057         bool found = false;
1058
1059         mutex_lock(&ec->mutex);
1060         list_for_each_entry(handler, &ec->list, node) {
1061                 if (value == handler->query_bit) {
1062                         found = true;
1063                         break;
1064                 }
1065         }
1066         mutex_unlock(&ec->mutex);
1067         return found ? acpi_ec_get_query_handler(handler) : NULL;
1068 }
1069
1070 static void acpi_ec_query_handler_release(struct kref *kref)
1071 {
1072         struct acpi_ec_query_handler *handler =
1073                 container_of(kref, struct acpi_ec_query_handler, kref);
1074
1075         kfree(handler);
1076 }
1077
1078 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1079 {
1080         kref_put(&handler->kref, acpi_ec_query_handler_release);
1081 }
1082
1083 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1084                               acpi_handle handle, acpi_ec_query_func func,
1085                               void *data)
1086 {
1087         struct acpi_ec_query_handler *handler =
1088             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1089
1090         if (!handler)
1091                 return -ENOMEM;
1092
1093         handler->query_bit = query_bit;
1094         handler->handle = handle;
1095         handler->func = func;
1096         handler->data = data;
1097         mutex_lock(&ec->mutex);
1098         kref_init(&handler->kref);
1099         list_add(&handler->node, &ec->list);
1100         mutex_unlock(&ec->mutex);
1101         return 0;
1102 }
1103 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1104
1105 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1106                                           bool remove_all, u8 query_bit)
1107 {
1108         struct acpi_ec_query_handler *handler, *tmp;
1109         LIST_HEAD(free_list);
1110
1111         mutex_lock(&ec->mutex);
1112         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1113                 if (remove_all || query_bit == handler->query_bit) {
1114                         list_del_init(&handler->node);
1115                         list_add(&handler->node, &free_list);
1116                 }
1117         }
1118         mutex_unlock(&ec->mutex);
1119         list_for_each_entry_safe(handler, tmp, &free_list, node)
1120                 acpi_ec_put_query_handler(handler);
1121 }
1122
1123 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1124 {
1125         acpi_ec_remove_query_handlers(ec, false, query_bit);
1126 }
1127 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1128
1129 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1130 {
1131         struct acpi_ec_query *q;
1132         struct transaction *t;
1133
1134         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1135         if (!q)
1136                 return NULL;
1137         INIT_WORK(&q->work, acpi_ec_event_processor);
1138         t = &q->transaction;
1139         t->command = ACPI_EC_COMMAND_QUERY;
1140         t->rdata = pval;
1141         t->rlen = 1;
1142         return q;
1143 }
1144
1145 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1146 {
1147         if (q) {
1148                 if (q->handler)
1149                         acpi_ec_put_query_handler(q->handler);
1150                 kfree(q);
1151         }
1152 }
1153
1154 static void acpi_ec_event_processor(struct work_struct *work)
1155 {
1156         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1157         struct acpi_ec_query_handler *handler = q->handler;
1158
1159         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1160         if (handler->func)
1161                 handler->func(handler->data);
1162         else if (handler->handle)
1163                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1164         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1165         acpi_ec_delete_query(q);
1166 }
1167
1168 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1169 {
1170         u8 value = 0;
1171         int result;
1172         struct acpi_ec_query *q;
1173
1174         q = acpi_ec_create_query(&value);
1175         if (!q)
1176                 return -ENOMEM;
1177
1178         /*
1179          * Query the EC to find out which _Qxx method we need to evaluate.
1180          * Note that successful completion of the query causes the ACPI_EC_SCI
1181          * bit to be cleared (and thus clearing the interrupt source).
1182          */
1183         result = acpi_ec_transaction(ec, &q->transaction);
1184         if (!value)
1185                 result = -ENODATA;
1186         if (result)
1187                 goto err_exit;
1188
1189         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1190         if (!q->handler) {
1191                 result = -ENODATA;
1192                 goto err_exit;
1193         }
1194
1195         /*
1196          * It is reported that _Qxx are evaluated in a parallel way on
1197          * Windows:
1198          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1199          *
1200          * Put this log entry before schedule_work() in order to make
1201          * it appearing before any other log entries occurred during the
1202          * work queue execution.
1203          */
1204         ec_dbg_evt("Query(0x%02x) scheduled", value);
1205         if (!queue_work(ec_query_wq, &q->work)) {
1206                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1207                 result = -EBUSY;
1208         }
1209
1210 err_exit:
1211         if (result)
1212                 acpi_ec_delete_query(q);
1213         if (data)
1214                 *data = value;
1215         return result;
1216 }
1217
1218 static void acpi_ec_check_event(struct acpi_ec *ec)
1219 {
1220         unsigned long flags;
1221
1222         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1223                 if (ec_guard(ec)) {
1224                         spin_lock_irqsave(&ec->lock, flags);
1225                         /*
1226                          * Take care of the SCI_EVT unless no one else is
1227                          * taking care of it.
1228                          */
1229                         if (!ec->curr)
1230                                 advance_transaction(ec);
1231                         spin_unlock_irqrestore(&ec->lock, flags);
1232                 }
1233         }
1234 }
1235
1236 static void acpi_ec_event_handler(struct work_struct *work)
1237 {
1238         unsigned long flags;
1239         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1240
1241         ec_dbg_evt("Event started");
1242
1243         spin_lock_irqsave(&ec->lock, flags);
1244         while (ec->nr_pending_queries) {
1245                 spin_unlock_irqrestore(&ec->lock, flags);
1246                 (void)acpi_ec_query(ec, NULL);
1247                 spin_lock_irqsave(&ec->lock, flags);
1248                 ec->nr_pending_queries--;
1249                 /*
1250                  * Before exit, make sure that this work item can be
1251                  * scheduled again. There might be QR_EC failures, leaving
1252                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1253                  * item from being scheduled again.
1254                  */
1255                 if (!ec->nr_pending_queries) {
1256                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1257                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1258                                 acpi_ec_complete_query(ec);
1259                 }
1260         }
1261         spin_unlock_irqrestore(&ec->lock, flags);
1262
1263         ec_dbg_evt("Event stopped");
1264
1265         acpi_ec_check_event(ec);
1266 }
1267
1268 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1269         u32 gpe_number, void *data)
1270 {
1271         unsigned long flags;
1272         struct acpi_ec *ec = data;
1273
1274         spin_lock_irqsave(&ec->lock, flags);
1275         advance_transaction(ec);
1276         spin_unlock_irqrestore(&ec->lock, flags);
1277         return ACPI_INTERRUPT_HANDLED;
1278 }
1279
1280 /* --------------------------------------------------------------------------
1281  *                           Address Space Management
1282  * -------------------------------------------------------------------------- */
1283
1284 static acpi_status
1285 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1286                       u32 bits, u64 *value64,
1287                       void *handler_context, void *region_context)
1288 {
1289         struct acpi_ec *ec = handler_context;
1290         int result = 0, i, bytes = bits / 8;
1291         u8 *value = (u8 *)value64;
1292
1293         if ((address > 0xFF) || !value || !handler_context)
1294                 return AE_BAD_PARAMETER;
1295
1296         if (function != ACPI_READ && function != ACPI_WRITE)
1297                 return AE_BAD_PARAMETER;
1298
1299         if (ec->busy_polling || bits > 8)
1300                 acpi_ec_burst_enable(ec);
1301
1302         for (i = 0; i < bytes; ++i, ++address, ++value)
1303                 result = (function == ACPI_READ) ?
1304                         acpi_ec_read(ec, address, value) :
1305                         acpi_ec_write(ec, address, *value);
1306
1307         if (ec->busy_polling || bits > 8)
1308                 acpi_ec_burst_disable(ec);
1309
1310         switch (result) {
1311         case -EINVAL:
1312                 return AE_BAD_PARAMETER;
1313         case -ENODEV:
1314                 return AE_NOT_FOUND;
1315         case -ETIME:
1316                 return AE_TIME;
1317         default:
1318                 return AE_OK;
1319         }
1320 }
1321
1322 /* --------------------------------------------------------------------------
1323  *                             Driver Interface
1324  * -------------------------------------------------------------------------- */
1325
1326 static acpi_status
1327 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1328
1329 static void acpi_ec_free(struct acpi_ec *ec)
1330 {
1331         if (first_ec == ec)
1332                 first_ec = NULL;
1333         if (boot_ec == ec)
1334                 boot_ec = NULL;
1335         kfree(ec);
1336 }
1337
1338 static struct acpi_ec *acpi_ec_alloc(void)
1339 {
1340         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1341
1342         if (!ec)
1343                 return NULL;
1344         mutex_init(&ec->mutex);
1345         init_waitqueue_head(&ec->wait);
1346         INIT_LIST_HEAD(&ec->list);
1347         spin_lock_init(&ec->lock);
1348         INIT_WORK(&ec->work, acpi_ec_event_handler);
1349         ec->timestamp = jiffies;
1350         ec->busy_polling = true;
1351         ec->polling_guard = 0;
1352         return ec;
1353 }
1354
1355 static acpi_status
1356 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1357                                void *context, void **return_value)
1358 {
1359         char node_name[5];
1360         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1361         struct acpi_ec *ec = context;
1362         int value = 0;
1363         acpi_status status;
1364
1365         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1366
1367         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1368                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1369         return AE_OK;
1370 }
1371
1372 static acpi_status
1373 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1374 {
1375         acpi_status status;
1376         unsigned long long tmp = 0;
1377         struct acpi_ec *ec = context;
1378
1379         /* clear addr values, ec_parse_io_ports depend on it */
1380         ec->command_addr = ec->data_addr = 0;
1381
1382         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1383                                      ec_parse_io_ports, ec);
1384         if (ACPI_FAILURE(status))
1385                 return status;
1386         if (ec->data_addr == 0 || ec->command_addr == 0)
1387                 return AE_OK;
1388
1389         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1390                 /*
1391                  * Always inherit the GPE number setting from the ECDT
1392                  * EC.
1393                  */
1394                 ec->gpe = boot_ec->gpe;
1395         } else {
1396                 /* Get GPE bit assignment (EC events). */
1397                 /* TODO: Add support for _GPE returning a package */
1398                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1399                 if (ACPI_FAILURE(status))
1400                         return status;
1401                 ec->gpe = tmp;
1402         }
1403         /* Use the global lock for all EC transactions? */
1404         tmp = 0;
1405         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1406         ec->global_lock = tmp;
1407         ec->handle = handle;
1408         return AE_CTRL_TERMINATE;
1409 }
1410
1411 /*
1412  * Note: This function returns an error code only when the address space
1413  *       handler is not installed, which means "not able to handle
1414  *       transactions".
1415  */
1416 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1417 {
1418         acpi_status status;
1419
1420         acpi_ec_start(ec, false);
1421
1422         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1423                 acpi_ec_enter_noirq(ec);
1424                 status = acpi_install_address_space_handler(ec->handle,
1425                                                             ACPI_ADR_SPACE_EC,
1426                                                             &acpi_ec_space_handler,
1427                                                             NULL, ec);
1428                 if (ACPI_FAILURE(status)) {
1429                         if (status == AE_NOT_FOUND) {
1430                                 /*
1431                                  * Maybe OS fails in evaluating the _REG
1432                                  * object. The AE_NOT_FOUND error will be
1433                                  * ignored and OS * continue to initialize
1434                                  * EC.
1435                                  */
1436                                 pr_err("Fail in evaluating the _REG object"
1437                                         " of EC device. Broken bios is suspected.\n");
1438                         } else {
1439                                 acpi_ec_stop(ec, false);
1440                                 return -ENODEV;
1441                         }
1442                 }
1443                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1444         }
1445
1446         if (!handle_events)
1447                 return 0;
1448
1449         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1450                 /* Find and register all query methods */
1451                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1452                                     acpi_ec_register_query_methods,
1453                                     NULL, ec, NULL);
1454                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1455         }
1456         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1457                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1458                                           ACPI_GPE_EDGE_TRIGGERED,
1459                                           &acpi_ec_gpe_handler, ec);
1460                 /* This is not fatal as we can poll EC events */
1461                 if (ACPI_SUCCESS(status)) {
1462                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1463                         acpi_ec_leave_noirq(ec);
1464                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1465                             ec->reference_count >= 1)
1466                                 acpi_ec_enable_gpe(ec, true);
1467                 }
1468         }
1469         /* EC is fully operational, allow queries */
1470         acpi_ec_enable_event(ec);
1471
1472         return 0;
1473 }
1474
1475 static void ec_remove_handlers(struct acpi_ec *ec)
1476 {
1477         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1478                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1479                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1480                         pr_err("failed to remove space handler\n");
1481                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1482         }
1483
1484         /*
1485          * Stops handling the EC transactions after removing the operation
1486          * region handler. This is required because _REG(DISCONNECT)
1487          * invoked during the removal can result in new EC transactions.
1488          *
1489          * Flushes the EC requests and thus disables the GPE before
1490          * removing the GPE handler. This is required by the current ACPICA
1491          * GPE core. ACPICA GPE core will automatically disable a GPE when
1492          * it is indicated but there is no way to handle it. So the drivers
1493          * must disable the GPEs prior to removing the GPE handlers.
1494          */
1495         acpi_ec_stop(ec, false);
1496
1497         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1498                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1499                                         &acpi_ec_gpe_handler)))
1500                         pr_err("failed to remove gpe handler\n");
1501                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1502         }
1503         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1504                 acpi_ec_remove_query_handlers(ec, true, 0);
1505                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1506         }
1507 }
1508
1509 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1510 {
1511         int ret;
1512
1513         ret = ec_install_handlers(ec, handle_events);
1514         if (ret)
1515                 return ret;
1516
1517         /* First EC capable of handling transactions */
1518         if (!first_ec) {
1519                 first_ec = ec;
1520                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1521         }
1522
1523         acpi_handle_info(ec->handle,
1524                          "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1525                          ec->gpe, ec->command_addr, ec->data_addr);
1526         return ret;
1527 }
1528
1529 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1530 {
1531         struct acpi_table_ecdt *ecdt_ptr;
1532         acpi_status status;
1533         acpi_handle handle;
1534
1535         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1536                                 (struct acpi_table_header **)&ecdt_ptr);
1537         if (ACPI_FAILURE(status))
1538                 return false;
1539
1540         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1541         if (ACPI_FAILURE(status))
1542                 return false;
1543
1544         *phandle = handle;
1545         return true;
1546 }
1547
1548 static int acpi_ec_add(struct acpi_device *device)
1549 {
1550         struct acpi_ec *ec = NULL;
1551         bool dep_update = true;
1552         acpi_status status;
1553         int ret;
1554
1555         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1556         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1557
1558         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1559                 boot_ec_is_ecdt = true;
1560                 ec = boot_ec;
1561                 dep_update = false;
1562         } else {
1563                 ec = acpi_ec_alloc();
1564                 if (!ec)
1565                         return -ENOMEM;
1566
1567                 status = ec_parse_device(device->handle, 0, ec, NULL);
1568                 if (status != AE_CTRL_TERMINATE) {
1569                         ret = -EINVAL;
1570                         goto err_alloc;
1571                 }
1572
1573                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1574                     ec->data_addr == boot_ec->data_addr) {
1575                         boot_ec_is_ecdt = false;
1576                         /*
1577                          * Trust PNP0C09 namespace location rather than
1578                          * ECDT ID. But trust ECDT GPE rather than _GPE
1579                          * because of ASUS quirks, so do not change
1580                          * boot_ec->gpe to ec->gpe.
1581                          */
1582                         boot_ec->handle = ec->handle;
1583                         acpi_handle_debug(ec->handle, "duplicated.\n");
1584                         acpi_ec_free(ec);
1585                         ec = boot_ec;
1586                 }
1587         }
1588
1589         ret = acpi_ec_setup(ec, true);
1590         if (ret)
1591                 goto err_query;
1592
1593         if (ec == boot_ec)
1594                 acpi_handle_info(boot_ec->handle,
1595                                  "Boot %s EC used to handle transactions and events\n",
1596                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1597
1598         device->driver_data = ec;
1599
1600         ret = !!request_region(ec->data_addr, 1, "EC data");
1601         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1602         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1603         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1604
1605         if (dep_update) {
1606                 /* Reprobe devices depending on the EC */
1607                 acpi_walk_dep_device_list(ec->handle);
1608         }
1609         acpi_handle_debug(ec->handle, "enumerated.\n");
1610         return 0;
1611
1612 err_query:
1613         if (ec != boot_ec)
1614                 acpi_ec_remove_query_handlers(ec, true, 0);
1615 err_alloc:
1616         if (ec != boot_ec)
1617                 acpi_ec_free(ec);
1618         return ret;
1619 }
1620
1621 static int acpi_ec_remove(struct acpi_device *device)
1622 {
1623         struct acpi_ec *ec;
1624
1625         if (!device)
1626                 return -EINVAL;
1627
1628         ec = acpi_driver_data(device);
1629         release_region(ec->data_addr, 1);
1630         release_region(ec->command_addr, 1);
1631         device->driver_data = NULL;
1632         if (ec != boot_ec) {
1633                 ec_remove_handlers(ec);
1634                 acpi_ec_free(ec);
1635         }
1636         return 0;
1637 }
1638
1639 static acpi_status
1640 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1641 {
1642         struct acpi_ec *ec = context;
1643
1644         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1645                 return AE_OK;
1646
1647         /*
1648          * The first address region returned is the data port, and
1649          * the second address region returned is the status/command
1650          * port.
1651          */
1652         if (ec->data_addr == 0)
1653                 ec->data_addr = resource->data.io.minimum;
1654         else if (ec->command_addr == 0)
1655                 ec->command_addr = resource->data.io.minimum;
1656         else
1657                 return AE_CTRL_TERMINATE;
1658
1659         return AE_OK;
1660 }
1661
1662 static const struct acpi_device_id ec_device_ids[] = {
1663         {"PNP0C09", 0},
1664         {ACPI_ECDT_HID, 0},
1665         {"", 0},
1666 };
1667
1668 /*
1669  * This function is not Windows-compatible as Windows never enumerates the
1670  * namespace EC before the main ACPI device enumeration process. It is
1671  * retained for historical reason and will be deprecated in the future.
1672  */
1673 void __init acpi_ec_dsdt_probe(void)
1674 {
1675         struct acpi_ec *ec;
1676         acpi_status status;
1677         int ret;
1678
1679         /*
1680          * If a platform has ECDT, there is no need to proceed as the
1681          * following probe is not a part of the ACPI device enumeration,
1682          * executing _STA is not safe, and thus this probe may risk of
1683          * picking up an invalid EC device.
1684          */
1685         if (boot_ec)
1686                 return;
1687
1688         ec = acpi_ec_alloc();
1689         if (!ec)
1690                 return;
1691
1692         /*
1693          * At this point, the namespace is initialized, so start to find
1694          * the namespace objects.
1695          */
1696         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1697         if (ACPI_FAILURE(status) || !ec->handle) {
1698                 acpi_ec_free(ec);
1699                 return;
1700         }
1701
1702         /*
1703          * When the DSDT EC is available, always re-configure boot EC to
1704          * have _REG evaluated. _REG can only be evaluated after the
1705          * namespace initialization.
1706          * At this point, the GPE is not fully initialized, so do not to
1707          * handle the events.
1708          */
1709         ret = acpi_ec_setup(ec, false);
1710         if (ret) {
1711                 acpi_ec_free(ec);
1712                 return;
1713         }
1714
1715         boot_ec = ec;
1716
1717         acpi_handle_info(ec->handle,
1718                          "Boot DSDT EC used to handle transactions\n");
1719 }
1720
1721 /*
1722  * If the DSDT EC is not functioning, we still need to prepare a fully
1723  * functioning ECDT EC first in order to handle the events.
1724  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1725  */
1726 static int __init acpi_ec_ecdt_start(void)
1727 {
1728         acpi_handle handle;
1729
1730         if (!boot_ec)
1731                 return -ENODEV;
1732         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1733         if (!boot_ec_is_ecdt)
1734                 return -ENODEV;
1735
1736         /*
1737          * At this point, the namespace and the GPE is initialized, so
1738          * start to find the namespace objects and handle the events.
1739          *
1740          * Note: ec->handle can be valid if this function is called after
1741          * acpi_ec_add(), hence the fast path.
1742          */
1743         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1744                 if (!acpi_ec_ecdt_get_handle(&handle))
1745                         return -ENODEV;
1746                 boot_ec->handle = handle;
1747         }
1748
1749         /* Register to ACPI bus with PM ops attached */
1750         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1751 }
1752
1753 #if 0
1754 /*
1755  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1756  * set, for which case, we complete the QR_EC without issuing it to the
1757  * firmware.
1758  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1759  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1760  */
1761 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1762 {
1763         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1764         EC_FLAGS_QUERY_HANDSHAKE = 1;
1765         return 0;
1766 }
1767 #endif
1768
1769 /*
1770  * On some hardware it is necessary to clear events accumulated by the EC during
1771  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1772  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1773  *
1774  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1775  *
1776  * Ideally, the EC should also be instructed NOT to accumulate events during
1777  * sleep (which Windows seems to do somehow), but the interface to control this
1778  * behaviour is not known at this time.
1779  *
1780  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1781  * however it is very likely that other Samsung models are affected.
1782  *
1783  * On systems which don't accumulate _Q events during sleep, this extra check
1784  * should be harmless.
1785  */
1786 static int ec_clear_on_resume(const struct dmi_system_id *id)
1787 {
1788         pr_debug("Detected system needing EC poll on resume.\n");
1789         EC_FLAGS_CLEAR_ON_RESUME = 1;
1790         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1791         return 0;
1792 }
1793
1794 /*
1795  * Some ECDTs contain wrong register addresses.
1796  * MSI MS-171F
1797  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1798  */
1799 static int ec_correct_ecdt(const struct dmi_system_id *id)
1800 {
1801         pr_debug("Detected system needing ECDT address correction.\n");
1802         EC_FLAGS_CORRECT_ECDT = 1;
1803         return 0;
1804 }
1805
1806 /*
1807  * Some DSDTs contain wrong GPE setting.
1808  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1809  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1810  */
1811 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1812 {
1813         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1814         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1815         return 0;
1816 }
1817
1818 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1819         {
1820         ec_correct_ecdt, "MSI MS-171F", {
1821         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1822         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1823         {
1824         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1825         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1826         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1827         {
1828         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1829         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1830         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1831         {
1832         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1833         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1834         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1835         {
1836         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1837         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1838         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1839         {
1840         ec_honor_ecdt_gpe, "ASUS X580VD", {
1841         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1842         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1843         {
1844         ec_clear_on_resume, "Samsung hardware", {
1845         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1846         {},
1847 };
1848
1849 void __init acpi_ec_ecdt_probe(void)
1850 {
1851         struct acpi_table_ecdt *ecdt_ptr;
1852         struct acpi_ec *ec;
1853         acpi_status status;
1854         int ret;
1855
1856         /* Generate a boot ec context. */
1857         dmi_check_system(ec_dmi_table);
1858         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1859                                 (struct acpi_table_header **)&ecdt_ptr);
1860         if (ACPI_FAILURE(status))
1861                 return;
1862
1863         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1864                 /*
1865                  * Asus X50GL:
1866                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1867                  */
1868                 return;
1869         }
1870
1871         ec = acpi_ec_alloc();
1872         if (!ec)
1873                 return;
1874
1875         if (EC_FLAGS_CORRECT_ECDT) {
1876                 ec->command_addr = ecdt_ptr->data.address;
1877                 ec->data_addr = ecdt_ptr->control.address;
1878         } else {
1879                 ec->command_addr = ecdt_ptr->control.address;
1880                 ec->data_addr = ecdt_ptr->data.address;
1881         }
1882         ec->gpe = ecdt_ptr->gpe;
1883         ec->handle = ACPI_ROOT_OBJECT;
1884
1885         /*
1886          * At this point, the namespace is not initialized, so do not find
1887          * the namespace objects, or handle the events.
1888          */
1889         ret = acpi_ec_setup(ec, false);
1890         if (ret) {
1891                 acpi_ec_free(ec);
1892                 return;
1893         }
1894
1895         boot_ec = ec;
1896         boot_ec_is_ecdt = true;
1897
1898         pr_info("Boot ECDT EC used to handle transactions\n");
1899 }
1900
1901 #ifdef CONFIG_PM_SLEEP
1902 static int acpi_ec_suspend(struct device *dev)
1903 {
1904         struct acpi_ec *ec =
1905                 acpi_driver_data(to_acpi_device(dev));
1906
1907         if (!pm_suspend_no_platform() && ec_freeze_events)
1908                 acpi_ec_disable_event(ec);
1909         return 0;
1910 }
1911
1912 static int acpi_ec_suspend_noirq(struct device *dev)
1913 {
1914         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1915
1916         /*
1917          * The SCI handler doesn't run at this point, so the GPE can be
1918          * masked at the low level without side effects.
1919          */
1920         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1921             ec->reference_count >= 1)
1922                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1923
1924         acpi_ec_enter_noirq(ec);
1925
1926         return 0;
1927 }
1928
1929 static int acpi_ec_resume_noirq(struct device *dev)
1930 {
1931         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1932
1933         acpi_ec_leave_noirq(ec);
1934
1935         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1936             ec->reference_count >= 1)
1937                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1938
1939         return 0;
1940 }
1941
1942 static int acpi_ec_resume(struct device *dev)
1943 {
1944         struct acpi_ec *ec =
1945                 acpi_driver_data(to_acpi_device(dev));
1946
1947         acpi_ec_enable_event(ec);
1948         return 0;
1949 }
1950
1951 void acpi_ec_mark_gpe_for_wake(void)
1952 {
1953         if (first_ec && !ec_no_wakeup)
1954                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1955 }
1956 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
1957
1958 void acpi_ec_set_gpe_wake_mask(u8 action)
1959 {
1960         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
1961                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1962 }
1963
1964 bool acpi_ec_dispatch_gpe(void)
1965 {
1966         u32 ret;
1967
1968         if (!first_ec)
1969                 return false;
1970
1971         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
1972         if (ret == ACPI_INTERRUPT_HANDLED) {
1973                 pm_pr_dbg("EC GPE dispatched\n");
1974                 return true;
1975         }
1976         return false;
1977 }
1978 #endif /* CONFIG_PM_SLEEP */
1979
1980 static const struct dev_pm_ops acpi_ec_pm = {
1981         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1982         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1983 };
1984
1985 static int param_set_event_clearing(const char *val,
1986                                     const struct kernel_param *kp)
1987 {
1988         int result = 0;
1989
1990         if (!strncmp(val, "status", sizeof("status") - 1)) {
1991                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1992                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1993         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1994                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1995                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1996         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1997                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1998                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1999         } else
2000                 result = -EINVAL;
2001         return result;
2002 }
2003
2004 static int param_get_event_clearing(char *buffer,
2005                                     const struct kernel_param *kp)
2006 {
2007         switch (ec_event_clearing) {
2008         case ACPI_EC_EVT_TIMING_STATUS:
2009                 return sprintf(buffer, "status");
2010         case ACPI_EC_EVT_TIMING_QUERY:
2011                 return sprintf(buffer, "query");
2012         case ACPI_EC_EVT_TIMING_EVENT:
2013                 return sprintf(buffer, "event");
2014         default:
2015                 return sprintf(buffer, "invalid");
2016         }
2017         return 0;
2018 }
2019
2020 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2021                   NULL, 0644);
2022 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2023
2024 static struct acpi_driver acpi_ec_driver = {
2025         .name = "ec",
2026         .class = ACPI_EC_CLASS,
2027         .ids = ec_device_ids,
2028         .ops = {
2029                 .add = acpi_ec_add,
2030                 .remove = acpi_ec_remove,
2031                 },
2032         .drv.pm = &acpi_ec_pm,
2033 };
2034
2035 static inline int acpi_ec_query_init(void)
2036 {
2037         if (!ec_query_wq) {
2038                 ec_query_wq = alloc_workqueue("kec_query", 0,
2039                                               ec_max_queries);
2040                 if (!ec_query_wq)
2041                         return -ENODEV;
2042         }
2043         return 0;
2044 }
2045
2046 static inline void acpi_ec_query_exit(void)
2047 {
2048         if (ec_query_wq) {
2049                 destroy_workqueue(ec_query_wq);
2050                 ec_query_wq = NULL;
2051         }
2052 }
2053
2054 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2055         {
2056                 .ident = "Thinkpad X1 Carbon 6th",
2057                 .matches = {
2058                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2059                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2060                 },
2061         },
2062         {
2063                 .ident = "ThinkPad X1 Carbon 6th",
2064                 .matches = {
2065                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2066                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2067                 },
2068         },
2069         {
2070                 .ident = "ThinkPad X1 Yoga 3rd",
2071                 .matches = {
2072                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2073                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2074                 },
2075         },
2076         { },
2077 };
2078
2079 int __init acpi_ec_init(void)
2080 {
2081         int result;
2082         int ecdt_fail, dsdt_fail;
2083
2084         /* register workqueue for _Qxx evaluations */
2085         result = acpi_ec_query_init();
2086         if (result)
2087                 return result;
2088
2089         /*
2090          * Disable EC wakeup on following systems to prevent periodic
2091          * wakeup from EC GPE.
2092          */
2093         if (dmi_check_system(acpi_ec_no_wakeup)) {
2094                 ec_no_wakeup = true;
2095                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2096         }
2097
2098         /* Drivers must be started after acpi_ec_query_init() */
2099         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2100         /*
2101          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2102          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2103          * settings but invalid DSDT settings.
2104          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2105          */
2106         ecdt_fail = acpi_ec_ecdt_start();
2107         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2108 }
2109
2110 /* EC driver currently not unloadable */
2111 #if 0
2112 static void __exit acpi_ec_exit(void)
2113 {
2114
2115         acpi_bus_unregister_driver(&acpi_ec_driver);
2116         acpi_ec_query_exit();
2117 }
2118 #endif  /* 0 */