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