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