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_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  96         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
  97         EC_FLAGS_EC_REG_CALLED,         /* OpReg ACPI _REG method called */
  98         EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
  99         EC_FLAGS_STARTED,               /* Driver is started */
 100         EC_FLAGS_STOPPED,               /* Driver is stopped */
 101         EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 102 };
 103
 104 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 105 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 106
 107 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 108 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 109 module_param(ec_delay, uint, 0644);
 110 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 111
 112 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 113 module_param(ec_max_queries, uint, 0644);
 114 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 115
 116 static bool ec_busy_polling __read_mostly;
 117 module_param(ec_busy_polling, bool, 0644);
 118 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 119
 120 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 121 module_param(ec_polling_guard, uint, 0644);
 122 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 123
 124 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 125
 126 /*
 127  * If the number of false interrupts per one transaction exceeds
 128  * this threshold, will think there is a GPE storm happened and
 129  * will disable the GPE for normal transaction.
 130  */
 131 static unsigned int ec_storm_threshold  __read_mostly = 8;
 132 module_param(ec_storm_threshold, uint, 0644);
 133 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 134
 135 static bool ec_freeze_events __read_mostly;
 136 module_param(ec_freeze_events, bool, 0644);
 137 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 138
 139 static bool ec_no_wakeup __read_mostly;
 140 module_param(ec_no_wakeup, bool, 0644);
 141 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 142
 143 struct acpi_ec_query_handler {
 144         struct list_head node;
 145         acpi_ec_query_func func;
 146         acpi_handle handle;
 147         void *data;
 148         u8 query_bit;
 149         struct kref kref;
 150 };
 151
 152 struct transaction {
 153         const u8 *wdata;
 154         u8 *rdata;
 155         unsigned short irq_count;
 156         u8 command;
 157         u8 wi;
 158         u8 ri;
 159         u8 wlen;
 160         u8 rlen;
 161         u8 flags;
 162 };
 163
 164 struct acpi_ec_query {
 165         struct transaction transaction;
 166         struct work_struct work;
 167         struct acpi_ec_query_handler *handler;
 168         struct acpi_ec *ec;
 169 };
 170
 171 static int acpi_ec_submit_query(struct acpi_ec *ec);
 172 static void advance_transaction(struct acpi_ec *ec, bool interrupt);
 173 static void acpi_ec_event_handler(struct work_struct *work);
 174
 175 struct acpi_ec *first_ec;
 176 EXPORT_SYMBOL(first_ec);
 177
 178 static struct acpi_ec *boot_ec;
 179 static bool boot_ec_is_ecdt;
 180 static struct workqueue_struct *ec_wq;
 181 static struct workqueue_struct *ec_query_wq;
 182
 183 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 184 static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
 185 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 186
 187 /* --------------------------------------------------------------------------
 188  *                           Logging/Debugging
 189  * -------------------------------------------------------------------------- */
 190
 191 /*
 192  * Splitters used by the developers to track the boundary of the EC
 193  * handling processes.
 194  */
 195 #ifdef DEBUG
 196 #define EC_DBG_SEP      " "
 197 #define EC_DBG_DRV      "+++++"
 198 #define EC_DBG_STM      "====="
 199 #define EC_DBG_REQ      "*****"
 200 #define EC_DBG_EVT      "#####"
 201 #else
 202 #define EC_DBG_SEP      ""
 203 #define EC_DBG_DRV
 204 #define EC_DBG_STM
 205 #define EC_DBG_REQ
 206 #define EC_DBG_EVT
 207 #endif
 208
 209 #define ec_log_raw(fmt, ...) \
 210         pr_info(fmt "\n", ##__VA_ARGS__)
 211 #define ec_dbg_raw(fmt, ...) \
 212         pr_debug(fmt "\n", ##__VA_ARGS__)
 213 #define ec_log(filter, fmt, ...) \
 214         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 215 #define ec_dbg(filter, fmt, ...) \
 216         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 217
 218 #define ec_log_drv(fmt, ...) \
 219         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 220 #define ec_dbg_drv(fmt, ...) \
 221         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 222 #define ec_dbg_stm(fmt, ...) \
 223         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 224 #define ec_dbg_req(fmt, ...) \
 225         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 226 #define ec_dbg_evt(fmt, ...) \
 227         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 228 #define ec_dbg_ref(ec, fmt, ...) \
 229         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 230
 231 /* --------------------------------------------------------------------------
 232  *                           Device Flags
 233  * -------------------------------------------------------------------------- */
 234
 235 static bool acpi_ec_started(struct acpi_ec *ec)
 236 {
 237         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 238                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 239 }
 240
 241 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 242 {
 243         /*
 244          * There is an OSPM early stage logic. During the early stages
 245          * (boot/resume), OSPMs shouldn't enable the event handling, only
 246          * the EC transactions are allowed to be performed.
 247          */
 248         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 249                 return false;
 250         /*
 251          * However, disabling the event handling is experimental for late
 252          * stage (suspend), and is controlled by the boot parameter of
 253          * "ec_freeze_events":
 254          * 1. true:  The EC event handling is disabled before entering
 255          *           the noirq stage.
 256          * 2. false: The EC event handling is automatically disabled as
 257          *           soon as the EC driver is stopped.
 258          */
 259         if (ec_freeze_events)
 260                 return acpi_ec_started(ec);
 261         else
 262                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 263 }
 264
 265 static bool acpi_ec_flushed(struct acpi_ec *ec)
 266 {
 267         return ec->reference_count == 1;
 268 }
 269
 270 /* --------------------------------------------------------------------------
 271  *                           EC Registers
 272  * -------------------------------------------------------------------------- */
 273
 274 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 275 {
 276         u8 x = inb(ec->command_addr);
 277
 278         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 279                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 280                    x,
 281                    !!(x & ACPI_EC_FLAG_SCI),
 282                    !!(x & ACPI_EC_FLAG_BURST),
 283                    !!(x & ACPI_EC_FLAG_CMD),
 284                    !!(x & ACPI_EC_FLAG_IBF),
 285                    !!(x & ACPI_EC_FLAG_OBF));
 286         return x;
 287 }
 288
 289 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 290 {
 291         u8 x = inb(ec->data_addr);
 292
 293         ec->timestamp = jiffies;
 294         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 295         return x;
 296 }
 297
 298 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 299 {
 300         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 301         outb(command, ec->command_addr);
 302         ec->timestamp = jiffies;
 303 }
 304
 305 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 306 {
 307         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 308         outb(data, ec->data_addr);
 309         ec->timestamp = jiffies;
 310 }
 311
 312 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 313 static const char *acpi_ec_cmd_string(u8 cmd)
 314 {
 315         switch (cmd) {
 316         case 0x80:
 317                 return "RD_EC";
 318         case 0x81:
 319                 return "WR_EC";
 320         case 0x82:
 321                 return "BE_EC";
 322         case 0x83:
 323                 return "BD_EC";
 324         case 0x84:
 325                 return "QR_EC";
 326         }
 327         return "UNKNOWN";
 328 }
 329 #else
 330 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 331 #endif
 332
 333 /* --------------------------------------------------------------------------
 334  *                           GPE Registers
 335  * -------------------------------------------------------------------------- */
 336
 337 static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
 338 {
 339         acpi_event_status gpe_status = 0;
 340
 341         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 342         return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
 343 }
 344
 345 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 346 {
 347         if (open)
 348                 acpi_enable_gpe(NULL, ec->gpe);
 349         else {
 350                 BUG_ON(ec->reference_count < 1);
 351                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 352         }
 353         if (acpi_ec_gpe_status_set(ec)) {
 354                 /*
 355                  * On some platforms, EN=1 writes cannot trigger GPE. So
 356                  * software need to manually trigger a pseudo GPE event on
 357                  * EN=1 writes.
 358                  */
 359                 ec_dbg_raw("Polling quirk");
 360                 advance_transaction(ec, false);
 361         }
 362 }
 363
 364 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 365 {
 366         if (close)
 367                 acpi_disable_gpe(NULL, ec->gpe);
 368         else {
 369                 BUG_ON(ec->reference_count < 1);
 370                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 371         }
 372 }
 373
 374 /* --------------------------------------------------------------------------
 375  *                           Transaction Management
 376  * -------------------------------------------------------------------------- */
 377
 378 static void acpi_ec_submit_request(struct acpi_ec *ec)
 379 {
 380         ec->reference_count++;
 381         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 382             ec->gpe >= 0 && ec->reference_count == 1)
 383                 acpi_ec_enable_gpe(ec, true);
 384 }
 385
 386 static void acpi_ec_complete_request(struct acpi_ec *ec)
 387 {
 388         bool flushed = false;
 389
 390         ec->reference_count--;
 391         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 392             ec->gpe >= 0 && ec->reference_count == 0)
 393                 acpi_ec_disable_gpe(ec, true);
 394         flushed = acpi_ec_flushed(ec);
 395         if (flushed)
 396                 wake_up(&ec->wait);
 397 }
 398
 399 static void acpi_ec_mask_events(struct acpi_ec *ec)
 400 {
 401         if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 402                 if (ec->gpe >= 0)
 403                         acpi_ec_disable_gpe(ec, false);
 404                 else
 405                         disable_irq_nosync(ec->irq);
 406
 407                 ec_dbg_drv("Polling enabled");
 408                 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 409         }
 410 }
 411
 412 static void acpi_ec_unmask_events(struct acpi_ec *ec)
 413 {
 414         if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 415                 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 416                 if (ec->gpe >= 0)
 417                         acpi_ec_enable_gpe(ec, false);
 418                 else
 419                         enable_irq(ec->irq);
 420
 421                 ec_dbg_drv("Polling disabled");
 422         }
 423 }
 424
 425 /*
 426  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 427  *                                      the flush operation is not in
 428  *                                      progress
 429  * @ec: the EC device
 430  *
 431  * This function must be used before taking a new action that should hold
 432  * the reference count.  If this function returns false, then the action
 433  * must be discarded or it will prevent the flush operation from being
 434  * completed.
 435  */
 436 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 437 {
 438         if (!acpi_ec_started(ec))
 439                 return false;
 440         acpi_ec_submit_request(ec);
 441         return true;
 442 }
 443
 444 static void acpi_ec_submit_event(struct acpi_ec *ec)
 445 {
 446         /*
 447          * It is safe to mask the events here, because acpi_ec_close_event()
 448          * will run at least once after this.
 449          */
 450         acpi_ec_mask_events(ec);
 451         if (!acpi_ec_event_enabled(ec))
 452                 return;
 453
 454         if (ec->event_state != EC_EVENT_READY)
 455                 return;
 456
 457         ec_dbg_evt("Command(%s) submitted/blocked",
 458                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 459
 460         ec->event_state = EC_EVENT_IN_PROGRESS;
 461         /*
 462          * If events_to_process is greater than 0 at this point, the while ()
 463          * loop in acpi_ec_event_handler() is still running and incrementing
 464          * events_to_process will cause it to invoke acpi_ec_submit_query() once
 465          * more, so it is not necessary to queue up the event work to start the
 466          * same loop again.
 467          */
 468         if (ec->events_to_process++ > 0)
 469                 return;
 470
 471         ec->events_in_progress++;
 472         queue_work(ec_wq, &ec->work);
 473 }
 474
 475 static void acpi_ec_complete_event(struct acpi_ec *ec)
 476 {
 477         if (ec->event_state == EC_EVENT_IN_PROGRESS)
 478                 ec->event_state = EC_EVENT_COMPLETE;
 479 }
 480
 481 static void acpi_ec_close_event(struct acpi_ec *ec)
 482 {
 483         if (ec->event_state != EC_EVENT_READY)
 484                 ec_dbg_evt("Command(%s) unblocked",
 485                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 486
 487         ec->event_state = EC_EVENT_READY;
 488         acpi_ec_unmask_events(ec);
 489 }
 490
 491 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 492 {
 493         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 494                 ec_log_drv("event unblocked");
 495         /*
 496          * Unconditionally invoke this once after enabling the event
 497          * handling mechanism to detect the pending events.
 498          */
 499         advance_transaction(ec, false);
 500 }
 501
 502 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 503 {
 504         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 505                 ec_log_drv("event blocked");
 506 }
 507
 508 /*
 509  * Process _Q events that might have accumulated in the EC.
 510  * Run with locked ec mutex.
 511  */
 512 static void acpi_ec_clear(struct acpi_ec *ec)
 513 {
 514         int i;
 515
 516         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 517                 if (acpi_ec_submit_query(ec))
 518                         break;
 519         }
 520         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 521                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 522         else
 523                 pr_info("%d stale EC events cleared\n", i);
 524 }
 525
 526 static void acpi_ec_enable_event(struct acpi_ec *ec)
 527 {
 528         spin_lock(&ec->lock);
 529         if (acpi_ec_started(ec))
 530                 __acpi_ec_enable_event(ec);
 531         spin_unlock(&ec->lock);
 532
 533         /* Drain additional events if hardware requires that */
 534         if (EC_FLAGS_CLEAR_ON_RESUME)
 535                 acpi_ec_clear(ec);
 536 }
 537
 538 #ifdef CONFIG_PM_SLEEP
 539 static void __acpi_ec_flush_work(void)
 540 {
 541         flush_workqueue(ec_wq); /* flush ec->work */
 542         flush_workqueue(ec_query_wq); /* flush queries */
 543 }
 544
 545 static void acpi_ec_disable_event(struct acpi_ec *ec)
 546 {
 547         spin_lock(&ec->lock);
 548         __acpi_ec_disable_event(ec);
 549         spin_unlock(&ec->lock);
 550
 551         /*
 552          * When ec_freeze_events is true, we need to flush events in
 553          * the proper position before entering the noirq stage.
 554          */
 555         __acpi_ec_flush_work();
 556 }
 557
 558 void acpi_ec_flush_work(void)
 559 {
 560         /* Without ec_wq there is nothing to flush. */
 561         if (!ec_wq)
 562                 return;
 563
 564         __acpi_ec_flush_work();
 565 }
 566 #endif /* CONFIG_PM_SLEEP */
 567
 568 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 569 {
 570         bool guarded;
 571
 572         spin_lock(&ec->lock);
 573         /*
 574          * If firmware SCI_EVT clearing timing is "event", we actually
 575          * don't know when the SCI_EVT will be cleared by firmware after
 576          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 577          * acceptable period.
 578          *
 579          * The guarding period is applicable if the event state is not
 580          * EC_EVENT_READY, but otherwise if the current transaction is of the
 581          * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
 582          * and it should not be applied to let the transaction transition into
 583          * the ACPI_EC_COMMAND_POLL state immediately.
 584          */
 585         guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 586                 ec->event_state != EC_EVENT_READY &&
 587                 (!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
 588         spin_unlock(&ec->lock);
 589         return guarded;
 590 }
 591
 592 static int ec_transaction_polled(struct acpi_ec *ec)
 593 {
 594         int ret = 0;
 595
 596         spin_lock(&ec->lock);
 597         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 598                 ret = 1;
 599         spin_unlock(&ec->lock);
 600         return ret;
 601 }
 602
 603 static int ec_transaction_completed(struct acpi_ec *ec)
 604 {
 605         int ret = 0;
 606
 607         spin_lock(&ec->lock);
 608         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 609                 ret = 1;
 610         spin_unlock(&ec->lock);
 611         return ret;
 612 }
 613
 614 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 615 {
 616         ec->curr->flags |= flag;
 617
 618         if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
 619                 return;
 620
 621         switch (ec_event_clearing) {
 622         case ACPI_EC_EVT_TIMING_STATUS:
 623                 if (flag == ACPI_EC_COMMAND_POLL)
 624                         acpi_ec_close_event(ec);
 625
 626                 return;
 627
 628         case ACPI_EC_EVT_TIMING_QUERY:
 629                 if (flag == ACPI_EC_COMMAND_COMPLETE)
 630                         acpi_ec_close_event(ec);
 631
 632                 return;
 633
 634         case ACPI_EC_EVT_TIMING_EVENT:
 635                 if (flag == ACPI_EC_COMMAND_COMPLETE)
 636                         acpi_ec_complete_event(ec);
 637         }
 638 }
 639
 640 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
 641 {
 642         if (t->irq_count < ec_storm_threshold)
 643                 ++t->irq_count;
 644
 645         /* Trigger if the threshold is 0 too. */
 646         if (t->irq_count == ec_storm_threshold)
 647                 acpi_ec_mask_events(ec);
 648 }
 649
 650 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
 651 {
 652         struct transaction *t = ec->curr;
 653         bool wakeup = false;
 654         u8 status;
 655
 656         ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
 657
 658         status = acpi_ec_read_status(ec);
 659
 660         /*
 661          * Another IRQ or a guarded polling mode advancement is detected,
 662          * the next QR_EC submission is then allowed.
 663          */
 664         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 665                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 666                     ec->event_state == EC_EVENT_COMPLETE)
 667                         acpi_ec_close_event(ec);
 668
 669                 if (!t)
 670                         goto out;
 671         }
 672
 673         if (t->flags & ACPI_EC_COMMAND_POLL) {
 674                 if (t->wlen > t->wi) {
 675                         if (!(status & ACPI_EC_FLAG_IBF))
 676                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 677                         else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
 678                                 acpi_ec_spurious_interrupt(ec, t);
 679                 } else if (t->rlen > t->ri) {
 680                         if (status & ACPI_EC_FLAG_OBF) {
 681                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 682                                 if (t->rlen == t->ri) {
 683                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 684                                         wakeup = true;
 685                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 686                                                 ec_dbg_evt("Command(%s) completed by hardware",
 687                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 688                                 }
 689                         } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
 690                                 acpi_ec_spurious_interrupt(ec, t);
 691                         }
 692                 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
 693                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 694                         wakeup = true;
 695                 }
 696         } else if (!(status & ACPI_EC_FLAG_IBF)) {
 697                 acpi_ec_write_cmd(ec, t->command);
 698                 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 699         }
 700
 701 out:
 702         if (status & ACPI_EC_FLAG_SCI)
 703                 acpi_ec_submit_event(ec);
 704
 705         if (wakeup && interrupt)
 706                 wake_up(&ec->wait);
 707 }
 708
 709 static void start_transaction(struct acpi_ec *ec)
 710 {
 711         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 712         ec->curr->flags = 0;
 713 }
 714
 715 static int ec_guard(struct acpi_ec *ec)
 716 {
 717         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 718         unsigned long timeout = ec->timestamp + guard;
 719
 720         /* Ensure guarding period before polling EC status */
 721         do {
 722                 if (ec->busy_polling) {
 723                         /* Perform busy polling */
 724                         if (ec_transaction_completed(ec))
 725                                 return 0;
 726                         udelay(jiffies_to_usecs(guard));
 727                 } else {
 728                         /*
 729                          * Perform wait polling
 730                          * 1. Wait the transaction to be completed by the
 731                          *    GPE handler after the transaction enters
 732                          *    ACPI_EC_COMMAND_POLL state.
 733                          * 2. A special guarding logic is also required
 734                          *    for event clearing mode "event" before the
 735                          *    transaction enters ACPI_EC_COMMAND_POLL
 736                          *    state.
 737                          */
 738                         if (!ec_transaction_polled(ec) &&
 739                             !acpi_ec_guard_event(ec))
 740                                 break;
 741                         if (wait_event_timeout(ec->wait,
 742                                                ec_transaction_completed(ec),
 743                                                guard))
 744                                 return 0;
 745                 }
 746         } while (time_before(jiffies, timeout));
 747         return -ETIME;
 748 }
 749
 750 static int ec_poll(struct acpi_ec *ec)
 751 {
 752         int repeat = 5; /* number of command restarts */
 753
 754         while (repeat--) {
 755                 unsigned long delay = jiffies +
 756                         msecs_to_jiffies(ec_delay);
 757                 do {
 758                         if (!ec_guard(ec))
 759                                 return 0;
 760                         spin_lock(&ec->lock);
 761                         advance_transaction(ec, false);
 762                         spin_unlock(&ec->lock);
 763                 } while (time_before(jiffies, delay));
 764                 pr_debug("controller reset, restart transaction\n");
 765                 spin_lock(&ec->lock);
 766                 start_transaction(ec);
 767                 spin_unlock(&ec->lock);
 768         }
 769         return -ETIME;
 770 }
 771
 772 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 773                                         struct transaction *t)
 774 {
 775         int ret = 0;
 776
 777         /* start transaction */
 778         spin_lock(&ec->lock);
 779         /* Enable GPE for command processing (IBF=0/OBF=1) */
 780         if (!acpi_ec_submit_flushable_request(ec)) {
 781                 ret = -EINVAL;
 782                 goto unlock;
 783         }
 784         ec_dbg_ref(ec, "Increase command");
 785         /* following two actions should be kept atomic */
 786         ec->curr = t;
 787         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 788         start_transaction(ec);
 789         spin_unlock(&ec->lock);
 790
 791         ret = ec_poll(ec);
 792
 793         spin_lock(&ec->lock);
 794         if (t->irq_count == ec_storm_threshold)
 795                 acpi_ec_unmask_events(ec);
 796         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 797         ec->curr = NULL;
 798         /* Disable GPE for command processing (IBF=0/OBF=1) */
 799         acpi_ec_complete_request(ec);
 800         ec_dbg_ref(ec, "Decrease command");
 801 unlock:
 802         spin_unlock(&ec->lock);
 803         return ret;
 804 }
 805
 806 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 807 {
 808         int status;
 809         u32 glk;
 810
 811         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 812                 return -EINVAL;
 813         if (t->rdata)
 814                 memset(t->rdata, 0, t->rlen);
 815
 816         mutex_lock(&ec->mutex);
 817         if (ec->global_lock) {
 818                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 819                 if (ACPI_FAILURE(status)) {
 820                         status = -ENODEV;
 821                         goto unlock;
 822                 }
 823         }
 824
 825         status = acpi_ec_transaction_unlocked(ec, t);
 826
 827         if (ec->global_lock)
 828                 acpi_release_global_lock(glk);
 829 unlock:
 830         mutex_unlock(&ec->mutex);
 831         return status;
 832 }
 833
 834 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 835 {
 836         u8 d;
 837         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 838                                 .wdata = NULL, .rdata = &d,
 839                                 .wlen = 0, .rlen = 1};
 840
 841         return acpi_ec_transaction(ec, &t);
 842 }
 843
 844 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 845 {
 846         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 847                                 .wdata = NULL, .rdata = NULL,
 848                                 .wlen = 0, .rlen = 0};
 849
 850         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 851                                 acpi_ec_transaction(ec, &t) : 0;
 852 }
 853
 854 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 855 {
 856         int result;
 857         u8 d;
 858         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 859                                 .wdata = &address, .rdata = &d,
 860                                 .wlen = 1, .rlen = 1};
 861
 862         result = acpi_ec_transaction(ec, &t);
 863         *data = d;
 864         return result;
 865 }
 866
 867 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 868 {
 869         u8 wdata[2] = { address, data };
 870         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 871                                 .wdata = wdata, .rdata = NULL,
 872                                 .wlen = 2, .rlen = 0};
 873
 874         return acpi_ec_transaction(ec, &t);
 875 }
 876
 877 int ec_read(u8 addr, u8 *val)
 878 {
 879         int err;
 880         u8 temp_data;
 881
 882         if (!first_ec)
 883                 return -ENODEV;
 884
 885         err = acpi_ec_read(first_ec, addr, &temp_data);
 886
 887         if (!err) {
 888                 *val = temp_data;
 889                 return 0;
 890         }
 891         return err;
 892 }
 893 EXPORT_SYMBOL(ec_read);
 894
 895 int ec_write(u8 addr, u8 val)
 896 {
 897         if (!first_ec)
 898                 return -ENODEV;
 899
 900         return acpi_ec_write(first_ec, addr, val);
 901 }
 902 EXPORT_SYMBOL(ec_write);
 903
 904 int ec_transaction(u8 command,
 905                    const u8 *wdata, unsigned wdata_len,
 906                    u8 *rdata, unsigned rdata_len)
 907 {
 908         struct transaction t = {.command = command,
 909                                 .wdata = wdata, .rdata = rdata,
 910                                 .wlen = wdata_len, .rlen = rdata_len};
 911
 912         if (!first_ec)
 913                 return -ENODEV;
 914
 915         return acpi_ec_transaction(first_ec, &t);
 916 }
 917 EXPORT_SYMBOL(ec_transaction);
 918
 919 /* Get the handle to the EC device */
 920 acpi_handle ec_get_handle(void)
 921 {
 922         if (!first_ec)
 923                 return NULL;
 924         return first_ec->handle;
 925 }
 926 EXPORT_SYMBOL(ec_get_handle);
 927
 928 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 929 {
 930         spin_lock(&ec->lock);
 931         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 932                 ec_dbg_drv("Starting EC");
 933                 /* Enable GPE for event processing (SCI_EVT=1) */
 934                 if (!resuming) {
 935                         acpi_ec_submit_request(ec);
 936                         ec_dbg_ref(ec, "Increase driver");
 937                 }
 938                 ec_log_drv("EC started");
 939         }
 940         spin_unlock(&ec->lock);
 941 }
 942
 943 static bool acpi_ec_stopped(struct acpi_ec *ec)
 944 {
 945         bool flushed;
 946
 947         spin_lock(&ec->lock);
 948         flushed = acpi_ec_flushed(ec);
 949         spin_unlock(&ec->lock);
 950         return flushed;
 951 }
 952
 953 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 954 {
 955         spin_lock(&ec->lock);
 956         if (acpi_ec_started(ec)) {
 957                 ec_dbg_drv("Stopping EC");
 958                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 959                 spin_unlock(&ec->lock);
 960                 wait_event(ec->wait, acpi_ec_stopped(ec));
 961                 spin_lock(&ec->lock);
 962                 /* Disable GPE for event processing (SCI_EVT=1) */
 963                 if (!suspending) {
 964                         acpi_ec_complete_request(ec);
 965                         ec_dbg_ref(ec, "Decrease driver");
 966                 } else if (!ec_freeze_events)
 967                         __acpi_ec_disable_event(ec);
 968                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 969                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 970                 ec_log_drv("EC stopped");
 971         }
 972         spin_unlock(&ec->lock);
 973 }
 974
 975 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 976 {
 977         spin_lock(&ec->lock);
 978         ec->busy_polling = true;
 979         ec->polling_guard = 0;
 980         ec_log_drv("interrupt blocked");
 981         spin_unlock(&ec->lock);
 982 }
 983
 984 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
 985 {
 986         spin_lock(&ec->lock);
 987         ec->busy_polling = ec_busy_polling;
 988         ec->polling_guard = ec_polling_guard;
 989         ec_log_drv("interrupt unblocked");
 990         spin_unlock(&ec->lock);
 991 }
 992
 993 void acpi_ec_block_transactions(void)
 994 {
 995         struct acpi_ec *ec = first_ec;
 996
 997         if (!ec)
 998                 return;
 999
1000         mutex_lock(&ec->mutex);
1001         /* Prevent transactions from being carried out */
1002         acpi_ec_stop(ec, true);
1003         mutex_unlock(&ec->mutex);
1004 }
1005
1006 void acpi_ec_unblock_transactions(void)
1007 {
1008         /*
1009          * Allow transactions to happen again (this function is called from
1010          * atomic context during wakeup, so we don't need to acquire the mutex).
1011          */
1012         if (first_ec)
1013                 acpi_ec_start(first_ec, true);
1014 }
1015
1016 /* --------------------------------------------------------------------------
1017                                 Event Management
1018    -------------------------------------------------------------------------- */
1019 static struct acpi_ec_query_handler *
1020 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1021 {
1022         struct acpi_ec_query_handler *handler;
1023
1024         mutex_lock(&ec->mutex);
1025         list_for_each_entry(handler, &ec->list, node) {
1026                 if (value == handler->query_bit) {
1027                         kref_get(&handler->kref);
1028                         mutex_unlock(&ec->mutex);
1029                         return handler;
1030                 }
1031         }
1032         mutex_unlock(&ec->mutex);
1033         return NULL;
1034 }
1035
1036 static void acpi_ec_query_handler_release(struct kref *kref)
1037 {
1038         struct acpi_ec_query_handler *handler =
1039                 container_of(kref, struct acpi_ec_query_handler, kref);
1040
1041         kfree(handler);
1042 }
1043
1044 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1045 {
1046         kref_put(&handler->kref, acpi_ec_query_handler_release);
1047 }
1048
1049 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1050                               acpi_handle handle, acpi_ec_query_func func,
1051                               void *data)
1052 {
1053         struct acpi_ec_query_handler *handler;
1054
1055         if (!handle && !func)
1056                 return -EINVAL;
1057
1058         handler = kzalloc(sizeof(*handler), GFP_KERNEL);
1059         if (!handler)
1060                 return -ENOMEM;
1061
1062         handler->query_bit = query_bit;
1063         handler->handle = handle;
1064         handler->func = func;
1065         handler->data = data;
1066         mutex_lock(&ec->mutex);
1067         kref_init(&handler->kref);
1068         list_add(&handler->node, &ec->list);
1069         mutex_unlock(&ec->mutex);
1070
1071         return 0;
1072 }
1073 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1074
1075 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1076                                           bool remove_all, u8 query_bit)
1077 {
1078         struct acpi_ec_query_handler *handler, *tmp;
1079         LIST_HEAD(free_list);
1080
1081         mutex_lock(&ec->mutex);
1082         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1083                 /*
1084                  * When remove_all is false, only remove custom query handlers
1085                  * which have handler->func set. This is done to preserve query
1086                  * handlers discovered thru ACPI, as they should continue handling
1087                  * EC queries.
1088                  */
1089                 if (remove_all || (handler->func && handler->query_bit == query_bit)) {
1090                         list_del_init(&handler->node);
1091                         list_add(&handler->node, &free_list);
1092
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         flush_workqueue(ec_query_wq);
1104 }
1105 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1106
1107 static void acpi_ec_event_processor(struct work_struct *work)
1108 {
1109         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1110         struct acpi_ec_query_handler *handler = q->handler;
1111         struct acpi_ec *ec = q->ec;
1112
1113         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1114
1115         if (handler->func)
1116                 handler->func(handler->data);
1117         else if (handler->handle)
1118                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1119
1120         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1121
1122         spin_lock(&ec->lock);
1123         ec->queries_in_progress--;
1124         spin_unlock(&ec->lock);
1125
1126         acpi_ec_put_query_handler(handler);
1127         kfree(q);
1128 }
1129
1130 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1131 {
1132         struct acpi_ec_query *q;
1133         struct transaction *t;
1134
1135         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1136         if (!q)
1137                 return NULL;
1138
1139         INIT_WORK(&q->work, acpi_ec_event_processor);
1140         t = &q->transaction;
1141         t->command = ACPI_EC_COMMAND_QUERY;
1142         t->rdata = pval;
1143         t->rlen = 1;
1144         q->ec = ec;
1145         return q;
1146 }
1147
1148 static int acpi_ec_submit_query(struct acpi_ec *ec)
1149 {
1150         struct acpi_ec_query *q;
1151         u8 value = 0;
1152         int result;
1153
1154         q = acpi_ec_create_query(ec, &value);
1155         if (!q)
1156                 return -ENOMEM;
1157
1158         /*
1159          * Query the EC to find out which _Qxx method we need to evaluate.
1160          * Note that successful completion of the query causes the ACPI_EC_SCI
1161          * bit to be cleared (and thus clearing the interrupt source).
1162          */
1163         result = acpi_ec_transaction(ec, &q->transaction);
1164         if (result)
1165                 goto err_exit;
1166
1167         if (!value) {
1168                 result = -ENODATA;
1169                 goto err_exit;
1170         }
1171
1172         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1173         if (!q->handler) {
1174                 result = -ENODATA;
1175                 goto err_exit;
1176         }
1177
1178         /*
1179          * It is reported that _Qxx are evaluated in a parallel way on Windows:
1180          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1181          *
1182          * Put this log entry before queue_work() to make it appear in the log
1183          * before any other messages emitted during workqueue handling.
1184          */
1185         ec_dbg_evt("Query(0x%02x) scheduled", value);
1186
1187         spin_lock(&ec->lock);
1188
1189         ec->queries_in_progress++;
1190         queue_work(ec_query_wq, &q->work);
1191
1192         spin_unlock(&ec->lock);
1193
1194         return 0;
1195
1196 err_exit:
1197         kfree(q);
1198
1199         return result;
1200 }
1201
1202 static void acpi_ec_event_handler(struct work_struct *work)
1203 {
1204         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1205
1206         ec_dbg_evt("Event started");
1207
1208         spin_lock(&ec->lock);
1209
1210         while (ec->events_to_process) {
1211                 spin_unlock(&ec->lock);
1212
1213                 acpi_ec_submit_query(ec);
1214
1215                 spin_lock(&ec->lock);
1216
1217                 ec->events_to_process--;
1218         }
1219
1220         /*
1221          * Before exit, make sure that the it will be possible to queue up the
1222          * event handling work again regardless of whether or not the query
1223          * queued up above is processed successfully.
1224          */
1225         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1226                 bool guard_timeout;
1227
1228                 acpi_ec_complete_event(ec);
1229
1230                 ec_dbg_evt("Event stopped");
1231
1232                 spin_unlock(&ec->lock);
1233
1234                 guard_timeout = !!ec_guard(ec);
1235
1236                 spin_lock(&ec->lock);
1237
1238                 /* Take care of SCI_EVT unless someone else is doing that. */
1239                 if (guard_timeout && !ec->curr)
1240                         advance_transaction(ec, false);
1241         } else {
1242                 acpi_ec_close_event(ec);
1243
1244                 ec_dbg_evt("Event stopped");
1245         }
1246
1247         ec->events_in_progress--;
1248
1249         spin_unlock(&ec->lock);
1250 }
1251
1252 static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)
1253 {
1254         /*
1255          * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
1256          * changes to always trigger a GPE interrupt.
1257          *
1258          * GPE STS is a W1C register, which means:
1259          *
1260          * 1. Software can clear it without worrying about clearing the other
1261          *    GPEs' STS bits when the hardware sets them in parallel.
1262          *
1263          * 2. As long as software can ensure only clearing it when it is set,
1264          *    hardware won't set it in parallel.
1265          */
1266         if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
1267                 acpi_clear_gpe(NULL, ec->gpe);
1268
1269         advance_transaction(ec, true);
1270 }
1271
1272 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1273 {
1274         spin_lock(&ec->lock);
1275
1276         clear_gpe_and_advance_transaction(ec, true);
1277
1278         spin_unlock(&ec->lock);
1279 }
1280
1281 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1282                                u32 gpe_number, void *data)
1283 {
1284         acpi_ec_handle_interrupt(data);
1285         return ACPI_INTERRUPT_HANDLED;
1286 }
1287
1288 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1289 {
1290         acpi_ec_handle_interrupt(data);
1291         return IRQ_HANDLED;
1292 }
1293
1294 /* --------------------------------------------------------------------------
1295  *                           Address Space Management
1296  * -------------------------------------------------------------------------- */
1297
1298 static acpi_status
1299 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1300                       u32 bits, u64 *value64,
1301                       void *handler_context, void *region_context)
1302 {
1303         struct acpi_ec *ec = handler_context;
1304         int result = 0, i, bytes = bits / 8;
1305         u8 *value = (u8 *)value64;
1306
1307         if ((address > 0xFF) || !value || !handler_context)
1308                 return AE_BAD_PARAMETER;
1309
1310         if (function != ACPI_READ && function != ACPI_WRITE)
1311                 return AE_BAD_PARAMETER;
1312
1313         if (ec->busy_polling || bits > 8)
1314                 acpi_ec_burst_enable(ec);
1315
1316         for (i = 0; i < bytes; ++i, ++address, ++value)
1317                 result = (function == ACPI_READ) ?
1318                         acpi_ec_read(ec, address, value) :
1319                         acpi_ec_write(ec, address, *value);
1320
1321         if (ec->busy_polling || bits > 8)
1322                 acpi_ec_burst_disable(ec);
1323
1324         switch (result) {
1325         case -EINVAL:
1326                 return AE_BAD_PARAMETER;
1327         case -ENODEV:
1328                 return AE_NOT_FOUND;
1329         case -ETIME:
1330                 return AE_TIME;
1331         default:
1332                 return AE_OK;
1333         }
1334 }
1335
1336 /* --------------------------------------------------------------------------
1337  *                             Driver Interface
1338  * -------------------------------------------------------------------------- */
1339
1340 static acpi_status
1341 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1342
1343 static void acpi_ec_free(struct acpi_ec *ec)
1344 {
1345         if (first_ec == ec)
1346                 first_ec = NULL;
1347         if (boot_ec == ec)
1348                 boot_ec = NULL;
1349         kfree(ec);
1350 }
1351
1352 static struct acpi_ec *acpi_ec_alloc(void)
1353 {
1354         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1355
1356         if (!ec)
1357                 return NULL;
1358         mutex_init(&ec->mutex);
1359         init_waitqueue_head(&ec->wait);
1360         INIT_LIST_HEAD(&ec->list);
1361         spin_lock_init(&ec->lock);
1362         INIT_WORK(&ec->work, acpi_ec_event_handler);
1363         ec->timestamp = jiffies;
1364         ec->busy_polling = true;
1365         ec->polling_guard = 0;
1366         ec->gpe = -1;
1367         ec->irq = -1;
1368         return ec;
1369 }
1370
1371 static acpi_status
1372 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1373                                void *context, void **return_value)
1374 {
1375         char node_name[5];
1376         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1377         struct acpi_ec *ec = context;
1378         int value = 0;
1379         acpi_status status;
1380
1381         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1382
1383         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1384                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1385         return AE_OK;
1386 }
1387
1388 static acpi_status
1389 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1390 {
1391         acpi_status status;
1392         unsigned long long tmp = 0;
1393         struct acpi_ec *ec = context;
1394
1395         /* clear addr values, ec_parse_io_ports depend on it */
1396         ec->command_addr = ec->data_addr = 0;
1397
1398         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1399                                      ec_parse_io_ports, ec);
1400         if (ACPI_FAILURE(status))
1401                 return status;
1402         if (ec->data_addr == 0 || ec->command_addr == 0)
1403                 return AE_OK;
1404
1405         /* Get GPE bit assignment (EC events). */
1406         /* TODO: Add support for _GPE returning a package */
1407         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1408         if (ACPI_SUCCESS(status))
1409                 ec->gpe = tmp;
1410         /*
1411          * Errors are non-fatal, allowing for ACPI Reduced Hardware
1412          * platforms which use GpioInt instead of GPE.
1413          */
1414
1415         /* Use the global lock for all EC transactions? */
1416         tmp = 0;
1417         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1418         ec->global_lock = tmp;
1419         ec->handle = handle;
1420         return AE_CTRL_TERMINATE;
1421 }
1422
1423 static bool install_gpe_event_handler(struct acpi_ec *ec)
1424 {
1425         acpi_status status;
1426
1427         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1428                                               ACPI_GPE_EDGE_TRIGGERED,
1429                                               &acpi_ec_gpe_handler, ec);
1430         if (ACPI_FAILURE(status))
1431                 return false;
1432
1433         if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1434                 acpi_ec_enable_gpe(ec, true);
1435
1436         return true;
1437 }
1438
1439 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1440 {
1441         return request_threaded_irq(ec->irq, NULL, acpi_ec_irq_handler,
1442                                     IRQF_SHARED | IRQF_ONESHOT, "ACPI EC", ec) >= 0;
1443 }
1444
1445 /**
1446  * ec_install_handlers - Install service callbacks and register query methods.
1447  * @ec: Target EC.
1448  * @device: ACPI device object corresponding to @ec.
1449  * @call_reg: If _REG should be called to notify OpRegion availability
1450  *
1451  * Install a handler for the EC address space type unless it has been installed
1452  * already.  If @device is not NULL, also look for EC query methods in the
1453  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1454  * handler for the EC, if possible.
1455  *
1456  * Return:
1457  * -ENODEV if the address space handler cannot be installed, which means
1458  *  "unable to handle transactions",
1459  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1460  * or 0 (success) otherwise.
1461  */
1462 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1463                                bool call_reg)
1464 {
1465         acpi_status status;
1466
1467         acpi_ec_start(ec, false);
1468
1469         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1470                 acpi_ec_enter_noirq(ec);
1471                 status = acpi_install_address_space_handler_no_reg(ec->handle,
1472                                                                    ACPI_ADR_SPACE_EC,
1473                                                                    &acpi_ec_space_handler,
1474                                                                    NULL, ec);
1475                 if (ACPI_FAILURE(status)) {
1476                         acpi_ec_stop(ec, false);
1477                         return -ENODEV;
1478                 }
1479                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1480                 ec->address_space_handler_holder = ec->handle;
1481         }
1482
1483         if (call_reg && !test_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags)) {
1484                 acpi_execute_reg_methods(ec->handle, ACPI_ADR_SPACE_EC);
1485                 set_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags);
1486         }
1487
1488         if (!device)
1489                 return 0;
1490
1491         if (ec->gpe < 0) {
1492                 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1493                 int irq = acpi_dev_gpio_irq_get(device, 0);
1494                 /*
1495                  * Bail out right away for deferred probing or complete the
1496                  * initialization regardless of any other errors.
1497                  */
1498                 if (irq == -EPROBE_DEFER)
1499                         return -EPROBE_DEFER;
1500                 else if (irq >= 0)
1501                         ec->irq = irq;
1502         }
1503
1504         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1505                 /* Find and register all query methods */
1506                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1507                                     acpi_ec_register_query_methods,
1508                                     NULL, ec, NULL);
1509                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1510         }
1511         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1512                 bool ready = false;
1513
1514                 if (ec->gpe >= 0)
1515                         ready = install_gpe_event_handler(ec);
1516                 else if (ec->irq >= 0)
1517                         ready = install_gpio_irq_event_handler(ec);
1518
1519                 if (ready) {
1520                         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1521                         acpi_ec_leave_noirq(ec);
1522                 }
1523                 /*
1524                  * Failures to install an event handler are not fatal, because
1525                  * the EC can be polled for events.
1526                  */
1527         }
1528         /* EC is fully operational, allow queries */
1529         acpi_ec_enable_event(ec);
1530
1531         return 0;
1532 }
1533
1534 static void ec_remove_handlers(struct acpi_ec *ec)
1535 {
1536         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1537                 if (ACPI_FAILURE(acpi_remove_address_space_handler(
1538                                         ec->address_space_handler_holder,
1539                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1540                         pr_err("failed to remove space handler\n");
1541                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1542         }
1543
1544         /*
1545          * Stops handling the EC transactions after removing the operation
1546          * region handler. This is required because _REG(DISCONNECT)
1547          * invoked during the removal can result in new EC transactions.
1548          *
1549          * Flushes the EC requests and thus disables the GPE before
1550          * removing the GPE handler. This is required by the current ACPICA
1551          * GPE core. ACPICA GPE core will automatically disable a GPE when
1552          * it is indicated but there is no way to handle it. So the drivers
1553          * must disable the GPEs prior to removing the GPE handlers.
1554          */
1555         acpi_ec_stop(ec, false);
1556
1557         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1558                 if (ec->gpe >= 0 &&
1559                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1560                                  &acpi_ec_gpe_handler)))
1561                         pr_err("failed to remove gpe handler\n");
1562
1563                 if (ec->irq >= 0)
1564                         free_irq(ec->irq, ec);
1565
1566                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1567         }
1568         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1569                 acpi_ec_remove_query_handlers(ec, true, 0);
1570                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1571         }
1572 }
1573
1574 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device, bool call_reg)
1575 {
1576         int ret;
1577
1578         ret = ec_install_handlers(ec, device, call_reg);
1579         if (ret)
1580                 return ret;
1581
1582         /* First EC capable of handling transactions */
1583         if (!first_ec)
1584                 first_ec = ec;
1585
1586         pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1587                 ec->data_addr);
1588
1589         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1590                 if (ec->gpe >= 0)
1591                         pr_info("GPE=0x%x\n", ec->gpe);
1592                 else
1593                         pr_info("IRQ=%d\n", ec->irq);
1594         }
1595
1596         return ret;
1597 }
1598
1599 static int acpi_ec_add(struct acpi_device *device)
1600 {
1601         struct acpi_ec *ec;
1602         int ret;
1603
1604         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1605         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1606
1607         if (boot_ec && (boot_ec->handle == device->handle ||
1608             !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1609                 /* Fast path: this device corresponds to the boot EC. */
1610                 ec = boot_ec;
1611         } else {
1612                 acpi_status status;
1613
1614                 ec = acpi_ec_alloc();
1615                 if (!ec)
1616                         return -ENOMEM;
1617
1618                 status = ec_parse_device(device->handle, 0, ec, NULL);
1619                 if (status != AE_CTRL_TERMINATE) {
1620                         ret = -EINVAL;
1621                         goto err;
1622                 }
1623
1624                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1625                     ec->data_addr == boot_ec->data_addr) {
1626                         /*
1627                          * Trust PNP0C09 namespace location rather than ECDT ID.
1628                          * But trust ECDT GPE rather than _GPE because of ASUS
1629                          * quirks. So do not change boot_ec->gpe to ec->gpe,
1630                          * except when the TRUST_DSDT_GPE quirk is set.
1631                          */
1632                         boot_ec->handle = ec->handle;
1633
1634                         if (EC_FLAGS_TRUST_DSDT_GPE)
1635                                 boot_ec->gpe = ec->gpe;
1636
1637                         acpi_handle_debug(ec->handle, "duplicated.\n");
1638                         acpi_ec_free(ec);
1639                         ec = boot_ec;
1640                 }
1641         }
1642
1643         ret = acpi_ec_setup(ec, device, true);
1644         if (ret)
1645                 goto err;
1646
1647         if (ec == boot_ec)
1648                 acpi_handle_info(boot_ec->handle,
1649                                  "Boot %s EC initialization complete\n",
1650                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1651
1652         acpi_handle_info(ec->handle,
1653                          "EC: Used to handle transactions and events\n");
1654
1655         device->driver_data = ec;
1656
1657         ret = !!request_region(ec->data_addr, 1, "EC data");
1658         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1659         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1660         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1661
1662         /* Reprobe devices depending on the EC */
1663         acpi_dev_clear_dependencies(device);
1664
1665         acpi_handle_debug(ec->handle, "enumerated.\n");
1666         return 0;
1667
1668 err:
1669         if (ec != boot_ec)
1670                 acpi_ec_free(ec);
1671
1672         return ret;
1673 }
1674
1675 static void acpi_ec_remove(struct acpi_device *device)
1676 {
1677         struct acpi_ec *ec;
1678
1679         if (!device)
1680                 return;
1681
1682         ec = acpi_driver_data(device);
1683         release_region(ec->data_addr, 1);
1684         release_region(ec->command_addr, 1);
1685         device->driver_data = NULL;
1686         if (ec != boot_ec) {
1687                 ec_remove_handlers(ec);
1688                 acpi_ec_free(ec);
1689         }
1690 }
1691
1692 static acpi_status
1693 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1694 {
1695         struct acpi_ec *ec = context;
1696
1697         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1698                 return AE_OK;
1699
1700         /*
1701          * The first address region returned is the data port, and
1702          * the second address region returned is the status/command
1703          * port.
1704          */
1705         if (ec->data_addr == 0)
1706                 ec->data_addr = resource->data.io.minimum;
1707         else if (ec->command_addr == 0)
1708                 ec->command_addr = resource->data.io.minimum;
1709         else
1710                 return AE_CTRL_TERMINATE;
1711
1712         return AE_OK;
1713 }
1714
1715 static const struct acpi_device_id ec_device_ids[] = {
1716         {"PNP0C09", 0},
1717         {ACPI_ECDT_HID, 0},
1718         {"", 0},
1719 };
1720
1721 /*
1722  * This function is not Windows-compatible as Windows never enumerates the
1723  * namespace EC before the main ACPI device enumeration process. It is
1724  * retained for historical reason and will be deprecated in the future.
1725  */
1726 void __init acpi_ec_dsdt_probe(void)
1727 {
1728         struct acpi_ec *ec;
1729         acpi_status status;
1730         int ret;
1731
1732         /*
1733          * If a platform has ECDT, there is no need to proceed as the
1734          * following probe is not a part of the ACPI device enumeration,
1735          * executing _STA is not safe, and thus this probe may risk of
1736          * picking up an invalid EC device.
1737          */
1738         if (boot_ec)
1739                 return;
1740
1741         ec = acpi_ec_alloc();
1742         if (!ec)
1743                 return;
1744
1745         /*
1746          * At this point, the namespace is initialized, so start to find
1747          * the namespace objects.
1748          */
1749         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1750         if (ACPI_FAILURE(status) || !ec->handle) {
1751                 acpi_ec_free(ec);
1752                 return;
1753         }
1754
1755         /*
1756          * When the DSDT EC is available, always re-configure boot EC to
1757          * have _REG evaluated. _REG can only be evaluated after the
1758          * namespace initialization.
1759          * At this point, the GPE is not fully initialized, so do not to
1760          * handle the events.
1761          */
1762         ret = acpi_ec_setup(ec, NULL, true);
1763         if (ret) {
1764                 acpi_ec_free(ec);
1765                 return;
1766         }
1767
1768         boot_ec = ec;
1769
1770         acpi_handle_info(ec->handle,
1771                          "Boot DSDT EC used to handle transactions\n");
1772 }
1773
1774 /*
1775  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1776  *
1777  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1778  * found a matching object in the namespace.
1779  *
1780  * Next, in case the DSDT EC is not functioning, it is still necessary to
1781  * provide a functional ECDT EC to handle events, so add an extra device object
1782  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1783  *
1784  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1785  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1786  */
1787 static void __init acpi_ec_ecdt_start(void)
1788 {
1789         struct acpi_table_ecdt *ecdt_ptr;
1790         acpi_handle handle;
1791         acpi_status status;
1792
1793         /* Bail out if a matching EC has been found in the namespace. */
1794         if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1795                 return;
1796
1797         /* Look up the object pointed to from the ECDT in the namespace. */
1798         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1799                                 (struct acpi_table_header **)&ecdt_ptr);
1800         if (ACPI_FAILURE(status))
1801                 return;
1802
1803         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1804         if (ACPI_SUCCESS(status)) {
1805                 boot_ec->handle = handle;
1806
1807                 /* Add a special ACPI device object to represent the boot EC. */
1808                 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1809         }
1810
1811         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1812 }
1813
1814 /*
1815  * On some hardware it is necessary to clear events accumulated by the EC during
1816  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1817  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1818  *
1819  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1820  *
1821  * Ideally, the EC should also be instructed NOT to accumulate events during
1822  * sleep (which Windows seems to do somehow), but the interface to control this
1823  * behaviour is not known at this time.
1824  *
1825  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1826  * however it is very likely that other Samsung models are affected.
1827  *
1828  * On systems which don't accumulate _Q events during sleep, this extra check
1829  * should be harmless.
1830  */
1831 static int ec_clear_on_resume(const struct dmi_system_id *id)
1832 {
1833         pr_debug("Detected system needing EC poll on resume.\n");
1834         EC_FLAGS_CLEAR_ON_RESUME = 1;
1835         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1836         return 0;
1837 }
1838
1839 /*
1840  * Some ECDTs contain wrong register addresses.
1841  * MSI MS-171F
1842  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1843  */
1844 static int ec_correct_ecdt(const struct dmi_system_id *id)
1845 {
1846         pr_debug("Detected system needing ECDT address correction.\n");
1847         EC_FLAGS_CORRECT_ECDT = 1;
1848         return 0;
1849 }
1850
1851 /*
1852  * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1853  * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1854  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1855  */
1856 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1857 {
1858         pr_debug("Detected system needing DSDT GPE setting.\n");
1859         EC_FLAGS_TRUST_DSDT_GPE = 1;
1860         return 0;
1861 }
1862
1863 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1864         {
1865                 /*
1866                  * MSI MS-171F
1867                  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1868                  */
1869                 .callback = ec_correct_ecdt,
1870                 .matches = {
1871                         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1872                         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),
1873                 },
1874         },
1875         {
1876                 /*
1877                  * HP Pavilion Gaming Laptop 15-cx0xxx
1878                  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1879                  */
1880                 .callback = ec_honor_dsdt_gpe,
1881                 .matches = {
1882                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1883                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),
1884                 },
1885         },
1886         {
1887                 /*
1888                  * HP Pavilion Gaming Laptop 15-cx0041ur
1889                  */
1890                 .callback = ec_honor_dsdt_gpe,
1891                 .matches = {
1892                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1893                         DMI_MATCH(DMI_PRODUCT_NAME, "HP 15-cx0041ur"),
1894                 },
1895         },
1896         {
1897                 /*
1898                  * HP Pavilion Gaming Laptop 15-dk1xxx
1899                  * https://github.com/systemd/systemd/issues/28942
1900                  */
1901                 .callback = ec_honor_dsdt_gpe,
1902                 .matches = {
1903                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1904                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-dk1xxx"),
1905                 },
1906         },
1907         {
1908                 /*
1909                  * HP 250 G7 Notebook PC
1910                  */
1911                 .callback = ec_honor_dsdt_gpe,
1912                 .matches = {
1913                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1914                         DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"),
1915                 },
1916         },
1917         {
1918                 /*
1919                  * Samsung hardware
1920                  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1921                  */
1922                 .callback = ec_clear_on_resume,
1923                 .matches = {
1924                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
1925                 },
1926         },
1927         {}
1928 };
1929
1930 void __init acpi_ec_ecdt_probe(void)
1931 {
1932         struct acpi_table_ecdt *ecdt_ptr;
1933         struct acpi_ec *ec;
1934         acpi_status status;
1935         int ret;
1936
1937         /* Generate a boot ec context. */
1938         dmi_check_system(ec_dmi_table);
1939         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1940                                 (struct acpi_table_header **)&ecdt_ptr);
1941         if (ACPI_FAILURE(status))
1942                 return;
1943
1944         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1945                 /*
1946                  * Asus X50GL:
1947                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1948                  */
1949                 goto out;
1950         }
1951
1952         ec = acpi_ec_alloc();
1953         if (!ec)
1954                 goto out;
1955
1956         if (EC_FLAGS_CORRECT_ECDT) {
1957                 ec->command_addr = ecdt_ptr->data.address;
1958                 ec->data_addr = ecdt_ptr->control.address;
1959         } else {
1960                 ec->command_addr = ecdt_ptr->control.address;
1961                 ec->data_addr = ecdt_ptr->data.address;
1962         }
1963
1964         /*
1965          * Ignore the GPE value on Reduced Hardware platforms.
1966          * Some products have this set to an erroneous value.
1967          */
1968         if (!acpi_gbl_reduced_hardware)
1969                 ec->gpe = ecdt_ptr->gpe;
1970
1971         ec->handle = ACPI_ROOT_OBJECT;
1972
1973         /*
1974          * At this point, the namespace is not initialized, so do not find
1975          * the namespace objects, or handle the events.
1976          */
1977         ret = acpi_ec_setup(ec, NULL, false);
1978         if (ret) {
1979                 acpi_ec_free(ec);
1980                 goto out;
1981         }
1982
1983         boot_ec = ec;
1984         boot_ec_is_ecdt = true;
1985
1986         pr_info("Boot ECDT EC used to handle transactions\n");
1987
1988 out:
1989         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1990 }
1991
1992 #ifdef CONFIG_PM_SLEEP
1993 static int acpi_ec_suspend(struct device *dev)
1994 {
1995         struct acpi_ec *ec =
1996                 acpi_driver_data(to_acpi_device(dev));
1997
1998         if (!pm_suspend_no_platform() && ec_freeze_events)
1999                 acpi_ec_disable_event(ec);
2000         return 0;
2001 }
2002
2003 static int acpi_ec_suspend_noirq(struct device *dev)
2004 {
2005         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2006
2007         /*
2008          * The SCI handler doesn't run at this point, so the GPE can be
2009          * masked at the low level without side effects.
2010          */
2011         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2012             ec->gpe >= 0 && ec->reference_count >= 1)
2013                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2014
2015         acpi_ec_enter_noirq(ec);
2016
2017         return 0;
2018 }
2019
2020 static int acpi_ec_resume_noirq(struct device *dev)
2021 {
2022         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2023
2024         acpi_ec_leave_noirq(ec);
2025
2026         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2027             ec->gpe >= 0 && ec->reference_count >= 1)
2028                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2029
2030         return 0;
2031 }
2032
2033 static int acpi_ec_resume(struct device *dev)
2034 {
2035         struct acpi_ec *ec =
2036                 acpi_driver_data(to_acpi_device(dev));
2037
2038         acpi_ec_enable_event(ec);
2039         return 0;
2040 }
2041
2042 void acpi_ec_mark_gpe_for_wake(void)
2043 {
2044         if (first_ec && !ec_no_wakeup)
2045                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2046 }
2047 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2048
2049 void acpi_ec_set_gpe_wake_mask(u8 action)
2050 {
2051         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2052                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2053 }
2054
2055 static bool acpi_ec_work_in_progress(struct acpi_ec *ec)
2056 {
2057         return ec->events_in_progress + ec->queries_in_progress > 0;
2058 }
2059
2060 bool acpi_ec_dispatch_gpe(void)
2061 {
2062         bool work_in_progress = false;
2063
2064         if (!first_ec)
2065                 return acpi_any_gpe_status_set(U32_MAX);
2066
2067         /*
2068          * Report wakeup if the status bit is set for any enabled GPE other
2069          * than the EC one.
2070          */
2071         if (acpi_any_gpe_status_set(first_ec->gpe))
2072                 return true;
2073
2074         /*
2075          * Cancel the SCI wakeup and process all pending events in case there
2076          * are any wakeup ones in there.
2077          *
2078          * Note that if any non-EC GPEs are active at this point, the SCI will
2079          * retrigger after the rearming in acpi_s2idle_wake(), so no events
2080          * should be missed by canceling the wakeup here.
2081          */
2082         pm_system_cancel_wakeup();
2083
2084         /*
2085          * Dispatch the EC GPE in-band, but do not report wakeup in any case
2086          * to allow the caller to process events properly after that.
2087          */
2088         spin_lock(&first_ec->lock);
2089
2090         if (acpi_ec_gpe_status_set(first_ec)) {
2091                 pm_pr_dbg("ACPI EC GPE status set\n");
2092
2093                 clear_gpe_and_advance_transaction(first_ec, false);
2094                 work_in_progress = acpi_ec_work_in_progress(first_ec);
2095         }
2096
2097         spin_unlock(&first_ec->lock);
2098
2099         if (!work_in_progress)
2100                 return false;
2101
2102         pm_pr_dbg("ACPI EC GPE dispatched\n");
2103
2104         /* Drain EC work. */
2105         do {
2106                 acpi_ec_flush_work();
2107
2108                 pm_pr_dbg("ACPI EC work flushed\n");
2109
2110                 spin_lock(&first_ec->lock);
2111
2112                 work_in_progress = acpi_ec_work_in_progress(first_ec);
2113
2114                 spin_unlock(&first_ec->lock);
2115         } while (work_in_progress && !pm_wakeup_pending());
2116
2117         return false;
2118 }
2119 #endif /* CONFIG_PM_SLEEP */
2120
2121 static const struct dev_pm_ops acpi_ec_pm = {
2122         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2123         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2124 };
2125
2126 static int param_set_event_clearing(const char *val,
2127                                     const struct kernel_param *kp)
2128 {
2129         int result = 0;
2130
2131         if (!strncmp(val, "status", sizeof("status") - 1)) {
2132                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2133                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2134         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2135                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2136                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2137         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2138                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2139                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2140         } else
2141                 result = -EINVAL;
2142         return result;
2143 }
2144
2145 static int param_get_event_clearing(char *buffer,
2146                                     const struct kernel_param *kp)
2147 {
2148         switch (ec_event_clearing) {
2149         case ACPI_EC_EVT_TIMING_STATUS:
2150                 return sprintf(buffer, "status\n");
2151         case ACPI_EC_EVT_TIMING_QUERY:
2152                 return sprintf(buffer, "query\n");
2153         case ACPI_EC_EVT_TIMING_EVENT:
2154                 return sprintf(buffer, "event\n");
2155         default:
2156                 return sprintf(buffer, "invalid\n");
2157         }
2158         return 0;
2159 }
2160
2161 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2162                   NULL, 0644);
2163 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2164
2165 static struct acpi_driver acpi_ec_driver = {
2166         .name = "ec",
2167         .class = ACPI_EC_CLASS,
2168         .ids = ec_device_ids,
2169         .ops = {
2170                 .add = acpi_ec_add,
2171                 .remove = acpi_ec_remove,
2172                 },
2173         .drv.pm = &acpi_ec_pm,
2174 };
2175
2176 static void acpi_ec_destroy_workqueues(void)
2177 {
2178         if (ec_wq) {
2179                 destroy_workqueue(ec_wq);
2180                 ec_wq = NULL;
2181         }
2182         if (ec_query_wq) {
2183                 destroy_workqueue(ec_query_wq);
2184                 ec_query_wq = NULL;
2185         }
2186 }
2187
2188 static int acpi_ec_init_workqueues(void)
2189 {
2190         if (!ec_wq)
2191                 ec_wq = alloc_ordered_workqueue("kec", 0);
2192
2193         if (!ec_query_wq)
2194                 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2195
2196         if (!ec_wq || !ec_query_wq) {
2197                 acpi_ec_destroy_workqueues();
2198                 return -ENODEV;
2199         }
2200         return 0;
2201 }
2202
2203 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2204         {
2205                 .matches = {
2206                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2207                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2208                 },
2209         },
2210         {
2211                 .matches = {
2212                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2213                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2214                 },
2215         },
2216         {
2217                 .matches = {
2218                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2219                         DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2220                 },
2221         },
2222         { },
2223 };
2224
2225 void __init acpi_ec_init(void)
2226 {
2227         int result;
2228
2229         result = acpi_ec_init_workqueues();
2230         if (result)
2231                 return;
2232
2233         /*
2234          * Disable EC wakeup on following systems to prevent periodic
2235          * wakeup from EC GPE.
2236          */
2237         if (dmi_check_system(acpi_ec_no_wakeup)) {
2238                 ec_no_wakeup = true;
2239                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2240         }
2241
2242         /* Driver must be registered after acpi_ec_init_workqueues(). */
2243         acpi_bus_register_driver(&acpi_ec_driver);
2244
2245         acpi_ec_ecdt_start();
2246 }
2247
2248 /* EC driver currently not unloadable */
2249 #if 0
2250 static void __exit acpi_ec_exit(void)
2251 {
2252
2253         acpi_bus_unregister_driver(&acpi_ec_driver);
2254         acpi_ec_destroy_workqueues();
2255 }
2256 #endif  /* 0 */